FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Cave, RJ Newton, MD AF Cave, RJ Newton, MD TI Calculation of electronic coupling matrix elements for ground and excited state electron transfer reactions: Comparison of the generalized Mulliken-Hush and block diagonalization methods SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID APPROXIMATELY DIABATIC STATES; MOLECULAR WAVE-FUNCTIONS; LONG-RANGE INTERACTIONS; ANO BASIS-SETS; PERTURBATION-THEORY; ROW ATOMS; RHODOPSEUDOMONAS-VIRIDIS; BACTERIAL PHOTOSYNTHESIS; ABINITIO CALCULATIONS; CONICAL INTERSECTION AB Two independent methods are presented for the nonperturbative calculation of the electronic coupling matrix element (H-ab) for electron transfer reactions using ab initio electronic structure theory. The first is based on the generalized Mulliken-Hush (GMH) model, a multistate generalization of the Mulliken Hush formalism for the electronic coupling. The second is based on the block diagonalization (ED) approach-of Cederbaum, Domcke, and co-workers. Detailed quantitative comparisons of the two methods are carried out based on results for (a) several states of the system Zn2OH2+ and (b) the low-lying states of the benzene-Cl atom complex and its contact ion pair. Generally good agreement between the two methods is obtained over a range of geometries. Either method can be applied at an arbitrary nuclear geometry and, as a result, may be used to test the validity of the Condon approximation. Examples of nonmonotonic behavior of the electronic coupling as a function of nuclear coordinates are observed for Zn2OH2+. Both methods also yield a natural definition of the effective distance (r(DA)) between donor (D) and acceptor (A) sites, in contrast to earlier approaches which required independent estimates of r(DA), generally based on molecular structure data. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RP Cave, RJ (reprint author), HARVEY MUDD COLL, DEPT CHEM, CLAREMONT, CA 91711 USA. NR 78 TC 274 Z9 277 U1 4 U2 49 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 JUN 8 PY 1997 VL 106 IS 22 BP 9213 EP 9226 DI 10.1063/1.474023 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB879 UT WOS:A1997XB87900026 ER PT J AU Imai, M Kato, T Schneider, D AF Imai, M Kato, T Schneider, D TI Fluctuations and growth of a cubic network observed in a nonionic surfactant system SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHASE-TRANSFORMATIONS; WATER AB We have investigated stability of a cubic lattice having a periodic-minimal surface in a nonionic surfactant system using a time resolved small-angle neutron scattering technique. The cubic lattice transformed from a lamellar phase showed polycrystalline scattering patterns and a strong fluctuation of the diffraction intensity as a function of time. The intensity distribution analysis indicates that the domain coarsening proceeds until 2000 min and then the coarsening is suppressed. At a critical temperature, such fluctuating peaks suddenly grow to a monocrystalline pattern showing no intensity fluctuations. On the contrary, in the case of the cubic lattice transformed from a hexagonal phase, the polycrystalline diffraction peaks also showed fluctuating behavior, but in this case, the domain coarsening is suppressed and the scattering intensity fluctuates around an equilibrium value. We consider that the fluctuations arise from the polycrystalline cubic network trapped in a metastable state. (C) 1997 American Institute of Physics. C1 TOKYO METROPOLITAN UNIV,FAC SCI,HACHIOJI,TOKYO 19203,JAPAN. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP Imai, M (reprint author), UNIV TOKYO,INST SOLID STATE PHYS,TOKAI,IBARAKI 31911,JAPAN. NR 16 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 1997 VL 106 IS 22 BP 9362 EP 9371 DI 10.1063/1.474005 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB879 UT WOS:A1997XB87900041 ER PT J AU Balachandran, U Dusek, JT Maiya, PS Ma, B Mieville, RL Kleefisch, MS Udovich, CA AF Balachandran, U Dusek, JT Maiya, PS Ma, B Mieville, RL Kleefisch, MS Udovich, CA TI Ceramic membrane reactor for converting methane to syngas SO CATALYSIS TODAY LA English DT Article DE membrane reactor; methane conversion; syngas; perovkites; ceramics ID PARTIAL OXIDATION; OXYGEN; CONVERSION AB Certain perovskite-type oxides (ABO(3)) containing transition metals on the B-site shaw mixed (electronic/ionic) conductivity. These mixed-conductivity oxides are promising materials for oxygen-permeating membranes that can operate without electrodes or external electrical circuitry. Oxides in the system Sr-Fe-Co-O permeate large amounts of oxygen, and extruded tubes of these materials have been evaluated in a reactor operating at approximate to 850 degrees C for direct conversion of methane into syngas (CO + H-2) in the presence of a reforming catalyst. Methane conversion efficiencies of > 99% were observed, and some of the reactor tubes have been operated for more than 1000h. Membrane tubes were fabricated from calcined powders by a plastic extrusion technique. Ceramic powders in the Sr-Fe-Co-O system were made by solid-state reaction of the constituent carbonates, oxides, and/or nitrates. The chemical-phase behavior of the ceramic powders with varying stoichiometries were studied by high-temperature in-situ X-ray diffraction (XRD) as a function of oxygen partial pressure. The sintered extruded tubes were also characterized by XRD and scanning electron microscopy. C1 AMOCO RES CTR,NAPERVILLE,IL 60566. RP Balachandran, U (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 22 TC 176 Z9 185 U1 3 U2 31 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD JUN 6 PY 1997 VL 36 IS 3 BP 265 EP 272 DI 10.1016/S0920-5861(96)00229-5 PG 8 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA XF745 UT WOS:A1997XF74500004 ER PT J AU Ha, T Enderle, T Chemla, DS Selvin, PR Weiss, S AF Ha, T Enderle, T Chemla, DS Selvin, PR Weiss, S TI Quantum jumps of single molecules at room temperature SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OPTICAL MICROSCOPY; FLUORESCENCE; SPECTROSCOPY; PARAMETERS; MEMBRANE AB The room temperature dynamics of single fluorescent dye molecules adsorbed on dry surfaces was investigated with submillisecond time resolution. Rapid turn-on and off events that satisfy stochastic statistics of quantum jumps were observed. These jumps were most likely intersystem crossing transitions to the triplet state, individually resolved due to the extended triplet state lifetime tau(off) in the dry condition. Saturation study of such single molecules confirmed the extended tau(off). Distributions in intersystem crossing yield Y-ISC and in tau(off), probably due to different local environment, were measured. Moreover, individual molecules exhibited abrupt changes in tau(off) and Y-ISC, correlated with spectral changes of the molecular emission. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,INST MOL DESIGN,BERKELEY,CA 94720. RP Ha, T (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Ha, Taekjip/B-9506-2009; weiss, shimon/B-4164-2009 OI Ha, Taekjip/0000-0003-2195-6258; weiss, shimon/0000-0002-0720-5426 NR 29 TC 145 Z9 147 U1 0 U2 18 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 JUN 6 PY 1997 VL 271 IS 1-3 BP 1 EP 5 DI 10.1016/S0009-2614(97)00440-5 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XC866 UT WOS:A1997XC86600001 ER PT J AU Deng, L Garrett, WR Payne, MG AF Deng, L Garrett, WR Payne, MG TI Pressure dependence of the ac Stark shifts in nitric oxide: Resonant multiphoton spectroscopy without space charge SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SPECTRA; IONIZATION AB Measurements of ac Stark shifts and broadening have been made on several multiphoton resonant rotational-vibronic levels in nitric oxide (NO). The levels and laser wavelengths are carefully chosen so that the number of ions produced can be kept low and the complication due to space charge can be avoided. It is found that the ac Stark effects are independent of the pressure. C1 OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831. RP Deng, L (reprint author), GEORGIA SO UNIV,DEPT PHYS,STATESBORO,GA 30360, USA. RI Deng, Lu/B-3997-2012 NR 9 TC 3 Z9 3 U1 0 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 JUN 6 PY 1997 VL 271 IS 1-3 BP 15 EP 18 DI 10.1016/S0009-2614(97)00438-7 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XC866 UT WOS:A1997XC86600003 ER PT J AU Longfellow, CA Smoliar, LA Lee, YT Lee, YR Yeh, CY Lin, SM AF Longfellow, CA Smoliar, LA Lee, YT Lee, YR Yeh, CY Lin, SM TI The photodissociation dynamics of hexafluoropropene examined at 193 nm SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OXYGEN-ATOMS; TETRAFLUOROETHYLENE AB The photodissociation of hexafluoropropene at 193 nm was studied using photofragment translational spectroscopy. One primary channel results in loss of a fluorine atom; from the maximum translational energy release, a value of 121 kcal/mol was determined to be the upper limit for the C-F bond dissociation energy. In addition, elimination of CF2 and CF3 competes with C-F bond cleavage. A branching fraction, CF2:F:CF3, of 0.42:0.41:0.17 was found among these three primary channels. A comparison of UV photolysis and infrared multiphoton dissociation experiments suggests that excitation and dissociation on an excited state surface competes with internal conversion and dissociation from the ground state. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. ACAD SINICA,INST ATOM & MOL SCI,TAIPEI 10617,TAIWAN. RP Longfellow, CA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012 NR 24 TC 7 Z9 7 U1 0 U2 2 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 JUN 6 PY 1997 VL 271 IS 1-3 BP 33 EP 39 DI 10.1016/S0009-2614(97)00445-4 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XC866 UT WOS:A1997XC86600006 ER PT J AU Shen, YR AF Shen, YR TI Optical physics - Solitons made simple SO SCIENCE LA English DT Editorial Material C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Shen, YR (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 5 TC 55 Z9 63 U1 0 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 6 PY 1997 VL 276 IS 5318 BP 1520 EP 1520 DI 10.1126/science.276.5318.1520 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XC701 UT WOS:A1997XC70100027 ER PT J AU Webb, OF Bienkowski, PR Matrubutham, U Evans, FA Heitzer, A Sayler, GS AF Webb, OF Bienkowski, PR Matrubutham, U Evans, FA Heitzer, A Sayler, GS TI Kinetics and response of a Pseudomonas fluorescens HK44 biosensor SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE polycyclic aromatic hydrocarbon; in situ; biosensor; immobilized cell ID CATABOLIC REPORTER BACTERIUM; SALICYLATE BIOAVAILABILITY; NAPHTHALENE CATABOLISM; BIOLUMINESCENCE; DIFFUSION AB The reporter bacterium, Pseudomonas fluorescens HK44 (HK44), was characterized in an immobilized state to investigate utility for deployment as a remote sensor in the subsurface. A packed-bed reactor with alginate-immobilized HK44 simulated hydrodynamic conditions such as might be found in a subsurface environment. The reporter bacterium, HK44, harbors a reporter plasmid, pUTK21, which contains a transcriptional fusion between the nahG gene in the lower pathway of the catabolic plasmic NAH7 and a luxCDABE gene cassette. The upper nah pathway and the lux pathway in pUTK21 are induced by salicylate. The lux enzymes catalyze the light reaction. HK44 demonstrated a quantitative relationship between salicylate concentration and degradation. Light intensity mimicked salicylate concentration, whereas degradation was first order in biomass and first order in salicylate concentration, with a degradation constant of 2.23 x 10(-2) dm(3) g(-1) min(-1). (C) 1977 John Wiley & Sons, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Webb, OF (reprint author), UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,10515 RES DR,SUITE 100,KNOXVILLE,TN 37932, USA. NR 30 TC 19 Z9 19 U1 1 U2 3 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 JUN 5 PY 1997 VL 54 IS 5 BP 491 EP 502 DI 10.1002/(SICI)1097-0290(19970605)54:5<491::AID-BIT8>3.0.CO;2-9 PG 12 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WW139 UT WOS:A1997WW13900008 PM 18634140 ER PT J AU Qian, Y Zhu, ZH Lo, YH Huffaker, DL Deppe, DG Hou, HQ Hammons, BE Lin, W Tu, YK AF Qian, Y Zhu, ZH Lo, YH Huffaker, DL Deppe, DG Hou, HQ Hammons, BE Lin, W Tu, YK TI Submilliamp 1.3 mu m vertical-cavity surface-emitting lasers with threshold current density of < 500A/cm(2) SO ELECTRONICS LETTERS LA English DT Article DE vertical cavity surface emitting lasers; semiconductor junction lasers AB High performance 1.3 mu m vertical-cavity surface-emitting lasers (VCSELs) using oxygen implantation in wafer-bonded GaAs/AlGaAs mirrors are demonstrated. A record low threshold current density of 454A/cm(2) and a threshold current of 0.83mA have been achieved for pulsed operation at 20 degrees C. The maximum CW and pulsed operating temperatures are 40 and 112 degrees C, respectively. C1 Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. Sandia Natl Labs, Dept Semicond Mat, Albuquerque, NM 87185 USA. Univ Texas, Dept Elect & Comp Engn, Microelect Res Ctr, Austin, TX 78712 USA. RP Qian, Y (reprint author), Cornell Univ, Sch Elect Engn, Phillips Hall, Ithaca, NY 14853 USA. NR 5 TC 21 Z9 21 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 5 PY 1997 VL 33 IS 12 BP 1052 EP 1054 DI 10.1049/el:19970679 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA YX446 UT WOS:000072040800039 ER PT J AU Potter, BG Simmons-Potter, K Brannon, PJ AF Potter, BG Simmons-Potter, K Brannon, PJ TI Ionising radiation response of photosensitive germanosilicate thin films: A new radiation sensor strategy SO ELECTRONICS LETTERS LA English DT Article DE radiation effects; optical fibres ID DYNAMICS; FIBERS AB The effect of x-ray irradiation on the absorption behaviour of highly photosensitive germanosilicate thin films is evaluated. The corresponding impact on the optical response of photosensitive Bragg gratings written into these materials indicates that these structures may be useful as ionising radiation sensor elements. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Potter, BG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 5 PY 1997 VL 33 IS 12 BP 1073 EP 1075 DI 10.1049/el:19970687 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA YX446 UT WOS:000072040800053 ER PT J AU Blum, O Hafich, MJ Klem, JF Baucom, K Allerman, A AF Blum, O Hafich, MJ Klem, JF Baucom, K Allerman, A TI Wet thermal oxidation of AlAsSb against As/Sb ratio SO ELECTRONICS LETTERS LA English DT Article DE oxidation; semiconductor technology AB The authors describe lateral steam oxidation of the AlAsSb material system, varying the As/Sb ratio. Large oxidation depths are obtained for a variety of As/Sb ratios, as long as both As and Sb are present. Ln comparison, oxidation of AlAs is much slower, whereas AlSb does not appear to oxidise at all. Qualitatively different oxides are obtained from AlAs0.56Sb0.44 and AlAs0.16Sb0.84. C1 Sandia Natl Labs, Dept 1312, Albuquerque, NM 87185 USA. RP Blum, O (reprint author), Sandia Natl Labs, Dept 1312, MS0603, Albuquerque, NM 87185 USA. NR 5 TC 9 Z9 9 U1 1 U2 3 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 5 PY 1997 VL 33 IS 12 BP 1097 EP 1099 DI 10.1049/el:19970684 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA YX446 UT WOS:000072040800069 ER PT J AU Pilgrim, JS Taatjes, CA AF Pilgrim, JS Taatjes, CA TI Infrared absorption probing of the Cl+C2H4 reaction: Direct measurement of Arrhenius parameters for hydrogen abstraction SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FLASH KINETIC SPECTROSCOPY; CL ATOM REACTIONS; ETHYL RADICALS; LASER; CHLORINE; SPECTRA; DISPROPORTIONATION; RECOMBINATION; ACETYLENE; EMISSION AB The laser photolysis/infrared long path absorption technique has been used to study the reaction of Cl atoms with C2H4. The time-resolved population of HCl produced in the reaction is monitored by continuous infrared absorption after pulsed photolytic generation of Cl atoms. At room temperature, the reaction proceeds principally through addition to form a chloroethyl radical, and the HCl production at 10 Torr is almost exclusively via secondary reactions. Above 500 K the abstraction channel dominates the HCl production, allowing direct extraction of Arrhenius parameters for the hydrogen abstraction, The abstraction rates are extracted by correcting the total rate by the HCl yield, which is determined by comparison with the Cl + C3H8 reaction. The abstraction reaction is well-described between 500 and 800 K by the simple Arrhenius expression k(T) (6.2 +/- 1.4) x 10(-11)e(-(3400+/-450/T) cm(3) molecule(-1) s(-1) (2 sigma). The activation energy determined in the present work would yield a heat of formation of the vinyl radical of Delta H degrees(f,298)(C2H3) = 71.3 +/- 1.3 kcal mol(-1) when combined with an extrapolation of published 298-495 K measurements of the HCl + C2H3 activation energy. A third-law analysis al 500 K yields Delta H degrees(f,298)(C2H3) = 71.6 +/- 0.3 kcal mol(-1). C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 29 TC 34 Z9 34 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 5 PY 1997 VL 101 IS 23 BP 4172 EP 4177 DI 10.1021/jp970117i PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XD263 UT WOS:A1997XD26300005 ER PT J AU Imre, DG Xu, J Tang, IN McGraw, R AF Imre, DG Xu, J Tang, IN McGraw, R TI Ammonium bisulfate water equilibrium and metastability phase diagrams SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AEROSOLS; DROPLETS AB Though ammonium bisulfate is one of the most common of atmospheric hygroscopic aerosols, knowledge of its interaction with water has, until now, been extremely limited. This paper presents our observations on single isolated ammonium bisulfate aerosol particles, as they interact with water vapor at temperatures ranging from -40 to 30 degrees C. The complete phase diagram in the temperature/composition as well as the pressure/temperature domains has been derived here for the first time, mapping out equilibrium and metastable to stable phase transitions. A new low-temperature crystalline hydrate phase that might have an important role in processes occurring in the upper troposphere has been discovered. C1 SUNY, INST TERR & PLANETARY ATMOSPHERES, NEW YORK, NY 11794 USA. RP Imre, DG (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. NR 14 TC 28 Z9 29 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 5 PY 1997 VL 101 IS 23 BP 4191 EP 4195 DI 10.1021/jp9704426 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XD263 UT WOS:A1997XD26300008 ER PT J AU More, MB Ray, D Armentrout, PB AF More, MB Ray, D Armentrout, PB TI Cation-ether complexes in the gas phase: Bond dissociation energies of K+(dimethyl ether)(x), x=1-4; K+(1,2-dimethoxyethane)(x), x=1 and 2; and K+(12-crown-4) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID COLLISION-INDUCED DISSOCIATION; CROWN-ETHERS; MACROCYCLIC CHEMISTRY; ION COMPLEXATION; BINDING-ENERGIES; CHARGE-TRANSFER; REACTION-RATES; ALKALI; DEPENDENCE; THERMOCHEMISTRY AB Bond dissociation energies (BDEs) of K+[O(CH3)(2)](x), x = 1-4; K+[(CH2OCH3)(2)](x), x = 1 and 2; and K+[c-(C2H4O)(4)] are reported. The BDEs are determined experimentally by analysis of the thresholds for collision-induced dissociation of the cation-ether complexes by xenon measured using guided ion beam mass spectrometry. in all cases, the primary and lowest energy dissociation channel observed experimentally is endothermic loss of one Ligand molecule. The cross section thresholds are interpreted to yield O and 298 K Bh)Es after accounting for the effects of multiple ion-molecule collisions, internal energy of the complexes, and unimolecular decay rates. Trends in the BDEs determined by experiment and recent theoretical nb initio calculations are in good agreement, with experimental values being systematically lower than the theoretical values by 5 +/- 3 kJ/mol per metal-oxygen interaction. Comparisons to trends in the BDEs for analogous Li+ and Na+ complexes reveal that Li+ is bound less strongly than expected when compared with analogous Na+ and K+ complexes. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. NR 54 TC 85 Z9 85 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 5 PY 1997 VL 101 IS 23 BP 4254 EP 4262 DI 10.1021/jp964015o PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XD263 UT WOS:A1997XD26300017 ER PT J AU Ferrere, S Zaban, A Gregg, BA AF Ferrere, S Zaban, A Gregg, BA TI Dye sensitization of nanocrystalline tin oxide by perylene derivatives SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID TIO2 FILMS; PHOTOELECTROCHEMICAL CHARACTERIZATION; TITANIUM-DIOXIDE; COLLOIDAL TIO2; CONVERSION; LIGHT; PHOTOSENSITIZATION; ELECTRICITY; ELECTRODES; PHOTOCHEMISTRY AB A new sensitizing dye-semiconductor system comprised of perylene derivatives on SnO2 has been characterized. The tetracarboxylic acid form (''PTCA'') of the commercially available dye perylene-3,4,9,10-tetracarboxylic dianhydride and the novel compound perylene-3,4-dicarboxylic acid-9,10-(5-phenanthroline)carboximide (''PPDCA'') adsorb strongly to the surface of colloidal films of SnO2 and inject electrons into the semiconductor film upon absorption of light. A Nm of PPDCA on SnO2 yields a short circuit photocurrent density of 3.26 mA/cm(2), a photovoltage of -0.45 V, and an overall cell efficiency of 0.89% at one sun Light intensity. Estimates of the oxidation potential of adsorbed PPDCA indicate that it may also be useful in a water-splitting configuration. The results presented here indicate that the perylene-SnO2 system is a promising dye-semiconductor combination and warrants further study. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 35 TC 682 Z9 696 U1 6 U2 102 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 5 PY 1997 VL 101 IS 23 BP 4490 EP 4493 DI 10.1021/jp970683d PG 4 WC Chemistry, Physical SC Chemistry GA XD262 UT WOS:A1997XD26200003 ER PT J AU Vasenkov, S Frei, H AF Vasenkov, S Frei, H TI UV-visible absorption spectroscopy and photochemistry of an alkene center dot O-2 contact charge-transfer system in large NaY crystals SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ZEOLITE-Y; SELECTIVE OXIDATION; RED-LIGHT; O-2; PHOTOOXIDATION AB Single layers of 40 mu m NaY crystals were prepared on a CaF2 support. These are sufficiently transparent to allow recording of reactants occluded in the zeolite pores by W-visible transmission spectroscopy for the first time. Spectra of 2,3-dimethyl-2-butene (DMB) and oxygen gas loaded into the zeolite revealed the true absorption profile of the DMB . O-2 charge-transfer contact complex. Visible-light-induced reaction was monitored by in situ Fourier transform infrared spectroscopy. Irradiation resulted in the same selective oxidation to 2,3-dimethyl-3-hydroperoxy-1-butene observed previously in highly scattering pellets of 1 mu m NaY particles. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,MS CALVIN LAB,BERKELEY,CA 94720. NR 24 TC 28 Z9 31 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 5 PY 1997 VL 101 IS 23 BP 4539 EP 4543 DI 10.1021/jp970006j PG 5 WC Chemistry, Physical SC Chemistry GA XD262 UT WOS:A1997XD26200011 ER PT J AU Zhang, LP Kuhn, M Diebold, U Rodriguez, JA AF Zhang, LP Kuhn, M Diebold, U Rodriguez, JA TI Thermal stability of ultrathin Cr films on Pt(111) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY-ELECTRON DIFFRACTION; PHOTOEMISSION; GROWTH; ALLOY; CO/PT(111); INTERFACE; ABINITIO; NI(111); METALS; CO AB The thermal stability of ultrathin chromium films on Pt(111) has been studied using low-energy He+ ion scattering spectroscopy, X-ray photoelectron spectroscopy, low-energy electron diffraction, and scanning tunneling microscopy. At room temperature, Cr grows on Pt(111) with a modified Stranski-Krastanov growth mode (almost complete wetting of the first two layers with subsequent three-dimensional island growth). Upon annealing, chromium diffuses into the Pt lattice. This causes a smoothening of the surface features. A flat Pt(111) surface, devoid of Cr, is regained after prolonged annealing above 770 K. Ar lower temperatures, metastable Cr-Pt surface alloys are formed. The apparent composition and stability of these surface alloys are dependent upon the amount of Cr deposited initially. Both the Cr adlayer and Pt surface atoms were found to be perturbed at the interface. Experimental and theoretical results indicate that a redistribution of charge between Pt and Cr occurs upon alloy formation with the greatest perturbation experienced by the Pt atoms. C1 TULANE UNIV,DEPT PHYS,NEW ORLEANS,LA 70118. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Diebold, Ulrike/A-3681-2010 OI Diebold, Ulrike/0000-0003-0319-5256 NR 31 TC 14 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 5 PY 1997 VL 101 IS 23 BP 4588 EP 4596 DI 10.1021/jp9627786 PG 9 WC Chemistry, Physical SC Chemistry GA XD262 UT WOS:A1997XD26200018 ER PT J AU Douglas, MR Ooguri, H Shenker, SH AF Douglas, MR Ooguri, H Shenker, SH TI Issues in M(atrix) theory compactification SO PHYSICS LETTERS B LA English DT Article AB We discuss issues concerning M(atrix) theory compactifications on curved spaces. We argue from the form of the graviton propagator on curved space that excited string states do not decouple from the annulus DO-brane v(4) amplitude, unlike the flat space case. This argument shows that a large class of quantum mechanical systems with a finite number of degrees of freedom cannot reproduce supergravity answers. We discuss the specific example of an ALE space and suggest sources of possible higher derivative terms that might help reproduce supergravity results. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. RP Douglas, MR (reprint author), RUTGERS STATE UNIV,DEPT PHYS & ASTRON,POB 849,PISCATAWAY,NJ 08855, USA. RI Ooguri, Hirosi/A-4407-2011 NR 21 TC 46 Z9 46 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 JUN 5 PY 1997 VL 402 IS 1-2 BP 36 EP 42 DI 10.1016/S0370-2693(97)00424-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD049 UT WOS:A1997XD04900007 ER PT J AU Maharana, J AF Maharana, J TI S-duality and compactification of type IIB superstring action SO PHYSICS LETTERS B LA English DT Article ID STRING EFFECTIVE ACTION; SCALE FACTOR DUALITY; SPACE; SUPERGRAVITY; DIMENSIONS; SYMMETRIES; REDUCTION AB The SL(2,R) invaraint ten dimensional type IIB superstring effective action is compactified on a torus to D spacetime dimensions. The transformation properties of scalar, vector and tensor fields, appearing after the dimensional reduction, are obtained in order to maintain the SL(2, R) invariance of the reduced effective action. The symmetry of the action enables one to generate new string vacua from known configurations. As illustrative examples, new black hole solutions are obtained in five and four dimensions from a given set of solutions of the equations of motion. (C) 1997 Published by Elsevier Science B.V. C1 INST PHYS,BHUBANESWAR 751005,ORISSA,INDIA. RP Maharana, J (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 64 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 JUN 5 PY 1997 VL 402 IS 1-2 BP 64 EP 70 DI 10.1016/S0370-2693(97)00444-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD049 UT WOS:A1997XD04900011 ER PT J AU Wu, GH Kiers, K Ng, JN AF Wu, GH Kiers, K Ng, JN TI Testing time reversal invariance in exclusive semileptonic B meson decays SO PHYSICS LETTERS B LA English DT Article ID TRANSVERSE TAU-POLARIZATION; K-MU-3 DECAYS; MUON POLARIZATION; CP-VIOLATION; HEAVY MESONS; WEAK DECAYS; SYSTEMS; SEARCH; MODEL AB We demonstrate that polarization measurements in exclusive semileptonic B decays are powerful tools for unraveling non-standard model sources of T-violation. Measurements of the transverse polarization of the tau lepton in the B --> D tau<(nu)over bar> and B --> D*tau<(nu)over bar> decays probe separately effective scalar and pseudoscalar CP-violating four-Fermi interactions, whereas the D* polarization in the B --> D*l<(nu)over bar> (l = e, mu) decay is sensitive to an effective right-handed quark current interaction. Two T-odd polarization structures exist involving the D* polarization and they can be isolated and studied separately. An estimate of these T-odd effects is also given in the context of supersymmetric theories. (C) 1997 Elsevier Science B.V. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP TRIUMF, THEORY GRP, 4004 WESBROOK MALL, VANCOUVER, BC V6T 2A3, CANADA. NR 37 TC 6 Z9 6 U1 0 U2 0 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 JUN 5 PY 1997 VL 402 IS 1-2 BP 159 EP 166 DI 10.1016/S0370-2693(97)00403-6 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD049 UT WOS:A1997XD04900024 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Djaoshvili, N vonDombrowski, S Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pietra, C Pinder, CN Pinter, G Regenfus, C Reissmann, J Resag, S Roethel, W Schmidt, P 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 Zou, BS AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Djaoshvili, N vonDombrowski, S Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pietra, C Pinder, CN Pinter, G Regenfus, C Reissmann, J Resag, S Roethel, W Schmidt, P 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 Zou, BS TI Measurement of the decay distribution of eta'->pi(+)pi(-)gamma and evidence for the box anomaly SO PHYSICS LETTERS B LA English DT Article ID FORM-FACTOR; COLLISIONS; CHARGE; MESON AB The distribution of m(pi(+)pi(-)) in the decay eta' --> pi(+)pi(-)gamma has been measured with the Crystal Barrel detector. The results are based on a total of 7392 observed eta' decays. The box anomaly constant is extracted from this and its value is found to agree well with theoretical expectations. The pseudoscalar nonet parameters (f(1), f(8) and theta(PS)) are determined. Finally, we find that there is a problem of consistency between QCD and the standard VDM assumption. (C) 1997 Published by Elsevier Science B.V. C1 RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV BONN,D-53115 BONN,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,CH-1211 GENEVA 4,SWITZERLAND. UNIV HAMBURG,D-76021 HAMBURG,GERMANY. UNIV KARLSRUHE,D-76021 KARLSRUHE,GERMANY. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MAINZ,D-55099 MAINZ,GERMANY. UNIV MUNICH,D-80333 MUNICH,GERMANY. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. UNIV PARIS 06,LPNHE,F-75252 PARIS,FRANCE. RP Abele, A (reprint author), UNIV CALIF BERKELEY,LBNL,BERKELEY,CA 94720, USA. NR 26 TC 40 Z9 40 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 JUN 5 PY 1997 VL 402 IS 1-2 BP 195 EP 206 DI 10.1016/S0370-2693(97)00479-6 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD049 UT WOS:A1997XD04900029 ER PT J AU Seeger, PA Rokop, SE Palmer, PD Henderson, SJ Hobart, DE Trewhella, J AF Seeger, PA Rokop, SE Palmer, PD Henderson, SJ Hobart, DE Trewhella, J TI Neutron resonance scattering shows specific binding of plutonium to the calcium-binding sites of the protein calmodulin and yields precise distance information SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PEPTIDE COMPLEX; RECOGNITION; RESOLUTION; DOMAIN; TARGETS; CRYSTAL; KINASE; HELIX; NMR AB We have successfully substituted Pu-240(3+) for Ca2+ in the calcium-binding protein calmodulin and used neutron resonance scattering from the bound Pu-240 to demonstrate that the Pu binds specifically to the Ca2+ sites and also to measure the distance between the ion binding sites within individual domains of the protein. Pu-240 has a strong nuclear resonance at 0.278 Angstrom, and at this wavelength the coherent scattering from Pu-240 is > 1000 times that of any other nucleus present in a protein. The ionic radius of Pu3+ is very similar to that of Ca2+, and hence eve chose this species to substitute for Ca2+ in the protein. We identified solution conditions that stabilize Pu3+ in solution at near neutral pH for 6-7 h in order to form the Pu/calmodulin complex under conditions favorable for both complex formation and maintaining the structural integrity of the protein. We collected small-angle neutron scattering data from solutions of 4(Pu-240(3+)). calmodulin, which contain periodic terms that are directly related to the distances between the Ca2+-binding sites. The shorter Pu-Pu distance, i.e., the average distance between the two sites within each globular domain of calmodulin, is found to be 11.8 +/- 0.4 Angstrom, in excellent agreement with the value of 11.7 Angstrom from crystallographic determinations. This is the first use of neutron resonance scattering as a structural probe in a protein. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. OI Trewhella, Jill/0000-0002-8555-6766 NR 35 TC 11 Z9 11 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 JUN 4 PY 1997 VL 119 IS 22 BP 5118 EP 5125 DI 10.1021/ja9633124 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA XC669 UT WOS:A1997XC66900007 ER PT J AU Stang, PJ Cao, DH Chen, KC Gray, GM Muddiman, DC Smith, RD AF Stang, PJ Cao, DH Chen, KC Gray, GM Muddiman, DC Smith, RD TI Molecular architecture via coordination: Marriage of crown ethers and calixarenes with molecular squares, unique tetranuclear metallamacrocycles from metallacrown ether and metallacalixarene complexes via self-assembly SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RAY CRYSTAL-STRUCTURE; RESONANCE MASS-SPECTROMETER; IODONIUM-TRANSITION-METAL; MACROCYCLIC SQUARES; SUPRAMOLECULAR COMPLEXES; ELECTROSPRAY-IONIZATION; PHOSPHORUS-DONOR; CATION BINDING; CHEMISTRY; LIGAND AB Reaction of metallacrown and metallacalixarene platinum bistriflates with bipyridine as well as other bidentate connector ligands results in the formation of tetranuclear macrocycles via self-assembly that combine crown ether and calixarene chemistry with molecular squares. Multinuclear NMR spectroscopy and electrospray mass spectrometry are employed to characterize these unique supramolecular species. The calixarene metallamacrocycles are used in simple transport experiments to carry sulfonate salts from one aqueous phase into another through chloroform. C1 UNIV ALABAMA, DEPT CHEM, BIRMINGHAM, AL 35294 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Stang, PJ (reprint author), UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 82 TC 123 Z9 123 U1 6 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 JUN 4 PY 1997 VL 119 IS 22 BP 5163 EP 5168 DI 10.1021/ja9642267 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA XC669 UT WOS:A1997XC66900012 ER PT J AU Norby, P AF Norby, P TI Hydrothermal conversion of zeolites: An in situ synchrotron X-ray powder diffraction study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CRYSTALLIZATION; CANCRINITES AB Hydrothermal conversion of zeolite LTA by LiCl(aq) is an efficient synthesis route for zeolite Li-A(BW), LiAlSiO4 . H2O, resulting in highly crystalline materials. In the present work hydrothermal crystallization of zeolite Li-A(BW) was followed in situ by time resolved synchrotron X-ray powder diffraction. These experiments were combined with ex situ scanning electron microscopy on partially converted samples. Fitting of the crystallization curves with rate expressions indicated limited nucleation and showed that intermediate amorphous or solute phases were not present in any significant amount. Partially converted samples were prepared in situ, making it possible to monitor the progress of crystallization and to determine the degree of conversion in each sample. Scanning electron microscope images of 40 and 60% converted samples showed that the parent zeolite LTA crystallites to a large degree serve as nucleation centers for the crystallization of zeolite Li-A(BW). The zeolite Li-A(BW) crystals grow radially from the nucleation site, forming clusters of flat needle-like crystals. The information obtained from the combined experiments clearly shows that the hydrothermal conversion of zeolite LTA into zeolite Li-A(BW) is a solution-mediated process. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RI Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 25 TC 102 Z9 102 U1 0 U2 28 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 JUN 4 PY 1997 VL 119 IS 22 BP 5215 EP 5221 DI 10.1021/ja964245g PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA XC669 UT WOS:A1997XC66900019 ER PT J AU Clark, DL Conradson, SD Neu, MP Palmer, PD Runde, W Tait, CD AF Clark, DL Conradson, SD Neu, MP Palmer, PD Runde, W Tait, CD TI XAFS structural determination of Np(VII). Evidence for a trans dioxo cation under alkaline solution conditions SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ABSORPTION FINE-STRUCTURE; CARBONATE COMPLEXES; RAY; CHEMISTRY; ALKOXIDE C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. GT SEABORG INST TRANSACTINIUM SCI,LIVERMORE,CA 94551. RP Clark, DL (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MAIL STOP G739,LOS ALAMOS,NM 87545, USA. RI Clark, David/A-9729-2011 NR 19 TC 26 Z9 26 U1 3 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 JUN 4 PY 1997 VL 119 IS 22 BP 5259 EP 5260 DI 10.1021/ja964053l PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA XC669 UT WOS:A1997XC66900028 ER PT J AU Alaimo, PJ Arndtsen, BA Bergman, RG AF Alaimo, PJ Arndtsen, BA Bergman, RG TI Synthesis of tertiary and other sterically demanding alkyl and aryl complexes of iridium by aldehyde C-H bond activation SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RAY CRYSTAL-STRUCTURE; HYDROCARBONS C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 30 TC 39 Z9 39 U1 0 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 JUN 4 PY 1997 VL 119 IS 22 BP 5269 EP 5270 DI 10.1021/ja970245k PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA XC669 UT WOS:A1997XC66900033 ER PT J AU Vossmeyer, T DeIonno, E Heath, JR AF Vossmeyer, T DeIonno, E Heath, JR TI Light-directed assembly of nanoparticles SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE clusters; gold; nanostructures; photochemistry ID CHEMICAL SYNTHESIS; MONOLAYERS; SURFACES C1 UNIV CALIF LOS ANGELES,LAWRENCE BERKELEY LAB,INST MOL DESIGN,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. NR 24 TC 113 Z9 113 U1 2 U2 15 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD JUN 2 PY 1997 VL 36 IS 10 BP 1080 EP 1083 DI 10.1002/anie.199710801 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA XF482 UT WOS:A1997XF48200009 ER PT J AU Sun, CJ Anwar, MZ Chen, Q Yang, JW Khan, MA Shur, MS Bykhovski, AD LilientalWeber, Z Kisielowski, C Smith, M Lin, JY Xiang, HX AF Sun, CJ Anwar, MZ Chen, Q Yang, JW Khan, MA Shur, MS Bykhovski, AD LilientalWeber, Z Kisielowski, C Smith, M Lin, JY Xiang, HX TI Quantum shift of band-edge stimulated emission in InGaN-GaN multiple quantum well light-emitting diodes SO APPLIED PHYSICS LETTERS LA English DT Article ID ROOM-TEMPERATURE AB We report on the band-edge stimulated emission in InGaN-GaN multiple quantum well light-emitting diodes with varying widths and barrier thicknesses of the quantum wells. In these devices, we observe that the stimulated emission peak wavelength shifts to shorter values with decreasing well thickness. From the comparison of the results of the quantum mechanical calculations of the subbands energies with the measured data, we estimate the effective conduction- and valence-band discontinuities at the GaN-In0.13Ga0.87N heterointerface to be approximately 130-155 and 245-220 meV, respectively. We also discuss the effect of stress on the estimated values of band discontinuities. (C) 1997 American Institute of Physics. C1 RENSSELAER POLYTECH INST,DEPT ELECT COMP & SYST ENGN,TROY,NY 12180. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV VIRGINIA,DEPT ELECT ENGN,CHARLOTTESVILLE,VA 22903. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. KANSAS STATE UNIV,DEPT PHYS,MANHATTAN,KS 66506. RP Sun, CJ (reprint author), APA OPT INC,2950 N 84TH LANE,BLAINE,MN 55434, USA. RI Lin, Jingyu/A-7276-2011; Liliental-Weber, Zuzanna/H-8006-2012; Jiang, Hongxing/F-3635-2011; Shur, Michael/A-4374-2016 OI Lin, Jingyu/0000-0003-1705-2635; Jiang, Hongxing/0000-0001-9892-4292; Shur, Michael/0000-0003-0976-6232 NR 12 TC 76 Z9 76 U1 1 U2 10 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 JUN 2 PY 1997 VL 70 IS 22 BP 2978 EP 2980 DI 10.1063/1.118762 PG 3 WC Physics, Applied SC Physics GA XB501 UT WOS:A1997XB50100017 ER PT J AU Devine, RAB Autran, JL Warren, WL Vanheusdan, KL Rostaing, JC AF Devine, RAB Autran, JL Warren, WL Vanheusdan, KL Rostaing, JC TI Interfacial hardness enhancement in deuterium annealed 0.25 mu m channel metal oxide semiconductor transistors SO APPLIED PHYSICS LETTERS LA English DT Article ID CHARGE AB Interfacial degradation induced by hot-electron injection has been studied in n-channel metal oxide semiconductor transistors with channel lengths down to 0.2 mu m. The devices were annealed in either H-2 of D-2 containing atmospheres. The channel transconductance and threshold voltage variations. induced by hot-electron injection into the gate are consistent with interface state generation. Charge pumping experiments confirm this conclusion. The lifetime for a 10% reduction in the transconductance is enhanced by similar to 10 times for devices annealed in D-2 containing atmospheres as compared to those annealed in H-2. (C) 1997 American Institute of Physics. C1 INST NATL SCI APPL,PHYS MAT LAB,F-69621 VILLEURBANNE,FRANCE. SANDIA NATL LABS,ADV MAT LAB,ALBUQUERQUE,NM 87185. AIR LIQUIDE RES & DEV,F-78350 JOUY EN JOSAS,FRANCE. RP Devine, RAB (reprint author), FRANCE TELECOM,CTR NATL ETUD TELECOMMUN,BP 98,F-38243 MEYLAN,FRANCE. RI Autran, Jean-Luc/A-8538-2010 OI Autran, Jean-Luc/0000-0001-9893-014X NR 7 TC 64 Z9 64 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 JUN 2 PY 1997 VL 70 IS 22 BP 2999 EP 3001 DI 10.1063/1.118769 PG 3 WC Physics, Applied SC Physics GA XB501 UT WOS:A1997XB50100024 ER PT J AU Antoshechkin, I Bogenhagen, DF Mastrangelo, IA AF Antoshechkin, I Bogenhagen, DF Mastrangelo, IA TI The HMG-box mitochondrial transcription factor xl-mtTFA binds DNA as a tetramer to activate bidirectional transcription SO EMBO JOURNAL LA English DT Article DE HMG box; mitochondria; mtTFA; STEM; transcription ID YEAST MITOCHONDRIA; MOLECULAR-BASIS; RNA-POLYMERASE; PROTEIN; SRY; PURIFICATION; REPLICATION; MECHANISM; ELEMENTS; JUNCTION AB The mitochondrial HMG-box transcription factor xl-mtTFA activates bidirectional transcription by binding to a site separating two core promoters in Xenopus laevis mitochondrial DNA (mtDNA). Three independent approaches were used to study the higher order structure of xl-mtTFA binding to this site. First, coimmunoprecipitation of differentially tagged recombinant mtTFA derivatives established that the protein exists as a multimer. Second, in vitro chemical crosslinking experiments provided evidence of cross-linked dimers, trimers and tetramers of xl-mtTFA. Finally, high resolution scanning transmission electron microscopy (STEM) established that xl-mtTFA binds to the specific promoter-proximal site predominantly as a tetramer. Computer analysis of several previously characterized binding sites for xl-mtTFA revealed a fine structure consisting of two half-sites in a symmetrical orientation. The predominant sequence of this dyad symmetry motif shows homology to binding sites of sequence-specific EMG-box-containing proteins such as Sry and Lef-1. We suggest that bidirectional activation of transcription results from the fact that binding of a tetramer of xl-mtTFA permits symmetrical interactions with other components of the transcription machinery at the adjacent core promoters. C1 SUNY STONY BROOK,DEPT PHARMACOL SCI,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NCRR NIH HHS [RR0177]; NHGRI NIH HHS [NIHGM29681] NR 38 TC 35 Z9 36 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD JUN 2 PY 1997 VL 16 IS 11 BP 3198 EP 3206 DI 10.1093/emboj/16.11.3198 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XE748 UT WOS:A1997XE74800022 PM 9214636 ER PT J AU Stewart, FF Lash, RP Singler, RE AF Stewart, FF Lash, RP Singler, RE TI Synthesis and characterization of esterified poly[(aryloxy)phosphazene]s SO MACROMOLECULES LA English DT Article ID PHOSPHAZENE POLYMER MEMBRANES; POLYPHOSPHAZENE; ELECTROLYTES; SEPARATION AB Four new phosphazene polymers were synthesized using an esterification methodology. It was found that poly[bis(4-carboxylatophenoxy)phosphazene] reacts with neat alcohols and catalytic acid at reflux to form polymers with varying chemical and physical properties. Esters were prepared from the following alcohols; 2-methoxyethanol, 2,2'-methoxyethoxyethanol, 2-ethoxyethanol, and 1-butanol. The resulting new polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and were found to have the expected ester pendant groups homogeneously substituted onto the phosphorus-nitrogen backbone. Laser light scattering (LLS) was used to determine that during the modification process molecular weight of the polymer is conserved, suggesting that under the conditions of the esterification process no chain scission occurs. C1 US MIL ACAD,DEPT CHEM,W POINT,NY 10996. RP Stewart, FF (reprint author), LOCKHEED MARTIN IDAHO TECHNOL CO,IDAHO NATL ENGN & ENVIRONM LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 35 TC 12 Z9 14 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 2 PY 1997 VL 30 IS 11 BP 3229 EP 3233 DI 10.1021/ma9618991 PG 5 WC Polymer Science SC Polymer Science GA XC528 UT WOS:A1997XC52800016 ER PT J AU Cui, ST Cochran, HD Cummings, PT Kumar, SK AF Cui, ST Cochran, HD Cummings, PT Kumar, SK TI Computer simulations of the static scattering from model polymer blends SO MACROMOLECULES LA English DT Article ID INTEGRAL-EQUATION THEORY; NEUTRON-SCATTERING; CONCENTRATION FLUCTUATIONS; THERMODYNAMICS; PARAMETER; MIXTURES; DEPENDENCE; MELTS AB To understand the unusual composition and wave vector, q, dependent Flory interaction parameters, chi, obtained from small angle neutron scattering (SANS), we have calculated the three partial structure factors for symmetric binary polymer blends with relatively strong interactions between dissimilar monomers using molecular dynamics simulations. In agreement with past work we find that the radii of gyration of the chains are altered on blending. The following new results emerged from our simulations. The single-chain form factors in the blends follow Gaussian statistics at all distances larger than a monomer diameter, confirming the Flory-de Gennes conjecture that correlations in condensed polymer phases are screened over short length scales. The R-g's deduced from these form factors are in agreement with simulation-determined values and illustrate conclusively that the single chain term in the incompressible random-phase approximation (i-RPA) is altered on blending. The three partial structure factors obtained from the simulations, each of which follows an Ornstein-Zernike behavior, have different q dependences and extrapolate to different values in the thermodynamic limit. The different q dependences can be explained qualitatively by a compressible RPA formalism proposed by Tang and Freed. We then show that any form chosen to combine these partial structure factors into a single total scattering function will, in general, not have a q dependence that is describable by the incompressible RPA. This explains the experimentally observed q dependence of the chi parameter derived from the i-RPA. Finally, a thermodynamic analysis on the zero wave-vector limit of the partial structure factors shows that their absolute values are different from each other due to the effects of density fluctuations, as well as the different partial molar volumes of the two species in the blend. These results serve to emphasize the important role played by compressibility on the scattering obtained from simple polymer mixtures with large excess volumes on mixing. C1 PENN STATE UNIV,DEPT MAT SCI & ENGN,UNIVERSITY PK,PA 16802. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 32 TC 11 Z9 11 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 JUN 2 PY 1997 VL 30 IS 11 BP 3375 EP 3382 DI 10.1021/ma961020h PG 8 WC Polymer Science SC Polymer Science GA XC528 UT WOS:A1997XC52800035 ER PT J AU Choi, HM Ji, CR AF Choi, HM Ji, CR TI Light-cone quark model predictions for radiative meson decays SO NUCLEAR PHYSICS A LA English DT Article DE radiative meson decays; light-cone quark model; transition form factors; eta-eta' mixing ID PERTURBATIVE QUANTUM CHROMODYNAMICS; INTERMEDIATE MOMENTUM-TRANSFER; ELECTRON-DEUTERON SCATTERING; ELECTROMAGNETIC FORM-FACTORS; PION WAVE-FUNCTION; QCD SUM-RULES; RELATIVISTIC MODEL; NUCLEON; TRANSITION; LATTICE AB We investigate the radiative decay of pseudoscalar (pi, K, eta, eta'), vector (rho, K*, omega, phi) and axial-vector (A(1)) mesons using a simple relativistic constituent quark model. For both simplicity and relativity, we take advantage of the distinguished features in the light-cone quantization method: (1) the Fock state expansion of meson wave functions are not contaminated by the vacuum fluctuation, (2) the problem of assigning quantum numbers J(PC) to mesons is circumvented by the Melosh transformation. Except the well-known constituent quark masses of (u, d, s) quarks and the spin-averaged meson masses, the only parameter in the model is the Gaussian parameter beta which determines the broadness (or sharpness) of the radial wave function, Our overall predictions of pseudoscalar, vector and axial-vector meson radiative decay processes are in remarkably good agreement with the experimental data. (C) 1997 Elsevier Science B.V. C1 TJNAF,NEWPORT NEWS,VA 23606. RP Choi, HM (reprint author), N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695, USA. RI Ji, Chueng/J-2623-2013 NR 60 TC 28 Z9 29 U1 0 U2 2 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 JUN 2 PY 1997 VL 618 IS 3 BP 291 EP 316 DI 10.1016/S0375-9474(97)00052-3 PG 26 WC Physics, Nuclear SC Physics GA XD867 UT WOS:A1997XD86700002 ER PT J AU Kintner, JC Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, D Chacon, AD Chance, JL Choi, Y Costa, S Elliott, JB Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Lisa, MA Matis, HS McMahan, M McParland, C Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Scharenberg, R Scott, A Shao, Y Srivastava, B Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K AF Kintner, JC Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, D Chacon, AD Chance, JL Choi, Y Costa, S Elliott, JB Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Lisa, MA Matis, HS McMahan, M McParland, C Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Scharenberg, R Scott, A Shao, Y Srivastava, B Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K TI Pion flow and antiflow in 1.15 A GeV Au+Au SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; MOMENTUM-DEPENDENT INTERACTIONS; COLLECTIVE FLOW; EQUATION; STATE; EMISSION; MATTER AB Transverse flow has been studied as a function of impact parameter for pions and protons from the reaction 1.15A GeV Au-197 + Au-197. We observe an ''antiflow'' behavior for both pi(+) and pi(-) in peripheral collisions. C1 UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CATANIA,I-95129 CATANIA,ITALY. IST NAZL FIS NUCL,I-95129 CATANIA,ITALY. KENT STATE UNIV,KENT,OH 44242. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. PURDUE UNIV,W LAFAYETTE,IN 47907. TEXAS A&M UNIV,COLLEGE STN,TX 77843. 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 18 TC 36 Z9 37 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 JUN 2 PY 1997 VL 78 IS 22 BP 4165 EP 4168 DI 10.1103/PhysRevLett.78.4165 PG 4 WC Physics, Multidisciplinary SC Physics GA XB779 UT WOS:A1997XB77900007 ER PT J AU Ferry, D Hoang, PNM Suzanne, J Biberian, JP VanHove, MA AF Ferry, D Hoang, PNM Suzanne, J Biberian, JP VanHove, MA TI Structure of physisorbed molecules on an oxide surface from potential calculations and dynamical low-energy electron diffraction analysis: Acetylene on MgO(100) SO PHYSICAL REVIEW LETTERS LA English DT Article ID MGO(001) AB Semiempirical potential calculations have been combined with a dynamical low-energy electron diffraction analysis to determine the complete structure of molecules physisorbed on an oxide surface, namely, acetylene (C2H2) adsorbed on MgO(100) at T = 88 K. This allows determination of the adsorption sites and the molecule-molecule and molecule-substrate distances. The results are consistent with molecules that lie almost parallel to the surface in a herringbone structure. Neither molecule nor substrate exhibits significant distortions, due to the weak physisorption. C1 UNIV FRANCHE COMTE,FAC SCI LA BOULOIE,URA CNRS 771,MOL PHYS LAB,F-25030 BESANCON,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV AIX MARSEILLE 3,CRMC2 CNRS,MARSEILLE,FRANCE. RP Ferry, D (reprint author), FAC SCI LUMINY,DEPT PHYS,CMRC2 CNRS,CASE 901,F-13288 MARSEILLE 9,FRANCE. RI Van Hove, Michel/A-9862-2008; Ferry, Daniel/O-2664-2014 OI Van Hove, Michel/0000-0002-8898-6921; Ferry, Daniel/0000-0003-1469-9871 NR 19 TC 23 Z9 23 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 JUN 2 PY 1997 VL 78 IS 22 BP 4237 EP 4240 DI 10.1103/PhysRevLett.78.4237 PG 4 WC Physics, Multidisciplinary SC Physics GA XB779 UT WOS:A1997XB77900025 ER PT J AU Krotov, YA Lee, DH Louie, SG AF Krotov, YA Lee, DH Louie, SG TI Low energy properties of (n, n) carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID ONE-DIMENSIONAL CONDUCTORS; MICROTUBULES; FERROMAGNETS; TUBULES; CHAINS; MODEL; GAS AB According to band theory, an ideal undoped (n,n) carbon nanotube is metallic. We show that the electron-electron interaction causes it to become Mott insulating with a spin gap. More interestingly, upon doping it develops superconducting fluctuations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Krotov, YA (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 21 TC 126 Z9 126 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 2 PY 1997 VL 78 IS 22 BP 4245 EP 4248 DI 10.1103/PhysRevLett.78.4245 PG 4 WC Physics, Multidisciplinary SC Physics GA XB779 UT WOS:A1997XB77900027 ER PT J AU DeWilde, Y Iavarone, M Welp, U Metlushko, V Koshelev, AE Aranson, I Crabtree, GW Canfield, PC AF DeWilde, Y Iavarone, M Welp, U Metlushko, V Koshelev, AE Aranson, I Crabtree, GW Canfield, PC TI Scanning tunneling microscopy observation of a square Abrikosov lattice in LuNi2B2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUX-LINE-LATTICE; II SUPERCONDUCTORS; SPECTROSCOPY; 2H-NBSE2; PHASE AB We present scanning tunneling microscopy measurements of the (001) surface of a LuNi(2)B2C borocarbide single crystal at 4.2 K. In zero field, the conductance versus voltage characteristics recorded at various locations on the sample reproducibly provide a gap value of 2.2 meV. In a magnetic field of 1.5 and 0.375 T, the recordings of the conductance as a function of position reveal a regular square vortex lattice tilted by 45 degrees with respect to the crystalline a axis. This unusual result is correlated with an in-plane anisotropy of the upper critical field H(c2)parallel to(45 degrees)/H(p)arallel to(c2)(0) = 0.92 at 4.2 K and is analyzed within the framework of Ginzburg-Landau theory. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. RP DeWilde, Y (reprint author), ARGONNE NATL LAB,DIV SCI MAT,SCI & TECHNOL CTR SUPERCONDUCTIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Iavarone, Maria/C-3628-2008; Aranson, Igor/I-4060-2013; Canfield, Paul/H-2698-2014; Koshelev, Alexei/K-3971-2013; OI Koshelev, Alexei/0000-0002-1167-5906; De Wilde, Yannick/0000-0002-5973-1460 NR 34 TC 145 Z9 145 U1 2 U2 12 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 JUN 2 PY 1997 VL 78 IS 22 BP 4273 EP 4276 DI 10.1103/PhysRevLett.78.4273 PG 4 WC Physics, Multidisciplinary SC Physics GA XB779 UT WOS:A1997XB77900034 ER PT J AU Gschneidner, KA Pecharsky, VK Fort, D AF Gschneidner, KA Pecharsky, VK Fort, D TI Novel thermal effects at the first order magnetic phase transition in erbium, and a comparison with dysprosium SO PHYSICAL REVIEW LETTERS LA English DT Article ID SOLID-STATE ELECTROTRANSPORT; SINGLE-CRYSTAL AB In low temperature studies of ultrapure erbium (and dysprosium) we have discovered unusual thermal effects at the first order magnetic transformation of erbium (congruent to 19 K). These include (1) superheating (i.e., the metal is colder after heat has been added to it than before the heat pulse), (2) supercooling, and (3) the existence of metastable intermediate phases during this phase transformation in erbium (four on heating and two on cooling). In comparison, dysprosium exhibits both superheating and supercooling, but no intermediate metastable phases are observed. Furthermore, none of these effects are observed in less pure metals. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. UNIV BIRMINGHAM,SCH MET & MAT,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RP Gschneidner, KA (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 16 TC 28 Z9 28 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 2 PY 1997 VL 78 IS 22 BP 4281 EP 4284 PG 4 WC Physics, Multidisciplinary SC Physics GA XB779 UT WOS:A1997XB77900036 ER PT J AU Paulsen, MD Rustad, JR Hay, BP AF Paulsen, MD Rustad, JR Hay, BP TI Conformational analysis of crown ethers .2. 15-crown-5 SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE conformational search; molecular mechanics; MM3; crown ether; solvent effects ID MOLECULAR MECHANICS MM3; ELECTRON-SPIN-RESONANCE; FORCE-FIELD; CRYSTAL-STRUCTURE; COMPLEXES; TEMPERATURE; CHLORIDES; SOLVENTS; DESIGN; ESTERS AB An extensive conformational search of 15-crown-5 was performed with the MM3 force field yielding 3623 conformers ranging in steric energy from 21.40 to 56.24 kcal mol(-1). Free energies and conformer population are reported for the gas phase. A continuum dielectric model is used to estimate the conformer populations in a variety of solvents. The three conformers observed in crystal structures containing 15-crown-5 molecules that do not form inner sphere complexes with metal ions are predicted to be among the most populated conformations in condensed phases. Comparison of the structural features of the crystallographically observed conformers with those of the energy minimized MM3 structures demonstrates that the MM3 force field well reproduces that experimentally observed structural features. Predicted conformer populations are consistent with C-13 NMR and vibrational spectra. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW LAB, MSIN K9 77, RICHLAND, WA 99352 USA. NR 64 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD JUN 2 PY 1997 VL 397 BP 1 EP 12 DI 10.1016/S0166-1280(96)04946-9 PG 12 WC Chemistry, Physical SC Chemistry GA XJ804 UT WOS:A1997XJ80400001 ER PT J AU Chiu, SW Cheung, YS Ma, NL Li, WK Ng, CY AF Chiu, SW Cheung, YS Ma, NL Li, WK Ng, CY TI A G2 ab initio study of C2H5S isomers: Structures, energetics, and unimolecular reaction pathways SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE Gaussian-2 theory; C2H5S radicals; unimolecular rearrangements; unimolecular dissociations ID VACUUM ULTRAVIOLET PHOTODISSOCIATION; TEMPERATURE-DEPENDENT KINETICS; NEGATIVE ACTIVATION-ENERGIES; HALOCARBENE CYCLO-ADDITIONS; SUBSTITUTED ETHYL RADICALS; BOND-DISSOCIATION ENERGIES; DIMETHYL SULFIDE; ALKYL RADICALS; RATE CONSTANTS; OH RADICALS AB The potential energy surface of C2H5S isomers has been studied with the G2 ab initio method. The structures and G2 heats of formation of the six stable isomers/conformers, CH3CH2S (1), syn-CH3CHSH (2), anti-CH3CHSH (3), CH3SCH2 (4), gauche-HSCH2CH2 (5), and anti-HSCH2CH2 (6), have been reported previously (Chem. Phys. Lett., 213 (1993) 250; J. Chem. Phys., 104 (1996) 130). Their structural properties upon change of conformation can be rationalized by the perturbative molecular orbital model. The C2H5S radicals are very flexible due to low-energy barriers for rotations and inversions. Unimolecular rearrangements are exclusively 1,2- and 1,3-H shifts with large G2 activation energies at 0 K: E-a(1 --> 3) = 147.0 kJ mol(-1), E-a(1 --> 5) = 140.0 kJ mol(-1), E-a(2 --> 5) = 187.2 kJ mol(-1), E-a(3 --> 6) = 191.7 kJ mol(-1), and E-a(4 --> 4) = 176.9 kJ mol(-1). The TS structures for the unimolecular decompositions: 5 --> C2H4 + SH (6), 1 --> CH3 + H2CS (7), acid 4 --> CH3 + H2CS (8) are loose and product-like. Their UHF determinant functions have considerable spin contamination ([S-2] approximate to 0.96-1.08). Energy barriers for the analogous reactions of 6 and 7 for the oxygen analogs were also computed and compared to the observed rate parameters. In general, it is found that the G2 method is still reliable to estimate the reaction barriers for systems with [S-2] less than or equal to 0.96. Correction with spin projection is required for systems with [S-2] > 1.0. Among the reactions of C2H5S studied in this work, the pathway with the lowest energy is 6. The G2 E-a = 41.7 kJ mol(-1) for 6 at 700 K is in good agreement with Shum and Benson's (Int. J. Chem. Kinet., 17 (1985) 277, 749) estimated value (46 kJ mol(-1)). At the same temperature, the calculated E-a's for 7 and 8, after spin-projection corrections, are 158.9 kJ mol(-1) and 109.0 kJ mol(-1), respectively, in agreement with the estimated E-a's (145.5 kJ mol(-1) for 7 and 101.3 kJ mol(-1) for 8). The addition reaction CH3 + H2CS --> 4 ((8) under bar) is predicted to be negative temperature dependent with an E-a of -3.0 kJ mol(-1) at 700 K. This is in line with the lower bound of the estimated E-a (ca. 11.7 kJ mol(-1) +/- 12.6 kJ mol(-1)) for (8) under bar at 644 K as reported by Shum and Benson. (C) 1997 Elsevier Science B.V. C1 CHINESE UNIV HONG KONG,DEPT CHEM,SHATIN 100083,NT,HONG KONG. IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. RP Chiu, SW (reprint author), UNIV ILLINOIS,NATL CTR SUPERCOMP APPLICAT,URBANA,IL 61801, USA. NR 58 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD JUN 2 PY 1997 VL 397 BP 87 EP 101 PG 15 WC Chemistry, Physical SC Chemistry GA XJ804 UT WOS:A1997XJ80400009 ER PT J AU Blackford, LS Cleary, A Petitet, A Whaley, RC Demmel, J Dhillon, I Ren, H Stanley, K Dongarra, J Hammarling, S AF Blackford, LS Cleary, A Petitet, A Whaley, RC Demmel, J Dhillon, I Ren, H Stanley, K Dongarra, J Hammarling, S TI Practical experience in the numerical dangers of heterogeneous computing SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE distributed-memory systems; floating-point arithmetic; heterogeneous processor networks; message passing; numerical software; reliability ID LINEAR ALGEBRA SUBPROGRAMS; MODEL IMPLEMENTATION; TEST PROGRAMS; EXTENDED SET AB Special challenges exist in writing reliable numerical library software for heterogeneous computing environments. Although a lot of software for distributed-memory parallel computers has been written, porting this software to a network of workstations requires careful consideration. The symptoms of heterogeneous computing failures can range from erroneous results without warning to deadlock. Some of the problems are straightforward to solve, but for others the solutions are not so obvious, or incur an unacceptable overhead. Making software robust on heterogeneous systems often requires additional communication. We describe and illustrate the problems encountered during the development of ScaLAPACK and the NAG Numerical PVM Library. Where possible, we suggest ways to avoid potential pitfalls, or if that is not possible, we recommend that the software not be used on heterogeneous networks. C1 UNIV CALIF BERKELEY,DIV COMP SCI,BERKELEY,CA 94720. OAK RIDGE NATL LAB,KNOXVILLE,TN 37996. NUMER ALGORITHMS GRP LTD,OXFORD OX2 8DR,ENGLAND. RP Blackford, LS (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. RI Whaley, R./G-4234-2011; Dongarra, Jack/E-3987-2014 NR 21 TC 13 Z9 13 U1 0 U2 1 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD JUN PY 1997 VL 23 IS 2 BP 133 EP 147 DI 10.1145/264029.264030 PG 15 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA YF110 UT WOS:A1997YF11000001 ER PT J AU Bouaricha, A Schnabel, RB AF Bouaricha, A Schnabel, RB TI Algorithm 768: TENSOLVE: A software package for solving systems of nonlinear equations and nonlinear least-squares problems using tensor methods SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE nonlinear equations; nonlinear least squares; rank-deficient matrices; tensor methods AB This article describes a modular software package for solving systems of nonlinear equations and nonlinear least-squares problems, using a new class of methods called tensor methods. It is intended for small-to medium-sized problems, say with up to 100 equations and unknowns, in cases where it is reasonable to calculate the Jacobian matrix or to approximate it by finite differences at each iteration. The software allows the user to choose between a tensor method and a standard method based on a linear model. The tensor method approximates F(x) by a quadratic model, where the second-order term is chosen so that the model is hardly more expensive to form, store, or solve than the standard linear model. Moreover, the software provides two different global strategies: a line search approach and a two-dimensional trust region approach. Test results indicate that, in general, tensor methods are significantly more efficient and robust than standard methods on small-and medium-sized problems in iterations and function evaluations. C1 UNIV COLORADO,DEPT COMP SCI,BOULDER,CO 80309. RP Bouaricha, A (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 23 Z9 23 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD JUN PY 1997 VL 23 IS 2 BP 174 EP 195 DI 10.1145/264029.264032 PG 22 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA YF110 UT WOS:A1997YF11000003 ER PT J AU Weihs, TP Barbee, TW Wall, MA AF Weihs, TP Barbee, TW Wall, MA TI Hardness, ductility, and thermal processing of Cu/Zr and Cu/Cu-Zr nanoscale multilayer foils SO ACTA MATERIALIA LA English DT Article ID COPPER ZIRCONIUM; FILMS; ALLOYS; SYSTEM; METAL AB The hardness, ductility, and thermal processing of Cu/Zr and Cu/Cu-Zr multilayers were investigated by indenting, bending, and heating a series of Free-standing multilayer foils. The foils were deposited with alternate, nanoscale layers of Cu and Zr, and then thermally processed to produce three additional nanostructures: alternate layers of Cu and amorphous Cu-Zr(aCu-Zr); alternate layers of Cu and Cu51Zr14; and a non-layered structure with small Cu grains in large Cu9Zr2 grains. The hardness and ductility of the foils depended strongly on the degree of thermal processing and varied dramatically with the volume fraction of the Zr or Cu-Zr phases in each of the four nanostructures. The dependence of hardness on volume Fraction was stronger when the films were indented parallel to their layering than when the foils were indented perpendicular to their layering. This result demonstrates that plastic deformation is anisotropic in these multilayer samples. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RI Weihs, Timothy/A-3313-2010 NR 21 TC 20 Z9 21 U1 0 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN PY 1997 VL 45 IS 6 BP 2307 EP 2315 DI 10.1016/S1359-6454(96)00370-9 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XE069 UT WOS:A1997XE06900008 ER PT J AU Liu, C Huang, Y Stout, MG AF Liu, C Huang, Y Stout, MG TI On the asymmetric yield surface of plastically orthotropic materials: A phenomenological study SO ACTA MATERIALIA LA English DT Article AB Hill's (1948) yield criterion for plastically orthotropic solids is extended to include materials whose tensile and compressive yield stresses, obtained from uniaxial loading tests, are different. First, we review and discuss the classic yield criteria in plasticity theory including plastically isotropic and anisotropic materials. Then, we present a yield criterion for plastic anisotropic solids whose initial yield surface may not be symmetric about the origin in stress space. The new criterion is based on the criterion given by Hill (Proc. Roy. Soc. London A, 1948, 193, 281) for anisotropic solids and the criterion proposed by Drucker and Prager (Q. Appl. Math., 1952, 10, 157) for soil whose tensile and compressive strengths are far apart. The coefficients that appear in the new criterion can be determined from uniaxial tension and compression, and simple shearing tests. The formulae for the determination of those coefficients are given. Specifically, the new criterion is applied to the yielding of thin sheets where a plane stress condition prevails. Finally, the prediction of the criterion is compared with the experimental data obtained by Lee and Backofen (Trans. Metall. Soc. AIME, 1966, 236, 1966) on titanium alloy sheets. (C) 1997 Acta Metallurgica Inc. C1 MICHIGAN TECHNOL UNIV,DEPT MECH ENGN & ENGN MECH,HOUGHTON,MI 49931. RP Liu, C (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MST-5,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI Huang, Yonggang/B-6998-2009 NR 5 TC 39 Z9 47 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN PY 1997 VL 45 IS 6 BP 2397 EP 2406 DI 10.1016/S1359-6454(96)00349-7 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XE069 UT WOS:A1997XE06900016 ER PT J AU Simmons, JW AF Simmons, JW TI Strain hardening and plastic flow properties of nitrogen-alloyed Fe-17Cr-(8-10)Mn-5Ni austenitic stainless steels SO ACTA MATERIALIA LA English DT Article ID BEHAVIOR AB In this study, the uniform plastic strain behavior of a series of high-nitrogen (0.13 to 1.0 wt% N) austenitic stainless steels was modeled using the modified Ludwik equation proposed by Ludwigson: sigma = K-1 epsilon(n1) + Delta, where Delta = e((K2+n2 epsilon). The following comments can be made regarding the plastic flow behavior: (1) the strain hardening rate increases proportionally with nitrogen; (2) deviation of the flow curves From the Ludwik behavior (i.e. Delta) increases with nitrogen, (3) the strength coefficient (K-1) increases proportionally with nitrogen; (4) increasing nitrogen results in small decreases in the true-strain at ultimate load and therefore has a negative effect on the strain hardening exponent, n(1); (5) true yield stress [exp(K-2)] increases proportionally to nitrogen. correlating with the engineering yield stress. (6) n(2) becomes more negative, but changes only slightly with large increases in nitrogen; and (7) the transition strain epsilon(L) decreases only slightly with increasing nitrogen indicating that higher nitrogen levels; in the materials studied, extend the range whereby the Ludwik relation accurately describes the flow behavior. The effect of nitrogen on the transition strain observed is contradictory to the notion that stacking fault energy decreases with increasing nitrogen. However, the transition strain exhibited by these materials (higher than most f.c.c. materials) is consistent with very low stacking fault energy f.c.c. materials. RP Simmons, JW (reprint author), US DOE,ALBANY RES CTR,1450 QUEEN AVE SW,ALBANY,OR 97321, USA. NR 14 TC 41 Z9 50 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN PY 1997 VL 45 IS 6 BP 2467 EP 2475 DI 10.1016/S1359-6454(96)00343-6 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XE069 UT WOS:A1997XE06900023 ER PT J AU McKamey, C AF McKamey, C TI Oak Ridge Chapter of ASM International organized technical session for WATTec '97 SO ADVANCED MATERIALS & PROCESSES LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP McKamey, C (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD JUN PY 1997 VL 151 IS 6 BP 91 EP 91 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA ZA405 UT WOS:000072360200030 ER PT J AU Torczynski, JR Rader, DJ AF Torczynski, JR Rader, DJ TI The virtual cyclone: A device fur nonimpact particle separation SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID IMPACTOR; PERFORMANCE; CALIBRATION; COLLECTION; DRAG; JET AB The virtual cyclone, a geometrically uncomplicated device that separates particles from a flow stream by nonimpact particle separation, is discussed. In contradistinction to a cyclone, the particle-laden flow is deflected from its original direction by a wall that curves away from the original flow direction, rather than into it. The computational fluid dynamics code FIDAP (Fluid Dynamics International) is used to perform two-dimensional fluid-flow and particle-motion calculations for a representative device geometry. Flow patterns are found to be insensitive to Reynolds number for values above 100 regardless of whether the how is laminar or turbulent. Particle-motion calculations for laminar-flow cases indicate that the virtual cyclone geometry examined accomplishes nonimpact particle separation. An approximate analytical relation describing virtual cyclone nonimpact particle separation is developed and found to be in agreement with the numerical simulations. (C) 1997 American Association for Aerosol Research. RP Torczynski, JR (reprint author), SANDIA NATL LABS,MS 0834,DEPT 9112,ENGN SCI CTR,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUN PY 1997 VL 26 IS 6 BP 560 EP 573 DI 10.1080/02786829708965453 PG 14 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA XA222 UT WOS:A1997XA22200006 ER PT J AU Oh, CH Kochan, RJ Beller, JM AF Oh, CH Kochan, RJ Beller, JM TI Numerical analysis and data comparison of a supercritical water oxidation reactor SO AICHE JOURNAL LA English DT Article ID TECHNOLOGY AB Supercritical water oxidation of isopropyl alcohol was investigated in a pilot-scale reactor. A computational fluid-dynamics model developed reveals the detailed flow field, chemical-component distribution, temperature distribution, and salt-particle trajectories in the reactor flow domain. The near-wall fluid temperature from the numerical analysis was compared with experimental temperature data. The temperature comparison was within a 3% error band. The effect of the chemical kinetic rate was investigated for four different rates. Turbulent salt-particle trajectories were also calculated to investigate the effect of particle sizes on salt deposit on the wall Also, a method of calculating the adiabatic reaction temperature was developed to estimate reaction temperatures prior to a full numerical simulation. RP Oh, CH (reprint author), LOCKHEED MARTIN IDAHO TECHNOL CO,IDAHO NATL ENGN & ENVIRONM LAB,IDAHO FALLS,ID 83415, USA. NR 37 TC 16 Z9 16 U1 1 U2 4 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 JUN PY 1997 VL 43 IS 6 BP 1627 EP 1636 DI 10.1002/aic.690430626 PG 10 WC Engineering, Chemical SC Engineering GA XD322 UT WOS:A1997XD32200025 ER PT J AU Yoder, BK Richards, WG Sommardahl, C Sweeney, WE Michaud, EJ Wilkinson, JE Avner, ED Woychik, RP AF Yoder, BK Richards, WG Sommardahl, C Sweeney, WE Michaud, EJ Wilkinson, JE Avner, ED Woychik, RP TI Differential rescue of the renal and hepatic disease in an autosomal recessive polycystic kidney disease mouse mutant - A new model to study the liver lesion SO AMERICAN JOURNAL OF PATHOLOGY LA English DT Article ID MURINE MODEL; PROTOONCOGENE EXPRESSION; MECKEL SYNDROME; CYSTIC-DISEASE; ANIMAL-MODELS; MESSENGER-RNA; CPK MOUSE; MUTATION; HEREDITARY; GENE AB Autosomal recessive polycystic kidney disease (ARPKD) is characterized by biliary and renal lesions that produce significant morbidity and mortality. The biliary ductal ectasia and hepatic portal fibrosis associated with ARPKD have not been well studied even though such lesions markedly affect the clinical course of patients after renal replacement therapy such as dialysis or transplantation, Here we describe the generation of a new mouse model to study the hepatic lesions associated with polycystic kidney disease This model was generated by differentially rescuing the renal pathology in the orpk mutant mouse that displays a hepatorenal pathology that is similar to that seen in human patients with ARPKD. This was accomplished by expressing, as a transgene in the mutant animals, the cloned wild-type version of the gene associated with the mutant locus in this line of mice. Although renal function in the rescue animals is normal, the liver still exhibits biliary and ductular hyperplasia along with varying degrees of hepatic portal fibrosis that is indistinguishable from that in the mutant animals. Most important, the rescue animals survive significantly longer than mutants and will permit a more detailed analysis of the clinical and cellular pathophysiology of the hepatic defect associated with this disease. C1 OAK RIDGE NATL LAB,DIV LIFE SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PATHOL,KNOXVILLE,TN. CASE WESTERN RESERVE UNIV,DEPT PEDIAT,CLEVELAND,OH 44106. FU NIDDK NIH HHS [1 RO1 DK45633, 5 RO1 DK44875] NR 65 TC 29 Z9 29 U1 0 U2 2 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 JUN PY 1997 VL 150 IS 6 BP 2231 EP 2241 PG 11 WC Pathology SC Pathology GA XB700 UT WOS:A1997XB70000032 PM 9176412 ER PT J AU Gu, F Marchetti, AA Straume, T AF Gu, F Marchetti, AA Straume, T TI Determination of iodine in milk and oyster tissue samples using combustion and peroxydisulfate oxidation SO ANALYST LA English DT Article DE iodine; iodine-129; gas chromatography; combustion; peroxydisulfate; milk; oyster tissue ID NEUTRON-ACTIVATION ANALYSIS; TRACE-ELEMENTS; FOODS AB Two methods are described for the preparation of samples for total iodine measurement in biological matrices, In the first method, the samples mere combusted in a stream of oxygen to release iodine that, subsequently, was trapped in a solution as iodide, The second method is a new approach in which the samples were oxidized in a basic solution of peroxydisulfate. In this case, the iodine was retained in solution as iodate, Total iodine was measured by gas chromatographic analysis of the 2-iodopentan-3-one derivative, The methods were tested using Standard Reference Materials (SRMs) 1549 Non-Fat Milk Powder, and 1566a and 1566 Oyster Tissue, Also, KI and KIO3 were used for testing the procedures, The results obtained for the SRMs, given as average +/- standard deviation in mu g g(-1), were: 3.39 +/- 0.14 and 3.40 +/- 0.23 for SRM 1549; 4.60 +/- 0.42 and 4.51 +/- 0.45 for SRM 1566a; and 2.84 +/- 0.16 and 2.76 +/- 0.06 for SRM 1566; values corresponding to combustion and wet oxidation, respectively, Overall, the absolute recoveries varied between 91 and 103%, These methods can also be used in the preparation of targets for the measurement of I-129 using accelerator mass spectrometry. C1 SHANGHAI INST RADIAT MED,SHANGHAI 200032,PEOPLES R CHINA. RP Gu, F (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH ECOL ASSESSMENT DIV,POB 808,LIVERMORE,CA 94551, USA. NR 16 TC 27 Z9 27 U1 0 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0003-2654 J9 ANALYST JI Analyst PD JUN PY 1997 VL 122 IS 6 BP 535 EP 537 DI 10.1039/a607555j PG 3 WC Chemistry, Analytical SC Chemistry GA XH105 UT WOS:A1997XH10500007 PM 9282400 ER PT J AU Martin, SJ Spates, JJ Wessendorf, KO Schneider, TW Huber, RJ AF Martin, SJ Spates, JJ Wessendorf, KO Schneider, TW Huber, RJ TI Resonator oscillator response to liquid loading SO ANALYTICAL CHEMISTRY LA English DT Article ID SHEAR MODE RESONATORS; QUARTZ; MICROBALANCE; CRYSTALS; CONTACT; MASS AB The resonant frequency of a thickness-shear mode resonator operated in contact with a fluid was measured with a network analyzer and with an oscillator circuit, The network analyzer measures changes in the device's intrinsic resonant frequency, which varies linearly with (rho eta 1)(1/2), where rho and eta are liquid density and viscosity, respectively. The resonator/oscillator combination, however, responds differently to liquid loading than the resonator alone, By applying the operating constraints of the oscillator to an equivalent-circuit model for the liquid-loaded resonator, the response of the resonator/oscillator pair can be determined, By properly tuning the resonator/oscillator pair, the dynamic range of the response can be extended and made more linear, closely tracking the response of the resonator alone, This allows the system to measure higher viscosity and higher density liquids with greater accuracy. C1 UNIV UTAH,DEPT ELECT ENGN,SALT LAKE CITY,UT 84112. RP Martin, SJ (reprint author), SANDIA NATL LABS,MICROSENSOR RES & DEV DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 20 TC 48 Z9 50 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1997 VL 69 IS 11 BP 2050 EP 2054 DI 10.1021/ac961194x PG 5 WC Chemistry, Analytical SC Chemistry GA XC375 UT WOS:A1997XC37500020 PM 21639245 ER PT J AU Lermer, N Barnes, MD Kung, CY Whitten, WB Ramsey, JM AF Lermer, N Barnes, MD Kung, CY Whitten, WB Ramsey, JM TI High efficiency molecular counting in solution: Single-molecule detection in electrodynamically focused microdroplet streams SO ANALYTICAL CHEMISTRY LA English DT Article ID LASER-INDUCED FLUORESCENCE; BURST DETECTION; ELECTROPHORESIS; PHYCOERYTHRIN; BIOTECHNOLOGY; CAPILLARY AB We report fluorescence detection of individual rhodamine 6G molecules using a linear quadrupole to focus streams of microdroplets through the waist of a counterpropagating cw Ar+ laser. Since the terminal velocity scales as the square of the droplet diameter, the droplet-laser interaction time was ''tunable'' between 5 and 200 ms by using water samples spiked with a small, variable (2-5% v/v) amount of glycerol. Fluorescence bursts from droplets containing single molecules were clearly distinguished from the blanks in real time with an average signal-to-noise ratio of about 10, limited primarily by photobleaching and droplet size fluctuations (<1%). The volume throughput rates associated with this approach (similar to 10 pL/s) are roughly 10(3) higher than those associated with particle levitation techniques, with minimal sacrifice in sensitivity, Total molecular detection efficiencies of about 80% (at >99% confidence) were obtained for 100 and 15 fM rhodamine 6G solutions, in good agreement with detailed theoretical calculations and statistical limitations. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 42 TC 48 Z9 48 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1997 VL 69 IS 11 BP 2115 EP 2121 DI 10.1021/ac970093b PG 7 WC Chemistry, Analytical SC Chemistry GA XC375 UT WOS:A1997XC37500031 PM 21639255 ER PT J AU Severs, JC Smith, RD AF Severs, JC Smith, RD TI Characterization of the microdialysis junction interface fcr capillary electrophoresis microelectrospray ionization mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROSPRAY-IONIZATION; ZONE ELECTROPHORESIS; SENSITIVITY; PROTEINS AB A capillary electrophoresis/electrospray ionization mass spectrometry (CE/ESI-MS) interface, based on an electric circuit across a microdialysis membrane surrounding a short capillary segment closely connected to the separation capillary terminus, is demonstrated to be sensitive, efficient, and rugged, A microspray type ionization emitter produces a stable electrospray at the low now rates provided by CE and thus avoids both the need for a makeup liquid now provided by liquid junction or sheath now interfaces and the subsequent dilution and reduction in sensitivity. Reproducibility studies and comparisons with CE/UV and the CE/sheath now interface with ESI-MS are presented. Additionally, postrun acidification via the microdialysis junction interface is demonstrated and shown to be capable of denaturing the holomyoglobin protein noncovalent complex while maintaining separation efficiency. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 21 TC 54 Z9 55 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1997 VL 69 IS 11 BP 2154 EP 2158 DI 10.1021/ac9611226 PG 5 WC Chemistry, Analytical SC Chemistry GA XC375 UT WOS:A1997XC37500037 PM 21639258 ER PT J AU Zhou, JZ Palumbo, AV Tiedje, JM AF Zhou, JZ Palumbo, AV Tiedje, JM TI Sensitive detection of a novel class of toluene-degrading denitrifiers, Azoarcus tolulyticus, with small-subunit rRNA primers and probes SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID POLYMERASE CHAIN-REACTION; RIBOSOMAL DATABASE PROJECT; SP-NOV; PCR; SEDIMENTS; DNA AB Azoarcus tolulyticus is a new class of widely distributed, toluene-degrading denitrifiers of potential importance in remediating benzene, toluene, ethylbenzene, and gene (BTEX)-contaminated environments. To detect these organisms in the environment, 16S rRNA gene-based phylogenetic probes were developed. Two sets of specific PCR amplification primers and two oligonucleotide hybridization probes were designed and tested against both closely and distantly related environmental isolates. All of these primers and probes were specific to the species A. tolulyticus. The sensitivity of the PCR amplification primer sets was evaluated with DNA isolated from A. tolulyticus Tol-4 pure culture and from sterile soils seeded with a known number of Tol-4 and Escherichia call cells. These primer sets were able to detect 1 fg to 1 pg of template DNA from the pure culture and 1.11 x 10(2) to 1.1 x 10(8) Tol-4 cells per g of soil in the presence of 1.56 x 10(10) E. coli cells. These two PCR amplification primers were also successfully tested at two field sites. The primers identified the A. tolulyticus strains among the toluene-degrading bacteria isolated from a low-O-2-high-NO3- aquifer at Moffett Field, Calif. Also, the presence of A. tolulyticus was detected in the groundwater samples from a BTEX-contaminated aquifer at an industrial site in Detroit, Mich., which showed anaerobic toluene degradation. C1 MICHIGAN STATE UNIV, CTR MICROBIAL ECOL, E LANSING, MI 48824 USA. OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 FU NIEHS NIH HHS [ES-04911] NR 24 TC 22 Z9 26 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 1997 VL 63 IS 6 BP 2384 EP 2390 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA XB705 UT WOS:A1997XB70500042 PM 9172359 ER PT J AU Guschin, DY Mobarry, BK Proudnikov, D Stahl, DA Rittmann, BE Mirzabekov, AD AF Guschin, DY Mobarry, BK Proudnikov, D Stahl, DA Rittmann, BE Mirzabekov, AD TI Oligonucleotide microchips as genosensors for determinative and environmental studies in microbiology SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID AMMONIA-OXIDIZING BACTERIA; HYBRIDIZATION PROBES; IDENTIFICATION; DIVERSITY; PHYLOGENY; SEQUENCES; ECOLOGY; CELLS AB The utility of parallel hybridization of environmental nucleic acids to many oligonucleotides immobilized in a matrix of polyacrylamide gel pads on a glass slide (oligonucleotide microchip) was evaluated. Oligonucleotides complementary to small-subunit rRNA sequences of selected microbial groups, encompassing key genera of nitrifying bacteria, were shown to selectively retain labeled target nucleic acid derived from either DNA or RNA forms of the target sequences. The utility of varying the probe concentration to normalize hybridization signals and the use of multicolor detection for simultaneous quantitation of multiple probe-target populations were demonstrated. C1 NORTHWESTERN UNIV,DEPT CIVIL ENGN,EVANSTON,IL 60208. VA ENGELHARDT MOL BIOL INST,JOINT HUMAN GENOME PROGRAM,MOSCOW 117984,RUSSIA. ARGONNE NATL LAB,JOINT HUMAN GENOME PROGRAM,ARGONNE,IL 60439. NR 36 TC 238 Z9 256 U1 0 U2 8 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 1997 VL 63 IS 6 BP 2397 EP 2402 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA XB705 UT WOS:A1997XB70500044 PM 9172361 ER PT J AU Kadam, KL Newman, MM AF Kadam, KL Newman, MM TI Development of a low-cost fermentation medium for ethanol production from biomass SO APPLIED MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article ID SIMULTANEOUS SACCHARIFICATION AB Nutrient cost is an important aspect in the fermentation of biomass to ethanol. With a goal of developing a cost-effective fermentation medium, several industrially available nutrient sources were evaluated for their effectiveness in the simultaneous saccharification and fermentation of pretreated poplar with Saccharomyces cerevisiae D(5)A. These studies showed that a low-cost medium containing 0.3% corn steep liquor and 2.5 mM MgSO4 . 7H(2)O was similar in performance to a nutrient-rich medium. Besides its low cost, this alternative medium consists of components that are available on a commercial scale, thereby making it industrially relevant. RP Kadam, KL (reprint author), NATL RENEWABLE ENERGY LAB,BIOTECHNOL CTR FUELS & CHEM,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 9 TC 68 Z9 68 U1 2 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0175-7598 J9 APPL MICROBIOL BIOT JI Appl. Microbiol. Biotechnol. PD JUN PY 1997 VL 47 IS 6 BP 625 EP 629 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA XK882 UT WOS:A1997XK88200001 PM 9237386 ER PT J AU Chen, CI Taylor, RT AF Chen, CI Taylor, RT TI Batch and fed-batch bioreactor cultivations of a Thermus species with thermophilic BTEX-degrading activity SO APPLIED MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article ID METHYLOSINUS-TRICHOSPORIUM OB3B; METHANE MONO-OXYGENASES; DEGRADATION; TOLUENE; BIODEGRADATION; SPECIFICITIES; SUBSTRATE; XYLENE AB The thermophilic bacterium, Thermus species ATCC 27978, which is capable of aerobically degrading benzene, toluene, ethylbenzene, and the xylenes (BTEX), was cultured in 5-1 fermenters on a Castenholz salts-tryptone medium. This bacterium can be cultivated more conveniently at 45 degrees C, a temperature substantially lower than its optimal growth temperature (approx. 60 degrees C). Yet, the washed harvested cells from such cultures display the same initial BTEX-degrading activity as those when Thermus sp. is grown at its higher optimal temperature. Two bioreactor cultivation modes, batch and fed batch, were investigated. More biomass and more BTEX-degrading activity (assayed at 60 degrees C) were generated in fed-batch cultures than in the growth-limited batch cultures. The former yielded a biomass concentration of 2.5 g dry cell weight (DCW) 1(-1) and whole-cell degrading specific activities of 7.6 +/- 1.3, 10.1 +/- 1.9, 9.8 +/- 2.1 2.3 +/- 0.5, and 4.6 +/- 0.9 nmol degraded (mg DCW)(-1) min(-1) for benzene, toluene, ethylbenzene, m-xylene, and the o- plus p-xylenes (unresolved mixture), respectively. Although the formation of cellular BTEX-degrading activity is growth-associated, a slow to moderate specific growth rate of 0.02 - 0.07 h(-1) favors the production of BTEX-degrading activity, while a high growth rate, of the order of 0.16 h(-1), is detrimental to its production. The washed harvested Thermus sp. cells were capable of degrading BTEX over a broad range of thermophilic incubation temperatures, 45-77 degrees C. RP Chen, CI (reprint author), LAWRENCE LIVERMORE NATL LAB,ENVIRONM MICROBIAL BIOTECHNOL FACIL,LIVERMORE,CA 94551, USA. NR 19 TC 7 Z9 9 U1 1 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0175-7598 J9 APPL MICROBIOL BIOT JI Appl. Microbiol. Biotechnol. PD JUN PY 1997 VL 47 IS 6 BP 726 EP 733 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA XK882 UT WOS:A1997XK88200018 ER PT J AU Scherer, JJ Voelkel, D Rakestraw, DJ AF Scherer, JJ Voelkel, D Rakestraw, DJ TI Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) in low pressure flames SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID FLIGHT MASS-SPECTROSCOPY; CARBON-MONOXIDE; COMBUSTION; SILICIDES; KINETICS AB We report the first application of Infrared Cavity Ringdown Laser Absorption Spectroscopy (IR-CRLAS) as a diagnostic tool for combustion chemistry studies. The high sensitivity (10(-5) fractional absorption) and generality of IR-CRLAS for combustion studies is demonstrated for low pressure laminar flames and is shown to be robust even in sooting environments with high temperature gradients. The ability to obtain (1-D) spatially resolved spectra of both reactants and products within a narrow spectral region is also demonstrated. In these initial flame studies, two information rich mid-infrared spectral regions are probed at Doppler-limited resolution, centered about 1.5 mu m and 3.3 mu m. C1 MAX PLANCK INST STROMUNGSFORSCH, D-37073 GOTTINGEN, GERMANY. RP Scherer, JJ (reprint author), SANDIA NATL LABS, COMBUST RES FACIL, M-S 9055, LIVERMORE, CA 94551 USA. NR 23 TC 50 Z9 51 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD JUN PY 1997 VL 64 IS 6 BP 699 EP 705 DI 10.1007/s003400050236 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA XD558 UT WOS:A1997XD55800012 ER PT J AU Stallard, BR Rowe, RK Howard, AJ Hadley, GR Vawter, GA Wendt, JR Fritz, IJ AF Stallard, BR Rowe, RK Howard, AJ Hadley, GR Vawter, GA Wendt, JR Fritz, IJ TI Near-infrared spectroscopy with a dispersive waveguide device SO APPLIED SPECTROSCOPY LA English DT Article DE optical sensors; near-IR spectroscopy; optical waveguides ID QUANTITATIVE SPECTRAL-ANALYSIS AB Miniature, low-cost sensors are in demand for a variety of applications in industry, medicine, and environmental sciences. As a first step in developing such a sensor, we have etched a grating into a GaAs rib waveguide to serve as a wavelength-dispersive element. The device was fabricated with the techniques of metal-organic chemical vapor deposition, electron-beam lithography, optical lithography, and reactive ion-beam etching. While full integration is the eventual goal of this work, for the present, a functional spectrometer was constructed with the addition of a discrete source, sample cell, lenses, and detector. The waveguide spectrometer has a spectral resolution of 7.5 nm and a spectral dispersion of 0.11 degrees/nm. As presently configured, it functions in the spectral range of 1500 to 1600 nm. A demonstration of the analytical capability of the waveguide spectrometer is presented. The problem posed is the determination of diethanol amine in an ethanol solution (about 10 to 100 gn). This procedure involves the detection of the first overtone of the NH stretch at 1545 nm in a moderately absorbing solvent background. The standard error of prediction for the determination was 5.4 g/L. RP Stallard, BR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 5 TC 1 Z9 2 U1 1 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUN PY 1997 VL 51 IS 6 BP 880 EP 882 DI 10.1366/0003702971941179 PG 3 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA XF544 UT WOS:A1997XF54400019 ER PT J AU Williams, PT Krauss, RM AF Williams, PT Krauss, RM TI Associations of age, adiposity, menopause, and alcohol intake with low-density lipoprotein subclasses SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE age; puberty; alcohol; adiposity; menopause; low-density lipoproteins ID ESTER TRANSFER PROTEIN; GRADIENT GEL-ELECTROPHORESIS; PARTICLE-SIZE DISTRIBUTION; MODERATELY OVERWEIGHT MEN; APOLIPOPROTEINS A-I; HEPATIC LIPASE; MYOCARDIAL-INFARCTION; PLASMA-LIPOPROTEINS; ACUTE INHIBITION; ETHANOL WITHDRAWAL AB We used nondenaturing polyacrylamide gradient gel electrophoresis to examine the associations of age, adiposity, menopause, and alcohol intake with LDL subclasses in 355 individuals. The absorbency of protein stain was used as an index of mass concentrations at intervals of 0.05 nm within seven LDL subclasses: LDL-IVB (22.0 to 23.2 nm). LDL-IVA (23.3 to 24.1 nm), LDL-IIIB (24.2 to 24.6 nm). LDL-IIIA (24.7 to 25.5 nm), LDL-II (25.5 to 26.4 nm), LDL-I (26.0 to 28.5 nm), and intermediate-size lipoproteins (ISL, 28.0 to 32.0 nm). Age and alcohol intake were obtained from questionnaires, and body mass index was computed from clinic measurements of weight and height. In adult men. body mass index correlated positively with LDL-III. and alcohol intake correlated positively with larger LDL-I. Age was positively correlated with LDL-IIIA and ISL in both men and women and with LDL-IIIB and LDL-II in women. Postmenopausal women had higher LDL-IIIA, LDL-II, and ISL than both premenopausal and premenarchal females. Adult males, greater than or equal to 18 years old, had higher levels of LDL-IIIA and LDL-II than younger males. Adjustment for fasting plasma triglyceride levels eliminated the significant associations between age and LDL-IIIA in both men and women and between age and LDL-II in women. Partial correlation analyses showed that reductions in the LDL peak diameter associated with increasing age, male sexual maturation, menopause, and adiposity are attributable to increases in the LDL-ILIA subclass. Thus, densitometric measurements of protein-stained gradient gels reveal specific relationships between LDL subclasses and age, adiposity, and alcohol intake beyond those identified by the LDL peak or average diameter. RP Williams, PT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BLDG 934,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL-49857, HL-24462, HL-45652] NR 64 TC 30 Z9 33 U1 0 U2 2 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD JUN PY 1997 VL 17 IS 6 BP 1082 EP 1090 PG 9 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA XF781 UT WOS:A1997XF78100011 PM 9194758 ER PT J AU Bischof, OB Becker, RH AF Bischof, OB Becker, RH TI Radio observations of 4079 quasars SO ASTRONOMICAL JOURNAL LA English DT Article ID BRIGHT AB Using the NVSS radio catalog, we have searched for radioemission from 4079 quasars taken from the 1996 version of the Veron-Cetty & Veron [ESO Scientific Report No. X (1996)] quasar catalog. The comparison resulted in the positive detection of radio emission from 799 quasars. Of these, 168 are new radio detections. Examination of the radio luminosities shows a dramatic increase in the fraction of radio-loud quasars from the current epoch to z=0.5 and a gradual decline beyond z=1.0. Inspection of the radio-loud fraction as a function of M-B shows little dependence fainter than M-B=-29.5. (C) 1997 American Astronomical Society. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP Bischof, OB (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 8 TC 24 Z9 24 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 1997 VL 113 IS 6 BP 2000 EP 2005 DI 10.1086/118412 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XC119 UT WOS:A1997XC11900005 ER PT J AU Ambrosio, M Antolini, R Auriemma, G Baker, R Baldini, A Barbarino, GC Barish, BC Battistoni, G Bellotti, R Bemporad, C Bernardini, P Bilokon, H Bisi, V Bloise, C Bosio, T Bower, C Bussino, S Cafagna, F Calicchio, M Campana, D Carboni, M Castellano, M Cecchini, S Cei, F Chiarella, V Corona, A Coutu, S DeBenedictis, L DeCataldo, G Dekhissi, H DeMarzo, C DeMitri, I DeVincenzi, M DiCredico, A Erriquez, O Fantini, R Favuzzi, C Forti, C Fusco, P Giacomelli, G Giannini, G Giglietto, N Goretti, M Grassi, M Green, P Grillo, A Guarino, F Guarnaccia, P Gustavino, C Habig, A Hanson, K Hawthorne, A Heinz, R Hong, JT Iarocci, E Katsavounidis, E Kearns, E Kyriazopoulou, S Lamanna, E Lane, C Levin, DS Lipari, P Liu, G Liu, R Longley, NP Longo, MJ Ludlam, G Maaroufi, F Mancarella, G Mandrioli, G MargiottaNeri, A Marini, A Martello, D MarzariChiesa, A Mazziotta, MN Michael, DG Mikheyev, S Miller, L Monacelli, P Montaruli, T Monteno, M Mufson, S Musser, J Nicolo, D Nolty, R Okada, C Orth, C Osteria, G Paganini, S Palamara, O Parlati, S Patera, V Patrizii, L Pazzi, R Peck, CW Petrera, S Pignatano, ND Pistilli, P Popa, V Raino, A Reynoldson, J Ronga, F Rubizzo, U Sanzgiri, A Sartogo, F Satriano, C Satta, L Scapparone, E Scholberg, K Sciubba, A SerraLugaresi, P Severi, M Sitta, M Spinelli, P Spinetti, M Spurio, M Steinberg, R Stone, JL Sulak, LR Surdo, A Tarle, G Togo, V Valente, V Walter, CW Webb, R AF Ambrosio, M Antolini, R Auriemma, G Baker, R Baldini, A Barbarino, GC Barish, BC Battistoni, G Bellotti, R Bemporad, C Bernardini, P Bilokon, H Bisi, V Bloise, C Bosio, T Bower, C Bussino, S Cafagna, F Calicchio, M Campana, D Carboni, M Castellano, M Cecchini, S Cei, F Chiarella, V Corona, A Coutu, S DeBenedictis, L DeCataldo, G Dekhissi, H DeMarzo, C DeMitri, I DeVincenzi, M DiCredico, A Erriquez, O Fantini, R Favuzzi, C Forti, C Fusco, P Giacomelli, G Giannini, G Giglietto, N Goretti, M Grassi, M Green, P Grillo, A Guarino, F Guarnaccia, P Gustavino, C Habig, A Hanson, K Hawthorne, A Heinz, R Hong, JT Iarocci, E Katsavounidis, E Kearns, E Kyriazopoulou, S Lamanna, E Lane, C Levin, DS Lipari, P Liu, G Liu, R Longley, NP Longo, MJ Ludlam, G Maaroufi, F Mancarella, G Mandrioli, G MargiottaNeri, A Marini, A Martello, D MarzariChiesa, A Mazziotta, MN Michael, DG Mikheyev, S Miller, L Monacelli, P Montaruli, T Monteno, M Mufson, S Musser, J Nicolo, D Nolty, R Okada, C Orth, C Osteria, G Paganini, S Palamara, O Parlati, S Patera, V Patrizii, L Pazzi, R Peck, CW Petrera, S Pignatano, ND Pistilli, P Popa, V Raino, A Reynoldson, J Ronga, F Rubizzo, U Sanzgiri, A Sartogo, F Satriano, C Satta, L Scapparone, E Scholberg, K Sciubba, A SerraLugaresi, P Severi, M Sitta, M Spinelli, P Spinetti, M Spurio, M Steinberg, R Stone, JL Sulak, LR Surdo, A Tarle, G Togo, V Valente, V Walter, CW Webb, R TI Seasonal variations in the underground muon intensity as seen by MACRO SO ASTROPARTICLE PHYSICS LA English DT Article ID ENERGY-SPECTRA; COSMIC-RAYS AB Using 5.33 x 10(6) single muons collected in 1.46 x 10(4) live hours by MACRO during the period 1991-1994, we have searched for a correlation between variations in the underground muon rate, N-mu, and seasonal temperature variations in the atmosphere. These correlations are found to be present with high statistical significance. Analysis of the relatively complete December 1992-December 1994 subset of the data yields a value for the temperature coefficient, alpha(T) = (T/N-mu)(partial derivative N-mu/partial derivative T) = 0.83 +/- 0.13. Analysis of the total data Set gives consistent results. We have compared this result with the hypothesis that the muons observed in MACRO come from pion decays alone. Although our result is consistent with the 'pion only' hypothesis, a discussion of the sensitivity of our data sample to the kaon component of the cascades leading to observed muons underground will also be presented. (C) 1997 Elsevier Science B.V. C1 IST NAZL FIS NUCL,I-80125 NAPLES,ITALY. UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109. UNIV LECCE,DIPARTIMENTO FIS,I-73100 LECCE,ITALY. IST NAZL FIS NUCL,I-73100 LECCE,ITALY. UNIV AQUILA,DIPARTIMENTO FIS,I-67100 LAQUILA,ITALY. IST NAZL FIS NUCL,I-67100 LAQUILA,ITALY. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. INDIANA UNIV,DEPT ASTRON,BLOOMINGTON,IN 47405. IST NAZL FIS NUCL,LAB NAZL GRAN SASSO,I-67010 ASSERGI,LAQUILA,ITALY. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ROMA,ITALY. DREXEL UNIV,DEPT PHYS,PHILADELPHIA,PA 19104. CALTECH,PASADENA,CA 91125. BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. UNIV BOLOGNA,DIPARTIMENTO FIS,I-40126 BOLOGNA,ITALY. IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV BARI,DIPARTIMENTO FIS,I-70126 BARI,ITALY. IST NAZL FIS NUCL,I-70126 BARI,ITALY. IST NAZL FIS NUCL,I-56010 PISA,ITALY. UNIV PISA,DIPARTIMENTO FIS,I-56010 PISA,ITALY. UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY. IST NAZL FIS NUCL,I-00185 ROME,ITALY. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. UNIV TURIN,DIPARTIMENTO FIS SPERIMENTALE,I-10125 TURIN,ITALY. IST NAZL FIS NUCL,I-10125 TURIN,ITALY. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. SWARTHMORE COLL,SWARTHMORE,PA 19081. UNIV BASILICATA,I-85100 POTENZA,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. CNR,IST TESRE,I-40129 BOLOGNA,ITALY. SCUOLA NORMALE SUPER PISA,I-56010 PISA,ITALY. UNIV MOHAMED I,FAC SCI,OUJDA,MOROCCO. UNIV ROMA TRE,DIPARTIMENTO FIS,ROME,ITALY. UNIV TRIESTE,I-34100 TRIESTE,ITALY. IST NAZL FIS NUCL,I-34100 TRIESTE,ITALY. UNIV ROME,DIPARTIMENTO ENERGET,I-00185 ROME,ITALY. RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. RP Ambrosio, M (reprint author), UNIV NAPLES,DIPARTIMENTO FIS,I-80125 NAPLES,ITALY. RI Lamanna, Ernesto/C-7658-2012; Barbarino, Giancarlo/L-2559-2015; Martello, Daniele/J-3131-2012; Mazziotta, Mario /O-8867-2015; Cei, Fabrizio/M-8891-2016; Guarino, Fausto/I-3166-2012; De Mitri, Ivan/C-1728-2017; Spurio, Maurizio/G-4170-2012; giglietto, nicola/I-8951-2012; Castellano, Marcello/J-3428-2012; Cafagna, Francesco/A-9299-2010; gustavino, carlo/K-4355-2015; OI Spurio, Maurizio/0000-0002-8698-3655; ERRIQUEZ, Onofrio/0000-0002-9784-6568; Carboni, Massimo/0000-0003-4296-3799; Petrera, Sergio/0000-0002-6029-1255; Coutu, Stephane/0000-0003-2923-2246; Lamanna, Ernesto/0000-0002-7844-8230; Barbarino, Giancarlo/0000-0001-9253-3397; Martello, Daniele/0000-0003-2046-3910; Mazziotta, Mario /0000-0001-9325-4672; Cei, Fabrizio/0000-0002-8313-3540; Guarino, Fausto/0000-0003-1427-9885; De Mitri, Ivan/0000-0002-8665-1730; giglietto, nicola/0000-0002-9021-2888; Castellano, Marcello/0000-0002-4211-2903; Cafagna, Francesco/0000-0002-7450-4784; Bellotti, Roberto/0000-0003-3198-2708; gustavino, carlo/0000-0003-3232-7027; SPINELLI, Paolo/0000-0001-6688-8864; Sciubba, Adalberto/0000-0002-3301-9176; Monteno, Marco/0000-0002-3521-6333; Chiarella, Vitaliano/0000-0002-4210-2924 NR 28 TC 79 Z9 80 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD JUN PY 1997 VL 7 IS 1-2 BP 109 EP 124 DI 10.1016/S0927-6505(97)00011-X PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XF107 UT WOS:A1997XF10700012 ER PT J AU Taha, H AF Taha, H TI Modeling the impacts of large-scale albedo changes on ozone air quality in the South Coast Air Basin SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE albedo; ambient temperatures; mesoscale modeling; photochemistry; urban airshed model ID EMISSION RATES; TEMPERATURE; LIGHT AB It is expected that high-albedo materials will be used widely in urban areas particularly in warm and hot climates of the U.S. This will likely happen if high-albedo measures are adopted in building energy codes and urban planning regulations. The changes would mean that portions of urbanized airsheds may become more reflective to solar radiation than they currently are. This paper describes a modeling study that was aimed at analyzing the mesoscale meteorological and ozone air quality impacts of large-scale increases in surface albedo in California's South Coast Air Basin (SoCAB). For a late-August episode, the simulations indicate that implementing high-albedo materials in the SoCAB would have a net effect of reducing ozone concentrations. With extreme increases in albedo, peak concentrations at 3 p.m. decrease by up to 7% (from 220 down to 205 ppb) while the total ozone mass in the mixed layer decreases by up to 640 metric tons (a decrease of 4.7%). Largest reductions in concentrations at 3 p.m. are on the order of 50 ppb whereas the largest increases are on the order of 20 ppb. With respect to the National Ambient Air Quality Standard, domain-wide population-weighted exceedance exposure to ozone decreases by up to 16% during peak afternoon hours and by up to 10% during the day-time. (C) 1997 Elsevier Science Ltd. RP Taha, H (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MS 90-2000,BERKELEY,CA 94720, USA. RI Liu, Yanan/J-3680-2012 NR 30 TC 76 Z9 77 U1 1 U2 6 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 JUN PY 1997 VL 31 IS 11 BP 1667 EP 1676 DI 10.1016/S1352-2310(96)00336-6 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WR161 UT WOS:A1997WR16100008 ER PT J AU Emmons, LK Carroll, MA Hauglustaine, DA Brasseur, GP Atherton, C Penner, J Sillman, S Levy, H Rohrer, F Wauben, WMF VanVelthoven, PFJ Wang, Y Jacob, D Bakwin, P Dickerson, R Doddridge, B Gerbig, C Honrath, R Hubler, G Jaffe, D Kondo, Y Munger, JW Torres, A VolzThomas, A AF Emmons, LK Carroll, MA Hauglustaine, DA Brasseur, GP Atherton, C Penner, J Sillman, S Levy, H Rohrer, F Wauben, WMF VanVelthoven, PFJ Wang, Y Jacob, D Bakwin, P Dickerson, R Doddridge, B Gerbig, C Honrath, R Hubler, G Jaffe, D Kondo, Y Munger, JW Torres, A VolzThomas, A TI Climatologies of NOx and NOy: A comparison of data and models SO ATMOSPHERIC ENVIRONMENT LA English DT Review ID GENERAL-CIRCULATION MODEL; ARCTIC STRATOSPHERIC EXPEDITION; OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; REACTIVE ODD-NITROGEN; GLOBAL LIGHTNING DISTRIBUTIONS; NITRIC-OXIDE MEASUREMENTS; TRACE GAS CONCENTRATIONS; GASEOUS DRY DEPOSITION; SEASONAL-VARIATION; UPPER TROPOSPHERE AB Climatologies of tropospheric NOx(NO + NO2) and NOy (total reactive nitrogen: NOx + NO3 + 2 x N2O5 + HNO2 + HNO3 + HNO4 + ClONO2 + PAN (peroxyacetylnitrate) + other organic nitrates) have been compiled from data previously published and, in most cases, publicly archived. Emphasis has been on non-urban measurements, including rural and remote ground sites, as well as aircraft data. Although the distribution of data is sparse, a compilation in this manner can begin to provide an understanding of the spatial and temporal distributions of these reactive nitrogen species. The cleanest measurements in the boundary layer are in Alaska, northern Canada and the eastern Pacific, with median NO mixing ratios below 10 pptv, NOx below 50 pptv, and NOy below 300 pptv. The highest NO values (greater than 1 ppbv) were found in eastern North America and Europe, with correspondingly high NOy (similar to 5 ppbv). A significantly narrower range of concentrations is seen in the free troposphere, particularly at 3-6 km, with NO typically about 10 pptv in the boreal summer. NO increases with altitude to similar to 100 pptv at 9-12 km, whereas NOy does not show a trend with altitude, but varies between 100 and 1000 pptv. Decreasing mixing ratios eastward of the Asian and North American continents are seen in all three species at all altitudes. Model-generated climatologies of NOx and NOy from six chemical transport models are also presented and are compared with observations in the boundary layer and the middle troposphere for summer and winter. These comparisons test our understanding of the chemical and transport processes responsible for these species distributions. Although the model results show differences between them, and disagreement with observations, none are systematically different for all seasons and altitudes. Some of the differences between the observations and model results may likely be attributed to the specific meteorological conditions at the time that measurements were made differing from the model meteorology, which is either climatological how from GCMs or actual meteorology for an arbitrary year. Differences in emission inventories, and convection and washout schemes in the models will also affect the calculated NOx and NOy distributions. (C) 1997 Elsevier Science Ltd. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, ICG, JULICH, GERMANY. ROYAL NETHERLANDS METEOROL INST, NL-3730 AE DE BILT, NETHERLANDS. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV MARYLAND, COLLEGE PK, MD 20742 USA. MICHIGAN TECHNOL UNIV, HOUGHTON, MI 49931 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. UNIV ALASKA, FAIRBANKS, AK 99701 USA. NAGOYA UNIV, NAGOYA, AICHI, JAPAN. NASA, WALLOPS FLIGHT FACIL, WALLOPS ISL, VA USA. RP Emmons, LK (reprint author), UNIV MICHIGAN, DEPT ATMOSPHER OCEAN & SPACE SCI, ANN ARBOR, MI 48109 USA. RI Hubler, Gerhard/E-9780-2010; Dickerson, Russell/F-2857-2010; Kondo, Yutaka/D-1459-2012; Rohrer, Franz/I-2052-2012; Gerbig, Christoph/L-3532-2013; Wang, Yuhang/B-5578-2014; Volz-Thomas, Andreas/J-7223-2012; Munger, J/H-4502-2013; Emmons, Louisa/R-8922-2016; OI Dickerson, Russell/0000-0003-0206-3083; Rohrer, Franz/0000-0003-3436-3419; Gerbig, Christoph/0000-0002-1112-8603; Volz-Thomas, Andreas/0000-0003-3700-1667; Munger, J/0000-0002-1042-8452; Emmons, Louisa/0000-0003-2325-6212; Sillman, Sanford/0000-0001-6250-1191 NR 176 TC 93 Z9 95 U1 0 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 1997 VL 31 IS 12 BP 1851 EP 1904 DI 10.1016/S1352-2310(96)00334-2 PG 54 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WU835 UT WOS:A1997WU83500009 ER PT J AU Abdallah, CT Dorato, P Bredemann, M AF Abdallah, CT Dorato, P Bredemann, M TI New sufficient conditions for strong simultaneous stabilization SO AUTOMATICA LA English DT Article; Proceedings Paper CT IFAC Symposium on Robust Control Design CY SEP 14-16, 1994 CL RIO JANEIRO, BRAZIL SP IFAC DE simultaneous stabilization; linear systems; interpolation algorithm ID FEEDBACK-STABILIZATION; INTERPOLATION; PLANTS AB We present sufficient conditions for the existence of a single stable controller to stabilize a set of n SISO plants: P-1, P-2,..., P-n (strong simultaneous stabilization). As is well known, this is equivalent to the existence of a single controller, not necessarily stable, to stabilize n+1 plants (simultaneous stabilization). The basic assumption required in this paper is that all the plants have the same unstable zeros. A practical example of where such an assumption holds is when each plant has the same pure delay, which is approximated by a non-minimum-phase rational function. The results here are applied to examples of this type. (C) Elsevier Science Ltd. C1 SANDIA NATL LABS,DIV 9222,ALBUQUERQUE,NM 87185. RP Abdallah, CT (reprint author), UNIV NEW MEXICO,DEPT EECE,ALBUQUERQUE,NM 87131, USA. NR 13 TC 10 Z9 11 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0005-1098 J9 AUTOMATICA JI Automatica PD JUN PY 1997 VL 33 IS 6 BP 1193 EP 1196 DI 10.1016/S0005-1098(97)00021-6 PG 4 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA XJ132 UT WOS:A1997XJ13200017 ER PT J AU deSouza, ON Ornstein, RL AF deSouza, ON Ornstein, RL TI Effect of periodic box size on aqueous molecular dynamics simulation of a DNA dodecamer with particle-mesh Ewald method SO BIOPHYSICAL JOURNAL LA English DT Article ID FORCE-FIELD; B-DNA; PROTEINS; RNA AB The particle-mesh Ewald (PME) method is considered to be both efficient and accurate for the evaluation of long-range electrostatic interactions in large macromolecular systems being studied by molecular dynamics simulations. This method assumes ''infinite'' periodic boundary conditions resembling the symmetry of a crystal environment. Can such a ''solid-state'' method accurately portray a macromolecular solute such as DNA in solution? To address this issue, we have performed three 1500-ps PME molecular dynamics (MD) simulations, each with a different box size, on the d(CGCGA(6)CG)-(CGT(6)CGCG) DNA dodecamer, The smallest box had the DNA solvated by a layer of water molecules of at least 5 Angstrom along each orthogonal direction. The intermediate size box and the largest box had the DNA solvated by a layer of water molecules of at least 10 Angstrom and 15 Angstrom, respectively, along each orthogonal direction. The intermediate size box in the present study is similar to the box size currently chosen by most workers in the field, Based on a comparison of RMSDs and curvature for this single DNA dodecamer sequence, the larger two box sizes do not appear to afford any extra benefit over the smallest box, The implications of this finding are briefly discussed. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Norberto de Souza, Osmar/B-7328-2013 OI Norberto de Souza, Osmar/0000-0002-4602-1208 NR 17 TC 65 Z9 66 U1 1 U2 6 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1997 VL 72 IS 6 BP 2395 EP 2397 PG 3 WC Biophysics SC Biophysics GA XA636 UT WOS:A1997XA63600001 PM 9168016 ER PT J AU Nilsson, SK Dooner, MS Tiarks, CY Weier, HU Quesenberry, PJ AF Nilsson, SK Dooner, MS Tiarks, CY Weier, HU Quesenberry, PJ TI Potential and distribution of transplanted hematopoietic stem cells in a nonablated mouse model SO BLOOD LA English DT Article ID BONE-MARROW CELLS; COLONY-FORMING CELLS; RHODAMINE-123 FLUORESCENCE; SPATIAL DISTRIBUTIONS; MICE; SPLEEN; TERM; PROLIFERATION; ENRICHMENT; PURIFICATION AB Increasingly, allogeneic and even more often autologous bone marrow transplants are being done to correct a wide variety of diseases. In addition, autologous marrow transplants potentially provide an opportune means of delivering genes in transfected, engrafting stem cells. However, despite its widespread clinical use and promising gene therapy applications, relatively little is known about the mechanisms of engraftment in marrow transplant recipients, This is especially so in the nonablated recipient setting. Our data show that purified lineage negative rhodamine 123/Hoechst 33342 dull transplanted hematopoietic stem cells engraft into the marrow of nonablated syngeneic recipients, These cells have multilineage potential, and maintain a distinct subpopulation with ''stem cell'' characteristics. The data also suggests a spatial localization of stem cell ''niches'' to the endosteal surface, with all donor cells having a high spatial affinity to this area. However, the level of stem cell engraftment observed following a transplant of ''stem cells'' was significantly lower than that expected following a transplant of the same number of unseparated marrow cells from which the purified cells were derived, suggesting the existence of a ''nonstem cell facilitator population,'' which is required in a nonablated syngeneic transplant setting. (C) 1997 by The American Society of Hematology. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. RP Nilsson, SK (reprint author), UNIV MASSACHUSETTS,MED CTR,CTR CANC,373 PLANTAT ST,SUITE 202,WORCESTER,MA 01605, USA. RI Nilsson, Susie/C-5563-2015 OI Nilsson, Susie/0000-0002-7926-7335 FU NIDDK NIH HHS [NIDDK 49650-02, NIDDK 50222-01] NR 40 TC 113 Z9 114 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD JUN 1 PY 1997 VL 89 IS 11 BP 4013 EP 4020 PG 8 WC Hematology SC Hematology GA XD379 UT WOS:A1997XD37900015 PM 9166840 ER PT J AU Popp, RA Popp, DM Shinpock, SG Yang, MY Mural, JG Aguinaga, MD Kopsombut, P Roa, PD Turner, EA Rubin, EM AF Popp, RA Popp, DM Shinpock, SG Yang, MY Mural, JG Aguinaga, MD Kopsombut, P Roa, PD Turner, EA Rubin, EM TI A transgenic mouse model of hemoglobin S Antilles disease SO BLOOD LA English DT Article ID SICKLE-CELL DISEASE; MICE; EXPRESSION; HYPOXIA; DAMAGE; GLOBIN; SAD AB Hemoglobin (Hb) S Antilles is a naturally occurring form of sickling human Hb but causes a more severe phenotype than Hb S. Two homozygous viable Hb S Antilles transgene insertions from Tg58Ru and Tg98Ru mice were bred into MHOAH mice that express high oxygen affinity (P-50 similar to 24.5 mm Hg) rather than normal (P-50 similar to 40 mm Hg) mouse Hbs, The rationale was that the high oxygen affinity MHOAH Hb, the lower oxygen affinity of Hb S Antilles than Hb S (P-50 similar to 40 v 26.5 mm Hg), and the lower solubility of deoxygenated Hb S Antilles than Hb S (similar to 11 v 18 g/dL) would favor deoxygenation and polymerization of human Hb S Antilles in MHOAH mouse red blood cells (RBCs). The Tg58 x Tg98 mice produced have a high and balanced expression (similar to 50% each) of h alpha and h beta(S Antilles) globins, 25% to 35% of their RBCs are misshapen in vivo, and in vitro deoxygenation of their blood induces 30% to 50% of the RBCs to form classical looking, elongated sickle cells with pointed ends. Tg58 x Tg98 mice exhibit reticulocytosis, an elevated white blood cell count and lung and kidney pathology commonly found in sickle cell patients, which should make these mice useful for experimental studies on possible therapeutic intervention of sickle cell disease. (C) 1997 by The American Society of Hematology. C1 UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37830. MEHARRY MED COLL,CTR COMPREHENS SICKLE CELL,NASHVILLE,TN 37208. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CELL & MOL BIOL,BERKELEY,CA 94720. RP Popp, RA (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. NR 23 TC 14 Z9 14 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD JUN 1 PY 1997 VL 89 IS 11 BP 4204 EP 4212 PG 9 WC Hematology SC Hematology GA XD379 UT WOS:A1997XD37900040 PM 9166865 ER PT J AU Hartse, HE Taylor, SR Phillips, WS Randall, GE AF Hartse, HE Taylor, SR Phillips, WS Randall, GE TI A preliminary study of regional seismic discrimination in central Asia with emphasis on western China SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID NUCLEAR TEST SITE; SPECTRAL DISCRIMINATION; NTS EXPLOSIONS; EARTHQUAKES; WAVES; TIBET; VERIFICATION; EVENTS AB In support of a Comprehensive Test Ban Treaty, we have started to evaluate regional seismic-event discrimination capabilities for central Asia, emphasizing western China. We have measured noise and signal levels of over 260 earthquakes and 26 underground nuclear explosions recorded at the broadband, digital station WMQ in western China and over 120 earthquakes and five nuclear explosions at station AAK in Kyrgyzstan. The explosions are from the Kazakh Test Site (KTS) and Lop Nor, China. The earthquakes are mostly from northwest China. Event magnitudes (measured as either m(b) or M-L) range between 2.5 and 6.5 and maximum event-station distance is about 1700 km. We formed phase, spectral, cross-spectral, short-period/long-period, and long-period ratios to test many possible event discriminants. All ratios were corrected for distance effects before forming ratio-versus-magnitude discrimination plots. The most consistent discriminants for separating earthquakes from explosions are P/S phase ratios for frequencies above 3 to 4 Hz. P-wave (f > 1 Hz) to Rayleigh-wave (0.03 Hz < f < 0.1 Hz) ratios are also effective, but surface-waves are difficult to measure for magnitudes below about 4.5. For the P/S ratios, separation between earthquakes and explosions increases with frequency, and for the P/R ratios, separation increases with increasing P frequency. The P (3 to 6 Hz)/S (0.75 to 1.5 Hz) cross-spectral ratios also separate earthquakes and explosions. These cross-spectral ratios may prove quite useful because, due to weak high-frequency L-g signals from explosions, the high-frequency P/L-g ratio sometimes cannot be evaluated, but the P (3 to 6 Hz)/L-g (0.75 to 1.5 Hz) can be evaluated successfully. P spectral ratios (3 to 6 Hz/0.75 to 1.5 Hz) also separate earthquakes and explosions but not quite as consistently as the P/S ratios. However, P spectral ratios may prove useful in cases where path effects block or highly attenuate S-n and L-g waves, rendering the P/S ratios unavailable. In contrast to Nevada Test Site (NTS) events, the L-g (3 to 6 Hz/0.75 to 1.5 Hz) spectral ratio does not separate earthquakes and nuclear explosions in central Asia. This observation may be a source effect. as Asian explosions are thought to be detonated in highly lithified rocks below the water table, while most of the smaller (m(b) < 4.8) NTS explosions have been detonated in poorly lithified rocks above the water table. dFor station AAK, the short-period spectral and cross-spectral ratios identify a few earthquakes (not recorded at WMQ) from the north Pamir region that plot with the Lop Nor explosions. The waveforms from these earthquakes lack surface waves and a distinct L-g phase. These events, which we interpret as having occurred in a subducted slab, do separate from the explosions on high-frequency (f > 4 Hz) P/S discrimination plots. For station WMQ, long-period R/L (Rayleigh-wave/Love-wave) ratios separate KTS explosions and Asian earthquakes. However, R/L ratios fail to identify the large Lop Nor explosions recorded at station AAK because the Love waves an as large as the Rayleigh waves, suggesting that strong tectonic release occurs with these explosions. Because we have examined only one path at a single station for these explosions, source-radiation pattern may be influencing this observation. RP LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, GEOPHYS GRP, EES-3, LOS ALAMOS, NM 87545 USA. NR 43 TC 76 Z9 81 U1 1 U2 6 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1997 VL 87 IS 3 BP 551 EP 568 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XF578 UT WOS:A1997XF57800004 ER PT J AU Lehnert, BE Goodwin, EH AF Lehnert, BE Goodwin, EH TI Extracellular factor(s) following exposure to alpha particles can cause sister chromatid exchanges in normal human cells SO CANCER RESEARCH LA English DT Article ID SUPEROXIDE-DISMUTASE; CLASTOGENIC FACTORS; CHROMOSOMAL DAMAGE; RESPIRATORY-TRACT; EPITHELIAL-CELLS; RADON PROGENY; DNA-DAMAGE; X-RAYS; RADIATION; INDUCTION AB The mechanism(s) by which or particles like those emitted from inhaled radon and radon progeny cause their mutagenic and carcinogenic effects remains unclear, Although direct nuclear traversals by or particles mag be involved in mediating these outcomes, increasing evidence indicates that alpha particles can cause alterations in DNA in the absence of direct ''hits'' to cell nuclei, Using the occurrence of excessive sister chromatid exchanges (SCEs) as an index of DNA damage in human lung fibroblasts, we investigated the hypothesis that alpha particles may induce DNA damage via the generation of extracellular factors, We have found that a relatively low dose of or particles indeed results in the generation of extracellular factors, which, upon transfer to unexposed normal human cells, can cause excessive SCEs to an extent equivalent to that observed when the cells are directly irradiated with the Same irradiation dose, A short-lived, SCE-inducing factor(s) was generated in alpha-irradiated culture medium containing serum in the absence of cells; it was found that the activity of this factor can be promptly inhibited by superoxide dismutase, A more persistent SCE-inducing factor(s), which can survive freeze-thawing, is heat labile and also can be inhibited by superoxide dismutase, was produced by fibroblasts after exposure to alpha particles, These results indicate that the initiating target for alpha-particle-induced genetic changes can be larger than the nuclear compartment alone and even larger than the cytoplasmic compartment, How transmissible factors like those observed here lit vitro may extend to the in vivo condition in the context of alpha-particle-induced carcinogenesis in the respiratory tract and elsewhere remains to be determined. RP Lehnert, BE (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,CELL & MOL BIOL GRP,MS M888,LOS ALAMOS,NM 87545, USA. NR 52 TC 211 Z9 225 U1 0 U2 5 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 JUN 1 PY 1997 VL 57 IS 11 BP 2164 EP 2171 PG 8 WC Oncology SC Oncology GA XB759 UT WOS:A1997XB75900020 PM 9187116 ER PT J AU Dale, EC Yang, XL Moore, SK Shyamala, G AF Dale, EC Yang, XL Moore, SK Shyamala, G TI Murine 86-kDa heat shock protein gene and promoter SO CELL STRESS & CHAPERONES LA English DT Article ID CHICKEN HSP90-BETA; EXPRESSION; CELLS; RECEPTORS; BINDING; ASSOCIATION; SEQUENCE; FAMILY; STRESS; KINASE AB The class of 90 kDa heat shock proteins (HspSO) is among the most abundant heat shock proteins (Hsps) in eukaryotic cells. In vertebrates, HspSO is encoded by two distinct gene families giving rise to products of 84 and 86 kDa. In mice the expression of these two genes, hsp84 and hsp86, vary with respect to each other in responses to stress, and also in response to signals for growth and development. Therefore, as a step towards understanding the molecular basis for the differential regulation of these two genes, we have isolated and characterized genomic clones of the murine hsp86 gene and its 5' flanking region. The gene is composed of eleven exons interrupted by 10 introns. The 5' region contains consensus TATA, several stimulatory protein-1 binding site (SP1) elements as well as six consensus heat shock elements (HSE) 5' of the transcription start site. An 806 bp fragment of the 5' promoter region conferred constitutive expression upon a reporter gene and this expression was increased upon heat shock. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. US FDA,DIV METAB & ENDOCRINE DRUG PROD,ROCKVILLE,MD 20857. FU NCI NIH HHS [CA54828] NR 35 TC 16 Z9 16 U1 0 U2 0 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH EH1 3AF, MIDLOTHIAN, SCOTLAND SN 1355-8145 J9 CELL STRESS CHAPERON JI Cell Stress Chaperones PD JUN PY 1997 VL 2 IS 2 BP 87 EP 93 DI 10.1379/1466-1268(1997)002<0087:MKHSPG>2.3.CO;2 PG 7 WC Cell Biology SC Cell Biology GA XG200 UT WOS:A1997XG20000003 PM 9250399 ER PT J AU King, PE Yim, SCS AF King, PE Yim, SCS TI Control of noisy chaotic motion in a system with nonlinear excitation and restoring forces SO CHAOS LA English DT Article ID PERIODIC-ORBITS; DYNAMIC-SYSTEMS AB In this study we examine the complex and chaotic oscillations of a dynamical system with nonlinear excitation and restoring forces for the purpose of controlling these oscillatory states. The physical system, modeled as a system of first-order nonlinear ordinary differential equations, takes into account a geometric nonlinearity in the restoring force, a quadratic viscous drag, and a harmonic excitation force. It is controlled using small perturbations about a selected unstable cycle and control is instigated for periodic cycles of varying periodicities The controller, when applied on the dynamical system with additive random noise in the excitation, successfully controls the system with noise levels in excess of 5% of the total energy, giving the first evidence that (stochastic) control of these systems is possible. (C) 1997 American Institute of Physics. C1 OREGON STATE UNIV,CORVALLIS,OR 97331. RP King, PE (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 30 TC 1 Z9 2 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1054-1500 J9 CHAOS JI Chaos PD JUN PY 1997 VL 7 IS 2 BP 290 EP 300 DI 10.1063/1.166228 PG 11 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA XE151 UT WOS:A1997XE15100009 ER PT J AU Soong, Y Gamwo, IK Blackwell, AG Mundorf, KR Harke, FW Schehl, RR Zarochak, MF AF Soong, Y Gamwo, IK Blackwell, AG Mundorf, KR Harke, FW Schehl, RR Zarochak, MF TI Ultrasonic measurement of solids concentration in an autoclave reactor at high temperature SO CHEMICAL ENGINEERING JOURNAL LA English DT Article DE ultrasonic; solids concentration; autoclave reactor ID SUSPENSIONS; HOLDUP; PROPAGATION; BED AB An ultrasonic technique was developed to measure the slurry concentration in an autoclave reactor. Preliminary measurements were conducted on slurries consisting of molten FT-200 wax, glass beads, and nitrogen bubbles at a typical Fischer-Tropsch (FT) synthesis temperature of 265 degrees C. The data show that the velocity and attenuation of the sound are well-defined functions of the solid and gas concentrations in the molten FT-200 wax. The results suggest possibilities for directly measuring solids concentration during operation of a three-phase slurry reactor under the reaction temperature and with molten FT-200 wax. (C) 1997 Elsevier Science S.A. RP Soong, Y (reprint author), US DOE,FED ENERGY TECHNOL CTR,POB 10940,PITTSBURGH,PA 15236, USA. NR 24 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0923-0467 J9 CHEM ENG J JI Chem. Eng. J. PD JUN PY 1997 VL 67 IS 3 BP 175 EP 180 DI 10.1016/S1385-8947(97)00066-1 PG 6 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA YC521 UT WOS:A1997YC52100003 ER PT J AU Wu, HM Small, GJ AF Wu, HM Small, GJ TI Symmetry adapted basis defect patterns for analysis of the effects of energy disorder on cyclic arrays of coupled chromophores SO CHEMICAL PHYSICS LA English DT Article ID BACTERIAL REACTION CENTERS; PRIMARY CHARGE SEPARATION; RHODOBACTER-SPHAEROIDES; DISPERSIVE KINETICS; ANTENNA; COMPLEX; SPECTROSCOPY; POLYSILANES; DYNAMICS; STATE AB The effects of diagonal and off-diagonal energy disorder on the exciton level structure and spectroscopic properties of cyclic (C-n) arrays of coupled chromophores are analyzed using symmetry adapted basis defect patterns (BDP). An important aspect of this approach is that any arbitrary defect pattern can be expressed as a superposition of BDP. Determination of the effects of each BDP on the exciton manifold allows for a systematic approach to the question of whether or not energy disorder can account for spectroscopic data given a zero-order C-n-Hamiltonian. The insights provided by representation theory and the BDP are illustrated with an application to a C-9-ring of bacteriochlorophyll molecules such as found in light harvesting complex 2 of purple bacteria. An understanding of how energy disorder affects exciton level structure is essential for understanding inter-exciton level relaxation dynamics. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 34 TC 28 Z9 30 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JUN 1 PY 1997 VL 218 IS 3 BP 225 EP 234 DI 10.1016/S0301-0104(97)00074-8 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB745 UT WOS:A1997XB74500001 ER PT J AU Jankowiak, R Ariese, F Zamzow, D Luch, A Kroth, H Seidel, A Small, GJ AF Jankowiak, R Ariese, F Zamzow, D Luch, A Kroth, H Seidel, A Small, GJ TI Conformational studies of stereoisomeric tetrols derived from syn- and anti-dibenzo[a,l] pyrene diol epoxides SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID POLYACRYLAMIDE-GEL ELECTROPHORESIS; POLYCYCLIC AROMATIC-HYDROCARBONS; REGION 11,12-DIOL 13,14-EPOXIDES; BENZOPYRENE DNA-ADDUCTS; TUMOR-INITIATING ACTIVITY; MOUSE SKIN; DIBENZOPYRENE; FJORD; IDENTIFICATION; QUANTITATION AB An understanding of the conformational behavior of the stereoisomeric tetrols at the 11,12,13,14-positions of dibenzo[a,l]pyrene (DB[a,l]P) is essential for the spectroscopic identification of DNA adducts derived from the biologically highly active fjord region syn- and anti-DB[a,l]P-11,12-diol 13,14-epoxides. Conformational effects are expected to play an important role in DNA-DB[a,l]P diol epoxide reactivity, base-sequence specificity, and conformation dependent repair. The results of conformational studies on trans-anti-, cis-anti-, and cis-syn-DB[a,l]P tetrol isomers are presented and compared to the results obtained previously for trans-syn-DB[a,l]P tetrol (Carcinogenesis 17, 829-837, 1996). Molecular mechanics, dynamical simulations, and semiempirical calculations of electronic transitions are used to interpret the low-temperature fluorescence spectra and H-1 NMR data. Molecular dynamics simulations (in vacuo) identified two conformers (I and II) for each of the tetrol isomers; in all conformations the aromatic ring system is severely distorted. Fluorescence line-narrowing (FLN) spectroscopy identified tyro distinct conformational species for the trans-anti isomer, one occurring in ethanol and the other occurring in a glycerol/water matrix. The corresponding structures are assigned based on the S-1 <-- S-0 transition energies calculated for conformers I and II, respectively. H-1 NMR spectroscopy confirmed the structure of conformer I at room temperature. In contrast to trans-syn-DB[a,l]P tetrol (where the major conformation was identified as a boat structure), both conformations of trans-anti-DB[a,l]P tetrol feature a half-chair structure for the cyclohexenyl ring with different orientations of the hydroxyl groups. For cis-anti- and cis-syn-DB[a,l]P tetrols, only a single conformer is detected by FLN spectroscopy. The NMR results for the latter appear to be most consistent with a mixture of two half-chair conformers I and II, while for the cis-anti isomer a flattened, boatlike conformation was observed. The generally good agreement between the NMR coupling constants and those estimated theoretically indicates that these structures should serve as good starting points for spectroscopic or computational studies of DNA adducts derived from DB[a,l]P diol epoxides. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. UNIV MAINZ,INST TOXICOL,D-55131 MAINZ,GERMANY. RP Jankowiak, R (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011, USA. FU NCI NIH HHS [P01 CA 49210-05] NR 36 TC 13 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD JUN PY 1997 VL 10 IS 6 BP 677 EP 686 DI 10.1021/tx960211a PG 10 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA XE583 UT WOS:A1997XE58300008 PM 9208175 ER PT J AU Hwang, RQ Bartelt, MC AF Hwang, RQ Bartelt, MC TI Scanning tunneling microscopy studies of metal on metal epitaxy SO CHEMICAL REVIEWS LA English DT Review ID BY-LAYER GROWTH; MEDIATED ISLAND GROWTH; MOLECULAR-BEAM EPITAXY; THIN-FILM GROWTH; HOMOEPITAXIAL GROWTH; ALLOY FORMATION; SUBMONOLAYER EPITAXY; SURFACE-DIFFUSION; SIZE DISTRIBUTION; AU FILMS RP Hwang, RQ (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 105 TC 67 Z9 68 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD JUN PY 1997 VL 97 IS 4 BP 1063 EP 1082 DI 10.1021/cr960070h PG 20 WC Chemistry, Multidisciplinary SC Chemistry GA XF530 UT WOS:A1997XF53000004 ER PT J AU Carpick, RW Salmeron, M AF Carpick, RW Salmeron, M TI Scratching the surface: Fundamental investigations of tribology with atomic force microscopy SO CHEMICAL REVIEWS LA English DT Review ID SELF-ASSEMBLED MONOLAYERS; SCANNING-TUNNELING-MICROSCOPY; LANGMUIR-BLODGETT-FILMS; MOLECULARLY THIN-FILMS; STICK-SLIP MOTION; SCALE FRICTION; ULTRAHIGH-VACUUM; NANOMETER-SCALE; LIQUID-FILMS; ALKANETHIOL MONOLAYERS C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 287 TC 718 Z9 733 U1 22 U2 155 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 EI 1520-6890 J9 CHEM REV JI Chem. Rev. PD JUN PY 1997 VL 97 IS 4 BP 1163 EP 1194 DI 10.1021/cr960068q PG 32 WC Chemistry, Multidisciplinary SC Chemistry GA XF530 UT WOS:A1997XF53000009 ER PT J AU Smith, RD Bruce, JE Wu, QY Lei, QP AF Smith, RD Bruce, JE Wu, QY Lei, QP TI New mass spectrometric methods for the study of noncovalent associations of biopolymers SO CHEMICAL SOCIETY REVIEWS LA English DT Review ID ELECTROSPRAY-IONIZATION; IONS; COMPLEXES; PROTEINS; TETRAMER; BINDING AB The use of electrospray ionization-mass spectrometry (ESI-MS) for the characterization of noncovalent complexes of biomacromolecules in solution is based upon the gentle nature of the electrospray process that allows a wide range of associations to be transferred intact to the gas phase as fully desolvated complexes, Examples include multimeric proteins, oligonucleotide duplexes, DNA-drug complexes and enzyme-inhibitor complexes, Various studies have indicated that at least some qualities of the three-dimensional solution structures are retained in the gas phase, Recent investigations have also shown the relative stabilities of complexes in the gas phase can be very different than the same complexes in solution, In spite of this, the use of very gentle electrospray interface conditions can provide a direct reflection of relative solution abundances for similar complexes, Competitive binding experiments using sets of ligands have been shown to yield insights regarding relative binding affinities in solution. The potential for high throughput affinity screening of combinatorial libraries using ESI-MS is described based upon the multi-stage MS capability of Fourier transform ion cyclotron resonance instrumentation and involving the characterization of components (after dissociation) of the library constituents initially present as complexes with a target biopolymer in the ion trap, This approach combines, in one rapid experiment, both affinity selection by complex formation with a biopolymer and the identification of the ligands selected from combinatorial mixtures, thus providing information on the relative binding affinities of the library constituents, The present status, limitations and promise of these methods are discussed. RP Smith, RD (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 35 TC 163 Z9 165 U1 3 U2 22 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0306-0012 J9 CHEM SOC REV JI Chem. Soc. Rev. PD JUN PY 1997 VL 26 IS 3 BP 191 EP 202 DI 10.1039/cs9972600191 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA XN591 UT WOS:A1997XN59100006 ER PT J AU Mahal, LK Bertozzi, CR AF Mahal, LK Bertozzi, CR TI Engineered cell surfaces: Fertile ground for molecular landscaping SO CHEMISTRY & BIOLOGY LA English DT Article ID DECAY-ACCELERATING FACTOR; MEMBRANE PROTEIN PHOE; ESCHERICHIA-COLI; FUCOSYL-TRANSFERASE; SIALIC-ACID; INTACT-CELLS; RECEPTOR; BIOSYNTHESIS; ANALOGS; BINDING AB The cell surface contains a wealth of information that determines how cells interact with their environment. Methods for directing the cell surface expression of novel protein-based and oligosaccharide-based epitopes are stimulating new directions in biotechnology and biomedical research. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP Mahal, LK (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Mahal, Lara/0000-0003-4791-8524 NR 59 TC 42 Z9 42 U1 0 U2 7 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD JUN PY 1997 VL 4 IS 6 BP 415 EP 422 DI 10.1016/S1074-5521(97)90193-9 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XK271 UT WOS:A1997XK27100002 PM 9224572 ER PT J AU Li, J Josowicz, M AF Li, J Josowicz, M TI Synthesis and characterization of electropolymerized poly(cyclophosphazene-benzoquinone) SO CHEMISTRY OF MATERIALS LA English DT Article ID PHOSPHAZENES; POLYPHOSPHAZENES; SPECTRA AB Formation of a inorganic-organic hybrid material from hexachlorocyclotriphosphazene, (NPCl2)(3), and quinone precursors directly at the electrode surface was studied. These materials are formed from electrochemically generated quinone radical anion and quinone dianion at the electrode surface followed by nucleophilic substitution of the chlorine on the phosphazene heterocycle. The polymerization process is controlled by the electrochemical-chemical-electrochemical-chemical.. (ECEC..) mechanism and is independent of the concentration of the BQ in the solution. The chemical composition of the poly(cyclophosphazene-benzoquinone), PPBQ, material was examined by elemental analysis and the X-ray photoelectron spectroscopy. P-31 Nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray diffraction were used to characterize the chemical structure of the material. The results confirm that the PPBQ is formed by replacement of four chlorine atoms on one (NPCl2)(3) precursor by four quinones which are linked directly to the phosphorus through their oxygens. The resulting material is amorphous, chemically inert, electrically nonconducting, nonflammable, and porous. The thickness of PPBQ and porosity of the PPBQ can be controlled electrochemically. C1 PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. NR 41 TC 3 Z9 5 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 1997 VL 9 IS 6 BP 1451 EP 1462 DI 10.1021/cm9701365 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA XE922 UT WOS:A1997XE92200023 ER PT J AU Solanki, RS Gorti, JK AF Solanki, RS Gorti, JK TI Implementation of an integer optimization platform using object oriented programming SO COMPUTERS & OPERATIONS RESEARCH LA English DT Article AB A wide range of integer optimization formulations have been successfully used in a variety of applications dealing with distribution, production, finance, and a host of other areas. Since the general integer optimization problem is NP-complete, specialized theory and techniques have evolved to utilize the special structures in individual applications. This has led to different categories and sub-categories of techniques that need to be evaluated in selecting a solution strategy for a new integer optimization formulation. The availability of computer packages or callable libraries for only a few techniques results in the need to either modify an existing code or implement a new code from scratch. This article illustrates the utility of object oriented programming methodology in implementing a modular, reusable library of techniques that can be extended easily to develop code for solving new integer optimization formulations. The flexibility in the library allows for easy customization of existing techniques for new applications as well as development of new techniques that utilize the code in the existing library. The ease of customization or reusability of this library is depicted by comparing it with the code written in conventional programming languages, such as Fortran or C. (C) 1997 Elsevier Science Ltd. C1 LOCKHEAD MARTIN ENERGY SYST,OPERAT RES GRP,RES STAFF,OAK RIDGE,TN 37831. RP Solanki, RS (reprint author), OAK RIDGE NATL LAB,CTR TRANSPORTAT ANAL,OAK RIDGE,TN 37831, USA. NR 8 TC 1 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0305-0548 J9 COMPUT OPER RES JI Comput. Oper. Res. PD JUN PY 1997 VL 24 IS 6 BP 549 EP 557 DI 10.1016/S0305-0548(96)00066-4 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Industrial; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA WU889 UT WOS:A1997WU88900006 ER PT J AU Foster, I Thiruvathukal, GK Tuecke, S AF Foster, I Thiruvathukal, GK Tuecke, S TI Technologies for ubiquitous supercomputing: A Java interface to the Nexus communication system SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article; Proceedings Paper CT Workshop on Java for Computational Science and Engineering - Simulation and Modeling CY DEC 16-17, 1996 CL SYRACUSE, NY AB We use the term ubiquitous supercomputing to refer to systems that integrate low- and midrange computing systems, advanced networks and remote high-end computers with the goal of enhancing the computational power accessible from local environments, Such systems promise to enable new applications in areas as diverse as smart instruments and collaborative environments, However, they also demand tools for transporting code between computers and for establishing flexible, dynamic communication structures, In this article, we propose that these requirements be satisfied by introducing Java classes that implement the global pointer and remote service request mechanisms defined by a communication library called Nexus, Java supports transportable code; Nexus provides communication support and represents the core communication framework for Globus, a project building infrastructure for ubiquitous supercomputing, We explain how this NexusJava library is implemented and illustrate its use with examples. (C) 1997 by John Wiley & Sons, Ltd. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. NR 15 TC 4 Z9 4 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD JUN PY 1997 VL 9 IS 6 BP 465 EP 475 PG 11 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA XG612 UT WOS:A1997XG61200005 ER PT J AU Garcia, HE AF Garcia, HE TI A hierarchical platform for implementing hybrid systems in process control SO CONTROL ENGINEERING PRACTICE LA English DT Article DE hybrid systems; discrete-event; hierarchical systems; object-oriented application AB This paper describes a development platform for the description, analysis and implementation of real-time control systems, consisting of a mixture of continuous and discrete components. Hybrid and discrete-event system techniques are used for formally defining the control and supervisory system requirements. These requirements result from functional characteristics specified for the process to be controlled. Based on the specifications, a series of control components belonging to a finite set of object classes is defined and arranged in a hierarchical architecture, The hierarchical topology is a simple tree, where any component has a single parent. Object-oriented technologies are used to implement the notion of component classes. With this formal description of process functionality, a computer software generator interprets the control specifications and produces executable control software. This software reacts to environmental responses by executing the supervisory and control actions required to achieve the desired process behavior. The paper only describes the conceptual idea of the proposed control development platform in a general manner. As an example, an application of this platform is presented for developing the control software for a production process that converts metallic sodium from nuclear reactors to sodium carbonate for safe waste disposal. RP Garcia, HE (reprint author), ARGONNE NATL LAB, POB 2528, IDAHO FALLS, ID 83403 USA. NR 15 TC 3 Z9 6 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0661 J9 CONTROL ENG PRACT JI Control Eng. Practice PD JUN PY 1997 VL 5 IS 6 BP 779 EP 789 DI 10.1016/S0967-0661(97)00062-2 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA XG617 UT WOS:A1997XG61700005 ER PT J AU Klarer, P AF Klarer, P TI Small scale intelligence for lunar exploration SO CONTROL ENGINEERING PRACTICE LA English DT Article DE rovers; swarms; mobile robots; autonomy; lunar exploration; telerobotic; small scale intelligence AB A comparison of Small Scale Intelligence (SSI) with conventional Artificial Intelligence (AI) and teleoperation for mobile robot control is presented here. A simple simulation of a randomized swarm of SSI revers is described, which provides some expected performance parameters for such systems, and provides a point of comparison with AI and teleoperation in terms of searching a defined space. The SSI technique is then illustrated by applying it to solving a postulated task for a lunar rover. An approach to the hybridization of Small Scale Intelligence (SSI) control systems with a telerobotic man-machine interface is also briefly proposed and discussed. The purpose of this paper is to explore how the SSI approach might be applied to a lunar rover system, and what potential advantages such an approach may have over more conventional approaches. RP Klarer, P (reprint author), SANDIA NATL LABS,POB 5800,MS1125,ALBUQUERQUE,NM 87185, USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0967-0661 J9 CONTROL ENG PRACT JI Control Eng. Practice PD JUN PY 1997 VL 5 IS 6 BP 859 EP 863 DI 10.1016/S0967-0661(97)00071-3 PG 5 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA XG617 UT WOS:A1997XG61700014 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 Voltage spike observation in superconducting cable-in-conduit conductor under ramped magnetic fields .1. Experiment SO CRYOGENICS LA English DT Article; Proceedings Paper CT ICEC16/ICMC CY MAY 20-24, 1996 CL KITAKYUSHU, JAPAN DE voltage spike; dB/dt; cable-in-conduit conductor AB A 27-strand hybrid superconducting cable-in-conduit conductor (CICC) was fabricated and tested under quickly-ramped high magnetic fields. When the field increased linearly on the CICC, the voltage signal showed several intermittent spikes before it quenched. This paper describes an observation of peculiar voltage spikes during these ramp-rate limitation experiments. The voltage spikes are interpreted as quench precursors and understood as current redistribution events within the local cable inside the conduit. A quantitative correlation is obtained for the magnetic field at which the first voltage spike occurs during ramping fields. The non-uniform current distribution among the strands and the induced loop current in the cable, which is generated by ramped fields, are found to be responsible for the voltage spikes. (C) 1997 Elsevier Science Ltd. 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 12 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JUN PY 1997 VL 37 IS 6 BP 299 EP 304 DI 10.1016/S0011-2275(97)00018-0 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA XG618 UT WOS:A1997XG61800004 ER PT J AU Sales, BC AF Sales, BC TI Novel thermoelectric materials SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID THERMAL-CONDUCTIVITY; FIGURE; MERIT; SUPERLATTICES; TRANSPORT; TEMPERATURE; LAFE4P12; COSB3; CRYSTALS AB Several new approaches to the design of improved thermoelectric materials have stimulated a resurgence of interest in this very old field. Within the past two years materials have been developed that validated one or more of these new ideas. Perhaps the most significant development is the concept and realization of materials that conduct electricity like a crystalline solid but heat like a glass. In these materials a weakly bound atom or molecule 'rattler' is used to lower the thermal conductivity of the solid without severely affecting electronic conduction, thus leading to improved thermoelectric efficiency. RP Sales, BC (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,NOVEL MAT GRP,BLDG 3150,MS 6056,OAK RIDGE,TN 37831, USA. NR 44 TC 20 Z9 20 U1 1 U2 22 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 JUN PY 1997 VL 2 IS 3 BP 284 EP 289 DI 10.1016/S1359-0286(97)80116-7 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XL161 UT WOS:A1997XL16100003 ER PT J AU Schmid, I Dean, PN AF Schmid, I Dean, PN TI Introduction to the biosafety guidelines for sorting of unfixed cells SO CYTOMETRY LA English DT Editorial Material DE flow cytometry; biohazard; occupational health; safety; cell sorting; aerosol containment AB Cell sorting of biologic specimens by flow cytometry has become a widely used technique in research and clinical laboratories. Because viable biologic specimens can contain infectious agents, precautions need to be taken to prevent the exposure of operators of flow cytometers to biohazards arising from the use of these instruments. The International Society of Analytical Cytology (ISAC) recognized the need for establishing guidelines for sorting of un fixed cells and initiated the formation of a Biohazard Working Group, which has produced a set of recommendations that can aid in preventing such exposures. The guidelines contain recommendations on 1) sample handling, 2) training and protection of operators, 3) laboratory design, 4) cell sorter setup and maintenance, and 5) testing the instrument for the efficiency of aerosol containment. (C) 1997 Wiley-Liss, Inc. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Schmid, I (reprint author), UNIV CALIF LOS ANGELES,DEPT HEMATOL & ONCOL,12-236 FACTOR BLDG,10833 LE CONTE AVE,LOS ANGELES,CA 90095, USA. FU NCI NIH HHS [CA-16042]; NIAID NIH HHS [AI-28697] NR 0 TC 5 Z9 5 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD JUN 1 PY 1997 VL 28 IS 2 BP 97 EP 98 DI 10.1002/(SICI)1097-0320(19970601)28:2<97::AID-CYTO1>3.0.CO;2-D PG 2 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XC495 UT WOS:A1997XC49500001 PM 9181298 ER PT J AU Schmid, I Nicholson, JKA Giorgi, JV Janossy, G Kunkl, A Lopez, PA Perfetto, S Seamer, LC Dean, PN AF Schmid, I Nicholson, JKA Giorgi, JV Janossy, G Kunkl, A Lopez, PA Perfetto, S Seamer, LC Dean, PN TI Biosafety guidelines for sorting of unfixed cells SO CYTOMETRY LA English DT Article DE flow cytometry; biohazard; occupational health; safety; cell sorting; aerosol containment ID HUMAN-IMMUNODEFICIENCY-VIRUS; INACTIVATION; SURVIVAL; AEROSOL; SPREAD AB The International Society of Analytical Cytology (ISAC) Biohazard Working Group presents guidelines for sorting of unfixed cells, including known biohazardous samples, using jet-in-air, deflected droplet cell sorters. There is a risk that personnel operating these instruments could become exposed to droplets and aerosols containing biological agents present in the samples. The following guidelines can aid in the prevention of exposures of laboratory personnel to pathogens contained in the sort samples. The document provides biosafety recommendations for sample handling, operator training and protection, laboratory facility design, and instrument setup and maintenance. In addition, it describes in detail methods for assessment of instrument aerosol containment. Recommendations provided here may also help laboratories to obtain institutional and/or regulatory agency approval for sorting of unfixed and known biohazardous samples. (C) 1997 Wiley-Liss, Inc. C1 CTR DIS CONTROL & PREVENT,ATLANTA,GA. ROYAL FREE HOSP MED,LONDON,ENGLAND. UNIV GENOA,SAN MARTINO HOSP,GENOA,ITALY. CYTOMAT INC,FT COLLINS,CO. WALTER REED ARMY INST RES,DEPT HIV DIS PREVENT,ROCKVILLE,MD. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Schmid, I (reprint author), UNIV CALIF LOS ANGELES,DEPT HEMATOL & ONCOL,12-236 FACTOR BLDG,10833 LE CONTE AVE,LOS ANGELES,CA 90095, USA. FU NCI NIH HHS [CA-16042]; NIAID NIH HHS [AI-28697] NR 27 TC 25 Z9 26 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD JUN 1 PY 1997 VL 28 IS 2 BP 99 EP 117 DI 10.1002/(SICI)1097-0320(19970601)28:2<99::AID-CYTO2>3.0.CO;2-B PG 19 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XC495 UT WOS:A1997XC49500002 PM 9181299 ER PT J AU Seamer, LC Bagwell, CB Barden, L Redelman, D Salzman, GC Wood, JCS Murphy, RF AF Seamer, LC Bagwell, CB Barden, L Redelman, D Salzman, GC Wood, JCS Murphy, RF TI Proposed new data file standard for flow cytometry, version FCS 3.0 SO CYTOMETRY LA English DT Article DE FCS 3.0; Data File Standard; flow cytometry AB In 1984, the first flow cytometry data file format was proposed as Flow Cytometry Standard 1.0 (FCS1.0). FCS 1.0 provided a uniform file format allowing data acquired on one computer to be correctly read and interpreted on other computers running a variety of operating systems. That standard was modified in 1990 and adopted by the Society of Analytical Cytology as FCS 2.0. Here, we report on an update of the FCS 2.0 standard which we propose to designate FCS 3.0. We have retained the basic four segment structure of earlier versions (HEADER, TEXT, DATA and ANALYSIS) in order to maintain analysis software compatibility, where possible. The changes described in this proposal include a method to collect fries larger than 100 megabytes (not possible in earlier versions of the standard), the Inclusion of international characters in the TEXT portions of the file, a method of verifying data integrity using a 16-bit cyclic redundancy check, and increased keyword ord support far cluster analysis and time acquisition. This report summarizes the work of the ISAC Data File Standards Committee. The complete and detailed FCS 3.0 standard is available through the ISAC office [Sherwood Group, 60 Revere Drive, Ste 500, Northbrook, IL 60062, phone: (847) 480-9080 ext. 231, fax: (847) 480-9282, E-mail: isac@sherwood-group.com] or through the internet at the ISAC WWW site, http://nucleus.immunol.washingtsn.edu/ISAC.html. (C) 1997 Wiley-Liss, Inc. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. VER SOFTWARE HOUSE,TOPSHAM,ME. NIH,BETHESDA,MD 20892. SIERRA CYTOMETRY,RENO,NV. COULTER CORP,HIALEAH,FL. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. RP Seamer, LC (reprint author), UNIV NEW MEXICO,CANC RES & TREATMENT CTR,915 CAMINO SALUD NE,ALBUQUERQUE,NM 87131, USA. NR 5 TC 44 Z9 46 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD JUN 1 PY 1997 VL 28 IS 2 BP 118 EP 122 DI 10.1002/(SICI)1097-0320(19970601)28:2<118::AID-CYTO3>3.0.CO;2-B PG 5 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XC495 UT WOS:A1997XC49500003 PM 9181300 ER PT J AU Friedman-Hill, EJ Whiteside, RA AF Friedman-Hill, EJ Whiteside, RA TI idldoc: Automatic documentation for CORBA IDL SO DR DOBBS JOURNAL LA English DT Article C1 Sandia Natl Labs, Tech Staff, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MILLER FREEMAN, INC PI SAN FRANCISCO PA 600 HARRISON ST,, SAN FRANCISCO, CA 94107 USA SN 1044-789X J9 DR DOBBS J JI Dr. Dobbs J. PD JUN PY 1997 VL 22 IS 6 BP 46 EP + PG 7 WC Computer Science, Software Engineering SC Computer Science GA V2812 UT WOS:000168725700019 ER PT J AU Ham, KD Adams, SM Peterson, MJ AF Ham, KD Adams, SM Peterson, MJ TI Application of multiple bioindicators to differentiate spatial and temporal variability from the effects of contaminant exposure on fish SO ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY LA English DT Article ID RESPONSES; STREAM; PCB AB Bioindicators of fish health were measured from 1989 through 1994 in populations of redbreast sunfish (Lepomis auritus) at three sites within a stream receiving inputs of mixed contaminants from an industrial facility, and at two reference sites, Bioindicator responses differed for fish from contaminated and reference sites throughout the study period, but temporal trends at contaminated sites reflected improved water quality associated with pollution-control efforts, Temporal variability unrelated to contaminant exposure strongly influenced the response of bioindicators at both reference and contaminated sites, but spatial variability rarely influenced these responses, Temporal variability was less influential on slower responding indicators at higher levels of biological organization. The diverse response characteristics of indicators increased the ability to differentiate natural from anthropogenic sources of variability, Integrated bioindicator responses were compared among site-year groups by multivariate canonical analysis, The primary canonical variable, associated with differences in growth, exhibited trends consistent with the timing of pollution-control efforts, Two indicators of contaminant exposure (7-ethoxyresorufin O-deethylase activity and polychlorinated biphenyls in fish muscle) also exhibited trends consistent with the timing of pollution-control efforts, but the likelihood of possible mechanistic linkages cannot be assessed with available data. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 42 TC 21 Z9 21 U1 0 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0147-6513 J9 ECOTOX ENVIRON SAFE JI Ecotox. Environ. Safe. PD JUN PY 1997 VL 37 IS 1 BP 53 EP 61 DI 10.1006/eesa.1997.1522 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA XG516 UT WOS:A1997XG51600008 PM 9212336 ER PT J AU Schipper, L Ting, M Khrushch, M Golove, W AF Schipper, L Ting, M Khrushch, M Golove, W TI The evolution of carbon dioxide emissions from energy use in industrialized countries: an end-use analysis SO ENERGY POLICY LA English DT Article DE CO2 emissions; energy use; climate policy ID DECOMPOSITION; CONSUMPTION AB Over the 1970s and 1980s, emissions of carbon dioxide from energy use fell in per capita, per unit GDP, and in some cases in absolute terms in 10 industrialized countries studied by LBNL, These declines were driven principally by falling end-use energy intensities and the decreasing carbon content of energy, By the early 1990s, however, a slowdown in the decline of intensities and the continued growth of GDP and energy services activity have reversed the trends in absolute emissions, LBNL concludes that CO, emissions will continue to rise in the future unless energy intensities and/or the carbon content of energy can be decreased at an accelerated rate via policy changes, technological innovation and/or behavioural adaptation. (C) 1997 Published by Elsevier Science Ltd. RP Schipper, L (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,ENERGY ANAL PROGRAM,MS 90-4000,BERKELEY,CA 94720, USA. NR 26 TC 54 Z9 55 U1 2 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN-JUL PY 1997 VL 25 IS 7-9 BP 651 EP 672 DI 10.1016/S0301-4215(97)00058-X PG 22 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YG748 UT WOS:A1997YG74800002 ER PT J AU Freeman, SL Niefer, MJ Roop, JM AF Freeman, SL Niefer, MJ Roop, JM TI Measuring industrial energy intensity: practical issues and problems SO ENERGY POLICY LA English DT Article DE energy intensity; industry; demand indicators AB Because of limitations on the availability and quality of data, energy analysts and policy makers are forced to use indicators of industrial energy intensity (energy input/industrial output) that are less than ideal, In this paper, we identify and discuss several issues and problems that arise in the construction of commonly-used industrial energy intensity indicators; in particular, we focus on issues that arise due to the use of alternative measures of output in intensity indicators, Several commonly-used indicators of industry-level energy intensity were constructed for several US manufacturing industries in order to illustrate these issues and problems, We find that trends in energy intensity based on value of output (eg value of production) can diverge quite sharply from trends in energy intensity based on volume of output (eg tons of output), Discrepancies between value-and volume-based indicators of energy intensity in large part appear to be due to the way in which industrial output statistics are constructed under the US Standard Industrial Classification system, Discrepancies may also be the result of measurement errors in price deflators and simple definitional differences between various value-based measures of output, We conclude that policy makers should carefully examine and understand the limitations of commonly-used energy intensity indicators before such indicators serve as a basis for policy decisions. (C) 1997 Published by Elsevier Science Ltd. RP Freeman, SL (reprint author), PACIFIC NW NATL LAB,901 D ST SW,STE 900,WASHINGTON,DC 20024, USA. NR 18 TC 52 Z9 52 U1 2 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN-JUL PY 1997 VL 25 IS 7-9 BP 703 EP 714 DI 10.1016/S0301-4215(97)00062-1 PG 12 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YG748 UT WOS:A1997YG74800006 ER PT J AU Worrell, E Price, L Martin, N Farla, J Schaeffer, R AF Worrell, E Price, L Martin, N Farla, J Schaeffer, R TI Energy intensity in the iron and steel industry: a comparison of physical and economic indicators SO ENERGY POLICY LA English DT Article DE industrial energy intensity; energy efficiency; iron and steel AB Energy consumption of the iron and steel industry is examined in seven countries (Brazil, China, France, Germany, Japan, Poland and the United States) for the period 1980-1991, Using a decomposition analysis based on physical indicators for process type and product mix, we decompose intra-sectoral structural changes and efficiency improvements, Specific energy consumption decreased in all countries except Poland, Efficiency improvement played a key role in Brazil, China, Germany and the US, while structural changes were the main driver for energy savings in France and Japan, We also compare the use of various economic indicators to physical indicators and find that they do not track physical developments well in Poland or the developing countries we studied, In the industrialized countries, value added based energy intensity indicators generally reflect the specific energy consumption better than other economic indicators, although large differences occur in individual years, We found a smaller correlation between other economic indicators (gross output and value of shipments) and specific energy consumption, We conclude that use of physical energy intensity indicators improves comparability between countries, provides greater information for policy-makers regarding intra-sectoral structural changes, and provides detailed explanations for observed changes in energy intensity. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,BERKELEY,CA 94720. FED UNIV RIO DE JANEIRO,BR-21945970 RIO JANEIRO,BRAZIL. RP Worrell, E (reprint author), UNIV UTRECHT,DEPT SCI TECHNOL & SOC,PADUALAAN 14,NL-3584 CH UTRECHT,NETHERLANDS. RI Worrell, Ernst/L-5455-2013; Farla, Jacco/L-6871-2013 OI Worrell, Ernst/0000-0002-0199-9755; Farla, Jacco/0000-0002-6629-8706 NR 47 TC 105 Z9 112 U1 4 U2 25 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN-JUL PY 1997 VL 25 IS 7-9 BP 727 EP 744 DI 10.1016/S0301-4215(97)00064-5 PG 18 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YG748 UT WOS:A1997YG74800008 ER PT J AU Farla, J Blok, K Schipper, L AF Farla, J Blok, K Schipper, L TI Energy efficiency developments in the pulp and paper industry - A cross-country comparison using physical production data SO ENERGY POLICY LA English DT Article DE cross-country comparison; energy efficiency; pulp and paper industry AB A method is presented for cross-country, cross-time comparison of energy efficiency developments in the manufacturing industry, The method is based on the use of physical production data as a measure of activity growth for the manufacturing industry, The methodology was applied to the pulp and paper industry of eight countries of the Organization for Economic Cooperation and Development (OECD), With the methodology it is possible to follow energy efficiency developments, separately, for fuel and electricity consumption. Between 1973 and 1991, the production growth in the pulp and paper industry in the analysed countries would have resulted in an average increase in the primary energy consumption by 42%, Changes in the product mix had hardly any effect on the primary energy consumption, Because of energy efficiency improvements, the growth of primary energy consumption was limited to only 16%, The average annual efficiency improvement amounted to 1.6%, The methodology presented enables physical energy efficiency comparisons to be made between countries without the need for data at the process level. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Farla, J (reprint author), UNIV UTRECHT,DEPT SCI TECHNOL & SOC,PADUALAAN 14,NL-3584 CH UTRECHT,NETHERLANDS. RI Farla, Jacco/L-6871-2013; Blok, Kornelis/D-9532-2014 OI Farla, Jacco/0000-0002-6629-8706; NR 23 TC 59 Z9 60 U1 3 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN-JUL PY 1997 VL 25 IS 7-9 BP 745 EP 758 DI 10.1016/S0301-4215(97)00065-7 PG 14 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YG748 UT WOS:A1997YG74800009 ER PT J AU Golove, WH Schipper, LJ AF Golove, WH Schipper, LJ TI Restraining carbon emissions: measuring energy use and efficiency in the USA SO ENERGY POLICY LA English DT Article DE carbon emissions; energy policy; factorial decomposition AB In this paper, we discuss the difficulties in measuring the effectiveness of policies intended to encourage compliance with international carbon restraint agreements, We establish the connection between energy consumption and carbon emissions, and demonstrate a method of disaggregating changes in each into changes in economic activity and structure, energy intensity and fuel mix factors, We utilize this method to analyze the historical trends in energy consumption and carbon emissions in the USA from 1960 to 1993, We analyze the contributions of the various factors to the restraint or encouragement of energy use and carbon emissions, We conclude that, in general, changes in the levels of economic activity have tended, all other factors being equal, to increase emissions, whereas declines in energy intensity and shifts in fuel mix have tended to restrain emissions, Changes in economic structure have had mixed effects, Finally, we discuss the problems with the available data which make the observation of the impact of energy and carbon policies difficult. (C) 1997 Published by Elsevier Science Ltd. RP Golove, WH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,MS 90-4000,BERKELEY,CA 94720, USA. NR 9 TC 26 Z9 28 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN-JUL PY 1997 VL 25 IS 7-9 BP 803 EP 812 DI 10.1016/S0301-4215(97)00070-0 PG 10 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YG748 UT WOS:A1997YG74800014 ER PT J AU Plotkin, SE AF Plotkin, SE TI Our automotive future SO ENVIRONMENT LA English DT Editorial Material RP Plotkin, SE (reprint author), ARGONNE NATL LAB,CTR TRANSPORTAT RES,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU HELDREF PUBLICATIONS PI WASHINGTON PA 1319 EIGHTEENTH ST NW, WASHINGTON, DC 20036-1802 SN 0013-9157 J9 ENVIRONMENT JI Environment PD JUN PY 1997 VL 39 IS 5 BP 3 EP 4 PG 2 WC Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology GA XC977 UT WOS:A1997XC97700002 ER PT J AU Lambert, SJ Balsley, SD AF Lambert, SJ Balsley, SD TI Stable-isotopes of groundwaters from the Albuquerque, New Mexico, basin: One decade later SO ENVIRONMENTAL GEOLOGY LA English DT Article DE groundwater; geochemistry; stable-isotopes; resources AB In the spring of 1995, 24 samples were collected from a widely distributed system of municipal water wells in Albuquerque, N.M., and analyzed for hydrogen (delta D) and oxygen (delta(18)O) isotopic compositions. delta D values for 15 of these samples are largely similar to those reported by Yapp in 1985, but have locally become more negative by as much as 5 per mil (parts per thousand). delta D - delta(18)O data define two endmembers that are well aligned along the familiar meteoric water line (MWL): (1) the eastern domain (mountain precipitation runoff), having delta D > - 86 parts per thousand (similar to the criteria of Yapp) and delta(18)O > - 12.1 parts per thousand (this work); and (2) a central basin domain, which may be in part derived from water seepage from the Rio Grande, having delta D < - 95 parts per thousand and delta(18)O < - 13.2 parts per thousand. Only a few wells across the basin have delta D values near the ''baseline'' value of the Rio Grande, defined by Yapp as - 92 parts per thousand. The proximity of these wells to the Rio Grande is consistent with recharge by seepage from the river bed under baseline conditions. Extensive pumping in the eastern domain and West Mesa areas may be partly responsible for an apparent expansion of the central-basin regime of water more depleted in delta D, much as a plume migrating in response to transient perturbations in original hydraulic gradients. Vertically stacked groundwater occurrences having limited interconnection are inferred from the significant differences in isotopic compositions of samples from two wells screened at multiple depths. The central and western parts of the basin are little influenced by contributions from the eastern domain. Some groundwaters from the western part of the basin plot below the MWL and clearly cannot be mixtures solely of the eastern domain and central basin endmembers. The origins of these western groundwaters and the most depleted central basin groundwaters are as yet unknown, but we speculate they may have received recharge under climatic conditions different from the present. C1 SANDIA NATL LABS,DEPT GEOCHEM,ALBUQUERQUE,NM 87185. NR 12 TC 0 Z9 0 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD JUN PY 1997 VL 31 IS 3-4 BP 199 EP 204 PG 6 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA XF980 UT WOS:A1997XF98000009 ER PT J AU Ames, BN Gold, LS AF Ames, BN Gold, LS TI The causes and prevention of cancer: Gaining perspective SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Symposium on Mechanisms and Prevention of Environmentally Caused Cancers CY 1995 CL SANTA FE, NM SP Lovelace Inst, US DOE, Bioserv Biotechnol, Johnson & Johnson Inc, Int Life Sci Inst, Dako Corp, VWR, SW Sci Res Inc DE causes of cancer; environmental carcinogens; diet and cancer ID LOW-INCOME HOUSEHOLDS; HEPATITIS-C VIRUS; REPUBLIC-OF-CHINA; COLON-CANCER; UNITED-STATES; BREAST-CANCER; LUNG-CANCER; HEPATOCELLULAR PROLIFERATION; COLORECTAL ADENOMA; RESIDENTIAL RADON AB Epidemiological studies have identified several factors that are likely to have a major effect on reducing rates of cancer: reduction of smoking, increased consumption of fruits and vegetables, and control of infections. Other factors include avoidance of intense sun exposure, increased physical activity, and reduced consumption of alcohol and possibly red meat. Risks of many types of cancer can already be reduced, and the potential for further reductions is great. In the United States, cancer death rates for-all cancers combined are decreasing, if lung cancer (90% of which is due to smoking), is excluded from the analysis. We review the research on causes of cancer and show why much cancer is preventable. The idea that traces of synthetic chemicals, such as DDT, are major contributors to human cancer is not supported by the evidence, yet public concern and resource allocation for reduction of chemical pollution are very high, in part because standard risk assessment uses linear extrapolation from limited data in high-dose animal cancer tests. These tests are done at the maximum tolerated dose (MTD) and are typically misinterpreted to mean that low doses of synthetic chemicals and industrial pollutants are relevant to human cancer. About half the chemicals tested, whether synthetic or natural, are carcinogenic to rodents at such high doses. Almost ail chemicals in the human diet are natural. For example, 99.99% of the pesticides we eat are naturally present in plants to ward off insects and other predators. Half of the natural pesticides that have been tested at the MTD are rodent carcinogens. Cooking food produces large numbers of natural dietary chemicals. Roasted coffee, for example, contains more than 1000 chemicals: of 27 tested, 19 are rodent carcinogens. Increasing evidence supports the idea that the high frequency of positive results in rodent bioassays is due to testing at the MTD, which frequently can cause chronic cell killing and consequent cell replacement-a risk factor for cancer that can be limited to high doses. Because default risk assessments use linear extrapolation. which ignores effects of the high dose itself, low-dose risks are often exaggerated. - Environ Health Perspect 105(Suppl 4):865-873 (1997). C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. RP Ames, BN (reprint author), UNIV CALIF BERKELEY, DIV BIOCHEM & MOL BIOL, 401 BARKER HALL, BERKELEY, CA 94720 USA. FU NCI NIH HHS [CA39910]; NIEHS NIH HHS [ESO1898] NR 137 TC 49 Z9 54 U1 5 U2 11 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD JUN PY 1997 VL 105 SU 4 BP 865 EP 873 DI 10.2307/3433296 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA XN297 UT WOS:A1997XN29700022 PM 9255573 ER PT J AU Salt, DE Pickering, IJ Prince, RC Gleba, D Dushenkov, S Smith, RD Raskin, I AF Salt, DE Pickering, IJ Prince, RC Gleba, D Dushenkov, S Smith, RD Raskin, I TI Metal accumulation by aquacultured seedlings of Indian mustard SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ABSORPTION FINE-STRUCTURE; MAIZE SEEDLINGS; HEAVY-METALS; CADMIUM; PHYTOCHELATINS; ROOTS; PEPTIDES; GLUTATHIONE; PROGRAM; PLANTS AB Indian mustard (Brassica juncea (L.) Czern) seedlings grown in aerated water (aquacultured) were able to accumulate various metals from artificially contaminated water over a range of environmentally relevant metal concentrations. Seedlings concentrated the divalent cations Pb(ll), Sr(ll), Cd(ll), and Ni(ll) 500-2000 times and concentrated the monovalent Cs(I) and hexavalent Cr(IV) 100-250 times from artificially contaminated water containing the competing ions Ca, Mg, K, SO4, and NO3. Seedlings also removed Cd from artificially contaminated water over a broad Cd concentration range. At the lowest Cd concentration studied, Cd levels were reduced to below 10 ppb (mu g/L). In the absence of competing ions, Cd accumulation in seedlings increased 47-fold. This suggests that a better understanding of the biological processes governing uptake and accumulation of Cd by seedlings should allow the application of modern genetic engineering techniques to improve their selectivity and capacity for Cd removal from waters containing high levels of competing ions. As a first step in this process, we have started to define the tissue and cellular localization of Cd, its accumulation rates and possible uptake mechanisms, and the role of intracellular chelates in Cd detoxification. Intracellular Cd accumulation in seedlings was mediated by saturable transport system(s) and was inhibited competitively in shoots and noncompetitively in roots by Ca2+, Zn2+, and Mn2+. Phytochelatins, the Cd-binding peptides known to be involved in Cd resistance in mature plants, also accumulated in B. juncea seedlings exposed to Cd. Using X-ray absorption spectroscopy, we determined that over time the percentage of Cd bound to phytochelatins in vivo increased from 34% after 6 h of Cd exposure to 60% after 72 h. The remaining intracellular Cd appeared to be octahedrally coordinated by oxygen atoms possibly from organic acids. Our results suggest that the use of aquacultured seedlings of B. juncea could provide a novel approach to the treatment of various metal-contaminated waste streams such as landfill, mining and various industrial runoffs, and leachates. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. EXXON RES & ENGN CO,ANNANDALE,NJ 08801. PHYTOTECH INC,MONMOUTH JCT,NJ 08852. RP Salt, DE (reprint author), RUTGERS STATE UNIV,COOK COLL,CTR AGR & MOL BIOL,NEW BRUNSWICK,NJ 08903, USA. RI Salt, David/B-3864-2009; Pickering, Ingrid/A-4547-2013; OI Dushenkov, Vyacheslav/0000-0001-5176-7461; Pickering, Ingrid/0000-0002-0936-2994 NR 39 TC 136 Z9 157 U1 3 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1997 VL 31 IS 6 BP 1636 EP 1644 DI 10.1021/es960802n PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XB620 UT WOS:A1997XB62000027 ER PT J AU Robinson, AL Sextro, RG AF Robinson, AL Sextro, RG TI Radon entry into buildings driven by atmospheric pressure fluctuations SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOIL-GAS ENTRY; EXPERIMENTAL BASEMENT; AIR-FLOW; TRANSPORT AB To examine the effects of atmospheric pressure fluctuations on radon entry into houses, we report measurements of soil-gas and advective radon entry made using an experimental basement. Based on these measurements, we quantify the contribution of atmospheric pressure fluctuations, steady indoor-outdoor pressure differences, and molecular diffusion to the long-term radon entry rate into the experimental basement. In the absence of a steady indoor-outdoor pressure difference, atmospheric pressure fluctuations at the study site induce a radon entry rate 1.5 times greater than that due to molecular diffusion. A steady indoor-outdoor pressure difference reduces the contribution of atmospheric pressure fluctuations to the longterm radon entry rate. For sustained indoor-outdoor pressure differences with a magnitude greater than 1.5 Pa, atmospheric pressure fluctuations have essentially no effect on the time-averaged radon entry rate into the experimental structure. The results of this study demonstrate that under certain conditions, such as periods during which indoor-outdoor pressure differences are small, atmospheric pressure fluctuations will contribute measurably to the total radon entry rate into a building, potentially doubling indoor concentrations. However, in absolute terms, atmospheric pressure fluctuations drive approximately the same amount of entry as molecular diffusion and,therefore, will probably not cause houses to have long-term, elevated indoor radon concentrations. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV ENERGY & ENVIRONM, BERKELEY, CA 94720 USA. RI Robinson, Allen/I-5713-2012; Robinson, Allen/M-3046-2014 OI Robinson, Allen/0000-0003-1053-7090; Robinson, Allen/0000-0002-1819-083X NR 25 TC 24 Z9 24 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1997 VL 31 IS 6 BP 1742 EP 1748 DI 10.1021/es960715v PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XB620 UT WOS:A1997XB62000042 ER PT J AU Beasley, TM Cooper, LW Grebmeier, JM Kilius, LR Synal, HA AF Beasley, TM Cooper, LW Grebmeier, JM Kilius, LR Synal, HA TI Cl-36 and I-129 in the Yenisei, Kolyma, and Mackenzie rivers SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; SEDIMENTS; IODINE C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TORONTO,ISOTRACE LAB,TORONTO,ON M5S 1A7,CANADA. ETH HONGGERBERG,INST INTERMEDIATE PHYS,CH-8093 ZURICH,SWITZERLAND. RP Beasley, TM (reprint author), US DOE,201 VARICK ST,NEW YORK,NY 10014, USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013 OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568 NR 23 TC 20 Z9 20 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1997 VL 31 IS 6 BP 1834 EP 1836 DI 10.1021/es9609361 PG 3 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XB620 UT WOS:A1997XB62000056 ER PT J AU Widrig, DL Boopathy, R Manning, JF AF Widrig, DL Boopathy, R Manning, JF TI Bioremediation of TNT-contaminated soil: A laboratory study SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE bioremediation; land farming; molasses; TNT; radiolabeling ID NITROAROMATIC COMPOUNDS; AEROBIC CONDITIONS; 2,4,6-TRINITROTOLUENE; EXPLOSIVES AB This research presented a bench-scale investigation of an innovative approach to land farming for the bioremediation of 2,4,6-trinitrotoluene (TNT)-contaminated soils. Molasses, which contains sugar, nitrogen, vitamins, and minerals, was used as cosubstrate and this process combines several advantages of conventional land farming with the use of molasses for the biological degradation of TNT and its derivatives. In the optimum treatment, contaminated soil was amended with shredded grass and managed in an operating cycle where it was alternatively flooded with a dilute molasses solution, then drained, passively aerated, and finally tilled when moisture conditions were optimum. Soil TNT concentrations in all treatments receiving molasses were reduced from approximately 4,000-mg/kg levels initially to less than 100 mg/kg in 12 months, and to less than 1 mg/kg in the optimum treatment in this same time. Concentrations of the primary metabolic intermediates and bacterial populations were also tracked. Radiolabeling studies confirmed that the biomass enhanced by the treatments could mineralize approximately 20% of [C-14] from a contaminant spike after 22 d. A shredded grass amendment in the optimum treatment was shown to increase moisture retention during aeration phases. The results of this bench-scale study are promising with regard to transferring the process to full-scale applications. C1 ARGONNE NATL LAB, DIV ENVIRONM RES, ARGONNE, IL 60439 USA. NR 20 TC 39 Z9 40 U1 0 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUN PY 1997 VL 16 IS 6 BP 1141 EP 1148 DI 10.1897/1551-5028(1997)016<1141:BOTCSA>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA XC442 UT WOS:A1997XC44200008 ER PT J AU Lin, WY Lin, CP Yeh, SJ Hsieh, BT Tsai, ZT Ting, G Yen, ZC Wang, SJ Knapp, FF Stabin, MF AF Lin, WY Lin, CP Yeh, SJ Hsieh, BT Tsai, ZT Ting, G Yen, ZC Wang, SJ Knapp, FF Stabin, MF TI Rhenium-188 hydroxyethylidene diphosphonate: A new generator-produced radiotherapeutic drug of potential value for the treatment of bone metastases SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE rhenium-188; hydroxyethylidene diphosphonate; systemic radiotherapy; bone metastases; biodistribution ID PAINFUL OSSEOUS METASTASES; DOUBLE-BLIND CROSSOVER; SKELETAL METASTASES; RADIATION-THERAPY; PROSTATE-CANCER; SR-89; PALLIATION; EFFICACY; RE-186 AB The search for an ideal radioisotope for systemic radiotherapy continues. As a generator-produced radioisotope emitting both beta and gamma rays and having a short physical half-life of 16.9 h, rhenium-188 is a very good potential candidate for systemic radiotherapy. In this study, we labeled hydroxyethylidene diphosphonate (HEDP) with Re-188 and analyzed the biodistribution and bone uptake following intravenous injection in rats to assess its potential for clinical use, The rats were injected with approximately 14.8 MBq (0.4 mCi) Re-188-HEDP in a volume of 0.1 ml intravenously and then sacrificed at 1 h, 24 h, or 48 h (four rats at each time). Samples (about 0.1 g) of lung, liver, kidney, spleen, testis, muscle, stool, and bone (thoracic vertebra) were taken and weighed carefully. In addition, a 1-ml sample of blood was drawn from the heart and 1 mi of urine was taken from the urinary bladder immediately after killing. Tissue concentrations were calculated and expressed as percent injected dose per gram or per milliliter (% ID/g or ml). Bone lesions were created in the right tibial bone in three rabbits to calculate the lesion to normal uptake ratio (L/N ratio). The biodistribution data showed that the radioactivity in the bone tissue was as high as 1.877% ID/g at 1 h and that it climbed to 2.017% ID/g at 4 h. The activity level in the kidney was highest at 1 h but declined rapidly throughout the study. The radioactivities in the lung, liver, muscle, spleen, testis, blood, and stool were all lower than 0.3% ID/g at 1 h and also declined rapidly. The biological half-life in bone was the longest (60.86 h). In contrast, the biological half-lives in muscle and blood were short (2.99 h and 6.21 h respectively). The concentrations of radioactivity in muscle, spleen, testis, and stool were quite low throughout the study, Most of the radiotracer was excreted by the urinary system, The L/N ratio was 4.23 +/- 0.21 in rabbits injected with Re-188-HEDP and 4.25 +/- 0.23 in those injected with technetium-99m methylene diphosphonate. In conclusion, we would suggest that Re-188-HEDP is a very good potential candidate for the treatment of bone metastases because of the following characteristics: (1) it is generator produced: (2) it has a short half-life; (3) it emits gamma rays suitable for imaging; (4) there is highly selective uptake in the skeletal system and bone lesions; and (5) it has a low non-target uptake and rapid clearance in nonosseous tissue. C1 TAICHUNG VET GEN HOSP,DEPT NUCL MED,TAICHUNG 407,TAIWAN. NATL TSING HUA UNIV,INST NUCL SCI,HSINCHU,TAIWAN. NATL YANG MING UNIV,TAIPEI 112,TAIWAN. INST NUCL ENERGY RES,LUNGTAN 32500,TAIWAN. OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. OAK RIDGE INST SCI & EDUC,RADIAT INTERNAL DOSE INFORMAT CTR,OAK RIDGE,TN. NR 29 TC 58 Z9 73 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD JUN PY 1997 VL 24 IS 6 BP 590 EP 595 DI 10.1007/BF00841394 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA XG494 UT WOS:A1997XG49400002 PM 9169563 ER PT J AU Dobson, FS Chesser, RK Hoogland, JL Sugg, DW Foltz, DW AF Dobson, FS Chesser, RK Hoogland, JL Sugg, DW Foltz, DW TI Do black-tailed prairie dogs minimize inbreeding? SO EVOLUTION LA English DT Article DE Cynomys; F-statistics; gene diversity; gene dynamics; inbreeding; social behavior ID GENE FLOW; SUBDIVIDED POPULATIONS; CYNOMYS-LUDOVICIANUS; F-STATISTICS; NATURAL-POPULATIONS; GROUND-SQUIRREL; POCKET GOPHERS; MATING SYSTEM; DISPERSAL; DIVERSITY AB Considerable controversy surrounds the importance of inbreeding in natural populations. The rate of natural inbreeding and the influences of behavioral mechanisms that serve to promote or minimize inbreeding (e.g., philopatry vs. dispersal) are poorly understood. We studied inbreeding and social structuring of a population of black-railed prairie dogs (Cynomys ludovicianus) to assess the influence of dispersal and mating behavior on patterns of genetic variation. We examined 15 years of data on prairie dogs, including survival and reproduction, social behavior, pedigrees, and allozyme alleles. Pedigrees revealed mean inbreeding coefficients (F) of 1-2%. A breeding-group model that incorporated details of prairie dog behavior and demography was used to estimate values of fixation indices (Estimates). Model predictions were consistent with the minimization of inbreeding within breeding groups (''coteries,'' asymptotic F-IL = -0.18) and random mating within the subpopulation (''colony,'' asymptotic F-IS = 0.00). Estimates from pedigrees (mean F-IL = -0.23, mean F-is = 0.00) and allozyme data (mean F-lL = -0.21, mean F-IS = -0.01) were consistent with predictions of the model. The breeding-group model, pedigrees, and allozyme data showed remarkably congruent results, and indicated strong genetic structuring within the colony (F-LS = 0.16, 0.19 and 0.17, respectively). We concluded that although inbreeding occurred in the colony, the rate of inbreeding was strongly minimized at the level of breeding groups, but not at the subpopulation level. The behavioral mechanisms most important to the minimization of inbreeding appeared to be patterns of male-biased dispersal of both subadults and adults, associated with strong philopatry of females. Incest avoidance also occurred, associated with recognition of close kin via direct social learning within the breeding groups. C1 AUBURN UNIV,ALABAMA AGR EXPT STN,AUBURN,AL 36849. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. UNIV GEORGIA,DEPT GENET,ATHENS,GA 30602. UNIV MARYLAND,APPALACHIAN ENVIRONM LAB,FROSTBURG,MD 21532. SUNY COLL GENESEO,DEPT BIOL,GENESEO,NY 14454. LOUISIANA STATE UNIV,DEPT ZOOL & PHYSIOL,BATON ROUGE,LA 70803. RP Dobson, FS (reprint author), AUBURN UNIV,DEPT ZOOL & WILDLIFE SCI,AUBURN,AL 36849, USA. RI Hoogland, John/B-3950-2015 NR 58 TC 69 Z9 69 U1 0 U2 25 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 SN 0014-3820 J9 EVOLUTION JI Evolution PD JUN PY 1997 VL 51 IS 3 BP 970 EP 978 DI 10.2307/2411170 PG 9 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA XM065 UT WOS:A1997XM06500028 ER PT J AU Chandler, DP Li, SM Spadoni, CM Drake, GR Balkwill, DL Fredrickson, JK Brockman, FJ AF Chandler, DP Li, SM Spadoni, CM Drake, GR Balkwill, DL Fredrickson, JK Brockman, FJ TI A molecular comparison of culturable aerobic heterotrophic bacteria and 16S rDNA clones derived from a deep subsurface sediment SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE bacteria; 16S rRNA; PCR; subsurface; sediment ID RIBOSOMAL-RNA GENES; COMMUNITY STRUCTURE; PCR AMPLIFICATION; DIVERSITY; ENVIRONMENT; SEQUENCES; ENUMERATION; ALLELES; PROBES; SOIL AB Culture-based techniques have traditionally been the primary tools utilized for studying the microbiology of terrestrial subsurface environments. Recently, nucleic acid-based methods have been employed to further characterize the microbial diversity in subsurface sediments and rocks, but the results have not been related to individual bacteria cultivated from the same environment. Restriction fragment length profiles of 16S rRNA genes derived from bulk community DNA or bacterial isolates were compared to determine the efficacy of PCR-based methods for studying microbial diversity and phylogeny in a deep (188 m) subsurface environment. The phylogenetic relatedness between 16S rRNA genes of enrichment cultures and individual clones was also determined through DNA sequence analysis of 16S rRNA genes. Restriction fragment length profiles from PCR clone libraries accounted for 64% of recovered isolates and 55% of the estimated culturable diversity based upon their 16S rDNA RFLP signatures. DNA sequence comparisons between the 16S rDNA of the most commonly occurring isolates and clones confirmed that similar DNA. sequences were contained within the RFLP groups used to categorize the isolates and clones. For 7 of 8 RFLP groups for which DNA sequences were obtained, nearest neighbor assignments corresponded at the genus level but suggested that 16S rDNA sequences from multiple genera were contained within single RFLP profiles. Phylogenetic analysis of 16S rRNA sequences supported the nearest neighbor inferences and indicated that 16S rDNA clones derived from bulk sediment were specifically related to isolates recovered on enrichment plates. This study has shown that a majority of the cultivated aerobic heterotrophic bacteria in a subsurface sediment could be described by 16S rDNA clones obtained from directly extracted DNA, but that PCR-based methods cannot account for all organisms from a given sample. Consequently, a more comprehensive assessment of microbial diversity in subsurface (and probably other) environments can be obtained by using a combination of culture- and molecular-based techniques than by using either method alone. C1 FLORIDA STATE UNIV, DEPT BIOL SCI, TALLAHASSEE, FL 32306 USA. RP Chandler, DP (reprint author), PACIFIC NW LAB, ENVIRONM MICROBIOL, 900 BATTELLE BLVD,MAIL STOP K4-06, RICHLAND, WA 99352 USA. NR 38 TC 55 Z9 55 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD JUN PY 1997 VL 23 IS 2 BP 131 EP 144 DI 10.1111/j.1574-6941.1997.tb00397.x PG 14 WC Microbiology SC Microbiology GA XL011 UT WOS:A1997XL01100005 ER PT J AU Hu, Y Zhou, H Liu, HL Wu, DT Prausnitz, JM AF Hu, Y Zhou, H Liu, HL Wu, DT Prausnitz, JM TI Estimation of vapor-liquid equilibria for polymer solutions by a group-contribution method SO FLUID PHASE EQUILIBRIA LA English DT Article DE vapor-liquid equilibria; polymer solutions; hydrogen-bonded systems ID CONTRIBUTION FLORY EQUATION; SOLVENT ACTIVITIES; PHASE-EQUILIBRIA; PREDICTION; DEPENDENCE; MIXTURES; SYSTEMS; STATE AB A new group-contribution method is presented for prediction of vapor-liquid equilibria of polymer solutions. It is based on a close-packed lattice model developed previously; this model contains a revised Flory-Huggins entropy and a series expression for excess internal energy, as well as a double-lattice model to account for specific, oriented interactions. The group-contribution method includes three contributions: the combinatorial and free-volume contribution which is primarily responsible for entropy, the van der Waals energy contribution responsible for dispersion and polar forces, and the specific energy contribution from hydrogen bonding. Most of the model parameters can be estimated using pure-component properties, either from experimental data or from group-contribution methods in the literature. The group-contribution method described in this work gives parameters for the cross specific interaction energy from hydrogen bonding between segments of polymers and segments of solvents. Parameters for pairs of groups are obtained by correlating experimental data for vapor pressures and infinite-dilution activity coefficients of solvents in polymer solutions. The method shown here gives improved results for prediction when compared with those of other group-contribution models. (C) 1997 Elsevier Science B.V. C1 DUPONT CO INC,MARSHALL LAB,PHILADELPHIA,PA 19146. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Hu, Y (reprint author), E CHINA UNIV SCI & TECHNOL,THERMODYNAM RES LAB,SHANGHAI 200237,PEOPLES R CHINA. NR 21 TC 16 Z9 16 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD JUN PY 1997 VL 134 IS 1-2 BP 43 EP 54 DI 10.1016/S0378-3812(97)00041-1 PG 12 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA XJ578 UT WOS:A1997XJ57800003 ER PT J AU Laudal, D Nott, B Brown, T Roberson, R AF Laudal, D Nott, B Brown, T Roberson, R TI Mercury speciation methods for utility flue gas SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deut Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS AB Accurate measurement of mercury speciation (Hg-0 and Hg2+) in power plant flue gas is necessary to model the fate and transport of mercury in the atmosphere and understand and evaluate the effectiveness of mercury control technologies. Research work jointly sponsored by the Electric Power Research Institute (EPRT) and the U.S. Department of Energy (DOE) is currently under way at the University of North Dakota Energy & Environmental Research Center to determine whether U.S. Environmental Protection Agency (EPA) Method 29 or other methods can speciate mercury. Five different methods have been tested, and it has been found that EPA Method 29 does not speciate mercury properly in coal-generated flue gas. Two methods that show promise are the tris-buffer and the Ontario Hydro methods. C1 ELECT POWER RES INST,PALO ALTO,CA 94303. US DOE,FED ENERGY TECHNOL CTR,PITTSBURGH,PA 15236. RMB CONSULTING & RES INC,RALEIGH,NC 27612. RP Laudal, D (reprint author), UNIV N DAKOTA,ENERGY & ENVIRONM RES CTR,POB 9018,GRAND FORKS,ND 58202, USA. NR 5 TC 23 Z9 28 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD JUN PY 1997 VL 358 IS 3 BP 397 EP 400 DI 10.1007/s002160050436 PG 4 WC Chemistry, Analytical SC Chemistry GA XF901 UT WOS:A1997XF90100007 ER PT J AU Smith, DH Haddad, GJ Grimm, U AF Smith, DH Haddad, GJ Grimm, U TI Composition and chemistry of particulates from a PFBC demonstration plant SO FUEL LA English DT Article DE pressurized fluidized bed combustors; particulates; composition AB Particulates from the combustor bed drain, cyclone drain and filter cakes of the Tidd 70 MWe pressurized fluidized bed combustion plant were analysed for particle size distribution and for compounds derived from the dolomitic sulfur sorbent injected into the bed. As expected, the bed material consisted chiefly of coal ash, orthorhombic CaSO4 and MgO. The elutriated particles captured by the cyclone and filters also contained ash and CaSO4, but X-ray diffraction patterns revealed that the Mg in the filter cakes was present as a compound known in the literature as Mg3Ca(SO4)(4). Analyses showed that the compound in question was formed in the filter cakes, yielded its production rate, and showed that it was the product of the (unintended) reduction of SO2 emissions by the filter vessel. However, it was also shown that the correct stoichiometry of this important compound is Mg2Ca(SO4)(3), not Mg3Ca(SO4)(4). C1 US DOE,FED ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. NR 9 TC 18 Z9 18 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD JUN PY 1997 VL 76 IS 8 BP 727 EP 732 DI 10.1016/S0016-2361(97)00026-4 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XF389 UT WOS:A1997XF38900007 ER PT J AU Balding, DJ Torney, DC AF Balding, DJ Torney, DC TI The design of pooling experiments for screening a clone map SO FUNGAL GENETICS AND BIOLOGY LA English DT Article DE experimental design; group testing; clone library screening; clone map ID ARTIFICIAL-CHROMOSOME LIBRARIES AB We consider nonadaptive pooling designs for unique-sequence screening of a 1530-clone map of Aspergillus nidulans. The map has the properties that the clones are, with possibly a few exceptions, ordered and no more than 2 of them cover any point on the genome. We propose two subdesigns of the Steiner system S(3, 5, 65), one with 65 pools and approximately 118 clones per pool, the other with 54 pools and about 142 clones per pool. Each design allows 1 or 2 positive clones to be detected, even in the presence of substantial experimental error rates. Move efficient designs are possible if the overlap information in the map is exploited, if there is no constraint on the number of clones in a pool, and if no error tolerance is required. An information theory lower bound requires at least 12 pools to satisfy these minimal criteria, and an ''interleaved binary'' design can be constructed on 20 pools, with about 380 clones per pool. However, the designs with more pools have important properties of robustness to various possible errors and general applicability to a wider class of pooling experiments. (C) 1997 Academic Press. C1 UNIV READING,DEPT APPL STAT,READING RG6 6FN,BERKS,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RI Balding, David/G-9898-2011 OI Balding, David/0000-0002-1480-6115 NR 9 TC 12 Z9 15 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1087-1845 J9 FUNGAL GENET BIOL JI Fungal Genet. Biol. PD JUN PY 1997 VL 21 IS 3 BP 302 EP 307 DI 10.1006/fgbi.1997.0985 PG 6 WC Genetics & Heredity; Mycology SC Genetics & Heredity; Mycology GA XU727 UT WOS:A1997XU72700007 PM 9290242 ER PT J AU Xia, K Bleam, W Helmke, PA AF Xia, K Bleam, W Helmke, PA TI Studies of the nature of Cu2+ and Pb2+ binding sites in soil humic substances using X-ray absorption spectroscopy SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ELECTRON-SPIN-RESONANCE; NEAR-EDGE STRUCTURE; FULVIC-ACID; MULTIPLE-SCATTERING; AQUEOUS-SOLUTION; FINE-STRUCTURE; BOND LENGTHS; COPPER(II) COMPLEXATION; STABILITY-CONSTANTS; XANES SPECTROSCOPY AB We have investigated the binding environments of Cu2+ and Pb2+ complexed by soil humic substances using synchrotron-based X-ray absorption spectroscopy. With the assistance of bond network analysis, analysis of X-ray absorption near edge structure (XANES) and radial structure functions derived from extended X-ray absorption fine structure (EXAFS) spectra of Cu-humate at pH 4, 5, and 6 yielded a tetragonally-distorted octahedral binding environment for Cu with 4 O atoms at an average distance of 1.94 (A) over circle, 2 O atoms at an average distance of 2.02 (A) over circle, and 4 C atoms at an average distance of 3.13 (A) over circle. Analysis of Pb-humate samples at pH 4, 5, and 6 yielded 4 O atoms at average distances between 2.46 (A) over circle to 2.32 (A) over circle and 2 C atoms at an average distance of 3.26 (A) over circle for Pb. We interpret the presence of C atoms in the second atomic shell of the metal binding site as evidence that both Cu(2+)and Pb2+ form innersphere complexes with soil humic substances. Within the pH range 4-6,there is no significant change in the structure of the binding sites for either Cu or Pb. Copyright (C) 1997 Elsevier Science Ltd C1 BROOKHAVEN NATL LAB, NATL SYNCHROTRON LIGHT SOURCE DEPT, UPTON, NY 11973 USA. RP Xia, K (reprint author), UNIV WISCONSIN, DEPT SOIL SCI, MADISON, WI 53706 USA. NR 65 TC 117 Z9 123 U1 2 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1997 VL 61 IS 11 BP 2211 EP 2221 DI 10.1016/S0016-7037(97)00079-3 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XE654 UT WOS:A1997XE65400005 ER PT J AU Xia, K Bleam, W Helmke, PA AF Xia, K Bleam, W Helmke, PA TI Studies of the nature of binding sites of first row transition elements bound to aquatic and soil humic substances using X-ray absorption spectroscopy SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ION-SELECTIVE ELECTRODE; NEAR-EDGE STRUCTURE; FULVIC-ACID; MULTIPLE-SCATTERING; STABILITY-CONSTANTS; FINE-STRUCTURE; COPPER(II) COMPLEXATION; COMPLEXING CAPACITY; XANES SPECTROSCOPY; AQUEOUS-SOLUTION AB The coordination environments of first row transition elements (Co, Ni, Cu, and Zn) complexed by aquatic and soil humic substances were studied using X-ray absorption spectroscopy (XAS). With the assistance of bond network analysis, analysis of X-ray absorption near edge structure (XANES) spectra and radial structure functions (RSF) derived from extended X-ray absorption fine structure (EXAFS) spectra of Co, Ni, Cu, and Zn in humic substances indicate an octahedral binding environment for Co, Ni, and Zn and a tetragonally-distorted octahedral binding environment for Cu. Analysis of EXAFS spectra of each element provides detailed information on the internuclear distances, bond angles, and Debye-Waller factors within the first two atomic shells surrounding Co, Ni, Cu, and Zn bound to humic substances. We interpret the presence of C atoms in the second atomic shell of the metal binding site as further evidence that Co, Ni, Cu, and Zn form innersphere complexes with humic substances. The number and type of ligands involved in the binding are different for different elements. Copyright (C) 1997 Elsevier Science Ltd C1 BROOKHAVEN NATL LAB, NATL SYNCHROTRON LIGHT SOURCE DEPT, UPTON, NY 11973 USA. RP Xia, K (reprint author), UNIV WISCONSIN, DEPT SOIL SCI, MADISON, WI 53706 USA. NR 71 TC 81 Z9 82 U1 0 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JUN PY 1997 VL 61 IS 11 BP 2223 EP 2235 DI 10.1016/S0016-7037(97)00080-X PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XE654 UT WOS:A1997XE65400006 ER PT J AU Papike, JJ Fowler, GW Shearer, CK AF Papike, JJ Fowler, GW Shearer, CK TI Evolution of the lunar crust: SIMS study of plagioclase from ferroan anorthosites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID FRACTIONAL CRYSTALLIZATION; PARTITION-COEFFICIENTS; ORTHO-PYROXENE; MOON; ELEMENTS; MODEL; SUITE AB The lunar crust, down to a depth of similar to 65 km, is composed of older (>4.5 Ga) ferroan anorthosites and younger (4.43-4.17 Ga) Mg-suite lithologies which include dunites, troctolites, and norites. The anorthosites are generally inferred to represent floating cumulates in a lunar magma ocean (possible depth 800 km, moon's radius similar to 1,738 km). The cumulates that are inferred to be located near the base of the magma ocean are dominantly olivine and pyroxene. The last dregs of the magma ocean are enriched in incompatible elements and have been named KREEP (K, rare earth elements, P). KREEP, formed in this manner, is probably concentrated near the crust/mantle boundary at similar to 70 km depth. We are attempting to characterize melts parental to ferroan anorthosites and Mg-suite norites by analyzing REEs (La, Ce, Nd, Sm, Eu, Dy, Er, Yb) and Ba, Sr, and Y in their cumulus plagioclase. If the cumulus grains have not been compromised by postcrystallization effects and if we know the relevant mineral/melt partition coefficients (Ds) we can invert the trace element data for plagioclase to parental melt compositions. Melts parental to ferroan anorthosites are estimated to contain REE at concentrations ten to fifty times chondrites. Melts parental to the earlier crystallizing anorthosites (lower REE) have virtually no Eu anomaly, while melts parental to later crystallizing anorthosites (higher REE) have small negative Eu anomalies. This is qualitatively consistent with the fractionation of Eu relative to other REE by crystallization of plagioclase with large positive Eu anomalies. Melts parental to the Mg-suite have much higher total REE and very large negative Eu anomalies. The characteristics of Mg-suite norite parental magmas may have been derived by the assimilation of KREEP (near the crust/mantle boundary) by Mg-rich basaltic melts formed deeper in the cumulate pile or near the contact between the lower cumulate horizons of the magma ocean and primitive, unprocessed lunar mantle (similar to 800 km). Copyright (C) 1997 Elsevier Science Ltd. RP Papike, JJ (reprint author), UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,INST METEORIT,SANDIA NATL LABS,ION MICROPROBE FACIL,ALBUQUERQUE,NM 87131, USA. NR 41 TC 27 Z9 27 U1 1 U2 8 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 JUN PY 1997 VL 61 IS 11 BP 2343 EP 2350 DI 10.1016/S0016-7037(97)00086-0 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XE654 UT WOS:A1997XE65400017 ER PT J AU Skulan, J DePaolo, DJ Owens, TL AF Skulan, J DePaolo, DJ Owens, TL TI Biological control of calcium isotopic abundances in the global calcium cycle SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CARBON-DIOXIDE; FRACTIONATION; KINETICS; BUDGET AB Measurements of Ca-44/Ca-40, expressed as delta(44)Ca, were made on igneous rocks and on shell and bone material from modern organisms to investigate the magnitude and origins of calcium isotopic fractionation in nature. The results document a span of 4 parts per thousand in delta(44)Ca, measured with the double spike technique to a precision of +/- 0.15 parts per thousand Volcanic rocks, including basalt and rhyolite, show little variability and cluster near delta(44)Ca = 0 +/- 0.2. Systematic analysis of biological samples indicates that biological processing of calcium discriminates against heavy isotopes, and that biological fractionation is the primary generator of calcium isotopic fractionation in nature. Preliminary data suggest that calcium becomes isotopically lighter as it moves through food chains. Calcium carbonate shells of marine microorganisms and deep-sea carbonate ooze have delta(44)Ca about 1.0 parts per thousand lower than seawater; this fractionation causes seawater to be enriched in heavy calcium (delta(44)Ca = +0.9) relative to igneous rocks. Marine organisms consequently are isotopically heavier than their terrestrial counterparts at similar trophic level. The calcium isotopic composition of living and fossil organisms may record information on diet and environment. Copyright (C) 1997 Elsevier Science Ltd. C1 EO LAWRENCE BERKELEY NATL LAB,DIV EARTH SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT INTEGRAT BIOL,BERKELEY,CA 94720. RP Skulan, J (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY CTR ISOTOPE GEOCHEM,BERKELEY,CA 94720, USA. NR 22 TC 141 Z9 149 U1 6 U2 41 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 JUN PY 1997 VL 61 IS 12 BP 2505 EP 2510 DI 10.1016/S0016-7037(97)00047-1 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XL836 UT WOS:A1997XL83600013 ER PT J AU Duffy, PB Caldeira, K AF Duffy, PB Caldeira, K TI Sensitivity of simulated salinity in a three-dimensional ocean model to upper ocean transport of salt from sea-ice formation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION MODELS; WORLD OCEAN; MIXED LAYER AB We show that explicit representation of sinking of salt rejected during sea-ice formation dramatically improves simulated salinity in an ocean general circulation model (OGCM). In our ''control'' simulation, rejected salt goes into the top model layer, and simulated salinities are typical of OGCMs: the deep ocean is too fresh, and the intermediate-depth salinity minimum associated with Antarctic Intermediate Water is absent. These problems are eliminated in our ''test'' simulation, in which we distribute rejected salt uniformly over the upper 160 m. Also, the strength of the Antarctic Circumpolar Current is more realistic in this simulation. These results show the need for, but do not provide, a better representation of sinking of rejected salt. The sensitivity of our model to sinking of rejected salt suggests that a similar sensitivity may exist in the real ocean, and that loss of Antarctic sea ice might have major effects. RP Duffy, PB (reprint author), LAWRENCE LIVERMORE NATL LAB,CLIMATE SYST MODELING GRP,LIVERMORE,CA 94550, USA. RI Caldeira, Ken/E-7914-2011 NR 30 TC 34 Z9 34 U1 0 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 JUN 1 PY 1997 VL 24 IS 11 BP 1323 EP 1326 DI 10.1029/97GL01294 PG 4 WC Geosciences, Multidisciplinary SC Geology GA XD217 UT WOS:A1997XD21700011 ER PT J AU Johnson, JR Cheng, CZ AF Johnson, JR Cheng, CZ TI Kinetic Alfven waves and plasma transport at the magnetopause SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUBSOLAR MAGNETOPAUSE; MAGNETIC SHEAR; FLUCTUATIONS; LAYER AB Large amplitude compressional type ULF waves can propagate from the magnetosheath to the magnetopause where there are large gradients in density, pressure and magnetic field. These gradients efficiently couple compressional waves with shear/kinetic Alfven waves near the Alfven field-line resonance location (omega = k(parallel to)v(A)). We present a solution of the kinetic-MHD wave equations for this process using a realistic equilibrium profile including full ion Larmor radius effects and wave-particle resonance interactions for electrons and ions to model the dissipation. For northward IMF a KAW propagates backward to the magnetosheath. For southward IMF the wave remains in the magnetopause but can propagate through the k(parallel to) = 0 location. The quasilinear theory predicts that transport due to KAWs at the magnetopause primarily results from the perpendicular electric field coupling with magnetic drift effects with diffusion coefficient D-perpendicular to similar to 10(9) m(2)/s. For southward IMF additional transport can occur because magnetic islands form at the k(parallel to) = 0 location. Due to the broadband nature of the observed waves these islands can overlap leading to stochastic transport which is larger than that due to quasilinear effects. RP Johnson, JR (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. RI Cheng, Chio/K-1005-2014 NR 15 TC 117 Z9 116 U1 0 U2 5 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 JUN 1 PY 1997 VL 24 IS 11 BP 1423 EP 1426 DI 10.1029/97GL01333 PG 4 WC Geosciences, Multidisciplinary SC Geology GA XD217 UT WOS:A1997XD21700036 ER PT J AU Stow, SH AF Stow, SH TI Ethics & earth science SO GEOTIMES LA English DT Editorial Material RP Stow, SH (reprint author), OAK RIDGE NATL LAB,ETH OFF,FEDC BLDG,104 UNION VALLEY RD,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD JUN PY 1997 VL 42 IS 6 BP 5 EP 5 PG 1 WC Geosciences, Multidisciplinary SC Geology GA XB279 UT WOS:A1997XB27900006 ER PT J AU Norby, RJ Edwards, NT Riggs, JS Abner, CH Wullschleger, SD Gunderson, CA AF Norby, RJ Edwards, NT Riggs, JS Abner, CH Wullschleger, SD Gunderson, CA TI Temperature-controlled open-top chambers for global change research SO GLOBAL CHANGE BIOLOGY LA English DT Article DE Acer sp.; air temperature; elevated CO2; exposure methods; field experiments; global warming ID ELEVATED CO2; BIOMASS PRODUCTION; PLANT-RESPONSES; AIR-POLLUTION; FIELD; SEEDLINGS AB To enable experiments on the interactive effects of elevated atmospheric CO2 and increased air temperature on physiological processes in trees to be carried out, we altered the standard design of open-top chambers by replacing blowers with evaporative coolers and in-line heaters, with a feedback control system to maintain ambient or elevated air temperatures within the chambers. Ambient and elevated (+ 4 degrees C) temperature regimes were attained consistently and reliably throughout the growing season, with high reproducibility between chambers. From May through December the average of nearly 300,000 temperature measurements was 18.5 degrees C in ambient air, 18.9 +/- 0.6 degrees C in six ambient chambers, and 22.4 +/- 0.9 degrees C in six elevated temperature chambers. The difference in soil temperature between ambient and elevated chambers was 1.2 degrees C. Absolute humidity (vapour pressure) in the chambers was higher than that of ambient air, but it was generally similar between temperature treatments. Vapour pressure deficit therefore was higher in elevated temperature chambers than in ambient chambers, and this difference is considered an inseparable part of the temperature treatment. The addition of a temperature control system to open-top chambers removes what has been an important flaw in this important tool for global change research. C1 OAK RIDGE NATL LAB,DIV INSTRUMENTAT & CONTROLS,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,PLANT & EQUIPMENT DIV,OAK RIDGE,TN 37831. RP Norby, RJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,BLDG 1059,OAK RIDGE,TN 37831, USA. RI Wullschleger, Stan/B-8297-2012; Norby, Richard/C-1773-2012 OI Wullschleger, Stan/0000-0002-9869-0446; Norby, Richard/0000-0002-0238-9828 NR 20 TC 72 Z9 84 U1 1 U2 35 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD JUN PY 1997 VL 3 IS 3 BP 259 EP 267 DI 10.1046/j.1365-2486.1997.00072.x PG 9 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA XF048 UT WOS:A1997XF04800010 ER PT J AU Durbin, PW Kullgren, B Xu, JD Raymond, KN AF Durbin, PW Kullgren, B Xu, JD Raymond, KN TI New agents for in vivo chelation of Uranium(VI): Efficacy and toxicity in mice of multidentate catecholate and hydroxypyridinonate ligands SO HEALTH PHYSICS LA English DT Article DE uranium; chelation; kidneys; mice ID SEQUESTERING AGENTS; ACTINIDES; EXCRETION; RAT; ENTEROBACTIN; INTOXICATION; 3,4,3-LIHOPO; RETENTION; THERAPY; REMOVAL AB Soluble uranyl ion [UO22+, U(VI)] is a kidney poison. Uranyl ion accumulates in bone, and the high specific activity uranium isotopes induce bone cancer. Although sought since the 1940's, no multidentate ligand was identified, until now, that efficiently and stably binds U(VI) at physiological pH, promotes its excretion, and reduces deposits in kidneys and bone. Ten multidentate ligands patterned after natural siderophores and composed of sulfocatechol [CAM(S)], carboxycatechol [CAM(C)], or hydroxypyridinone [Me-3,2-HOPO] metal-binding units have been tested for in vivo chelation of U(VI). Ligands were injected intraperitoneally tip) into mice 3 min after intravenous (iv) injection of U-233 or U232+235 as UO2Cl2 [ligand-to-metal molar ratio 75 to 92]. Regardless of backbone structure, denticity, or binding unit, all 10 ligands significantly reduced kidney U(VI) compared with controls or with mice given CaNa3-DTPA, and four CAM(S) or CAM(C) ligands also significantly reduced skeleton U(VI). Several ligands removed U(VI) from kidneys, when injected at 1 or 24 h. Injected at molar ratios greater than or equal to 300, 5-LIO(Me-3,2-HOPO) and TREN-(Me-3,2-HOPO) reduced kidney U(VI) to about 10% of control. Given orally to fasted mice at molar ratios greater than or equal to 300, those ligands significantly reduced kidney U(VI). In mice injected iv with 0.42 mu mol kg(-1) of U-235 and given 100 mu mol kg(-1) of one of those Me-3,2-HOPO ligands ip daily for 10 d starting at 1 h after the U(VI)) loss of kidney U(VI) was greatly accelerated, and the kidneys of treated mice showed no microscopic evidence of renal injury. Crystals of uranyl chelates with linear tetradentate ligands containing bidentate Me-3,2-HOPO groups demonstrate a 1:1 structure. Considering low toxicity, effectiveness, and reasonable cost, the structurally simple linear tetradentate ligands based on the 5-LI backbone (diaminopentane) offer the most promising approach to a clinically acceptable therapeutic agent for U(VI). Work is in progress to identify the most suitable CAM or HOPO binding unit(s). C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. FU NIEHS NIH HHS [ES02698] NR 72 TC 60 Z9 64 U1 5 U2 22 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 JUN PY 1997 VL 72 IS 6 BP 865 EP 879 DI 10.1097/00004032-199706000-00006 PG 15 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 XA233 UT WOS:A1997XA23300007 PM 9169929 ER PT J AU Price, PN AF Price, PN TI Predictions and maps of county mean indoor radon concentrations in the mid-Atlantic states SO HEALTH PHYSICS LA English DT Article DE radon; modeling, dose assessment; geology; surveys ID HOMES AB Measured surface radium content, geologic province information, information on the fraction of homes with basements and with living-area basements, and measurements from the EPA/State Residential Radon Surveys, were used in a Bayesian mixed effects regression to predict the distributions of short-term winter and annual living area average radon concentrations by county in the mid-Atlantic states. The information provided by those explanatory variables is roughly equivalent to collecting an extra 12 observations per county, effectively doubling the amount of information in a typical county. Predicted county geometric means are subject to standard errors of 15% to 30% for typical counties, with the uncertainty in a given county depending on the number of radon measurements in the county and the amount of information about the geologic province that contains the county. After controlling for soil radium concentration and the effect of measuring in a basement vs. the first floor, typical geologic provinces are found to be associated with elevation or depression of indoor radon concentrations by 30% on average, with some provinces having effects of considerably larger magnitude. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, INDOOR ENVIRONM PROGRAM, BERKELEY, CA 94720 USA. NR 20 TC 13 Z9 13 U1 0 U2 1 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 JUN PY 1997 VL 72 IS 6 BP 893 EP 906 DI 10.1097/00004032-199706000-00008 PG 14 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 XA233 UT WOS:A1997XA23300009 PM 9169931 ER PT J AU Tufano, DR AF Tufano, DR TI Automotive HUDs: The overlooked safety issues SO HUMAN FACTORS LA English DT Article ID ACCOMMODATION; EYE AB The transfer of tactical aviation technology into automobiles is creating information display requirements that are likely to be met by use of the head-up display (HUD). These developments are based largely on conclusions that the HUD-related safety issues raised in the aviation HUD literature can be dismissed and that the benefits of using HUDs are certain. Such conclusions either neglect relevant research or are supported by a very small amount of evidence, much of which is either irrelevant or generated within a flawed methodological paradigm. This critical review covers the issues of (a) HUD focal distance and its effect on the perception of outside objects and (b) the effects of HUD imagery on visual attention. The issues of focal distance, cognitive capture, and the inherent connection between the two may have a greater impact on safety in the automotive context than they do in aviation. RP Tufano, DR (reprint author), OAK RIDGE NATL LAB, COGNIT SYST & HUMAN FACTORS GRP, POB 2008, OAK RIDGE, TN 37831 USA. NR 27 TC 33 Z9 33 U1 3 U2 6 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD JUN PY 1997 VL 39 IS 2 BP 303 EP 311 DI 10.1518/001872097778543840 PG 9 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA XP833 UT WOS:A1997XP83300011 PM 9302890 ER PT J AU Adams, DG Fitzgerald, DS Ortiz, S AF Adams, DG Fitzgerald, DS Ortiz, S TI An annunciator architecture for the year 2000 SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB Exciting new safeguards and security technologies are on the horizon, and some are even on the shelves today. Self-testing sensors, smart sensors, and intelligent alarm analyzers are all designed to provide useful information to the operator. However, today's current annunciator systems were not designed to accommodate these new technologies. New display technologies are also changing,the look and feel of the annunciator of the future. Annunciator technology needs to ''catch up'' to these other security technologies. This paper presents the concept for a new, object-oriented approach to annunciator architecture design. The new architecture could accommodate simple, switch-closure devices as well as information-rich sensors and intelligent analyzers. In addition the architecture could allow other leading-edge interfaces to be easily integrated into the annunciator system. These technologies will reduce operator workload and aid the operator in making informed security decisions. RP Adams, DG (reprint author), SANDIA NATL LABS,SECUR TECHNOL DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD JUN PY 1997 VL 12 IS 6 BP 25 EP 28 DI 10.1109/62.587054 PG 4 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA XA689 UT WOS:A1997XA68900006 ER PT J AU Jensen, J Woodfin, G AF Jensen, J Woodfin, G TI Relational databases create online publications SO IEEE COMMUNICATIONS MAGAZINE LA English DT Article AB Relational databases that are accessible and updatable via the Internet afford Web designers many advantages over traditional HTML documents. The Automatic Interactive Database Approach (AIDA) to Web publishing eliminates old information, creates automatic links, and reduces memory requirements by using virtual html pages. The pages are consistent, reliable, and up to date. RP Jensen, J (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0163-6804 J9 IEEE COMMUN MAG JI IEEE Commun. Mag. PD JUN PY 1997 VL 35 IS 6 BP 152 EP 155 DI 10.1109/35.587721 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA XC732 UT WOS:A1997XC73200028 ER PT J AU Biefeld, RM Kurtz, SR Allerman, AA AF Biefeld, RM Kurtz, SR Allerman, AA TI The metal-organic chemical vapor deposition growth and properties of InAsSb mid-infrared (3-6-mu m) lasers and LED's SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article ID CONTINUOUS-WAVE OPERATION; STRAINED-LAYER SUPERLATTICES; 3.5 MU-M; QUANTUM-WELLS; INAS1-XSBX; TEMPERATURE; DIODES; ALLOYS AB We describe the metal-organic chemical vapor deposition (MOCVD) growth of AlAs1-xSbx cladding layers and InAsSb-InAs multiple-quantum well (MQW) and InAsSb-InAsP strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. The AlAs1-xSbx cladding layers were successfully doped p-or n-type using diethylzinc or tetraethyltin, respectively. By changing the layer thickness and composition of SLS's and MQW's, we have prepared structures,vith low temperature (<20 K) photoluminescence wavelengths ranging from 3.2 to 6.0 mu m. We have made gain-guided injection lasers using undoped p-type AlAs0.16Sb0.84 for optical confinement and both strained InAsSb-InAs MQW and InAsSb-InAsP SLS active regions. The lasers and light-emitting diodes (LED's) utilize the semi-metal properties of a GaAsSb(p)-InAs(n) heterojunction as a source for electrons injected into active regions. A multiple-stage LED utilizing this semi-metal injection scheme is reported. Gain-guided, injected lasers with a strained InAsSb-InAs MQW active region operated up to 210 K in pulsed mode with an emission wavelength of 3.8-3.9 mu m and a characteristic temperature of 29-40 K. We also present results for both optically pumped and injection lasers with InAsSb-InAsP SLS active regions. The maximum operating temperature of an optically pumped 3.7-mu m strained-layer superlattice (SLS) laser was 240 K. An SLS LED emitted at 4.0 mu m with 80 mu W of power at 300 K. RP Biefeld, RM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 27 TC 19 Z9 19 U1 0 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD JUN PY 1997 VL 3 IS 3 BP 739 EP 748 DI 10.1109/2944.640629 PG 10 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YE078 UT WOS:A1997YE07800005 ER PT J AU Choquette, KD Geib, KM Ashby, CIH Twesten, RD Blum, O Hou, HQ Follstaedt, DM Hammons, BE Mathes, D Hull, R AF Choquette, KD Geib, KM Ashby, CIH Twesten, RD Blum, O Hou, HQ Follstaedt, DM Hammons, BE Mathes, D Hull, R TI Advances in selective wet oxidation of AlGaAs alloys SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE materials processing; materials science and technology; optoelectronic device; semiconductor device fabrication; semiconductor lasers ID VERTICAL-CAVITY LASERS; SURFACE-EMITTING LASERS; QUANTUM-WELL HETEROSTRUCTURES; DISTRIBUTED BRAGG REFLECTORS; WATER-VAPOR OXIDATION; NATIVE-OXIDE; LASING CHARACTERISTICS; ALXGA1-XAS LAYERS; THERMAL-OXIDATION; BURIED ALGAAS AB We review the chemistry, microstructure, and processing of buried oxides converted from AlGaAs layers using wet oxidation. Hydrogen is shown to have a central role in the oxidation reaction as the oxidizing agent and to reduce the intermediate product As2O3 to As. The stable oxide is amorphous (AlxGa1-x)(2)O-3 which has no defects along the oxide/semiconductor interfaces but can exhibit strain at the oxide terminus due to volume shrinkage. The influence of gas flow, gas composition, temperature, Al-content, and layer thickness on the oxidation rate are characterized to establish a reproducible process. Linear oxidation sates with Arrhenius activation energies which strongly depend upon AlAs mole fraction are found. The latter produces strong oxidation selectivity between AlGaAs layers with slightly differing Al-content. Oxidation selectivity to thickness is also shown for layer thickness <60 nm, Differences between the properties of buried oxides converted from AlGaAs and AlAs layers and the impact on selectively oxidized vertical cavity laser lifetime are reported. C1 UNIV VIRGINIA, DEPT MAT SCI, CHARLOTTESVILLE, VA 22903 USA. RP SANDIA NATL LABS, CTR CPDS SEMICOND SCI & TECHNOL, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 55 TC 177 Z9 178 U1 4 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1077-260X EI 1558-4542 J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD JUN PY 1997 VL 3 IS 3 BP 916 EP 926 DI 10.1109/2944.640645 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA YE078 UT WOS:A1997YE07800021 ER PT J AU Martovetsky, NN AF Martovetsky, NN TI Analysis of losses in ITER joints in a varying parallel field SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB One of the options for a design of a Central Solenoid in ITER and other tokamak machines is pancake wound modules. In this configuration joints have to be placed in maximum magnetic field with high changing rate. Joints should be designed to have at least the same or larger temperature margin as that for the conductor in the same field. We show that joints in parallel field can be designed to meet this requirement along with reasonably low DC resistance. Losses in parallel field are calculated and design features which can suppress AC losses without increasing DC resistance are discussed. Recommendations for low loss, low DC resistance joints are made. RP Martovetsky, NN (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 10 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 266 EP 269 DI 10.1109/77.614481 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400037 ER PT J AU Lue, JW Lubell, MS Jones, EC Demko, JA Kroeger, DM Martin, PM Sinha, U Hughey, RL AF Lue, JW Lubell, MS Jones, EC Demko, JA Kroeger, DM Martin, PM Sinha, U Hughey, RL TI Test of two prototype high-temperature superconducting transmission cables SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Two 500-A class prototype high-temperature superconducting cables have been constructed by Southwire Company and tested at Oak Ridge National Laboratory (ORNL), In the first cable, no insulation was used to separate the individual HTS tapes, In the second cable, Kapton tape was used to insulate the HTS tapes between successive layers for the study of AC loss and current distribution, The cables were tested with both DC and AC currents in liquid nitrogen from 77 to 69 K. Both cables achieved DC critical current, I-c greater than 500 A, A calorimetric technique that measures the cable temperature rise under ac currents was used to measure the ac loss of the cables, The un-insulated cable showed a cryoresistive behavior under the 60 Hz AC currents. The insulated cable started to show measurable ac loss at current where there was corresponding DC resistive voltage. C1 SOUTHWIRE CO,CARROLLTON,GA 30119. RP Lue, JW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 4 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 302 EP 305 DI 10.1109/77.614490 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400046 ER PT J AU Daney, DE Boenig, HJ Maley, MP McMurry, DE DeBlanc, BG AF Daney, DE Boenig, HJ Maley, MP McMurry, DE DeBlanc, BG TI Ac loss calorimeter for three-phase cable SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A calorimeter for measuring ac losses in meter-long lengths of HTS superconducting power transmission line cables is described. The Calorimeter, which is based on a temperature difference technique, has a precision of 1 mW and measures single, two-phase (coupling), and three-phase Our measurements show significant coupling losses between phases. RP Daney, DE (reprint author), LOS ALAMOS NATL LAB,SUPERCONDUCT TECHNOL CTR,POB 1663,LOS ALAMOS,NM 87545, USA. NR 3 TC 16 Z9 16 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 310 EP 313 DI 10.1109/77.614492 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400048 ER PT J AU Yang, ZJ Hull, JR AF Yang, ZJ Hull, JR TI Energy loss in superconducting bearing systems SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID LEVITATION; FLYWHEEL; STORAGE AB The field- and frequency-dependent AC susceptibility of a melt-textured Y-Ba-Cu-O was measured at 77 K and under various field conditions. The RMS values of the applied AC induction (B-ac,B-rms) were scanned up to 13 mT, and the DC inductions were 0, 20, 40, 75, and 100 mT. The frequencies scanned ranged from 10 to 3800 Hz. The experiments show that AC susceptibility of the HTS largely depends on frequency and on both the AC and DC induction. RP Yang, ZJ (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 9 Z9 9 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 318 EP 321 DI 10.1109/77.614494 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400050 ER PT J AU Sinha, U Hughey, RL Hesterlee, J Lue, JW Lubell, MS Hawsey, RA Martin, PM Demko, JA AF Sinha, U Hughey, RL Hesterlee, J Lue, JW Lubell, MS Hawsey, RA Martin, PM Demko, JA TI Design and construction of LN2-cooled prototype superconducting transmission cable SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Southwire Company has initiated an R&D project to develop superconducting underground transmission cable using the newly developed high-temperature superconductors (HTS). In collaboration with Oak Ridge National Laboratory (ORNL), two 500 A and one 2000 A prototype cables have been designed, constructed, and tested(1), The cables were wound with Bi-2223/Ag HTS tapes acquired from Intermagnetics General Corporation (IGC), and tested with both de and ac currents in liquid nitrogen (LN2). Critical currents of 900 A dc or better were achieved for the first two cables. The third cable was tested to an ac current over 2200 A(rms). This paper describes the design rationale, the construction process, and the highlights of the test results. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Sinha, U (reprint author), SOUTHWIRE CO,CARROLLTON,GA 30119, USA. NR 3 TC 9 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 351 EP 354 DI 10.1109/77.614501 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400057 ER PT J AU Shu, QS Fouaidy, M Junquera, T Moeller, WD Proch, D AF Shu, QS Fouaidy, M Junquera, T Moeller, WD Proch, D TI Highest performance of TESLA 9-cell superconducting RF cavities by overcoming quenches in superfluid LHe SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Accelerating gradients Eacc = 26 MV/m with a world record Q of 3 x 10(10) in 9-cell TESLA superconducting RF (SRF) cavities have been reached in CW and pulsed RF modes. On the way to reaching the excellent performance, we experimentally characterized quench natures (most serious obstacle to higher gradients), investigated the Kapitza conduction and boiling heat transfer between cavities and LHe II, and studied the quench behaviors both in He II and normal LHe. Finally, we discuss the possibilities of further greatly raising the accelerating gradients to 50-100 MV/m by use of Nb3Sn and some HTc superconducting materials. C1 INST NUCL PHYS,ORSAY,FRANCE. THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA. RP Shu, QS (reprint author), DESY,DEUTSCH ELEKTRONEN SYNCHROTRON,NOTKESTR 85,D-2000 HAMBURG,GERMANY. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 371 EP 374 DI 10.1109/77.614506 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400062 ER PT J AU Benesch, JF Wiseman, M AF Benesch, JF Wiseman, M TI Tests of a prototype magnetostrictive tuner for superconducting cavities SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The Continuous Electron Beam Accelerator (CEBA) uses mechanical tuners at 2 K driven by room temperature stepping motors in a feedback loop to maintain cavity frequency at 1497 MHz, A modification of the existing system was designed, replacing a passive section of the mechanical tuner with a magnetostrictive tuning element consisting of a nickel rod and an industrially supplied 0.25 T superconducting solenoid, This assembly was tested with several magnetic shield configurations designed to keep the stray flux at the niobium cavity below 1 mu T when the cavity was normal, to maintain cavity Q. Results of the tests, including change in cavity performance when the cavity was locally quenched near the end of the solenoid, showed that a multilayer shield of 6mm of steel, with sheets of mu metal, niobium and mu metal spaced appropriately outside the thick steel, was effective in containing the flux, both remanent and current-driven, preventing any change in cavity Q upon cool down or quench with an external heater near the end of the solenoid, Hysteresis attributed to the nickel magnetostrictive element was observed. RP Benesch, JF (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 375 EP 377 DI 10.1109/77.614507 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400063 ER PT J AU Lubell, MS Lue, JW Palaszewski, B AF Lubell, MS Lue, JW Palaszewski, B TI Large-bore, superconducting magnets for high-energy density propellant storage SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID FIELD AB A study has been conducted on the design of large-bore, superconducting solenoid magnets in an effort to determine how weight and cost scales with field and size. The fields considered ranged from 0.5 to 20 T and bore sizes from 3 to 10 m, the designs are based on light-weight, high-performance superconducting magnet designs using cable-in-conduit niobium-titanium and niobium-tin conductors. All methods to reduce the weight of the magnets are used, and both aluminum and stainless steel are considered for the structure. With the length of the magnets fixed at 10 m, the amount and cost of the conductor is determined for each field and bore size, The largest magnets are determined for each field value that have weights under 10(4), 10(5), and 10(6) kg. The cost scales as the square root of stored energy and in millions of dollars is twice the product of field (T) and bore (m). C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Lubell, MS (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 412 EP 418 DI 10.1109/77.614517 PN 1 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400073 ER PT J AU Martovetsky, NN Chaplin, MR AF Martovetsky, NN Chaplin, MR TI Detection of the normal zone with cowound sensors in cable-in conduit conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Tokamaks in the future will use superconducting cable-in-conduit-conductors (CICC) in all Poloidal Field (PF) & Toroidal Field (TF) magnets. Conventional quench detection, the measurement of Small resistive normal-zone voltages (<1.V) in the magnets will be complicated by the presence of large inductive voltages (>4 kV). In the quench detection design for TPX, we have considered several different locations for internal co-wound voltage sensors in the cable cross-section as the primary mechanism to cancel this inductive noise. The Noise Rejection Experiment (NRE) at LLNL has been designed to evaluate which internal locations will produce the best inductive-noise cancellation, and provide us with experimental data for comparison with developed earlier theory. The details of the experiments and resulting data are presented and analyzed. RP Martovetsky, NN (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 8 TC 6 Z9 6 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 451 EP 454 DI 10.1109/77.614531 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400082 ER PT J AU Morgan, GH Kahn, SA Willen, EH AF Morgan, GH Kahn, SA Willen, EH TI Stacked magnets for a muon accelerator SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A proposed muon-muon collider [1] uses a final accelerator which is separate from the collider ring. To minimize acceleration time and hence loss of muons by decay, a possible design for this accelerator consists of two, long, parallel linacs having a large energy gain per pass and semi-circular arcs of fixed-field magnets at each end, The muons would make 10 to 20 passes around the final accelerator ring, with an input energy of 250 Gev and output energy of 2 Tev; the present design assumes 16 passes, The recirculator magnets, described here for the end arcs, consist of an array of 16 apertures arranged in four adjacent, vertical stacks having four, 50 mm apertures in a stack, each stack having an iron yoke in common. This type of,configuration reduces cost by taking advantage of coupling between apertures, but results in some undesirable skew harmonics, The highest dipole field is 7 tesla, and there is an 0.406 T difference between adjacent apertures in a stack. A similar quadrupole stack having a maximum gradient of 175 T/m is also presented. RP Morgan, GH (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 543 EP 546 DI 10.1109/77.614561 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400104 ER PT J AU Caspi, S Chow, K DellOrco, D Hannaford, R Higley, H Lietzke, A McInturff, A Morrison, M Morrison, L Scanlan, RM VanOort, H AF Caspi, S Chow, K DellOrco, D Hannaford, R Higley, H Lietzke, A McInturff, A Morrison, M Morrison, L Scanlan, RM VanOort, H TI Design and construction of a hybrid - Nb3Sn, NbTi - dipole magnet SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A two layer superconducting dipole magnet - D19H, with a Nb3Sn inner layer and a NbTi outer layer was designed, constructed and tested, The 50mm bore inner layer of an existing NbTi dipole magnet (D19A), has been removed and replaced with a Nb3Sn coil, The outer NbTi coil, collars, iron yoke, ring, collets and outer skin from the disassembled D19A magnet have all been reused, Employing glass insulated cable with aluminum-bronze poles and end spacers the Nb3Sn coil was reacted at 660 degrees C for 240 hours and fully epoxy impregnated, The design and construction of the magnet are described and test results reported elsewhere in these proceedings[1]. RP Caspi, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 4 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 547 EP 550 DI 10.1109/77.614562 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400105 ER PT J AU vanOort, JM Scanlan, RM AF vanOort, JM Scanlan, RM TI The pipe-quadrupole, an alternative for high gradient interaction region quadrupole designs SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB In the design of interaction region (IR) quadrupoles for high luminosity colliders such as the LHC or a possible upgrade of the Tevatron, the radiation heating of the coil windings is an important issue, Two obvious solutions to this problem can be chosen. The first is to reduce the heat load by added shielding, increased cooling with fins or using Nb3Sn to increase the temperature margin, The second solution eliminates the conductor from the areas with the highest radiation intensity, which are located on the symmetry-axes of the midplanes of the coils, A novel quadrupole design is presented, in which the conductor is wound on four half-moon shaped supports, forming elongated toroid sections, The assembly of the four shapes yields a quadrupole field with an active flux return path, and a void in the high radiation area, This void can be occupied by a liquid helium cooling pipe to lower the temperature of the windings from the inside, The coil layout, harmonic optimization and mechanical design are shown, together with the calculated temperature rise for the radiation load of the LHC interaction region quadrupoles. RP vanOort, JM (reprint author), EO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 551 EP 554 DI 10.1109/77.614563 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400106 ER PT J AU Heger, T Kerby, J AF Heger, T Kerby, J TI Mechanical analysis of a high gradient quadrupole for the LHC SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The magnetic design of the LHC interaction region quadrupole by the BNL, FNAL, LBNL collaboration eliminates the manufacturing complication of a graded cable splice in the outer coil and still attains a maximum gradient above 235 T/m. The mechanical design includes strong preloaded collars, shims to adjust the fit between components when warm, contact between the collar and iron when cold for better coil support, and a closed iron to reduce harmonics. This paper summarizes mechanical finite element results for assembly, cooldown to 1.8 K, and excitation to maximum gradient. RP Heger, T (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 566 EP 569 DI 10.1109/77.614567 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400110 ER PT J AU Huang, Y Kerby, J Mazur, PO Peterson, TJ Zlobin, A AF Huang, Y Kerby, J Mazur, PO Peterson, TJ Zlobin, A TI Thermal design of a high gradient quadrupole for the LHC interaction regions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The LHC high gradient quadrupole coils are subject to a continuous heat load due to the beam-induced energy deposition during operation. All heat deposited in the coil must be removed so that the magnets will remain in a superconducting state. The quadrupole magnets are designed to be cooled with stagnant pressurized He II. This paper summarizes the heat flow analyses from the insulated coil to the boiling saturated He II for the LHC interaction region quadrupoles. The effects of cable surface heat nux and cooling channel heights on the thermal characteristics of the magnets are studied. He II heat exchanger designs, arranged internally and externally are compared. RP Huang, Y (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 578 EP 581 DI 10.1109/77.614570 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400113 ER PT J AU Zlobin, AV AF Zlobin, AV TI Quench protection of a high gradient quadrupole for the LHC interaction regions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The energy stored in a superconducting (SC) accelerator magnet is usually dissipated after a quench in the normal zones of the coil, heating the coils and producing a voltage drop between the turns inside the magnet and between coil and ground. This paper presents the results of the analysis of the quench protection problem for a high gradient quadrupole for the LHC interaction regions. RP Zlobin, AV (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 5 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 582 EP 585 DI 10.1109/77.614571 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400114 ER PT J AU Mitchell, DV Heger, T Nobrega, A Ozelis, JP AF Mitchell, DV Heger, T Nobrega, A Ozelis, JP TI Mechanical studies of the Fermilab Low Beta Quadrupole collared coils SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Finite element results of Low Beta Quadrupole magnets are compared to measurements from three mechanical models, Stress, as with internal strain gauges, and radial deflections, as measured with a precision measuring device, are compared to the finite element analysis, The results indicate that measured internal are in agreement with calculations but measured deflections are approximately 1.8 times lower than predicted, The findings will help develop better analyzing and manufacturing techniques to be used on developing the High Gradient Quadrupole magnet. RP Mitchell, DV (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 586 EP 589 DI 10.1109/77.614572 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400115 ER PT J AU Ozelis, JP Bause, P Bossert, R Dominguez, J Feher, S Heger, T AF Ozelis, JP Bause, P Bossert, R Dominguez, J Feher, S Heger, T TI Development of collar lamination strain gauges for coil stress measurements in superconducting accelerator magnets SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A new type of strain gauge has been developed for measuring coil stresses in superconducting magnets. It consists of commercial film-type strain gauges mounted directly on the pole-tip area of coil collar laminations. These gauges, are extremely simple to manufacture, calibrate, and install in prototype magnets. We discuss the motivation for and design of these gauges, present results from calibration tests performed at 300 K and 4.2 K, and compare these results with calibration of existing beam-type transducer gauges. We discuss calibration reproducibility, reliability, and accuracy. We also present preliminary coil stress measurements using these gauges in a model quadrupole magnet during the collaring, yoking, cool down, and excitation processes. RP Ozelis, JP (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 6 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 590 EP 593 DI 10.1109/77.614573 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400116 ER PT J AU Milward, SR Morris, JM Nobes, S Smith, KD Street, AJ Townsend, MC Treadgold, JR Wiatrzyk, JM Kirby, GA Ostojic, R Taylor, TM Strait, J AF Milward, SR Morris, JM Nobes, S Smith, KD Street, AJ Townsend, MC Treadgold, JR Wiatrzyk, JM Kirby, GA Ostojic, R Taylor, TM Strait, J TI Progress in the development of the 1-m model of the 70 mm aperture quadrupole for the LHC low-beta insertions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID DESIGN AB Within the LHC magnet development program Oxford Instruments has built a one metre model of the 70 mm aperture low-beta quadrupole. The magnet features a four layer coil wound from two 8.2 mm wide graded NbTi cables, and is designed for 250 T/m at 1.9 K. The magnet has previously been tested between 4.5 K and 2.3 K. In this paper we review the magnet rebuild and the subsequent tests. Results an magnet training at 4.3 K and 1.9 K are presented along with the results related to quench protection studies. We also present the first results of magnetic field measurements done at room and liquid nitrogen temperatures. C1 CERN,CH-1211 GENEVA 23,SWITZERLAND. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL. RP Milward, SR (reprint author), OXFORD INSTRUMENTS,OXFORD OX8 1TH,OXON,ENGLAND. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 594 EP 597 DI 10.1109/77.614574 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400117 ER PT J AU Bossert, R Feher, S Gourlay, SA Heger, T Kerby, J Lamm, MJ Limon, PJ Mazur, PO Nicol, T Nobrega, F Orris, D Ozelis, JP Peterson, T Schlabach, P Strait, J Tompkins, J Zlobin, A Lietzke, A McInturff, AD Scanlan, R AF Bossert, R Feher, S Gourlay, SA Heger, T Kerby, J Lamm, MJ Limon, PJ Mazur, PO Nicol, T Nobrega, F Orris, D Ozelis, JP Peterson, T Schlabach, P Strait, J Tompkins, J Zlobin, A Lietzke, A McInturff, AD Scanlan, R TI Tests of Fermilab low-beta quadrupoles SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The recently revived superconducting magnet program at Fermilab is currently focused on the development of high gradient quadrupoles for possible use in the Large Hadron Collider (LHC) interaction regions at CERN. In order to provide input for the new quadrupole design which will operate in superfluid helium, we have tested a Fermilab Tevatron low-beta quadrupole cold mass and compared its low temperature performance to a newly assembled heavily instrumented version which was mechanically modified to take advantage of the gain in critical current. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. RP Bossert, R (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 598 EP 601 DI 10.1109/77.614575 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400118 ER PT J AU Lietzke, A McInturff, AD Scanlan, RM Bossert, R Feher, S Gourlay, SA Lamm, MJ Limon, PJ Nobrega, F Ozelis, JP Zlobin, AV AF Lietzke, A McInturff, AD Scanlan, RM Bossert, R Feher, S Gourlay, SA Lamm, MJ Limon, PJ Nobrega, F Ozelis, JP Zlobin, AV TI Superfluid performance of Tevatron IR quad heaters SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A collaborative team from the two laboratories measured the performance of Tevatron interaction region (IR) quadrupole at temperatures from 1.8 K to 4.4 K. These studies included measurement of their performance as function of temperature as well as measurement of the effectiveness of the protection heaters, diffusion times were measured for various temperatures, current levels, and power densities. These results and their implications on the design of magnet protection systems and magnet design operating in this temperature range will be discussed. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Lietzke, A (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 606 EP 609 DI 10.1109/77.614577 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400120 ER PT J AU Lassiter, SR Wood, SA Brindza, PD AF Lassiter, SR Wood, SA Brindza, PD TI Magnetic measurements of large aperture superconducting quadrupole magnets for TJNAF's high momentum spectrometer SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The results of the field mapping measurements of Thomas Jefferson National Accelerator Facility's three large aperture, cold iron, laminated yoke superconducting quadrupole magnets for the High Momentum Spectrometer will be presented. These magnets were mapped using a rotating coil assembly housed within a G-10 drum. A description of the apparatus and technique used to map the magnets over an excitation range of 0 to 2 tesla will be described. This method of mapping provides for an almost real time measurement of field strength, effective field length, field gradient, transfer function and the determination of symmetry planes. The hysteresis loop and affects of eddy currents will be shown. A comparison of the measured field values with calculated values will also be given. RP Lassiter, SR (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 4 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 614 EP 617 DI 10.1109/77.614579 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400122 ER PT J AU Brindza, PD Beck, D Laszewski, R Bartoszek, L Wands, R Mitchell, D AF Brindza, PD Beck, D Laszewski, R Bartoszek, L Wands, R Mitchell, D TI Superconducting toroidal magnet design for the G0 experiment at TJNAF SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB An eight coil Superconducting toroidal magnetic spectrometer has been designed for the GO experiment to be performed at Thomas Jefferson National Accelerator Facility (TJNAF). The toroid is designed so that the particle trajectories pass through the magnet insulating vacuum. The magnet is made of aluminum structural components with a copper stabilized indirectly cooled conductor. The toroid is 2 meters long, 4 meters outside diameter and is oriented with its major axis horizontal. This orientation allows its use as an eight fold symmetric focusing spectrometer. The SC magnet has a stored energy of 6.5 Mjoules, The design and analysis of this device will be presented. The plans and status of magnet system procurement will be presented. The RFP [1] was issued in May 1996. C1 UNIV ILLINOIS,LOOMIS LAB PHYS,URBANA,IL 61801. RP Brindza, PD (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 618 EP 621 DI 10.1109/77.614580 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400123 ER PT J AU Green, MA AF Green, MA TI A superconducting spectrometer magnet system for the detection of heavy isotopes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID STORAGE-RING AB LASSY is a proposed large angle gas filled spectrometer for detecting and analyzing heavy nuclei generated when a heavy ion beam (such as fully stripped argon) collides with an actinide thin film target (such as curium). With luck, superheavy nuclei, up to atomic number 114 to 116, can be produced at the target. In order to improve, the acceptance and resolution of the shortest lived nuclei, the length of the magnet system must be as short as possible. The LASSY spectrometer consists of a 4 to 6T superconducting magnet that produces 2.5 Tm of bending (bend radius induction product) with a bend angle of 135 degrees or more. particles generated at the target (and their decay products) must be focused on an electronic detector less than 3 meters from the target. The resulting spectrometer magnet is quite complex with sections that focus as well as band the particles from the target. This report presents two possible designs for a large superconducting bending magnet that is a pure bending magnet in the canter with defocusing bending sections at the ends of the magnet. This paper shows how one might build a bending magnet that is in sections, section having a tunable quadrupole and sextupole field in addition to the dipole field. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 EI 1558-2515 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 622 EP 625 DI 10.1109/77.614581 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400124 ER PT J AU Bunce, G Morse, WM Benante, J Cullen, JR Danby, GT Endo, K Fedotovich, GV Geller, J Green, MA Grossmann, A GrossePerdckamp, M Haeberlen, U Hseuh, H Hirabayashi, H Hughes, VW Jackson, JW Jia, LX Jungmann, K Krienen, F Larsen, R Khazin, B Kawall, D Meng, W Pai, C Polk, I Prigl, R Putlitz, GZ Redin, S Roberts, BL Ryskulov, N Semertzidas, Y Shutt, R Snydstrup, L Tallerico, T vonWalter, P Woodle, K Yamamoto, A AF Bunce, G Morse, WM Benante, J Cullen, JR Danby, GT Endo, K Fedotovich, GV Geller, J Green, MA Grossmann, A GrossePerdckamp, M Haeberlen, U Hseuh, H Hirabayashi, H Hughes, VW Jackson, JW Jia, LX Jungmann, K Krienen, F Larsen, R Khazin, B Kawall, D Meng, W Pai, C Polk, I Prigl, R Putlitz, GZ Redin, S Roberts, BL Ryskulov, N Semertzidas, Y Shutt, R Snydstrup, L Tallerico, T vonWalter, P Woodle, K Yamamoto, A TI Test results of the g-2 superconducting solenoid magnet system SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The g-2 experiment dipole consists of a single 48 turn, 15.1 meter diameter outer solenoid and a pair of 24 turn inner solenoids, 13.4 meters in diameter. The inner solenoids are hooked in series and are run at a polarity that is opposite that of the outer solenoid, thus creating a dipole field in the space between the inner and outer solenoids, The dipole flux is returned by a C shaped continuous iron. The superconducting solenoid coils are closely coupled to the solenoid mandrels and as such are subject to quench back. This report presents the results of various tests on the g-2 magnet system operating within its iron return yoke. These tests include quench back time constant measurements for the inner and outer solenoids and measurements of the response of the two-phase forced cooled helium cryogenic system to magnet quenches. The overall effectivness of the g-2 magnet quench protection system was measured. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. YALE UNIV,NEW HAVEN,CT 06520. KEK NAT LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. BOSTON UNIV,BOSTON,MA 02215. UNIV HEIDELBERG,D-69120 HEIDELBERG,GERMANY. MAX PLANCK INST MED RES,D-69120 HEIDELBERG 1,GERMANY. BUDKER INST NUCL PHYS,RU-630090 NOVOSIBIRSK,RUSSIA. RP Bunce, G (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Jungmann, Klaus/A-7142-2010; jungmann, klaus/H-1581-2013 OI jungmann, klaus/0000-0003-0571-4072 NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 626 EP 629 DI 10.1109/77.614582 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400125 ER PT J AU Green, MA Weggel, RJ AF Green, MA Weggel, RJ TI A 20 T hybrid solenoid for the collection of pions for a muon collider SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB In order to generate intense muon beams for a muon collider, intense pion beams must be produced in a stationary proton beam target. The pions produced by the target must be captured before they can go through phase rotation and decay into muons. A 20 T solenoid with a clear bore of 150 mm can capture particles with a transverse momentum of 225 MeV/c or less. As the captured particles leave the capture solenoid, the magnetic induction is decreased to 5 T while the beam pipe diameter increases to 300 mm. Phase rotation of the pions and the decay of the pions to muons will occur at 5 T. The capture solenoid and the solenoids just downstream from the capture solenoid are subject to high heat loads (up to 4.8 MW) and radiation loads from the target. The conventional inner solenoid of the 20 T hybrid magnet system and the water cooled absorber will absorb virtually all of the particle energy from the target thus protecting the superconducting part of the solenoid system from excessive radiation heating. This report also describes the solenoid magnets from the capture zone to the solenoidal beam channel within the phase rotation RF cavities. C1 MIT,CAMBRIDGE,MA 02139. RP Green, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 642 EP 645 DI 10.1109/77.614586 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400129 ER PT J AU Daugherty, MA Coulter, JY Hults, WL Daney, DE Hill, DD McMurry, DE Martinez, MC Phillips, LG Willis, JO Boenig, HJ Prenger, FC Rodenbush, AJ Young, S AF Daugherty, MA Coulter, JY Hults, WL Daney, DE Hill, DD McMurry, DE Martinez, MC Phillips, LG Willis, JO Boenig, HJ Prenger, FC Rodenbush, AJ Young, S TI HTS high gradient magnetic separation system SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID COMPOSITE AB We report on the assembly, characterization and operation of a high temperature superconducting (HTS) magnetic separator. The magnet is made of 624 m of Silver/BSCCO superconducting wire and has overall dimensions of 18 cm OD, 15.5 cm height and 5 cm ID. The HTS current leads are designed to operate with the warm end at 75 K and the cold end at 27 K. The system operates in a vacuum and is cooled by a two stage Gifford-McMahon cryocooler. The upper stage of the cryocooler cools the thermal shield and two heat pipe thermal intercepts, The lower stage of the cryocooler cools the HTS magnet and the bottom end of the HTS current leads. The HTS magnet was initially characterized in liquid cryogens. We report on the current-voltage (I-V) characteristics of the HTS magnet at temperatures ranging from 15 to 45 K. At 40 K the magnet can generate a central field of 2.0 T at a current of 120 A. C1 AMER SUPERCOND CORP,WESTBOROUGH,MA. RP Daugherty, MA (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 6 TC 5 Z9 5 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 650 EP 653 DI 10.1109/77.614588 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400131 ER PT J AU Seol, SY Cha, YS Niemann, RC Hull, JR AF Seol, SY Cha, YS Niemann, RC Hull, JR TI Prediction of burnout of a conduction-cooled BSCCO current lead SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTING CURRENT LEADS; TEMPERATURE AB A one-dimensional heat conduction model is employed to predict burnout of a Bi2Sr2CaCu2O8 current lead, The upper end of the lead is assumed to be at 77 K and the lower end is at 4 K. The results show that burnout always occurs at the warmer end of the lead. The lead reaches its temperature in two distinct stages. the temperature rises slowly when part of the lead is in flux-flow As the local state. As the local temperapure, it begins to increase shaply. Burnout time depends strongly on flux-flow resistivity. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Seol, SY (reprint author), CHONNAM NATL UNIV,DEPT MECH ENGN,KWANGJU 700757,SOUTH KOREA. NR 11 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 696 EP 699 DI 10.1109/77.614599 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400142 ER PT J AU Fisher, BL Lanagan, MT Balachandran, U Honjo, S Hara, T AF Fisher, BL Lanagan, MT Balachandran, U Honjo, S Hara, T TI Design of a high-current AC downlink using Bi-based superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Recent processing developments in Bi1.8Pb0.4Sr2Ca2Cu3Ox (BSCCO-2223) bars have produced bulk BSCCO-2223 bars with properties advantageous for power applications. Cold isostatically pressed (CIP) and sinter-forged BSCCO-2223 both have low AC loss, which make them desirable for use in power devices. Thermal conductivity of the CIP bars is lower than that of the previously used sinter-forged samples by a factor of 2. CIP bars with cross-sectional areas of approximate to 0.75 cm(2) and carrying 250 A RMS transport current have AC loss values of 30 mu J/cycle-cm at 50 Hz and 77 K. A pair of prototype downlinks were designed and built with sinter forged bars to deliver a continuous AC current of 1500 A over a temperature gradient of 77 to 4.2 K while delivering about approximate to 200 mW of heat to the liquid-helium-cooled end. This paper will discuss the design considerations and modeling of downlinks, which supply high AC currents over the 77 to 4.2 K temperature gradient with low thermal losses. C1 TOKYO ELECT POWER CO LTD,YOKOHAMA,KANAGAWA 230,JAPAN. RP Fisher, BL (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 711 EP 714 DI 10.1109/77.614603 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400146 ER PT J AU Lietzke, AF Benjegerdes, R Caspi, S DellOrco, D Harnden, W McInturff, AD Morrison, M Scanlan, RM Taylor, CE vanOort, JM AF Lietzke, AF Benjegerdes, R Caspi, S DellOrco, D Harnden, W McInturff, AD Morrison, M Scanlan, RM Taylor, CE vanOort, JM TI Test results for a Nb3Sn dipole magnet SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A cosine theta type dipole magnet using Nb3Sn conductor have been designed, built and tested. D19H is a two-layer dipole magnet with a Nb3Sn inner layer and a recycled NbTi outer layer. Coil-pairs are connected with two of the four Nb3Sn splices in a high field region, and compressed by a ring and collet system. The ramp-rate sensitivity and the splice resistances were pleasingly low; and the 4.4K training was rapid. At 1.8K, however, the unusually high frequency of outer-coil fast-motion events increased with current, effectively creating a training-ceiling at 90% of the expected outer-layer limit (10.2 T). A low end-load applied to a relatively fluffy outer layer is believed to have caused this training limit. The end-load was increased; but a retest was aborted after the magnet failed a precautionary hipot test. RP Lietzke, AF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 3 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 739 EP 742 DI 10.1109/77.614609 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400152 ER PT J AU Green, MA Willen, E AF Green, MA Willen, E TI Superconducting dipoles and quadrupoles for a 2 TeV muon collider SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB At 2 TeV the mean life time for a muon is 41.6 ms. In order to achieve high luminosity at the collider collision point, the dipole central induction for the storage ring should be over 8 T. The storage ring carries muon over 1000 turns through the ring before they decay away. Muons decay to two neutrinos and an electron or positron (depending on the charge of the decaying muon). Seventy percent of the muon energy will be taken away by the neutrinos. The electrons (at average energies of 700 GeV) and the photons (at energies up to 2.1 GeV) are quite penetrating. At the design luminosity of the muon collider, the superconducting dipoles and quadrupoles in the storage ring must contain muon beams (up to 1.4x10(14) muons per second) that will deposit over 1.8 kW per meter of energy into the storage ring. This report presents two design approaches for superconducting dipoles and quadrupoles than can be used for the muon collider storage ring. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Green, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 743 EP 746 DI 10.1109/77.614610 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400153 ER PT J AU Bossert, R Feher, S Gourlay, SA Heger, T Huang, Y Kerby, J Lamm, MJ Limon, PJ Mazur, PO Nobrega, F Ozelis, JP Sabbi, G Strait, J Zlobin, AV Caspi, S Dellorco, D McInturff, AD Scanlan, RM VanOort, JM Gupta, RC AF Bossert, R Feher, S Gourlay, SA Heger, T Huang, Y Kerby, J Lamm, MJ Limon, PJ Mazur, PO Nobrega, F Ozelis, JP Sabbi, G Strait, J Zlobin, AV Caspi, S Dellorco, D McInturff, AD Scanlan, RM VanOort, JM Gupta, RC TI Development of a high gradient quadrupole for the LHC interaction regions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A collaboration of Fermilab, Lawrence Berkeley National Laboratory and Brookhaven National Laboratory is engaged in the design of a high gradient quadrupole suitable for use in the LHC interaction regions. The cold iron design incorporates a two-layer, cos(2 theta) coil geometry with a 70 mm aperture operating in superfluid helium. This paper summarizes the progress on a magnetic, mechanical and thermal design that meets the requirements of maximum gradient above 250 T/m, high field quality and provision for adequate cooling in a high radiation environment. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Bossert, R (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 11 TC 19 Z9 19 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 751 EP 754 DI 10.1109/77.614612 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400155 ER PT J AU Brindza, PD Fowler, MJ Wines, RT Lassiter, SR Milward, SR Pearmain, S Schouten, J Oda, N Tamura, K Ramsauer, F Wenger, S Bogensberger, P Sammer, H Dermoetz, H AF Brindza, PD Fowler, MJ Wines, RT Lassiter, SR Milward, SR Pearmain, S Schouten, J Oda, N Tamura, K Ramsauer, F Wenger, S Bogensberger, P Sammer, H Dermoetz, H TI Commissioning the superconducting magnets for the High Momentum Spectrometer (HMS) at TJNAF SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CEBAF AB The High Momentum Spectrometer (HMS) became operational in June 1994 and is now in routine use as a nuclear physics spectrometer in Hall C at TJNAF. The commissioning including installation, cooldown, initial operation, testing and acceptance of the SC Quadrupoles and SC Dipole of the HMS will be discussed. Results of measurements performed on the magnets will be presented. The loss of a Dipole current lead, failure analysis and the repairs will be discussed. A brief discussion of the Hall C SC magnet cryogenics will be included. C1 OXFORD INSTRUMENTS LTD,OXFORD OC2 0DX,ENGLAND. JAPAN STEEL WORKS LTD,MURORAN,HOKKAIDO,JAPAN. ELIN EA,MAGNETECN,WEIZ,AUSTRIA. JOHANEAUM RES,ATF,GRAZ,AUSTRIA. RP Brindza, PD (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 12 TC 6 Z9 6 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 755 EP 758 DI 10.1109/77.614613 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400156 ER PT J AU Walker, MS Hazelton, DW Gardner, MT Rice, JA Walker, DG Trautwein, CM Ternullo, NJ Shi, X Weloth, JM Sokolowski, RS List, FA AF Walker, MS Hazelton, DW Gardner, MT Rice, JA Walker, DG Trautwein, CM Ternullo, NJ Shi, X Weloth, JM Sokolowski, RS List, FA TI Performance of coils wound from long lengths of surface-coated, reacted, BSCCO-2212 conductor SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB React-before-wind surface-coated BSCCO-2212 is being established as a relatively low cost HTS conductor for practical applications. Quality tape is presently being manufactured in lengths of 450 to 500m at a cost estimated to be 1/3 to 1/5 of the industry costs of BSCCO-2223 powder-in-tube tape. Robust, mechanically sound coils for applications ranging from NMR insert magnets to transformer windings are being made from this BSCCO-2212 tape. The coils have performed consistently through test and thermal cycling without degradation and operate as projected from short sample measurements. A hybrid approach, which uses mainly BSCCO-2212 augmented by BSCCO-2223 conductor in the high radial field end regions. is expected to halve the overall superconductor cost for magnet systems. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Walker, MS (reprint author), INTERMAGNET GEN CORP,LATHAM,NY 12110, USA. NR 13 TC 18 Z9 18 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 889 EP 892 DI 10.1109/77.614646 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400189 ER PT J AU Scanlan, RM McInturff, AD Taylor, CE Caspi, S DellOrco, D Higley, H Gourlay, S Bossert, R Brandt, J Zlobin, AV AF Scanlan, RM McInturff, AD Taylor, CE Caspi, S DellOrco, D Higley, H Gourlay, S Bossert, R Brandt, J Zlobin, AV TI Design and fabrication of a high aspect ratio cable for a high gradient quadrupole magnet SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The Large Hadron Collider interaction regions require quadrupoles with a 70 mm diameter bore, a gradient of 250 T/m, and good cooling so that the magnets can operate in a high radiation background without quenching. In order to meet these stringent requirements, a two-layer magnet with a high aspect ratio cable has been designed. This cable utilizes the SSC inner and outer layer strands, which have been optimized and are available in large quantities. The initial design parameters for both cables are 15.2 mm width; the inner cable has 38 strands of 0.8 mm diam wire and a keystone angle of 0.99 deg. The outer cable has 46 strands of 0.65 mm diam wire and a keystone angle of 0.69 deg. These cables have been fabricated and then subjected to a number of tests to insure their performance in the quadrupole. These test results, including model coil winding studies, electrical property measurements, and mechanical property measurements will be presented. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Scanlan, RM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 936 EP 938 DI 10.1109/77.614658 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400201 ER PT J AU Hwang, KP Finkel, P Wallace, A Naumovich, G Zbasnik, J Martovetsky, N AF Hwang, KP Finkel, P Wallace, A Naumovich, G Zbasnik, J Martovetsky, N TI Design, fabrication and testing of a production line for TPX demonstration conductor SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A complete production line for fabricating CICC dummy conductor has been designed, constructed and tested for TPX program. The line is capable of producing up to 500 meters of CICC conductor and is scaleable up to 1.5 km in length. The line consists of a payoff spool for feeding cable inside the tubes, a welding station, a drawing station which includes dies and a bull-block, and a takeup spool. We have demonstrated the fabrication of the conductors. Two types of conductor, one for TF and the other one for PP coil have been produced. The conduit materials are Incoloy 908, which are formed from strips. The cables are made from OFHC copper strands. The detail design, fabrication and testing of each component of the system is presented in this paper. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Hwang, KP (reprint author), EVERSON ELECT CO,BETHLEHEM,PA 18017, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 939 EP 941 DI 10.1109/77.614659 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400202 ER PT J AU Ghosh, AK Sampson, WB Wilson, MN AF Ghosh, AK Sampson, WB Wilson, MN TI Minimum quench energies of Rutherford cables and single wires SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The stability of magnet conductors may be characterized by their minimum quench energy (MQE), i.e. the minimum energy pulse (of small extent and short duration) needed to trigger a quench, Using small graphite paste and epoxy heaters, we have measured the MQE on a broad range of single wires and Rutherford cables as a function of current, field, temperature and pulse duration, Surface heat transfer to the helium plays an important role. For the cables, we find that specially processed 'porous-metal' cables have by far the highest degree of stability. Measurements are compared with theory. C1 CERN,CH-1211 GENEVA 23,SWITZERLAND. RP Ghosh, AK (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 4 TC 19 Z9 19 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 954 EP 957 DI 10.1109/77.614663 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400206 ER PT J AU Adam, JD Leroy, D Oberli, LR Richter, D Wilson, MN Wolf, R Higley, H McInturff, AD Scanlan, RM Nijhuis, A tenKate, HHJ Wessel, S AF Adam, JD Leroy, D Oberli, LR Richter, D Wilson, MN Wolf, R Higley, H McInturff, AD Scanlan, RM Nijhuis, A tenKate, HHJ Wessel, S TI Rutherford cables with anisotropic transverse resistance SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Putting a resistive core into the center of a Rutherford cable increases resistance between strands in the crossover direction, which greatly reduces the coupling currents, even when the resistance to adjacent turns remains small. This allows one to improve stability by soldering strands together or using porous metal, without incurring a penalty of increased coupling. We describe our manufacturing methods and an experimental measurement of coupling. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV TWENTE,NL-7500 AE ENSCHEDE,NETHERLANDS. RP Adam, JD (reprint author), CERN,CH-1211 GENEVA 23,SWITZERLAND. NR 6 TC 17 Z9 17 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 958 EP 961 DI 10.1109/77.614664 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400207 ER PT J AU Collings, EW Sumption, MD Kim, SW Wake, M Shintomi, T Nijhuis, A tenKate, HHJ Scanlan, RM AF Collings, EW Sumption, MD Kim, SW Wake, M Shintomi, T Nijhuis, A tenKate, HHJ Scanlan, RM TI Suppression and control of coupling currents in stabrite-coated Rutherford cable with cores of various materials and thicknesses SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID LOSSES; MAGNETS; FIELD; LHC AB Calorimetric and magnetic measurements of AC loss have been performed on stabrite-coated Rutherford cable conforming to the Large Hadron Collider (LHC) inner-winding (28 strand) specification, with the applied field directed either perpendicular to the broad face (the face-on, FO, orientation) or parallel to it (edge-on, EO). It was found that the insertion of a thin metallic or insulating core into the cable suppressed the FO AC loss under typical conditions by a factor of 10 and rendered it practically insensitive to the application of cold uniaxial stress (of up to about 78 MPa). The FO loss having been suppressed, it could also be controlled (i.e. finely adjusted) by changing the level compaction (by varying core thickness at thickness) or external compaction (by changing the overall thickness of the fable). Of course the EO loss was much less sensitive to the presence of a core, the use of which therefore enabled the FO and EO losses to be independently adjusted. C1 KEK NAT LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. UNIV TWENTE,NL-7500 AE ENSCHEDE,NETHERLANDS. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Collings, EW (reprint author), OHIO STATE UNIV,COLUMBUS,OH 43210, USA. RI Sumption, Mike/N-5913-2016 OI Sumption, Mike/0000-0002-4243-8380 NR 25 TC 16 Z9 16 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 962 EP 966 DI 10.1109/77.614665 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400208 ER PT J AU Jayakumar, R Gwinn, D Montgomery, B Minervini, J Gung, CY Randall, R Beck, W Childs, R Thibeault, E Smith, B Hrycaj, T Wohlwend, J Paganini, D Gertsch, P Hawley, L Miyata, G Martovetsky, N Zbasnik, J Reed, R AF Jayakumar, R Gwinn, D Montgomery, B Minervini, J Gung, CY Randall, R Beck, W Childs, R Thibeault, E Smith, B Hrycaj, T Wohlwend, J Paganini, D Gertsch, P Hawley, L Miyata, G Martovetsky, N Zbasnik, J Reed, R TI Fabrication of ITER central solenoid model coil inner module SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The US Home Team is responsible for the design and fabrication of the inner module for the ITER Central Solenoid Model Coil, to be installed and tested at JAERI, Japan. The design of the coil has been completed and the fabrication is being carried out,In the first phase, all the tooling for the fabrication have been installed, facilities established, process specifications developed and materials procured. The fabrication approach will be confirmed by various trials, and fabrication of two full-size dummy layers. Following; this, the fabrication of the 10 layer module occurs between June 1996 and December 1997. The paper describes the tooling and facilities, the process and supporting R&D. Progress in the fabrication is reported. C1 LOCKHEED MARTIN,SAN DIEGO,CA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. CRYOGEN MAT INC,BOULDER,CO. RP Jayakumar, R (reprint author), MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139, USA. NR 2 TC 4 Z9 4 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 981 EP 984 DI 10.1109/77.614669 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400212 ER PT J AU Leung, EM Rodriguez, A Albert, GW Burley, B Dew, M Gurrola, P Madura, D Miyata, G Muehleman, K Nguyen, L Pidcoe, S Ahmed, S Dishaw, G Nieto, C Kersenbaum, I Gamble, B Russo, C Boenig, H Peterson, D Motowildo, L Haldar, P AF Leung, EM Rodriguez, A Albert, GW Burley, B Dew, M Gurrola, P Madura, D Miyata, G Muehleman, K Nguyen, L Pidcoe, S Ahmed, S Dishaw, G Nieto, C Kersenbaum, I Gamble, B Russo, C Boenig, H Peterson, D Motowildo, L Haldar, P TI High temperature superconducting fault current limiter development SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A near term High Temperature Superconductor (HTS) application is the Fault Current Limiter (FCL). This paper describes the development and testing of a 2.4 kV, 2.2 kArms fault current, 150 Arms continuous current, I-ITS FCL that uses a Bi-2223 Ag based conductor. The Lockheed Martin team, which included Southern California Edison (SCE), American Superconductor Corporation (ASC), and Las Alamos National Laboratory (LANL), completed in October 1995 a two year Phase I program. This unit has undergone a six-week extensive testing at SCE's Center Substation in Norwalk, California. The unit's capability and test results are presented. Plans for the construction of higher rating units including a Phase II program are outlined. Descriptions of the underlying principle of a FCL and how it can benefit the power utility industry are also presented. C1 SO CALIF EDISON CO,IRWINDALE,CA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. INTERMAGNET GEN CORP,LATHAM,NY 12110. RP Leung, EM (reprint author), LOCKHEED MARTIN CORP,RANCHO BERNARDO,CA, USA. NR 5 TC 21 Z9 26 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 985 EP 988 DI 10.1109/77.614670 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400213 ER PT J AU Deis, TA Eror, NG Lelovic, M Prorok, BC Balachandran, U AF Deis, TA Eror, NG Lelovic, M Prorok, BC Balachandran, U TI Properties of freeze-dried Bi2Sr2CaCu2O8+d: Effects of Ag doping and analysis of powder-in-tube tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CRITICAL-CURRENT DENSITIES; SUPERCONDUCTING PROPERTIES; OXYGEN STOICHIOMETRY; WIRES; CONDUCTORS; SYSTEM AB Low level doping (less than or equal to 1 atomic %) of Ag in Bi2Sr2CaCu2O8+d was performed via freeze-drying of nitrate solutions. Effects of Ag doping on the c-axis lattice parameter, oxygen content and critical temperature were monitored. Powder-in-tube tapes were fabricated using both Ag-doped and undoped Bi2Sr2CaCu2O8+d powders. Tapes were processed using a partial melt heat treatment in flowing oxygen. The effects of Ag doping on the critical current and microstructure were investigated, specifically the Ag-Bi2Sr2CaCu2O8+d interface region. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Deis, TA (reprint author), UNIV PITTSBURGH,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15261, USA. RI Prorok, Barton/A-7404-2010 NR 20 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1037 EP 1040 DI 10.1109/77.614695 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400226 ER PT J AU Smith, BA Hale, JR Zhukovsky, A Michael, PC Minervini, JV Olmstead, MM Dekow, GL Rosati, J Camille, RJ Gung, CY Gwinn, D Silva, F Fairfax, SA Shen, S Knoopers, HG Wessel, S Krooshoop, HJG Shevchenko, OA Godeke, A tenKate, HHJ AF Smith, BA Hale, JR Zhukovsky, A Michael, PC Minervini, JV Olmstead, MM Dekow, GL Rosati, J Camille, RJ Gung, CY Gwinn, D Silva, F Fairfax, SA Shen, S Knoopers, HG Wessel, S Krooshoop, HJG Shevchenko, OA Godeke, A tenKate, HHJ TI PTF, a new facility for pulse field testing of large scale superconducting cables and joints SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB A magnetic Pulse Test Facility (PTF), in which samples of CICC electrical joints from each ITER home team will be tested, has been fabricated at the MIT Plasma Fusion Center under an ITER task agreement. Construction of this facility has recently been completed, and an initial test phase on the first CICC joint sample has begun. PTF includes capabilities for sample currents up to 50 kA from a superconducting transformer developed by the University of Twente, magnetic fields up to 6.6 T with ramp rates to +1.5 T/s and -20 T/s, and a cryogenic interface, supplying supercritical helium with flow rates to 20 g/s through each CICC leg at controlled temperatures to 10 K and pressures to 10 atmospheres. A sophisticated, multiple-channel data acquisition system is provided to processed, digitally recorded sensor signals from both the sample and the facility. The facility is totally remote-controlled from a control room through a fiber optic link, and qualified users worldwide are afforded secured access to test data on a 24-hour basis via the Internet. The facility has successfully exercised the first joint sample over the ITER test spectrum with positive results. C1 FAILURE ANAL ASSOCIATES,CAMBRIDGE,MA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. UNIV TWENTE,LOW TEMP DIV,ENSCHEDE,NETHERLANDS. RP Smith, BA (reprint author), MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139, USA. OI Michael, Philip/0000-0003-4906-6169 NR 8 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1049 EP 1052 DI 10.1109/77.614700 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH864 UT WOS:A1997XH86400229 ER PT J AU Dietderich, DR Scanlan, RM AF Dietderich, DR Scanlan, RM TI Nb3Sn artificial pinning microstructures SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Extension of the APC approach to Nb3Sn requires that a second phase be incorporated into the Nb3Sn layer. The second phase would increase pinning strength by either reducing the grain size or by the second phase pinning the flux itself. The following criteria for elements to be candidates for the APC approach are: (1) they must form intermetallic compounds with Cu or Sn and (2) they must have negligible solubility in Cu and Nb or they must be strong oxide formers. Many of the rare earth elements satisfy these criteria. To circumvent the large strains required to produce wires with a fine distribution of the second phase, film deposition techniques have been used. Critical current densities for Nb films doped with Ti and Y are about 4,000 A/mm(2) at 6T and 4.2K. RP Dietderich, DR (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1201 EP 1204 DI 10.1109/77.620719 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600022 ER PT J AU Findikoglu, AT Arendt, PN Groves, JR Foltyn, SR Peterson, EJ Reagor, DW Jia, QX AF Findikoglu, AT Arendt, PN Groves, JR Foltyn, SR Peterson, EJ Reagor, DW Jia, QX TI Microwave surface resistance of YBa2Cu3O7-delta films on polycrystalline alumina and Ni-based alloy substrates with ion-beam-assisted-deposited buffer layers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTING THIN-FILMS; SAPPHIRE; GROWTH; LOSSES AB We measured the microwave surface resistance R-s of superconducting YBa2Cu3O7-x (YBCO) films on buffered polycrystalline alumina and Ni-based alloy substrates using parallel-plate technique, We observed a strong correlation between the low-power R-s and the in-plane mosaic spread of the YBCO films. A 0.4-mu m-thick YBCO film with an in-plan mosaic spread of 6.6 degrees (7 degrees) on a buffered polycrystalline Ni-based alloy (buffered polycrystalline alumina) substrate showed an R-s of 0.51 m Omega (1.89 m Omega) at 76 K and 0.17 m Omega (0.21 m Omega) at 4 K. RP Findikoglu, AT (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MS K763,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 17 TC 2 Z9 2 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1232 EP 1235 DI 10.1109/77.620735 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600030 ER PT J AU Goretta, KC Jiang, M Kupperman, DS Lanagan, MT Singh, JP Vasanthamohan, N Hinks, DG Mitchell, JF Richardson, JW AF Goretta, KC Jiang, M Kupperman, DS Lanagan, MT Singh, JP Vasanthamohan, N Hinks, DG Mitchell, JF Richardson, JW TI Strength and flexibility of bulk high-T-c superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID MECHANICAL-PROPERTIES; THERMAL-EXPANSION; CURRENT-DENSITY; STRAIN; TAPES; TEMPERATURE; BI2SR2CACU2OX; COEFFICIENTS; YBA2CU3O7-X; CONDUCTORS AB Strength, fracture toughness, and elastic modulus data for bulk high-temperature superconductors, commercial 99.9% Ag, and a 1.2 at.% Mg/Ag alloy have been collected These data have been used to calculate fracture strains for bulk conductors. The calculations indicate that the superconducting cores of clad tapes should begin to fracture at strains below 0.2%. In addition, residual strains in Ag-clad (Bi,Pb)(2)Sr2Ca2Cu3Ox tapes have been measured by neutron diffraction. An explanation is offered for why many tapes appear to be able to tolerate large strains before exhibiting a reduction in current transport. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Goretta, KC (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439, USA. NR 36 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1307 EP 1310 DI 10.1109/77.620765 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600048 ER PT J AU Telschow, KL Bruneel, FW Walter, JB Koo, LS AF Telschow, KL Bruneel, FW Walter, JB Koo, LS TI Noncontacting ultrasonic and electromagnetic HTS tape NDE SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Two noncontacting nondestructive evaluation techniques, one electromagnetic the other ultrasonic, for inspection of high temperature superconducting tapes are described. Results for Ag-clad BSCCO tapes are given. RP Telschow, KL (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 8 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1319 EP 1322 DI 10.1109/77.620768 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600051 ER PT J AU Schwartzkopf, LA Finnemore, DK AF Schwartzkopf, LA Finnemore, DK TI Ramp rate effect in Bi2Sr2Ca2Cu3O10+delta formation SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The properties of Ag-sheathed Bi2223 tapes depend strongly on the thermomechanical treatment processing parameters. We have examined the conversion of precursor powders to Bi2223 in heat-treated tapes as a function of ramp-to-temperature rate. Tapes containing precursor powders were ramped at rates from 50 degrees C/h to 800 degrees C/h to a Anal temperature of 835 degrees C, then held for 50 h, all in 20% O-2 and 80% N-2. The composition of the tapes was then determined by x-ray diffraction and by low-temperature magnetization measurements. The heat-treated tapes consisted almost entirely of a mixture of Bi2212 and Bi2223. The volume ratio of Bi2223 to Bi2212 in the tapes depended on the ramp rate in a complicated way; the volume ratio was largest (1.17) at 50 degrees C/h, the slowest ramp rate. C1 IOWA STATE UNIV,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. RP Schwartzkopf, LA (reprint author), MANKATO STATE UNIV,DEPT PHYS & ASTRON,MANKATO,MN 56002, USA. NR 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1415 EP 1417 DI 10.1109/77.620836 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600075 ER PT J AU Ghosh, AK Sampson, WB AF Ghosh, AK Sampson, WB TI Critical current measurements of NbTi wires in the temperature range 4.2 - 1.8 K SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB The critical currents of several NbTi wires have been measured in boiling helium in the temperature range 4.2 - 1.8 K and at magnetic fields up to 10 T. In some instances, I-c (defined at a resistivity of 10(-14) ohm) can be measured over the entire temperature range while for other conductors the quench drops below I-c as the temperature is reduced and the critical current cannot be determined. For most of these strands I-c can again be measured once the helium bath is in the superfluid state but for some wires it is not possible to measure the effective resistivity even in superfluid. Conductors fabricated by the same manufacturer can exhibit completely different behavior. In general there is a tendency for wires with high intrinsic current density and relatively low copper content to perform erratically at the lower temperature. RP Ghosh, AK (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 1 TC 1 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1459 EP 1462 DI 10.1109/77.620847 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600086 ER PT J AU Wei, WH Sun, YG Schwartz, J Goretta, K Balachandran, U Bhargava, A AF Wei, WH Sun, YG Schwartz, J Goretta, K Balachandran, U Bhargava, A TI Preparation and properties of nanosize TiO2 and MgO-Doped Bi2Sr2CaCu2Ox tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID FLUX; CRYSTALS; DEFECTS; LINE AB Nanosize MgO and TiO2 particles were added to the Bi2Sr2CaCu2Ox, powder with 20% molar fraction. Powder-in-tube Ag-sheathed tapes were made from the doped powders and heat treated by partial melting processing, Heat treatment optimization was carried out to increase the critical current density, Scanning electron microscopy and energy-dispersive Xray spectra were used to study the phases present in the tapes, The effect of MgO additions on the flux pinning behavior was investigated by magnetic hysteresis and transport critical current measurements at various temperatures and fields. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. UNIV QUEENSLAND,ELECTRON MICROSCOPE DIV,BRISBANE,QLD 4072,AUSTRALIA. RP Wei, WH (reprint author), FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32310, USA. RI Schwartz, Justin/D-4124-2009 OI Schwartz, Justin/0000-0002-7590-240X NR 11 TC 12 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1556 EP 1559 DI 10.1109/77.620871 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600110 ER PT J AU Li, Q Tsay, YN Zhu, Y Suenaga, M Gu, GD Koshizuka, N AF Li, Q Tsay, YN Zhu, Y Suenaga, M Gu, GD Koshizuka, N TI Electromagnetic properties of high angle [001] twist grain boundaries in Bi2Sr2CaCu2O8+delta bicrystals SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTOR BI2SR2CA2CU3O10 AB Detailed measurement of electrical resistivity and V-1 curves as a function of temperature and magnetic field up to 9 T were performed on several superconducting Bi2Sr2CaCu2O8+delta (Bi-2212) bicrystals with symthetic high angle [001] twist grain boundaries. We found that the resistive onset temperature and field (at level of 10 nV) for all of the measured high angle twist boundaries were similar to those for their constituent single crystals. Furthermore, these boundaries were able to carry critical current as high as the single crystals. Our results suggested absence of weak-link behavior in the high angle [001] twist grain boundaries of Bi-2212 bicrystals. C1 ISTEC,SUPERCONDUCT RES LAB,TOKYO 135,JAPAN. RP Li, Q (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 5 TC 16 Z9 16 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1584 EP 1587 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600117 ER PT J AU Venturini, EL Newcomer, PP Siegal, MP Overmyer, DL AF Venturini, EL Newcomer, PP Siegal, MP Overmyer, DL TI Enhanced vortex pinning in annealed TlBa2CaCu2Ox thin films SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CU-O CRYSTALS; CRITICAL CURRENTS; ION IRRADIATION; FLUX-CREEP; SUPERCONDUCTORS; IRREVERSIBILITY; MAGNETIZATION; YBA2CU3O7; DEFECTS; MODEL AB Furnace anneals of TIBa2CaCu2Ox thin films at temperatures above 500 degrees C cause partial TIOx loss. High-resolution transmission electron microscopy images reveal nanometer-scale discontinuities (pinched stacking faults) in the microstructure of annealed films. Significant increases in the vortex pinning potential and critical current density at elevated temperatures in strong magnetic fields are observed and are attributed to the presence of these localized defects. RP Venturini, EL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1592 EP 1595 DI 10.1109/77.620880 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600119 ER PT J AU Merchant, NN Fischer, AK Maroni, VA Carter, WL Parrella, RD AF Merchant, NN Fischer, AK Maroni, VA Carter, WL Parrella, RD TI Identification and quantification of phases formed during the processing of (Bi,Pb)(2)Sr2Ca2Cu3Ox/Ag composite conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID TAPES; EVOLUTION; (BI AB Scanning electron microscopy, energy dispersive Xray analysis (including X-ray dot mapping), X-ray diffraction and computer-based image analysis have been used to study nonsuperconducting secondary phases I:hat evolve during the processing of (Bi,Pb)(2)Sr2Ca2Cu2Ox/Ag composite conductors, These investigations have provided nea information and insights about specific alkaline earth cuprates (AECs) and lead-rich phases. We can conclusively identify (Ca,Sr)(2)CuO3, (Ca,Sr)(14)Cu24O41 (14/24), and CuO phases, the alkaline earth plumbates, and a (Bi,Pb)-Sr-Ca-Cu-O 3221 phase with a wide range of Pb/Bi ratios. These techniques also help in differentiating voids from secondary phases and alkaline earth plumbates front the lead-rich 3221 phase. C1 AMER SUPERCONDUCTOR CORP,WESTBOROUGH,MA 01581. RP Merchant, NN (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 13 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1608 EP 1611 DI 10.1109/77.620884 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600123 ER PT J AU Mueller, CH Galt, D Treece, RE Rivkin, TV Webb, JD Moutinho, HR Dalberth, M Rogers, CT AF Mueller, CH Galt, D Treece, RE Rivkin, TV Webb, JD Moutinho, HR Dalberth, M Rogers, CT TI Infrared characterization of SrTiO3 thin films using attenuated total reflectance SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID YBA2CU3O7-X/SRTIO3 AB Attenuated Total Reflectance was used to measure phonon vibration frequencies over the range 425-800 cm(-1) of SrTiO3 thin films deposited either directly on LaAlO3, or on YBCO-coated LaAlO3 single crystal substrates. In the s-polarized spectra, the transverse optic Ti-O stretching vibration shifted to lower frequencies as the film thickness increased, which was attributed to damping caused by the generation of lower frequency phonon modes. The transverse Ti-O stretching vibration was also observed in the p-polarized spectra, but was more heavily damped, which indicates the damping is more pronounced when the electric field has a component perpendicular to the film surface. Damping of the transverse modes was attributed to coupling of these modes to other phonon modes, and may be a source of the high losses at microwave frequencies. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV COLORADO,BOULDER,CO 80309. RP Mueller, CH (reprint author), SCT,GOLDEN,CO 80401, USA. NR 12 TC 1 Z9 1 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1628 EP 1631 DI 10.1109/77.620889 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600128 ER PT J AU Suenaga, M Fukumoto, Y Wiesmann, HJ Haldar, P Budhani, R AF Suenaga, M Fukumoto, Y Wiesmann, HJ Haldar, P Budhani, R TI Effects of dc transport currents on ac losses by the magnetically induced currents in a Ag sheathed Bi(2223) tape SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID ALTERNATING-CURRENT LOSSES; (BI,PB)(2)SR2CA2CU3O10 TAPES AB ac losses at 60Hz for a Ag sheathed Bi(2223) by a magnetically induced current technique were measured as a function of applied ac field and de transport current. The results were qualitatively in agreement with the theory, which is based on the Bean critical state model, by T. Ogasawara, et al. (Cryogenics, Vol. 19, Dec. 1979, pp. 236-740). Possible sources for some quantitative disagreements between the results and the theory are discussed. C1 KOBE STEEL LTD,NISHI KU,KOBE,HYOGO 65122,JAPAN. INTERMAGNET GEN CORP,LATHAM,NY 12110. INDIAN INST TECHNOL,KANPUR,UTTAR PRADESH,INDIA. RP Suenaga, M (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 11 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1674 EP 1678 DI 10.1109/77.620900 PN 2 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600139 ER PT J AU Breitwisch, MJ Kouzoudis, D Ostenson, JE Finnemore, DK Balachandran, U AF Breitwisch, MJ Kouzoudis, D Ostenson, JE Finnemore, DK Balachandran, U TI Characterization of interfacial growth between Bi(2212) and Ag coating SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID BI2SR2CA2CU3O10+DELTA AB The growth of hillocks at the interface between Bi(2212) and Ag has been found to occur over a wide range of oxygen partial pressure and in the vicinity of 700 degrees C, a temperature far below the Bi(2212)-Bi(2223) conversion temperature. These hillocks have been examined by environmental scanning microscope (ESEM) and regular SEM in secondary and backscattering modes. Definitive chemical analysis is still an open question. The Ag is highly mobile at these temperatures. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Breitwisch, MJ (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1691 EP 1694 DI 10.1109/77.620904 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600143 ER PT J AU Sengupta, S Corpus, J Gaines, JR Todt, VR Zhang, XF Miller, DJ Varanasi, C McGinn, PJ AF Sengupta, S Corpus, J Gaines, JR Todt, VR Zhang, XF Miller, DJ Varanasi, C McGinn, PJ TI Fabrication and characterization of melt-processed YBCO SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID YBA2CU3OX AB Large domain YBCO are fabricated by using a melt processing technique for magnetic levitation applications. A Nd1+xBa2-xCu3Oy seed is used to initiate grain growth and to control the orientation of YBCO grains. Samples as large as 50 mm diameter have been fabricated by utilizing this method. Microstructural studies reveals two distinct regions in these levitators due to different growth mechanisms along the a/b and c axes. Some initial result on the mass production of these levitators are also reported. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. UNIV NOTRE DAME,DEPT CHEM ENGN,NOTRE DAME,IN 46556. RP Sengupta, S (reprint author), SUPERCONDUCT COMPONENTS,COLUMBUS,OH, USA. NR 8 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1723 EP 1726 DI 10.1109/77.620912 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600151 ER PT J AU Sengupta, S Todt, VR Goretta, KC Miller, DJ Chen, YL Balachandran, U AF Sengupta, S Todt, VR Goretta, KC Miller, DJ Chen, YL Balachandran, U TI Effects of carbon additions to melt-processed YBa2Cu3Ox and Bi2Sr2CaCu2Oy compacts SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTING TAPES; BI; MICROSTRUCTURE; MAGNETIZATION; FILMS AB YBa2Cu3Ox (Y-123) and Bi2Sr2CaCu2Oy (Bi-2212) compacts were partial-melt processed. Carbon was introduced into the compacts either by vibratory milling in an organic solution or by heat treating in an atmosphere containing a controlled concentration of CO2. The presence of carbon had a strong effect on the melting response of Y-123, but not Bi-2212. For both materials, magnetic-hysteresis width was strongly expanded with added carbon. Transmission electron microscopy revealed nanometer-stale precipitates In specimens exposed to excess carbon. These precipitates are thought to be responsible for enhanced flux pinning. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Sengupta, S (reprint author), SUPERCONDUCT COMPONENTS INC,COLUMBUS,OH 43212, USA. NR 21 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1727 EP 1730 DI 10.1109/77.620913 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600152 ER PT J AU Todt, VR Zhang, XF Miller, DJ AF Todt, VR Zhang, XF Miller, DJ TI Nucleation and growth of single- and multiple-domain YBa2Cu3Ox levitators: Influence of seed crystallography SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID THIN-FILMS; GRAIN-BOUNDARIES; CRYSTAL-GROWTH; SUPERCONDUCTORS; BICRYSTALS; MICROSTRUCTURE AB Large diameter YBa2Cu3Ox levitators have been fabricated using seeded melt processing, Two types of levitators have been produced: single-domain, obtained using flat NdBa2Cu3Ox seeds, and five-domain, obtained using cubic NdBa2Cu3Ox seeds, The difference in these two types of levitators can be attributed to differences in nucleation and solidification processes, In particular, the nucleation of multiple (five) domain levitators may be related directly to the crystallography of the cubic seeding crystals which also exhibit a multiple-domain structure, Single-domain levitators are produced by seeding with plate-like seed crystals which are composed of a single domain. Subsequent growth of the levitator is dominated by anisotropic solidification, Using these types of seeds, we developed a dual-seeded melt textured growth process for the production of bulk bicrystals which are useful for studies of grain boundary transport behavior. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. RP Todt, VR (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 8 Z9 8 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1801 EP 1804 DI 10.1109/77.620932 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600170 ER PT J AU Niemann, RC Evans, DJ Fisher, BL Brockenborough, WE Roberts, PR Rodenbush, AJ AF Niemann, RC Evans, DJ Fisher, BL Brockenborough, WE Roberts, PR Rodenbush, AJ TI Characterization of high-current, high-temperature superconductor current lead elements SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CRYOGENIC DEVICES; DESIGN AB A conductor element consisting of laminated stack of high temperature superconductor (HTS) powder-in-tube (PIT) tapes is suitable for incorporation into current leads. The details of an application of such conductor elements to a current lead for a SMES system are presented. The fabrication of the laminated-conductor elements made with BSCCO 2223 PIT tapes is described. The critical current measurement method and results for two such conductor elements are presented. Performance was evaluated with variable temperatures and with variable applied fields. C1 AMER SUPERCOND CORP,WESTBOROUGH,MA 01581. RP Niemann, RC (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 7 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1829 EP 1832 DI 10.1109/77.620939 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600177 ER PT J AU Siegal, MP Overmyer, DL Venturini, EL Newcomer, PP Dunn, R Dominguez, F Padilla, RR Sokolowski, SS AF Siegal, MP Overmyer, DL Venturini, EL Newcomer, PP Dunn, R Dominguez, F Padilla, RR Sokolowski, SS TI Importance of thermodynamics and kinetics in the growth of thin film TlBaCaCuO superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID ZERO RESISTANCE AB The importance of near-equilibrium thermodynamics in the growth of TlBaCaCuO materials is well-documented; i.e, the independent control of sample temperature, Tl-oxide partial pressure, and oxygen partial pressure. Here we demonstrate how this is accomplished using a simple version of the crucible process. In addition, we report the relevance of growth kinetics. Superconducting thin films are grown in a two-step process. First, similar to 2000 Angstrom thick, amorphous Ba2CaCu2Ox and Ba2Ca2Cu3Ox precursors are sputter-deposited onto LaAlO3(100) substrates. Films are then thallinated and annealed using the crucible-pellet process. With this method, it is possible to grow essentially single-phase Tl-1212, Tl-1223, Tl-2212, and Tl-2223 thin films. Under similar thermodynamic conditions, we find that different phases dominate the film growth as a function of reaction time. For example, the Tl-x212 phases generally nucleate first, and then, depending on growth conditions, convert to the Tl-1223 or Tl-2223 phase with extended annealing times. We demonstrate that knowledge of both the thermodynamics and the kinetics of growth can yield high-quality films of each of the major Tl-superconducting phases. RP Siegal, MP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 15 Z9 17 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1881 EP 1886 DI 10.1109/77.620952 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600190 ER PT J AU Newcomer, PP Siegal, MP Venturini, EL Morosin, B Overmyer, DL AF Newcomer, PP Siegal, MP Venturini, EL Morosin, B Overmyer, DL TI Microstructural changes in TlBa2CaCu2O7-delta thin films after reducing anneals which enhance critical current density SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTORS; IRRADIATION AB Microstructural changes in TlBa2CaCu2O7-partial derivative (Tl-1212) epitaxial thin films resulting from low oxygen partial pressure furnace anneals at 600 degrees C are studied using high resolution transmission electron microscopy (TEM), These postgrowth anneals have been shown to significantly raise the superconducting transition temperature from 70 to 90 K, and greatly improve the magnetic flux pinning and the critical current density, Changes occur in both the microstructure and the morphology of the films that correlate with changes in J(c). Plan view TEM and high-resolution cross-sectional TEM analysis of the films before and after anneals demonstrates changes in the lattice fringe image, overall contrast modulation, and nanometer-scale discontinuities. RP Newcomer, PP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1887 EP 1890 DI 10.1109/77.620953 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600191 ER PT J AU Sagar, S Lahiri, K Shi, DL Yang, JZ AF Sagar, S Lahiri, K Shi, DL Yang, JZ TI Effect of sample geometry on levitation force in seeded-melt-grown single-domain YBa2Cu3Ox SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Magnetic levitation force is a key factor that influences energy loss in flywheel energy storage applications. Experiments on the relationships between levitation force and YB2Cu3Ox sample geometry have been conducted. The levitation force has been measure for single-domain YBa2Cu3Ox samples with different thicknesses and diameters. It has been found that the thickness dependence agrees quite well with a current model. However, the measured levitation force was found only within the linear regime. the levitation force in fact increases as the diameter decreases until a threshold value is reached. As the diameter of HTS sample is reduced smaller than the testing magnet (d=12 mm), the force experiences a rather rapid fall. This behavior can be qualitatively described by a magnetic dipole model based on Meissner currents. Other factors that dominate levitation force are also discussed. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Sagar, S (reprint author), UNIV CINCINNATI,DEPT MAT SCI & ENGN,CINCINNATI,OH 45221, USA. NR 6 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1929 EP 1932 DI 10.1109/77.620963 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600201 ER PT J AU Parilla, PA McGraw, JM Schulz, DL Wendelin, J Bhattacharya, RN Blaugher, RD Ginley, DS Voigt, JA Roth, EP AF Parilla, PA McGraw, JM Schulz, DL Wendelin, J Bhattacharya, RN Blaugher, RD Ginley, DS Voigt, JA Roth, EP TI Development of buffer layers for high quality Tl-Pb-Sr-Ba-Ca-Cu-O thick films on flexible metal substrates SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Previous work has demonstrated the ability to grow extremely high quality Tl0.5Pb0.5Sr1.6Ba0.4Ca2Cu3Ox epitaxial films up to 15 mu m thick using melt growth techniques on single crystal LaAlO3 substrates, This melt growth process is an ideal candidate for producing high quality superconducting films on flexible metal substrates with textured buffer layers; however, the textured buffer layer of choice, cubic yttria-stabilized zirconia (YSZ), appears to be incompatible with the melt growth of Tl-Pb-Sr-Ba-Ca-Cu-O films, In this work, we investigate textured buffer layers which are compatible with the epitaxial growth of Tl0.5Pb0.5Sr1.6Ba0.4Ca2Cu3Ox films. Crucial properties for the successful development of a suitable buffer layer are lattice matching, chemical stability, and texture, Buffer layer materials investigated are CeO2 and LaAlO3 grown using a UV (248 nm) pulsed excimer laser deposition system equipped with multiple targets and a controlled ambient, Influence of substrate temperature and ambient gas pressure and flow on buffer growth are analyzed via XRD characterization. Highly textured buffer layers have been fabricated. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Parilla, PA (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 8 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1969 EP 1972 DI 10.1109/77.620973 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600211 ER PT J AU Gray, KE Steel, DG Hettinger, JD Miller, DJ Washburn, BR Ware, M Parkman, JT Yoder, ME Moreau, C Eddy, MM AF Gray, KE Steel, DG Hettinger, JD Miller, DJ Washburn, BR Ware, M Parkman, JT Yoder, ME Moreau, C Eddy, MM TI Effects of vortex-vortex interactions on ion-track pinning in high-T-c superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID COLUMNAR DEFECTS; DISSIPATION; CRYSTALS; BI2SR2CACU2O8; IRRADIATION; ANISOTROPY; BEHAVIOR AB Many superconductor applications rely on the ability to pin vortex lattices, This ability depends on structural defects to pin individual vortices, but vortex-vortex interactions often play an important role in pinning the other vortices, Experimental progress on this complex problem can be made by introducing random arrays of well-defined pinning centers and studying the flux dynamics for a range of vortex densities (i.e., fields), The results of such studies in epitaxial Tl2Ba2CaCu2Oy films containing ion tracks show the importance of vortex-vortex interactions. As an example, the effective pinning field of the defects rises to many times the ion-dose field for temperatures well below T-c. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. SUPERCONDUCTOR TECHNOL INC,SANTA BARBARA,CA 93111. RP Gray, KE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ware, Morgan/I-8233-2012; Washburn, Brian/A-1308-2013 OI Ware, Morgan/0000-0002-9998-4139; NR 17 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1987 EP 1992 DI 10.1109/77.620979 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600216 ER PT J AU Kim, DH Shim, SY Park, JH Kim, YH Kim, CH Jang, JW Hahn, TS Choi, SS Hettinger, JD Steel, DG Gray, KE AF Kim, DH Shim, SY Park, JH Kim, YH Kim, CH Jang, JW Hahn, TS Choi, SS Hettinger, JD Steel, DG Gray, KE TI Effect of heavy-ion irradiation on transport properties of YBa2Cu3Ox films SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SPLAYED COLUMNAR DEFECTS; LINEAR DEFECTS; VORTEX MOTION; CRYSTALS; IRREVERSIBILITY; SUPERCONDUCTORS AB We have investigated the effect of heavy-ion irradiation on the transport properties of YBa2Cu3Ox thin films. Parallel columnar defects to the c axis and crossed columnar defects were introduced into films by heavy-ion irradiation with dose equivalent to 1 or 2 T vortex density. The electrical transport properties including resistivity, critical current density, and the Hall resistivity were measured as a function of temperature, applied magnetic field, and fluence. The irreversibility line defined as an onset of dissipation progressively shifted to higher temperature with increasing dosage and showed its dependence on inclination angle. Critical current also showed a clear enhancement compared to the unirradiated samples. The Hall scaling behavior and the Hall conductivity were modified after heavy-ion irradiation. C1 KOREA ADV INST SCI & TECHNOL,SEOUL 131791,SOUTH KOREA. ROWAN COLL,GLASSBORO,NJ 08028. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Kim, DH (reprint author), YEUNGNAM UNIV,KYUNGSAN 712749,SOUTH KOREA. NR 15 TC 5 Z9 5 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 1997 EP 2000 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600218 ER PT J AU Sutton, RA McHenry, ME Sickafus, KE AF Sutton, RA McHenry, ME Sickafus, KE TI Annealing of irradiation induced defects in a LaSrCuO crystal SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID YBA2CU3O7-DELTA SINGLE-CRYSTALS; NEUTRON-IRRADIATION; CRITICAL CURRENTS AB Annealing experiments were performed on a LSCO single crystal irradiated with fast neutrons to a fluence of 2.52 x 10(18) n/cm(2). This fluence increased the critical current density by a factor of 2-3. The sample was annealed for a total of 4.5 hours at 200 degrees C and 8 hours at 300 degrees C. It was found that annealing of LSCO has a much lesser effect on its critical current density, particularly along the c axis, compared to YBCO. It is hypothesized that the reduced annealing effect is due to the formation of either a more stable interstitial cluster (compared to the Cu-O cluster in YBCO), or dusters which do not act as pinning sites. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Sutton, RA (reprint author), CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213, USA. RI McHenry, Michael/B-8936-2009 NR 12 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2001 EP 2004 DI 10.1109/77.620982 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600219 ER PT J AU Willis, JO Holesinger, TG Coulter, JY Maley, MP AF Willis, JO Holesinger, TG Coulter, JY Maley, MP TI Magnetic field and orientation dependence of J(c) in Bi-2212 round wires SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CRITICAL-CURRENT-DENSITY; THICK-FILMS; ANISOTROPY; TAPES AB We have performed measurements of the magnetic field dependence of the magnetic field dependence of the critical current density J(c) of Bi-2212/Ag round wire produced by isothermal melt processing. In contrast to the case for flat tape, there is very little dependence of J(c) on the direction of the magnetic field as it is rotated normal to the wire axis, which is the direction of the nominal current flow. However, when the angle of the magnetic field direction is rotated from normal to the wire axis to parallel to that axis, J(c) at 64 K and 0.2 T increases by more than a factor of four. Again, this is in contrast to the results observed for Bi-2212/Ag and Bi-2223/Ag flat tapes, which show no anisotropy under similar experimental conditions. We can explain these differences in angular anisotropy by referring to the microstructure of these two conductor types, which have distinctly different types of grain alignment. We discuss the general behavior of the dependence of J(c) on the orientation of a magnetic field for high temperature superconductors. RP Willis, JO (reprint author), LOS ALAMOS NATL LAB,SUPERCOND TECHNOL CTR,MS-K763,LOS ALAMOS,NM 87545, USA. NR 13 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2022 EP 2025 DI 10.1109/77.620987 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600224 ER PT J AU Li, Q Riley, GN Parrella, RD Fleshler, S Rupich, MW Carter, WL Willis, JO Coulter, JY Bingert, JF Sikka, VK Parrell, JA Larbalestier, DC AF Li, Q Riley, GN Parrella, RD Fleshler, S Rupich, MW Carter, WL Willis, JO Coulter, JY Bingert, JF Sikka, VK Parrell, JA Larbalestier, DC TI Progress in superconducting performance of rolled multifilamentary Bi-2223 HTS composite conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CRITICAL-CURRENT DENSITY; SHEATHED TAPES; ENHANCEMENT AB Significant enhancements in critical current densities in rolled multifilamentary Bi-2223 HTS composite conductors have been achieved using the powder-in-tube (PIT) technique. At 77 K and self field, oxide critical current densities (J(c)) of 55 kA/cm(2), overall or engineering critical current densities (J(e)) of 15 kA/cm(2), and critical currents (I-c) of 125 A have been achieved in different rolled multifilamentary composites. Progress in achieving such high electrical performance is believed to stem in part from an improvement of grain connectivity by reducing weak links. The Jc dependence on magnetic field (B) and the degree of c-axis texture of these high quality conductors have been investigated at various temperatures. Our results also demonstrate that the critical current retention in magnetic field can be independently controlled from the self field critical current density, suggesting that flux pinning improvements and weak link reductions can be separately engineered into Bi-2223 composites fabricated using manufacturable processes. C1 LOS ALAMOS NATL LAB,SUPERCOND TECHNOL CTR,LOS ALAMOS,NM 87545. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV WISCONSIN,CTR APPL SUPERCOND,MADISON,WI 53706. RP Li, Q (reprint author), AMER SUPERCOND CORP,WESTBOROUGH,MA 01581, USA. RI Larbalestier, David/B-2277-2008 OI Larbalestier, David/0000-0001-7098-7208 NR 17 TC 52 Z9 53 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2026 EP 2029 DI 10.1109/77.620988 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600225 ER PT J AU Talvacchio, J Forrester, MG Hunt, BD McCambridge, JD Young, RM Zhang, XF Miller, DJ AF Talvacchio, J Forrester, MG Hunt, BD McCambridge, JD Young, RM Zhang, XF Miller, DJ TI Materials basis for a six-level epitaxial HTS digital circuit process SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID JUNCTIONS; FILMS AB We have developed a process for fabrication of HTS single-flux-quantum logic circuits based on edge SNS junctions which requires six epitaxial film layers and six mask levels, The process was successfully applied to fabrication of small-scale circuits (less than or equal to 10 junctions), This paper examines the materials properties affecting the reproducibility of YBCO-based SNS junctions, the low inductance provided by an integrated YBCO ground plane, and electrical isolation by SrTiO3 or Sr2AlTaO6 ground-plane and junction insulator layers, Some of the critical processing parameters identified by electrical measurements, TEM, SEM, and AFM were control of second-phase precipitates in YBCO, oxygen diffusion, Ar ion-milling parameters, and preparation of surfaces for subsequent high-temperature depositions. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Talvacchio, J (reprint author), NORTHROP GRUMMAN SCI & TECHNOL CTR,PITTSBURGH,PA 15235, USA. NR 12 TC 9 Z9 9 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2051 EP 2056 DI 10.1109/77.620994 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600231 ER PT J AU Chudzik, MP Polzin, BJ Thayer, R Picciolo, JJ Fisher, BL Lanagan, MT AF Chudzik, MP Polzin, BJ Thayer, R Picciolo, JJ Fisher, BL Lanagan, MT TI Fabrication and characterization of (Bi,Pb)-Sr-Ca-Cu-O (2223) bars SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Bulk bars for current lead applications were fabricated from (Bi,Pb)-Sr-Ca-Cu .. O (Bi-2223) for low thermal conductivity and high critical current. Bars measuring 17.8 cm in length were made by uniaxially pressing Bi-2223 powder of controlled (1.7/0.34)223 and (1.8/0.4)223 phase composition, The bulk bars were densified by subjecting them to a schedule of alternate liquid-phase sintering and cold isostatic pressing. Liquid-phase sintering temperatures wc:re optimized from differential thermal analysis and microstructure morphology. Phase purity and microstructure were evaluated by X-ray diffraction and scanning electron microscopy. Low-resistance silver contacts were applied to the bars by hot-pressing at 820 degrees C and 3 MPa. Critical current densities approximate to 1000 A/cm(2) (critical currents of 750 A at 77 K in self-field conditions) were achieved. RP Chudzik, MP (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 2 Z9 2 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2102 EP 2105 DI 10.1109/77.621006 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600243 ER PT J AU Cha, YS Seol, SY Evans, DJ Hull, JR AF Cha, YS Seol, SY Evans, DJ Hull, JR TI Flux-flow resistivity of three high-temperature superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB Results of experiments on flux-flow resistivity (the relationship of voltage to current) of three high-temperature superconductors are described. The superconductors are a melt-cast BSCCO 2212 rod, a single-filament BSCCO powder-in-tube (PIT) tape, and a multifilament PIT tape. The flux-flow resistivity of those superconductors was measured at three temperatures: 77 K (saturated liquid nitrogen), 87 K (saturated liquid argon), and 67 K (subcooled liquid nitrogen). Implications of the present results for practical applications are discussed. C1 CHONNAM NATL UNIV,DEPT ENGN MECH,KWANGJU 700757,SOUTH KOREA. RP Cha, YS (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 7 TC 5 Z9 5 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2122 EP 2125 DI 10.1109/77.621011 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600248 ER PT J AU Balachandran, U Iyer, AN Jammy, R Chudzik, M Lelovic, M Krishnaraj, P Eror, NG Haldar, P AF Balachandran, U Iyer, AN Jammy, R Chudzik, M Lelovic, M Krishnaraj, P Eror, NG Haldar, P TI Processing and characterization of Ag-clad Bi-2223 superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID CRITICAL-CURRENT DENSITY; MECHANICAL-PROPERTIES; TAPES; CONDUCTORS AB Practical applications of high-temperature superconductors will be governed by their current transport and mechanical characteristics. With careful control of the processing parameters high-quality long-length mono- and multifilament Bi-2223 conductors have been fabricated by the powder-in-tube technique. A critical current density (J(c)) of up to 1.2 x 10(4) A cm(-2) has been observed at 77 K in a 1260-m-long multifilament conductor containing 37 monocore filaments. A high-temperature superconducting magnet and a prototype transformer were fabricated and characterized from such long-length conductors. Extensive studies on the in-situ strain characteristics of the mono- and multifilament conductors have been conducted. Multilayer silver/superconductor composite tapes, fabricated by a novel chemical etching technique, were also observed to exhibit improved strain tolerance characteristics. To further improve the current characteristics of the Bi-2223 tapes the wire-in-tube technique was adopted. A J(c) value > 10(5) A cm(-2) at 77 K and in self field have been obtained in a Bi-2223 tape fabricated by the wire-in-tube method. C1 UNIV PITTSBURGH,PITTSBURGH,PA 15261. INTERMAGNET GEN CORP,LATHAM,NY 12110. RP Balachandran, U (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 14 TC 9 Z9 9 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2207 EP 2210 DI 10.1109/77.621032 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH866 UT WOS:A1997XH86600269 ER PT J AU Lee, AT Gildemeister, JM Lee, SF Richards, PL AF Lee, AT Gildemeister, JM Lee, SF Richards, PL TI Voltage-biased high-T-c superconducting infrared bolometers with strong electrothermal feedback SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID NOISE AB In the current generation of high-T-c bolometers the thermal conductance is often chosen for a short time-constant rather than for optimal sensitivity. We describe a novel bolometer bias and readout scheme that promises to relax this constraint. Voltage bias of the superconductor results in strong negative electrothermal feedback that greatly reduces the time-constant of the bolometer. We estimate that a decrease of more than one order of magnitude in time-constant should be possible with existing high-T-c thermometers. We give theoretical estimates of the performance gain with voltage bias for several bolometers that have been reported in the literature. We find cases where the sensitivity can be greatly improved (by changing the thermal conductance) while holding the time constant fixed and others where the bolometer can be made much faster while maintaining the sensitivity. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RP Lee, AT (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 13 TC 29 Z9 29 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2378 EP 2381 DI 10.1109/77.621718 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700028 ER PT J AU Dantsker, E Tanaka, S Nilsson, PA Kleiner, R Clarke, J AF Dantsker, E Tanaka, S Nilsson, PA Kleiner, R Clarke, J TI Low excess flux noise in YBa2Cu3O7-x dc SQUIDs cooled in static magnetic fields SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID MAGNETOMETERS AB We have investigated the effect of device geometry on the excess low frequency 1/f noise of thin-film YBCO dc SQUIDS cooled in static magnetic fields. The key factor in eliminating this noise is the reduction of the linewidth of the SQUID loop to a value below the average separation of the flux vortices. The spectral density of the flux noise in these devices was independence of cooling field up to 33 mu T in the best case. Estimates indicate that incorporating this device into a directly-coupled magnetometer would not increase the noise further. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Dantsker, E (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Nilsson, Per-Ake/C-3802-2008 OI Nilsson, Per-Ake/0000-0002-9488-7890 NR 8 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2772 EP 2775 DI 10.1109/77.621812 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700122 ER PT J AU Findikoglu, AT Jia, QX Reagor, DW AF Findikoglu, AT Jia, QX Reagor, DW TI Superconductor/nonlinear-dielectric bilayers for tunable and adaptive microwave devices SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID THIN-FILMS; SR0.5BA0.5TIO3 AB We have designed, fabricated and characterized electrically tunable and adaptive microwave devices using coplanar waveguide (CPW) structures which incorporate bilayers of superconducting YBa2Cu3O7-x and nonlinear dielectric SrTiO3 on 1 cm x 1 cm x 0.5 mm LaAlO3 substrates. The microwave devices include voltage-tunable phase shifters and delay lines, voltage-tunable mixers, and voltage-tunable and adaptive bandpass filters. Under de voltage bias, these compact CPW devices exhibit more than 360 degrees relative phase shift at 2 GHz, more than 30 dB tunability in mixed microwave power between 0.7 GHz and 5.9 GHz, and fine-tunable symmetric filter profile at around 2.5 GHz with less than 2% bandwidth and more than 15% adaptive range. RP Findikoglu, AT (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MS K763,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 12 TC 21 Z9 21 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 2925 EP 2928 DI 10.1109/77.621917 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700159 ER PT J AU Jia, QX Reagor, D Wu, XD Mombourquette, C Foltyn, SR AF Jia, QX Reagor, D Wu, XD Mombourquette, C Foltyn, SR TI Characterization of ramp edge-geometry Ag:YBa2Cu3O7-x/PrBa2Cu3O7-x/Ag:YBa2Cu3O7-x junctions and dc SQUIDs SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID SUPERCONDUCTOR JOSEPHSON-JUNCTIONS; QUANTUM INTERFERENCE DEVICES; BARRIERS; YBA2CU3O7-X; LAYERS; NOISE AB High-temperature superconducting Josephson junctions and dc SQUIDs were fabricated using a ramp edge-geometry SNS configuration. Ag-doped YBa2Cu3O7-x was used as electrodes and PrBa2Cu3O7-x as barrier. The IcRn value of the junctions was in excess of 120 mu V at 75 K, The dc SQUIDs showed a flux modulation depth, partial derivative V/partial derivative Phi, over 150 mu V/Phi(0) at 75K. The flux noise of the devices, measured with de bias currents operated at 75 K, showed a 1/f dependence at low frequency having values below 100 mu Phi(0)Hz(-1/2) (the best values in the range of 30 similar to 40 mu Phi(0)Hz(-1/2)) at 1 Hz and less than 5 mu Phi(0)Hz(-1/2) in the white noise region. The voltage modulation and magnetic field noise were 37 mu V and similar to 2 pTHz(-1/2) at 1 kHz for the directly-coupled dc SQUID magnetometers (with a pick-up loop 6 mm x 3.5 mm) based on the ramp edge-geometry SNS configuration. RP Jia, QX (reprint author), LOS ALAMOS NATL LAB,SUPERCONDUCT TECHNOL CTR,POB 1663,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 27 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 3005 EP 3008 DI 10.1109/77.621956 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700178 ER PT J AU Lee, TS Chemla, YR Dantsker, E Clarke, J AF Lee, TS Chemla, YR Dantsker, E Clarke, J TI High-T-c SQUID microscope for room temperature samples SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID YBA2CU3O7-DELTA; MAGNETOMETER AB A high-T-C SQUID microscope has been constructed for imaging samples at room temperature and atmospheric pressure, The SQUID is mounted on the upper end of a sapphire rod, cooled to liquid nitrogen temperature, below a 3-mu m thick silicon nitride vacuum window, This arrangement yields a SQUID-to-sample separation as low as 15 mu m. A sample can be placed on the window or scanned over the SQUID to produce magnetic images. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 16 TC 42 Z9 42 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 EI 1558-2515 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 3147 EP 3150 DI 10.1109/77.621999 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700213 ER PT J AU Netel, H Jochum, J Labov, SE Mears, CA Frank, M Chow, D Lindeman, MA Hiller, LJ AF Netel, H Jochum, J Labov, SE Mears, CA Frank, M Chow, D Lindeman, MA Hiller, LJ TI Proximity effect and hot-electron diffusion in Ag/Al2O3/Al tunnel junctions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA AB We have fabricated Ag/Al2O3/Al tunnel junctions on Si substrates using a new process. This process was developed to fabricate superconducting tunnel junctions (STJs) on the surface of a superconductor. These junctions allow us to study the proximity effect of a superconducting Al film on a normal metal trapping layer, In addition, these devices allow us to measure the hot-electron diffusion constant using a single junction. Lastly these devices will help us optimize the design and fabrication of tunnel junctions on the surface of high-Z, ultra-pure superconducting crystals. C1 UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94550. RP Netel, H (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,POB 808,L-401,LIVERMORE,CA 94550, USA. RI Frank, Matthias/O-9055-2014 NR 5 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 3379 EP 3382 DI 10.1109/77.622099 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700269 ER PT J AU Mears, CA Labov, SE Frank, M Netel, H Hiller, LJ Lindeman, MA Chow, D Barfknecht, AT AF Mears, CA Labov, SE Frank, M Netel, H Hiller, LJ Lindeman, MA Chow, D Barfknecht, AT TI High-resolution superconducting X-ray spectrometers with an active area of 282 mu m x 282 mu m SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID DETECTORS; ENERGY; JUNCTIONS; NOISE AB Superconducting tunnel junctions coupled to superconducting absorbers may be used as high-resolution, high-efficiency X-ray spectrometers, ire have tested devices with niobium Xray absorbing layers coupled to aluminum layers that serve as quasiparticle traps. In this work we measure the current pulses from a large-area tunnel junction using an amplifier based on an array of 100 SQUIDs. Using this amplifier and a 282 mu m x 282 mu m junction, we have measured an energy resolution of 19 eV FWHM for 1.5 keV X rays and 21 eV for 2.6 keV X rays. The area of this junction is eight times area of any junction previously measured to such high energy resolution. C1 LAWRENCE LIVERMORE NATL LAB,DEPT APPL SCI,DAVIS,CA. CONDUCTUS INC,SUNNYVALE,CA 94086. RP Mears, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA 94550, USA. RI Frank, Matthias/O-9055-2014 NR 17 TC 15 Z9 15 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 3415 EP 3418 DI 10.1109/77.622114 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700278 ER PT J AU Mueller, CH Treece, RE Rivkin, TV Miranda, FA Moutinho, HR SwartzlanderFranz, A Dalberth, M Rogers, CT AF Mueller, CH Treece, RE Rivkin, TV Miranda, FA Moutinho, HR SwartzlanderFranz, A Dalberth, M Rogers, CT TI Tunable SrTiO3 varactors using parallel plate and interdigital structures SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1996 Applied Superconductivity Conference CY AUG 25-30, 1996 CL PITTSBURGH, PA ID HETEROSTRUCTURES AB The dielectric properties of SrTiO3 (STO)/YBCO and STO films deposited on LaAlO3 substrates were evaluated, for potential varactor applications wherein the capacitance is altered via a de voltage applied across the STO film. The optimal growth temperature for the STO films in the STO/YBCO structures was 800 degrees C; higher temperatures resulted in interfacial degradation and poor film quality, and lower temperatures resulted in films with lower dielectric constants (epsilon(r)) and tunabilities. Interdigital varactors comprised of STO films deposited directly on LaAlO3 displayed higher tunabilities and significantly lower losses. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV COLORADO,BOULDER,CO 80309. RP Mueller, CH (reprint author), SCT,GOLDEN,CO 80401, USA. NR 14 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1997 VL 7 IS 2 BP 3512 EP 3515 DI 10.1109/77.622151 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XH867 UT WOS:A1997XH86700303 ER PT J AU Miller, A Muljadi, E Zinger, DS AF Miller, A Muljadi, E Zinger, DS TI A variable speed wind turbine power control SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article; Proceedings Paper CT 1996 IEEE/PES Summer Meeting CY JUL 28-AUG 01, 1996 CL DENVER, CO SP IEEE Power Engn Soc, PES AB To optimize the power in a wind turbine the speed of the turbine should be able to vary with the wind speed. A simple control is proposed that will allow an induction motor to run a turbine at its maximum power coefficient. The control uses a standard V/Hz converter and controls the frequency to where achieve the desired power at a given turbine speed. C1 NO ILLINOIS UNIV,DE KALB,IL 60115. NATL RENEWABLE ENERGY LAB,POWER ELECT SYST,GOLDEN,CO. RP Miller, A (reprint author), UNIV IDAHO,MOSCOW,ID 83843, USA. NR 7 TC 150 Z9 161 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD JUN PY 1997 VL 12 IS 2 BP 181 EP 186 DI 10.1109/60.629701 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA XB624 UT WOS:A1997XB62400022 ER PT J AU Davis, MH Khotanzad, A Flamig, DP Harms, SE AF Davis, MH Khotanzad, A Flamig, DP Harms, SE TI A physics-based coordinate transformation for 3-D image matching SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE coordinate transformation; image matching; physics-based vision; splines ID RADIAL BASIS FUNCTIONS; REGISTRATION; SPLINES; SYSTEM; MR AB Many image matching schemes are based on mapping coordinate locations, such as the locations of landmarks, in one image to corresponding locations in a second image. A new approach to this mapping (coordinate transformation), called the elastic body spline (EBS), is described. The spline is based on a physical model of a homogeneous, isotropic three-dimensional (3-D) elastic body, The model can approximate the way that some physical objects deform. The EBS as well as the affine transformation, the thin plate spline [1], [2] and the volume spline [3] are used to match 3-D magnetic resonance images (MRI's) of the breast that are used in the diagnosis and evaluation of breast cancer. These coordinate transformations are evaluated with different types of deformations and different numbers of corresponding (paired) coordinate locations. In all but one of the cases considered, using the EBS yields more similar images than the other methods. C1 SO METHODIST UNIV, DEPT ELECT ENGN, DALLAS, TX 75275 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV ARKANSAS MED SCI HOSP, DEPT RADIOL, LITTLE ROCK, AR 72205 USA. NR 55 TC 163 Z9 166 U1 1 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0278-0062 EI 1558-254X J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD JUN PY 1997 VL 16 IS 3 BP 317 EP 328 DI 10.1109/42.585766 PG 12 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 XC715 UT WOS:A1997XC71500009 PM 9184894 ER PT J AU Phillips, JW Leahy, RM Mosher, JC AF Phillips, JW Leahy, RM Mosher, JC TI MEG-based imaging of focal neuronal current sources SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE Bayesian imaging; magnetoencephalogram; mean field annealing; minimum norm ID BIOMAGNETIC INVERSE PROBLEM; HUMAN-BRAIN; LOCALIZATION; IMAGES; EEG; RECONSTRUCTION; RESTORATION AB We describe a new approach to imaging neural current sources from measurements of the magnetoencephalogram (MEG) associated with sensory, motor, or cognitive brain activation. Many previous approaches to this problem have concentrated on the use of weighted minimum norm (WMN) inverse methods. While these methods ensure a unique solution, they do not introduce information specific to the MEG inverse problem, often producing overly smoothed solutions and exhibiting severe sensitivity to noise. We describe a Bayesian formulation of the inverse problem in which a Gibbs prior is constructed to reflect the sparse focal nature of neural current sources associated with evoked response data. We demonstrate the method with simulated and experimental phantom data, comparing its performance with several WMN methods. C1 UNIV SO CALIF,INST SIGNAL & IMAGE PROC,LOS ANGELES,CA 90089. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. FU NEI NIH HHS [R01-EY08610]; NIMH NIH HHS [R01-MH53213] NR 44 TC 128 Z9 132 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 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD JUN PY 1997 VL 16 IS 3 BP 338 EP 348 DI 10.1109/42.585768 PG 11 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 XC715 UT WOS:A1997XC71500011 PM 9184896 ER PT J AU Britton, CL Bryan, WL Emery, MS Ericson, MN Musrock, MS Simpson, ML Smith, MC Walker, JW Wintenberg, AL Young, GR Allen, MD Clonts, LG Jones, RL Kennedy, EJ Smith, RS Boissevain, J Jacak, BV Jaffe, D Kapustinsky, JS SimonGillo, J Sullivan, JP VanHecke, H Xu, N AF Britton, CL Bryan, WL Emery, MS Ericson, MN Musrock, MS Simpson, ML Smith, MC Walker, JW Wintenberg, AL Young, GR Allen, MD Clonts, LG Jones, RL Kennedy, EJ Smith, RS Boissevain, J Jacak, BV Jaffe, D Kapustinsky, JS SimonGillo, J Sullivan, JP VanHecke, H Xu, N TI Design and performance of beam test electronics for the PHENIX Multiplicity Vertex Detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID SDC SILICON TRACKER AB The system architecture and test results of the custom circuits and beam test system for the Multiplicity-Vertex Detector (MVD) for the PHENIX detector collaboration at the Relativistic Heavy Ion Collider (RHIC) are presented in this paper. The final detector per-channel signal processing chain will consist of a preamplifier-gain stage, a current-mode summed multiplicity discriminator, a 64-deep analog memory (simultaneous read-write), a post-memory analog correlator, and a 10-bit 5 mu s ADC. The Heap Manager provides all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Beam test (16-cell deep memory) performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 mu-m n-well CMOS process used for preamplifier fabrication. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Britton, CL (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 23 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 283 EP 288 DI 10.1109/23.603657 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200004 ER PT J AU Kipnis, I Collins, T DeWitt, J Dow, S Frey, A Grillo, A Johnson, R Kroeger, W Leona, A Luo, L Mandelli, E Manfredi, PF Melani, M Momayezi, M Morsani, F Nyman, M PedraliNoy, M Poplevin, P Spencer, E Re, V Roe, N AF Kipnis, I Collins, T DeWitt, J Dow, S Frey, A Grillo, A Johnson, R Kroeger, W Leona, A Luo, L Mandelli, E Manfredi, PF Melani, M Momayezi, M Morsani, F Nyman, M PedraliNoy, M Poplevin, P Spencer, E Re, V Roe, N TI A time-over-threshold machine: The readout integrated circuit for the BABAR silicon vertex tracker SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID DETECTOR AB A low-noise, mixed-signal, 128-channel CMOS integrated circuit containing the complete readout electronics for the BABAR Silicon Vertex Tracker has been developed. The outstanding feature of the present implementation is the ability to perform simultaneously low-level signal acquisition, derandomizing data storage, sparsification and data transmission on a single monolithic chip. The signals from the detector strips are amplified, shaped by a CR-RC2 filter with digitally selectable peaking time of 100 ns, 200 ns, 300 ns, or 400 ns, and then presented to a time-over-threshold processor to implement a compression type analog-to-digital conversion. The digital information is stored, sparsified and read out through a serial link upon receipt of a command. The digital section operates from a 60 MHz incoming clock. Noise measurements at 200 ns peaking time and 3.5 mW total power dissipation per channel yield an equivalent noise charge of 600 el, rms at 12 pF added source capacitance, The chip measures 5.7 mm x 8.3 mm and contains 330k transistors. The first full-scale prototype was fabricated in a radiation soft 0.8 mu m, 3-metal CMOS process. The same circuit is now being fabricated in an analogous radiation hard technology. C1 UNIV PAVIA,IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-56010 PISA,ITALY. UNIV CALIF SANTA CRUZ,SANTA CRUZ INST PARTICLE PHYS,SANTA CRUZ,CA 95064. RP Kipnis, I (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. OI Re, Valerio/0000-0003-0697-3420 NR 13 TC 54 Z9 55 U1 0 U2 5 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 JUN PY 1997 VL 44 IS 3 BP 289 EP 297 DI 10.1109/23.603658 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200005 ER PT J AU Jackson, RG Blalock, TV Simpson, ML Wintenberg, AL Young, GR AF Jackson, RG Blalock, TV Simpson, ML Wintenberg, AL Young, GR TI Integrated constant-fraction discriminator shaping techniques for the PHENIX lead-scintillator calorimeter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID SYSTEMS; CMOS AB The suitability of several on-chip constant-fraction discriminator (CFD) shaping methods for use in the multichannel PHENIX Lead-Scintillator detector has been investigated. Three CFD circuits utilizing a distributed R-C delay-line, a lumped-element R-C delay-line, and the Nowlin shaping method have been realized in a standard 1.2-mu n-well CMOS process. A CFD using ideal delay-line shaping was also studied for comparison. Time walk for 5 ns risetime input signals over a dynamic range of - 2 V to - 20 mV was less than +/- 175 ps, +/- 150 ps, +/- 150, and +/- 185 ps while worst case rms timing jitter measured 85 ps, 90 ps, 100 ps, and 65 ps, respectively, for the four methods mentioned above. Area requirements for the three candidate methods tested including the fraction circuit were 172 mu x 70 mu, 160 mu x 65 mu, and 179 mu x 53 mu, respectively. The fraction circuit area for the external delay-line circuit was 67 mu x 65 mu. Each shaping method studied consumed no power from the de supply. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Jackson, RG (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 11 TC 8 Z9 8 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 JUN PY 1997 VL 44 IS 3 BP 303 EP 307 DI 10.1109/23.603660 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200007 ER PT J AU Ericson, MN Allen, MD Musrock, MS Walker, JW Britton, CL Wintenberg, AL Young, GR AF Ericson, MN Allen, MD Musrock, MS Walker, JW Britton, CL Wintenberg, AL Young, GR TI Development of a front end controller heap manager for PHENIX SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A controller/heap manager has been designed for applicability to all detector subsystem types of PHENIX. The heap manager performs all functions associated with front end electronics control including ADC and analog memory control, data collection, command interpretation and execution, and data packet forming and communication. Interfaces to the unit consist of a timing and control bus, a serial bus, a parallel data bus, and a trigger interface. The topology developed is modular so that many functional blocks are identical for a number of subsystem types. Programmability is maximized through the use of flexible modular functions and implementation using field programmable gate arrays (FPGAs). Details of unit design and functionality will be discussed with particular detail given to subsystems having analog memory-based front end electronics. In addition, mode control, serial functions, and FPGA implementation details will be presented. RP Ericson, MN (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 7 TC 3 Z9 3 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 JUN PY 1997 VL 44 IS 3 BP 312 EP 317 DI 10.1109/23.603662 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200009 ER PT J AU OConnor, P Gramegna, G Rehak, P Corsi, F Marzocca, C AF OConnor, P Gramegna, G Rehak, P Corsi, F Marzocca, C TI CMOS preamplifier with high linearity and ultra low noise for x-ray spectroscopy SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID DETECTORS; SILICON AB We report here an ultra low noise charge sensitive monolithic CMOS amplifier (CSA) suitable for small anode capacitance (200fF), low leakage current solid state detectors. The CSA is continuously sensitive, the charge from the input node being drained by a feedback transistor Mf biased as a resistor with effective values in the G Omega range. This very high value was achieved by a novel scheme which tracks threshold variations, and power supply and temperature fluctuations. A good linearity of the CSA conversion gain is achieved (<0.1% up to 1.8fC input charge) by inserting a voltage divider between the output of the CSA and the source of Mf. The equivalent noise charge (ENC) of the CSA is equal to the theoretical lower limit imposed by the flicker noise. The circuit has been fabricated in two different CMOS technologies. With no detector connected, we measure a room-temperature ENC of 9 e(-) rms at 12 mu sec shaping time. When coupled to a cooled detector a FWHM of 111 eV is obtained at 2.4 mu sec shaping, corresponding to an ENC of 13e(-) rms. This is the best reported energy resolution ever obtained with a CMOS preamplifier. C1 POLITECN BARI,DIPARTIMENTO ELETTROTECN & ELETTRON,I-70125 BARI,ITALY. RP OConnor, P (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. OI CORSI, Francesco/0000-0003-2425-2272; Marzocca, Cristoforo/0000-0002-2804-2275 NR 16 TC 26 Z9 26 U1 2 U2 7 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 JUN PY 1997 VL 44 IS 3 BP 318 EP 325 DI 10.1109/23.603663 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200010 ER PT J AU Wintenberg, AL Simpson, ML Young, GR Palmer, RL Moscone, CG Jackson, RG AF Wintenberg, AL Simpson, ML Young, GR Palmer, RL Moscone, CG Jackson, RG TI A CMOS variable gain amplifier for PHENIX electromagnetic calorimeter and RICH energy measurements SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A variable gain amplifier (VGA) has been developed for equalizing the gains of integrating amplifier channels used with multiple photomultiplier tubes operating from common high-voltage supplies. The PHENIX lead-scintillator electromagnetic calorimeter will operate in that manner, and gain equalization is needed to preserve the dynamic range of the analog memory and ADC following the integrating amplifier. The VGA is also needed for matching energy channel gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5-bit digital control, and the risetime is held between 15 and 23 ns using switched compensation in the VGA. An additional feature is gated baseline restoration. Details of the design and results from several prototype devices fabricated in 1.2-mu m Orbit CMOS are presented. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Wintenberg, AL (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 3 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 326 EP 330 DI 10.1109/23.603664 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200011 ER PT J AU Abbott, B Angstadt, B Borcherding, F Johnson, M Martin, M AF Abbott, B Angstadt, B Borcherding, F Johnson, M Martin, M TI A fast, first level, R phi hardware trigger for the D0 central fiber tracker using field programmable gate arrays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB An R phi trigger was developed using the eight doublet layers of axial fibers in the new Central Fiber Tracker for the DO Upgrade Detector at Fermilab [1]. This trigger must be formed in less than 500 nsec and distributed to other parts of the detector for a level 1 trigger decision. The high speed is achieved by using massively parallel AND/OR logic realized in state-of-the-art field programmable gate arrays, FPGAs. The programmability of the FPGAs allows corrections to the track roads for the as-built detector and for dynamically changing the transverse momentum threshold. To reduce the number of fake tracks at high luminosity, the narrowest possible roads must be used which pushes the total number of roads into the thousands. Monte Carlo simulations of the track trigger were run to develop the trigger algorithms and a vendor specific commercially available simulator was used to develop and test the FPGA programming. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Abbott, B (reprint author), NYU,NEW YORK,NY 10003, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 354 EP 357 DI 10.1109/23.603670 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200016 ER PT J AU Baldin, B Bardon, O Fitzpatrick, T Golovtsov, V Hansen, S Larwill, M Los, S Matveev, M Neustroev, P Podstavkov, V Rotolo, C Uvarov, L Vaniev, V Wood, D AF Baldin, B Bardon, O Fitzpatrick, T Golovtsov, V Hansen, S Larwill, M Los, S Matveev, M Neustroev, P Podstavkov, V Rotolo, C Uvarov, L Vaniev, V Wood, D TI D0 muon readout electronics design SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The readout electronics designed for the DO Muon Upgrade [1] are described. These electronics serve three detector subsystems and one trigger system. The front-ends and readout hardware are synchronized by means of timing signals broadcast from the DO Trigger Framework. The front-end electronics have continuously running digitizers and two levels of buffering resulting in nearly deadtimeless operation. The raw data is corrected and formatted by 16-bit fixed point DSP processors. These processors also perform control of the data buffering. The data transfer from the front-end electronics located on the detector platform is performed by serial links running at 160 Mbit/s. The design and test results of the subsystem readout electronics and system interface are discussed. C1 IHEP,PROTVINO 142284,MOSCOW REGION,RUSSIA. NORTHEASTERN UNIV,BOSTON,MA 02115. PNPI,ST PETERSBURG 188350,GATCHINA,RUSSIA. RP Baldin, B (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 4 TC 3 Z9 3 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 JUN PY 1997 VL 44 IS 3 BP 363 EP 369 DI 10.1109/23.603672 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200018 ER PT J AU Emery, MS Frank, SS Britton, CL Wintenberg, AL Simpson, ML Ericson, MN Young, GR Clonts, LG Allen, MD AF Emery, MS Frank, SS Britton, CL Wintenberg, AL Simpson, ML Ericson, MN Young, GR Clonts, LG Allen, MD TI A multi-channel ADC for use in the PHENIX detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A custom CMOS analog to digital converter was designed and a prototype 8-channel ADC ASIC was fabricated in a 1.2 mu m process. The circuit uses a Wilkinson-type architecture which is suitable for use in multi-channel applications such as the PHENIX detector. The ADC design features include a differential positive-ECL input for the high speed clock and selectable control for 11 or 12-bit conversions making it suitable for use in multiple PHENIX subsystems. Circuit topologies and ASIC layout specifics, including power consumption, maximum clock speed, INL, and DNL are discussed. The ADC performed to 11-bit accuracy. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Emery, MS (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 5 TC 19 Z9 19 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 374 EP 378 DI 10.1109/23.603674 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200020 ER PT J AU Gramegna, G OConnor, P Rehak, P Hart, S AF Gramegna, G OConnor, P Rehak, P Hart, S TI Low-noise CMOS preamplifier-shaper for silicon drift detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB We have designed a 16-channel preamplifier-shaper for particle tracking using silicon drift detectors (SDD). The preamplifier, which is optimized for a detector capacitance of 0.2 - 0.8 pF, uses two new circuit techniques to achieve a low noise (ENC 120 e(-) + 62 e(-)/pF), high linearity (< 0.5% to 50 fC), and good tolerance to process variations and temperature and power supply fluctuations. The circuit is continuously sensitive, has no digital signals on chip, and requires no external components or critical adjustments. The peaking time of the shaper is 50 nsec and the power dissipation, including an off-chip driver, is 6.5 mW/channel. The circuit is fabricated in 1.2 mu m CMOS and can accomodate detector leakage currents of up to 1.5 uA. Although the circuit was developed for use with particle tracking detectors, these techniques are also well-suited for the design of lower-noise preamplifiers for high-resolution X-ray spectroscopy systems. C1 POLITECN BARI,DEE,I-70125 BARI,ITALY. WAYNE STATE UNIV,DETROIT,MI. RP Gramegna, G (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 7 TC 24 Z9 25 U1 3 U2 3 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 JUN PY 1997 VL 44 IS 3 BP 385 EP 388 DI 10.1109/23.603676 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200022 ER PT J AU Smith, RS Kennedy, EJ Jackson, RG Simpson, ML Britton, CL Bryan, WL Jagadish, U Young, GR Jacak, BV Kapustinsky, J Oscarson, A AF Smith, RS Kennedy, EJ Jackson, RG Simpson, ML Britton, CL Bryan, WL Jagadish, U Young, GR Jacak, BV Kapustinsky, J Oscarson, A TI A discriminator with a current-sum multiplicity output for the PHENIX multiplicity vertex detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A current output multiplicity discriminator for use in the front-end electronics (FEE) of the Multiplicity Vertex Detector (MVD) for the PHENIX detector at RHIC has been fabricated in the a 1.2-mu m CMOS, n-well process. The discriminator is capable of triggering on input signals ranging from 0.25 MIP to 5 MIP. Frequency response of the discriminator is such that the circuit is capable of generating an output for every bunch crossing (105 ns) of the RHIC collider. Channel-to-channel threshold matching was adjustable to +/- 0.05 MIP. One channel of multiplicity discriminator occupied an area of 85 mu m x 630 mu m and consumed 515 mu W from a single 5-V supply. Details of the design and results from prototype device testing are presented. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LUND UNIV,S-22100 LUND,SWEDEN. RP Smith, RS (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 5 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 389 EP 392 DI 10.1109/23.603677 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200023 ER PT J AU Holland, SE Wang, NW Moses, WW AF Holland, SE Wang, NW Moses, WW TI Development of low noise, back-side illuminated silicon photodiode arrays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID PET DETECTOR MODULE; QUANTUM EFFICIENCY; PIN PHOTODIODE; OPTICAL-PROPERTIES; FABRICATION; DEPTH AB We have developed low noise, high quantum efficiency photodiode arrays for use with positron-emission tomography (PET). A fabrication process developed for high-energy physics detectors was modified to allow for back-side illumination. A back-side contact consisting of a thin (10 nm) n(+) polysilicon layer covered by an indium tin oxide (ITO) antireflection coating (57 nm) results in > 70% quantum efficiency over the wavelength range of 400-1000 nm, The photodiodes are operated fully depleted (300 mu m thick) resulting in a measured capacitance of 3.2 pF and typical leakage currents of 20-50 pA for a 3 mm square element. At room temperature the noise measured at a shaping time of 4 mu s is 140 e(-) rms. When coupled to a CsI(TI) scintillator and excited with 141 keV gamma rays, the energy resolution is 12% fwhm. RP Holland, SE (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Holland, Stephen/H-7890-2013 NR 23 TC 51 Z9 52 U1 1 U2 4 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 JUN PY 1997 VL 44 IS 3 BP 443 EP 447 DI 10.1109/23.603687 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200033 ER PT J AU Shah, KS Bennett, P Klugerman, M Moy, L Cirignano, L Dmitriyev, Y Squillante, MR Olschner, F Moses, WW AF Shah, KS Bennett, P Klugerman, M Moy, L Cirignano, L Dmitriyev, Y Squillante, MR Olschner, F Moses, WW TI Lead iodide optical detectors for gamma ray spectroscopy SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB This paper describes the research performed in developing low noise, high quantum efficiency lead iodide photodetectors for use with scintillators. These photodetectors operate with very low leakage current and show high quantum efficiency (>60% in 350 to 500 mm region. Successful scintillation studies have been performed at room temperature as well as elevated temperatures (100 degrees C) using PbI2 photodetectors with LSO and CsI(Na) scintillators. Detailed analysis of noise has also been performed and potential applications are discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Shah, KS (reprint author), RADIAT MONITORING DEVICES INC,44 HUNT ST,WATERTOWN,MA 02172, USA. NR 5 TC 26 Z9 31 U1 0 U2 7 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 JUN PY 1997 VL 44 IS 3 BP 448 EP 450 DI 10.1109/23.603688 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200034 ER PT J AU Adams, D Baumbaugh, B Borcherding, F Dunnigan, M Marchant, J Potashnik, S Ruchti, R Warchol, J Wayne, M AF Adams, D Baumbaugh, B Borcherding, F Dunnigan, M Marchant, J Potashnik, S Ruchti, R Warchol, J Wayne, M TI Scintillating pad detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB We have been investigating the performance of scintillating pad detectors, individual small tiles of scintillator that are read out with wavelength-shifting fibers and visible light photon counters, for application in high luminosity colliding beam experiments such as the DO Upgrade. Such structures could provide ''pixel'' type readout over large fiducial volumes for tracking, preshower detection and triggering. C1 UNIV NOTRE DAME,NOTRE DAME,IN 46556. RICE UNIV,HOUSTON,TX 77251. RP Adams, D (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 455 EP 459 DI 10.1109/23.603690 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200036 ER PT J AU Ambrogiani, M Baldini, W Bettoni, D Bombonati, M Bonsi, D Calabrese, R Luppi, E Mussa, R Stancari, G AF Ambrogiani, M Baldini, W Bettoni, D Bombonati, M Bonsi, D Calabrese, R Luppi, E Mussa, R Stancari, G TI Construction and performance of a cylindrical scintillating fiber detector for experiment 835 at FNAL SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID LIGHT PHOTON COUNTERS; TRACKING AB A tracking detector made of scintillating fibers has been built for the Fermilab experiment E835 [1]. The tracker is being used for a high resolution measurement of the polar angle theta and to provide a first level trigger, exploiting the fast response and very good time resolution of the signal from the fibers. The small amount of light from the fibers is detected by solid state devices (VLPC: Visible Light Photon Counters), with very high quantum efficiency. This paper reports about the construction of the tracker and gives the first results on the detector performance: light yield/mip, efficiency, signal homogeneity and time resolution. C1 IST NAZL FIS NUCL,I-44100 FERRARA,ITALY. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Ambrogiani, M (reprint author), UNIV FERRARA,I-44100 FERRARA,ITALY. RI Luppi, Eleonora/A-4902-2015; Calabrese, Roberto/G-4405-2015; OI Luppi, Eleonora/0000-0002-1072-5633; Calabrese, Roberto/0000-0002-1354-5400; Mussa, Roberto/0000-0002-0294-9071 NR 13 TC 10 Z9 10 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 JUN PY 1997 VL 44 IS 3 BP 460 EP 463 DI 10.1109/23.603691 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200037 ER PT J AU Toney, JE Brunett, BA Schlesinger, TE James, RB Eissler, EE AF Toney, JE Brunett, BA Schlesinger, TE James, RB Eissler, EE TI Correlation of nuclear spectrometer performance with uniformity and resistivity in cadmium zinc telluride SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB We have used low-temperature photoluminescence (PL) spectroscopy and room-temperature photoluminescence mapping as a measure of composition variation in cadmium zinc telluride grown by high-pressure Bridgman. We have correlated the uniformity, as measured by the line width of the bound exciton peak in the low-temperature spectrum and the degree of variation in the peak position in the room-temperature map, with the peak-to-valley ratio of the 59.5 keV photopeak in the pulse-height spectrum of Am-241. For detectors having active areas of 10-30 mm(2), the PL measurements can be combined with resistivity measurements to give a strong predictor of detector performance. For arrays of 1 mm diameter detectors, the correlation between these material parameters and detector performance is much weaker. Our measurements show that material parameters and detector performance can vary substantially between points on a 1 cm(2) sample. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. EV PROD,SAXONBURG,PA 16056. RP Toney, JE (reprint author), CARNEGIE MELLON UNIV,DEPT ELECT & COMP ENGN,PITTSBURGH,PA 15213, USA. NR 4 TC 6 Z9 6 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 499 EP 503 DI 10.1109/23.603699 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200044 ER PT J AU Lopes, JAM dosSantos, JMF Conde, CAN Morgado, RE AF Lopes, JAM dosSantos, JMF Conde, CAN Morgado, RE TI An integrated photosensor readout for gas proportional scintillation counters SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID DETECTOR; XENON; CSI AB A xenon gas proportional scintillation counter has been instrumented with a novel photosensor to replace the photomultiplier tube normally used to detect the vacuum ultraviolet (VUV) secondary scintillation from xenon. In this implementation, the collector grid of a planar gas proportional scintillation counter also functions as a multiwire proportional chamber to detect and amplify the photoelectrons emitted from a reflective CsI photocathode located in the xenon gas. This integrated concept combines greater simplicity, compactness, and ruggedness with low power consumption. An energy resolution of 12% was obtained for 59.6-keV x-rays. C1 UNIV COIMBRA,DEPT FIS,P-3000 COIMBRA,PORTUGAL. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Lopes, JAM (reprint author), INST SUPER ENGN,COIMBRA,PORTUGAL. RI matias-lopes, jose/H-6074-2012; dos Santos, Joaquim/B-3058-2015; OI matias-lopes, jose/0000-0002-6366-2963; Conde, Carlos/0000-0002-1387-2161; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 12 TC 13 Z9 13 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 JUN PY 1997 VL 44 IS 3 BP 517 EP 520 DI 10.1109/23.603703 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200048 ER PT J AU Bento, ACSSM dosSantos, JMF Morgado, RE AF Bento, ACSSM dosSantos, JMF Morgado, RE TI Effect of grid misalignment on the uniformity of response of gas proportional scintillation counters SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID X-RAY SPECTROMETRY; PERFORMANCE; XENON; FIELD AB In the present work we revisit the simplifying assumptions of an earlier theoretical treatment on the effects of grid misalignment on the performance of a planar gas proportional scintillation counter (GPSC). We present new experimental and computational results to establish the dependence of the effects of misalignment in terms of the reduced electric field in the scintillation region, the finite size of the electron cloud, and the solid angle subtended by the photosensor. It is shown that solid angle effects will offset to some degree the effects of grid misalignment in an optimized detector. For the reduced fields normally used in the scintillation region of an optimized GPSC (5 V cm(-1)torr(-1)), misalignments as large as 3% have less than a 2% effect on pulse-amplitude variations. This effect is less than the statistical fluctuations in the number of primary electrons nominally produced in the absorption of x-rays in the 1- to 6-keV energy region. For reduced fields closer to the scintillation threshold (1 V cm(-1)torr(-1)), 15% variations in pulse amplitudes are possible, although it is unlikely that a GPSC would be operated under such unfavorable conditions. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Bento, ACSSM (reprint author), UNIV COIMBRA,DEPT FIS,P-3000 COIMBRA,PORTUGAL. RI dos Santos, Joaquim/B-3058-2015; OI dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 19 TC 2 Z9 2 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 JUN PY 1997 VL 44 IS 3 BP 527 EP 533 DI 10.1109/23.603705 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200050 ER PT J AU Peurrung, AJ Reeder, PL Lepel, EA Stromswold, DC AF Peurrung, AJ Reeder, PL Lepel, EA Stromswold, DC TI Location of neutron sources using moderator-free directional thermal neutron detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The use of neutron detectors designed to record only those thermalized neutrons coming from a highly specific direction can provide enhanced capability for applications such as locating nuclear weapons material or monitoring storage vaults containing special nuclear materials. Such a detection system should be as free of moderator as possible to assure effective directionality. We provide evidence from computer modeling and experimental tests that this technique allows the identification and localization of neutron sources at greater distances and narrower angular resolution than would be possible with conventional moderating neutron detectors. RP Peurrung, AJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 6 TC 3 Z9 3 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 JUN PY 1997 VL 44 IS 3 BP 543 EP 550 DI 10.1109/23.603708 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200053 ER PT J AU Bowyer, SM Miley, HS Thompson, RC Hubbard, CW AF Bowyer, SM Miley, HS Thompson, RC Hubbard, CW TI Automated particulate sampler for comprehensive test ban treaty verification (the DOE radionuclide aerosol sampler/analyzer) SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The Comprehensive Test Ban Treaty (CTBT) [1] was recently signed by President Clinton and is intended to eliminate all nuclear weapons testing. One way in which the treaty seeks to accomplish this is by the establishment of The International Monitoring System. As stated in the latest Working Papers of the Draft CTBT, ''The International Monitoring System shall comprise facilities for seismological monitoring, radionuclide monitoring including certified laboratories, hydroacoustic monitoring, infrasound monitoring, and respective means of communication, and shall be supported by the International Data Centre of the Technical Secretariat''. Radionuclide monitoring consists of both radionuclides associated with particulates and relevant noble gases. This type of monitoring is quite valuable since indications of a nuclear test in the form of radioactive particulate or radioactive noble gases may be detected at great distances from the detonation site. The system presented here is concerned only with radioactive particulate monitoring and is described as an automated sampler/analyzer which has been developed for the Department of Energy (DOE) at the Pacific Northwest National Laboratory (PNNL). RP Bowyer, SM (reprint author), PACIFIC NW LAB, POB 999,P8-08, RICHLAND, WA 99352 USA. NR 2 TC 9 Z9 9 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 JUN PY 1997 VL 44 IS 3 BP 551 EP 556 DI 10.1109/23.603709 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200054 ER PT J AU Tumer, TO ONeill, TJ Hurley, K Ogelman, H Paulos, RJ Puetter, RC Kipnis, I Hamilton, WJ Proctor, R AF Tumer, TO ONeill, TJ Hurley, K Ogelman, H Paulos, RJ Puetter, RC Kipnis, I Hamilton, WJ Proctor, R TI All-sky X-ray & gamma-ray astronomy monitor (AXGAM) SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID CDZNTE AB A wide field-of-view, arcsecond imaging, high energy resolution x-ray and low energy gamma ray detector is proposed for a future space mission. It is specifically designed to detect and find counterparts at other wavelengths for Gamma Ray Bursts (GRBs). Detection of GRBs requires wide field-of-view (pi to 2 pi field-of-view) and high sensitivity. This will be achieved by using high quantum efficiency CdZnTe pixel detectors with a low energy threshold (few keV) to observe the larger flux levels at lower energies, and large effective area (625 to 1,000 cm(2)) per coded aperture imaging module. Counterpart searches can only be done with ultra high angular resolution detectors (10 to 30 arcsecond FWHM) which gives 1 to 5 arcsecond position determination especially for strong GRBs. A few arcsecond size error box is expected to contain at most one object observed at another wavelength. This will be achieved by using ultra high spatial resolution pixel detectors (50 x 50 to 100 x 100 microns) and a similar resolution coded aperture to achieve the required angular resolution. AXGAM also has two other important advantages over similar detectors: (1) excellent low energy response (> 1 keV) and (2) high energy resolution (<6% at 5.9 keV, <3% at 14 keV, <4% at 122 keV). The low energy range may provide important new information on GRBs and the high energy resolution is expected to help in the observation and identification of emission and absorption lines in the GRB spectrum. The effective energy range is planned to be 2 to 200 keV which is exceptionally wide for such a detector. AXGAM will be built in the form of a hemispherical array using a coded aperture mask in a hemispherical dome arrangement placed over a two-dimensional, high resolution CdZnTe pixel detector array using newly developed p-i-n detector technology. The p-i-n structure decreases the electron and hole trapping effect and increases energy resolution significantly. The major scientific goals of the proposed mission in addition to continuously monitoring gamma-ray bursts, is to observe AGNs, transient phenomena, isolated and binary pulsars, and solar flares. A space deployed AXGAM detector is expected to observe few hundred gamma ray bursts per year. C1 UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV WISCONSIN,MADISON,WI 53706. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92093. LAWRENCE BERKELEY LAB,BERKELEY,CA 94551. HUGHES AIRCRAFT CO,DEVICE DEV & ENG DEP,SANTA BARBARA,CA 93117. GAMMA METR,SAN DIEGO,CA 92121. RP Tumer, TO (reprint author), UNIV CALIF RIVERSIDE,INST GEOPHYS & PLANETARY PHYS,RIVERSIDE,CA 92521, USA. NR 14 TC 5 Z9 5 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 572 EP 576 DI 10.1109/23.603713 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200058 ER PT J AU Sinev, NB Brau, JE Dervan, P Etzion, E Watts, S Smy, M Hertzbach, S Strauss, M Trandafir, A Burrows, P Dong, D Kelsy, J Kendall, H Lee, I Lia, V Osborne, L Ross, D Taylor, F Verdier, R Damerell, C English, R Jackson, D Lintern, L Ohishi, N Breidenbach, M Chou, A Crawford, G Foss, M Haller, G Hoeflich, J Huffer, M Jaros, J Masuda, H Russell, J Skarpaas, K Dong, S Usher, T Abe, K Hasuko, K Nagamine, T Suekane, F Yashima, J Yuta, H Arodzero, A Frey, R Huber, J Weiss, E Serbo, V Zapalac, G Baltay, C Emmet, W Liu, M Manly, S Moore, T Sinnott, J Snyder, J AF Sinev, NB Brau, JE Dervan, P Etzion, E Watts, S Smy, M Hertzbach, S Strauss, M Trandafir, A Burrows, P Dong, D Kelsy, J Kendall, H Lee, I Lia, V Osborne, L Ross, D Taylor, F Verdier, R Damerell, C English, R Jackson, D Lintern, L Ohishi, N Breidenbach, M Chou, A Crawford, G Foss, M Haller, G Hoeflich, J Huffer, M Jaros, J Masuda, H Russell, J Skarpaas, K Dong, S Usher, T Abe, K Hasuko, K Nagamine, T Suekane, F Yashima, J Yuta, H Arodzero, A Frey, R Huber, J Weiss, E Serbo, V Zapalac, G Baltay, C Emmet, W Liu, M Manly, S Moore, T Sinnott, J Snyder, J TI Performance of the new vertex detector at SLD SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB During the past year, the SLD collaboration completed the construction and began the operation of a new vertex detector (VXD3) employing 307 million pixels. This detector, based on 96 CCDs of 13 cm(2) area each, is an upgrade of the original vertex detector of SLD (VXD2), made possible by advances in the technology of CCD detectors. Its improved impact parameter resolution, larger solid angle coverage and virtually error0free track linking will enhance the SLD measurement of the polarization-enhanced forward-backward asymmetry for band c- quarks, increase the precision of the measurement of the b-fraction in hadronic Z decays, and open the possibility to observe B-5(0)-mixing. Full separation of primary, secondary and tertiary vertices is accessible. A description of the mechanics and electronics of VXD3 are presented along with results from the first data. C1 BRUNEL UNIV,UXBRIDGE UB8 3PH,MIDDX,ENGLAND. COLORADO STATE UNIV,FT COLLINS,CO 80523. UNIV MASSACHUSETTS,AMHERST,MA 01003. MIT,CAMBRIDGE,MA 02139. RUTHERFORD APPLETON LAB,CHILTON,ENGLAND. NAGOYA UNIV,NAGOYA,AICHI,JAPAN. STANFORD LINEAR ACCELERATOR CTR,SLD COLLABORAT,STANFORD,CA 94309. TOHOKU UNIV,SENDAI,MIYAGI 980,JAPAN. UNIV WASHINGTON,SEATTLE,WA 98195. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06520. RP Sinev, NB (reprint author), UNIV OREGON,EUGENE,OR 97403, USA. NR 3 TC 1 Z9 1 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 587 EP 591 DI 10.1109/23.603716 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200061 ER PT J AU Betts, W Bieser, F Bossingham, R Botlo, M Cherney, M Chrin, J Colarco, P Crawford, H Dao, K Diaz, H Greiner, DE Greiner, L Hjort, EL Jacobson, S Jared, RC Judd, E Klein, SR Lebedev, AN LeVine, MJ Lindenstruth, V Lisa, MA Marks, K McParland, C McShane, TS Meier, J Nguyen, MT Olson, DL Sakrejda, I Schambach, J Scheetz, RA Stone, NTB Tull, CE Visser, G Vu, C Wieman, H Yee, E AF Betts, W Bieser, F Bossingham, R Botlo, M Cherney, M Chrin, J Colarco, P Crawford, H Dao, K Diaz, H Greiner, DE Greiner, L Hjort, EL Jacobson, S Jared, RC Judd, E Klein, SR Lebedev, AN LeVine, MJ Lindenstruth, V Lisa, MA Marks, K McParland, C McShane, TS Meier, J Nguyen, MT Olson, DL Sakrejda, I Schambach, J Scheetz, RA Stone, NTB Tull, CE Visser, G Vu, C Wieman, H Yee, E TI Results from the STAR TPC system test SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A system test of various components of the Solenoidal Tracker at RHIC (STAR) detector, operating in concert, has recently come on-line. Communication between a major sub-detector, a sector of the Time Projection Chamber (TPC), and the trigger, data acquisition and slow controls systems has been established, enabling data from cosmic ray muons to be collected. First results from an analysis of the TPC data are presented. These include measurements of system noise, electronic parameters such as amplifier gains and pedestal values, and tracking resolution for cosmic ray muons and laser induced ionization tracks. A discussion on the experience gained in integrating the different components for the system test is also given. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. BROOKHAVEN NATL LAB,UPTON,NY 11973. CREIGHTON UNIV,DEPT PHYS,OMAHA,NE 68178. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. MOSCOW ENGN PHYS INST,MOSCOW 115409,RUSSIA. RP Betts, W (reprint author), UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712, USA. RI Colarco, Peter/D-8637-2012 OI Colarco, Peter/0000-0003-3525-1662 NR 4 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 592 EP 597 DI 10.1109/23.603717 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200062 ER PT J AU Pandey, SU Bellwied, R Beuttenmueller, R Chen, W Cooper, D DiMassimo, D Dou, L Dyke, H Elliot, D French, A Hall, J Hoffmann, GW Humanic, TJ Kirkman, J Kotov, IV Kraner, HW Liaw, CJ LoCurto, G Lynn, D Paganis, S Pruneau, C Read, D Rykov, V Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Vilkelis, G Wilson, WK AF Pandey, SU Bellwied, R Beuttenmueller, R Chen, W Cooper, D DiMassimo, D Dou, L Dyke, H Elliot, D French, A Hall, J Hoffmann, GW Humanic, TJ Kirkman, J Kotov, IV Kraner, HW Liaw, CJ LoCurto, G Lynn, D Paganis, S Pruneau, C Read, D Rykov, V Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Vilkelis, G Wilson, WK TI Behavior of silicon drift detectors in large magnetic fields. SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID ELECTRONS; CHAMBERS AB A 45x45 mm rectangular n-type Silicon Drift Detector was studied in magnetic fields ranging from 0 to 4.7 T and for drift fields from 200 to 380 V/cm. Transport properties of electrons in silicon (Hall mobility, drift mobility and magnetoresistance) were determined by pulsing the detector with a Nd:Yag laser at different drift lengths and measuring both the transverse deflections of the signal and the increases in drift time versus an applied magnetic field. The width of the signal in both the drift and anode direction increased with magnetic field. The magnetic field was aligned parallel and normal to the the drift direction. The detector was found to operate well for conditions expected in future experiments at the RHIC collider and experiment E896 at Brookhaven National Laboratory. C1 WAYNE STATE UNIV, DETROIT, MI 48201 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. UNIV TEXAS, AUSTIN, TX 78712 USA. RP Pandey, SU (reprint author), OHIO STATE UNIV, COLUMBUS, OH 43210 USA. RI Takahashi, Jun/B-2946-2012; OI Takahashi, Jun/0000-0002-4091-1779; PAGANIS, STATHES/0000-0002-1950-8993 NR 19 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 610 EP 614 DI 10.1109/23.603720 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200065 ER PT J AU Cho, HS Hong, WS Palaio, N Kadyk, J Luk, KB PerezMendez, V Joo, KS Vujic, J AF Cho, HS Hong, WS Palaio, N Kadyk, J Luk, KB PerezMendez, V Joo, KS Vujic, J TI Spark damage studies of microgap gas chambers with various anode strip metals SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID DETECTOR AB Since the effects of spark damage by discharges and aging are very sensitive to metal used for anode strips, several microgap gas chambers (MGCs) have been fabricated with various anode strip metals: aluminum, gold, chromium, nickel, and titanium-tungsten, and a systematic study of spark damage effects has been made to compare their relative sensitivity to failure, over a range of electrical discharge energies. The results of aging studies are being presented separately. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720. RP Cho, HS (reprint author), UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720, USA. NR 7 TC 4 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 635 EP 639 DI 10.1109/23.603724 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200069 ER PT J AU Rehak, P Smith, GC Yu, B AF Rehak, P Smith, GC Yu, B TI A method for reduction of parallax broadening in gas-based position sensitive detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID RAY AB A description is given of the principle and experimental verification of a new method which significantly reduces broadening of the position response, due to parallax, for radiation incident on a detector at finite angles of incidence. The technique, which can be implemented in gas-based position-sensitive detectors with planar geometry, substantially improves position resolution for scattering experiments using X-rays and neutrons, and will permit larger angular coverage than has previously been possible. An improvement of nearly a factor four in rms position resolution is predicted, which is confirmed by measurements using a gas proportional X-ray detector with delay-line position encoding. RP Rehak, P (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 7 TC 12 Z9 13 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 JUN PY 1997 VL 44 IS 3 BP 651 EP 655 DI 10.1109/23.603727 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200072 ER PT J AU Wieman, H Anderssen, E Banerjee, A Betts, W Bossingham, R Ghazikhanian, V Gong, W Greiner, D Harper, G Huang, H Hjort, E Kotchenda, L Lebedev, A Sakrejda, I Shuman, D Smith, M Sobel, A Stone, N Stringfellow, B Trainor, T Trentalange, S Wells, R AF Wieman, H Anderssen, E Banerjee, A Betts, W Bossingham, R Ghazikhanian, V Gong, W Greiner, D Harper, G Huang, H Hjort, E Kotchenda, L Lebedev, A Sakrejda, I Shuman, D Smith, M Sobel, A Stone, N Stringfellow, B Trainor, T Trentalange, S Wells, R TI STAR TPC at RHIC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB Design information, construction methods and testing results are given for the STAR TPC which will be installed at the BNL RHIC Collider. C1 UNIV TEXAS,AUSTIN,TX 78712. UNIV CALIF LOS ANGELES,LOS ANGELES,CA. UNIV WASHINGTON,SEATTLE,WA 98195. PURDUE UNIV,W LAFAYETTE,IN 47907. MOSCOW PHYS ENGN INST,MOSCOW,RUSSIA. RP Wieman, H (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Sobel, Adam/K-4014-2015 OI Sobel, Adam/0000-0003-3602-0567 NR 19 TC 37 Z9 37 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 671 EP 678 DI 10.1109/23.603731 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200076 ER PT J AU Brooks, ML Lee, DM Sondheim, W AF Brooks, ML Lee, DM Sondheim, W TI Alignment systems for the PHENIX muon tracking chambers SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The alignment systems required for the PHENIX muon tracking chamber system will be described. These systems include the system that has been developed to accurately electro-etch cathode strip foils with respect to external fiducial marks to a 25 mu m accuracy, as well as the system that is being developed to measure the relative alignment of three stations of chambers spanning 4.5 meters, to an accuracy of 25 mu m. RP Brooks, ML (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 3 TC 2 Z9 2 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 JUN PY 1997 VL 44 IS 3 BP 683 EP 686 DI 10.1109/23.603733 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200078 ER PT J AU Bellwied, R Beuttenmuller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffman, GW Humanic, T Kotova, AI Kotov, IV Kraner, HW Li, Z Liaw, CJ Lynn, D Ray, L Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK AF Bellwied, R Beuttenmuller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffman, GW Humanic, T Kotova, AI Kotov, IV Kraner, HW Li, Z Liaw, CJ Lynn, D Ray, L Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK TI Double particle resolution in STAR silicon drift detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The inner tracking detector of the STAR experiment at the BNL Relativistic Heavy Ion Collider will consist of a three layer barrel structure of 216 silicon drift detectors. Calculations of the two-hit resolution achievable for these detectors are presented in this article. The effects on two-hit resolution of the electronic's response function, frequency of signal digitization and noise level are discussed. C1 OHIO STATE UNIV,COLUMBUS,OH 43210. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV TEXAS,AUSTIN,TX 78712. WAYNE STATE UNIV,DETROIT,MI 48202. IHEP,PROTVINO,RUSSIA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 687 EP 690 DI 10.1109/23.603734 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200079 ER PT J AU Luke, PN Amman, M Prettyman, TH Russo, PA Close, DA AF Luke, PN Amman, M Prettyman, TH Russo, PA Close, DA TI Electrode design for coplanar-grid detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID SEMICONDUCTOR-DETECTORS AB The coplanar-grid charge sensing technique provides a method for improving the spectral response of gamma-ray detectors based on compound semiconductors, which typically have poor charge transport properties. The technique functions by effectively modifying the charge induction characteristics of the detector such that the dependence of detector signal on the depth of radiation interaction is minimized. The effectiveness of this technique however can be compromised by non-uniform charge induction characteristics across the detector. This paper examines such non-uniformity due to fringe effects near the detector edges. Alternate electrode configurations are studied that provide effective compensation for such effects. Results from experimental measurements and computer simulations are presented. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Luke, PN (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. OI Prettyman, Thomas/0000-0003-0072-2831 NR 7 TC 26 Z9 27 U1 0 U2 3 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 JUN PY 1997 VL 44 IS 3 BP 713 EP 720 DI 10.1109/23.603739 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200084 ER PT J AU Unno, Y Nakao, M Fujita, K Ciocio, A Dane, J Dubbs, T Emes, J Gilchriese, M Grillo, A Haber, C Handa, T Holland, S Iwasaki, H Iwata, Y Kashigin, S Kipnis, I Kohriki, T Kondo, T Kroeger, W LozanoBahilo, J Moorhead, G Ohsugi, T Pier, S Rowe, B Sadrozinski, HFW Shapiro, M Siegrist, J Spencer, E Spieler, H Tamura, N Takashima, R Terada, S Wilder, M AF Unno, Y Nakao, M Fujita, K Ciocio, A Dane, J Dubbs, T Emes, J Gilchriese, M Grillo, A Haber, C Handa, T Holland, S Iwasaki, H Iwata, Y Kashigin, S Kipnis, I Kohriki, T Kondo, T Kroeger, W LozanoBahilo, J Moorhead, G Ohsugi, T Pier, S Rowe, B Sadrozinski, HFW Shapiro, M Siegrist, J Spencer, E Spieler, H Tamura, N Takashima, R Terada, S Wilder, M TI Beam test of a large area n-on-n silicon strip detector with fast binary readout electronics SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A large area (60 mm x 60 mm) n-bulk and n-strip readout silicon strip detector prototype was fabricated for the ATLAS SCT detector. Detector modules with a strip length of 12 cm were made by butting two detectors. One of the 12 cm modules was irradiated with protons to a fluence of 1.2 x 10(14) p/cm(2), and a beam test was carried out for the non-irradiated and the irradiated detector modules. Efficiency and noise occupancy were analyzed using the beam test data. High efficiency was obtained for both detectors in the bias voltages down to about half the full depletion voltage. The noise occupancy was <2 x 10(-4) for the 12 cm strips. The measurement of the edge region exhibited a difference in the sensitivity under the bias resistance where no extension of the n(+)-implant was fabricated: the non-irradiated detector showed sensitivity while the irradiated detector did not. The result was confirmed with a laser. C1 OKAYAMA UNIV,OKAYAMA 700,JAPAN. HIROSHIMA UNIV,HIGASHIHIROSHIMA,HIROSHIMA 724,JAPAN. UNIV CALIF IRVINE,IRVINE,CA 92717. LBNL,BERKELEY,CA 94720. UNIV MELBOURNE,PARKVILLE,VIC 3052,AUSTRALIA. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. KYOTO UNIV,FUSHIMI KU,KYOTO 612,JAPAN. RP Unno, Y (reprint author), KEK NAT LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. RI Moorhead, Gareth/B-6634-2009; Holland, Stephen/H-7890-2013; Lozano-Bahilo, Julio/F-4881-2016 OI Moorhead, Gareth/0000-0002-9299-9549; Lozano-Bahilo, Julio/0000-0003-0613-140X NR 8 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 736 EP 742 DI 10.1109/23.603742 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200087 ER PT J AU Cho, HS Hong, WS Palaio, N Kadyk, J Luk, KB PerezMendez, V Burks, M Retiere, F Joo, KS Vujic, J AF Cho, HS Hong, WS Palaio, N Kadyk, J Luk, KB PerezMendez, V Burks, M Retiere, F Joo, KS Vujic, J TI Performance of microgap gas chambers fabricated with selected anode metals SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB Microgap gas chambers (MGCs) fabricated with selected anode metals, including aluminum, gold, chromium, and nickel, have been used in order to study the properties of gas gain, aging, and spark damage by discharges. In this paper, we present studies of the behavior of gas gain with respect to several operating parameters, and the accelerated aging. The results of spark damage tests are being presented separately. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Cho, HS (reprint author), UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720, USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 747 EP 751 DI 10.1109/23.603744 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200089 ER PT J AU Hubbard, CW McKinnon, AD AF Hubbard, CW McKinnon, AD TI Client-server architecture applied to system automation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB Control software for an automated particulate air sampler is described. The software is divided into a number of small, cooperating server processes each of which is responsible for the control of a particular device or subsystem. For each process an effort was made to isolate the details of the underlying device or subsystem from the server interface. This makes it possible to change the hardware without making changes to any of the server's client processes. A single supervisor process is responsible for overall system control. Design of the control algorithm was facilitated by employing a state machine model. Such a model is easy to study, easy to modify and provides a clear understanding of the control mechanism to programmers and non-programmers alike. A state machine library was developed which greatly eased the task of implementing the design and ensured that the control algorithm detailed by the state machine model was the same algorithm actually employed. RP Hubbard, CW (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI McKinnon, Archibald/0000-0002-3963-783X NR 0 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 783 EP 787 DI 10.1109/23.603752 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200097 ER PT J AU Zoeller, MM Adam, W Bauer, C Baumann, I Colledani, C Conway, J Delpierre, P Djama, F Dulinski, W Fallou, A Fish, D Gan, KK Grigoriev, E Hallewell, G HallWilton, R Han, S Hrubec, J Husson, D Kagan, H Kania, D Kass, R Knopfle, KT Krammer, M Manfredi, PF Meier, D Pan, LS Pernegger, H Pernicka, M Re, V Roe, S Roff, D Rudge, A Schaeffer, M Schnetzer, S Speziali, V Stone, R Tapper, RJ Tesarek, R Thomson, GB Trischuk, W Turchetta, R Walsh, AM Weilhammer, P Ziock, H AF Zoeller, MM Adam, W Bauer, C Baumann, I Colledani, C Conway, J Delpierre, P Djama, F Dulinski, W Fallou, A Fish, D Gan, KK Grigoriev, E Hallewell, G HallWilton, R Han, S Hrubec, J Husson, D Kagan, H Kania, D Kass, R Knopfle, KT Krammer, M Manfredi, PF Meier, D Pan, LS Pernegger, H Pernicka, M Re, V Roe, S Roff, D Rudge, A Schaeffer, M Schnetzer, S Speziali, V Stone, R Tapper, RJ Tesarek, R Thomson, GB Trischuk, W Turchetta, R Walsh, AM Weilhammer, P Ziock, H TI Performance of CVD diamond microstrip detectors under particle irradiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB The inherent properties of diamond make it an ideal material for detectors in the high rate, high radiation environments near the collision point of future colliders such as the LHC. We have constructed charged particle position sensitive detectors using high quality Chemical Vapor Deposited (CVD) diamond. Using detectors with a 50 mu m strip pitch, we achieved a most probable signal-to-noise ratio of 27/1 and a position resolution of 12-15 mu m. To ascertain the radiation hardness properties of CVD diamond, we have exposed detectors to 10 MRad Co-60, 5 X 10(14) 300 MeV pions/cm(2), 10(14) 500 MeV protons/cm(2), and 10(15) neutrons/cm(2). The results show that CVD diamond is an extremely radiation hard material and well suited for particle detector production. C1 AUSTRIAN ACAD SCI,INST HOCHENERGIEPHYS,A-1050 VIENNA,AUSTRIA. MPI KERNPHYS,D-69029 HEIDELBERG,GERMANY. CTR RECH NUCL,LEPSI,F-67037 STRASBOURG,FRANCE. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. CPPM,F-13288 MARSEILLE,FRANCE. UNIV BRISTOL,BRISTOL BS8 1TL,AVON,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV PAVIA,DIPARTIMENTO ELETTR,I-27100 PAVIA,ITALY. CERN,CH-1211 GENEVA 23,SWITZERLAND. SANDIA NATL LABS,LIVERMORE,CA 94550. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. RP Zoeller, MM (reprint author), OHIO STATE UNIV,COLUMBUS,OH 43210, USA. RI Krammer, Manfred/A-6508-2010; Grigoriev, Eugene/K-6650-2013; OI Krammer, Manfred/0000-0003-2257-7751; Grigoriev, Eugene/0000-0001-7235-9715; Re, Valerio/0000-0003-0697-3420 NR 9 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 815 EP 818 DI 10.1109/23.603758 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200103 ER PT J AU Eremin, V Ivanov, A Verbitskaya, E Li, Z Schmidt, B AF Eremin, V Ivanov, A Verbitskaya, E Li, Z Schmidt, B TI Long term instabilities in the defect assembly in irradiated high resistivity silicon detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID REVERSE AB Transformation of radiation induced, carbon related defects in high resistivity silicon detectors under multistep irradiation and annealing has been investigated in connection with the problem of reverse annealing of the effective space charge concentration, N-eff, in the space charge region of irradiated detectors. Kinetic behavior of these defects as possible candidates which affect N-eff has been studied using C-DLTS (capacitance deep level transient spectroscopy) technique after room temperature and elevated temperature annealing. Defect transformation has been identified in the form the decay of radiation induced interstitial carbon, which follows the equation of a first order reaction, and the simultaneous generation of C-i-O-i and C-i-C-s complexes. It has been shown that the concentration of the C-i-O-i complex increased at RT (room temperature, 22 degrees C) annealing and obeyed the second order reaction. Successive steps of irradiation and annealing were performed, which stimulated excessive concentration of the C-i-O-i complex; generated additional centers in silicon increased oxygen content from heat treatment applied in the detector manufacturing. The results imply that the instability in the defect assembly in irradiated silicon can arise from the complexes including impurities of carbon and oxygen. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. FORSCHUNGSZENTRUM ROSSENDORF EV,D-01314 DRESDEN,GERMANY. RP Eremin, V (reprint author), RUSSIAN ACAD SCI,IOFFE PHYSICOTECH INST,ST PETERSBURG 194021,RUSSIA. RI Verbitskaya, Elena/D-1521-2014; Ivanov, Alexander/E-3993-2014 NR 12 TC 2 Z9 2 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 JUN PY 1997 VL 44 IS 3 BP 819 EP 824 DI 10.1109/23.603759 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200104 ER PT J AU Li, Z Li, CJ Verbitskaya, E AF Li, Z Li, CJ Verbitskaya, E TI Study of bulk damage in high resistivity silicon detectors irradiated by high dose of Co-60 gamma-radiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID CHARGES N-EFF; SPECTROSCOPY AB Displacement damage (or bulk damage) induced by high dose (>200 Mrad) gamma-radiation in high resistivity (6-10 k Omega-cm) silicon detectors has been studied. It has been found that detector bulk leakage current increases with gamma dose at a rate of 3.3x10(-7) A/cm(3)/Mrad. This damage rate of bulk leakage current originates from the introduction of generation centers and at a dose of 210 Mrad of gamma-radiation is comparable to that induced by 1x10(12) n/cm(2) of neutron radiation. Nearly 100% donor removal and/or compensation was found in detectors irradiated to 215 Mrad. Space charge sign inversion (SCSI) was observed in detectors irradiated to greater than or equal to 215 Mrad using transient current technique (TCT). As many as six deep levels have been observed by current deep level transient spectroscopy (I-DLTS). There was insignificant annealing and no reverse annealing even after elevated temperature treatment for detectors irradiated to 215 Mrad. A small amount of reverse annealing (10 to 15%) has been observed during the room temperature storage period of about 11 months for detectors irradiated to 500 Mrad. RP BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Verbitskaya, Elena/D-1521-2014 NR 14 TC 13 Z9 13 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 834 EP 839 DI 10.1109/23.603761 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200106 ER PT J AU Hull, EL Pehl, RH Varnell, LS AF Hull, EL Pehl, RH Varnell, LS TI The effects of 199 MeV proton radiation damage on CdZnTe photon detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID GERMANIUM AB Four CdZnTe detectors were irradiated with 199 MeV protons to simulate the damaging radiation in space. The gamma-ray spectra of Am-241 and Co-57 as well as the detector leakage currents were monitored at room temperature to assess the effects of radiation damage. Surprisingly, after a fluence of a few x 10(8) p/cm(2) gamma-ray peak shifts and resolution degradation became visible. After a fluence of 5x10(9) p/cm(2) the degradation was quite dramatic. An analysis of these effects dearly demonstrates that radiation damage causes electron trapping in CdZnTe detectors. No increase in leakage current or electronic noise was observed. Radiation damage effects in CdZnTe and germanium detectors are compared. CdZnTe detectors are similar to 250 times more sensitive to radiation damage than germanium detectors per unit charge-drift distance. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Hull, EL (reprint author), INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408, USA. NR 11 TC 8 Z9 8 U1 0 U2 5 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 JUN PY 1997 VL 44 IS 3 BP 870 EP 873 DI 10.1109/23.603768 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200113 ER PT J AU Burger, A Chen, H Tong, J Shi, D George, MA Chen, KT Collins, WE James, RB Stahle, CM Bartlett, LM AF Burger, A Chen, H Tong, J Shi, D George, MA Chen, KT Collins, WE James, RB Stahle, CM Bartlett, LM TI Investigation of electrical contacts for Cd1-xZnxTe nuclear radiation detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB A comparative study of four different metal deposition methods on detector grade Cd1-xZnxTe crystal has been done using current-voltage (I-V) characterization and Ba-133 gamma spectroscopy. Electroless Au contact and thermal evaporated Au contact have been found to yield a smaller leakage current and a more linear/symmetric I-V curve than that of sputtered Pt and Au contact. An optimum detector performance can be achieved by combining the thermal evaporated Au deposition method with a chemical surface treatment consisting of 5%Br-MeOH followed by 2% Br-20% lactic acid in ethylene glycol. Low temperature photoluminescence spectra of Cd1-xZnxTe samples corresponding to these different metallization schemes are also presented and discussed. C1 SANDIA NATL LABS,ADV ELECT MFG TECHNOL DEPT,LIVERMORE,CA 94550. NASA,GODDARD SPACE FLIGHT CTR,OSC,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,NRC,GREENBELT,MD 20771. RP Burger, A (reprint author), FISK UNIV,DEPT PHYS,CTR PHOTON MAT & DEVICES,NASHVILLE,TN 37208, USA. NR 5 TC 40 Z9 43 U1 2 U2 9 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 JUN PY 1997 VL 44 IS 3 BP 934 EP 938 DI 10.1109/23.603780 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200125 ER PT J AU Walton, JT Hong, WS Luke, PN Wang, NW Ziemba, FP AF Walton, JT Hong, WS Luke, PN Wang, NW Ziemba, FP TI Amorphous silicon crystalline silicon heterojunctions for nuclear radiation detector applications SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID GE DETECTORS; FABRICATION; CONTACTS AB Results on the characterization of the electrical properties of amorphous silicon films for the three different growth methods, RF sputtering, PECVD, and LPCVD are reported. The performance of these a-Si films as heterojunctions on high resistivity p-type and n-type crystalline silicon is examined by measuring the noise, leakage current and the alpha particle response of 5 mm diameter detector structures. It is demonstrated that heterojunction detectors formed by RF sputtered films and PECVD films are comparable in performance with conventional surface barrier detectors. The results indicate that the a-Si/c-Si heterojunctions have the potential to greatly simplify detector fabrication. Directions for future avenues of nuclear particle detector development are indicated. C1 QUANTRAD SENSOR INC,SANTA CLARA,CA 95054. RP Walton, JT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 12 TC 3 Z9 3 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 JUN PY 1997 VL 44 IS 3 BP 961 EP 964 DI 10.1109/23.603785 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200130 ER PT J AU Gruber, GJ Derenzo, SE AF Gruber, GJ Derenzo, SE TI Conceptual design of a novel instrument for producing intense pulses of 10 ps X-rays for ultra-fast fluorescence measurements SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID BEAM CHOPPING SYSTEM; LIFETIME MEASUREMENTS; ELECTRON AB We report a conceptual design of a novel bench-top device for producing intense, fast pulses of x-rays with 10 ps fwhm (full-width at half-maximum) x-ray pulse width, 120 keV maximum energy, 100 kHz repetition rate, and 1 A peak current onto the x-ray anode. The device includes three sections: (1) an electron gun that generates 5 ns wide pulses of electrons; (2) solenoidal magnetic lenses and rectangular deflection plates that focus the electrons onto an aperture plate and sweep the pulsed beam past the slit aperture, respectively; and (3) a tungsten anode onto which the post-aperture electrons are focused, producing x-ray pulses. Solenoidal magnetic lenses with a current density of 150 A.turns/cm(2) focus the 120 keV electron beam to a spot diameter of 0.32 mm such that a deflection plate dV/dt of 10(13) V/s (achieved with power triode circuitry) will yield x-ray pulse widths of about 10 ps. We used EGUN, an electron optics and gun design program, to simulate the electron trajectories throughout the instrument. RP Gruber, GJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 14 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 965 EP 969 DI 10.1109/23.603786 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200131 ER PT J AU Schmid, GJ Lee, IY Deleplanque, MA Hendriks, P Stephens, FS Vetter, K Asztalos, SJ Clark, RM Diamond, RM Fallon, P Kruecken, R Macchiavelli, AO MacLeod, RW AF Schmid, GJ Lee, IY Deleplanque, MA Hendriks, P Stephens, FS Vetter, K Asztalos, SJ Clark, RM Diamond, RM Fallon, P Kruecken, R Macchiavelli, AO MacLeod, RW TI Gamma-ray cluster identification in a spherical shell of highly segmented germanium detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB Research and development is proceeding on a new gamma-ray detector array for nuclear physics: the Gamma-Ray Energy Tracking Array (GRETA). This array will consist of a spherical shell of highly segmented Ge detectors. By obtaining the energy and position of each interaction point, high efficiency and peak-to-total ratios can be obtained as compared with existing arrays. Here we discuss the computer algorithms that are needed to process the raw data and maximize the performance of the array. The results of these algorithms on Monte Carlo simulated data are presented. RP Schmid, GJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 7 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 JUN PY 1997 VL 44 IS 3 BP 975 EP 978 DI 10.1109/23.603788 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200133 ER PT J AU Hong, WS Cho, HS PerezMendez, V Kadyk, J Palaio, N AF Hong, WS Cho, HS PerezMendez, V Kadyk, J Palaio, N TI Gas avalanche pixel detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA ID ELECTRONIC CONDUCTIVITY; MICROSTRIP CHAMBERS; PERFORMANCE; SUBSTRATA AB We describe the structure and avalanche gain of gaseous pixel detectors. Each anode is a square 20 mu m x 20 mu m in size connected to an individual pad through a plated center section. The cathodes are plated squares interconnected to a common lead. The anode squares have a pitch of 200 mu m in both x- and y- directions. The anodes and cathodes are aluminum layers deposited on amorphous silicon alloyed with carbon (a-Si:C:H) to produce a bulk resistivity of similar to 10(13) Omega cm. Measurements on signals from a group of anodes shows an avalanche gas gain close to 10(4) at a cathode-anode potential of 640 volts using a gas mixture of 50/50 argon-ethane. The avalanche gain is about a factor of 3 higher than that of microstrip devices we have tested, having the same pitch. For our initial measurements, 16 anodes were connected together to a charge sensitive preamplifier. In a final chamber each anode would be connected to an a-Si:H p-i-n readout diode with signals read out sequentially as in flat screen devices. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. RP Hong, WS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720, USA. NR 19 TC 6 Z9 6 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 JUN PY 1997 VL 44 IS 3 BP 1001 EP 1005 DI 10.1109/23.603793 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200138 ER PT J AU Chase, RL Rescia, S AF Chase, RL Rescia, S TI A linear low power remote preamplifier for the atlas liquid argon EM calorimeter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB In a previous paper [1], it was shown that, for shaping times of the order of the transmission line delay, a remote, external preamplifier could perform as well as one connected directly to a liquid argon calorimeter. Here we describe an improved circuit configuration where, by attributing the functions of low noise and high dynamic range to two different transistors, the linearity can be improved and the noise can be decreased while reducing the power dissipation by a factor of three (to about 50 mW). The gain (i.e., the transresistance) and the input impedance can be chosen independently without changing the power supply voltages and power dissipation. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Chase, RL (reprint author), LAB ACCELERATEUR LINEAIRE,F-91405 ORSAY,FRANCE. RI Rescia, Sergio/D-8604-2011 OI Rescia, Sergio/0000-0003-2411-8903 NR 2 TC 13 Z9 13 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 JUN PY 1997 VL 44 IS 3 BP 1028 EP 1032 DI 10.1109/23.603798 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200143 ER PT J AU McKinnon, AD Hubbard, CW AF McKinnon, AD Hubbard, CW TI Automating communications with and developing user interfaces for remote data acquisition and analysis systems SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB Many remote sensor applications require the deployment of automated data acquisition systems. These systems must provide a reliable and robust method of transferring acquired data to an appropriate data center. Remote users also require a means to verify the state-of-health of the sensors and a method of installing improved control software as needed. Research at PNNL on automated radionuclide systems for the Comprehensive Test Ban Treaty has developed a robust and automated method of data transmission. User interfaces for these systems allow one to use simple text-based communications protocols (kermit, telnet), or the X Windows environment. The use of Tcl/Tk aided in the rapid development of the X Windows user interfaces. RP McKinnon, AD (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI McKinnon, Archibald/0000-0002-3963-783X NR 3 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 1062 EP 1064 DI 10.1109/23.603804 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200149 ER PT J AU Scerbo, JA Satpute, SN Donkin, JY Reister, RA AF Scerbo, JA Satpute, SN Donkin, JY Reister, RA TI Safety system augmentation at Russian Nuclear Power Plants SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Nuclear Science Symposium and Medical Imaging Conference CY NOV 03-09, 1996 CL ANAHEIM, CA AB This paper describes the design and procurement of a Class 1E DC power supply system to upgrade plant safety at the Kola Nuclear Power Plant (NPP). Kola NPP is located above the Arctic circle at Polyarnie Zorie, Murmansk, Russia. Kola NPP consists of four units. Units 1 and 2 have VVER-440/230 type reactors: Units 3 and 4 have VVER-440/213 type reactors. The VVER-440 reactor design is similar to the pressurized water reactor design used in the US. This project provided redundant, Class 1E DC station batteries and DC switchboards for Kola NPP, Units 1 and 2. The new DC power supply system was designed and procured in compliance with current nuclear design practices and requirements. Technical issues that needed to be addressed included reconciling the requirements in both US and Russian codes and satisfying the requirements of the Russian nuclear regulatory authority. Close interface with ATOMENERGOPROEKT (AEP), the Russian design organization, KOLA NPP plant personnel, and GOSATMNADZOR (GAN), the Russian version of US Nuclear Regulatory Commission, was necessary to develop a design that would assure compliance with current Russian design requirements. Hence, this project was expected to serve as an example for plant upgrades at other similar VVER-440 nuclear plants. In addition to technical issues, the project needed to address language barriers and the logistics of shipping equipment to a remote section of the Former Soviet Union (FSU). This project was executed by Burns and Roe under the sponsorship of the US DOE as part of the International Safety Program (INSP). The INSP is a comprehensive effort, in cooperation with partners in other countries, to improve nuclear safety worldwide.. A major element within the INSP is the improvement of the safety of Soviet-designed nuclear reactors. C1 US DOE,GERMANTOWN,MD 20874. RP Scerbo, JA (reprint author), BURNS & ROE,800 KINDERKAMACK RD,ORADELL,NJ 07649, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 1084 EP 1088 DI 10.1109/23.603809 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF302 UT WOS:A1997XF30200154 ER PT J AU Casey, ME Eriksson, L Schmand, M Andreaco, MS Paulus, M Dahlbom, M Nutt, R AF Casey, ME Eriksson, L Schmand, M Andreaco, MS Paulus, M Dahlbom, M Nutt, R TI Investigation of LSO crystals for high spatial resolution positron emission tomography SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Medical Imaging Conference (MIC) / Nuclear Science Symposium (NSS) CY NOV 05-09, 1996 CL ANAHEIM, CA SP Inst Elect & Electr Engineers ID PET DETECTOR MODULE; PIN PHOTODIODE; DEPTH; DESIGN AB In order to achieve high sensitivity and maintain good uniform spatial resolution over the field of view in high resolution PET systems, adequate depth of interaction information must be extracted from the crystal. A phoswich detector can supply one solution to the depth of interaction problem. In this approach,two or more scintillators exhibiting different light decay times are positioned on top of each other and separated by pulse shape discrimination. Initially, our experiments focused on separating different types of scintillators such as LSO and GSO or LSO and YSO. These combinations were all well separated as expected. During the investigation, a shift in the time distribution of different samples of LSO was noticed. Further investigation showed two groups of LSO. The shift in the zero cross time was more than twice the FWHM of the time distribution. A single photon experiment revealed that the decay time of the 'fast' crystal was 33.4 nanoseconds while the decay of the 'slow' crystal was 42.2 nanoseconds. A spectral plot revealed that the spectral output of the 'slow' crystal was skewed to the longer wavelengths as compared to the 'fast' crystal. Further investigation on other crystal samples revealed decay times between the two extremes, suggesting a continuum in the light decay. C1 KAROLINSKA INST, STOCKHOLM, SWEDEN. MAX PLANCK INST, COLOGNE, GERMANY. OAK RIDGE NATL LAB, OAK RIDGE, TN USA. UNIV CALIF LOS ANGELES, LOS ANGELES, CA USA. RP CTI PET SYST, KNOXVILLE, TN USA. NR 12 TC 63 Z9 63 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 1109 EP 1113 DI 10.1109/23.596973 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF300 UT WOS:A1997XF30000003 ER PT J AU Huber, JS Moses, WW Derenzo, SE Ho, MH Andreaco, MS Paulus, MJ Nutt, R AF Huber, JS Moses, WW Derenzo, SE Ho, MH Andreaco, MS Paulus, MJ Nutt, R TI Characterization of a 64 channel PET detector using photodiodes for crystal identification SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Medical Imaging Conference (MIC) / Nuclear Science Symposium (NSS) CY NOV 05-09, 1996 CL ANAHEIM, CA SP Inst Elect & Electr Engineers ID MODULE; ARRAY; DEPTH AB We present performance results for a prototype PET detector module consisting of 64 LSO scintillator crystals (3x3x20 mm) coupled on one end to a single photomultiplier tube and on the opposite end to a 64 pixel array of 3 mm square silicon photodiodes (typical pixel parameters are 5 pF capacitance, 300 pA dark current, and 73% quantum efficiency at 415 nm). The photomultiplier tube (PMT) provides an accurate timing pulse and energy threshold for all crystals in the module, the silicon photodiodes (PD) identify the crystal of interaction, the sum (PD+PMT) provides a total energy signal, and the PD/(PD+PMT) ratio determines the depth of interaction. With 32 of the channels instrumented, the detector module correctly identifies the crystal of interaction (where ''correct'' includes the adjacent 4 crystals) 79+/-4% of the time with high detection efficiency. The timing resolution for a single LSO detector module is 750 ps fwhm, while its pulse height resolution at 511 keV is 24+/-3% fwhm. The depth of interaction (DOI) measurement resolution is 8+/-1 mm fwhm. C1 CTI INC,KNOXVILLE,TN 37932. RP Huber, JS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 13 TC 26 Z9 28 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 JUN PY 1997 VL 44 IS 3 BP 1197 EP 1201 DI 10.1109/23.596987 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF300 UT WOS:A1997XF30000017 ER PT J AU Ross, SG Gullberg, GT Huesman, RH AF Ross, SG Gullberg, GT Huesman, RH TI The effect of heart motion on kinetic parameter estimates for dynamic cardiac SPECT SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1996 Medical Imaging Conference (MIC) / Nuclear Science Symposium (NSS) CY NOV 05-09, 1996 CL ANAHEIM, CA SP Inst Elect & Electr Engineers ID RECONSTRUCTION ALGORITHMS; EMISSION AB Dynamic cardiac SPECT is used to estimate kinetic rate parameters that describe the washin and washout of tracer activity between the blood and the myocardial tissue. These kinetic parameters correlate to myocardial perfusion. There are, however, many physical aspects associated with dynamic SPECT which introduce bias and variance into the estimates. This paper describes a study which investigates the effect of heart motion on kinetic parameter estimates. Dynamic SPECT simulations are performed using a beating version of the MCAT phantom. The amount of blood and background activity in the myocardial tissue regions of interest is shown to vary over the cardiac cycle causing errors in the kinetic parameter estimates, particularly estimates of the washin rate constant. The effect of cardiac motion on kinetic parameter estimates is reduced by bias and variance introduced by photon noise and geometric collimator response. This suggests that techniques used to correct for motion must do so without further reducing photon statistics. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV UTAH, DEPT RADIOL, SALT LAKE CITY, UT 84132 USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1997 VL 44 IS 3 BP 1409 EP 1416 DI 10.1109/23.597021 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA XF300 UT WOS:A1997XF30000051 ER PT J AU Rao, NSV Uppuluri, VRR Oblow, EM AF Rao, NSV Uppuluri, VRR Oblow, EM TI On stochastic approximation algorithms for classes of PAC learning problems SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS LA English DT Article; Proceedings Paper CT IEEE World Congress on Computational Intelligence CY 1994 CL ORLANDO, FL SP IEEE ID NETWORKS AB The classical stochastic approximation methods are shown to yield algorithms to solve several formulations of the PAC learning problem defined on the domain [0,1](d). Under some smoothness conditions on the probability measure functions, simple algorithms to solve some PAC learning problems are proposed based on networks of nonpolynomial units (e.g. artificial neural networks). Conditions on the sizes of the samples required to ensure the error bounds are derived using martingale inequalities. RP Rao, NSV (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 31 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1083-4419 J9 IEEE T SYST MAN CY B JI IEEE Trans. Syst. Man Cybern. Part B-Cybern. PD JUN PY 1997 VL 27 IS 3 BP 516 EP 522 DI 10.1109/3477.584958 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics SC Automation & Control Systems; Computer Science GA WY939 UT WOS:A1997WY93900014 PM 18255890 ER PT J AU Goldstein, B Wofsy, C AF Goldstein, B Wofsy, C TI Dissociation of multivalent antibody-antigen interactions - Reply SO IMMUNOLOGY TODAY LA English DT Letter ID SURFACE C1 UNIV NEW MEXICO,DEPT MATH & STAT,ALBUQUERQUE,NM 87131. RP Goldstein, B (reprint author), LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP,POB 1663,LOS ALAMOS,NM 87545, USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0167-5699 J9 IMMUNOL TODAY JI Immunol. Today PD JUN PY 1997 VL 18 IS 6 BP 306 EP 306 DI 10.1016/S0167-5699(97)80029-1 PG 1 WC Immunology SC Immunology GA XD238 UT WOS:A1997XD23800014 ER PT J AU Mohanty, P Seibert, M AF Mohanty, P Seibert, M TI Action of K-crown ether on photosystem II electron transport: Characterization of the site of action SO INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS LA English DT Article ID PHOTOSYNTHETIC OXYGEN EVOLUTION; ANACYSTIS-NIDULANS; CHLOROPHYLL-A; BINDING SITE; MANGANESE; SILICOMOLYBDATE; FLUORESCENCE; MEMBRANE; SPINACH; PROTEIN AB We have investigated the inhibitory effect of K-crown (18-crown-6 potassium picrate) on photosystem II (PSII)-enriched membrane fragments and O-2-evolving core complexes. K-crown at 2-4 mu M inhibits about half the control level of O-2-evolution activity in both types of PSII samples. Oxygen evolution studies demonstrated that the ether works by inactivating the centres and not by interfering with antenna function or energy transfer to the reaction centre. K-crown does not disrupt binding of the extrinsic proteins associated with O, evolution nor complex with bound Ca2+ or Cl- cofactors, but rather it directly inhibits electron transfer after the tetrameric Mn cluster. Fluorescence studies on active and Tris-treated samples showed that K-crown does not prevent artificial donors from transferring electrons to PSII but like DCMU inhibits on the acceptor side after Q(A), the primary quinone acceptor. However, the ether is a leaky inhibitor and may also act as a weak donor when the Mn cluster is not present. Oxygen-production experiments using silicomolybdate as an artificial acceptor (which accepts from both pheophytin and Q(B) in PSII membranes) demonstrated that the inhibition is at or near the DCMU site. C1 JAWAHARLAL NEHRU UNIV, SCH LIFE SCI, NEW DELHI 110067, INDIA. RP Mohanty, P (reprint author), NATL RENEWABLE ENERGY LAB, CTR BASIC SCI, GOLDEN, CO 80401 USA. NR 30 TC 2 Z9 2 U1 0 U2 1 PU COUNCIL SCIENTIFIC INDUSTRIAL RESEARCH PI NEW DELHI PA PUBL & INFO DIRECTORATE, NEW DELHI 110012, INDIA SN 0301-1208 J9 INDIAN J BIOCHEM BIO JI Indian J. Biochem. Biophys. PD JUN PY 1997 VL 34 IS 3 BP 241 EP 248 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA XW560 UT WOS:A1997XW56000002 PM 9425742 ER PT J AU Yu, JJ Yu, QQ Jin, Y Chang, SG AF Yu, JJ Yu, QQ Jin, Y Chang, SG TI Reduction of sulfur dioxide by methane to elemental sulfur over supported cobalt catalysts SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID HIGH-TEMPERATURE REDUCTION; ALUMINA AB Cobalt oxides supported on several types of carriers (silica, molecular sieves 5A and 13X, and gamma-Al2O3) were evaluated for the reduction of sulfur dioxide by methane to elemental sulfur. Results showed that gamma-Al2O3 is the most effective carrier and that, with a molar ratio of 2 to 1 of sulfur dioxide to methane in a feed gas, the sulfur yield reached a maximum value of 87.5% at a space velocity of 5000 h(-1) and a temperature of 840 degrees C. X-ray diffraction results revealed that mixtures of cobalt oxide and cobalt sulfide components were observed. The effects of temperature, space velocity, and molar ratio of sulfur dioxide to methane in the feed on the activity of the cobalt catalyst supported on gamma-Al2O3 were investigated. The effect of feed gas containing a hydrogen sulfide contaminant was also studied. A catalyst size-dependence study was performed to determine the influence of the internal diffusion. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. NR 13 TC 19 Z9 30 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JUN PY 1997 VL 36 IS 6 BP 2128 EP 2133 DI 10.1021/ie950575i PG 6 WC Engineering, Chemical SC Engineering GA XC612 UT WOS:A1997XC61200022 ER PT J AU Zheng, Z Anthony, RG Miller, JE AF Zheng, Z Anthony, RG Miller, JE TI Modeling multicomponent ion exchange equilibrium utilizing hydrous crystalline silicotitanates by a multiple interactive ion exchange site model SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID CESIUM AB An equilibrium multicomponent ion exchange model is presented for the ion exchange of group I metals by TAM-5, a hydrous crystalline silicotitanate. On the basis of the data from ion exchange and structure studies, the solid phase is represented as Na3X instead of the usual form of NaX. By using this solid phase representation, the solid can be considered as an ideal phase. A set of model ion exchange reactions is proposed for ion exchange between H+, Na+, K+, Rb+, and Cs+. The equilibrium constants for these reactions were estimated from experiments with simple ion exchange systems. Bromley's model for activity coefficients of electrolytic solutions was used to account for liquid phase nonideality. Bromley's model parameters for CsOH at high ionic strength and for NO2- and Al(OH)(4)(-) were estimated in order to apply the model for complex waste simulants. The equilibrium compositions and distribution coefficients of counterions were calculated for complex simulants typical of DOE wastes by solving the equilibrium equations for the model reactions and material balance equations. The predictions match the experimental results within 10% for all of these solutions. C1 TEXAS A&M UNIV,DEPT CHEM ENGN,KINET CATALYSIS & REACT ENGN LAB,COLLEGE STN,TX 77843. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI Miller, James/C-1128-2011 OI Miller, James/0000-0001-6811-6948 NR 20 TC 22 Z9 22 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JUN PY 1997 VL 36 IS 6 BP 2427 EP 2434 DI 10.1021/ie960546n PG 8 WC Engineering, Chemical SC Engineering GA XC612 UT WOS:A1997XC61200058 ER PT J AU Song, JS Szalda, DJ Bullock, RM AF Song, JS Szalda, DJ Bullock, RM TI Hydride transfer reactions of transition metal hydrides in the preparation of [Cp(CO)(3)W(eta(1)-aldehyde)]+OTf- and [Cp(CO)(3)W(eta(1)-ketone)]+OTf- complexes SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; hydrogenation; aldehyde complexes; ketone complexes; hydride complexes; tungsten complexes ID RAY CRYSTAL-STRUCTURE; HOMOGENEOUS CATALYTIC-HYDROGENATION; AROMATIC ALDEHYDE COMPLEXES; DIELS-ALDER REACTIONS; CARBON-MONOXIDE; KETONE COMPLEXES; FORMALDEHYDE COMPLEX; ORGANOMETALLIC COMPLEXES; ACETALDEHYDE COMPLEX; PI/SIGMA EQUILIBRIA AB The reaction of Ph(C=O)Cl with Cp(CO)(3)WH and HOTf gives the eta(1)-aldehyde complex [Cp(CO)(3)W eta(1)-PhCHO)] +OTf-. The structure of [Cp(CO)(3)W(eta(1) -PhCHO)] +OTf- (C16H11F3O7SW) was determined by single crystal X-ray diffraction (triclinic, space group P (1) over bar, a = 10.639(5), b = 10.752(4), c = 10.096(3) Angstrom, a = 91.38(3), beta 117.08(3), gamma = 66.01(4)degrees, Z = 2). Decomposition of this compound in CH2Cl2 solution follows first-order kinetics (k = 3.6(2) X 10(-4) s(-1) at 25 degrees C) and produces free PhCHO and Cp(CO)(3)WOTf. The eta(1)-CH3CHO complex [Cp(CO)(3)W(eta(1)-CH3CHO)]+OTf- was similarly prepared from the reaction of acetyl chloride with Cp(CO),WH and HOTf. Hydrogenation of alpha,beta-unsaturated aldehydes by Cp(CO)(3)WH and HOTf produces [Cp(CO)(3)W(eta 1-RCHO)]+OTf- complexes that were isolated and fully characterized; analogous reactions with alpha,beta-unsaturated ketones gives [Cp(CO)(3)W(eta(1)-O = CRR')]+OTf- complexes. All of these aldehyde and ketone complexes with OTf- release free aldehyde or ketone in solution and produce Cp(CO)(3) WOTf, but[Cp(CO)(3)W(eta(1)-2-butanone)]+BAr'(-)(4) (Ar'=3,5-bis(trifluoromethyl)phenyl) is much more stable. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 100 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JUN PY 1997 VL 259 IS 1-2 BP 161 EP 172 DI 10.1016/S0020-1693(97)05545-X PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA XJ293 UT WOS:A1997XJ29300016 ER PT J AU Albinati, A Chaloupka, S Eckert, J Venanzi, LM Wolfer, MK AF Albinati, A Chaloupka, S Eckert, J Venanzi, LM Wolfer, MK TI Synthetic, structural and inelastic neutron scattering studies of the hydridobridged cationic complexes [(PMe3)(2)(Y)Pt(mu-H)Pt(Y)(PMe3)(2)](+) (Y=Ph, C6F5, C6Cl5) and of [(PEt3)(2)(H)Pt(mu-H)Pt(Ph)(PEt3)(2)](+) SO INORGANICA CHIMICA ACTA LA English DT Article DE diplatinum complexes; mono-hydrido-bridged compounds; phosphine complexes; crystal structures; inelastic incoherent neutron scattering spectroscopy ID TRANSITION-METAL COMPLEXES; HYDROGEN AB The mono-hydrido-bridged diplatinum complexes [(PMe3)(2)(C6X5)Pt(mu-H)Pt(C6X5)(PMe3)(2)](CF3SO3) (X = H, F, Cl) were prepared from the corresponding mononuclear species trans-[PtH(C6X5)(PMe3)(2)] and trans-[Pt(C6X5)(S)(PMe3)(2)](CF3SO3) (S = weakly coordinating solvent). The X-ray crystal structures of [(PMe3)(2)(Ph)Pt(mu-H)Pt(Ph)(PMe3)(2)][BPh4], prepared from the corresponding triflate (space group P (1) over bar, a=13.731(5), b=16.192(2), c=23.425(8) Angstrom, alpha=96.46(2), beta=100.54(3), gamma=95.05(2)degrees, Z=4, R=0.043, R-w=0.056 for 6914 observed reflections) and of [(PMe3)(2)(C6F5)Pt(mu-H)Pt(C6F5)(PMe3)(2)](CF3SO3). CH2Cl2 (space group P2(1)/n, a=11.762(2), b=19.500(3), c=19.112(3), beta=105.64(1), Z=4, R=0.038, R-w=0.049 for 2528 observed reflections) were determined. Both cations contain the two planar [Pt(C6X5)(PMe3)(2)] moieties bridged by a hydride ligand, the Pt-Pt bonds being 3.0641(7) and 3.0969(9) Angstrom for X=H and 3.009(1) Angstrom for X=F. Inelastic incoherent neutron scattering studies were carried out on [(PMe3)(2)(C6F5)Pt(mu-H)Pt(C6F5) (PMe3)(2)](CF3SO3), [(PEt3)(2)(H)Pt(mu-H)Pt(Ph)(PEt3)(2)](CF3SO3) and [(PEt3)(2)(Ph)Pt(mu-H)Pt(Ph)(PEt3)(2)](CF3SO3), and vibrational data for the Pt-H-Pt fragments obtained. The values of the nu(asym)/nu(sym) ratios and a semi-empirical correlation were used to obtain approximate values of the Pt-H-Pt bond angles in compounds of this type. C1 ETH ZURICH,ANORGAN CHEM LAB,CH-8092 ZURICH,SWITZERLAND. UNIV MILAN,IST CHIM FARMACEUT,I-20131 MILAN,ITALY. LOS ALAMOS NATL LAB,LOS ALAMOS NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. RI Albinati, Alberto/I-1262-2015 OI Albinati, Alberto/0000-0002-8779-3327 NR 29 TC 20 Z9 20 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JUN PY 1997 VL 259 IS 1-2 BP 305 EP 316 DI 10.1016/S0020-1693(97)05509-6 PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA XJ293 UT WOS:A1997XJ29300032 ER PT J AU Lang, RF Ju, TD Kiss, G Hoff, CD Bryan, JC Kubas, GJ AF Lang, RF Ju, TD Kiss, G Hoff, CD Bryan, JC Kubas, GJ TI Reactions of the complexes M(Pr-3)(2)(CO)(3) (M=Cr, Mo, W; R=Pr-i, Cy) with thiols, hydrogen sulfide, disulfides, hydrogen iodide and iodine. The role of heteroatoms in determining the metal-hydrogen bond strength at a sterically crowded metal center SO INORGANICA CHIMICA ACTA LA English DT Article DE chromium complexes; molybdenum complexes; tungsten complexes; thiol complexes; hydrogen sulfide complexes ID H BONDS; ENTHALPIES; TUNGSTEN; ENERGIES; NITROGEN AB The complexes M(PCy3)(2)(CO)(3) (M=Cr, Mo, W) react with phenyl disulfide to form stable 17-electron radical complexes M-.(PCy3)(2)(CO)(3)(SPh). Reaction with other alkyl and aryl disulfides also yields stable radicals and reaction with I-2 yields W-.(PiPr(3))(2)(CO)(3)(I). Reaction with thiols, hydrogen sulfide and hydrogen iodide yield the corresponding 18-electron hydrides W((PPr3)-Pr-i)(2)(CO)(3)(H)(X). The crystal structure of W((PPr3)-Pr-i)(2)(CO)(3)(H)(I) is reported and allows comparison with the structure of the radical complex W-.((PPr3)-Pr-i)2(CO)(3)(I). The W-H bond strengths in these heteroatom complexes are low, 55-57 kcal mol(-1). In spite of steric crowding, H atom transfer from W((PPr3)-Pr-i)(2)(CO)(3)(H)(SPh) to Cr-.(CO)(2)(PPh3)Cp occurs readily due to the stronger nature of the Cr-H bond formed. The chromium radical does not appear to attack the molecular hydrogen complex W(Pr-3)(2)(CO)(3)(H-2) or its dihydride form W(Pr-3)(2)(CO)(3)(H)(2) based on rate of hydrogenation studies. Phenyl disulfide does react with either W(Pr-3)(2)(CO)(3)(H-2) or its dihydride tautomer W(Pr-3)(2)(CO)(3)(H)(2) to form thiophenol and W(Pr-3)(2)(CO)(3)(SPh.). This reaction is proposed to proceed by reaction of (.)SPhradicals which are generated in situ. These studies are used to bracket the first W-H bond dissociation energy in W(Pr-3)(2)(CO)(3)(H)(2). Additional studies of H atom and heteoratom transfer are described. C1 LOS ALAMOS NATL LAB,INC 4,LOS ALAMOS,NM 87545. UNIV MIAMI,DEPT CHEM,CORAL GABLES,FL 33124. NR 21 TC 15 Z9 15 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JUN PY 1997 VL 259 IS 1-2 BP 317 EP 327 DI 10.1016/S0020-1693(97)05510-2 PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA XJ293 UT WOS:A1997XJ29300033 ER PT J AU Albinati, A Klooster, WT Koetzle, TF Fortin, JB Ricci, JS Eckert, J Fong, TP Lough, AJ Morris, RH Golombek, AP AF Albinati, A Klooster, WT Koetzle, TF Fortin, JB Ricci, JS Eckert, J Fong, TP Lough, AJ Morris, RH Golombek, AP TI Single-crystal X-ray and neutron diffraction structure determination and inelastic neutron scattering study of the dihydrogen complex trans-[Ru(H-2)(H)(dppe)(2)] [BPh4] SO INORGANICA CHIMICA ACTA LA English DT Article DE ruthenium complexes; dihydrogen complexes; hydride complexes; neutron scattering; crystal structures ID MOLECULAR-HYDROGEN COMPLEXES; M = FE; SPECTROSCOPIC PROPERTIES; IRON COMPLEX; R =; LIGAND; ETA-2-DIHYDROGEN; METAL; ROTATION; BARRIER AB The structure of the complex trans-[Ru(eta(2)-H-2)(H)(dppe)(2)][BPh4] (1), dppe=PPh2CH2CH2PPh2, has been determined by single-crystal X-ray diffraction at 123 K and neutron diffraction at 12 K, The core of the complex has a distorted octahedral geometry about ruthenium with the dihydrogen ligand trans to hydride and eclipsing a trans-P-Ru-P asis that is bent away from the hydrogens with a P-Ru-P angle of 167.9(4)degrees. The crystallographically determined H-H distance is 0.83(8) (X-ray) or 0.82(3) (neutron) Angstrom. The latter value, when corrected for the shortening caused by the torsional libration of the H-2 ligand, increases to about 0.94 Angstrom. The long Ru-(H-2) distance of 1.81(2) Angstrom (neutron), compared to the terminal hydride to ruthenium distance of 1.64(2) Angstrom (neutron), is consistent with the lability of the dihydrogen ligand, which is partially lost from the crystal by treatment with vacuum. The analogous iron complex trans-[Fe(eta(2)-H-2)(H)(dppe)(2)][BPh4] (2) has similar features except that the Fe-H(H-2) distances are much shorter and the H-2 ligand is correspondingly less labile. An inelastic neutron scattering study of the powder of 1 at 5 K reveals two broad inelastic peaks flanking the elastic peak. With the assumption that the dihydrogen librates in a double-minimum potential, the barrier to dihydrogen reorientation is calculated to be 1.0 to 1.4 kcal mol(-1), depending upon which of the H-H distances is used, This barrier is less than that for the iron analog, determined for its BF4 salt, therefore suggesting that there may be less d(pi) --> sigma* backbonding in 1 than 2. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. UNIV SO MAINE,DEPT CHEM,PORTLAND,ME 04104. LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. UNIV TORONTO,DEPT CHEM,TORONTO,ON M5S 3H6,CANADA. RP Albinati, A (reprint author), UNIV MILAN,INST PHARMACEUT CHEM,I-20131 MILAN,ITALY. RI Albinati, Alberto/I-1262-2015; Morris, Robert/R-8760-2016 OI Albinati, Alberto/0000-0002-8779-3327; Morris, Robert/0000-0002-7574-9388 NR 42 TC 24 Z9 24 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JUN PY 1997 VL 259 IS 1-2 BP 351 EP 357 DI 10.1016/S0020-1693(97)05521-7 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA XJ293 UT WOS:A1997XJ29300037 ER PT J AU Calvin, M AF Calvin, M TI Forty years of photosynthesis and related activities SO INTERDISCIPLINARY SCIENCE REVIEWS LA English DT Review ID PHOTOSENSITIZED ELECTRON-TRANSPORT; BRIDGED MANGANESE COMPLEXES; MIXED-VALENCE INTERACTIONS; LIPID VESICLE WALLS; ARTIFICIAL PHOTOSYNTHESIS; QUANTUM YIELDS; SIO2 COLLOIDS; FUEL; ENERGY; BIOSYNTHESIS AB At the heart of this review are the 10 years of work leading up to the award of the Nobel Prize for Chemistry in 1961 for the elucidation of the multiple steps in the path of carbon during photosynthesis, a process now universally known as the Calvin cycle, Also described are the background to the author's first forays into the brand new terrain of biochemistry, early work on the effects of deuterium oxide on biological systems, and research into hydrocarbon producing plants as sources of energy and the construction of an artificial photosynthetic system. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Calvin, M (reprint author), UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 83 TC 2 Z9 2 U1 4 U2 22 PU MANEY PUBLISHING PI LEEDS PA STE 1C, JOSEPHS WELL, HANOVER WALK, LEEDS LS3 1AB, W YORKS, ENGLAND SN 0308-0188 J9 INTERDISCIPL SCI REV JI Interdiscip. Sci. Rev. PD JUN PY 1997 VL 22 IS 2 BP 138 EP 148 PG 11 WC Multidisciplinary Sciences; Social Sciences, Interdisciplinary SC Science & Technology - Other Topics; Social Sciences - Other Topics GA XM448 UT WOS:A1997XM44800007 ER PT J AU Brown, NJ Li, GP Koszykowski, ML AF Brown, NJ Li, GP Koszykowski, ML TI Mechanism reduction via principal component analysis SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID CHEMICAL-KINETICS; COMBUSTION; MODELS; DIFFUSION; FLAMES AB Principal component analysis, an advanced technique of sensitivity analysis, has been used to determine reduced mechanisms that can model species and temperature profiles in Plug Flow Reactors (PFR), Premixed Laminar Flames (PLF), and Perfectly Stirred Reactors (PSR) for two H-2/air and two CH4/air mechanisms over a range of input parameters including initial temperature, equivalence ratio, and residence time. The results show that principal component analysis can be used effectively to reduce a comprehensive mechanism that contains unimportant reactions to a reduced mechanism that contains necessary and sufficient reactions. The accuracy of a reduced mechanism determined from principal component analysis can be easily controlled by carefully selecting reduction criteria. For the conditions chosen here, namely the requirement that radical profiles computed with reduced and comprehensive mechanisms agree to within 5%, substantial reductions were not achieved. Principal component analysis is able to resolve the influence of stoichiometry, combustor type, and mechanism on mechanism reduction. The two H-2/air mechanisms were each reduced to mechanisms that can model ail the cases considered, and the extent of reduction in each was very similar and modest. For H-2/air chemistry, equivalence ratio had little effect on reduction. Combustor type was slightly more influential with the number of required reactions decreasing from PFR to PLF to PSR combustion. Relative to the H-2/air system, principal component analysis of the CH4/air system is more difficult because of mechanism size. For CH4/air combustion, if we consider all equivalence ratios, PLFs require the most reactions, if individual equivalence ratios are examined, PFRs require the greatest number of reactions. Combustor type influences mechanism reduction substantially because of the different couplings between the fluid mechanics and chemistry. In H-2/air combustion rich combustion required the fewest reactions and in CH4/air, it required the most. Reduction must be achieved by considering the entire mechanism since reactions interact in concert, for example, reactions unimportant in one CH, mechanism are often important in the other. (C) 1997 John Wiley & Sons. Inc. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP Brown, NJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 36 TC 40 Z9 44 U1 0 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD JUN PY 1997 VL 29 IS 6 BP 393 EP 414 DI 10.1002/(SICI)1097-4601(1997)29:6<393::AID-KIN1>3.0.CO;2-P PG 22 WC Chemistry, Physical SC Chemistry GA XA684 UT WOS:A1997XA68400001 ER PT J AU Rickert, M Nagel, K AF Rickert, M Nagel, K TI Experiences with a simplified microsimulation for the Dallas/Fort-Worth area SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE traffic; cellular automata; complex systems; parallel computing; route planning; shortest paths ID MODEL AB We describe a simple framework for microsimulation of city traffic. A medium-sized excerpt of Dallas was used to examine different levels of simulation fidelity of a cellular automaton method for the traffic flow simulation and a simple intersection model. We point out problems arising with the granular structure of the underlying rules of motion. C1 LOS ALAMOS NATL LAB,TSA,DO,SA,LOS ALAMOS,NM 87545. SANTA FE INST,SANTA FE,NM 87501. RP Rickert, M (reprint author), UNIV COLOGNE,CTR PARALLEL COMP,D-50923 COLOGNE,GERMANY. NR 16 TC 34 Z9 35 U1 1 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD JUN PY 1997 VL 8 IS 3 BP 483 EP 503 DI 10.1142/S0129183197000400 PG 21 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA XD435 UT WOS:A1997XD43500004 ER PT J AU Nagel, K Barrett, CL AF Nagel, K Barrett, CL TI Using microsimulation feedback for trip adaptation for realistic traffic in Dallas SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE traffic simulation; assignment; route planning ID MODEL AB This paper presents a day-to-day re-routing relaxation approach for traffic simulations. Starting from an initial planset for the routes, the route-based microsimulation is executed. The result of the microsimulation is fed into a re-router, which re-routes a certain percentage of all trips. This approach makes the traffic patterns in the microsimulation much more reasonable. Further, it is shown that the method described in this paper can lead to strong oscillations in the solutions. C1 SANTA FE INST,SANTA FE,NM 87501. RP Nagel, K (reprint author), LOS ALAMOS NATL LAB,TSA,DO,SA,MS M997,LOS ALAMOS,NM 87545, USA. NR 23 TC 37 Z9 37 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD JUN PY 1997 VL 8 IS 3 BP 505 EP 525 DI 10.1142/S0129183197000412 PG 21 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA XD435 UT WOS:A1997XD43500005 ER PT J AU Koch, V AF Koch, V TI Aspects of chiral symmetry SO INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS LA English DT Review ID HEAVY-ION COLLISIONS; FINITE-TEMPERATURE; KAON CONDENSATION; NUCLEAR-MATTER; PHASE-TRANSITION; STAR MATTER; HIGH-ENERGY; SUM-RULES; LAGRANGIANS; MASSES AB This article is an attempt to a pedagogical introduction and review into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential ideas of chiral perturbation theory. Some applications to the physics of ultrarelativistic heavy ion collisions will be presented. RP Koch, V (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 56 TC 63 Z9 63 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-3013 J9 INT J MOD PHYS E JI Int. J. Mod. Phys. E-Nucl. Phys. PD JUN PY 1997 VL 6 IS 2 BP 203 EP 249 DI 10.1142/S0218301397000147 PG 47 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA XR828 UT WOS:A1997XR82800001 ER PT J AU Hwang, JK Ramayya, AV Hamilton, JH Kormicki, J Peker, LK Babu, BRS Ginter, TN TerAkopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Asztalos, SJ Chu, SY Gregorich, KE Lee, IY Macchiavelli, AO Macleod, RW Rasmussen, JO Cole, JD Aryaeinejad, R ButlerMoore, K Dardenne, YX Drigert, MW Stoyer, MA Wild, JF Becker, JA Bernstein, LA Lougheed, RW Moody, KJ Donangelo, R Prussin, SG Griffin, HC AF Hwang, JK Ramayya, AV Hamilton, JH Kormicki, J Peker, LK Babu, BRS Ginter, TN TerAkopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Asztalos, SJ Chu, SY Gregorich, KE Lee, IY Macchiavelli, AO Macleod, RW Rasmussen, JO Cole, JD Aryaeinejad, R ButlerMoore, K Dardenne, YX Drigert, MW Stoyer, MA Wild, JF Becker, JA Bernstein, LA Lougheed, RW Moody, KJ Donangelo, R Prussin, SG Griffin, HC TI Identification of the nu(3/2)-[521] band in Nd-153 and the gamma-transitions in Nd-149 SO INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS LA English DT Article AB From an experiment with Gammasphere and a Cf-252 spontaneous fission source, two bands with signatures -i and +i are identified in Nd-153. Also several transitions in Nd-149 are observed for the first time. The band with signature -i in Nd-153 shows no back bending, similar to the one observed in Er-161. The signature splitting observed in the ground band of Nd-153 is similar to the ones observed in N = 93 isotones in this mass region. In Nd-149 the new transitions are placed into a band with a proposed configuration of nu(11/2)-[505]. C1 JOINT INST NUCL RES,DUBNA 141980,RUSSIA. JOINT INST HEAVY ION RES,OAK RIDGE,TN 37835. MISSISSIPPI STATE UNIV,DEPT PHYS,MISSISSIPPI STATE,MS 39762. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. FED UNIV RIO DE JANEIRO,BR-68528 RIO JANEIRO,RG,BRAZIL. UNIV MICHIGAN,ANN ARBOR,MI 48104. UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720. RP Hwang, JK (reprint author), VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235, USA. NR 10 TC 9 Z9 9 U1 1 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-3013 J9 INT J MOD PHYS E JI Int. J. Mod. Phys. E-Nucl. Phys. PD JUN PY 1997 VL 6 IS 2 BP 331 EP 339 DI 10.1142/S0218301397000226 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA XR828 UT WOS:A1997XR82800009 ER PT J AU Williams, TO Addessio, FL AF Williams, TO Addessio, FL TI A general theory for laminated plates with delaminations SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID HIGH-ORDER THEORY; COMPOSITE; DEFORMATION; INTERFACE AB An approximate analytical model for the behavior of a laminated composite plate in the presence of delaminations and other local effects is presented. The model is based on a generalized displacement formulation implemented at the layer level. The governing equations for a layer are obtained using the principle of virtual work. These governing equations for a layer are used in conjunction with the explicit satisfaction of both the interfacial traction continuity and the interfacial displacement jump conditions between layers to develop the governing equations for a laminated composite plate, including delaminations. The fundamental unknowns in the theory are the dis placements in the layers and the interfacial tractions. The theory is sufficiently general that any constitutive model for the interfacial fracture (i.e. delamination) as well as for the layer behavior can be incorporated in a consistent fashion into the theory. The interfacial displacement jumps are expressed in an internally consistent fashion in terms of the fundamental unknown interfacial tractions. The current theory imposes no restrictions on the size, location, distribution, or direction of growth of the delaminations. Therefore, the theory can predict the initiation and growth of delaminations al any location as well as interactive effects between delaminations at different locations within the laminate. Pagano's exact solution for the cylindrical bending of a laminated plate has been modified to include the effects of delamination. An interface model, which expressed the displacement jump as a linear function of the surface tractions, was implemented into this modification of the exact solution. This extension was used to validate the approximate plate theory. The correlation between the approximate approach and the exact solution is seen to be excellent. The approximate plate theory is seen to give very accurate predictions for the interfacial tractions in a direct and consistent fashion, i.e. without the need to use integration of the pointwise equilibrium equations. This allows the interfacial displacement jumps in the presence of delaminations to be modeled accurately. It is seen that these displacement jumps have a significant effect on both the macroscopic and microscopic behavior of a laminated plate. (C) 1997 Published by Elsevier Science Ltd. RP Williams, TO (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MSB216,LOS ALAMOS,NM 87545, USA. NR 22 TC 61 Z9 67 U1 1 U2 6 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 JUN PY 1997 VL 34 IS 16 BP 2003 EP & DI 10.1016/S0020-7683(96)00131-X PG 21 WC Mechanics SC Mechanics GA WZ248 UT WOS:A1997WZ24800003 ER PT J AU Gropp, W Lusk, E AF Gropp, W Lusk, E TI Sowing MPICH: A case study in the dissemination of a portable environment for parallel scientific computing SO INTERNATIONAL JOURNAL OF SUPERCOMPUTER APPLICATIONS AND HIGH PERFORMANCE COMPUTING LA English DT Article; Proceedings Paper CT 3rd Workshop on Environments and Tools for Parallel Scientific Computing CY AUG 22-23, 1996 CL DOMAINE FAVERGES TOUR, FRANCE SP CNRS, US Natl Sci Fdn, Ecole Normale Super Lyon, Lab Comp Sci Parallelism, Univ Tennessee, Comp Sci Dept AB MPICH is an implementation of the MPI specification for a standard message-passing library interface. This paper focuses on the lessons learned from preparing MP[CH for diverse parallel computing environments. These lessons include how to prepare software for configuration in unknown environments; how to structure software to absorb contributions by others; how to automate the preparation of man pages, Web pages, and other documentation; how to automate prerelease testing for both correctness and performance; and how to manage the inevitable problem reports with a minimum of resources for support. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. OI Gropp, William/0000-0003-2905-3029 NR 13 TC 15 Z9 15 U1 1 U2 2 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 SN 1078-3482 J9 INT J SUPERCOMPUT AP JI Int. J. Supercomput. Appl. High Perform. Comput. PD SUM PY 1997 VL 11 IS 2 BP 103 EP 114 DI 10.1177/109434209701100204 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications SC Computer Science GA XB642 UT WOS:A1997XB64200004 ER PT J AU Foster, I Kesselman, C AF Foster, I Kesselman, C TI Globus: A metacomputing infrastructure toolkit SO INTERNATIONAL JOURNAL OF SUPERCOMPUTER APPLICATIONS AND HIGH PERFORMANCE COMPUTING LA English DT Article; Proceedings Paper CT 3rd Workshop on Environments and Tools for Parallel Scientific Computing CY AUG 22-23, 1996 CL DOMAINE FAVERGES TOUR, FRANCE SP CNRS, US Natl Sci Fdn, Ecole Normale Super Lyon, Lab Comp Sci Parallelism, Univ Tennessee, Comp Sci Dept AB The Globus system is intended to achieve a vertically integrated treatment of application, middleware, and network. A low-level toolkit provides basic mechanisms such as communication, authentication, network information, and data access. These mechanisms are used to construct various higher level metacomputing services, such as parallel programming tools and schedulers. The longterm goal is to build an adaptive wide area resource environment (AWARE), an integrated set of higher level services that enable applications to adapt to heterogeneous and dynamically changing metacomputing environments. Preliminary versions of Globus components were deployed successfully as part of the I-WAY networking experiment. C1 UNIV SO CALIF, INST INFORMAT SCI, MARINA DEL REY, CA 90292 USA. RP Foster, I (reprint author), ARGONNE NATL LAB, DIV MATH & COMP SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. OI Kesselman, Carl/0000-0003-0917-1562 NR 29 TC 1500 Z9 1574 U1 1 U2 13 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1078-3482 J9 INT J SUPERCOMPUT AP JI Int. J. Supercomput. Appl. High Perform. Comput. PD SUM PY 1997 VL 11 IS 2 BP 115 EP 128 DI 10.1177/109434209701100205 PG 14 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications SC Computer Science GA XB642 UT WOS:A1997XB64200005 ER PT J AU Finnan, JM Burke, JI Jones, MB AF Finnan, JM Burke, JI Jones, MB TI A note on a non-destructive method of chlorophyll determination in wheat (Triticum aestivum L) SO IRISH JOURNAL OF AGRICULTURAL AND FOOD RESEARCH LA English DT Article DE chlorophyll; flag leaves; spring wheat ID LEAF GREENNESS; NITROGEN; METER; N,N-DIMETHYLFORMAMIDE AB The relationship between the chlorophyll content of wheat flag leaves estimated by a chemical method in the laboratory and that obtained using a Minolta chlorophyll meter was evaluated. A statistically significant (r(2) 0.85, P < 0.001) linear relationship was found to exist between extractable chlorophyll and meter readings when chlorophyll content was expressed on a leaf area basis. A further improvement in the relationship was obtained when a quadratric function was fitted to the data (r(2) 0.88). The use of the quadratic equation for predicting chlorophyll concentrations from meter readings was validated using an independent data set. Predicted values of chlorophyll content on this data set were highly correlated (r(2) 0.91) with the measured chlorophyll concentrations. The results indicate that this rapid technique for chlorophyll determination can play a useful role in many areas of crop science especially where estimates of leaf senescence are required. RP Finnan, JM (reprint author), TEAGASC,OAK PK RES CTR,CARLOW,IRELAND. RI Finnan, John/D-1326-2016 NR 19 TC 8 Z9 8 U1 0 U2 2 PU TEAGASC PI DUBLIN PA 19 SANDYMOUNT AVE, DUBLIN 4, IRELAND SN 0791-6833 J9 IRISH J AGR FOOD RES JI Irish J. Agr. Food Res. PD JUN PY 1997 VL 36 IS 1 BP 85 EP 89 PG 5 WC Agriculture, Multidisciplinary; Food Science & Technology SC Agriculture; Food Science & Technology GA XP536 UT WOS:A1997XP53600009 ER PT J AU Hecker, SS AF Hecker, SS TI DOE and the national labs SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP Hecker, SS (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SUM PY 1997 VL 13 IS 4 BP 6 EP 6 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA XK379 UT WOS:A1997XK37900002 ER PT J AU Finn, M AF Finn, M TI Limiting scientist immigration SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP Finn, M (reprint author), OAK RIDGE INST SCI & ECUC,OAK RIDGE,TN, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SUM PY 1997 VL 13 IS 4 BP 14 EP 15 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA XK379 UT WOS:A1997XK37900013 ER PT J AU Floquet, N Valot, CM Mesnier, MT Niepce, JC Normand, L Thorel, A Kilaas, R AF Floquet, N Valot, CM Mesnier, MT Niepce, JC Normand, L Thorel, A Kilaas, R TI Ferroelectric domain walls in BaTiO3: Fingerprints in XRPD diagrams and quantitative HRTEM image analysis SO JOURNAL DE PHYSIQUE III LA English DT Article; Proceedings Paper CT 2nd Meeting on Piezo-Pyro-Ferroelectric Materials and Devices CY MAR, 1996 CL LIMOGES, FRANCE SP Soc Elect & Electr ID BARIUM-TITANATE; ELECTRON-MICROSCOPY; PHASE-TRANSITION; THIN-FILMS; CRYSTALS; PBTIO3; FIELD; TEM AB The structure of ferroelectric domain walls in BaTiO3 has been investigated through two complementary approaches, a global ope by the fine analysis of X-ray diffraction patterns, the other essentially local via a quantitative image analysis method developed and applied to High Resolution Transmission Electron Microscopy images. These two original approaches converge towards a clear description of 90 degrees walls which are shown to be a 4-6 nm wide region where the crystallographic discontinuity is accommodated by irregular atomic displacements. The results given here demonstrate that the usual structural theoretical description of walls commonly accepted for energy calculations are far too simplistic. The two underlying methodologies which have been developed to carry out these approaches can possibly be applied to other ferroelectrics, but without any doubt to other systems where twins or coherent interfaces are expected. C1 ECOLE MINES PARIS,CTR MAT,F-91003 EVRY,FRANCE. UNIV BOURGOGNE,LAB RECH REACTIVITE SOLIDES,UMR 5613 CNRS,F-21004 DIJON,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP Floquet, N (reprint author), CTR RECH MECANISMES CROISSANCE CRISTALLINE,UPR 7251 CNRS,CAMPUS LUMINY,CASE 913,F-13288 MARSEILLE 9,FRANCE. NR 28 TC 52 Z9 53 U1 3 U2 26 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 1155-4320 J9 J PHYS III JI J. Phys. III PD JUN PY 1997 VL 7 IS 6 BP 1105 EP 1128 PG 24 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Fluids & Plasmas SC Materials Science; Physics GA XF770 UT WOS:A1997XF77000002 ER PT J AU Thiyagarajan, P Epperson, JE Crawford, RK Carpenter, JM Klippert, TE Wozniak, DG AF Thiyagarajan, P Epperson, JE Crawford, RK Carpenter, JM Klippert, TE Wozniak, DG TI The time-of-flight small-angle neutron diffractometer (SAD) at IPNS, Argonne National Laboratory SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID DATA ACQUISITION-SYSTEM; SCATTERING DATA; RESOLUTION; MICELLAR AB The design, development and performance of the time-of-flight (TOF) small-angle diffractometer (SAD) at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory are described. Similar TOE-SANS instruments are in operation at the pulsed neutron sources at Los Alamos National Laboratory, USA, at Rutherford Appleton Laboratory, England, and at KEK, Japan. These instruments have an advantage by comparison with their steady-state counterparts in that a relatively wide range of momentum transfer (q) can be monitored in a single experiment without the need to alter the collimation or the sample-to-detector distance. This feature makes SANS experiments easy and very effective for studying systems such as those undergoing phase transitions under different conditions, samples that cannot be easily reproduced for repetitive experiments, and systems under high temperature, pressure or shear. Three standard samples are used to demonstrate that the quality of the SANS data from SAD is comparable with those from other established steady-state SANS facilities. Two examples are given to illustrate that the wide q region accessible in a single measurement at SAD is very effective for following the time-dependent phase transitions in paraffins and temperature- and pressure-dependent phase transitions in model biomembranes. RP Thiyagarajan, P (reprint author), ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 53 TC 106 Z9 107 U1 0 U2 7 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 JUN 1 PY 1997 VL 30 BP 280 EP 293 DI 10.1107/S0021889896013398 PN 3 PG 14 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XJ447 UT WOS:A1997XJ44700008 ER PT J AU Mildner, DFR ChenMayer, HH Sharov, VA Fokin, VS Reeder, PL AF Mildner, DFR ChenMayer, HH Sharov, VA Fokin, VS Reeder, PL TI The number of reflections for neutron transmission through cylindrical channels SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB The fraction of trajectories that have a given number of reflections during the passage of a neutron beam through a long cylindrical channel is determined when the angular divergence of the incident beam is less than the critical angle of the inner surface of the channel. This is useful for estimating the reflectivity from neutron-transmission measurements. The results are shown on a universal curve. C1 XRAY OPT SYST INC, ALBANY, NY 12205 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RUSSIAN ACAD SCI, INST PHYS & TECHNOL, MOSCOW 117218, RUSSIA. RP Mildner, DFR (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 6 TC 2 Z9 2 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 JUN 1 PY 1997 VL 30 BP 324 EP 326 DI 10.1107/S002188989601374X PN 3 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XJ447 UT WOS:A1997XJ44700013 ER PT J AU Alkire, RW Rotella, FJ AF Alkire, RW Rotella, FJ TI An incident-beam monitor for use in protein crystallography at a synchrotron source SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SILICON PHOTODIODE DETECTOR; X-RAY-DIFFRACTION; POSITION MONITOR; PIN DIODE; COLLIMATOR; X8C AB A compact incident-beam monitor has been developed for use in synchrotron protein crystallography at the National Synchrotron Light Source beamline X8C. Incident-beam intensity is monitored by measurement of the radiation scattered from a thin polymer film into a PIN diode. For improved statistical accuracy, the scattering film can be replaced by a thin metal foil. Fluorescent radiation emitted by the metal foil increases the beam-monitoring signal up to 50 times relative to that produced by scattering alone. With this design, the forward-scattered radiation is restricted to an area not larger than the beam stop, minimizing excessive background radiation. Support materials have been optimized so that no unwanted edge effects are present between 6 and 19.5 keV, making the detector useful for monitoring incident-beam intensities over the wide range of absorption edges often associated with multiwavelength anomalous diffraction (MAD) experiments. Accurate incident-beam monitoring also simplifies optimization of the X-ray beam through the diffractometer collimation after each new electron orbit is established in the synchrotron. RP Alkire, RW (reprint author), ARGONNE NATL LAB,CTR MECH BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 16 TC 7 Z9 7 U1 0 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 JUN 1 PY 1997 VL 30 BP 327 EP 332 DI 10.1107/S002188989601401X PN 3 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XJ447 UT WOS:A1997XJ44700014 ER PT J AU Agamalian, M Wignall, GD Triolo, R AF Agamalian, M Wignall, GD Triolo, R TI Optimization of a Bonse-Hart Ultra-Small-Angle Neutron Scattering facility by elimination of the rocking-curve wings SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SATURATED-HYDROCARBON POLYMERS; DOUBLE-CRYSTAL DIFFRACTOMETER; LOW-DENSITY POLYETHYLENE; BLENDS; THERMODYNAMICS; HYDROGEN; SANS AB The ORNL Ultra-Small-Angle Neutron Scattering (USANS) facility at the High Flux Isotope Reactor (HIFR) has been recently upgraded, using the Bonse-Hart technique. Si(111) triple-bounce channel-cut single crystals have been used for both the monochromator and analyzer. The total width of the rocking curve of the analyzer is about 1.6 '' and the wavelength of the primary neutron beam is 2.59 Angstrom. It has been demonstrated that, owing to the low neutron absorption of silicon, the wings of the rocking curve are generally contaminated by neutrons propagating and diffracting inside the walls of channel-cut crystals. This parasitic intensity has been eliminated by the cutting of a groove in the long wall and the insertion of a cadmium absorber (0.6 mm thick). This modification effectively suppresses the wings of the rocking curve by over two orders of magnitude and thus dramatically improves the sensitivity of the diffractometer. The upgraded facility has been tested with several samples, including a polystyrene latex with a radius of 2.50 x 10(4) Angstrom as determined by optical microscopy. The average radius calculated from USANS data is 2.48 x 10(4) Angstrom in excellent agreement with independently determined dimensions. The minimum accessible scattering vector of the upgraded USANS facility is Q(min) similar or equal to 2 x 10(-5) Angstrom(-1), which corresponds to a maximum resolvable real-space dimension of 2 pi/Q(min) similar or equal to 3 x 10(5) Angstrom (30 mu m). C1 UNIV PALERMO,I-90123 PALERMO,ITALY. RP Agamalian, M (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Agamalian, Michael/0000-0002-9112-2534 NR 39 TC 86 Z9 86 U1 0 U2 5 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 JUN 1 PY 1997 VL 30 BP 345 EP 352 DI 10.1107/S0021889896014343 PN 3 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XJ447 UT WOS:A1997XJ44700017 ER PT J AU Bolt, R Albertsson, J Svensson, G Stahl, K Hanson, JC AF Bolt, R Albertsson, J Svensson, G Stahl, K Hanson, JC TI A synchrotron X-ray study of ferroelectric switching, domain reversal and piezoelectric moduli in CsTiOAsO4 under an applied electric field SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID NONLINEAR OPTICAL-PROPERTIES; IONIC-CONDUCTIVITY; CRYSTAL-STRUCTURE; KTIOPO4; KTIOASO4; GROWTH AB Single crystals of caesium titanyl arsenate (CTA, CsTiOAsO4), with space group Pna2(1) and isomorphous with potassium titanyl phosphate (KTP, KTiOPO4), have been studied using high-resolution synchrotron X-rays. During the experiments, an electric field was applied along the polar axis [001]. Single-crystal plates, between 300 and 450 mu m thick along [001], were polarized by a variable square wave of frequency 20 Hz alternately applied to each side of the plate. A field-induced splitting of the + / - peaks for reflections hkl with l not equal 0 was observed. This splitting provides information about the coercive field, polarizability and the piezoelectric strain tenser. Two of the piezoelectric coefficients of CTA could be estimated as d(31) similar or equal to 1 and d(33) similar or equal to 27 pm V-1. Whereas the coercive fields were estimated at 2300 Vmm(-1) the held necessary to reverse the domains just once in CTA was found to be either 560 or 1550 V mm(-1), depending on the polarity of the reversed domain in relation to the polarity of the nonswitched part of the crystal. C1 TECH UNIV DENMARK,DEPT CHEM,DK-2800 LYNGBY,DENMARK. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Bolt, R (reprint author), CHALMERS UNIV TECHNOL,DEPT INORGAN CHEM,S-41296 GOTHENBURG,SWEDEN. RI Hanson, jonathan/E-3517-2010; OI Stahl, Kenny/0000-0002-4459-3026 NR 20 TC 5 Z9 5 U1 0 U2 2 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 JUN 1 PY 1997 VL 30 BP 383 EP 387 DI 10.1107/S0021889897000708 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XJ447 UT WOS:A1997XJ44700021 ER PT J AU Varvayanni, M Bartzis, JG Catsaros, N Deligiannis, P Elderkin, CE AF Varvayanni, M Bartzis, JG Catsaros, N Deligiannis, P Elderkin, CE TI Simulation of nocturnal drainage flows enhanced by deep canyons: The Rocky Flats case SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID COMPLEX TERRAIN; WIND FLOW; TOPOGRAPHY; VELOCITY; ATHENS; GREECE AB The DELTA-ADREA (discretization with elements of triangle approach-atmospheric dispersion of pollutants over irregular terrain) numerical prediction model, developed at the National Center for Scientific Research Demokritos, is specifically designed to perform wind field calculations over terrains of high complexity. The numerical model has the capability to handle air-ground interaction processes by describing the ground-surface details while keeping the computation time at a reasonable level. The numerical model is applied here to a high-resolution topographical representation of the region surrounding the Rocky Flats Facility in Colorado, based on a digitized map consisting of approximately 4.8 x 10(6) points. Wind field calculations over the region are made using the atmospheric experimental data of 4 February 1991, collected by the participants within the Atmospheric Studies in Complex Terrain research program. The numerical predictions indicate strong drainage flows created at different altitudes with interaction between them, resulting in a quite complicated mesoscale wind field during nighttime. Available observations support the predicted flow features. C1 NCSR DEMOKRITOS, INST NUCL PHYS, INST NUCL TECHNOL & RADIAT PROTECT, ATHENS 15310, GREECE. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 29 TC 5 Z9 5 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 1997 VL 36 IS 6 BP 775 EP 791 DI 10.1175/1520-0450-36.6.775 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XF586 UT WOS:A1997XF58600013 ER PT J AU Davis, WE Thorp, JM Lee, RN AF Davis, WE Thorp, JM Lee, RN TI Variability of SO4=, total sulfate, NO3-, and total nitrate scavenging ratios for the frontal boundary study SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID ACID DEPOSITION MODEL; PRECIPITATION CHEMISTRY; UNITED-STATES; H2O2 AB Precipitation and air concentration data collected during a U.S. Department of Energy-sponsored Frontal Boundary Study (FBS) were used to calculate scavenging ratios. The precipitation data were collected on a 100 km x 100 km surface grid containing 36 sampling sites, while the air concentration data were collected by aircraft. Radar and rawinsonde data were used to position the aircraft into the air moss feeding the precipitation. The coordination of the aircraft data with surface precipitation data allows the calculation of scavenging ratios. During the study, three out of seven events sampled allowed the calculation of scavenging ratios for SO4=, total sulfate, NO3-, and total nitrate. The 36 precipitation samplers allowed calculation of multiple scavenging ratios to represent an event. From these scavenging ratios, both a geometric mean and a geometric standard deviation of the scavenging ratio were calculated for each event. The geometric mean (geometric standard deviation) scavenging ratio for total sulfate is 6 x 10(4) (1.1) for 10 October 1989, 10 x 10(4) (1.5) for 16-17 October 1989, and 4 x 10(4) (1.3) for 31 October 1989. For SO4= the scavenging ratios are 10 x 10(5) (1.1) for 10 October 1989, 4 x 10(5) (1.5) for 16-17 October 1989, and 3 x 10(5) (1.3) for 31 October 1989. The scavenging ratio for NO2- is 3 x 10(6) (1.2) for 10 October 1989, 10 x 10(6) (1.4) for 16-17 October 1989, and 0.4 x 10(6) (1.5) for 31 October 1989. The scavenging ratio for total nitrate is 2 x 10(6) (1.2) for 10 October 1989, 2 x 10(6) (1.4) For 16-17 October 1989, and 0.2 x 10(6) (1.5) for 31 October 1989. The most important finding is the small variation of the numbers within the events as reflected in the geometric standard deviations. These values ranged from 1.1 to 1.5. Based on these results, a single scavenging ratio can be used on a 100 km x 100 km area with a minimum of error. Two other results were found when comparing these scavenging ratios to total precipitation in the sampler. The comparison revealed that the variation in the scavenging ratio increased with decreasing total precipitation. The increase was up to a factor of 2 for less than 5 mm when compared with greater than 5 mm of total precipitation. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RUST FED SERV HANFORD, RICHLAND, WA USA. NR 22 TC 7 Z9 7 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JUN PY 1997 VL 36 IS 6 BP 792 EP 800 DI 10.1175/1520-0450-36.6.792 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XF586 UT WOS:A1997XF58600014 ER PT J AU Falkenstein, Z AF Falkenstein, Z TI The influence of ultraviolet illumination on OH formation in dielectric barrier discharges of Ar/O-2/H2O: The Joshi effect SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PLASMAS; MECHANISMS; KINETICS; OXYGEN; OZONE AB The influence of ultraviolet (UV) illumination on the formation of hydroxyl radicals in dielectric barrier discharges (DBD)in mixtures of Ar/O-2/H2O (79/18/3) will be presented, The UV is provided from a spectrally calibrated, commercial low pressure mercury lamp while the irradiance power of the discharge cell has been previously determined. First, the filamentary character of the DBD is shown by measurement of the relative intensity of the transition OH(A(2) Sigma-->(XII)-I-2, 0-0) with integrated emission spectroscopy as a function of the absolute water concentration at different energy densities coupled into the gas. Then, the influence of UV illumination on the hydroxyl emission is shown by time-gated and time-resolved emission spectroscopy of OH(A(2) Sigma-->(XII)-I-2). The results of the combined process is an increased total emission but reduced emission for each microdischarge. This result corresponds to an increase in the number of microdischarges which is supported by the measurement of the microdischarge current. (C) 1997 American Institute of Physics. RP Falkenstein, Z (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 24 TC 50 Z9 52 U1 1 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 JUN 1 PY 1997 VL 81 IS 11 BP 7158 EP 7162 DI 10.1063/1.365313 PG 5 WC Physics, Applied SC Physics GA XC348 UT WOS:A1997XC34800008 ER PT J AU Tarver, CM Breithaupt, RD Kury, JW AF Tarver, CM Breithaupt, RD Kury, JW TI Detonation waves in pentaerythritol tetranitrate SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EXPLOSIVES AB Fabry-Perot laser interferometry was used to obtain nanosecond time resolved particle velocity histories of the free surfaces of tantalum discs accelerated by detonating pentaerythritol tetranitrate (PETN) charges and of the interfaces between PETN detonation products and lithium fluoride crystals. The experimental records were compared to particle velocity histories calculated using very finely zoned meshes of the exact dimensions with the DYNA2D hydrodynamic code. The duration of the PETN detonation reaction zone was demonstrated to be less than the 5 ns initial resolution of the Fabry-Perot technique, because the experimental records were accurately calculated using an instantaneous chemical reaction, the Chapman-Jouguet (C-J) model of detonation, and the reaction product Jones-Wilkins-Lee (JWL) equation of state for PETN detonation products previously determined by supracompression (overdriven detonation) studies. Some of the PETN charges were pressed to densities approaching the crystal density and exhibited the phenomenon of superdetonation. An ignition and growth Zeldovich-von Neumann-Doring (ZND) reactive flow model was developed to explain these experimental records and the results of previous PETN shock initiation experiments on single crystals of PETN. Good agreement was obtained for the induction time delays preceding chemical reaction, the run distances at which the initial shock waves were overtaken by the detonation waves in the compressed PETN, and the measured particle velocity histories produced by the overdriven detonation waves before they could relax to steady state C-J velocity and pressure. (C) 1997 American Institute of Physics. RP LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 37 TC 40 Z9 43 U1 0 U2 11 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 JUN 1 PY 1997 VL 81 IS 11 BP 7193 EP 7202 DI 10.1063/1.365318 PG 10 WC Physics, Applied SC Physics GA XC348 UT WOS:A1997XC34800014 ER PT J AU Sengupta, S Shi, DL Luo, JS Buzdin, A Gorin, V Todt, VR Varanasi, C McGinn, PJ AF Sengupta, S Shi, DL Luo, JS Buzdin, A Gorin, V Todt, VR Varanasi, C McGinn, PJ TI Effect of extremely fine Y2BaCuO5 precipitates on the critical current density of melt-processed YBa2Cu3Ox SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID HIGH-TC SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; CU-O SUPERCONDUCTOR; II SUPERCONDUCTORS; SINGLE-CRYSTALS; PINNING-FORCE; OXIDE SUPERCONDUCTORS; MAGNETIC-RELAXATION; PARTICLE-SIZE; SCALING LAWS AB Based on previously developed melt processing methods, Y2BaCuO5 (211) precipitates with various size were obtained in YBa2Cu3Ox (123). In particular. a wide distribution of 211 size from 100 Angstrom to 10 mu m has been found to exist in the matrix of 123, and strongly effected the critical current density, J(c). An enhancement of J(c) was always found to be associated with the presence of extremely fine 211 precipitates. The flux pinning by these precipitates can be understood by considering the interaction of Au: lines with cavities. It was found that although the flux Lines are strongly pinned by cavities, the effectiveness decreases with the increasing number of flux lines trapped by them. (C) 1997 American Institute of Physics. C1 UNIV CINCINNATI,DEPT MAT SCI,CINCINNATI,OH 45221. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV NOTRE DAME,DEPT CHEM ENGN,NOTRE DAME,IN 46556. RP Sengupta, S (reprint author), SUPERCONDUCT COMPONENTS INC,1145 CHESAPEAKE AVE,COLUMBUS,OH 43212, USA. RI Buzdin, Alexander/I-6038-2013 NR 103 TC 13 Z9 13 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 JUN 1 PY 1997 VL 81 IS 11 BP 7396 EP 7408 DI 10.1063/1.365280 PG 13 WC Physics, Applied SC Physics GA XC348 UT WOS:A1997XC34800042 ER PT J AU Wagener, R Nemesure, S Schwartz, SE AF Wagener, R Nemesure, S Schwartz, SE TI Aerosol optical depth over oceans: High space- and time-resolution retrieval and error budget from satellite radiometry SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ZONE COLOR SCANNER; ANTHROPOGENIC AEROSOLS; 3-DIMENSIONAL MODEL; GREENHOUSE GASES; AVHRR DATA; SCATTERING; ATMOSPHERES; ATLANTIC; SULFATE; SYSTEM AB A method to retrieve aerosol vertical optical depth at 0.64 mu m from satellite observations of cloud-free scenes over oceans with high spatial resolution (similar to 1 degrees) and instantaneous temporal resolution is described and evaluated. The observed radiance is treated as the linear sum of contributions to path radiance by different scattering processes in the atmosphere-ocean system. This treatment allows examination of errors in the retrieved vertical aerosol optical depth contributed by each process and approximation. Random error in retrieved aerosol optical depth is typically 0.03. The systematic error due to absolute calibration uncertainty in the measured radiance is 0.01. The largest errors and biases are due to radiative transfer approximations (+22%) and assumptions regarding aerosol microphysical and optical properties (-20%). The latter errors, which are due to the optical properties (e.g., phase function), vary systematically with latitude and season because of the variation of the mean observing geometry. This method is applied to Advanced Very High Resolution Radiometer global area coverage data, and example maps of aerosol optical depth are presented for specific dates in July and October 1986. The aerosol optical depth derived from the satellite data is suitable for examining large aerosol signatures by instantaneous comparison of the amplitude and location of aerosol plumes with model predictions based on meteorological conditions at and preceding the time of observation. C1 BROOKHAVEN NATL LAB,ANALYT SCI DIV,UPTON,NY 11973. BROOKHAVEN NATL LAB,ENVIRONM CHEM DIV,UPTON,NY 11973. RI Wagener, Richard/B-5445-2008; Schwartz, Stephen/C-2729-2008 OI Wagener, Richard/0000-0003-3892-1182; Schwartz, Stephen/0000-0001-6288-310X NR 39 TC 25 Z9 25 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD JUN PY 1997 VL 14 IS 3 BP 577 EP 590 DI 10.1175/1520-0426(1997)014<0577:AODOOH>2.0.CO;2 PN 2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA XC595 UT WOS:A1997XC59500001 ER PT J AU Zhang, YB Ayalew, S Lacks, SA AF Zhang, YB Ayalew, S Lacks, SA TI The rnhB gene encoding RNase HII of Streptococcus pneumoniae and evidence of conserved motifs in Eucaryotic genes SO JOURNAL OF BACTERIOLOGY LA English DT Article ID POLYACRYLAMIDE-GEL-ELECTROPHORESIS; COLI RIBONUCLEASE-H; ESCHERICHIA-COLI; SALMONELLA-TYPHIMURIUM; NUCLEOTIDE-SEQUENCE; MISMATCH REPAIR; DNA-REPLICATION; ENZYMES; EXONUCLEASE; TRANSLATION AB A single RNase H enzyme was detected in extracts of Streptococcus pneumoniae. The gene encoding this enzyme mas cloned and expressed in Escherichia coli, as demonstrated by its ability to complement a double-mutant rnhA recC strain, Sequence analysis of the cloned DNA revealed an open reading frame of 290 codons that encodes a polypeptide of 31.9 kDa. The predicted protein exhibits a low level of homology (19% identity of amino acid residues) to RNase HII encoded by rnhB of E. coli, Identification of the S. pneumoniae RNase HII translation start site by amino-terminal sequencing of the protein and of mRNA start sites by primer extension with reverse transcriptase showed that the major transcript encoding rnhB begins at the protein start site. Comparison of the S. pneumoniae and E. coli RNase HII sequences and sequences of other, putative bacterial rnhB gene products surmised from sequencing data revealed three conserved motifs. Use of these motifs to search for homologous genes in eucaryotes demonstrated the presence of rnhB genes in a yeast and a roundworm. Partial rnhB gene sequences were detected among expressed sequences of mouse and human cells. From these data, it appears that RNase HII is universally present in living cells. C1 BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. FU NIAID NIH HHS [AI14885] NR 44 TC 21 Z9 23 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD JUN PY 1997 VL 179 IS 12 BP 3828 EP 3836 PG 9 WC Microbiology SC Microbiology GA XE300 UT WOS:A1997XE30000002 PM 9190796 ER PT J AU Ornstein, RL Zheng, YJ AF Ornstein, RL Zheng, YJ TI Ab initio quantum mechanics analysis of imidazole C-H center dot center dot center dot O water hydrogen bonding and a molecular mechanics forcefield correction SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID INFRARED MATRIX-ISOLATION; NEUTRON-DIFFRACTION DATA; SET SUPERPOSITION ERROR; NUCLEIC-ACIDS; BONDED COMPLEXES; H...O; PROTEINS; BASES; ATOMS; FIELD AB While it is well established that classical hydrogen bonds play an important role in enzyme structure, function and dynamics, the role of weaker, but 'activated' C-H donor hydrogen bonds is poorly understood. The most important such case involves histidine which often plays a direct role in enzyme catalysis and possesses the most acidic C-H donor group of the standard amino acids. In the present study, we obtained optimized geometries and hydrogen bond interaction energies for C-H ... O hydrogen bonded complexes between methane, ethyl ene, benzene, acetylene, and imidazole with water at the MP2-FC/6-31++G(2d,2p) and MP2-FC/aug-cc-pVDZ//MP2-FC/6-31++G(2d,2p) levels of theory. A strong linear relationship is obtained between the stability of the various hydrogen bonded complexes and both separation distances for H ... O and C----O. In general, these calculations indicate that CH ... O interactions can be classified as hydrogen bonding interactions, albeit significantly weaker than the classical hydrogen bonds, but significantly stronger than just van der Waals interactions. For instance, while the electronic energy of stabilization at the MP2-FC/aug-cc-pVDZ//MP2-FC/6-31++G(2d,2p) level of theory of a water O-H ... O water hydrogen bond is 4.36 kcal/mol more stable than the methane C-H ... O water interaction, the water-water hydrogen bond is only 2.06 kcal/mol more stable than the imidazole C-e-H ... O water hydrogen bond. Neglecting this latter hydrogen bonding interaction is obviously unacceptable. We next compare the potential energy surfaces for the imidazole C-e-H ... O water and imidazole N-d-H ... O hydrogen bonded complexes computed at the MP2/6-31++G(2d,2p) level of theory with the potential energy surface computed using the AMBER molecular mechanics program and forcefields. While the Weiner et al and Cornell et al AMBER forcefields reasonably account for the imidazole N-H ... O water interaction, these forcefields do not adequately account for the imidazole C-e-H ... O water hydrogen bond. A forcefield modification is offered that results in excellent agreement between the ab initio and molecular mechanics geometry and energy for this C-H ... O hydrogen bonded complex. RP Ornstein, RL (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, K1-83, RICHLAND, WA 99352 USA. NR 59 TC 32 Z9 32 U1 0 U2 3 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 1997 VL 14 IS 6 BP 657 EP 665 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA XE036 UT WOS:A1997XE03600001 PM 9195335 ER PT J AU Buchko, GW Kennedy, MA AF Buchko, GW Kennedy, MA TI Human nucleotide excision repair protein XPA: H-1 NMR and CD solution studies of a synthetic peptide fragment corresponding to the zinc-binding domain (101-141) SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID XERODERMA-PIGMENTOSUM; SECONDARY STRUCTURE; CIRCULAR-DICHROISM; DNA-REPAIR; AQUEOUS-SOLUTIONS; DAMAGED DNA; SPECTROSCOPY; HELIX; SPECTRUM; EXCHANGE AB A peptide corresponding to residues 101-141 of the human nucleotide excision repair protein XPA was synthesized with an isoleucine substituted for L138 and its solution structure studied by circular dichroism and homonuclear H-1 NMR spectroscopy. The peptide, (XPA-41), contains a C-4-type zinc-binding motif, C105-(X)(2)-C108-(X)(17)-C126-(X)(2)-C129, which XPA requires for damaged-DNA binding activity. The proton resonances of XPA-41 without zinc (apoXPA-41) were assigned using homonuclear TOCSY, NOESY and DQF-COSY data and show the ape-zinc peptide is a random coil. The peptide was folded with the addition of 1.2 equivalents of ZnCl2 in dilute solution at pH 4.0. Electrospray ionization mass spectroscopy illustrated an increase in the molecular weight of XPA-41 by 65 amu. Circular dichroism spectra of the zinc-folded peptide (zXPA-41) showed the acquisition of elements of secondary structure. Such a conclusion was confirmed with H-1 NMR data collected at 25 degrees C, pH 6.3. H-alpha-secondary shifts and NOE patterns indicate that regions V102-C105 and G109-F112 form an anti-parallel beta-sheet and residues N128-K137 form a nascent alpha-helix. Rapid exchange of most amide resonances between S115-C126 prohibited unambiguous assignment of all the proton resonances in this region. However, a 1.19 ppm downfield shift of the H-alpha resonance of T125 relative to the ape-zinc peptide, together with downfield shifted H-alpha resonances for the adjacent residues (P124 and L123), suggest a second beta-sheet is present in the S115-C126 region. On the basis of structural similarities to GATA-1 (Science 261:438-446), a homology generated structure for zXPA-41 was made, using GATA-1 as the template, which satisfied all the observed NOEs. Using the hybrid homology-NMR based zXPA-41 structure and analogy to GATA-1, models for the role played by the zinc-binding core (101-141) of XPA in DNA damage recognition are proposed. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Buchko, Garry/G-6173-2015 OI Buchko, Garry/0000-0002-3639-1061 NR 57 TC 6 Z9 6 U1 0 U2 1 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 1997 VL 14 IS 6 BP 677 EP + PG 15 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA XE036 UT WOS:A1997XE03600003 PM 9195337 ER PT J AU Lundmark, PJ Kubas, GJ Butcher, RJ AF Lundmark, PJ Kubas, GJ Butcher, RJ TI Formation of the syn-isomer of [Cp*MoO(mu-S)](2) SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article ID COMPLEXES; SULFUR AB The structure of the title compound, syn-[Cp*MoO(mu-S)](2), 1, has been determined. 1 crystallized in the monoclinic space group C2/c with dimensions a = 11.758(2), b = 12.243(2), 15.585(3)Angstrom, beta = 104.63(3)degrees. The reaction of CP*Mo-2(2)(S-2)(S)(S2O3) With Me2PhP produces syn-[Cp*MoO(mu-S)](2) and Me2PhPO. The compounds [Cp'MoO(mu-S)](2) [Cp' = Cp, CpMe, Cp*] can exist as either the syn-or anti-isomers. The present structure, syn-[Cp*MoO(mu-S)](2) is compared with the structure of the anti-isomer and with the previously determined structure of syn-[Cp*MoO(mu-S)](2) in a different space group. C1 LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. RI G, Neela/H-3016-2014 NR 6 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD JUN PY 1997 VL 27 IS 6 BP 377 EP 379 DI 10.1007/BF02576572 PG 3 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA XU884 UT WOS:A1997XU88400008 ER PT J AU Wilson, AK Dunning, TH AF Wilson, AK Dunning, TH TI Benchmark calculations with correlated molecular wave functions .10. Comparison with ''exact'' MP2 calculations on Ne, HF, H2O, and N-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-BASIS SETS; AB-INITIO; CORRELATION ENERGIES; MOLLER-PLESSET; DIMER; SYSTEMS; BORON; ARGON; HSO AB The convergence of the MP2 valence correlation energy and pair energies for the correlation consistent basis sets has been investigated. Ne, HF, H2O, and N-2 were studied. For all of these molecules, accurate MP2 correlation and pair energies are available from the recent MP2-R12. calculations of W. Klopper [J. Chem. Phys. 102, 6168 (1995)]. The magnitudes of the calculated MP2 valence correlation and pair energies are found to increase systematically with increasing basis set size, with the cc-pV6Z basis set yielding 97.4%-98.3% of the MP2 valence correlation energy. A detailed analysis of the results for Ne reveals that the error due to truncation of the radial functions in the cc-pV6Z set is comparable to that due to neglect of higher angular momentum functions. Procedures for extrapolating the results to the complete basis set limit have also been investigated. (C) 1997 American Institute of Physics. RP Wilson, AK (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 31 TC 153 Z9 153 U1 0 U2 11 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 JUN 1 PY 1997 VL 106 IS 21 BP 8718 EP 8726 DI 10.1063/1.473932 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA478 UT WOS:A1997XA47800010 ER PT J AU Kedziora, GS Shavitt, I AF Kedziora, GS Shavitt, I TI Calculation and fitting of potential energy and dipole moment surfaces for the water molecule: Fully ab initio determination of vibrational transition energies and band intensities SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUARTIC FORCE-FIELD; MANY-BODY METHODS; GROUND-STATE; WAVE-FUNCTIONS; BASIS-SETS; ABINITIO CALCULATION; H2O; ATOMS; H-3+; FREQUENCIES AB Potential energy and dipole moment surfaces for the water molecule have been generated by multireference singles-and-doubles configuration interaction calculations using a large basis set of the averaged-atomic-natural-orbital type and a six-orbital-six-electron complete-active-space reference space. The surfaces are suitable for modeling vibrational transitions up to about 11000 cm(-1) above the ground state. A truncated singular-value decomposition method has been used to fit the surfaces. This fitting method is numerically stable and is a useful tool for examining the effectiveness of various fitting function forms in reproducing the calculated surface points and in extrapolating beyond these points. The fitted surfaces have been used for variational calculations of the 30 lowest band origins and the corresponding band intensities for transitions from the ground vibrational state. With a few exceptions, the results compare well with other calculations and with experimental data. (C) 1997 American Institute of Physics. C1 OHIO STATE UNIV, DEPT CHEM, COLUMBUS, OH 43210 USA. RP Kedziora, GS (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 50 TC 23 Z9 23 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1997 VL 106 IS 21 BP 8733 EP 8745 DI 10.1063/1.473959 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA478 UT WOS:A1997XA47800012 ER PT J AU Hsu, CW Heimann, P Evans, M Stimson, S Fenn, PT Ng, CY AF Hsu, CW Heimann, P Evans, M Stimson, S Fenn, PT Ng, CY TI A high resolution pulsed field ionization photoelectron study of O-2 using third generation undulator synchrotron radiation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THRESHOLD PHOTOELECTRON; COHERENT XUV; SPECTROSCOPY; SPECTRA; STATES; OXYGEN AB We have improved a newly developed experimental scheme for high resolution pulsed field ionization photoelectron (PFI-PE) studies [Hsu et al., Rev. Sci. Instrum. (in press)] using the high resolution monochromatized multibunch undulator synchrotron source of the Chemical Dynamics Beamline at the Advanced Light Source. This improved scheme makes possible PFI-PE measurements with essentially no contamination by background electrons arising from direct photoionization and prompt autoionization processes. We present here a preliminary analysis of the rotationally resolved PFI-PE spectrum for O-2 obtained at a resolution of 0.5 meV (full-width-at-half-maximum) in the photon energy range of 18.1-19.4 eV, yielding accurate ionization energies for the transitions O-2(+)(b (4) Sigma(g)(-), upsilon(+) = 0-9, N+ = 1) <-- O-2(X (3) Sigma(g)(-), upsilon = 0, N = 1). (C) 1997 American Institute of Physics. C1 US DOE,AMES LAB,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,ADV LIGHT SOURCE,BERKELEY,CA 94720. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 28 TC 31 Z9 32 U1 1 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 JUN 1 PY 1997 VL 106 IS 21 BP 8931 EP 8934 DI 10.1063/1.473956 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA478 UT WOS:A1997XA47800035 ER PT J AU Chen, TH Henderson-Sellers, A Milly, PCD Pitman, AJ Beljaars, ACM Polcher, J Abramopoulos, F Boone, A Chang, S Chen, F Dai, Y Desborough, CE Dickinson, RE Dumenil, L Ek, M Garratt, JR Gedney, N Gusev, YM Kim, J Koster, R Kowalczyk, EA Laval, K Lean, J Lettenmaier, D Liang, X Mahfouf, JF Mengelkamp, HT Mitchell, K Nasonova, ON Noilhan, J Robock, A Rosenzweig, C Schaake, J Schlosser, CA Schulz, JP Shao, Y Shmakin, AB Verseghy, DL Wetzel, P Wood, EF Xue, Y Yang, ZL Zeng, Q AF Chen, TH Henderson-Sellers, A Milly, PCD Pitman, AJ Beljaars, ACM Polcher, J Abramopoulos, F Boone, A Chang, S Chen, F Dai, Y Desborough, CE Dickinson, RE Dumenil, L Ek, M Garratt, JR Gedney, N Gusev, YM Kim, J Koster, R Kowalczyk, EA Laval, K Lean, J Lettenmaier, D Liang, X Mahfouf, JF Mengelkamp, HT Mitchell, K Nasonova, ON Noilhan, J Robock, A Rosenzweig, C Schaake, J Schlosser, CA Schulz, JP Shao, Y Shmakin, AB Verseghy, DL Wetzel, P Wood, EF Xue, Y Yang, ZL Zeng, Q TI Cabauw experimental results from the project for intercomparison of land-surface parameterization schemes SO JOURNAL OF CLIMATE LA English DT Article ID ANNUAL WATER-BALANCE; SOIL-MOISTURE; BIOSPHERE MODEL; BOUNDARY-LAYER; ECMWF MODEL; CLIMATE; HYDROLOGY; STORAGE; FLUXES; GCMS AB In the Project for Intercomparison of Land-Surface Parameterization Schemes phase 2a experiment, meteorological data for the year 1987 from Cabauw, the Netherlands, were used as inputs to 23 land-surface flux schemes designed for use in climate and weather models. Schemes were evaluated by comparing their outputs with long-term measurements of surface sensible heat fluxes into the atmosphere and the ground, and of upward longwave radiation and total net radiative fluxes, and also comparing them with latent heat fluxes derived from a surface energy balance. Tuning of schemes by use of the observed flux data was not permitted. On an annual basis, the predicted surface radiative temperature exhibits a range of 2 K across schemes, consistent with the range of about 10 W m(-2) in predicted surface net radiation. Most modeled values of monthly net radiation differ from the observations by less than the estimated maximum monthly observational error (+/-10 W m(-2)). However, modeled radiative surface temperature appears to have a systematic positive bias in most schemes; this might be explained by an error in assumed emissivity and by models' neglect of canopy thermal heterogeneity. Annual means of sensible and latent heat fluxes, into which net radiation is partitioned, have ranges across schemes of 30 W m(-2) and 25 W m(-2), respectively. Annual totals of evapotranspiration and runoff, into which the precipitation is partitioned, both have ranges of 315 mm. These ranges in annual heat and water fluxes were approximately halved upon exclusion of the three schemes that have no stomatal resistance under non-water-stressed conditions. Many schemes tend to underestimate latent heat flux and overestimate sensible heat flux in summer, with a reverse tendency in winter. For six schemes, root-mean-square deviations of predictions from monthly observations are less than the estimated upper bounds on observation errors (5 W m(-2) for sensible heat flux and 10 W m(-2) for latent heat flux). Actual runoff at the site is believed to be dominated by vertical drainage to groundwater, but several schemes produced significant amounts of runoff as overland flow or interflow. There is a range across schemes of 184 mm (40% of total pore volume) in the simulated annual mean root-zone soil moisture. Unfortunately, no measurements of soil moisture were available for model evaluation. A theoretical analysis suggested that differences in boundary conditions used in various schemes are not sufficient to explain the large variance in soil moisture. However, many of the extreme values of soil moisture could be explained in terms of the particulars of experimental setup or excessive evapotranspiration. C1 MACQUARIE UNIV, CLIMAT IMPACTS CTR, SYDNEY, NSW 2109, AUSTRALIA. US GEOL SURVEY, PRINCETON, NJ USA. NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ USA. ROYAL NETHERLANDS METEOROL INST, NL-3730 AE DE BILT, NETHERLANDS. CNRS, METEOROL DYNAM LAB, PARIS, FRANCE. SCI SYST & APPLICAT INC, NEW YORK, NY USA. NASA, GODDARD SPACE FLIGHT CTR, MESOSCALE DYNAM & PRECIPITAT BRANCH, GREENBELT, MD 20771 USA. PHILLIPS LAB, GPAB, HANSCOM AFB, MA USA. NOAA, DEV DIV, NATL CTR ENVIRONM PREDICT, CAMP SPRINGS, MD USA. CHINESE ACAD SCI, INST ATMOSPHER PHYS, BEIJING, PEOPLES R CHINA. UNIV ARIZONA, INST ATMOSPHER PHYS, TUCSON, AZ 85721 USA. MAX PLANCK INST METEOROL, HAMBURG, GERMANY. CSIRO, DIV ATMOSPHER RES, ASPENDALE, VIC 3195, AUSTRALIA. UNIV READING, DEPT METEOROL, READING, BERKS, ENGLAND. RUSSIAN ACAD SCI, INST WATER PROBLEMS, MOSCOW 103064, RUSSIA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. NASA, GODDARD SPACE FLIGHT CTR, HYDROL SCI BRANCH, GREENBELT, MD 20771 USA. METEOROL OFF, HADLEY CTR CLIMATE PREDICT & RES, BRACKNELL, BERKS, ENGLAND. UNIV WASHINGTON, DEPT CIVIL ENGN, SEATTLE, WA 98195 USA. PRINCETON UNIV, DEPT CIVIL ENGN & OPERAT RES, PRINCETON, NJ 08544 USA. ECMWF, READING, BERKS, ENGLAND. GKSS FORSCHUNGSZENTRUM GEESTHACHT GMBH, INST ATMOSPHER PHYS, GEESTHACHT, GERMANY. METEO FRANCE, CNRM, TOULOUSE, FRANCE. UNIV MARYLAND, DEPT METEOROL, COLLEGE PK, MD 20742 USA. NATL WEATHER SERV, NOAA, OFF HYDROL, SILVER SPRING, MD USA. UNIV NEW S WALES, CTR ADV NUMER COMPUTAT ENGN & SCI, SYDNEY, NSW, AUSTRALIA. INST GEOG, MOSCOW, RUSSIA. ATMOSPHER ENVIRONM SERV, CLIMATE RES BRANCH, DOWNSVIEW, ON, CANADA. CTR OCEAN LAND ATMOSPHERE STUDIES, CALVERTON, MD USA. RI Yang, Zong-Liang/B-4916-2011; Pitman, Andrew/A-7353-2011; Henderson-Sellers, Ann/H-5323-2011; Koster, Randal/F-5881-2012; Chen, Fei/B-1747-2009; lettenmaier, dennis/F-8780-2011; Nasonova, Olga/B-6093-2014; gusev, yugeniy/G-4711-2014; Robock, Alan/B-6385-2016; Shao, Yaping/G-3606-2013; Dai, Yongjiu/D-6261-2014; OI Pitman, Andrew/0000-0003-0604-3274; Koster, Randal/0000-0001-6418-6383; lettenmaier, dennis/0000-0003-3317-1327; gusev, yugeniy/0000-0003-3886-2143; Shao, Yaping/0000-0002-2041-5479; Dai, Yongjiu/0000-0002-3588-6644; Wood, Eric/0000-0001-7037-9675 NR 49 TC 229 Z9 245 U1 3 U2 28 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PD JUN PY 1997 VL 10 IS 6 BP 1194 EP 1215 DI 10.1175/1520-0442(1997)010<1194:CERFTP>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XJ208 UT WOS:A1997XJ20800004 ER PT J AU Dalgaard, JZ Moser, MJ Hughey, R Mian, IS AF Dalgaard, JZ Moser, MJ Hughey, R Mian, IS TI Statistical modeling, phylogenetic analysis and structure prediction of a protein splicing domain common to inteins and hedgehog proteins SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE hidden Markov model; intein; hedgehog; endonuclease; klbA domain; protein splicing ID INTRON-ENCODED ENDONUCLEASE; ARCHAEA DNA-POLYMERASE; HIDDEN MARKOV-MODELS; SECONDARY STRUCTURE; INTERVENING SEQUENCES; BRANCHED INTERMEDIATE; ESCHERICHIA-COLI; GENE; ELEMENTS; INFORMATION AB Inteins, introns spliced at the protein level, and the hedgehog family of proteins involved in eucaryotic development both undergo autocatalytic proteolysis. Here, a specific and sensitive hidden Markov model (HMM) of a protein splicing domain shared by inteins and the hedgehog proteins has been trained and employed for further analysis. The HMM characterizes the common features of this domain including the position where a site-specific DNA endonuclease domain is inserted in the majority of the inteins, The HMM was used to identify several new putative inteins, such as that in the Methanococcus jannaschii klbA protein, and to generate a multiple sequence alignment of sequences possessing this domain, Phylogenetic analysis suggests that hedgehog proteins evolved from inteins, Secondary and tertiary structure predictions suggest that the domain has a structure similar to a beta-sandwich, Similarities between the serine protease cleavage mechanism and the protein splicing reaction mechanism are discussed, Examination of the locations of inteins indicates that they are not inserted randomly in an extein, but are often inserted at functionally important positions in the host proteins, A specific and sensitive HMM for a domain present in klbA proteins identified several additional bacterial and archaeal family members, and analysis of the site of insertion of the intein suggests residues that may be functionally important, This domain may play a role in formation of surface-associated protein complexes. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. UNIV CALIF SANTA CRUZ, BASKIN CTR COMP ENGN & INFORMAT SCI, SANTA CRUZ, CA 95064 USA. RP NCI, FREDERICK CANC RES & DEV CTR, ABL BASIC RES PROGRAM,POB B,BLDG 539, ROOM 154, FREDERICK, MD 21702 USA. NR 78 TC 60 Z9 61 U1 0 U2 1 PU MARY ANN LIEBERT, INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1066-5277 EI 1557-8666 J9 J COMPUT BIOL JI J. Comput. Biol. PD SUM PY 1997 VL 4 IS 2 BP 193 EP 214 DI 10.1089/cmb.1997.4.193 PG 22 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA XH952 UT WOS:A1997XH95200009 PM 9228618 ER PT J AU Newman, N AF Newman, N TI The energetics of the GaN MBE reaction: A case study of meta-stable growth SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID MOLECULAR-BEAM EPITAXY; PRESSURE SOLUTION GROWTH; HOLLOW ANODE DISCHARGE; GALLIUM NITRIDE; 00.1 SAPPHIRE; 111 SILICON; EQUILIBRIUM PRESSURE; LAYER THICKNESS; THIN-FILMS; QUALITY AB The very large kinetic and thermodynamic barriers present in the GaN system make it ideally suited for studying the fundamental mechanisms involved in synthesizing meta-stable solids. In this paper, the critical factors necessary for the successful growth of GaN thin films under meta-stable conditions are outlined. Experimental results of GaN synthesis by plasma-enhanced Molecular Beam Epitaxy (MBE) are used to illustrate the key steps in the process and to demonstrate the validity of the approach. The issues involved in improving the quality of thin films using meta-stable growth methods are explicitly outlined in order that the method can be successfully applied to other epitaxial systems. C1 UC BERKELEY, BERKELEY, CA USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP NORTHWESTERN UNIV, DEPT ELECT & COMP ENGN, CTR QUANTUM DEVICES, EVANSTON, IL 60208 USA. RI Newman, Nathan/E-1466-2011 OI Newman, Nathan/0000-0003-2819-9616 NR 57 TC 52 Z9 52 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 EI 1873-5002 J9 J CRYST GROWTH JI J. Cryst. Growth PD JUN PY 1997 VL 178 IS 1-2 BP 102 EP 112 DI 10.1016/S0022-0248(97)00083-3 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XK704 UT WOS:A1997XK70400009 ER PT J AU Zolper, JC AF Zolper, JC TI Ion implantation in group III-nitride semiconductors: A tool for doping and defect studies SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID LIGHT-EMITTING-DIODES; CHEMICAL VAPOR-DEPOSITION; ANNEALING BEHAVIOR; GAN; GAAS; DOPANTS; BLUE; NITROGEN; EPITAXY; OXYGEN AB Ion implantation is a flexible process technology fbr introducing an array of doping or compensating impurities into semiconductors. As the crystal quality of the group III-nitride materials continues to improve, ion implantation is playing an enabling role in exploring new dopant species and device structures. In this paper we review the recent developments in ion implantation processing of these materials with a particular emphasis on how this technology has brought new understanding to this materials system. In particular, the use of ion implantation to characterize impurity luminescence, doping, and compensation in III-nitride materials is reviewed. In addition, we address the nature of implantation induced damage in GaN which demonstrates a very strong resistance to amorphization while at the same time forming damage that is not easily removed by thermal annealing. Finally, we review the coupling of implantation with high temperature rapid thermal annealing to better understand the thermal stability of these materials and the redistribution properties of the common dopant (Si, O, Be, Mg, Ca, and Zn). RP Zolper, JC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 47 TC 40 Z9 40 U1 3 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JUN PY 1997 VL 178 IS 1-2 BP 157 EP 167 DI 10.1016/S0022-0248(97)00076-6 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XK704 UT WOS:A1997XK70400013 ER PT J AU Breshears, DD Myers, OB Johnson, SR Meyer, CW Martens, SN AF Breshears, DD Myers, OB Johnson, SR Meyer, CW Martens, SN TI Differential use of spatially heterogeneous soil moisture by two semiarid woody species: Pinus edulis and Juniperus monosperma SO JOURNAL OF ECOLOGY LA English DT Article DE competition; juniper; pinon; plant water potential; woodland ID NORTHERN NEW-MEXICO; WATER-USE; HERBACEOUS VEGETATION; CATASTROPHE-THEORY; USE EFFICIENCY; GREAT-BASIN; WOODLANDS; DYNAMICS; GRADIENT; SIERRAN AB 1 Soil moisture in semiarid woodlands varies both vertically with depth and horizontally between canopy patches beneath woody plants and the intercanopy patches that separate them, such that shallow soil layers in intercanopy locations are wettest, yet few studies have considered both dimensions of spatial variability in testing for acquisition of resources by plants. 2 Three hypotheses were tested relative to the use of shallow water in intercanopy locations by two coexisting semiarid-woodland tree species, Pinus edulis (a pinon) and Juniperus monosperma (a juniper): (i) both P. edulis and J. monosperma can use shallow water from intercanopy locations;. (ii) J. monosperma is able to obtain more shallow water from intercanopy locations than P. edulis, and (iii) the spatial arrangement of the trees influences the amount of water they obtain. Soil moisture and plant water potential (i.e. plant water stress) were measured before and after the addition of water to shallow depths (0-30 cm) of intercanopy locations for trees of both species in two spatial arrangements: isolated and paired with a contiguous tree of the other species. 3 Both species responded to the addition of shallow water in intercanopy locations, as measured by plant water potential. The response of J. monosperma was significantly greater than that of P. edulis, as measured by depletion of shallow soil moisture in intercanopy locations and by change in plant water potential per unit change in soil water potential (the difference was not detectable on the basis of plant water potential alone); in addition, the amount of depletion was correlated with basal area of J. monosperma but not of P. edulis. The responses were not influenced by spatial arrangement (isolated vs. paired with a contiguous tree of the other species). 4 The results of this study are consistent with differences in the relative abundances of the two species across locations, suggesting that species differences in ability to use shallow water in intercanopy locations is important in structuring semiarid woodlands. Further, the results suggest that current theoretical concepts for semiarid ecosystems, which ignore either vertical or horizontal variability in soil moisture, may be inadequate for predicting changes in the ratio of woody to herbaceous plant biomass, particularly for plant communities with co-dominant woody species that differ in ability to acquire spatially heterogeneous resources. RP Breshears, DD (reprint author), LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,MAIL STOP J495,LOS ALAMOS,NM 87545, USA. RI Myers, Orrin/F-1130-2010; Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 69 TC 83 Z9 88 U1 1 U2 21 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0022-0477 J9 J ECOL JI J. Ecol. PD JUN PY 1997 VL 85 IS 3 BP 289 EP 299 DI 10.2307/2960502 PG 11 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA XK152 UT WOS:A1997XK15200003 ER PT J AU Yoon, H VanScyoc, JM Goorsky, MS Hermon, H Schieber, M Lund, JC James, RB AF Yoon, H VanScyoc, JM Goorsky, MS Hermon, H Schieber, M Lund, JC James, RB TI Investigation of the effects of polishing and etching on the quality of Cd1-xZnxTe using spatial mapping techniques SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1996 US Workshop on The Physics and Chemistry of II-VI Materials CY OCT 22-24, 1996 CL LAS VEGAS, NV SP USA, Night Vis & Electro Opt Syst Directorate, USN, Naval Res Lab, USAF, Wright Labs, Amer Phys Soc, Minerals Met & Mat Soc DE alpha particle mapping; cadmium zinc telluride; etching; high resolution x-ray diffraction; polishing; radiation detectors ID PRESSURE BRIDGMAN METHOD; RAY-DETECTORS; GAMMA-RAY AB We examined the effects of polishing and etching on the structural and electrical properties of various high pressure Bridgman Cd1-xZnxTe (CZT) crystals using high resolution x-ray diffraction (HRXRD) and alpha particle mapping. Two etching solutions investigated are: (1) standard bromine-methanol solution, and (2) standard solution mixed with lactic acid. HRXRD, and in particular, triple axis x-ray diffraction (TAXRD) showed the effectiveness of the bromine-methanol etch in removing residual strain and damage from the CZT crystal. TAXRD mapping of a similar to 5 cm(2) CZT crystal after etching resulted in a reduction of the average rocking curve full width at half maximum to 15 arc-sec (compared to 23 are-sec for the ''as-received''). Alpha particle mapping of the electron risetime and the pulse height spectrum, along with leakage current measurements, showed varying effects of the different etching solutions on the surface properties (and hence their influence on the electrical and detector properties). These preliminary results show the importance and the sensitivity of the overall detector properties on the surface preparation conditions of CZT crystals used as radiation detectors. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP Yoon, H (reprint author), UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90095, USA. NR 17 TC 26 Z9 28 U1 0 U2 8 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 JUN PY 1997 VL 26 IS 6 BP 529 EP 533 DI 10.1007/s11664-997-0189-2 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA XF164 UT WOS:A1997XF16400011 ER PT J AU Yoo, SS Jennings, G Montano, PA AF Yoo, SS Jennings, G Montano, PA TI Linear X-ray detector array made on bulk CdZnTe for 30 similar to 100 keV energy SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1996 US Workshop on The Physics and Chemistry of II-VI Materials CY OCT 22-24, 1996 CL LAS VEGAS, NV SP USA, Night Vis & Electro Opt Syst Directorate, USN, Naval Res Lab, USAF, Wright Labs, Amer Phys Soc, Minerals Met & Mat Soc DE CdTe; CdZnTe; gamma-ray detector; high pressure Bridgman; linear array; radiation detector; x-ray detector AB A CdZnTe detector grown by the high pressure Bridgman (HPB) growth technique was tested using high energy x-rays (30 similar to 100 keV), and the performance was compared with a commercially available NaI scintillating detector of 5 cm thickness. The charge collection efficiency of a CdZnTe detector is as high as 90% at relatively low electric field, 600 V/cm. At high x-ray photon energies, the detection efficiency is reduced due to the thickness of the CdZnTe. A 32 channel linear array was fabricated on 1.2 similar to 1.7 mm thick CdZnTe, of which the detector area was 175 x 800 mu m(2) and the pitch size 250 mu m. The measured dark current for the 16 element detector was as low as 0.1 pA at 800 V/cm with an excellent uniformity. Energy spectra were measured using a Co-57 radiation source. A small pixel effect and charge sharing were observed. The energy resolution was improved and compared with the large area detector. The array detector gave an average 5.8% full-width-half-maximum (FWHM) at 122 keV photopeak. The large area detector of the same material before fabrication exhibited a low energy tail at the photopeak, which limits the photopeak FWHM to 8%. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Yoo, SS (reprint author), UNIV ILLINOIS,DEPT PHYS,MICROPHYS LAB,CHICAGO,IL 60607, USA. NR 18 TC 4 Z9 4 U1 0 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 JUN PY 1997 VL 26 IS 6 BP 750 EP 755 DI 10.1007/s11664-997-0227-0 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA XF164 UT WOS:A1997XF16400049 ER PT J AU Nguyen, HD Sato, C Wu, J Douglass, RW AF Nguyen, HD Sato, C Wu, J Douglass, RW TI Modeling biofiltration of gas streams containing TEX components SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article; Proceedings Paper CT 1st USC TRG Conference on Biofiltration CY OCT 05-06, 1995 CL UNIV SO CALIF AT LOS ANGELES, LOS ANGELES, CA SP Univ So Calif, Los Angeles, Reynolds Grp HO UNIV SO CALIF AT LOS ANGELES ID WASTE AIR BIOTREATMENT; BIOLOGICAL FILTER; DYNAMIC-MODEL; REMOVAL; BIOFILTERS; BIODEGRADATION; HYDROCARBONS; CONTAMINANTS; TRANSPORT; BEHAVIOR AB This paper describes a phenomenological model for simulating the removal of toluene, ethylbenzene and o-xylene (TEX) from contaminated air streams by a biofilter. The phenomena incorporated into the model are interphase mass transfer between the gas and the aqueous biofilm with equilibrium partition, advection, diffusion, and biological reactions. The reaction rate for each TEX component is quantified using a more generalized Monod equation to allow for inhibitive effects in the presence of multiple substrates. Solutions to the system of coupled nonlinear partial differential equations representing component mass conservation are obtained by a fully implicit finite difference method with first-order accuracy in time and second-order accuracy in space. A parametric study is performed to evaluate the sensitivity of the Peclet number and the normalized mass transfer coefficient, both of which show strong influence on the removal rates. Comparison of the concentration distribution along the biofilter against available measured data and the exact closed-form solution indicates a good agreement with discrepancies being within experimental uncertainties. C1 IDAHO STATE UNIV,COLL ENGN,POCATELLO,ID 83209. RP Nguyen, HD (reprint author), IDAHO NAT ENGN & ENVIRONM LAB,IDAHO FALLS,ID 83415, USA. NR 25 TC 18 Z9 19 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD JUN PY 1997 VL 123 IS 6 BP 615 EP 621 DI 10.1061/(ASCE)0733-9372(1997)123:6(615) PG 7 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XA706 UT WOS:A1997XA70600015 ER PT J AU Varadaraj, K Kumari, SS Skinner, DM AF Varadaraj, K Kumari, SS Skinner, DM TI Molecular characterization of four members of the alpha-tubulin gene family of the Bermuda land crab Gecarcinus lateralis SO JOURNAL OF EXPERIMENTAL ZOOLOGY LA English DT Article ID 3' UNTRANSLATED REGION; BETA-TUBULIN; MESSENGER-RNA; TRYPANOSOMA-BRUCEI; DROSOPHILA-MELANOGASTER; SEQUENCE HETEROGENEITY; GENOMIC ORGANIZATION; NUCLEOTIDE-SEQUENCE; SATELLITE DNA; BRINE SHRIMP AB Four alpha-tubulin isoforms recovered from a cDNA library from regenerating limb buds of the Bermuda land crab Gecarcinus lateralis have been characterized. Two clones (alpha 1 and (alpha 2) contained complete coding sequences with start and stop codons; the other two clones were partial, lacking 5' ends. The four isoforms showed high homology in their coding sequences but rather low homology in their non-coding regions. Identity between the nucleotide sequences of alpha 1 and alpha 2 was 83.4%; between their predicted amino acid sequences it was 88.9%. The inferred number of amino acid residues for both alpha 1 and alpha 2 was 451, and their calculated molecular weights were 58.29 and 58.45 kDa, respectively. The greatest divergence in the predicted crab alpha-tubulin proteins occurred near the carboxy terminus, as in alpha-tubulins of other organisms. When compared with other species, nucleotide sequences of all four clones showed highest homology to alpha-tubulin genes of an insect (Drosophila melanogaster), while their predicted amino acid sequences were most highly homologous to an alpha-tubulin of a mammal (Rattus norvegicus). Southern blots revealed a total of five to seven alpha-tubulin genes encoded in the G. lateralis genome. Northern blots showed single bands of approximately 2.2 kb with an alpha 1-tubulin probe and 1.9 kb with an alpha 2-tubulin probe. mRNA levels of both tubulin isoforms appeared to be independently regulated at different stages of the intermolt cycle in both epidermis and limb buds. Western blots of 1D gels of proteins from epidermis, limb buds, or claw muscle showed tissue- and stage-specific changes in tubulin content; similar analyses on blots of 2D gels revealed differences in the number of alpha-tubulin isoforms that were expressed. (C) 1997 Wiley-Liss, Inc.dagger. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. E TENNESSEE STATE UNIV,DEPT ANAT & CELL BIOL,JOHNSON CITY,TN 37614. NR 69 TC 9 Z9 10 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0022-104X J9 J EXP ZOOL JI J. Exp. Zool. PD JUN 1 PY 1997 VL 278 IS 2 BP 63 EP 77 DI 10.1002/(SICI)1097-010X(19970601)278:2<63::AID-JEZ1>3.3.CO;2-E PG 15 WC Zoology SC Zoology GA WW906 UT WOS:A1997WW90600001 PM 9143139 ER PT J AU Liljegren, LM AF Liljegren, LM TI Ensemble-average equations of a particulate mixture SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT ASME Fluid Engineering Conference CY 1993 CL WASHINGTON, DC SP ASME ID FLUID SOLID MIXTURE; SPHERICAL-PARTICLES; SUSPENSION; STRESS; FLOW AB A method of evaluating the transfer terms appearing in the ensemble-average fluid (t)ransport equation is developed and applied to obtain the transport equations describing flow of a dilute particulate mixture containing solid spherical particles. The equations apply in the limit where interactions between phases are both quasi-steady and viscous, which is defined as flows that meet the three criterion Re-f(a/L)(2) much less than 1, nu(f) tau/a(2) much greater than 1, and Re-p much less than 1. In this limit, the terms describing transfer of momentum between the two phases of the mixture are evaluated to O(1) in the particle radius and O(gamma(p)) in the particle phase density. The continuity equations and consistency principle are exact. When the first two correlations are not met, the transport equations require the terms that describe virtual mass forces; when the third is not met, the transport equations require terms that describe Oseen corrections to the drag term. RP Liljegren, LM (reprint author), PACIFIC NW LAB, DEPT ANALYT SCI, POB 999, RICHLAND, WA 99352 USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD JUN PY 1997 VL 119 IS 2 BP 428 EP 434 DI 10.1115/1.2819151 PG 7 WC Engineering, Mechanical SC Engineering GA XE299 UT WOS:A1997XE29900025 ER PT J AU Piet, SJ DiPace, L Federici, G Holland, DF McCarthy, KA Nisan, S Oda, Y Seki, Y Topilski, LN AF Piet, SJ DiPace, L Federici, G Holland, DF McCarthy, KA Nisan, S Oda, Y Seki, Y Topilski, LN TI Source term and mobilization assessment in NSSR-1 of ITER SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE ITER; tritium; activation products; dust; corrosion products ID RELEASE; CARBON; LAYER AB We describe the radioactive sources in the International Thermonuclear Experimental Reactor (ITER). The most important sources are co-deposited tritium, tritiated water, tokamak dust, and corrosion products. The co-deposited tritium is limited to 1 kg-T; the total on-site tritium inventory in the Basic Performance Phase (BPP) is 4 kg-T. Tritiated water concentrations are kept below 0.2 g-T/m(3) in the divertor; other coolant loops have lower tritium concentrations. The in-vessel dust inventory is up to 100 kg-W, 100 kg-Be, and 200 kg-C. The activated corrosion product inventory is kept below 10 kg per loop. C1 EURATOM,ENEA FUS,CR FRASCATI,FRASCATI,ITALY. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. CEA,F-91190 GIF SUR YVETTE,FRANCE. JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. RP Piet, SJ (reprint author), ITER,JOINT CENT TEAM,SAN DIEGO,CA, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 11 EP 17 DI 10.1023/A:1022500610193 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900003 ER PT J AU Brereton, S McLouth, L Odell, B Singh, M Tobin, M Trent, M Yatabe, J AF Brereton, S McLouth, L Odell, B Singh, M Tobin, M Trent, M Yatabe, J TI Overview of the preliminary safety analysis of the national ignition facility SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE NIF; ICF; tritium; fusion safety; safety analysis AB The National Ignition Facility (NIF) is a proposed U.S. Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, New Mexico, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 individual laser beams onto a tiny deuterium-tritium target located at the center of a spherical target chamber. The NIF has been classified as a low hazard, radiological facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis report be prepared under DOE Order 5481.1B, Safety Analysis and Review System.((1)), A Preliminary Safety Analysis Report (PSAR) has been approved, which documents and evaluates the safety issues associated with the construction, operation, and decommissioning of the NIF.((2)) RP Brereton, S (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 10 TC 4 Z9 4 U1 2 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 85 EP 94 DI 10.1023/A:1022517113828 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900011 ER PT J AU Anderl, RA Longhurst, GR Pawelko, RJ Oates, MA AF Anderl, RA Longhurst, GR Pawelko, RJ Oates, MA TI Implanted deuterium retention and release in carbon-coated beryllium SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE fusion; beryllium; tritium; coatings; mobilization; experiments AB Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Angstrom. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Angstrom revealed that exposure to a temperature of 400 degrees C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400 degrees C and an incident deuterium flux of approximately 6 X 10(19) D/m(2)-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples. RP Anderl, RA (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 4 TC 8 Z9 8 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 95 EP 100 DI 10.1023/A:1022569130666 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900012 ER PT J AU Anderl, RA Pawelko, RJ Oates, MA Smolik, GR McCarthy, KA AF Anderl, RA Pawelko, RJ Oates, MA Smolik, GR McCarthy, KA TI Steam-chemical reactivity studies for irradiated beryllium SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE fusion; beryllium; chemical reactivity; tritium; mobilization ID TRITIUM; TEMPERATURES; RELEASE AB This paper reports the results of an experimental study to determine the influence of neutron irradiation effects on the chemical reactivity of beryllium exposed to steam. The study entailed measurements of the following: (1) swelling of irradiated Be specimens annealed at temperatures ranging from 450 degrees C to 1200 degrees C, (2) hydrogen generation rates for unirradiated Be control specimens exposed to steam at temperatures from 450 degrees C to 1200 degrees C, and (3) hydrogen generation rates and tritium mobilization rates for irradiated Be exposed to steam at temperatures from 450 degrees C to 700 degrees C. For irradiated Be, swelling occurred at temperatures above 600 degrees C and it increased to about 56% for an anneal temperature of 1200 degrees C. Tritium and He-4 were released concurrently from specimens that were annealed at 800 degrees C and above. Steam-Be reactivity measurements for the control specimens were consistent with previous work at temperatures above 700 degrees C, and the new measurements extended the reactivity database down to 450 degrees C. Steam-reactivity measurements for irradiated Be were comparable to control specimens for 600 degrees C and below, but, they indicated a significant enhancement in the chemical reactivity at 700 degrees C. RP Anderl, RA (reprint author), LOCKHEED MARTIN IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 17 TC 11 Z9 11 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 101 EP 108 DI 10.1023/A:1022521214736 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900013 ER PT J AU Carmack, WJ Smolik, GR McCarthy, KA AF Carmack, WJ Smolik, GR McCarthy, KA TI Mobilization of 316 stainless steel from 500 to 800 degrees C in steam SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst AB This paper presents the results of steam exposure tests of 316 stainless steel in the Fusion Aerosol Source Test (FAST) facility. The tests were performed at temperatures of 500, 600, 700, and 800 degrees C. These tests were conducted to measure the mobilized material resulting from the steam exposure conditions at each temperature. A steam volume flow rate of 21-27 standard liters per minute was maintained in the test sections for a duration of 5 hours. These conditions simulate postulated accident conditions in the International Thermonuclear Experimental Reactor (ITER) relevant scenarios. These data will be used in safety assessments for ITER. We compared the data obtained in these tests with data from the Volatilization of Activation Product Oxides Reactor (VAPOR) facility at 800 degrees C. The data obtained in the tests show the following: (1) There is a progressive increase of measured mass flux for Fe, Mo, Mn, Zn, and Cr with test temperature between 500 degrees C and 800 degrees C. (2) Mass flux measurements from FAST and VAPOR agree within a factor of three for elements with volatile oxide or hydroxide species such as Cr and Mo. (3) Mass fluxes of elements associated with oxide spalling in VAPOR, mainly Fe and Mn, were up to a factor of 90 lower in the FAST test than in the VAPOR test at 800 degrees C. (4) Detection limits in FAST were lower than those measured in VAPOR due to the larger surface area of the source in FAST tests. RP Carmack, WJ (reprint author), LOCKHEED MARTIN IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,FUS SAFETY PROGRAM,POB 1625,IDAHO FALLS,ID 83415, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 109 EP 112 DI 10.1023/A:1022573231575 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900014 ER PT J AU McCarthy, KA Smolik, GR Anderl, RA Carmack, WJ Longhurst, GR AF McCarthy, KA Smolik, GR Anderl, RA Carmack, WJ Longhurst, GR TI An overview of INEL fusion safety R&D facilities SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst AB The Fusion Safety Program at the Idaho National Engineering Laboratory has the lead for fusion safety work in the United States. Over the years, we have developed several experimental facilities to provide data for fusion reactor safety analyses. We now have four major experimental facilities that provide data for use in safety assessments. The Steam-Reactivity Measurement System measures hydrogen generation rates and tritium mobilization rates in high-temperature (up to 1200 degrees C) fusion relevant materials exposed to steam. The Volatilization of Activation Product Oxides Reactor Facility provides information on mobilization and transport and chemical reactivity of fusion relevant materials at high temperature (up to 1200 degrees C) in an oxidizing environment (air or steam). The Fusion Aerosol Source Test Facility is a scaled-up version of VAPOR. The ion-implantation/thermal-desorption system is dedicated to research into processes and phenomena associated with the interaction of hydrogen isotopes with fusion materials. In this paper we describe the capabilities of these facilities. RP McCarthy, KA (reprint author), IDAHO NATL ENGN LAB,LMITCO,FUS SAFETY PROGRAM,POB 1625,IDAHO FALLS,ID 83415, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 113 EP 118 DI 10.1023/A:1022525315645 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900015 ER PT J AU Merrill, BJ Cadwallader, LC Petti, DA AF Merrill, BJ Cadwallader, LC Petti, DA TI Safety analysis results for cryostat ingress accidents in ITER SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE ITER safety; ITER cryostat pressurization; LOCAs into the ITER cryostat AB Accidents involving the ingress of air, helium, or water into the cryostat of the International Thermonuclear Experimental Reactor (ITER) tokamak design have been analyzed with a modified version of the MELCOR code for the ITER Non-site Specific Safety Report (NSSR-1). The air ingress accident is the result of a postulated breach of the cryostat boundary into an adjoining room. MELCOR results for this accident demonstrate that the condensed air mass and increased heat loads are not a magnet safety concern, but that the partial vacuum in the adjoining room must be accommodated in the building design. The water ingress accident is the result of a postulated magnet are that results in melting of a Primary Heat Transport System (PHTS) coolant pipe, discharging PHTS water and PHTS water activated corrosion products and HTO into the cryostat. MELCOR results for this accident demonstrate that the condensed water mass and increased heat loads are not a magnet safety concern, that the cryostat pressure remains below design limits, and that the corrosion product and HTO releases are well within the ITER release limits. RP Merrill, BJ (reprint author), IDAHO NATL ENGN LAB,FUS SAFETY PROGRAM,POB 1625,IDAHO FALLS,ID 83415, USA. RI Cadwallader, Lee/F-6933-2014 NR 6 TC 3 Z9 3 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 119 EP 124 DI 10.1023/A:1022577332483 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900016 ER PT J AU Petti, DA Merrill, BJ Polkinghorne, ST Cadwallader, LC Moore, RL AF Petti, DA Merrill, BJ Polkinghorne, ST Cadwallader, LC Moore, RL TI Safety analysis results for ITER in-vessel loss of coolant events SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst AB A number of postulated in-vessel loss of coolant accidents (LOCAs) associated with the first wall and baffle cooling systems of the ITER detailed design have been analyzed for the ITER Non-site Specific Safety Report (NSSR-1). A range of break sizes from one first wall tube break (1.57 x 10(-4) m(2)) to damage to all in-vessel components (0.6 m(2) break) have been examined. These events span the ITER event classification from likely events to extremely unlikely events. In addition, in-vessel pipe breaks in combination with bypass of the two confinement barriers through a generic penetration have been examined. In all cases, when the vacuum vessel pressure suppression system is activated, most of the radioactive inventory is carried to the suppression pool where it remains for the duration of the event. Releases in these events are well within ITER release limits. RP Petti, DA (reprint author), IDAHO NATL ENGN LAB,FUS SAFETY PROGRAM,POB 1625,IDAHO FALLS,ID 83415, USA. RI Cadwallader, Lee/F-6933-2014 NR 8 TC 3 Z9 4 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 125 EP 131 DI 10.1023/A:1022529416554 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900017 ER PT J AU Piet, SJ Brereton, SJ Perlado, JM Seki, Y Tanaka, S Tobin, MT AF Piet, SJ Brereton, SJ Perlado, JM Seki, Y Tanaka, S Tobin, MT TI Overview of safety and environmental issues for inertial fusion energy SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE inertial fusion; tritium; activation products; safety; environment ID DRIVEN IFE REACTOR AB This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the first structural wall from fusion pulses. This protective fluid or granular bed also moderates and absorbs most neutrons before they reach the first structural wall. Although the protective fluid activates, most candidate fluids have low activation hazard. Hands-on maintenance seems practical for the driver, target factory, and secondary coolant systems; remote maintenance is likely required for the reaction chamber, primary coolant, and vacuum exhaust cleanup systems. The driver and fuel target facility are well separated from the main reaction chamber. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. UNIV TOKYO,TOKYO,JAPAN. INST FUS NUCL,MADRID,SPAIN. RP Piet, SJ (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 19 TC 0 Z9 0 U1 1 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 133 EP 140 DI 10.1023/A:1022581400624 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900018 ER PT J AU Honda, T Bartels, HW Uckan, NA Seki, Y Okazaki, T AF Honda, T Bartels, HW Uckan, NA Seki, Y Okazaki, T TI Development of safety assessment method for plasma anomaly events in fusion reactors SO JOURNAL OF FUSION ENERGY LA English DT Article; Proceedings Paper CT International-Atomic-Energy-Agency (IAEA) Technical Committee Meeting on Development in Fusion Safety CY OCT 21-25, 1996 CL NAKA, JAPAN SP Int Atom Energy Agcy, Tech Comm, Japan Atom Energy Res Inst DE ITER; plasma physics; safety assessment; overpower; passive plasma shutdown ID THERMONUCLEAR EXPERIMENTAL REACTOR; ANALYSIS CODE SYSTEM AB The objective of the study is to provide a safety assessment method for plasma transients including thermal response of in-vessel components. We developed a plasma physics model for safety analysis which has been implemented in a safety analysis code (SAFALY). The SAFALY code consists of a 0-D plasma dynamics model and a 1-D thermal behavior model of in-vessel components in the thickness direction. The code can treat hydraulic accidents using the results from a hydraulic code and analyze a passive plasma shutdown due to the impurity release from the wall. The overpower events in International Thermonuclear Experimental Reactor (ITER) were investigated, when the fueling rate and confinement improvement changes. The results show no significant damage to the confinement boundary of ITER is expected, as long as the cooling system works normally. C1 ITER SAN DIEGO JOINT WORK SITE,SAFETY ENVIRONM & HLTH DIV,LA JOLLA,CA 92037. OAK RIDGE NATL LAB,ITER PROGRAM,OAK RIDGE,TN 37831. JAPAN ATOM ENERGY RES INST,NAKA FUS RES ESTAB,NAKA,IBARAKI 31101,JAPAN. RP Honda, T (reprint author), HITACHI LTD,HITACHI RES LAB,1-1,OMIKA CHO,7 CHOME,HITACHI,IBARAKI 31912,JAPAN. NR 8 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 1997 VL 16 IS 1-2 BP 175 EP 179 DI 10.1023/A:1022593803350 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG939 UT WOS:A1997XG93900024 ER PT J AU Farrugia, CJ Erkaev, NV Biernat, HK Lawrence, GR Elphic, RC AF Farrugia, CJ Erkaev, NV Biernat, HK Lawrence, GR Elphic, RC TI Plasma depletion layer model for low Alfven Mach number: Comparison with ISEE observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ANISOTROPY FLUID MODEL; MAGNETIC-FIELD; DAYSIDE MAGNETOPAUSE; AMPTE/IRM OBSERVATIONS; MAGNETOSHEATH; RECONNECTION; SHEAR; PARAMETERS; BOUNDARY; REGION AB Together with the magnetic shear across the magnetopause, the solar wind Alfven Mach number, M-A infinity plays a central role in determining the structure of the magnetosheath. Recent theoretical modeling has shown, in particular, that as M-A infinity decreases, the region adjacent to the sunward side of the magnetopause where the interplanetary magnetic field (IMF) exerts a strong influence on the flow (i.e., the so-called ''plasma depletion layer''), is no longer confined to a thin layer similar to 0.3 Earth radii (R-E) thick but occupies an increasingly larger fraction of the magnetosheath. Furthermore, the model predicts the possibility of a plasma depletion layer for low M-A infinity, irrespective of the size of the magnetic shear at the magnetopause, In this paper we study three examples of low latitude ISEE 2 passes through the dayside magnetosheath near noon: December 3, 1979; October 5, 1979; and November 11, 1979, In all three examples, MA, was lower than normal. During the December 3 pass (which we treat qualitatively), we find evidence of a plasma depletion layer when the IMF was pointing south, On the other two passes (which we study quantitatively), the interplanetary magnetic field was strongly northward pointing, leading to low magnetic shear at the respective magnetopause crossings, The October 5 pass was under steady interplanetary conditions and we find good agreement between theory and data, Temporal variations of the interplanetary medium during the November 11 pass necessitated an extension of the steady state theory to encompass piecewise steady (on average) interplanetary conditions, Better agreement with the data results when the theory is extended further to correct the total pressure at the sunward side of the magnetopause by integrating the magnetic tension term across the layer. For wide plasma depletion layers, this correction can be substantial. C1 AUSTRIAN ACAD SCI,SPACE RES INST,A-8042 GRAZ,AUSTRIA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RUSSIAN ACAD SCI,CTR COMP,KRASNOYARSK 660036,RUSSIA. UNIV SUSSEX,DEPT PHYS & ASTRON,CTR SPACE SCI,BRIGHTON BN1 9QH,E SUSSEX,ENGLAND. UNIV MALTA,DEPT MATH SCI & TECH EDUC,MSIDA,MALTA. RI Erkaev, Nikolai/M-1608-2013 OI Erkaev, Nikolai/0000-0001-8993-6400 NR 29 TC 16 Z9 16 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1997 VL 102 IS A6 BP 11315 EP 11324 DI 10.1029/97JA00410 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XD974 UT WOS:A1997XD97400008 ER PT J AU Ober, DM Horwitz, JL Thomsen, MF Elphic, RC McComas, DJ Belian, RD Moldwin, MB AF Ober, DM Horwitz, JL Thomsen, MF Elphic, RC McComas, DJ Belian, RD Moldwin, MB TI Premidnight plasmaspheric ''plumes'' SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; QUANTITATIVE SIMULATION; GEOSYNCHRONOUS ORBIT; ELECTRIC-FIELD; BULGE REGION; SUBSTORM; DYNAMICS; BOUNDARY AB To explain observations of brief intervals of cold, dense plasma by geosynchronous satellites in the midnight sector prior to or during substorm onset, it has recently been proposed that dense plasmaspheric plasma is drawn out to geosynchronous orbit in the premidnight region by inductive electric fields during the growth phase of a geomagnetic substorm. We present here the results of a statistical study of such intervals observed with the Los Alamos magnetospheric plasma analyzer (MPA) on geosynchronous satellite 1989-046 between March and December 1993. We find that these premidnight cold plasma intervals occur only after extended periods of low magnetospheric activity identified by Kp and the midnight boundary index (MBI). We also find that the satellite typically enters the cold plasma region from the trough region and exits it into the plasma sheet. Finally, while measurements of the flow velocity of the cold plasma are rendered uncertain by the asymmetric spacecraft charge or photoelectron sheath, such measurements show no evidence of the outward flow that would be expected from the extrusion hypothesis. Rather, there are some indications that these cold plasma regions flow sunward in the (corotation) satellite frame. These results suggest an alternative explanation for the premidnight cold plasma: corotation-dominated transport of dayside plasmaspheric structures into the premidnight sector. The implications of our observations for the extrusion hypothesis and for the alternative explanation are discussed. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. FLORIDA INST TECHNOL,DEPT PHYS & SPACE SCI,MELBOURNE,FL 32901. RP Ober, DM (reprint author), UNIV ALABAMA,CTR SPACE PLASMA & AERONOM RES,HUNTSVILLE,AL 35899, USA. RI Moldwin, Mark/F-8785-2011 OI Moldwin, Mark/0000-0003-0954-1770 NR 24 TC 17 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1997 VL 102 IS A6 BP 11325 EP 11334 DI 10.1029/97JA00562 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XD974 UT WOS:A1997XD97400009 ER PT J AU Zong, QG Wilken, B Reeves, GD Daglis, IA Doke, T Iyemori, T Livi, S Maezawa, K Mukai, T Kokubun, S Pu, ZY Ullaland, S Woch, J Lepping, R Yamamoto, T AF Zong, QG Wilken, B Reeves, GD Daglis, IA Doke, T Iyemori, T Livi, S Maezawa, K Mukai, T Kokubun, S Pu, ZY Ullaland, S Woch, J Lepping, R Yamamoto, T TI Geotail observations of energetic ion species and magnetic field in plasmoid-like structures in the course of an isolated substorm event SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRAVELING COMPRESSION REGIONS; NEAR-EARTH MAGNETOTAIL; DEEP GEOMAGNETIC TAIL; FLUX ROPES; DISTANT MAGNETOTAIL; RECONNECTION PROCESSES; ISEE-3 OBSERVATIONS; BOUNDARY-LAYER; MAGNETOSPHERE; CDAW-8 AB On January 15, 1994, the ion spectrometer high energy particle - low energy particle detector (HEP-LD) on the Japanese spacecraft Geotail observed five quasi-periodic energetic ion bursts in the deep tail (X=-96 RE) These bursts were associated with plasmoid-like structures in the magnetic field components. In addition, three multiple TCR groups were identified in the interval. The observations in the distant tail occurred during a time interval of substorm activity which also produced multiple injections in the geosynchronous orbit region. The HEP-LD observations show that B-z bipolar plasmoid-like structures are associated with tailward flowing particle bursts. However, earthward flowing particle bursts are predominantly associated with bipolar signatures in B-y. In addition, an oxygen burst was seen in the back of a plasmoid (postplasmoid) which showed both B-y and B-z bipolar magnetic field signatures. The oxygen burst lasted for 23 min, and the density ratio (O/H) reached 15% for the HEP-LD energy range (in the same plasmoid, this ratio was approximately 1% before the oxygen burst). The oxygen burst exhibited a strong beam-like structure which occupied only 6 similar to 7% of the full solid angle (4 pi). We suggest that energized oxygen ions of ionospheric origin travel downtail in the narrow postplasmoid-plasma sheet which trails the plasmoid. Furthermore, we suggest that the magnetosphere dissipated larger quantities of energy during this very intense substorm event by ejecting multiple relatively small plasmoids rather than through the formation and ejection of a single large plasmoid. C1 WASEDA UNIV,ADV RES CTR SCI & ENGN,TOKYO,JAPAN. KYOTO UNIV,FAC SCI,KYOTO 60601,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NAGOYA UNIV,DEPT PHYS,NAGOYA,AICHI 46401,JAPAN. INST SPACE & ASTRONAUT SCI,KANAGAWA 229,JAPAN. NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA,AICHI 442,JAPAN. BEIJING UNIV,DEPT GEOPHYS,BEIJING 100871,PEOPLES R CHINA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV BERGEN,BERGEN,NORWAY. RP Zong, QG (reprint author), MAX PLANCK INST AERON,D-37191 KATLENBURG DUHM,GERMANY. RI Daglis, Ioannis/L-6100-2013; Reeves, Geoffrey/E-8101-2011 OI Daglis, Ioannis/0000-0002-0764-3442; Reeves, Geoffrey/0000-0002-7985-8098 NR 77 TC 50 Z9 55 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1997 VL 102 IS A6 BP 11409 EP 11428 DI 10.1029/97JA00076 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XD974 UT WOS:A1997XD97400016 ER PT J AU Oprea, M Perelson, AS AF Oprea, M Perelson, AS TI Somatic mutation leads to efficient affinity maturation when centrocytes recycle back to centroblasts SO JOURNAL OF IMMUNOLOGY LA English DT Article ID FOLLICULAR DENDRITIC CELLS; PRIMARY IMMUNE-RESPONSE; CENTER B-CELLS; GERMINAL-CENTERS; ANTIBODY DIVERSITY; SELECTION; ANTIGEN; PROLIFERATION; MEMORY; (4-HYDROXY-3-NITROPHENYL)ACETYL AB Although most mutations are deleterious, an interplay between somatic mutation and selection within germinal centers (GC) results in rapid generation of high affinity memory B cells. How high affinity B cells with large numbers of mutations are generated and preserved within GC containing at their peak only a few thousand cells has been puzzling, We have developed a model of somatic mutation and B cell expansion within a GC that resolves this puzzle, We show that the frequent recycling of Ag-selected centrocytes back into centroblasts can lead to efficient affinity maturation, Memory cells are generated in large numbers even when most of the selected centrocytes recycle back into centroblasts, Our model suggests that a germinal center reaction in which the output of cells is low up to the point of GC dissociation, followed by the release of centrocytes into the periphery, is advantages for generating high affinity memory. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT COMP SCI,ALBUQUERQUE,NM 87131. SANTA FE INST,SANTA FE,NM 87501. FU NIAID NIH HHS [AI28433] NR 47 TC 87 Z9 89 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD JUN 1 PY 1997 VL 158 IS 11 BP 5155 EP 5162 PG 8 WC Immunology SC Immunology GA XA063 UT WOS:A1997XA06300015 PM 9164931 ER PT J AU SantoDomingo, JW Radway, JC Wilde, EW Hermann, P Hazen, TC AF SantoDomingo, JW Radway, JC Wilde, EW Hermann, P Hazen, TC TI Immobilization of Burkholderia cepacia in polyurethane-based foams: Embedding efficiency and effect on bacterial activity SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE polyurethane; immobilization; Burkholderia cepacia ID PSEUDOMONAS SP; CELLS; DEGRADATION AB Immobilization of the trichloroethylene-degrading bacterium Burkholderia cepacia was evaluated using hydrophilic polyurethane foam. The influence of several foam formulation parameters upon cell retention was examined. Surfactant type was a major determinant of retention; a lecithin-based compound retained more cells than pluronic- or silicone-based surfactants. Excessive amounts of surfactant led to increased washout of bacteria. Increasing the biomass concentration in the foam from 4.8 to 10.5% dry weight per wet weight of foam resulted in fewer cells being washed out. Embedding at reduced temperature did not significantly affect retention, while the use of a silane binding agent gave inconsistent results. The optimal formulation retained all but 0.2% of total embedded cells during passage of 2 L of water through columns containing 2 g of foam, All foam formulations tested reduced the culturability of embedded cells by several orders of magnitude, but O-2 consumption and CO2 evolution rates of embedded cells were never less than 50% of those of free cells. Nutrient amendments stimulated an increase in cell volume and ribosomal activity in immobilized cells as indicated by hybridization studies using fluorescently labeled ribosomal probes. These results indicate that, although immobilized cells were mostly nonculturable, they were metabolically active and thus could be used for biodegradation of toxic compounds. C1 MATRIX R&D CORP,DOVER,NH 03820. RP SantoDomingo, JW (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,BLDG 704-8T,AIKEN,SC 29808, USA. RI Hazen, Terry/C-1076-2012 OI Hazen, Terry/0000-0002-2536-9993 NR 24 TC 5 Z9 5 U1 0 U2 1 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD JUN PY 1997 VL 18 IS 6 BP 389 EP 395 PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA XK176 UT WOS:A1997XK17600007 ER PT J AU Redmond, J Barney, P AF Redmond, J Barney, P TI Vibration control of stiff beams and plates using structurally integrated PZT stack actuators SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article ID COMPOSITE PLATES; EMBEDDED ACTUATORS; SHAPE CONTROL; SIMULATION; FEEDBACK; CHATTER; SHELLS AB An actuation technique suitable for controlling bending vibrations in thick beams and plates is described. This work is motivated by vibration problems encountered in manufacturing that require greater control authority than can be obtained using surface mounted PZT patches or PVDF films. Instead, PZT stack actuators mounted in material cutouts are used to induce bending moments in the host structure. Experimental results are provided for the case of a cantilevered bar and a lithography platen used in the manufacture of integrated circuits. Good coupling between the extensional motion of the actuators and the bending deformation of the host structures is illustrated, and significant increases in first mode damping are achieved in both examples using a positive position feedback compensator. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Redmond, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 3 Z9 5 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD JUN PY 1997 VL 8 IS 6 BP 525 EP 535 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA YM534 UT WOS:000071074400005 ER PT J AU Lee, S Morimoto, H Williams, PG AF Lee, S Morimoto, H Williams, PG TI Synthesis of high specific radioactivity 3,5-[H-3(6)]dimethoxy-4-hydroxyacetophenone, an inducing compound of the vir gene in Agrobacterium tumefaciens SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE Agrobacterium tumefaciens; acetosyringone; tritiomethyl iodide ID SIGNAL MOLECULES; VIRULENCE GENES; T-DNA; PROTEIN; ACTIVATION AB Acetosyringone (3,5-dimethoxy-4-hydroxyacetophenone, 1) is one of the plant signals that induce the vir genes of Agrobacterium tumefaciens which causes crown gall tumors on dicotyledonous plants. Vir gene induction is enhanced by other environmental factors like specific monosaccarides and acidic pH. However, it is still unclear how the inducer interacts with Agrobacterium. To identify the receptor(s) in Agrobacterium tumefaciens to which the plant signal binds, highly radioactive acetosyringone (3,5-[H-3(6)]dimethoxy-4-hydroxyacetophenone, 6) was synthesized using (CH3I)-H-3 which was generated by two different methods. In Method 1, (CH3I)-H-3 was generated from 4-[methyl-H-3]methoxy biphenyl to give methyl species with tritium NMR peak intensity ratios ((CH3)-H-3:(CH2H)-H-3:(CHH2)-H-3 = 44:42:14), and a calculated specific radioactivity of 56.1 Ci/mmole. Method 2 gave higher specific radioactivity reagent (72.6 Ci/mmole), with measured NMR peak intensity ratios of ((CH3)-H-3:(CH2H)-H-3:(CHH2)-H-3=87:7:6). C1 EO LAWRENCE BERKELEY NATL LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. EO LAWRENCE BERKELEY NATL LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DEPT PHARMACEUT CHEM,SAN FRANCISCO,CA 94143. RP Lee, S (reprint author), UNIV WASHINGTON,DEPT CHEM,BOX 351700,SEATTLE,WA 98195, USA. NR 21 TC 7 Z9 9 U1 1 U2 1 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 JUN PY 1997 VL 39 IS 6 BP 461 EP 470 DI 10.1002/(SICI)1099-1344(199706)39:6<461::AID-JLCR992>3.0.CO;2-K PG 10 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA XC266 UT WOS:A1997XC26600002 ER PT J AU Abulafia, Y Shaulov, A Wolfus, Y Prozorov, R Burlachkov, L Majer, D Zeldov, E Vinokur, VM Yeshurun, Y AF Abulafia, Y Shaulov, A Wolfus, Y Prozorov, R Burlachkov, L Majer, D Zeldov, E Vinokur, VM Yeshurun, Y TI Hall-array measurements of flux creep parameters in Y-Ba-Cu-O crystals SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors CY AUG 02-06, 1996 CL KARLSRUHE, GERMANY ID HIGH-TEMPERATURE SUPERCONDUCTORS; YBA2CU3O7-X; DEPENDENCE; GROWTH; FILMS AB We describe the details of a new method for studying thermally activated flux creep in superconductors. This method employs an array of microscopic Hall sensors to probe the time evolution of the field profile in the sample. We analyze these data on the basis of a continuity equation which takes into account contributions to the relaxation process from both the in-plane and out-of-plane components of the induction field. This analysis enables direct determination of flux creep parameters such as the flux-line current density, flux-line velocity and the activation energy for flux creep. We demonstrate this method by presenting experimental data far YBa2Cu3O7-x crystals in the remanent state and in the presence of a field. C1 WEIZMANN INST SCI,DEPT CONDENSED MATTER PHYS,IL-76100 REHOVOT,ISRAEL. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Abulafia, Y (reprint author), BAR ILAN UNIV,DEPT PHYS,INST SUPERCONDUCT,IL-52900 RAMAT GAN,ISRAEL. RI Prozorov, Ruslan/A-2487-2008; Zeldov, Eli/K-1546-2012 OI Prozorov, Ruslan/0000-0002-8088-6096; Zeldov, Eli/0000-0002-8200-4974 NR 17 TC 5 Z9 5 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD JUN PY 1997 VL 107 IS 5-6 BP 455 EP 465 DI 10.1007/BF02397227 PG 11 WC Physics, Applied; Physics, Condensed Matter SC Physics GA XD606 UT WOS:A1997XD60600002 ER PT J AU Balberg, I Lubianiker, Y Shinar, J Partee, J Shapira, Y Burstein, L Weisz, SZ Gomez, M AF Balberg, I Lubianiker, Y Shinar, J Partee, J Shapira, Y Burstein, L Weisz, SZ Gomez, M TI The relation between phototransport and photoluminescence in porous silicon SO JOURNAL OF LUMINESCENCE LA English DT Article; Proceedings Paper CT 1996 International Conference on luminescence and Optical Spectroscopy of Condensed Matter (ICL 96) CY AUG 18-23, 1996 CL PRAGUE, CZECH REPUBLIC SP Charles Univ, Fac Math & Phys, Acad Sci Czech Republic, Inst Phys, Czech Minist Educ Youth & Sport, Int Union Pure & Appl Phys, European Commiss, WE Heraeus Fdn DE porous silicon; transport; phototransport; surface photovoltage AB We present a summary of a comprehensive study of transport, phototransport, surface photovoltage spectroscopy and luminescence of self-standing films of mesoporous and nanoporous silicon. We conclude that the visible luminescence arises from optical bandtail transitions in the silicon crystallites, while the transport is via a disordered silicon shell that wraps the crystallites. C1 IOWA STATE UNIV,AMES LAB,DEPT PHYS & ASTRON,AMES,IA 50011. TEL AVIV UNIV,DEPT ELECT ENGN,IL-89678 RAMAT AVIV,ISRAEL. UNIV PUERTO RICO,DEPT PHYS,RIO PIEDRAS,PR 00931. RP Balberg, I (reprint author), HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD JUN PY 1997 VL 72-4 BP 314 EP 315 DI 10.1016/S0022-2313(96)00150-0 PG 2 WC Optics SC Optics GA XK428 UT WOS:A1997XK42800116 ER PT J AU Knox, RS Laible, PD Sawicki, DA Talbot, MFJ AF Knox, RS Laible, PD Sawicki, DA Talbot, MFJ TI Does excited chlorophyll a equilibrate in solution? SO JOURNAL OF LUMINESCENCE LA English DT Article; Proceedings Paper CT 1996 International Conference on luminescence and Optical Spectroscopy of Condensed Matter (ICL 96) CY AUG 18-23, 1996 CL PRAGUE, CZECH REPUBLIC SP Charles Univ, Fac Math & Phys, Acad Sci Czech Republic, Inst Phys, Czech Minist Educ Youth & Sport, Int Union Pure & Appl Phys, European Commiss, WE Heraeus Fdn DE chlorophyll; equilibration; fluorescence; Kennard-Stepanov relation AB A modified Kennard-Stepanov analysis of fluorescing systems is applied to chlorophyll a in various solvents. It suggests departures from thermal equilibrium in the emitting states. C1 CORNELL UNIV,PLANT BIOL SECT,ITHACA,NY 14853. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP Knox, RS (reprint author), UNIV ROCHESTER,DEPT PHYS & ASTRON,ROCHESTER,NY 14627, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD JUN PY 1997 VL 72-4 BP 580 EP 581 DI 10.1016/S0022-2313(97)00055-0 PG 2 WC Optics SC Optics GA XK428 UT WOS:A1997XK42800220 ER PT J AU Savoini, B Santiuste, JEM Gonzalez, R Chen, Y AF Savoini, B Santiuste, JEM Gonzalez, R Chen, Y TI Thermochemical reduction of Pr3+-doped yttria-stabilized zirconia SO JOURNAL OF LUMINESCENCE LA English DT Article; Proceedings Paper CT 1996 International Conference on luminescence and Optical Spectroscopy of Condensed Matter (ICL 96) CY AUG 18-23, 1996 CL PRAGUE, CZECH REPUBLIC SP Charles Univ, Fac Math & Phys, Acad Sci Czech Republic, Inst Phys, Czech Minist Educ Youth & Sport, Int Union Pure & Appl Phys, European Commiss, WE Heraeus Fdn DE Zr; Pr3+; defects; optical properties AB Thermochemical reduction (TCR) up to 1900 K of Pr3+-doped yttria-stabilized zirconia single crystals has been studied using optical techniques. Ln contrast to undoped samples, only one absorption band peaking at similar to 375 nm was observed in reduced samples. Excitation experiments show that the 4f5d interconfigurational band of Pr3+ overlaps the excitation band responsible for the intrinsic luminescence. After TCR the 4f5d band shifts to higher energies. Both the appearance of the 375 nm absorption band and the shift of the Pr3+ 4f5d excitation band are related to oxygen vacancy formation after TCR. C1 US DOE, OFF BASIC ENERGY SCI, DIV SCI MAT, GERMANTOWN, MD 20874 USA. RP UNIV CARLOS III MADRID, DEPT FIS, ESCUELA POLITECN SUPER, BUTARQUE 15, E-28911 LEGANES, MADRID, SPAIN. RI Munoz Santiuste, Juan/K-7461-2015; OI Munoz Santiuste, Juan/0000-0001-6286-139X; SAVOINI, BEGONA/0000-0002-7347-7569 NR 5 TC 6 Z9 6 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 EI 1872-7883 J9 J LUMIN JI J. Lumines. PD JUN PY 1997 VL 72-4 BP 714 EP 715 DI 10.1016/S0022-2313(96)00383-3 PG 2 WC Optics SC Optics GA XK428 UT WOS:A1997XK42800273 ER PT J AU Jones, MCG LaraCurzio, E Kopper, A Martin, DC AF Jones, MCG LaraCurzio, E Kopper, A Martin, DC TI The lateral deformation of cross-linkable PPXTA fibres SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID HIGH-PERFORMANCE FIBERS; POLY(P-PHENYLENE TEREPHTHALAMIDE) FIBERS; TRANSVERSE MECHANICAL-PROPERTIES; XTA COPOLYMER FIBERS; COMPRESSIVE STRENGTH; POLYMER FIBERS; ARAMID FIBERS; BEHAVIOR; FIBRILLAR; TENSILE AB The lateral deformation properties of oriented polymer fibres were examined by transverse compressive and torsional experiments. A modified interfacial test system machine was used to study the transverse compressive deformation behaviour of thermally cross-linkable poly(p-1,2-dihydrocyclobutaphenylene terephthalamide) (PPXTA) fibres and of a number of commercially available polymers (Nomex, nylon, Kevlar, Dacron) and ceramic (Nicalon and FP) fibres. The torsional (shear) modulus G of PPXTA and Kevlar poly(p-phenylene terephthalamide) (PPTA) fibres was measured by pendulum experiments. During both fibre torsion and transverse compression, the deformation involves materials slip on (hk0) planes, in the [001] direction for the torsion and the [hk0] directions for transverse compression. The intermolecular crosslinks in PPXTA did not significantly modify the elastic transverse modulus E-t and caused only slight (13%) increase in shear modulus G. However, the plastic transverse properties of cross-linked PPXTA were significantly different than those of uncross-linked PPXTA. The stress at the proportional limit <(sigma)over bar>(p), determined from the transverse load-displacement curves, was substantially higher for the cross-linked fibres than for the uncross-linked fibres. In addition, the cross-linked PPXTA fibres exhibited a large strain recoverable response reminiscent of elastomers, whereas the PPTA and uncross-linked PPXTA fibres exhibited a large strain irreversible response. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. UNIV MICHIGAN,CTR MACROMOL SCI & ENGN,ANN ARBOR,MI 48109. RI Martin, David/B-1838-2008 OI Martin, David/0000-0003-1195-3838 NR 47 TC 11 Z9 11 U1 0 U2 10 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 JUN 1 PY 1997 VL 32 IS 11 BP 2855 EP 2871 DI 10.1023/A:1018672400459 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA XD827 UT WOS:A1997XD82700008 ER PT J AU Malaga, CA Weller, RE Buschbom, RL Baer, JF Kimsey, BB AF Malaga, CA Weller, RE Buschbom, RL Baer, JF Kimsey, BB TI Reproduction of the owl monkey (Aotus spp.) in captivity SO JOURNAL OF MEDICAL PRIMATOLOGY LA English DT Article DE conception; interbirth interval; gestation length; birth seasonality; night monkey ID KARYOTYPE; NANCYMAI AB The reproduction performance of captive owl monkeys, a breed used extensively in biomedical research, was observed at the Battelle Primate Facility (BPF). The colony grew through captive breeding, imports from the Peruvian Primatological Project, and others to a peak size of 730. It included seven karyotypes of Aotus sp. Results showed that owl monkeys can breed successfully in a laboratory in numbers sufficient to sustain modest research programs. Reproductive success increases when pairs are compatible, of the same karyotype, and stabilized; however, mated pairs of different karyotype are also productive. Under conditions of controlled lighting and heating, owl monkeys at BPF showed no birth peak nor birth season. C1 PACIFIC NW LAB, LIFE SCI CTR, RICHLAND, WA USA. CALTECH, DIV BIOL, PASADENA, CA 91125 USA. RP Malaga, CA (reprint author), UNIV PUERTO RICO, ANIM RESOURCES CTR, MED SCI CAMPUS, POB 365067, SAN JUAN, PR 00936 USA. NR 19 TC 7 Z9 9 U1 0 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0047-2565 J9 J MED PRIMATOL JI J. Med. Primatol. PD JUN PY 1997 VL 26 IS 3 BP 147 EP 152 PG 6 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA XW110 UT WOS:A1997XW11000005 PM 9379481 ER PT J AU Gieray, RA Reilly, PTA Yang, M Whitten, WB Ramsey, JM AF Gieray, RA Reilly, PTA Yang, M Whitten, WB Ramsey, JM TI Real-time detection of individual airborne bacteria SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE airborne bacteria; laser ablation mass spectrometry; bioaerosols ID TANDEM MASS-SPECTROMETRY; FAST ATOM BOMBARDMENT; AEROSOL-PARTICLES; IONIZATION; MICROORGANISMS; BIOAEROSOLS; ANALYZER AB Airborne bacteria and bacterial spores were directly sampled by an ion trap mass spectrometer with an atmospheric pressure inlet system. Samples were aerosolized from suspensions of single species. The organisms were individually characterized in real time by laser ablation mass spectrometry. Either positive or negative ions could be studied. Ions of a particular value of mit (mass to charge ratio) could be further characterized by tandem mass spectrometry in the ion trap. (C) 1997 Elsevier Science BN. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 30 TC 43 Z9 45 U1 5 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD JUN PY 1997 VL 29 IS 3 BP 191 EP 199 DI 10.1016/S0167-7012(97)00049-3 PG 9 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA XV705 UT WOS:A1997XV70500006 ER PT J AU Chang, BC Fei, RA Sears, TJ AF Chang, BC Fei, RA Sears, TJ TI Mid-infrared diode laser spectroscopy of (X)over-tilde(1)A' (HCCl)-Cl-35 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID HCCL; TRANSITION; SPECTRUM; BANDS; GAPS; NU-2 AB The observation of the C-Cl stretching fundamental of (HCCl)-Cl-35 in its ground (X) over tilde(1)A' state is reported. HCCl was formed in a continuous flow system by the excimer laser photolysis of CHBr2Cl at 193 nm and the transient absorption recorded by infrared diode laser spectroscopy. The band has a-type character and the fundamental vibrational frequency is found to be 811.5963 cm(-1). No evidence was found for perturbations in either the ground or vibrationally excited states, implying that the excited triplet (a) over tilde(3)A '' states lies above the C-Cl stretching level in HCCl. The observed rotation-vibration transitions were well fit by a standard asymmetric rotor Hamiltonian. There is a decrease in the A rotational constant on vibrational excitation, suggesting that some bend-C-Cl stretch coupling is present. (C) 1997 Academic Press. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Chang, BC (reprint author), NATL CENT UNIV,DEPT CHEM,CHUNGLI 32054,TAIWAN. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 27 TC 26 Z9 26 U1 2 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1997 VL 183 IS 2 BP 341 EP 346 DI 10.1006/jmsp.1997.7291 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XE286 UT WOS:A1997XE28600016 ER PT J AU Fajardo, JC Sigel, GH Edwards, BC Epstein, RI Gosnell, TR Mungan, CE AF Fajardo, JC Sigel, GH Edwards, BC Epstein, RI Gosnell, TR Mungan, CE TI Electrochemical purification of heavy metal fluoride glasses for laser-induced fluorescent cooling applications SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 10th International Symposium on Non-Oxide Glasses CY JUN 19-22, 1996 CL CORNING, NY SP Alfred Univ, Corning Inc ID MELTS AB An electrochemical purification stage has been incorporated into the conventional fabrication process of heavy metal fluoride glasses. This change was undertaken to reduce the absorption losses associated with residual transition metal impurities, particularly the Fe2+ band at 1.0 mu m Purified samples doped with ytterbium exhibited net cooling due to anti-stokes fluorescence and a relative cooling efficiency of about 2% was observed via photothermal deflection spectroscopy. Pumping to the lower Stark levels of the F-2(5/2) manifold, followed by population redistribution across this manifold and fluorescence to the ground state, results in net cooling. This cooling can be achieved only if energy transfer and the extrinsic absorptive component of the host glass are suppressed. C1 RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Fajardo, JC (reprint author), CORNING INC,SCI & TECHNOL,SP-DV-02-5,CORNING,NY 14831, USA. NR 13 TC 24 Z9 24 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 JUN PY 1997 VL 213 BP 95 EP 100 DI 10.1016/S0022-3093(96)00662-X PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA XG221 UT WOS:A1997XG22100020 ER PT J AU Barnard, DJ Dace, GE Buck, O AF Barnard, DJ Dace, GE Buck, O TI Acoustic harmonic generation due to thermal embrittlement of Inconel 718 SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE thermal embrittlement; fracture toughness; fractography; strain-to-failure; small punch test; acoustic nonlinearity; second harmonic amplitude AB This paper describes an attempt to characterize the deterioration of a structural material's mechanical properties by nonlinear acoustics. In this particular case, the damage was caused by ''thermal embrittlement'' during which the material, here the nickel-based alloy Inconel 718, loses a significant fraction of its fracture toughness. Harmonic generation was the experimental method used to characterize the microstructural changes in the material as a function of exposure time at elevated temperatures. Tests were performed on two heats of Inconel 718 with slightly different chemistries, with one heat showing particular sensitivity of the fracture toughness to the elevated temperature exposure with corresponding higher changes in the nonlinearity parameter. As a mechanical measure of the fracture toughness deterioration, a small specimen punch test was used in which the ductility of a thin slice of material is determined. A clear difference between the two heats was noted in the metallographic examination, which is reflected in the harmonic generation as well as the punch test data. An explanation for the changes of the harmonic generation during the embrittlement process is speculative at the present time. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Barnard, DJ (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 17 TC 35 Z9 37 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD JUN PY 1997 VL 16 IS 2 BP 67 EP 75 DI 10.1007/BF02683879 PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA XP554 UT WOS:A1997XP55400002 ER PT J AU Barnard, DJ Dace, GE Rehbein, DK Buck, O AF Barnard, DJ Dace, GE Rehbein, DK Buck, O TI Acoustic harmonic generation at diffusion bonds SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE diffusion bonds; bond strength; reflected acoustic energy; acoustic nonlinearity; second harmonic amplitude AB The distortion of a sinusoidal acoustic wave at unbonded interfaces has been determined in terms of the first and second harmonic amplitudes. The results demonstrate for the first time that the second harmonic can reach the theoretically predicted maximum value. As also predicted, the harmonic generation efficiency at unbonded interfaces first increases and then decreases with an externally applied compressive load. The technique has been applied to diffusion bonded specimens in an attempt to quantify their achieved strength. As already demonstrated earlier, the energy reflected from such diffusion bonds is also useful to characterize their strength. Indications are that a combination of reflected energy and harmonic generation data could be a powerful tool to quantify the strength of diffusion bonds, particularly those of nearly perfect strength. A strength determination of diffusion bonds by nondestructive evaluation is a necessity for the qualification of such bonds in critical applications. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Barnard, DJ (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 26 TC 21 Z9 25 U1 1 U2 7 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD JUN PY 1997 VL 16 IS 2 BP 77 EP 89 DI 10.1007/BF02683880 PG 13 WC Materials Science, Characterization & Testing SC Materials Science GA XP554 UT WOS:A1997XP55400003 ER PT J AU Jones, RH Steiner, D Heinisch, HL Newsome, GA Kerch, HM AF Jones, RH Steiner, D Heinisch, HL Newsome, GA Kerch, HM TI Radiation resistant ceramic matrix composites SO JOURNAL OF NUCLEAR MATERIALS LA English DT Review ID SILICON-CARBIDE; POLYATOMIC MATERIALS; MOLECULAR-DYNAMICS; NICALON FIBERS; SELF-DIFFUSION; CRACK-GROWTH; SIC FIBERS; IRRADIATION; DAMAGE; POTENTIALS AB Ceramic matrix composites are of interest for nuclear applications because of their high-temperature properties, corrosion resistance, fracture toughness relative to monolithic ceramics, and low neutron activation and after heat. Evaluations of the radiation resistance of commercially available SiC/SiC composites have revealed their promise for this application, but also the need for further development to achieve the desired performance. This paper summarizes the results of a workshop cosponsored by the Offices of Fusion Energy and Basic Energy Sciences of the US Department of Energy and Lockheed-Martin Corporation with forty attendees from national laboratories, universities and industry. A number of promising routes for optimizing the radiation stability of ceramic matrix composites were identified at this workshop. These routes included the newer, more stoichiometric fibers and alternate fiber/matrix interfaces and matrix processing routes. C1 RENSSELAER POLYTECH INST, DEPT ENVIRONM & ENERGY ENGN, TROY, NY 12180 USA. KNOLLS ATOM POWER LAB, SCHENECTADY, NY 12301 USA. US DOE, OFF BASIC ENERGY SCI, DIV MAT SCI, GERMANTOWN, MD 20874 USA. RP PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 62 TC 59 Z9 59 U1 2 U2 37 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 JUN PY 1997 VL 245 IS 2-3 BP 87 EP 107 DI 10.1016/S0022-3115(97)00022-6 PG 21 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XD272 UT WOS:A1997XD27200001 ER PT J AU Garner, FA Black, CA Edwards, DJ AF Garner, FA Black, CA Edwards, DJ TI Factors which control the swelling of Fe-Cr-Ni ternary austenitic alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID MICROSTRUCTURAL EVOLUTION; MECHANICAL-PROPERTIES; IRRADIATION; HELIUM AB In agreement with limited earlier studies, a comprehensive irradiation experiment conducted in both EBR-II and FFTF demonstrates that while cold-working usually decreases void swelling of ternary Fe-Cr-Ni alloys at relatively low irradiation temperatures, it in general increases swelling at higher irradiation temperatures, Aging of cold-worked specimens to produce cellular dislocation networks tends to further increase swelling, especially at higher nickel levels. The swelling of ternary alloys at lower nickel levels also appears to be sensitive to details of the preirradiation annealing treatment. The differences in the details of reactor operating conditions also exert an influence on void nucleation and thereby on the duration of the transient regime of swelling. In the current irradiation series this leads to the swelling developed in EBR-II at similar to 30 dpa being consistently larger than that in FFTF. All of these results confirm an earlier conclusion that the primary variability of void swelling of FeCrNi alloys lies in the incubation and transient regimes, rather than in the steady-state swelling rate regime. Under certain conditions, the transient regime can be made to approach 0 dpa. C1 WYMAN GORDEN INVESTMENT CASTINGS, CARSON CITY, NV 89706 USA. RP Garner, FA (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 20 TC 15 Z9 16 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 1997 VL 245 IS 2-3 BP 124 EP 130 DI 10.1016/S0022-3115(97)00016-0 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XD272 UT WOS:A1997XD27200004 ER PT J AU Kim, KH Lee, DB Kim, CK Hofman, GE Paik, KW AF Kim, KH Lee, DB Kim, CK Hofman, GE Paik, KW TI Characterization of U-2 wt% Mo and U-10 wt% Mo alloy powders prepared by centrifugal atomization SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID MECHANISMS AB The characteristics of high density U-Mo alloy powder solidified rapidly by the centrifugal atomization process have been examined. The results indicate that most of the atomized U-Mo alloy particles have a smooth surface and near-perfect spherical shape. The atomized powder, irrespective of particle size, is found to be single phase gamma-U alloy with isotropic structure and non-dendritic grain. The continuous cooling DSC trace of U-2 wt% Mo alloy shows a small, broad endothermic peak originated from the formation of alpha-U phase and U2Mo phase, whereas that of U-10 wt% Mo alloy shows no peak over all temperature ranges associated with the decomposition of gamma-U phase. The gamma-U phase of U-2 wt% Mo powder is decomposed as the alpha-U phase and the U2Mo phase after an annealing treatment at 400 degrees C for 100 h. But the gamma-U phase of atomized U-10 wt% Mo powder remains as it was. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. KOREA ADV INST SCI & TECHNOL,YUSONG GU,TAEJON 305701,SOUTH KOREA. RP Kim, KH (reprint author), KOREA ATOM ENERGY RES INST,YUSONG GU,150 DUKJIN DONG,TAEJON 305353,SOUTH KOREA. NR 18 TC 48 Z9 48 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 1997 VL 245 IS 2-3 BP 179 EP 184 DI 10.1016/S0022-3115(97)00011-1 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XD272 UT WOS:A1997XD27200011 ER PT J AU Uz, M Natesan, K Hang, VB AF Uz, M Natesan, K Hang, VB TI Oxidation kinetics and microstructure of V-(4-5) wt% Cr-(4-5) wt% Ti alloys exposed to air at 300-650 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID VANADIUM ALLOYS; FUSION-REACTORS; ACTIVATION AB We conducted a systematic study to determine the effects of time and temperature of air exposure on the oxidation behavior and microstructure of V-4Cr-4Ti and V-5Cr-5Ti alloys. All samples were from 1 mm thick cold-rolled sheets, and each was annealed in vacuum at 1050 degrees C for 1 h prior to high-temperature exposure. Different samples from each alloy were heated in ambient air at 500 degrees C for times ranging from 24 to approximate to 2000 h, and in a thermogravimetric analysis (TGA) apparatus at temperatures ranging from 300 to 650 degrees C. Models describing the oxidation kinetics, oxide type and its thickness, alloy grain size, and depth of oxygen diffusion in the substrate alloy were determined for the two alloys and compared. The results showed that the oxide layers that formed on the surfaces of both alloys in air at 300-650 degrees C are protective, and that the V-5Cr-5Ti alloy is slightly more oxidation-resistant than the V-4Cr-4Ti alloy. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. LAFAYETTE COLL,DEPT CHEM ENGN,EASTON,PA 18042. MERCK PHARMACEUT,TECH OPERAT DIV,RAHWAY,NJ. NR 37 TC 25 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 1997 VL 245 IS 2-3 BP 191 EP 200 DI 10.1016/S0022-3115(97)00008-1 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XD272 UT WOS:A1997XD27200013 ER PT J AU Edgemon, GL Danielson, MJ Bell, GEC AF Edgemon, GL Danielson, MJ Bell, GEC TI Detection of stress corrosion cracking and general corrosion of mild steel in simulated defense nuclear waste solutions using electrochemical noise analysis SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Underground waste tanks fabricated from mild steel store more than 253 million liters of high level radioactive waste from 50 years of weapons production at the Hanford Site. The probable modes of corrosion failures are reported as nitrate stress corrosion cracking and pitting. In an effort to develop a waste tank corrosion monitoring system, laboratory tests were conducted to characterize electrochemical noise data for both uniform and localized corrosion of mild steel and other materials in simulated waste environments. The simulated waste solutions were primarily composed of ammonium nitrate or sodium nitrate and were held at approximately 97 degrees C. The electrochemical noise of freely corroding specimens was monitored, recorded and analysed for periods ranging between 10 and 500 h. At the end of each test period, the specimens were examined to correlate electrochemical noise data with corrosion damage. Data characteristic of uniform corrosion and stress corrosion cracking are presented. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. MJ SCHIFF & ASSOCIATES INC, CLAREMONT, CA 91711 USA. RP Edgemon, GL (reprint author), LOCKHEED MARTIN HANFORD CORP, POB 1970, MSIN, RI-30, RICHLAND, WA 99352 USA. NR 35 TC 16 Z9 17 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 1997 VL 245 IS 2-3 BP 201 EP 209 DI 10.1016/S0022-3115(97)00005-6 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XD272 UT WOS:A1997XD27200014 ER PT J AU Susskind, H Weber, DA Lau, YH Park, TL Atkins, HL Franceschi, D Meek, AG Ivanovic, M Wielopolski, L AF Susskind, H Weber, DA Lau, YH Park, TL Atkins, HL Franceschi, D Meek, AG Ivanovic, M Wielopolski, L TI Impaired permeability in radiation-induced lung injury detected by technetium-99m-DTPA lung clearance SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE radiation-induced lung injury; radiation pneumonitis; radiotherapy; technetium-99m-DTPA; lung clearance ID BRONCHOALVEOLAR LAVAGE; THORACIC IRRADIATION; PNEUMONITIS; AEROSOL; GA-67-CITRATE; RADIOTHERAPY; PERFUSION; CANCER; ACID AB This study evaluates the use of the Tc-99m-DTPA aerosol lung clearance method to investigate radiation-induced lung changes in eight patients undergoing radiotherapy for lung or breast carcinoma. The sensitivity of the method was compared with chest radiography for detecting radiation-induced changes in the lung, regional alterations within (irradiated region) and outside (shielded region) the treatment ports, effect of irradiated lung volume, and dependence on time after radiotherapy, Methods: Serial DTPA lung clearance studies were performed before the first radiation treatment (baseline), then weekly during a 5- to 7-wk course, and up to 12 times post-therapy over periods of 56-574 days, The total activity deposited in the lungs for each study was similar to 150 mu Ci (similar to 5.6 MBq), DTPA clearance, expressed in terms of the biological half-time, t(1/2), was computed from the slopes of the least-squares fit regression lines of the time-activity curves for the first 10 min for irradiated and shielded lung regions, Results: Major findings include: (a) significant and early DTPA t(1/2) changes were observed in all patients during and after radiotherapy; (b) changes in DTPA t(1/2) values were observed in both irradiated and shielded lung regions in all patients suggesting a radiation-induced systemic reaction; (c) changes in DTPA t(1/2) values were correlated (p < 0.05) with the irradiated lung volumes; (d) significantly reduced DTPA t(1/2) values were observed in three patients who subsequently presented with clinical symptoms and/or radiographic changes consistent with radiation pneumonitis (t(1/2) fell to 19% +/- 6% of baseline values, compared with 64% +/- 17% in the remaining patients [p < 0.01]); (e) the onset of decreased DTPA t(1/2) values in these three patients occurred 35-84 days before clinical symptoms and/or radiographic changes; and (f) DTPA t(1/2) tended to approach baseline values with time after radiotherapy, suggesting a long-term recovery in lung injury, Conclusion: These observations show significant and early alterations in DTPA lung clearance during and after radiotherapy that may provide a sensitive assay to monitor changes in radiation-induced lung injury and may facilitate early therapeutic intervention. C1 SUNY STONY BROOK,DEPT RADIAT ONCOL,UNIV HOSP,STONY BROOK,NY 11794. RP Susskind, H (reprint author), BROOKHAVEN NATL LAB,CLIN RES CTR,BOX 5000,UPTON,NY 11973, USA. NR 28 TC 16 Z9 16 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD JUN PY 1997 VL 38 IS 6 BP 966 EP 971 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA XD639 UT WOS:A1997XD63900034 PM 9189152 ER PT J AU Honda, T Bartels, HW Uckan, NA Okazaki, T Seki, Y AF Honda, T Bartels, HW Uckan, NA Okazaki, T Seki, Y TI Analyses of passive plasma shutdown during ex-vessel loss of coolant accident in the first wall/shield blanket of fusion reactor SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE ITER; safety analysis; passive plasma shutdown; loss of coolant; plasma dynamics; thermal analysis; impurities; disruption; density limit; heat transfer AB An ex-vessel loss of coolant accident (LOCA) in the first wall/shield blanket of a fusion reactor has been analyzed by a hybrid code consisting of plasma dynamics and heat transfer analysis of in-vessel components. We investigated possibility of passive plasma shutdown scenario during the accident in International Thermonuclear Experimental Reactor (ITER). The safety analysis code which we developed can treat impurity concentration from the first wall and the divertor with a transport probability into the main plasma and a time delay given as input. It was found that the plasma is passively shutdown by a density limit disruption due to beryllium release from heated first wall surfaces about 168 seconds after the LOCA, when the transport probability of beryllium from the first wall into the plasma and the time delay were assumed to be 10(-2) and the energy confinement time, respectively. At that time, the surface temperature of the outboard center (plasma facing component (PFC) with beryllium) and the temperature of the coolant tube in the first wall (stainless steel 316) reach about 1,120 degrees C and about 1,080 degrees C, respectively. Although the coolant tube does not melt, the copper heat sink between the PFC and the coolant tube melts before the passive shutdown. The heat sink of copper in the outboard baffle also melts before the passive shutdown, though the PEC surface of tungsten does not melt. Consequently, we have a possibility of passive plasma shutdown before the cooling tubes melt during the ex-LOCA of the first wall/shield blanket in ITER, however, further studies are needed all the effects an plasma burn control, impurity release and emission of implanted D-T fuel. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA, IBARAKI 31101, JAPAN. ITER, JOINT CENT TEAM, SAN DIEGO, CA USA. RP HITACHI LTD, HITACHI RES LAB, OMIKA CHO, HITACHI, IBARAKI 31912, JAPAN. NR 9 TC 5 Z9 5 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD JUN PY 1997 VL 34 IS 6 BP 538 EP 543 DI 10.1080/18811248.1997.9733706 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XN570 UT WOS:A1997XN57000002 ER PT J AU Grant, KE Mong, GM Clauss, SA Wahl, KL Campbell, JA AF Grant, KE Mong, GM Clauss, SA Wahl, KL Campbell, JA TI Determination of monobutyl phosphate and dibutyl phosphate in mixed hazardous wastes by ion-pair chromatography SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article ID TRIBUTYL-PHOSPHATE; DEGRADATION; SYSTEM AB Ion-pair chromatography was tested for its applicability in determining monobutyl phosphate (MBP) and dibutyl phosphate (DBP), which are degradation products of tributyl phosphate, in Hanford tank wastes. In tests with simulant waste mixtures. tetrahexylammonium bromide, an ion-pairing agent, was used to complex with all three phosphate species. Recovery studies indicated that ion-pairing chromatography is quantitative for determining the analytes in spiked samples. Initial results demonstrated that DBP could be detected easily and was fairly well separated from other peaks, but MBP was frequently lost due to large negative peaks. When a preconcentration column proce dure was used to clean up the waste-sample matrix, and the negative peaks disappeared. Results indicated that 80% of MBP and 90% of DBP could be recovered. Most of the radioactivity was removed from actual waste tank samples so that additional sample preparation could be performed safely in a fume hood rather than a hot cell. Dibutyl phosphate was identified in an actual tank waste, but MBP was not found; this result was confirmed by ion chromatography with conductivity detection. C1 PACIFIC NW LAB, ADV ORGAN ANALYT MAT GRP, RICHLAND, WA 99352 USA. NR 11 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 1997 VL 220 IS 1 BP 31 EP 35 DI 10.1007/BF02035343 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV489 UT WOS:A1997XV48900006 ER PT J AU Lueck, HB Hudson, BS Friedrich, DM Zgierski, MZ AF Lueck, HB Hudson, BS Friedrich, DM Zgierski, MZ TI Resonance Raman studies of benzene derivatives with methoxy substitution: Conformational symmetry-breaking effects SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article ID GEOMETRY ASSIGNMENT; STATES AB Resonance Raman intensities show that methoxy substitution induces considerable allowed character to the L-a transition of benzene. In symmetric 1,3,5-trisubstituted benzene derivatives the induced allowed character should cancel by symmetry. However, in 1,3,5-trimethoxybenzene the resonance Raman spectrum shows a strong fundamental transition of v(8), the clear signature of an allowed transition. It is shown that this is due to the presence of a C-s conformer of 1,3,5-trimethoxybenzene in which one of the three methoxy groups is rotated relative to the other two. This is supported by ab initio calculations of conformational energy, induced transition moment and the splitting of the v1 band. (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV OREGON, DEPT CHEM, EUGENE, OR 97403 USA. UNIV OREGON, INST PHYS CHEM, EUGENE, OR 97403 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NATL RES COUNCIL CANADA, STEACIE INST MOL SCI, OTTAWA, ON K1A 0R6, CANADA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD JUN PY 1997 VL 28 IS 6 BP 455 EP 458 DI 10.1002/(SICI)1097-4555(199706)28:6<455::AID-JRS123>3.3.CO;2-3 PG 4 WC Spectroscopy SC Spectroscopy GA XH953 UT WOS:A1997XH95300010 ER PT J AU Gosling, FG Fehner, TR AF Gosling, FG Fehner, TR TI The social causes of environmental destruction in Latin America - Painter,M, Durham,WH SO JOURNAL OF SOCIAL HISTORY LA English DT Book Review RP Gosling, FG (reprint author), US DOE,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU CARNEGIE MELLON UNIV PRESS PI PITTSBURGH PA CARNEGIE MELLON UNIV J SOCIAL HIST, PITTSBURGH, PA 15213 SN 0022-4529 J9 J SOC HIST JI J. Soc. Hist. PD SUM PY 1997 VL 30 IS 4 BP 984 EP 987 PG 4 WC History SC History GA XB850 UT WOS:A1997XB85000016 ER PT J AU Woodward, PM Sleight, AW Vogt, T AF Woodward, PM Sleight, AW Vogt, T TI Ferroelectric tungsten trioxide SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID WO3 AB The structure of a low-temperature form of tungsten trioxide, epsilon-WO3, has been determined for the first time. Earlier inconclusive evidence for ferroelectricity in this form is confirmed. There are at least six forms of WO3, but epsilon-WO3 is the only form now shown to be acentric. The structure analysis of epsilon-WO3 was based primarily on Rietveld analysis of high-resolution neutron diffraction data obtained at 15 K. Higher resolution synchrotron X-ray diffraction data were used to confirm the space group. This epsilon-form of WO3 is monoclinic with a space group of Pc, a = 5.278 Angstrom, b = 5.156 Angstrom, c = 7.664 Angstrom, beta = 91.762 degrees, and Z = 4. During the transformation from triclinic delta-WO3 to the monoclinic epsilon-WO3, no change in the octahedral tilt system occurs, but there are significant shifts in the W atom positions. These W atom shifts result in an enhancement of the long-short bond distance alternation in the [110] direction (the [100] direction of the delta-phase), which is related to changes in electrical and optical properties. (C) 1997 Academic Press. C1 OREGON STATE UNIV,DEPT CHEM,CORVALLIS,OR 97331. OREGON STATE UNIV,CTR ADV MAT RES,CORVALLIS,OR 97331. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 35 TC 107 Z9 112 U1 12 U2 53 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUN PY 1997 VL 131 IS 1 BP 9 EP 17 DI 10.1006/jssc.1997.7268 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XL406 UT WOS:A1997XL40600002 ER PT J AU Grey, IE Roth, RS Balmer, ML AF Grey, IE Roth, RS Balmer, ML TI The crystal structure of Cs2TiSi6O15 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID TITANOSILICATE; CESIUM AB Crystals of a new titanosilicate phase, Cs2TiSi6O15, were grown from a cesium vanadate flux. The compound has monoclinic symmetry, space group C2/c, with a 13.386(5), b = 7.423(3), c = 15.134(5) Angstrom = beta = 107.71(3)degrees, Z = 4. The crystal structure was solved using single crystal X-ray data (MoK alpha radition) and refined to R(F) = 0.039 for 1874 unique reflections. In the structure, isolated titanium-centred octahedra and silica-centred tetrahedra share all corners to form an open framework structure containing large cavities in which the cesium ions are located. Each cavity is bound by three 5-rings, two 6-rings, and two 8-rings. The cavities are linked via the 8-rings into channels parallel to [101]. The cesium ions occur in pairs along the channels, separated by 3.765(2) Angstrom. (C) 1997 Academic Press. C1 NIST, GAITHERSBURG, MD 20899 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Grey, IE (reprint author), CSIRO, DIV MINERALS, MELBOURNE, VIC, AUSTRALIA. NR 20 TC 13 Z9 13 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 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUN PY 1997 VL 131 IS 1 BP 38 EP 42 DI 10.1006/jssc.1997.7298 PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XL406 UT WOS:A1997XL40600005 ER PT J AU McNamara, GR Garcia, AL Alder, BJ AF McNamara, GR Garcia, AL Alder, BJ TI A hydrodynamically correct thermal lattice Boltzmann model SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE lattice Boltzmann equation; Rayleigh-Benard convection; numerical stability ID NAVIER-STOKES EQUATION; BOUNDARY-CONDITIONS; GAS AUTOMATA; SIMULATIONS; CONVECTION; DYNAMICS AB A three-dimensional lattice-Boltzmann model which yields correct hydrodynamics at the Navier-Stokes level of the Chapman-Enskog expansion requires a minimum of 26 velocities. We present results For a model with one additional velocity, determined by maximizing the equilibrium entropy. For compressible Rayleigh-Benard convection the model is more accurate but considerably less stable, than a previous, approximate 21-speed model. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. SAN JOSE STATE UNIV,DEPT PHYS,SAN JOSE,CA 95192. RP McNamara, GR (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 19 TC 40 Z9 42 U1 1 U2 13 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD JUN PY 1997 VL 87 IS 5-6 BP 1111 EP 1121 DI 10.1007/BF02181274 PG 11 WC Physics, Mathematical SC Physics GA XK860 UT WOS:A1997XK86000011 ER PT J AU Coutsias, A Wester, MJ Perelson, AS AF Coutsias, A Wester, MJ Perelson, AS TI Nucleation theory of cell surface capping SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE aggregation; phase transition; addition reactions; capping; sol-gel transformation; nucleation ID 2 DISTINCT MECHANISMS; REDISTRIBUTION; MACROMOLECULES AB We propose a new theory of cell surface capping based on the principles of nucleation. When antibody interacts with cell surface molecules, the molecules initially form small aggregates called patches that later coalesce into a large aggregate called a cap. While a cap can form by patches bring pulled together by action of the cell's cytoskeleton, in the case of some molecules, disruption of the cytoskeleton does not prevent cap formation. Diffusion of large aggregates on a cell surface is slow, and thus we propose that a cap can form solely through the diffusion of small aggregates containing just one or a few cell surface molecules. Here we consider the extreme case in which single molecules are mobile, but aggregates of all larger sizes are immobile. We show that a set of patches in equilibrium with a ''sea'' of free cell surface molecules can undergo a nucleation-type phase transition in which the largest patch will bind free cell surface molecules, deplete the concentration of such molecules in the ''sea,'' and thus cause the other patches to shrink in size. We therefore show that a cap can form without patches having to move, collide with each other, and aggregate. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Coutsias, A (reprint author), UNIV NEW MEXICO, DEPT MATH & STAT, ALBUQUERQUE, NM 87131 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD JUN PY 1997 VL 87 IS 5-6 BP 1179 EP 1203 PG 25 WC Physics, Mathematical SC Physics GA XK860 UT WOS:A1997XK86000016 ER PT J AU Yang, ZJ AF Yang, ZJ TI Note on polarization of electron beam SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE electron and positron beam; superconductor; Meissner effect ID TC SUPERCONDUCTING LENSES; SYSTEM; TUBE AB Based on the classical theory of electrodynamics, we show the feasibility of using superconductors to realize transversal and longitudinal polarizations of electron beams. The results can in principle be used with beams of positron and/or other particles with magnetic moments without major modifications. We briefly discuss applications of polarized electron beams in physical sciences and technology. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 15 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 1997 VL 10 IS 3 BP 241 EP 246 DI 10.1007/BF02770558 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA XQ501 UT WOS:A1997XQ50100011 ER PT J AU Ovchinnikov, YN Kresin, VZ AF Ovchinnikov, YN Kresin, VZ TI Critical field and impurity scattering: Application to layered and 3D superconducting systems SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE critical field; impurity scattering; anisotropy ID CRITICAL MAGNETIC-FIELD AB An efficient and rigorous method of evaluating the critical field H-c2 is developed. The method allows one to consider in a regular way the angular dependence of the scattering cross-section. The method is applied to layered and 3D superconductors. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Ovchinnikov, YN (reprint author), UNIV KARLSRUHE,INST CONDENSED MATTER THEORY,KAISERSTR 12,D-76128 KARLSRUHE,GERMANY. NR 15 TC 3 Z9 3 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 1997 VL 10 IS 3 BP 257 EP 263 DI 10.1007/BF02770561 PG 7 WC Physics, Applied; Physics, Condensed Matter SC Physics GA XQ501 UT WOS:A1997XQ50100014 ER PT J AU Wang, CM Pan, XQ Gu, H Duscher, G Hoffmann, MJ Cannon, RM Ruhle, M AF Wang, CM Pan, XQ Gu, H Duscher, G Hoffmann, MJ Cannon, RM Ruhle, M TI Transient growth bands in silicon nitride cooled in rare-earth-based glass SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GRAIN-GROWTH; CERAMICS AB Silicon nitride (Si3N4) particles embedded in various R-Si-Al-O-N glasses (R = La, Nd, Gd, Yb) have been systematically studied by high-resolution transmission electron microscopy and by analytical electron microscopy. The particles typically show an internal growth band, which is attributed to the enhanced growth of the particles in the supersaturated silicate liquid during cooling and reheating. The electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy analysis reveal that the growth band typically contains lanthanide elements. This trapping, especially of the lighter lanthanide elements, within the lattice of the beta-SiAlON is obviously beyond the general expectation that the lighter lanthanide ions hardly form solid solutions with either alpha- or beta-Si3N4. This ultimately provides some clues regarding the mobility of the lanthanide ions in the liquids and also revives interest in the general question of the possible effect of a cooling stage on the structures and compositions of the intergranular film and of the grain/glass interface in the Si3N4-based polycrystalline ceramics. C1 MAX PLANCK INST MET RES, INST WERKSTOFFWISSENSCH, D-70174 STUTTGART, GERMANY. UNIV KARLSRUHE, INST CERAM MECH ENGN, D-76131 KARLSRUHE, GERMANY. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Duscher, Gerd/G-1730-2014 OI Duscher, Gerd/0000-0002-2039-548X NR 20 TC 19 Z9 19 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1997 VL 80 IS 6 BP 1397 EP 1404 PG 8 WC Materials Science, Ceramics SC Materials Science GA XF130 UT WOS:A1997XF13000010 ER PT J AU Jackson, TB Virkar, AV More, KL Dinwiddie, RB Cutler, RA AF Jackson, TB Virkar, AV More, KL Dinwiddie, RB Cutler, RA TI High-thermal-conductivity aluminum nitride ceramics: The effect of thermodynamic, kinetic, and microstructural factors SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PHASE-COMPOSITION; SINTERING AIDS; AIN CERAMICS; ADDITIVES; ALN; DIFFUSIVITY AB Improvement in the thermal conductivity of aluminum nitride (AIN) can be realized by additives that have a high thermodynamic affinity toward alumina (Al2O3), as is clearly demonstrated in the aluminum nitride-yttria (AlN-Y2O3) system, A wide variety of lanthanide dopants are compared at equimolar lanthanide oxide:alumina (Ln(2)O(3): Al2O3, where Ln is a lanthanide element) ratios, with samaria (Sm2O3) and lutetia (Lu2O3) being the dopants that give the highest- and lowest-thermal-conductivity AIN composites, respectively, The choice of the sintering aid and the dopant level is much more important than the microstructure that evolves during sintering, A contiguous AIN phase provides rapid heat conduction paths, even at short sintering times, AlN contiguity decreases slightly as the annealing times increase in the range of 1-1000 min at 1850 degrees C. However, a substantial increase in thermal conductivity results, because of purification of AIN grains by dissolution-reprecipitation and bulk diffusion, Removal of grain-boundary phases, with a concurrent increase in AIN contiguity, occurs at high annealing temperatures or at long times and is a natural consequence of high dihedral angles (poor wetting) in liquid-phase-sintered AIN ceramics. C1 UNIV UTAH, DEPT MAT SCI, SALT LAKE CITY, UT 84112 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CERAMATEC INC, SALT LAKE CITY, UT 84119 USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 49 TC 141 Z9 164 U1 6 U2 61 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1997 VL 80 IS 6 BP 1421 EP 1435 PG 15 WC Materials Science, Ceramics SC Materials Science GA XF130 UT WOS:A1997XF13000013 ER PT J AU Zhu, YT Blumenthal, WR Taylor, ST Lowe, TC Zhou, BL AF Zhu, YT Blumenthal, WR Taylor, ST Lowe, TC Zhou, BL TI Analysis of size dependence of ceramic fiber and whisker strength SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SILICON-CARBIDE FIBERS; COMPOSITE-MATERIALS; REINFORCED COMPOSITES; WEIBULL DISTRIBUTION; MATRIX COMPOSITE; ALUMINA FIBERS; CARBON-FIBERS; FRACTURE; MODEL AB The strengths of ceramic fibers and whiskers have been observed to increase with decreasing fiber diameter and length, Typically, both surface flaws and volume hams exist in ceramic fibers and whiskers, which makes it impossible to characterize the strength dependence of both the diameter and the length with a single-modal Weibull distribution function, Our data also show that the single-modal Weibull distribution is inadequate to characterize the strength of fibers with varying diameters even in the case of a constant fiber length, In addition, experimental data also show that, for sapphire whiskers whose surface flaws mere removed by chemical polishing, the whisker strength has a much stronger size dependence on diameter than predicted by the single-modal Weibull function, which indicates that factors other than those characterized by the Weibull function also play a role in the strength of sapphire whiskers, In this paper, the factors affecting the strengths of ceramic fibers and whiskers are analyzed in terms of Weibull statistics, fracture mechanics, and ham size density variation with varying fiber diameters, A three-parameter modified Weibull distribution, which combines the above strength-affecting factors, is proposed to characterize both the diameter and the length dependence for ceramic fibers and whiskers with or without surface flaws, Characterization of the strength data of sapphire whiskers and Nicalon SiC fibers with varying diameters shows the validity of the modified Weibull distribution function. C1 CHINESE ACAD SCI,MET RES INST,SHENYANG,PEOPLES R CHINA. RP Zhu, YT (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 48 TC 27 Z9 27 U1 3 U2 13 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1997 VL 80 IS 6 BP 1447 EP 1452 PG 6 WC Materials Science, Ceramics SC Materials Science GA XF130 UT WOS:A1997XF13000015 ER PT J AU Borst, MA Lee, WY Zhang, Y Liaw, PK AF Borst, MA Lee, WY Zhang, Y Liaw, PK TI Preparation and characterization of chemically vapor deposited ZrO2 coating on nickel and ceramic fiber substrates SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ZIRCONIA AB Monoclinic ZrO2 was deposited on several metallic and ceramic substrates by reacting ZrCl4, CO2, and H-2 at temperatures of 800 degrees to 1050 degrees C. Ni substrates reacted significantly in the ZrO2 coating environment since the coating was porous and contained a considerable amount of Ni, In contrast, the coating deposited on SiC and aluminoborosilicate fibers was highly crystalline, faceted, and dense without any apparent interaction with the substrate materials. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Borst, MA (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 17 TC 8 Z9 8 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1997 VL 80 IS 6 BP 1591 EP 1594 PG 4 WC Materials Science, Ceramics SC Materials Science GA XF130 UT WOS:A1997XF13000035 ER PT J AU Tikare, V Choi, SR AF Tikare, V Choi, SR TI Combined mode I mode II fracture of 12-mol%-ceria-doped tetragonal zirconia polycrystalline ceramic SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HOT-PRESSED SI3N4; SURFACE FLAWS; TOUGHNESS AB The mode I, mode II, and combined mode I-mode II fracture behavior of ceria-doped tetragonal zirconia polycrystalline (Ce-TZP) ceramic was studied, The single-edge-precracked-beam (SEPB) samples were fractured using the asymmetric four-point-bend geometry. The ratio of mode I to mode II loading was varied by varying the degree of asymmetry in the four-point-bend geometry. The minimum strain energy density theory best described the mixed-mode fracture behavior of Ce-TZP with the mode I fracture toughness, K-IC = 8.2 +/- 0.6 MPa . m(1/2), and the mode II fracture toughness, K-IIC = 8.6 +/- 1.3 MPa . m(1/2). C1 CLEVELAND STATE UNIV,CLEVELAND,OH 44115. RP Tikare, V (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 11 Z9 11 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUN PY 1997 VL 80 IS 6 BP 1624 EP 1626 PG 3 WC Materials Science, Ceramics SC Materials Science GA XF130 UT WOS:A1997XF13000043 ER PT J AU Stephenson, JL VanBerkel, GJ McLuckey, SA AF Stephenson, JL VanBerkel, GJ McLuckey, SA TI Ion-ion proton transfer reactions of bio-ions involving noncovalent interactions: Holomyoglobin SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ELECTROSPRAY MASS-SPECTROMETRY; ASSISTED LASER DESORPTION; MULTIPLY-CHARGED IONS; CYTOCHROME-C IONS; MOLECULE REACTIONS; DIELECTRIC POLARIZABILITY; LARGE BIOMOLECULES; COULOMB ENERGY; PROTEIN IONS; IONIZATION AB Multiply protonated horse skeletal muscle holomyoglobin and apomyoglobin have been subjected to ion-ion proton transfer reactions with anions derived from perfluoro-1,3-dimethylcyclohexane in a quadrupole ion trap operated with helium as a bath gas at 1 mtorr. Neither the apomyoglobin nor holomyoglobin ions show any sign of fragmentation associated with charge state reduction to the 1 + charge state. This is particularly noteworthy for the holomyoglobin ions, which retain the noncovalently bound heme group. For example, no sign of heme loss is associated with charge state reduction from the 9+ charge state of holomyoglobin to the 1+ charge state despite the eight consecutive highly exothermic proton transfer reactions required to bring about this charge change. This result is consistent with calculations that show the combination of long ion lifetime and the high ion-helium collision rate relative to the ion-ion collision rate makes fragmentation unlikely for high mass ions in the ion trap environment even for noncovalently bound complexes of moderate binding strength. The ion-ion proton transfer rates for holo- and apomyoglobin ions of the same charge state also were observed to be indistinguishable, which supports the expectation that ion-ion proton transfer rates are insensitive to ion structure and are determined primarily by the attractive Coulomb field. (C) 1997 American Society for Mass Spectrometry. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 47 TC 42 Z9 42 U1 1 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUN PY 1997 VL 8 IS 6 BP 637 EP 644 DI 10.1016/S1044-0305(97)00023-8 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA XA225 UT WOS:A1997XA22500008 ER PT J AU Dasaradhi, L Stark, PC Huber, VJ Smith, PH Jarvinen, GD Gopalan, AS AF Dasaradhi, L Stark, PC Huber, VJ Smith, PH Jarvinen, GD Gopalan, AS TI 4-tert-butylcalix[4]arene tetrahydroxamate chelators for the selective extraction of actinide ions: Synthesis and preliminary metal ion extraction studies SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID CALIXARENE-BASED URANOPHILES; SEQUESTERING AGENTS; MOLECULAR MECHANICS; SOLVENT-EXTRACTION; DESIGN; LIGANDS; CALIX<4>ARENES; RECOGNITION; COMPLEXES; CATIONS AB Organic extractants capable of selective and efficient removal of actinides such as plutonium and americium from aqueous process waste streams are potentially useful in radioactive waste remediation. In this context, with the help of molecular modelling, the 4-tert-butylcalix[4]arene tetrahydroxamate chelators 1 and 2 have been identified as structures capable of achieving the selective solvent extraction of actinide(iv) ions from aqueous solutions. The syntheses of 1 and 2 from 4-tert-butylcalix[4]arene have been accomplished in moderate yields using short synthetic sequences. Some extraction studies have been performed using Th4+ (as a surrogate for Pu4+), Fe3+, UO22+ and Cu2+ to estimate the metal ion selectivity and extraction efficacy of these chelators. Our preliminary results show these ligands are capable of extracting thorium(IV) efficiently but that they may not be selective for its extraction in the presence of iron(III). C1 NEW MEXICO STATE UNIV,DEPT CHEM & BIOCHEM,LAS CRUCES,NM 88003. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 45 TC 26 Z9 26 U1 1 U2 8 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD JUN PY 1997 IS 6 BP 1187 EP 1192 DI 10.1039/a607354i PG 6 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA XF315 UT WOS:A1997XF31500021 ER PT J AU Eckert, J Varma, R Diebolt, L Reid, M AF Eckert, J Varma, R Diebolt, L Reid, M TI Effects of cycling conditions of active material from discharged Ni positive plates studied by inelastic neutron scattering spectroscopy SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PROTON DYNAMICS; NICKEL ELECTRODES; MANGANESE OXIDES; DIFFRACTION; INSERTION; WATER; SPECTROMETER; HYDROXIDES; GAMMA-MNO2; BRUCITE AB A series of cycled Ni battery plate materials has been examined by means of inelastic neutron scattering spectroscopy in order to determine the nature of the protons in the discharged and cycled material. Our results clearly demonstrate that some amount of the NiOOH phases which form on oxidation does not convert back to p-Ni(OH), upon discharging the battery and that this amount increases with the number of cycles the battery undergoes. Moreover, we have identified vibrational signatures of lattice water and found that its amount increases with KOH concentration used in the cell. Since cells operated at higher KOH concentrations are known to fail after fewer cycles, our inelastic neutron scattering studies clearly implicate the irreversible formation of lattice water as one of the main reasons for this failure. C1 ARIZONA STATE UNIV,DEPT CHEM & BIOCHEM,TEMPE,AZ 85281. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Eckert, J (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 37 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 1895 EP 1899 DI 10.1149/1.1837717 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800019 ER PT J AU Zou, F Thierry, D Isaacs, HS AF Zou, F Thierry, D Isaacs, HS TI A high-resolution probe for localized electrochemical impedance spectroscopy measurements SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID STEEL AB A high-resolution probe consisting of two platinum microelectrodes, 10 mu m in diameter, that permits localized electrochemical impedance spectroscopy measurements was developed and tested. The measurements were made using platinum disks as current sources with defined geometry in an insulating plane. The ac current distribution measured in solution using the probe was compared with analytical solutions and computer simulations. The spatial resolution of the probe was tested and defined by varying the height of the probe and the distance between the microelectrodes. C1 BROOKHAVEN NATL LAB,DEPT MAT SCI,UPTON,NY 11973. RP Zou, F (reprint author), SWEDISH CORROS INST,S-10405 STOCKHOLM,SWEDEN. NR 14 TC 61 Z9 62 U1 1 U2 7 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 1957 EP 1965 DI 10.1149/1.1837729 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800031 ER PT J AU Zhang, JG Benson, DK Tracy, CE Deb, SK Czanderna, AW Bechinger, C AF Zhang, JG Benson, DK Tracy, CE Deb, SK Czanderna, AW Bechinger, C TI Chromic mechanism in amorphous WO3 films SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID NUCLEAR-REACTION ANALYSIS; SMALL-POLARON ABSORPTION; THIN-FILMS; TUNGSTEN-OXIDE; ELECTROCHROMISM; OXYGEN; WXMO1-XO3; HYDROGEN AB We propose a new model for the chromic mechanism in amorphous tungsten oxide films (WO3-y. nH(2)O). This model not only explains a variety of seemingly conflicting experimental results reported in the literature that cannot be explained by existing models, it also has practical implications with respect to improving the coloring efficiency and durability of electrochromic devices. According to this model, a typical as-deposited tungsten oxide film has tungsten mainly in W6+ and W4+ states and can be represented as W1-y6+Wy4+O3-y. nH(2)O. The proposed chromic mechanism is based on the small polaron transition between the charge-induced W5+ state and the original W4+ state instead of the W5+ and W6+ states as suggested in previous models. The correlation between the electrochromic and photochromic behavior in amorphous tungsten oxide films is also discussed. C1 UNIV KONSTANZ,D-78434 CONSTANCE,GERMANY. RP Zhang, JG (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 35 TC 124 Z9 126 U1 12 U2 62 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 2022 EP 2026 DI 10.1149/1.1837737 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800039 ER PT J AU Harrar, JE Quong, R Rigdon, LP McGuire, RR AF Harrar, JE Quong, R Rigdon, LP McGuire, RR TI Scale-up studies of the electrosynthesis of dinitrogen pentoxide in nitric acid SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ANHYDROUS HNO3; TRANSPORT; MEMBRANES; MEDIA AB The method for the electrosynthesis of N2O5 in nitric acid hy anodic oxidation of N2O4 has been scaled up to produce quantities of 15 to 50 kg of solution containing 20 to 30 weight percent N2O5. A two- or three-cell, divided, plate-and- frame electrolyzer operated in the bipolar mode was employed to test various combinations of candidate electrode coatings and separators, and to study the electrochemical characteristics of the process. Two sizes of electrolyzers were used, each having single-electrode areas of 0.096 and 0.25 m(2). The best performing anode/substrate materials were either Pt-Lr on niobium, or IrO2 on aluminum; the best cathode materials were Pt or Pt-Ir on niobium. The preferred cell separator is a hydrophilic, porous polytetrafluorene-ethylene diaphragm, but an FEP-polymer anion-exchange membrane is also satisfactory. Production of N2O5 was achieved with chemical yields of 80 to 90% and current efficiencies of 50 to 70%. Maximum current densities were in the range of 0.1 to 0.2 A cm(-2); Cell voltages were 3 to 5 V and specific energies were 1.6 to 1.8 kWh kg(-1). In the electrolyzer catholyte, N2O4 is generated at nearly theoretical yield, and could be recovered and recycled as an anolyte feedstock. The E-0' of the N2O5/N2O4 couple in anhydrous nitric acid was estimated to be + 1.66 +/- 0.02 V vs. SHE. RP Harrar, JE (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 60 TC 11 Z9 15 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 2032 EP 2044 DI 10.1149/1.1837739 PG 13 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800041 ER PT J AU Vartuli, CB Pearton, SJ Lee, JW Polyakov, AY Shin, M Greve, DW Skronowski, M Shul, RJ AF Vartuli, CB Pearton, SJ Lee, JW Polyakov, AY Shin, M Greve, DW Skronowski, M Shul, RJ TI Electron cyclotron resonance plasma etching of AlGaN in Cl-2/Ar and BCl3/Ar plasmas SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID GAN; INN AB A comparison of etch rates for AlxGa1-xN alloys was performed in Cl-2/Ar and BCl3/Ar electron cyclotron resonance plasmas. The etch rates were generally found to decrease with increasing AlN concentration, due to the increasing average bond strengths at higher Al compositions. The fastest rates were found in the Cl-2/Ar chemistry, with rates of similar to 3500 Angstrom/min for GaN, 1700 Angstrom/min for AlN, 2500 Angstrom/min for Al0.31Ga0.69N, and 3300 Angstrom/min for Al0.2Ga0.8N. The etched surfaces were also smoother with the Cl-2/Ar plasma chemistry than the BCl3/Ar plasma chemistry. The etch selectivities for GaN over Al0.2Ga0.8N, Al(0.3)1Ga(0.69)N, and AlN were quite low, less than or equal to 5 for all conditions, and this is due to the ion-driven nature of the removal mechanism. C1 CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Vartuli, CB (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 23 TC 6 Z9 6 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 2146 EP 2149 DI 10.1149/1.1837754 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800056 ER PT J AU Ghislotti, G Nielsen, B AsokaKumar, P Lynn, KG DiMauro, LF Bottani, CE Corni, F Tonini, R Ottaviani, GP AF Ghislotti, G Nielsen, B AsokaKumar, P Lynn, KG DiMauro, LF Bottani, CE Corni, F Tonini, R Ottaviani, GP TI Visible light emission from silicon implanted and annealed SiO2 layers SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ROOM-TEMPERATURE; POROUS SILICON; THIN-FILMS; LUMINESCENCE; PHOTOLUMINESCENCE; INTERFACE; FABRICATION; DEFECTS; CENTERS; GLASS AB Silicon implanted and annealed SiO2 layers are studied usin g photoluminescence (PL) and positron annihilation spectroscopy (PAS). Two PL emission bands are observed. a band centered at 560 nm is present in as-implanted samples and it is still observed after 1000 degrees C annealing. The emission time is fast. A second band centered at 780 nm is detected after 1000 degrees C annealing. The intensity of the 780 nm band further increased when hydrogen annealing was performed. The emission time is long (1 mu s to 0.2 ms). PAS results show that defects produced by implantation anneal at 600 degrees C. Based on the annealing behavior and on the emission times, the origin of the two bands is discussed. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. POLITECN MILAN,DIPARTIMENTO INGN NUCL,I-20133 MILAN,ITALY. UNIV MODENA,DIPARTIMENTO FIS,I-41100 MODENA,ITALY. RI Nielsen, Bent/B-7353-2009; OI Nielsen, Bent/0000-0001-7016-0040; Bottani, Carlo Enrico/0000-0002-2015-7043 NR 34 TC 14 Z9 14 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1997 VL 144 IS 6 BP 2196 EP 2199 DI 10.1149/1.1837764 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XH828 UT WOS:A1997XH82800066 ER PT J AU Berman, SM Jewett, DL Benson, BR Law, TM AF Berman, SM Jewett, DL Benson, BR Law, TM TI Despite different wall colors, vertical scotopic illuminance predicts pupil size SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article ID PERFORMANCE AB Previously we have determined, with a full field of view, the relative contributions of scotopic and photopic luminance to pupil size at light levels typical of building interiors. Those studies were carried out in a white room with uniform reflectance, and with the viewed surfaces having an approximately uniform luminance distribution. To enhance the usefulness of the past results to lighting practice, we have constructed a "simulated office" where the viewed walls can have one of four very different colors, with quite different luminance distributions. This allows examination of interaction effects between wall spectral reflectivity and light source spectral distribution. In the present study pupil sizes were obtained while subjects were viewing a very small screen television. A remote pupillometer was used, allowing subjects to sit in a comfortable chair without the inconvenience of chin rests or head gear Seventeen subjects between the ages of 27 and 47 years were studied using illumination provided by conventional lamps, either a WW or a daylight lamp. Pupil size variation was predicted by the value of the scotopic vertical illuminance at the eye. Even though the WW lamps are 50 per cent more efficacious than daylight light lamps in terms of photopic lumens per watt, daylight lamps can be as much as twice as efficacious in eliciting pupil size. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Energy & Environm, Berkeley, CA 94720 USA. RP Berman, SM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Energy & Environm, Berkeley, CA 94720 USA. NR 8 TC 8 Z9 8 U1 0 U2 3 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 59 EP + PG 8 WC Optics SC Optics GA ZC938 UT WOS:000072634100032 ER PT J AU Rubinstein, F AF Rubinstein, F TI On the prediction of energy savings for a daylight dimming system - Discussion SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Rubinstein, F (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 88 EP 89 PG 2 WC Optics SC Optics GA ZC938 UT WOS:000072634100043 ER PT J AU Beltran, LO Lee, ES Selkowitz, SE AF Beltran, LO Lee, ES Selkowitz, SE TI Advanced optical daylighting systems: Light shelves and light pipes SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article AB We present two perimeter daylighting systems that passively redirect beam sunlight further from the window wall using special optical films, an optimized geometry, and a small glazing aperture. The objectives of these systems are to increase daylight illuminance levels at 4.6-9.1 m (15-30 ft) from the window aperture with minimum solar heat gains and to improve the uniformity of the daylighting luminance gradient across the room under variable solar conditions throughout the year. The designs were developed through a series of computer-assisted ray-tracing studies, laser visualization techniques, and photometric measurements and observations using physical scale models. Bi-directional illuminance measurements in combination with analytical routines were then used to simulate daylight performance for any solar position, and were incorporated into the DOE-2.1E building energy analysis computer program to evaluate energy savings. Results show increased daylight levels and an improved luminance gradient throughout the year compared to conventional daylighting systems. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. RP Beltran, LO (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. NR 7 TC 20 Z9 20 U1 0 U2 5 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 91 EP + PG 15 WC Optics SC Optics GA ZC938 UT WOS:000072634100047 ER PT J AU Siminovitch, M AF Siminovitch, M TI Application of CIE glare index for daylighting evaluation - Discussion SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Siminovitch, M (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 126 EP 126 PG 1 WC Optics SC Optics GA ZC938 UT WOS:000072634100060 ER PT J AU Jennings, J Moezzi, M Brown, R Mills, E Sardinsky, R Heckendorn, B Lerman, D Tribwell, L AF Jennings, J Moezzi, M Brown, R Mills, E Sardinsky, R Heckendorn, B Lerman, D Tribwell, L TI Residential lighting: The data to date SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article AB This report provides background data upon which residential lighting fixture energy conservation programs can be built. The current stock of residential lighting is described by usage level, lamp wattage, fixture type, and location within the house. Data are discussed which indicate that 27 percent of incandescent residential fixtures are responsible for over 80 percent of residential lighting energy use, and justify targeting these fixtures as candidates for retrofit with energy efficient fixtures. Fixtures determined to have the highest energy use are hardwired ceiling fixtures in kitchens, portable fixtures in living/family rooms, hardwired fixtures in dining rooms, and hardwired outdoor fixtures. An assessment of the market for residential fixtures shows that nearly half of new residential fixtures are imported, about 60 percent of new fixtures sold are hardwired, and about half of all new fixtures sold are for ceiling installation. C1 Lawrence Berkeley Lab, Lighting Res Grp, Energy & Environm Div, Berkeley, CA 94720 USA. RP Jennings, J (reprint author), Lawrence Berkeley Lab, Lighting Res Grp, Energy & Environm Div, Berkeley, CA 94720 USA. NR 14 TC 3 Z9 3 U1 1 U2 2 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 129 EP + PG 11 WC Optics SC Optics GA ZC938 UT WOS:000072634100062 ER PT J AU Rubinstein, F AF Rubinstein, F TI Analysis of daylight photocell placement and view in a small office - Discussion SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Rubinstein, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 1997 VL 26 IS 2 BP 159 EP 159 PG 1 WC Optics SC Optics GA ZC938 UT WOS:000072634100071 ER PT J AU Shin, HJ Jeong, KH Johnson, DC Kevan, SD Noh, MK Warwick, T AF Shin, HJ Jeong, KH Johnson, DC Kevan, SD Noh, MK Warwick, T TI Study of TiSe2/NbSe2 superlattices with scanning transmission X-ray microscopy SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article ID MOLECULAR-BEAM EPITAXY; 3D TRANSITION-METALS; TRANSPORT-PROPERTIES; ABSORPTION; SPECTROSCOPY; DICHROISM; EDGES AB A scanning transmission X-ray microscope (STXM) has been applied to study TiSe2/NbSe2 superlattices crystallized from an elementally modulated film. The STXM images show that the superlattice sample has structures with sizes on the order of one micrometer in the x-y plane. X-ray absorption spectra (XAS) show that the titanium in the structure is in the form of a mixture of crystalline TiSe2 and metallic Ti. The structure shows interfacial nucleation of the layers in the kinetic trapping method with different domain sizes for different sets of TiSe2 and NbSe2 layer numbers in a unit-cell. The XAS obtained using the STXM provide detailed chemical and structural information generally not available using conventional total electron yield detection. C1 YONSEI UNIV,DEPT PHYS,SEOUL 120749,SOUTH KOREA. UNIV OREGON,INST MAT SCI,EUGENE,OR 97403. ADV LIGHT SOURCE,BERKELEY,CA 94710. RP Shin, HJ (reprint author), POHANG UNIV SCI & TECHNOL,POHANG ACCELERATOR LAB,POHANG 790784,SOUTH KOREA. RI Kevan, Stephen/F-6415-2010 OI Kevan, Stephen/0000-0002-4621-9142 NR 18 TC 6 Z9 6 U1 0 U2 6 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD JUN PY 1997 VL 30 IS 3 BP 575 EP 579 PG 5 WC Physics, Multidisciplinary SC Physics GA XE866 UT WOS:A1997XE86600014 ER PT J AU Osirmski, M Barton, DL AF Osirmski, M Barton, DL TI Degradation mechanisms in AlGaN/InGaN/GaN light sources SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT Proceedings of the 1996 Seoul International Symposium on the Physics of Semiconductors and Applications CY OCT 21-22, 1996 CL KOREA INST SCI & TECHNOL, SEOUL, SOUTH KOREA SP Korea Res Fdn, Korea Informat Soc Dev Inst, Samsung Electr Co Ltd, Hyundai Electr Co Ltd, LG Semicon Co Ltd, Korea Federat Sci & Technol Soc HO KOREA INST SCI & TECHNOL ID N-TYPE GAN; EMITTING DIODES; FILMS AB Our investigations of device Lifetime and the main degradation mechanisms in Nichia blue LEDs date back to Spring 1994. Following the initial studies of rapid failures under high current electrical pulses, where metal migration was identified as the cause of degradation, we have placed a number of Nichia NLPB-500 LEDs on a series of Life tests. The first test ran for 1000 hours under normal operating conditions (20 mA at 23 degrees C). As no noticeable degradation was observed, the second room temperature test involved the same devices but with a range of currents between 20 and 70 mA. After 1600 hours, some degradation was observed in devices driven at 60 and 70 mA, but it was still less than 20%. The subsequent tests, still underway, included stepping up the temperature by 10 degrees C in 500 h intervals, with currents the same as in the second test. This work reviews the failure analysis that was performed on the degraded devices and the degradation mechanisms that were identified. Also, preliminary data on high current degradation of quantum-well LEDs is reported. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP UNIV NEW MEXICO, CTR HIGH TECHNOL MAT, ALBUQUERQUE, NM 87131 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 EI 1976-8524 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD JUN PY 1997 VL 30 SU S BP S13 EP S20 PG 8 WC Physics, Multidisciplinary SC Physics GA XJ375 UT WOS:A1997XJ37500004 ER PT J AU Yi, KS Quinn, JJ AF Yi, KS Quinn, JJ TI Composite fermion descriptions of electrons on a magnetic sphere SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT Proceedings of the 1996 Seoul International Symposium on the Physics of Semiconductors and Applications CY OCT 21-22, 1996 CL KOREA INST SCI & TECHNOL, SEOUL, SOUTH KOREA SP Korea Res Fdn, Korea Informat Soc Dev Inst, Samsung Electr Co Ltd, Hyundai Electr Co Ltd, LG Semicon Co Ltd, Korea Federat Sci & Technol Soc HO KOREA INST SCI & TECHNOL ID EXCITATIONS; HIERARCHY; SYSTEMS; STATES AB Electrons on a magnetic sphere is studied using the composite Fermion picture, and the relationship between the value of the degeneracy NL of the lowest electron energy shell and the number of electrons N is examined for a given Laughlin condensed state. Phenomenological quasiparticle energies and their interactions are used to evaluate the ground state energies of the closed composite Fermion shells having fillings of v=2/5 and 2/7. For states close to the Laughlin v=1/3 state, the lowest energy sector of the energy spectrum is compared in two different mean-field composite Fermion descriptions. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37969. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Yi, KS (reprint author), PUSAN NATL UNIV,DEPT PHYS,PUSAN 609735,SOUTH KOREA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD JUN PY 1997 VL 30 SU S BP S204 EP S208 PG 5 WC Physics, Multidisciplinary SC Physics GA XJ375 UT WOS:A1997XJ37500041 ER PT J AU McArthur, JV Tuckfield, RC AF McArthur, JV Tuckfield, RC TI Information length: Spatial and temporal parameters among stream bacterial assemblages SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article; Proceedings Paper CT 3rd Symposium on New Concepts in Stream Ecology: An Integrated Approach CY OCT, 1995 CL AIKEN, SC SP Savannah River Ecol Lab, US DOE, Univ Georgia Res Foundat DE information spiraling concept; information length; colonization distance; energy load; bacteria; lotic ID DESERT STREAM; HYPORHEIC ZONE; GENETIC DIVERSITY; NITROGEN DYNAMICS; RIVER; POPULATION; ECOSYSTEM; EPILITHON; DISTURBANCE; COMMUNITIES AB Bacteria, while known to be an integral part of all ecosystems, are seldom studied except as a single taxonomic unit. Few ecological studies even acknowledge the extraordinary functional and species diversity of bacteria. Recent research has elucidated some important facts about bacteria in stream ecosystems. For instance, the dynamics of bacterial genomes within a stream suggest that populations of these organisms are more stable temporally than spatially. We develop predictive models and testable hypotheses based on the information spiraling concept to describe the ecology of stream bacteria and to define 2 new terms: colonization distance and information length Colonization distance (D-c) is the maximum distance downstream from original colony establishment at which a new colony of bacteria can be established. Information length (L-l) is defined as the maximum length over which a gene has an effect on an ecosystem process independent of a specific host. These terms are modeled relative to the average temporal energy load (joules/min) in the stream. Energy inputs that exceed biologically defined limits of use result in ecosystem energy leaks regardless of information length. Our models predict that information length should be shorter in montane streams than in Coastal plain streams of southeastern USA. Furthermore, assuming equal average energy load between streams, the stream with the largest energy load variance will leak more energy downstream. Therefore, temperate streams should be less efficient than tropical streams at utilizing energy within a reach. RP McArthur, JV (reprint author), SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802, USA. NR 38 TC 8 Z9 8 U1 0 U2 1 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD JUN PY 1997 VL 16 IS 2 BP 347 EP 357 DI 10.2307/1468023 PG 11 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA XD620 UT WOS:A1997XD62000005 ER PT J AU Hehlen, MP AF Hehlen, MP TI Reabsorption artifacts in measured excited-state lifetimes of solids SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID EMISSION PROPERTIES; LASER; FLUORESCENCE; ABSORPTION; CRYSTALS; IONS; YAG; YLF AB The effect of repeated radiative energy transfer on the observed excited-state lifetime tau(obs) Of a luminescent species in a solid is studied by Monte Carlo simulations. Increasing the sample path length, the reabsorption coefficient, or the luminescence quantum yield significantly lengthens tau(obs), relative to its intrinsic value tau(0). This effect is additionally amplified by total internal reflection. Room-temperature lifetimes of F-2(5/2) in YAG:1%Yb3+ and I-4(11/2) in YLF:5%Er3+ were measured in a spherically refractive-index-matched geometry, yielding the low values of 0.9489 +/- 0.0006 and 3.75 +/- 0.01 ms, respectively. It is concluded that lifetimes obtained from non-refractive-index matched experiments are usually significantly overestimated. The technique presented is easily applicable to room-temperature excited-state lifetime measurements of many luminescent solids. (C) 1997 Optical Society of America. RP Hehlen, MP (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,MAIL STOP E535,LOS ALAMOS,NM 87545, USA. NR 25 TC 25 Z9 26 U1 0 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 1997 VL 14 IS 6 BP 1312 EP 1318 DI 10.1364/JOSAB.14.001312 PG 7 WC Optics SC Optics GA XC639 UT WOS:A1997XC63900007 ER PT J AU Nilsen, J AF Nilsen, J TI Design of a picosecond-laser-driven Ni-like Mo x-ray laser near 20 nm SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID AMPLIFICATION; SELENIUM AB The gain is predicted for a solid molybdenum target illuminated by several joules of combined energy from a nanosecond laser pulse to create a preplasma followed by a picosecond laser pulse to drive the gain. Gains greater than 300 cm(-1) are predicted for the Ni-like Mo 4d S-1(0) --> 4p P-1(1) transition at 18.9 nm, which is driven by the monopole collisional excitation. High gain is also predicted for a self-photo-pumped 4f 1P(1) --> 4d (1)p(1) transition at 22.0 nm and several other transitions driven by inner shell collisional ionization. (C) 1997 Optical Society of America. RP Nilsen, J (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 23 TC 35 Z9 35 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 1997 VL 14 IS 6 BP 1511 EP 1514 DI 10.1364/JOSAB.14.001511 PG 4 WC Optics SC Optics GA XC639 UT WOS:A1997XC63900034 ER PT J AU Parks, WP Hoffman, EE Lee, WY Wright, IG AF Parks, WP Hoffman, EE Lee, WY Wright, IG TI Thermal barrier coatings issues in advanced land-based gas turbines SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE advanced turbine systems; bond coatings; combustion turbines; land-based turbines; thermal barrier coatings AB The Department of Energy's Advanced Turbine Systems (ATS) program is aimed at fostering the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost, The proposed duty cycle of ATS machines will emphasize different criteria in the selection of materials for the critical components. In particular, thermal barrier coatings (TBCs) will be an essential feature of the hot gas path components in these machines, The goals of the ATS will require significant improvements in TBC technology, since these turbines will be totally reliant on TBCs, which will be required to function on critical components such as the first-stage vanes and blades for times considerably longer than those experienced in current applications, Important issues include the mechanical and chemical stability of the ceramic layer and the metallic bond coat, the thermal expansion characteristics and compliance of the ceramic layer, and the thermal conductivity across the thickness of the ceramic layer. C1 US DOE,OFF IND TECHNOL,WASHINGTON,DC 20585. DEPT ENERGY,OAK RIDGE OPERAT OFF,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 12 TC 32 Z9 32 U1 1 U2 7 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 1997 VL 6 IS 2 BP 187 EP 192 DI 10.1007/s11666-997-0011-y PG 6 WC Materials Science, Coatings & Films SC Materials Science GA XD633 UT WOS:A1997XD63300016 ER PT J AU Schweitzer, MH Johnson, C Zocco, TG Horner, JR Starkey, JR AF Schweitzer, MH Johnson, C Zocco, TG Horner, JR Starkey, JR TI Preservation of biomolecules in cancellous bone of Tyrannosaurus rex SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article ID FOSSIL BONES; BIRDS; SEISMOSAURUS; COLLAGEN; PROTEINS; DINOSAUR AB An exceptionally well preserved specimen of the tyrannosaurid dinosaur Tyrannosaurus rex Osborn shows little evidence of permineralization or other diagenetic effects. It appears that the cancellous bone tissues of the specimen may have been protected from water infiltration or mineral deposition by the very dense cortical bone which surrounds them. The cancellous tissues provided an opportunity to test the hypothesis that indigenous biomolecules might be preserved over the course of millions of years under the appropriate conditions. HPLC analysis of extracts from the bone tissues revealed the presence of molecules with light absorbance maxima consistent with nucleic acids and peptides/proteins. Analyses of bone extracts for amino acid content yielded ratios similar to those found for modern ostrich and horse bone. A high molar glycine ratio and the presence of hydroxylysine peaks in bony tissue samples from the T. rex suggests the presence of collagen type I remnants. Results indicate that the analyzed tissue contains numerous biomolecules. While some of the biomolecules are most likely contaminants, the probable presence of collagen type I suggests that some molecules of dinosaurian origin remain in these tissues. C1 Montana State Univ, Dept Biol, Bozeman, MT 59717 USA. Montana State Univ, Museum Rockies, Bozeman, MT 59717 USA. Montana State Univ, Dept Chem, Bozeman, MT 59717 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Montana State Univ, Dept Microbiol, Bozeman, MT 59717 USA. RP Schweitzer, MH (reprint author), Montana State Univ, Dept Biol, Bozeman, MT 59717 USA. NR 30 TC 23 Z9 25 U1 0 U2 7 PU SOC VERTEBRATE PALEONTOLOGY PI CHICAGO PA 401 NORTH MICHIGAN AVE, CHICAGO, IL 60611-4267 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD JUN PY 1997 VL 17 IS 2 BP 349 EP 359 PG 11 WC Paleontology SC Paleontology GA YM886 UT WOS:000071111500007 ER PT J AU Leitner, T Kumar, S Albert, J AF Leitner, T Kumar, S Albert, J TI Tempo and mode of nucleotide substitutions in gag and env gene fragments in human immunodeficiency virus type 1 populations with a known transmission history SO JOURNAL OF VIROLOGY LA English DT Article ID DEPENDENT DNA POLYMERASE; REVERSE TRANSCRIPTION; G->A HYPERMUTATION; MITOCHONDRIAL-DNA; EVOLUTION; RNA; SEQUENCES; RATES; RECOMBINATION; GENOME AB The complex evolutionary process of human immunodeficiency virus type 1 (HIV-1) is marked by a high level of genetic variation. It has been shown that the HIV-1 genome is characterized by variable and more constant regions, unequal nucleotide frequencies, and preference for G-to-A substitutions. However, this knowledge has largely been neglected in phylogenetic analyses of HIV-1 nucleotide sequences, even though these analyses are applied to a number of important biological questions. The purpose of this study,vas to identify a realistic model of HIV-1 evolution and to statistically test if the application of such a model significantly improves the accuracy of phylogenetic analyses. A unique and recently reported HIV-1 transmission cluster consisting of nine infected individuals, for whom the direction and time for each transmission were exactly known, formed the basis for the analyses which were performed under a general model of nucleotide substitution using population sequences from the env V3 and p17(gag) regions of the HIV-1 genome. Examination of seven different substitution models by maximum-likelihood methods revealed that the fit of the general reversible (REV) model was significantly better than that of simpler models, indicating that it is important to account for the asymmetric substitution pattern of HIV-1 and that the nucleotide substitution rate varied significantly across sites. The shape parameter alpha, which describes the variation across sites by a gamma distribution, was estimated to be 0.38 and 0.25 for env V3 and p17(gag), respectively. In env V3, the estimated average transition/ transversion rate ratio was 1.42. Thus, the REV model with variable rates across sites (described by a gamma distribution) provides the best description of HIV-1 evolution, whereas simple models are unrealistic and inaccurate. It is likely that the accuracy of phylogenetic studies of HIV-1 and many other viruses would improve substantially by the use of more realistic nucleotide substitution models. This is especially true when attempts are made to estimate the age of distant viral ancestors from contemporary viral sequences. C1 PENN STATE UNIV,DEPT BIOL,UNIVERSITY PK,PA 16802. KAROLINSKA INST,SWEDISH INST INFECT DIS CONTROL,DEPT CLIN VIROL,S-10521 STOCKHOLM,SWEDEN. PENN STATE UNIV,INST MOL EVOLUT GENET,UNIVERSITY PK,PA 16802. RP Leitner, T (reprint author), LOS ALAMOS NATL LAB,GRP T 10,MS K710,LOS ALAMOS,NM 87542, USA. RI Kumar, Sudhir/F-1411-2011 NR 54 TC 89 Z9 90 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0022-538X J9 J VIROL JI J. Virol. PD JUN PY 1997 VL 71 IS 6 BP 4761 EP 4770 PG 10 WC Virology SC Virology GA WZ571 UT WOS:A1997WZ57100067 PM 9151870 ER PT J AU Hill, WR Dimick, SM McNamara, AE Branson, CA AF Hill, WR Dimick, SM McNamara, AE Branson, CA TI No effects of ambient UV radiation detected in periphyton and grazers SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID NATURAL ULTRAVIOLET-RADIATION; B RADIATION; EARTHS SURFACE; SHORT-TERM; PHOTOSYNTHESIS; COMMUNITY; PHYTOPLANKTON; ECOSYSTEMS; LIMITATION; GROWTH AB The vulnerability of periphyton and gazers to current and future levels of ultraviolet radiation (UV) has important ramifications for energy flow in shallow waters. We reduced ambient UV levels in a Tennessee stream with UV-opaque Plexiglas suspended over the stream and compared periphyton under these Plexiglas filters to periphyton under UV-transparent polyvinylidene film. The experiments were performed three times, from autumn 1993 to summer 1994. The last experiment included a treatment with reduced snail densities, so potential interactions between grazing and UV could be identified. Periphyton biomass and photosynthesis were not significantly affected by reduced UV in any of the three experiments, indicating ambient UV effects were minor, at most. Grazing by snails (Elimia clavaeformis) tightly controlled periphyton biomass and primary production in all three experiments. Snail densities were not significantly affected by ambient UV, eliminating the possibility of a solar cascade of indirect effects. Snails may be less vulnerable to UV than are soft-bodied gazers such as chironomids, and periphyton in southern U.S. streams may be adapted to naturally high levels of UV. The results of this study clearly imply that previous reports of UV impacts on periphyton and gazers cannot be generalized. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Duke Univ, Dept Chem, Durham, NC 27704 USA. Colgate Univ, Dept Biol, Hamilton, NY 13346 USA. RP Hill, WR (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 22 TC 36 Z9 36 U1 1 U2 4 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUN PY 1997 VL 42 IS 4 BP 769 EP 774 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA YM179 UT WOS:000071037700015 ER PT J AU Gutowska, A Kim, SW AF Gutowska, A Kim, SW TI Thermosensitive hydrogel coatings: Synthesis and heparin release SO MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT 36th International Symposium on Macromolecules (IUPAC MACRO SEOUL 96) CY AUG 04-09, 1996 CL SEOUL, SOUTH KOREA SP Int Union Pure & Appl Chem, Polym Soc Korea, Minist Sci & Technol Republic Korea, Korea Petrochem Ind Assoc, Korea Sci & Engn Fdn, Korea Res Fdn AB The synthesis and drug release properties of crosslinked N-isopropylacrylamide (NiPAAm) copolymer coatings on the surface of a hydrophobic poly(ester-urethane) tubing were examined. A method was designed to coat hydrophobic polymer surface with a thermosensitive gel layer. Crosslinked NiPAAm copolymer coatings were synthesized using W-initiated polymerization. The feasibility of using NiPAAm based gels as heparin releasing thermosensitive coatings was investigated. Heparin, a high molecular weight hydrophilic solute, was loaded into hydrogels using a simple solution sorption technique. The release of heparin from NiPAAm copolymer gel coatings was compared to that of crosslinked NiPAAm copolymers. The gel coatings demonstrated a more gradual and prolonged heparin release as compared to gel disks of the same composition. C1 UNIV UTAH, CCCD, DEPT PHARMACEUT & PHARMACEUT CHEM, SALT LAKE CITY, UT 84112 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 7 TC 3 Z9 3 U1 1 U2 2 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD JUN PY 1997 VL 118 BP 545 EP 551 DI 10.1002/masy.19971180172 PG 7 WC Polymer Science SC Polymer Science GA XP301 UT WOS:A1997XP30100071 ER PT J AU Fisher, WG Meyer, KE Wachter, EA Perl, DR Kulowitch, PJ AF Fisher, WG Meyer, KE Wachter, EA Perl, DR Kulowitch, PJ TI Laser induced fluorescence imaging of thermal damage in polymer matrix composites SO MATERIALS EVALUATION LA English DT Article AB A simple, fluorescence based imaging system has been developed that is capable of identifying regions of thermal damage in polymer matrix composites (PMCs). These materials are playing an increasingly important role in the production of high performance vehicles and air-craft, where their low weight and high mechanical strength, combined with advancements in manufacturing technology ensure increased use for a variety of applications. Of particular concern in the aerospace industry is the tendency of some PMC materials to become irreversibly damaged when exposed to elevated temperatures. Traditional nondestructive testing (NDT) techniques are capable of defecting physical anomalies such as cracks and delaminations but cannot detect initial heat damage, which occurs on a molecular scale. Spectroscopic techniques such as laser induced fluorescence provide an attractive means for detecting this type of damage and are amenable to imaging large, irregularly shaped surfaces. In this report we describe instrumentation capable of rapidly detecting thermal damage in graphite epoxy components and suggest improvements which will enable this technology to make quantitative judgments concerning the mechanical strength properties of heat damaged specimens. C1 USN,NAVAL AVIAT DEPOT,NAS N ISL,SAN DIEGO,CA 92135. USN,NAVAL AIR WARFARE CTR,DIV AIRCRAFT,PATUXENT RIVER,MD 20670. RP Fisher, WG (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 8 TC 3 Z9 3 U1 1 U2 3 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD JUN PY 1997 VL 55 IS 6 BP 726 EP 729 PG 4 WC Materials Science, Characterization & Testing SC Materials Science GA XC539 UT WOS:A1997XC53900026 ER PT J AU Wolfenstine, J Sperry, CD Goretta, KC Routbort, JL Lanagan, MT Bloom, I Kaun, TD Krumpelt, M AF Wolfenstine, J Sperry, CD Goretta, KC Routbort, JL Lanagan, MT Bloom, I Kaun, TD Krumpelt, M TI Elevated-temperature creep strength of LiFeO2, LiCoO2 and NiO-5(at%) Li2O SO MATERIALS LETTERS LA English DT Article DE elevated-temperature creep strength; LiFeO2; LiCoO2; fuel cells ID DEFORMATION; CERAMICS AB The elevated-temperature creep strength of several alternative cathode materials (LiFeO2 and LiCoO2, both pure and doped) for potential use in molten carbonate fuel cells was compared to the currently used Li (1-5 at%)-doped NiO. It was observed that at 1000 degrees C, LiFeO2, LiFeO2-12.5 at% NiO, LiFeO2-9 at% MgO and LiCoO2 have a lower strength than NiO-5 at% Li2O. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP Wolfenstine, J (reprint author), UNIV CALIF IRVINE,DEPT CHEM & BIOCHEM ENGN,IRVINE,CA 92697, USA. NR 16 TC 2 Z9 2 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JUN PY 1997 VL 31 IS 3-6 BP 251 EP 254 DI 10.1016/S0167-577X(96)00278-9 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA XF567 UT WOS:A1997XF56700016 ER PT J AU Plovnick, RH Fathi, Z Kiggans, JO AF Plovnick, RH Fathi, Z Kiggans, JO TI Low-density silicon nitride beads as high-temperature microwave furnace insulation SO MATERIALS RESEARCH BULLETIN LA English DT Article DE ceramics; nitrides; mechanical properties AB Low-density Si3N4 spheroidal beads 3-4 mm in diameter have been made by an alginate route starting from Si3N4 powder. The beads have been characterized by chemical, X-ray diffraction and compression test techniques. The ability of the beads to couple with microwave power has been investigated in nitrogen atmosphere at fixed frequency of 2.45 GHz at power levels to 5 kW, and at variable frequency from 4-6.5 GHz at power levels to 1.4 kW. The beads showed no signs of deterioration in nitrogen at temperatures up to 1800 degrees C, and seem promising as high-temperature microwave furnace insulation. (C) 1997 Elsevier Science Ltd. C1 LAMBDA TECHNOL INC,RALEIGH,NC 27622. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Plovnick, RH (reprint author), 3M CO,CERAM TECHNOL CTR,3M CTR 2013N06,ST PAUL,MN 55144, USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 13 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 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD JUN PY 1997 VL 32 IS 6 BP 749 EP 754 DI 10.1016/S0025-5408(97)00046-9 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA XA494 UT WOS:A1997XA49400014 ER PT J AU Dogan, ON Hawk, JA Laird, G AF Dogan, ON Hawk, JA Laird, G TI Solidification structure and abrasion resistance of high chromium white irons SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID FE-CR-C; CAST IRONS; EUTECTIC COMPOSITION; FRACTURE-TOUGHNESS; LIQUIDUS SURFACE; HEAT-TREATMENT; WEAR; CARBIDES; ALLOYS; MICROTEXTURE AB Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process. RP US DOE, ALBANY RES CTR, ALBANY, OR 97321 USA. NR 70 TC 131 Z9 145 U1 3 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1997 VL 28 IS 6 BP 1315 EP 1328 DI 10.1007/s11661-997-0267-3 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XF224 UT WOS:A1997XF22400004 ER PT J AU Vanheusden, K Schwank, JR Warren, WL Fleetwood, DM Devine, RAB AF Vanheusden, K Schwank, JR Warren, WL Fleetwood, DM Devine, RAB TI Radiation-induced H+ trapping in buried SiO2 SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 10th Biennial Conference on Insulating Films on Semiconductors (INFOS 97) CY JUN 10-14, 1997 CL STENUNGSUND, SWEDEN ID IRRADIATION AB The irradiation response of mobile H+ in the buried oxide of SOI materials is investigated as a function of applied electric field during irradiation. It is observed that H+ trapping occurs near the substrate Si/SiO2 interface during irradiation under positive top Si bias (Eox 2 +0.2 MV/cm); this effect is not observed when the irradiation is performed in the absence of bias or under negative bias. Post irradiation proton detrapping data show that the positive bias/irradiation combination activates a shallow proton trap in the buried oxide near the substrate Si/SiO2 interface. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 6 TC 8 Z9 8 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD JUN PY 1997 VL 36 IS 1-4 BP 241 EP 244 DI 10.1016/S0167-9317(97)00056-7 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA XG177 UT WOS:A1997XG17700052 ER PT J AU Schwank, JR AF Schwank, JR TI Advantages and limitations of silicon-on-insulator technology in radiation environments SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 10th Biennial Conference on Insulating Films on Semiconductors (INFOS 97) CY JUN 10-14, 1997 CL STENUNGSUND, SWEDEN ID SOI; DEVICES; SEU; TRANSPORT; SIMOX; IMPLANTATION; HARDNESS; ERRORS; OXYGEN; SRAM AB The fact that silicon-on-insulator (SOI) ICs are built on an insulating layer gives them unique advantages in radiation environments. SOI ICs are inherently less prone to single-event effects and high dose rate transient effects. However, floating body bipolar effects can limit the hardness of SOI devices unless steps are taken to reduce them. The buried oxide of a SOI transistor makes total-dose response more complex and hardening more challenging than for bulk-silicon ICs. If proper measures are taken to harden SOI ICs, they can have significant performance and hardness advantages over bulk-silicon ICs in space and nuclear environments. RP SANDIA NATL LABS, POB 5800, MS-1083, ALBUQUERQUE, NM 87185 USA. NR 41 TC 7 Z9 7 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 EI 1873-5568 J9 MICROELECTRON ENG JI Microelectron. Eng. PD JUN PY 1997 VL 36 IS 1-4 BP 335 EP 342 DI 10.1016/S0167-9317(97)00076-2 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA XG177 UT WOS:A1997XG17700071 ER PT J AU Anderson, MT Martin, JE Odinek, JG Newcomer, PP Wilcoxon, JP AF Anderson, MT Martin, JE Odinek, JG Newcomer, PP Wilcoxon, JP TI Monolithic periodic mesoporous silica gels SO MICROPOROUS MATERIALS LA English DT Article DE periodic mesoporous silica; porosity; fractal; adsorption; particulate gel AB We have synthesized monolithic, surfactant-templated particulate gels that have pore volumes and surface areas comparable to silica xerogels and aerogels. The gels have a complex microstructure with micro-, meso- and macroscopic features that emerge over five orders of magnitude in length (1) amorphous silica walls (characterized by a broad distribution of Si-Si spacings of approximate to 0.4 nm), (2) periodic hexagonal arrays of 1-d channels within each particle (approximate to 3 nm channel diameter), (3) a feature in the gas adsorption measurements that indicates a second class of approximate to 10-50 nm diameter mesopores, (4) particles that are approximate to 150 to approximate to 500 nm in diameter, (5) interparticle pores that are on the order of the particle size, and (6) fractal domains larger than the particle size (>10 000 nm). The microstructure can be controlled by the varying the initial silica content, the template size, the drying conditions, or the calcination conditions. The wet gel monoliths exhibit calculated densities as low as approximate to 0.02 g/cm(3); the dried and calcined gels have bulk densities that range from 0.3 to 0.5 g/cm(3). The materials possess large interparticle (1.1-2.2 cm(3)/g) and intraparticle (0.3-0.6 cm(3)/g) porosities. (C) 1997 Elsevier Science B.V. C1 SANDIA NATL LABS, NANOSTRUCT & ADV MAT CHEM DEPT, ALBUQUERQUE, NM 87185 USA. RP Anderson, MT (reprint author), SANDIA NATL LABS, ENCAPSULANTS & POROUS MAT DEPT, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 14 TC 35 Z9 35 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6513 J9 MICROPOROUS MATER JI Microporous Mater. PD JUN PY 1997 VL 10 IS 1-3 BP 13 EP 24 DI 10.1016/S0927-6513(96)00105-8 PG 12 WC Chemistry, Applied; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA XH566 UT WOS:A1997XH56600002 ER PT J AU Tice, RR Yager, JW Andrews, P Crecelius, E AF Tice, RR Yager, JW Andrews, P Crecelius, E TI Effect of hepatic methyl donor status on urinary excretion and DNA damage in B6C3F1 mice treated with sodium arsenite SO MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH LA English DT Article DE arsenic; sodium arsenite; DNA damage; single cell gel electrophoresis; comet assay; micronucleus assay; hepatic methyl donor status; nutrition; choline deficient diet; urinary excretion ID INDUCED CELL-TRANSFORMATION; MULTIPLE RISK-FACTORS; DISEASE ENDEMIC AREA; ARTESIAN WELL WATER; PROTEIN CROSS-LINKS; STRAND BREAKS; MALIGNANT NEOPLASMS; BLACKFOOT DISEASE; SMELTER WORKERS; BONE-MARROW AB This study evaluated the effect of hepatic methyl donor status on the ability of sodium arsenite (2.5, 5.0 and 10.0 mg/kg) administered by gavage once on four consecutive days to induce DNA damage in male B6C3F1 mice. Maintenance on a choline-deficient (CD) diet prior to treatment resulted in mice with hepatic methyl donor deficiency (HMDD) and altered arsenical metabolism, as demonstrated by a decreased total urinary excretion of inorganic and organic arsenicals. The alkaline (pH greater than 13) Single Cell Gel (SCG) assay was used to evaluate for the induction of DNA damage (single strand breaks, alkali labile sites, DNA crosslinking) in blood leukocytes, liver parenchymal cells, and cells sampled from bladder, lung, and skin, while the bone marrow erythrocyte micronucleus (MN) assay was used to assess for the induction of chromosomal damage in bone marrow cells. Treatment with sodium arsenite one or four times induced a significant decrease in DNA migration (indicative of DNA crosslinking) in bladder and liver parenchymal cells of hepatic methyl donor sufficient (HMDS) mice, but in skin cells of HMDD mice. Both HMDD and HMDS mice exhibited a significant increase in the frequency of micronucleated polychromatic erythrocytes (MN-PCE) in bone marrow following four, but not following one, treatments. However, the positive response occurred at a lower dose for HMDS mice and, in these mice, bone marrow toxicity, as demonstrated by a significant reduction in the percentage of PCE, was present also. These results indicate that hepatic methyl donors deficiency significantly decreases the total urinary excretion of orally administered sodium arsenite and markedly modulates target organ arsenic-induced DNA damage, with an apparent shift from liver and bladder to skin. C1 ELECT POWER RES INST, PALO ALTO, CA 94303 USA. BATTELLE PACIFIC NW LABS, SEQUIM, WA 98382 USA. RP Tice, RR (reprint author), INTEGRATED LAB SYSTEMS, POB 13501, RES TRIANGLE PK, NC 27709 USA. NR 69 TC 71 Z9 72 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-5742 EI 1388-2139 J9 MUTAT RES-REV MUTAT JI Mutat. Res.-Rev. Mutat. Res. PD JUN PY 1997 VL 386 IS 3 BP 315 EP 334 DI 10.1016/S1383-5742(97)00004-5 PG 20 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XG035 UT WOS:A1997XG03500017 PM 9219569 ER PT J AU Joachimiak, A AF Joachimiak, A TI Capturing the misfolds: Chaperone-peptide-binding motifs SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID 3-DIMENSIONAL STRUCTURE; CRYSTAL-STRUCTURE; PROTEIN; RECEPTOR; HSP90; GROEL AB Recently, the crystal structure of the N-terminal fragment of human Hsp90-alpha chaperone and its complex with geldanamycin and the crystal structure of the N-terminal domain of yeast Hsp90 have been determined at high resolution. These structures reveal features that shed new light on the Hsp90 chaperone-protein interactions. C1 NORTHWESTERN UNIV,DEPT BIOCHEM MOL BIOL & CELL BIOL,EVANSTON,IL 60208. RP Joachimiak, A (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 35 TC 10 Z9 11 U1 0 U2 0 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 JUN PY 1997 VL 4 IS 6 BP 430 EP 434 DI 10.1038/nsb0697-430 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XC452 UT WOS:A1997XC45200005 PM 9187647 ER PT J AU Hashem, S AF Hashem, S TI Optimal linear combinations of neural networks SO NEURAL NETWORKS LA English DT Article DE optimal linear combination; model selection; function approximation; collinearity; robust estimation; mixture of experts ID LATENT ROOT REGRESSION; COMBINING FORECASTS; ECONOMIC FORECASTS; EFFICIENCY; ACCURACY; MODEL AB Neural network-based modeling often involves trying multiple networks with different architectures and training parameters in order to achieve acceptable model accuracy. Typically, one of the trained networks is chosen as best, while the rest are discarded. Hashem and Schmeiser (1995) proposed using optimal linear combinations of a number of trained neural networks instead of using a single best network. Combining the trained networks may help integrate the knowledge acquired by the components networks and thus improve model accuracy. In this paper, we extend the idea of optimal linear combinations (OLCs) of neural networks and discuss issues related to the generalization ability of the combined model. We then present two algorithms for selecting the component networks for the combination to improve the generalization ability of OLCs. Our experimental results demonstrate significant improvements in model accuracy, as a result of using OLCs, compared to using the apparent best network. (C) 1997 Elsevier Science Ltd. C1 PACIFIC NW LAB, RICHLAND, WA USA. NR 57 TC 243 Z9 254 U1 1 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0893-6080 J9 NEURAL NETWORKS JI Neural Netw. PD JUN PY 1997 VL 10 IS 4 BP 599 EP 614 DI 10.1016/S0893-6080(96)00098-6 PG 16 WC Computer Science, Artificial Intelligence SC Computer Science GA XJ019 UT WOS:A1997XJ01900002 ER PT J AU Vitela, JE Reifman, J AF Vitela, JE Reifman, J TI Premature saturation in backpropagation networks: Mechanism and necessary conditions SO NEURAL NETWORKS LA English DT Article DE feedforward neural networks; backpropagation training algorithm; premature saturation; flat spot; necessary conditions AB The mechanism that gives rise to the phenomenon of premature saturation of the output units of feedforward multilayer neural networks during training with the standard backpropagation algorithm is described. The entire process of premature saturation is characterized by three distinct stages, and it is concluded that the momentum term plays the leading role in the occurrence of the phenomenon. The necessary conditions for the occurrence of premature saturation are presented, and a method is proposed, based on these conditions, that eliminates the occurrence of the phenomenon. The validity of the conditions and the proposed method are illustrated through simulation results. (C) 1997 Elsevier Science Ltd. C1 ARGONNE NATL LAB,REACTOR ANAL DIV,ARGONNE,IL 60439. NR 12 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 0893-6080 J9 NEURAL NETWORKS JI Neural Netw. PD JUN PY 1997 VL 10 IS 4 BP 721 EP 735 DI 10.1016/S0893-6080(96)00117-7 PG 15 WC Computer Science, Artificial Intelligence SC Computer Science GA XJ019 UT WOS:A1997XJ01900010 ER PT J AU Theofanous, TG Liu, C Additon, S Angelini, S Kymalainen, O Salmassi, T AF Theofanous, TG Liu, C Additon, S Angelini, S Kymalainen, O Salmassi, T TI In-vessel coolability and retention of a core melt SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The efficacy of external flooding of a reactor vessel as a severe accident management strategy is assessed for an AP600-like reactor design. The overall approach is based on the risk oriented accident analysis methodology (ROAAM) and the assessment includes consideration of bounding scenarios and sensitivity studies, as well as arbitrary parametric evaluations that allow for the delineation of the failure boundaries. The: technical treatment in this assessment includes: (a) new data on energy flow from either volumetrically heated pools or non-heated layers on top, boiling and critical heat flux in inverted, curved geometries, emissivity of molten (superheated) samples of steel, and chemical reactivity proof tests; (b) a simple but accurate mathematical formulation that allows prediction of thermal loads by means of convenient hand calculations; (c) a detailed model programmed on the computer to sample input parameters over the uncertainty ranges, and to produce probability distributions of thermal loads and margins for departure from nucleate boiling at each angular position on the lower head; and (d) detailed structural evaluations that demonstrate that departure from nucleate boiling is a necessary and sufficient criterion for failure. Quantification of the input parameters is carried out for an AP600-like design, and the results of the assessment demonstrate that lower head failure is 'physically unreasonable.' Use of this conclusion for any specific application is subject to verifying the required reliability of the depressurization an cavity-flooding systems, and to showing the appropriateness (in relation to the database presented here, or by further testing as necessary) of the thermal insulation design and of the external surface properties of the lower head, Including any applicable coatings. (C) 1997 Elsevier Science S.A. C1 IVO INT LTD,NUCL POWER ENGN,FIN-01019 IVO,FINLAND. KAISER HILL,US DOE,GOLDEN,CO 80402. RP Theofanous, TG (reprint author), UNIV CALIF SANTA BARBARA,CTR RISK STUDIES SAFETY,SANTA BARBARA,CA 93106, USA. NR 52 TC 91 Z9 109 U1 1 U2 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUN PY 1997 VL 169 IS 1-3 BP 1 EP 48 DI 10.1016/S0029-5493(97)00009-5 PG 48 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL524 UT WOS:A1997XL52400002 ER PT J AU Chu, TY Bainbridge, BL Simpson, RB Bentz, JH AF Chu, TY Bainbridge, BL Simpson, RB Bentz, JH TI Ex-vessel boiling experiments: Laboratory- and reactor-scale testing of the flooded cavity concept for in vessel core retention .1. Observation of quenching of downward-facing surfaces SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article ID HEAT-TRANSFER; NUCLEATE AB This paper presents the results of a series of quenching experiments to examine the boiling curve of relative large downward-facing surfaces. The test masses are 61 cm in diameter and the downward-facing surface is either flat or curved. The work is motivated by the need to assess the ex-vessel boiling process for in-vessel core retention. The critical heat flux is found to be approximately 50 W cm(-2). The nucleate boiling regime and the critical heat flux regime are found to be characterized by cyclic two-phase flow patterns. (C) 1997 Elsevier Science S.A. RP Chu, TY (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 19 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUN PY 1997 VL 169 IS 1-3 BP 77 EP 88 DI 10.1016/S0029-5493(96)01278-2 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL524 UT WOS:A1997XL52400005 ER PT J AU Chu, TY Bentz, JH Slezak, SE Pasedag, WF AF Chu, TY Bentz, JH Slezak, SE Pasedag, WF TI Ex-vessel boiling experiments: Laboratory- and reactor-scale testing of the flooded cavity concept for in-vessel core retention .2. Reactor-scale boiling experiments of the flooded cavity concept for in-vessel core retention SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB This paper summarizes the results of a reactor-scale ex-vessel boiling experiment for assessing the flooded cavity design of the heavy water new production reactor. The simulated reactor vessel has a cylindrical diameter of 3.7 m and a torispherical bottom head. Boiling outside the reactor vessel was found to be subcooled nucleate boiling. The subcooling mainly results from the gravity head, which in turn results from flooding the side of the reactor vessel. The boiling process exhibits a cyclic pattern with four distinct phases: direct liquid-solid contact. bubble nucleation and growth, coalescence, and vapor mass dispersion. The results show that, under prototypic heat load and heat flux distributions, the flooded cavity will be effective for in-vessel core retention in the heavy water new production reactor. The results also demonstrate that the heat dissipation requirement for in-vessel core retention, for the central region of the lower head of an AP-600 advanced light water reactor, can be met with the flooded cavity design. (C) 1997 Elsevier Science S.A. C1 US DOE,GERMANTOWN,MD 20874. RP Chu, TY (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 13 TC 18 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUN PY 1997 VL 169 IS 1-3 BP 89 EP 99 DI 10.1016/S0029-5493(96)01279-4 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL524 UT WOS:A1997XL52400006 ER PT J AU Fournier, KB Pacella, D May, MJ Finkenthal, M Goldstein, WH AF Fournier, KB Pacella, D May, MJ Finkenthal, M Goldstein, WH TI Calculation of the radiative cooling coefficient for molybdenum in a low density plasma SO NUCLEAR FUSION LA English DT Article ID ATOMIC PROCESSES; ITER; EXCITATIONS; DIVERTOR; TOKAMAKS; DESIGN; IONS AB The radiative cooling coefficient for molybdenum (Z = 42) in a low density (n(e) less than or equal to 10(15) cm(-3)) plasma is calculated. First, the molybdenum charge state distribution (CSD) is computed using the best available atomic physics data for ground state recombination and ionization, including the rates of excitation-autoionization for Mo6+ to Mo13+ and Mo23+ to Mo32+. The emissivities of Mo4+ to Mo41+ are then found using a collisional-radiative model such that the contributions from metastable levels to an ion's emissivity are taken into account. The CSD and the radiative emissivity for all molybdenum ions are combined to yield the total radiative cooling coefficient for molybdenum in a low density plasma. A radiative loss coefficient over 2 orders of magnitude smaller than that predicted by an 'average ion' model for temperatures relevant to tokamak divertor and scrape-off layer plasmas (T-e less than or similar to 50 eV) is found. The cooling coefficient of the present work varies from a factor of 2 smaller to a factor of 2 larger than that predicted by the 'average ion' model for all other plasma temperatures. The coefficient calculated in the present work is benchmarked against the measured bolometric loss profile from a molybdenum dominated shot in the Frascati Tokamak Upgrade (FTU). C1 EURATOM,ENEA FUS,CTR RIC FRASCATI,FRASCATI,ITALY. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. RP Fournier, KB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 36 TC 30 Z9 30 U1 0 U2 8 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 JUN PY 1997 VL 37 IS 6 BP 825 EP 834 DI 10.1088/0029-5515/37/6/I09 PG 10 WC Physics, Fluids & Plasmas SC Physics GA XP374 UT WOS:A1997XP37400009 ER PT J AU May, MJ Finkenthal, M Regan, SP Moos, HW Terry, JL Goetz, JA Graf, MA Rice, JE Marmar, ES Fournier, KB Goldstein, WH AF May, MJ Finkenthal, M Regan, SP Moos, HW Terry, JL Goetz, JA Graf, MA Rice, JE Marmar, ES Fournier, KB Goldstein, WH TI The measurement of the intrinsic impurities of molybdenum and carbon in the Alcator C-Mod tokamak plasma using low resolution spectroscopy SO NUCLEAR FUSION LA English DT Article ID X-RAY-SPECTRUM; POLYCHROMATOR; EXCITATIONS; DISCHARGES; TRANSPORT; COPPER AB The intrinsic impurity content of molybdenum and carbon was measured in the Alcator C-Mod tokamak using low resolution, multilayer mirror (MLM) spectroscopy (Delta lambda similar to 1-10 Angstrom). Molybdenum was the dominant high-Z impurity and originated from the molybdenum armour tiles covering all of the plasma facing surfaces (including the inner column, the poloidal divertor plates and the ion cyclotron resonant frequency (ICRF) limiter:) at Alcator C-Mod. Despite the all metal first wall, a carbon concentration of 1 to 2% existed in the plasma and was the major low-Z impurity in Alcator C-Mod. Thus, the behaviour of intrinsic molybdenum and carbon penetrating into the main plasma and the effect on the plasma must be measured and characterized during various modes of Alcator C-Mod operation. To this end, soft X ray extreme ultraviolet (XUV) emission lines of charge states, ranging from hydrogen-like to helium-like lines of carbon (radius/minor radius, r/a similar to 1) at the plasma edge to potassium- to chlorine-like (0.4 < r/a < 0.6) and magnesium- to sodium-like (r/a < 0.4) lines of molybdenum in the main plasma, were measured using a novel, low resolution, photometrically calibrated polychromator with MLMs as dispersive elements. The MLM spectra were investigated in detail, and comparisons with high resolution spectroscopy were made. The utility of low resolution spectroscopy to diagnose tokamak plasmas is presented, and meaningful information about impurity behaviour was obtainable owing to the specific choice of the observed spectral regions. Ab initio physics rates from the HULLAC atomic physics package were input into the collisional radiative (CR) model and the multiple ionization state transport (MIST) code, and both MIST and the CR model were used in the interpretation of the molybdenum spectrum. The carbon spectrum was interpreted using the MIST code and the direct impact rates of Itikawa (Itakawa, Y., et al., At Data Nucl. Data Tables 33 (1985) 149), which were incorporated into the collisional radiative model. The intrinsic ion concentrations, their contribution to the Z(eff) value, and the power losses through Line radiation were estimated. For the diverted ohmically heated plasma examined, the intrinsic molybdenum and carbon concentrations in the core plasma were found to be similar to 1.2x10(10) and similar to 1.7x10(12) cm(-3), respectively. These measurements were obtained before the plasma facing components were boronized. The calculated radiated power from molybdenum was 170 kW; for carbon it was 45 kW. The contribution to the measured Z(eff)-1 value of similar to 0.8 was similar to 0.11 for molybdenum and similar to 0.5 for carbon. C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP May, MJ (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,PLASMA SPECT GRP,BALTIMORE,MD 21218, USA. NR 35 TC 9 Z9 9 U1 0 U2 5 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 JUN PY 1997 VL 37 IS 6 BP 881 EP 896 DI 10.1088/0029-5515/37/6/I13 PG 16 WC Physics, Fluids & Plasmas SC Physics GA XP374 UT WOS:A1997XP37400013 ER PT J AU Barton, CJ Gill, RL Casten, RF Brenner, DS Zamfir, NV Zilges, A AF Barton, CJ Gill, RL Casten, RF Brenner, DS Zamfir, NV Zilges, A TI Coulomb excitation of radioactive nuclear beams in inverse kinematics SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Coulomb excitation; radioactive beams; inverse kinematics AB Two techniques for determining B(E2:0(1)(+)--> 2(1)(+)) values using low-energy Coulomb excitation of Radioactive Nuclear Beams in inverse kinematics are presented. One method, applicable if the lifetime of the excited state is similar to 1 ns, uses a linear array of NaI(T1) detectors to measure the decay curve, and thus the 2(1)(+) state lifetime, for Coulomb excited radioactive beam nuclei as they decay in flight downstream from a carbon excitation target. In the second method, useful when lifetimes are short, <1 ns, or for low intensity beams, a through-well NaI(T1) detector is used to measure the Coulomb excitation cross section from which the B(E2:0:(+)(1)--> 2(1)(+)) value is calculated. The results of test experiments with beams of stable Os isotopes are presented. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. CLARK UNIV,WORCESTER,MA 01610. YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. UNIV COLOGNE,INST KERNPHYS,D-50937 COLOGNE,GERMANY. RI Zamfir, Nicolae Victor/F-2544-2011; Zilges, Andreas/G-9984-2011 NR 10 TC 10 Z9 10 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 JUN 1 PY 1997 VL 391 IS 2 BP 289 EP 300 DI 10.1016/S0168-9002(97)00416-6 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XL507 UT WOS:A1997XL50700005 ER PT J AU Ahmad, S Bonner, BE Buchanan, JA Carter, P Chan, CS Clement, JM Eiseman, SE Empl, A Etkin, A Foley, KJ Hackenburg, RW Hallman, TJ Kramer, MA Lindenbaum, SJ Longacre, RS Love, WA Madansky, L Mattingly, AC Morris, TW Mutchler, GS Peaslee, DC Platner, ED Saulys, AC Toshkov, S AF Ahmad, S Bonner, BE Buchanan, JA Carter, P Chan, CS Clement, JM Eiseman, SE Empl, A Etkin, A Foley, KJ Hackenburg, RW Hallman, TJ Kramer, MA Lindenbaum, SJ Longacre, RS Love, WA Madansky, L Mattingly, AC Morris, TW Mutchler, GS Peaslee, DC Platner, ED Saulys, AC Toshkov, S TI Strangeness production in antiproton nucleus interactions SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 4th Biennial Conference on Low Energy Antiproton Physics Leap 96 CY AUG 27-31, 1996 CL DINKELSBUHL, GERMANY ID 4 GEV/C; MATTER AB Results on the measurement of inclusive K-S degrees, n and <(Lambda)over bar> production cross sections and rapidity distributions for antiproton interactions on lead, copper and carbon nuclear targets at beam momenta of 5.2, 7.0 and 8.8 GeV/c are reported. Simulations employing a conventional Intra-nuclear cascade model were able to reproduce the experimental results. Hence, no compelling evidence for the formation of exotic quark-gluon states of matter was found. C1 CUNY CITY COLL,NEW YORK,NY 10031. BROOKHAVEN NATL LAB,UPTON,NY 11973. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. UNIV MARYLAND,COLLEGE PK,MD 20742. RP Ahmad, S (reprint author), RICE UNIV,TW BONNER NUCL LAB,HOUSTON,TX 77251, USA. NR 9 TC 5 Z9 6 U1 0 U2 1 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 JUN PY 1997 SU 56A BP 118 EP 121 DI 10.1016/S0920-5632(97)00262-4 PG 4 WC Physics, Particles & Fields SC Physics GA XJ392 UT WOS:A1997XJ39200019 ER PT J AU Chung, SU AF Chung, SU TI Current status of J(PC)-exotic mesons SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 4th Biennial Conference on Low Energy Antiproton Physics Leap 96 CY AUG 27-31, 1996 CL DINKELSBUHL, GERMANY ID GEV/C; SYSTEM AB An exotic meson with J(PC) = 1(-+) has been studied by three groups, in the vicinity of the a(2)(1320) meson in the decay channel pi eta. The current status and future prospects of this exotic meson, especially on the new result coming from the data of BNL-E852 Collaboration, are given. RP Chung, SU (reprint author), BROOKHAVEN NATL LAB,BLDG 510A,POB 5000,UPTON,NY 11973, USA. NR 7 TC 5 Z9 5 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 JUN PY 1997 SU 56A BP 234 EP 239 DI 10.1016/S0920-5632(97)00281-8 PG 6 WC Physics, Particles & Fields SC Physics GA XJ392 UT WOS:A1997XJ39200038 ER PT J AU Barnes, T AF Barnes, T TI Radial and orbital q(q)over-bar excitations: ''Higher quarkonia'' SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 4th Biennial Conference on Low Energy Antiproton Physics Leap 96 CY AUG 27-31, 1996 CL DINKELSBUHL, GERMANY ID MESONS; MODEL; HYBRID; DECAY AB Identification of the spectrum of non- exotica such as glueballs, hybrids and molecules will require a detailed understanding of radially and orbitally excited quarkonia, since these states are a background to non- states. The data likely to become available experimentally on these higher-mass resonances are their total widths and strong branching fractions to dominant modes. We advocate the use of these branching fractions to distinguish quarkonia from exotica; in this contribution we summarize our recent detailed P-3(0) decay model calculations of the 374 two-body open-flavor decay modes of the 32 lightest states above 1S and 1P, which should be useful for this program. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Barnes, T (reprint author), OAK RIDGE NATL LAB,DIV PHYS,THEORET & COMPUTAT PHYS GRP,POB 2008,OAK RIDGE,TN 37831, USA. NR 26 TC 1 Z9 1 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 JUN PY 1997 SU 56A BP 240 EP 247 PG 8 WC Physics, Particles & Fields SC Physics GA XJ392 UT WOS:A1997XJ39200039 ER PT J AU Reyes, MA Berisso, MC Christian, D Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, B Kreisler, MN Lee, S Markianos, K Moreno, G Sosa, M Wehmann, A Wesson, D AF Reyes, MA Berisso, MC Christian, D Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, B Kreisler, MN Lee, S Markianos, K Moreno, G Sosa, M Wehmann, A Wesson, D TI Spin-parity analysis of the centrally produced KsKs system at 800 GeV SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 4th Biennial Conference on Low Energy Antiproton Physics Leap 96 CY AUG 27-31, 1996 CL DINKELSBUHL, GERMANY AB Results are presented of the spin-parity analysis on a sample of centrally produced mesons in the reaction pp-->p(slow)(KsKs)p(fast) with 800 GeV protons on liquid hydrogen. The spin-parity analysis in the mass region between threshold and 1.58 GeV/c(2) shows that the KsKs system is produced mainly in S wave. The f(0)(1500) is clearly observed in this region. Above 1.58 GeV/c(2) two solution are possible, one with mainly S wave and another with mainly D wave. This ambiguity prevents a unique determination of the spin of the f(J)(1710) meson. C1 UNIV MASSACHUSETTS,AMHERST,MA 01003. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL. COLUMBIA UNIV,NEVIS LABS,NEW YORK,NY. UNIV ILLINOIS,CHAMPAIGN,IL 61820. RP Reyes, MA (reprint author), UNIV GUANAJUATO,LEON,GUANAJUATO,MEXICO. OI Hartouni, Edward/0000-0001-9869-4351 NR 10 TC 2 Z9 2 U1 2 U2 3 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 JUN PY 1997 SU 56A BP 285 EP 290 DI 10.1016/S0920-5632(97)00289-2 PG 6 WC Physics, Particles & Fields SC Physics GA XJ392 UT WOS:A1997XJ39200046 ER PT J AU Holzscheiter, MH Bendiscioli, G Bertin, A Bollen, G Bruschi, M Cesar, C Charlton, M Corradini, M DePedis, D Doser, M Eades, J Fedele, R Feng, X Galluccio, F Goldman, T Hangst, JS Hayano, R Horvath, D Hughes, RJ King, NSP Kirsebom, K Knudsen, H Lagomarsino, V Landua, R Laricchia, G Lewis, RA LodiRizzini, E Macri, M Manuzio, G Marconi, U Masullo, MR Merrison, JP Moller, SP Morgan, GL Nieto, MM Piccinini, M Poggiani, R Rotondi, A Rouleau, G Salvini, P SempriniCesari, N Smith, GA Surko, CM Testera, G Torelli, G Uggerhoj, E Vaccaro, VG Venturelli, L Vitale, A Widmann, E Yamazaki, T Yamazaki, Y Zanello, D Zoccoli, A AF Holzscheiter, MH Bendiscioli, G Bertin, A Bollen, G Bruschi, M Cesar, C Charlton, M Corradini, M DePedis, D Doser, M Eades, J Fedele, R Feng, X Galluccio, F Goldman, T Hangst, JS Hayano, R Horvath, D Hughes, RJ King, NSP Kirsebom, K Knudsen, H Lagomarsino, V Landua, R Laricchia, G Lewis, RA LodiRizzini, E Macri, M Manuzio, G Marconi, U Masullo, MR Merrison, JP Moller, SP Morgan, GL Nieto, MM Piccinini, M Poggiani, R Rotondi, A Rouleau, G Salvini, P SempriniCesari, N Smith, GA Surko, CM Testera, G Torelli, G Uggerhoj, E Vaccaro, VG Venturelli, L Vitale, A Widmann, E Yamazaki, T Yamazaki, Y Zanello, D Zoccoli, A TI Antihydrogen production and precision experiments SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 4th Biennial Conference on Low Energy Antiproton Physics Leap 96 CY AUG 27-31, 1996 CL DINKELSBUHL, GERMANY ID GRAVITATIONAL ACCELERATION; ATOMIC-HYDROGEN; MAGNETIC TRAP; POSITRONIUM; CPT; ANTIPROTONS; COLLISIONS; SPECTROSCOPY; ANTIMATTER; VIOLATION AB The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. In recent years impressive progress has been achieved in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and in storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. Once antihydrogen atoms have been captured at low energy, spectroscopic methods can be applied to interrogate their atomic structure with extremely high precision and compare it to its normal matter counterpart, the hydrogen atom. Especially the 1S-2S transition, with a lifetime of the excited state of 122 msec and thereby a natural linewidth of 5 parts in 10(16), offers in principle the possibility to directly compare matter and antimatter properties at a level B1 of 1 part in 10(18). C1 UNIV PAVIA, I-27100 PAVIA, ITALY. IST NAZL FIS NUCL, I-27100 PAVIA, ITALY. UNIV BOLOGNA, BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. CERN, CH-1211 GENEVA, SWITZERLAND. ESCOLA TECN FED DO CEARA, BR-60040531 FORTALEZA, CEARA, BRAZIL. UCL, DEPT PHYS & ASTRON, LONDON WC1E 6BT, ENGLAND. UNIV BRESCIA, BRESCIA, ITALY. IST NAZL FIS NUCL, BRESCIA, ITALY. UNIV ROMA LA SAPIENZA, ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV AARHUS, INST PHYS & ASTRON, DK-8000 AARHUS C, DENMARK. UNIV TOKYO, TOKYO, JAPAN. UNIV GENOA, I-16146 GENOA, ITALY. IST NAZL FIS NUCL, I-16146 GENOA, ITALY. PENN STATE UNIV, OSMOND LAB 303, UNIVERSITY PK, PA 16802 USA. UNIV PISA, I-56100 PISA, ITALY. IST NAZL FIS NUCL, I-56100 PISA, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. RP LOS ALAMOS NATL LAB, MS H803-P-23, LOS ALAMOS, NM 87545 USA. RI Horvath, Dezso/A-4009-2011; Widmann, Eberhard/G-2545-2011; Marconi, Umberto/J-2263-2012; Hayano, Ryugo/F-7889-2012; Yamazaki, Yasunori/N-8018-2015; Fedele, Renato/I-6689-2012; OI Rotondi, Alberto/0000-0003-1921-6808; Widmann, Eberhard/0000-0003-0486-6023; Marconi, Umberto/0000-0002-5055-7224; Hayano, Ryugo/0000-0002-1214-7806; Yamazaki, Yasunori/0000-0001-5712-0853; Fedele, Renato/0000-0003-3130-0287; merrison, jonathan/0000-0003-4362-6356 NR 79 TC 28 Z9 28 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JUN PY 1997 SU 56A BP 336 EP 348 DI 10.1016/S0920-5632(97)00296-X PG 13 WC Physics, Particles & Fields SC Physics GA XJ392 UT WOS:A1997XJ39200053 ER PT J AU Dong, DJ Vandegrift, GF AF Dong, DJ Vandegrift, GF TI Alkaline peroxide processing of low-enriched uranium targets for Mo-99 production - Decomposition of hydrogen peroxide SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB The recent progress on the alkaline peroxide processing of low-enriched uranium targets for the production of Mo-99, a parent nuclide of the widely used medical isotope Tc-99m, is reported. Kinetic studies were undertaken to investigate the decomposition of hydrogen peroxide in alkaline solution in contact with a uranium metal surface. It was found that the decomposition of hydrogen peroxide essentially follows the kinetic trend of uranium dissolution and can be classified into two regimes, depending on the hydroxide concentration. In the low-base regime (<0.2 M), both the hydrogen peroxide and hydroxide concentrations affect the rate of peroxide decomposition. In the high-base regime (>0.2 M), the rate of peroxide decomposition is independent of alkali concentration. When the acid/base equilibrium between H2O2 and O2H- is taken into account, the overall rate of hydrogen peroxide disappearance can be described as a 0.25th order reaction with respect to hydrogen peroxide concentration over NaOH concentrations ranging from 0.01 to 5 M. Empirical kinetics models are proposed and discussed. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP Dong, DJ (reprint author), OWENS CORNING SCI & TECHNOL CTR,2790 COLUMBUS RD,GRANVILLE,OH 43023, USA. NR 23 TC 6 Z9 6 U1 0 U2 4 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 1997 VL 126 IS 2 BP 213 EP 223 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XD202 UT WOS:A1997XD20200008 ER PT J AU Buchholz, BA Hutter, JC Vandegrift, GF AF Buchholz, BA Hutter, JC Vandegrift, GF TI Dissolution kinetics of U3Si2 particles in alkaline hydrogen peroxide SO NUCLEAR TECHNOLOGY LA English DT Article AB Nonproliferation concerns leading to the conversion from high- to low-enriched uranium sparked interest in U3Si2 dispersion targets as an option for Mo-99 production. Dissolution of irradiated targets is an important step in recovering fission-product Mo-99. Alkaline hydrogen peroxide solutions dissolved U3Si2 particles in an open batch reactor; samples were analyzed for total peroxide and uranium concentrations as functions of time and temperature. Dissolution rates are highest at 1 to 1.5 M NaON and change little for initial base concentrations from 0.5 to 2.5 M NaON, indicating relatively robust process conditions. Uranium dissolution rates depend most strongly on the equilibrium concentration of the peroxyl ion (O2H-), an equilibrium product of hydrogen peroxide (H2O2) and hydroxyl ion (OH-). Temperature and equilibrium concentrations of O2H- and OH- are included in a uranium dissolution rate model. RP Buchholz, BA (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Buchholz, Bruce/G-1356-2011 NR 17 TC 0 Z9 0 U1 1 U2 4 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUN PY 1997 VL 118 IS 3 BP 225 EP 232 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XB178 UT WOS:A1997XB17800003 ER PT J AU Allen, MJ Bradbury, EM Balhorn, R AF Allen, MJ Bradbury, EM Balhorn, R TI AFM analysis of DNA-protamine complexes bound to mica SO NUCLEIC ACIDS RESEARCH LA English DT Article ID ATOMIC-FORCE MICROSCOPY; SPERM CHROMATIN; MAMMALIAN SPERM; INDUCED CONDENSATION; ULTRASTRUCTURE; ORGANIZATION; SPERMATOZOA; SEQUENCE; NUCLEAR; FIBERS AB A novel method for reconstituting sperm chromatin was used to investigate how protamine 1 condenses DNA. Complexes formed in vitro using linearized plasmid DNA were imaged and measured by atomic force microscopy (AFM). The structures formed were found to be highly dependent on the sample preparation method used for reconstitution. Interstrand, side-by-side fasiculation of DNA and toroidal-like structures only 1-2 DNA diameters thick were observed for complexes formed in solution following direct mixing of the DNA and protamine. Large chromatin aggregates were also observed on the mica. However, if the DNA was first allowed to attach to the mica prior to addition of the protamine, well-defined toroidal complexes were formed without any observed DNA fasiculation or aggregate formation. The diameter of the toroids measured 30.6-50.2 nm (mean 39.4 nm). The dimensions of these structures indicate that the condensed DNA is stacked vertically by four to five turns, with each coil containing as little as 360-370 bp of 'B'-form DNA. This approach for preparing and imaging DNA-protamine complexes permits the analysis of intermediate structures 'trapped' on the mica as partially formed toruses of nucleoprotamine. C1 UNIV CALIF DAVIS,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. RP Allen, MJ (reprint author), DIGITAL INSTRUMENTS,520 E MONTECITO ST,SANTA BARBARA,CA 93103, USA. NR 37 TC 129 Z9 133 U1 3 U2 25 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUN 1 PY 1997 VL 25 IS 11 BP 2221 EP 2226 DI 10.1093/nar/25.11.2221 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XD490 UT WOS:A1997XD49000025 PM 9153324 ER PT J AU Joh, S Evans, GH AF Joh, S Evans, GH TI Heat transfer and flow stability in a rotating disk stagnation flow chemical vapor deposition reactor SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article ID MODEL; GAS AB The flow and heat transfer in a vertical high-speed rotating disk/stagnation flow chemical vapor deposition (CVD) reactor is studied with particular emphasis on the effects of the spacing (H) over bar between the stationary gas inlet and the rotating disk. In both one- and two-dimensional (1-D and 2-D) analyses the Navier-Stokes and energy equations are soh,ed for hydrogen to determine the effects of (H) over bar, flow rate, disk spin rate, buoyancy, and finite geometry on the gas flow patterns and the heat transfer from Be disk. The I-D results show that the heat transfer from the rotating disk, Nu(1D), depends on the flow parameter (SP = \<(mu)over bar>(in)\/root<(omega)over bar><(nu)over bar>(in)) and the disk Reynolds number (Re-omega = (r) over bar(d)(2)<(omega)over bar>/<(nu)over bar>(in)) to a much greater extent at smaller spacings A = (H) over bar/(r) over bar(d) = 0.54) than at larger spacings (A = 2.16). For SP values of 0.92 and 4.5 and for both spacings studied, Nu(1D) approaches the value for an infinite rotating disk in a semi-infinite medium for Re-omega > 450 approximately, except for the case at SP = 4.5 and A = 0.54, where Nu(1D) is significantly larger. The 2-D results show a larger effect of Sp on the radial variation of Nu(2D) for larger values of A (the uniformity of Nu(2D) is improved significantly at the larger A when the inlet velocity matches the asymptotic value for an infinite rotating disk). For both values of A there is greater nonuniformity of Nu(2D) at the larger value of SP; when the disk is ''starved'' (SP = 0.23, Re-omega = 456), there is gas recirculation above the rotating disk. The results are only slightly affected when (r) over bar(0)/(r) over bar(d) is varied by approximately 30% (from 1.1 to 1.4) for the conditions SP = 0.23, A = 0.54, and Re-omega = 456. C1 SANDIA NATL LABS,THERMAL & PLASMA PROC DEPT,LIVERMORE,CA 94551. NOVELLUS SYST INC,SAN JOSE,CA 95134. NR 14 TC 10 Z9 11 U1 0 U2 2 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD JUN PY 1997 VL 31 IS 8 BP 867 EP 879 DI 10.1080/10407789708914069 PG 13 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA XH309 UT WOS:A1997XH30900005 ER PT J AU Burns, SP Christon, MA AF Burns, SP Christon, MA TI Spatial domain-based parallelism in large-scale, participating-media, radiative transport applications SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID HEAT-TRANSFER AB Parallelism for gray participating-media radiation heat transfer may be placed in two primary categories: spatial and angular domain-based parallelism. Angular-based decomposition is limited for large-scale applications, however, given the memory required to store the spatial grid on each processor. Therefore, the objective of this work is to examine the application of spatial domain-based parallelism to large-scale, three-dimensional, participating-media radiation transport calculations using a massively parallel supercomputer architecture. Both scaled and fixed problem size efficiencies are presented for an application of the discrete ordinate method to a three-dimensional, nonscattering radiative transport application with nonuniform absorptivity. The data presented show that the spatial domain-based decomposition paradigm results in some degradation in the parallel efficiency but provides useful speed-up for large computational grids. C1 SANDIA NATL LABS,COMPUTAT PHYS R&D DEPT,ALBUQUERQUE,NM 87185. RP Burns, SP (reprint author), SANDIA NATL LABS,UNSTEADY & REACT FLUID MECH DEPT,MS 0836,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 19 Z9 19 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD JUN PY 1997 VL 31 IS 4 BP 401 EP 421 DI 10.1080/10407799708915117 PG 21 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA XH315 UT WOS:A1997XH31500002 ER PT J AU Wang, GJ He, YD AF Wang, GJ He, YD TI Probability description of final-state distribution in independent fragmentation model SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA A-NUCLEI PARTICLES AND FIELDS LA English DT Article ID JETS AB We present a probability account of the density distribution for final states in a class of independent fragmentation models. The formalism leads to a simple but exact expression for the single-particle distribution of the final states. As an example, me discuss a particular model used in high-energy parton-parton and e(+)e(-) scatterings - the independent jet fragmentation model. The universality and simplicity of the probability description allow us to apply our formalism to various physical processes of fragmentation nature. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. LAWRENCE BERKELEY LAB, INST NUCL & PARTICLE ASTROPHYS, BERKELEY, CA 94720 USA. RP Wang, GJ (reprint author), WAYNE STATE UNIV, DEPT PHYS, DETROIT, MI 48202 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 1124-1861 J9 NUOVO CIMENTO A JI Nuovo Cimento Soc. Ital. Fis. A-Nucl. Part. Fields PD JUN PY 1997 VL 110 IS 6 BP 599 EP 610 PG 12 WC Physics, Particles & Fields SC Physics GA YA875 UT WOS:A1997YA87500005 ER PT J AU With, KA King, AW AF With, KA King, AW TI The use and misuse of neutral landscape models in ecology SO OIKOS LA English DT Review ID HIERARCHICALLY STRUCTURED LANDSCAPES; FRACTAL LANDSCAPES; NULL MODELS; PATTERNS; COEXISTENCE; THRESHOLDS; DISPERSAL; INDEXES AB Neutral landscape models (NLMs) were developed from percolation theory nearly a decade ago. Since then, the original random percolation maps have undergone adaptive radiation and NLMs now include a diverse array of spatially explicit models based on theoretical distributions derived from fractal geometry and spectral synthesis. The purpose of NLMs is to provide null models of landscape structure as a baseline for comparison with real landscape patterns, or for evaluating the effects of landscape structure on ecological processes. As the use of NLMs has expanded beyond the domain of theoretical landscape ecology to applications in other areas of ecology, there is an increased risk that NLMs will be used inappropriately, or that their function will be misunderstood or misinterpreted. NLMs are being subjected to the same general criticisms levied against null models in other areas of ecology. For this reason, we clarify the purpose of NLMs, review the contributions of NLMs to ecology, and evaluate the appropriate use of NLMs in ecological research. NLMs have already made several contributions to ecology: (1) development of spatial indices to describe landscape patterns; (2) prediction of critical thresholds in ecological phenomena; (3) definition of landscape connectivity; (4) development of ''species' perceptions'' of landscape structure; (5) provision of a general model of spatial complexity; and (6) determination of the ecological consequences of spatial heterogeneity. In the future, emphasis on NLMs should shift from theoretical development to application and model testing. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP With, KA (reprint author), BOWLING GREEN STATE UNIV,DEPT BIOL SCI,BOWLING GREEN,OH 43403, USA. RI With, Kimberly/J-5124-2014 OI With, Kimberly/0000-0001-5570-1515 NR 49 TC 145 Z9 152 U1 5 U2 50 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0030-1299 J9 OIKOS JI Oikos PD JUN PY 1997 VL 79 IS 2 BP 219 EP 229 DI 10.2307/3546007 PG 11 WC Ecology SC Environmental Sciences & Ecology GA WZ103 UT WOS:A1997WZ10300002 ER PT J AU Tyler, JA Hargrove, WW AF Tyler, JA Hargrove, WW TI Predicting spatial distribution of foragers over large resource landscapes: A modeling analysis of the Ideal Free Distribution SO OIKOS LA English DT Article ID COD GADUS-MORHUA; DERIVING POPULATION PARAMETERS; SOUTHERN GULF; ST-LAWRENCE; INDIVIDUAL VARIATIONS; UNEQUAL COMPETITORS; PATCHY ENVIRONMENT; HABITAT SELECTION; FORAGING BEHAVIOR; PREDATION RISK AB Ideal Free Distributions (IFD) have successfully been used to describe the spatial distributions of animals in heterogeneous or patchy environments over relatively small areas. Ideal Free theory and the logic underlying it have recently been used to describe animal distributions over large landscapes and in doing so, these studies have not precisely met all of the assumptions of the IFD. Here, we use an individual-based simulation model of a population of generalized foragers to test the ability of the IFD to predict the equilibrium distribution of organisms in a large environment. Conditions of the model meet the assumptions of Ideal Free theory. Food abundance follows a fractal distribution spatially through the environment. Model foragers have a type II functional response and a marginal-value theorem type patch departure rule. Foragers may move through the environment without cost, and foraging does not affect food availability. In a simulation experiment, we manipulate the scale of heterogeneity in food distribution, the number of foragers in the population, the distance foragers move, and the scale of IFD predictions to determine the ability of the IFD to predict equilibrium spatial distribution of foragers. The experiment shows that correlations between IFD predictions and the distribution of simulated foragers were lower when food had a fractal distribution than when food resources had a random spatial distribution. IFD predictions best fit simulated forager distributions on fractal food landscapes when the scale at which distributions were measured was similar to the maximum movement distance of the foragers. Large differences between maximum movement distance and scale of measure resulted in low correlations between equilibrium distributions of simulated foragers and IFD predictions. These results indicate that the IFD is likely not a good predictor of animal distributions in large environments and that the extent of the area over which an IFD is used should be similar to the maximum daily movement of the animals under study. C1 OAK RIDGE NATL LAB, COMPUTAT PHYS & ENGN DIV, OAK RIDGE, TN 37831 USA. RP SUNY COLL BUFFALO, GREAT LAKES CTR, 1300 ELMWOOD AVE, BUFFALO, NY 14222 USA. NR 69 TC 40 Z9 40 U1 3 U2 28 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0030-1299 EI 1600-0706 J9 OIKOS JI Oikos PD JUN PY 1997 VL 79 IS 2 BP 376 EP 386 DI 10.2307/3546022 PG 11 WC Ecology SC Environmental Sciences & Ecology GA WZ103 UT WOS:A1997WZ10300017 ER PT J AU James, DFV Wolf, E AF James, DFV Wolf, E TI Cross-spectrally pure light and the spectral modulation law SO OPTICS COMMUNICATIONS LA English DT Article ID YOUNG INTERFERENCE EXPERIMENT; COHERENCE AB Mandel's concept of cross-spectral purity is generalized to apply not only to certain kinds of beams, but also to some fields in three-dimensional regions of space. Examples of such fields are given. The results also provide justification for the use of the so-called reduction formula for cross-spectrally pure beams in previous analysis of the Hanbury-Brown-Twiss experiments, relating to the determination of the degree of coherence of light from photoelectric measurements. C1 UNIV ROCHESTER, DEPT PHYS & ASTRON, ROCHESTER, NY 14627 USA. UNIV ROCHESTER, ROCHESTER THEORY CTR OPT SCI & ENGN, ROCHESTER, NY 14627 USA. UNIV ROCHESTER, INST OPT, ROCHESTER, NY 14627 USA. RP James, DFV (reprint author), LOS ALAMOS NATL LAB, THEORET PHYS DIV T4, MAIL STOP B268, LOS ALAMOS, NM 87545 USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 14 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 EI 1873-0310 J9 OPT COMMUN JI Opt. Commun. PD JUN 1 PY 1997 VL 138 IS 4-6 BP 257 EP 261 DI 10.1016/S0030-4018(96)00777-8 PG 5 WC Optics SC Optics GA XA078 UT WOS:A1997XA07800003 ER PT J AU Hehlen, MP Cockroft, NJ Gosnell, TR Bruce, AJ Nykolak, G Shmulovich, J AF Hehlen, MP Cockroft, NJ Gosnell, TR Bruce, AJ Nykolak, G Shmulovich, J TI Uniform upconversion in high-concentration Er3+-doped soda lime silicate and aluminosilicate glasses SO OPTICS LETTERS LA English DT Article ID COOPERATIVE UP-CONVERSION; EXCITED-STATE ABSORPTION; DOPED FIBER AMPLIFIERS; WAVE-GUIDES; 980 NM; MECHANISMS AB Uniform upconversion in erbium-doped silicate glasses is investigated as a function of glass composition, concentration, and fabrication method. Comparisons of upconversion coefficients are made among soda lime silicate and aluminosilicate bulk glasses and soda lime silicate waveguides. Comparisons are also made with studies performed by other researchers. The results indicate that both the composition and the preparation method of the glass affect the value of the upconversion coefficient, with as much as a factor-of-4 variation observed at fixed Er3+ concentration. Values of the upconversion coefficient are found to be consistent with the Forster-Dexter microscopic model. (C) 1997 Optical Society of America. C1 LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Hehlen, MP (reprint author), LOS ALAMOS NATL LAB,MS E543,LOS ALAMOS,NM 87545, USA. NR 19 TC 69 Z9 72 U1 1 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 1997 VL 22 IS 11 BP 772 EP 774 DI 10.1364/OL.22.000772 PG 3 WC Optics SC Optics GA XC137 UT WOS:A1997XC13700008 PM 18185657 ER PT J AU Womble, DE Greenberg, DS AF Womble, DE Greenberg, DS TI Parallel I/O: An introduction SO PARALLEL COMPUTING LA English DT Editorial Material DE parallelism; data distribution; file systems; parallel I/O AB As an introduction to and motivation for this special issue we discuss the definition of parallel I/O, why it is necessary and the major issues that need to be addressed. We expand on the research issues by recording an e-mailed 'roundtable' discussion among the authors of papers in this issue. The authors were asked to respond to three questions concerning the state of and needed direction of research in parallel I/O. Authors were also given the chance to respond to each others' answers. RP Womble, DE (reprint author), SANDIA NATL LABS,POB 5800,MAIL STOP 1110,ALBUQUERQUE,NM 87185, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD JUN 1 PY 1997 VL 23 IS 4-5 BP 403 EP 417 DI 10.1016/S0167-8191(97)00007-0 PG 15 WC Computer Science, Theory & Methods SC Computer Science GA XD069 UT WOS:A1997XD06900002 ER PT J AU Fukushima, H Jenkins, ML Kirk, MA AF Fukushima, H Jenkins, ML Kirk, MA TI On the determination of the nature of defect clusters produced by displacement cascades .1. A critique of the two-and-a-half-dimensional technique as applied to small clusters in silver and copper SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; STACKING-FAULT TETRAHEDRA; IRRADIATED SILVER; MOLECULAR-DYNAMICS; TEM; DAMAGE AB The application of the two-and-a-half-dimensional (2 1/2 D) technique to the analysis of the nature of small point-defect clusters in ion-irradiated silver and copper has been explored. A modification of the technique which allows the identification of reciprocal-lattice spike effects has been made. However, even with this modification a comparison of analyses of the same clusters by 2 1/2 D and the Black-White contrast method showed that 2 1/2 D analyses of small faulted point-defect clusters are unreliable. C1 UNIV OXFORD,DEPT MAT,OXFORD OX1 3PH,ENGLAND. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Fukushima, H (reprint author), HIROSHIMA UNIV,FAC ENGN,1-4-1 KAGAMIYAMA,HIGASHIHIROSHIMA 739,JAPAN. NR 26 TC 7 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUN PY 1997 VL 75 IS 6 BP 1567 EP 1582 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA XD500 UT WOS:A1997XD50000005 ER PT J AU Fukushima, H Jenkins, ML Kirk, MA AF Fukushima, H Jenkins, ML Kirk, MA TI On the determination of the nature of defect clusters produced by displacement cascades .2. Application of stereo imaging techniques to heavy-ion damage in copper SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; IRRADIATION; METALS AB The black-white (B-W) stereo technique has been critically assessed and applied to the determination of the nature of small point-defect clusters in copper produced by Kr+ heavy-ion irradiation at room temperature. Several precautions were introduced in an attempt to improve the reliability of the analysis. It was found that most defects lying in the first approximately 10 nm of the foil are vacancy in nature, together with some of the deeper clusters. There was no unequivocal evidence for interstitial clusters. Some were more likely to be interstitial than vacancy on the criteria chosen, although the evidence is weak. Defects sometimes showed inconsistent contrast from one imaging condition to another, demonstrating the difficulty of placing them in the layer structure with complete confidence. The near impossibility of establishing that interstitial clusters are not present is shown by the fact that over half (53%) the total number of clusters could not be analysed because they did not show clear B-W contrast in a minimum number of imaging conditions. Various correlations are made between parameters such as defect sizes with the depths of the defects in the foil. C1 UNIV OXFORD,DEPT MAT,OXFORD OX1 3PH,ENGLAND. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Fukushima, H (reprint author), HIROSHIMA UNIV,FAC ENGN,1-4-1 KAGAMIYAMA,HIGASHIHIROSHIMA 739,JAPAN. NR 22 TC 10 Z9 10 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUN PY 1997 VL 75 IS 6 BP 1583 EP 1602 PG 20 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA XD500 UT WOS:A1997XD50000006 ER PT J AU Devanathan, R Yu, N Sickafus, KE Nastasi, M Grimsditch, M Okamoto, PR AF Devanathan, R Yu, N Sickafus, KE Nastasi, M Grimsditch, M Okamoto, PR TI Elastic instability in ion-beam-irradiated magnesium aluminate spinel SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID SOLID-STATE AMORPHIZATION; CATION DISORDER; TRANSFORMATION; CRYSTALLINE; CERAMICS AB We present the first observation of an irradiation-induced instability in the shear modulus of MgAl2O4 spinel. Brillouin scattering was used to determine the elastic constant C-44 following 400 keV Xe2+ irradiation of single-crystal spinel at 100 K. The corresponding structural changes were determined using electron microscopy. The results confirm a two-step transformation to the amorphous state through an intermediate metastable crystalline phase. The shear elastic constant decreases by about 35% upon amorphization. This low-temperature radiation response, which is in contrast with the radiation resistance observed at elevated temperatures, is discussued in terms of the ability of spinel to accommodate cation disorder and the free-energy difference between the liquid and solid states. C1 LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RI Devanathan, Ram/C-7247-2008 OI Devanathan, Ram/0000-0001-8125-4237 NR 33 TC 6 Z9 6 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD JUN PY 1997 VL 75 IS 6 BP 793 EP 801 DI 10.1080/13642819708205707 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA XD501 UT WOS:A1997XD50100001 ER PT J AU Hanson, AL Bajt, S AF Hanson, AL Bajt, S TI Investigation of the pre-edge inelastic X-ray scattering by several 3d transition-metal compounds SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID RESONANT RAMAN-SCATTERING; ABSORPTION-EDGE; FLUORESCENCE; SPECTROSCOPY; EMISSION; TI AB Spectra of X-rays scattered by compounds of 3d transition elements exhibit structure when the energies of the incident X-rays are a few electronvolts below the elements' K-absorption edge energies. This structure is the result of an inelastic scattering process and has been studied in compounds of chromium, iron and copper with a high-energy resolution wavelength-dispersive spectrometer. When the energies of the incident X-rays were tuned between the pre edge peak and the absorption edge, the energy of the resonantly scattered Xrays were always measured to be equal to the energy of the characteristic K alpha X-rays. This observation is in disagreement with the prediction of the present theoretical models for resonant scattering which were derived assuming the interactions to be fast collisions. C1 UNIV CHICAGO,CHICAGO,IL 60637. RP Hanson, AL (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Bajt, Sasa/G-2228-2010 NR 28 TC 7 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER 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 JUN PY 1997 VL 75 IS 6 BP 909 EP 924 DI 10.1080/13642819708205716 PG 16 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA XD501 UT WOS:A1997XD50100010 ER PT J AU Alexander, FJ Garcia, AL Alder, BJ AF Alexander, FJ Garcia, AL Alder, BJ TI The consistent Boltzmann algorithm for the van der Waals equation of state SO PHYSICA A LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM AB The direct-simulation Monte Carlo method is generalized by introducing an advection displacement that models a hard-core exclusion with a weak and constant interparticle attraction, Simulation results demonstrate that both the van der Waals equation of state and its Maxwell tie-line construction can be obtained. C1 BOSTON UNIV,CTR COMPUTAT SCI,BOSTON,MA 02215. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 15 TC 24 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 196 EP 201 DI 10.1016/S0378-4371(97)00142-8 PG 6 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200017 ER PT J AU Mansour, MM Baras, F Garcia, AL AF Mansour, MM Baras, F Garcia, AL TI On the validity of hydrodynamics in plane Poiseuille flows SO PHYSICA A LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM DE hydrodynamics; kinetic theory; Boltzmann equation; BGK approximation; molecular dynamics; direct simulation Monte Carlo ID MOLECULAR-DYNAMICS SIMULATIONS; RAYLEIGH-BENARD CONVECTION; HEAT; GAS; TRANSPORT; PATTERNS; SLIP AB Microscopic simulations of plane Poiseuille flow for a dilute gas are presented. Although the flow is laminar (Reynolds number approximate to 10) and sub-sonic, the temperature and pressure profiles measured in the simulations differ qualitatively from the hydrodynamic predictions. The results are in agreement with a recent theoretical analysis based on the asymptotic solution of the BGK model of the Boltzmann equation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,BERKELEY,CA 94720. RP Mansour, MM (reprint author), FREE UNIV BRUSSELS,CTR NONLINEAR PHENOMENA & COMPLEX SYST,CP 231,BLVD TRIOMPHE,CAMPUS PLAINE,B-1050 BRUSSELS,BELGIUM. RI Baras, Florence/A-5679-2009 NR 47 TC 61 Z9 62 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 255 EP 267 DI 10.1016/S0378-4371(97)00149-0 PG 13 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200024 ER PT J AU Ladd, AJC Kinney, JH AF Ladd, AJC Kinney, JH TI Elastic constants of cellular structures SO PHYSICA A LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM AB Lattice models for calculating the elastic properties of cellular structures are described; on small scales the elastic constants are isotropic, both in two and three dimensions. Stresses are transmitted by harmonic springs that connect the nodes surrounding each volume element. The force constants of the springs are determined by the local elastic stiffness, which can vary from element to element. The model was tested by comparing the elastic constants of periodic two-dimensional microstructures with analytic results. Then it was applied to calculations of the elastic constants of samples of human trabecular bone, using images of the microstructure determined by X-ray transmission microscopy. RP Ladd, AJC (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 10 TC 40 Z9 40 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 349 EP 360 DI 10.1016/S0378-4371(97)00158-1 PG 12 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200033 ER PT J AU Wang, JH Li, J Yip, S Wolf, D Phillpot, S AF Wang, JH Li, J Yip, S Wolf, D Phillpot, S TI Unifying two criteria of Born: Elastic instability and melting of homogeneous crystals SO PHYSICA A LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM ID LATTICE INSTABILITY; MOLECULAR-DYNAMICS; AMORPHIZATION; STABILITY; STATE AB The criteria formulated by M. Born for the onset of melting (1939) and lattice stability (1940) are re-examined on the basis of more general considerations of elastic instabilities. With the aid of molecular dynamics simulations, we show that (1) Born's stability criteria are valid only in the case of zero external stress, and (2) his thermoelastic melting criterion, with some modification, is valid for the homogeneous process (mechanical melting or upper limit of superheating) which can occur when the free-energy-based heterogeneous process (melting by nucleation and growth) is kinetically suppressed. These and other related recent results on crack nucleation, pressure-induced polymorphic transition and amorphization emphasize the fundamental role of elastic instabilities in triggering unstable structural responses of homogeneous crystals. C1 MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. RI Li, Ju/A-2993-2008; Phillpot, Simon/J-9117-2012; OI Li, Ju/0000-0002-7841-8058; Phillpot, Simon/0000-0002-7774-6535 NR 24 TC 53 Z9 53 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 396 EP 403 DI 10.1016/S0378-4371(97)00161-1 PG 8 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200036 ER PT J AU Alder, B AF Alder, B TI Highly discretized dynamics SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM AB The efforts in the last ten years or so to find a particle dynamics, wherein, the spatial coordinates are confined to lattice positions and the velocity coordinates to a few speeds, have unfortunately failed. It was hoped to duplicate the success of the Ising model, which would have allowed, if not for an analytic treatment, at least much more efficient computational methods to deal with hydrodynamic transport phenomena, particularly turbulence. The next course of action, in view of this failure, will be discussed after the reasons for the failure are outlined. RP Alder, B (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 5 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 193 EP 195 DI 10.1016/S0378-4371(97)00141-6 PG 3 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200016 ER PT J AU Posch, HA Hoover, WG AF Posch, HA Hoover, WG TI Simulation of two-dimensional Kolmogorov flow with smooth particle applied mechanics SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM ID HYDRODYNAMICS; TURBULENCE AB Smooth-particle applied mechanics is an interesting alternative method for the simulation of hydrodynamic flows. In this grid-free procedure the various fields are calculated by summing up the contributions from neighboring particles which are smoothly distributed in space according to a weighting function. The motion equations for these particles are ordinary differential equations similar - and in special cases isomorphic - to the atomistic equations of motion. We apply the method to two-dimensional Kolmogorov flow, where the fluid in the top and bottom half of the tube is accelerated in opposite directions. By varying the Reynolds number the transition from laminar flow to a stationary flow with symmetrically placed vortices is followed. C1 LAWRENCE LIVERMORE NATL LAB, DEPT PHYS, LIVERMORE, CA 94551 USA. UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA 94551 USA. RP UNIV VIENNA, INST EXPT PHYS, BOLTZMANNGASSE 5, A-1090 VIENNA, AUSTRIA. NR 19 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 EI 1873-2119 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 286 EP 296 DI 10.1016/S0378-4371(97)00152-0 PG 11 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200027 ER PT J AU Holian, BL Lomdahl, PS Zhou, SJ AF Holian, BL Lomdahl, PS Zhou, SJ TI Fracture simulations via large-scale nonequilibrium molecular dynamics SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT Proceedings of the Euroconference on the Microscopic Approach to Complexity in Non-Equilibrium Molecular Simulations CY JUL 15-19, 1996 CL ECOLE NORMALE SUPER LYON, CECAM, LYON, FRANCE SP Training & Mobil Res Program European Communit HO ECOLE NORMALE SUPER LYON, CECAM ID STRESS AB We describe the historical development of large-scale nonequilibrium molecular-dynamics (NEMD) computer simulations of fracture at Los Alamos. We have found that dynamic crack propagation leads to energy buildup that seeds instabilities, such as dislocation emission and branching. Recent three-dimensional simulations have shed light on ductile fracture mechanisms, including sequences of dislocation emission in various modes that are strikingly different from anything previously conjectured. The future for constitutive modeling, based on observations of dynamical features in such NEMD simulations is quite bright, and one such example is discussed. RP Holian, BL (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 18 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 1997 VL 240 IS 1-2 BP 340 EP 348 DI 10.1016/S0378-4371(97)00157-X PG 9 WC Physics, Multidisciplinary SC Physics GA XE562 UT WOS:A1997XE56200032 ER PT J AU Schefer, J Schwarzenbach, D Fischer, P Koetzle, T Haussuhl, S Rudlinger, M AF Schefer, J Schwarzenbach, D Fischer, P Koetzle, T Haussuhl, S Rudlinger, M TI Single-crystal and powder neutron diffraction investigations of thermal motions in K2PtCl6 as a function of temperature SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE anharmonic effects; anisotropy; crystal structures; diffraction; single-crystal neutron diffraction; X-ray scattering ID ELECTRON-DENSITY AB By means of neutron diffraction the crystal structure and thermal motions of the ions in FCC K2PtCl6 were investigated in the temperature range from 20 to 380 K, extending the analysis to anharmonic terms, Associated with PtCl6 octahedra librations the Cl- ions vibrate mainly perpendicular to the Pt-Cl bonds. This thermal motion and also the isotropic thermal vibrations of the metal ions increase essentially with temperature, resulting in an isotropic thermal expansion. Within the experimental accuracy anharmonicity seems to be of minor importance. C1 PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. UNIV LAUSANNE,CH-1015 LAUSANNE,SWITZERLAND. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV COLOGNE,D-50764 COLOGNE,GERMANY. RP Schefer, J (reprint author), ETH ZURICH,NEUTRON SCATTERING LAB,CH-5232 VILLIGEN,SWITZERLAND. RI Schefer, Jurg/G-3960-2012 NR 6 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 137 EP 138 DI 10.1016/S0921-4526(96)00927-1 PG 2 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600055 ER PT J AU Benmore, CJ Formisano, F Magli, R Bafile, U Barocchi, F Egelstaff, PA Robinson, RA Verkerk, P AF Benmore, CJ Formisano, F Magli, R Bafile, U Barocchi, F Egelstaff, PA Robinson, RA Verkerk, P TI An experimental investigation of the interaction law of Kr atoms through small-angle neutron scattering SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE small-angle neutron scattering; structure factors; liquids ID COEFFICIENTS; GAS AB The first direct determination of the London dispersive contribution to the long-range interaction energy of pairs of krypton atoms is discussed. The result, obtained using a SANS technique, is in good agreement with previous estimates present in literature. C1 UNIV FLORENCE,DIPARTIMENTO ENERGET S STECCO,I-50139 FLORENCE,ITALY. UNIV GUELPH,DEPT PHYS,GUELPH,ON N1G 2W1,CANADA. UNIV FLORENCE,DIPARTIMENTO FIS,I-50125 FLORENCE,ITALY. INFM,UNITA RIC FIRENZE,I-50125 FLORENCE,ITALY. CNR,IST ELETTRON QUANTIST,I-50127 FLORENCE,ITALY. LOS ALAMOS NATL LAB,LOS ALAMOS NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. DELFT UNIV TECHNOL,INTERFAC REACTOR INST,NL-2629 JB DELFT,NETHERLANDS. RI Formisano, Ferdinando/G-8888-2013; OI Benmore, Chris/0000-0001-7007-7749 NR 9 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 313 EP 315 DI 10.1016/S0921-4526(96)00969-6 PG 3 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600118 ER PT J AU Zheludev, A Shirane, G Sasago, Y Koide, N Uchinokura, K AF Zheludev, A Shirane, G Sasago, Y Koide, N Uchinokura, K TI Spiral order in Ba2CuGe2O7 SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE antiferromagnetism; spin waves; chiral systems ID SQUARE HEISENBERG LATTICE; MAGNETIC-STRUCTURES; PHASE-DIAGRAM; SPIN; MNSI; CUGEO3; STATE; FEGE AB The quasi-two-dimensional square-lattice antiferromagnet Ba2CuGe2O7 was studied by neutron scattering and bulk magnetic techniques. An incommensurate magnetic spiral structure with the propagation vector (1 + xi,xi,0) (xi = 0.027) was observed below T-N = 3.26 K. The spin dynamics can be adequately described by conventional spin-wave theory with two exchange constants: nearest-neighbor in-plane antiferromagnetic coupling J(1) approximate to 0.48 meV and interplane ferromagnetic interaction J(3) approximate to 0.013 meV. This set of exchange parameters apparently fails to explain the spiral order. The non-centrosymmetric crystal structure suggests that the incommensurate phase may be the result of a Dzyaloshin-skii-Moriya instability of the Neel ground state. C1 UNIV TOKYO,DEPT APPL PHYS,BUNKYO KU,TOKYO 113,JAPAN. RP Zheludev, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,BLD 510-B,BOX 5000,UPTON,NY 11973, USA. NR 14 TC 2 Z9 2 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 546 EP 548 DI 10.1016/S0921-4526(97)89261-7 PG 3 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600203 ER PT J AU Lake, B Tennant, DA AF Lake, B Tennant, DA TI Models of magnetic excitations in the dimer-chain compound CuWO4 SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE antiferromagnetism; Heisenberg magnets; low-dimensional systems; spin waves AB The magnetic excitations in the ordered phase of the spin-1/2, dimer-chain compound CuWO4 are discussed using a model where pairs of Cu spins form dimers whose eigenstates are modified by the mean field ordering of the surrounding Cu ions. This theory is as successful as spin-wave theory in describing the excitations although with different exchange constants. The reduced moment, value of T-N, and longitudinal scattering predicted by the two models are discussed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Lake, B (reprint author), UNIV OXFORD,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI Tennant, David/Q-2497-2015; OI Tennant, David/0000-0002-9575-3368; Lake, Bella/0000-0003-0034-0964 NR 4 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 557 EP 559 DI 10.1016/S0921-4526(96)01178-7 PG 3 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600207 ER PT J AU Boothroyd, AT Mukherjee, A Fulton, S Perring, TG Eccleston, RS Mook, HA Wanklyn, BM AF Boothroyd, AT Mukherjee, A Fulton, S Perring, TG Eccleston, RS Mook, HA Wanklyn, BM TI High-energy magnetic excitations in CuO SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE antiferromagnetism; Heisenberg chain; one-dimensional systems; spin waves ID CUPRIC OXIDE; CHAIN AB We have used inelastic neutron scattering to study the magnetic excitations in CuO, a quasi 1-D antiferromagnet, along the chain direction, [zeta, 0, <(zeta)over bar>]. The low-energy excitations can be described adequately by linear spin wave theory, but at high energies the magnetic scattering exhibits characteristics of the spinon model. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Boothroyd, AT (reprint author), UNIV OXFORD,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. NR 7 TC 11 Z9 11 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 731 EP 733 DI 10.1016/S0921-4526(96)01133-7 PG 3 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600274 ER PT J AU Tils, P Loewenhaupt, M Loong, CK Schober, H AF Tils, P Loewenhaupt, M Loong, CK Schober, H TI Crystal fields and exchange interactions in HoT4Al8 with T=Mn and Fe SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE crystal fields; magnetic anisotropy; permanent magnets AB We investigated the magnetic excitations in polycrystalline samples of hard magnet related compounds HoMn4Al8 and HoFe4Al8 by neutron spectroscopy. For both compounds the magnetic spectra at energies below 15 meV are dominated by the response of the Ho3+ ions. In HoMn4Al8 we observed pure crystal-field transitions within the Ho3+ J = 8 ground multiplet which is split into 9 singlets and 4 doublets under the low point-group symmetry of 4/mmm. In HoFe4Al8 the Ho crystal-field-split states are perturbed by the molecular field of the ordered Fe sublattice. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP Tils, P (reprint author), TECH UNIV DRESDEN,INST ANGEW PHYS & DIDAKTIK,D-01062 DRESDEN,GERMANY. NR 4 TC 1 Z9 1 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 JUN PY 1997 VL 234 BP 739 EP 740 DI 10.1016/S0921-4526(96)01158-1 PG 2 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600277 ER PT J AU Blanco, JA Fak, B Nicklow, RM Roessli, B Schmitt, D AF Blanco, JA Fak, B Nicklow, RM Roessli, B Schmitt, D TI Dynamics of PrNi2Si2 in its modulated magnetic phase SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE critical phenomena; incommensurate structures; rare-earth compounds; spin waves ID EXCITATIONS AB Results of inelastic neutron scattering in the amplitude-modulated magnetic phase of PrNi2Si2 are presented. The main, lowest longitudinal branch of the dispersion curve exhibits a shape much more dispersive than that present above T-N=20 K. Close to the incommensurate vector Q=(0, 0, 0.875), a critical behaviour occurs, characterized by the appearance of a new longitudinal magnetic excitation at low energy, showing a nearly complete softening for q=Q. Both low-energy excitations could be interpreted as phasons and amplitudons. Results are analyzed by a generalized susceptibility formalism. C1 CNRS,LAB LOUIS NEEL,F-38042 GRENOBLE 9,FRANCE. UNIV OVIEDO,DEPT FIS,E-33007 OVIEDO,SPAIN. CEA GRENOBLE,DRFMC,SPSMS,MDN,F-38054 GRENOBLE 9,FRANCE. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE 9,FRANCE. RI Blanco, Jesus/L-6508-2014 OI Blanco, Jesus/0000-0002-8054-1442 NR 4 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 756 EP 757 DI 10.1016/S0921-4526(96)01153-2 PG 2 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600284 ER PT J AU Keimer, B Aksay, IA Bossy, J Bourges, P Fong, HF Milius, DL Regnault, LP Reznik, D Vettier, C AF Keimer, B Aksay, IA Bossy, J Bourges, P Fong, HF Milius, DL Regnault, LP Reznik, D Vettier, C TI Spin excitations and phonons in YBa2Cu3O6+x: A status report SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE spin excitations; phonons; YBa2Cu3O6+x ID HIGH-TEMPERATURE SUPERCONDUCTORS; NEUTRON-SCATTERING; MAGNETIC EXCITATIONS; ORDER-PARAMETER; GAP ANISOTROPY; SYSTEM; MODES AB A review is made of recent developments in inelastic neutron scattering experiments on spin excitations and phonons in the high-temperature superconductor YBa2Cu3O6+x and its antiferromagnetic precursor YBa2Cu3O6.2. These experiments include the detection of high-energy ''optical'' spin waves and the determination of the full spin Hamiltonian in YBa2Cu3O6.2, detailed investigations of the 40 meV magnetic resonance peak in the superconducting state of YBa2Cu3O7 and its precursors in underdoped YBa2Cu3O6+x, and experiments on the effect of superconductivity on phonon lifetimes in YBa2Cu3O7. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. CEA SACLAY,LAB LEON BRILLOUIN,CEA,CNRS,F-91191 GIF SUR YVETTE,FRANCE. CEA GRENOBLE,DEPT RECH FONDAMENTALE MATIERE CONDENSEE,SERV PHYS STAT MAGNETISME & SUPRACONDUCT,F-38054 GRENOBLE 9,FRANCE. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. RP Keimer, B (reprint author), PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544, USA. RI Aksay, Ilhan/B-9281-2008 NR 39 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 821 EP 829 DI 10.1016/S0921-4526(96)01111-8 PG 9 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600309 ER PT J AU Hiess, A Boucherle, JX Givord, F Schweizer, J LelievreBerna, E Tasset, F Gillon, B Canfield, PC AF Hiess, A Boucherle, JX Givord, F Schweizer, J LelievreBerna, E Tasset, F Gillon, B Canfield, PC TI Magnetization density in the intermediate valence compound YbAl3 SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE hybridization; intermediate valence; magnetization density; polarized neutrons AB Polarized neutron diffraction studies have been performed at various temperatures on a flux grown single crystal of YbAl3. Only the Yb carries a field-induced magnetic moment, which is well described by a free in ion Yb3+ form factor. The thermal variation of the localized 4f Yb moment exhibits a second maximum at T approximate to 130 K. A small temperature-independent positive conduction electron polarization is suggested. These results are important to the understanding of the YbAl3 ground state. C1 CEA GRENOBLE,DEPT RECH FONDAMENTALE MAT CONDENSEE,DRFMC,SPSMS MDN,F-38054 GRENOBLE 9,FRANCE. COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,INST TRANSURANIUM ELEMENTS,D-76125 KARLSRUHE,GERMANY. CEA SACLAY,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Hiess, A (reprint author), INST MAX VON LAUE PAUL LANGEVIN,BP 156X,F-38042 GRENOBLE,FRANCE. RI Canfield, Paul/H-2698-2014 NR 5 TC 4 Z9 4 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 886 EP 887 DI 10.1016/S0921-4526(96)01175-1 PG 2 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600331 ER PT J AU Hiess, A Bonnet, M Burlet, P Ressouche, E Sanchez, JP Boudarot, F Waerenborgh, JC Zwirner, S Wastin, F Rebizant, J Lander, GH Suard, E Smith, JL AF Hiess, A Bonnet, M Burlet, P Ressouche, E Sanchez, JP Boudarot, F Waerenborgh, JC Zwirner, S Wastin, F Rebizant, J Lander, GH Suard, E Smith, JL TI Magnetic structures of NpBe13 and NpPd2Al3 SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE heavy fermions; magnetic structures ID SUPERCONDUCTIVITY AB To learn more about the U heavy-fermion superconductors UBe13 and UPd2Al3 we have performed a series of Mossbauer, susceptibility, and neutron experiments on polycrystalline and single crystals of the Np analogs, which have identical crystal structures. In the case of NpBe13 (T-N = 4.9 K) the ordering wave vector q = [1/3 00] gives information on where to search for possible magnetic correlations in UBe13. In NpPd2Al3 (T-N = 38 K) we observe initially an incommensurate wave vector, but at 27 K a commensurate wave vector appears in addition. C1 COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,INST TRANSURANIUM ELEMENTS,D-76125 KARLSRUHE,GERMANY. CEA GRENOBLE,DEPT RECH FONDAMENTALE MAT CONDENSEE,F-38054 GRENOBLE,FRANCE. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. RI SUARD, Emmanuelle/E-9579-2012; Waerenborgh, Joao/C-3701-2011 OI SUARD, Emmanuelle/0000-0001-5966-5929; Waerenborgh, Joao/0000-0001-6171-4099 NR 5 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 893 EP 894 DI 10.1016/S0921-4526(96)01181-7 PG 2 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600334 ER PT J AU Meggers, K Priesmeyer, HG Stalder, M Vogel, S Trela, W AF Meggers, K Priesmeyer, HG Stalder, M Vogel, S Trela, W TI Single-shot neutron transmission diffraction SO PHYSICA B LA English DT Article; Proceedings Paper CT 1st European Conference on Neutron Scattering (ECNS 96) CY OCT 08-11, 1996 CL INTERLAKEN, SWITZERLAND SP European Neutron Scattering Assoc, Paul Scherrer Inst, Villigen, Swiss Soc Neutron Scattering DE pulsed neutrons; transmission; diffraction; phase transitions; residual stress AB Low-energy neutron transmission diffraction has been successfully demonstrated to be a powerful experimental method to investigate changes in crystal structure development down to the millisecond range. Bragg edge diffraction measurements thus can be the basis for future experiments like strain radiography, determination of the strain-rate dependent elastic properties of engineering materials, temporal development of phase changes, structural properties of materials under extreme environmental conditions like high pressure or temperature states. At high instantaneous neutron bursts current-mode detection can be used, which enables both transient and stroboscopic measurements. Progress has been made in rapid data acquisiton and analysis as well as temperature measurement by resonance doping. C1 CHRISTIAN ALBRECHTS UNIV KIEL,INST REINE & ANGEW KERNPHYS,D-24098 KIEL,GERMANY. SIEMENS AG,D-8000 MUNICH,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RI Lujan Center, LANL/G-4896-2012; OI Vogel, Sven C./0000-0003-2049-0361 NR 5 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 1997 VL 234 BP 1160 EP 1162 DI 10.1016/S0921-4526(97)00155-5 PG 3 WC Physics, Condensed Matter SC Physics GA XG666 UT WOS:A1997XG66600428 ER PT J AU Anglin, JR Paz, JP Zurek, WH AF Anglin, JR Paz, JP Zurek, WH TI Deconstructing decoherence SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM BROWNIAN-MOTION; WAVE PACKET; ATOM INTERFEROMETER; GENERAL ENVIRONMENT; LOCALIZATION; DISSIPATION; REDUCTION; SODIUM; CAVITY; MODELS AB The study of environmentally induced superselection and of the process of decoherence was originally motivated by the search for the emergence of classical behavior out of the quantum substrate, in the macroscopic limit [W. H. Zurek, Phys. Rev. D 24, 1516 (1981); 26, 1862 (1982)]. This limit, and other simplifying assumptions, have allowed the derivation of several simple results characterizing the onset of environmentally induced superselection; but these results are increasingly often regarded as a complete phenomenological characterization of decoherence in any regime. This is not necessarily the case: the examples presented in this paper counteract this impression by violating several of the simple general rules. This is relevant because decoherence is now beginning to be tested experimentally [C. Monroe et al., Science 272, 1131 (1996); M. Brune et al., Phys. Rev. Lett. 77, 4887 (1996)], and one may anticipate that, in at least some of the proposed applications (e.g., quantum computers), only the basic principle of ''monitoring by the environment'' will survive. The phenomenology of decoherence may turn out to be significantly different. C1 UNIV BUENOS AIRES,FAC CIENCIAS EXACTAS & NAT,DEPT FIS,RA-1428 BUENOS AIRES,DF,ARGENTINA. RP Anglin, JR (reprint author), LOS ALAMOS NATL LAB,POB 1663,MAIL STOP B288,LOS ALAMOS,NM 87545, USA. RI Paz, Juan/C-5947-2008 NR 33 TC 80 Z9 80 U1 2 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1997 VL 55 IS 6 BP 4041 EP 4053 DI 10.1103/PhysRevA.55.4041 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XE372 UT WOS:A1997XE37200014 ER PT J AU Datskos, PG Pinnaduwage, LA Kielkopf, JF AF Datskos, PG Pinnaduwage, LA Kielkopf, JF TI Photophysical and electron attachment properties of ArF-excimer-laser irradiated H-2 SO PHYSICAL REVIEW A LA English DT Article ID NEGATIVE-ION FORMATION; MOLECULAR-HYDROGEN; CROSS-SECTIONS; DISSOCIATIVE ATTACHMENT; 2-PHOTON EXCITATION; DOUBLE-MINIMUM; RADIATIVE LIFETIMES; SUPEREXCITED STATES; EXCITED-STATES; H FORMATION AB Detailed electron attachment and spectroscopic measurements are reported on ArF-excimer-laser irradiated H-2. These studies indicate that previously reported efficient H- formation in ArF-laser irradiated H-2 is due to electron attachment to high-lying Rydberg (HR) states indirectly populated by the laser irradiation. Electron attachment studies indicate a lifetime of greater than or equal to 40 ns for the electron attaching state(s): The spectroscopic studies show that vacuum ultraviolet emission due to the B (1) Sigma(u)(+) --> X (1) Sigma(g)(+) transitions continues for up to similar to 100 ns after the termination of the laser pulse and thus that the B state is populated by cascades from higher-lying states with longer lifetimes. The temporal profile of Lyman-alpha emission due to the H(n = 2) to H(n = 1) transitions is consistent with the production of H(n = 2) states by electron attachment to HR states. C1 UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. RP OAK RIDGE NATL LAB, HLTH SCI RES DIV, POB 2008, OAK RIDGE, TN 37831 USA. NR 57 TC 29 Z9 29 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1997 VL 55 IS 6 BP 4131 EP 4142 DI 10.1103/PhysRevA.55.4131 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XE372 UT WOS:A1997XE37200026 ER PT J AU Rescigno, TN Baertschy, M Byrum, D McCurdy, CW AF Rescigno, TN Baertschy, M Byrum, D McCurdy, CW TI Making complex scaling work for long-range potentials SO PHYSICAL REVIEW A LA English DT Article ID BASIS-SET APPROXIMATION; RESONANCE ENERGIES; CROSS-SECTIONS; AMPLITUDES; SCATTERING; SYSTEMS; PHOTOIONIZATION; DISTORTIONS; FRAMEWORK; SPECTRUM AB We examine finite basis set implementations of complex scaling procedures for computing scattering amplitudes and cross sections. While ordinary complex scaling, i.e., the technique of multiplying all interparticle distances in the Hamiltonian by a complex phase factor, is known to provide convergent cross-section expressions only for exponentially bounded potentials, we propose a generalization, based on Simon's exterior complex scaling technique, that works for long-range potentials as well. We establish an equivalence between a class of complex scaling transformations carried out on the time-independent Schrodinger equation and a procedure commonly referred to as the method of complex basis functions. The procedure is illustrated with a numerical example. C1 UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,COMP SCI DIRECTORATE,BERKELEY,CA 94720. RP Rescigno, TN (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA 94550, USA. NR 35 TC 87 Z9 87 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 JUN PY 1997 VL 55 IS 6 BP 4253 EP 4262 DI 10.1103/PhysRevA.55.4253 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XE372 UT WOS:A1997XE37200042 ER PT J AU Arp, U LeBrun, T Southworth, SH MacDonald, MA Jung, M AF Arp, U LeBrun, T Southworth, SH MacDonald, MA Jung, M TI X-ray fluorescence and Auger-electron coincidence spectroscopy of vacancy cascades in atomic argon SO PHYSICAL REVIEW A LA English DT Article ID POST-COLLISION INTERACTION; INNER-SHELL PHOTOIONIZATION; ANGULAR-DISTRIBUTION; SYNCHROTRON RADIATION; K-EDGE; POSTCOLLISION INTERACTION; MULTIPOLE CORRECTIONS; CORE RESONANCES; LOW ENERGIES; AR AB Argon L-2,L-3-M2,3M2,3 Auger-electron spectra were measured in coincidence with K alpha fluorescent x rays in studies of K-shell vacancy decays at several photon energies above the K threshold and on the 1s-->4p resonance. The complex spectra recorded by conventional electron spectroscopy are greatly simplified when recorded in coincidence with fluorescent x rays, allowing a more detailed analysis of the vacancy cascade process. The resulting coincidence spectra are compared with Hartree-Fock calculations, which include shake-up transitions in the resonant case. Small energy shifts of the coincident electron spectra are attributed to postcollision interaction with 1s photoelectrons. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. EPSRC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Arp, U (reprint author), NIST,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Arp, Uwe/C-2854-2009; OI Arp, Uwe/0000-0002-6468-9455 NR 67 TC 17 Z9 17 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1997 VL 55 IS 6 BP 4273 EP 4284 DI 10.1103/PhysRevA.55.4273 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XE372 UT WOS:A1997XE37200045 ER PT J AU Munter, AE Heuser, BJ Ruckman, MW AF Munter, AE Heuser, BJ Ruckman, MW TI In situ neutron-reflectometry measurements of hydrogen and deuterium absorption in a Pd/Nb/Pd layered film SO PHYSICAL REVIEW B LA English DT Article ID THIN-FILMS AB We present in situ neutron-reflectivity measurements of the hydrogen and deuterium absorption from the gas phase in a Pd/Nb/Pd thin film multilayer. Hydrogen and deuterium were both preferentially absorbed into the Nb layer at room temperature and at a pressure of 10 Torr. Genetic algorithm fits to the specular data indicate concentrations of approximately 0.71 [H]/[Nb] and 0.51 [D]/[Nb], placing the Nb well into the beta phase (or an alpha'-like phase). C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Munter, AE (reprint author), UNIV ILLINOIS,DEPT NUCL ENGN,214 NEL,103 S GOODWIN AVE,URBANA,IL 61801, USA. NR 15 TC 7 Z9 8 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 JUN 1 PY 1997 VL 55 IS 21 BP 14035 EP 14038 DI 10.1103/PhysRevB.55.14035 PG 4 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100001 ER PT J AU Tang, MJ Colombo, L Zhu, J delaRubia, TD AF Tang, MJ Colombo, L Zhu, J delaRubia, TD TI Intrinsic point defects in crystalline silicon: Tight-binding molecular dynamics studies of self-diffusion, interstitial-vacancy recombination, and formation volumes SO PHYSICAL REVIEW B LA English DT Article ID BORON AB Tight-binding molecular dynamics simulations are performed to study self-diffusion, interstitial-vacancy recombination, and formation volumes of point defects in crystalline silicon. The results show that (i) self-diffusion is dominated by vacancies (V) at low temperature and by interstitials (I) at high temperature; (ii) interstitial-vacancy recombination at room temperature leads to formation of a metastable I-V complex, which has an annihilation energy barrier of 1.1 eV; (iii) interstitial and vacancy relaxation volumes in silicon are approximately equal in magnitude and opposite in sign. C1 UNIV MILAN, IST NAZL FIS MAT, I-20133 MILAN, ITALY. UNIV MILAN, DIPARTIMENTO FIS, I-20133 MILAN, ITALY. RP Tang, MJ (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, L-268, LIVERMORE, CA 94550 USA. RI Colombo, Luciano/D-9013-2013 OI Colombo, Luciano/0000-0001-5335-4652 NR 45 TC 259 Z9 262 U1 1 U2 21 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 JUN 1 PY 1997 VL 55 IS 21 BP 14279 EP 14289 DI 10.1103/PhysRevB.55.14279 PG 11 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100048 ER PT J AU Lascialfari, A Gatteschi, D Borsa, F Cornia, A AF Lascialfari, A Gatteschi, D Borsa, F Cornia, A TI Spin dynamics in mesoscopic size magnetic systems: A H-1 NMR study in rings of iron (III) ions SO PHYSICAL REVIEW B LA English DT Article ID MOLECULES; CLUSTERS; STATE; WHEEL AB Two magnetic molecular clusters containing almost coplanar rings of iron(III) ions with spin S = 5/2 have been investigated by H-1 NMR and relaxation measurements. The first system, which will be referred to as Fe6, is a molecule of general formula [NaFe6(OCH3)(12)(C17O4H15)(6)]+ClO4- or [NaFe6(OCH3)(12)(C15H11O2)(6)]+ClO4- or [LiFe6(OCH3)(12)(C15H11O2)(6)]+ClO4- while the second type of ring, denoted Fe10, corresponds to the molecule [Fe-10(OCH3)(20)(C2H2O2Cl)(10)]. The H-1 NMR linewidth is broadened by the nuclear dipolar interaction and by the dipolar coupling of the protons with the iron (III) paramagnetic moment. It is found that the nuclear spin-lattice relaxation rate, T-1(-1), of the proton is a sensitive probe of the Fe spin dynamics. In both clusters, T-1(-1) decreases with decreasing temperatures from room temperature, goes through a peak just below about 30 K in Fe6 and 10 K in Fe10, and it drops exponentially to very small values at helium temperature. The temperature dependence of the relaxation rate is discussed in terms of the fluctuations of the local spins within the allowed total spin configurations in the framework of the weak collision theory to describe the nuclear relaxation. We use the calculated energy levels for the Fe6 ring based on a Heisenberg Hamiltonian and the value of J obtained from the fit of the magnetic susceptibility to describe semiquantitatively the behavior T-1(-1) vs T. The exponential drop of T-1(-1) at low temperature is consistent with a nonmagnetic singlet ground state separated by an energy gap from the first excited triplet state. The values obtained for the gap energies are E-T/k = 12 K for Fe10 and E-T/k = 38 K for Fe6 which are almost twice as big as the values deduced from susceptibility measurements. At all temperatures the relaxation rate decreases with increasing magnetic field, i.e., NMR resonance frequency. This effect could be related to the long time persistence of the spin correlation functions typical of diffusive modes in low dimensional magnetic systems. It is argued that the data presented are a direct experimental study of spin dynamics in mesoscopic spin rings and should afford a test for exact analytical and/or numerical solutions. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. UNITA INFM,DEPT PHYS A VOLTA,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,SEZ PAVIA,I-27100 PAVIA,ITALY. UNIV MODENA,DEPT CHEM,I-41100 MODENA,ITALY. RP Lascialfari, A (reprint author), UNIV FLORENCE,DEPT CHEM,FLORENCE,ITALY. RI Gatteschi, Dante/B-5429-2008; Cornia, Andrea/N-8587-2015; OI Cornia, Andrea/0000-0001-9765-3128; Gatteschi, Dante/0000-0002-4859-4317 NR 30 TC 84 Z9 84 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 JUN 1 PY 1997 VL 55 IS 21 BP 14341 EP 14349 DI 10.1103/PhysRevB.55.14341 PG 9 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100056 ER PT J AU Smirnov, AV Bratkovsky, AM AF Smirnov, AV Bratkovsky, AM TI Complex three-dimensional magnetic ordering in ultrathin films of fcc Co upon deposition of Cu SO PHYSICAL REVIEW B LA English DT Article ID COBALT FILMS; ANISOTROPY; INTERFACE; TRANSITION; CR AB We present an nb initio analysis of easy magnetization axis ''switching'' recently discovered in experiments on Co ultrathin films with a deposited submonolayer of Cu. The present large scale calculations show that the nanomagnetic pattern of a stepped Co(001) surface 2-3 monolayers thick with submonolayer quantities of Cu has a complex three-dimensional character. We show that the maximum noncollinearity of spin directions is about 300, and the ''switching'' has a reentrant character as a function of Co coverage. C1 HEWLETT PACKARD LABS,PALO ALTO,CA 94304. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 28 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1997 VL 55 IS 21 BP 14434 EP 14438 DI 10.1103/PhysRevB.55.14434 PG 5 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100068 ER PT J AU Lawrence, JM Shapiro, SM Sarrao, JL Fisk, Z AF Lawrence, JM Shapiro, SM Sarrao, JL Fisk, Z TI Inelastic neutron scattering in single-crystal YbInCu4 SO PHYSICAL REVIEW B LA English DT Article ID VALENCE TRANSITION; ANDERSON LATTICE; YBXIN1-XCU2 AB We have measured the momentum and energy dependence of the spin fluctuations in the low-temperature mixed-valent state and the high-temperature integral-valent state of YbInCu4, using flux-grown single crystals and a triple axis spectrometer. The magnetic scattering can be fit with a Lorentzian power spectrum, with positions and halfwidths equal E-0(+) = 2.3 meV and Gamma(+) = 1.8 meV in the high-temperature state at 50 K and E-0(-) = 40.2 meV and Gamma(-) = 12.3 meV in the low-temperature state at 20 K. Within the experimental uncertainties, the line shape as a function of energy transfer (i.e., the power spectrum) does not depend on momentum transfer Q. The static susceptibility (X)(Q) is no more than 10% larger at the zone boundary than at zone center for the [1,0,0] direction. The results compare reasonably well to the predictions of the Anderson impurity model and to earlier measurements on polycrystalline samples. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. RP Lawrence, JM (reprint author), UNIV CALIF IRVINE,IRVINE,CA 92697, USA. NR 15 TC 48 Z9 48 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 JUN 1 PY 1997 VL 55 IS 21 BP 14467 EP 14472 DI 10.1103/PhysRevB.55.14467 PG 6 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100072 ER PT J AU Vasquez, RP Novikov, DL Freeman, AJ Siegal, MP AF Vasquez, RP Novikov, DL Freeman, AJ Siegal, MP TI Electronic structure of TlBa2CaCu2O7-delta SO PHYSICAL REVIEW B LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; HIGH-TEMPERATURE SUPERCONDUCTORS; T-C SUPERCONDUCTORS; CORE-LEVEL; DOPING DEPENDENCE; SINGLE-CRYSTALS; STATE PROPERTIES; PHOTOEMISSION; SPECTRA; BA AB The core levels of TlBa2CaCu2O7-delta (Tl-1212) epitaxial films have been measured with x-ray photoelectron spectroscopy (XPS). The valence electronic structure has been determined using the full-potential linear muffin-tin-orbital band-structure method and measured with XPS. The calculations show that a van Hove singularity (VHS) lies above the Fermi level (E-F) for the stoichiometric compound (delta = 0), while for 50% oxygen vacancies in the Tl-O layer (delta = 0.5) E-F is in close proximity to the VHS. Samples annealed in nitrogen (to reduce the hole overdoping by the removal of oxygen) exhibit higher core-level binding energies and a higher T-c, consistent with a shift of E-F closer to the VHS. Comparisons are made to the core levels and valence bands of Tl2Ba2CaCu2O8+delta (Tl-2212) and HgBa2CaCu2O6+delta (Hg-1212). The similarity of the Cu 2p(3/2) spectra for Tl-1212 and Tl-2212 indicates that the number of Tl-O layers has little effect on the Cu-O bonding. However, the Tl-1212 and Hg-1212 Cu 2p(3/2) signals exhibit differences which suggest that the replacement of Tl3+ with Hg2+ results in a decrease in the O 2p --> Cu 3d charge-transfer energy and differences in the probabilities of planar vs apical oxygen charge transfer and/or Zhang-Rice singlet-state formation. Differences between the Tl-1212 and the Tl-2212 and Hg-1212 measured valence bands are consistent with the calculated Cu 3d and (Tl,Hg) 6s/5d partial densities of states. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Vasquez, RP (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,PASADENA,CA 91109, USA. NR 48 TC 16 Z9 16 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 JUN 1 PY 1997 VL 55 IS 21 BP 14623 EP 14631 DI 10.1103/PhysRevB.55.14623 PG 9 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100088 ER PT J AU Kostic, P Veal, B Paulikas, AP Welp, U Todt, VR Gu, C Geiser, U Williams, JM Carlson, KD Klemm, RA AF Kostic, P Veal, B Paulikas, AP Welp, U Todt, VR Gu, C Geiser, U Williams, JM Carlson, KD Klemm, RA TI Paramagnetic Meissner effect in Nb - Reply SO PHYSICAL REVIEW B LA English DT Editorial Material ID HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTALS AB Rice and Sigrist (RS) have proposed a d-wave mechanism to explain the paramagnetic Meissner effect (PME) observed in some inhomogeneous samples of high-T-c superconductors. However, the observation of a PME in some inhomogeneous samples of Nb (an s-wave superconductor) demonstrates that a d-wave pairing mechanism is not needed to produce the effect. Moreover, the remarkable similarity between the PME observed in these Nb and in the high-T-c samples argues that the same mechanism is operable in both types of superconductors. In this Reply, new measurements on La(2)CuOQ(4+delta) and on irradiated Nb are discussed, which strongly support the notion that the PME is most likely associated with layered T-c inhomogeneities. Further experiments to test this notion are proposed. We also discuss critically the three experiments proposed by RS to distinguish between two PME mechanisms unrelated to layered T-c inhomogeneities. RP Kostic, P (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 28 TC 19 Z9 19 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 JUN 1 PY 1997 VL 55 IS 21 BP 14649 EP 14652 DI 10.1103/PhysRevB.55.14649 PG 4 WC Physics, Condensed Matter SC Physics GA XE371 UT WOS:A1997XE37100093 ER PT J AU Zang, J Chakravarty, S Bishop, AR AF Zang, J Chakravarty, S Bishop, AR TI Interchain coupling effects and solitons in CuGeO3 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-PEIERLS TRANSITION; MAGNETIC PHASE-DIAGRAM; DOPED CUGEO3; DIMERIZATION; SYSTEMS; STATE; POLYACETYLENE; LATTICE; CHAINS AB The effects of interchain coupling on solitons and soliton lattice structures in CuGeO3 are explored. It is shown that interchain coupling substantially increases the soliton width and changes the soliton lattice structures in the incommensurate phase. It is proposed that the experimentally observed large soliton width in CuGeO3 is mainly due to interchain coupling effects. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV CALIF LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90095. RP Zang, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. NR 33 TC 27 Z9 27 U1 0 U2 0 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 JUN 1 PY 1997 VL 55 IS 22 BP 14705 EP 14708 PG 4 WC Physics, Condensed Matter SC Physics GA XF602 UT WOS:A1997XF60200006 ER PT J AU Reyes, AP Tang, XP Bachman, HN Halperin, WP Martindale, JA Hammel, PC AF Reyes, AP Tang, XP Bachman, HN Halperin, WP Martindale, JA Hammel, PC TI Vortex melting in polycrystalline YBa2Cu3O7 from O-17 NMR SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL YBA2CU3O7; LAYERED SUPERCONDUCTORS; THERMAL FLUCTUATIONS; Y-89 NMR; TRANSITION; LINE; VORTICES; STATE; FIELD; DEPENDENCE AB Line-shape analysis of O-17 NMR spectra is used to probe vortex melting and dynamics in aligned powders of YBa2O3O7. Vortex transitions are identified by comparing their dynamics with the NMR time scale. Lineshape changes indicate a well-defined melting transition at a temperature, T-m. Below T-m there is a coexistence regime of solid and liquid vortices with a lower bound, T-g, which marks complete vortex freezing. C1 SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Reyes, AP (reprint author), NORTHWESTERN UNIV,EVANSTON,IL 60208, USA. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 32 TC 28 Z9 28 U1 0 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 JUN 1 PY 1997 VL 55 IS 22 BP 14737 EP 14740 PG 4 WC Physics, Condensed Matter SC Physics GA XF602 UT WOS:A1997XF60200014 ER PT J AU Hjortstam, O Baberschke, K Wills, JM Johansson, B Eriksson, O AF Hjortstam, O Baberschke, K Wills, JM Johansson, B Eriksson, O TI Magnetic anisotropy and magnetostriction in tetragonal and cubic Ni SO PHYSICAL REVIEW B LA English DT Article ID MAGNETOCRYSTALLINE ANISOTROPY; ORBITAL MAGNETISM; SYSTEMS; METALS; BAND; COBALT; ENERGY; FE; CO AB The magnetic anisotropy energy (MAE) of face-centered-tetragonal (fct) Ni is calculated as a function of the axial c/a ratio. It is shown that the MAE for fct Ni is tremendously enhanced relative to the MAE for fec Ni. The theoretical results are compared with measurements done by means of ferromagnetic resonance on fct Ni films grown on a Cu(001) substrate. Both experiment and theory show that the tetragonal distortion of Ni is crucial for the understanding of the transition to the out-of-plane magnetization for Ni Alms on Cu(001) for thicknesses above similar to 7 atomic monolayers. We have also calculated the magnetostrictive constants for fee Ni and obtained lambda(001) = - 245 x 10(-6) and lambda(111) = - 110 x 10(-6). The relation between lambda(001) and the MAE of fct Ni is investigated by means of magnetoelastic theory as well as by first principles calculations. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. FREE UNIV BERLIN,INST PHYS EXPT,D-14195 BERLIN,GERMANY. RP Hjortstam, O (reprint author), UPPSALA UNIV,DEPT PHYS,BOX 530,UPPSALA,SWEDEN. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 26 TC 110 Z9 111 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 JUN 1 PY 1997 VL 55 IS 22 BP 15026 EP 15032 DI 10.1103/PhysRevB.55.15026 PG 7 WC Physics, Condensed Matter SC Physics GA XF602 UT WOS:A1997XF60200049 ER PT J AU Engelbrecht, JR Randeria, M deMelo, CARS AF Engelbrecht, JR Randeria, M deMelo, CARS TI BCS to Bose crossover: Broken-symmetry state SO PHYSICAL REVIEW B LA English DT Article ID COHERENCE LENGTH SUPERCONDUCTORS; EINSTEIN CONDENSATION; FERMI-LIQUID; GAS; TRANSITION AB A functional integral formulation, used previously to calculate T-c and describe normal state proper-ties of the BCS-Bose crossover, is extended to T < T-c. The saddle point approximation is shown to be qualitatively correct for T much less than T-c for all couplings, in contrast to the situation above T-c. Several features of the crossover an described. The difference between the T = 0 ''pair size'' and the (prefactor of the T dependent) Ginzburg-Landau coherence length is pointed out: the two quantities are the same only in the BCS limit. The evolution of the collective modes from the BCS to the Bose regime is discussed together with the mixing of the amplitude and phase in the absence of a particle-hole symmetry. C1 BOSTON COLL,DEPT PHYS,CHESTNUT HILL,MA 02167. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. TATA INST FUNDAMENTAL RES,THEORET PHYS GRP,BOMBAY 400005,MAHARASHTRA,INDIA. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Engelbrecht, JR (reprint author), LOS ALAMOS NATL LAB,CMS MS-K765,LOS ALAMOS,NM 87545, USA. NR 18 TC 296 Z9 297 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 JUN 1 PY 1997 VL 55 IS 22 BP 15153 EP 15156 DI 10.1103/PhysRevB.55.15153 PG 4 WC Physics, Condensed Matter SC Physics GA XF602 UT WOS:A1997XF60200064 ER PT J AU Bailey, DB Sigrist, M Laughlin, RB AF Bailey, DB Sigrist, M Laughlin, RB TI Fractional vortices on grain boundaries: The case for broken time-reversal symmetry in high-temperature superconductors SO PHYSICAL REVIEW B LA English DT Article ID D-WAVE SUPERCONDUCTIVITY; HIGH-TC SUPERCONDUCTORS; ORDER-PARAMETER; ANYON TECHNIQUES; MAGNETIC-FLUX; YBA2CU3O7-DELTA; BREAKING; MODEL; YBA2CU3O6.95; GAP AB We discuss the problem of broken time-reversal symmetry near grain boundaries in a d-wave superconductor based on a Ginzburg-Landau theory. It is shown that such a state can lead to fractional Vortices on the grain boundary. Both analytical and numerical results show the structure of this type of state. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. ETH HONGGERBERG,CH-8093 ZURICH,SWITZERLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Bailey, DB (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. RI Sigrist, Manfred/C-4570-2008 OI Sigrist, Manfred/0000-0002-8627-5093 NR 41 TC 35 Z9 35 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 JUN 1 PY 1997 VL 55 IS 22 BP 15239 EP 15247 DI 10.1103/PhysRevB.55.15239 PG 9 WC Physics, Condensed Matter SC Physics GA XF602 UT WOS:A1997XF60200073 ER PT J AU Friar, JL Payne, GL AF Friar, JL Payne, GL TI Nuclear polarizabilities and logarithmic sum rules SO PHYSICAL REVIEW C LA English DT Article ID ELECTRIC POLARIZABILITY; POLARIZATION CORRECTIONS; DEUTERON; POTENTIALS; HYDROGEN; SHIFTS AB The electric polarizability and logarithmic mean-excitation energy are calculated for the deuteron using techniques introduced in atomic physics. These results are then used to improve limits on the atomic-deuterium frequency shift due to nuclear polarization in the unretarded dipole limit, as well as confirming previous results. C1 UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. RP Friar, JL (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 29 TC 32 Z9 32 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 JUN PY 1997 VL 55 IS 6 BP 2764 EP 2767 DI 10.1103/PhysRevC.55.2764 PG 4 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100003 ER PT J AU Hauschild, K Bernstein, LA Becker, JA Archer, DE Bauer, RW McNabb, DP Cizewski, JA Ding, KY Younes, W Krucken, R Diamond, RM Clark, RM Fallon, P Lee, IY Macchiavelli, AO MacLeod, R Schmid, GJ Deleplanque, MA Stephens, FS Kelly, WH AF Hauschild, K Bernstein, LA Becker, JA Archer, DE Bauer, RW McNabb, DP Cizewski, JA Ding, KY Younes, W Krucken, R Diamond, RM Clark, RM Fallon, P Lee, IY Macchiavelli, AO MacLeod, R Schmid, GJ Deleplanque, MA Stephens, FS Kelly, WH TI Yrast superdeformed band in Pb-194: J(pi) and E-x SO PHYSICAL REVIEW C LA English DT Article ID SHAPE ISOMER; GAMMA-DECAY; STATES AB The yrast superdeformed band in Pb-194 has been populated using the Yb-174(Mg-25,5n)Pb-194 reaction at E-beam = 130 MeV. Decay gamma rays were detected using the GAMMASPHERE array at the 88-Inch Cyclotron. Twelve gamma-ray transitions have been observed directly linking three members of the Pb-194 yrast superdeformed band to low-lying normal deformed levels. Anisotropy measurements indicate that these linking decays include E1, M1, and mixed M1/E2 multipolarities. The radiative widths deduced are very inhibited, typically B(E1)similar to 10(-8) Weisskopf units (W.u.) and B(M1)similar to 10(-5) W.u. Without recourse to a priori assumptions J(pi) = 6(+) and E-x = 4878.4(3) keV have been unambiguously assigned to the lowest-lying observed superdeformed state (the state populated by the 170-keV intraband transition). The intensity of the observed primaries accounts for 21(2)% of the superdeformed band population. C1 RUTGERS STATE UNIV,NEW BRUNSWICK,NJ 08903. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. IOWA STATE UNIV,AMES,IA 50011. RP Hauschild, K (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Hauschild, Karl/A-6726-2009; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 38 TC 81 Z9 81 U1 1 U2 3 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 JUN PY 1997 VL 55 IS 6 BP 2819 EP 2825 DI 10.1103/PhysRevC.55.2819 PG 7 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100010 ER PT J AU Kahane, S Raman, S Bhatt, KH AF Kahane, S Raman, S Bhatt, KH TI Angular-momentum structure of the yrast bands of deformed nuclei SO PHYSICAL REVIEW C LA English DT Article ID SHELL-MODEL DESCRIPTION; LOW-ENERGY STRUCTURE; PSEUDO-SU(3) MODEL AB We have quantitatively analyzed the wave functions of the low-lying yrast states of deformed, heavy nuclei (specifically U-238 and Er-168) given by different models to determine the relative contribution of the valence nucleons to the total angular momentum of the nucleus. In all models, an yrast state is generated, as expected, by collective contributions from both proton and neutron angular momenta. We have also examined the relative contribution of valence nucleons in the normal-parity states and in the abnormal-parity, high-j, intruder states to the yrast angular momentum. If the stares with definite angular momenta projected from the Nilsson intrinsic state of the nucleus are assumed to provide a good approximation to the structure of the yrast band, the contribution of nucleons in the abnormal-parity states to the yrast angular momentum is shown to be about the same as that of nucleons in the normal-parity states. This result is in marked contrast to the assumption made in two prominent models (pseudo-SU3 model and its symplectic extension and fermion dynamic symmetric model) that the nucleons in abnormal-parity states, do not, in the first approximation. contribute any angular momentum to the yrast band. We also find that the distribution of angular momenta contained in the intrinsic state of the abnormal-parity nucleons in the j(n) configuration, which does not have any SU3 symmetry, is surprisingly similar to the distribution of angular momenta contained in an SU3 intrinsic state with the same average value of angular momentum. C1 UNIV MISSISSIPPI,DEPT PHYS & ASTRON,UNIVERSITY,MS 38677. JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. NUCL RES CTR,BEER SHEVA,ISRAEL. RP Kahane, S (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 38 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 1997 VL 55 IS 6 BP 2885 EP 2908 DI 10.1103/PhysRevC.55.2885 PG 24 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100017 ER PT J AU Gehring, J Back, BB Chan, KC Freer, M Henderson, D Jiang, CL Rehm, KE Schiffer, JP Wolanski, M Wuosmaa, AH AF Gehring, J Back, BB Chan, KC Freer, M Henderson, D Jiang, CL Rehm, KE Schiffer, JP Wolanski, M Wuosmaa, AH TI Deep-inelastic scattering in Xe-124,Xe-136+Ni-58,Ni-64 at energies near the Coulomb barrier SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION REACTIONS; FISSION; FUSION AB Cross sections, angular distributions, and mass distributions have been measured for deep-inelastic scattering in Xe-124 + Ni-58 and Xe-136 + Ni-64 at laboratory energies in the vicinity of the Coulomb barrier. The mass distributions show distinct components due to deep-inelastic and fissionlike processes. The strength of deep-inelastic scattering is similar in the two systems measured and comparable to previous measurements in Ni-58 + Sn-112,Sn-124. C1 UNIV CHICAGO,CHICAGO,IL 60637. RP Gehring, J (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Freer, Martin/F-9379-2013 NR 15 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 1997 VL 55 IS 6 BP 2959 EP 2964 DI 10.1103/PhysRevC.55.2959 PG 6 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100022 ER PT J AU Song, CS Koch, V AF Song, CS Koch, V TI Chemical relaxation time of pions in hot hadronic matter SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; STRANGE ANTI-BARYONS; QUARK-GLUON PLASMA; PARTON EQUILIBRATION; MESONS; TEMPERATURE; MODEL; GAS AB We calculate characteristic time scales for the chemical equilibration of pions in hot hadronic matter using an effective chiral Lagrangian. We find that inelastic processes involving vector and axial vector mesons reduce the chemical equilibration time by a factor of similar to 10 compared to the result previously calculated in chiral perturbation theory. For a temperature of T similar to 160 MeV we obtain a chemical relaxation time of tau(ch)similar or equal to 7 fm/c, which is comparable with typical time scales for a hadronic system generated in SPS-energy heavy-ion collisions. The effect of baryons is also estimated and found to be negligible for SPS energies but might be important for AGS energies. We predict that chemical freeze-out should take place at considerably higher temperatures Delta T similar or equal to 40 MeV than thermal freeze-out and that the hadronic phase would not sustain a pion chemical potential larger than 50 MeV. RP Song, CS (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, MS70A-3307, BERKELEY, CA 94720 USA. NR 35 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 1997 VL 55 IS 6 BP 3026 EP 3037 DI 10.1103/PhysRevC.55.3026 PG 12 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100032 ER PT J AU SchaffnerBielich, J Greiner, C Diener, A Stocker, H AF SchaffnerBielich, J Greiner, C Diener, A Stocker, H TI Detectability of strange matter in heavy ion experiments SO PHYSICAL REVIEW C LA English DT Article ID QUARK-MATTER; H-DIBARYON; COLLISIONS; SEARCH; HYPERNUCLEI; PARTICLES; DROPLETS; GEV/C; SEPARATION; OBJECTS AB We discuss the properties of two distinct forms of hypothetical strange matter, small lumps of strange quark matter (strangelets) and of hyperon matter [metastoble exotic multihypernuclear objects (MEMO's)], with special emphasis on their relevance for present and future heavy ion experiments. The masses of small strangelets up to A(B)=40 are calculated using the MIT bag model with shell mode filling for various bag parameters. The strangelets are checked for possible strong and weak hadronic decays, also taking into account multiple hadron decays. It is found that strangelets which are stable against strong decay are most likely highly negatively charged, contrary to previous findings. Strangelets can be stable against weak hadronic decay but their masses and charges are still rather high. This has serious impact on the present high sensitivity searches in heavy ion experiments at the AGS and CERN facilities. On the other hand, highly charged MEMO's no predicted on the basis of an extended relativistic mean-field model, Those objects could be detected in future experiments searching for short-lived, rare composites. It is demonstrated that future experiments can be sensitive to a much wider variety of strangelets. C1 UNIV FRANKFURT,INST THEORET PHYS,D-60054 FRANKFURT,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV GIESSEN,INST THEORET PHYS,D-35392 GIESSEN,GERMANY. RP SchaffnerBielich, J (reprint author), NIELS BOHR INST,BLEGDAMSVEJ 17,DK-2100 COPENHAGEN,DENMARK. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 61 TC 75 Z9 76 U1 1 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 JUN PY 1997 VL 55 IS 6 BP 3038 EP 3046 DI 10.1103/PhysRevC.55.3038 PG 9 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100033 ER PT J AU Wang, XN Huang, Z AF Wang, XN Huang, Z TI Medium-induced parton energy loss in gamma+jet events of high-energy heavy-ion collisions SO PHYSICAL REVIEW C LA English DT Article ID QUARK-GLUON-PLASMA; INCLUSIVE CROSS-SECTION; WEAK-BOSON PRODUCTION; LUND MONTE-CARLO; NUCLEAR-DEPENDENCE; HADRON-COLLISIONS; JET FRAGMENTATION; E+E-PHYSICS; QCD; MODEL AB The effect of medium-induced parton energy loss on jet fragmentation is studied in high-energy heavy-ion collisions. It is shown that an effective jet fragmentation function can be extracted from the inclusive p(T) spectrum of charged particles in the opposite direction of a tagged direct photon with a fixed transverse energy. We study the modification of the effective jet fragmentation function due to pac-ton energy loss in AA as compared to pp collisions, including E-T Smearing from initial-state radiations for the photon-tagged jets. The effective fragmentation function at z=p(T)\E-T(y) similar to 1 in pA collisions is shown to be sensitive to the additional E-T smearing due to initial multiple parton scatterings whose effect must be subtracted out in AA collisions in order to extract the effective parton energy loss. Jet quenching in deeply inelastic lepton-nucleus scatterings as a measure of the parton energy loss in cold nuclear matter is also discussed. We also comment on the experimental feasibilities of the proposed study at the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies and some alternative measurements such as using Z(0) as a tag at the LHC energy. C1 UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. RP Wang, XN (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, MS 70A-3307, BERKELEY, CA 94720 USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 49 TC 114 Z9 115 U1 0 U2 0 PU AMER 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 JUN PY 1997 VL 55 IS 6 BP 3047 EP 3061 DI 10.1103/PhysRevC.55.3047 PG 15 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100034 ER PT J AU Ahmad, I Austin, SM Back, BB Betts, RR Calaprice, FP Chan, KC Chishti, AA Conner, C Dunford, RW Fox, JD Freedman, SJ Freer, M Greenberg, JS Gazes, SB Hallin, AL Happ, T Henderson, D Kaloskamis, NI Kashy, E Kutschera, W Last, J Lister, CJ Liu, M Maier, MR Mercer, DJ Mikolas, D Perera, PAA Rhein, MD Roa, DE Schiffer, JP Trainor, TA Wilt, P Winfield, JS Wolanski, M Wolfs, FLH Wuosmaa, AH Xu, G Young, A Yurkon, JE AF Ahmad, I Austin, SM Back, BB Betts, RR Calaprice, FP Chan, KC Chishti, AA Conner, C Dunford, RW Fox, JD Freedman, SJ Freer, M Greenberg, JS Gazes, SB Hallin, AL Happ, T Henderson, D Kaloskamis, NI Kashy, E Kutschera, W Last, J Lister, CJ Liu, M Maier, MR Mercer, DJ Mikolas, D Perera, PAA Rhein, MD Roa, DE Schiffer, JP Trainor, TA Wilt, P Winfield, JS Wolanski, M Wolfs, FLH Wuosmaa, AH Xu, G Young, A Yurkon, JE TI Internal pair conversion in heavy nuclei SO PHYSICAL REVIEW C LA English DT Article ID ION COLLISIONS; COULOMB BARRIER; EMISSION; STATES; U-238 AB Positrons and electrons from the internal pair conversion (IPC) decay of states populated in near-barrier collisions of very heavy ions have been studied using the APEX spectrometer. Using inelastic Pb-206 + Pb-206 scattering at 5.90 MeV/nucleon, the gamma and IPC branches of the well-known E1 decay of the first J(pi) = 3(-) state were kinematically reconstructed and the IPC-to-gamma branching ratio was determined to be beta = (4.0 +/- 0.7) x 10(-4). We have also performed experiments with actinide beams or targets; U-238 + Ta-181, Pb-208 + U-238, Pb-208 + Th-232, and U-238 + Th-232, which resulted in the observation of new gamma-ray transitions from high-lying states in Th-232 and U-238. None of these were populated with sufficient strength such that IPC could produce statistically significantly peaks in positron-electron sum energy spectra. C1 MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. YALE UNIV,WNSL,NEW HAVEN,CT 06520. FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. UNIV ROCHESTER,NUCL STRUCT RES LAB,ROCHESTER,NY 14627. QUEENS UNIV,DEPT PHYS,KINGSTON,ON K7L 3N6,CANADA. GSI DARMSTADT,D-64291 DARMSTADT,GERMANY. UNIV WASHINGTON,NUCL PHYS LAB,SEATTLE,WA 98195. RP Ahmad, I (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. RI Hallin, Aksel/H-5881-2011; Freer, Martin/F-9379-2013 NR 19 TC 4 Z9 4 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 JUN PY 1997 VL 55 IS 6 BP R2755 EP R2759 PG 5 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100001 ER PT J AU Krucken, R Lee, IY AF Krucken, R Lee, IY TI Do superdeformed bands decay via electric monopole transitions? SO PHYSICAL REVIEW C LA English DT Article ID SHAPE COEXISTENCE; LIFETIMES; HG-192; STATES; ND-135; STRENGTH; NUCLEUS AB The strength of electric monopole transitions in the decay out of superdeformed bands is discussed on the basis of the mixing of superdeformed and normal-deformed states. The decay of superdeformed bands in the mass-190 region as well as the decay of the bands in Nd-133 and Nd-135 is investigated. Even though the values obtained for the electric monopole strength are very large, it is shown that E0 transitions cannot play an important role in the decay of superdeformed bands. RP Krucken, R (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. RI Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 38 TC 4 Z9 4 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 JUN PY 1997 VL 55 IS 6 BP R2760 EP R2763 PG 4 WC Physics, Nuclear SC Physics GA XF031 UT WOS:A1997XF03100002 ER PT J AU Gibbons, LK Barker, AR Briere, RA Makoff, G Papadimitriou, V Patterson, JR Schwingenheuer, B Somalwar, SV Wah, YW Winstein, B Winston, R Woods, M Yamamoto, H Bock, GJ Coleman, R Enagonio, J Hsiung, YB Ramberg, EJ Stanfield, K Tschirhart, R Yamanaka, T Swallow, EC Gollin, GD Karlsson, M Okamitsu, JK Debu, P Peyaud, B Turlay, R Vallage, B AF Gibbons, LK Barker, AR Briere, RA Makoff, G Papadimitriou, V Patterson, JR Schwingenheuer, B Somalwar, SV Wah, YW Winstein, B Winston, R Woods, M Yamamoto, H Bock, GJ Coleman, R Enagonio, J Hsiung, YB Ramberg, EJ Stanfield, K Tschirhart, R Yamanaka, T Swallow, EC Gollin, GD Karlsson, M Okamitsu, JK Debu, P Peyaud, B Turlay, R Vallage, B TI CP and CPT symmetry tests from the two-pion decays of the neutral kaon with the Fermilab E731 detector SO PHYSICAL REVIEW D LA English DT Article ID TO-LEADING ORDER; PARTICLE PROPERTIES; KS REGENERATION; VIOLATION; EPSILON'/EPSILON; SEARCH; SYSTEM; QUARK; MASS; KL->PI-0-GAMMA-GAMMA AB We present a comprehensive treatment of the precise determinations of the parameters Re(epsilon'/epsilon), tau(S), Delta m, phi(+-), and Delta phi in the neutral kaon system with the Fermilab E731 detector. Together, these determinations allow accurate studies of both CP and CPT symmetry. Details of the detector and its performance and the data analysis are given. The extensive Monte Carlo simulation of the detector and comparison with data are also presented. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. CENS,DEPT ASTROPHYS PHYS PARTICULES PHYS NUCL & INSTRU,F-91191 GIF SUR YVETTE,FRANCE. ELMHURST COLL,DEPT PHYS,ELMHURST,IL 60126. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 76 TC 74 Z9 74 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 JUN 1 PY 1997 VL 55 IS 11 BP 6625 EP 6715 DI 10.1103/PhysRevD.55.6625 PG 91 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800001 ER PT J AU Wackeroth, D Hollik, W AF Wackeroth, D Hollik, W TI Electroweak radiative corrections to resonant charged gauge boson production SO PHYSICAL REVIEW D LA English DT Article ID STANDARD MODEL; WIDTH; RENORMALIZATION; WEAK; INVARIANCE; DECAY AB The electroweak O(alpha) contribution to the resonant single W production in a general four-fermion process is discussed with particular emphasis on a gauge-invariant decomposition into a QED-like and weak part. The cross section in the vicinity of the resonance can be represented in terms of a convolution of a ''hard'' Breit-Wigner cross section, comprising the (m(t),M-H)-dependent weak one-loop corrections, with a universal radiator function. The numerical impact of the various contributions on the W line shape are discussed, together with the concepts of s-dependent and constant width approaches. Analytic formulas for the W decay width are also provided including the one-loop electroweak and QCD corrections. C1 UNIV KARLSRUHE,INST THEORET PHYS,D-76128 KARLSRUHE,GERMANY. RP Wackeroth, D (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 48 TC 54 Z9 54 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 JUN 1 PY 1997 VL 55 IS 11 BP 6788 EP 6818 DI 10.1103/PhysRevD.55.6788 PG 31 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800010 ER PT J AU Gottlieb, S Heller, UM Kennedy, AD Kim, S Kogut, JB Liu, C Renken, RL Sinclair, DK Sugar, RL Toussaint, D Wang, KC AF Gottlieb, S Heller, UM Kennedy, AD Kim, S Kogut, JB Liu, C Renken, RL Sinclair, DK Sugar, RL Toussaint, D Wang, KC TI Thermodynamics of lattice QCD with two light quarks on a 16(3)x8 lattice .2. SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PHASE-TRANSITION; HIGH-TEMPERATURE QCD; GAUGE-THEORY; NUMBER SUSCEPTIBILITY; HADRONIC SPECTRUM; 2-FLAVOR QCD; 2 FLAVORS; PLASMA AB We have extended our earlier simulations of the high-temperature behavior of lattice QCD with two light flavors of staggered quarks on a 16(3)x8 lattice to a lower quark mass (m(q)=0.00625). The transition from hadronic matter to a quark-gluon plasma is observed at 6/g(2)=5.49(2) corresponding to a temperature of Tc approximate to 140 MeV. We present measurements of observables which probe the nature of the quark-gluon plasma and serve to distinguish it from hadronic matter. Although the transition is quite abrupt, we have seen no indications that it is first order. C1 FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. SEOUL NATL UNIV, CTR THEORET PHYS, SEOUL, SOUTH KOREA. UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. MORGAN STANLEY & CO INC, NEW YORK, NY 10036 USA. UNIV CENT FLORIDA, DEPT PHYS, ORLANDO, FL 32816 USA. ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. CHINA GRAD SCH THEOL, KOWLOON, HONG KONG. RP INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. NR 36 TC 95 Z9 94 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 JUN 1 PY 1997 VL 55 IS 11 BP 6852 EP 6860 DI 10.1103/PhysRevD.55.6852 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800015 ER PT J AU Bernard, C Blum, T DeTar, C Gottlieb, S Rummukainen, K Heller, UM Hetrick, JE Toussaint, D Karkkainen, L Sugar, RL Wingate, M AF Bernard, C Blum, T DeTar, C Gottlieb, S Rummukainen, K Heller, UM Hetrick, JE Toussaint, D Karkkainen, L Sugar, RL Wingate, M TI Equation of state for two flavor QCD at N-t=6 SO PHYSICAL REVIEW D LA English DT Article ID PHASE-TRANSITION; GAUGE-THEORY; QUANTUM CHROMODYNAMICS; LATTICES AB We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)(-1) and find that cutoff effects are substantially reduced compared to an earlier study using a=(4T)(-1). However, it is likely that significant cutoff effects remain. We fit the lattice data to expected forms of the free energy density for a second order phase transition at zero-quark mass, which allows us to extrapolate the equation of state to m(q)=0 and to extract the speed of sound. We find that the equation of state depends weakly on the quark mass for small quark mass. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. NOKIA RES CTR, FIN-33721 TAMPERE, FINLAND. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP WASHINGTON UNIV, DEPT PHYS, ST LOUIS, MO 63130 USA. OI Hetrick, James/0000-0002-0740-2251; Heller, Urs M./0000-0002-2780-5584; Wingate, Matthew/0000-0001-6568-988X; DeTar, Carleton/0000-0002-0216-6771 NR 35 TC 96 Z9 96 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 JUN 1 PY 1997 VL 55 IS 11 BP 6861 EP 6869 DI 10.1103/PhysRevD.55.6861 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800016 ER PT J AU Kilgore, WB Giele, WT AF Kilgore, WB Giele, WT TI Next-to-leading order gluonic three-jet production at hadron colliders SO PHYSICAL REVIEW D LA English DT Article ID CROSS-SECTIONS; COLLISIONS; AMPLITUDES; SCATTERING; ALGORITHM AB We report the results of a next-to-leading order event generator of purely gluonic jet production. This calculation is the first step in the construction of a full next-to-leading order calculation of three-jet production at hadron colliders. Several jet algorithms commonly used in experiments are implemented and their numerical stability is investigated. RP Kilgore, WB (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 30 TC 63 Z9 63 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 JUN 1 PY 1997 VL 55 IS 11 BP 7183 EP 7190 DI 10.1103/PhysRevD.55.7183 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800048 ER PT J AU Gupta, R Bhattacharya, T AF Gupta, R Bhattacharya, T TI Light quark masses from lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID WILSON FERMIONS; HADRON SPECTRUM; STAGGERED FERMIONS; DECAY CONSTANTS; CP-VIOLATION; 2 FLAVORS; CONTINUUM; OPERATORS; SPECTROSCOPY; SIZE AB We present estimates of the masses of light quarks using lattice data. Our main results are based on a global analysis of ail the published data for Wilson, Sheikholeslami-Wohlert (clover), and staggered fermions, both in the quenched approximation and with n(f) = 2 dynamical flavors. We find that the values of masses with the various formulations agree after extrapolation to the continuum limit for the n(f) = 0 theory. Our best estimates, in the (MSS) over bar scheme at mu = 2 GeV, are (m) over bar = 3.4 +/- 0.4 +/- 0.3 MeV and m(s) = 100 +/- 21 +/- 10 MeV in the quenched approximation. The n(f) = 2 results, (m) over bar = 2.7 +/- 0.3 +/- 0.3 MeV and m(s) = 68 +/- 12 +/- 7 MeV, are preliminary. (A linear extrapolation in nf would further reduce these estimates for the physical case of three dynamical flavors.) These estimates are smaller than phenomenological estimates based on sum rules, but maintain the ratios predicted by chiral perturbation theory. The new results have a significant impact on the extraction of epsilon'/epsilon from the standard model. Using the same lattice data we estimate the quark condensate using the GeIl-MannOakes-Renner relation. Again the three formulations give consistent results after extrapolation to a = 0, andthe value turns out to be correspondingly larger, roughly preserving m(s)[(psi)over bar>psi>]. RP LOS ALAMOS NATL LAB, GRP T-8, MAIL STOP B-285, LOS ALAMOS, NM 87545 USA. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 56 TC 76 Z9 76 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 JUN 1 PY 1997 VL 55 IS 11 BP 7203 EP 7217 DI 10.1103/PhysRevD.55.7203 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800050 ER PT J AU Mahlon, G Parke, S AF Mahlon, G Parke, S TI Improved spin basis for angular correlation studies in single top quark production at the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID W-GLUON FUSION; HEAVY QUARKS; APPROXIMATION; COLLIDER AB We show in single top quark production that the spin of the top quark is correlated with the direction of the d-type quark in the event. For single top-quark production in the W* channel, the d-type quark comes dominantly from the antiproton at the Fermilab Tevatron, whereas for the W-gluon fusion channel the spectator jet is the d-type quark the majority of the time at this machine. Our results are that 98% of the top quarks from the W* process have their spins in the antiproton direction, and 96% of the top quarks in the W-gluon fusion process have their spins in the spectator jet direction. We also compare with the more traditional, but less effective, helicity basis. The direction of the top quark spin is reflected in angular correlations in its decay products. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Mahlon, G (reprint author), UNIV MICHIGAN,DEPT PHYS,500 E UNIV AVE,ANN ARBOR,MI 48109, USA. NR 31 TC 88 Z9 88 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 JUN 1 PY 1997 VL 55 IS 11 BP 7249 EP 7254 DI 10.1103/PhysRevD.55.7249 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800053 ER PT J AU Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sharma, V Gronberg, J Hill, TS Kutschke, R Lange, DJ Menary, S Morrison, RJ Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M Lee, SJ ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fisher, KD Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X AF Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sharma, V Gronberg, J Hill, TS Kutschke, R Lange, DJ Menary, S Morrison, RJ Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M Lee, SJ ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fisher, KD Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X TI nu(tau) helicity from h(+/-) energy correlations SO PHYSICAL REVIEW D LA English DT Article ID TAU-NEUTRINO HELICITY; DECAY CORRELATIONS; LIBRARY; PARAMETERS; LEPTONS AB We report a measurement of the magnitude of the nu(tau) helicity from tau-pair events taken with the CLEO detector at the CESR electron-positron storage ring. Events in which each tau undergoes the decay tau-->h nu, with h a charged pion or kaon, are analyzed for energy correlations between the daughter hadrons, yielding \xi(h)\ = 1.03 +/- 0.06 +/- 0.04, with the first error statistical and the second systematic. C1 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,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. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV TEXAS,AUSTIN,TX 78712. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Coan, TE (reprint author), SO METHODIST UNIV,DALLAS,TX 75275, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 22 TC 3 Z9 3 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 1997 VL 55 IS 11 BP 7291 EP 7295 DI 10.1103/PhysRevD.55.7291 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XD018 UT WOS:A1997XD01800057 ER PT J AU Posch, HA Hoover, WG AF Posch, HA Hoover, WG TI Time-reversible dissipative attractors in three and four phase-space dimensions SO PHYSICAL REVIEW E LA English DT Article ID SIMPLE CHAOTIC FLOWS; NUMERICAL EXPERIMENTS; CANONICAL DYNAMICS; BEHAVIOR; OSCILLATOR; ORDER; GAS AB We establish the dissipative nature of several three- and four-dimensional time-reversible phase-space flows and study their ergodicity. Three- and four-dimensional generalizations of the equilibrium Nose-Hoover oscillater provide the simplest robust continuous models for time-reversible nonequilibrium dissipative systems. Most such systems exhibit discontinuities or periodicities. We have discovered one set of four ordinary differential equations which is simultaneously robust, time-reversible, dissipative, and ergodic, with solutions free of any discontinuities and periodicities. C1 UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA 94551 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP UNIV VIENNA, INST EXPT PHYS, BOLTZMANNGASSE 5, A-1090 VIENNA, AUSTRIA. NR 27 TC 25 Z9 25 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1997 VL 55 IS 6 BP 6803 EP 6810 DI 10.1103/PhysRevE.55.6803 PN A PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG965 UT WOS:A1997XG96500068 ER PT J AU Hu, YC Ecke, RE Ahlers, G AF Hu, YC Ecke, RE Ahlers, G TI Convection under rotation for Prandtl numbers near 1: Linear stability, wave-number selection, and pattern dynamics SO PHYSICAL REVIEW E LA English DT Article ID RAYLEIGH-BENARD CONVECTION; SPIRAL DEFECT CHAOS; CYLINDRICAL CONTAINER; HEAT-TRANSFER; THERMAL-CONVECTION; FLOW PATTERNS; VECTOR FIELD; TURBULENCE; ONSET; TIME AB Rayleigh-Benard convection with rotation about a vertical axis was studied with the shadowgraph imaging method up to a dimensionless rotation rate Omega of 22. Most of the results are for a cylindrical convection cell with a radius-to-height ratio Gamma = 40 that contained CO2 at 33.1 bars with a Prandtl number sigma = 0.93. Measurements of the critical Rayleigh number R-c and wave number k(c) for 0 < Omega < 22 agree well with predictions based on linear stability analysis. Above onset and with rotation, the average wave number and details of the pattern dynamics were studied. For Omega less than or similar to 5, the initial onset was to a pattern of straight or slightly curved rolls. For 0.1 less than or similar to epsilon = Delta T/Delta T-c - 1 less than or similar to 0.5 but below the onset of spiral-defect chaos, rotation with Omega less than or similar to 8 produced weak perturbations of nonrotating patterns. Typically, this gave an ''S-shaped'' distortion of the zero-rotation pattern of straight or somewhat curved rolls. Rotation had a stronger effect on thr source and motions of dislocation defects. For Omega > 0 the defects were generated primarily at the wall, whereas for Omega = 0 they were nucleated in the bulk via the skewed-varicose instability. Rotation picked a preferred direction of motion for the defects once they formed. For epsilon greater than or similar to 0.5, recognizable spiral-defect chaos and the oscillatory instability were observed for Omega less than or similar to 12. For Omega greater than or equal to 8, domain growth and front propagation suggestive of the Kuppers-Lortz instability were observed from onset up to an epsilon value that increased with Omega. Increasing epsilon at fixed Omega less than or similar to 12 enhanced dislocation-defect dynamics over Kuppers-Lortz front propagation. Quantitative measurements of average pattern wave numbers, correlation lengths, and spatially averaged roll curvature as functions of epsilon and R are presented, At a fixed Omega greater than or similar to 10, the average wave number had two distinct wave-number-selection regions with different slopes as a function of epsilon, one above epsilon approximate to 0.45 and thr other near onset. The slope for epsilon near onset reached a minimum Omega = 12.1 and increased Linearly for 12 < Omega < 20. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,CTR NONLINEAR STUDIES,SANTA BARBARA,CA 93106. RP Hu, YC (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,CONDENSED MATTER & THERMAL PHYS GRP,LOS ALAMOS,NM 87545, USA. OI Ecke, Robert/0000-0001-7772-5876 NR 78 TC 42 Z9 42 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1997 VL 55 IS 6 BP 6928 EP 6949 DI 10.1103/PhysRevE.55.6928 PN A PG 22 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG965 UT WOS:A1997XG96500083 ER PT J AU Roder, J Roder, H Kramer, L AF Roder, J Roder, H Kramer, L TI Linear stability analysis of bifurcations with a spatially periodic, fluctuating control parameter SO PHYSICAL REVIEW E LA English DT Article ID NEMATIC LIQUID-CRYSTALS; RAYLEIGH-BENARD CONVECTION; MULTIPLICATIVE STOCHASTIC-PROCESSES; GINZBURG-LANDAU EQUATIONS; SWIFT-HOHENBERG EQUATION; HYDRODYNAMIC FLUCTUATIONS; EXTERNAL NOISE; ELECTROHYDRODYNAMIC INSTABILITIES; PROBABILITY-DISTRIBUTIONS; THERMAL FLUCTUATIONS AB Multiplicative noise in spatially extended systems produces different effects depending upon whether the noise is spatially homogeneous or spatially varying. Whereas in previous work a stochastic distribution was treated, here we consider the spatially periodic case, which is more amenable to an experimental approach, in particular in the electrically driven instabilities of nematic liquid crystals. We shall principally be interested in the threshold for the onset of symmetry breaking instabilities controlled by bifurcations in several stochastic partial differential equations. For the Ginzburg-Landau and Swift-Hohenberg equations we calculate the behavior of the threshold for all moments to second order in the noise strength, allowing one to reconstruct the full probability distribution. For a system of two coupled equations which mimics electroconvection in nematic liquid crystals (the ''one-dimensional model''), we calculate the first two moments up to second order and estimate the threshold for convection. The general conclusion of our work is that spatially periodic noise induces a reduction in the threshold similar to the stochastically distributed case. We propose that this reduction be independent of the periodicity of the noise to first order in the noise strength, the dependence on period appearing only at second order. This is in contrast to spatially homogeneous noise where threshold shifts may be entirely absent. C1 UNIV BAYREUTH,LEHRSTUHL THEORET PHYS 2,D-85440 BAYREUTH,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV BARCELONA,DEPT ECM,BARCELONA,SPAIN. NR 73 TC 6 Z9 6 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1997 VL 55 IS 6 BP 7068 EP 7078 DI 10.1103/PhysRevE.55.7068 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG966 UT WOS:A1997XG96600002 ER PT J AU Rozsnyai, BF AF Rozsnyai, BF TI Collisional-radiative average-atom model for hot plasmas SO PHYSICAL REVIEW E LA English DT Article ID ALUMINUM PLASMAS; DENSITY; MATTER AB A collisional-radiative ''average-atom'' (AA) model is presented for the calculation of opacities of hot plasmas that are not in the condition of local thermodynamic equilibrium (LTE). The electron impact and radiative rate constants are calculated using the dipole oscillator strengths of the average atom. A key element of the model is the photon escape probability, which at present is calculated for a semi-infinite slab. The Fermi statistics renders the rate equations for the AA level occupancies nonlinear, which requires iterations until the steady-state AA level occupancies are found. Detailed electronic configurations are built into the model after the self-consistent non-LTE AA state is found. The model shows a continuous transition from the non-LTE to the LTE state depending on the optical thickness of the plasma. RP Rozsnyai, BF (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 26 TC 17 Z9 20 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1997 VL 55 IS 6 BP 7507 EP 7521 DI 10.1103/PhysRevE.55.7507 PN B PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG966 UT WOS:A1997XG96600048 ER PT J AU Doering, CR Hyman, JM AF Doering, CR Hyman, JM TI Energy stability bounds on convective heat transport: Numerical study SO PHYSICAL REVIEW E LA English DT Article ID SHEAR-DRIVEN TURBULENCE; VARIATIONAL BOUNDS; INCOMPRESSIBLE FLOWS; DISSIPATION AB The concept of nonlinear energy stability has recently been extended to deduce bounds on energy dissipation and transport in incompressible flows, even for turbulent flows. In this approach an effective stability condition on ''background'' flow or temperature profiles is derived, which when satisfied ensures that the profile produces a rigorous upper estimate to the bulk dissipation. Optimization of the test background profiles in search of the lowest upper bounds leads to nonlinear Euler-Lagrange equations for the extremal profile. In this paper, in the context of convective heat transport in the Boussinesq equations, we describe numerical solutions of the Euler-Lagrange equations for the optimal background temperature and present the numerical computation of the implied bounds. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS B284,LOS ALAMOS,NM 87545. RP Doering, CR (reprint author), UNIV MICHIGAN,DEPT MATH,ANN ARBOR,MI 48109, USA. NR 27 TC 16 Z9 16 U1 1 U2 3 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 JUN PY 1997 VL 55 IS 6 BP 7775 EP 7778 DI 10.1103/PhysRevE.55.7775 PN B PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG966 UT WOS:A1997XG96600081 ER PT J AU He, XY Luo, LS AF He, XY Luo, LS TI A priori derivation of the lattice Boltzmann equation SO PHYSICAL REVIEW E LA English DT Article ID NAVIER-STOKES EQUATION; GAS AUTOMATA; HYDRODYNAMICS; MODELS AB The lattice Boltzmann equation (LBE) is directly derived from the Boltzmann equation by discretization in both time and phase space. A procedure to systematically derive discrete velocity models is presented. A LBE algorithm with arbitrary mesh grids is proposed and a numerical simulation of the backward-facing step is conducted. The numerical result agrees well with experimental and previous numerical results. Various improvements on the LBE models are discussed, and an explanation of the instability of the existing LBE thermal models is also provided. C1 LOS ALAMOS NATL LAB,COMPLEX SYST GRP T13,THEORET T DIV,LOS ALAMOS,NM 87545. NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23681. RP He, XY (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS-B258,LOS ALAMOS,NM 87545, USA. RI Luo, Li-Shi/A-4561-2011 OI Luo, Li-Shi/0000-0003-1215-7892 NR 26 TC 435 Z9 439 U1 7 U2 35 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 JUN PY 1997 VL 55 IS 6 BP R6333 EP R6336 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XG965 UT WOS:A1997XG96500006 ER PT J AU Zou, QS He, XY AF Zou, QS He, XY TI On pressure and velocity boundary conditions for the lattice Boltzmann BGK model SO PHYSICS OF FLUIDS LA English DT Article ID NAVIER-STOKES EQUATION; SIMULATION; FLOWS AB Pressure (density) and velocity boundary conditions are studied for 2-D and 3-D lattice Boltzmann BGK models (LBGK) and a new method to specify these conditions is proposed. These conditions are constructed in consistency with the wall boundary condition, based on the idea of bounceback of the non-equilibrium distribution. When these conditions are used together with the incompressible LBGK model [J. Stat. Phys. 81, 35 (1995)] the simulation results recover the analytical solution of the plane Poiseuille flow driven by a pressure (density) difference. The half-way wall bounceback boundary condition is also used with the pressure (density) inlet/outlet conditions proposed in this paper and in Phys. Fluids 8, 2527 (1996) to study 2-D Poiseuille flow and 3-D square duct flow. The numerical results are approximately second-order accurate. The magnitude of the error of the half-way wall bounceback boundary condition is comparable with that of other published boundary conditions and it has better stability behavior. (C) 1997 American institute of Physics. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP,LOS ALAMOS,NM 87545. KANSAS STATE UNIV,DEPT MATH,MANHATTAN,KS 66506. RP Zou, QS (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 19 TC 786 Z9 828 U1 22 U2 142 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 JUN PY 1997 VL 9 IS 6 BP 1591 EP 1598 DI 10.1063/1.869307 PG 8 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA XB197 UT WOS:A1997XB19700007 ER PT J AU Rightley, PM Vorobieff, P Benjamin, RF AF Rightley, PM Vorobieff, P Benjamin, RF TI Evolution of a shock-accelerated thin fluid layer SO PHYSICS OF FLUIDS LA English DT Article ID RAYLEIGH-TAYLOR; INSTABILITY; PATTERNS; GROWTH AB Multi-exposure flow visualization experiments with laser-sheet illumination provide growth-rate measurement of Richtmyer-Meshkov instability of a thin, perturbed heavy-gas layer embedded in a lower-density gas and accelerated by a planar shock wave. The measurements clearly show the three-stage transition to turbulence of this gas-curtain instability and the single-event coexistence of the three primary flow morphologies discovered previously. The shock-induced circulation for each event is estimated using a simple model based on Richtmyer-Meshkov instability and an infinite linear array of vortex points. These estimates are consistent with simplified flow simulations using a finite-core vortex-blob model. RP Rightley, PM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Vorobieff, Peter/B-3376-2011; OI Vorobieff, Peter/0000-0003-0631-7263 NR 21 TC 42 Z9 48 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 JUN PY 1997 VL 9 IS 6 BP 1770 EP 1782 DI 10.1063/1.869299 PG 13 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA XB197 UT WOS:A1997XB19700023 ER PT J AU Zhang, DS Wei, GW Kouri, DJ Hoffman, DK AF Zhang, DS Wei, GW Kouri, DJ Hoffman, DK TI Burgers' equation with high Reynolds number SO PHYSICS OF FLUIDS LA English DT Article AB Burgers' equation, involving very high Reynolds numbers, is numerically solved by using a new approach based on the distributed approximating functional for representing spatial derivatives of the velocity field. For moderately large Reynolds numbers, this simple approach can provide very high accuracy while using a small number of grid points. In the case where the Reynolds number greater than or equal to 10(5), the exact solution is not available and a discrepancy exists in the literature. Our results clarify the behavior of the solution under these conditions. (C) 1997 American Institute of Physics. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Zhang, DS (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. RI Wei, Guowei /E-1852-2011 NR 16 TC 17 Z9 18 U1 0 U2 0 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 JUN PY 1997 VL 9 IS 6 BP 1853 EP 1855 DI 10.1063/1.869305 PG 3 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA XB197 UT WOS:A1997XB19700035 ER PT J AU Hu, GZ Krommes, JA Bowman, JC AF Hu, GZ Krommes, JA Bowman, JC TI Statistical theory of resistive drift-wave turbulence and transport SO PHYSICS OF PLASMAS LA English DT Article ID REALIZABLE MARKOVIAN CLOSURE; LINEAR GYROKINETIC EQUATIONS; PLASMA EDGE TURBULENCE; ANOMALOUS TRANSPORT; SELF-ORGANIZATION; TOKAMAK EDGE; FLUCTUATIONS; DYNAMICS; SIMULATIONS; INSTABILITY AB Resistive drift-wave turbulence in a slab geometry is studied by statistical closure methods and direct numerical simulations. The two-field Hasegawa-Wakatani (HW) fluid model, which evolves the electrostatic potential and plasma density self-consistently, is a paradigm for understanding the generic nonlinear behavior of multiple-field plasma turbulence. A gyrokinetic derivation of the HW model is sketched. The recently developed Realizable Markovian Closure (RMC) is applied to the HW model; spectral properties, nonlinear energy transfers, and turbulent transport calculations are discussed. The closure results are also compared to direct numerical simulation results; excellent agreement is found. The transport scaling with the adiabaticity parameter, which measures the strength of the parallel electron resistivity, is analytically derived and understood through weak- and strong-turbulence analyses. No evidence is found to support previous suggestions that coherent structures cause a large depression of saturated transport from its quasilinear value in the hydrodynamic regime of the HW model. Instead, the depression of transport is well explained by the spectral balance equation of the (second-order) statistical closure when account is taken of incoherent noise. (C) 1997 American Institute of Physics. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. EURATOM,MAX PLANCK INST PLASMAPHYS,D-85748 GARCHING,GERMANY. NR 74 TC 26 Z9 26 U1 0 U2 3 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 JUN PY 1997 VL 4 IS 6 BP 2116 EP 2133 DI 10.1063/1.872377 PG 18 WC Physics, Fluids & Plasmas SC Physics GA XB803 UT WOS:A1997XB80300012 ER PT J AU Chance, MS AF Chance, MS TI Vacuum calculations in azimuthally symmetric geometry SO PHYSICS OF PLASMAS LA English DT Article ID MHD STABILITY; CODE; PLASMAS; ERATO AB A robustly accurate and effective method is presented to solve Laplace's equation in general azimuthally symmetric geometry for the magnetic scalar potential in the region surrounding a plasma discharge which may or may not contain external conductors. These conductors can be topologically toroidal or spherical, and may have toroidal gaps in them. The solution is incorporated into the various magnetohydrodynamic stability codes either through the volume integrated perturbed magnetic energy in the vacuum region or through the continuity requirements for the normal component of the perturbed magnetic field and the total perturbed pressure across the unperturbed plasma-vacuum boundary. The method is based upon using Green's second identity and the method of collocation. As useful by-products, the eddy currents and the simulation of Mirnov loop measurements are calculated. RP Chance, MS (reprint author), PRINCETON UNIV, PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 22 TC 56 Z9 57 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUN PY 1997 VL 4 IS 6 BP 2161 EP 2180 DI 10.1063/1.872380 PG 20 WC Physics, Fluids & Plasmas SC Physics GA XB803 UT WOS:A1997XB80300017 ER PT J AU Sanford, TWL Nash, TJ Mock, RC Spielman, RB Struve, KW Hammer, JH DeGroot, JS Whitney, KG Apruzese, JP AF Sanford, TWL Nash, TJ Mock, RC Spielman, RB Struve, KW Hammer, JH DeGroot, JS Whitney, KG Apruzese, JP TI Dynamics of a high-power aluminum-wire array Z-pinch implosion SO PHYSICS OF PLASMAS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; MODEL; PLASMAS AB Annular Al-wire Z-pinch implosions on the Saturn accelerator [D.D. Bloomquist et al., Proceedings, 6th Pulsed Power Conference (Institute of Electrical and Electronics Engineers, New York, 1987), p. 310] that have high azimuthal symmetry exhibit both a strong first and weaker second x-ray burst that correlate with strong and weaker radial compressions, respectively. Measurements suggest that the observed magnetic Rayleigh-Taylor (RT) instability prior to the first compression seeds an m=0 instability observed later. Analyses of axially averaged spectral data imply that, during the first compression, the plasma is composed of a hot core surrounded by a cooler plasma halo. Two-dimensional (2-D) radiation magnetohydrodynamic computer simulations show that a RT instability grows to the classic bubble and spike structure during the course of the implosion. The main radiation pulse begins when the bubble reaches the axis and ends when the spike finishes stagnating on axis and the first compression ends. These simulations agree qualitatively with the measured characteristics of the first x-ray pulse and the overall energetics, and they provide a 2-D view into the plasma hydrodynamics of the implosion. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. USN,RES LAB,RADIAT HYDRODYNAM BRANCH,WASHINGTON,DC 20375. RP Sanford, TWL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 34 TC 52 Z9 54 U1 1 U2 3 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 JUN PY 1997 VL 4 IS 6 BP 2188 EP 2203 DI 10.1063/1.872382 PG 16 WC Physics, Fluids & Plasmas SC Physics GA XB803 UT WOS:A1997XB80300019 ER PT J AU Brandan, ME Satchler, GR AF Brandan, ME Satchler, GR TI The interaction between light heavy-ions and what it tells us SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE elastic scattering; heavy ions; interaction potentials; absorption; nuclear equation of state; rainbows ID QUASI-ELASTIC SCATTERING; REACTION CROSS-SECTIONS; NUCLEUS-NUCLEUS POTENTIALS; FOLDING-MODEL POTENTIALS; DENSITY-DEPENDENT INTERACTIONS; LONG-RANGE ABSORPTION; MEV LI-6 IONS; 318 MEV LI-6; INELASTIC-SCATTERING; OPTICAL-MODEL AB Significant progress has been achieved during the last decade in our knowledge and understanding of the optical potential between two light heavy-ions. This has mostly been a consequence of the measurement of accurate and extensive elastic differential cross sections. Some of these data, covering over eight orders of magnitude in cross section, extend to sufficiently large scattering angles that they show remarkable refractive effects which remind one of features of the scattering of alpha particles by nuclei that have been known since the work of Goldberg some twenty years ago. Refractive effects, particularly nuclear rainbows, are evident in C-12 + C-12 and O-16 + O-16 angular distributions at bombarding energies between 6 and 100 MeV per nucleon. Their angular location and cross section have led to the determination of the gross features of the local optical potentials and in many cases have removed ambiguities in the depths of the real parts of the potentials. The resulting phenomenological potentials are strongly attractive (''deep''), with relatively weak absorption, and depend upon the bombarding energy. The optical model potential for such heavy-ions is no longer simply a way to parameterize scattering data (or perhaps just one of many ways). Ambiguities have been resolved, and a good understanding of the theoretical basis of its features has been attained. The folding model is central to this understanding, coupled with increased insight into the nature of realistic effective nucleon-nucleon interactions. This Report reviews the experimental evidence, its interpretation, and what we have learnt from it. Much of the interpretation becomes especially transparent when couched in the language of semiclassical scattering theory. We summarize this language, as well as the basic features of the theory of the optical model. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. RP Brandan, ME (reprint author), UNIV NACL AUTONOMA MEXICO,INST FIS,AP 20-364,MEXICO CITY 01000,DF,MEXICO. RI Brandan, Maria-Ester/K-9014-2012 OI Brandan, Maria-Ester/0000-0002-1165-3440 NR 209 TC 319 Z9 330 U1 1 U2 10 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 JUN PY 1997 VL 285 IS 4-5 BP 143 EP 243 DI 10.1016/S0370-1573(96)00048-8 PG 101 WC Physics, Multidisciplinary SC Physics GA XF890 UT WOS:A1997XF89000001 ER PT J AU Grunder, HA AF Grunder, HA TI DOE's Jefferson Lab: What's in a name? SO PHYSICS TODAY LA English DT Letter RP Grunder, HA (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA, USA. NR 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 1997 VL 50 IS 6 BP 11 EP & PG 2 WC Physics, Multidisciplinary SC Physics GA XD174 UT WOS:A1997XD17400002 ER PT J AU Drell, S AF Drell, S TI US position on test ban treaty explained, key terms clarified SO PHYSICS TODAY LA English DT Letter RP Drell, S (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 1997 VL 50 IS 6 BP 13 EP & DI 10.1063/1.881791 PG 2 WC Physics, Multidisciplinary SC Physics GA XD174 UT WOS:A1997XD17400003 ER PT J AU Haeberli, W DeLuca, PM Davis, JC AF Haeberli, W DeLuca, PM Davis, JC TI Henry Herman Barschall - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Haeberli, W (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. NR 1 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 1997 VL 50 IS 6 BP 106 EP 108 DI 10.1063/1.881755 PG 3 WC Physics, Multidisciplinary SC Physics GA XD174 UT WOS:A1997XD17400029 ER PT J AU Hanna, SS Kurath, D Peterson, GA AF Hanna, SS Kurath, D Peterson, GA TI David Rittenhouse Inglis - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV MASSACHUSETTS,AMHERST,MA 01003. RP Hanna, SS (reprint author), STANFORD UNIV,STANFORD,CA 94305, USA. NR 1 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUN PY 1997 VL 50 IS 6 BP 109 EP 110 DI 10.1063/1.881757 PG 2 WC Physics, Multidisciplinary SC Physics GA XD174 UT WOS:A1997XD17400031 ER PT J AU McKay, RML Geider, RJ LaRoche, J AF McKay, RML Geider, RJ LaRoche, J TI Physiological and biochemical response of the photosynthetic apparatus of two marine diatoms to Fe stress SO PLANT PHYSIOLOGY LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; CENTRAL NORTH PACIFIC; IRON-LIMITATION; PHYTOPLANKTON PHOTOSYNTHESIS; PHAEODACTYLUM-TRICORNUTUM; POLYACRYLAMIDE GELS; ENERGY-CONVERSION; NITROGEN-FIXATION; PHOTOSYSTEM-II; PROTEINS AB Flavodoxin is a small electron-transfer protein capable of replacing ferredoxin during periods of Fe deficiency. When evaluating the suitability of flavodoxin as a diagnostic indicator for Fe limitation of phytoplankton growth, we examined its expression in two marine diatoms we cultured using trace-metal-buffered medium. Thalassiosira weissflogii and Phaeodactylum tricornutum were cultured in ethylenediaminetetraacetic acid-buffered Sargasso Sea water containing from 10 to 1000 nM added Fe. Trace-metal-buffered cultures of each diatom maintained high growth rates across the entire range of Fe additions. Similarly, declines in chlorophyll/cell and in the ratio of photosystem II variable-to-maximum fluorescence were negligible (P. tricornutum) to moderate (T. weissflogii; 54% decline in chlorophyll/cell and 22% decrease in variable-to-maximum fluorescence). Moreover, only minor variations in photosynthetic parameters were observed across the range of additions. In contrast, flavodoxin was expressed to high levels in low-Fe cultures. Despite the inverse relationship between flavodoxin expression and Fe content of the medium, its expression was seemingly independent of any of the indicators of cell physiology that were assayed. It appears that flavodoxin is expressed as an early-stage response to Fe stress and that its accumulation need not be intimately connected to limitations imposed by Fe on the growth rate of these diatoms. C1 UNIV DELAWARE, COLL MARINE STUDIES, LEWES, DE 19958 USA. MARINE BIOL ASSOC UNITED KINGDOM LAB, THE LABORATORY, PLYMOUTH PL1 2PB, DEVON, ENGLAND. RP McKay, RML (reprint author), BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI LaRoche, Julie/A-1109-2010; OI McKay, Robert/0000-0003-2723-5371 NR 55 TC 77 Z9 80 U1 2 U2 10 PU AMER SOC PLANT BIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUN PY 1997 VL 114 IS 2 BP 615 EP 622 PG 8 WC Plant Sciences SC Plant Sciences GA XE156 UT WOS:A1997XE15600027 ER PT J AU Reiman, AH Ku, LP Monticello, DA Nuhrenberg, C Cooper, WA AF Reiman, AH Ku, LP Monticello, DA Nuhrenberg, C Cooper, WA TI MHD calculations for MHH2 SO PLASMA PHYSICS REPORTS LA English DT Article ID MAGNETOHYDRODYNAMIC EQUILIBRIA; CONFIGURATIONS; STABILITY AB A survey of the magnetohydrodynamic (MHD) properties of the quasi-axisymmetric configuration MHH2 has been performed using a suite of MHD codes: the PIES code at Princeton for studying loss of equilibrium flux surfaces; three-dimensional Mercier and ballooning codes at Lausanne; and the global ideal MHD stability code CAS3D as well as Mercier and ballooning codes at IPP, Greifswald. C1 MAX PLANCK INST PLASMA PHYS, TEILINST GREIFSWALD, IPP, EURATOM ASSOC, D-17491 GREIFSWALD, GERMANY. ECOLE POLYTECH FED LAUSANNE, ASSOC EURATOM CONFEDERAT SUISSE, CTR RECH PHYS PLASMAS,CRPP,PPB, CH-1015 LAUSANNE, SWITZERLAND. RP Reiman, AH (reprint author), PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 23 TC 5 Z9 5 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1063-780X J9 PLASMA PHYS REP+ JI Plasma Phys. Rep. PD JUN PY 1997 VL 23 IS 6 BP 472 EP 482 PG 11 WC Physics, Fluids & Plasmas SC Physics GA XH320 UT WOS:A1997XH32000004 ER PT J AU Spong, DA Hirshman, SP Whitson, JC AF Spong, DA Hirshman, SP Whitson, JC TI Confinement properties of small aspect ratio tokamak/stellarator hybrid devices SO PLASMA PHYSICS REPORTS LA English DT Article ID TRANSPORT-COEFFICIENTS; FIELDS; STELLARATORS AB We have examined the confinement properties for a range of small aspect ratio tokamak/stellarator hybrid devices. Vacuum rotational transform is produced in these configurations using relatively simple tilted/modulated toroidal magnetic field coils, which can then be supplemented with driven plasma current. The. iota profile is tokamak-like with a maximum in the center and decreasing towards the plasma edge. Evaluation of confinement characteristics is carried out on several levels including B-min, B-max, contours, longitudinal adiabatic invariant J* contours, guiding-center trajectories, and Monte Carlo simulations starting with a random ensemble of particles. We find that confinement generally improves with increasing driven current, lower ripple, increasing magnetic field, and increasing electric field. Another avenue for confinement improvement is through optimization of the magnetic geometry. The tools mentioned above for evaluating confinement suggest several simple criteria as targets for the magnetic optimizations. RP Spong, DA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Spong, Donald/C-6887-2012 OI Spong, Donald/0000-0003-2370-1873 NR 23 TC 10 Z9 10 U1 0 U2 0 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 JUN PY 1997 VL 23 IS 6 BP 483 EP 491 PG 9 WC Physics, Fluids & Plasmas SC Physics GA XH320 UT WOS:A1997XH32000005 ER PT J AU Shaing, KC Hazeltine, RD Zarnstorff, MC AF Shaing, KC Hazeltine, RD Zarnstorff, MC TI Ion transport process close to magnetic axis in tokamaks SO PLASMA PHYSICS REPORTS LA English DT Article ID CONFINEMENT; PLASMAS AB Ion transport in the region close to the magnetic axis in tokamaks is investigated by solving the drift kinetic equation with the proper orbit topology taken into account. It is found that ion thermal conductivity remains finite in that region. The scaling of the thermal conductivity can be understood in terms of a random walk process in units of the poloidal flux. 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 4 Z9 4 U1 0 U2 1 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 JUN PY 1997 VL 23 IS 6 BP 523 EP 530 PG 8 WC Physics, Fluids & Plasmas SC Physics GA XH320 UT WOS:A1997XH32000011 ER PT J AU Hoisington, MA Duke, JR Apen, PG AF Hoisington, MA Duke, JR Apen, PG TI High temperature, polymeric, structural foams from high internal phase emulsion polymerizations SO POLYMER LA English DT Article DE foams; high internal phase emulsion; styrene ID IN-OIL EMULSIONS; MICROCELLULAR FOAMS; MICROSTRUCTURES; STABILITY; STYRENE AB High temperature, polymeric, structural foams were prepared using a high internal phase emulsion (HIPE) to copolymerize styrene with maleimide based monomers. In this work, N-ethylmaleimide and a bismaleimide (BMI) monomer, bis(3-ethyl-5-methyl-4-maleimide-phenyl) were successfully free-radically copolymerized with styrene in a water-in-oil HIPE to produce polymeric foams with glass transition temperatures (T(g)s) ranging from 140 to 220 degrees C depending on composition. The ethylmaleimide and BMI were uniformly Incorporated throughout the polymer, which allowed the thermal performance of the foams to be tailored by controlling the concentration of ethylmaleimide and BMI modifiers. In addition, the thermal oxidative stability of the foam systems increased with increasing concentration of maleimide based monomers. The resulting polymeric foams contained an open cell morphology with cell sizes of approximately 10 mu m in diameter. Compression tests of the high temperature foam systems showed that compression strengths of approximately 700-850 kPa were obtainable at foam densities under 80 mg cm(-3) (5.0 lb ft(-3)). (C) 1997 Elsevier Science Ltd. RP Hoisington, MA (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,POLYMERS & COATINGS GRP,MS E549,LOS ALAMOS,NM 87545, USA. NR 44 TC 19 Z9 20 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PD JUN PY 1997 VL 38 IS 13 BP 3347 EP 3357 DI 10.1016/S0032-3861(96)00883-X PG 11 WC Polymer Science SC Polymer Science GA XD071 UT WOS:A1997XD07100015 ER PT J AU Kreitz, PA Addis, L Galic, H Johnson, T AF Kreitz, PA Addis, L Galic, H Johnson, T TI The virtual library in action: Collaborative international control of high-energy physics pre-prints SO PUBLISHING RESEARCH QUARTERLY LA English DT Article AB This article discusses how control of the grey literature in high-energy physics preprints developed through a collaborative effort of librarians and physicists. It highlights the critical steps in the development process and describes one model of a rapidly evolving virtual library for high-energy physics information. In conclusion, this article extends this physics model to other areas of grey literature management. C1 STANFORD LINEAR ACCELERATOR CTR,DIV RES,STANFORD,CA 94309. RP Kreitz, PA (reprint author), STANFORD LINEAR ACCELERATOR CTR,TECH INFORMAT SERV,POB 4349,MS 82,STANFORD,CA 94309, USA. NR 12 TC 7 Z9 7 U1 0 U2 1 PU TRANSACTION PERIOD CONSORTIUM PI NEW BRUNSWICK PA DEPT 3091 RUTGERS-THE STATE UNIV OF NJ, NEW BRUNSWICK, NJ 08903 SN 1053-8801 J9 PUBLISH RES Q JI Publ. Res. Q. PD SUM PY 1997 VL 13 IS 2 BP 24 EP 32 DI 10.1007/s12109-997-0016-x PG 9 WC Communication; Information Science & Library Science SC Communication; Information Science & Library Science GA YB838 UT WOS:A1997YB83800004 ER PT J AU Rush, JD Cabelli, DE AF Rush, JD Cabelli, DE TI The reactions of a dinuclear ferric complex (oxo) di-iron(III) triethylenetetraamminehexaacetate, Fe2O(ttha)(2-), with oxidizing and reducing free radicals. A pulse radiolysis study SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID AQUEOUS-SOLUTIONS; IRON COMPLEXES; MECHANISM; SITE AB The rate constants at which oxidizing and reducing radicals react with the dinuclear iron(III) complex Fe2O(ttha)(2-) were measured in neutral aqueous solution. The rate constants for reduction of the complex by . CO2.- (CH3CHOH)-C-. and O-2(.-) were found to be comparable with rate constants previously measured in mononuclear iron(III) polyaminocarboxylate systems. Fe2O(ttha)(2-) reacts slowly with O-2(.-) (k(8) = (1.2 +/- 0.2) x 10(4) dm(3) mol(-1) s(-1)) and, hence, is a relatively poor catalyst for the dismutation of superoxide radical. The hydrated electron reduces the complex at a diffusion-controlled rate in a process which consumes one proton: e(aq)(-) + Fe2O(ttha)(2-) --> (Fe2O)-O-III,II(ttha)(3-) The reduction by carbon-centered radicals produces a (III,II) mixed-valence complex with an absorption spectrum different from that of the Fe-2(II,III) species produced from reduction by the hydrated electron. The oxidizing radicals (OH)-O-. and . CO3- appear to act as reductants of the complex via ligand oxidation rather than by oxidation of the (Fe2O)-O-III core to (Fe2O)-O-III,IV. In the former case ligand attack appears to occur mainly at the methylene carbon of a glycinate group. The decarboxylation product, CO2, was detected by its aquation reaction in the presence of a pH sensitive dye, bromthymol blue. RP Rush, JD (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 34 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD JUN PY 1997 VL 49 IS 6 BP 661 EP 674 DI 10.1016/S0969-806X(96)00195-8 PG 14 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA XE635 UT WOS:A1997XE63500009 ER PT J AU Carnes, BA Groer, PG Kotek, TJ AF Carnes, BA Groer, PG Kotek, TJ TI Radium dial workers: Issues concerning dose response and modeling SO RADIATION RESEARCH LA English DT Article ID RETENTION; BONE AB The mortality pattern of women who began employment as luminizers in the radium dial industry before 1930 was followed through 1990. Hazard models with time-dependent covariates were used on mortality data either organized by individual death times or grouped into cross-classified person-year tables. These models were used to quantify trends in mortality associated with either death from or diagnosis of bone sarcoma or head carcinoma, The accumulation of skeletal doses from Ra-226 and Ra-228 was an important predictor of the risk of death from bone sarcoma. Women exposed to Ra-226 at ages associated with active bone growth were at greater risk of bone sarcoma than women receiving even larger exposures at an age when their skeletons would have been fully developed. Exposure to only Ra-226 was found to be an important predictor of risk for carcinoma of the mastoid air cells and paranasal sinuses. For the cranial sites, where adult dimensions are attained early in life, an effect of age at exposure could not be detected. (C) 1997 by Radiation Research Society. C1 UNIV TENNESSEE,DEPT NUCL ENGN,KNOXVILLE,TN 37996. ARGONNE NATL LAB,ENVIRONM ASSESSMENT DIV,ARGONNE,IL 60439. RP Carnes, BA (reprint author), ARGONNE NATL LAB,CTR MECH BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 34 TC 28 Z9 29 U1 0 U2 2 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 JUN PY 1997 VL 147 IS 6 BP 707 EP 714 DI 10.2307/3579484 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA XC885 UT WOS:A1997XC88500008 PM 9189169 ER PT J AU Jensen, RH Reynolds, JC Robbins, J Bigbee, WL Grant, SG Langlois, RG Pineda, JD Lee, TS Barker, C AF Jensen, RH Reynolds, JC Robbins, J Bigbee, WL Grant, SG Langlois, RG Pineda, JD Lee, TS Barker, C TI Glycophorin a as a biological dosimeter for radiation dose to the bone marrow from iodine-131 SO RADIATION RESEARCH LA English DT Article ID CHERNOBYL ACCIDENT; HPRT GENE; A LOCUS; MUTATIONS; UKRAINE; CANCER; ASSAY; DNA AB The frequency of peripheral blood erythrocyte variants exhibiting allelic loss of glycophorin A (N/M antigen) has been used previously as a biological dosimeter to assess somatic mutations in bone marrow cells from external whole-body irradiation. The aim of the present study was to determine whether this marker could be used as a measure of bone marrow genotoxicity induced by I-131 in the treatment of thyroid cancer. Flow cytometry of immunolabeled erythrocytes was performed to enumerate glycophorin A variants before and after eight therapy doses of I-131 administered to five patients with differentiated thyroid carcinoma. Bone marrow radiation exposure from each dose was calculated from the integrated retention of I-131 in the whole body and in the blood, In addition, the accumulated dose to the bone marrow received from earlier I-131 therapy was calculated for each patient. Regression analysis was performed on the frequency of two glycophorin A variant cell types (N/0 and N/N) as a function of accumulated dose to the bone marrow. Frequency of N/0 variant cells showed a significant dose-related increase with a slope of 10.9 x 10(-6) per sievert. This dose effect is about one-half that previously observed after whole-body external irradiation at high dose rate, This decreased response could be explained by the low dose rate of the radiation to the bone marrow from I-131. (C) 1997 by Radiation Research Society. C1 NIH,CTR CLIN,DEPT NUCL MED,BETHESDA,MD 20892. NIH,GENET & BIOCHEM BRANCH,ENDOCRINOL SECT,BETHESDA,MD 20892. UNIV PITTSBURGH,GRAD SCH PUBL HLTH,DEPT OCCUPAT ENVIRONM HLTH,PITTSBURGH,PA 15238. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. RP Jensen, RH (reprint author), UNIV CALIF SAN FRANCISCO,SCH MED,DEPT LAB MED,SAN FRANCISCO,CA 94143, USA. RI Grant, Stephen/D-6984-2014 OI Grant, Stephen/0000-0002-9236-0913 FU NCI NIH HHS [N01-CP-50520] NR 24 TC 9 Z9 10 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 JUN PY 1997 VL 147 IS 6 BP 747 EP 752 DI 10.2307/3579490 PG 6 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA XC885 UT WOS:A1997XC88500014 PM 9189175 ER PT J AU Kelly, LA Trunk, JG Sutherland, JC AF Kelly, LA Trunk, JG Sutherland, JC TI Time-resolved fluorescence polarization measurements for entire emission spectra with a resistive-anode, single-photon-counting detector: The fluorescence Omnilyzer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PHOTOMULTIPLIER TUBE; RESOLUTION AB We report a fluorescence analyzer that records simultaneously the temporal profiles for both orthogonal linear polarizations for all wavelengths in a fluorescence emission spectrum. The Analyzer combines a resistive-anode single-photon-counting photomultiplier, imaging spectrograph, Wollaston polarizer, multiparameter analyzer with histograming memory, and standard timing electronics. The spectrograph disperses the fluorescence spectrum across the photocathode of the photomultiplier, and the Wollaston polarizer separates the spectra of the two polarizations in opposite directions from the center of the photocathode perpendicular to the direction of spectral dispersion. The locations at which each photon reaches the photocathode is determined by the ratios of the charges read from the four corners of the resistive anode. One of the two address coordinates that determine where in histogramming memory each photon is recorded is obtained by measuring the time of arrival of the photon at the detector relative to the pulse of light that excites the fluorescence. The second address coordinate is obtained by combining the most-significant bit of the location of the event along the direction on the resistive anode corresponding to the polarization of the photon with the multibit digital value indicating photon wavelength. Storing the data directly into histogramming memory permits display of the data set as it is recorded. Both the spectral and temporal calibrations of the fluorescence analyzer are independent of the polarization of the fluorescence. The approximate to 100 ps temporal resolution of the resistive-anode detector is well matched to the approximate to 1 ns full width at half-maximum pulses of Light produced by the synchrotron storage ring that we use as the excitation source, but laser excitation could also be used with this detector. Recording simultaneously all of the data required for the global analysis of the time evolution of both linear polarization components of fluorescence, and thus, time-resolved anisotropy, reduces the duration of exposure of the sample to the excitation beam, hence, facilitating studies of fragile or photosensitive biological specimens. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. NR 13 TC 10 Z9 11 U1 0 U2 0 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 JUN PY 1997 VL 68 IS 6 BP 2279 EP 2286 DI 10.1063/1.1148173 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400005 ER PT J AU Barnes, MD Lermer, N Whitten, WB Ramsey, JM AF Barnes, MD Lermer, N Whitten, WB Ramsey, JM TI CCD based approach to high-precision size and refractive index determination of levitated microdroplets using Fraunhofer diffraction SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LIGHT-SCATTERING TECHNIQUES; AEROSOL-PARTICLE; DROPLETS; MICROPARTICLE; MICROSPHERES AB We describe a fast and convenient method of high precision size and refractive index determination of electrodynamically levitated microdroplets using Fraunhofer diffraction. The diffraction data were obtained with a 16-bit, unintensified charge coupled device (CCD) camera, and converted into angle-resolved elastic scattering intensity patterns by means of a carefully determined set of transformation parameters. The angular scattering patterns were analyzed without any a priori estimate of the droplet size and only a nominal estimate (approximate to 2%) of the refractive index. Experimental angular scattering patterns were fit to calculated patterns from Mie theory using a graded step-size and scaling algorithm and optimized with respect to both droplet diameter and refractive index (real part only) with a precision of less than or equal to 3 parts in 10(4) and 1 part in 10(3), respectively. Potential application to quantitative fluorescence and Raman spectroscopy, as well as mixture analysis in microdroplets is discussed. (C) 1997 American Institute of Physics. RP Barnes, MD (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 22 TC 36 Z9 36 U1 2 U2 5 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 JUN PY 1997 VL 68 IS 6 BP 2287 EP 2291 DI 10.1063/1.1148134 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400006 ER PT J AU Decrock, P Kanter, EP Nolen, JA AF Decrock, P Kanter, EP Nolen, JA TI Low-energy stripping of Kr+, Xe+, and Pb+ beams in helium and nitrogen SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CHARGE STATES; IONS; DISTRIBUTIONS AB Stripping efficiencies for Kr+, Xe+, and Pb+ beams in helium and nitrogen gas targets have been measured at energies varying between 0.8 and 2.0 MeV. The stripping yields were determined for different target densities, ranging from single-collision conditions to equilibrium. Based on these results, approximate predictions of the equilibrium charge state distributions for low velocity (v/c=0.0040-0.0060) heavy ions with 281.1X10(7)), the zoom electrode of the first intensifier is gated using a similar to 10 kV laser triggered spark gap. The stability of this spark gap has been greatly improved by frequency doubling the laser trigger light. (C) 1997 American Institute of Physics. C1 PRINCETON UNIV, PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Yamauchi, T (reprint author), JAPAN ATOM ENERGY RES INST, DEPT FUS PLASMA RES, TOKAI, IBARAKI 31911, JAPAN. NR 5 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1997 VL 68 IS 6 BP 2384 EP 2386 DI 10.1063/1.1148132 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400022 ER PT J AU Cates, MR Beshears, DL Allison, SW Simmons, GM AF Cates, MR Beshears, DL Allison, SW Simmons, GM TI Phosphor thermometry at cryogenic temperatures SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The temperature dependence of the lifetimes of two phosphors, La2O2S:Eu and Mg4FGeO6:Mn is presented from 300 to 11 and 140 to 8 K, respectively. Emission from the D-5(3) State of La2O2S:Eu reveals a strong temperature dependence from 11 to about 130 K, where the signal becomes too weak to measure accurately. Emission from the F-4(2) State of Mg4FGeO6:Mn changes throughout the temperature range measured. Both of these materials are used for higher temperature thermometry applications. This work illustrates their utility down to liquid helium temperatures. (C) 1997 American Institute of Physics. RP Cates, MR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE CTR MFG TECHNOL,OAK RIDGE,TN 37831, USA. OI Allison, Stephen/0000-0002-5887-5403 NR 15 TC 8 Z9 10 U1 0 U2 4 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 JUN PY 1997 VL 68 IS 6 BP 2412 EP 2417 DI 10.1063/1.1148125 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400026 ER EF