FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Utter, SB Beiersdorfer, P Lopez-Urrutia, JRC Widmann, K AF Utter, SB Beiersdorfer, P Lopez-Urrutia, JRC Widmann, K TI Position and size of the electron beam in the high-energy electron beam ion trap SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE EBIT; spectroscopic measurements; Helmholtz coils; bucking coil current ID X-RAY SPECTROMETER AB In the last decade, many spectroscopic studies have been performed using the electron beam ion trap. Often these measurements rely on the electron beam as an effective slit, yet until now, no systematic study of the position and size of the electron beam under various operating conditions has been made. Here, we present a thorough study of the electron beam's position and size (and thus the electron density) as affected by various operating parameters, and give optimal parameter ranges for operating the device as a spectroscopic source. It is shown that the diameter is constant as the energy is varied, which is important for accurate cross-section measurements. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94551 USA. Auburn Univ, Dept Phys, Auburn, AL 36839 USA. RP Utter, SB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, POB 5508, Livermore, CA 94551 USA. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 11 TC 36 Z9 36 U1 2 U2 2 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 4 PY 1999 VL 428 IS 2-3 BP 276 EP 283 DI 10.1016/S0168-9002(99)00139-4 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 206QK UT WOS:000080890400004 ER PT J AU Khalatyan, N Fujii, K Okuno, H Abe, T Hoshina, K Kato, Y Kurihara, Y Kuroiwa, H Matsui, T Nitoh, O Sugiyama, A Takahashi, K Watanabe, T Yoshida, T AF Khalatyan, N Fujii, K Okuno, H Abe, T Hoshina, K Kato, Y Kurihara, Y Kuroiwa, H Matsui, T Nitoh, O Sugiyama, A Takahashi, K Watanabe, T Yoshida, T TI Designing of stereo-wire geometry for a long cylindrical drift chamber with small jet cells SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE stereo-wire geometry; drift chamber; gravitational sags AB Common problems in designing stereo-wire geometry for a long cylindrical drift chamber with small jet cells are described and possible ways to approach them are discussed in detail. Among these problems, special emphasis is put on the surface field variation along an anode wire due to the geometrical deformation of the cell structure. Also estimated is the surface field variation due to electrostatic and gravitational sags, based on the sags measured for a 4.6 m-long test chamber. These field variations are translated into gain variation along the stereo wires and used to constrain the stereo geometry. (C) 1999 Elsevier Science B.V. All rights reserved. C1 KEK, High Energy Accelerator Res Org, Dept Phys, Tsukuba, Ibaraki 3050801, Japan. Tokyo Univ Agr & Technol, Tokyo 1848588, Japan. Nagoya Univ, Dept Phys, Nagoya, Aichi 4648602, Japan. Kogakuin Univ, Tokyo 1638677, Japan. Kinki Univ, Osaka 5778502, Japan. SLAC, Stanford, CA USA. RP Khalatyan, N (reprint author), KEK, High Energy Accelerator Res Org, Dept Phys, 1-1 Oho, Tsukuba, Ibaraki 3050801, Japan. RI Nitoh, Osamu/C-3522-2013 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 4 PY 1999 VL 428 IS 2-3 BP 403 EP 412 DI 10.1016/S0168-9002(99)00175-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 206QK UT WOS:000080890400016 ER PT J AU Elleaume, H Charvet, AM Berkvens, P Berruyer, G Brochard, T Dabin, Y Dominguez, MC Draperi, A Fiedler, S Goujon, G Le Duc, G Mattenet, M Nemoz, C Perez, M Renier, M Schulze, C Spanne, P Suortti, P Thomlinson, W Esteve, F Bertrand, B Le Bas, JF AF Elleaume, H Charvet, AM Berkvens, P Berruyer, G Brochard, T Dabin, Y Dominguez, MC Draperi, A Fiedler, S Goujon, G Le Duc, G Mattenet, M Nemoz, C Perez, M Renier, M Schulze, C Spanne, P Suortti, P Thomlinson, W Esteve, F Bertrand, B Le Bas, JF TI Instrumentation of the ESRF medical imaging facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE synchrotron; medical imaging; monochromatic beams; angiography; computed tomography; germanium detector ID INTRAVENOUS CORONARY ANGIOGRAPHY; BENT LAUE MONOCHROMATOR; SYNCHROTRON-RADIATION; SYSTEM AB At the European Synchrotron Radiation Facility (ESRF) a beamport has been instrumented for medical research programs. Two facilities have been constructed for alternative operation. The first one is devoted to medical imaging and is focused on intravenous coronary angiography and computed tomography (CT). The second facility is dedicated to pre-clinical microbeam radiotherapy (MRT). This paper describes the instrumentation for the imaging facility. Two monochromators have been designed, both are based on bent silicon crystals in the Laue geometry. A versatile scanning device has been built for pre-alignment and scanning of the patient through the X-ray beam in radiography or CT modes. An intrinsic germanium detector is used together with large dynamic range electronics (16 bits) to acquire the data. The beamline is now at the end of its commissioning phase; intravenous coronary angiography is intended to start in 1999 with patients and the CT pre-clinical program is underway on small animals. The first in vivo images obtained on animals in angiography and CT modes are presented to illustrate the performances of these devices. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ J Fourier, Unite IRM, CHU, F-38043 Grenoble, France. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Paul Scherrer Inst, Swiss Light Source, CH-5232 Villigen, Switzerland. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Elleaume, H (reprint author), Univ J Fourier, Unite IRM, CHU, BP 217, F-38043 Grenoble, France. RI Elleaume, Helene/F-2554-2013 NR 20 TC 84 Z9 85 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 4 PY 1999 VL 428 IS 2-3 BP 513 EP 527 DI 10.1016/S0168-9002(99)00167-9 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 206QK UT WOS:000080890400028 ER PT J AU Ren, B Dilmanian, FA Chapman, LD Ivanov, I Wu, XY Zhong, Z Huang, X AF Ren, B Dilmanian, FA Chapman, LD Ivanov, I Wu, XY Zhong, Z Huang, X TI A bent Laue-Laue monochromator for a synchrotron-based computed tomography system SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE bent crystal monochromator; beam smiling; harmonics rejection; Laue spot; CT ID X-RAYS; REFLECTIVITY; CRYSTALS; ENERGY; CT AB We designed and tested a two-crystal bent Laue-Laue monochromator for wide, fan-shaped synchrotron X-ray beams for the program multiple energy computed tomography (MECT) at the National Synchrotron Light Source (NSLS). MECT employs monochromatic X-ray beams from the NSLS's X17B superconducting wiggler beamline for computed tomography (CT) with an improved image quality. MECT uses a fixed horizontal fan-shaped beam with the subject's apparatus rotating around a vertical axis. The new monochromator uses two Czochralski-grown Si[1 1 1] crystals, 0.7 and 1.4 mm thick, respectively, and with thick ribs on their upper and lower ends. The crystals are bent cylindrically, with the axis of the cylinder parallel to the fan beam, using 4-rod benders with two fixed rods and two movable ones. The bent-crystal feature of the monochromator resolved the difficulties we had had with the flat Laue-Laue design previously used in MECT, which included (a) inadequate beam intensity, (b) excessive fluctuations in beam intensity, and (c) instability of the shape of the beam's horizontal profile. Compared with that earlier monochromator, the bent Laue-Laue device tested at 42 and 108 keV showed about a 10-fold larger beam flux, about 5 times better beam stability, 10-fold less harmonic contamination, and a smaller energy bandwidth at certain bending radii. The present work gave us better understanding of the basis for the beam-smiling effect in bent-crystal monochromators, and allowed us to refine the theoretical method of estimating the beam-harmonic contamination in bent-crystal monochromators. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. IIT, Ctr Synchrotron Radiat Res & Instrumentat, Chicago, IL 60616 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Ren, B (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RI Chapman, Dean/I-6168-2013 OI Chapman, Dean/0000-0001-6590-4156 NR 15 TC 10 Z9 12 U1 0 U2 3 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 4 PY 1999 VL 428 IS 2-3 BP 528 EP 550 DI 10.1016/S0168-9002(99)00056-X PG 23 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 206QK UT WOS:000080890400029 ER PT J AU Hu, MY Sturhahn, W Toellner, TS Hession, PM Sutter, JP Alp, EE AF Hu, MY Sturhahn, W Toellner, TS Hession, PM Sutter, JP Alp, EE TI Data analysis for inelastic nuclear resonant absorption experiments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SYNCHROTRON-RADIATION; SCATTERING AB Inelastic nuclear resonant absorption method has been applied to study lattice dynamics. The data evaluation procedure for such experiments using synchrotron radiation is presented. Various moments of the measured spectra provide model-independent information on vibrational excitations, such as the recoilless fraction, the average kinetic energy per nucleus, and the average force constant. In addition, the partial phonon density of states is extracted assuming a harmonic lattice model. A measurement performed on ct-iron is shown as an example. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RP Hu, MY (reprint author), Argonne Natl Lab, Adv Photon Source, 431 D002, Argonne, IL 60439 USA. RI Hu, Michael/C-7571-2013 OI Hu, Michael/0000-0002-3718-7169 NR 10 TC 31 Z9 31 U1 0 U2 2 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 4 PY 1999 VL 428 IS 2-3 BP 551 EP 555 DI 10.1016/S0168-9002(99)00134-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 206QK UT WOS:000080890400030 ER PT J AU West, GB Brown, JH Enquist, BJ AF West, GB Brown, JH Enquist, BJ TI The fourth dimension of life: Fractal geometry and allometric scaling of organisms SO SCIENCE LA English DT Article ID BIOLOGY AB Fractal-like networks effectively endow Life with an additional fourth spatial dimension. This is the origin of quarter-power scaling that is so pervasive in biology, Organisms have evolved hierarchical branching networks that terminate in size-invariant units, such as capillaries, Leaves, mitochondria, and oxidase molecules. Natural selection has tended to maximize both metabolic capacity, by maximizing the scaling of exchange surface areas, and internal efficiency, by minimizing the scaling of transport distances and times. These design principles are independent of detailed dynamics and explicit models and should apply to virtually all organisms. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. RP Los Alamos Natl Lab, Div Theoret, MS B285, Los Alamos, NM 87545 USA. EM gbw@lanl.gov OI Enquist, Brian/0000-0002-6124-7096 NR 12 TC 815 Z9 862 U1 13 U2 156 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JUN 4 PY 1999 VL 284 IS 5420 BP 1677 EP 1679 DI 10.1126/science.284.5420.1677 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 202TM UT WOS:000080668300047 PM 10356399 ER PT J AU Zhu, JH Liu, CT AF Zhu, JH Liu, CT TI Environmental effects in NiTi-based alloys SO SCRIPTA MATERIALIA LA English DT Article DE intermetallic compounds; hydrogen embrittlement; plastic property; shape memory effect ID ROOM-TEMPERATURE DUCTILITY; EMBRITTLEMENT; FRACTURE; NI3AL C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Zhu, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 19 TC 11 Z9 12 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN 4 PY 1999 VL 41 IS 1 BP 55 EP 60 DI 10.1016/S1359-6462(99)00125-6 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 221DC UT WOS:000081707900009 ER PT J AU Palnitkar, SS Bin, B Jimenez, LS Morimoto, H Williams, PG Paul-Pletzer, K Parness, J AF Palnitkar, SS Bin, B Jimenez, LS Morimoto, H Williams, PG Paul-Pletzer, K Parness, J TI [H-3]Azidodantrolene: Synthesis and use in identification of a putative skeletal muscle dantrolene binding site in sarcoplasmic reticulum SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID CA2+ RELEASE CHANNEL; RYANODINE RECEPTOR; MALIGNANT HYPERTHERMIA; CALCIUM-RELEASE; SODIUM AB Dantrolene sodium is a medically important hydantoin derivative that interferes with release of Ca2+ from intracellular stores of skeletal muscle by an unknown mechanism. Identification of the molecular target of dantrolene would greatly aid in understanding both the mechanism of action of the drug and the dynamics of intracellular Ca2+ release in muscle. [H-3]Azidodantrolene was designed and synthesized as a photoaffinity analogue in order to identify a putative dantrolene receptor in skeletal muscle. Introduction of 1 mole-atom of tritium into aldehyde 5b was required during radioligand synthesis in order to ensure high enough specific activity for detection of photo-cross-linked proteins by fluorographic methods. This was accomplished by reduction of ester 3 with custom synthesized, 100% tritium-labeled lithium triethylborotritide, followed by oxidation to 5b by manganese(IV) oxide. Compound 6b was demonstrated to be greater than or equal to 95% tritium-labeled at the imine position by NMR spectroscopy, and the specific radioactivity of [H-3]azidodantrolene sodium was empirically determined by HPLC and liquid scintillation counting to be 24.4 Ci/mmol, similar to 85% of theoretical maximum. [H-3]Azidodantrolene was found to be pharmacologically active in ligand-receptor binding studies with skeletal muscle sarcoplasmic reticulum membranes. Photo-cross-linking experiments analyzed by SDS-PAGE and tritium fluorography have identified a similar to 160-kDa specifically labeled protein as the putative, intracellular, skeletal muscle dantrolene receptor. This photolabeled protein comigrates with a protein in Western blots immunologically cross-reactive to a polyclonal anti-rabbit skeletal muscle ryanodine receptor antibody. Thus, the putative dantrolene receptor may be related to the skeletal muscle ryanodine receptor. C1 Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Anesthesia, New Brunswick, NJ 08901 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Pharmacol, New Brunswick, NJ 08901 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Pediat, New Brunswick, NJ 08901 USA. Rutgers State Univ, Dept Chem, Piscataway, NJ 08855 USA. EO Lawrence Berkeley Natl Lab, Natl Tritium Labelling Facil, Berkeley, CA 94720 USA. EO Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif San Francisco, Sch Pharm, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. RP Parness, J (reprint author), Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Anesthesia, Clin Acad Bldg-Suite 3100,125 Paterson St, New Brunswick, NJ 08901 USA. FU NCRR NIH HHS [P41 RR01237]; NIAMS NIH HHS [AR45593-01] NR 30 TC 29 Z9 30 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD JUN 3 PY 1999 VL 42 IS 11 BP 1872 EP 1880 DI 10.1021/jm9805079 PG 9 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA 203YY UT WOS:000080736800002 PM 10354395 ER PT J AU Chen, LX Jager, WJH Niemczyk, MP Wasielewski, MR AF Chen, LX Jager, WJH Niemczyk, MP Wasielewski, MR TI Effects of pi-conjugation attenuation on the photophysics and exciton dynamics of poly(p-phenylenevinylene) polymers incorporating 2,2 '-bipyridines SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PHOTOINDUCED ABSORPTION; SEMICONDUCTING POLYMERS; STIMULATED-EMISSION; POLARON PAIRS; METAL; PHOTOEXCITATIONS; SPECTROSCOPY; OLIGOMERS; VINYLENE); SPECTRA AB The effect of pi-conjugation attenuation on the photophysics and exciton dynamics of two conjugated polymers 1 and 2 are examined in solution. The structures of polymers 1 and 2 have 2,2'-bipyridyl-5-vinylene units that alternate with one and three 2,5-bis(n-decyloxy)-1,4-phenylenevinylene monomer units, respectively. The photophysics and exciton dynamics of polymers 1 and 2 were compared to those of the homopolymer, poly(2,5-bis(2'-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV). A series of changes in the photophysics of polymers 1 and 2 were found as a result of pi-conjugation attenuation. These changes include blue shifts in absorption and emission spectra, spectral diffusion in stimulated emission, enhancement in photoluminescence quantum yields and lifetimes, and increases in photoinduced absorption intensities and lifetimes. These changes are systematically more pronounced in polymer 1 than in, polymer 2 and are correlated with pi-conjugation attenuation in the polymers due to twisting of the 2,2'-bipyridine groups about the 2,2' single bond. An exciton dynamics model involving an ensemble of initial exciton states localized on oligomeric segments within the polymer with different conjugation lengths is proposed to describe the observed differences between polymers 1 and 2 and BEH-PPV. When the electronic coupling between these segments is strong, the polymer displays characteristics that are close to those of a one-dimensional semiconductor. However, when these couplings are weakened by groups, such as the 2,2'-bipyridine that attenuate pi-conjugation, the polymer displays properties of an ensemble of oligomers. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Chen, LX (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 48 TC 49 Z9 51 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 3 PY 1999 VL 103 IS 22 BP 4341 EP 4351 DI 10.1021/jp990248e PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 203HP UT WOS:000080702700003 ER PT J AU Seydoux, R Pines, A Haake, M Reimer, JA AF Seydoux, R Pines, A Haake, M Reimer, JA TI NMR with a continuously circulating flow of laser-polarized Xe-129 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; CROSS-POLARIZATION; SPIN-EXCHANGE; SURFACE NMR; XENON; SPECTROSCOPY; ENHANCEMENT; GAS; RELAXATION; ZEOLITES AB In this paper we describe the construction of an apparatus for optical pumping of Xe-129 in a circulating gas system connected to a probe for static high-field NMR. The optimal working conditions for the optical pumping under flow are explored, yielding a continuous gas now with a steady-state spin-polarization of about 2%. It is shown that on various types of high surface area materials a steady-state of adsorbed laser-polarized xenon can be;reached with polarizations of about 0.3%. NMR spectroscopy of this layer is greatly facilitated due to the renewable magnetization under the continuous-flow conditions allowing unprecedented fast detection of two-dimensional NMR experiments with laser-polarized Xe. The steady-state spin-polarization of adsorbed Xe-129 gives rise to cross-relaxation to surface nuclei such as H-1 and Si-29. A direct spin-polarization-induced nuclear Overhauser effect (SPINOE) to heteronuclei is observed with an enhancement factor of about 20-30. A method is presented for simple modulation of the spin-polarization direction in the fringe field of the high-field magnet; this is exploited to obtain difference SPINOE spectra to highlight only the surface nuclei. Furthermore, a transfer via cross-polarization (CP) from adsorbed Xe to surface protons is demonstrated to select surface groups with reduced mobility compared to SPINOE detection. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Seydoux, R (reprint author), Bruker AG, Ind Str 26, CH-8117 Fallarden, Switzerland. NR 35 TC 50 Z9 50 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 3 PY 1999 VL 103 IS 22 BP 4629 EP 4637 DI 10.1021/jp9821984 PG 9 WC Chemistry, Physical SC Chemistry GA 203HN UT WOS:000080702600011 ER PT J AU Chang, TM Dang, LX AF Chang, TM Dang, LX TI Detailed study of potassium solvation using molecular dynamics techniques SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID DILUTE AQUEOUS-SOLUTIONS; NA+-NA+; WATER; IONS; CL; HYDRATION; METHANOL; ASSOCIATION; FRICTION; ALKALI AB Molecular dynamics simulations are carried out to examine the solvation properties and the ion-solvation shell exchange process of the K+ ion in liquid water; chloroform, and carbon tetrachloride. The solvent molecules are found to form well-defined solvation shells around the K+ ion and show a preferred orientational order toward the ion. The induced dipole moment distribution of K+ becomes broader and shifts to a larger average value from chloroform to carbon tetrachloride to water. It is observed that the K+ ion diffuses more rapidly in the aqueous phase than in liquid chloroform and carbon tetrachloride. We have also evaluated both ion and first solvent shell velocity autocorrelation functions and the residence time autocorrelation functions for the ion in water, chloroform, and carbon tetrachloride. The residence time is found to be 9.4 ps for water and about 30 ps for both chloroform and carbon tetrachloride. By use of a constrained molecular dynamics technique,: the first solvation shell exchange process is investigated. It is found that an estimate using equilibrium solvation and classical transition-state theory overestimates the dissociation rate of the K+ ion. Including the dynamical effects using Grote-Hynes theory yields more accurate dissociation rates. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dang, LX (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 31 TC 38 Z9 38 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 3 PY 1999 VL 103 IS 22 BP 4714 EP 4720 DI 10.1021/jp982079o PG 7 WC Chemistry, Physical SC Chemistry GA 203HN UT WOS:000080702600023 ER PT J AU Shkrob, IA Sauer, MC Trifunac, AD AF Shkrob, IA Sauer, MC Trifunac, AD TI Photophysics of hole injection in liquid cycloalkanes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID AQUEOUS CHLORIDE-ION; TRANS-DECALIN; IRRADIATED CYCLOHEXANE; RADICAL CATIONS; SPECTROSCOPY; HYDROCARBONS; FEMTOSECOND AB In Liquid cycloalkanes, single-photon excitation of solute radical cations leads to rapid transfer of a valence band electron and formation of a free solvent hole ("hole injection"). Quantum yields for this process upon 2.3 and 5 eV laser excitation of several aromatic radical cations in trans-decalin are reported and the photophysics of the hole injection in cycloalkane liquids is discussed. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 27 TC 6 Z9 6 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 3 PY 1999 VL 103 IS 22 BP 4773 EP 4780 DI 10.1021/jp9900178 PG 8 WC Chemistry, Physical SC Chemistry GA 203HN UT WOS:000080702600031 ER PT J AU Land, TA Martin, TL Potapenko, S Palmore, GT De Yoreo, JJ AF Land, TA Martin, TL Potapenko, S Palmore, GT De Yoreo, JJ TI Recovery of surfaces from impurity poisoning during crystal growth SO NATURE LA English DT Article ID MECHANISMS; KINETICS AB Growth and dissolution of crystal surfaces are central to processes as diverse as pharmaceutical manufacturing(1,2), corrosion(3), single-crystal production(4) and mineralization in geochemical and biological environments(5,6). Impurities are either unavoidable features of these processes or intentionally introduced to modify the products. Those that act as inhibiting agents induce a so-called 'dead zone', a regime of low supersaturation where growth ceases. Models based on the classic theory of Cabrera and Vermilyea(7) explain behaviour near the dead zone in terms of the pinning of elementary step motion by impurities(8,9). Despite general acceptance of this theory, a number of commonly investigated systems exhibit behaviour not predicted by such models(10). Moreover, no clear microscopic picture of impurity-step interactions currently exists, Here we use atomic force microscopy to investigate the potassium dihydrogen phosphate {100} surface as it emerges from the dead zone, We show that traditional models are not able to account for the behaviour of this system because they consider only elementary steps, whereas it is the propagation of macrosteps (bunches of monolayer steps) that leads to resurrection of growth out of the dead zone. We present a simple physical model of this process that includes macrosteps and relates characteristics of growth near the dead zone to the timescale for impurity adsorption. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Land, TA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. NR 13 TC 147 Z9 153 U1 7 U2 48 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 3 PY 1999 VL 399 IS 6735 BP 442 EP 445 DI 10.1038/20886 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 202TH UT WOS:000080667900041 ER PT J AU Bialas, A Koch, V AF Bialas, A Koch, V TI Event-by-event fluctuations and inclusive distributions SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS AB Event-by-event observables are compared with conventional inclusive measurements. We find that moments of event-by-event fluctuations are closely related to inclusive correlation functions. Implications for upcoming heavy ion experiments are discussed. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Jagiellonian Univ, M Smoluchowshi Inst Phys, Krakow, Poland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bialas, A (reprint author), Jagiellonian Univ, M Smoluchowshi Inst Phys, Krakow, Poland. NR 7 TC 48 Z9 49 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 3 PY 1999 VL 456 IS 1 BP 1 EP 4 DI 10.1016/S0370-2693(99)00479-7 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 207EJ UT WOS:000080922500001 ER PT J AU Csaki, C Graesser, M Terning, J AF Csaki, C Graesser, M Terning, J TI Late inflation and the moduli problem of sub-millimeter dimensions SO PHYSICS LETTERS B LA English DT Article AB We consider a recent model with sub-millimeter sized extra dimensions, where the field that determines the size of the extra dimensions (the radion) also acts as an inflaton. The radion is also a stable modulus, and its coherent oscillations can potentially overclose the Universe. It has been suggested that a second round of late inflation can solve this problem, however we find that this scenario does not allow for sufficient reheating of the Universe. (C) 1999 Published by EIsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Theoret Phys Grp, Ernest Orlando Lawerence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Csaki, C (reprint author), Univ Calif Berkeley, Theoret Phys Grp, Ernest Orlando Lawerence Berkeley Natl Lab, Berkeley, CA 94720 USA. OI Terning, John/0000-0003-1367-0575 NR 7 TC 25 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 3 PY 1999 VL 456 IS 1 BP 16 EP 21 DI 10.1016/S0370-2693(99)00422-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 207EJ UT WOS:000080922500004 ER PT J AU Hurst, JK Lymar, SV AF Hurst, JK Lymar, SV TI Cellularly generated inorganic oxidants as natural microbicidal agents SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID ESCHERICHIA-COLI; HYPOCHLOROUS ACID; CATALYZED OXIDATION; HYDROGEN-PEROXIDE; HUMAN-NEUTROPHILS; CARBON-DIOXIDE; PEROXYNITRITE; MYELOPEROXIDASE; TOXICITY; CHLORINATION C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hurst, JK (reprint author), Washington State Univ, Dept Chem, Pullman, WA 99164 USA. NR 48 TC 41 Z9 42 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD JUN PY 1999 VL 32 IS 6 BP 520 EP 528 DI 10.1021/ar9703488 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 208UB UT WOS:000081009300008 ER PT J AU Haile, SM Klooster, WT AF Haile, SM Klooster, WT TI Single-crystal neutron diffraction study of beta-Cs-3(HSO4)(2)[H2-x(SxP(1-x))O-4] (x similar or equal to 0.5) at 15 K SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID SUPERPROTONIC CONDUCTIVITY; CS-3(HSO4)(2)(H2PO4); BONDS AB The structure of beta-Cs-3(HSO4)(2)[H2-x(SxP1-x)O-4] has been examined by single-crystal neutron diffraction at 15 K. The compound crystallizes in space group C2/c and contains four formula units in the unit cell, with lattice parameters a = 19.769(9), b = 7.685(2), c = 8.858 (3) Angstrom and beta = 100.60 (4)degrees. Refinement of P, S and H site occupancies indicated that the value of x (in the stoichiometry) is 0.500 (6). This, together with the unit-cell volume of 1322.8(14)Angstrom(3), implies a density of 3.463 Mg m(-3). The structure contains zigzag rows of XO4 anions, where X = P or S, that alternate, in a checkerboard fashion, with zigzag rows of Cs cations. Moreover, there is one proton site, H(3), with an occupancy of 0.25 and one X-atom site, X(1), that is occupied by 0.5 P and 0.5 S. These features are in general agreement with a previous X-ray structure determination carried out at 298 K. In contrast to the X-ray study, however, it was found that two different structural models adequately fit the diffraction data. In the first model, the proton vacancies and the P atoms were assumed to be randomly distributed over the H(3) and X(1) sites, respectively, and to have no impact on the local structure. In the second model, several atoms were assigned split occupancies over two neighboring sites, to reflect the presence or absence of a proton vacancy, and the presence of P or S on the X(1) site. Refinement assuming the first model, in which anisotropic displacement parameters for 12 of 14 atom sites in the asymmetric unit were employed, yielded residuals wR(F-2) = 0.084 and wR(F) = 0.038. For the second model, in which anisotropic displacement parameters were utilized for only the five atoms that were not split relative to the first model, the residuals were wR(F-2) = 0.081 and wR(F) = 0.036. C1 CALTECH, Pasadena, CA 91125 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Haile, SM (reprint author), CALTECH, Pasadena, CA 91125 USA. RI Haile, Sossina/I-3448-2015 NR 16 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 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Sci. PD JUN 1 PY 1999 VL 55 BP 285 EP 296 DI 10.1107/S0108768198013573 PN 3 PG 12 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 214MT UT WOS:000081332300004 ER PT J AU Chakoumakos, BC Sales, BC Mandrus, D Keppens, V AF Chakoumakos, BC Sales, BC Mandrus, D Keppens, V TI Disparate atomic displacements in skutterudite-type LaFe(3)CoSb(12), a model for thermoelectric behavior SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID LATTICE THERMAL-CONDUCTIVITY; LAFE4P12 STRUCTURE; RARE-EARTH; ANTIMONIDES; PARAMETERS; TRANSITION; CRYSTALS; PNICTIDES AB Mean-square atomic displacements in lanthanum triiron cobalt dodecaantimonide, determined as a function of temperature using single-crystal neutron diffraction, show that the La atom exhibits an anomalously large displacement at room temperature, U(eq) = 0.0196 (9) Angstrom(2), because it is too small to fill the atomic cage formed by the corner-linked octahedral framework of M(4)Sb(12), M = Fe, Co. Site-occupancy refinements show 25% vacancies on the La site and an actual Fe:Co ratio of 2.17:1. Analysis of the temperature dependence of the atomic displacements identifies a significant temperature-independent component for the La atom ascribed to static disorder, which amounts to 19% of the room-temperature value. The large-amplitude rattling of the La atom can be effectively linked to the dramatic decrease of the lattice contribution to the thermal conductivity, which is a key factor for improving the thermoelectric behavior of these materials. This structure-property relationship offers a new paradigm for the exploration of thermoelectric materials. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chakoumakos, BC (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM kou@ornl.gov RI Mandrus, David/H-3090-2014; Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 31 TC 68 Z9 69 U1 0 U2 15 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Sci. PD JUN 1 PY 1999 VL 55 BP 341 EP 347 DI 10.1107/S0108768198018345 PN 3 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 214MT UT WOS:000081332300011 ER PT J AU Iversen, BB Larsen, FK Pinkerton, AA Martin, A Darovsky, A Reynolds, PA AF Iversen, BB Larsen, FK Pinkerton, AA Martin, A Darovsky, A Reynolds, PA TI Accurate charge densities in days - use of synchrotrons, image plates and very low temperatures SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID SEED-SKEWNESS METHOD; X-RAY-DIFFRACTION; NEUTRON-DIFFRACTION; ELECTRON-DENSITY; SPIN-DENSITY; COCL42 ION; 9 K; (ND4)2CU(SO4)2.6D2O; REFLECTION; ABSORPTION AB Extensive synchrotron (28 K) and conventional sealed-tube (9 K) X-ray diffraction data have been collected on tetrakis(dimethylphosphinodithioato-S,S')thorium(IV), [Th(S2PMe2)(4)]. The use of very low temperatures, well below those obtained with liquid-nitrogen cooling, is crucial for the accuracy of the data. This is due to minimization of temperature-dependent systematic errors such as TDS and anharmonicity, and extension and intensification of the data in reciprocal space. Comparison of structural parameters derived separately from the sealed-tube data and the synchrotron data shows good agreement. The synchrotron data are markedly superior when comparing refinement residuals, standard uncertainties (s.u.'s) of the data and s.u.'s of the derived parameters. However, the study suggests that there are still small uncorrected systematic errors in the data. The very large extent [(sin theta/lambda)(max) = 1.77 Angstrom(-1)] of the synchrotron data and the very low temperature at which they were collected makes it possible to separate anharmonic effects from electron-deformation effects even with only an X-ray data set at a single temperature. The electron density shows a large polarization of the outer Th core of d-type symmetry. This deformation is successfully modelled with contracted multipolar functions, which are only slightly correlated with anharmonic expansions in reciprocal space when using the full extent of the data. In the data collection more than a factor of 100 in speed is gained by use of image-plate area detectors at the synchrotron source compared with conventional sequential measurements. Thus accurate, very low temperature synchrotron-radiation diffraction data can now be measured within days, which makes electron-density studies of compounds beyond the first transition series more frequently within reach. C1 Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark. Univ Toledo, Dept Chem, Toledo, OH 43606 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Iversen, BB (reprint author), Aarhus Univ, Dept Chem, Langelandsgade 140, DK-8000 Aarhus C, Denmark. OI pinkerton, alan/0000-0002-2239-1992 NR 39 TC 41 Z9 41 U1 3 U2 8 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Sci. PD JUN 1 PY 1999 VL 55 BP 363 EP 374 DI 10.1107/S0108768198010398 PN 3 PG 12 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 214MT UT WOS:000081332300014 ER PT J AU Walsh, MA Dementieva, I Evans, G Sanishvili, R Joachimiak, A AF Walsh, MA Dementieva, I Evans, G Sanishvili, R Joachimiak, A TI Taking MAD to the extreme: ultrafast protein structure determination SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID MACROMOLECULAR STRUCTURES; ANOMALOUS DIFFRACTION; SELENOMETHIONYL PROTEINS; CRYSTALLOGRAPHIC PHASES; SYNCHROTRON-RADIATION; HUMAN GENOME; CRYOCRYSTALLOGRAPHY; REFINEMENT; MODELS; WARP AB Multiwavelength anomalous diffraction data were measured in 23 min from a 16 kDa selenomethionyl-substituted protein, producing experimental phases to 2.25 Angstrom resolution. The data were collected on a mosaic 3 x 3 charge-coupled device using undulator radiation from the Structural Biology Center 19ID beamline at the Argonne National Laboratory's Advanced Photon Source. The phases were independently obtained semiautomatically by two crystallographic program suites, CCP4 and CNS. The quality and speed of this data acquisition exemplify the opportunities at third-generation synchrotron sources for high-throughput protein crystal structure determination. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Northwestern Univ, Dept Biochem Mol Biol & Cell Biol, Evanston, IL 60208 USA. RP Joachimiak, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave,Bldg 202, Argonne, IL 60439 USA. RI Walsh, Martin/I-1566-2013; Evans, Gwyndaf/R-5524-2016 OI Walsh, Martin/0000-0001-5683-1151; Evans, Gwyndaf/0000-0002-6079-2201 NR 30 TC 117 Z9 123 U1 0 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 1999 VL 55 BP 1168 EP 1173 DI 10.1107/S0907444999003698 PN 6 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 208NG UT WOS:000080997500008 PM 10329779 ER PT J AU Terwilliger, TC AF Terwilliger, TC TI sigma(2)(R), a reciprocal-space measure of the quality of macromolecular electron-density maps SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CRYSTALLOGRAPHY; RESOLUTION AB It has previously been shown that the presence of distinct regions of solvent and protein in macromolecular crystals leads to a high value of the standard deviation of local r.m.s. electron density and that this can in turn be used as a reliable measure of the quality of macromolecular electron-density maps [Terwilliger & Berendzen (1999a).Acta Cryst D55,501-505]. Here, it is demonstrated that a similar measure, sigma(R)(2), the variance of the local roughness of the electron density, can be calculated in reciprocal space. The formulation is suitable for rapid evaluation of macromolecular crystallographic phases, for phase improvement and for ab initio phasing procedures. C1 Univ Calif Los Alamos Natl Lab, Struct Biol Grp, Los Alamos, NM 87545 USA. RP Terwilliger, TC (reprint author), Univ Calif Los Alamos Natl Lab, Struct Biol Grp, Mail Stop M888, Los Alamos, NM 87545 USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 13 TC 11 Z9 11 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 1999 VL 55 BP 1174 EP 1178 DI 10.1107/S0907444999003583 PN 6 PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 208NG UT WOS:000080997500009 PM 10329780 ER PT J AU Delahaye, JP AF Delahaye, JP CA CLIC study team TI CLIC, a 0.5 to 5 TeV e(+/-) compact linear collider SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Cracow Epiphany Conference on Electron-Positron Colliders CY JAN 05-10, 1999 CL KRAKOW, POLAND AB The CLIC study of high-energy (0.5-5 TeV), high-luminosity (10(34)-10(35) cm(-2) s(-1)) e(+/-) linear collider is presented. Beam acceleration using high-frequency (30 GHz) normal-conducting structures operating at high accelerating fields (100 to 200 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Based on new beam and linac parameters derived from a recently developed set of general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called Two Beam Acceleration (TBA) method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at tow frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and results from the CLIC Test Facility (CTF), assessing the feasibility of the scheme, are described. C1 CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. CEA Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Delahaye, JP (reprint author), CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. NR 19 TC 9 Z9 9 U1 1 U2 1 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUN PY 1999 VL 30 IS 6 BP 2029 EP 2039 PG 11 WC Physics, Multidisciplinary SC Physics GA 214MH UT WOS:000081331400019 ER PT J AU Chadwick, MB Dietrich, FS Kerman, AK Koning, AJ Grimes, SM Kawai, M Love, WG Herman, M Petrovich, F Walker, G Watanabe, Y Wolter, H Avrigeanu, M Betak, E Chiba, S Delaroche, JP Gadioli, E Hilaire, S Hussein, MS Kawano, T Lindsay, R Marcinkowski, A Marianski, B Mustafa, M Ramstrom, E Reffo, G Richter, WA Ross, MA Yoshida, S AF Chadwick, MB Dietrich, FS Kerman, AK Koning, AJ Grimes, SM Kawai, M Love, WG Herman, M Petrovich, F Walker, G Watanabe, Y Wolter, H Avrigeanu, M Betak, E Chiba, S Delaroche, JP Gadioli, E Hilaire, S Hussein, MS Kawano, T Lindsay, R Marcinkowski, A Marianski, B Mustafa, M Ramstrom, E Reffo, G Richter, WA Ross, MA Yoshida, S TI Open problems in quantum-mechanical approaches to multistep direct nuclear reactions SO ACTA PHYSICA SLOVACA LA English DT Article ID INELASTIC-SCATTERING; STATISTICAL-THEORY; OPTICAL-MODEL; PRECOMPOUND REACTIONS; NEUTRON EMISSION; COMPOUND; CONTINUUM; ENERGIES; DEPENDENCE; DENSITIES AB Open problems in the theoretical formulation and computational implementation of multistep direct preequilibrium reactions are discussed. Recommendations for future research on both theoretical and experimental aspects of the problem are given. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Netherlands Energy Res Fdn, ECN, NL-1755 ZG Petten, Netherlands. Ohio Univ, Athens, OH 45701 USA. Kyushu Univ, Dept Phys, Fukuoka 8128581, Japan. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Int Atom Energy Agcy, A-1400 Vienna, Austria. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Indiana Univ, Bloomington, IN 47408 USA. Kyushu Univ, Dept Adv Energy Eng Sci, Kasuga, Fukuoka 8168580, Japan. Univ Munich, Dept Phys, D-85748 Garching, Germany. Inst Phys & Nucl Eng Horia Hulubei, Bucharest 76900, Romania. Slovak Acad Sci, Inst Phys, SK-84228 Bratislava, Slovakia. Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. CEA, Serv Phys Nucl, F-91680 Bruyeres Le Chatel, France. Univ Milan, Dept Phys, I-20133 Milan, Italy. Univ Sao Paulo, Inst Phys, BR-01498 Sao Paulo, Brazil. Univ Western Cape, ZA-7535 Bellville, South Africa. Soltan Inst Nucl Studies, PL-00681 Warsaw, Poland. Uppsala Univ, Dept Neutron Res, S-61182 Nykoping, Sweden. Univ Stellenbosch, ZA-7600 Stellenbosch, South Africa. Tohoku Univ, Sendai, Miyagi 980, Japan. RP Chadwick, MB (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Avrigeanu, Marilena/B-6068-2011; Lindsay, Robert/F-1578-2013; Chiba, Satoshi/E-8193-2014; U-ID, Kyushu/C-5291-2016 OI Avrigeanu, Marilena/0000-0002-0881-3466; Lindsay, Robert/0000-0002-7243-185X; NR 45 TC 10 Z9 10 U1 0 U2 0 PU SLOVAK ACAD SCIENCES INST PHYSICS PI BRATISLAVA PA DUBRAVSKA CESTA 9, 842 28 BRATISLAVA, SLOVAKIA SN 0323-0465 J9 ACTA PHYS SLOVACA JI Acta Phys. Slovaca PD JUN PY 1999 VL 49 IS 3 BP 365 EP 379 PG 15 WC Physics, Multidisciplinary SC Physics GA 207KX UT WOS:000080937000007 ER PT J AU Chilakapati, A AF Chilakapati, A TI Optimal design of a subsurface redox barrier SO AICHE JOURNAL LA English DT Article ID TRANSPORT; CHROMIUM AB Harmful contaminants such as chromium (Cr+6), and TCE carl be removed from groundwater by reactions with reduced subsurface sediments. Establishing an in situ Fe(II) barrier through the reduction of soil-bound Fe(III) to Fe(II) by injecting a sodium dithionite (Na2S2O4) solution is studied. Critical to this problem is the possible formation and expansion of a zone around die injection, where all the soil-bound Fe(III) is reduced to Fe(II). Different reaction models apply inside and outside of this zone so that a determination of this moving boundary is a fundamental part of the solution. The complete analytic solution to this problem was used to develop optimal process parameters, such as injection rate and operational time, that maximize the radius of the Fe(III)-reduced zone when a given mass of sodium dithionite is injected at a well. When a large reduction [>63% of initially, present Fe(III)] is desired, the results indicate that it is better to use a low flow rate to form a Fe(III)-free zone around the injection. The opposite is true for smaller reductions (<63%), so that a faster injection rate that avoids the formation of the Fc(III)-free zone yields a larger reduction zone. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Chilakapati, A (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 16 TC 4 Z9 4 U1 0 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD JUN PY 1999 VL 45 IS 6 BP 1342 EP 1350 DI 10.1002/aic.690450618 PG 9 WC Engineering, Chemical SC Engineering GA 204LC UT WOS:000080764900017 ER PT J AU Van't Hof, J AF Van't Hof, J TI Increased nuclear DNA content in developing cotton fiber cells SO AMERICAN JOURNAL OF BOTANY LA English DT Article DE cotton; development; fibers; Gossypium hirsutum; Malvaceae; nuclear DNA ID GENES; ENDOREDUPLICATION; DIFFERENTIATION; DIVISION; ROOT AB The nuclear DNA content of developing cotton fiber cells (Gossypium hirsutum, cv. MD51ne) increases similar to 24% after 2 d postanthesis (dpa). The amount of nuclear DNA at 2 dpa is 5.4 +/- 0.27 pg. At 3-4 dpa it increases to 6.7 +/- 0.24 pg and by 5 dpa it is 6.8 +/- 0.70 pg. These values were obtained by nuclear fluorescence after staining with Hoechst 33258. Human oral squamous cell nuclei were used as a DNA standard. Nuclear DNA content increases in fibers growing on either fertilized or unfertilized ovules. The increase also is detectable in Feulgen stained nuclei using two-wavelength cytospectrophotometry. All measurements were made on isolated fiber cell nuclei using a newly developed method tailored to cotton fiber cells. The results imply that during the early stages of development fiber cell nuclei either selectively amplify certain sequences or enter S-phase replicating a portion of their genome. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Van't Hof, J (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 29 TC 22 Z9 24 U1 0 U2 1 PU BOTANICAL SOC AMER INC PI COLUMBUS PA OHIO STATE UNIV-DEPT BOTANY 1735 NEIL AVE, COLUMBUS, OH 43210 USA SN 0002-9122 J9 AM J BOT JI Am. J. Bot. PD JUN PY 1999 VL 86 IS 6 BP 776 EP 779 PG 4 WC Plant Sciences SC Plant Sciences GA 208WW UT WOS:000081015700003 PM 10371719 ER PT J AU Tittiranonda, P Rempel, D Armstrong, T Burastero, S AF Tittiranonda, P Rempel, D Armstrong, T Burastero, S TI Effect of four computer keyboards in computer users with upper extremity musculoskeletal disorders SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article DE computer keyboard; musculoskeletal disorders; randomized clinical trial; office ergonomics; carpal tunnel syndrome ID WORK; SYMPTOMS; POSTURE; DESIGN AB Eighty computer users with musculoskeletal disorders participated in a 6-month, randomized, placebo-controlled trial evaluating the effects of four computer keyboards on clinical findings, pain severity, functional hand status, and comfort. The alternative geometry keyboards tested were: the Apple Adjustable Keyboard(TM) [kb1], Comfort Keyboard System(TM) [kb2], Microsoft Natural Keyboard(TM) [kb3], and placebo. Compared to placebo, kb3 and to a lesser extent kb1 groups demonstrated an improving trend in pain severity and hand function following 6 months of keyboard use. However there was no corresponding consistent improvement in clinical findings in the alternative geometry keyboard groups compared to the placebo group. Overall, there was a significant correlation between improvement of pain severity and greater satisfaction with the keyboards. These results provide evidence that keyboard users may experience a reduction in hand pain after several months of use of some alternative geometry keyboards. Am. J. Ind. Med. 35:647-661, 1999. Published 1999 Wiley-Liss, Inc.dagger. C1 Lawrence Livermore Natl Lab, Interdisciplinary Ergon Res Program, Livermore, CA USA. Univ Calif San Francisco, Dept Med, Div Environm & Occupat Med, San Francisco, CA USA. Univ Michigan, Ctr Ergon, Ann Arbor, MI 48109 USA. RP Burastero, S (reprint author), Lawrence Livermore Natl Lab, Dept Hlth Serv, L-723,7000 East Ave, Livermore, CA 94551 USA. RI Rempel, David/E-8424-2013 NR 42 TC 70 Z9 70 U1 1 U2 11 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD JUN PY 1999 VL 35 IS 6 BP 647 EP 661 PG 15 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 194DJ UT WOS:000080176600012 PM 10332518 ER PT J AU Milonni, PW AF Milonni, PW TI Resource letter: AOA-1: Adaptive optics for astronomy SO AMERICAN JOURNAL OF PHYSICS LA English DT Review ID LASER-GUIDE-STAR; WAVE-FRONT SENSOR; ATMOSPHERIC-TURBULENCE COMPENSATION; MESOSPHERIC SODIUM LAYER; FIELD-OF-VIEW; SYNTHETIC BEACON; SHEARING INTERFEROMETER; SPECKLE PATTERNS; PERFORMANCE; TELESCOPES AB This is a guide to the basic concepts and the literature on adaptive optics for astronomy. (C) 1999. American Association of Physics Teachers. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Milonni, PW (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 111 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD JUN PY 1999 VL 67 IS 6 BP 476 EP 485 DI 10.1119/1.19310 PG 10 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 201ET UT WOS:000080582600022 ER PT J AU Wang, SY Biesiot, PM Skinner, DM AF Wang, SY Biesiot, PM Skinner, DM TI Toward an understanding of satellite DNA function in Crustacea SO AMERICAN ZOOLOGIST LA English DT Article; Proceedings Paper CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 03-07, 1998 CL BOSTON, MA SP Soc Integrat & Comparat Bio ID RIBONUCLEIC-ACID; GENE-EXPRESSION; METHYLATION; SEQUENCES; TRANSCRIPTION; COMPLEX; RNA; DROSOPHILA; PATTERNS; VARIANTS AB A G+C-rich Satellite DNA (stDNA) in Gecarcinus lateralis with a repeat unit of 2.1 kbp makes up approximately 3% (16,000 copies/nucleus) of the land crab genome. We used sequences from conserved domains of the repeat unit to construct probes for exploring the possibility of the repeat units being transcribed into RNA, their distribution in genomic DNA, and their methylation status. A transcription product hybridizing with TRU-EXON, a region of the satellite bordered by possible exon splice junctions, was found only in land crabs, whereas transcription products that hybridized to 3'END, a 368 bp fragment at the 3'-end of the satellite, were also found in several other crustaceans. Transcription products that hybridized to AMPL-3, a probe from an amplified segment of the satellite, were not found in land crabs but were found in lobsters. In land crabs, several poly(A)+RNA transcripts that hybridized to 3'END were specific for DNA strand, tissue, and intermolt stage. The diversity of transcripts suggests that transcription of the satellite is related to the organization of the repeated DNA in the crab genome, and that some satellite domains may be transcribed because of their position relative to functional genes. This observation is supported by the additional observation that the satellite is differentially methylated. Repeats organized in tandem in the satellite are methylated, whereas those interspersed in main component DNA (mcDNA) are not. Because DNA methylation is a means of silencing transcription, our results suggest that satellite sequences that are transcribed are those interpersed in mcDNA. DNA methylation patterns are also tissue-specific; of the seven tissues examined (gill, claw muscle, body muscle, limb buds, midgut gland, testis, and ovary), gill stDNA is the least methylated. The observed differences in methylation levels are not attributable to stage in the intermolt cycle or to sex. This is the first report indicating the presence of 5-methylcytosine (m(5)C) in a crustacean. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. E Tennessee State Univ, Dept Biophys, Johnson City, TN 37614 USA. RP Wang, SY (reprint author), Univ So Mississippi, Dept Biol Sci, Hattiesburg, MS 39406 USA. EM Shiao.Wang@usm.edu; Patricia.Biesiot@usm.edu NR 66 TC 3 Z9 3 U1 0 U2 4 PU SOC INTEGRATIVE COMPARATIVE BIOLOGY PI MCLEAN PA 1313 DOLLEY MADISON BLVD, NO 402, MCLEAN, VA 22101 USA SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD JUN PY 1999 VL 39 IS 3 BP 471 EP 486 PG 16 WC Zoology SC Zoology GA 220QX UT WOS:000081679900002 ER PT J AU Jensen, PK Pasa-Tolic, L Anderson, GA Horner, JA Lipton, MS Bruce, JE Smith, RD AF Jensen, PK Pasa-Tolic, L Anderson, GA Horner, JA Lipton, MS Bruce, JE Smith, RD TI Probing proteomes using capillary isoelectric focusing-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID MULTIPLY-CHARGED IONS; GENE-EXPRESSION; DNA MICROARRAY; PROTEINS; ELECTROPHORESIS; IDENTIFICATION; ACCUMULATION; SAMPLES; GENOME AB Unlike the genome, the proteome is exquisitely sensitive to cellular conditions and will consist of proteins having abundances dependent upon stage in the cell cycle, cell differentiation, response to environmental conditions (nutrients, temperature, stress, etc.), or disease state(s). Therefore, the study of proteomes under well-defined conditions can provide a better understanding of complex biological processes and inference of protein function. Thus, much faster, more sensitive, and precise capabilities for the characterization of cellular constituents are desired. We describe progress in the development and initial application of the powerful combination of capillary isoelectric focusing (CIEF) and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry for measurements of the proteome of the model system Escherichia coli. Isotope depletion of the growth media has been used to improve mass measurement accuracy, and the comparison of CIEF-FTICR results for the analysis of cell lysates harvested from E. coli cultured in normal and isotopically depleted media are presented. The initial studies have revealed 400-1000 putative proteins in the mass range 2-100 kDa from total injections of similar to 300 ng off. coli proteins in a single CIEF-FTICR analysis. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. 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 31 TC 191 Z9 199 U1 1 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1999 VL 71 IS 11 BP 2076 EP 2084 DI 10.1021/ac990196p PG 9 WC Chemistry, Analytical SC Chemistry GA 200RL UT WOS:000080553800017 PM 10366890 ER PT J AU Song, XD Swanson, BI AF Song, XD Swanson, BI TI Direct, ultrasensitive, and selective optical detection of protein toxins using multivalent interactions SO ANALYTICAL CHEMISTRY LA English DT Article ID WHOLE-CELL BIOSENSOR; COLORIMETRIC DETECTION; MEMBRANE-RECEPTORS; CHOLERA-TOXIN; BINDING; FLUORESCENCE; ASSAY; TRANSDUCTION; OXIDASE; DRUGS AB Three highly sensitive, selective, and reagent-free optical signal transduction methods for detection of polyvalent proteins have been developed by directly coupling distance-dependent fluorescence self-quenching and/or resonant-energy transfer to the protein-receptor binding events. The ganglioside GM1, as the recognition unit for cholera toxin (CT), was covalently labeled with fluorophores and then incorporated into a biomimetic membrane surface. The presence of CT with five binding sites for GM1 causes dramatic change for the fluorescence of the labeled GM1. (1) In the scheme using fluorescence self-quenching as a signal-transduction mechanism, the fluorescence intensity drops significantly as a result of aggregation of the fluorophore-labeled GM1 on a biomimetic surface, (2) BS: labeling GM1 with a fluorescence energy transfer pair; aggregation of the labeled GM1 results in a decrease hi donor fluorescence and an increase in acceptor fluorescence, providing a unique signature for selective protein-receptor binding. (3) In the third scheme, using the biomimetic surface as part of signal transduction and combining both fluorescence self-quenching and energy-transfer mechanisms to enhance the signal transduction, a signal amplification was achieved. The detection systems can reliably detect less than 0.05 nM CT with fast response (less than 5 min). This approach can easily be: adapted to any biosensor scheme that relies on multiple receptors or co-receptors. The methods can also be applied to investigate the kinetics and thermodynamics of the multivalent interactions. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Song, XD (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 49 TC 80 Z9 81 U1 0 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1999 VL 71 IS 11 BP 2097 EP 2107 DI 10.1021/ac981145f PG 11 WC Chemistry, Analytical SC Chemistry GA 200RL UT WOS:000080553800020 PM 10366891 ER PT J AU Van Orden, A Cai, H Goodwin, PM Keller, RA AF Van Orden, A Cai, H Goodwin, PM Keller, RA TI Efficient detection of single DNA fragments in flowing sample streams by two photon fluorescence excitation SO ANALYTICAL CHEMISTRY LA English DT Article ID MOLECULE DETECTION; 2-PHOTON-EXCITED FLUORESCENCE; IDENTIFICATION; SIZE; COUMARIN-120; SPECTROSCOPY; ABSORPTION; MICROSCOPY; CYTOMETRY; LIQUIDS AB This paper reports the demonstration of efficient single molecule detection in flow cytometry by two-photon fluorescence excitation. We have used two-photon excitation (TPE) to detect single DNA fragments as small as 383 base pairs (bp) labeled with the intercalating dye, POPO-1, at a dye:nucleotide ratio of 1:5. TPE of the dye-DNA complexes uas accomplished using a mode-locked, 120 fs pulse width Ti:sapphire laser operating at 810 nm. POPO-1 labeled DNA fragments of 1.1 kilobase pairs (kbp) and larger were sequentially detected in our non cytometry system with a detection efficiency of nearly 100%. The detection efficiency for the 383 bp DNA fragments was approximately 75%. We also demonstrate the ability to distinguish between different sized DNA fragments in a mixture by their individual fluorescence burst sizes by TPE, These studies indicate that using TPE for single molecule now cytometry experiments lowers the intensity of the background radiation try approximately an order of magnitude compared to one-photon excitation, due to the large separation between the excitation and emission wavelengths in TPE. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. RP Keller, RA (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS M888, Los Alamos, NM 87545 USA. RI Van Orden, Alan/N-4219-2015 NR 45 TC 32 Z9 32 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1999 VL 71 IS 11 BP 2108 EP 2116 DI 10.1021/ac9811221 PG 9 WC Chemistry, Analytical SC Chemistry GA 200RL UT WOS:000080553800021 PM 21662745 ER PT J AU Bandey, HL Martin, SJ Cernosek, RW Hillman, AR AF Bandey, HL Martin, SJ Cernosek, RW Hillman, AR TI Modeling the responses of thickness-shear mode resonators under various loading conditions SO ANALYTICAL CHEMISTRY LA English DT Article ID QUARTZ RESONATOR; MASS AB We develop a general model that describes the electrical responses of thickness-shear mode resonators subject to a variety of surface conditions. The model incorporates a physically diverse set of single-component loadings, including rigid solids, viscoelastic media, and fluids (Newtonian or Maxwellian). The model allows any number of these components to be combined in any configuration. Such multiple loadings are representative of a variety of physical situations encountered in electrochemical and other liquid-phase applications, as well as gas-phase applications. In the general case, the response of the composite load is not a linear combination of the individual component responses. We discuss application of the model in a qualitative diagnostic fashion to gain insight into the nature of the interfacial structure, and in a quantitative fashion to extract appropriate physical parameters such as liquid viscosity and density and polymer shear moduli. C1 Sandia Natl Labs, Microsensor Res & Dev Dept, Albuquerque, NM 87185 USA. Univ Leicester, Dept Chem, Leicester LE1 7RH, Leics, England. RP Bandey, HL (reprint author), Sandia Natl Labs, Microsensor Res & Dev Dept, Albuquerque, NM 87185 USA. NR 28 TC 195 Z9 197 U1 1 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1999 VL 71 IS 11 BP 2205 EP 2214 DI 10.1021/ac981272b PG 10 WC Chemistry, Analytical SC Chemistry GA 200RL UT WOS:000080553800035 PM 21662758 ER PT J AU Socki, RA Romanek, CS Gibson, EK AF Socki, RA Romanek, CS Gibson, EK TI On line technique for measuring stable oxygen and hydrogen isotopes from microliter quantities of water SO ANALYTICAL CHEMISTRY LA English DT Article ID O-18 AB Detailed here is a method for extracting and analyzing oxygen and hydrogen isotopes from 10 mu L-sized water samples. Based on the traditional CO2-H2O equilibration technique, the oxygen isotope exchange reaction is done exclusively in sealed 6-mm (o.d.) Pyrex tubes at 25 degrees C, with full isotope exchange completed in at least 28 h. Using the same water sample employed in the O-18 equilibration, D/H extractions are done in separate sealed 6-mm (o.d.) Pyrex tubes by reaction with Zn at 450 degrees C to form H-2(g). Provided that a correction factor is applied to O-18 analyses, accuracy and precision for both O-18 and D/H are comparable to standard techniques using much larger samples. C1 NASA, Houston, TX 77058 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Socki, RA (reprint author), NASA, C-23 Lockheed Martin,2400 Rd, Houston, TX 77058 USA. NR 15 TC 20 Z9 20 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 1999 VL 71 IS 11 BP 2250 EP 2253 DI 10.1021/ac981140i PG 4 WC Chemistry, Analytical SC Chemistry GA 200RL UT WOS:000080553800042 PM 10366895 ER PT J AU Zhou, JZ Palumbo, AV Strong, JM AF Zhou, JZ Palumbo, AV Strong, JM TI Phylogenetic characterization of a mixed microbial community capable of degrading carbon tetrachloride SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article DE carbon tetrachloride; bioremediation; phylogeny; microbial community ID 16S RIBOSOMAL-RNA; DIVERSITY; GENES AB Two bacterial communities (NO92 and GBS) capable of degrading carbon tetrachloride (CT) were enriched from in-house CT-contaminated water. These communities are able to degrade CT in the presence of toluene. To characterize the community structure and diversity, one enrichment (NO92) was subjected to 16S ribosomal RNA (rRNA) gene-based molecular analysis. The 16S rRNA genes were amplified from the bulk genomic community DNA and. cloned into plasmid vectors. Unique 16S rRNA gene clones, i.e., phylotypes, were detected by four tetrameric restriction enzymes. Together, 123 16S rRNA gene clones were obtained; thirty-one showed different restriction fragment length polymorphism (RFLP) patterns. About 73% of the clones belong to two dominant RFLP patterns. Phylogenetic analysis based on the partial 16S rRNA gene sequences of 10 major phylotypes showed that all the phylotypes that were sequenced were affiliated with the high G+C Gram-positive bacteria. Whereas seven of the phylotypes (similar to 80% of the clones) were closely related to Rhodococcus, the other three (similar to 5% of the clones) were related to Curtobacterium. These results suggest that this CT-degrading community is diverse but is predominated by closely related bacterial groups. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Zhou, JZ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM zhouj@ornl.gov RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 NR 25 TC 4 Z9 4 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD JUN PY 1999 VL 80 IS 3 BP 243 EP 253 DI 10.1385/ABAB:80:3:243 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 232JM UT WOS:000082367600005 ER PT J AU Knauss, KG Dibley, MJ Leif, RN Mew, DA Aines, RD AF Knauss, KG Dibley, MJ Leif, RN Mew, DA Aines, RD TI Aqueous oxidation of trichloroethene (TCE): a kinetic analysis SO APPLIED GEOCHEMISTRY LA English DT Article ID ALIPHATIC-COMPOUNDS; TEMPERATURE; GROUNDWATER; PRESSURE; WATER AB An empirical kinetic rate law appropriate for many ground waters (neutral pH, aerobic) has been determined for the aqueous oxidation of trichloroethene (TCE), one of the most volumetrically important chlorinated hydrocarbon pollutants. Mass balances were monitored by measuring both the rate of disappearance of TCE and the rate of appearance of CO2 and Cl-. Dilute buffer solutions were used to fix pH and stoichiometrically sufficient amounts of dissolved O-2 were used to make the reactions pseudo zero-order in O-2 Using a standard chemical kinetic approach, two orders-of-magnitude in initial TCE concentration were spanned and the resulting double-log plot (log concentration vs. log initial rate) was used to determine the rate constant (k = 5.77 +/- 1.06x10(-7) s(-1)) and "true" (i.e., with respect to concentration, not time) reaction order (n(c) = 0.85 +/- 0.03) for the rate law. By determining rate constants over the temperature interval 343-373 K, the Arrhenius activation energy (E-a) for the reaction was determined to be 108.0 +/- 4.5 kJ/mol. The rate law and derived kinetic parameters may be used in reactive transport simulators in order to account for aqueous oxidation of TCE as a function of temperature. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, Livermore, CA 94550 USA. RP Knauss, KG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, POB 5508, Livermore, CA 94550 USA. RI knauss, kevin/K-2827-2012; Aines, Roger/A-2013-2013 NR 29 TC 9 Z9 11 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD JUN PY 1999 VL 14 IS 4 BP 531 EP 541 DI 10.1016/S0883-2927(98)00084-5 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 192TC UT WOS:000080080400009 ER PT J AU Benzi, M Tuma, M AF Benzi, M Tuma, M TI A comparative study of sparse approximate inverse preconditioners SO APPLIED NUMERICAL MATHEMATICS LA English DT Article; Proceedings Paper CT 15th IMACS World Congress on Scientific Computation, Modelling and Applied Mathematics CY AUG 24, 1997-AUG 29, 1998 CL BERLIN, GERMANY DE sparse linear systems; sparse matrices; preconditioned Krylov subspace methods; incomplete factorizations; factorized approximate inverses; SPAI; FSAI; incomplete biconjugation ID LINEAR ALGEBRA COMPUTATIONS; MINIMAL RESIDUAL ALGORITHM; CONJUGATE-GRADIENT METHOD; PARALLEL ALGORITHMS; SYSTEMS; MATRIX; FACTORIZATIONS; COMPUTERS AB A number of recently proposed preconditioning techniques based on sparse approximate inverses are considered. A description of the preconditioners is given, and the results of an experimental comparison performed on one processor of a Gray C98 vector computer using sparse matrices from a variety of applications are presented. A comparison with more standard preconditioning techniques, such as incomplete factorizations, is also included. Robustness, convergence rates, and implementation issues are discussed, (C) 1999 Elsevier Science B.V. and IMACS. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Acad Sci Czech Republ, Inst Comp Sci, Prague 18207 8, Czech Republic. RP Benzi, M (reprint author), Univ Calif Los Alamos Natl Lab, MS B256, Los Alamos, NM 87545 USA. RI Tuma, Miroslav/A-5946-2014 OI Tuma, Miroslav/0000-0003-2808-6929 NR 82 TC 132 Z9 141 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 J9 APPL NUMER MATH JI Appl. Numer. Math. PD JUN PY 1999 VL 30 IS 2-3 BP 305 EP 340 DI 10.1016/S0168-9274(98)00118-4 PG 36 WC Mathematics, Applied SC Mathematics GA 191AF UT WOS:000079997600012 ER PT J AU Naulleau, PP Goldberg, KA AF Naulleau, PP Goldberg, KA TI Dual-domain point diffraction interferometer SO APPLIED OPTICS LA English DT Article ID EXTREME-ULTRAVIOLET LITHOGRAPHY; AT-WAVELENGTH INTERFEROMETRY; RADIATION; ACCURACY; OPTICS; SYSTEM AB The phase-shifting point diffraction interferometer has recently been developed and implemented at Lawrence Berkeley National Laboratory to meet the significant metrology challenge of characterizing extreme ultraviolet projection lithography systems. Here we present a refined version of this interferometer that overcomes the original design's susceptibility to noise attributed to scattered light. The theory of the new hybrid spatial- and temporal-domain (dual-domain) point diffraction interferometer is described in detail and experimental results are presented. (C) 1999 Optical Society of America. OCIS codes: 050.1970, 050.5080, 120.2650, 120.3180, 260.7200. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Naulleau, PP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. NR 20 TC 13 Z9 17 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 1999 VL 38 IS 16 BP 3523 EP 3533 DI 10.1364/AO.38.003523 PG 11 WC Optics SC Optics GA 200RM UT WOS:000080553900011 PM 18319953 ER PT J AU Wang, HC Graff, DK Schoonover, JR Palmer, RA AF Wang, HC Graff, DK Schoonover, JR Palmer, RA TI Static and dynamic infrared linear dichroic study of a polyester polyurethane copolymer using step-scan FT-IR and a photoelastic modulator SO APPLIED SPECTROSCOPY LA English DT Article DE vibrational linear dichroism (VLD); dynamic infrared linear dichroism (DIRLD); step-scan FT-IR; photoelastic modulator (PEM); signal processing; polyurethane elastomer; orientation function ID TIME-RESOLVED SPECTROSCOPY; FOURIER-TRANSFORM IR; POLYMERS; FILMS; POLYPROPYLENE; ORIENTATION; DEFORMATION; TEMPERATURE; SPECTRA AB Dynamic infrared linear dichroism (DIRLD) measurements of films of a thermo-plastic polyester/polyurethane random copolymer (Estane 5703, B. F. Goodrich) are reported. Step-scan Fourier transform infrared (FT-IR) is used for dynamic measurements, and a photoelastic modulator (PEM) is used to create broadband polarization modulation as the carrier frequency for the strain modulation, A novel modulation/demodulation strategy has been employed that simplifies the triple-modulation experiment into a double-modulation experiment; the theory is thoroughly discussed. Both static and dynamic dichroic absorption difference spectra have been measured on the prestretched polymer film. The results are of high signal-to-noise ratio (SNR) and clearly indicate the static and dynamic orientation of the transition dipole moments due to the tensile deformation. The dynamic orientation responses are primarily in phase with the perturbation. The orientation magnitudes of the infrared absorption hands are quantified and compared, and the orientations of the hard and soft domains are differentiated. To assist in the interpretation of the dynamically measured data, we also describe a static linear dichroic measurement using a wire-grid polarizer and FT-IR in the rapid-scan mode for a sample incrementally drawn until the point of breaking, The orientation functions of selected bands have been calculated, and the static results agree with the dynamic data, indicating the dependency of the dynamic orientation response on the preorientation state. C1 Univ Calif Los Alamos Natl Lab, CST, Los Alamos, NM 87545 USA. Duke Univ, Dept Chem, Durham, NC 27708 USA. RP Palmer, RA (reprint author), Univ Calif Los Alamos Natl Lab, CST, Mail Stop J586, Los Alamos, NM 87545 USA. NR 28 TC 32 Z9 32 U1 1 U2 7 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUN PY 1999 VL 53 IS 6 BP 687 EP 696 DI 10.1366/0003702991947126 PG 10 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 210PD UT WOS:000081113100014 ER PT J AU Foster, NS Amonette, JE Autrey, ST AF Foster, NS Amonette, JE Autrey, ST TI In situ detection of chromate using photoacoustic spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE photoacoustic spectroscopy; chromate; Cr(VI); molar absorptivity; adsorption kinetics; iron oxide; hematite; aqueous speciation; phosphate; nondestructive analysis ID NATURAL-WATERS; CHROMIUM; LANTHANIDE; SPECIATION; SOILS AB Pulsed-laser photoacoustic spectroscopy (LPAS) can be used to nondestructively assay aqueous Cr(VI) concentrations at trace levels. The technique involves the absorption of light pulses at 371 nm by Cr(VI) species (predominately chromate and bichromate). The absorbed energy is subsequently released in the form of heat generating a local pressure wave that is detected by an ultrasonic transducer. Because the total absorptivity of a Cr(VI) solution depends on the mixture of Cr(VI) species present and, thus, is strongly correlated with pH, a simple working expression relating solution absorbance to pH was developed, and molar absorptivities for several Cr(VI) species are reported. The detection limit for Cr(VI), which is effectively determined by the absorptivity of water, is reported to be 1 ng mL(-1) at pH 6. Detection limits near 0.3 ng mL(-1) would be expected for solutions at pH 8 and above, where the absorptivities of Cr(VI) species are greater. The nondestructive nature of this technique makes in situ studies of trace-level Cr(VI) chemistry in small volumes possible. We show how the technique can be used to study, in essentially real time, the thermodynamics and kinetics of Cr(VI) sorption by hematite (alpha-Fe2O3) powder, and the effect of competing ions, such as phosphate, on these properties. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Foster, NS (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-96, Richland, WA 99352 USA. NR 36 TC 8 Z9 8 U1 3 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUN PY 1999 VL 53 IS 6 BP 735 EP 740 DI 10.1366/0003702991947180 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 210PD UT WOS:000081113100020 ER PT J AU Tribble, DL Barcellos-Hoff, MH Chu, BM Gong, EL AF Tribble, DL Barcellos-Hoff, MH Chu, BM Gong, EL TI Ionizing radiation accelerates aortic lesion formation in fat-fed mice via SOD-inhibitable processes SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE atherosclerosis; lipoproteins; ionizing radiation; inflammation; antioxidants ID LOW-DENSITY-LIPOPROTEIN; CORONARY-ARTERY DISEASE; CELL-ADHESION MOLECULES; SUPEROXIDE-DISMUTASE; LEUKOCYTE ADHESION; POTENTIAL ROLE; INDUCTION; MODEL; RADIOPROTECTION; ATHEROGENESIS AB Ionizing radiation promotes formation of reactive oxygen species, including the superoxide anion (O-2(-)). To evaluate whether O-2(-) or O-2(-)-mediated perturbations may contribute to the known atherogenic effects of radiation, we examined aortic lesion formation in irradiated C57BL/6 mice and evaluated the effects of CuZn-superoxide dismutase (CuZn-SOD) overexpression. Ten-week-old mice were exposed to a 2-, 4-, or 8-Gy dose of 250-keV x-rays to the upper thorax and then placed on a high-fat diet for 18 weeks. Based on quantitative lipid staining of serial sections of the proximal aorta, mean lesion area was increased with increasing radiation dose and was 3-fold greater in 8-Gy-irradiated than sham-irradiated mice (7800 +/- 2140 versus 2635 +/- 709 mu m(2), P<0.05). These effects were absolutely dependent on a high-fat diet, which had to be introduced within 1 to 2 weeks of the radiation exposure, suggesting the early involvement of atherogenic lipoproteins that were elevated in response to the diet. The importance of radiation-induced oxidative stress was supported by the observation of a 2-fold lower mean lesion area in irradiated CuZn-SOD transgenic mice than in their irradiated, nontransgenic littermates (3026 +/- 1590 versus 6102 +/- 1834 mu m(2), P<0.05). Lucigenin-enhanced chemiluminescence, used as an index of aortic O-2(-) concentrations, was significantly elevated in the postradiation period, and this response was reduced in CuZn-SOD transgenics. On the basis of these results, we propose that radiation may be a useful tool for initiating oxidative or redox-regulated events that promote atherogenesis and for testing the antiatherogenic properties of antioxidants. C1 Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA USA. RP Tribble, DL (reprint author), Univ Calif Berkeley, Donner Lab, Room 465, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [R01 HL54606, R03 HL60533-01] NR 41 TC 58 Z9 68 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD JUN PY 1999 VL 19 IS 6 BP 1387 EP 1392 PG 6 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA 206XF UT WOS:000080905100004 PM 10364068 ER PT J AU Weller, RE Lyu, CW Wolters, C Atlas, RM AF Weller, RE Lyu, CW Wolters, C Atlas, RM TI Universities and the biological and toxin weapons convention SO ASM NEWS LA English DT Article C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Battelle Mem Inst, Ctr Publ Hlth Res & Evaluat, Durham, NC USA. Univ Louisville, Louisville, KY 40292 USA. NR 0 TC 5 Z9 5 U1 1 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0044-7897 J9 ASM NEWS JI ASM News PD JUN PY 1999 VL 65 IS 6 BP 403 EP 409 PG 7 WC Microbiology SC Microbiology GA 206EU UT WOS:000080865000016 ER PT J AU Alonso, MV Minniti, D Zijlstra, AA Tolstoy, E AF Alonso, MV Minniti, D Zijlstra, AA Tolstoy, E TI Infrared photometry of the inner regions of the dwarf irregular galaxy NGC 3109 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : Hertzsprung-Russel (KR) and C-M diagrams; galaxies : abundances; galaxies : evolution; galaxies : individual : NGC 3109; galaxies : irregular; infrared : galaxies ID LATE-TYPE STARS; MAGELLANIC CLOUDS; BOLOMETRIC CORRECTIONS; GLOBULAR-CLUSTERS; CEPHEID VARIABLES; NEARBY GALAXIES; STANDARD STARS; GIANT BRANCH; LOCAL GROUP; NGC-3109 AB We present VIJHK photometry for stars in a 0.8 x 2.0 kpc(2) inner field of the dwarf irregular galaxy NGC 3109. The infrared photometry reaches 3 magnitudes fainter than previous work. Optical and infrared color-color and color-magnitude diagrams, and a bolometric luminosity function are constructed, confirming the presence of an intermediate-age stellar population. We also present a logL/L-. vs logT(eff) diagram of the galaxy and compare the results with the theoretical isochrones of Bertelli et al. (1994) for Z = 0.004 and Y = 0.24. The comparison suggests that most of the stars detected in the IR are 10(9) yr or younger. We compare the infrared color-magnitude diagrams of NGC 3 109 with the composite color-magnitude diagrams of LMC clusters and of the outer disk of the Scd galaxy M33. They show similar stellar content in these late-type systems. C1 Astron Observ, RA-5000 Cordoba, Argentina. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. European So Observ, D-85748 Garching, Germany. UMIST, Dept Phys, Manchester M60 1QD, Lancs, England. Space Telescope European Coordinating Facil, D-85748 Garching, Germany. RP Alonso, MV (reprint author), Astron Observ, Laprida 854, RA-5000 Cordoba, Argentina. EM vicky@oac.uncor.edu NR 39 TC 5 Z9 5 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 1 BP 33 EP 44 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 203FK UT WOS:000080697300007 ER PT J AU Schaab, C Sedrakian, A Weber, F Weigel, MK AF Schaab, C Sedrakian, A Weber, F Weigel, MK TI Impact of internal heating on the thermal evolution of neutron stars SO ASTRONOMY & ASTROPHYSICS LA English DT Review DE stars : neutron; stars : evolution ID X-RAY-EMISSION; LIQUID-METAL PHASE; DENSE MATTER; ROSAT OBSERVATIONS; SUPERNOVA REMNANT; SPIN-DOWN; PULSAR GLITCHES; DRIP SUPERFLUID; PAIR EMISSION; VORTEX CREEP AB The impact of various competing heating processes on the thermal evolution of neutron stars is investigated. We show that internal heating leads to significantly enhanced surface temperatures for pulsars of middle and old age. The heating due to thermal creep of pinned vortices and due to outward motion of proton vortices in the interior of the star leads to a better agreement with the observed data in the case of enhanced cooling. The strong pinning models are ruled out by a comparison with the cooling data on the old pulsars. For millisecond pulsars, the heating due to thermal creep of pinned vortices and chemical heating of the core have the largest impact on the surface temperatures. The angular dependence of the heating rates require two dimensional cooling simulations in general. Such a simulation is performed for a selected case in order to check the applicability of one-dimensional codes used in the past. C1 Univ Munich, Inst Theoret Phys, D-80333 Munich, Germany. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Munich, Sekt Phys, D-85748 Garching, Germany. RP Schaab, C (reprint author), Univ Munich, Inst Theoret Phys, Theresienstr 37, D-80333 Munich, Germany. EM schaab@gsm.sue.physik.uni-muenchen.de RI Schaab, Christoph/C-6098-2008 NR 117 TC 31 Z9 31 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 1999 VL 346 IS 2 BP 465 EP 480 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 212PK UT WOS:000081225300021 ER PT J AU Vestrand, WT Sreekumar, P AF Vestrand, WT Sreekumar, P TI RXTE observations of PKS 2155-304 during the November 1997 gamma-ray outburst SO ASTROPARTICLE PHYSICS LA English DT Article DE X-rays; gamma-rays; BL Lacertae objects; PKS 2155-304 AB We present X-ray observations of the nearby BL Lac PKS 2155-304 taken when it was undergoing a GeV/TeV gamma-ray outburst. During the outburst we measured X-ray fluxes in the 2-10 keV band that are the largest ever observed for PKS 2155-304, Comparison of these November 1997 measurements and other X-ray observations made contemporaneously with GeV or TeV gamma-ray observations indicate that X-ray and gamma-ray emissions are correlated. Measurements with X-ray all-sky monitors such as the ASM/RXTE and MOXE can therefore signal the presence of outbursts at gamma-ray energies from PKS 2155-304. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Vestrand, WT (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. NR 9 TC 12 Z9 12 U1 0 U2 0 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 1999 VL 11 IS 1-2 BP 197 EP 199 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 212PW UT WOS:000081226300034 ER PT J AU Scoccimarro, R Couchman, HMP Frieman, JA AF Scoccimarro, R Couchman, HMP Frieman, JA TI The bispectrum as a signature of gravitational instability in redshift space SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; large-scale structure of universe; methods : numerical; methods : statistical ID GALAXY CORRELATION-FUNCTIONS; LARGE-SCALE BIAS; POWER SPECTRUM; REAL; FLUCTUATIONS; EVOLUTION; DISTORTIONS; SIMULATIONS; UNIVERSE; 3-POINT AB The bispectrum provides a characteristic signature of gravitational instability that can be used to probe the Gaussianity of the initial conditions and the bias of the galaxy distribution. We study how this signature is affected by redshift distortions using perturbation theory and high-resolution numerical simulations. We obtain perturbative results for the multipole expansion of the redshift-space bispectrum that provide a natural way to break the degeneracy between bias and Omega present in measurements of the redshift-space power spectrum. We propose a phenomenological model that incorporates the perturbative results and also describes the bispectrum in the transition to the nonlinear regime. We stress the importance of nonlinear effects and show that inaccurate treatment of these can lead to significant discrepancies in the determination of bias from galaxy redshift surveys. At small scales we find that the bispectrum monopole exhibits a strong configuration dependence that reflects the velocity dispersion of clusters. Therefore the hierarchical model for the three-point function does not hold in redshift space. C1 CITA, McLennan Phys Labs, Toronto, ON M5S 3H8, Canada. Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Scoccimarro, R (reprint author), CITA, McLennan Phys Labs, 60 St George St, Toronto, ON M5S 3H8, Canada. NR 35 TC 101 Z9 102 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 531 EP 540 DI 10.1086/307220 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700001 ER PT J AU Hui, L Rutledge, RE AF Hui, L Rutledge, RE TI The b distribution and the velocity structure of absorption peaks in the Ly alpha forest SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; intergalactic medium; quasars : absorption lines ID PHOTOIONIZED INTERGALACTIC MEDIUM; GRAVITATIONAL COLLAPSE; MODEL; STATISTICS; EVOLUTION; CLOUDS AB A theory is developed that relates the observed b parameter of a Ly alpha absorption line to the velocity curvature of the corresponding peak in the optical depth fluctuation. Its relation to the traditional interpretation of b as the thermal broadening width is discussed. It is demonstrated that, independent of the details of the cosmological model, the differential b distribution has a high-b asymptote of dN/db proportional to b(-m), where m greater than or equal to 5, when we make the reasonable assumption that low-curvature fluctuations are statistically favored over high-curvature ones. There in general always exist lines much broader than the thermal width. We develop a linear perturbative analysis of the optical depth fluctuation, which yields a single-parameter prediction for the full b distribution. In addition to exhibiting the high-velocity tail, it qualitatively explains the observed sharp low-b cutoff-a simple reflection of the fact that high-curvature fluctuations are relatively rare. Although the existence of the high-b asymptote, which is independent of the validity of the linear expansion, is consistent with the observed b distribution, a detailed comparison of the linear prediction with six observational data sets indicates that higher order corrections are not negligible. The perturbative analysis nonetheless offers valuable insights into the dependence of the b distribution on cosmological parameters such as Omega and the power spectrum. A key parameter is the effective smoothing scale of the optical depth fluctuation, which is in turn determined by three scales: the thermal broadening width, the baryon smoothing scale (approximately the Jeans scale), and the observation/simulation resolution. The first two are determined by reionization history, but are comparable in general, whereas the third varies by about an order of magnitude in current hydrodynamic simulations. Studies with non-resolution-dominated b distributions can be used to probe the reionization history of the universe. C1 Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. RP Hui, L (reprint author), Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. NR 27 TC 36 Z9 37 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 541 EP 548 DI 10.1086/307202 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700002 ER PT J AU Perlmutter, S Aldering, G Goldhaber, G Knop, RA Nugent, P Castro, PG Deustua, S Fabbro, S Goobar, A Groom, DE Hook, IM Kim, AG Kim, MY Lee, JC Nunes, NJ Pain, R Pennypacker, CR Quimby, R Lidman, C Ellis, RS Irwin, M McMahon, RG Ruiz-Lapuente, P Walton, N Schaefer, B Boyle, BJ Filippenko, AV Matheson, T Fruchter, AS Panagia, N Newberg, HJM Couch, WJ AF Perlmutter, S Aldering, G Goldhaber, G Knop, RA Nugent, P Castro, PG Deustua, S Fabbro, S Goobar, A Groom, DE Hook, IM Kim, AG Kim, MY Lee, JC Nunes, NJ Pain, R Pennypacker, CR Quimby, R Lidman, C Ellis, RS Irwin, M McMahon, RG Ruiz-Lapuente, P Walton, N Schaefer, B Boyle, BJ Filippenko, AV Matheson, T Fruchter, AS Panagia, N Newberg, HJM Couch, WJ TI Measurements of Omega and Lambda from 42 high-redshift supernovae SO ASTROPHYSICAL JOURNAL LA English DT Review DE cosmology : observations; distance scale; supernovae : general ID LIGHT-CURVE SHAPES; IA SUPERNOVAE; COSMOLOGICAL CONSTANT; HUBBLE CONSTANT; TIME DILATION; GLOBULAR-CLUSTERS; SN 1994D; MODELS; DUST; EXTINCTION AB We report measurements of the mass density, Omega(M), and cosmological-constant energy density, Omega(Lambda), of the universe based on the analysis of 42 type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these supernovae, at redshifts between 0.18 and 0.83, are fitted jointly with a set of supernovae from the Calan/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. All supernova peak magnitudes are standardized using a SN Ia light-curve width-luminosity relation. The measurement yields a joint probability distribution of the cosmological parameters that is approximated by the relation 0.8 Omega(M) - 0.6 Omega(Lambda), approximate to -0.2 +/- 0.1 in the region of interest (Omega(M) less than or similar to 1.5). For a flat (Omega(M) + Omega(Lambda) = 1) cosmology we find Omega(M)(flat) = 0.28(-0.08)(+0.09) (1 sigma statistical)(-0.04)(+0.05) (identified systematics). The data are strongly inconsistent with a Lambda = 0 flat cosmology, the simplest inflationary universe model. An open, Lambda = 0 cosmology also does not fit the data well: the data indicate that the cosmological constant is nonzero and positive, with a confidence of P(Lambda > 0)= 99%, including the identified systematic uncertainties. The best-fit age of the universe relative to the Hubble time is t(0)(flat) = 14.9(-1.1)(+1.4)(0.63/h) Gyr for a flat cosmology. The size of our sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We find no significant differences in either the host reddening distribution or Malmquist bias between the low-redshift Calan/Tololo sample and our high-redshift sample. Excluding those few supernovae that are outliers in color excess or fit residual does not significantly change the results. The conclusions are also robust whether or not a width-luminosity relation is used to standardize the supernova peak magnitudes. We discuss and constrain, where possible, hypothetical alternatives to a cosmological constant. C1 EO Lawrence Berkeley Natl Lab, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA. European So Observ, La Silla, Chile. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Barcelona, Dept Astron, Barcelona, Spain. Isaac Newton Grp, La Palma, Spain. Yale Univ, Dept Astron, New Haven, CT 06511 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ New S Wales, Sydney, NSW, Australia. RP Perlmutter, S (reprint author), Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. RI Perlmutter, Saul/I-3505-2015; Nunes, Nelson/P-1758-2015 OI Perlmutter, Saul/0000-0002-4436-4661; Nunes, Nelson/0000-0002-3837-6914 NR 108 TC 8438 Z9 8519 U1 21 U2 157 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 565 EP 586 DI 10.1086/307221 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700004 ER PT J AU Murray, SD Raymondson, DA Urbanski, RA AF Murray, SD Raymondson, DA Urbanski, RA TI Coalescence and star formation in collapsing flattened systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; ISM : clouds; methods : n-body simulations; open clusters and associations : general; stars : formation ID LARGE-MAGELLANIC-CLOUD; GALACTIC GLOBULAR-CLUSTERS; L1630 MOLECULAR CLOUD; INITIAL CONDITIONS; YOUNG CLUSTERS; INSTABILITIES; AGE; ELLIPTICITIES; LUMINOSITY; EVOLUTION AB We report on the results of N-body simulations of star formation resulting from mergers during the collapse of dynamically cold, flattened systems of cloudlets. Such evolution is expected to occur in several models of cluster star formation. As was found previously in the case of spherical systems, the resulting star clusters have half-mass radii that are significantly smaller than the initial values for the systems. Stars that form early in the collapse have large final orbital radii and retain a strong memory of the initial ellipticity of the system. Stars that form later have smaller final radii and retain less memory. If we examine only those stars within the final half-mass radii of the models, we find that they follow a much less ellipsoidal distribution than do stars at larger radii. Their ellipticities, however, generally exceed those of young, dynamically unevolved massive star clusters in the LMC. The best comparisons with the observed ellipticities are found in models for which the initial system minor-to-major axis ratios b/a greater than or similar to 0.2, system kinetic-to-potential energy ratios Q greater than or similar to 0.1, covering factors f(tau) less than or similar to 0.2, or initial cloud masses M-i much less than M-G. In the above, f(tau) is the fraction of the projected area of the system covered by the cloudlets, and M-G is the critical mass for gravitational instability of the cloudlets, which are assumed to evolve isothermally. The ratio M-i/M-G is taken to be one of the model parameters. All of these ranges of parameters tend to delay the onset of star formation until late in the collapse, when the system is less elliptical. Systems with M-i much less than M-G tend to produce very flat stellar initial mass functions, much flatter than observed. Unless, therefore, f(tau) less than or similar to 0.2 results from the fragmentation of the parent cloud, systems such as the young LMC clusters are unlikely to have formed from extremely flattened or dynamically cold initial conditions, even in the presence of dissipation during star formation. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Murray, SD (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-022,POB 808, Livermore, CA 94550 USA. RI Murray, Stephen/I-8685-2016 OI Murray, Stephen/0000-0001-5597-090X NR 38 TC 2 Z9 2 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 829 EP 840 DI 10.1086/307226 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700023 ER PT J AU Salmonson, JD Wilson, JR AF Salmonson, JD Wilson, JR TI General relativistic augmentation of neutrino pair annihilation energy deposition near neutron stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE elementary particles; relativity; stars : neutron; supernova : general ID R-PROCESS; BINARY; COLLAPSE; MODEL AB General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a factor of more than 4 in the regime applicable to Type II supernovae, and by up to a factor of 30 for collapsing neutron stars. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Salmonson, JD (reprint author), Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. NR 17 TC 48 Z9 48 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 1999 VL 517 IS 2 BP 859 EP 865 DI 10.1086/307232 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 208VC UT WOS:000081011700026 ER PT J AU Vanden Berk, DE Lauroesch, JT Stoughton, C Szalay, AS Koo, DC Crotts, APS Blades, JC Melott, AL Boyle, BJ Broadhurst, TJ York, DG AF Vanden Berk, DE Lauroesch, JT Stoughton, C Szalay, AS Koo, DC Crotts, APS Blades, JC Melott, AL Boyle, BJ Broadhurst, TJ York, DG TI Clustering properties of low-redshift QSO absorption systems toward the Galactic poles SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review ID LYMAN-ALPHA FOREST; LARGE-SCALE DISTRIBUTION; HUBBLE-SPACE-TELESCOPE; C-IV ABSORPTION; ABSORBING GALAXIES; QUASAR SPECTRA; GASEOUS EXTENT; LINE SYSTEMS; TO-ZEM; EVOLUTION AB We examine the clustering properties of low-redshift Ly alpha and heavy-element QSO absorption line systems seen in the spectra of 13 QSOs at the Galactic poles. This is the densest sample of similar to 1 degrees separated QSOs observed spectroscopically with the Hubble Space Telescope to date. At the median redshift of the Ly alpha sample (z approximate to 0.7), the QSO lines of sight are separated on transverse scales from about 15 to 200 h(-1) Mpc (q(o) = 0.5, H = 100 h km s(-1) Mpc(-1)), allowing the three-dimensional clustering of the absorbers to be examined on those scales. The Galactic poles are also regions where relatively deep and wide-field galaxy redshift surveys have taken place, so the distributions of galaxies and Ly alpha systems can be compared within the same volume of space. There are 545 total absorption lines detected in the complete sample from 13 QSOs. We identify 307 Ly alpha systems, of which 18 contain heavy-element lines. We confirm the relatively slow redshift number density evolution for Ly alpha systems at z less than or similar to 1. There are also five likely C IV doublets in our sample, for which the Ly alpha line is not accessible. The main results are summarized as follows: 1. Most, but not all, of the very low-z (z < 0.2) Ly alpha systems appear to be associated with large-scale structures traced by luminous galaxies, based upon the spectrum of the low-redshift QSO PG 1309 + 355. 2. On scales of 2.5 to 5 h(-1) Mpc, the line-of-sight correlation function shows a positive and significant clustering amplitude, xi(los) = 0.95 +/- 0.28, for systems with rest equivalent width, W, exceeding 0.24 Angstrom. Most of this signal can be accounted for by a small number of Ly alpha "clumps," which typically contain about five systems spanning similar to 20 h(-1) Mpc. There is qualitative evidence that the strength of the correlation function rises with the limiting Ly alpha rest equivalent width. 3. Over half of the heavy-element systems are either in groups or have a nearby "clump" of Ly alpha lines. However, there is only weak evidence for a significant heavy-element/Ly alpha cross-correlation function. 4. There is no clear evidence that the Ly alpha systems are distributed in redshift "peaks" and "voids" as is characteristic for the galaxies. In particular, there is no significant periodicity detected on the scale of 128 h(-1) Mpc, which had been detected for the galaxies located in the same direction of the sky. There is marginal evidence for a 41.5 h(-1) Mpc "periodicity" in the distribution, which is seen for all equivalent width-limited samples. 5. The three-dimensional Ly alpha radial correlation function shows no significant departures from a random sample at any scale or using any limiting equivalent width. This indicates that if there are sheetlike structures spanning separations on the order of 30 h(-1) Mpc or more, they are not clearly traced by Ly alpha systems. 6. The fraction of Ly alpha lines with W > 0.24 Angstrom, which may be clustered in the same way as the heavy-element systems detected mostly at higher redshifts, is about 39% +/- 6%. This value is likely to depend on the limiting equivalent width and redshift of the sample. These results are consistent with a picture of the Ly alpha forest at low redshift in which some fraction of the Ly alpha lines arise in close proximity to galaxies and structures traced by galaxies, but in which a substantial fraction of the systems are also more uniformly distributed and are largely unrelated to the distribution of luminous galaxies. The results also appear to be in broad agreement with numerical simulations of the intergalactic medium, which suggest that the denser regions traced by luminous galaxies are also traced by the stronger Ly alpha systems, but that Ly alpha systems also arise in the more general underlying distribution of matter in the universe. C1 Univ Chicago, Chicago, IL 60635 USA. Northwestern Univ, Evanston, IL 60208 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Anglo Australian Observ, Epping, NSW 2121, Australia. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Vanden Berk, DE (reprint author), Univ Texas, McDonald Observ, RLM 15-308, Austin, TX 78712 USA. EM devb@astro.as.utexas.edu; jtl@elvis.astro.nwu.edu; stoughto@sdss.fnal.gov; szalay@tardis.pha.jhu.edu; koo@helios.ucsc.edu; arlin@astro.columbia.edu; blades@stsci.edu; melott@kusmos.phsx.ukans.edu; bjb@aaoepp.aao.gov.au; tjb@wibble.berkeley.edu; don@oddjob.uchicago.edu NR 120 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUN PY 1999 VL 122 IS 2 BP 355 EP 414 DI 10.1086/313218 PG 60 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 219PV UT WOS:000081616400001 ER PT J AU Riley, WJ Robinson, AL Gadgil, AJ Nazaroff, WW AF Riley, WJ Robinson, AL Gadgil, AJ Nazaroff, WW TI Effects of variable wind speed and direction on radon transport from soil into buildings: model development and exploratory results SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE radon transport; wind; indoor air quality; contaminant transport; soil-gas transport; Duhamel's theorem; modeling ID ATMOSPHERIC-PRESSURE FLUCTUATIONS; GAS ENTRY; HOUSES; DRIVEN; SIMULATION; AIR AB We describe a novel modeling technique, based on Duhamel's theorem, to study the effects of time-varying winds on radon transport in soil near buildings. The technique, implemented in the model RapidSTART, reduces computational times for transient, three-dimensional, wind-induced soil-gas and radon transport by three to four orders of magnitude compared with conventional finite-difference models. To test model performance, we compared its predictions to analytical solutions of one-dimensional soil-column flow, finite-difference simulations of how around a full-scale house, and measurements of transient soil-gas and radon entry into an experimental basement structure. These comparisons demonstrate that RapidSTART accurately simulates time-dependent radon transport through soil and its entry into buildings. As demonstrated in a previous study, steady winds can significantly affect radon entry. In this paper, we extend the findings of that study by applying RapidSTART to explore the impacts of fluctuating wind speed and direction on radon entry into a prototypical house. In soils with moderate to high permeability, wind fluctuations have a small to moderate effect on the soil-gas radon concentration field and entry rate into the building. Fluctuating wind direction dominates the impact on radon entry rates, while fluctuating wind speed has little effect. For example, in a soil with a permeability of 10(-10) m(2), diurnal oscillations in wind direction can increase the predicted radon entry rate by up to 30% compared to steady-state predictions. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Lawrence Berkeley Natl Lab, Indoor Environm Program, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RP Riley, WJ (reprint author), Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. RI Nazaroff, William/C-4106-2008; Robinson, Allen/I-5713-2012; Robinson, Allen/M-3046-2014; Riley, William/D-3345-2015; OI Nazaroff, William/0000-0001-5645-3357; Robinson, Allen/0000-0003-1053-7090; Robinson, Allen/0000-0002-1819-083X; Riley, William/0000-0002-4615-2304; Gadgil, Ashok/0000-0002-0357-9455 NR 32 TC 24 Z9 25 U1 2 U2 10 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 1999 VL 33 IS 14 BP 2157 EP 2168 DI 10.1016/S1352-2310(98)00374-4 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 187GL UT WOS:000079778700003 ER PT J AU Cho, CY Liu, CW Wemmer, DE Schultz, PG AF Cho, CY Liu, CW Wemmer, DE Schultz, PG TI Cyclic and linear oligocarbamate ligands for human thrombin SO BIOORGANIC & MEDICINAL CHEMISTRY LA English DT Article DE thrombin; oligocarbamate; combinatorial library; cyclizarion; peptidomimetic ID HUMAN ALPHA-THROMBIN; STRUCTURE-BASED DESIGN; ACTIVE-SITE; SELECTIVE INHIBITORS; PROTEASE INHIBITORS; BLOOD-COAGULATION; PEPTIDE MIXTURES; BINDING; LIBRARY; DISCOVERY AB Several classes of compounds have been tested as potential inhibitors of the serine protease thrombin, an important regulator of blood coagulation cascades. We describe here the discovery of a new class of thrombin inhibitors based on an unnatural carbamate biopolymer. Oligocarbamate thrombin inhibitors were identified through the screening of diverse cyclic trimer, cyclic tetramer, and linear tetramer libraries using the one bead, one peptide method. Whereas the cyclic trimer oligocarbamate ligands bound thrombin with modest affinity, a cyclic tetramer oligocarbamate inhibited thrombin with an apparent Ki of 31 nM. Linear oligocarbamate tetramers bound thrombin with inhibition constants in the 100-nM range. These nonpeptidic, oligomeric molecules may provide the basis for further drug development and studies of thrombin-ligand interactions. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Struct Biol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. RP Schultz, PG (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 28 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0968-0896 J9 BIOORGAN MED CHEM JI Bioorg. Med. Chem. PD JUN PY 1999 VL 7 IS 6 BP 1171 EP 1179 DI 10.1016/S0968-0896(99)00028-0 PG 9 WC Biochemistry & Molecular Biology; Chemistry, Medicinal; Chemistry, Organic SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA 210AY UT WOS:000081084000023 PM 10428389 ER PT J AU Lins, RD Briggs, JM Straatsma, TP Carlson, HA Greenwald, J Choe, S McCammon, JA AF Lins, RD Briggs, JM Straatsma, TP Carlson, HA Greenwald, J Choe, S McCammon, JA TI Molecular dynamics studies on the HIV-1 integrase catalytic domain SO BIOPHYSICAL JOURNAL LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; DNA-BINDING DOMAIN; PHOTO-CROSS-LINKING; TYPE-1 INTEGRASE; ACTIVE-SITE; RETROVIRAL INTEGRASE; ZINC-BINDING; PROTEIN; RESIDUES; IDENTIFICATION AB The HIV-I integrase, which is essential for viral replication, catalyzes the insertion of viral DNA into the host chromosome, thereby recruiting host cell machinery into making viral proteins. It represents the third main HIV enzyme target for inhibitor design, the first two being the reverse transcriptase and the protease. Two l-ns molecular dynamics simulations have been carried out on completely hydrated models of the HIV-1 integrase catalytic domain, one with no metal ions and another with one magnesium ion in the catalytic site. The simulations predict that the region of the active site that is missing in the published crystal structures has (at the time of this work) more secondary structure than previously thought. The flexibility of this region has been discussed with respect to the mechanistic function of the enzyme. The results of these simulations will be used as part of inhibitor design projects directed against the catalytic domain of the enzyme. C1 Univ Calif San Diego, Dept Pharmacol, La Jolla, CA 92093 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Salk Inst, San Diego, CA 92186 USA. RP Briggs, JM (reprint author), Univ Houston, Dept Biol & Biochem, Houston, TX 77204 USA. RI Lins, Roberto/J-7511-2012; OI Lins, Roberto/0000-0002-3983-8025; Carlson, Heather/0000-0002-7495-1699 FU NIGMS NIH HHS [GM56553] NR 50 TC 70 Z9 71 U1 0 U2 2 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1999 VL 76 IS 6 BP 2999 EP 3011 DI 10.1016/S0006-3495(99)77453-9 PG 13 WC Biophysics SC Biophysics GA 200TT UT WOS:000080556700012 PM 10354426 ER PT J AU Hlavacek, WS Posner, RG Perelson, AS AF Hlavacek, WS Posner, RG Perelson, AS TI Steric effects on multivalent ligand-receptor binding: Exclusion of ligand sites by bound cell surface receptors SO BIOPHYSICAL JOURNAL LA English DT Article ID EQUILIBRIUM STATISTICAL-MECHANICS; BASOPHILIC LEUKEMIA-CELLS; NON-COOPERATIVE BINDING; FC-EPSILON-RI; CROSS-LINKING; IMMUNE-RESPONSE; DNA-PROTEIN; ANTIBODY; MODEL; ADSORPTION AB Steric effects can influence the binding of a cell surface receptor to a multivalent ligand, To account for steric effects arising from the size of a receptor and from the spacing of binding sites on a ligand, we extend a standard mathematical model for ligand-receptor interactions by introducing a steric hindrance factor. This factor gives the fraction of unbound ligand sites that are accessible to receptors, and thus available for binding, as a function of ligand site occupancy. We derive expressions for the steric hindrance factor for various cases in which the receptor covers a compact region on the ligand surface and the ligand expresses sites that are distributed regularly or randomly in one or two dimensions. These expressions are relevant for ligands such as linear polymers, proteins, and viruses. We also present numerical algorithms that can be used to calculate steric hindrance factors for other cases. These theoretical results allow us to quantify the effects of steric hindrance on ligand-receptor kinetics and equilibria. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. No Arizona Univ, Dept Chem, Flagstaff, AZ 86011 USA. RP Perelson, AS (reprint author), Univ Calif Los Alamos Natl Lab, T-10,MS K710, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433, AI35997] NR 72 TC 63 Z9 64 U1 0 U2 13 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1999 VL 76 IS 6 BP 3031 EP 3043 DI 10.1016/S0006-3495(99)77456-4 PG 13 WC Biophysics SC Biophysics GA 200TT UT WOS:000080556700015 PM 10354429 ER PT J AU Gao, JM Wu, QYQ Carbeck, J Lei, QP Smith, RD Whitesides, GM AF Gao, JM Wu, QYQ Carbeck, J Lei, QP Smith, RD Whitesides, GM TI Probing the energetics of dissociation of carbonic anhydrase-ligand complexes in the gas phase SO BIOPHYSICAL JOURNAL LA English DT Article ID IONIZATION MASS-SPECTROMETRY; PROTEIN CHARGE LADDERS; CYTOCHROME-C; BINDING; IONS; CONFORMATION; RESOLUTION; ASSOCIATIONS; INHIBITORS; VACUO AB This paper describes the use of electrospray ionization-fourier transform ion cyclotron mass spectrometry (ESI-FTICR-MS) to study the relative stabilities of noncovalent complexes of carbonic anhydrase II (CAII, EC 4.2.1.1) and benzenesulfonamide inhibitors in the gas phase. Sustained off-resonance irradiation collision-induced dissociation (SORI-CID) was used to determine the energetics of dissociation of these CAII-sulfonamide complexes in the gas phase. When two molecules of a benzenesulfonamide (1) were bound simultaneously to one molecule of CAII, one of them was found to exhibit significantly weaker binding (Delta E-50 = 0.4 V, where E-50 is defined as the amplitude of sustained off-resonance irradiation when 50% of the protein-ligand complexes are dissociated). In solution, the benzenesulfonamide group coordinates as an anion to a Zn(II) ion bound at the active site of the enzyme. The gas phase stability of the complex with the weakly bound inhibitor was the same as that of the inhibitor complexed with apoCAII (i.e., CAII with the Zn(II) ion removed from the binding site). These results indicate that specific interactions between the sulfonamide group on the inhibitor and the Zn(II) ion on CAII were preserved in the gas phase. Experiments also showed a higher gas phase stability for the complex of para-NO2-benzenesulfonamide-CAII than that for ortho-NO2-benzenesulfonamide-CAII complex. This result further suggests that steric interactions of the inhibitors with the binding pocket of CAII parallel those in solution. Overall, these results are consistent with the hypothesis that CAII retains, at least partially, the structure of its binding pocket in the gas phase on the time scale (seconds to minutes) of the ESI-FTICR measurements. C1 Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Whitesides, GM (reprint author), Harvard Univ, Dept Chem & Chem Biol, 12 Oxford St, Cambridge, MA 02138 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NIGMS NIH HHS [GM53558] NR 40 TC 37 Z9 38 U1 0 U2 3 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1999 VL 76 IS 6 BP 3253 EP 3260 DI 10.1016/S0006-3495(99)77477-1 PG 8 WC Biophysics SC Biophysics GA 200TT UT WOS:000080556700036 PM 10354450 ER PT J AU Savikhin, S Xu, W Soukoulis, V Chitnis, PR Struve, WS AF Savikhin, S Xu, W Soukoulis, V Chitnis, PR Struve, WS TI Ultrafast primary processes in photosystem I of the cyanobacterium Synechocystis sp PCC 6803 SO BIOPHYSICAL JOURNAL LA English DT Article ID PSI CORE ANTENNA; ENERGY-TRANSFER; TEMPERATURE-DEPENDENCE; FLUORESCENCE SPECTROSCOPY; EXCITATION DYNAMICS; CHARGE SEPARATION; LINEAR DICHROISM; CENTER COMPLEXES; PARTICLES; SIMULATIONS AB Ultrafast primary processes in the trimeric photosystem I core antenna-reaction center complex of the cyanobacterium Synechocystis sp. PCC 6803 have been examined in pump-probe experiments with similar to 100 fs resolution. A global analysis of two-color profiles, excited at 660 nm and probed at 5 nm intervals from 650 to 730 nm, reveals 430 fs kinetics for spectral equilibration among bulk antenna chlorophylls, At least two lifetime components (2.0 and 6.5 ps in our analysis) are required to describe equilibration of bulk chlorophylls with far red-absorbing chlorophylls (>700 nm), Trapping at P700 occurs with 24-ps kinetics. The multiphasic bulk <-> red equilibration kinetics are intriguing, because prior steady-state spectral studies have suggested that the core antenna in Synechocystis sp. contains only one red-absorbing chlorophyll species (C708). The disperse kinetics may arise from inhomogeneous broadening in C708, The one-color optical anisotropy at 680 nm (near the red edge of the bulk antenna) decays with 590 fs kinetics; the corresponding anisotropy at 710 nm shows similar to 3.1 ps kinetics. The latter may signal equilibration among symmetry-equivalent red chlorophylls, bound to different monomers within trimeric photosystem I. C1 Iowa State Univ, Dept Chem, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Biochem & Biophys, Ames, IA 50011 USA. RP Struve, WS (reprint author), Iowa State Univ, Dept Chem, Ames Lab, US DOE, Gilman Hall, Ames, IA 50011 USA. NR 38 TC 48 Z9 51 U1 0 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1999 VL 76 IS 6 BP 3278 EP 3288 DI 10.1016/S0006-3495(99)77480-1 PG 11 WC Biophysics SC Biophysics GA 200TT UT WOS:000080556700039 PM 10354453 ER PT J AU Chemla, YR Grossman, HL Lee, TS Clarke, J Adamkiewicz, M Buchanan, BB AF Chemla, YR Grossman, HL Lee, TS Clarke, J Adamkiewicz, M Buchanan, BB TI A new study of bacterial motion: Superconducting quantum interference device microscopy of magnetotactic bacteria SO BIOPHYSICAL JOURNAL LA English DT Article ID DYNAMICS AB The recently developed "microscope" based on a high-T-c de SQUID (superconducting quantum interference device) is used to detect the magnetic fields produced by the motion of magnetotactic bacteria, which have permanent dipole moments. The bacteria, in growth medium at room temperature, can be brought to within 15 mu m of a SQUID at liquid nitrogen temperature. Measurements are performed on both motile and nonmotile bacteria. In the nonmotile case, we obtain the power spectrum of the magnetic field noise produced by the rotational Brownian motion of the ensemble of bacteria. Furthermore, we measure the time-dependent field produced by the ensemble in response to an applied uniform magnetic field. In the motile case, we obtain the magnetic field power spectra produced by the swimming bacteria. Combined, these measurements determine the average rotational drag coefficient, magnetic moment, and the frequency and amplitude of the vibrational and rotational modes of the bacteria in a unified set of measurements. In addition, the microscope can easily resolve the motion of a single bacterium. This technique can be extended to any cell to which a magnetic tag can be attached. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Chemla, YR (reprint author), Univ Calif Berkeley, Dept Phys, 366 LeConte 7300, Berkeley, CA 94720 USA. NR 27 TC 38 Z9 39 U1 2 U2 7 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 1999 VL 76 IS 6 BP 3323 EP 3330 DI 10.1016/S0006-3495(99)77485-0 PG 8 WC Biophysics SC Biophysics GA 200TT UT WOS:000080556700044 PM 10354458 ER PT J AU Christian, AT Garcia, HE Tucker, JD AF Christian, AT Garcia, HE Tucker, JD TI Extending the useful life span of DNA probes for fluorescence in situ hybridization SO BIOTECHNIQUES LA English DT Article ID AMPLIFICATION; PCR C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Tucker, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-452, Livermore, CA 94551 USA. FU NCI NIH HHS [CA55861] NR 6 TC 0 Z9 0 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD JUN PY 1999 VL 26 IS 6 BP 1068 EP + PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 204HK UT WOS:000080758100014 PM 10376143 ER PT J AU Do, MT Harp, JM Norris, KC AF Do, MT Harp, JM Norris, KC TI A test of a pattern recognition system for identification of spiders SO BULLETIN OF ENTOMOLOGICAL RESEARCH LA English DT Article ID NEURAL NETWORKS; IMAGE-ANALYSIS; BIODIVERSITY; ORGANISMS AB Growing interest in biodiversity and conservation has increased the demand for accurate and consistent identification of arthropods. Unfortunately, professional taxonomists are already overburdened and underfunded and their numbers are not increasing with significant speed to meet the demand. In an effort to bridge the gap between professional taxonomists and non-specialists by making the results of taxonomic research more accessible, we present a partially automated pattern recognition system utilizing artificial neural networks (ANNs). Various artificial neural networks were trained to identify spider species using only digital images of female genitalia, from which key shape information had been extracted by wavelet transform. Three different sized networks were evaluated based on their ability to discriminate a test set of six species to either the genus or the species level. The species represented three genera of the wolf spiders (Araneae: Lycosidae). The largest network achieved the highest accuracy, identifying specimens to the correct genus 100% of the time and to the correct species an average of 81% of the time. In addition, the networks were most accurate when identifying specimens in a hierarchical system, first to genus and then to species. This test system was surprisingly accurate considering the small size of our training set. C1 Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Life Sci, Knoxville, TN 37996 USA. Univ Tennessee, Grad Sch Biomed Sci, Oak Ridge Lab, Knoxville, TN 37996 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Dept Ecol, Knoxville, TN 37996 USA. RP Norris, KC (reprint author), Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. NR 20 TC 31 Z9 33 U1 1 U2 1 PU C A B INTERNATIONAL PI WALLINGFORD PA C/O PUBLISHING DIVISION, WALLINGFORD OX10 8DE, OXON, ENGLAND SN 0007-4853 J9 B ENTOMOL RES JI Bull. Entomol. Res. PD JUN PY 1999 VL 89 IS 3 BP 217 EP 224 PG 8 WC Entomology SC Entomology GA 227CC UT WOS:000082059900003 ER PT J AU Sample, BE Arenal, CA AF Sample, BE Arenal, CA TI Allometric models for interspecies extrapolation of wildlife toxicity data SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID BIRDS C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Sample, BE (reprint author), CH2M HILL, 2485 Natomas Pk Dr,Suite 600, Sacramento, CA 95833 USA. NR 16 TC 18 Z9 22 U1 3 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD JUN PY 1999 VL 62 IS 6 BP 653 EP 663 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 200RH UT WOS:000080553500001 PM 10353989 ER PT J AU Anderson, DN Taylor, SR Anderson, KK AF Anderson, DN Taylor, SR Anderson, KK TI Discrimination information in phase amplitude thresholds with application to Western China regional data SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB This article develops a regional seismic discrimination method using information inherent in phase amplitudes that are unmeasurable due to small signal amplitudes and high noise levels. The method, quadratic negative evidence discrimination (QNED), is an enhancement to the teleseismic techniques proposed by Elvers (1974) and is extended to regional dicrimination. The method presented in this article is developed for a single seismic station and makes use of the empirical evidence in the regional P-g versus L-g discriminant (see Pomeroy et al., 1983). We develop the equations necessary to compute-the station-specific, missed-explosion, and false-alarm error rates. These error rates depend on the required minimum signal-to-noise ratio (S/N) and can be adjusted, within limits, to desired levels. We also show that these equations are an accurate assessment of the errors in seismic discrimination. We propose that many of the current approaches to assessing seismic discrimination errors are often overly optimistic. For some applications, this disparity can be significant. For an application to Western China regional data [P-g versus L-g (1.5 to 3 Hz)], a widely used estimate of the missed-explosion error rate is 20%, leading to the perception that explosions can be identified with an accuracy rare or 80%. A proper accounting of the missed-explosion error rate, using QNED, shows that explosions can be identified with accuracy rate of only 73%. C1 Pacific NW Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Anderson, DN (reprint author), Pacific NW Lab, POB 999,902 Battelle Blvd, Richland, WA 99352 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1999 VL 89 IS 3 BP 648 EP 656 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 208WV UT WOS:000081015600006 ER PT J AU Withers, M Aster, R Young, C AF Withers, M Aster, R Young, C TI An automated local and regional seismic event detection and location system using waveform correlation SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LONG-PERIOD SEISMOGRAMS; MIDCRUSTAL MAGMA BODY AB We report on the development of an automated Local Waveform. Correlation Event Detection System (LWCEDS) and its application to the New Mexico Tech Seismic Network. LWCEDS is,an adaptation of a global system, WCEDS, a matched filtering algorithm for global Comprehensive Test Ban Treaty (CTBT) monitoring applications developed at Sandia National Laboratories and New Mexico Tech. Although the current CTBT monitoring system is based on teleseismic phase detection, effort is being placed on research to highlight specific areas of the globe for which local and regional seismic networks could be employed. An automated waveform correlation regional location system could also serve as a rapid alert and automated location system by providing magnitude and hypocenter information within a few minutes of the occurrence of a hazardous earthquake. In the LWCEDS algorithm, processed waveforms are correlated with theoretical travel-time envelopes, and a grid search is. performed to identify the space-time solutions that yield the highest correlations. High correlation indicates that an event has occurred and that a good approximation to the correct origin time and hypocenter has been determined; explicit phase identification is not required. To avoid the large computational expense of calculating la complete correlation for each grid point, we use a laterally homogeneous velocity model and reformulate the problem into a single matrix multiplication and matrix assessment for each time step. LWCEDS has been successfully tested on a suite of local and regional seismic events selected to span the range of expected event quality. Preliminary results from our sparse network show typical epicentral errors of less than 3 km for local events and, with notable exceptions, to within 10 to 20 km for regional events. Similar results were obtained during an on-line experiment conducted to generate daily bulletins during the time period from 3 December 1996 through 7 January 1997. Data from 156 triggers were processed, including 33 teleseisms, 102 regional events (includes explosions), and 21 local earthquakes. Results from this expanded test set are encouraging but reveal the need for a method to mask or flag various electronic and telemetry spikes. C1 New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA. New Mexico Inst Min & Technol, Geophys Res Ctr, Socorro, NM 87801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Withers, M (reprint author), Univ Memphis, Ctr Earthquake Res & Informat, Memphis, TN 38152 USA. RI Aster, Richard/E-5067-2013 OI Aster, Richard/0000-0002-0821-4906 NR 17 TC 21 Z9 21 U1 0 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 1999 VL 89 IS 3 BP 657 EP 669 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 208WV UT WOS:000081015600007 ER PT J AU Clark, RH Campbell, AA Klumb, LA Long, CJ Stayton, PS AF Clark, RH Campbell, AA Klumb, LA Long, CJ Stayton, PS TI Protein electrostatic surface distribution can determine whether calcium oxalate crystal growth is promoted or inhibited SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article DE biomineralization; electrostatic potential; protein adsorption; calcium oxalate ID BIOMINERALIZATION; HYDROXYAPATITE; CRYSTALLIZATION; MINERALIZATION; MONOHYDRATE; INTERFACES; STRATEGIES; ADSORPTION; STATHERIN; MATRIX AB Acidic proteins found in mineralized tissues act as nature's crystal engineers, where they play a key role in promoting or inhibiting the growth of minerals such as hydroxyapatite and calcium oxalate. Despite their importance in such fundamental physiological processes as bone and tooth formation, however, there is remarkably little known of the protein structure-function relationships that govern crystal recognition. We have taken a model system approach to elucidate some of the relationships between protein surface chemistry and secondary crystal growth of biological minerals. We show here that the distribution of electrostatic surface charge on our model protein, Protein G, determined whether the secondary growth of calcium oxalate, the principal mineral phase of kidney stones, was promoted or inhibited when the proteins were preadsorbed at low and equivalent surface coverages of <10%. The native Protein G, which contains 10 surface carboxylates, increased the rate of calcium oxalate growth from aqueous solution under constant composition conditions up to 97%, whereas a site-directed mutant with six of the surface charges removed inhibited the growth rate by 60%. The adsorption isotherms of both proteins were determined and suggested that the differences in electrostatic surface properties also lead to differences in protein orientation on the crystal surface. These results demonstrate that differences in electrostatic surface potential of proteins can directly determine whether secondary calcium oxalate growth is promoted or inhibited, and a model is proposed that suggests the distribution of carboxylate residues determines the interrelated binding orientation and exposed surface chemistry of the adsorbed Protein G. C1 Univ Washington, Dept Bioengn, Seattle, WA 98195 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Stayton, PS (reprint author), Univ Washington, Dept Bioengn, Box 352125, Seattle, WA 98195 USA. FU NIDCR NIH HHS [DE 12554] NR 30 TC 23 Z9 24 U1 0 U2 14 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD JUN PY 1999 VL 64 IS 6 BP 516 EP 521 DI 10.1007/s002239900642 PG 6 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 197GL UT WOS:000080357000010 PM 10341024 ER PT J AU Lewandowski, JLV Persson, M AF Lewandowski, JLV Persson, M TI Effect of magnetic field structure on collisional drift waves SO CANADIAN JOURNAL OF PHYSICS LA English DT Article ID STELLARATOR GEOMETRY; ANOMALOUS TRANSPORT; INSTABILITIES; TURBULENCE; EQUATIONS; SURFACES; TOKAMAKS; MODEL AB A 3-field model for collisional drift waves, in the ballooning representation, for a low-pressure stellarator plasma is presented. The 3-field model, which includes the effects of a finite radial mode number (theta(k)) , is solved as an initial-value problem along the magnetic field line. It is shown that for a stellarator with low global magnetic shear, theta(k)=0 corresponds to the fastest linear growth rate. The effects of the magnetic field structure for the tokamak and stellarator configurations are discussed in a comparative way. C1 Inst Adv Studies, Plasma Phys Lab, Princeton, NJ 08543 USA. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. RP Lewandowski, JLV (reprint author), Inst Adv Studies, Plasma Phys Lab, Princeton, NJ 08543 USA. NR 34 TC 1 Z9 1 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4204 J9 CAN J PHYS JI Can. J. Phys. PD JUN PY 1999 VL 77 IS 6 BP 447 EP 461 DI 10.1139/cjp-77-6-447 PG 15 WC Physics, Multidisciplinary SC Physics GA 251NE UT WOS:000083451100003 ER PT J AU Beck, CW Congdon, JD AF Beck, CW Congdon, JD TI Effects of individual variation in age and size at metamorphosis on growth and survivorship of southern toad (Bufo terrestris) metamorphs SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID ANURAN SCAPHIOPUS-COUCHII; SEXUAL SELECTION; LARVAL DENSITY; AMPHIBIAN METAMORPHOSIS; AMBYSTOMA-OPACUM; FITNESS; PERFORMANCE; POPULATION; HISTORY; FOWLERI AB We conducted two experiments with the southern toad (Bufo terrestris) to examine whether individual variation in (i) metamorph body size and metabolic rate and (ii) age and size at metamorphosis were related to differences in survivorship or growth rate of postmetamorphic individuals. Results from the first experiment indicated that neither initial body size nor metabolic rate was related to survivorship or growth. Results from the second experiment showed that (i) size at metamorphosis was positively correlated with survivorship to first census (after 2 weeks), (ii) age and size at metamorphosis had no significant effect on survivorship from first to second census (after 2 months), (iii) size at metamorphosis had a marginally significant positive effect on survivorship from metamorphosis to second census, and (iv) age and size at metamorphosis were not significantly correlated with total growth. Our results suggest that in the southern toad, size at metamorphosis may lead to early differences in survival, size, and growth that later disappear. Furthermore, early differences in growth and survival attributable to size at metamorphosis are not due to size-related differences in metabolic rate. Therefore, although age and size at metamorphosis affect metabolic rate, they may not be related to fitness via effects on postmetamorphic survival and growth. C1 Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Beck, CW (reprint author), Emory Univ, Dept Biol, Atlanta, GA 30322 USA. NR 28 TC 44 Z9 46 U1 0 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD JUN PY 1999 VL 77 IS 6 BP 944 EP 951 DI 10.1139/cjz-77-6-944 PG 8 WC Zoology SC Zoology GA 252NW UT WOS:000083509500014 ER PT J AU Lager, GA Xie, QY Ross, FK Rossman, GR Armbruster, T Rotella, FJ Schultz, AJ AF Lager, GA Xie, QY Ross, FK Rossman, GR Armbruster, T Rotella, FJ Schultz, AJ TI Hydrogen-atom positions in P4/nnc vesuvianite SO CANADIAN MINERALOGIST LA English DT Article DE vesuvianite; crystal-structure refinement; neutron diffraction; hydrogen atoms ID CRYSTAL-STRUCTURE AB The crystal structure of a large crystal (11.0 x 7.8 x 4.7 mm) of gem-quality Fe-bearing vesuvianite [a 15.533 (11), c 11.785(16) Angstrom, V 2843(5) Angstrom(3); epsilon 1.713(5), omega 1.710(5), 2V 0 degrees(5); D 3.43 g cm(-3); 3.68 wt% FeO] from Kenya has been refined at 298 K by single-crystal neutron-diffraction methods to a weighted R value of 3.9% for 1448 unique Bragg reflections. No violations of P4/nnc space-group symmetry were observed on examination of the crystal by time-of-flight neutron methods. The protons are associated with oxygen atom, O(11) [H(1) 0.4592(7), 0.4814(9), 0.3083(8)] and O(10) [H(2) 0.25, 0.25, 0.280(10)], as predicted by bond-valence calculations. Difference-Fourier maps show a double minimum between adjacent O(10) atoms along c, indicating a statistical distribution of H(2) between two sites. The partial occupancy of the H(1) site (85%) is consistent with the substitution of fluorine for oxygen at the O(11) site. Although hydrogrossular and vesuvianite have similar structures and occur in many of the same environments, theneutron-diffraction results rule out the possibility of a hydrogarnet-type substitution [(O4H4)(4-) = (SiO4)(4-)] in this specimen. Its infrared spectrum (6500-7500 cm(-1)) most closely resembles that of intermediate-fluorine, boron-poor vesuvianite. C1 Univ Louisville, Dept Geog & Geosci, Louisville, KY 40292 USA. Univ Missouri, Res Reactor Facil, Columbia, MO 65211 USA. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Bern, Lab Chem & Mineral Crystallog, CH-3012 Bern, Switzerland. Argonne Natl Lab, IPNS Div, Argonne, IL 60439 USA. RP Lager, GA (reprint author), Univ Louisville, Dept Geog & Geosci, Louisville, KY 40292 USA. OI Rossman, George/0000-0002-4571-6884; Armbruster, Thomas/0000-0002-9586-2097 NR 17 TC 19 Z9 20 U1 0 U2 4 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN, ONTARIO K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD JUN PY 1999 VL 37 BP 763 EP 768 PN 3 PG 6 WC Mineralogy SC Mineralogy GA 243UA UT WOS:000083014600017 ER PT J AU Dingley, KH Curtis, KD Nowell, S Felton, JS Lang, NP Turteltaub, KW AF Dingley, KH Curtis, KD Nowell, S Felton, JS Lang, NP Turteltaub, KW TI DNA and protein adduct formation in the colon and blood of humans after exposure to a dietary-relevant dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine SO CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION LA English DT Article ID HETEROCYCLIC AMINE CARCINOGENS; ACCELERATOR MASS-SPECTROMETRY; METABOLIC-ACTIVATION; CYTOCHROME P4501A2; COVALENT BINDING; AROMATIC-AMINES; HUMAN TISSUES; PHIP; RAT; FOOD AB Epidemiology studies have indicated that certain dietary components, including well-cooked meat, are risk determinants for colon cancer. Cooked meat can contain significant quantities of heterocyclic aromatic amines (HCAs), which have been established as carcinogens in laboratory animals, 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is usually the most mass-abundant HCA, with concentrations up to 480 ppb, We used accelerator mass spectrometry to establish whether DNA and protein adducts can be detected in humans exposed to a quantity of PhIP comparable with levels of exposure that occur in the diet, Five human volunteers were administered a dietary-relevant dose of [C-14]PhIP (70-84 mu g) 48-72 h before surgery for removal of colon tumors, Blood samples were collected at various time points, and albumin, hemoglobin, and WBC DNA were extracted for analysis by accelerator mass spectrometry, Tissue samples were collected during surgery and used to assess either tissue available doses of [C-14]PhIP or adduct levels, The results of this study show: (a) PhIP is activated to a form that will bind to albumin, hemoglobin, and WBC DNA in peripheral blood, WBC DNA adducts were unstable and declined substantially over 24 h; (b) PhIP is bioavailable to the colon, with levels in normal tissue in the range 42-122 pg PhIP/g tissue; and (c) PhIP binds to both protein and DNA in the colon, DNA adduct levels in the normal tissue were 35-135 adducts/10(12) nucleotides, which was significantly lower than tumor tissue, The results of this study demonstrate that PhIP is bioavailable to the human colon following defined dietary-relevant doses and forms DNA and protein adducts. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Little Rock Vet Affairs Hosp, Surg Serv 112LR, Little Rock, AR 72205 USA. Univ Arkansas Med Sci, Arkansas Canc Res Ctr, Little Rock, AR 72205 USA. RP Turteltaub, KW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-452,7000 East Ave, Livermore, CA 94551 USA. FU NCI NIH HHS [CA55861, CA58697, CA55751] NR 41 TC 139 Z9 142 U1 1 U2 10 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 1055-9965 J9 CANCER EPIDEM BIOMAR JI Cancer Epidemiol. Biomarkers Prev. PD JUN PY 1999 VL 8 IS 6 BP 507 EP 512 PG 6 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA 204TJ UT WOS:000080780100004 PM 10385140 ER PT J AU Lunn, RM Langlois, RG Hsieh, LL Thompson, CL Bell, DA AF Lunn, RM Langlois, RG Hsieh, LL Thompson, CL Bell, DA TI XRCC1 polymorphisms: Effects on aflatoxin B-1-DNA adducts and glycophorin A variant frequency SO CANCER RESEARCH LA English DT Article ID STRAND-BREAK REPAIR; SISTER-CHROMATID EXCHANGE; DNA-REPAIR; POLY(ADP-RIBOSE) POLYMERASE; GENOMIC STABILITY; CELL-LINES; A LOCUS; GENE; EXPRESSION; MUTATIONS AB Hereditary genetic defects in DNA repair lead to increased risk of cancer. Polymorphisms in several DNA repair genes have been identified; however, the impact on repair phenotype has not been elucidated. We explored the relationship between polymorphisms in the DNA repair enzyme, XRCC1 (codons 194, 280, and 399), and genotoxic end points measured in two populations: (a) placental aflatoxin B-1 DNA (AFB(1)-DNA) adducts in a group of Taiwanese maternity subjects (rr = 120); and (b) somatic glycophorin A (GPA) variants in erythrocytes from a group of North Carolina smokers and nonsmokers (11 = 59), AFB(1),-DNA adducts were measured by ELISA, and erythrocyte GPA variant frequency (NN and N phi was assessed in MN heterozygotes with a flow cytometric assay. XRCC1 genotypes were identified by PCR-RFLPs. The XRCC1 399Gln allele was significantly associated with higher levels of both AFB(1)-DNA adducts and GPA NN mutations. Individuals with the 399Gln allele were at risk for detectable adducts (odds ratio, 2.4; 95% confidence interval, 1.1-5.4; P = 0.03), GPA NN variant frequency was significantly higher in 399Gln homozygotes (19.6 x 10(-6)) than in Gln/Arg heterozygotes (11.4 x 10(-6); P < 0.05) or Arg/Arg homozygotes (10.1 x 10(-6); P = 0.01), No significant effects were observed for other XRCC1 polymorphisms. These results suggest that the Arg399Gln amino acid change may alter the phenotype of the XRCC1 protein, resulting in deficient DNA repair. C1 NIEHS, LCBRA, Res Triangle Pk, NC 27709 USA. NIEHS, Div Extramural Res & Training, Res Triangle Pk, NC 27709 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Chang Gung Med Coll, Dept Publ Hlth, Tao Yuan 10018, Taiwan. RP Bell, DA (reprint author), NIEHS, LCBRA, POB 12233,MD C3-03, Res Triangle Pk, NC 27709 USA. NR 28 TC 455 Z9 486 U1 3 U2 13 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JUN 1 PY 1999 VL 59 IS 11 BP 2557 EP 2561 PG 5 WC Oncology SC Oncology GA 203NA UT WOS:000080712700011 PM 10363972 ER PT J AU Behr, TM Behe, M Stabin, MG Wehrmann, E Apostolidis, C Molinet, R Strutz, F Fayyazi, A Wieland, E Gratz, S Koch, L Goldenberg, DM Becker, W AF Behr, TM Behe, M Stabin, MG Wehrmann, E Apostolidis, C Molinet, R Strutz, F Fayyazi, A Wieland, E Gratz, S Koch, L Goldenberg, DM Becker, W TI High-linear energy transfer (LET) alpha versus low-LET beta emitters in radioimmunotherapy of solid tumors: Therapeutic efficacy and dose-limiting toxicity of Bi-213- versus Y-90-labeled CO17-1A Fab ' fragments in a human colonic cancer model SO CANCER RESEARCH LA English DT Article ID RELATIVE BIOLOGICAL EFFECTIVENESS; NUDE-MOUSE MODEL; IN-VIVO; MONOCLONAL-ANTIBODIES; ANTI-CD20 ANTIBODY; RENAL UPTAKE; PHASE I/II; CARCINOMA; ANTIGEN; DOSIMETRY AB Recent studies suggest that radioimmunotherapy (RIT) with high-linear energy transfer (LET) radiation may have therapeutic advantages over conventional low-LET (e.g., beta(-)) emissions. Furthermore, fragments may be more effective in controlling tumor growth than complete IgG. However, to the best of our knowledge, no investigators have attempted a direct comparison of the therapeutic efficacy and toxicity of a systemic targeted therapeutic strategy, using high-LET alpha versus low-LET beta emitters in vivo. The aim of this study was, therefore, to assess the toxicity and antitumor efficacy of RIT with the alpha emitter Bi-213/Po-213, as compared to the beta emitter Y-90, linked to a monovalent Fab' fragment in a human colonic cancer xenograft model in nude mice. Biodistribution studies of Bi-213- Or Y-88-labeled benzyl-diethylene-triamine-pentaacetate-conjugated Fab' fragments of the murine monoclonal antibody CO17-1A were performed in nude mice bearing s.c. human colon cancer xenografts. Bi-213 was readily obtained from an "in-house" Ac-225/Bi-213 generator. It decays by beta(-) and 440-keV gamma emission, with a t(1/2) of 45.6 min, as compared to the ultra-short-lived alpha emitter, Po-213 (t(1/2) = 4.2 mu s) For therapy, the mice were injected either with Bi-213- or Y-90-labeled CO17-1A Fab', whereas control groups were left untreated or were given a radiolabeled irrelevant control antibody. The maximum tolerated dose (MTD) of each agent was determined. The mice were treated with or without inhibition of the renal accretion of antibody fragments by D-lysine (T. M. Behr et at, Cancer Res., 55: 3825-3834, 1995), bone marrow transplantation, or combinations thereof. Myelotoxicity and potential second-organ toxicities, as well as tumor growth, were monitored at,weekly intervals. Additionally, the therapeutic efficacy of both Bi-213- and Y-90-Iabeled CO17-1A Fab' was compared in a GW-39 model metastatic to the liver of nude mice. In accordance with kidney uptake values of as high as greater than or equal to 80% of the injected dose per gram, the kidney was the first dose-limiting organ using both Y-90- and Bi-213-labeled Fab' fragments. Application of D-lysine decreased the renal dose by >3-fold. Accordingly, myelotoxicity became dose limiting with both conjugates. By using lysine protection, the MTD of Y-90-Fab' wits 250 mu Ci and the MTD of Bi-213-Fab' was 700 mu Ci, corresponding to blood doses of 5-8 Gy. Additional bone marrow transplantation allowed for an increase of the MTD of Y-90-Fab' to 400 mu Ci and for Bi-213-Fab' to 1100 mu Ci, respectively. At these very dose levels, no biochemical or histological evidence of renal damage was observed (kidney doses of <35 Gy). At equitoxic dosing, Bi-213-labeled Fab' fragments were significantly more effective than the respective Y-90-Iabeled conjugates. In the metastatic model, all untreated controls died from rapidly progressing hepatic metastases at 6-8 weeks after tumor inoculation, whereas a histologically confirmed cure was observed in 95% of those animals treated with 700 mu Ci of Bi-213-Fab' 10 days after model induction, which is in contrast to an only 20% cure rate in mice treated with 250 mu Ci of Y-90-Fab'. These data show that RIT with alpha emitters may be therapeutically more effective than conventional beta emitters. Surprisingly, maximum tolerated blood doses were, at 5-8 Gy, very similar between high-LET alpha and low-LET beta emitters. Due to its short physical half-life, Bi-213 appears to be especially suitable for use in conjunction with fast-clearing fragments. C1 Univ Gottingen, Dept Nucl Med, D-37075 Gottingen, Germany. Univ Gottingen, Dept Internal Med Nephrol, D-37075 Gottingen, Germany. Univ Gottingen, Dept Pathol, D-37075 Gottingen, Germany. Univ Gottingen, Dept Clin Chem, D-37075 Gottingen, Germany. Oak Ridge Associated Univ, Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Inst Transuranium Elements, D-76125 Karlsruhe, Germany. Garden State Canc Ctr, Belleville, NJ 07109 USA. RP Behr, TM (reprint author), Univ Gottingen, Dept Nucl Med, Robert Koch Str 40, D-37075 Gottingen, Germany. RI Behe, Martin/E-2941-2013 FU NCI NIH HHS [CA39841] NR 52 TC 99 Z9 100 U1 1 U2 6 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JUN 1 PY 1999 VL 59 IS 11 BP 2635 EP 2643 PG 9 WC Oncology SC Oncology GA 203NA UT WOS:000080712700025 PM 10363986 ER PT J AU James, F Sepulveda, M Charton, F Quinones, I Guiochon, G AF James, F Sepulveda, M Charton, F Quinones, I Guiochon, G TI Determination of binary competitive equilibrium isotherms from the individual chromatographic band profiles SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE isotherm; chromatography; band profiles; enantiomers ID NONLINEAR CHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; ADSORPTION; SEPARATION; IDENTIFICATION; ENANTIOMERS; SIMULATION; MODEL AB A numerical solution of the inverse problem of nonlinear chromatography is described and validated. This method allows the determination of best numerical estimates of the coefficients of an isotherm model from the individual elution profiles of the two components of a binary mixture. The sample size must be large enough for the two bands to interfere strongly and for their maximum concentrations to exceed the range within which the isotherm equation is needed. In two cases, excellent agreement was observed between the equilibrium isotherm equations obtained by this new method and those determined by the classical combination of elution by characteristic points and binary frontal analysis. In the first case, the adsorption of the ketoprofen enantiomers on a cellulose-based chiral phase is accounted for by a competitive Bilangmuir isotherm. In the second case, the adsorption of benzyl alcohol and 2-phenylethanol on C18 silica is accounted for by a competitive Langmuir model. The importance of using the proper boundary conditions (i.e., a realistic injection profile) is stressed. The new method seems especially well suited for the rapid determination of the isotherms of enantiomers needed for the computer-assisted optimization of the separation of mixtures of these compounds, e.g., in simulated moving-bed applications. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Orleans, CNRS, UMR 6628, MAPMO, F-45067 Orleans, France. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Concepcion, Dept Ingn Matemat, Concepcion, Chile. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 611 Buehler Hall, Knoxville, TN 37996 USA. OI Sepulveda, Mauricio/0000-0001-8463-3830 NR 41 TC 63 Z9 64 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD JUN PY 1999 VL 54 IS 11 BP 1677 EP 1696 DI 10.1016/S0009-2509(98)00539-9 PG 20 WC Engineering, Chemical SC Engineering GA 190WU UT WOS:000079988900006 ER PT J AU Fish, RH AF Fish, RH TI Fluorous biphasic catalysis: A new paradigm for the separation of homogeneous catalysts from their reaction substrates and products SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE biphasic catalysis; fluorocarbon solvents; fluoroponytails; homogeneous catalysis; separation ID TRANSITION-METAL CATALYSIS; IMMOBILIZATION PRINCIPLE; PERFLUORINATED SOLVENTS; EPOXIDATION; ALKENES; HYDROFORMYLATION; COMPLEXES; MEDIA; TAILS; MN AB The concept of fluorous biphasic catalysis (FBC) represents a new paradigm for the separation of homogeneous catalysts from their substrates and the products emanating from these reactions. Since its published inception four years ago, FBC has been demonstrated in a variety of catalytic reactions that encompass hydroformylation, hydrogenation, hydroboration, hydride reduction, alkene epoxidation, and alkane and alkene functionalization. The common theme in all these homogeneous catalysis reactions, accomplished under FBC conditions, is the modification of the homogeneous catalyst with long-chain fluoroponytails to render them soluble in the fluorous phase; most hydrophobic substrates, and, to a large extent, hydrophilic products, are relatively insoluble in fluorocarbon solvents. The fact that fluorocarbon solvents are apparently nontoxic provides the FBC concept with a possible entry to the new Green Chemistry regime of being environmentally friendly, and therefore potentially attractive in a wide variety of industrial processes for the catalytic production of important organic chemicals worldwide. Clearly, FBC has caught the imagination of many colleagues all over the world, and thus, the outpouring of new fluorocarbon-soluble catalysts for the aforementioned applications will continue unabated into the next millennium. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fish, RH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 22 TC 188 Z9 190 U1 1 U2 32 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD JUN PY 1999 VL 5 IS 6 BP 1677 EP 1680 DI 10.1002/(SICI)1521-3765(19990604)5:6<1677::AID-CHEM1677>3.3.CO;2-O PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 205ND UT WOS:000080826700001 ER PT J AU Chang, YT Gray, NS Rosania, GR Sutherlin, DP Kwon, S Norman, TC Sarohia, R Leost, M Meijer, L Schultz, PG AF Chang, YT Gray, NS Rosania, GR Sutherlin, DP Kwon, S Norman, TC Sarohia, R Leost, M Meijer, L Schultz, PG TI Synthesis and application of functionally diverse 2,6,9-trisubstituted purine libraries as CDK inhibitors SO CHEMISTRY & BIOLOGY LA English DT Article DE apoptosis; CDK inhibitor; cell-based assay; cell-cycle arrest; 2,6,9-trisubstituted purine library ID CYCLIN-DEPENDENT KINASES; CELL-CYCLE; ROSCOVITINE; OLOMOUCINE; ANALOGS; POTENT AB Background: Purines constitute a structural class of protein ligands involved in mediating an astonishing array of metabolic processes and signal pathways in all living organisms. Synthesis of purine derivatives targeting specific purine-binding proteins in vivo could lead to versatile read compounds for use as biological probes or drug candidates. Results: We synthesized several libraries of 2,6,9-trisubstituted purines using both solution- and solid-phase chemistry, and screened the compounds for inhibition of cyclin-dependent kinase (CDK) activity and human leukemic cell growth. Lead compounds were optimized by iterative synthesis based on structure-activity relationships (SARs), as well as analysis of several CDK-inhibitor cocrystal structures, to afford several interesting compounds including one of the most potent CDK inhibitors known to date. Unexpectedly, some compounds with similar CDK inhibitory activity arrested cellular proliferation at distinctly different phases of the cell cycle, and another inhibitor directly induced apoptosis, bypassing cell-cycle arrest. Some of these compounds selectively inhibited growth of cells derived from specific tumors. Conclusions: 2,6,9-Trisubstituted purines have various and potent biological activities, despite high concentrations of competing endogenous purine ligands in living cells. Purine libraries constitute a versatile source of small molecules that affect distinct biochemical pathways mediating different cellular functions. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Dept Chem, Berkeley, CA 94720 USA. CNRS, Biol Stn, F-29682 Roscoff, France. RP Schultz, PG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Chang, Young-Tae/B-2780-2010 OI Chang, Young-Tae/0000-0002-1927-3688 NR 21 TC 248 Z9 255 U1 1 U2 13 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD JUN PY 1999 VL 6 IS 6 BP 361 EP 375 DI 10.1016/S1074-5521(99)80048-9 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 261GH UT WOS:000084001000006 PM 10375538 ER PT J AU Wiederrecht, GP Niemczyk, MP Svec, WA Wasielewski, MR AF Wiederrecht, GP Niemczyk, MP Svec, WA Wasielewski, MR TI Photorefractivity in nematic liquid crystals doped with a conjugated polymer: Mechanisms for enhanced charge transport SO CHEMISTRY OF MATERIALS LA English DT Article ID ACCEPTOR MOLECULES; ELECTRON-DONOR; DIFFRACTION; GAIN AB A new mechanism for space-charge field formation in photorefractive liquid-crystal composites containing poly(2,5-bis(2'-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N'-dioctyl-1,4:5,8-naphthalenediimide, NI, is observed. The results show that charge migration over lon distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Wasielewski, MR (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 25 TC 17 Z9 17 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 1999 VL 11 IS 6 BP 1409 EP + DI 10.1021/cm9901008 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 206NN UT WOS:000080886100004 ER PT J AU Lugmair, CG Tilley, TD Rheingold, AL AF Lugmair, CG Tilley, TD Rheingold, AL TI Di(tert-butyl)phosphate complexes of aluminum: Precursors to aluminum phosphate xerogels and thin films SO CHEMISTRY OF MATERIALS LA English DT Article ID METAL-IONS; GALLOPHOSPHONATES; PARTICLES; CATALYSTS; GALLIUM AB Reactions of HO(O)P((OBu)-Bu-t)(z) with Al2Me6 and [Al((OPr)-Pr-i)(3)](4) gave the new molecular aluminum phosphate complexes [Me2AlO2P((OBu)-Bu-t)(2)](2) (1) and [Al((OPr)-Pr-i)(2)O2P((OBu)-Bu-t)(2)](4) (2), respectively. In the solid state, 1 exists as a centrosymmetric dimer consisting of two four-coordinate Al centers bridged by two phosphate groups. In the solid state 2 exists as a centrosymmetric tetramer in which the unique half of the tetramer consists of two aluminum atoms bridged by two di(tert-butyl)phosphate groups. The central part of the molecule contains a planar Al2O2 four-membered ring containing two symmetry-related Al(1) atoms bridged by two -(OPr)-Pr-i ligands. Solution-phase thermolyses of 1 and 2 in organic solvents led to the formation of transparent and opaque xerogels, respectively, after air-drying. The xerogel derived from 1 in 2-propanol had a surface area of 442 m(2) g(-1) after calcination to 600 degrees C in air. Thin, transparent films of aluminum phosphate were prepared by chemical vapor deposition (CVD) using both 1 and 2 as molecular precursors. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 25 TC 58 Z9 58 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 1999 VL 11 IS 6 BP 1615 EP 1620 DI 10.1021/cm990057o PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 206NN UT WOS:000080886100032 ER PT J AU Szostek, B Tinklenberg, JA Aldstadt, JH AF Szostek, B Tinklenberg, JA Aldstadt, JH TI A simple method for the quantitative microextraction of polychlorinated biphenyls from soils and sediments SO CHEMOSPHERE LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; SUPERCRITICAL-FLUID EXTRACTION; SOXHLET AB We demonstrate the quantitative extraction of polychlorinated biphenyls (PCBs) from environmental solids by using a microscale adaptation of pressurized fluid extraction (mu PFE), The stainless steel extraction cells are filled with a solid sample and solvent and are healed at elevated temperature. After cooling the cell to room temperature, we determined PCBs in the extract by direct injection to a gas chromatograph with an electron capture detection system. This extraction method was tested on a set of PCB-spiked solid matrices and on a PCB-contaminated river sediment (NIST SRM 1939). Recoveries were measured for eight PCB congeners spiked into two soil types with hexane extraction at 100 degrees C (>81.9 +/- 5.4% to 112.5 +/- 10.1%). The extraction process for SRM 1939 with hexane at 300 degrees C provided significantly higher recoveries for several representative PCB congeners than reported for a duplicate 16-hour Soxhlet extraction with a mixture of organic solvents (acetone/hexane). (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Aldstadt, JH (reprint author), Univ Wisconsin, Dept Chem, 3210 N Cramer St, Milwaukee, WI 53211 USA. EM aldstadt@uwm.edu NR 13 TC 5 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD JUN PY 1999 VL 38 IS 13 BP 3131 EP 3139 DI 10.1016/S0045-6535(98)00519-0 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA 184BW UT WOS:000079590300015 ER PT J AU Beck, DF Boyack, KW Bray, OH Siemens, WD AF Beck, DF Boyack, KW Bray, OH Siemens, WD TI Landscapes, games, and maps for technology planning SO CHEMTECH LA English DT Article C1 Sandia Natl Labs, Ctr Informat Proc, Livermore, CA 94550 USA. Sandia Natl Labs, Business Intelligence & Anal Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Ctr Informat Proc, Livermore, CA 94550 USA. EM kboyack@sandia.gov OI Boyack, Kevin/0000-0001-7814-8951 NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2703 J9 CHEMTECH JI Chemtech PD JUN PY 1999 VL 29 IS 6 BP 8 EP 16 PG 9 WC Chemistry, Applied SC Chemistry GA 202UL UT WOS:000080670500007 ER PT J AU Zhou, FX Zhang, Y Huang, F Liu, Q AF Zhou Fa-xiu Zhang Yi Huang Fei Liu Qi TI SPATIAL PATTERN OF THE AIR-SEA INTERACTION NEAR THE SOUTH CHINA SEA DURING WINTER SO CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY LA English DT Article DE air-sea interaction; SST; South China Sea; Asian monsoon AB This paper delineates the coupled and principal patterns of sea surface temperature (SST) and surface wind near the South China Sea (SCS), and discusses the mechanism of air-sea coupling near the SCS and their association with the Asian monsoon. Singular value decomposition (SVD) and single field principal component analysis (PCA) are applied to the SST and wind anomalies from the 1979-1995 NCEP/NCAR reanalysis data. The leading SVD mode explains a predominant amount of squared covariance between the SST and zonal or meridional wind. During winter, the meridional wind's relation to the SST is better than the relation of zonal wind to SST. Despite the large magnitude of the squared covariance between SST and zonal or meridional wind, the spatial patterns of the first mode of SVD between the SST and meridional wind are similar. They both exhibit ellipse-shaped variance with the center near the SCS and a northeast-southwest oriented main axis. The spatial patterns of the leading mode of SVD between the SST and zonal wind are also similar to a certain degree. The zonal wind is not as closely correlated to the SST as the meridional wind is. These results suggest that the meridional wind and SST are strongly coupled during the winter season, and that there is a certain coupled action system in the SCS. C1 [Zhou Fa-xiu; Huang Fei; Liu Qi] Ocean Univ Qingdao, Qingdao 266003, Peoples R China. [Zhang Yi] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Zhou, FX (reprint author), Ocean Univ Qingdao, Qingdao 266003, Peoples R China. FU NSFC [49676276]; LASG FX Project 49676276 supported by NSFC, this work is also supported by LASG. NR 3 TC 1 Z9 6 U1 0 U2 2 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING, 100717, PEOPLES R CHINA SN 0254-4059 J9 CHIN J OCEANOL LIMN JI Chin. J. Oceanol. Limnol. PD JUN PY 1999 VL 17 IS 2 BP 132 EP 141 PG 10 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA V23MI UT WOS:000208346500006 ER PT J AU Gentle, AP Holz, DE Miller, WA Wheeler, JA AF Gentle, AP Holz, DE Miller, WA Wheeler, JA TI Apparent horizons in simplicial Brill wave initial data SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article AB We use Regge calculus to construct initial data for a particular class of Brill wave metrics and compare the results with a corresponding continuum solution, finding excellent agreement. We then search for trapped surfaces in both sets of initial data, and provide an independent verification of the existence of an apparent horizon once a critical gravitational wave amplitude is passed. Our estimate of this critical value, using both the Regge and continuum solutions, supports recent findings. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RP Gentle, AP (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-6,MS B288, Los Alamos, NM 87545 USA. NR 9 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD JUN PY 1999 VL 16 IS 6 BP 1979 EP 1985 DI 10.1088/0264-9381/16/6/326 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 207QU UT WOS:000080948200028 ER PT J AU Gentle, AP AF Gentle, AP TI Simplicial Brill wave initial data SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID REGGE CALCULUS; GRAVITATIONAL-WAVES; EVOLUTION AB Regge calculus is used to construct initial data for vacuum axisymmetric Brill waves at a moment of time symmetry. We argue that only a tetrahedral lattice can successfully reproduce the continuum solution, and develop a simplicial axisymmetric lattice based on the coordinate structure of the continuum metric. This is used to construct initial data for Brill waves in an otherwise flat spacetime, and for the distorted black hole spacetime of Bernstein. These initial data sets are shown to be second-order accurate approximations to the corresponding continuum solutions. C1 Monash Univ, Dept Math & Stat, Clayton, Vic 3168, Australia. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gentle, AP (reprint author), Monash Univ, Dept Math & Stat, Clayton, Vic 3168, Australia. NR 17 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD JUN PY 1999 VL 16 IS 6 BP 1987 EP 2003 DI 10.1088/0264-9381/16/6/327 PG 17 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 207QU UT WOS:000080948200029 ER PT J AU Elliot, WC Edenfield, NM Wampler, JM Matisoff, G Long, PE AF Elliot, WC Edenfield, NM Wampler, JM Matisoff, G Long, PE TI The kinetics of the smectite to illite transformation in Cretaceous bentonites, Cerro Negro, New Mexico SO CLAYS AND CLAY MINERALS LA English DT Article DE bentonite; Cerro Negro; Cretaceous; illite; I-S; K-Ar; kinetics; microorganisms; New Mexico; smectite ID NORTH-SEA; MODEL; ILLITIZATION; BASIN; GEOTHERMOMETER; METAMORPHISM; CONSTRAINTS; TEMPERATURE; MECHANISMS; DIAGENESIS AB The thermal effects, as well as the survivability and origins of microorganisms in Cretaceous recks, are evaluated from the timing and extent of the smectite to illite transformation in Cretaceous bentonites collected from cores outside the thermal aureole of the Pliocene Cerro Negro volcanic neck. Overall, randomly ordered mixed-layered illite-smectite (I-S) is the predominant clay mineral in these bentonites, and the K-Ar ages of I-S range from 36 to 48 Ma (21 analyses, two additional analyses were outside this range). Increased temperature from burial is thought to be the primary factor forming I-S in these bentonites. Kinetic model calculations of the smectite to illite transformation are also consistent with T-S formed by burial without any appreciable thermal effects due to the emplacement of Cerro Negro. In a core angled toward Cerro Negro, the percentages of illite layers in I-S from the bentonite closest to Cerro Negro are slightly higher (32-37%) than in most other bentonites in this study. The K-Ar ages of the closest I-S are slightly younger as a group (38-43 Ma; Average = 41 Ma; N = 4) than those of I-S further from Cerro Negro in the same core (41-48 Ma; Average = 44 Ma; N = 6). A small amount of illite in this I-S may have formed by heat from the emplacement of Gene Negro, but most illite formed from burial. Vitrinite reflectance, however, appears to record the effects of heating from Cerro Negro better than I-S. Tentatively, the temperature of this heat pulse, based on vitrinite data alone, ranged from 100 to 125 degrees C and this is most evident in the CNAR core. The upper temperature, 125 degrees C, approximates the sterilization temperatures for most microorganisms, and these temperatures probably reduced a significant portion of the microbial population. Thermophiles may have survived the increased temperatures from the combined effects of burial and the intrusion of Cerro Negro. C1 Georgia State Univ, Dept Geol, Atlanta, GA 30303 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Case Western Reserve Univ, Dept Geol Sci, Cleveland, OH 44106 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Elliot, WC (reprint author), Georgia State Univ, Dept Geol, Atlanta, GA 30303 USA. RI Long, Philip/F-5728-2013 OI Long, Philip/0000-0003-4152-5682 NR 42 TC 14 Z9 14 U1 0 U2 1 PU CLAY MINERALS SOC PI CHANTILLY PA 3635 CONCORDE PKWY, STE 500, CHANTILLY, VA 20151-1125 USA SN 0009-8604 EI 1552-8367 J9 CLAY CLAY MINER JI Clay Clay Min. PD JUN PY 1999 VL 47 IS 3 BP 286 EP 296 DI 10.1346/CCMN.1999.0470304 PG 11 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA 209JP UT WOS:000081044700004 ER PT J AU Ford, RG Bertsch, PM AF Ford, RG Bertsch, PM TI Distinguishing between surface and bulk dehydration-dehydroxylation reactions in synthetic goethites by high-resolution thermogravimetric analysis SO CLAYS AND CLAY MINERALS LA English DT Article DE crystallinity; dehydroxylation; goethite; thermogravimetry; nonstoichiometric water; TEM; XRD ID AL-SUBSTITUTED GOETHITES; IRON-OXIDES; VARYING CRYSTALLINITY; ALUMINOUS GOETHITES; PARTICLE-SIZE; FERRIHYDRITE; DISSOLUTION; MORPHOLOGY; HEMATITE; CRYSTALLIZATION AB Synthetic goethites studied by high-resolution thermogravimetry (HRTGA) show variability in surface characteristics and structural stability as a function of aging conditions. Goethites were synthesized at either pH 6 or 11, at temperatures of 40 or 70 degrees C, and in the presence or absence of sorbed Mn or Pb. Data from HRTGA analysis revealed at least four distinct weight-loss events near goethite dehydroxylation that relate to 1) three events involving the evolution of water associated with surface Fe-O functional groups and 2) bulk dehydroxylation of goethite during transformation to hematite. The relative mass of evolved surface and bulk structural water was related to the predominant particle morphology as determined by transmission electron microscopy (TEM). Differentiation of surface and bulk decomposition reactions allowed the identification of bulk structural dehydroxylation. Goethite crystallinity, estimated by the bulk dehydroxylation temperature, appeared to depend on the kinetics of crystallization. This trend was most evident for systems aged at pH 11 and 40 degrees C. Greater concentrations of coprecipitated Mn or Pb dramatically improved goethite crystallinity as indicated by higher dehydroxylation temperatures and smaller widths of the (110) Bragg reflection. Comparison of bulk dehydroxylation temperatures for these samples to other preparations suggests that structural defects predominated over the effects of particle size and Mn/Pb substitution in determining goethite thermal stability. A conceptual model is proposed to account for the disparate dehydroxylation profiles displayed by goethites of varying crystallinity. C1 Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Ford, RG (reprint author), Univ Delaware, Dept Plant & Soil Sci, Newark, DE 19717 USA. NR 42 TC 23 Z9 23 U1 0 U2 7 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 USA SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD JUN PY 1999 VL 47 IS 3 BP 329 EP 337 DI 10.1346/CCMN.1999.0470309 PG 9 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA 209JP UT WOS:000081044700009 ER PT J AU Hodis, HN Mack, WJ Krauss, RM Alaupovic, P AF Hodis, HN Mack, WJ Krauss, RM Alaupovic, P TI Pathophysiology of triglyceride-rich lipoproteins in atherothrombosis: Clinical aspects SO CLINICAL CARDIOLOGY LA English DT Article DE angiography; apolipoprotein C-III; atherosclerosis; cholesterol; coronary artery,lipoprotein; low-density lipoprotein; triglyceride; ultrasonography ID CORONARY-ARTERY DISEASE; DENSITY LIPOPROTEINS; PROGRESSION; ATHEROSCLEROSIS; CHOLESTEROL; LOVASTATIN; TRIAL; ANGIOGRAPHY; THICKNESS; THERAPY AB Invasive and noninvasive arterial imaging are important techniques used to study atherosclerosis and, specifically, to evaluate the atherogenecity of triglyceride-rich lipoproteins (TRL). Serial coronary angiography trials show significant benefit from lowering low-density Lipoprotein cholesterol (LDL-C) which serves to retard lesion progression. Even with aggressive LDL-C reduction, however, up to half of patients demonstrate continued progression of atherosclerosis. Angioraphic studies reveal that lowering LDL-C has the most impact on severe lesions, those greater than or equal to 50% diameter stenosis, whereas TRL (and their apolipoprotein markers) have been identified as a driving factor behind progression of mild-to-moderate lesions <50% diameter stenosis. Quantitative coronary angiography (QCA) has demonstrated that progression of mild-to-moderate lesions are among the most significant predictors of clinical coronary events, and that lowering TRL reduces progression of coronary artery disease to the same degree as the lowering of LDL-C. C1 Univ So Calif, Sch Med, Atherosclerosis Res Unit, Div Cardiol, Los Angeles, CA 90033 USA. Univ Calif Berkeley, Donner Lab, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Oklahoma Med Res Fdn, Lipid & Lipoprot Lab, Oklahoma City, OK 73104 USA. RP Hodis, HN (reprint author), Univ So Calif, Sch Med, Atherosclerosis Res Unit, Div Cardiol, 2250 Alcazar St,CSC 132, Los Angeles, CA 90033 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU CLINICAL CARDIOLOGY PUBL CO PI MAHWAH PA PO BOX 832, MAHWAH, NJ 07430-0832 USA SN 0160-9289 J9 CLIN CARDIOL JI Clin. Cardiol. PD JUN PY 1999 VL 22 IS 6 SU 2 BP II15 EP II20 PG 6 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA 204MU UT WOS:000080768700004 PM 10376192 ER PT J AU Gronbech-Jensen, N AF Gronbech-Jensen, N TI Summation of logarithmic interactions in nonrectangular periodic media SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE long-range interactions; lattice summations; vortex dynamics ID SUPERCONDUCTORS AB We present a set of expressions for practical evaluation of energies, including self-energies, and forces between particles interacting logarithmically in a finite two-dimensional nonrectangular system with periodic boundary conditions. The formalism can be used for fast and accurate, dynamical or Monte Carlo, simulations of interacting line charges or interactions between point and line charges. The expressions are shown to converge to usual computer accuracy (similar to 10(-16)) by adding only few terms in a single sum of standard trigonometric functions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. RP Gronbech-Jensen, N (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 15 TC 43 Z9 43 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUN PY 1999 VL 119 IS 2-3 BP 115 EP 121 DI 10.1016/S0010-4655(99)00200-3 PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 225PZ UT WOS:000081971100002 ER PT J AU Shi, Z Kouri, DJ Wei, GW Hoffman, DK AF Shi, Z Kouri, DJ Wei, GW Hoffman, DK TI Generalized symmetric interpolating wavelets SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE interpolating distributed approximating functional wavelets ID COMPACTLY SUPPORTED WAVELETS; MULTIRATE FILTER-BANKS; ANTICAUSAL INVERSES; FEATURE ENHANCEMENT; PACKETS; REPRESENTATION; CONSTRUCTION; COMPRESSION; MAMMOGRAMS; TRANSFORMS AB A new class of biorthogonal wavelets-interpolating distributed approximating functional (DAF) wavelets are proposed as a powerful basis for scale-space functional analysis and approximation. The important advantage is that these wavelets can be designed with infinite smoothness in both time and frequency spaces, and have as well symmetric interpolating characteristics. Boundary adaptive wavelets can be implemented conveniently by simply shifting the window envelope. As examples, generalized Lagrange wavelets and generalized Sine wavelets are presented and discussed in detail. Efficient applications in computational science and engineering are explored. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Houston, Dept Phys, Houston, TX 77204 USA. Natl Univ Singapore, Dept Computat Sci, Singapore 119260, Singapore. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Shi, Z (reprint author), Univ Houston, Dept Phys, Houston, TX 77204 USA. RI Wei, Guowei /E-1852-2011 NR 61 TC 14 Z9 16 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUN PY 1999 VL 119 IS 2-3 BP 194 EP 218 DI 10.1016/S0010-4655(99)00185-X PG 25 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 225PZ UT WOS:000081971100009 ER PT J AU Jadach, S Placzek, W Skrzypek, M Ward, BFL Was, Z AF Jadach, S Placzek, W Skrzypek, M Ward, BFL Was, Z TI Monte Carlo program KoralW 1.42 for all four-fermion final states in e(+)e(-) collisions SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE radiative corrections; initial-state radiation (ISR); leading-logarithms (LL) approximation; heavy boson W; 4-fermion processes; Monte Carlo (MC) simulation/generation; quantum electrodynamics (QED); quantum chromodynamics (QCD); Yennie-Frautschi-Suura (YFS) exponentiation; standard model (SM); LEP2 ID W-PAIR PRODUCTION; ELECTROWEAK RADIATIVE-CORRECTIONS; FRAUTSCHI-SUURA EXPONENTIATION; (UN)STABLE W+W PRODUCTION; QED CORRECTIONS; HELICITY AMPLITUDES; 4-FERMION PROCESSES; BHABHA SCATTERING; CROSS-SECTION; LOW ANGLES AB The Monte Carlo program KoralW version 1.42 is presented, It generates all four-fermion final states with multibranch dedicated Monte Carlo presamplers and complete, massive, Born matrix elements, The presamplers cover the entire phase space. Multiphoton bremsstrahlung is implemented in the ISR approximation within the YFS formulation with the O(alpha(3)) leading-log matrix element. The anomalous WWV couplings are implemented in CC03 approximation. The standard decay libraries (JETSET, PHOTOS, TAUOLA) are interfaced. The semi-analytical CC03-type code KorWan for differential and total cross sections is included. (C) 1999 Elsevier Science B.V. All rights reserved. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Inst Nucl Phys, PL-30055 Krakow, Poland. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Jagiellonian Univ, Inst Comp Sci, Krakow, Poland. RP Jadach, S (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 42 TC 84 Z9 84 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUN PY 1999 VL 119 IS 2-3 BP 272 EP 311 DI 10.1016/S0010-4655(99)00219-2 PG 40 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 225PZ UT WOS:000081971100013 ER PT J AU Brunschwig, BS Sutin, N AF Brunschwig, BS Sutin, N TI Energy surfaces, reorganization energies, and coupling elements in electron transfer SO COORDINATION CHEMISTRY REVIEWS LA English DT Review DE electron transfer; energy surfaces; reorganization energies; electronic coupling elements ID MIXED-VALENCE MOLECULES; CHARGE-TRANSFER; EXCITED-STATES; COMPLEXES; CENTERS; SYSTEM AB The effects of changes in the shapes and intersections of the reactant and product free-energy surfaces on the vertical reorganization parameter and the free energy of activation for an electron self-exchange reaction are considered. Parabolic free energy surfaces provide a very good description of the inner-shell reorganization process even when the stretching force constants for the oxidized and reduced forms of the redox couple differ by a factor of two. The activation energy depends on the reorganization criterion and the contributions of the individual reactants to the inner-shell barrier are quite sensitive to the model used. Optical charge transfers and the consequences of reactant, product, and transition state stabilization in weakly interacting and very strongly interacting systems are also considered. Relationships between the equilibrium constant for the comproportionation reaction forming the mixed-valence complex and the optical charge transfer parameters are presented. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Brunschwig, BS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brunschwig, Bruce/G-4249-2011 NR 34 TC 198 Z9 199 U1 6 U2 51 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD JUN PY 1999 VL 187 BP 233 EP 254 DI 10.1016/S0010-8545(98)00255-0 PG 22 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 210QN UT WOS:000081116300011 ER PT J AU Goods, SH Bradshaw, RW AF Goods, SH Bradshaw, RW TI Constant extension rate testing of IN625LCF in molten nitrate salt SO CORROSION SCIENCE LA English DT Article DE deformation; exposure; fracture strain; area reduction; UTS AB Constant extension rate testing was used to examine the interaction between deformation and exposure of a nickel-based alloy to an oxidizing molten salt environment. Fracture strain, reduction in area and ultimate strength (UTS) were measured as parameters indicative of the susceptibility of the alloy to environmental degradation. INCONEL 625LCF specimens were tested at 600 degrees C in the salt medium and at initial strain rates between 4 x 10(-8) and 2 x 10(-5) sec(-1). The structure of the oxide film on specimens tested in the molten salt was affected by the imposed continuous deformation. Deformation resulted in an oxide film that was twice as thick as that formed on unstrained sail-exposed surfaces. Further, deformation resulted in significant cracking in the surface oxide. Metallographic observations suggested that some of this cracking initiated quite early in the mechanical tests. Specimens tested in the salt medium exhibited an increase in ductility, as measured by reduction in area and fracture strain, relative to control specimens tested in air, while strength was unaffected. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Mat Reliabil Dept, Sandia, CA USA. Sandia Natl Labs, Dept Chem Mat, Sandia, CA USA. RP Goods, SH (reprint author), Sandia Natl Labs, Mat Reliabil Dept, Sandia, CA USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0010-938X J9 CORROS SCI JI Corrosion Sci. PD JUN PY 1999 VL 41 IS 6 BP 1119 EP 1137 DI 10.1016/S0010-938X(98)00175-9 PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 195MD UT WOS:000080254000008 ER PT J AU Garrity, GM Hunter-Cevera, J AF Garrity, GM Hunter-Cevera, J TI Bioprospecting in the developing world SO CURRENT OPINION IN MICROBIOLOGY LA English DT Review ID MICROBIAL DIVERSITY; BIODIVERSITY; CONSERVATION; DISCOVERY AB During the past ten years, species-rich nations in the developing world have sought to capitalize on their 'biological patrimony' through a variety of business relationships with multinational corporations as a means of underwriting their conservation efforts. Initially lauded, these relationships have generated more rhetoric than revenues to date. The ramifications of these results on bioprospecting are discussed along with the foreseeable changes in models of collaboration. C1 Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. Michigan State Univ, Bergeys Manual Trust, E Lansing, MI 48824 USA. US DOE, Ernest Orlando Lawrence Natl Lab, Ctr Environm Biotechnol, Berkeley, CA USA. RP Garrity, GM (reprint author), Michigan State Univ, Dept Microbiol, 152 Giltner Hall, E Lansing, MI 48824 USA. RI Garrity, George/F-7551-2013 OI Garrity, George/0000-0002-4465-7034 NR 44 TC 1 Z9 1 U1 0 U2 4 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1369-5274 J9 CURR OPIN MICROBIOL JI Curr. Opin. Microbiol. PD JUN PY 1999 VL 2 IS 3 BP 236 EP 240 DI 10.1016/S1369-5274(99)80041-1 PG 5 WC Microbiology SC Microbiology GA 206AH UT WOS:000080853500002 PM 10383870 ER PT J AU Baskes, MI AF Baskes, MI TI The status role of modeling and simulation in materials science and engineering SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID ATOMISTIC SIMULATIONS; COMPUTER-SIMULATION; TRANSITION-METALS; LATTICE-DEFECTS; CROSS-SLIP; CRACK-TIP; DISLOCATION; FRACTURE; HYDROGEN; EMISSION AB Four materials modeling and simulation copies have been reviewed. Dislocation modeling shows significant progress in using the results of atomistic dislocation interaction calculations as input to discrete dislocation models, which, in turn, are now able to predict stress-strain relationships. Atomistic models have now been used to predict dynamic and microstructural effects on fracture. Continuum solidification models are now able to predict microstructural features. Plasticity models have been formulated that include dislocation and grain size distributions. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Mat Reliabil Dept, Livermore, CA 94551 USA. RP Sandia Natl Labs, Mat Reliabil Dept, MS 9403, Livermore, CA 94551 USA. EM baskes@ca.sandia.gov NR 28 TC 10 Z9 11 U1 3 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-0286 EI 1879-0348 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD JUN PY 1999 VL 4 IS 3 BP 273 EP 277 DI 10.1016/S1359-0286(99)00019-4 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 238UH UT WOS:000082730700007 ER PT J AU Pohl, RO Liu, X Crandall, RS AF Pohl, RO Liu, X Crandall, RS TI Lattice vibrations of disordered solids SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID LOW-TEMPERATURE PROPERTIES; LOW-ENERGY EXCITATIONS; ELASTIC PROPERTIES; INTERNAL-FRICTION; THERMAL-CONDUCTIVITY; MODEL GLASS; HEAT; CRYSTALS; SILICON; ALLOYS AB The recent discovery of an amorphous solid without low-energy tunneling excitations (Two-Level-Systems) has shown that the amorphous structure is not their primary cause, as had previously been widely accepted. It has also been shown that these excitations arise as the crystalline order is gradually disturbed, and that their number densities saturate at their characteristic level regardless of whether the crystal amorphizes or not. It is concluded that the nature of the defects, and the cause for their saturation density, should be explored in disordered crystals, rather than in amorphous solids. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Cornell Univ, Dept Phys, Ithaca, NY 14853 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Pohl, RO (reprint author), Cornell Univ, Dept Phys, Ithaca, NY 14853 USA. NR 33 TC 17 Z9 17 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD JUN PY 1999 VL 4 IS 3 BP 281 EP 287 DI 10.1016/S1359-0286(99)00028-5 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 238UH UT WOS:000082730700009 ER PT J AU Planchart, A You, Y Schimenti, JC AF Planchart, A You, Y Schimenti, JC TI Deletion mapping of a t haplotype locus, Tcd1/Tcs1, involved in transmission ratio distortion and infertility in male mice SO DEVELOPMENTAL BIOLOGY LA English DT Meeting Abstract C1 Jackson Lab, Bar Harbor, ME 04684 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37381 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD JUN 1 PY 1999 VL 210 IS 1 MA 223 BP 218 EP 218 PG 1 WC Developmental Biology SC Developmental Biology GA 207CN UT WOS:000080918000230 ER PT J AU Collazo-Davila, C Bengu, E Marks, LD Kirk, M AF Collazo-Davila, C Bengu, E Marks, LD Kirk, M TI Nucleation of cubic boron nitride thin films SO DIAMOND AND RELATED MATERIALS LA English DT Article DE cubic boron nitride; electron bombardment; ion bombardment; nucleation; TEM ID PULSED-LASER DEPOSITION; ION IRRADIATION; HIGH-PRESSURE; C-BN; ASSISTED DEPOSITION; HIGH-TEMPERATURE; DIAMOND; THRESHOLD; CLUSTERS; GROWTH AB High-energy electrons (300 keV to 1 MeV) in a transmission electron microscope have been used to cause ballistic atomic displacements in hexagonal boron nitride. The high-resolution imaging capabilities of the TEM have allowed us to study the effect of the atomic displacements on the crystal structure of the BN. We report the formation of nanoarches - fullerene structures consisting of half of a BN nanotube capping the ends of the planar BN graphitic sheets. To form a basis of comparison between the high-energy electron bombardment and the ion bombardment typically used for cubic BN film growth, TRIM calculations were also performed to simulate Ar+ ion bombardment of hexagonal BN. A model is presented, indicating a process through which the nanoarches can serve as nucleation sites for the cubic phase of BN. The nucleation model is consistent with current experimental reports on the formation of cubic BN thin films. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bengu, E (reprint author), Northwestern Univ, Dept Mat Sci & Engn, 2225 N Campus Dr, Evanston, IL 60208 USA. RI Marks, Laurence/B-7527-2009 NR 44 TC 21 Z9 21 U1 2 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD JUN PY 1999 VL 8 IS 6 BP 1091 EP 1100 DI 10.1016/S0925-9635(99)00092-8 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 205JM UT WOS:000080817600017 ER PT J AU Starosvetsky, D Khaselev, O Starosvetsky, J Armon, R Yahalom, J AF Starosvetsky, D Khaselev, O Starosvetsky, J Armon, R Yahalom, J TI The role of sulfides in iron activation in chloride-containing solutions SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID SULFATE-REDUCING BACTERIA; STAINLESS-STEEL; MILD-STEEL; CORROSION AB The mechanism of iron activation in sulfide-containing solutions was studied. It was shown that sulfide did not induce the activation of a prepassivated electrode in solutions free of chloride, however, a significant reduction of the pitting potential occurs in the presence of chloride. The effect was associated with sulfide salt layer formation over activated sites during metastable pit growth, which prevented their repassivation. Due to a low-solubility product, ferrous sulfide can precipitate on iron surfacse at a much lower ferrous ion concentration compared to ferrous chloride. Hence, the transition from metastable to stable pit growth could be expected at much lower pit growth current densities and as a result at potentials well below the breakdown potential as measured in chloride solutions. (C) 1999 The Electrochemical Society. S1099-0062(99)01-053-6. All rights reserved. C1 Technion Israel Inst Technol, Fac Mat Engn, IL-32000 Haifa, Israel. Technion Israel Inst Technol, Fac Civil Engn, IL-32000 Haifa, Israel. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Starosvetsky, D (reprint author), Technion Israel Inst Technol, Fac Mat Engn, IL-32000 Haifa, Israel. NR 12 TC 2 Z9 2 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD JUN PY 1999 VL 2 IS 6 BP 265 EP 266 DI 10.1149/1.1390806 PG 2 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 187VG UT WOS:000079808300005 ER PT J AU Yang, XQ Sun, X McBreen, J AF Yang, XQ Sun, X McBreen, J TI New findings on the phase transitions in Li1-xNiO2: in situ synchrotron X-ray diffraction studies SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE lithium batteries; lithium nickel oxide; in situ X-ray diffraction; intercalation cathode materials ID SECONDARY LITHIUM CELLS; R(3)OVER-BAR-M; LINIO2 AB A synchrotron X-ray source was used for in situ X-ray diffraction (XRD) studies on a Li1-xNiO2 cathode in the transmission mode. New phase transitions, different from those published in the literature, were observed. When a Li \ LiNiO2 cell was charged at the C/13 and C/84 rates in the 3.5 to 5.1 V range, there were two first-order phase transitions. with all three phases having a hexagonal structure. These new findings question the interpretation of XRD patterns used in the literature as evidence for monoclinic phase formation in this system during charge. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Yang, XQ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 7 TC 43 Z9 47 U1 6 U2 38 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1388-2481 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD JUN PY 1999 VL 1 IS 6 BP 227 EP 232 DI 10.1016/S1388-2481(99)00046-6 PG 6 WC Electrochemistry SC Electrochemistry GA 240UZ UT WOS:000082846300007 ER PT J AU Gao, QF Pang, HM Yeung, ES AF Gao, QF Pang, HM Yeung, ES TI Simultaneous genetic typing from multiple short tandem repeat loci using a 96-capillary array electrophoresis system SO ELECTROPHORESIS LA English DT Article DE short tandem repeat; genetic typing; multiple capillary array electrophoresis ID CAPILLARY GEL-ELECTROPHORESIS; HIGH-RESOLUTION; DNA; FLUORESCENCE; SEPARATIONS; PRECISION; PRIMERS; MATRIX; CHIPS AB Short tandem repeat (STR) markers are highly polymorphic and widely used in human identification and genetic mapping. We demonstrate fast and reliable genotyping based on the four STR loci VWF, THO1, TPOX, CSF1PO by multiple-capillary array electrophoresis. Extracted human genomic DNA was amplified by polymerase chain reaction (PCR). The PCR products were mixed with pooled allelic ladder as an absolute standard and coinjected from a 96-vial tray. Separations were performed in polyvinylpyrrolidone (PVP) sieving matrix with a one-hour turnaround time, with no degradation over 27 runs. Simultaneous one-color laser-induced fluorescence detection was achieved by using a charge-coupled device (CCD) camera. The allele peaks for the unknown sample were identified by comparing the normalized peak intensities of the mixtures to those of the pooled ladder by using a straightforward algorithm. An extremely high level of confidence in matching the bands was indicated with negligible crosstalk (< 0.89%) between adjacent capillaries. This scheme is applicable for STR genotyping with high resolution, high speed and high throughput. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. FU NHGRI NIH HHS [HG-01385] NR 33 TC 37 Z9 39 U1 1 U2 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD JUN PY 1999 VL 20 IS 7 BP 1518 EP 1526 DI 10.1002/(SICI)1522-2683(19990601)20:7<1518::AID-ELPS1518>3.3.CO;2-X PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 210PB UT WOS:000081112900025 PM 10424475 ER PT J AU Vine, E Nakagami, H Murakoshi, C AF Vine, E Nakagami, H Murakoshi, C TI The evolution of the US energy service company (ESCO) industry: from ESCO to Super ESCO SO ENERGY LA English DT Article AB As the restructuring of the US electric utility industry proceeds, utility companies are expected to be either competing or partnering with Super ESCOs to provide energy-efficiency services and energy to utility customers. In this paper, Super ESCOs and utilities were interviewed to see how these organizations are currently interacting and planning to interact in the future. As part of this investigation, the types: of products and services Super ESCOs will be providing in the future and how utility restructuring will affect their business were examined. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Jyukankyo Res Inst, Tokyo, Japan. RP Vine, E (reprint author), Lawrence Berkeley Lab, Bldg 90-2000, Berkeley, CA 94720 USA. NR 9 TC 17 Z9 18 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD JUN PY 1999 VL 24 IS 6 BP 479 EP 492 DI 10.1016/S0360-5442(99)00009-2 PG 14 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA 202ZT UT WOS:000080683000002 ER PT J AU Stetiu, C AF Stetiu, C TI Energy and peak power savings potential of radiant cooling systems in US commercial buildings SO ENERGY AND BUILDINGS LA English DT Article DE peak power; radiant cooling system; commercial building AB The paper describes a parametric study developed to estimate the energy and peak power savings potential of radiant cooling systems in commercial buildings in the US. The study is based on the numerical modeling of a radiant cooling system and an all-air system at different locations in the US. The results show that a building equipped with a radiant cooling system can be operated in any US climate with low risk of condensation. For the office space examined in the study, employing a radiant cooling system instead of a traditional all-air system can save on average 30% of the energy consumption and 27% of the peak power demand due to space conditioning. The savings potential is climate-dependent, and is larger in retrofitted buildings than in new construction. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Stetiu, C (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 11 TC 66 Z9 72 U1 3 U2 14 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD JUN PY 1999 VL 30 IS 2 BP 127 EP 138 DI 10.1016/S0378-7788(98)00080-2 PG 12 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 211DC UT WOS:000081143800003 ER PT J AU Behne, M AF Behne, M TI Indoor air quality in rooms with cooled ceilings. Mixing ventilation or rather displacement ventilation? SO ENERGY AND BUILDINGS LA English DT Article DE indoor; ceiling; ventilation AB Experimental investigations and practical experiences in Europe have proved that hydronic cooled ceilings are able to remove high cooling lends without impairing thermal comfort. As hydronic cooled ceilings cannot remove latent loads and pollutants, e.g., CO2, VOCs, odors, additional ventilation has to be applied. Often, displacement ventilation is used, which is able to provide lower pollutant levels in the occupation zone than mixing flow systems, if the occupants are causing most of the pollution. Unfortunately, the advantage of the displacement flow, in respect to the air quality, can vanish when cooled ceilings are used to remove the major part of the sensible cooling load. For these applications, a combination of a cooled ceiling with a mixing ventilation system might be more appropriate. This paper presents the results of an investigation examining the distribution of tracer gas in a test chamber which is equipped with a radiant cooled ceiling. There is both a displacement flow system and a mixing flow system available, so that the concentrations of the tracer gas within the occupation zone characterizing the air quality can be compared directly and evaluated under similar conditions. The vertical air temperature rise is taken into consideration as well, as it influences the displacement flow and is an important issue for assessing thermal comfort. The results show the interaction of the portion of the cooling load being removed by the supply air, the air quality in the occupied zone and the vertical air temperature rise. The figures and tables presented show which of the two supply air systems investigated have advantages over the other. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Behne, M (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 23 TC 50 Z9 52 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD JUN PY 1999 VL 30 IS 2 BP 155 EP 166 DI 10.1016/S0378-7788(98)00083-8 PG 12 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 211DC UT WOS:000081143800006 ER PT J AU Gadgil, A Jannuzzi, GM Silva, E Leonardi, ML AF Gadgil, A Jannuzzi, GM Silva, E Leonardi, ML TI A cost-neutral energy strategy incorporating renewables and energy-efficiency for the city of Manaus in Brazilian Amazonia SO ENERGY POLICY LA English DT Article AB We report an assessment of maximum feasible cost-neutral reduction in the environmental impacts of energy demand growth in the city of Manaus, Brazil. Manaus is a rapidly growing city located in the heart of the Amazonian rainforest (1500 km of rainforest in all directions). Owing to its geographical isolation, it is attractive to explore the extent to which modern renewable and energy efficiency technologies can move it towards energy sustainability - or at least significantly reduce or delay the next expansion of its conventional energy supply project - without increasing the net present value (NPV) of the energy scenario from the societal perspective. Our results, based on collection and analysis of new and existing data, show that on a technical fix basis (ie, without political support for broader policy changes for reducing conventional energy use), about a quarter of conventional energy consumption for the year 2002 can be cost-neutrally replaced with efficiency and renewables. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. Univ Estadual Campinas, NEPAM, Environm Res Ctr, Campinas, Brazil. RP Gadgil, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Mailstop 90-3058, Berkeley, CA 94720 USA. EM ajgadgil@lbl.gov RI Jannuzzi, Gilberto/A-6601-2013; OI Jannuzzi, Gilberto/0000-0002-5716-6947; Gadgil, Ashok/0000-0002-0357-9455 NR 19 TC 0 Z9 0 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD JUN PY 1999 VL 27 IS 6 BP 357 EP 367 DI 10.1016/S0301-4215(99)00019-1 PG 11 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 252KB UT WOS:000083499700005 ER PT J AU Stephen, JR Chang, YJ Gan, YD Peacock, A Pfiffner, SM Barcelona, MJ White, DC Macnaughton, SJ AF Stephen, JR Chang, YJ Gan, YD Peacock, A Pfiffner, SM Barcelona, MJ White, DC Macnaughton, SJ TI Microbial characterization of a JP-4 fuel-contaminated site using a combined lipid biomarker/polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)-based approach SO ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID FATTY-ACID BIOMARKERS; 16S RIBOSOMAL-RNA; COMMUNITY STRUCTURE; SUBSURFACE; BIOMASS; PROFILES; SOILS; SEDIMENTS; BACTERIUM; TOXICITY AB The impact of pollution on soil microbial communities and subsequent bioremediation can be measured quantitatively in situ using direct, non-culture-dependent techniques. Such techniques have advantages over culture-based methods, which often account for less than 1% of the extant microbial community. In 1988, a JP-4 fuel spill contaminated the glacio-fluvial aquifer at Wurtsmith Air Force Base, Michigan, USA. In this study, lipid biomarker characterization of the bacterial and eukaryotic communities was combined with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of the eubacterial community to evaluate correlation between contaminant (JP-4 fuel) concentration and community structure shifts. Vadose, capillary fringe and saturated zone samples were taken from cores within and up- and down-gradient from the contaminant plume, Lipid biomarker analysis indicated that samples from within the plume contained increased biomass, with large proportions of typically Gram-negative bacteria. Outside the plume, lipid profiles indicated low-biomass microbial communities compared with those within the initial spill site. 16S rDNA sequences derived from DGGE profiles from within the initial spill site suggested dominance of the eubacterial community by a limited number of phylogenetically diverse organisms. Used in tandem with pollutant quantification, these molecular techniques should facilitate significant improvements over current assessment procedures for the determination of remediation end-points. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Univ Michigan, Dept Civil & Environm Engn, Natl Ctr Integrated Bioremediat Res & Dev, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Macnaughton, SJ (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 10515 Res Dr,Suite 300, Knoxville, TN 37932 USA. NR 47 TC 51 Z9 53 U1 0 U2 7 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1462-2912 J9 ENVIRON MICROBIOL JI Environ. Microbiol. PD JUN PY 1999 VL 1 IS 3 BP 231 EP 241 DI 10.1046/j.1462-2920.1999.00030.x PG 11 WC Microbiology SC Microbiology GA 277ZB UT WOS:000084962500007 PM 11207742 ER PT J AU Barton, JW Davison, BH Klasson, KT Gable, CC AF Barton, JW Davison, BH Klasson, KT Gable, CC TI Estimation of mass transfer and kinetics in operating trickle-bed bioreactors for removal of VOCS SO ENVIRONMENTAL PROGRESS LA English DT Article ID BIOFILTRATION AB Long-term, stable operation of trickle-bed bioreactors remains desirable but is difficult to achieve for industrial processes, which generate continuous streams of dilute gaseous hydrocarbons. Mass transfer and kinetics parameters are difficult to measure, complicating predictive estimates. Two methods are presented which were used to predict the importance of mass transfer versus kinetics limitations in operating trickle-bed biofilters. Both methods altered the overall activity of the biofilter and estimated the effective mass transfer coefficient (K(L)a) by varying the VOC (volatile organic contaminant) loading rate and concentration. The first method altered the total bed temperature of a well-established biofilter to effect a change. The second method used with developing biofilters possessing low biomass, involved addition of cultured biomass to the recirculating liquid to effect an overall change in VOC removal capacity. Results and modeling from these experiments are presented for a mixed culture trickle-bed bioreactor that is capable of consuming sparingly soluble alkanes, such as pentane and isobutane. Methods to control overgrowth are discussed which were used to operate one reactor continuously for over 24 months with sustained degradation of volatile alkanes with a rate of 50 g h(-1) m(-3). C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Barton, JW (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RI Davison, Brian/D-7617-2013; OI Davison, Brian/0000-0002-7408-3609; Klasson, K. Thomas/0000-0003-3358-3081 NR 12 TC 8 Z9 8 U1 1 U2 9 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD SUM PY 1999 VL 18 IS 2 BP 87 EP 92 DI 10.1002/ep.670180212 PG 6 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 220PT UT WOS:000081674900006 ER PT J AU Holman, HYN Tsang, YW Holman, WR AF Holman, HYN Tsang, YW Holman, WR TI Mineralization of sparsely water soluble polycyclic aromatic hydrocarbons in a water table fluctuation zone SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID HYDROPHOBIC ORGANIC-COMPOUNDS; REDUCING CONDITIONS; MICROBIAL BIOMASS; CONTAMINATED SOILS; HARBOR SEDIMENTS; AEROBIC AQUIFER; DEGRADATION; NAPHTHALENE; KINETICS; OXYGEN AB The mineralization potential of sparsely water-soluble polycyclic aromatic hydrocarbons (PAHs) within a highly diesel-contaminated watertable fluctuation zone (WTFZ) was investigated using core-scale column microcosms. Experimental conditions mimicked overall seasonal changes in water and oxygen content at the site. During the first aerobic winter, PAH mineralization rates in the freshly contaminated soil were fastest for contaminant [C-14]- naphthalene which was the least hydrophobic and most water-soluble. Lowering the water table nearly doubled the mineralization rates of all [C-14]PAHs studied. During the oxygen-poor summer, all mineralization rates were insignificant and failed to respond to water table changes. Neither a return to water-saturated aerobic (winter) conditions nor lowering the water table under aerobic conditions induced detectable mineralization of [C-14]naphthalene, but lowering the water table did markedly hasten the still slow mineralization of [C-14]phenanthrene and [C-14]anthracene. The time-dependent mineralization behavior and its response to water table fluctuations were explicable in terms of microbial responses to the changing oxygen content and depleting mineral nutrients. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Holman, HYN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Holman, Hoi-Ying/N-8451-2014 OI Holman, Hoi-Ying/0000-0002-7534-2625 NR 47 TC 7 Z9 7 U1 0 U2 0 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 1 PY 1999 VL 33 IS 11 BP 1819 EP 1824 DI 10.1021/es980701k PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 202MC UT WOS:000080655400028 ER PT J AU Stephen, JR Chang, YJ MacNaughton, SJ Whitaker, SL Hicks, CL Leung, KT Flemming, CA White, DC AF Stephen, JR Chang, YJ MacNaughton, SJ Whitaker, SL Hicks, CL Leung, KT Flemming, CA White, DC TI Fate of a metal-resistant inoculum in contaminated and pristine soils assessed by denaturing gradient gel electrophoresis SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE microbial ecology; toxic metals; denaturing gradient gel electrophoresis polymerase chain reaction ID 16S RIBOSOMAL-RNA; BACTERIA; GENES; AMPLIFICATION; SEQUENCES; PCR AB Cesium, cadmium, cobalt, and strontium are four contaminants frequently found in soils at biotoxic levels. Introduction of certain nongenetically modified bacteria has been frequently suggested as a method for the immobilization of heavy metal contaminants in soil, thereby reducing runoff and bioavailability. In this study, we have used the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) to track the survival of five bacterial species added to soil microcosms with and without the addition of a mixture of these metals. The PCR primers targeted conserved regions of the 16S rDNA molecule present in all bacteria. The reaction products were shown to reflect the relative abundance of the bacteria both in mixtures of pure cultures and against a background of all the eubacterial species present in the soil following inoculation. Three of the species (Pseudomonas aeruginosa FRD-1, Shewanella putrifaciens 200, and Desulfovibrio vulgaris Hildenborough) decreased rapidly following inoculation into both soils. The proportion of Alcaligenes eutrophus CH34 remained at a constant level throughout the 8-week experiment in both soil treatments. Sphingomonas aromaticivorans B0695 showed toxic metal-dependent survival in that its relative abundance dropped rapidly in pristine soil but remained at approximately inoculation levels throughout the experiment in contaminated microcosms. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Microbial Insights, Rockford, TN 37850 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP White, DC (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 10515 Res Dr,Suite 300, Knoxville, TN 37932 USA. EM milipids@aol.com NR 27 TC 26 Z9 27 U1 2 U2 4 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 1999 VL 18 IS 6 BP 1118 EP 1123 DI 10.1897/1551-5028(1999)018<1118:FOAMRI>2.3.CO;2 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 197YG UT WOS:000080393500007 ER PT J AU Hopkins, WA Rowe, CL Congdon, JD AF Hopkins, WA Rowe, CL Congdon, JD TI Elevated trace element concentrations and standard metabolic rate in banded water snakes (Nerodia fasciata) exposed to coal combustion wastes SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE coal combustion wastes; snakes; trace elements; standard metabolic rate ID RANA-CATESBEIANA; BUFO-TERRESTRIS; SOUTHERN TOADS; SELENIUM; CALIFORNIA; ALLIGATORS; TISSUE; GROWTH; COSTS AB Trace element concentrations in banded water snakes, Nerodia fasciata, and representative prey items from a site polluted by coal combustion wastes were compared with concentrations in conspecifics from a nearby reference site. Water snakes accumulated high concentrations of trace elements, especially arsenic (As) and selenium (Se), in the polluted habitat. In addition to being exposed to contaminants in water and sediments, snakes in the polluted site are exposed to contaminants by ingesting prey items that have elevated whole-body concentrations of trace elements, including As, cadmium (Cd), and Se. Snakes from the polluted site exhibited mean standard metabolic rates (SMR) 32% higher than snakes from the reference site. As a result, snakes from the polluted site appear to have elevated allocation of energy to maintenance and theoretically should have less energy available for growth, reproduction, and storage. Our findings are consistent with physiological responses recently documented in other organisms from the polluted site. We hypothesize that long-term exposure to coal ash-derived trace elements and the resultant accumulation of some elements are responsible for observed increases in SMR. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. Auburn Univ, Dept Zool & Wildlife Sci, Auburn, AL 36849 USA. Univ Puerto Rico, Dept Biol, Rio Piedras, PR 00931 USA. RP Hopkins, WA (reprint author), Savannah River Ecol Lab, Aiken, SC 29802 USA. RI Schneider, Larissa/C-9863-2012; Rowe, Christopher/D-5271-2012 NR 40 TC 111 Z9 112 U1 1 U2 21 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUN PY 1999 VL 18 IS 6 BP 1258 EP 1263 DI 10.1897/1551-5028(1999)018<1258:ETECAS>2.3.CO;2 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 197YG UT WOS:000080393500027 ER PT J AU Pan, JW Bebin, EM Chu, WJ Hetherington, HP AF Pan, JW Bebin, EM Chu, WJ Hetherington, HP TI Ketosis and epilepsy: P-31 spectroscopic imaging at 4.1 T SO EPILEPSIA LA English DT Article DE ketosis; epilepsy; P-31 spectroscopy; metabolism; bioenergetics ID ENERGY-METABOLISM; KETOGENIC DIETS; CEREBRAL GRAY; WHITE-MATTER; RAT-BRAIN; RESOLUTION; PROTON AB Purpose: To determine whether changes in the high-energy phosphates occur with use of the ketogenic diet in patients with intractable epilepsy. Methods: P-31 magnetic resonance spectroscopic imaging studies were performed at 4.1 T in seven patients with intractable epilepsy (four Lennox-Gastaut syndrome, one absence, one primary generalized tonic-clonic, and one partial complex) before and after institution of the ketogenic diet. Coronal H-1 anatomic imaging also was performed to provide correlation to the P-31 data. Results: Taking the patients as a group, the ratio of phosphocreatine (PC)/gamma-adenosine triphosphate (ATP) measured at baseline (regular diet) compared with that measured after the ketogenic diet showed a small but significant increase from 0.61 +/- 0.08 to 0.69 +/- 0.08 (p < 0.05). Comparing the ratio of PCr inorganic phosphorus (P-i) measured at baseline with the postketogenic diet, there was a significant increase from 2.45 +/- 0.27 to 2.99 +/- 0.44 (p < 0.05). Conclusions: As a group, improvement of energy metabolism occurs with use of the ketogenic diet. This is in agreement with the chronic ketosis studies performed earlier in rodents. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11793 USA. Univ Alabama, Ctr Nucl Imaging Res, Dept Pediat, Birmingham, AL USA. Univ Alabama, Ctr Nucl Imaging Res, Dept Med, Birmingham, AL USA. RP Pan, JW (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490,POB 5000, Upton, NY 11793 USA. FU NCRR NIH HHS [RR-11811] NR 24 TC 66 Z9 69 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0013-9580 J9 EPILEPSIA JI Epilepsia PD JUN PY 1999 VL 40 IS 6 BP 703 EP 707 DI 10.1111/j.1528-1157.1999.tb00766.x PG 5 WC Clinical Neurology SC Neurosciences & Neurology GA 203DK UT WOS:000080692200004 PM 10368066 ER PT J AU Benhar, O Fantoni, S Lykasov, GI AF Benhar, O Fantoni, S Lykasov, GI TI On the behavior of the nuclear spectral function at high momentum and removal energy SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID MULTIPLE HADRON-PRODUCTION; SCATTERING; QUARK; ELECTRON; TARGETS; MODEL; DEUTERON AB We propose a procedure to extrapolate the nuclear spectral function P(\k\, E) obtained from nonrelativistic many-body theory to large values of three-momentum and removal energy. Our approach is based on phenomenological information extracted from both soft hadron-nucleus interactions; in the regime where the proton inclusive spectrum is dictated by Regge asymptotic, and deep-inelastic lepton-nucleus collisions. The extrapolated P(\k\, E) is used to compute the semi-inclusive spectra of backward protons produced in electron-nucleus scattering. C1 Jefferson Lab, Newport News, VA 23606 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Ist Nazl Fis Nucl, Sez Trieste, I-30014 Trieste, Italy. Joint Inst Nucl Res, Dubna 141980, Moscow Region, Russia. Interdisciplinary Lab Adv Studies, Trieste, Italy. RP Benhar, O (reprint author), Ist Nazl Fis Nucl, Sez Roma 1, I-00185 Rome, Italy. RI Benhar, Omar/J-6044-2012 OI Benhar, Omar/0000-0001-6818-9215 NR 14 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD JUN PY 1999 VL 5 IS 2 BP 137 EP 141 DI 10.1007/s100500050269 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 212XY UT WOS:000081244000004 ER PT J AU Cleri, F Keblinski, P Colombo, L Wolf, D Phillpot, SR AF Cleri, F Keblinski, P Colombo, L Wolf, D Phillpot, SR TI On the electrical activity of sp(2)-bonded grain boundaries in nanocrystalline diamond SO EUROPHYSICS LETTERS LA English DT Article ID VAPOR-DEPOSITED DIAMOND; AMORPHOUS-CARBON; ATOMIC-STRUCTURE; RAMAN-SPECTROSCOPY; FIELD-EMISSION; TIGHT-BINDING; GAP STATES; FILMS; ENERGY; MICROSCOPY AB By means of tight-binding molecular dynamics simulations we find that the ground-state atomic structure of a typical high-energy grain boundary in diamond is highly disordered with a large fraction of sp(2) bonded atoms. This structure gives rise to localised bands within the band gap. We describe how multiphonon assisted hopping conduction can arise from such electronic states in high-energy grain boundaries, giving in turn a basis for the experimentally observed conductivity and electron field emission in nanocrystalline diamond. Simulated electron-energy-loss spectra indicate correlations between the disordered atomic structure and features of the electronic structure. C1 Ctr Ric Casaccia, Div Mat Avanzati, Ente Nazl Nuove Tecnol Energia & Ambiente, I-00100 Rome, AD, Italy. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Milan Bicocca, Ist Nazl Fis Mat, I-20125 Milan, Italy. Univ Milan Bicocca, Dipartimento Sci Mat, I-20125 Milan, Italy. RP Cleri, F (reprint author), Ctr Ric Casaccia, Div Mat Avanzati, Ente Nazl Nuove Tecnol Energia & Ambiente, CP 2400, I-00100 Rome, AD, Italy. RI Phillpot, Simon/J-9117-2012; Colombo, Luciano/D-9013-2013 OI Colombo, Luciano/0000-0001-5335-4652 NR 24 TC 47 Z9 47 U1 0 U2 9 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUN 1 PY 1999 VL 46 IS 5 BP 671 EP 677 DI 10.1209/epl/i1999-00318-5 PG 7 WC Physics, Multidisciplinary SC Physics GA 202LH UT WOS:000080653400020 ER PT J AU Thompson, JA Jarvinen, G AF Thompson, JA Jarvinen, G TI Using water-soluble polymers to remove dissolved metal ions SO FILTRATION & SEPARATION LA English DT Article ID MEMBRANE FILTRATION; ULTRAFILTRATION; SEPARATION C1 Polylonix Separat Technol Inc, Dayton, NJ 08810 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thompson, JA (reprint author), Polylonix Separat Technol Inc, 2351 US Route 130,POB 1004, Dayton, NJ 08810 USA. NR 10 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0015-1882 J9 FILTR SEPARAT JI Filtr. Sep. PD JUN PY 1999 VL 36 IS 5 BP 28 EP 32 PG 5 WC Engineering, Chemical SC Engineering GA 204HY UT WOS:000080759500003 ER PT J AU Prausnitz, JM AF Prausnitz, JM TI Thermodynamics and the other chemical engineering sciences: old models for new chemical products and processes SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 8th International Conference on Properties and Phase Equilibria for Product and Process Design CY APR 26-MAY 01, 1998 CL NOORDWIJKERHOUT, NETHERLANDS SP AKZO Nobel, Delft Univ Technol, DSM Res, Fac Appl Sci, TUDelf, Lab Appl Thermodynam & Phase Equilibria, TUDelft, Natl Sci Fdn USA, Purac Biochem, Shell Nederland BV, Solvay Pharmaceut, Unilever Res, Univ Fdn Delft DE molecular thermodynamics; polymer blends; Landau-Ginzburg expansion; drug-delivery system; Fick's law; protein solutions ID POLYMER AB Much recent academic research in molecular thermodynamics has been directed toward ever-more-complex theories without adequate attention to how such theories may be used in contemporary chemical technology; too often, researchers develop theories for their own sake, delegating to others (who?) to figure out how to use them. For new chemical product design, it is typically necessary to inter-relate thermodynamics with other sciences (notably mass transfer); for chemical process design, it is desirable to direct molecular-thermodynamic ideas toward evolving industries (e.g., biotechnology). Toward those ends, conventional models can often provide helpful information. To illustrate, three examples are briefly discussed: first, design of a drug-delivery system and second, design of polymer blends to achieve desired mechanical properties. In both examples, the key to success is not the conventional molecular model but its combination with Fickian diffusion. The third example concerns precipitation of proteins from aqueous salt solutions; a remarkably simple model shows how equilibria in protein solutions are qualitatively different from those in conventional solutions. Calculations show that, for protein solutions, on a plot of temperature vs, concentration, the freezing line (for liquid-solid equilibria) lies above the liquid-liquid coexistence curve, as verified by experiment. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Prausnitz, JM (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 12 TC 13 Z9 13 U1 1 U2 9 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 1999 VL 158 BP 95 EP 111 DI 10.1016/S0378-3812(99)00115-6 PG 17 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 207UY UT WOS:000080955200011 ER PT J AU Bertucco, A Elvassore, N Fermeglia, M Prausnitz, JM AF Bertucco, A Elvassore, N Fermeglia, M Prausnitz, JM TI A perturbed-hard-sphere-chain equation of state for phase equilibria of mixtures containing a refrigerant and a lubricant oil SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 8th International Conference on Properties and Phase Equilibria for Product and Process Design CY APR 26-MAY 01, 1998 CL NOORDWIJKERHOUT, NETHERLANDS SP AKZO Nobel, Delft Univ Technol, DSM Res, Fac Appl Sci, TUDelf, Lab Appl Thermodynam & Phase Equilibria, TUDelft, Natl Sci Fdn USA, Purac Biochem, Shell Nederland BV, Solvay Pharmaceut, Unilever Res, Univ Fdn Delft DE equation of state; refrigerant; lubricant oil; vapor-liquid equilibria; liquid-liquid equilibria ID ISOTHERMAL FLASH PROBLEM; THERMODYNAMIC PROPERTIES; LIQUID-EQUILIBRIA; HYDROFLUOROCARBONS; VAPOR; R-125 AB A modification of the perturbed-hard-sphere-chain equation of state (EOS) is used to describe vapor-liquid (VLE) and liquid-liquid equilibria (LLE) of mixtures containing new-generation refrigerants and a lubricant oil. For refrigerants, pure-component parameters are obtained from thermodynamic data. For the oil, they are predicted by a group-contribution method, and the calculation is checked on liquid density values of polyol-ester lubricants. Extension to mixtures is performed by using conventional one-fluid mixing rules with binary interaction parameters regressed from VLE experimental data, VLE calculations are reported for mixtures containing a refrigerant and a polyol-ester lubricant over wide temperature and concentration ranges. The thermodynamic condition for LLE is checked. If two liquid phases are present, LLE is calculated and compared with experimental measurements. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Padua, Ist Impianti Chim, I-35131 Padua, Italy. Univ Trieste, DICAMP, I-34100 Trieste, Italy. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Bertucco, A (reprint author), Univ Padua, Ist Impianti Chim, Via Marzolo 9, I-35131 Padua, Italy. OI Fermeglia, Maurizio/0000-0001-8810-5082 NR 19 TC 17 Z9 17 U1 1 U2 6 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 1999 VL 158 BP 183 EP 191 DI 10.1016/S0378-3812(99)00152-1 PG 9 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 207UY UT WOS:000080955200019 ER PT J AU Tirosh, O Sen, CK Roy, S Kobayashi, MS Packer, L AF Tirosh, O Sen, CK Roy, S Kobayashi, MS Packer, L TI Neuroprotective effects of alpha-lipoic acid and its positively charged amide analogue SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE thioctic acid; antioxidants; redox; neurotoxicity; free radicals ID PROGRAMMED CELL-DEATH; GLUTAMATE TOXICITY; OXIDATIVE STRESS; CYSTINE UPTAKE; INHIBITION; LINE; SYSTEMS; PEROXIDATION; METABOLISM; APOPTOSIS AB Elevated levels of extracellular glutamate have been linked to reactive oxygen species mediated neuronal damage and brain disorders. Lipoic acid is a potent antioxidant that has previously been shown to exhibit neuroprotection in clinical studies. A new positively charged water soluble lipoic acid amide analog, 2-(N,N-dimethylamine) ethylamido lipoate . HCl (LA-plus), with a better cellular reduction and retention of the reduced form was developed. This novel antioxidant was tested for protection against glutamate induced cytotoxicity in a HT4 neuronal cell line. Glutamate treatment for 12 h resulted in significant release of LDH from cells to the medium suggesting cytotoxicity. Measurement of intracellular peroxides showed marked (up to 200%) increase after 6 h of glutamate treatment. Compared to lipoic acid, LA-plus was more effective in (1) protecting cells against glutamate induced cytotoxicity, (2) preventing glutamate induced loss of intracellular GSH, and (3) disallowing increase of intracellular peroxide level following the glutamate challenge. The protective effect of LA-plus was found to be independent of its stereochemistry, The protective function of this antioxidant was synergistically enhanced by selenium. These results demonstrate that LA-plus is a potent protector of neuronal cells against glutamate-induced cytotoxicity and associated oxidative stress. (C) 1999 Elsevier Science Inc. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Environm Energies Technol Div, Berkeley, CA USA. RP Packer, L (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 251 Life Sci Addit, Berkeley, CA 94720 USA. RI Sen, Chandan/A-8762-2013; Roy, sashwati/E-3990-2011 FU NIDDK NIH HHS [DK 50430]; NIGMS NIH HHS [GM 27345] NR 32 TC 70 Z9 74 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD JUN PY 1999 VL 26 IS 11-12 BP 1418 EP 1426 DI 10.1016/S0891-5849(99)00014-3 PG 9 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 210VY UT WOS:000081126400008 PM 10401605 ER PT J AU Thompson, HA Parks, GA Brown, GE AF Thompson, HA Parks, GA Brown, GE TI Dynamic interactions of dissolution, surface adsorption, and precipitation in an aging cobalt(II)-clay-water system SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; AQUEOUS-SOLUTION; WATER INTERFACE; ANION-EXCHANGE; ALUMINUM-OXIDE; METAL-IONS; KAOLINITE; HYDROXIDE; KINETICS; SORPTION AB We have studied the dynamic interactions of mineral dissolution, cation surface adsorption, and precipitation in aqueous slurries initially containing kaolinite and millimolar quantities of cobalt(II) in 0.1 molar NaNO3 solution. Batch slurries spent an initial 24 hours at pH 4.2, then NaOH was added to increase pH to 7.8, where pH was maintained for several months. Dissolved Co, Al, and Si concentrations were monitored by ICP-MS; solid-phase products were characterized using EXAFS and TEM. At low pH, kaolinite dissolved, releasing Al and Si to solution. Aluminum hydroxide and aluminosilicate phases precipitated rapidly as pH increased. Cobalt uptake from solution began as pH increased and continued throughout the remainder of the experiment. Rapid surface adsorption and precipitation accounted for early Co uptake; much slower precipitation caused continued Co uptake. Cobalt adsorbed on kaolinite in the form of hydroxy-bridged polymers or multimers and precipitated as a hydrotalcite-like solid that contained aluminum ions derived from kaolinite and aluminum hydroxide dissolution. The cobalt hydrotalcite precipitate had the approximate stoichiometry [Co6Al2(OH)(16)(A(n-))(2/n)], with nitrate or silicate anions occupying A sites. Precipitate particles were several nanometers in diameter and some probably precipitated homogeneously. Some of the Co originally adsorbed was later incorporated into precipitate. Slow kaolinite dissolution near neutral pH limited the rate of Co uptake by precipitation, thereby accounting for the slow second stage of Co uptake. Continued changes in solution composition indicate that even this relatively simple system did not reach equilibrium under fixed solution conditions after several months. For this set of conditions, cobalt hydrotalcite appears to be the stable Go-containing phase, and its precipitation can reduce dissolved metal ion concentrations below levels achievable by simple adsorption on kaolinite. Copyright (C) 1999 Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Thompson, HA (reprint author), Univ Calif Los Alamos Natl Lab, MS D469, Los Alamos, NM 87545 USA. NR 54 TC 82 Z9 83 U1 1 U2 16 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 1999 VL 63 IS 11-12 BP 1767 EP 1779 DI 10.1016/S0016-7037(99)00125-8 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 227KT UT WOS:000082080100012 ER PT J AU Renne, PR WoldeGabriel, G Hart, WK Heiken, G White, TD AF Renne, PR WoldeGabriel, G Hart, WK Heiken, G White, TD TI Chronostratigraphy of the Miocene-Pliocene Sagantole Formation, Middle Awash Valley, Afar rift, Ethiopia SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID FOSSIL ELEPHANTOIDS; TIME-SCALE; AR-40/AR-39; HOMINID; AGE; GEOCHRONOLOGY; VOLCANISM; INTERCALIBRATION; AUSTRALOPITHECUS; STRATIGRAPHY AB The Sagantole Formation comprises more than 200 m of lacustrine, alluvial, and volcaniclastic sediments, plus compositionally bimodal tephras and basaltic lavas, exposed in a domelike horst named the Central Awash Complex in the southwestern Afar rift of Ethiopia, The Sagantole Formation is widely known for abundant vertebrate faunas, including the 4.4 Ma primitive hominid Ardipithecus ramidus. New Lithostratigraphic data are used to subdivide the Sagantole Formation into the Kuseralee, Gawto, Haradaso, Aramis, Beidareem, Adgantole, and Belohdelie Members, in ascending order. The members are defined on the basis of lithologic differences and laterally continuous bounding tephras. Ar-40/Ar-39 dating of 12 intercalated volcanic units firmly establishes the age of the Sagantole Formation to be 5.6 to 3.9 Ma, significantly older than previous proposals based on erroneous correlations. Magnetostratigraphic data reveal eight paleomagnetic polarity zones, which can be correlated unambiguously with the Thvera, Sidufjall, Nunivak, and Cochiti Subchrons of the Gilbert Chron, Thus, by reference to the geomagnetic polarity time scale, seven additional chronological datums can be placed in the Sagantole Formation. With a total of 19 such datums, the age resolution anywhere in the Sagantole Formation is better than +/-100 k.y., making this the best-dated Miocene-Pliocene succession in Africa. C1 Berkeley Geochronol Ctr, Berkeley, CA 94709 USA. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Miami Univ, Dept Geol, Oxford, OH 45056 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Lab Human Evolutionary Studies, Museum Vertebrate Zool, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. RP Renne, PR (reprint author), Berkeley Geochronol Ctr, 2455 Ridge Rd, Berkeley, CA 94709 USA. NR 38 TC 66 Z9 68 U1 0 U2 7 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUN PY 1999 VL 111 IS 6 BP 869 EP 885 DI 10.1130/0016-7606(1999)111<0869:COTMPS>2.3.CO;2 PG 17 WC Geosciences, Multidisciplinary SC Geology GA 201KR UT WOS:000080594400006 ER PT J AU Marshak, A Oreopoulos, L Davis, AB AF Marshak, A Oreopoulos, L Davis, AB TI Horizontal radiative fluxes in clouds and accuracy of the Independent Pixel Approximation at absorbing wavelengths SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOCUMULUS CLOUDS; OPTICAL DEPTH; ABSORPTION; ALBEDO AB For absorbing wavelengths, we discuss the effect of horizontal solar radiative fluxes in clouds on the accuracy of a conventional plane-parallel radiative transfer calculation for a single pixel, known as the Independent Pixel Approximation (IPA). Vertically integrated horizontal fluxes can be represented as a sum of three components: the IPA accuracies for reflectance, transmittance and absorptance. We show that IPA accuracy for reflectance always improves with more absorption, while the IPA accuracy for transmittance is less sensitive to the changes in absorption: with respect to the non-absorbing case, it may first deteriorate for weak absorption and then improve again for strongly absorbing wavelengths. IPA accuracy for absorptance always deteriorates with more absorption. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate Radiat Branch, MC 913, Greenbelt, MD 20771 USA. RI Oreopoulos, Lazaros/E-5868-2012; Marshak, Alexander/D-5671-2012 OI Oreopoulos, Lazaros/0000-0001-6061-6905; NR 15 TC 12 Z9 12 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 1 PY 1999 VL 26 IS 11 BP 1585 EP 1588 DI 10.1029/1999GL900306 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 202PG UT WOS:000080660900019 ER PT J AU Quay, P Stutsman, J Wilbur, D Snover, A Dlugokencky, E Brown, T AF Quay, P Stutsman, J Wilbur, D Snover, A Dlugokencky, E Brown, T TI The isotopic composition of atmospheric methane SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID TROPOSPHERIC METHANE; GROWTH-RATE; CARBON; CH4; OXIDATION; OH; C-14; HEMISPHERE; DEPLETION; EMISSIONS AB Measurements of the C-13/C-12, D/H and C-14 composition Of atmospheric methane (CH4) between 1988 and 1995 are presented. The C-13/C-12 measurements represent the first global data set with time series records presented for Point Barrow, Alaska (71 degrees N), Olympic Peninsula, Washington (48 degrees N), Mauna Loa, Hawaii (20 degrees N), American Samoa (14 degrees S), Cape Grim, Australia (41 degrees S), and Baring Head, New Zealand (41 degrees S). North-south trends of the C-13/C-12 and D/H of atmospheric CH4 from air samples collected during oceanographic research cruises in the Pacific Ocean are also presented. The mean annual delta(13)C increased southward from about -47.7 parts per thousand at 71 degrees N to -47.2 parts per thousand at 41 degrees S. The amplitude of the seasonal cycle in delta(13)C ranged from about 0.4 parts per thousand at 71 degrees N to 0.1 parts per thousand at 14 degrees S. The seasonal delta(13)C cycle at sites in tropical latitudes could be explained by CH4 loss via reaction with OH radical, whereas at temperate and polar latitudes in the northern hemisphere seasonal changes in the delta(13)C Of th, CH4 source were needed to explain the seasonal cycle. The higher delta(13)C value in the southern (-47.2 parts per thousand) versus northern (-47.4 parts per thousand) hemisphere was a result of interhemispheric transport of CH4. A slight interannual delta(13)C increase of 0.02+/-0.005 parts per thousand yr(-1) was measured at all sites between 1990 and 1995. The mean delta D of atmospheric CH4 was -86+/-3 parts per thousand between 1989 and 1995 with a 10 parts per thousand depletion in the northern versus southern hemisphere. The C-14 content of CH4 measured at 48 degrees N increased from 122 to 128 percent modern between 1987 and 1995. The proportion of CH4 released from fossil sources was 18+/-9% in the early 1990s as derived from the C-14 content of CH4. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Quay, P (reprint author), Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA. NR 63 TC 187 Z9 192 U1 1 U2 49 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD JUN PY 1999 VL 13 IS 2 BP 445 EP 461 DI 10.1029/1998GB900006 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 213GQ UT WOS:000081264700010 ER PT J AU Vorobiova, MI Degteva, MO Burmistrov, DS Safronova, NG Kozheurov, VP Anspaugh, LR Napier, BA AF Vorobiova, MI Degteva, MO Burmistrov, DS Safronova, NG Kozheurov, VP Anspaugh, LR Napier, BA TI Review of historical monitoring data on Techa River contamination SO HEALTH PHYSICS LA English DT Article DE contamination, environmental; plutonium; exposure, population; monitoring, environmental ID POPULATION AB The Mayak Production Association was the first Russian site for the production and separation of plutonium. The extensive increase in plutonium production during 1948-1955, as well as the absence of reliable waste-management technology, resulted in significant releases of liquid radioactive effluent into the rather small Techa River. This resulted in chronic external and internal exposure of about 30,000 residents of riverside communities; these residents form the cohort of an epidemiologic investigation. Analysis of the available historical monitoring data indicates that the following reliable data sets can be used for reconstruction of doses received during the early periods of operation of the Mayak Production Association: Temporal pattern of specific beta activity of river water for several sites in the upper Techa region since July 1951; average annual values of specific beta activity of river water and bottom sediments as a function of downstream distance for the whole river since 1951; external gamma-exposure rates near the shoreline as a function of downstream distance for the whole Techa River since 1952; and external gamma-exposure rate as a function of distance from the shoreline for several sites in the upper and middle Techa since 1951. C1 Urals Res Ctr Radiat Med, Chelyabinsk, Russia. Univ Utah, Salt Lake City, UT 84112 USA. Pacific NW Natl Lab, Richland, WA USA. NR 35 TC 41 Z9 43 U1 0 U2 3 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 1999 VL 76 IS 6 BP 605 EP 618 DI 10.1097/00004032-199906000-00003 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 196WQ UT WOS:000080331200002 PM 10334576 ER PT J AU Sun, C Lee, D AF Sun, C Lee, D TI Plutonium fecal and urinary excretion functions: Derivation from a systemic whole-body retention function SO HEALTH PHYSICS LA English DT Article DE excretion; fecal; whole body counting; plutonium; bioassay ID MODEL; PU AB Liver-bile secretion directly influences the content of plutonium in feces. To assess the reliability of plutonium metabolic models and to improve the accuracy of interpreting plutonium fecal data, we developed a compartmental model that simulates the metabolism of plutonium in humans. With this model, we can describe the transport of plutonium contaminants in the systemic organs and tissues of the body, including fecal and urine excretions, without using elaborate kinetic information, The parameter values of the models, which describe the translocation rates and recycling of plutonium in the body, can be derived from a multi-term exponential systemic function for whole-body retention. The analytical derivations and algorithms for solving translocation parameter values are established for the model and illustrated by applying them to the biokinetics and bioassay of plutonium. This study describes how to (1) design a physiological model for incorporating liver biliary secretion and for obtaining a fecal-excretion function, (2) develop an analytical solution for identifying the translocation-parameter values incorporating the recycling of plutonium in the body, and (3) derive a set of urinary and fecal excretion-functions from a published systemic whole-body retention function, generally acknowledged to be accurate, as a real and practical example. C1 Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. Korea Inst Nucl Safety, Regulatory Res, Nucl Safety Technol Div, Taejon 305600, South Korea. NR 39 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD JUN PY 1999 VL 76 IS 6 BP 619 EP 627 DI 10.1097/00004032-199906000-00004 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 196WQ UT WOS:000080331200003 PM 10334577 ER PT J AU Anderson, J Kahn, B LaBone, T Brown, L Harris, F AF Anderson, J Kahn, B LaBone, T Brown, L Harris, F TI Solubility of various forms of strontium titanate in lungs: In vitro and in vivo studies SO HEALTH PHYSICS LA English DT Article DE inhalation; Sr-90; lungs, rodent; radioactivity, airborne AB At the In-Tank Precipitation Facility of the Savannah River Site, strontium and other radionuclides are removed from high-level radioactive waste and sent to the Defense Waste Processing Facility, Strontium removal is accomplished by adsorption using a slurry that includes monosodium titan ate, which forms strontium titanate with unknown lung solubility characteristics. The purpose of this study was to determine the solubility of strontium titanate in the form created at the In-Tank Precipitation facility. An in vitro dissolution study was done with a slurry simulant and with several types of strontium titanate, and the results were compared, An in vivo study was also performed with high-fired SrTiO3 in rats. Strontium and titanium were measured by inductively-coupled plasma/atomic emission spectrometry, The data from both studies were used independently to assign the compounds to an absorption type based on criteria specified in ICRP 71. Results of the in vitro studies showed that the Defense Waste Processing Facility simulant should be assigned to Type M and the strontium titanate should be assigned to Type S. Results of the in vivo study verified that SrTiO3 should be assigned to Type S, Lung clearance data of SrTiO3 from rats showed that 85% cleared within the first 24 h and the remaining 15% cleared with a half-time of 130 d, The initial rapid clearance is attributed to deposition in airways as compared to the alveolar region. C1 Georgia Inst Technol, Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. Emory Univ, Dept Pediat, Atlanta, GA 30322 USA. Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. NR 13 TC 3 Z9 3 U1 1 U2 6 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD JUN PY 1999 VL 76 IS 6 BP 628 EP 634 DI 10.1097/00004032-199906000-00005 PG 7 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 196WQ UT WOS:000080331200004 PM 10334578 ER PT J AU Scarpitta, S Odin-McCabe, J Gaschott, R Meier, A Klug, E AF Scarpitta, S Odin-McCabe, J Gaschott, R Meier, A Klug, E TI Comparison of four Sr-90 groundwater analytical methods SO HEALTH PHYSICS LA English DT Article DE Sr-90; groundwater; sampling; liquid scintillation AB Data are presented for 45 Long Island groundwater samples each measured for Sr-90 using four different analytical methods. Sr-90 levels were first established by two New York State certified laboratories, one of which used the U.S. Environmental Protection Agency Radioactive Strontium in Drinking Water Method 905.0. Three of the Sr-90 methods evaluated at Brookhaven National Laboratory can reduce analysis time by more than 50%. They were (a) an Environmental Measurements Laboratory Cerenkov technique and (b) two commercially available products that utilize strontium-specific crown-ethers supported on either a resin or membrane disk. Method independent inter-laboratory bias was <12% based on Sr-90 results obtained using both U.S, Department of Energy/Environmental Measurements Laboratory and U.S. EPA/National Environmental Radiation Laboratory samples of known activity concentration. Brookhaven National Laboratory prepared a National Institute of Standards and Technology traceable Sr-90 tap-water sample used to quantify test method biases. With gas proportional or liquid scintillation counting, minimum detectable levels (MDLs) of 37 Bq m(-3) (1 pCi L-1) were achievable for both crown-ether methods using a l-L processed sample beta counted for 1 h, The primary radiological contaminants of the Brookhaven National Laboratory groundwater samples were H-3 (14.8-518 kBq m(-3)) and Sr-90/Y (37 Bq m(-3)-18.5 kBq m(-3)). Thirty samples were above the U.S. EPA drinking water standard of 300 Bq m(-3) for beta emitting Sr-90, Regression of paired data sets show ed that both crown-ether methods quantified Sr-90 levels to within 5% of the "EPA method results" for samples greater than the drinking water standard and within 30-40% for samples less than the drinking water standard. The Cerenkov method, with a minimum detectable level of 150 Bq m(-3), was only useful for samples greater than the drinking water standard and underestimated Sr-90 levels by 13%. Precision, as measured by the relative percent difference and mean difference statistics, was acceptable for both crown-ether methods when compared to the paired "EPA method" results. Cerenkov method precision exceeded predefined acceptance criteria for 12 of 33 samples analyzed. C1 Brookhaven Natl Lab, Analyt Serv, Upton, NY 11973 USA. NR 23 TC 12 Z9 14 U1 0 U2 3 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 1999 VL 76 IS 6 BP 644 EP 656 DI 10.1097/00004032-199906000-00008 PG 13 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 196WQ UT WOS:000080331200007 PM 10334581 ER PT J AU Myers, OB AF Myers, OB TI On aggregating species for risk assessment SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE exposure assessment; exposure guilds; multivariate analysis; pinon-juniper woodlands AB Different combinations of species characteristics like dietary strategies and foraging tactics define unique pathways for material cycling and energy flow in ecosystems. I used multivariate cluster analysis on a species attribute matrix to identify groups of species with similar vulnerabilities of exposure to contaminants. The clusters of species may also have similar functions in ecosystems, because they use similar resources in similar ways. Cluster analyses produced hierarchical dendrograms of species relationships that were difficult to characterize with simple labels like herbivore or insectivore. Regardless of whether multivariate analyses are used for aggregating species into exposure guilds, the species attribute matrix is a concise statement of assumptions about how species function in ecosystems. By using species characteristics to aggregate and define assessments, it is hoped that assessment endpoints will be ecologically relevant. C1 Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Los Alamos, NM 87545 USA. RP Myers, OB (reprint author), Univ Calif Los Alamos Natl Lab, Environm Sci Grp, MS J495, Los Alamos, NM 87545 USA. RI Myers, Orrin/F-1130-2010 NR 13 TC 2 Z9 4 U1 1 U2 2 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD JUN PY 1999 VL 5 IS 3 BP 559 EP 574 DI 10.1080/10807039991289536 PG 16 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 213RL UT WOS:000081287000011 ER PT J AU Young, RA Opresko, DM Watson, AP Ross, RH King, J Choudhury, H AF Young, RA Opresko, DM Watson, AP Ross, RH King, J Choudhury, H TI Deriving toxicity values for organophosphate nerve agents: A position paper in support of the procedures and rationale for deriving oral RfDs for chemical warfare nerve agents SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Review DE sarin; soman; tabun; VX; cholinesterase inhibitor; anticholinesterase ID ORGANO-PHOSPHATE; CHOLINESTERASE ACTIVITY; SOMAN TOXICITY; ACETYLCHOLINE-RECEPTORS; MUSCARINIC RECEPTORS; REPETITIVE INJECTION; BEHAVIORAL TOXICITY; 4 STEREOISOMERS; RAT; SARIN AB During the process of deriving oral Reference Dose (RfDs) values for chemical warfare agents, several issues arose regarding the identification of adverse effect levels and the application of uncertainty factors. For those agents that function as cholinesterase inhibitors (e.g., agents VX, GA, GB, and GD), these issues included the following: (1) Is the endpoint of blood cholinesterase inhibition an indicator of toxicity or a biomarker of exposure? (2) Can an experimental animal species be more sensitive than humans, thereby eliminating the need for an animal-to-human uncertainty factor? (3) Can the uncertainty factor that is used to extrapolate from a lowest-observed adverse-effect-level (LOAEL) to a no-observed-adverse-effect-level (NOAEL) be less than the default value of 10? (4) Can an oral RfD be derived from non-oral toxicity data? (5) Can an uncertainty factor of less than 10 be used to extrapolate from subchronic to chronic exposure (i.e., is the critical effect adequately described by the subchronic exposure data)? (6) What constitutes an adequate data base for organophosphate cholinesterase inhibitors, and what uncertainty factor should be used for an incomplete data base? Analysis of relevant data resulted in the following selection and justifications of uncertainty factors. For uncertainty associated with intraspecies extrapolation (UFH), physiologic and pathologic conditions affecting cholinesterase activity levels justified maintaining a UFH of 10 for all of the nerve agents. Because available data indicated that humans tended to be more sensitive than rats regarding anticholinesterase effects, an interspecies variability (UFA) factor of 10 was retained for agents GA, GB, and GD. For agent VX, however, the available data revealed that the domestic sheep test species exhibited sensitivity equivalent to or greater than that of humans thereby justifying a UFA of 1. For uncertainties regarding extrapolation from subchronic-to-chronic exposure data, consideration of information on the physiology of cholinergic systems and the available toxicity data for the nerve agents and other cholinesterase inhibitors indicated that a UFS of 3 was justified for all four of the nerve agents. For uncertainties regarding LOAEL-to-NOAEL extrapolation (UFL), the selection of agent GB, GD, and VX doses resulting in cholinesterase inhibition in the absence of clinical signs of toxicity (biomarker of exposure) justified this endpoint as a minimal LOAEL and a UFL of 3. For agent GA, a NOAEL was used, and therefore no UFL was required. The uncertainty factor for data base completeness (UFD),was based upon several considerations. Of primary concern was the fact that chronic toxicity studies are not considered an essential component of the data base requirements for cholinesterase inhibitors because of the unlikelihood that the endpoint will change with an increase in exposure time beyond that defined as a subchronic exposure. Additionally, limited data regarding reproductive and developmental toxicity were not considered to represent critical toxicity endpoints for the nerve agents or cholinesterase inhibitors in general. Although the data base for agents GA, GB, and GD were lacking reproductive and developmental toxicity data to some extent, a UFD of 3 was justified for the aforementioned reasons. The data base for agent VX was considered complete and a UFD of 1 was selected for development of the RfD for this agent. A modifying factor (MF) to reflect qualitative assessment of additional uncertainties in the critical study or data base that are not addressed by uncertainty factors was limited to agent GA due to the route-to-route (i.e., intraperitoneal to oral) extrapolation and to insure the equivalent oral NOAEL was not overestimated. This article provides a brief overview of the nerve agents, information on cholinergic systems that is pertinent to deriving toxicity values for nerve agents and other organophosphate cholinesterase inhibitors, and a discussion of key issues regarding the use of uncertainty factors in RfD derivations. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. USA, Ctr Environm, Aberdeen Proving Ground, MD USA. US EPA, Natl Ctr Environm Assessment, Cincinnati, OH 45268 USA. RP Young, RA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. NR 142 TC 8 Z9 8 U1 0 U2 7 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD JUN PY 1999 VL 5 IS 3 BP 589 EP 634 DI 10.1080/10807039991289554 PG 46 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 213RL UT WOS:000081287000013 ER PT J AU Maurice, D Hawk, JA AF Maurice, D Hawk, JA TI Ferric chloride leaching of a mechanically activated pentlandite-chalcopyrite concentrate SO HYDROMETALLURGY LA English DT Article DE ferric chloride; pentlandite-chalcopyrite concentrate; mechanical activation ID SULFATE; MEDIA AB Mechanical activation accelerates the leaching of non-ferrous metals from sulfide ores by increasing the surface area and reactivity of the concentrate, and through lattice distortions resulting from deformation due to milling. In this study we examine the feasibility of applying the process to a complex ore concentrate containing both pentlandite and chalcopyrite through the use of a horizontal ball mill for the mechanical activation of chalcopyrite, using a concentrated (similar to 5 M Cl-) ferric chloride solution for the leaching. The kinetics of dissolution are correlated with specific area and with line broadening as determined by X-ray diffraction. Mechanical activation improves the kinetics both of copper extraction from the chalcopyrite, and of nickel extraction from the pentlandite. As both leached readily using the ferric chloride solution, selective leaching using this lixiviant does not seem feasible. (C) 1999 Elsevier Science B.V. All rights reserved. C1 US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. RP Maurice, D (reprint author), US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. NR 10 TC 18 Z9 18 U1 3 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-386X J9 HYDROMETALLURGY JI Hydrometallurgy PD JUN PY 1999 VL 52 IS 3 BP 289 EP 312 DI 10.1016/S0304-386X(99)00021-3 PG 24 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 217AA UT WOS:000081475600006 ER PT J AU Gibbard, SG Macintosh, B Gavel, D Max, CE de Pater, I Ghez, AM Young, EF McKay, CP AF Gibbard, SG Macintosh, B Gavel, D Max, CE de Pater, I Ghez, AM Young, EF McKay, CP TI Titan: High-resolution speckle images from the Keck Telescope SO ICARUS LA English DT Article DE Titan; infrared observations; surfaces, satellite ID TRIPLE CORRELATION; GEOMETRIC ALBEDO; BINARY STARS; MU-M; ATMOSPHERE; AEROSOLS; SURFACE; MODEL; SATELLITES; RECOVERY AB Saturn's large moon Titan is unique among planetary satellites in that it possesses a thick atmosphere and a haze layer that is opaque to visible light. This haze is believed to be composed of organic compounds produced by the photolysis of methane. It has been suggested that the photochemical products of methane photolysis, primarily ethane, would "rain out" over time and may produce reservoirs of liquid hydrocarbons on Titan's surface. Such material would appear very dark, with an albedo less than or equal to 0.02 (Khare et al. 1990, Bull. Am. Astron, Sec. 22, 1033). Such low-albedo regions have not been previously detected on Titan's surface. Here we report observations of Titan at a resolution of 0.04 arcsec (0.02 arcsec/pixel) using the technique of speckle imaging from the 10-m Keck I Telescope. By observing Titan at specific infrared wavelengths which are windows through its atmosphere, we have made both an albedo map of Titan's surface at 1.6 and 2.1 mu m and an estimate of Titan's haze optical depth at these wavelengths. We clearly distinguish low-albedo features (reflectance <0.05) on Titan's surface. (C) 1999 Academic Press. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. SW Res Inst, Boulder, CO USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gibbard, SG (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. EM sgibbard@beowulf.llnl.gov OI Max, Claire/0000-0003-0682-5436 NR 50 TC 63 Z9 63 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUN PY 1999 VL 139 IS 2 BP 189 EP 201 DI 10.1006/icar.1999.6095 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216XJ UT WOS:000081469500003 ER PT J AU Gibbard, SG Levy, EH Lunine, JI de Pater, I AF Gibbard, SG Levy, EH Lunine, JI de Pater, I TI Lightning on Neptune SO ICARUS LA English DT Article DE Neptune; electromagnetic processes; lightning ID ICE CRYSTAL INTERACTIONS; THUNDERSTORM ELECTRIFICATION; ELECTROSTATIC DISCHARGES; LABORATORY MEASUREMENTS; MOIST CONVECTION; CHARGE-TRANSFER; VOYAGER-2; MAGNETOSPHERE; ATMOSPHERE; JUPITER AB Electrostatic discharges in planetary atmospheres appear to be common throughout the Solar System, occurring on Earth, Jupiter, Saturn, Uranus, and possibly Venus and Neptune, Lightning is generally caused by the separation of electric charge on precipitating particles and therefore requires the presence of condensed cloud layers. Neptune has several cloud layers, including a high-altitude methane cloud, a H(2)S-NH(3) layer, and deeper layers of water and ammonium hydrosulfide (NH(4)SH). Neptune appears to be a good candidate for lightning and other dynamic atmospheric phenomena because of its large internal heat source. Despite the presence of radio-frequency whistlers often associated with lightning, lightning has never been optically detected on Neptune, This may indicate that lightning is occurring too deep in the atmosphere to be seen at visible wavelengths. We investigate the possibility of lightning on Neptune using a particle-growth and charge-separation model that has previously been successfully applied to the Earth and Jupiter. We find that lightning is inhibited in the deep water or NH(4)SH cloud because of the high atmospheric pressures there; lightning seems possible in the H(2)S-NH(3) cloud provided that transfer of charge can occur at a rate not less than 1% of that seen in water ice collisions, (C) 1999 Academic Press. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Gibbard, SG (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM sgibbard@beowulf.llnl.gov NR 40 TC 9 Z9 9 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD JUN PY 1999 VL 139 IS 2 BP 227 EP 234 DI 10.1006/icar.1999.6101 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 216XJ UT WOS:000081469500006 ER PT J AU Paxson, V AF Paxson, V TI End-to-end internet packet dynamics SO IEEE-ACM TRANSACTIONS ON NETWORKING LA English DT Article DE computer networks; computer network performance; computer network reliability; failure analysis; internet-working; stability AB We discuss findings from a large-scale study of Internet packet dynamics conducted by tracing 20 000 TCP bulk transfers between 35 Internet sites. Because we traced each 100-kbyte transfer at both the sender and the receiver, the measurements allow us to distinguish between the end-to-end behaviors due to the different directions of the Internet paths, which often exhibit asymmetries. We: 1) characterize the prevalence of unusual network events such as out-of-order delivery and packet replication; 2) discuss a robust receiver-based algorithm for estimating "bottleneck bandwidth" that addresses deficiencies discovered in techniques based on "packet pair;" 3) investigate patterns of packet loss, finding that loss events are not well modeled as independent and, furthermore, that the distribution of the duration of loss events exhibits infinite variance; and 4) analyze variations in packet transit delays as indicators of congestion periods, finding that congestion periods also span a wide range of time scales. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Network Res Grp, Berkeley, CA 94720 USA. RP Paxson, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Network Res Grp, Berkeley, CA 94720 USA. NR 27 TC 332 Z9 360 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1063-6692 J9 IEEE ACM T NETWORK JI IEEE-ACM Trans. Netw. PD JUN PY 1999 VL 7 IS 3 BP 277 EP 292 DI 10.1109/90.779192 PG 16 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 219VC UT WOS:000081627000001 ER PT J AU Cuttino, JF Miller, AC Schinstock, DE AF Cuttino, JF Miller, AC Schinstock, DE TI Performance optimization of a fast tool servo for single-point diamond turning machines SO IEEE-ASME TRANSACTIONS ON MECHATRONICS LA English DT Article DE anamorphic optics; diamond turning; diamond turning machine; fast tool servo; precision actuator; single-point diamond turning; ultraprecision control system AB This paper describes a new, fast tool servo system designed for fabrication of nonrotationally symmetric components using single-point diamond turning machines. A prototype device, designed for flexible interfacing to typical machine tool controllers, is described, along with performance testing data of tilted flat and off-axis conic sections. Techniques for controlling the piezoelectric actuator to less than 1% error are discussed. The performance of a standard integral controller shows a significant error due to hysteresis in the actuator. The effects of the hysteresis were reduced by implementing two control schemes, an optimized proportional, integral, derivative controller and a technique that utilizes a dynamic compensator module in conjunction with the linear controller. The compensator samples the hysteretic voltage/displacement relationship in real time and modifies the effective gain accordingly. Simulation results indicate that errors in the performance of the system caused by hysteresis in the system can be compensated and reduced by 90%. Experimental implementation results in an 80% reduction in the motion error caused by hysteresis, but peak-to-valley errors are limited by side effects from the compensation. C1 Univ Alabama, Metrol & Precis Engn Lab, Tuscaloosa, AL 35487 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tulsa, Dept Mech Engn, Tulsa, OK 74104 USA. RP Cuttino, JF (reprint author), Univ Alabama, Metrol & Precis Engn Lab, Tuscaloosa, AL 35487 USA. NR 10 TC 60 Z9 64 U1 6 U2 31 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1083-4435 J9 IEEE-ASME T MECH JI IEEE-ASME Trans. Mechatron. PD JUN PY 1999 VL 4 IS 2 BP 169 EP 179 DI 10.1109/3516.769543 PG 11 WC Automation & Control Systems; Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical SC Automation & Control Systems; Engineering GA 207YU UT WOS:000080964000007 ER PT J AU Dietderich, DR Scanlan, RM Walsh, RP Miller, JR AF Dietderich, DR Scanlan, RM Walsh, RP Miller, JR TI Critical current of superconducting Rutherford cable in high magnetic fields with transverse pressure SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID STRAIN AB For high energy physics applications superconducting cables are subjected to large stresses and high magnetic fields during service. It is essential to know how these cables perform under these operating conditions, A loading fixture capable of applying loads of up to 700kN has been developed by NHMFL for LBNL, This fixture permits uniform loading of straight cables over a 122 mm length in a split-pair solenoid in fields up to 12 T at 4.2 K, The first results from this system for Rutherford cables of internal-tin and modified jelly roll strand of Nb3Sn produced by IGC and TWC showed that little permanent degradation occurs up to 210 MPa. However, the cable made from internal-tin strand showed a 40 % reduction in I-c at 11T and 210 MPa while a cable made from modified jelly roll material showed only a 15 % reduction in I-c at 11T and 185 MPa. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Natl High Magnet Field Lab, Tallahassee, FL 32706 USA. RP Dietderich, DR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 8 TC 20 Z9 20 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 122 EP 125 DI 10.1109/77.783251 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100004 ER PT J AU Demko, JA Lue, JW Sinha, U Hughey, RL Dresner, L Olsen, SK AF Demko, JA Lue, JW Sinha, U Hughey, RL Dresner, L Olsen, SK TI Testing of the dependence of the number of layers on the performance of a one-meter HTS transmission cable section SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID POWER-LAW CRYOCONDUCTORS; HYSTERESIS LOSSES AB A one-meter long prototype transmission cable was constructed by Southwire Company consisting of four layers of helically wound Bi-2223/Ag HTS tapes. Measurements were made at Oak Ridge National Laboratory of the dc V-I characteristics and ac loss of the as received cable and after sequentially stripping the outermost layer so that a series of measurements for four-, three-, two-, and one-layer cables were completed, The differences in the cable performance could then be compared with existing theories. In its initial four-layer configuration the measured critical current was over 1500 A. After the removal of the outermost layer to form a three-layer cable, the critical current dropped to 881 A. The performance degradation that was measured is not in direct proportion to the number of tapes in the cable, The dc V-I characteristic curve, critical current, and ac losses are reported for each configuration. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Southwire Co, Carrollton, GA USA. Tech Univ Denmark, DK-2800 Lyngby, Denmark. RP Demko, JA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 7 TC 7 Z9 7 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 126 EP 129 DI 10.1109/77.783252 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100005 ER PT J AU Scanlan, RM Dietderich, DR Higley, HC Marken, KR Motowidlo, LR Sokolowski, R Hasegawa, T AF Scanlan, RM Dietderich, DR Higley, HC Marken, KR Motowidlo, LR Sokolowski, R Hasegawa, T TI Fabrication and test results for Rutherford-type cables made from BSCCO strands SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Wires based on the Bi-2212 HTS superconductor are becoming available commercially, with current densities that are attractive for some applications. We report here on our success in using these Bi-2212 wires to fabricate multistrand, kiloamp conductors that can be used to construct dipole and quadrupole magnets for particle accelerator applications. Multistrand cables have been made from several types of Bi-2212 wire supplied by two manufacturers. These cables were made with cores of various compositions and dimensions in order to optimize the fabrication process. In addition, cables have been made from aspected strands as well as round strands. Cable critical currents will be reported and compared for the various cable parameters investigated in this study. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Oxford Supercond Technol, Carteret, NJ USA. Intermagnet Gen Corp, Waterbury, CT USA. Showa Elect Wire & Cable, Kawasaki, Kanagawa, Japan. RP Scanlan, RM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 2 TC 32 Z9 32 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 130 EP 133 DI 10.1109/77.783253 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100006 ER PT J AU Gouge, MJ Demko, JA Lue, JW Stovall, JP Hughey, RL Martin, R Sinha, U AF Gouge, MJ Demko, JA Lue, JW Stovall, JP Hughey, RL Martin, R Sinha, U TI HTS cable test facility: Design and initial results SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A versatile, high-temperature superconducting (HTS) cable test facility has been designed and assembled at Oak Ridge National Laboratory (ORNL) in a joint program between ORNL and Southwire Company. The facility mission is to evaluate the performance of prototype HTS power transmission cables at lengths in the range of 1 to 5+ m, Power supplies are available for steady-state currents of 3,000 A (dc) and 2,000 A (ac) as well as up to 25,000 A (dc) for pulsed loading. Cryogenic cooling is provided by an Air Products liquid nitrogen supply system with the capability of providing about a kilowatt of cooling at pressures up to 10 bar over a temperature range of about 67 to 77 K, Electrical and cryogenic data are taken by dedicated sensors scanned by ten-channel multimeters connected via cable and fiber optic to a personal-computer-based, data acquisition system using the LabVIEW program. These diagnostics allow measurement of the dc V-I characteristics and ac loss of the cable, dielectric integrity via a partial discharge measurement, and cryogenic performance at rated voltage (7.2-kV ac) and current (1250 A). Initial results from facility commissioning and early HTS cable testing are reported. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Southwire Co, Carrollton, GA USA. RP Gouge, MJ (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 4 TC 9 Z9 11 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 134 EP 137 DI 10.1109/77.783254 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100007 ER PT J AU Walsh, RP Miller, JR O'Connor, TG AF Walsh, RP Miller, JR O'Connor, TG TI Critical current measurements on large conductors of niobium-titanium/copper cable embedded in an aluminum stabilizer SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Insertion of a flat, Rutherford type, cable of NbTi/Cu composite strands into a rectangular profile of high purity aluminum is an established method of superconductor fabrication for certain applications. Although this processing scheme has numerous advantages it produces a composite material whose properties are difficult to predict with precision. The BABAR detector magnet currently being tested at the Stanford Linear Accelerator Center, uses high-purity aluminum stabilized superconducting cable, The performance of the superconductor is dependent on the quality of the fabrication of the composite conductor. Here we present measurements of the critical transport current of BABAR production grade conductors up to 10 kA, and at fields up to 10 T, Data are related to production variables, compared to estimates From simple models, and evaluated with respect to design specifications. C1 Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Walsh, RP (reprint author), Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. NR 2 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 146 EP 148 DI 10.1109/77.783257 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100010 ER PT J AU Michael, PC Gung, CY Jayakumar, R Minervini, JV Martovetsky, NN AF Michael, PC Gung, CY Jayakumar, R Minervini, JV Martovetsky, NN TI Qualification of joints for the inner module of the ITER CS model coil SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID DESIGN; FIELD AB The US-ITER home team has constructed a prototype, low-loss, low-resistance lap joint sample using materials, fabrication techniques, machine tooling, and quality assurance procedures identical to those for the layer-to-layer joints in the inner module of the ITER Central Solenoid Model Coil. The joint sample was tested at the MIT Pulse Test Facility to 50kA current, in both parallel and transverse time-varying fields at ramp rates from 0.05 to 1.5T/s and background induction to 4T, to qualify its performance subject to ITER-relevant operating conditions. The joint shows dc resistance below 2.5 nOh and pulsed, transverse field losses for a 1.5s ramp at 0.4T/s below 90J; bot values are well within target limits for the ITER-CS joints. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Michael, PC (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. OI Michael, Philip/0000-0003-4906-6169 NR 9 TC 5 Z9 5 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 201 EP 204 DI 10.1109/77.783271 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100024 ER PT J AU Chow, KP Millos, GA AF Chow, KP Millos, GA TI Measurements of modulus of elasticity and thermal contraction of epoxy impregnated niobium-tin and niobium-titanium composites SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB In the high field magnet program at Lawrence Berkeley National Laboratory, accelerator magnet prototypes are designed with epoxy impregnated niobium-tin and niobium-titanium superconductor, Accurate mechanical property values are essential for magnet mechanical design and prediction of conductor performance. Two key mean property values are measured on coil samples: modulus of elasticity (Young's modulus) and mean thermal contraction, Measurements are made in compression and are conducted in three orthogonal directions, Modulus of elasticity measurements are currently conducted at room temperature and the mean thermal contraction is measured from room temperature to liquid nitrogen temperature. Room temperature values are compared with values estimated using the individual coil components. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Chow, KP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 5 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 213 EP 215 DI 10.1109/77.783274 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100027 ER PT J AU Ghosh, AK Sampson, WB Bauer, P Oberli, L AF Ghosh, AK Sampson, WB Bauer, P Oberli, L TI Minimum Quench Energy measurements on single strands for LHC main magnets SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID RUTHERFORD CABLES; WIRES AB 3The stability of magnet conductors can be characterized by their Minimum Quench Energies (MQE), i.e. the minimum energy pulse of small extent and short duration needed to initiate a quench. The MQE of a considerable number of prototype strands for the superconducting LHC magnets have been measured at BNL within the framework of the US-CERN accelerator collaboration. The main interest of this work was to study the effect of different strand designs, copper to superconductor ratios (Cu/Sc) and the source of the niobium-titanium alloy on MQE. Although MQE varied significantly between the strands, the measurements revealed that except for Cu/Sc ratio, these above stated parameters do not affect MQE in a consistent way. Numerical simulations indicate, that these tests made with a restricted helium volume and heat exchange surface were quasi-adiabatic in nature, and hence the influence of the cooling even in superfluid helium was minimal. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. CERN, CH-1211 Geneva 23, Switzerland. RP Ghosh, AK (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 5 TC 5 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 252 EP 256 DI 10.1109/77.783284 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100037 ER PT J AU Ghosh, AK Prodell, A Sampson, WB Scanlan, RM Leroy, D Oberli, LR AF Ghosh, AK Prodell, A Sampson, WB Scanlan, RM Leroy, D Oberli, LR TI Minimum Quench Energy measurements on prototype LHC inner cables in normal helium at 4.4 K and in superfluid He at 1.9 K SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID RUTHERFORD CABLES; WIRES AB The minimum energy of short duration (MQE) required to quench superconducting cables at fixed field for currents close to the critical current has been measured for several prototype LHC inner type cables. Measurements done both in normal helium at 4.4 K and also in superfluid helium at 1.9 K show that the level of cable compaction has a substantial effect on the conductor stability. It also appears that another parameter that significantly influences the ability of the conductor to absorb transient energy pulses is the inter-strand resistance, which can vary greatly depending on the cable design and the nature of the strand surface. This parameter seems to make a bigger difference to MQE at 1.9 K than at 4.4 K, Details of these measurements are presented. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. CERN, CH-1211 Geneva, Switzerland. RP Ghosh, AK (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 257 EP 260 DI 10.1109/77.783285 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100038 ER PT J AU Chan, KCD AF Chan, KCD TI Application of RF superconductivity to a high-current linac SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB In 1997, Los Alamos National Laboratory (LANL) initiated a development program for high-current, superconducting, proton-linac technology to build prototype components of this linac and demonstrate the feasibility. Seven hundred-MHz niobium cavities with elliptical shapes are being built, as well as power couplers to transfer high RF power to these cavities. The cavities and power couplers will be integrated in cryostats as linac cryomodules. This paper describes the linac design and the status of the development program. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chan, KCD (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 282 EP 284 DI 10.1109/77.783290 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100043 ER PT J AU Sampson, WB Ghosh, AK AF Sampson, WB Ghosh, AK TI The performance of BSCCO racetrack coils at 4.2 K SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Small racetrack shaped coils have been fabricated from commercial 2223 and 2212 BSCCO tapes conductors and tested in liquid helium at 4.2 K. These coils are insulated with Kapton film and provided with an array of voltage taps so that the characteristics of both straight and curved elements can be examined at various positions in the windings. The performance of the coils is compared to short sample measurements of the conductor. These small coils are prototypes of longer units which will be used in a test magnet designed to explore the potential of high temperature materials for the construction of dipoles and quadrupoles for future high energy accelerators and colliders. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sampson, WB (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 1 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 289 EP 292 DI 10.1109/77.783292 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100045 ER PT J AU Manlief, MD Picard, H Snitchler, G Ghosh, AK Harrison, M Sampson, WB Wanderer, P Dugan, G Rogers, J Temnykh, A Brandt, JS Limon, PJ Sood, RC AF Manlief, MD Picard, H Snitchler, G Ghosh, AK Harrison, M Sampson, WB Wanderer, P Dugan, G Rogers, J Temnykh, A Brandt, JS Limon, PJ Sood, RC TI The performance of Bi-Sr-Ca-Cu-O superconducting quadrupole coils SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A small saddle coil for quadrupole magnets was made in industry from BSCCO-2223 high temperature superconducting tape. The coil was made to help develop methods for winding the ends of small-aperture magnets. This coil has a radius of 35 mm. It was tested in liquid helium, and liquid nitrogen. Voltage taps have been installed so that V-I characteristics of both straight and curved elements can be examined. The performance of the coil will be compared to short sample measurements of pieces of conductor taken from the start and finish of the windings. C1 Amer Supercond Corp, Westborough, MA 01581 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Cornell Univ, Nucl Studies Lab, Ithaca, NY 14853 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Manlief, MD (reprint author), Amer Supercond Corp, Westborough, MA 01581 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 293 EP 296 DI 10.1109/77.783293 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100046 ER PT J AU Mulcahy, TM Hull, JR Uherka, KL Niemann, RC Abboud, RG Juna, JP Lockwood, JA AF Mulcahy, TM Hull, JR Uherka, KL Niemann, RC Abboud, RG Juna, JP Lockwood, JA TI Flywheel energy storage advances using HTS bearings SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID SUPERCONDUCTING MAGNETIC BEARINGS AB High-temperature-superconducting (HTS) bearings have the potential to reduce rotor idling losses and make flywheel energy storage economical. Demonstration of large, high-speed flywheels is key to market penetration. Toward this goal, we have developed and tested a flywheel system with 5- to 15-kg disk-shaped rotors. Rim speeds exceeded 400 m/s, and stored energies were >80 Wh. Test implementation required technological advances in nearly all aspects of the flywheel system. Features and limitations of the design and tests are discussed, especially those related to achieving greater energy storage levels. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Commonwealth Res Corp, Chicago, IL 60690 USA. RP Mulcahy, TM (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 20 Z9 23 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 297 EP 300 DI 10.1109/77.783294 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100047 ER PT J AU Green, MA Taylor, CE AF Green, MA Taylor, CE TI Three dimensional field calculations for a short superconducting dipole for the UCLA Ultra Compact Synchrotron SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The Ultra Compact Synchrotron (UCS), proposed for UCLA, is a compact 1.5 GeV electron light source with superconducting magnets to produce X rays with a critical energy of about 10 keV, The design physical length (cold length) for the dipole is 418 mm, The synchrotron requires that a uniform field be produced in a region that is 180 mm wide by 40 mm high by about 380 mm long. The end regions of the dipole should be short compared to the overall length of the dipole field region. A Vobly H type of dipole was selected for the synchrotron bending magnets. In order;for each dipole to bend a 1.5 GeV electron beam 30 degrees, the central induction must be in the range of 6.4 to 6.9 T (depending on the dipole magnetic length). The pole width for the dipole was set so that over 90 percent of the X rays generated by the magnet can be extracted. The three dimensional field calculations were done using TOSCA. This report shows that a Vobly type of dipole will behave magnetically as a conventional water cooled iron dominated dipole, The uniformity of the integrated magnetic field can be controlled by varying the current in the shield coil with respect to the gap and cross-over coils. The two dimensional field in the center of the magnet can be tuned to be very uniform over a width of 110 to 120 mm. The three dimensional calculations show that the magnetic length along a particle track in the dipole is about 29 mm longer than the length of the iron pole pieces. This report will present the three dimensional design of the UCS Vobly dipole and the results of the field calculations for that magnet. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Green, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 370 EP 373 DI 10.1109/77.783312 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100065 ER PT J AU Bossert, R Brandt, J DiMarco, J Lamm, MJ Nobrega, F Sabbi, G Schlabach, P Sylvester, C Tartaglia, MA Tompkins, JC Zlobin, AV AF Bossert, R Brandt, J DiMarco, J Lamm, MJ Nobrega, F Sabbi, G Schlabach, P Sylvester, C Tartaglia, MA Tompkins, JC Zlobin, AV TI Magnetic measurements of the Fermilab high gradient quadrupoles for the LHC interaction regions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Three short models of the MQXB quadrupole magnet for the LHC interaction regions have been built and tested at Fermilab. In this paper we present the magnetic field measurement results and compare them with expectations based on as-built dimensional parameters and with a preliminary table of field quality requirements. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. RP Bossert, R (reprint author), Fermi Natl Accelerator Lab, 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 374 EP 377 DI 10.1109/77.783313 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100066 ER PT J AU Hull, JR Mulcahy, TH AF Hull, JR Mulcahy, TH TI Gravimeter using high-temperature superconducting bearing SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID MAGNETIC-LEVITATION; DEPENDENCE; SUSPENSION; STIFFNESS AB We have developed a sensitive gravimeter concept that uses an extremely low-friction bearing based on a permanent magnet (PM) levitated over a high-temperature superconductor (HTS). A mass is attached to the PM by a cantilevered beam, and the combination of PM and HTS forms a bearing platform that has low resistance to rotational motion but high resistance to horizontal, vertical, or tilting motion. The combination acts as a low-loss torsional pendulum that can be operated in any orientation. Gravity acts on the cantilevered beam and attached mass, accelerating them. Variations in gravity can be detected by time-of-flight acceleration, or by a control coil or electrode that would keep the mass stationary. Calculation suggest that the HTS gravimeter would be as sensitive as present-day superconducting gravimeters that must be cooled to liquid helium temperatures, but the HTS gravimeter needs cooling only to liquid nitrogen temperatures. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Hull, JR (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 5 Z9 5 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 390 EP 393 DI 10.1109/77.783317 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100070 ER PT J AU Lue, JW Demko, JA Dresner, L Hughey, RL Sinha, U Tolbert, JC Olsen, SK AF Lue, JW Demko, JA Dresner, L Hughey, RL Sinha, U Tolbert, JC Olsen, SK TI AC losses of prototype HTS transmission cables SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Since 1995 Southwire Company and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested nine, 1-m long, high temperature superconducting (HTS) transmission cable prototypes. This paper summarizes the AC loss measurements of five of the cables not reported elsewhere, and compares the losses with each other and with theory developed by Dresner, Losses were measured with both a calorimetric and an electrical technique. Because of the broad resistive transition of the HTS tapes, the cables can be operated stably beyond their critical currents. The AC losses were measured in this region as well as below critical currents. Dresner's theory takes into account the broad resistive transition of the HTS tapes and calculates the AC losses both below and above the critical current. The two sets of AC loss data agree with each other and with the theory quite well. In particular, at low currents of incomplete penetration, the loss data agree with the theoretical prediction of hysteresis loss based on only the outer two layers carrying the total current. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Southwire Co, Carrollton, GA USA. Tech Univ Denmark, Dept Elect Power Engn, DK-2800 Lyngby, Denmark. RP Lue, JW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 5 TC 10 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 416 EP 419 DI 10.1109/77.783323 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100076 ER PT J AU Bossert, R Chichili, D Feher, S Heger, T Kerby, J Nobrega, A Novitski, I Ozelis, JP Zlobin, AV AF Bossert, R Chichili, D Feher, S Heger, T Kerby, J Nobrega, A Novitski, I Ozelis, JP Zlobin, AV TI Mechanical design and performance of the Fermilab high gradient quadrupole model magnets for the LHC interaction regions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The mechanical design of the Fermilab high gradient quadrupole (HGQ) magnet cold mass is presented, along with its expected behavior and performance under fabrication and operational conditions. Coil stresses, end forces and collared coil diameter measurements obtained during fabrication and cryogenic testing are also presented, and are discussed in the context of expected behavior and feedback into the design. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bossert, R (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 6 TC 2 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 459 EP 462 DI 10.1109/77.783334 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100087 ER PT J AU Caspi, S Bangerter, R Chow, K Faltens, A Gourlay, S Hinkins, R Gupta, R Lee, E McInturff, A Scanlan, R Taylor, C Wolgast, D AF Caspi, S Bangerter, R Chow, K Faltens, A Gourlay, S Hinkins, R Gupta, R Lee, E McInturff, A Scanlan, R Taylor, C Wolgast, D TI A superconducting quadrupole magnet array for a heavy ion fusion driver SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A multi-channel quadrupole array has been proposed to increase beam intensity and reduce space charge effects in a Heavy Ion Fusion Driver. A single array unit composed of several quadrupole magnets, each with its own beam line, will be placed within a ferromagnetic accelerating core whose cost is directly affected by the array size. A large number of focusing arrays will be needed along the accelerating path. The use of a superconducting quadrupole magnet array will increase the field and reduce overall cost. We report here on the design of a compact 3x3 superconducting quadrupole magnet array. The overall array diameter and length including the cryostat is 900x700 mm. Each of the 9 quadrupole magnets has a 79 mm warm bore and an operating gradient of 50 T/m over an effective magnetic length of 320 mm. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Caspi, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 5 TC 3 Z9 3 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 463 EP 466 DI 10.1109/77.783335 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100088 ER PT J AU Taylor, CE Caspi, S Chow, K Lietzke, A Jackson, A Wang, ST Chen, JY AF Taylor, CE Caspi, S Chow, K Lietzke, A Jackson, A Wang, ST Chen, JY TI Test of a high-field bend magnet for the ALS SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB It is possible to replace several of the existing 36 conventional 1.5T, 1 m long bend magnets in the ALS (Advanced Light Source) at LBNL with short, higher field superconducting magnets to produce synchrotron radiation with higher energy. We have built and tested four prototype magnets using different conductors, coil shapes, structural support, and fabrication methods. All reached the required field for bending 1.9 GeV electrons 10 degrees; however, the first three had excessive training. The final design, Superbend 4, reached short-sample current with no training. Construction details, stress analysis, and test results are presented for Superbend 4. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Wang NMR Inc, Livermore, CA USA. RP Taylor, CE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 6 TC 3 Z9 3 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 479 EP 482 DI 10.1109/77.783339 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100092 ER PT J AU Citver, G Barzi, E Burov, A Feher, S Limon, PJ Peterson, T AF Citver, G Barzi, E Burov, A Feher, S Limon, PJ Peterson, T TI Steady state and transient current lead analysis. SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A mathematical model of the gas-cooled, resistive portion of a binary current lead has been developed. An analytical solution of the time-dependent differential equations for the resistive portion of the forced flow cooled current lead is presented which allows one to calculate the evolution of the temperature profile and voltage drop. A comparison of analytical with numerical calculations and a comparison of the calculations with experimental data are given. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Citver, G (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 14 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 515 EP 518 DI 10.1109/77.783348 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100101 ER PT J AU Blumenfeld, PE Prenger, C Roth, EW Stewart, JA AF Blumenfeld, PE Prenger, C Roth, EW Stewart, JA TI High temperature superconducting current lead test facility with heat pipe intercepts SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A high temperature superconducting (HTS) current lead test facility using heat pipe thermal intercepts is under development Pt the Superconductivity Technology Center at Los Alamos National Laboratory, The facility can be configured for tests at currents up to 1000 A Mechanical cryocoolers provide refrigeration to the leads, Electrical isolation is maintained by intercepting thermal energy from the leads through cryogenic heat pipes, HTS lead warm end temperature is variable from 65 K to over 90 K by controlling heat pipe evaporator temperature. Cold end temperature is variable up to 30 K. Performance predictions in terms of heat pipe evaporator temperature as a function of lead current are presented for the initial facility configuration, which supports testing up to 200 A. Measurements are to include temperature and voltage gradient in the conventional and HTS lead sections, temperature distribution and heat transfer rate in the heat pipes, as well as optimum and off-optimum performance of the conventional lead sections. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Blumenfeld, PE (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 527 EP 530 DI 10.1109/77.783351 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100104 ER PT J AU Schwenterly, SW McConnell, BW Demko, JA Fadnek, A Hsu, J List, FA Walker, MS Hazelton, DW Murray, FS Rice, JA Trautwein, CM Shi, X Farrell, RA Bascunan, J Hintz, RE Mehta, SP Aversa, N Ebert, JA Bednar, BA Neder, DJ McIlheran, AA Michel, PC Nemec, JJ Pleva, EF Swenton, AC Swets, W Longsworth, RC Johnson, RC Jones, RH Nelson, JK Degeneff, RC Salon, SJ AF Schwenterly, SW McConnell, BW Demko, JA Fadnek, A Hsu, J List, FA Walker, MS Hazelton, DW Murray, FS Rice, JA Trautwein, CM Shi, X Farrell, RA Bascunan, J Hintz, RE Mehta, SP Aversa, N Ebert, JA Bednar, BA Neder, DJ McIlheran, AA Michel, PC Nemec, JJ Pleva, EF Swenton, AC Swets, W Longsworth, RC Johnson, RC Jones, RH Nelson, JK Degeneff, RC Salon, SJ TI Performance of a 1-MVA HTS demonstration transformer SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB We report on test results for a single-phase, 60-Hz, 13.8 kV/6.9 kV, 1-MVA high temperature superconducting (HTS) transformer which was completed in February, 1998. This transformer models in many ways a full scale section of a 30-MVA HTS commercial transformer design. The transformer windings are cryocooled in the range of 25K and are made with a low-cost, surface-coated BSCCO-2212 conductor. Heat leaks are reduced using a liquid nitrogen thermal ballast and reservoir. The use of high temperature superconductors can substantially reduce transformer losses, weight, size, noise and potential fire and environmental hazards. Designs promise stable operation through faults without thermal degradation, and at temperatures that allow efficient and reliable refrigeration. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Intermagnet Gen Corp, Latham, NY 12110 USA. Waukesha Elect Syst, Waukesha, WI 53186 USA. IGC APD Cryogen, Allentown, PA 18103 USA. Rochester Gas & Elect Co, Rochester, NY 14649 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. RP Schwenterly, SW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 6 TC 38 Z9 42 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 680 EP 684 DI 10.1109/77.783387 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100140 ER PT J AU Kerby, J Zlobin, AV Bossert, R Brandt, J Carson, J Chichili, D Dimarco, J Feher, S Lamm, MJ Limon, PJ Makarov, A Nobrega, F Novitski, I Orris, D Ozelis, JP Robotham, B Sabbi, G Schlabach, P Strait, JB Tartaglia, M Tompkins, JC Caspi, S McInturff, AD Scanlan, R AF Kerby, J Zlobin, AV Bossert, R Brandt, J Carson, J Chichili, D Dimarco, J Feher, S Lamm, MJ Limon, PJ Makarov, A Nobrega, F Novitski, I Orris, D Ozelis, JP Robotham, B Sabbi, G Schlabach, P Strait, JB Tartaglia, M Tompkins, JC Caspi, S McInturff, AD Scanlan, R TI Design, development and test of 2m quadrupole model magnets for the LHC inner triplet SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Fermilab and LBNL are in the midst of a model magnet program to develop and prove the design of quadrupoles for use in the LHC Interaction Region inner triplets. These magnets have a nominal gradient of 205 T/m in a 70 mm bore, and operate in superfluid helium at 1.9 K. The R&D program addresses magnetic, mechanical, thermal design and quench protection issues. This paper describes design, fabrication experience and test results from the first 2 m models. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. RP Kerby, J (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 689 EP 692 DI 10.1109/77.783389 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100142 ER PT J AU Gupta, R Chow, K Dietderich, D Gourlay, S Millos, G McInturff, A Scanlan, R Ramberger, S Russenschuck, S AF Gupta, R Chow, K Dietderich, D Gourlay, S Millos, G McInturff, A Scanlan, R Ramberger, S Russenschuck, S TI A high field magnet design for a future hadron collider SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB US high energy physics community is exploring the possibilities of building a Very Large Hadron Collider (VLHC) after the completion of LHC. This paper presents a high field magnet design option based on Nb3Sn technology. A preliminary magnetic and mechanical design of a 14-16 T, 2-in-1 dipole based on the "common coil design" approach is presented, The computer code ROXIE has been upgraded to perform the field quality optimization of magnets based on the racetrack coil geometry. A magnet R&D program to investigate the issues related to high field magnet designs is also outlined. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CERN, Geneva, Switzerland. RP Gupta, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 701 EP 704 DI 10.1109/77.783392 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100145 ER PT J AU Sumiyoshi, F Kawabata, S Gohda, T Kawagoe, A Shintomi, T Collings, EW Sumption, MD Scanlan, RM AF Sumiyoshi, F Kawabata, S Gohda, T Kawagoe, A Shintomi, T Collings, EW Sumption, MD Scanlan, RM TI AC losses in Nb3Sn Rutherford cables with a stainless steel core SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID COUPLING LOSSES AB Electric measurements of coupling losses in five-layer stacks of Nb3Sn Rutherford cables with a stainless steel (SS) core are made with the applied transverse magnetic-field both normal and parallel to the plane of the cable. For the former (face-on, FO) field case, a one-order reduction of the PO inter strand coupling loss due to the existence of the resistive core is clearly observed. The measured toss for the latter (edge-on, EO) field case is very small, that is, about 1/5000 times as large as the reduced loss. In order to explain these loss properties, two dimensional FEM analysis is carried out taking into account the details of the cable cross-section. The theoretical results show that the FO inter-strand coupling toss in the SS-cored cable is determined mainly by the thickness and conductivity of not only the SS core but also of the outermost bronze region, and that the negligible EO loss corresponds to the intra-strand coupling loss produced in isolated strands due to high surface-resistance of the side-by-side contact. C1 Kagoshima Univ, Kagoshima 890, Japan. High Energy Accelerator Res Org, Tsukuba, Ibaraki, Japan. Ohio State Univ, Columbus, OH 43210 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. RP Sumiyoshi, F (reprint author), Kagoshima Univ, Kagoshima 890, Japan. RI Sumption, Mike/N-5913-2016 OI Sumption, Mike/0000-0002-4243-8380 NR 5 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 731 EP 734 DI 10.1109/77.783399 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100152 ER PT J AU Collings, EW Sumption, MD Scanlan, RM Dietderich, DR Motowidlo, LR AF Collings, EW Sumption, MD Scanlan, RM Dietderich, DR Motowidlo, LR TI Low coupling loss core-strengthened Bi : 2212/Ag Rutherford cables SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CONDUCTORS; FIELDS AB In a comprehensive "vertically integrated" program multifilamentary (MF) high temperature superconducting (HTSC) Bi:2212/Ag strand was fabricated using the powder-in-tube process and heat treated in oxygen by a modified standard procedure. The reaction-heat-treatment (HT) was adjusted to maximize critical current (density), I-c (J(c)), as measured in various magnetic fields, B. A series of Rutherford cables was designed, each of which included a metallic (Nichrome-80) core for strengthening and reduction of coupling loss. Prior to cable winding a series of tests examined the possibility of strand "poisoning" by the core during HT. Small model Rutherford cables were wound, and after HT were prepared for I,(B) measurement and calorimetric measurement of AC loss and hence interstrand contact resistance(ICR). It was deduced that, if in direct contact with the strand during HT, the core material can degrade the I-c of the cable; but steps can be taken to eliminate this problem. Otherwise the core is unequivocally beneficial: the cored Bi:2212/Ag cable is mechanically strong and easy to handle and, from AC-loss results, yields an ICR that when extrapolated to large-hadron-collider (LHC) inner-winding specifications predicts a cable with a fairly satisfactory combination of low coupling loss and stability. C1 Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. Lawrence Berkeley Natl Lab, Superconducting Magnet Grp, Berkeley, CA 94707 USA. IGC Adv Superconductors, Waterbury, CT 06704 USA. RP Collings, EW (reprint author), Ohio State Univ, Dept Mat Sci & Engn, 116 W 19th Ave, Columbus, OH 43210 USA. RI Sumption, Mike/N-5913-2016 OI Sumption, Mike/0000-0002-4243-8380 NR 12 TC 4 Z9 4 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 758 EP 761 DI 10.1109/77.783405 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100158 ER PT J AU Willis, JO Daney, DE Maley, MP Coulter, JY Fleshler, S AF Willis, JO Daney, DE Maley, MP Coulter, JY Fleshler, S TI Single and multi-phase ac losses in HTS prototype power transmission conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Ac losses in several 1-m long high temperature superconductor (HTS) prototype multistrand conductors (PMCs) have been measured with a temperature-difference calorimeter. Both single-phase and three-phase losses were examined with ac currents up to 1000 A rms in the PMC. In addition, "two-phase" losses, with current flowing in the two normal conductor phases but not in the PMC, were also investigated. The calorimeter, designed specifically for these measurements in the liquid nitrogen temperature range, has a precision of 1 mW. The PMCs consist of two layers of helically-wound Bi-2223/Ag sheathed HTS tape, each layer wrapped with opposite pitch. Losses were found to depend on about the third power of the current - a result in agreement with the Bean-Norris model adapted to the double-helix configuration. Increasing either the critical current I-c of the tapes or decreasing the temperature of a PMC at fixed current resulted in decreased single-phase losses, in accord with the model. The three-phase losses indicate a significant interaction between phases and a smaller dependence on tape I-c than expected. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Amer Superconductor Corp, Westborough, MA 01581 USA. RP Willis, JO (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 778 EP 781 DI 10.1109/77.783410 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100163 ER PT J AU Lue, JW Lubell, MS Tomsic, MJ AF Lue, JW Lubell, MS Tomsic, MJ TI AC losses of HTS tapes and bundles with de-coupling barriers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Plastronic Inc. is working on a project for the Ballistic Missile Defense Organization to improve the strength and ac loss characteristics of Bi-based High Temperature Superconductors (HTS) for ac applications like motors, generators, and transmission cables. High strength, high amperage conductor is made by encapsulating bundles of HTS tapes with a non-silver sheath. With this technique, Cu-alloy spacers can be placed between Bi-2223/Ag HTS tapes to decouple the tapes under ac currents. AC losses were measured on conductor bundles with and without Cu-alloy spacers at ac currents up to 70 A and frequencies from 50 to 400 Hz. At frequencies up to about 100 Hg it was found that the bundle with resistive barriers had ac loss equal to the sum of individual tapes as expected from the Norris ellipse model. At higher frequencies, the Cu-alloy barrier was not as effective in reducing the ac loss. For single tapes, Zr-oxide was used to coat the HTS filaments before stacking to form a multifilament tape. AC loss measurements of 6-filament tapes with and without the oxide coating showed little effect of the coating when the loss was normalized to the square of the critical current as the theory suggests. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Plastron Inc, Tipp City, OH USA. RP Lue, JW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 4 TC 4 Z9 4 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 793 EP 796 DI 10.1109/77.783416 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100167 ER PT J AU O'Connor, TG Shen, S Fabbricatore, P Farinon, S Musenich, R Priano, C Bell, RA Berndt, M Burgess, W Craddock, W Keller, L Dormicchi, O Moreschi, P Penco, R Valente, P Valle, N AF O'Connor, TG Shen, S Fabbricatore, P Farinon, S Musenich, R Priano, C Bell, RA Berndt, M Burgess, W Craddock, W Keller, L Dormicchi, O Moreschi, P Penco, R Valente, P Valle, N TI Design and testing of the 1.5 T superconducting solenoid for the BaBar Detector at PEP-II in SLAC SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The 1.5 Tesla superconducting solenoid is part of the BABAR Detector located in the PEP-II B-Factory machine at the Stanford Linear Accelerator Center. The solenoid has a 2.8 m bore acid is 3.7 m long. The two layer solenoid is wound with an aluminum stabilized conductor which is graded axially to produce a +/- 3% field uniformity in the tracking region. The 24 month fabrication, 3 month installation and 1 month commissioning of the solenoid were completed on time and budget. This paper summarizes the culmination of a 3 year design, fabrication and testing program of the BABAR superconducting solenoid, The work was completed by an international collaboration between Ansaldo, INFN, LLNL, and SLAG. Critical current measurements of the superconducting strand, cable and conductor, cool-down, operation with the thermo-siphon cooling, fast and slow discharges, and magnetic forces are discussed in detail. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Ansaldo Energia, Genoa, Italy. RP O'Connor, TG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 847 EP 851 DI 10.1109/77.783429 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100180 ER PT J AU Rode, CH AF Rode, CH CA Jefferson Lab SRF Staff TI Temperature optimization for superconducting cavities SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Since our previous analysis of optimized operating temperature of superconducting cavities in an accelerator a decade ago, significant additional information has been discovered about SRF cavities. The most significant is the Q(0) (quality factor) shift across the Lambda line at higher gradients as a result of a slope in Q(0) vs. E-acc above Lambda. This is a result of the changing heat conduction conditions. We will discuss temperature optimizations as a function of gradient and frequency. The refrigeration hardware impacts and changes in cycle efficiency will be presented. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. RP Rode, CH (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. NR 5 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 873 EP 876 DI 10.1109/77.783435 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100186 ER PT J AU Waynert, JA Daney, DE Prenger, FC AF Waynert, JA Daney, DE Prenger, FC TI Thermal analysis of the APT power coupler and similarities to superconducting magnet current leads SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A detailed thermal analysis has been performed on the 210 kW, 700 MHz RF power coupler (PC) which transfers microwave energy from high power klystrons to the superconducting (SC) resonant cavities for the acceleration of protons. The work is part of the design for Accelerator Production of Tritium funded by the US Department of Energy. The PC is a co-axial design with the RF power transmitted in the annular region between two concentric cylinders. The PC provides a thermal connection from room temperature to superconducting niobium operating at 2.15 K. Heat transfer mechanisms considered are conduction, infra-red radiation, RF joule heating in normal and superconducting materials, and, forced and natural convection cooling. The objective of the thermal analysis is to minimize the required refrigeration power subject to manufacturability and reliability concerns. The problem is reminiscent of the optimization of superconducting magnet leads. The similarities and differences in the results between SC leads and PCs are discussed as well as the critical parameters in the PC optimization. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Waynert, JA (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 5 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 881 EP 884 DI 10.1109/77.783437 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100188 ER PT J AU Drury, M Fischer, J Preble, J Shu, QS AF Drury, M Fischer, J Preble, J Shu, QS TI Performance of the FEL cryomodules SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The Thomas Jefferson National Accelerator Facility (Jefferson Lab, formerly known as CEBAF) is building a highly efficient, kilowatt-level infrared free-electron laser, the IR Demo FEL. The IR FEL uses superconducting radio-frequency (SRF) cavities to accelerate the electron beam that provides energy for the laser. These cavities provide the high-gradient acceleration for the high average currents necessary for a compact FEL design. Currently, a quarter cryomodule injector and a full eight-cavity cryomodule have been installed in the FEL linac. These units were tested as part of the IR FEL commissioning process. The main focus of these tests was to determine the maximum stable operating gradient. The average maximum gradient reached by these ten cavities was 11 MV/m. Other tests included measurement of cavity parameters such as the unloaded Q (Qo) vs, gradient, the input coupling, calibration of field probes and behavior of the tuner mechanisms. This paper presents the results of those tests. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Northrop Grumman Co, Bethpage, NY 11714 USA. RP Drury, M (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 885 EP 887 DI 10.1109/77.783438 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100189 ER PT J AU Benesch, JF AF Benesch, JF TI Statistical analysis of cavity RF faults SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB During commissioning of the CEBAF accelerator it was found that cavities could not be the operated reliably at the gradients achieved for short periods during individual cavity commissioning. The principal hypothesis for the cause of about two thirds the faults seen is charging of the cold ceramic RF widow, which is 7.6 cm off the beam axis. Beginning in February 1995, most RF systems faults were automatically logged. Simple statistical analysis of the accumulated fault data was first applied in July 1995, with a substantial drop in fault rate recorded. The intent of the analysis was to predict the gradient for each cavity at which it would fault once every ten days, leading to a fault rate for the machine of about 33/day (330 cavities). This analysis method was pursued through July 1996 with substantial benefit. Cavity gradients were increased thereafter to obtain information for an upgrade to 6 GeV, with concomitant fault rate increases. In late 1996 and early 1997, in situ helium discharge processing was employed 88 cavities to reduce field emission. The methods used for the analysis of 30000+ faults recorded between February 1995 and December 1997 are presented. Comparisons of performance before and after helium processing are presented. C1 Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, Newport News, VA 23606 USA. RP Benesch, JF (reprint author), Thomas Jefferson Natl Accelerator Facil, Jefferson Lab, Newport News, VA 23606 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 888 EP 891 DI 10.1109/77.783439 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100190 ER PT J AU Kneisel, P AF Kneisel, P TI High gradient superconducting niobium cavities - A review of the present status SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Superconducting niobium cavities used in particle accelerators are limited in their rf performance by two phenomena: quench field levels below the theoretical limit of the material caused by defects, and field emission loading resulting from artificial contamination of the superconducting surfaces during surface treatment and assembly procedures. In recent years the community involved in SRF technology developments has successfully improved cavity performances by applying advanced surface treatment methods such as chemical polishing, electropolishing, tumbling, high temperature heat treatment, high pressure rinsing, "in situ" high peak power processing and clean room assembly procedures. In addition, improvements in the material properties such as thermal conductivity by "solid state gettering" and very strict QA methods, both in material inspection and during cavity fabrication, have resulted in cavity performance levels of E-acc up to 40 MV/m in monocells and gradients in the vicinity of 30 MV/m in multicell structures at Q-values of approximate to 10(10) at a temperature of 2K, More recently the fabrication of "seamless" cavities by spinning is being pursued with encouraging results. This process eliminates electron beam welds, which sometimes are the causes of performance degradations. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Kneisel, P (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 41 TC 4 Z9 4 U1 3 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1023 EP 1029 DI 10.1109/77.783472 PN 1 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100223 ER PT J AU Green, MA Eyssa, YM Miller, JR Palmer, RB Weggel, RJ AF Green, MA Eyssa, YM Miller, JR Palmer, RB Weggel, RJ TI The use of superconducting solenoids in a muon collider SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Superconducting solenoids are integral part of the proposed muon collider and Higgs factory. Superconducting solenoids that produce induction sup to 15 T will be used to capture pions that are produced by a proton beam impinging on a target contained within the solenoid. After the pions are captured they are phase rotated and allowed to decay to muons. The phase rotation and pion decay channel keeps the pions and muons captured in a 1.25 T solenoidal field surrounding radio frequency phase rotation system. Superconducting solenoids will also be integral part of the muon cooling system. Within the muon cooling channel, which is projected to be up to 300 meters long, solenoidal fields up to 30 T are needed. This report presents the latest thoughts on how superconducting solenoids will be used as part of the muon collider. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Brookhaven Natl Lab, Upton, NY 10973 USA. RP Green, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1049 EP 1052 DI 10.1109/77.783477 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100228 ER PT J AU Coletta, G Gherardi, L Gomory, F Cereda, E Ottoboni, V Daney, D Maley, M Zannella, S AF Coletta, G Gherardi, L Gomory, F Cereda, E Ottoboni, V Daney, D Maley, M Zannella, S TI Application of electrical and calorimetric methods to the AC loss characterization of cable conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Due to higher currents land therefore higher losses) compared to individual wires and tapes, the sc loss characterization of HTS cable conductors carrying transport current can be performed using calorimetric as well as electrical methods. We discuss the main features of two calorimetric methods, one based on temperature profile determination, and one, more recently developed, based on nitrogen boil-off rate, and of the electrical method, substantially derived from that already established for tapes, based on voltage measurement by a Lock-In amplifier: Advantages and limits of each approach are analysed and compared. Tests have been carried out with the three methods on samples 1 to 1.5 m long cut from a Bi-2223 cable conductor prototype fabricated by Pirelli in a longer length. Results obtained from measurements covering a wide range of currents are compared and thoroughly discussed. C1 Pirelli Cavi & Sistemi Spa, Milan, Italy. ENEL SRI, Segrate, MI, Italy. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Coletta, G (reprint author), Pirelli Cavi & Sistemi Spa, Milan, Italy. NR 8 TC 6 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1053 EP 1056 DI 10.1109/77.783478 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100229 ER PT J AU Ashworth, SP Suenaga, M AF Ashworth, SP Suenaga, M TI AC losses due to magnetic fields and transport currents SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The AC losses in a superconductor subjected both to an applied field and transport current may be considered as the losses of two power supplies, one providing the field the other driving the transport current, to the HTS sample. We present a brief justification of our method to measure these losses and then give the results of simultaneous measurements of the losses of both these power supplies to an HTS tape in an ac applied held and carrying an ac or de transport current. The magnetic losses for the case of field applied perpendicular to the tape face are shown to be very much larger than for the field parallel case, but both are small compared to the transport losses in the regions of field and currents of practical interest (i.e. when the superconductor is carrying currents comparable to the critical current). C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Ashworth, SP (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 6 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1061 EP 1064 DI 10.1109/77.783480 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100231 ER PT J AU Bossert, R DiMarco, J Feher, S Kerby, J Lamm, MJ Limon, PJ Nobrega, A Orris, D Ozelis, JP Strait, J Tartaglia, MA Tompkins, JC Zlobin, AV AF Bossert, R DiMarco, J Feher, S Kerby, J Lamm, MJ Limon, PJ Nobrega, A Orris, D Ozelis, JP Strait, J Tartaglia, MA Tompkins, JC Zlobin, AV TI Quench protection studies of short model high gradient quadrupoles SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB High gradient quadrupoles (HGQ) being developed for the CERN Large Hadron Collider (LHC) interaction regions will rely on strip heaters for quench protection. Tests were performed on strip heaters in two locations on 1.9 meter model quadrupoles to study heater response times from strip heater induced quenches and quench velocities and peak temperatures from spot heater induced quenches. The results for the two heater locations are presented and compared to prediction. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. RP Bossert, R (reprint author), Fermi Natl Accelerator Lab, Batavia, IL 60510 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1105 EP 1108 DI 10.1109/77.783491 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100242 ER PT J AU Kim, SW Leroy, D Wilson, MN Ghosh, AK Sampson, WB AF Kim, SW Leroy, D Wilson, MN Ghosh, AK Sampson, WB TI Stability measurements of Rutherford cables with various treatments SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB To improve the stability of Rutherford type superconducting cables, various methods of treating cables were considered and tested. These treatments include strand coating, partial soldering, "barber-pole" insulation and "porous metal" solder filling. To study the effect of these treatments, several cables were prepared and MQE (Minimum Quench Energy) values were measured. Coating, partial soldering or "barber-pole insulation" improved the relative stability for some cables. The "porous metal" filled cables showed higher MQE. However the results suggest that the porous metal process needs to be improved. The measured data for cables with various treatments are presented. C1 CERN, CH-1211 Geneva, Switzerland. Oxford Instruments, Abingdon, Oxon, England. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kim, SW (reprint author), CERN, CH-1211 Geneva, Switzerland. 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1145 EP 1148 DI 10.1109/77.783501 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100252 ER PT J AU Hull, JR SenGupta, S Gaines, JR AF Hull, JR SenGupta, S Gaines, JR TI Trapped-flux internal-dipole superconducting motor/generator SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID YBA2CU3O7-DELTA; MACHINES; MAGNETS; FIELD AB A new class of motor/generator utilizes the magnetic flux trapping capability of high-temperature superconductors (HTSs), The rotor consists of a cylindrical shell composed of HTS segments that act as trapped-field magnets, magnetized in such a way that a dipole magnetic field is produced in the interior of the shell. A stator coil assembly is placed in the interior of the shell, and current passing through the conductors of the coil produce a rotational torque, either as a hysteresis motor or as a synchronous motor. The coil may be either conventional, with copper wires and an iron core, or composed of superconductors that establish the trapped fields. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Superconduct Components Inc, Columbus, OH 43212 USA. RP Hull, JR (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 5 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1229 EP 1232 DI 10.1109/77.783522 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100273 ER PT J AU Fisher, LM Kalinov, AV Savel'ev, SE Voloshin, IF Haldar, P Myron, HW Balachandran, U AF Fisher, LM Kalinov, AV Savel'ev, SE Voloshin, IF Haldar, P Myron, HW Balachandran, U TI AC losses in Bi-2223 tapes and in the 1-kA transmission line model SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB We present here results of our study of the 5-m-long AC transmission line model with 1 kA current capability at 77 K, Primary attention was paid to the current characteristics and AC losses in individual tapes and in the core of the cable. The losses were measured as a function of AC magnetic field amplitude in various orientations of magnetic field with respect to the plane of the tape and filaments. Hysteresis losses were close to the losses in the AC regime, meaning that eddy current losses in tapes may be neglected when compared with hysteresis losses. We designed and constructed a 5-m-long model of the AC transmission line using multifilamentary Bi-2223 tapes, The current core of the model contains 120 tapes for the forward line and 120 tapes for the backward line. AC losses in the current core were substantially greater than those seen in the individual tapes. The reason for this is related to a complex magnetic field distribution inside the current core. C1 All Russian Elect Engn Inst, Moscow, Russia. Intermagnet Gen Corp, Latham, NY 12110 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Fisher, LM (reprint author), All Russian Elect Engn Inst, Moscow, Russia. RI Savel'ev, Sergey/A-5876-2011; Kalinov, Alexey/F-1832-2017 OI Savel'ev, Sergey/0000-0003-2771-230X; Kalinov, Alexey/0000-0003-4988-8330 NR 10 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1265 EP 1268 DI 10.1109/77.783531 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100282 ER PT J AU Cha, YS Evans, DJ Hull, JR AF Cha, YS Evans, DJ Hull, JR TI Measurement of critical current and transient characteristics of a high-temperature superconductor tube with a pulsed current supply SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID FAULT CURRENT LIMITER; PERFORMANCE; CYLINDER AB The transient response of a melt-cast-processed BSCCO-2212 superconductor tube was investigated by using a pulsed current supply. It was found that (a) the maximum induced current and the excitation current at field penetration increase with the maximum excitation current, and (b) there is a time delay between peak excitation current and peak magnetic field inside the superconductor. These observations can be explained by magnetic diffusion. The AC steady-state critical current of the superconductor was found to compare favorably with that of the pulsed current test when the excitation current is relatively low, but it falls below that of the pulsed current test when the excitation current is relatively high. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Cha, YS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1320 EP 1323 DI 10.1109/77.783545 PN 1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225LY UT WOS:000081964100296 ER PT J AU Solovyov, VF Wiesmann, HJ Wu, LJ Suenaga, M Feenstra, R AF Solovyov, VF Wiesmann, HJ Wu, LJ Suenaga, M Feenstra, R TI High rate deposition of 5 mu m thick YBa2Cu3O7 films using the BaF2 ex-situ post annealing process SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL CURRENTS; SUPERCONDUCTORS; GROWTH AB We have investgated the crystallization of thick YBCO films under various annealing conditions. The films were deposited by high-rate co-evaporation of Y, Cu and BaF2 onto room-temperature SrTiO3 substrates at rates exceeding 10 nm/s. TEM microscopy was performed to establish the microscopic structure of partially processed films and help elucidate the growth mechanism. In-situ resistivity measurements were used to monitor the crystallization of the YBCO films during the annealing process. Resistivity measurements and TEM microscopy of samples at different stages of the film growth are compared. Our results indicate that, in addition to oxygen partial pressure, water vapor pressure is an important parameter which defines the dynamics of film growth and crystallization. 5 mu m thick films with J(c) > 2 x 10(5) A/cm(2) (1 T H parallel to c) have been fabricated. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Solovyov, VF (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RI Solovyov, Vyacheslav/A-7724-2009; OI Solovyov, Vyacheslav/0000-0003-1879-9802 NR 10 TC 52 Z9 52 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1467 EP 1470 DI 10.1109/77.784669 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300011 ER PT J AU Coulter, JY Willis, JO Mann, MM Dowden, PC Foltyn, SR Arendt, PN Groves, JR DePaula, RF Maley, MP Peterson, DE AF Coulter, JY Willis, JO Mann, MM Dowden, PC Foltyn, SR Arendt, PN Groves, JR DePaula, RF Maley, MP Peterson, DE TI Magnetic-field anisotropy of high-critical current YBCO coated conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID YBA2CU3O7-DELTA THICK-FILMS AB High-critical current (>100 A) YBCO thick films, or coated conductors, are being developed for superconductor applications. The critical current I, of these materials exhibits a magnetic-field dependence that depends on the angle of the applied field. Measurement of this anisotropy is critical to the development of high temperature superconductor applications. We have developed the capability to characterize the magnetic-field anisotropy of large, high critical current YBCO superconductors as a function of angle. We have measured the magnetic-field anisotropy of the critical current in the H perpendicular to I orientation of three samples in fields from 0 to 7 T and at temperatures from 75 K to 64 K. The results of these measurements characterize the field dependence of these materials and reveal performance issues of importance to applications. In contrast to previous measurements on thin films, which show that I-c for the H parallel to c orientation has the strongest field dependence, we demonstrate that the intermediate angle of similar to 45 degrees to the normal to the tape plane shows the greatest field dependence for these coated conductors on technical substrates. The field performance, anisotropy, and temperature dependence are discussed in relation to sample quality. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Coulter, JY (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, MS-K763, Los Alamos, NM 87545 USA. NR 3 TC 8 Z9 8 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1487 EP 1489 DI 10.1109/77.784674 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300016 ER PT J AU Chudzik, MP Erck, R Lanagan, MT Kannewurf, CR AF Chudzik, MP Erck, R Lanagan, MT Kannewurf, CR TI Processing dependence of biaxial texture in yttria-stabilized zirconia by ion-beam-assisted deposition SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THIN-FILMS; BUFFER LAYERS; ORIENTATION AB Biaxially textured yttria (8 mol%)-stabilized zirconia (YSZ) thin films were deposited on randomly oriented Hastelloy C and Stainless Steel 304 at room temperature as a buffer layer for subsequent deposition of oriented YBa2Cu3Ox films, The 0.16-1.3 mu m thick YSZ films were deposited by e-beam evaporation at rates of 1.2-3.2 Angstrom/sec. Biaxially textured films were produced with an Ar/O-2 ion beam directed at the substrate during film growth. X-ray diffraction was used to study in-plane and out of-plane orientation as a function of ion bombardment angle, film thickness, ion to-atom flux ratio, and substrate material. In-plane and out-of-plane average-misorientation angles on these YSZ films that were deposited by ion-beam-assisted deposition were as low as 17 and 5.4 degrees, respectively, on as-received substrates. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Northwestern Univ, Dept Elect & Comp Engn, Evanston, IL 60208 USA. RP Chudzik, MP (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 9 Z9 9 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1490 EP 1493 DI 10.1109/77.784675 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300017 ER PT J AU Thieme, CLH Fleshler, S Buczek, DM Jowett, M Fritzemeier, LG Arendt, PN Foltyn, SR Coulter, JY Willis, JO AF Thieme, CLH Fleshler, S Buczek, DM Jowett, M Fritzemeier, LG Arendt, PN Foltyn, SR Coulter, JY Willis, JO TI Axial strain dependence at 77K of the critical current of thick YBaCuO films on Ni-alloy substrates with IBAD buffer layers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA AB The strain sensitivity of YBCO coated conductors has been investigated by measuring the critical current density J(c) in self field at 77K, as a function of applied tensile strain. The YBCO coated conductor used an Inconel substrate, One side was coated with a biaxially textured YSZ buffer layer, using Ion-Beam, Assisted-Deposition (IBAD), and was subsequently coated with a 2.5 micron thick YBa2Cu3O7-delta layer by Pulsed Laser Deposition (PLD), The superconductor was then coated with a silver cap layer. For the I-c-strain measurements 78 mm long sections were cut from a 115 cm long length. This was previously produced to demonstrate the feasibility of long YBCO coated er conductors using the IBAD process. At 77K up to 0.5% strain does not change J(c) by more than 3%. This strain dependence is better than the tensile stress dependence of J(c) when samples are bent at room temperature. C1 Amer Superconductor Corp, Westborough, MA 01581 USA. Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Amer Superconductor Corp, 2 Technol Dr, Westborough, MA 01581 USA. NR 9 TC 19 Z9 19 U1 0 U2 2 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 1999 VL 9 IS 2 BP 1494 EP 1497 DI 10.1109/77.784676 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300018 ER PT J AU Sheth, A Lasrado, V White, M Paranthaman, MP AF Sheth, A Lasrado, V White, M Paranthaman, MP TI Bench scale evaluation of batch mode dip-coating of sol-gel LaAlO3 buffer material SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THIN-FILMS; GROWTH; DEPOSITION AB In a joint program between the University of Tennessee Spare Institute (UTSI) and Oak Ridge National Laboratory (ORNL), thin films of lanthanum aluminate (LAO) were formed on (100) strontium titanate (STO) single crystals and on biaxially textured nickel by dip coating from sol-gel precursors and then annealing. XRD texture measurements were used to evaluate coating parameters including substrate withdrawal speed, degree of hydrolysis, and thermal processing temperature, duration, and atmosphere. LAO films on the order of 1000 thick showed 100% biaxial epitaxy on STO single crystals but only about 50% in-plane epitaxy on nickel. An increase in substrate withdrawal velocity resulted in thicker films. On STO film texture degraded with increased film thickness, but on nickel this effect was not noted, being obscured as a result of the rather poor and variable texture of the nickel substrate used. LAO on STO texture was improved by increases, within the ranges investigated, in the degree of hydrolysis, and in the thermal processing time, temperature, and oxygen concentration. No impediments to production scaleup were found. C1 Univ Tennessee, Inst Space, Tullahoma, TN 37388 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sheth, A (reprint author), Univ Tennessee, Inst Space, Tullahoma, TN 37388 USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 15 TC 10 Z9 10 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1514 EP 1518 DI 10.1109/77.784681 PN 2 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300023 ER PT J AU Foltyn, SR Arendt, PN Dowden, PC DePaula, RF Groves, JR Coulter, JY Jia, QX Maley, MP Peterson, DE AF Foltyn, SR Arendt, PN Dowden, PC DePaula, RF Groves, JR Coulter, JY Jia, QX Maley, MP Peterson, DE TI High-T-c coated conductors - Performance of meter-long YBCO/IBAD flexible tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID YBA2CU3O7-DELTA THICK-FILMS; DEPOSITION AB One meter long tapes based on 50-100 mu m thick by 1 cm wide nickel alloy substrates have been coated in a continuous process with a textured yttria-stabilized zirconia layer by ion beam-assisted deposition, followed by a 1-2 mu m thick layer of YBCO by pulsed laser deposition. The best result to date is a tape with a critical current (I-c) at 75 K of 96 A over an 87 cm measurement length. The overall critical current density and engineering current density are 1 MA/cm(2) and 10 kA/cm(2), respectively. Using a special probe, individual I-V curves were generated for each centimeter of tape length in order to investigate longitudinal uniformity of the transport properties: the highest and lowest I-c values fall within a range of +/- 25%. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Foltyn, SR (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, POB 1663, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 10 TC 119 Z9 119 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1519 EP 1522 DI 10.1109/77.784682 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300024 ER PT J AU Selvamanickam, V Galinski, G DeFrank, J Trautwein, C Haldar, P Balachandran, U Lanagan, M Chudzik, M AF Selvamanickam, V Galinski, G DeFrank, J Trautwein, C Haldar, P Balachandran, U Lanagan, M Chudzik, M TI Y-Ba-Cu-O film deposition by metal organic chemical vapor deposition on buffered metal substrates SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THICK-FILMS C1 Intermagnet Gen Corp, Latham, NY 12110 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Selvamanickam, V (reprint author), Intermagnet Gen Corp, Latham, NY 12110 USA. NR 6 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1523 EP 1526 DI 10.1109/77.784683 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300025 ER PT J AU Rupich, MW Palm, W Zhang, W Siegal, E Annavarapu, S Fritzemeier, L Teplitsky, MD Thieme, C Paranthaman, M AF Rupich, MW Palm, W Zhang, W Siegal, E Annavarapu, S Fritzemeier, L Teplitsky, MD Thieme, C Paranthaman, M TI Growth and characterization of oxide buffer layers for YBCO coated conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID FILMS AB Metal oxide films were grown on single crystal oxide substrates and deformation textured metal substrates by a metal organic deposition technique using metal alkoxides as the starting precursor materials. The crystallinity, grain alignment, and morphology of the oxide films depend on the process conditions and the substrate properties. Epitaxial oxide films were grown under a range of oxygen partial pressures and temperatures required for film formation on technologically important metal substrates. YBCO films grown on epitaxial LaAlO3 buffer layers on single crystal SrTiO3 had J(c)'s of 2.2 MA/cm(2) (77K, self-field) demonstrating the quality of the MOD derived oxide films. C1 Amer Superconduct Corp, Westborough, MA 01581 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Rupich, MW (reprint author), Amer Superconduct Corp, Westborough, MA 01581 USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 9 TC 15 Z9 18 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1527 EP 1530 DI 10.1109/77.784684 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300026 ER PT J AU Siegal, MP Overmyer, DL Venturini, EL Padilla, RR Provencio, PN AF Siegal, MP Overmyer, DL Venturini, EL Padilla, RR Provencio, PN TI Remarkable properties of Tl-Ba-Ca-Cu-O thin films following post-growth high-temperature annealing SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID SUPERCONDUCTORS; ENHANCEMENT AB Tl-2212 and Tl-1212 are the two easiest unsubstituted Tl-Ba-Ca-Cu-O superconducting thin films to grow, Both phases exhibit T-c greater than or equal to 95 K, J(c)(5K) > 10 MA/cm(2) and smooth morphologies, We report on the properties of both materials following one hour furnace anneals in dry ambients of pure oxygen or nitrogen at temperatures ranging from 50 - 700 degrees C, The stability of these films to high temperatures in each ambient is important for device processing. Of equal interest is the controlled partial volatilization of Tl-oxide at modest temperatures from nano-size regions within Tl-1212 films. We correlate such modifications with increases in flux pinning strength in Tl-1212 films. Tl-2212 films maintain their superconducting properties to even higher temperatures than Tl-1212 films. Optimum annealing appears to also increase flux pinning, although not to the same degree as for Tl-1212 films. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Siegal, MP (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 11 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1555 EP 1558 DI 10.1109/77.784691 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300033 ER PT J AU Lee, PJ Fischer, CM Gabr-Rayan, W Larbalestier, DC Naus, MT Squitieri, AA Starch, WL Barzi, EZA Limon, PJ Sabbi, G Zlobin, A Kanithi, H Hong, S McKinnell, JC Neff, D AF Lee, PJ Fischer, CM Gabr-Rayan, W Larbalestier, DC Naus, MT Squitieri, AA Starch, WL Barzi, EZA Limon, PJ Sabbi, G Zlobin, A Kanithi, H Hong, S McKinnell, JC Neff, D TI Development of high performance Nb-Ti(Fe) multifilamentary superconductor for the LHC insertion quadrupoles SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA ID ALLOYS AB A development program was initiated in order to develop strand with improved current density at 10.5 T and 1.9 K over existing SSCL designs. The two successful strand designs reported on here both utilized high Fe content Nb-47 wt%Ti alloys to improve the critical current density at high field by 7 %. At 10.5 T and 1.9 K, critical current densities exceeding 1450 A/mm(2) were obtained. In this paper we report detailed quantification of the macro- and micro-structures of these strands and correlate these with critical current density measurements at 1.9 It and 4.2 K. The high Fe content significantly reduced the alpha-Ti precipitate size. The linear relationship between critical current density and precipitate volume found is in agreement with earlier studies. High resolution FESEM electron backscatter contrast suggests a thin layer of high atomic number at grain boundaries. C1 Univ Wisconsin, Ctr Appl Superconduct, Dept Mat Sci & Engn, Madison, WI 53706 USA. Fermilab Natl Accelerator Lab, Batavia, IL USA. IGC Adv Superconductors, Waterbury, CT USA. Oxford Instruments, Supercond Technol, Carteret, NJ USA. RP Univ Wisconsin, Ctr Appl Superconduct, Dept Mat Sci & Engn, Madison, WI 53706 USA. RI Larbalestier, David/B-2277-2008; OI Larbalestier, David/0000-0001-7098-7208; Lee, Peter/0000-0002-8849-8995 NR 12 TC 7 Z9 8 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 1999 VL 9 IS 2 BP 1559 EP 1562 DI 10.1109/77.784692 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300034 ER PT J AU Lee, PJ Fischer, CM Larbalestier, DC Naus, MT Squitieri, AA Starch, WL Werner, RJ Limon, PJ Sabbi, G Zlobin, A Gregory, E AF Lee, PJ Fischer, CM Larbalestier, DC Naus, MT Squitieri, AA Starch, WL Werner, RJ Limon, PJ Sabbi, G Zlobin, A Gregory, E TI Development of high performance multifilamentary Nb-Ti-Ta superconductor for LHC insertion quadrupoles SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA ID ALLOYS AB A preliminary investigation of a new Nb-Ti-Ta (39wt%Nb, 44wt.%Ti, 17wt.%Ta) alloy has been investigated as a possible material for application at 1.9 K and 10.5 T in the insertion quadrupoles of LHC, 1550 A/mm(2), the highest yet reported critical current density at 10.5 T (1.9 K), was achieved in a monofilament of this material. The initial multifilamentary production strand produced a lower 10.5 T (1.9 K) critical current density of 1370 A/mm(2), Large variations in precipitate size were produced in the microstructures, which have yet to be fully optimized. Quantitative analysis of the microstructures in a be-44 wt.%Ti-15 wt.%Ta alloy reveals a linear relationship between volume % of alpha-Ti precipitate and critical current density at 5 T and 8 T (4.2 K), The increase in critical current with precipitate volume is less than for Nb-47 wt.%Ti. High resolution FESEM electron backscatter images suggest a high atomic number region adjacent to the grain boundaries after heat treatment. C1 Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. IGC Adv Superconductors, Waterbury, CT USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. EM lee@engr.wisc.edu RI Larbalestier, David/B-2277-2008; OI Larbalestier, David/0000-0001-7098-7208; Lee, Peter/0000-0002-8849-8995 NR 18 TC 5 Z9 12 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 1999 VL 9 IS 2 BP 1571 EP 1574 DI 10.1109/77.784695 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300037 ER PT J AU Kwon, C Kinder, LR Gim, Y Fan, Y Coulter, JY Maley, MP Foltyn, SR Peterson, DE Jia, QX AF Kwon, C Kinder, LR Gim, Y Fan, Y Coulter, JY Maley, MP Foltyn, SR Peterson, DE Jia, QX TI Fabrication and characterization of (Rare-Earth)-barium-copper-oxide (RE123 with RE = Y, Er, and Sm) films SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THIN-FILMS; YBA2CU3O7-DELTA; CHEMISTRY AB Epitaxial (Rare-Earth)Ba2Cu3O7 films, RE123, with RE = Y, Er, and Sm have been fabricated using pulsed laser deposition on various single crystal substrates. Deposition of each material is optimized for T-c. T-c values of 89.9 K, 91.0 K, and 93.0 K are obtained for Er123, Y123, and Sm123, respectively. T-c in RE123 films increases with increasing the ionic size of the rare-earth element as observed in bulk. Study of field- and angle-dependent J(c) shows that the vortex pinning anisotropy is also affected by the rare-earth element. The Sm123 film has the best pinning characteristics in high magnetic fields among the investigated materials. The results will be discussed in relation to the crystal chemistry and internal stress due to the ionic size of rare-earth element. C1 Univ Calif Los Alamos Natl Lab, Supercond Technol Ctr, Los Alamos, NM 87545 USA. RP Kwon, C (reprint author), Univ Calif Los Alamos Natl Lab, Supercond Technol Ctr, MS K763, Los Alamos, NM 87545 USA. RI Kwon, Chuhee/A-8687-2008; Jia, Q. X./C-5194-2008 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1575 EP 1578 DI 10.1109/77.784696 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300038 ER PT J AU Heinig, NF Daniels, GA Feldmann, M Polyanskii, A Larbalestier, DC Arendt, P Foltyn, S AF Heinig, NF Daniels, GA Feldmann, M Polyanskii, A Larbalestier, DC Arendt, P Foltyn, S TI Implications of low angle YBa2Cu3O7-x bicrystal transport characteristics for coated conductor applications SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THICKNESS DEPENDENCE; GRAIN-BOUNDARIES; THIN-FILMS AB Coated conductor (CC) YBa2Cu3O7-x prototypes can now be made with critical current density, J(c) (77K, 0T), values of 1 - 2 MA/cm(2) and full width half maximum (FWHM) in-plane misalignments of 7 degrees - 15 degrees. In order to understand better the current paths in such conductors, we have measured extended electric field - current density (E-J) characteristics in fields of 0 - 9 T at 77 IC, comparing the data to that obtained on thin film bicrystals. We find that the E-J curves of the CC show little sign of weak coupling. We also investigate the role sample thickness plays in intergranular high field transport by measuring E-J curves up to 8 Tesla on 7 degrees[001] tilt bicrystal films with thickness between 75 and 300 nm. We see that the intergrain irreversibility field increases with thickness, much as has been seen in single crystal samples. Magneto-optic imaging and scanning electron microscopy show that porosity in the YBa2Cu3O7-x layer and scratches in the ceramic buffer layers can also control J(c). These results show that the critical current density of coated conductors is limited on several length scales and by several different defect types. C1 Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Heinig, NF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Polyanskii, Anatolii/B-8794-2009; Larbalestier, David/B-2277-2008 OI Larbalestier, David/0000-0001-7098-7208 NR 12 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1614 EP 1617 DI 10.1109/77.784706 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300048 ER PT J AU Field, MB Byrne, TA Miller, DJ AF Field, MB Byrne, TA Miller, DJ TI The use of cubic Nd-Ba-Cu-O seeds to create theta[100], 90 degrees-theta[100], and theta[001] tilt Y-Ba-Cu-O grain boundaries SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID YBA2CU3O7-DELTA; BICRYSTALS; MISORIENTATION; TRANSPORT; YBACUO; GROWTH; FILMS AB Using seeding techniques to control the orientation of grains, we have been able to create a nide variety of YBa2Cu3O6+x grain boundaries. In addition to five domain samples with 90 degrees[100] twist and tilt grain boundaries, we have now developed a method to produce grain boundaries in the same sample that have the misorientations theta[001] tilt, theta[100] tilt, and 90 degrees-theta[100], where the misorientation angle theta is fully controllable. We will demonstrate how these boundaries can be synthesized, give experimental evidence via polarized light microscopy and electron backscatter patterns (EBSP) that the intended grain boundaries were indeed formed, and discuss the importance of these boundaries in future grain boundary studies. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Field, MB (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1618 EP 1621 DI 10.1109/77.784707 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300049 ER PT J AU Tsay, YN Li, Q Zhu, Y Suenaga, M Shibutani, K Shigaki, I Ogawa, R AF Tsay, YN Li, Q Zhu, Y Suenaga, M Shibutani, K Shigaki, I Ogawa, R TI Transport properties of Bi2Sr2CaCu2O8+delta bicrystals with [100] tilt grain boundaries SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID SUPERCONDUCTOR BI2SR2CA2CU3O10; TAPES AB We have successfully isolated more than a dozen of naturally-grown [100] tilt Bi2Sr2CaCu2O8+delta (Bi-2212) bicrystals for the study of the transport properties of the grain boundary. These bicrystals contain a single clean [100] nonbasal-plane-faced tilt grain boundary with various degrees of misorientation. Systematic transport measurements of these grain boundaries were performed in a wide range of temperature and magnetic field by measuring the resistance and the current-voltage characteristics for both single crystals and grain boundaries simultaneously. In addition, the microstructures of the grain boundaries in some of these bicrystals were studied by both conventional TEM and high-resolution electron microscopy (HREM). We found that almost all these [100] non-basal-plane-faced tilt grain boundary had a T-c depression (about 6 K to 9 K) as compared to their constituent single crystals. However, at low temperatures, these grain boundaries do not behavior like weak-links. In fact, several high angle tilt grain boundaries can carry the same amount of critical current as their constituent single crystals. Our results suggest that the effect of misorientation angle on the grain-boundary coupling strength in this type of Bi-2212 grain boundary is much less predominant than that in the same type of grain boundary of YBa2Cu3O7-delta (YBCO). C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Kobe Steel Ltd, Superconducting & Cryogen Technol Ctr, Nishi Ku, Kobe, Hyogo 65122, Japan. RP Tsay, YN (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 11 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1622 EP 1625 DI 10.1109/77.784708 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300050 ER PT J AU Parilla, PA Carlson, CM Wang, YT Bhattacharya, RN Blaugher, RD Ginley, DS Paranthaman, M Goyal, A Christen, DK Kroeger, DM AF Parilla, PA Carlson, CM Wang, YT Bhattacharya, RN Blaugher, RD Ginley, DS Paranthaman, M Goyal, A Christen, DK Kroeger, DM TI Buffer layers and thallination of Tl-based superconductors on flexible metal substrates SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID THICK-FILMS; LASER DEPOSITION; TAPES AB Reported here is the development of textured buffer layers that are compatible with Tl-based superconductor (SC) films on metallic substrates. Crucial properties for the successful development of a suitable buffer layer are appropriate lattice match, chemical stability, and a high degree of texture. Buffer layer materials investigated include cerium oxide, strontium titanate (STO), lanthanum aluminate (LAO), and lanthanum nickel oxide (LNO) which were grown using a pulsed excimer 248 nm laser deposition system equipped with multitarget and controlled ambient capabilities. Influence of substrate temperature and ambient pressure and flow on buffer layer growth are analyzed via XRD and AFM characterization. Highly textured buffer layers have been fabricated including epitaxial LAO/LNO/CeO2/Ni RABiTS configurations, Also reported are the results of thallination of Ba-Ca-Cu-O precursors on single crystal and buffered substrates using a hybrid 2-zone furnace. The hybrid 2-zone combines the advantages of crucible and standard 2-zone thallination processes. High quality Tl-1223 films with Jcm similar to 6.0 MA/cm(2)(0 T, 5 K) and 4.6 MA/cm(2) (0 T, 76 K) have been produced using the hybrid method. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Parilla, PA (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 15 TC 4 Z9 4 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1673 EP 1676 DI 10.1109/77.784773 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300063 ER PT J AU Bhattacharya, RN Parilla, PA Blaugher, RD Ren, ZF Li, W Wang, JH Wang, YT Hermann, AM Paranthaman, M Goyal, A Verebelyi, DT Christen, DK AF Bhattacharya, RN Parilla, PA Blaugher, RD Ren, ZF Li, W Wang, JH Wang, YT Hermann, AM Paranthaman, M Goyal, A Verebelyi, DT Christen, DK TI Superconducting (TlBi)(0.9)Sr1.6Ba0.4Ca2Cu3Ag0.2Ox films from electrodeposited precursors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT DENSITIES AB A low-cost electrodeposition (ED) method is reported for fabrication of high-temperature TI-oxide-based superconductors. Recent studies on the development of biaxially textured ED films on single-crystal and rolling-assisted biaxially textured Ni substrates are presented. Pole-figure measurements of electrodeposited (TI, Bi)-(Sr, Ba)-Ca-Cu-Ag-O (TBSBCCO) films, with thicknesses between 1-5 mu m, clearly show strong biaxial texturing. The rocking curve and phi scan of TBSBCCO on 300 Angstrom Ag/LaAlO3, show a full width half maximum (FWHM) of only 0.9 degrees and 1.2 degrees, respectively, consistent with a very high-quality film. Transport measurements for the ED films show J(c) values up to 7.84 x 10(5) A/cm(2) at 77 K in zero magnetic field. The preliminary results of electrodeposited TBSBCCO film on CeO2/YSZ/CeO2 on textured Ni showed primarily 1212 phase with a transport critical current density of 1.36 x 105 A/cm(2) at 77 K in zero field. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bhattacharya, RN (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 7 TC 7 Z9 7 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1681 EP 1683 DI 10.1109/77.784775 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300065 ER PT J AU Holesinger, TG Baldonado, PS Van Vo, N Dai, WM Marken, KR Hong, S AF Holesinger, TG Baldonado, PS Van Vo, N Dai, WM Marken, KR Hong, S TI Isothermal melt processing of Bi-2212 tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID BI2SR2CACU2OY AB Isothermal melt processing (IMP) has been used to produce phase-pure, high critical current density (J(c)) Bi-2212 tapes at temperatures as low as 780 degrees C. Bi-2212 tapes processed by IMP have yielded J(c) values up to 250 kA/cm(2) (I-c = 345 A) at liquid helium temperatures. Small test coils have been produced with J(c) values up to 150 kA/cm(2). The effects of the oxidation rate, processing temperature, and time spent in the partial melt on the superconducting properties and microstructure were investigated. Optimal superconducting properties result from the interplay of these parameters such that the grain size of the Bi-2212 phase in the polycrytalline core is allowed to coarsen and align itself with the silver sheath to form a well-connected superconductor, Deviations from optimal conditions result in either too little coarsening to form a well-aligned structure or instabilities in the coarsening process that lead to the formation of large secondary phases which disrupt connectivity. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oxford Superconducting Technol, Carteret, NJ 07008 USA. RP Holesinger, TG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1800 EP 1803 DI 10.1109/77.784805 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300095 ER PT J AU Bending, SJ Oral, A Clem, JR Kaya, II Ooi, S Tamegai, T Henini, M AF Bending, SJ Oral, A Clem, JR Kaya, II Ooi, S Tamegai, T Henini, M TI Direct observation of vortex lattice melting in Bi2Sr2CaCu2O8+delta single crystals SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID TRANSITION; SUPERCONDUCTORS; MICROSCOPY AB Scanning Hall probe microscopy has been used to investigate the melting of the vortex solid in Bi2Sr2CaCu2O8+delta single crystals. After waiting several minutes for fluctuations to die away, a nux solid with good six-fold order is observed below the melting line, Incommensurability effects lead to pronounced rotations of the solid as the field is varied. The peak-to-valley corrugation of the vortex lattice drops abruptly and discontinuously to zero at the melting line, consistent with a first order transition. Fits of a pancake vortex model to the data yield a Lindemann parameter C(L)similar to 0.19 in fair agreement with other estimates. There is also a clear indication of softening of the solid at very low fields, though we find no direct evidence for re-entrant melting. C1 Univ Bath, Dept Phys, Bath BA2 7AY, Avon, England. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan. Univ Nottingham, Dept Phys, Nottingham NG7 2RD, England. RP Bending, SJ (reprint author), Univ Bath, Dept Phys, Bath BA2 7AY, Avon, England. RI Tamegai, Tsuyoshi /C-6656-2011; Henini, Mohamed/E-8520-2012 OI Henini, Mohamed/0000-0001-9414-8492 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1820 EP 1823 DI 10.1109/77.784810 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300100 ER PT J AU Lin, WJ Hatton, PD Baudenbacher, F Santiso, J AF Lin, WJ Hatton, PD Baudenbacher, F Santiso, J TI Synchrotron X-ray studies of ultra-high-quality crystalline YBa2Cu3O7-delta in submicron thick films SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID 2-CIRCLE POWDER DIFFRACTOMETER; CRITICAL CURRENT-DENSITY; INTERFACE STRUCTURE; EPITAXIAL-FILMS; SCATTERING; STRAIN; DIFFRACTION; MORPHOLOGY; TEMPERATURE; RELAXATION AB The crystal structure of YBa2Cu3O7-delta thin films grown on SrTiO3 substrate was studied by high-resolution x-ray scattering using synchrotron radiation. The films were found to consist of two major components: mosaic aligned grains and an ultra-high-quality single-crystal film. The scattering of the former component gave the normal diffraction pattern and its coherent grain size was determined, by fitting the Bragg reflection profiles, to be 2500 Angstrom (horizontal) and 100 Angstrom (vertical), The signature of the ultra-high-quality film was only observed in low index Bragg reflections, From analysis of the peak profiles, the coherent length of this component was found to be tens of microns (horizontal) and 1800 Angstrom (vertical, the entire film thickness). An exponential strain field was found close to the interface which causes asymmetry in the theta-2 theta direction. We also found that the scattering intensity of this single crystal film was affected by the correlated roughnesses on the lattice planes, which replicate from the roughness of the substrate surface during growth, The Debye-Waller like roughness factor quickly diminishes the reflectivity as the diffraction angle (2 theta) increases, which prevents the observation of the ultra-high-quality film at high angle Bragg reflections. Furthermore, our results indicate that 95% of the film volume is occupied by this excellent single-crystal film. It is clear that the superconducting properties of the sample will reflect this high quality film, rather than the 5% mosaic grains. These observations may help to account for the enhanced transport properties of thin films compared to their bulk counterparts. C1 Univ Durham, Dept Phys, Durham DH1 3LE, England. Univ Cambridge, Interdisciplinary Res Ctr Superconduct, Cambridge CB3 0HE, England. RP Lin, WJ (reprint author), Argonne Natl Lab, DND, CAT, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Santiso, Jose/C-4423-2013; Hatton, Peter/J-8445-2014 NR 30 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1852 EP 1855 DI 10.1109/77.784818 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300108 ER PT J AU Goretta, KC Cuber, MM Feng, LR Fisher, BL Jiang, M Lanagan, MT Balachandran, U Xu, Y Xu, M AF Goretta, KC Cuber, MM Feng, LR Fisher, BL Jiang, M Lanagan, MT Balachandran, U Xu, Y Xu, M TI Microstructure and properties of Bi-Sr-Ca-Cu-O with additions of nanometer-scale alumina SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID FLUX-PINNING CENTERS; OXIDE ADDITIONS; SINGLE-CRYSTALS; SUPERCONDUCTIVITY; BI2SR2CACU2OX; AL2O3; TLBA2CA2CU3OX; SYSTEM; TAPES; TI AB Al2O3 particles approximate to 30 nm in size were added to Bi2Sr2CaCu2Ox in a 1:4 molar ratio, For comparison, 0.3- and approximate to 3-mu m Al2O3 particles were added to separate batches. All of the materials were partial-melt processed. The Al2O3 reacted during melting to form stable compounds, primarily of approximate composition (Sr,Ca)(2)AlO4. All additions caused slight decreases in the Te and melting point of the Bi2Sr2CaCu2Ox. The submicrometer Al2O3 additions induced large expansions in magnetic-hysteresis width at 6 K. Electron microscopy examination strongly suggested that the hysteresis expansion was related to alloying of the Bi2Sr2CaCu2Ox matrix rather than to pinning by volume defects. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Mankato State Univ, Mankato, MN 56001 USA. Univ Chicago, Chicago, IL 60637 USA. RP Goretta, KC (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 4 Z9 4 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1896 EP 1899 DI 10.1109/77.784829 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300119 ER PT J AU Lanagan, MT Goretta, KC Walter, DK Poeppel, RB Troendly, R McNallan, MJ Danyluk, S AF Lanagan, MT Goretta, KC Walter, DK Poeppel, RB Troendly, R McNallan, MJ Danyluk, S TI Near-net-shape fabrication of continuous Ag-clad Bi-based superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID TAPES; WIRES; DENSITY AB We have developed a near-net-shape process for Ag-clad Bi-2212 superconductors. This alternative to the powder-in-tube process offers the advantages of nearly continuous processing, minimization of processing steps, reasonable ability to control the Bi-2212/Ag ratio, and early development of favorable texture of the Bi-2212 grains. The powder is rolled into an Ag channel, a cap is applied, and the assembly is lightly rolled. To minimize distortion during heat treatment, it is especially important that the Bi-2212 powder be nearly free of volatile species such as carbon. A vacuum-calcination process was developed to control CO2 evolution during heating. Superconducting properties are discussed. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Superconducting Prod Co, Batavia, IL USA. RP Lanagan, MT (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1900 EP 1903 DI 10.1109/77.784830 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300120 ER PT J AU Groves, JR Arendt, PN Foltyn, SR DePaula, RF Wang, CP Hammond, RH AF Groves, JR Arendt, PN Foltyn, SR DePaula, RF Wang, CP Hammond, RH TI Ion-beam assisted deposition of bi-axially aligned MgO template films for YBCO coated conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID YTTRIA-STABILIZED-ZIRCONIA; THIN-FILMS AB We report the results of experiments with ion-beam-assisted deposition (IBAD) of MgO using in-situ monitoring with Reflected High-Energy Electron Diffraction (RHEED). Strips of polished Haynes 242 and Inconel 625 nickel-based super-alloys have been used as substrates for these experiments. The inplane texture of the MgO, as measured by x-ray phi scan, resulted in FWHM values between 11 and 15 degrees. Using pulsed-laser deposition, the IBAD MgO template films were then overcoated with buffer layer films and a final superconducting film of YBa2Cu3O7-delta. The best superconducting transport properties measured on these YBCO films were: an Ic (75K, self-field, 1 cm wide) of 41.6 A, and a narrow-bridge J(c) (1.35 mu m thick film) of 0.46 Ma/cm(2). C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci, Los Alamos, NM 87545 USA. Stanford Univ, Ginzton Lab, Stanford, CA 94305 USA. RP Groves, JR (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci, Los Alamos, NM 87545 USA. NR 8 TC 35 Z9 35 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1964 EP 1966 DI 10.1109/77.784846 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300136 ER PT J AU Cui, X List, FA Kroeger, DM Goyal, A Lee, DF Mathis, J Specht, ED Martin, PM Feenstra, R Verebelyi, DT Christen, DK Paranthaman, M AF Cui, X List, FA Kroeger, DM Goyal, A Lee, DF Mathis, J Specht, ED Martin, PM Feenstra, R Verebelyi, DT Christen, DK Paranthaman, M TI Reel-to-reel continuous deposition of epitaxial CeO2 buffer layers on biaxially textured Ni tapes by electron beam evaporation SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTING TAPES; FILMS; OXIDATION; METAL AB A reel-to-reel, electron beam evaporation system has been developed to continuously deposit epitaxial CeO2 and other oxide buffer layers on meter-long lengths of biaxially textured Ni tapes. The deposition system includes two interconnected electron beam evaporation chambers and a chamber in which as-rolled Ni tape is irt situ annealed to develop biaxial texture. An integral reel-to-reel system with tension control enables motion of the tape with little or no plastic deformation. When depositing epitaxial oxides on Ni, the formation of unfavorably oriented NiO is difficult to avoid. Oxide free, {100}<100> oriented Ni tapes are prepared by control of the partial pressures of H-2, H2O and O-2 during Ni annealing. X-ray phi-scans have been performed as a function of length to determine the crystallographic consistency of the epitaxial CeO2 over length. Results of SEM examinations of the CeO2 buffer layer microstructure are presented. Results for YBCO films deposited on short segments of these buffered substrates are summarized. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. RP Cui, X (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531 NR 10 TC 10 Z9 10 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 1967 EP 1970 DI 10.1109/77.784847 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300137 ER PT J AU Zhou, JP Jones, CE McDevitt, JT Gim, Y Goodenough, JB Kwon, C Jia, QX AF Zhou, JP Jones, CE McDevitt, JT Gim, Y Goodenough, JB Kwon, C Jia, QX TI Improved J(c) of bilayer YBa2Cu3O7-delta thin film structures SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID OXIDE SUPERCONDUCTORS; IRREVERSIBILITY LINE; COLUMNAR DEFECTS; CRYSTAL; TC AB Critical-current (J(c)) measurements for YBa2Cu3O7-delta (YBCO), Gd0.6Ca0.4Ba1.6La0.4Cu3O7-delta (TX-GBCO) and TX-CBCO/YBCO bilayers were performed different applied magnetic fields. rue film samples were prepared by pulsed laser deposition and patterned as microbridges. The highest J(c) (1.5 x 10(6) A/cm(2)) at 75 K in 5 Tesla (Hllab) was observed for TX-GBCO/YBCO bilayers, which showed a 40 % increase in J(c) over YBCO under the same conditions. The bilayer samples possess a T-c at 90 Ii and display superconducting properties similar to YBCO. A possible mechanisms for the high J(c) of bilayer YBCO films is discussed. Development of these bilayer and multilayer structures represents a promising new direction to improve the superconducting properties of YBCO since the TX-GBCO layer provide both protection against corrosion and a significant improvement in J(c). C1 Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. Univ Texas, Ctr Mat Sci & Engn, Austin, TX 78712 USA. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Zhou, JP (reprint author), Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. RI Kwon, Chuhee/A-8687-2008; Jia, Q. X./C-5194-2008; McDevitt, John/P-4108-2014 OI McDevitt, John/0000-0001-8789-9351 NR 21 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2002 EP 2005 DI 10.1109/77.784856 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300146 ER PT J AU Li, Q Tsay, YN Suenaga, M Wirth, G Gu, GD Koshizuka, N AF Li, Q Tsay, YN Suenaga, M Wirth, G Gu, GD Koshizuka, N TI Comparative studies of irreversibility lines and critical current in heavy ion irradiated Bi2Sr2CaCu2O8+delta bicrystals with [001] twist grain boundaries SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID COLUMNAR DEFECTS; TAPES AB Columnar defects, through 2.2 GeV Au-ions irradiation, were introduced into Bi2Sr2CaCu2O8+delta (Bi-2212) bicrystals with [001] twist grain boundaries. Studies of the effect of heavy ion irradiation on the transport properties of the bicrystals R-ere performed by measuring the irreversibility line and critical current within the constituent single crystals and across the [001] twist grain boundaries before and after irradiation. We found that the columnar defects greatly increased the irreversible temperature determined both within the single crystals and across the grain boundaries. However, the enhancement on critical current by the columnar defects measured across the grain boundaries is not significant, while more than an order of magnitude increase in the single crystal critical current was observed. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Gesellschaft Schwerionenforsch, D-64291 Darmstadt, Germany. ISTEC, Superconduct Res Lab, Tokyo 135, Japan. RP Li, Q (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 9 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2026 EP 2029 DI 10.1109/77.784862 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300152 ER PT J AU Miller, DJ Gray, KE Field, MB Kim, DH AF Miller, DJ Gray, KE Field, MB Kim, DH TI The influence of vortex pinning and grain boundary structure on critical currents across grain boundaries in YBa2Cu3Ox SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID BICRYSTALS; MISORIENTATION; BULK AB We have used studies of single grain boundaries in YBCO thin films and bulk bicrystals to study the influence of vortex pinning along a grain boundary on dissipation. The critical current density for transport across grain boundaries in thin films is typically more than an order of magnitude larger than that measured for transport across grain boundaries in bulk samples For low misorientation angles, the difference in critical current density within the grains that form the boundary can contribute to the substantial differences in current density measured across the boundary. However, substantial differences exist in the critical current density across boundaries in thin film compared to bulk bicrystals even in the higher angle regime in which grain boundary dissipation dominates. The differences in critical current density in this regime can be understood on the basis of vortex pinning along the boundary. C1 Argonne Natl Lab, Mat Sci Div, Argonne, IL 60439 USA. Yeungnam Univ, Dept Phys, Kyongsan 712749, South Korea. RP Miller, DJ (reprint author), Argonne Natl Lab, Mat Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2030 EP 2033 DI 10.1109/77.784863 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300153 ER PT J AU Kung, H Foltyn, SR Arendt, PN Maley, MP AF Kung, H Foltyn, SR Arendt, PN Maley, MP TI Characterization of the structure of Y-Ba-Cu-O coated conductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID GRAIN-BOUNDARIES; THICK-FILMS; YBA2CU3O7-DELTA AB Transmission electron microscopy (TEM) has been applied to the microstructural investigation of YBa2 Cu-3 O7-delta (YBCO) thick films deposited on polycrystalline Ni-based metal substrates by pulsed laser deposition. The films were found to be strongly textured with c-axis oriented grains aligned perpendicular to the substrates. Despite the large average in-plane misorientation (theta similar to 14 degrees), as was estimated from selected area electron diffraction and x-ray diffraction, TEM inspection reveals colonies of submicron-sized grains with low angle (theta less than or equal to 7 degrees) tilt grain boundaries. The linkage of the colony structures may provide a continuous percolation pathway for the supercurrent transport in YBCO, which may provide the mechanism for the higher than expected critical current density J(c). Periodic arrays of grain boundary dislocations were observed, which may serve as effective flux pinners. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Kung, H (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. NR 10 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2034 EP 2037 DI 10.1109/77.784864 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300154 ER PT J AU Goretta, KC Diko, P Jiang, M Cuber, MM Xu, M Ostenson, JE Sengupta, S AF Goretta, KC Diko, P Jiang, M Cuber, MM Xu, M Ostenson, JE Sengupta, S TI Annealing and mechanical properties of bulk Y-Ba-Cu-O SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA ID FRACTURE-TOUGHNESS; THERMAL-STRESSES; TEXTURED YBACUO; CURRENT-DENSITY; MELT; SUPERCONDUCTORS; YBA2CU3O7-DELTA; Y2BACUO5; MICROCRACKING; COMPOSITES AB Melt-processed YBa(2)Cu(3)O(x)/Y(2)BaCuO(5) and conventional polycrystalline sintered YBa(2)Cu(3)O(x) pellets were prepared. Elastic modulus, hardness, and fracture strength were measured on selected selections cut from the pellets. Strength in the melt-processed pellets ranged from 32 to 94 MPa and was highest in the center. Variations in strength were related to microstructural features, especially Y(2)BaCuO(5) distribution. To improve strength, we attempted to minimize microcracking by manipulating cooling rates and annealing times. We found that control of annealing reduced microcracking of the polycrystalline sintered pellets, but had little effect on the single-domain melt-processed pellets. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Chicago, Chicago, IL 60637 USA. Ames Lab, Ames, IA USA. Superconduct Components Inc, Columbus, OH USA. Slovak Acad Sci, Inst Expt Phys, Kosice 04353, Slovakia. RP Goretta, KC (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 23 TC 9 Z9 9 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2081 EP 2084 DI 10.1109/77.784876 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300166 ER PT J AU Chiba, T Li, Q Ashworth, SP Suenaga, M Haldar, P AF Chiba, T Li, Q Ashworth, SP Suenaga, M Haldar, P TI Angular dependence of ac losses at power frequencies for a stack of Bi2223/Ag tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID SHEATHED (BI,PB)(2)SR2CA2CU3O10 TAPES; ALTERNATING-CURRENT LOSSES; SUPERCONDUCTING TAPES; FIELDS AB ac losses for a stack of Bi2223/Ag were determined as a function of the angle between the applied ac magnetic field and the tape face. The results were compared with the ac losses calculated using the Bean critical-state model. Although the general qualitative behavior of the calculated loss as a function of the angle was in accord with the measured values, the model failed significantly in quantitative predictions of the losses. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Intermagnet Gen Corp, Latham, NY 12110 USA. RP Chiba, T (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 9 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2143 EP 2146 DI 10.1109/77.784891 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300181 ER PT J AU Paranthaman, H Lee, DF Feenstra, R Goyal, A Verebelyi, DT Christen, DK Specht, ED List, FA Martin, PM Kroeger, DM Ren, ZF Li, W Wang, DZ Lao, JY Wang, JH AF Paranthaman, H Lee, DF Feenstra, R Goyal, A Verebelyi, DT Christen, DK Specht, ED List, FA Martin, PM Kroeger, DM Ren, ZF Li, W Wang, DZ Lao, JY Wang, JH TI Optimization of buffer lagers on rolled-Ni substrates for high current YBCO and Tl,Bi-1223 coated conductors using ex-situ precursor approaches SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID ELECTRON-BEAM EVAPORATION; CRITICAL-CURRENT DENSITY; BIAXIALLY TEXTURED NI; SUPERCONDUCTING TAPES; FILMS; LAYERS; GROWTH AB High current YBa2Cu3O7-y (YBCO) and Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9-y (Tl,Bi-1223) coated conductors were fabricated on Rolling-Assisted Biaxially Textured Substrates (RABiTS) with a layer sequence of CeO2/YSZ/CeO2/Ni. The top and bottom CeO2 (Cerium oxide) lavers were deposited epitaxially on textured-Ni (100) substrates using reactive evaporation of Ce metal. The thickness of the CeO2 films was 200-400 Angstrom. The YSZ (Yttria Stabilized Zirconia) levers were also deposited epitaxially on CeO2-buffered Ni substrates either by rf magnetron sputtering or e-beam evaporation The thickness of the YSZ films was typically 3000-9000 Angstrom. The e-beam CeO2 films were dense, crack-free and columnar. The microstructure of sputtered PSZ was dense and the e-beam deposited YSZ was porous. To understand the stability of these buffer layers, the as-grown CeO2-buffered YSZ (both sputtered and e-beam)/CeO2/Ni substrates were annealed in a controlled oxygen furnace at various temperatures, RES studies indicate that the YSZ sputtered films were quite stable up to 780 degrees C and 200-mTorr oxygen. For e-beam YSZ films, there was an indication of diffusion of oxygen through these buffers into the Ni substrate. The Tl,Bi-1223 films,were grown on all e-beam buffers using pulsed laser ablation of precursor films followed by post-annealing, The YBCO films were grown on e-beam/sputtered buffers using e-beam co-evaporated Y-BaF2-Cu precursors followed by post-annealing. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. SUNY Buffalo, Buffalo, NY 14260 USA. RP Paranthaman, H (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Ren, Zhifeng/B-4275-2014; Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 11 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2268 EP 2271 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300212 ER PT J AU Park, C Norton, DP Christen, DK Verebelyi, DT Feenstra, R Budai, JD Goyal, A Lee, DF Specht, ED Kroeger, DM Paranthaman, M AF Park, C Norton, DP Christen, DK Verebelyi, DT Feenstra, R Budai, JD Goyal, A Lee, DF Specht, ED Kroeger, DM Paranthaman, M TI Long length fabrication of YBCO on rolling assisted biaxially textured substrates (RABiTS) using pulsed laser deposition SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT DENSITY; LARGE-AREA DEPOSITION; THIN-FILMS; SUPERCONDUCTING TAPES; YBA2CU3O7-X FILMS; ABLATION AB The continuous deposition of multilayer oxide films on moving long-length metallic substrates using pulsed laser deposition (PLD) is reported. Epitaxial YBCO/CeO2/yttria-stabilized zirconia (YSZ)/CeO2 layers were grown on 1cm X 10cm rolled-Ni tape substrates. The Ni tape was heated radiatively and translated while oxide layers were continuously deposited, The thickness and composition along the moving direction were to within +/-7% and +/-5%, respectively. The biaxial texture of the 10cm Ni tape was transferred through the buffer lavers to the topmost YBCO during the continuous deposition. The in-plane and out-of-plane texturing of YBCO and buffer layers were uniform along the scanning direction with variations less than +/-10% and +/-5%, respectively, The average transport zero field J(c) (77K) for numerous 10 cm samples was about 200,000 A/cm(2), with the highest J(c) and I-c values at 77K, 0T of 270,000 A/cm(2) and 16.7 ii respectively. This study demonstrates the feasibility of continuous multilayer, multi-component oxide film deposition on rolled-textured metal with uniform thickness, composition, and crystallographic orientation using PLD. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Park, C (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Yoon, Sejin/F-7637-2013; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016; Specht, Eliot/A-5654-2009 OI Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306; Specht, Eliot/0000-0002-3191-2163 NR 16 TC 22 Z9 23 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2276 EP 2279 DI 10.1109/77.784924 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300214 ER PT J AU Feher, S Glass, H Huang, Y Limon, PJ Orris, DF Ozelis, J Schlabach, P Tartaglia, MA Tompkins, JC AF Feher, S Glass, H Huang, Y Limon, PJ Orris, DF Ozelis, J Schlabach, P Tartaglia, MA Tompkins, JC TI HTS wire irradiation test with 8 GeV protons SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB The radiation level at High Energy Particle Accelerators (HEPA) can be high enough to damage electronic devices. Any active component near the accelerator must be radiation resistant. Since High Temperature Superconductors (HTS) have great potential to be used in HEPAs (e.g., in superconducting magnets, current leads, RF cavities), it is important to understand the radiation hardness of these materials. A radiation test of HTS wire (BSCCO-2223) was performed at Fermilab. The HTS sample was irradiated with 8 GeV protons and the critical current, I-c, was measured during the irradiation. The total radiation dose was 10.8 +/- 1.0 Mrad. No change in I-c was observed. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Feher, S (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2288 EP 2291 DI 10.1109/77.784927 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300217 ER PT J AU Venturini, EL Provencio, PN Doyle, BL Brice, DK AF Venturini, EL Provencio, PN Doyle, BL Brice, DK TI Strong vortex pinning by elongated, discontinuous defects in Tl-Ba-Ca-Cu-O films SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID SINGLE-CRYSTAL; CRITICAL CURRENTS; ION IRRADIATION; HIGH-ENERGY; THIN-FILMS; HEAVY-IONS; RESISTIVITY; SUPERCONDUCTORS; IRREVERSIBILITY; MAGNETIZATION AB Elongated, discontinuous defects provide strong vortex pinning and a corresponding large increase in critical current density in highly anisotropic Tl2Ba2CaCu2Ox (Tl-2212) thin films. We generate controlled, amorphous damage regions in Tl-2212 thin films ranging from short, discontinuous defects to continuous linear tracks using Au ion irradiation with incident energies of 30, 60 and 88 MeV. High-resolution TEM images and magnetization data allow correlation of microstructural damage with changes in the superconducting properties. Furnace annealing of an irradiated film shows that the enhanced pinning is stable to above 600 degrees C. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Venturini, EL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 25 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2292 EP 2295 DI 10.1109/77.784928 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300218 ER PT J AU Kim, JT Park, YK Park, JC Kang, WN Chu, CW Lim, HR Kim, DH Lee, JU Gray, KE AF Kim, JT Park, YK Park, JC Kang, WN Chu, CW Lim, HR Kim, DH Lee, JU Gray, KE TI Pinning effect on critical dynamics in Tl2Ba2CaCu2O8 films before and after introducing columnar defects SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA ID YBA2CU3O7-DELTA SINGLE-CRYSTALS; CRITICAL-BEHAVIOR; TRANSITION; HEAT AB The effect of columnar defects on the critical dynamics of superconducting Tl2Ba2CaCu2O8 (Tl-2212) film has been investigated. The Tl-2212 film was irradiated at 0 degrees C by. 1.3 GeV U-ions along the normal of the film surface. The dose of 6.0 x 10(10) ions/cm(2) of the U-ion irradiation corresponds to a matching field of 1.2 T, The in-plane longitudinal resistivity of the irradiated Tl-2212 has been measured as a function of magnetic field H and temperature T, The extracted fluctuation part of the conductivity sigma(xx)(T, H) of the unirradiated sample exhibits 3D-XY scaling behavior that reveals dynamic critical exponent z = 1.8 +/- 0.1 and static critical exponent v approximate to 1.338. The results indicate that the weak interlayer coupling along the c-axis of Tl-2212 significantly influences static critical exponent v and does not change dynamical critical exponent. After the irradiation, the fluctuation conductivities are enhanced by the strong pinnings and do not exhibit the same 3D-XY scaling behavior as for the unirradiated Tl-2212, Particularly at the low magnetic field values near the matching field of 1.2 T, the fluctuation conductivities show a clear deviation from the critical dynamics, suggesting that the pinning effect on the critical dynamics is significant. C1 Korea Res Inst Stand & Sci, Superconduct Grp, Taejon 305600, South Korea. Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Yeungnam Univ, Dept Phys, Kyongsan 712749, South Korea. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Kim, JT (reprint author), Korea Res Inst Stand & Sci, Superconduct Grp, POB 102, Taejon 305600, South Korea. NR 16 TC 2 Z9 2 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 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2296 EP 2299 DI 10.1109/77.784929 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300219 ER PT J AU Shoup, SS Shanmugham, S Cousins, D Hunt, AT Paranthaman, M Goyal, A Martin, P Kroeger, DM AF Shoup, SS Shanmugham, S Cousins, D Hunt, AT Paranthaman, M Goyal, A Martin, P Kroeger, DM TI Low-cost Combustion Chemical Vapor Deposition of epitaxial buffer layers and superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA ID CRITICAL-CURRENT DENSITY; THICK-FILMS; TAPES AB A new low-cost, open-atmosphere deposition technique, Combustion Chemical Vapor Deposition (CCVD) is used to deposit epitaxial buffer layers and high-temperature superconductors on oxide single-crystal substrates. The CCVD process has the potential for manufacturing buffer layers and superconductors onto textured metal substrates in a continuous reel-to-reel production. CCVD does not use vacuum equipment or reaction chambers required by conventional techniques, while its coating quality rivals and even exceeds that of conventional methods. Compounds being studied with the CCVD process include the buffer layers cerium oxide (CeO2), yttria stabilized zirconia (YSZ), strontium titanate (SrTiO3), lanthanum aluminate (LaAlO3), yttria (Y2O3), and ytterbium oxide (Yb2O3) and two rare earth superconductors, YBa2Cu3O7-x (YBCO) and YbBa2Cu3O7-x(YbBCO). C1 MicroCoating Technol Inc, Chamblee, GA 30341 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP MicroCoating Technol Inc, Chamblee, GA 30341 USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 7 TC 5 Z9 5 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 1999 VL 9 IS 2 BP 2426 EP 2429 DI 10.1109/77.784963 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300252 ER PT J AU Holesinger, TG Bingert, JF Willis, JO Li, Q Parrella, RD Teplitsky, MD Rupich, MW Riley, GN AF Holesinger, TG Bingert, JF Willis, JO Li, Q Parrella, RD Teplitsky, MD Rupich, MW Riley, GN TI Structural and compositional defects in high-J(c), Bi-2223 tapes SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT-DENSITY; GRAIN-BOUNDARIES; SHEATHED TAPES; MICROSTRUCTURE; GRANULARITY; POWDER AB High critical current density (J(c)) Bi-2223 multifilamentary tapes (55 kA/cm(2) less than or equal to J(c) less than or equal to 70 kA/cm(2), 77K and self-field) have been examined by transmission electron microscopy. Filament microstructures within the tapes consist of two distinct regions: a highly aligned,; dense colony structure (brick-wall) near the silver interface and a porous, poorly-textured interior region (impurity channel) that contains significantly more secondary phases. Quantitative compositional analysis clearly showed a heterogeneity in the Bi-2223 composition throughout the tapes. Spatial variations in composition were especially prevalent in the vicinity of secondary phases. Potential current limiting microstructures or defects were categorized depending upon the length scale at which they would operate. Macroscale defects were defined as potentially limiting current flow between regions of a filament. Mesoscale defects affect current flow between adjoining colonies, And finally, microscale defects were classified as potentially limiting current flow within a colony structure. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Amer Superconductor, Westborough, MA 01581 USA. RP Holesinger, TG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 23 TC 24 Z9 24 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2440 EP 2445 DI 10.1109/77.784969 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300255 ER PT J AU Balachandran, U Lelovic, M Prorok, BC Eror, NG Selvamanickam, V Haldar, P AF Balachandran, U Lelovic, M Prorok, BC Eror, NG Selvamanickam, V Haldar, P TI Advances in fabrication of Ag-clad Bi-2223 superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT DENSITY; SILVER-SHEATHED TAPES; COLUMNAR DEFECTS; (BI,PB)(2)SR2CA2CU3OX TAPES; IRREVERSIBILITY FIELD; TRANSPORT; MODEL; MAGNETIZATION; HEAT; BOUNDARIES AB Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi2Sr2Ca2Cu3Oy (Bi-2223) superconductors for various electric power applications. The transport current properties of long lengths of multifilament tapes were enhanced by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J(c) was > 10(4) A/cm(2) at 20 K in magnetic fields up to 3 T and parallel to the c axis, which is of interest for use in refrigerator-cooled magnets. An attempt was made to combine the good alignment of Bi-2223 grains in Ag-sheathed superconducting tapes to obtain high Je values at high temperature and low field, with the good intrinsic pinning of YBa2Cu3O7-d (Y-123) thin film, in order to maintain high J(c) values in high fields. A new composite multifilament tape was fabricated such that the central part contained Bi-2223 filaments, with the primary function of conducting the transport current. The central Bi-2223 filaments were surrounded by Y-123 thin film to shield the applied magnetic field and protect the Bi-2223 filaments. The J(c) values of the composite tape were better than those of an uncoated tape. In the case of 77 K applications, an I-c of approximate to 60 A was obtained in a 150-m-long tape and zero applied magnetic field. In-situ strain characteristics of the mono- and multifilament tapes were measured. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Pittsburgh, Pittsburgh, PA 15261 USA. Intermagnet Gen Corp, Latham, NY 12110 USA. RP Balachandran, U (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Prorok, Barton/A-7404-2010 NR 41 TC 14 Z9 14 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2474 EP 2479 DI 10.1109/77.784980 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300262 ER PT J AU Merchant, NN Miller, DJ Maroni, VA Parrella, RD Li, Q Rupich, MW Carter, WL Riley, GN AF Merchant, NN Miller, DJ Maroni, VA Parrella, RD Li, Q Rupich, MW Carter, WL Riley, GN TI Phase stability and grain growth in an Ag/Bi-2223 composite conductor prepared using fine-grained Bi-2223 as a precursor SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID WIRE; SUPERCONDUCTORS; MICROSTRUCTURE; EVOLUTION; PROGRESS AB We have investigated the stability and microstructural transformability of the Bi-2223 phase in a silver-sheathed monofilament composite Bi-2223 precursor was prepared using established procedures. The purpose of this study was to explore the prospects for growing textured, large-grain-size Bi-2223 from the fine-grained precursor by process parameter perturbations. These perturbations included thermal ramp up variations, programmed heat treatment temperature and oxygen pressure fluctuations, and parameter manipulations during cool-down. Our results show that the types of heat treatments used in conventional oxide-powder-in-tube (OPIT) processing do not facilitate Bi-2223 grain growth when the precursor powder is preconverted Bi-2223. We also observed that the Bi-2223 partially decomposed during conventional thermal ramp-up in 0.075 atm O-2, but that this decomposition can be inhibited by ramping up In a reduced oxygen pressure. A pathway was found for back reacting the fine-grained Bi-2223 (to Bi-2212, Bi-2201 and nonsuperconducting secondary phases), then reforming large-grained Bi-2223 in a colony microstructure having some distinct differences from that produced during conventional OPIT OPIT processing. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Amer Superconductor Corp, Westborough, MA 01581 USA. RP Merchant, NN (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2545 EP 2548 DI 10.1109/77.785005 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300278 ER PT J AU Verebelyi, DT Prouteau, C Feenstra, R Christen, DK AF Verebelyi, DT Prouteau, C Feenstra, R Christen, DK TI Critical current of YBCO grain boundaries in large magnetic fields SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTING TAPES; JOSEPHSON-JUNCTIONS; THIN-FILMS; YBA2CU3O7-DELTA; BICRYSTAL AB Superconducting electrical transport across single grain boundaries (GB's) in YBCO shows interesting behavior in substantial magnetic fields. Measurements on [001] tilt bicrystal YBCO thin films in strong magnetic fields are consistent with the following: Low-angle GB's (<10 degrees) are composed of well-ordered bridges that act as strong superconducting inter-granular links; large-angle GB's exhibit weak coupling behavior that retains a well defined critical current even at high field. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Verebelyi, DT (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2655 EP 2658 DI 10.1109/77.785032 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300305 ER PT J AU Cai, ZX Welch, DO Dubey, GS AF Cai, ZX Welch, DO Dubey, GS TI Numerical simulations of elastic properties of flux-line lattices in high-T-c superconductors SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID MONTE-CARLO SIMULATION; VORTEX-LATTICE; BI2SR2CACU2O8 CRYSTALS; IRREVERSIBILITY LINE; MODEL; TRANSITION AB We propose a quantitative model of the effective interaction between the magnetic flux-lines in a layered superconductor. It is derived from the Lawrence-Doniach model with all of its parameters derivable from experiments. Numerical simulations are performed using Langevin dynamics technique for parameters suitable for Bi-2212. We studied the elastic properties of flux line lattices with various values of interlayer coupling strength and pinning strengths. We show that the "softening" of the flux-line lattices with increasing temperature is mainly due to the increase of configurational entropy of the lattice. The calculated results show good agreement with experimental observations and provide a unique way to study the properties of flux-line lattices with random pinning. C1 Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. CUNY Hunter Coll, Dept Phys, New York, NY 10021 USA. RP Cai, ZX (reprint author), Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2674 EP 2677 DI 10.1109/77.785037 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300310 ER PT J AU Cai, ZX Zhu, YM AF Cai, ZX Zhu, YM TI Dislocation-assisted-diffusion model for the kinetics of bismuth cuprate 2212-to-2223 transformation SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID MECHANISM; PHASE; TAPE AB Recent transmission electron microscopy (TEM) experiments have shown that the transformation of the Bi cuprate 2212 phase to 2223 phase consists of random intercalation and fast growth of Ca/CuO2 planes in the Bi-2212 matrix. This contradicts with the prediction of the conventional nucleation and growth theory. A model is proposed which considers the cylindrical void created by the edge dislocation due to the insertion of a Ca/CuO2 plane to be a channel for fast ion diffusion. The experimentally observed time dependence of the volume fraction of Bi-2223 during the transformation is found to be consistent with a one-dimensional diffusion-controlled transformation mechanism, are predicted by our model; The formation energy of Bi-2223 is estimated and is consistent with the results of atomistic simulations. C1 Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. RP Cai, ZX (reprint author), Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2714 EP 2717 DI 10.1109/77.785046 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MA UT WOS:000081964300319 ER PT J AU Ozyuzer, L Miyakawa, N Zasadzinski, JF Yusof, Z Romano, P Kendziora, C Guptasarma, P Hinks, DG Gray, KE AF Ozyuzer, L Miyakawa, N Zasadzinski, JF Yusof, Z Romano, P Kendziora, C Guptasarma, P Hinks, DG Gray, KE TI Simultaneous quasiparticle and Josephson tunneling in BSCCO-2212 break junctions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID T-C SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; TEMPERATURE; SPECTROSCOPY; GAP; SYMMETRY AB Tunneling measurements are reported for superconductor-insulator-superconductor (SIS) break junctions on underdoped, optimally-doped, and overdoped single crystals of Bi2Sr2CaCu2O8+delta (Bi-2212). The junction I - V characteristics exhibit well-defined quasiparticle current jumps at eV = 2 Delta as well as hysteretic Josephson currents. The quasiparticle branch has been analyzed in the framework of d(x2-y2) (d-wave) superconductivity and indicates that there is preferential tunneling along the lobe directions of the d-wave gap. For overdoped Bi-2212 with T-c=62 K, the Josephson current is measured as a function of junction resistance, R-n, which varied by two orders of magnitude (1 k Omega to 100 k Omega). IcRn product is proportional to the 0.47 power of I-c and displays a maximum of 7.0 mV. When the hole doping is decreased from overdoped (T-c=62 K) to the underdoped regime (T-c=70 K), the average IcRn product increases as does the quasiparticle gap. The maximum IcRn is similar to 40% of the Delta/e at each doping level, with a value as high as 25 mV in underdoped Bi-2212. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Izmir Inst Technol, Dept Phys, Izmir, Turkey. Sci Univ Tokyo, Dept Appl Phys, Tokyo 162, Japan. IIT, Chicago, IL 60616 USA. USN, Res Lab, Washington, DC 20375 USA. RP Ozyuzer, L (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ozyuzer, Lutfi/H-3142-2011 NR 19 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2898 EP 2901 DI 10.1109/77.783635 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500015 ER PT J AU Kraus, RH Flynn, ER Espy, MA Matlashov, A Overton, W Peters, MV Ruminer, P AF Kraus, RH Flynn, ER Espy, MA Matlashov, A Overton, W Peters, MV Ruminer, P TI First results for a novel superconducting imaging-surface sensor array SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A superconducting imaging-surface system was constructed using 12 coplanar thin-film SQUID magnetometers located parallel to and spaced 2 cm from a 25 cm diameter lead imaging-plane. Some measurements included two additional sensors on the "back" side of the superconducting imaging-plane to study the field symmetry for our system. Performance was measured in a shielded can and in the open laboratory environment. Data from this system has been used to: (a) understand the noise characteristics of the dewar-SQUID imaging plate arrangement, (b) to verify the imaging principle, (c) measure the background rejection factor of the imaging plane, and (d) compare superconducting materials for the imaging plane. A phantom source field was measured at the sensors as a function of phantom distance from the sensor array to verify the imaging theory. Both the shape and absolute values of the measured and predicted curves agree very well indicating the system is behaving as a gradiometer in accordance with theory. The output from SQUIDs located behind the imaging surface that sense background fields can be used for software or analog background cancellation. Fields arising from sources close to the imaging plane were shielded form the background sensors by more than a factor of 1000, Measurement of the symmetry of sensor sensitivity to uniform fields exactly followed theoretical predictions. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kraus, RH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 2927 EP 2930 DI 10.1109/77.783643 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500023 ER PT J AU Cho, HM McDermott, R Oh, B Kouznetsov, KA Kittel, A Miller, JH Clarke, J AF Cho, HM McDermott, R Oh, B Kouznetsov, KA Kittel, A Miller, JH Clarke, J TI Low-frequency noise in field-cooled, directly coupled magnetometers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID QUANTUM INTERFERENCE DEVICES; MAGNETIC-FIELD; FLUX NOISE; 1/F NOISE AB We have studied the low-frequency noise properties of high-T-c directly coupled magnetometers involving de Superconducting Quantum Interference Devices (SQUIDs) connected to four different types of-pickup loop. Two of the pickup loops have a solid-washer design, while the other two comprise structures with narrow (4 mu m) linewidths. The devices were fabricated from YBCO thin films laser deposited on bicrystal substrates. The noise properties of the magnetometers cooled and maintained in static magnetic fields were measured at 77 K. The pickup loop contributes to the 1/f noise of held-cooled devices solely through vortex motion at tapered outer edges; this noise was eliminated by repatterning the edges to make them sharp. We demonstrate that solid-him washers can be replaced with narrow-linewidth structures without any loss in effective area. C1 Univ Houston, Houston, TX USA. Univ Houston, Texas Ctr Superconduct, Houston, TX USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Cho, HM (reprint author), LG Grp, Seoul, South Korea. NR 9 TC 19 Z9 19 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3294 EP 3297 DI 10.1109/77.783733 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500113 ER PT J AU Espy, MA Flynn, ER Kraus, RH Matlashov, AN AF Espy, MA Flynn, ER Kraus, RH Matlashov, AN TI Two methods for a first order hardware gradiometer using two HTS SQUIDs SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB Two types of first order electronic gradiometers have been developed using high temperature superconducting (HTS) SQUIDs. Gradiometry is accomplished in hardware by either 1) subtracting the output of the signal and background SQUIDs in a summing amplifier (parallel technique) or 2) converting the inverted background SQUID output to a magnetic field at the sensor SQUID (series technique). Balance levels achieved are 2000 and 1000 at 20 Hz for the parallel and series methods respectively. Balance level as a function of frequency is presented. Balance level for hardware gradiometry is limited by time delays from the electronics and how well the signal amplitudes are matched. A simple algorithm that allows one to estimate the limit on balance level from these factors is presented and compared with data. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Espy, MA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3302 EP 3305 DI 10.1109/77.783735 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500115 ER PT J AU Friedrich, S le Grand, JB Hiller, LJ Kipp, J Frank, M Labov, SE Cramer, SP Barfknecht, AT AF Friedrich, S le Grand, JB Hiller, LJ Kipp, J Frank, M Labov, SE Cramer, SP Barfknecht, AT TI High-resolution tunnel junction extreme ultraviolet detectors limited by quasiparticle counting statistics SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID X-RAY SPECTROMETERS; PARTICLE DETECTORS; NOISE AB Superconducting tunnel junctions (STJs) can be used as high-resolution high-count rate photon detectors. They are based on the measurement of the excess quasiparticle tunneling current caused by the absorption of a photon in one of the junction electrodes, We have fabricated Nb-Al-AlOx-Al-Nb tunnel junction detectors with different sizes and characterized them in sychrotron experiments. We present a study of the detector performance in the energy band between 50 and 1000 eV, For photon energies below 70 eV, the intrinsic device resolution of the best STJ devices agrees with the theoretical limit set by the statistics of the charge generation and tunneling processes. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Conductus Inc, Sunnyvale, CA 94086 USA. RP Friedrich, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-418, Livermore, CA 94550 USA. RI Frank, Matthias/O-9055-2014 NR 21 TC 26 Z9 26 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3330 EP 3333 DI 10.1109/77.783742 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500122 ER PT J AU Moeckly, BH Char, K Huang, Y Merkle, KL AF Moeckly, BH Char, K Huang, Y Merkle, KL TI Interface-engineered YBCO edge junctions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID C JOSEPHSON-JUNCTIONS AB We have fabricated all YBCO edge junctions which do not require the deposition of an interlayer or barrier material. Rather, through appropriate high-temperature vacuum annealing and in-situ ion plasma treatments, we have modified the junction interface in such a way as to lead to reliable weak link behavior. These devices display RSJ-type I-V characteristics with excellent magnetic field modulation. IcRn values over the range 0.5 to 3 mV and corresponding R(n)4 values of 6x10(-8) to 1.2x10(-9) Omega-cm(2) at 20 K are easily attained by varying the process, which is not possible in most high-T-c junction technologies. These junctions can also be very uniform and appear to be quite stable. We have observed an unusual response to applied microwave radiation, We have investigated the microstructure of these junctions using transmission electron microscopy (TEM). Results of these analyses lead us to believe these junctions are feasible as the basic components of a high-T-c circuit technology. C1 Conductus Inc, Sunnyvale, CA 94086 USA. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Moeckly, BH (reprint author), Conductus Inc, 969 W Maude Ave, Sunnyvale, CA 94086 USA. NR 8 TC 17 Z9 17 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3358 EP 3361 DI 10.1109/77.783749 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500129 ER PT J AU Jia, QX Fan, Y Kwon, C Mombourquette, C Reagor, D Cantor, R Zhou, JP Gim, Y Jones, C McDevitt, JT Goodenough, JB AF Jia, QX Fan, Y Kwon, C Mombourquette, C Reagor, D Cantor, R Zhou, JP Gim, Y Jones, C McDevitt, JT Goodenough, JB TI Development of ramp-edge SNS junctions using highly stable normal-metal barrier materials SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID JOSEPHSON-JUNCTIONS; DC SQUIDS; LAYERS AB By using a cation-modified and corrosion-resistant compound of (PryGd0.6-y)Ca0.4Ba1.6La0.4Cu3O7 (y = 0.4, 0.5, and 0.6) as normal-metal barrier materials, high-temperature superconducting Josephson junctions have been fabricated in a ramp-edge superconductor/normal-metal/superconductor (SNS) configuration. We have tuned the Pr substitution level in order to achieve the optimal electrical resistivity of the barrier layer for high-performance SNS junctions. The junctions fabricated with these normal-metal barriers show well-defined RSJ-like current vs voltage characteristics at liquid-nitrogen temperature. The junction performance is mainly controlled by the N-layer instead of the interface. We have also fabricated de superconducting quantum interference devices based on ramp-edge SNS technology with these normal-metal barriers. The ratio of peak-to-peak voltage modulation of the superconducting quantum interference devices to the IcRn product is more than 30%. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, MS K763, Los Alamos, NM 87545 USA. RI Kwon, Chuhee/A-8687-2008; Jia, Q. X./C-5194-2008; OI McDevitt, John T/0000-0001-8789-9351 NR 15 TC 0 Z9 0 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3374 EP 3377 DI 10.1109/77.783753 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500133 ER PT J AU Matlashov, A Kraus, RH Espy, M Ruminer, P Atencio, L Garachtchenko, A AF Matlashov, A Kraus, RH Espy, M Ruminer, P Atencio, L Garachtchenko, A TI Sequential read-out architecture for multi-channel SQUID systems SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB We describe a novel multi-channel sequential SQUID read-out technique that requires fewer wires than conventional units and also simplifies the electronics significantly. We designed and experimentally tested the sequential read-out electronics with up to 8 channels using LTS 8 x 8 mm(2) magnetometers with better than 3 fT/root Hz field resolution. We have investigated noise performance, amplitude-frequency characteristics, and cross-talk of the sequential read-out electronics for 2, 4, and 8 channels. We observed field resolution better than 4 fT/root Hz, 6 fT/root Hz, and 9 fT/root Hz for 2-, 4-, and 8-channel versions, respectively, We observed 10 kHz frequency bandwidth for the 8-channel version using 200 kHz modulation frequency. Cross-talk better than -90dB was measured for this system. A single-channel simulation was used to estimate the field resolution for systems with up to 128 channels. We found that the expected field resolution can be better than 15 fT/root Hz, 20 fT/root Hz, and 30 fT/root Hz for 32-, 64-, and 128-channel systems, respectively, with the sequential read-out technique. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Appl Mat Inc, Santa Clara, CA 95054 USA. RP Matlashov, A (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 1 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3672 EP 3675 DI 10.1109/77.783825 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500205 ER PT J AU Garachtchenko, A Matlashov, A Kraus, RH Cantor, R AF Garachtchenko, A Matlashov, A Kraus, RH Cantor, R TI Baseline distance optimization for SQUID gradiometers SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB We optimized the baseline length of SQUID-based symmetric axial gradiometers using a computer simulation. The signal-to-noise ratio (SNR) was used as the optimization criteria. We found that in most cases the optimal baseline is not equal to the depth of the primary source, rather it has a more complex dependence on the gradiometer balance and the ambient magnetic noise. We studied both first and second order gradiometers in simulated shielded environments and second order gradiometers in a simulated unshielded environment. The noise source was simulated as a distant dipolar source for the shielded case. We present optimal gradiometer baseline lengths for the various simulated situations. C1 Appl Mat Inc, Santa Clara, CA 95054 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Garachtchenko, A (reprint author), Appl Mat Inc, Santa Clara, CA 95054 USA. NR 1 TC 9 Z9 9 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3676 EP 3679 DI 10.1109/77.783826 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500206 ER PT J AU Espy, MA Atencio, L Flynn, ER Kraus, RH Matlashov, A AF Espy, MA Atencio, L Flynn, ER Kraus, RH Matlashov, A TI Design and preliminary results from a high temperature superconducting SQUID milliscope used for non-destructive evaluation SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID EDDY-CURRENT TECHNIQUE; NONDESTRUCTIVE EVALUATION; HTS SQUIDS; GRADIOMETER AB We present the design and preliminary results from a SQUID 'milliscope'. The device was designed for non-destructive evaluation (NDE) as part of the Enhanced Surveillance Program at Los Alamos National Laboratory. A high temperature superconducting (HTS) SQUID sensor is used to map magnetic fields induced in the sample. Eddy currents are induced in the conducting sample by a wire coil designed to produce minimal magnetic field at the SQUID when no sample is present. The features of interest are characterized by anomalies in the induced magnetic field. The goal of the instrument is sensitivity to small features generally buried under several intervening layers (similar to 1-20 mm) of conducting and/or non-conducting materials and robustness of design (i.e. the ability to operate in a noisy, unshielded environment). The device has primarily focussed on specific NDE problems such as the ability to detect buried "seams" in conducting materials and quantify the width of these seams. We present the design of the instrument, and some data to demonstrate its capabilities. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Espy, MA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3692 EP 3695 DI 10.1109/77.783830 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500210 ER PT J AU Espy, MA Matlashov, A Kraus, RH Ruminer, P Cooper, M Lamoreaux, S AF Espy, MA Matlashov, A Kraus, RH Ruminer, P Cooper, M Lamoreaux, S TI SQUIDS as detectors in a new experiment to measure the neutron electric dipole moment SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA AB A new experiment has been proposed at Los Alamos National Laboratory to measure the neutron electric dipole moment (EDM) to 4x10(-28) ecm, a factor of 250 times better than the current experimental limit. Such a measure of the neutron EDM would challenge the theories of supersymmetry and time reversal violation as the origin of the observed cosmological asymmetry in the ratio of baryons to antibaryons. One possible design for this new experiment includes the use of low temperature superconducting (LTS) SQUIDs coupled to large (similar to 100 cm(2)) pick-up coils to measure the precession frequency of the spin-polarized He-3 atoms that act as polarizer, spin analyzer, and detector for the ultra-cold neutrons used in the experiment. The method of directly measuring the 3He precession signal eliminates the need for very uniform magnetic fields (a major source of systematic error in these types of experiments). It is estimated that a nux of similar to 2x10(-16) Tm-2 (0.1 Phi(0)) will be coupled into the pick-up coils. To achieve the required signal-to-noise ratio one must have a flux resolution of d Phi(SQ)=5x10(-6) Phi(0)/Hz at 10 Hz. While this is close to the sensitivity available in commercial devices, the effects of coupling to such a large pick-up coil and nus noise from other sources in the experiment still need to be understood. To determine the feasibility of using SQUIDs in such an application we designed and built a superconducting test cell, which simulates major features of the proposed EDM experiment, and we developed a two-SQUID readout system that will reduce SQUID noise in the experiment. We present an overview of the EDM experiment with SQUIDs, estimations of required SQUID parameters and experimental considerations. We also present the measured performance of a single magnetometer in the test cell as well as the performance of the two SQUID readout technique. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Espy, MA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 4 TC 4 Z9 5 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 3696 EP 3699 DI 10.1109/77.783831 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500211 ER PT J AU Shaw, TJ Schlenga, K McDermott, R Clarke, J Chan, JW Kang, SH Morris, JW AF Shaw, TJ Schlenga, K McDermott, R Clarke, J Chan, JW Kang, SH Morris, JW TI High-T-c SQUID microscope study of the effects of microstructure and deformation on the remanent magnetization of steel SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID DUPLEX STAINLESS-STEEL; NONDESTRUCTIVE EVALUATION; MAGNETOMETRY; NDE AB We have studied the effects of heat treatment and mechanical stress on the remanent magnetization of ferromagnetic steels using a high-transition temperature (HTC) Superconducting QUantum Interference Device (SQUID) microscope. Samples were prepared by different heat treatments, which produced varied microstructures, and different rolling treatments, which produced varied levels of deformation. The samples were subsequently magnetized in fields of 50 mT, and the remanent magnetization was measured by rastering the sample over the SQUID using a two-dimensional (2D) translation stage with a scanning range of 50 mm X 50 mm. With a separation between the SQUID and sample of approximately 0.5 mm, this produced a 2D magnetic field image due to the local remanent magnetization of the sample. In addition, microstructural information was determined using optical imaging, allowing us to correlate the effects of heat treatment and mechanical stress on local remanent magnetization with detailed microstructural information, Since the strength and integrity of steels can be well predicted from microstructural information, correlation of this information with the 2D remanent magnetization images could lead to an effective method for the non-destructive evaluation of ferromagnetic steels through a simple measurement of remanent magnetization. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Shaw, TJ (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 11 TC 17 Z9 17 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 4107 EP 4110 DI 10.1109/77.783929 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500309 ER PT J AU Cirillo, M Merlo, V Gronbech-Jensen, N AF Cirillo, M Merlo, V Gronbech-Jensen, N TI Analysis of linear branches in the I-V characteristics of Josephson junctions SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CA AB Resistive branches have often been observed in the current-voltage characteristics of long Josephson junctions. In the present paper we perform a systematic numerical analysis of the generation of these branches when an external magnetic field is applied to the junctions. We show that the linear branches exist only over a limited voltage interval which is determined quantitatively, We also clarify to what extent the linear branches can be attributed to flux-flow effects. C1 Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Univ Roma Tor Vergata, Unita INFM, I-00133 Rome, Italy. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. RP Cirillo, M (reprint author), Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. OI merlo, vittorio/0000-0002-4858-3714 NR 10 TC 3 Z9 3 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 4137 EP 4140 DI 10.1109/77.783936 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500316 ER PT J AU Schlenga, K McDermott, RF Clarke, J de Souza, RE Wong-Foy, A Pines, A AF Schlenga, K McDermott, RF Clarke, J de Souza, RE Wong-Foy, A Pines, A TI High-T-c SQUIDs for low-field NMR and MRI of room temperature samples SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 1998 Applied Superconductivity Conference CY SEP 13-18, 1998 CL PALM DESERT, CALIFORNIA ID QUANTUM INTERFERENCE DEVICE; NUCLEAR-QUADRUPOLE RESONANCE; MAGNETIC-RESONANCE; DC SQUID; SPECTROMETER; FREQUENCIES AB We have constructed a high-T-c SQUID spectrometer to detect NMR signals from samples at room temperature in magnetic fields up to 3 mT. The multiloop SQUID magnetometer has a system noise of about 30 fT/Hz(1/2) at the relevant frequencies of 2 to 100 kHz, The magnetometer is operated in vacuum at 77 K, and is separated from the sample, which is less than 1.5 mm away, by a sapphire window, In a magnetic field of 2 mT we can detect the proton spin echo at 86 kHz without signal averaging. This sensitivity enables us to obtain one-dimensional images. In addition, we present data on hyperpolarized Xe-129, which has an optically pumped polarization of several percent. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Schlenga, K (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 18 TC 7 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 1999 VL 9 IS 2 BP 4424 EP 4427 DI 10.1109/77.784006 PN 3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 225MC UT WOS:000081964500386 ER PT J AU Smeys, P Griffin, PB Rek, ZU De Wolf, I Saraswat, KC AF Smeys, P Griffin, PB Rek, ZU De Wolf, I Saraswat, KC TI Influence of process-induced stress on device characteristics and its impact on scaled device performance SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE isolation technologies; MOSFET's; semiconductor junctions; X-ray measurements ID MICRO-RAMAN; SPECTROSCOPY; CONTRAST; STRAIN AB This paper reports on the effects of oxidation-induced stress on the generation current in pn-junction and gated diodes. It is observed that even in the regime where no extended defects are present, the generation current is a strong function of the compressive stress in the substrate. Experimental results are presented revealing an order of magnitude increase in generation current for stress changes of a few 100 MPa's, A stress-induced bandgap narrowing model that describes the relationship between the oxidation-induced stress and the generation current in MOS devices is proposed and experimentally verified. Using this model, we have calculated the stress-induced generation current in scaled shallow trench isolated (STI) devices due to reoxidation after STI formation. As the device pitch is reduced a large increase in stress and leakage current is observed, consistent with the experimental data. C1 Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. IMEC, B-3001 Louvain, Belgium. RP Smeys, P (reprint author), IBM Corp, Semicond R&D Ctr, Hopewell Junction, NY 12533 USA. NR 34 TC 48 Z9 48 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD JUN PY 1999 VL 46 IS 6 BP 1245 EP 1252 DI 10.1109/16.766893 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 200GZ UT WOS:000080532400028 ER PT J AU Buchler, M Funk, W Gutierrez, A Harr, RF Karchin, PE Liu, P Nam, S Shiu, JG Takach, SF Atiya, M Padrazo, D Arefiev, A Barsuk, S Khasanov, F Laptin, L Tchoudakov, V Tichimirov, I Titov, M Zaitsev, Y AF Buchler, M Funk, W Gutierrez, A Harr, RF Karchin, PE Liu, P Nam, S Shiu, JG Takach, SF Atiya, M Padrazo, D Arefiev, A Barsuk, S Khasanov, F Laptin, L Tchoudakov, V Tichimirov, I Titov, M Zaitsev, Y TI Design and operation of front-end electronics for the HERA-B muon detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB We have implemented: a cost-effective design for the readout electronics of both the anode wires and the cathode pads of large area proportional wire chambers for the HERA-B muon system based on the ASD-80 integrated circuit. To control and monitor the large number of readout channels, we have built a: distributed control system based on Philips Semiconductors' (IC)-C-2 bus and microcontrollers. To date we have installed about 10800 channels of muon chambers and electronics. The average single channel noise occupancy is less than 10(-5), and the detectors have been operated with target interaction rates as high as 70 MHz. C1 Wayne State Univ, Dept Phys, Detroit, MI 48201 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. RP Buchler, M (reprint author), Wayne State Univ, Dept Phys, Detroit, MI 48201 USA. NR 5 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 126 EP 132 DI 10.1109/23.775501 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800003 ER PT J AU Kandasamy, A O'Brien, E O'Connor, P Von Achen, W AF Kandasamy, A O'Brien, E O'Connor, P Von Achen, W TI A monolithic preamplifier-shaper for measurement of energy loss and transition radiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID DETECTORS AB A custom monolithic circuit has,been developed for the Time Expansion Chamber (TEC) of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). This detector identifies particles by sampling their ionization energy loss (dE/dx) over a 3 cm drift space and by detecting associated transition radiation (TR) photons. The requirement of being simultaneously sensitive to dE/dx and TR events requires a dual-gain system. We have developed a compact solution featuring an octal preamplifier/shaper (P/S) IC with a split gain stage. The circuit, fabricated in 1.2 mu m CMOS process, incorporates a trans-impedance preamplifier and a 70 ns unipolar CR-RC4 shaper with ion tail compensation and active DC offset cancellation. Digitally selectable gain, peaking time, and tail cancellation as well as channel-by-channel charge injection and disable can be configured in the system via a 3-wire interface. The 3.5 x 4.5 mm(2) die is packaged in a fine pitch 64-pin PQFP. Equivalent input noise is less than 1500 rms electrons at a power dissipation of 30 mW per channel. On a sample of 2400 chips, the DC offset was 2.3 +/- 3 mV rms without trimming. A chamber-mounted TEC-PS Printed Circuit Board (PCB) houses four P/S chips, on-beard calibration circuit, and 64 analog differential line drivers which transmit the shaped pulses to crate-mounted-flash ADC's 7 m apart. An RS-422 link provides digital configuration downloading and read back; and supplies the calibration strobe. The 24.6 cm x 9.5 cm board dissipates 8.5 W. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. RP Kandasamy, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 8 Z9 8 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 150 EP 155 DI 10.1109/23.775505 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800007 ER PT J AU Einsweiler, K Joshi, A Kleinfelder, S Luo, L Marchesini, R Milgrome, O Pengg, F AF Einsweiler, K Joshi, A Kleinfelder, S Luo, L Marchesini, R Milgrome, O Pengg, F TI Dead-time free pixel readout architecture for ATLAS front-end IC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID DETECTOR READOUT AB A low-power, sparse-scan, readout architecture has been-developed for the ATLAS pixel front-end electronics. The architecture supports a dual discriminator and extracts the time over threshold (TOT) information along with a 2-D spatial address of the hits and associates them with a unique 7-bit beam crossing number. The IC implements level-1 trigger filtering along with event building (grouping together all hits in a beam crossing) in the end of column (EOC) buffer. The events are transmitted over a 40 MHz serial data link with the protocol Supporting buffer overflow handling by appending error flags td events. This mixed-mode full custom IC is implemented in 0.8 mu HP process to meet the requirements for the pixel readout in the ATLAS inner detector. The circuits have been tested and the IC has been found to provide deadtime-less ambiguity-free readout at 40MHz data rate. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Einsweiler, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 166 EP 170 DI 10.1109/23.775508 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800010 ER PT J AU Bellwied, R Beuttenmuller, R Brandon, N Caines, H Chen, W DiMassimo, D Dyke, H Hoffmann, GW Humanic, TJ Kotova, AI Kotov, IV Kraner, HW Li, Z Lynn, D Minor, B Ott, G Pandey, SU Pruneau, C Rykov, VL Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK AF Bellwied, R Beuttenmuller, R Brandon, N Caines, H Chen, W DiMassimo, D Dyke, H Hoffmann, GW Humanic, TJ Kotova, AI Kotov, IV Kraner, HW Li, Z Lynn, D Minor, B Ott, G Pandey, SU Pruneau, C Rykov, VL Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK TI Two dimensional studies of dynamics of electron clouds in silicon drift detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID STAR EXPERIMENT AB The dynamics of electrons generated in silicon drift detectors is studied using an IR LED. Electrons were generated at different drift distances. In this way the evolution of the cloud in anode and drift directions as a function of drift time was measured. For the anode direction the method of cumulative functions was used to extract the electron cloud profiles. The cloud width was obtained also from measurements of the charge collected on a single anode as a function of the coordinate of the Tight spot. We present the first report of the experimental measurements of the cloud width in drift direction extracted from signal waveforms. The evolution of the electron cloud width with drift time is compared with theoretical calculations. Theoretical expectations agree with our experimental results. C1 Ohio State Univ, Columbus, OH 43210 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Texas, Austin, TX 78712 USA. Wayne State Univ, Detroit, MI 48201 USA. IHEP, RU-148284 Protvino, Moscow Region, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kotov, IV (reprint author), Ohio State Univ, Columbus, OH 43210 USA. RI Takahashi, Jun/B-2946-2012 OI Takahashi, Jun/0000-0002-4091-1779 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 176 EP 180 DI 10.1109/23.775510 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800012 ER PT J AU Schnetzer, S Adam, W Bauer, C Berdermann, E Bergonzo, P Bogani, F Borchi, E Brambilla, A Bruzzi, M Colledani, C Conway, J Dabrowski, W DaGraca, J Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fizzotti, F Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Jamieson, D Kagan, H Kania, D Kaplon, J Karl, C Kass, R Knoepfle, KT Krammer, M Logiudice, A Lu, R Manfredi, PF Manfredotti, C Marshall, RD Meier, D Mishina, M Oh, A Pan, LS Palmieri, VG Pernicka, M Pietz, A Pirollo, S Plano, R Polesello, P Prawer, S Pretzl, K Procario, M Re, V Riester, JL Roe, S Roff, D Rudge, A Runolfsson, O Russ, J Sciortino, S Somalwar, SV Speziali, V Stelzer, H Stone, R Suter, B Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Vittone, E Walsh, AM Wedenig, R Weilhammer, P White, C Ziock, H Zoeller, M AF Schnetzer, S Adam, W Bauer, C Berdermann, E Bergonzo, P Bogani, F Borchi, E Brambilla, A Bruzzi, M Colledani, C Conway, J Dabrowski, W DaGraca, J Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fizzotti, F Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Jamieson, D Kagan, H Kania, D Kaplon, J Karl, C Kass, R Knoepfle, KT Krammer, M Logiudice, A Lu, R Manfredi, PF Manfredotti, C Marshall, RD Meier, D Mishina, M Oh, A Pan, LS Palmieri, VG Pernicka, M Pietz, A Pirollo, S Plano, R Polesello, P Prawer, S Pretzl, K Procario, M Re, V Riester, JL Roe, S Roff, D Rudge, A Runolfsson, O Russ, J Sciortino, S Somalwar, SV Speziali, V Stelzer, H Stone, R Suter, B Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Vittone, E Walsh, AM Wedenig, R Weilhammer, P White, C Ziock, H Zoeller, M TI Tracking with CVD diamond radiation sensors at high luminosity colliders SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID READOUT AB Recent progress on developing diamond-based sensors for vertex detection at high luminosity hadron colliders is described. Measurements of the performance of diamond sensors after irradiation to fluences of up to 5 x 10(15) hadrons/cm(2) are shown. These indicate that diamond sensors will operate at distances as close as 5 cm from the interaction point at the Large Hadron Collider (LHC) for many years at full luminosity without significant degradation in performance. Measurements of the quality of the signals from diamond sensors as well as spatial uniformity are presented. Test beam results on measurements of diamond-based microstrip and pixels devices are described. C1 Rutgers State Univ, Piscataway, NJ 08854 USA. Osterreich Akad Wissensch, Inst Hochenergiephys, Vienna, Austria. MPI Kernphys, Heidelberg, Germany. GSI Darmstadt, D-6100 Darmstadt, Germany. LETI, Grenoble, France. LENS, Florence, Italy. Univ Florence, Florence, Italy. ULP, IN2P3, CNRS, LEPSI, Strasbourg, France. CERN, Geneva, Switzerland. CPPM, Marseille, France. LEPES, Grenoble, France. NIKHEF, Amsterdam, Netherlands. Univ Turin, Turin, Italy. Ohio State Univ, Columbus, OH 43210 USA. Univ Bristol, Bristol, Avon, England. Univ Melbourne, Melbourne, Vic, Australia. Univ Hamburg, Inst Expt Phys 2, D-2000 Hamburg, Germany. Univ Pavia, Dipartimento Elettron, Pavia, Italy. Fermilab, Batavia, IL USA. Lab Hochenergiephys, Bern, Switzerland. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Toronto, Toronto, ON, Canada. IIT, Chicago, IL 60616 USA. LANL, Los Alamos, NM USA. RP Schnetzer, S (reprint author), Rutgers State Univ, Piscataway, NJ 08854 USA. RI Jamieson, David/G-3753-2010; Krammer, Manfred/A-6508-2010; Lujan Center, LANL/G-4896-2012; Lo Giudice, Alessandro/J-4567-2012; Grigoriev, Eugene/K-6650-2013; Russ, James/P-3092-2014; Bruzzi, Mara/K-1326-2015; Bergonzo, Philippe/A-6567-2015; Gheeraert, Etienne/E-8071-2015; OI PRAWER, STEVEN/0000-0002-4959-0828; Krammer, Manfred/0000-0003-2257-7751; Lo Giudice, Alessandro/0000-0003-4753-3165; Grigoriev, Eugene/0000-0001-7235-9715; Russ, James/0000-0001-9856-9155; Bruzzi, Mara/0000-0001-7344-8365; Bergonzo, Philippe/0000-0002-0647-9134; Gheeraert, Etienne/0000-0002-9952-5805; Jamieson, David/0000-0001-7733-6715; vittone, ettore/0000-0003-3133-3687; Re, Valerio/0000-0003-0697-3420; Sciortino, Silvio/0000-0003-0570-7489 NR 6 TC 11 Z9 11 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 193 EP 200 DI 10.1109/23.775513 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800015 ER PT J AU Amman, M Luke, PN AF Amman, M Luke, PN TI Optimization criteria for coplanar-grid detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID CDZNTE DETECTORS AB The coplanar-grid charge-sensing technique is a powerful method to achieve excellent spectroscopic performance with large-volume, CdZnTe-based, gamma-ray detectors despite the poor charge transport characteristics of the CdZnTe material. Critical to the success of the technique are the charge induction characteristics of the sensing-grid electrodes as governed by the detector geometry and the grid design. In this paper we demonstrate through numerical calculations of the detector response that the criteria for optimizing the grid design depend on the particular method in which the coplanar-grid technique is implemented. We present the fundamental design criteria in terms of the desired charge induction on the grid electrodes for the commonly used coplanar-grid implementations. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Amman, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 11 TC 33 Z9 33 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 205 EP 212 DI 10.1109/23.775515 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800017 ER PT J AU Dezillie, B Li, Z Eremin, V Bruzzi, M Pirollo, S Pandey, SU Li, CJ AF Dezillie, B Li, Z Eremin, V Bruzzi, M Pirollo, S Pandey, SU Li, CJ TI Improved neutron radiation hardness for Si detectors: Application of low resistivity starting material and or manipulation of N-eff by selective filling of radiation-induced traps at low temperatures SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID SILICON DETECTORS AB Radiation-induced electrical changes in both space charge region (SCR) of Si detectors and bulk material (BM) have been studied for samples of diodes and resistors made on Si materials with different initial resistivities. The space charge sign inversion fluence (Phi(inv)) has been found to increase linearly with the initial doping concentration (the reciprocal of the resistivity), which gives improved radiation hardness to Si detectors fabricated from low resistivity material. The resistivity of the BM, on the other hand, has been observed to increase with the neutron fluence and approach a saturation value in the order of hundreds k Omega cm at high fluences, independent of the initial resistivity and material type. However, the fluence (Phi(s)), at which the resistivity saturation starts, increases with the initial doping concentrations and the value of Phi(s) is in the same order of that of Phi(inv) for all resistivity samples. Improved radiation hardness can also be achieved by the manipulation of the space charge concentration (N-eff) in SCR, by selective filling and/or freezing at cryogenic temperatures the charge state of radiation-induced traps, to values that will give a much smaller full depletion voltage. Models have been proposed to explain the experimental data. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, Moscow 117901, Russia. Univ Florence, Dipartimento Energet, I-50139 Florence, Italy. Wayne State Univ, Detroit, MI 48201 USA. Chinese Acad Sci, Inst Semicond, Beijing 100083, Peoples R China. RP Brookhaven Natl Lab, Upton, NY 11973 USA. RI Bruzzi, Mara/K-1326-2015 OI Bruzzi, Mara/0000-0001-7344-8365 NR 22 TC 28 Z9 28 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 1999 VL 46 IS 3 BP 221 EP 227 DI 10.1109/23.775518 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800020 ER PT J AU Nagarkar, VV Tipnis, SV Gupta, TK Miller, SR Gaysinskiy, VB Klugerman, Y Squillante, MR Entine, G Moses, WW AF Nagarkar, VV Tipnis, SV Gupta, TK Miller, SR Gaysinskiy, VB Klugerman, Y Squillante, MR Entine, G Moses, WW TI High speed X-ray imaging camera using a structured CsI(Tl) scintillator SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID PIXEL-ARRAY DETECTOR; DIFFRACTION AB New third generation x-ray sources such as the Advanced Photon Source have created a need for a detector that can provide multiple frames of detailed x-ray images on the millisecond time:scale. Such detectors will prove invaluable in applications, such as time-resolved x-ray diffraction, x-ray microtomography, as well as materials science applications like polymer processing. Currently, detectors capable of acquiring high resolution x-ray images at such high Speed do not exist, thus limiting progress in many of these important areas of research. To address these needs we have developed a prototype fast x-ray imaging system, using a structured CsI(Tl) scintillator coupled to a fast-frame 1K x 1K CCD. The system has been successfully employed to capture 1024 x 64 pixel x-ray images at a rate of 1000 frames per second (fps) with a 12 bit dynamic range. The system exceeds the capabilities of the current high speed x-ray imaging systems which typically operate at the rate of 30 fps. Fabrication of a large area detector is currently underway, using a microstructured CsI(TI) scintillator coupled to a fast-frame CCD with a 3:1 fiberoptic taper. The camera will operate in a burst mode, acquiring 8 1K x 1K images at rates up to: 1000 frames per second with 12 bit dynamic range. Higher image capture speeds can be accomplished by reducing the image area. This paper will discuss the specific characteristics of the CsI(Tl) screens, experimental details of the prototype and the new design for the large area detector being developed specifically for time-resolved x-ray diffraction experiments in structural biology. C1 Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Nagarkar, VV (reprint author), Radiat Monitoring Devices Inc, 44 Hunt St, Watertown, MA 02472 USA. NR 9 TC 17 Z9 18 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 232 EP 236 DI 10.1109/23.775520 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800022 ER PT J AU Brunett, BA Van Scyoc, JM Hilton, NR Lund, JC James, RB Schlesinger, TE AF Brunett, BA Van Scyoc, JM Hilton, NR Lund, JC James, RB Schlesinger, TE TI Fine-scale spatial response of CdZnTe radiation detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB Several studies have suggested that the uniformity of Cadmium Zinc Telluride (CZT) detectors play an important role in their performance when operated as gamma-ray spectrometers [1]. However, the detailed gamma response of simple planar detectors as a function of position over the device area is largely unknown. To address this issue we have built a system capable of measuring the detector response with a resolution of similar to 250 mu m. The system consists of a highly collimated (similar to 200 mu m) photon source (<150 keV) scanned over the detector using a computer controlled, two-axis translation stage, Fifteen samples configured as planar detectors were examined with the new apparatus. The material grade of the detectors examined varied from "counter" to "select discriminator". Two classes of spatial response variation were observed and are presented here. Infrared (IR) transmission images were also acquired for each sample and correlation between features in the pulse height spectrum and crystalline defects were observed. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Univ Arizona, Dept Phys, Tucson, AZ 85724 USA. Carnegie Mellon Univ, ECE Dept, Pittsburgh, PA 15213 USA. RP Brunett, BA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 6 TC 11 Z9 11 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 237 EP 242 DI 10.1109/23.775521 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800023 ER PT J AU Iwanczyk, JS Tull, CR Segal, JD Kenney, CJ Bradley, J Hedman, B Hodgson, KO AF Iwanczyk, JS Tull, CR Segal, JD Kenney, CJ Bradley, J Hedman, B Hodgson, KO TI Large area silicon drift detectors for X-rays - New results. SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID HIGH-RESISTIVITY SILICON; SPECTROSCOPY; PREAMPLIFIER; CHAMBER AB Large area silicon drift detectors, consisting of 8 mm and 12 mm diameter hexagons, were fabricated on 0.35 mm thick high resistivity n-type silicon. An external FET and a low-noise charge sensitive preamplifier were used for testing the prototype detectors. The detector performance was measured in the range -75 ts 25 degrees C using Peltier cooling, and from 0.125 to 6 mu s amplifier shaping time. Measured energy resolutions were 159 eV FWHM and 263 eV FWHM for the 0.5 cm(2) and 1 cm(2) detectors, respectively (at 5.9 keV, -75 degrees C, 6 Cls shaping time). The uniformity of the detector response over the entire active area (measured using 560 nm light) was < 0.5 %. C1 Photon Imaging Inc, Northridge, CA 91324 USA. Univ Hawaii, Dept Phys, Honolulu, HI 96822 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Iwanczyk, JS (reprint author), Photon Imaging Inc, 19355 Business Ctr Dr,Suite 8, Northridge, CA 91324 USA. NR 15 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 284 EP 288 DI 10.1109/23.775529 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800031 ER PT J AU Russ, WR Stuenkel, DO Valentine, JD Gross, KC AF Russ, WR Stuenkel, DO Valentine, JD Gross, KC TI An evaluation of radioxenon detection techniques for use with a fluid-based concentration system SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB A portable monitoring system to measure the quantity of radioxenon (Xe-131m, Xe-133, Xe-133m, and Xe-135) in the atmosphere is being developed which incorporates a fluid-based concentration system with a detection system. To this end a number of radioxenon detection techniques have been evaluated to determine the best method of analyzing the output of the concentration system, which may contain significant amounts of radon in addition to concentrated xenon. Three detector configurations have been tested to measure the characteristic electron/photon coincidence radiation: plastic scintillator/NaI(Tl), gas proportional detector/NaI(Tl), and liquid scintillator/NaI(Tl). In addition to standard coincidence measurements, sme additional gating criteria were also used: pulse height discrimination, pulse shape discrimination, and delayed coincidence. While the lowest relative minimum detectable activity was achieved using the liquid scintillator with delayed coincidence gating, the best performance for fieldable detection systems depends on the ratio of xenon to radon in the output of the concentration system. A high ratio favors the use of a gas proportional/NaI(Tl) detector using coincidence gating with pulse height discrimination. The use of a plastic scintillator/NaI(Tl) detector using coincidence gating with pulse shape discrimination is preferred when the ratio is low. C1 Univ Cincinnati, Nucl & Radiol Engn Program, Cincinnati, OH 45221 USA. Argonne Natl Lab, Reactor Anal Div, Argonne, IL 60439 USA. RP Russ, WR (reprint author), Georgia Inst Technol, Nucl & Radiol Engn Program, 900 Atlantic Dr, Atlanta, GA 30322 USA. NR 5 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 296 EP 301 DI 10.1109/23.775532 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800034 ER PT J AU Cho, HS Kadyk, J Han, SH Hong, WS Perez-Mendez, V Wenzel, W Pitts, K Martin, MD Hutchins, JB AF Cho, HS Kadyk, J Han, SH Hong, WS Perez-Mendez, V Wenzel, W Pitts, K Martin, MD Hutchins, JB TI GEM: Performance and aging tests SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID GAS AB Performance and aging tests have been done to characterize Gas Electron Multipliers: (GEMs), including further design improvements such as a thicker GEM and a closed GEM. Since the effective GEM gain is typically smaller than the absolute GEM gain, due to trapping of avalanche electrons at the bottom GEM electrode, we performed field simulations and measurements for better understanding, and discuss methods to eliminate. this effect. Other performance parameters of the GEMs are also presented, including absolute GEM gain, short-term and long-term gain stabilities. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Engn, Berkeley, CA 94720 USA. Univ Louisville, Dept Phys, Louisville, KY 40292 USA. RP Cho, HS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. NR 8 TC 13 Z9 13 U1 1 U2 1 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 1999 VL 46 IS 3 BP 306 EP 311 DI 10.1109/23.775534 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800036 ER PT J AU Yu, B Smith, GC Siddons, DP Pietraski, PJ Zojceski, Z AF Yu, B Smith, GC Siddons, DP Pietraski, PJ Zojceski, Z TI Position sensitive gas proportional detectors with anode blades SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID CHAMBERS AB The use of a thin metal blade to generate controlled electron multiplication in gas proportional mode has been studied. Measurements with x-rays have been made on assemblies of an anode blade and two adjacent cathodes in a test chamber. Systematic studies of various detector parameters and their influences on the multiplication process have been carried out. Devices constructed using this technique are very rugged and can be tailored to a curved geometry for the purposes of eliminating parallax error for small and large angle x-ray scattering experiments. Experimental results of a curved, one-dimensional position sensitive detector for synchrotron radiation, with an arc length of 20cm and a 45 degrees coverage, will be discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Yu, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 6 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 338 EP 341 DI 10.1109/23.775540 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800042 ER PT J AU Berenyi, A Chen, HK Dao, K Dow, SF Gehrig, SK Gill, MS Grace, C Jared, RC Johnson, JK Karcher, A Kasen, D Kirsten, FA Kral, JF LeClerc, CM Levi, ME von der Lippe, H Liu, TH Marks, KM Meyer, AB Minor, R Montgomery, AH Romosan, A AF Berenyi, A Chen, HK Dao, K Dow, SF Gehrig, SK Gill, MS Grace, C Jared, RC Johnson, JK Karcher, A Kasen, D Kirsten, FA Kral, JF LeClerc, CM Levi, ME von der Lippe, H Liu, TH Marks, KM Meyer, AB Minor, R Montgomery, AH Romosan, A TI Continuously live image processor for drift chamber track segment triggering SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB The first portion of the BABAR experiment Level 1 Drift Chamber Trigger pipeline is the Track Segment Finder (TSF). Using a-novel-method incorporating both occupancy and drift-time information, the TSF system continually searches for segments in the supercells of the full 7104-wire Drift Chamber hit image at 3.7 MHz. The TSF was constructed to operate in a potentially high beam-background environment while achieving high segment-finding efficiency, deadtime-free operation, a spatial resolution of < 0.7 mm and a per-segment event time resolution of < 70 ns. The TSF system consists of 24 hardware-identical TSF modules. These,are the most complex modules in the BABAR trigger. On each module, fully parallel segment finding proceeds in 20 pipeline steps. Each module consists of a 9U algorithm board and a 6U interface board. The 9U printed circuit board has 10 layers and contains 0.9 million gates implemented in 25 FPGAs, which were-synthesized from a total of 50,000 lines of VHDL, The boards were designed from the top-down with state-of-the-art CAD tools, which included gate-level board simulation. This methodology enabled production bf-a flawless board with no intermediate prototypes. It was fully tested with basic test patterns and 10(5) simulated physics events. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Berenyi, A (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Montgomery, Alexander/B-4969-2009 OI Montgomery, Alexander/0000-0003-4166-0534 NR 2 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 348 EP 353 DI 10.1109/23.775542 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800044 ER PT J AU Borcherding, F Grunendahl, S Johnson, M Martin, M Olsen, J Yip, K AF Borcherding, F Grunendahl, S Johnson, M Martin, M Olsen, J Yip, K TI A first level tracking trigger for the upgraded DO detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID FIBER AB A fast tracking trigger system based on a new scintillating fiber tracker is being built for the upgraded Dm detector for the Collider Run II at Fermilab. This fiber tracker trigger provides a first level hardware trigger, supplies track seeds for the first level muon trigger and for the second level trigger. The physics requirements and the corresponding algorithms for the hardware trigger will be described. Particularly, PLD (Programmable Logical Device) chips are used to implement our trigger algorithms to achieve pattern recognition from scintillating fiber hits and to format that information for delivery to other trigger systems. Detector trigger efficiency studies will also be presented. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Borcherding, F (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Yip, Kin/D-6860-2013 OI Yip, Kin/0000-0002-8576-4311 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 359 EP 364 DI 10.1109/23.775544 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800046 ER PT J AU Fabris, L Allen, PG Bucher, JJ Edelstein, NM Landis, DA Madden, NW Shuh, DK AF Fabris, L Allen, PG Bucher, JJ Edelstein, NM Landis, DA Madden, NW Shuh, DK TI A fast zero dead-time single channel analyzer for nuclear spectroscopy applications SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB We discuss a new approach to the design of single channel analyzers (SCAs) for high rate Nuclear Spectroscopy with an emphasis on accelerator-based X-ray Absorption Fine Structure (XAFS) applications. A brief overview of the entire spectroscopy system and a detailed description of the SCA circuit design are given together with some insight into the application and the reasons that led us to design a new concept in order to build our single channel analyzer. The advantages of this instrument ate then highlighted and the experimental results are presented. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Fabris, L (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 5 TC 3 Z9 5 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 417 EP 419 DI 10.1109/23.775555 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216XM UT WOS:000081469800057 ER PT J AU Moses, WW Derenzo, SE AF Moses, WW Derenzo, SE TI Prospects for time-of-flight PET using LSO scintillator SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Medical Imaging Conference CY NOV 12-14, 1998 CL TORONTO, CANADA ID GSO AB We present measurements of the timing properties of lutetium orthosilicate (LSO) scintillator crystals coupled to a photomultiplier tube (PMT) and excited by 511 keV photons. These crystals have dimensions suitable for use in PET cameras (3x3x30 mm(3)). Coincidence timing resolution of 475 ps fwhm is measured between detectors utilizing two such crystals, significantly worse than the 300 ps fwhm predicted based on first principles for small crystals and measured in 3 mm cubes. This degradation is found to be caused by the scintillation light undergoing multiple reflections at quasirandom angles within the scintillator crystal, which has two effects. First, it slows down the effective information propagation speed within the crystal (to an effective (n) over cap=3.9-5.3). Since the incident annihilation photon travels with n=1, information from interactions at different depths arrives at the PMT with different time delays. Second, the random nature of the reflection angles (and path lengths) introduce dispersion and so a 10%-90% rise time of 1 ns to the optical signal. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 19 TC 156 Z9 161 U1 2 U2 7 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 1999 VL 46 IS 3 BP 474 EP 478 DI 10.1109/23.775565 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216UA UT WOS:000081461200005 ER PT J AU Huber, JS Moses, WW AF Huber, JS Moses, WW TI Conceptual design of a high-sensitivity small animal PET camera with 4 pi coverage SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Medical Imaging Conference CY NOV 12-14, 1998 CL TORONTO, CANADA ID POSITRON-EMISSION-TOMOGRAPHY; RESOLUTION; SCANNER; PHOTODIODES; DEPTH AB We present a conceptual design of a high-sensitivity PET camera that completely encloses a small animal in a rectangular volume formed by 6 planar banks of detector modules. The 4 pi geometry and 3 attenuation-length fast scintillators provide significantly higher sensitivity than contemporary animal PET cameras, while the depth of interaction (DOI) measurement and small crystal width achieve isotropic, high spatial resolution. The absolute sensitivity is 24 kcps/mu Ci, similar to 120 times higher than contemporary systems; the true event count rate is increased by covering 10 times the solid angle using 80% efficient detectors. For a 29 g "mouse", the total scatter event rate is 11% of the total true event rate. A short (2 nsec) coincidence window and the absence of out of field activity implicit with whole animal coverage yield a small random fraction. Assuming a maximum system count rate of 10 Mcps (achievable with electronics under development), the noise equivalent count rate as a function of activity concentration has a maximum of 6.6 Mcps at 25 mu Ci/cc. 2D reconstruction algorithms indicate a spatial resolution of 2.3 mm fwhm through most of the field of view. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Huber, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 20 TC 34 Z9 36 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 498 EP 502 DI 10.1109/23.775569 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216UA UT WOS:000081461200009 ER PT J AU Paulus, MJ Sari-Sarraf, H Gleason, SS Bobrek, M Hicks, JS Johnson, DK Behel, JK Thompson, LH Allen, WC AF Paulus, MJ Sari-Sarraf, H Gleason, SS Bobrek, M Hicks, JS Johnson, DK Behel, JK Thompson, LH Allen, WC TI A new X-ray computed tomography system for laboratory mouse imaging SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Medical Imaging Conference CY NOV 12-14, 1998 CL TORONTO, CANADA ID RESOLUTION; SCANNER; ANIMALS AB Two versions of a new high-resolution x-ray computed tomography system are being developed to screen mutagenized mice in the Oak Ridge National Laboratory Mammalian Genetics Research Facility. The first prototype employs a single-pixel cadmium zinc telluride detector with a pinhole collimator operating in pulse counting mode. The second version employs a phosphor screen/CCD detector operating in current mode. The major system hardware includes a low-energy x-ray tube, two linear translation stages and a rotational stage. For the single-pixel detector, image resolution is determined by the step size of the detector stage; preliminary images have been acquired at 100 Irm and 250 mu m resolutions. The resolution of the phosphor screen detector Is determined by the modulation transfer function of the phosphor screen; images with resolutions approaching 50 mu m have been acquired. The system performance with the two detectors is described and recent images are presented. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Paulus, MJ (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 19 TC 74 Z9 74 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1999 VL 46 IS 3 BP 558 EP 564 DI 10.1109/23.775579 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 216UA UT WOS:000081461200019 ER PT J AU Peterfreund, N AF Peterfreund, N TI Robust tracking of position and velocity with Kalman snakes SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE active contour; Kalman snakes; optical-flow robust tracking ID OPTICAL-FLOW; OBJECTS; MODEL AB A new Kalman-filter based active contour model is proposed for tracking of nonrigid objects in combined spatio-velocity space. The model employs measurements of gradient-based image potential and of optical-flow along the contour as system measurements. In order to improve robustness to image clutter and to occlusions an optical-flow based detection mechanism is proposed. The method detects and rejects spurious measurements which are not consistent with previous estimation of image motion. C1 Oak Ridge Natl Lab, Ctr Engn Syst Adv Res, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Ctr Engn Syst Adv Res, POB 2008, Oak Ridge, TN 37831 USA. EM v4p@mars.epm.ornl.gov NR 22 TC 149 Z9 165 U1 2 U2 11 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD JUN PY 1999 VL 21 IS 6 BP 564 EP 569 DI 10.1109/34.771328 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 205KD UT WOS:000080819100008 ER PT J AU Boley, CD Rhodes, MA AF Boley, CD Rhodes, MA TI Modeling of plasma behavior in a plasma electrode Pockels cell SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE electrooptic switches; laser accessories; laser fusion; magnetohydrodynamics; plasma applications; plasma sheaths; Pockels effect ID SWITCHES; LASERS AB We present three interrelated models of plasma behavior in a plasma electrode Pockels cell (PEPC), In a PEPC, plasma discharges are formed on both sides of a thin, large-aperture electro-optic crystal (typically KDP). The plasmas act as optically transparent, highly conductive electrodes, allowing uniform application of a longitudinal field to induce birefringence in the crystal. First, we model the plasma in the thin direction, perpendicular to the crystal, via a one-dimensional fluid model. This yields the electron temperature and the density and velocity profiles in this direction as functions of the neutral pressure, the plasma channel width, and the discharge current density, Next, we model the temporal response of the crystal to the charging process, combining a circuit model with a model of the sheath which forms near the crystal boundary. This model gives the time-dependent voltage drop across the sheath as a function of electron density at the sheath entrance. Finally, we develop a two-dimensional MHD model of the planar plasma, in order to calculate the response of the plasma to magnetic fields. We show how the plasma uniformity is affected by the design of the current return, by the longitudinal field from the cathode magnetron, and by fields from other sources. This model also gives the plasma sensitivity to the boundary potential at which the top and bottom of the discharge are held, We validate these models by showing how they explain observations in three large Pockels cells built at Lawrence Livermore National Laboratory. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Boley, CD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 14 TC 15 Z9 17 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1999 VL 27 IS 3 BP 713 EP 726 DI 10.1109/27.774676 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 216NL UT WOS:000081448700010 ER PT J AU Zhang, T Tang, BY Zeng, ZM Chen, QC Chu, PK Brown, IG AF Zhang, T Tang, BY Zeng, ZM Chen, QC Chu, PK Brown, IG TI Enhancement and stabilization of cathodic arc using mesh anode SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE anode; cathodic arc; plasma ID SPOT MOTION; DEPOSITION; COATINGS AB The performance and characteristics of a cathodic are deposition apparatus consisting of a titanium cathode, an anode with and without a tungsten mesh, and a coil producing a focusing magnetic field between the anode and cathode are investigated. The are voltage V-a is measured with a fixed arc current for an anode diameter of 40 mm, The relationship between V-a and the magnetic field B with and without a mesh is obtained. In addition, the relationship between the are current I-a and V-c, the voltage to which the artificial transmission line was charged, is measured with and without the mesh to determine the minimum ignition voltage for the are when the anode hole diameter is 40 mm, The are resistance increases with the focusing magnetic strength B and decreases when using the mesh. Our results indicate that the high transparency and large area of the mesh allows a high plasma flux to penetrate the anode from the cathodic are. The mesh also stabilizes the cathodic are and gives better performance when used in concert with a focusing magnetic field. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Zhang, T (reprint author), City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong. RI Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 9 TC 13 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1999 VL 27 IS 3 BP 786 EP 790 DI 10.1109/27.774684 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 216NL UT WOS:000081448700018 ER PT J AU Goebel, DM Adler, EA Ponti, ES Feicht, JR Eisenhart, RL Lemke, RW AF Goebel, DM Adler, EA Ponti, ES Feicht, JR Eisenhart, RL Lemke, RW TI Efficiency enhancement in high power backward-wave oscillators SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE backward-wave oscillators; high power microwave source; Pasotron ID HPM SOURCE; PLASMA; PERFORMANCE AB High power microwave (HPM) sources based on the backward-wave oscillator (BWO) have been investigated for the past two decades primarily because of their potential for very high efficiency (15 to 40%) operation. Several different effects have been proposed to explain this high efficiency compared to conventional BWO's, One of the major contributors to the high efficiency of the plasma-filled Pasotron HPM BWO source is the presence of optimally phased end reflections. The Pasotron uses a long-pulse (greater than or equal to 100 mu s) plasma-cathode electron-gun and plasma-filled slow-wave structure to produce microwave pulses in the range of 1 to 10 MVV without the use of externally produced magnetic fields, The efficiency of the Pasotron can be enhanced by up to a factor of two when the device is configured as a standing-wave oscillator in which properly phased reflections from the downstream collector end of the finite length SWS constructively interfere with the fundamental backward-wave modes and improve the coupling of the beam to the circuit. Operation in this configuration increases the efficiency up to 30% hut causes the frequency to vary in discrete steps and the output power to change strongly with beam parameters and oscillation frequency. C1 Hughes Elect Dynam, Torrance, CA 90509 USA. HRL Labs, Malibu, CA 90265 USA. Eisenhart & Assoc, Woodland Hills, CA 91367 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Goebel, DM (reprint author), Hughes Elect Dynam, Torrance, CA 90509 USA. NR 29 TC 19 Z9 22 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1999 VL 27 IS 3 BP 800 EP 809 DI 10.1109/27.774686 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 216NL UT WOS:000081448700020 ER PT J AU Keidar, M Beilis, II AF Keidar, M Beilis, II TI Macroparticle reflection from a biased substrate in a vacuum arc deposition system SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE macroparticle; sheath; vacuum arc plasma ID DC GLOW-DISCHARGES; PLASMA; TRANSPORT; SHEATH; DUCTS; DUST AB The reflection of macroparticles, generated by a vacuum art, from a substrate biased negatively with respect to the surrounding plasma is considered. Charging of macroparticle in the near-substrate sheath and its influence on the macroparticle motion mere taken into account. It was found that macroparticles can be either reflected or attracted to the substrate depending strongly on the ion current density, The possibility of macroparticle reflection increases with negative bias voltage and saturates at about a few hundred volts. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Tel Aviv Univ, Elect Discharge & Plasma Lab, IL-69978 Tel Aviv, Israel. RP Keidar, M (reprint author), Cornell Univ, Dept Mech & Aerosp Engn, Ithaca, NY 14853 USA. NR 12 TC 17 Z9 20 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1999 VL 27 IS 3 BP 810 EP 812 DI 10.1109/27.774687 PG 3 WC Physics, Fluids & Plasmas SC Physics GA 216NL UT WOS:000081448700021 ER PT J AU Wohlberg, B de Jager, G AF Wohlberg, B de Jager, G TI A class of multiresolution stochastic models generating self-affine images SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Article DE fractals; higher order statistics; image coding; stochastic; signal models; wavelet transforms ID WAVELET AB Fractal image compression is based on the rather poorly motivated assumption that "natural" images exhibit significant affine selfsimilarity. The accuracy of this assumption is evaluated by a comparison between the statistics of natural images and those of a multiresolution stochastic model designed to generate images exhibiting affine self-similarity as assumed by fractal coding techniques. These comparisons suggest that self-affinity does not represent a particularly accurate characterization of image statistics. C1 Univ Cape Town, Dept Elect Engn, Digital Image Proc Lab, ZA-7925 Cape Town, South Africa. RP Wohlberg, B (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wohlberg, Brendt/M-7764-2015 OI Wohlberg, Brendt/0000-0002-4767-1843 NR 13 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 USA SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD JUN PY 1999 VL 47 IS 6 BP 1739 EP 1742 DI 10.1109/78.765153 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA 198KE UT WOS:000080422000027 ER PT J AU Wasiolek, PT Whicker, JJ Gong, HR Rodgers, JC AF Wasiolek, PT Whicker, JJ Gong, HR Rodgers, JC TI Room airflow studies using sonic anemometry SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE sonic anemometer; indoor air velocity; indoor turbulence; airflow patterns ID AIR AB To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s(-1) to 9.7 cm s(-1). There were complex flow patterns observed with turbulence intensities from 39% up to 108%. Ln the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s(-1) to 35.5 cm s(-1) with turbulence intensities from 33% to 108%. C1 Univ Calif Los Alamos Natl Lab, Hlth Phys Measurements Grp, Los Alamos, NM 87545 USA. RP Wasiolek, PT (reprint author), Univ Calif Los Alamos Natl Lab, Hlth Phys Measurements Grp, ESH-4,MS G761, Los Alamos, NM 87545 USA. NR 16 TC 12 Z9 12 U1 1 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0905-6947 J9 INDOOR AIR JI Indoor Air-Int. J. Indoor Air Qual. Clim. PD JUN PY 1999 VL 9 IS 2 BP 125 EP 133 DI 10.1111/j.1600-0668.1999.t01-2-00007.x PG 9 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA 208LA UT WOS:000080991400007 PM 10390937 ER PT J AU Bishop, RL Flesner, RL Dell'Orco, PC Spontarelli, T Larson, SA Bell, DA AF Bishop, RL Flesner, RL Dell'Orco, PC Spontarelli, T Larson, SA Bell, DA TI Base hydrolysis of HMX and HMX-based plastic-bonded explosives with sodium hydroxide between 100 and 155 degrees C SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID MASS-TRANSFER; KINETICS AB The degradation of HMX-based high explosives (HMX, PBX 9404, and PBX 9501) with sodium hydroxide solutions is described. To obtain practicable reaction rates, the reaction was carried out in a pressurized reactor at temperatures up to about 155 degrees C. Above about 70 degrees C, mass transfer rates significantly affect the observed reaction rate. Therefore, a solid-liquid mass transfer model, based on gas-liquid film theory, was developed to describe the reaction rate. This model successfully predicted the experimentally observed degradation of explosives. Similar work with sodium carbonate solutions was reported previously.(11) Faster reaction rates were observed with sodium hydroxide, a stronger base. Sodium hydroxide is preferred when the explosive contains a base-resistant binder, such as the binder used in PBX 9501, or when large, pressed pieces of explosives are used. Sodium carbonate hydrolysis and sodium hydroxide hydrolysis yielded the same degradation products. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wyoming, Dept Petr & Chem Engn, Laramie, WY 82071 USA. RP Bell, DA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS C920, Los Alamos, NM 87545 USA. NR 23 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JUN PY 1999 VL 38 IS 6 BP 2254 EP 2259 DI 10.1021/ie980522b PG 6 WC Engineering, Chemical SC Engineering GA 205NP UT WOS:000080827700010 ER PT J AU Simpson, MF Battisti, TJ AF Simpson, MF Battisti, TJ TI Adsorption of eutectic LiCl-KCl into zeolite 4A using a mechanically fluidized vacuum system SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB A high-temperature mixer has been used to absorb LiCl-KCl eutectic salt powders into zeolite 4A. In situ sampling has been performed, allowing for a time-resolved view of the adsorption reaction. The weight percent free (nonabsorbed) chloride ions has been used as a measure of the effectiveness of the adsorption process. Using zeolite 4A powder with no binder, the free chloride concentration leveled off at 0.4-0.5 wt % in less than 5 h at 500 degrees C. Zeolite 4A granules (-60 + 200 mesh) containing binder yielded a free chloride concentration of 0.02 wt % after 5 h at 500 degrees C. It is concluded that the improved performance from the granulated zeolite can be attributed to better mixing within the retort. A 50% reduction in the free chloride concentration below the melting point of the salt suggests that solid-state adsorption of the salt into the zeolite is possible. C1 Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Simpson, MF (reprint author), Argonne Natl Lab, POB 2528, Idaho Falls, ID 83403 USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JUN PY 1999 VL 38 IS 6 BP 2469 EP 2473 DI 10.1021/ie980635v PG 5 WC Engineering, Chemical SC Engineering GA 205NP UT WOS:000080827700036 ER PT J AU Cirino, NM Sblattero, D Allen, D Peterson, SR Marks, JD Jackson, PJ Bradbury, A Lehnert, BE AF Cirino, NM Sblattero, D Allen, D Peterson, SR Marks, JD Jackson, PJ Bradbury, A Lehnert, BE TI Disruption of anthrax toxin binding with the use of human antibodies and competitive inhibitors SO INFECTION AND IMMUNITY LA English DT Article ID PHAGE DISPLAY LIBRARIES; SINGLE-CHAIN ANTIBODIES; PROTECTIVE ANTIGEN; BACILLUS-ANTHRACIS; LETHAL FACTOR; MONOCLONAL-ANTIBODIES; PROTEOLYTIC ACTIVATION; EUKARYOTIC CELLS; RECEPTOR-BINDING; MAMMALIAN-CELLS AB The protective antigen (PA83) of Bacillus anthracis is integral to the mechanism of anthrax toxicity. We have isolated a human single-chain Fv antibody fragment (scFv) that blocks binding of a fluorescently tagged protective antigen (PA) moiety to cell surface receptors. Several phage-displayed scFv were isolated from a naive library biopanned against PA83. Soluble, monomeric scFv were characterized for affinity and screened for their capacity to disrupt receptor-mediated binding of PA. Four unique scFv bound to PA83, as determined by surface plasmon resonance, the tightest binder exhibiting a K-d, of 50 nM. Two scFv had similar affinities for natural PA83 and a novel, recombinant, 32-kDa carboxy-terminal PA fragment (PA32). Binding of scFv to green fluorescent protein fused to the amino-terminal 32-kDa fragment of B. anthracis edema factor, EGFP-EF32, was used to confirm specificity. Fusion of EGFP to PA32 facilitated development of a novel flow cytometric assay that showed that one of the scFv disrupted PA receptor binding. This method can now be used as a rapid assay for small molecule inhibitors of PA binding to cell receptors. The combined data presented suggest the potential utility of human scFv as prophylactics against anthrax poisoning. Moreover, recombinant PA32 may also be useful as a therapeutic agent to compete with anthrax toxins for cellular receptors during active infection. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. SISSA, I-34013 Trieste, Italy. Univ Calif San Francisco, Dept Anesthesia & Pharmaceut Chem, San Francisco, CA 94110 USA. RP Lehnert, BE (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, MS M888, Los Alamos, NM 87545 USA. NR 52 TC 28 Z9 34 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD JUN PY 1999 VL 67 IS 6 BP 2957 EP 2963 PG 7 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 199GX UT WOS:000080473600036 PM 10338505 ER PT J AU Brundermann, E Chamberlin, DR Haller, EE AF Brundermann, E Chamberlin, DR Haller, EE TI Novel design concepts of widely tunable germanium terahertz lasers SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT Colloquium on Sources, Detectors and Instruments in the FIR Region in Honour of Professor Dr Maurice F Kimmitt CY OCT 02, 1998 CL BERLIN, GERMANY DE germanium; far-infrared; semiconductor laser; tunable laser; local oscillator; heterodyne receivers ID FAR-INFRARED EMISSION; P-TYPE GERMANIUM; HOT-HOLE LASERS; GE; OPERATION; SUBMILLIMETER; OSCILLATION; STATES AB We explore the full parameter space for laser operation and compile guidelines for building improved Ge lasers, especially for continuous wave applications. We present laser emission from p-type Ge lasers with small volumes at high repetition rates and with inter-contact distances as low as 750 mu m The emission is analyzed as a function of the current-voltage characteristic. The Poisson equation is solved to determine the electric field distribution and two new laser designs are presented. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Brundermann, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Mailstop 2-200,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Bruendermann, Erik/J-7186-2016 OI Bruendermann, Erik/0000-0003-4119-3489 NR 26 TC 14 Z9 14 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD JUN PY 1999 VL 40 IS 3 BP 141 EP 151 DI 10.1016/S1350-4495(99)00006-7 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 206XB UT WOS:000080904700003 ER PT J AU Kreysa, E Gemund, HP Gromke, J Haslam, CGT Reichertz, L Haller, EE Beeman, JW Hansen, V Sievers, A Zylka, R AF Kreysa, E Gemund, HP Gromke, J Haslam, CGT Reichertz, L Haller, EE Beeman, JW Hansen, V Sievers, A Zylka, R TI Bolometer array development at the Max-Planck-lnstitut fur Radioastronomie SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT Colloquium on Sources, Detectors and Instruments in the FIR Region in Honour of Professor Dr Maurice F Kimmitt CY OCT 02, 1998 CL BERLIN, GERMANY DE bolometers; absorbers; micromachining AB Continuum radiometers based on bolometers have a long tradition at the Max-Planck-Institut fur Radioastronomie (MPIfR) in Bonn, Germany. Arrays of bolometers have been under development since the early 1990s. A small seven-element system, operating at 300 mK, saw first light in 1992 at the IRAM 30-m telescope and has been used successfully by numerous observers at that facility since then. While this array had a conventional 'composite' design, it was obvious that larger arrays, especially for higher frequencies, could take advantage of microfabrication technology. The recent MPIfR bolometer arrays employ a hybrid approach. They combine a single-mode horn array with a planar bolometer array on a single crystal Silicon wafer with Silicon-Nitride membranes. With efficient absorbing structures, the bolometers couple to the single mode of the radiation field collected by the horns, without needing integrating cavities. Readout is provided by NTD-Germanium thermistors that are attached to the absorbers. This paper covers the history of this development, the design aspects of the bolometer arrays, including the coupling to the telescope, and the status of work in progress. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Max Planck Inst Radioastron, D-5300 Bonn, Germany. UCB, Berkeley, CA USA. LBNL, Berkeley, CA USA. Berg Univ Gesamthsch Wuppertal, Wuppertal, Germany. IRAM, E-18012 Granada, Spain. Univ Heidelberg, ITA, Heidelberg, Germany. RP Kreysa, E (reprint author), Max Planck Inst Radioastron, Hugel 69, D-5300 Bonn, Germany. NR 4 TC 41 Z9 41 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD JUN PY 1999 VL 40 IS 3 BP 191 EP 197 DI 10.1016/S1350-4495(99)00010-9 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 206XB UT WOS:000080904700007 ER PT J AU McKone, TE AF McKone, TE TI The rise of exposure assessment among the risk sciences: An evaluation through case studies SO INHALATION TOXICOLOGY LA English DT Article ID VOLATILE ORGANIC-COMPOUNDS; TAP WATER; MODEL; INDOOR; AIR; CHLOROFORM; CHEMICALS; SOIL; DEPOSITION; INGESTION C1 Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP McKone, TE (reprint author), Univ Calif Berkeley, Sch Publ Hlth, 140 Warren Hall,7360, Berkeley, CA 94720 USA. NR 44 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0895-8378 J9 INHAL TOXICOL JI Inhal. Toxicol. PD JUN-JUL PY 1999 VL 11 IS 6-7 BP 611 EP 622 DI 10.1080/089583799197023 PG 12 WC Toxicology SC Toxicology GA 212UX UT WOS:000081236900017 PM 11203003 ER PT J AU Demo, P Kozisek, Z Sasik, R AF Demo, P Kozisek, Z Sasik, R TI Analytical calculation of time lag in nucleation process SO INORGANIC MATERIALS LA English DT Article ID HOMOGENEOUS NUCLEATION; BINARY NUCLEATION; KINETICS AB For theoretical modeling of nucleation, it is often adequate to focus attention only to the steady-state behavior of the system. This may by acceptable if the time required to reach steady state is negligible in comparison with the time scale of the experiment. On the other hand, when the time needed to reach the steady state is long (e.g., for nucleation in glass-forming melts) or in experiments with very short time scales (e.g., nozzle expansion or shock tubes), transient effects may become important and, ipso facto, are responsible for the instantaneous properties of the system. We present a method (based on combination of boundary layer theory and Green's functions technique) allowing to solve a Fokker-Planck-like equation and to obtain an analytical formula for the time lag. The accuracy of our approach is demonstrated by comparison with purely numerical simulations as well as with experimental data and previous analytical solutions (Shi et al. [1], Wilemski [2], Trinkaus and Yoo [3], Kashchiev [4]) applied to single component and also to binary systems. C1 Acad Sci Czech Republ, Inst Phys, Prague 16253 6, Czech Republic. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Demo, P (reprint author), Acad Sci Czech Republ, Inst Phys, Cukrovarnicka 10, Prague 16253 6, Czech Republic. RI Kozisek, Zdenek/F-7434-2014; Demo, Pavel/H-1432-2014 OI Kozisek, Zdenek/0000-0003-0823-5130; NR 9 TC 0 Z9 0 U1 0 U2 4 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O PLENUM/CONSULTANTS BUREAU 233 SPRING ST, NEW YORK, NY 10013 USA SN 0020-1685 J9 INORG MATER+ JI Inorg. Mater. PD JUN PY 1999 VL 35 IS 6 BP 593 EP 595 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 205NJ UT WOS:000080827200015 ER PT J AU Barnard, ST Bernardo, LM Simon, HD AF Barnard, ST Bernardo, LM Simon, HD TI An MPI implementation of the SPAI preconditioner on the T3E SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article ID APPROXIMATE AB The authors describe and test spai_1.1, a parallel MPI implementation of the sparse approximate inverse (SPAI) preconditioner. They show that SPAI can be very effective for solving a set of very large and difficult problems on a Gray T3E. The results clearly show the value of SPAI (and approximate inverse methods in general) as the Viable alternative to ILU-type methods when facing very large and difficult problems. The authors strengthen this conclusion by showing that spai_1.1 also has very good scaling behavior. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bernardo, LM (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 15 TC 20 Z9 20 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD SUM PY 1999 VL 13 IS 2 BP 107 EP 123 DI 10.1177/109434209901300202 PG 17 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 189MN UT WOS:000079909100002 ER PT J AU Steinkamp, MJ Clark, TT Harlow, FH AF Steinkamp, MJ Clark, TT Harlow, FH TI Two-point description of two-fluid turbulent mixing - I. Model formulation SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE spectral turbulence transport model; inhomogeneous turbulence; variable density turbulence; turbulent mixing; interfacial instability; two-phase turbulence; Rayleigh-Taylor instability; two-phase flow ID REYNOLDS-NUMBER; ISOTROPIC TURBULENCE; 2-EQUATION MODEL; SHEAR FLOWS AB We describe a two-point spectral transport approach to the investigation of fluid instability, generalized turbulence, and the interpenetration of fluids across an interface. The technique also applies to a single fluid with large variations in density. Departures of fluctuating velocity components from the local mean are far subsonic, but the mean Mach number can be large. This work is focused on flows with large variations in fluid density (e.g. two-field fluid interpenetration). The starting point for analysis is the set of Navier-Stokes equations, for which we assume relevance in our investigations, even in the presence of sharp density variations between fluids. Models for two-field analysis with drag representations for momentum exchange can also be used and are discussed previously. In this work departures from mean flow are included in the stochastic concept of turbulence. Reynolds decomposition into mean and fluctuating parts is carried out in the spirit of this generalized concept, which is meaningful despite arbitrariness as to which scales are identified as mean flow and which are identified as fluctuations. This spectral formulation motivates a novel description of the global effects of pressure due to incompressibility. We discuss its derivation and the modifications this 'nonlocal' formulation has on the turbulence spectra. We also discuss the consequences of spectral self-similarity exhibited by this model. This identification of spectral selfsimilarity in a circumstance of inhomogeneous, variable density turbulence is novel. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Clark, TT (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,Mail Stop-B216, Los Alamos, NM 87545 USA. EM ttc@lanl.gov NR 61 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-9322 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD JUN PY 1999 VL 25 IS 4 BP 599 EP 637 DI 10.1016/S0301-9322(98)00064-0 PG 39 WC Mechanics SC Mechanics GA 206WY UT WOS:000080904400003 ER PT J AU Steinkamp, MJ Clark, TT Harlow, FH AF Steinkamp, MJ Clark, TT Harlow, FH TI Two-point description of two-fluid turbulent mixing - II. Numerical solutions and comparisons with experiments SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE spectral turbulence transport model; inhomogeneous turbulence; variable density turbulence; turbulent mixing; interfacial instability; two-phase turbulence; Rayleigh-Taylor instability; two-phase flow ID RAYLEIGH-TAYLOR INSTABILITY; SIMULATION; GROWTH; MODEL AB The spectral turbulence transport model from part I of these two articles is compared with experiments of the late stages of turbulent mixing due to Rayleigh-Taylor instability, when the dynamics become approximately self-similar in response to a constant body force, We also examine the spectral dynamics of the flow immediately following a rapid transient in the body force. Generic forms for anisotropic spectral structure are described and then used as a basis for deriving spectrally integrated moment equations that can be more easily incorporated into computer codes for scientific and engineering analyses. We describe comparisons with experiments of this spectral formulation and indicate directions for refinement, analogous to those that are required for constant density turbulence transport. (C) 1994 Elsevier Science Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Clark, TT (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,Mail Stop-B216, Los Alamos, NM 87545 USA. EM ttc@lanl.gov NR 73 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-9322 EI 1879-3533 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD JUN PY 1999 VL 25 IS 4 BP 639 EP 682 DI 10.1016/S0301-9322(98)00065-2 PG 44 WC Mechanics SC Mechanics GA 206WY UT WOS:000080904400004 ER PT J AU Lucas, JN Deng, W Hsieh, WA Galvan, N Gale, KL Morrison, DP AF Lucas, JN Deng, W Hsieh, WA Galvan, N Gale, KL Morrison, DP TI Exposure temperature, but not donor age, is a confounding factor for in vitro translocation production by chronic irradiation SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID DOUBLE-STRAND BREAKS; DOSE-RESPONSE CURVE; HUMAN-LYMPHOCYTES; CHROMOSOME TRANSLOCATIONS; GAMMA-RAYS; RADIATION; ABERRATIONS; REPAIR; DNA; HYBRIDIZATION AB Purpose: To assess the effects of incubation temperature during irradiation, and of donor age, on the in vitro induction of chromosomal translocations in human lymphocytes. Material and methods: Lymphocytes from six human male donors were scored, using fluorescence in situ hybridization, for the presence of chromosomal translocations involving chromosomes 1 to 6 after in vitro, chronic exposure (delivered continuously over 48 h at 37 degrees C or at 20 degrees C) to tritium beta-rays or Co-60 gamma-rays. Results: No age-related difference in the alpha coefficients of the fitted induction curves was observed for gamma-ray-exposed lymphocytes obtained from four donors whose ages ranged from 24 to 79 years, or for tritium beta-ray-exposed lymphocytes from two donors aged 36 and 62 years. Duplicate samples from one donor, irradiated concurrently at 20 degrees C or 37 degrees C, gave significantly different alpha coefficients: 0.128 +/- 0.008 and 0.053 +/- 0.004, respectively (p < 0.0001). The S-ratio (the ratio of induced complete to incomplete translocations) was found to be independent of radiation dose, donor age and exposure temperature. Conclusions: For biodosimetry in chronic irradiation situations, the use of alpha coefficients derived from the dose-response curves of cells chronically irradiated in vitro at body temperature is recommended. With respect to induction rates, donor age does not appear to be a confounding factor. The S-ratio is independent of radiation doses, exposure temperatures, or donor ages. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sichuan Inst Occupat Hlth, Sichuan Inst Radiat Hlth & Protect, Chengdu 610041, Peoples R China. AECL Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. RP Lucas, JN (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 24 TC 4 Z9 4 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD JUN PY 1999 VL 75 IS 6 BP 673 EP 680 PG 8 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 208UT UT WOS:000081010800002 PM 10404996 ER PT J AU Bengelsdorf, HD AF Bengelsdorf, HD TI Rethinking nuclear energy SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 US Dept State, Washington, DC 20520 USA. US DOE, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SUM PY 1999 VL 15 IS 4 BP 22 EP 23 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 216NC UT WOS:000081447900021 ER PT J AU Hassberger, JA Isaacs, T Schock, RN AF Hassberger, JA Isaacs, T Schock, RN TI Rethinking nuclear energy SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hassberger, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SUM PY 1999 VL 15 IS 4 BP 22 EP 22 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 216NC UT WOS:000081447900020 ER PT J AU Bartynski, RA Qian, Q Hulbert, SL AF Bartynski, RA Qian, Q Hulbert, SL TI Line shape of the AgN23VV Auger spectrum measured by Auger-photoelectron coincidence spectroscopy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT International Conference on Coincidence Spectroscopy CY SEP 23-26, 1998 CL BREST, FRANCE ID AG AB We present Ag N3VV and N2VV Anger spectra obtained in coincidence with 4p(3/2) and 4p(1/2) core photoelectrons, respectively. We have also obtained the 4p(3/2) and 4p(1/2) core level spectra in coincidence with N3VV and N2VV Anger electrons. As the on-site Coulomb correlation energy of Ag, U, is comparable to the 4d band width, W, the coincidence Auger spectra exhibit aspects of both atomic-like and band-like components. We find a surprisingly large similar to 30% of the spectral weight of 2-hole decays is in the band-like region. Furthermore, the Auger spectra have large low energy tails that are attributed to nonradiative decays involving more than two electrons. In the coincidence core level spectra, the large (> 5 eV) lifetime broadening is eliminated, leaving a width of 2.5 eV associated with the Auger lifetime. This sharp peak in the coincidence photoemission spectrum resides on a broader feature owing to the properties of the Auger transitions. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Rutgers State Univ, Surface Modificat Lab, Piscataway, NJ 08855 USA. Brookhaven Natl Lab, Upton, NY 11972 USA. RP Bartynski, RA (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08855 USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD JUN PY 1999 VL 9 IS P6 BP 157 EP 160 DI 10.1051/jp4:1999635 PG 4 WC Physics, Multidisciplinary SC Physics GA 216XW UT WOS:000081470600036 ER PT J AU Eriksson, O Becker, JN Balatsky, AV Wills, JM AF Eriksson, O Becker, JN Balatsky, AV Wills, JM TI Novel electronic configuration in delta - Pu SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogenation; decomposition; activation; fracture; rate equation ID CRYSTAL-STRUCTURES; BRILLOUIN-ZONE; SPECIAL POINTS; SYSTEMS; METALS; BAND AB We present evidence for a unique electronic configuration, which we call the mixed-level state, that is consistent with most of the anomalous properties of partial derivative-Pu. The unique properties of this state result from a subdivision of the 5f manifold into orthogonal sub-sets, one with localized character, contributing atomic-like correlation to the total energy, and the other of itinerant character, contributing 5f-electron bonding to the total energy. The near-degeneracy of alpha- and delta-phases of Pu and the unusual equilibrium volume, elastic constants, and thermal expansion of delta-phase are consistent with this configuration. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Eriksson, O (reprint author), Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 23 TC 109 Z9 109 U1 2 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 1 PY 1999 VL 287 IS 1-2 BP 1 EP 5 DI 10.1016/S0925-8388(99)00063-8 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 206LG UT WOS:000080880100005 ER PT J AU Pecharsky, AO Gschneidner, KA AF Pecharsky, AO Gschneidner, KA TI Crystal structure and magnetic properties of the new ternary compound Ce3MnBi5 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE intermetallic; antiferromagnetism; crystal structures AB The crystal structure of the newly discovered compound Ce3MnBi5 was determined from X-ray single crystal diffraction data. The space group is P6(3)/mcm with the lattice parameters a = 9.627(3), c = 6.456(1) Angstrom. The compound crystallizes in the Ga4Ti5 structure type. There are no isostructural compounds in ternary systems with Sb and Pb substituted for Bi. The Ce3MnBi5 remains paramagnetic down to similar to 4.2 K, even though the paramagnetic Curie temperature (theta(p) = -53 K) suggests an antiferromagnetic ground state. The value of effective magnetic moment (rho(eff) = 5.85 mu(B)) per formula unit could be accounted for by two different electronic configurations of Ce and Mn atoms: 3Ce(3+) and 1Mn(4+) or 3Ce(4+) and 1Mn(2+). Bond distances arguments favor the first possibility. Magnetization measurements at 5 K indicate two metamagnetic (field-induced) transitions at similar to 1.3 and similar to 5 T, which we believe are due to impurities in the sample. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Gschneidner, KA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 13 TC 3 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 1 PY 1999 VL 287 IS 1-2 BP 67 EP 70 DI 10.1016/S0925-8388(99)00002-X PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 206LG UT WOS:000080880100017 ER PT J AU Bossis, I Wettemann, RP Welty, SD Vizcarra, JA Spicer, LJ Diskin, MG AF Bossis, I Wettemann, RP Welty, SD Vizcarra, JA Spicer, LJ Diskin, MG TI Nutritionally induced anovulation in beef heifers: Ovarian and endocrine function preceding cessation of ovulation SO JOURNAL OF ANIMAL SCIENCE LA English DT Article DE heifers; nutrition; ovaries; LH; estradiol ID GROWTH-FACTOR-I; HORMONE-RELEASING-FACTOR; DIETARY ENERGY-INTAKE; FOLLICLE-STIMULATING-HORMONE; NONESTERIFIED FATTY-ACIDS; IGF BINDING-PROTEINS; BOS-INDICUS HEIFERS; LUTEINIZING-HORMONE; BODY CONDITION; REPRODUCTIVE-PERFORMANCE AB Angus x Hereford heifers were used to determine endocrine and ovarian function preceding nutritionally induced anovulation. Six heifers were fed to maintain body condition score (M), and 12 heifers were fed a restricted diet (R) until they became anovulatory. Starting on d 13 of an estrous cycle, heifers were given PGF(2 alpha) every 16 d thereafter to synchronize and maintain 16 d estrous cycles. Ovarian structures of M and R heifers were monitored by ultrasonography daily from d 8 to ovulation (d 1 of the subsequent cycle) until R heifers became anovulatory. Concentrations of LH and FSH were quantified in serum samples collected every 10 min for 8 h on d 2 and 15 (48 h after PGF(2 alpha)), and estradiol and IGF-I were quantified in daily plasma samples from d 8 to 16 during the last ovulatory cycle (Cycle -2) and the subsequent anovulatory cycle (Cycle -1). During the last two cycles before anovulation, M heifers had 50% larger (P < .0001) ovulatory follicles than R heifers and 61% greater (P < .0001) growth rate of the ovulatory follicles. There was a treatment x cycle x day effect (P < .001)for concentrations of estradiol. The preovulatory increase in estradiol occurred in the R and M heifers during Cycle -2 but only in M heifers during Cycle -1. A treatment x cycle x day effect (P < .05) influenced LH concentrations. During Cycle -2, LH concentrations were similar for M and R heifers, but during Cycle -1, M heifers had greater LH concentrations than did R heifers. Concentrations of FSH were greater (P < .05) in R than M heifers after induced luteolysis when R heifers failed to ovulate. There was a treatment x cycle interaction (P < .05) for IGF-I concentrations, and M heifers had 4.7- and 8.6-fold greater IGF-I concentrations than did R heifers during Cycle -2 and -1, respectively. We conclude that growth rate and diameter of the ovulatory follicle, and concentrations of LH, estradiol, and IGF-I are reduced before the onset of nutritionally induced anovulation in beef heifers. C1 Oklahoma Agr Expt Stn, Dept Anim Sci, Stillwater, OK 74078 USA. TEAGASC, Athenry Res Ctr, Agr Food Dev Author, Athenry, Co Galway, Ireland. RP Wettemann, RP (reprint author), Oklahoma Agr Expt Stn, Dept Anim Sci, Stillwater, OK 74078 USA. OI Vizcarra, Jorge/0000-0002-4037-5216 NR 73 TC 79 Z9 83 U1 0 U2 2 PU AMER SOC ANIMAL SCIENCE PI SAVOY PA 1111 NORTH DUNLAP AVE, SAVOY, IL 61874 USA SN 0021-8812 J9 J ANIM SCI JI J. Anim. Sci. PD JUN PY 1999 VL 77 IS 6 BP 1536 EP 1546 PG 11 WC Agriculture, Dairy & Animal Science SC Agriculture GA 268XQ UT WOS:000084445300026 PM 10375231 ER PT J AU Zhang, TY Lee, S Guido, LJ Hsueh, CH AF Zhang, TY Lee, S Guido, LJ Hsueh, CH TI Criteria for formation of interface dislocations in a finite thickness epilayer deposited on a substrate SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STRAINED EPITAXIAL LAYER; ELASTIC-CONSTANTS; ARRAY; ENERGY; RELAXATION; STABILITY; MISFIT AB The critical epilayer thickness for the formation of misfit dislocations at the interface between an epilayer and a substrate with a finite thickness is derived in the present study. The analysis is based on the energy approach, in which the self-energy of dislocation, the interaction energy between the dislocation and free surfaces, and the lattice mismatch energy of substrate and epilayer are calculated. To satisfy the free surface condition, the methodology of superposition principle and Fourier transformation are used in analyzing the stress field due to the interface dislocation. The critical epilayer thickness is compared with those reported in the literature. (C) 1999 American Institute of Physics. [S0021-8979(99)06710-9]. C1 Hong Kong Univ Sci & Technol, Dept Mech Engn, Kowloon, Hong Kong. Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu, Taiwan. Yale Univ, Dept Elect Engn, New Haven, CT 06520 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Zhang, TY (reprint author), Hong Kong Univ Sci & Technol, Dept Mech Engn, Clear Water Bay, Kowloon, Hong Kong. RI Hsueh, Chun-Hway/G-1345-2011; Zhang, Tong-Yi/A-8828-2016 NR 27 TC 17 Z9 17 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1999 VL 85 IS 11 BP 7579 EP 7586 DI 10.1063/1.370558 PG 8 WC Physics, Applied SC Physics GA 197FL UT WOS:000080354300013 ER PT J AU Keinigs, RK Atchison, WL Faehl, RJ Thomas, VA Mclenithan, KD Trainor, RJ AF Keinigs, RK Atchison, WL Faehl, RJ Thomas, VA Mclenithan, KD Trainor, RJ TI One- and two-dimensional simulations of imploding metal shells SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELASTIC-PLASTIC SOLIDS; ACCELERATION INSTABILITY AB We report results of one- and two-dimensional (2D) magnetohydrodynamic simulations of imploding, cylindrical metal shells. One-dimensional simulations are used to calculate implosion velocities of heavy liners driven by 30 MA currents. Accelerated by the j X B force, 45 g aluminum/tungsten composite liners achieve velocities on the order of 13 km/s. Used to impact a tungsten target, the liner produces shock pressures of approximately 14 Mbar. The first 2D simulations of these liners are also described. These simulations have focused on two problems: (1) the interaction of the liner with the electrically conducting glide planes, and (2) the effect of realistic surface perturbations on the dynamics of the implosion. The former interaction is confined primarily to the region of the contact point between the liner and glide plane, and does not seriously affect the inner liner surface. However a 0.2 mu m surface perturbation has a significant effect on the implosion dynamics. (C) 1999 American Institute of Physics. [S0021-8979(99)05511-5]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Keinigs, RK (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 13 TC 12 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1999 VL 85 IS 11 BP 7626 EP 7634 DI 10.1063/1.370564 PG 9 WC Physics, Applied SC Physics GA 197FL UT WOS:000080354300019 ER PT J AU Cho, Y Kim, Y Weber, ER Ruvimov, S Liliental-Weber, Z AF Cho, Y Kim, Y Weber, ER Ruvimov, S Liliental-Weber, Z TI Chemical and structural transformation of sapphire (Al2O3) surface by plasma source nitridation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; C-PLANE SAPPHIRE; BUFFER LAYERS; GAN; GROWTH AB The chemical, morphological, and structural characteristics of nitrogen plasma treated c-plane sapphire substrate surfaces were studied by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The plasma treatment was carried out by exposing sapphire substrates (T-s = 700 degrees C) to a flow of 35 sccm of activated nitrogen species generated by a constricted-plasma source for 5-60 min. The emergence of the N 1s peak in XPS indicates nitrogen incorporation in sapphire as soon as after 5 min of nitridation. AFM images show that the sapphire contained a high density of islands after 1 h of nitridation. A thin polycrystalline AlN layer was observed on the nitridated sapphire surface by TEM. Both the thickness of the AlN layer and the N 1s photoelectron peak intensity increase nonlinearly with respect to nitridation time. The nonlinear relationship between the thickness of the nitridated layer and the reaction time suggests the growth of the AlN layer follows a diffusion limited growth mechanism. (C) 1999 American Institute of Physics. [S0021-8979(99)02510-4]. C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Cho, Y (reprint author), Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 16 TC 34 Z9 35 U1 1 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1999 VL 85 IS 11 BP 7909 EP 7913 DI 10.1063/1.370606 PG 5 WC Physics, Applied SC Physics GA 197FL UT WOS:000080354300061 ER PT J AU Toet, D Smith, PM Sigmon, TW Takehara, T Tsai, CC Harshbarger, WR Thompson, MO AF Toet, D Smith, PM Sigmon, TW Takehara, T Tsai, CC Harshbarger, WR Thompson, MO TI Laser crystallization and structural characterization of hydrogenated amorphous silicon thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EXCIMER-LASER; POLYCRYSTALLINE SILICON; SI FILMS; TRANSISTORS AB The influence of hydrogen and film thickness on the excimer laser-induced crystallization of plasma-enhanced chemical-vapor deposition-grown hydrogenated amorphous silicon thin films has been studied. Films with hydrogen concentrations varying from 1 to 10 at. % have been crystallized using short pulses from a XeCl excimer laser, at fluences sufficient to induce melting throughout the thickness of the films. Dehydrogenation prior to laser exposure was necessary only for films having initial hydrogen concentrations larger than 5 at. %. The structural properties of the laser-crystallized materials were studied by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The AFM measurements revealed that films requiring no dehydrogenation are smoother after laser crystallization than those requiring laser dehydrogenation, and that the roughness of these films increases as a function of film thickness, although it could be reduced by multiple laser exposure. Smoother films (root-mean-square roughness similar to 4.1 nm) were obtained by melting only the near-surface region of the film after the initial full melt exposure. TEM revealed that the laser-crystallized films consist of grains with sizes that are comparable to the film thickness. (C) 1999 American Institute of Physics. [S0021-8979(99)07811-1]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Appl Komatsu Technol, Santa Clara, CA 95054 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. RP Toet, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave,L-271, Livermore, CA 94550 USA. OI Thompson, Michael/0000-0002-4933-009X NR 30 TC 39 Z9 40 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1999 VL 85 IS 11 BP 7914 EP 7918 DI 10.1063/1.370607 PG 5 WC Physics, Applied SC Physics GA 197FL UT WOS:000080354300062 ER PT J AU Berry, EA Huang, LS Zhang, ZL Kim, SH AF Berry, EA Huang, LS Zhang, ZL Kim, SH TI Structure of the avian mitochondrial cytochrome bc(1) complex SO JOURNAL OF BIOENERGETICS AND BIOMEMBRANES LA English DT Article DE ubiquinol : cytochrome c oxidoreductase; membrane protein; electron transfer; structure determination ID IRON-SULFUR PROTEIN; INHIBITOR BINDING; BOVINE HEART; C REDUCTASE; BC1 COMPLEX AB There are now four structures of vertebrate mitochondrial bc(1) complexes available in the protein databases and structures from yeast and bacterial sources are expected soon. This review summarizes the new information with emphasis on the avian cytochrome bc(1) complex (PDB entries 1BCC and 3BCC). The Rieske iron-sulfur protein is mobile and this has been proposed to be important for catalysis. The binding sites for quinone have been located based on structures containing inhibitors and, in the case of the quinone reduction site Qi, the quinone itself. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Grad Grp Phys, Berkeley, CA 94720 USA. RP Berry, EA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. FU NIDDK NIH HHS [R01DK44842] NR 25 TC 27 Z9 28 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0145-479X J9 J BIOENERG BIOMEMBR JI J. Bioenerg. Biomembr. PD JUN PY 1999 VL 31 IS 3 BP 177 EP 190 DI 10.1023/A:1005459426843 PG 14 WC Biophysics; Cell Biology SC Biophysics; Cell Biology GA 258TB UT WOS:000083854300003 PM 10591524 ER PT J AU Davydov, RM Smieja, J Dikanov, SA Zang, Y Que, L Bowman, MK AF Davydov, RM Smieja, J Dikanov, SA Zang, Y Que, L Bowman, MK TI EPR properties of mixed-valent mu-oxo and mu-hydroxo dinuclear iron complexes produced by radiolytic reduction at 77 K SO JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY LA English DT Article DE mixed-valent species; dinuclear iron; EPR; radiolytic reduction ID ELECTRON-PARAMAGNETIC-RESONANCE; METHYLOSINUS-TRICHOSPORIUM OB3B; BRIDGED DIIRON COMPLEXES; HORSE SPLEEN APOFERRITIN; PURPLE ACID-PHOSPHATASE; RIBONUCLEOTIDE REDUCTASE; METHANE MONOOXYGENASE; ESCHERICHIA-COLI; ACTIVE-SITE; SPECTROSCOPIC CHARACTERIZATION AB Radiolytic reduction at 77 K of oxo/hydroxo-bridged dinuclear iron(III) complexes in frozen solutions forms kinetically stabilized, mixed-valent species in high yields that model the mixed-valent sites of non-heme, diiron proteins. The mixed-valent species trapped at 77 K retain ligation geometry similar to the initial diferric clusters. The shapes of the mixed-valent EPR signals depend strongly on the bridging ligands. Spectra of the Fe(II)OFe(III) species reveal an S = 1/2 ground state with small g-anisotropy as characterized by the uniaxial component (g(z)-g(av)/2 < 0.03) observable at temperatures as high as similar to 100 K. In contrast, hydroxo-bridged mixed-valent species are characterized by large g-anisotropy (g(z)-g(av)/2>0.03) and are observable only below 30 K. Annealing at higher temperatures causes structural relaxation and changes in the EPR characteristics, EPR spectral properties allow;the oxo- and hydroxo-bridged, mixed-valent diiron centers to be distinguished from each other and can help characterize the structure of mixed-valent centers in proteins. C1 Pacific NW Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Russian Acad Sci, Inst Chem Phys, Moscow 117977, Russia. Gonzaga Univ, Dept Chem, Spokane, WA 99258 USA. Russian Acad Sci, Inst Chem Kinet & Combust, Novosibirsk 630090, Russia. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. RP Bowman, MK (reprint author), Pacific NW Lab, WR Wiley Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 FU NIGMS NIH HHS [GM-38767] NR 62 TC 16 Z9 16 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-8257 J9 J BIOL INORG CHEM JI J. Biol. Inorg. Chem. PD JUN PY 1999 VL 4 IS 3 BP 292 EP 301 DI 10.1007/s007750050315 PG 10 WC Biochemistry & Molecular Biology; Chemistry, Inorganic & Nuclear SC Biochemistry & Molecular Biology; Chemistry GA 219NL UT WOS:000081613300006 PM 10439074 ER PT J AU Barsky, D Kool, ET Colvin, ME AF Barsky, D Kool, ET Colvin, ME TI Interaction and solvation energies of nonpolar DNA base analogues and their role in polymerase insertion fidelity SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID NUCLEIC-ACID BASES; 2ND-ORDER MOLLER-PLESSET; STATE KINETIC-ANALYSIS; AB-INITIO; REPLICATION FIDELITY; STEADY-STATE; REVERSE-TRANSCRIPTASE; NUCLEOTIDE INSERTION; DUPLEX STABILITY; CONTINUUM MODEL AB Although DNA polymerase fidelity has been mainly ascribed to Watson-Crick hydrogen bonds, two nonpolar isosteres for thymine (T) and adenine (A)-difluorotoluene (F) and benzimidazole (Z) -effectively mimic their natural counterparts in polymerization experiments with pol I O(F exo(-)) [JC Morales and ET Kool. Nature Struct Biol, 5, 950-954, 1998]. By ab initio quantum chemical gas phase methods (HF/6-31G* and MP2/6-31G**) and a solvent phase method (CPCM-HF/6-31G**), we find that the A-F interaction energy is 1/3 the A-T interaction energy in the gas phase and unstable in the solvent phase. The F-Z and T-Z interactions are very weak and T-Z is quite unstable in the solvent. Electrostatic solvation energy calculations on F, Z and toluene yield that Z is two times, and F and toluene are five times, less hydrophilic than the natural bases. Of the new "base-pairs" (F-Z, T-Z, and F-A), only FA formed an A-T-like arrangement in unconstrained optimizations. F-Z and T-Z do not freely form planar arrangements, and constrained optimizations show that large amounts of energy are required to make these pairs fit the exact A-T geometry, suggesting that the polymerase does not require all bases to conform to the exact A-T geometry. We discuss a model for polymerase/nucleotide binding energies and investigate the forces and conformational range involved in the polymerase geometrical selection. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Rochester, Dept Chem, Rochester, NY 14627 USA. Univ Rochester, Dept Biochem & Biophys, Rochester, NY 14627 USA. RP Barsky, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-452, Livermore, CA 94550 USA. NR 55 TC 51 Z9 51 U1 0 U2 3 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 1999 VL 16 IS 6 BP 1119 EP 1134 PG 16 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 206FL UT WOS:000080866600001 PM 10447197 ER PT J AU de Souza, ON Ornstein, RL AF de Souza, ON Ornstein, RL TI Molecular dynamics simulations of a protein-protein dimer: Particle-mesh Ewald electrostatic model yields far superior results to standard cutoff model SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID GLUTATHIONE-S-TRANSFERASE; DNA DODECAMER; UBIQUITIN; SYSTEMS AB In this article we present two 1000 ps molecular dynamics simulations on the rat mu-glutathione S-transferase dimeric enzyme in complex with the product 1-(S-glutathionyl)-2,4-dinitrobenzene, in a periodic box with explicit solvent molecules, and investigate the effect of long-range electrostatics models on the structure and dynamics of the dimer and its components. One simulation used the standard cutoff method 10 Angstrom, whilst the other used the particle-mesh Ewald (PME) method. We monitored the root mean-square atomic deviation (RMSD) from the initial crystal structure to examine the convergence of both simulations, as well as several other structural parameters such as the distance between active sites, rigid body rotation between domains in subunits, radius of gyration, B-factors, number of hydrogen bonds and salt bridges and solvent-accessible surface area. For example, with the PME method, the dimer structure remains much closer to the initial crystallographic structure with an average RMSD of 1.3 Angstrom +/- 0.1 Angstrom and 1.0 Angstrom +/- 0.1 Angstrom for all heavy and backbone atoms, respectively, in the last 200 ps; the respective values for the cutoff simulation are 4.7 Angstrom +/- 0.3 Angstrom and 4.2 Angstrom +/- 0.3 Angstrom. The large deviations observed in the cutoff simulation severely affected the stability of the enzyme dimer and its complex with the bound product. This finding is contrary to that found in a similar study of the monomeric protein ubiquitin [Fox, T. & Kollman, P. A. Proteins Struct. Func. Genet. 25, 315-334 (1996)]. Unlike the earlier published work, the present study provides evidence that the standard cutoff method is not generally valid for the study of protein complexes, or their subunits. C1 Battelle Mem Inst, Pacific NW Div, Richland, WA 99352 USA. RP de Souza, ON (reprint author), Battelle Mem Inst, Pacific NW Div, Mailstop K2-21, Richland, WA 99352 USA. RI Norberto de Souza, Osmar/B-7328-2013 OI Norberto de Souza, Osmar/0000-0002-4602-1208 NR 33 TC 36 Z9 36 U1 0 U2 4 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 1999 VL 16 IS 6 BP 1205 EP + PG 13 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 206FL UT WOS:000080866600008 ER PT J AU Yang, M Ohta, K Fleming, GR AF Yang, M Ohta, K Fleming, GR TI Three-pulse photon echoes for model reactive systems SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLAR SOLVATION DYNAMICS; BIMOLECULAR REACTIONS; KINETIC-THEORY; RHODOBACTER-SPHAEROIDES; CONDENSED PHASES; ENERGY-TRANSFER; PEAK SHIFT; LIQUID; SPECTROSCOPIES; PROBE AB A theoretical description of the three-pulse photon echo peak shift for model reaction systems is presented. An electronic two-state system with a finite upper-state lifetime and a three-state system in which electronic transitions can occur are considered. A probabilistic argument is employed to incorporate the incoherent transitions. New pathways describing the transition of electronic population are introduced and the nuclear propagator in the electronic population state is written by a convolution integral between those of the nonreactive two-state system weighted by some factors for the electronic transition. The response functions are given by multitime correlation functions and are analyzed by the cumulant expansion method. Some numerical calculations are presented and the influence of incoherent reactions on the peak shift is discussed. Comparison with experimental data confirms the existence of the effects predicted here. (C) 1999 American Institute of Physics. [S0021-9606(99)00321-9]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Yang, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Yang, Mino/0000-0001-9504-0280 NR 37 TC 45 Z9 46 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1999 VL 110 IS 21 BP 10243 EP 10252 DI 10.1063/1.478957 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 197MT UT WOS:000080369100004 ER PT J AU Iyengar, SS Parker, GA Kouri, DJ Hoffman, DK AF Iyengar, SS Parker, GA Kouri, DJ Hoffman, DK TI Symmetry-adapted distributed approximating functionals: Theory and application to the ro-vibrational states of H-3(+) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID H-3+ MOLECULAR ION; INFRARED PREDISSOCIATION SPECTRUM; DISCRETE VARIABLE REPRESENTATIONS; DEPENDENT SCHRODINGER-EQUATION; LIPPMANN-SCHWINGER EQUATIONS; QUANTUM REACTIVE SCATTERING; FOURIER METHOD SOLUTION; FOKKER-PLANCK EQUATION; FILTER-DIAGONALIZATION; POLYNOMIAL EXPANSION AB Symmetry-adapted Distributed Approximating Functionals (SADAFs) are derived and used to obtain a coordinate representation for the Adiabatically Adjusting Principal Axis Hyperspherical (APH) coordinates kinetic energy operator. The resulting expressions are tested by computing (J = 0) ro-vibrational states for the well-studied H-3(+) molecular ion system, by iterative diagonalization of the Hamiltonian matrix using the Arnoldi procedure. The SADAF representation and APH coordinate system are found to be computationally robust and accurate. (C) 1999 American Institute of Physics. [S0021-9606(99)01920-0]. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Oklahoma, Dept Phys, Norman, OK 73019 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Iyengar, SS (reprint author), Univ Houston, Dept Chem, Univ Pk, Houston, TX 77204 USA. RI Parker, Gregory/A-4327-2009; Iyengar, Srinivasan/B-5570-2017 OI Parker, Gregory/0000-0002-0225-8887; Iyengar, Srinivasan/0000-0001-6526-2907 NR 90 TC 17 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 1999 VL 110 IS 21 BP 10283 EP 10298 DI 10.1063/1.478962 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 197MT UT WOS:000080369100009 ER PT J AU Lexa, D AF Lexa, D TI The enthalpy of occlusion of the (lithium chloride plus potassium chloride) eutectic salt in zeolite 4A SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE zeolite; molten salt; lithium potassium chloride; occlusion; d.s.c. AB The molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature Delta(occ)H(m)(T-fus) was measured using differential scanning calorimetry. It was found that up to a mole fraction of the salt x = 0.931 in the (salt + zeolite) mixture, which is near the expected zeolite occlusion limit, Delta(occ)H(m)(T-fus) was negative and directly proportional tox. Thus, within this composition range, the partial molar enthalpy of occlusion of the (lithium chloride + potassium chloride) eutectic salt in zeolite 4A at the salt melting temperature is constant and equal to -(24 +/- 1) kJ . mol(-1). (C) 1999 Academic Press. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Lexa, D (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 3 Z9 3 U1 1 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JUN PY 1999 VL 31 IS 6 BP 811 EP 817 DI 10.1006/jcht.1999.0499 PG 7 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 200LF UT WOS:000080541200009 ER PT J AU Peters, LL Jindel, HK Gwynn, B Korsgren, C John, KM Lux, SE Mohandas, N Cohen, CM Cho, MR Golan, DE Brugnara, C AF Peters, LL Jindel, HK Gwynn, B Korsgren, C John, KM Lux, SE Mohandas, N Cohen, CM Cho, MR Golan, DE Brugnara, C TI Mild spherocytosis and altered red cell ion transport in protein 4.2-null mice SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article ID MURINE PALLID MUTATION; BLOOD-CELLS; HEREDITARY SPHEROCYTOSIS; MEMBRANE SKELETONS; CYTOPLASMIC DOMAIN; ANION TRANSPORT; BETA-SPECTRIN; BAND-3 AE1; BINDING; GENE AB Protein 4.2 is a major component of the red blood cell(RBC) membrane skeleton. We used targeted mutagenesis in embryonic stem (ES) cells to elucidate protein 4.2 functions in vivo. Protein 4.2-null (4.2(-/-)) mice have mild hereditary spherocytosis (HS). Scanning electron microscopy and ektacytometry confirm loss of membrane surface in 4.2(-/-) RBCs. The membrane skeleton architecture is intact, and the spectrin and ankyrin content of 4.2(-/-) RBCs are normal. Band 3 and band 3-mediated anion transport are decreased. Protein 4.2(-/-) RBCs show altered cation content (increased K+/decreased Na+) resulting in dehydration. The passive Na+ permeability and the activities of the Na-K-2Cl and K-Cl cotransporters, the Na/H exchanger, and the Gardos channel in 4.2(-/-) RBCs are significantly increased. Protein 4.2(-/-) RBCs demonstrate an abnormal regulation of cation transport by cell volume. Cell shrinkage induces a greater activation of Na/H exchange and Na-K-2Cl cotransport in 4.2(-/-) RBCs compared with controls. The increased passive Na+ permeability of 4.2(-/-) RBCs is also dependent on cell shrinkage. We conclude that protein 4.2 is important in the maintenance of normal surface area in RBCs and for normal RBC cation transport. C1 Jackson Lab, Bar Harbor, ME 04609 USA. St Elizabeths Med Ctr, Dept Biomed Res, Boston, MA 02135 USA. Childrens Hosp, Dept Med, Div Hematol Oncol, Boston, MA 02115 USA. Dana Farber Canc Inst, Dept Pediat Oncol, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Boston, MA 02115 USA. Brigham & Womens Hosp, Div Hematol, Boston, MA 02115 USA. Childrens Hosp, Dept Lab Med, Boston, MA 02115 USA. RP Jackson Lab, 600 Main St, Bar Harbor, ME 04609 USA. EM luanne@aretha.jax.org RI Brugnara, Carlo/A-8041-2010 OI Brugnara, Carlo/0000-0001-8192-8713 FU NCI NIH HHS [P30 CA034196]; NHLBI NIH HHS [HL-55321, P01 HL032262, R01 HL032854, R01 HL055321, R37 HL032854]; NIDDK NIH HHS [DK-26263, DK-34083, R01 DK026263, R01 DK034083, R01 DK050422, R37 DK026263] NR 52 TC 59 Z9 59 U1 0 U2 0 PU AMER SOC CLINICAL INVESTIGATION INC PI ANN ARBOR PA 35 RESEARCH DR, STE 300, ANN ARBOR, MI 48103 USA SN 0021-9738 EI 1558-8238 J9 J CLIN INVEST JI J. Clin. Invest. PD JUN PY 1999 VL 103 IS 11 BP 1527 EP 1537 DI 10.1172/JCI5766 PG 11 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA 251VY UT WOS:000083468100008 PM 10359562 ER PT J AU Istrail, S Schwartz, R King, J AF Istrail, S Schwartz, R King, J TI Lattice simulations of aggregation funnels for protein folding SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE aggregation; inclusion body; lattice; protein folding; simulation ID INCLUSION-BODY FORMATION; LONG-RANGE INTERACTIONS; MODEL; STABILITY; DYNAMICS; TRANSITION; POTENTIALS; POLYMERS; KINETICS AB A computer model of protein aggregation competing with productive folding is proposed. Our model adapts techniques from lattice Monte Carlo studies of protein folding to the problem of aggregation. However, rather than starting with a single string of residues, we allow independently folding strings to undergo collisions and consider their interactions in different orientations. We first present some background into the nature and significance of protein aggregation and the use of lattice Monte Carlo simulations in understanding other aspects of protein folding. The results of a series of simulation experiments involving simple versions of the model illustrate the importance of considering aggregation in simulations of protein folding and provide some preliminary understanding of the characteristics of the model, Finally, we discuss the value of the model in general and of our particular design decisions and experiments. We conclude that computer simulation techniques developed to study protein folding can provide insights into protein aggregation, and that a better understanding of aggregation may in turn provide new insights into and constraints on the more general protein folding problem. C1 Sandia Natl Labs, Dept Algorithms & Discrete Math, Albuquerque, NM 87185 USA. MIT, Comp Sci Lab, Cambridge, MA 02139 USA. MIT, Dept Biol, Cambridge, MA 02139 USA. RP Istrail, S (reprint author), Sandia Natl Labs, Dept Algorithms & Discrete Math, POB 5800, Albuquerque, NM 87185 USA. EM scistra@cs.sandia.gov RI Schwartz, Russell/A-1998-2016 OI Schwartz, Russell/0000-0002-4970-2252 NR 44 TC 41 Z9 42 U1 2 U2 6 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1066-5277 J9 J COMPUT BIOL JI J. Comput. Biol. PD SUM PY 1999 VL 6 IS 2 BP 143 EP 162 DI 10.1089/cmb.1999.6.143 PG 20 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 214TN UT WOS:000081343800001 PM 10421520 ER PT J AU Salinger, AG Shadid, JN Hutchinson, SA Hennigan, GL Devine, KD Moffat, HK AF Salinger, AG Shadid, JN Hutchinson, SA Hennigan, GL Devine, KD Moffat, HK TI Analysis of gallium arsenide deposition in a horizontal chemical vapor deposition reactor using massively parallel computations SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE CVD; finite element method; gallium arsenide; reactor design; parallel computing ID TRANSPORT; MOCVD; CVD AB A numerical analysis of the deposition of gallium arsenide from trimethylgallium (TMG) and arsine in a horizontal CVD reactor with tilted susceptor and a 3 " diameter rotating substrate is performed. The three-dimensional model includes complete coupling between fluid mechanics, heat transfer, and species transport, and is solved using an unstructured finite element discretization on a massively parallel computer. A reaction mechanism consisting of three surface and two bulk species, four surface reactions, and four gas phase species was used to model the deposition. The effects of three operating parameters (the disk rotation rate, inlet TMG fraction, and inlet velocity) and two design parameters (the tilt angle of the reactor base and the reactor width) on the growth rate and uniformity are presented. The nonlinear dependence of the growth rate uniformity on the key operating parameters is discussed in detail. Efficient and robust algorithms for massively parallel reacting flow simulations, as incorporated into our analysis code MFSalsa, make detailed analysis of this complicated system feasible. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Salinger, AG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 26 TC 25 Z9 25 U1 0 U2 3 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 1999 VL 203 IS 4 BP 516 EP 533 DI 10.1016/S0022-0248(99)00140-2 PG 18 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 206KH UT WOS:000080877900008 ER PT J AU Payne, DA Clem, PG AF Payne, DA Clem, PG TI Monolayer-mediated patterning of integrated electroceramics SO JOURNAL OF ELECTROCERAMICS LA English DT Article DE chemical solution processing; self-assembled monolayers; microcontact printing; PZT; LiNbO3; Ta2O5 ID SELF-ASSEMBLED MONOLAYERS; CHEMICAL-VAPOR-DEPOSITION; THIN-LAYERS; FABRICATION; FEATURES; ADSORPTION; SURFACES; FILMS; STAMP; GOLD AB Integrated electroceramic thin-film devices on semiconducting or insulating substrate materials offer a wide variety of attractive attributes, including high capacitance density, nonvolatile memory, sensor/actuator ability, and other unique electrical, electromechanical, magnetic and optical functions. Thus the ability to pattern such electroceramic thin films is a critical technology for future device realization. Patterned oxide thin-film devices are typically formed by uniform film deposition followed by somewhat complicated post-deposition ion-beam or chemical etching in a controlled environment i.e., a subtractive method. We review here an upset technology, a different way of patterning, by an additive approach, which allows for the selective deposition of electroceramic thin layers without such post-deposition etching. In this method, substrate surfaces are selectively functionalized with hydrophobic self-assembled monolayers to modify the adhesion of subsequently deposited solution-derived electroceramics. The selective functionalization is achieved through microcontact printing (mu-CP) of self-assembled monolayers of the chemical octadecyltrichlorosilane on substrates of current technical interest. Subsequent sol-gel deposition of ceramic oxides on these functionalized substrates, followed by lift-off from the monolayer, yields high quality, patterned oxide thin layers only on the unfunctionalized regions. A variety of micron-scale dielectric oxide devices have been fabricated by this method, with lateral resolution as fine as 0.5 mu m. In this paper, we review the monolayer patterning and electrical behavior of several patterned electroceramic thin films, including Pb(Zr,Ti)O-3 [PZT], LiNbO3, and Ta2O5. A multilevel example is also given which combines selective MOCVD deposition of metal electrodes and sol-gel patterned PZT for Pt//PZT//Pt//Si(100) ferroelectric memory cells. C1 Sandia Natl Labs, Direct Fabricat Dept, Albuquerque, NM 87185 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. RP Payne, DA (reprint author), Sandia Natl Labs, Direct Fabricat Dept, POB 5800, Albuquerque, NM 87185 USA. NR 29 TC 29 Z9 29 U1 2 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1385-3449 J9 J ELECTROCERAM JI J. Electroceram. PD JUN PY 1999 VL 3 IS 2 BP 163 EP 172 DI 10.1023/A:1009947211056 PG 10 WC Materials Science, Ceramics SC Materials Science GA 213GM UT WOS:000081264400007 ER PT J AU King, BH Dimos, D Yang, P Morissette, SL AF King, BH Dimos, D Yang, P Morissette, SL TI Direct-write fabrication of integrated, multilayer ceramic components SO JOURNAL OF ELECTROCERAMICS LA English DT Article DE direct fabrication; micropen; polymer; thick-film; ceramic thick-film; multilayer; rheology; MMICCs; passive components AB The need for advanced electronic ceramic components with smaller size, greater functionality and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. However, traditional tape casting and screen printing approaches are poorly suited to the requirements of rapid prototyping and small-lot manufacturing. To address this need, a direct-write approach for fabricating highly integrated, multilayer components using a Micropen to deposit slurries in precise patterns is being developed at Sandia. This approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way. Commercial ceramic thick-film pastes can be used directly in the system, as can polymer thick-film pastes (PTF). The quality of printed components depends on both the rheology and drying behavior of the pastes. Pastes with highly volatile solvents are inappropriate for the Micropen. This system has been used to make integrated passive devices such as RC filters, inductors, and voltage transformers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP King, BH (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 9 TC 24 Z9 25 U1 2 U2 14 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1385-3449 J9 J ELECTROCERAM JI J. Electroceram. PD JUN PY 1999 VL 3 IS 2 BP 173 EP 178 DI 10.1023/A:1009999227894 PG 6 WC Materials Science, Ceramics SC Materials Science GA 213GM UT WOS:000081264400008 ER PT J AU Berrah, N Langer, B Wills, AA Kukk, E Bozek, JD Farhat, A Gorczyca, TW AF Berrah, N Langer, B Wills, AA Kukk, E Bozek, JD Farhat, A Gorczyca, TW TI High-resolution angle-resolved measurements in atoms and molecules using advanced photoelectron spectroscopy at the ALS SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE photoelectron spectroscopy; two-dimensional time-of-flight electron spectroscopy; Auger electron spectroscopy ID NEON; RESONANCES; PHOTOIONIZATION; AUTOIONIZATION; SATELLITES AB A two-dimensional photoelectron imaging technique using time-of-flight spectrometry and a high-resolution SES-200 electron energy analyzer have been used with photons from the atomic and molecular undulator beamline of the Advanced Light Source to study the structure and dynamics of atoms and molecules. The analyzers are rotatable around the direction of the photon beam, allowing angular-dependent studies to be performed. Results on the photoexcitation and decay mechanisms of doubly excited resonances in neon illustrate the importance of spin-orbit effects for such a light atom, since significant breakdown of LS-coupling was measured for such a light atom. Also, fully vibrationally resolved Auger electron spectra measured under Resonant Raman conditions following the C 1s --> pi* excitation in a diatomic molecule, CO, is presented which allows us to probe the core excited states, their excitation and de-excitation dynamics with unprecedented resolution. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Tech Univ Berlin, Inst Atomar & Analyt Phys, D-10623 Berlin, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Berrah, N (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Langer, Burkhard/A-6504-2013; Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 22 TC 48 Z9 48 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 1 EP 11 DI 10.1016/S0368-2048(98)00464-2 PG 11 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000002 ER PT J AU Puttner, R Domke, M Gremaud, B Martins, M Schlachter, AS Kaindl, G AF Puttner, R Domke, M Gremaud, B Martins, M Schlachter, AS Kaindl, G TI New interseries interferences in doubly-excited helium SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA ID DOUBLE-EXCITATION STATES; HIGH-RESOLUTION AB We present spectra of doubly-excited P-1(o) states in helium below the N = 4, 6, 8, and 9 ionization thresholds measured with a resolution of Delta E congruent to 2.0 meV. A number of hitherto unobserved interseries interferences are reported. The spectra below the N = 8 and 9 ionization thresholds are assigned and analyzed using theoretical results obtained with the complex rotation method and diagonalization of sparse matrices. The resonances below the N = 9 ionization threshold reveal unexpected high values and strong fluctuations of the Fano parameter q. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Free Univ Berlin, Inst Phys Expt, D-14195 Berlin, Germany. Univ Paris 06, Lab Kastler Brossel T12 E1, F-75005 Paris, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Puttner, R (reprint author), Univ Oulu, Dept Phys Sci, FIN-90570 Oulu, Finland. OI Martins, Michael/0000-0002-1228-5029 NR 12 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 27 EP 32 DI 10.1016/S0368-2048(98)00467-8 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000005 ER PT J AU Denecke, R Morais, J Ynzunza, RX Menchero, JG Liesegang, J Fadley, CS AF Denecke, R Morais, J Ynzunza, RX Menchero, JG Liesegang, J Fadley, CS TI Magnetic circular dichroism in photoelectron angular distributions from Gd(0001) SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE magnetic circular dichroism; angle-resolved photoelectron spectroscopy; photoelectron diffraction ID X-RAY PHOTOEMISSION; CORE-LEVEL PHOTOEMISSION; SPIN POLARIZATION; HIGH-RESOLUTION; VALENCE STATES; 4F PHOTOEMISSION; LINEAR DICHROISM; THIN-FILMS; DIFFRACTION; SYSTEMS AB We report on the influence of photoelectron diffraction effects on magnetic circular dichroism in angular distribution as measured using core-level photoelectron spectroscopy. As an example system we study the effect by measuring azimuthal angle scans of the 4d core-level on a thick Gd(0001) film grown on W(110). Ln particular, for photoelectron emission in off-normal directions we observe deviations from the purl atomic picture which can be interpreted in terms of a multiple scattering theory. We also evaluate different measuring methods to see their influence on the angular behavior. Using high resolution data we can even study the state-specific contributions to the magnetic dichroism signal. The knowledge of these effects should help in interpreting absolute dichroism values on the basis of sum rules. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Denecke, R (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Morais, Jonder/E-5022-2013 OI Morais, Jonder/0000-0002-4143-1208 NR 32 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 263 EP 269 DI 10.1016/S0368-2048(98)00456-3 PG 7 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000044 ER PT J AU Teterin, YA Ivanov, KE Teterin, AY Lebedev, AM Utkin, IO Vukchevich, L AF Teterin, YA Ivanov, KE Teterin, AY Lebedev, AM Utkin, IO Vukchevich, L TI Auger and X-ray photoelectron spectroscopy study of the density of oxygen states in bismuth, aluminium, silicon and uranium oxides SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE XPS; Auger OKLL spectra; electron density; inner valence molecular orbitals (IVMO) ID SPECTRA AB The correlation of relative partial electron density at the oxygen ions with the intensity of Auger O KLL lines in Bi2O3, Al2O3, SiO2 and UO2 has been determined by Auger and X-ray photoelectron spectroscopic methods. The dependence of the relative intensities of Auger O KL2-3L2-3 and O KL1L2-3-lines was characterized from the binding energy of O 1s electrons. The electron density of the outer valence levels of oxygen increases as the relative intensities of Anger O KL2-3L2-3 and O KL1L2-3-lines increase. The fine structure observed in the O KL1L2-3 Auger and the O 2s XPS spectra has been explained by the formation of inner valence molecular orbitals (IVMO) from the interaction of electrons of the O 2s and filled metal ns shells. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Kurchatov Inst, Russian Res Ctr, Moscow 123182, Russia. Veljko Vlahovich Univ, Nat Math Dept, YU-81000 Podgorica, Yugoslavia. RP Ivanov, KE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 8 TC 17 Z9 18 U1 5 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 401 EP 405 DI 10.1016/S0368-2048(98)00405-8 PG 5 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000068 ER PT J AU Sacchi, M Hague, CF Gota, S Guiot, E Gautier-Soyer, M Pasquali, L Mrowka, S Gullikson, EM Underwood, JH AF Sacchi, M Hague, CF Gota, S Guiot, E Gautier-Soyer, M Pasquali, L Mrowka, S Gullikson, EM Underwood, JH TI Resonant scattering of polarized soft X-rays for the study of magnetic oxide layers SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE oxide layers; polarized soft X-rays; resonant scattering ID ABSORPTION-SPECTROSCOPY; EXCHANGE SCATTERING; EPITAXIAL-FILMS; IRON; GROWTH; DICHROISM; REFLECTIVITY; MULTILAYERS; SAPPHIRE; MOMENTS AB We report preliminary results that illustrate the potential of resonant scattering of polarized soft X-rays applied to the study of the magnetic properties of oxide layers. As a test case, we study iron oxides, a class of materials of high technological interest, especially when prepared in the form of thin epitaxial layers. (C) 1999 Elsevier Science B.V. All rights reserved. C1 CEA Saclay, DRECAM, SRSIM, F-91191 Gif Sur Yvette, France. Lab Chim Phys Mat & Rayonnement, F-75231 Paris, France. Ctr Univ Paris Sud, LURE, F-91405 Orsay, France. Ist Nazl Fis Mat, Sez Modena, I-41100 Modena, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Gota, S (reprint author), CEA Saclay, DRECAM, SRSIM, Bat 462, F-91191 Gif Sur Yvette, France. EM gota@belem.saclay.cea.fr RI Pasquali, Luca/K-2866-2015 OI Pasquali, Luca/0000-0003-0399-7240 NR 24 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 407 EP 412 DI 10.1016/S0368-2048(98)00500-3 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000069 ER PT J AU Herman, GS McDaniel, EP Joyce, SA AF Herman, GS McDaniel, EP Joyce, SA TI Interaction of D2O with the Fe3O4(111) and the biphase ordered structures on alpha-Fe2O3(0001) SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE hematite; iron oxide; water; X-ray photoelectron spectroscopy ID IRON-OXIDE SURFACES; ELECTRONIC-STRUCTURE; WATER; PHOTOEMISSION; SPECTROSCOPY; ADSORPTION; PT(111); FE2O3; LEED; XPS AB The interactions of D2O with the Fe3O4(111) and the biphase ordered structures on alpha-Fe2O3(0001) were studied with X-ray photoelectron spectroscopy (XPS), low energy electron diffraction, thermal desorption, and mass spectroscopy of recoiled ions. These studies indicate that D2O is weakly bound to the surface and that virtually none exists at the surface after a 10 Langmuir dose at 300 K. However, XPS indicates that when the sample is dosed with 3 Langmuirs at 85 K, a significant amount of molecular D2O is bound to the surface, with a lesser amount of hydroxyls present as well. (C) 1999 Elsevier Science BN. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Herman, GS (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM gs.herman@pnl.gov RI Joyce, Stephen/Q-7804-2016 OI Joyce, Stephen/0000-0003-1330-7362 NR 18 TC 19 Z9 19 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 433 EP 438 DI 10.1016/S0368-2048(98)00505-2 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000074 ER PT J AU Diaz, J Anders, S Zhou, X Moler, EJ Kellar, SA Hussain, Z AF Diaz, J Anders, S Zhou, X Moler, EJ Kellar, SA Hussain, Z TI Combined near edge X-ray absorption fine structure and X-ray photoemission spectroscopies for the study of amorphous carbon thin films SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE amorphous carbon; NEXAFS; XPS; thin films; amorphous surfaces ID DIAMOND-LIKE CARBON; SYNCHROTRON-RADIATION; NEUTRON-SCATTERING; ARC DEPOSITION; GRAPHITE; VACUUM; EXCITATION; EXCITONS; SPECTRA; ENERGY AB Near edge X-ray absorption fine structure (NEXAFS) and X-ray photoemission (XPS) spectroscopies were used to study the chemical bonding in hard amorphous carbon (a-C) thin films. The analysis of their XPS spectra obtained at different photon energy excitations showed that the fraction of sp(3) hybridized atoms increased from the surface to the bulk. About 90% of the carbon atoms became spl hybridized over the depth probed by XPS after annealing the film at 850 degrees C. The intensity of the pi* resonance in the NEXAFS spectrum of the hard a-C film annealed at 850 degrees C was significantly smaller than the same resonance in a softer film annealed at 350 degrees C. However, the sp(2) concentration of the former film, measured by XPS, was much higher. This demonstrates that the intensity of the pi* resonance in the NEXAFS spectra of a-C films is not strictly proportional to the concentration of sp(2) hybridized atoms, but it can be strongly influenced by other effects, such as the localized character of the particular pi* bonding present in the analyzed a-C film. A sharp resonance was observed at the same photon energy as the exciton in diamond, at 289.5 eV, in the NEXAFS spectra of the a-C films. This resonance might indicate that a proportion of carbon atoms in the analyzed films occupied similar sites as the carbon atoms in crystalline diamond. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Oviedo, Dept Fis, E-33007 Oviedo, Spain. RP Diaz, J (reprint author), Lawrence Berkeley Lab, I Cyclotron Rd, Berkeley, CA 94720 USA. EM jdiaz@condmat2.ciencias.uniovi.es RI Diaz, Javier/F-2381-2016; Raoux, Simone/G-3920-2016 NR 22 TC 14 Z9 15 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 545 EP 550 DI 10.1016/S0368-2048(98)00348-X PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000093 ER PT J AU Jimenez, I Terminello, LJ Himpsel, FJ Grush, M Callcott, TA AF Jimenez, I Terminello, LJ Himpsel, FJ Grush, M Callcott, TA TI Photoemission, X-ray absorption and X-ray emission study of boron carbides SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE boron carbide; boron; photoemission; X-ray absorption; fluorescence ID BANDS AB Photoemission (PES), X-ray absorption (XAS) and soft X-ray fluorescence (SXF) measurements have been performed on a variety of boron carbide samples to explore the possibilities of synchrotron-based spectroscopies in determining the atomic and electronic structure of this complex material. B4C bulk samples and powders, boron-rich BxC thin films, and boron powders (amorphous and crystalline) have been studied. The results are discussed in terms of the current structural models. (C) 1999 Elsevier Science B.V. All rights reserved. C1 CSIC, Inst Ciencia Mat, Madrid 28049, Spain. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Jimenez, I (reprint author), CSIC, Inst Ciencia Mat, Madrid 28049, Spain. RI Jimenez, Ignacio/F-7422-2010 OI Jimenez, Ignacio/0000-0001-5605-3185 NR 9 TC 10 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 611 EP 615 DI 10.1016/S0368-2048(98)00342-9 PG 5 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000106 ER PT J AU Kay, AW Arenholz, E Mun, BS de Abajo, JG Fadley, CS Denecke, R Hussain, Z Van Hove, MA AF Kay, AW Arenholz, E Mun, BS de Abajo, JG Fadley, CS Denecke, R Hussain, Z Van Hove, MA TI Multiple atom resonant photoemission: A new technique for studying near-neighbor atomic identities and bonding SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE resonant photoemission; metal oxides ID SPECTROSCOPY; 3D AB A new multi-atom resonant photoemission (MARPE) effect between core levels of neighboring atoms in multi-element samples has been observed. Experimental evidence for the effect and several possible applications are considered. Ln the metal oxides MnO, Fe2O3, and La0.7Sr0.3MnO3, we have observed a significant enhancement in the core-level photoelectron peak intensity associated with one element in the sample (e.g. Ols) when the excitation energy is tuned through an energetically deeper absorption edge of a second element (e.g. Mn2p or Fe2p or La3d). The effects observed are up to a 105% increase in peak intensity, and a 29% increase in energy-integrated intensity. A generalization of the theory of single-atom resonant photoemission has also been applied to MARPE, and is found to be in semiquantitative agreement with our experimental results. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Berkeley, Miller Inst, Berkeley, CA 94720 USA. RP Kay, AW (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RI Garcia de Abajo, Javier/A-6095-2009; Van Hove, Michel/A-9862-2008; Mun, Bongjin /G-1701-2013 OI Garcia de Abajo, Javier/0000-0002-4970-4565; Van Hove, Michel/0000-0002-8898-6921; NR 13 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 647 EP 652 DI 10.1016/S0368-2048(98)00329-6 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000113 ER PT J AU Faiz, M Zhou, X Moler, EJ Kellar, SA Hussain, Z Hamdan, NM Ziq, KA AF Faiz, M Zhou, X Moler, EJ Kellar, SA Hussain, Z Hamdan, NM Ziq, KA TI An X-ray absorption spectroscopic study of YBa2Cu3-xFexO7+y SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE high-T-c superconductors; XANES; XRD; YBa2Cu3-xFexO7+y ID HOLE CONCENTRATION; TEMPERATURE; SUPERCONDUCTORS; PHOTOELECTRON AB We report a study of X-ray absorption near-edge structure of the O K and Cu L-3 edges in YBa2Cu3-xFexO7+y for x=0.01, 0.05 and 0.15. We attribute the peaks below 529 eV in the O K edge spectra of YBa2Cu3-xFexO7+y to holes on the O sites. Our results show hole filling with increasing Fe content, which means that Fe enters the structure primarily in the formally trivalent oxidation state. Cu L-3 edge spectra reveal increased amounts of Cu3+ with increasing Fe content. The results are discussed in terms of charge balancing. (C) 1999 Elsevier Science B.V. All rights reserved. C1 King Fahd Univ Petr & Minerals, Dept Phys, Dhahran 31261, Saudi Arabia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Faiz, M (reprint author), King Fahd Univ Petr & Minerals, Dept Phys, Dhahran 31261, Saudi Arabia. EM mmfaiz@kfupm.edu.sa NR 20 TC 0 Z9 0 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 707 EP 711 DI 10.1016/S0368-2048(98)00402-2 PG 5 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000125 ER PT J AU Butorin, SM Magnuson, M Ivanov, K Shuh, DK Takahashi, T Kunii, S Guo, JH Nordgren, J AF Butorin, SM Magnuson, M Ivanov, K Shuh, DK Takahashi, T Kunii, S Guo, JH Nordgren, J TI Resonant inelastic soft-X-ray scattering at the 4d edge of Ce-based heavy-fermion materials SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE Resonant soft-X-ray scattering; Ce-based heavy-fermion systems; charge-transfer excitations; X-ray absorption ID SPECTROSCOPY; EXCITATIONS; MODEL AB Resonant X-ray scattering measurements were performed on CeB6, CeAl, gamma-Ce, and alpha-Ce at various incident-photon energies near the Ce 4d threshold. A pronounced inelastic scattering structure which has 4f character is observed at about 4 eV below the elastic peak. The structure shows a distinct resonant behavior as well as a dependence on the degree of 4f hybridization and can therefore be attributed to charge-transfer excitations to the 4f(0) state. The intensity of the elastic peak increases when going from the systems with low Kondo temperature T-K to those with high T-K which is consistent with a Kondo scale behavior. By analyzing the scattering data, a controversial issue on the validity of a single-impurity Anderson model in heavy-fermion materials is addressed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. RP Butorin, SM (reprint author), Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. RI Takahashi, Takashi/E-5080-2010; Magnuson, Martin/F-5145-2012 OI Magnuson, Martin/0000-0002-0317-0190 NR 8 TC 6 Z9 6 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 783 EP 786 DI 10.1016/S0368-2048(98)00369-7 PG 4 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000139 ER PT J AU Kurmaev, EZ Korotin, MA Galakhov, VR Finkelstein, LD Zabolotzky, EI Efremova, NN Stadler, S Ederer, DL Moewes, A Bartkowski, S Neumann, M Matsuno, J Mizokawa, T Fujimori, A Mitchell, J AF Kurmaev, EZ Korotin, MA Galakhov, VR Finkelstein, LD Zabolotzky, EI Efremova, NN Stadler, S Ederer, DL Moewes, A Bartkowski, S Neumann, M Matsuno, J Mizokawa, T Fujimori, A Mitchell, J TI X-ray emission and photoelectron spectra of Pr0.5Sr0.5MnO3 SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE X-ray emission resonant spectra; X-ray photoelectron spectra; manganites; electronic structure ID MAGNETIC-FIELD; PR1-XCAXMNO3; LA1-XSRXMNO3; PEROVSKITES; TRANSITION; PR1-XSRXMNO3 AB The results of measurements of X-ray photoelectron (XPS), X-ray emission (XES) and X-ray absorption spectra and LSDA band structure calculations of Pr0.5Sr0.5MnO3 are presented. The excitation energy dependence of Mn L-2.3 and O K-alpha X-ray emission spectra of Pr0.5Sr0.5MnO3 is measured using tunable synchrotron radiation. Comparing XPS and XES measurements and the LSDA band structure calculations, one concludes that the Mn 3d states are localized near the top of the valence band. Some differences in the Mn 3d-distribution in the upper part of the XPS valence band and Mn L-3 XES are due to spin selection rules. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Met Phys, Ural Div, Yekaterinburg 620219, Russia. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Louisiana State Univ, CAMD, Baton Rouge, LA 70803 USA. Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kurmaev, EZ (reprint author), Russian Acad Sci, Inst Met Phys, Ural Div, GSp-170, Yekaterinburg 620219, Russia. EM kurmaev@ifmlrs.uran.ru RI Korotin, Michael/J-3252-2013; Nechkina, Larisa/J-5974-2013; Kurmaev, Ernst/J-4254-2013; Mizokawa, Takashi/E-3302-2015; Galakhov, Vadim/J-6030-2013; Matsuno, Jobu/C-1737-2008 OI Korotin, Michael/0000-0002-9603-8374; Nechkina, Larisa/0000-0002-6268-7958; Kurmaev, Ernst/0000-0003-4625-4930; Mizokawa, Takashi/0000-0002-7682-2348; Galakhov, Vadim/0000-0002-1642-7362; Matsuno, Jobu/0000-0002-3018-8548 NR 20 TC 1 Z9 1 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 793 EP 798 DI 10.1016/S0368-2048(98)00426-5 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000141 ER PT J AU Denlinger, JD Gweon, GH Allen, JW Marcus, J Schlenker, C AF Denlinger, JD Gweon, GH Allen, JW Marcus, J Schlenker, C TI High-energy angle-resolved photoemission of NaMo6O17 SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE angle-resolved photoemission; molybdenum bronze; low-dimensional conductor ID FERMI-SURFACE; LIGHT-SOURCE; CONDUCTOR AB Angle-resolved photoelectron spectroscopy of quasi-two-dimensional NaMo6O17 has been investigated with photon energies greater than 70 eV. The underlying quasi-one-dimensional band structure is visualized in multiple Brillouin zones by the constant binding-energy intensity mapping technique. Brillouin zone intensity modulation effects are observed in Fermi-edge intensity maps both as a function of k(parallel to) (angle) and of k(z) (photon energy). Experimental challenges arising from small sample sizes, detection geometry and susceptibility to beam-induced surface damage are also discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Michigan, Randall Lab, Ann Arbor, MI 48109 USA. CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble 9, France. RP Denlinger, JD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 7-222,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM JDDenlinger@lbl.gov NR 14 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 805 EP 810 DI 10.1016/S0368-2048(98)00428-9 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000143 ER PT J AU Carlisle, JA Blankenship, SR Smith, RN Shirley, EL Terminello, LJ Jia, JJ Callcott, TA Ederer, DL AF Carlisle, JA Blankenship, SR Smith, RN Shirley, EL Terminello, LJ Jia, JJ Callcott, TA Ederer, DL TI Soft-X-ray fluorescence studies of solids SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE X-ray emission spectra; resonant X-ray scattering; band structure; excitons; graphite ID RESONANT INELASTIC-SCATTERING; BAND-STRUCTURE; GRAPHITE; ABSORPTION; EMISSION; EXCITONS; EDGE AB Resonant inelastic X-ray scattering (RIXS) has been observed in many systems above and below their core threshold. Below threshold, inelastic-loss features are observed, which disperse linearly with excitation energy, but as the excitation increases above the core binding energy, nonlinear dispersive effects are observed. These two effects are described by the same physics of coherent fluorescence. Very good agreement between experiment and simulated RIXS is achieved using a simple one-electron framework. However, significant questions have arisen concerning core-hole effects and their influence on RIXS. In this work, the role core-excitons play in the RIXS process is examined in finer detail in graphite, by using narrow-band excitation, and through comparison between experiment and simulated spectra which include the core-hole effects explicitly in the modeling. Based on these findings, we conclude that core-hole effects play a minor but detectable role in the RIXS observed from graphite. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Virginia Commonwealth Univ, Richmond, VA 23284 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Tennessee, Knoxville, TN 37996 USA. Tulane Univ, New Orleans, LA 70118 USA. RP Carlisle, JA (reprint author), Virginia Commonwealth Univ, Richmond, VA 23284 USA. EM jacarlis@vcu.edu NR 20 TC 3 Z9 3 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 839 EP 845 DI 10.1016/S0368-2048(98)00434-4 PG 7 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000149 ER PT J AU Ito, Y Tochio, T Vlaicu, AM Ohsawa, D Mukoyama, T Muramatsu, Y Perera, RCC Grush, MM Callcott, TA Sherman, E AF Ito, Y Tochio, T Vlaicu, AM Ohsawa, D Mukoyama, T Muramatsu, Y Perera, RCC Grush, MM Callcott, TA Sherman, E TI The contribution of the ligands around Cr to the resonant inelastic L X-ray emission spectra SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE resonant; soft X-ray; emission; absorption; Cr compounds ID ADVANCED LIGHT-SOURCE; FLUORESCENCE SPECTROSCOPY; INTENSITY RATIOS; L-EDGE; ABSORPTION; COMPLEXES; BEAMLINE; STATE AB L X-ray emission spectra in the energy region of the Cr 2p threshold on Cr compounds were measured and analysed using tunable synchrotron radiation. The X-ray absorption and emission spectra (XAES) of Cr (VI) are very different from those of Cr (III). It is considered that the difference in the soft X-ray emission is mainly attributed to the effect of the covalency in bonding, because the transition intensity of the KP, spectral line is sensitive for the valence electronic configuration. Therefore, it follows that XAES is very sensitive to the ligand environment in Cr compounds and relatively insensitive to the metal oxidation state, as Grush et al. suggested for Mn complexes [J. Electron. Spectros. Relat. Phenom. 92 (1998) 225]. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Chem Res Inst, Uji, Kyoto 6110011, Japan. NTT, Integrated Informat & Energy Syst Lab, Tokyo 180, Japan. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Rhein Westfal TH Aachen, Inst Phys 2, D-52056 Aachen, Germany. RP Ito, Y (reprint author), Kyoto Univ, Chem Res Inst, Uji, Kyoto 6110011, Japan. NR 18 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 851 EP 858 DI 10.1016/S0368-2048(98)00398-3 PG 8 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000151 ER PT J AU Young, AT Martynov, V Padmore, HA AF Young, AT Martynov, V Padmore, HA TI Magnetic high-resolution spectroscopy with Beamline 4.0.1-2: An elliptically polarizing undulator beamline at the Advanced Light Source SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE high resolution magnetic spectroscopy; Beamline 4.0.1-2; new facility ID CIRCULAR-DICHROISM AB A new facility at the Advanced Light Source, Lawrence Berkeley National Laboratory, for high resolution magnetic spectroscopy is described. Scheduled to begin operation by the end of 1998, Beamline 4.0.1-2 has an elliptically polarizing undulator (EPU) and a high resolution monochromator, covering the energy range from 90 to 2000 eV. Calculated performance of the undulator and monochromator are presented, including the estimated photon flux from the undulator and the expected spectral resolution of the monochromator. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Young, AT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 11 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 885 EP 889 DI 10.1016/S0368-2048(98)00409-5 PG 5 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000156 ER PT J AU Friedrich, S Hiller, LJ Frank, M le Grand, JB Mears, CA Niderost, B Labov, SE Barfknecht, AT LeGros, M Cramer, SP AF Friedrich, S Hiller, LJ Frank, M le Grand, JB Mears, CA Niderost, B Labov, SE Barfknecht, AT LeGros, M Cramer, SP TI Superconducting high-resolution X-ray detectors for metalloprotein L-edge spectroscopy SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 12th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-12) CY AUG 03-07, 1998 CL SAN FRANCISCO, CA DE cryogenic X-ray detectors; superconducting tunnel junctions; L-edge absorption spectroscopy ID PARTICLE DETECTORS; TUNNEL JUNCTION; SPECTROMETERS AB Superconducting tunnel junctions (Sns) can be used as high-resolution energy-dispersive X-ray detectors. STJ detectors are based on the measurement of an increased tunneling current from excess charge carriers that are excited above the superconducting energy gap by the absorption of an X-ray. Nb-based STJ detectors have a theoretical energy resolution limit below 5 eV FNHM for X-ray energies below 1 keV at count rates up to 10 000 counts/s. We have developed Nb-Al-AlOx-Al-Nb X-ray detectors and operated them in a cryostat below 0.4 K in synchrotron experiments. Their resolution varies between 4.6 and 8.9 eV FWHM for X-ray energies between 0.2 and 1 keV. We present fluorescence spectra of metalloproteins and discuss the potential of Sn detectors for fluorescence-detected L-edge absorption spectroscopy of dilute samples. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Conductus Inc, Sunnyvale, CA 94086 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Friedrich, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-418, Livermore, CA 94550 USA. EM sfriedrich@lbl.gov RI Frank, Matthias/O-9055-2014 NR 19 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUN PY 1999 VL 101 SI SI BP 891 EP 896 DI 10.1016/S0368-2048(98)00410-1 PG 6 WC Spectroscopy SC Spectroscopy GA 210JT UT WOS:000081102000157 ER PT J AU Hermon, H Schieber, M James, RB Lee, EY Yang, N Antolak, AJ Morse, DH Hackett, C Tarver, E Kolesnikov, NNP Ivanov, YN Komar, V Goorsky, MS Yoon, H AF Hermon, H Schieber, M James, RB Lee, EY Yang, N Antolak, AJ Morse, DH Hackett, C Tarver, E Kolesnikov, NNP Ivanov, YN Komar, V Goorsky, MS Yoon, H TI Analysis of CZT crystals and detectors grown in Russia and the Ukraine by high-pressure Bridgman methods SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 17th US Workshop on the Physics and Chemistry of II-VI Materials CY OCT 20-22, 1998 CL CHARLESTON, SOUTH CAROLINA SP US Army CECOM (NVESD), US Army SMDC, US Army Res Lab, Off Naval Res, AF Res Lab, Minerals Met & Mat Soc DE atomic force microscopy (AFM); Cd1-xZnxTe; gamma-ray detectors; ICP MS; proton-induced x-ray emission (PIXE); thermoelectric emission spectroscopy (TEES); x-ray diffraction (XRD) ID CD1-XZNXTE AB Sandia National Laboratories (SNL) is leading an effort to evaluate vertical high pressure Bridgman (VHPB) Cd1-xZnxTe (CZT) crystals grown in the former Soviet Union (FSU) (Ukraine and Russia), in order to study the parameters limiting the crystal quality and the radiation detector performance. The stoichiometry of the CZT crystals, with 0.04 80 degrees invariant latitude) magnetic latitudes are presented. Each pass of several across the polar cap was made during a period of persistent northward interplanetary magnetic field, and was characterized by the presence of several of these precipitation regions. In each case, the precipitation regions were associated with jets of enhanced antisunward convection, with electron precipitation restricted to the upward current region, and no energetic electron outflow in the downward current region, and ion precipitation spread over broader regions, possibly by time-of-flight effects. We compare these low-altitude features to those expected for source regions lying in a reconnection site at the lobe magnetopause, a bursty bulk flow in the plasma sheet, and a. surface wave on the low-latitude boundary layer (LLBL). We find that the lobe reconnection model successfully describes the observed electrodynamics of the arcs, as well as the electron and ion source temperatures, but can not readily explain the presence of precipitating O(+) and He(+) in addition to H(+) and He(++). The plasma sheet source model can explain the composition of the ion precipitation but predicts higher electron and ion source temperatures than are observed, may require the coincidence of bursty bulk flows with extensions of the plasma sheet into the lobe, and may not be consistant with other observations of auroral phenomenology. The LLBL surface wave model does not readily explain the observed electrodynamics of the arcs and is not consistent with the observed offsets between electron and ion precipitation. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. USAF Acad, Colorado Springs, CO 80841 USA. Lockheed Martin Palo Alto Res Lab, Palo Alto, CA 94304 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Bonnell, J (reprint author), Los Alamos Natl Lab, NIS-1,Mail Stop D466, Los Alamos, NM 87545 USA. EM jbon-nell@lanl.gov RI Peterson, WK/A-8706-2009 OI Peterson, WK/0000-0002-1513-6096 NR 51 TC 16 Z9 16 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1999 VL 104 IS A6 BP 12669 EP 12681 DI 10.1029/1999JA900085 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 201MY UT WOS:000080600400038 ER PT J AU Persoff, P Apps, J Moridis, G Whang, JM AF Persoff, P Apps, J Moridis, G Whang, JM TI Effect of dilution and contaminants on sand grouted with colloidal silica SO JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING LA English DT Article AB Colloidal silica is a low-viscosity chemical grout. Samples of grouted sand were made by pouring sand into liquid grout in molds, with the grout diluted to concentrations ranging from 5 to 27% silica by weight. The unconfined compressive strength of the grouted sand, measured after 7 days, was proportional to the silica concentration, up to a maximum of 400 kPa. The hydraulic conductivity of the grouted sand decreased with increasing silica concentration in a nearly log-linear manner down to a minimum of 2 x 10(-9) cm/s, and was below 1 x 10(-7) cm/s for grouts with 7.4% silica or more, inclusion of 5% volumetric saturation of organics (tetrachloroethene, CCl4, or aniline) in the samples had little effect on the strength or hydraulic conductivity. Samples were immersed in test liquids (organics, HCl diluted re pH 3, distilled water saturated with organics, and distilled water control) for up to 1 year. All samples increased in strength except for those immersed in aniline; samples immersed in water saturated with aniline were also weaker than control samples. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Dupont Co, Cent Res & Dev, Wilmington, DE 19880 USA. RP Persoff, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. NR 21 TC 24 Z9 25 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 1090-0241 J9 J GEOTECH GEOENVIRON JI J. Geotech. Geoenviron. Eng. PD JUN PY 1999 VL 125 IS 6 BP 461 EP 469 DI 10.1061/(ASCE)1090-0241(1999)125:6(461) PG 9 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA 198UT UT WOS:000080443200003 ER PT J AU Ott, JA Scott, DE AF Ott, JA Scott, DE TI Effects of toe-clipping and PIT-tagging on growth and survival in metamorphic Ambystoma opacum SO JOURNAL OF HERPETOLOGY LA English DT Article ID LARVAL DENSITY; TAGS C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Scott, DE (reprint author), Univ Georgia, Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. NR 23 TC 51 Z9 61 U1 0 U2 9 PU SOC STUDY AMPHIBIANS REPTILES PI ST LOUIS PA C/O ROBERT D ALDRIDGE, ST LOUIS UNIV, DEPT BIOLOGY, 3507 LACLEDE, ST LOUIS, MO 63103 USA SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD JUN PY 1999 VL 33 IS 2 BP 344 EP 348 DI 10.2307/1565740 PG 5 WC Zoology SC Zoology GA 208EC UT WOS:000080976500029 ER PT J AU Leong, KH Sabo, KR Altshuller, B Wilkinson, TL Albright, CE AF Leong, KH Sabo, KR Altshuller, B Wilkinson, TL Albright, CE TI Laser beam welding of 5182 aluminum alloy sheet SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE aluminum; laser beam welding; process parameters; threshold irradiance AB Conditions were determined for consistent coupling of a CO2 laser beam to weld 5182 aluminum alloy sheet. Full penetration butt and bead-on-plate welds on 0.8 and 1.8 mm sheets were performed. Process conditions examined included beam mode, spot size and irradiance, shielding gas flow, and edge quality and fitup. The observed weld quality variations with the different process parameters were consistent with physical phenomena and a threshold irradiance model. Optimal conditions were determined for obtaining consistent welds on 5182 alloy sheets. Formability and tensile tests were performed on the welded samples. All test failures occurred in the fusion zone. Reduction in formability and tensile strength of the welded samples are discussed with respect to weld profiles and process parameters. (C) 1999 Laser Institute of America. [S1042-346X(99)00501-X]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Alcan Int Ltd, Kingston, ON, Canada. Reynolds Met Co, Richmond, VA USA. Ohio State Univ, Columbus, OH 43210 USA. RP Leong, KH (reprint author), Penn State Univ, Appl Res Lab, State Coll, PA 16804 USA. NR 25 TC 9 Z9 9 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD JUN PY 1999 VL 11 IS 3 BP 109 EP 118 PG 10 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA 242HR UT WOS:000082934900002 ER PT J AU Sarthour, RS Goff, JP McMorrow, DF Yakhou, F Stunault, A Lidstrom, E Vigliante, A Ward, RCC Wells, MR AF Sarthour, RS Goff, JP McMorrow, DF Yakhou, F Stunault, A Lidstrom, E Vigliante, A Ward, RCC Wells, MR TI Induced magnetic order in Nd Pr superlattices SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE synchrotron; X-rays; magnetic superlattices AB Single-crystal Nd/Pr superlattices have been studied using resonance-enhanced magnetic X-ray scattering. Magnetic resonances were observed at the Ln edges of Nd and Pr, so it was possible to study the magnetism of both components of a superlattice: separately for the first time using synchrotron X-rays. The results demonstrate that the 5d bands are magnetically polarised in both elements, and suggest that the induced ordering in the Pr is localised. The induced moment profile across the Pr blocks has been determined and the results correlated with the observed magnetic coherence of the Nd. Thus new insight: is obtained on the nature of the induced ordering of the Pr and on the interlayer coupling mechanism. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Clarendon Lab, Oxford OX1 3PU, England. Riso Natl Lab, Dept Solid State Phys, DK-4000 Roskilde, Denmark. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Sarthour, RS (reprint author), Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM sarthour@av6.physics.ox.ac.uk RI McMorrow, Desmond/C-2655-2008 OI McMorrow, Desmond/0000-0002-4947-7788 NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 288 EP 290 DI 10.1016/S0304-8853(98)01116-0 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600093 ER PT J AU Schulthess, TC Butler, WH AF Schulthess, TC Butler, WH TI Exchange coupling and coercivity in ferro-antiferromagnetic bilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE ferro-antiferromagnetic bilayers; Landau-Lifshitz equation ID INTERFACES; FILMS AB A microscopic Heisenberg model which includes the magnetostatic interactions is constructed for CoO/Co bilayers. The Landau-Lifshitz equation of motion is used to study the equilibrium properties of spin configurations and it is shown how magnetization curves can be calculated. Flat interfaces with compensated antiferromagnetic interface planes show spin-flop coupling but no exchange bias. The magnetization reversal is however irreversible with very large coercivity. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS 6114, Oak Ridge, TN 37831 USA. EM schulthesstc@ornl.gov NR 14 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 321 EP 324 DI 10.1016/S0304-8853(98)01103-2 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600104 ER PT J AU Hilt, JZ Picconatto, JJ O'Brien, A Pechan, MJ Fullerton, EE AF Hilt, JZ Picconatto, JJ O'Brien, A Pechan, MJ Fullerton, EE TI Symmetry influence on interlayer coupling in epitaxial Co Cr trilayers grown on MgO (100) and (110) substrates SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE trilayers; FMR spectra ID MAGNETIC-ANISOTROPY; REORIENTATIONAL TRANSITION; CO/CR(001) SUPERLATTICES; MAGNETORESISTANCE; MULTILAYERS AB Trilayers of Co(15 Angstrom)/Cr(x)/Co(17 Angstrom) have been epitaxially sputtered onto MgO (1 0 0) and (1 1 0) substrates coated with Cr(1 0 0) and (2 1 1) buffer layers, respectively. The Cr thickness x is varied from 6 to 50 Angstrom. Both sample sets have the Co c-axis lying in the plane of the film, however, due to the four-fold symmetry of MgO (1 0 0), the Co layers form bicrystals with perpendicularly oriented c-axis. Ferromagnetic resonance measurements clearly show large two-fold and four-fold magnetic in-plane anisotropy for MgO (1 1 0) and MgO (1 0 0) samples, respectively. Magnetization measurements reveal interlayer coupling strengths peaked at a Cr thickness of approximately 10 Angstrom for both symmetries, but the strength decreases more slowly with increasing t(Cr) in the MgO(1 0 0) system, (C) 1999 Elsevier Science B.V. All rights reserved. C1 Miami Univ, Dept Phys, Oxford, OH 45056 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Pechan, MJ (reprint author), Miami Univ, Dept Phys, Oxford, OH 45056 USA. EM pechanmj@muohio.edu RI Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 13 TC 1 Z9 1 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 387 EP 390 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600124 ER PT J AU Shi, ZP Fishman, RS AF Shi, ZP Fishman, RS TI The role of Cr antiferromagnetism on interlayer magnetic coupling in Fe Cr multilayered systems SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE multilayers; RKKY coupling mechanism; SDW order parameter ID SPIN-DENSITY-WAVE; LAYERS; SUPERLATTICES; FE(100); SPACER AB Many experiments have verified the presence of a spin-density wave (SDW) within the Cr spacer of Fe/Cr multilayers and wedges. We review the recently proposed interlayer magnetic coupling mediated by a SDW. Unlike previously proposed mechanisms, this magnetic coupling is strongly temperature-dependent. Depending on the temperature and the number N of Cr monolayers (ML), the SDW may be either commensurate (C) or incommensurate (I) with the BCC Cr lattice. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Read Rite Corp, R&D Div, Fremont, CA 94539 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Shi, ZP (reprint author), Read Rite Corp, R&D Div, 44100 Osgood Rd, Fremont, CA 94539 USA. EM zhupei.shi@readrite.com RI Fishman, Randy/C-8639-2013 NR 17 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 391 EP 395 DI 10.1016/S0304-8853(98)01140-8 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600125 ER PT J AU Lohstroh, W Munzenberg, M Felsch, W Fritzsche, H Maletta, H Felcher, GP AF Lohstroh, W Munzenberg, M Felsch, W Fritzsche, H Maletta, H Felcher, GP TI Magnetic spiral structures in La Fe multilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE multilayers; polarized neutron reflectometry; magneto-optical Kerr effect AB The magnetic properties of La/Fe multilayers were tested by magneto-optical Kerr effect and polarized neutron reflectometry. The experiments indicated that above a layer thickness t(La) = 25 Angstrom the magnetic state of the virgin sample is represented by a spiral-like arrangement of magnetizations of subsequent Fe layers, whereas each Fe layer itself is ferromagnetic. Polarized neutron reflectometry shows that the helix has predominantly one chirality over the entire surface area of several cm(2). The magnetic spiral structure is imprinted during the growth process by rotating the sample in a small residual magnetic field. External magnetic field of 90 Oe are sufficient to erase the magnetic structure irreversibly. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Gottingen, Inst Phys 1, D-37073 Gottingen, Germany. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. RP Lohstroh, W (reprint author), Univ Gottingen, Inst Phys 1, Bunsenstr 9, D-37073 Gottingen, Germany. EM wlohstr@gwdg.de RI Munzenberg, Markus/B-1251-2010; OI Munzenberg, Markus/0000-0002-1332-5678; Fritzsche, Helmut/0000-0001-5288-8302 NR 4 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 440 EP 442 DI 10.1016/S0304-8853(98)01170-6 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600139 ER PT J AU Schumann, FO Hochstrasser, M Willis, RF Goodman, KG Tobin, JG AF Schumann, FO Hochstrasser, M Willis, RF Goodman, KG Tobin, JG TI On the magnetic instability of ultrathin FCCFexNi1-x films SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA ID THIN-FILMS; BEHAVIOR; CU(100); LAYERS; ALLOY AB The 'invar effect' in FexNi1-x alloys occurs when the Fe content approaches 65%. At this point, the magnetization falls to zero, and a martensitic structural transformation from an FCC to BCC lattice occurs. This paper addresses the question: what happens if this structural transformation is suppressed in an ultrathin alloy film? (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Schumann, FO (reprint author), Penn State Univ, Dept Phys, 104 Davey Lab, University Pk, PA 16802 USA. EM schumannn@phys.psu.edu RI Schumann, Frank /K-9364-2014; Tobin, James/O-6953-2015 NR 13 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 522 EP 524 DI 10.1016/S0304-8853(98)01238-4 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600165 ER PT J AU Yusuf, SM Osgood, RM Jiang, JS Sowers, CH Bader, SD Fullerton, EE Felcher, GP AF Yusuf, SM Osgood, RM Jiang, JS Sowers, CH Bader, SD Fullerton, EE Felcher, GP TI Magnetic profile in Nb Si superconducting multilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE Nb Si multilayers; magnetic profile; PNR AB Polarized neutron reflectivity measurements were conducted on [Nb(100 Angstrom),Si(15 Angstrom)] x N superconducting multilayers with a Tc similar to 7.5 K. Scope of the experiment was to verify the existence of arrays of vortices parallel to the surface above the critical field H(c1) = 400 Oe when a magnetic field was applied parallel to the film plane. Measurements at 1.6 K and 700 Oe in the zero-held-cooled condition, and at 30 Or after field cooling, indicated that reflectivity close to the first Bragg reflection of the multilayer was significantly dependent on the neutron spin. This effect was interpreted as due to Josephson-type vortices at and around the silicon layers. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Felcher, GP (reprint author), Argonne Natl Lab, Bldg 223, Argonne, IL 60439 USA. EM felcher@anlpns.pns.anl.gov RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 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 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 564 EP 566 DI 10.1016/S0304-8853(98)01215-3 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600178 ER PT J AU You, CY Shin, SC AF You, CY Shin, SC TI Simplified analytic formulae for magneto-optical Kerr effects in ultrathin magnetic films SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE magneto-optical Kerr effect; ultrathin magnetic film; multilayers; analytic expressions; magneto-optical; Fresnel coefficients AB Expressions are presented for various magneto-optical Kerr effects in the ultrathin film limit with arbitrary magnetization direction by considering the multiple reflections within an optically thin film. The Kerr effect of p- and s-polarization consists of products of two factors: the prefactor, dependent only on the optical parameters of the system, and the main factor of the polar Kerr effect for normal incidence in the ultrathin limit. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Korea Adv Inst Sci & Technol, Dept Phys, Yusong Gu, Taejon 305701, South Korea. Korea Adv Inst Sci & Technol, Ctr Nanospin Spintron Mat, Yusong Gu, Taejon 305701, South Korea. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Shin, SC (reprint author), Korea Adv Inst Sci & Technol, Dept Phys, Yusong Gu, 373-1 Kusong Dong, Taejon 305701, South Korea. EM scshin@convex.kaist.ac.kr RI You, Chun-Yeol/B-1734-2010; Shin, Sung-Chul/C-1992-2011 OI You, Chun-Yeol/0000-0001-9549-8611; NR 15 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 573 EP 577 DI 10.1016/S0304-8853(98)01209-8 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600181 ER PT J AU Sturhahn, W Roehlsberger, R Alp, EE Ruckert, T Schror, H Keune, W AF Sturhahn, W Roehlsberger, R Alp, EE Ruckert, T Schror, H Keune, W TI Phonon density of stales in Fe/Cr(001) superlattices and Tb-Fe thin-film alloys SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE phonon density of states; inelastic nuclear resonance scattering; superlattices; alloy films ID NUCLEAR RESONANT SCATTERING; METALLIC SUPERLATTICES; SYNCHROTRON-RADIATION AB Inelastic nuclear scattering of X-rays from the 14.413 keV nuclear resonance of (57)Fe was employed to measure directly the Fe-projected phonon density of states (DOS) in MBE-grown Fe/Cr(0 0 1) superlattices on MgO(0 0 1). The Mossbauer-inactive (56)Fe isotope was used in the Fe levers. A 1 Angstrom thick Mossbauer-active (57)Fe-probe layer (95% enriched) was placed at different locations within the Fe layers, This procedure permits to distinguish phonon density of states at the Fe-Cr-interface from that at the center of the Fe-film. Distinct differences have been observed in the DOS of our samples. The phonon DOS of an amorphous Tb(33)Fe(67) alloy film was found to be a broad and structureless hump, contrary to that of an epitaxial TbFe(2) film, which exhibits characteristic features. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Duisburg Gesamthsch, Lab Angew Phys, D-47048 Duisburg, Germany. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Keune, W (reprint author), Univ Duisburg Gesamthsch, Lab Angew Phys, D-47048 Duisburg, Germany. EM keune@uni-duisburg.de RI Rohlsberger, Ralf/J-4173-2013 OI Rohlsberger, Ralf/0000-0001-6005-5183 NR 10 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 590 EP 592 DI 10.1016/S0304-8853(98)01229-3 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600186 ER PT J AU Mishra, SR Cummins, TR Waddill, GD Gammon, WJ van der Laan, G Goodman, KW Tobin, JG AF Mishra, SR Cummins, TR Waddill, GD Gammon, WJ van der Laan, G Goodman, KW Tobin, JG TI Linear dichroism and resonant photoemission in Gd SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE linear dichroism; resonant photoemission ID MAGNETIC CIRCULAR-DICHROISM; CORE-LEVEL PHOTOEMISSION; FILMS; METAL; PHOTOABSORPTION; SYMMETRY; SYSTEMS AB Magnetic linear dichroism in angular distributions (MLDAD) from photoelectron emission was used to probe the nature of resonant photoemission. Gd 5p and Gd 4f emissions were investigated. Using novel theoretical simulations, we were able to show that temporal matching is a requirement for 'true' resonant photoemission, where the resonant photoemission retains the characteristics of photoelectron emission. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. SERC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Univ Missouri, Dept Phys, Rolla, MO 65401 USA. Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. RP Tobin, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM tobin1@llnl.gov RI Tobin, James/O-6953-2015; van der Laan, Gerrit/Q-1662-2015 OI van der Laan, Gerrit/0000-0001-6852-2495 NR 35 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 647 EP 649 DI 10.1016/S0304-8853(98)01104-4 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600202 ER PT J AU Osgood, RM Sinha, SK Freeland, JW Idzerda, YU Bader, SD AF Osgood, RM Sinha, SK Freeland, JW Idzerda, YU Bader, SD TI X-ray scattering from magnetically and structurally rough surfaces SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Metallic Multilayers (MML98) held Jointly with the EMRS Symposium on Magnetic Ultrathin Films and Ultrathin Film Nanostructures CY JUN 14-19, 1998 CL VANCOUVER, CANADA DE X-ray resonant magnetic scattering; surface roughness AB We present expressions for the resonant magnetic X-ray scattering (XRMS) by surfaces possessing roughness and analyze both the structural and magnetic roughness of a surface, as well as their correlation. We demonstrate that the leading contribution to the difference (Delta I) in the diffuse scattering between left- and right-circularly polarized light for a rough surface vanishes unless the structural and magnetic roughnesses are correlated, to leading order in the magnetization. The effects of magnetic domain structure and magnetic dead layers on the surface scattering are also discussed. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Expt Facilities Div, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. 3M Corp, 3M Ctr, St Paul, MN 55144 USA. USN, Res Lab, Div Sci Mat, Washington, DC 20379 USA. RP Sinha, SK (reprint author), Argonne Natl Lab, Expt Facilities Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM sksinha@aps.anl.gov RI Bader, Samuel/A-2995-2013 NR 13 TC 34 Z9 34 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 198-99 BP 698 EP 702 DI 10.1016/S0304-8853(98)01098-1 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 204TE UT WOS:000080779600219 ER PT J AU Clatterbuck, DM Lange, RJ Gschneidner, KA AF Clatterbuck, DM Lange, RJ Gschneidner, KA TI Magneto-optical properties of RMn6Sn6 (R = Gd, Tb, Dy, Ho, Er, Tm, Lu) single crystals SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE magneto-optical properties; Kerr effect; MOKE; crystal structure AB Single crystals of compounds in the series RMn6Sn6 (R = Gd-Tm, Lu) have been prepared by the flux growth technique. The crystal structure was found to be isotypic with HfFe6Ge6 for all of the compounds, and the variation of the lattice parameters with the lanthanide element exhibit the lanthanide contraction. The polar Kerr effect has been measured between 1.3 and 5 eV, and the structure of the spectra are similar for all of the compounds of the series. The maximum Kerr rotation found was 0.225 degrees in TbMn6Sn6, and the magnitude of the Kerr rotations scaled across the series as a function of the fraction saturation. This, combined with the temperature dependence, indicates that the Kerr rotation is primarily a function of the Mn moment and is independent of the lanthanide element present in the compound. The main features in the spectra shift to slightly higher energies as one moves from Gd to the end of the lanthanide series (i.e. Tm and Lu) which is related to the contraction in the lattice parameters. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. RP Gschneidner, KA (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. NR 15 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 1999 VL 195 IS 3 BP 639 EP 645 DI 10.1016/S0304-8853(99)00293-0 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 202UZ UT WOS:000080671700015 ER PT J AU Asano, KG Butcher, DJ Goeringer, DE McLuckey, SA AF Asano, KG Butcher, DJ Goeringer, DE McLuckey, SA TI Effective ion internal temperatures achieved via boundary activation in the quadrupole ion trap: Protonated leucine enkephalin SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE quadrupole ion trap; tandem mass spectrometry; boundary activation; protonated leucine enkephalin ID TANDEM MASS-SPECTROMETRY; COLLISION-INDUCED DISSOCIATION; SURFACE-INDUCED DISSOCIATION; PEPTIDE IONS; FRAGMENTATION PROCESSES; PRODUCT IONS; ENERGY; EXCITATION; KINETICS; SPECTRA AB The dissociation rate of protonated leucine enkephalin in a quadrupole ion trap was measured as a function of the proximity to which the ions are brought to a stability boundary. A bath gas temperature of 480 K was used so that a dissociation rate could be readily measured even when the parent ions were remote from a stability boundary. Changes in the dissociation rate as a function of d.c. potential applied to the ring electrode of the ion trap, used to bring ions close to a stability boundary, could then be attributed to the 'boundary activation' process. A relationship between dissociation rate and parent ion effective internal temperature, derived from a study involving conventional ion trap resonance excitation, was used to estimate effective ion internal temperatures achieved under the boundary activation conditions used here. Effective ion internal temperatures 170 K above the bath gas temperature could readily be achieved using boundary activation. However, the efficiency of the overall boundary activation experiment was compromised by an initial rapid parent ion loss that occurred upon application of the d.c. potential. After correction for this initial ion loss, dissociation rates and relatively low ion ejection rates could be measured. Effective ion internal temperatures achieved with boundary activation are similar to those observed previously using conventional resonance excitation. However, the generally poorer efficiencies associated with boundary activation that are observed with resonance excitation at high dissociation rates suggests that higher ion internal temperatures can be achieved with conventional resonance excitation. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Western Carolina Univ, Dept Chem & Phys, Cullowhee, NC 28723 USA. RP McLuckey, SA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI McLuckey, Scott/B-2203-2009; Asano, Keiji/L-3164-2016 OI McLuckey, Scott/0000-0002-1648-5570; Asano, Keiji/0000-0003-2254-3586 NR 52 TC 22 Z9 22 U1 1 U2 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD JUN PY 1999 VL 34 IS 6 BP 691 EP 698 DI 10.1002/(SICI)1096-9888(199906)34:6<691::AID-JMS823>3.3.CO;2-K PG 8 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 209FE UT WOS:000081036900013 ER PT J AU Rosen, RS Paddon, SP Kassner, ME AF Rosen, RS Paddon, SP Kassner, ME TI The variation of the yield stress of Ti alloys with strain rate at high temperatures SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE high-temperature strength; strain-rate sensitivity; titanium alloys AB This study extended investigation on the elevated-temperature yield-strength dependence of beta-phase titanium alloys on strain rate and temperature. Yield stresses were found to increase substantially with increasing strain rate at elevated temperatures due to the high strain-rate sensitivity of titanium at high temperatures. Above 1000 degrees C, the strain-rate sensitivities were found to increase substantially with increasing temperature and/or decreasing strain rate. The six alloys examined were TIMETAL 21S, Ti-15-3, Ti-6-4, Ti-13-11-3, Beta C, and Beta III. There was particular interest in determining the strain-rate sensitivity of these alloys through strain-rate change tests above 1000 degrees C. The yield stresses of all the titanium alloys at temperatures above 1093 degrees C were less than 1% of their ambient temperature values, Strain hardening was negligible in the alloys tested at these high temperatures. Extended tensile ductilities of 100 to 200% were observed due to the pronounced strain-rate sensitivity. The rate controlling mechanism for plasticity, based on activation energy and the strain-rate sensitivity measurements, is discussed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Oregon State Univ, Dept Mech Engn, Corvallis, OR 97331 USA. RP Rosen, RS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 21 TC 10 Z9 15 U1 1 U2 11 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD JUN PY 1999 VL 8 IS 3 BP 361 EP 367 DI 10.1361/105994999770346927 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 206NV UT WOS:000080886700011 ER PT J AU Mann, AB Cammarata, RC Nastasi, MA AF Mann, AB Cammarata, RC Nastasi, MA TI Nanoindentation: From angstroms to microns - Introduction SO JOURNAL OF MATERIALS RESEARCH LA English DT Editorial Material ID PENETRATION C1 Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mann, AB (reprint author), Johns Hopkins Univ, Dept Mat Sci & Engn, 3400 N Charles St, Baltimore, MD 21218 USA. RI Cammarata, Robert /A-3307-2010; Mann, Adrian/A-3992-2012 NR 6 TC 8 Z9 8 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2195 EP 2195 DI 10.1557/JMR.1999.0643 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600001 ER PT J AU Kiely, JD Jarausch, KF Houston, JE Russell, PE AF Kiely, JD Jarausch, KF Houston, JE Russell, PE TI Initial stages of yield in nanoindentation SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SURFACE-DIFFUSION; TUNNELING MICROSCOPY; INDENTATION; DEFORMATION; MECHANISMS; HARDNESS AB We have used the interfacial force microscope to perform nanoindentations on Au single-crystal surfaces. We have observed two distinct regimes of plastic deformation, which are distinguished by the magnitude of discontinuities in load relaxation. At lower stresses, relaxation occurs in small deviations from elastic behavior, while at the higher stresses they take the form of large load drops, often resulting in complete relaxation of the applied load. These major events create a relatively wide plastic zone that subsequently deepens more rapidly than it widens. We discuss these findings in terms of contrasting models of dislocation processes in the two regimes. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. N Carolina State Univ, Raleigh, NC 27695 USA. RP Kiely, JD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 48 Z9 48 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2219 EP 2227 DI 10.1557/JMR.1999.0298 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600005 ER PT J AU Hay, JC Bolshakov, A Pharr, GM AF Hay, JC Bolshakov, A Pharr, GM TI A critical examination of the fundamental relations used in the analysis of nanoindentation data SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELASTIC-PLASTIC SOLIDS; MECHANICAL-PROPERTIES; INDENTATION; HARDNESS; MODULUS; LOAD; CONTACT AB Methods for analyzing nanoindentation load-displacement data to determine hardness and elastic modulus are based on analytical solutions for the indentation of an elastic half-space by rigid axisymmetric indenters. Careful examination of Sneddon's solution for indentation by a rigid cone reveals several largely ignored features that have important implications for nanoindentation property measurement. Finite element and analytical results are presented that show corrections to Sneddon's equations are needed if accurate results are to be obtained. Without the corrections, the equations underestimate the load and contact stiffness in a manner that leads to errors in the measured hardness and modulus, with the magnitudes of the errors depending on the angle of the indenter and Poisson's ratio of the half-space. First order corrections are derived, and general implications for the interpretation of nanoindentation data are discussed. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. IBM Res, TJ Watson Res Ctr, Yorktown Heights, NY 10598 USA. Baker Hughes Inteq, Houston, TX 77267 USA. RP Pharr, GM (reprint author), Univ Tennessee, Dept Mat Sci & Engn, 434 Dougherty Engn Bldg, Knoxville, TN 37996 USA. NR 31 TC 258 Z9 259 U1 2 U2 42 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2296 EP 2305 DI 10.1557/JMR.1999.0306 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600013 ER PT J AU Moody, NR Strojny, A Medlin, DL Talin, A Gerberich, WW AF Moody, NR Strojny, A Medlin, DL Talin, A Gerberich, WW TI Substrate composition effects on the interfacial fracture of tantalum nitride films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; ADHESION; DELAMINATION; MICROSCRATCH; INDENTATION; MECHANICS; LOAD AB In this study we combined nanoscratch testing with a multilayer sapphire and aluminum nitride single-substrate system to determine the effects of interface composition and structure on susceptibility to fracture of hard, thin tantalum nitride films, Nanoindentation tests showed that the elastic moduli of the tantalum nitride and aluminum nitride films, as well as the sapphire substrate, were essentially equal at 400 GPa. On both portions of the substrate, these tests also showed that near surface hardness was near 35 GPa. Nanoscratch tests triggered long blisters and circular spalls on both the sapphire and aluminum nitride portions of the substrate. The blisters showed that the tantalum nitride film was subjected to a compressive residual stress of -6.7 GPa, The spalls showed that failure occurred along the tantalum nitride film-substrate interface regardless of substrate composition. Most importantly, the blisters and spalls showed that the mode I component of the fracture energies was essentially equal on both substrate materials at a value near 3.1 J/m(2), These energies are on the order of the energies for metallic bonding. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Motorola Inc, Tempe, AZ USA. RP Moody, NR (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 24 TC 14 Z9 26 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2306 EP 2313 DI 10.1557/JMR.1999.0307 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600014 ER PT J AU Gea, LA Budai, JD Boatner, LA AF Gea, LA Budai, JD Boatner, LA TI Formation and phase transition of VO2 precipitates embedded in sapphire SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ION-IMPLANTATION; THIN-FILMS AB Crystallographically coherent precipitates of vanadium dioxide (VO2) have been formed in the near-surface region of single crystals of sapphire (Al2O3) using a combination of ion implantation and thermal treatments. As in the case of either bulk VO2 single crystals or thin films of VO2, the thermally induced semiconductor-ro-metal phase transition of the embedded VO2 precipitates is accompanied by a large hysteretic change in the infrared optical transmission. The VO2 precipitate transition temperature (T-c, = 72 to 85 degrees C) is higher than that of bulk VO2 (T-c = 68 degrees C) and is sensitive to the implantation conditions. The present results show that the damage resulting from the coimplantation of vanadium and oxygen into an Al2O3 host lattice dictates the final microstructure of the VO2 precipitates and, consequently, affects the transition temperature, as well as the optical quality of the VO2/Al2O3 surface-nanocomposite precipitate system. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Boatner, Lynn/I-6428-2013; Budai, John/R-9276-2016 OI Boatner, Lynn/0000-0002-0235-7594; Budai, John/0000-0002-7444-1306 NR 22 TC 16 Z9 17 U1 0 U2 7 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2602 EP 2610 DI 10.1557/JMR.1999.0348 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600055 ER PT J AU Booth, CH Allen, PG Bucher, JJ Edelstein, NM Shuh, DK Marasinghe, GK Karabulut, M Ray, CS Day, DE AF Booth, CH Allen, PG Bucher, JJ Edelstein, NM Shuh, DK Marasinghe, GK Karabulut, M Ray, CS Day, DE TI Oxygen and phosphorus coordination around iron in crystalline ferric ferrous pyrophosphate and iron-phosphate glasses with UO2 or Na2O SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID STRUCTURAL-PROPERTIES; ABSORPTION-SPECTRA; SPECTROSCOPY; FE; FEATURES AB Fe K-edge x-ray absorption fine-structure (XAFS) measurements were performed on glass samples of (Fe3O4)(0.3)(P2O5)(0.7) With various amounts of Na2O or UO2, Near-edge and extended XAFS regions are studied and comparisons are made to several reference compounds. We find that iron in the base glass is similar to 25% divalent and that the Fe2+ coordination is predominantly octahedral, while Fe3+ sites are roughly split between tetrahedral and octahedral coordinations, Also, we measure roughly one Fe-O-P link per iron. Substitution of Na2O or UO2 up to 15 mol% primarily affects the first Fe-O shell. The results are compared to data from the related material Fe-3(P2O7)(2). C1 Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Missouri, Dept Phys, Dept Ceram Engn, Rolla, MO 65409 USA. Univ Missouri, Grad Ctr Mat Res, Rolla, MO 65409 USA. RP Los Alamos Natl Lab, MS K764, Los Alamos, NM 87545 USA. EM cbooth@lanl.gov RI Booth, Corwin/A-7877-2008 NR 24 TC 23 Z9 23 U1 1 U2 13 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD JUN PY 1999 VL 14 IS 6 BP 2628 EP 2639 DI 10.1557/JMR.1999.0352 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 235PE UT WOS:000082550600059 ER PT J AU Marr, AJ Sears, TJ AF Marr, AJ Sears, TJ TI Vibronic reassignment of the (A)over-tilde(1)A '' <- (X)over-tilde(1)A ' band system of bromomethylene SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Letter ID DIODE-LASER SPECTROSCOPY; ABSORPTION; HCBR; HCCL C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Marr, AJ (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 12 TC 23 Z9 23 U1 1 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD JUN PY 1999 VL 195 IS 2 BP 367 EP 370 DI 10.1006/jmsp.1999.7842 PG 4 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 200XL UT WOS:000080565400020 ER PT J AU Schaller, T Rong, CY Toplis, MJ Cho, H AF Schaller, T Rong, CY Toplis, MJ Cho, H TI TRAPDOR NMR investigations of phosphorus-bearing aluminosilicate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID SILICATE-GLASSES; DOUBLE-RESONANCE; STRUCTURAL ROLE; ZEOLITE HY; RATIO; QUADRUPOLAR; PHOSPHATES; SIO2-P2O5; VISCOSITY; SYSTEM AB The local environment of phosphorus in aluminosilicate glasses of variable sodium/aluminum ratio has been investigated using double-resonance magic angle spinning (MAS) nuclear magnetic resonance spectroscopy. The studied glasses have the general composition xNa(2)O-(1-x)Al2O3-2SiO(2) and contain approximately 4 mol% P2O5 The short-range dipolar couplings of phosphorus atoms to aluminum and sodium are used to deduce the connectivities of phosphate units to AlO4 tetrahedra and/or sodium by observing the effects on a P-31 MAS echo spectrum caused by simultaneous irradiation of the Al-27 or Na-23 resonance frequency. In this way, different phosphorus environments were identified. The observed resonances can be assigned to Na3PO4 and Na4P2O7 units, as well as phosphate tetrahedra coordinated to n aluminum atoms in the aluminosilicate framework (with n varying from 1 to 3). The results provide unambiguous evidence for the interaction of P with aluminum even in peralkaline compositions, confirming a recently proposed model describing the solution of phosphorus in aluminosilicate melts. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. Pacific NW Natl Lab, Envirom Mol Sci Lab, Richland, WA 99352 USA. CNRS, CRPG, F-54501 Vandoeuvre Nancy, France. RP Schaller, T (reprint author), Univ Essen Gesamthsch, Inst Organ Chem, D-45117 Essen, Germany. NR 31 TC 24 Z9 27 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN PY 1999 VL 248 IS 1 BP 19 EP 27 DI 10.1016/S0022-3093(99)00098-8 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 201YJ UT WOS:000080624600003 ER PT J AU Baumert, BM Muller, SJ AF Baumert, BM Muller, SJ TI Axisymmetric and non-axisymmetric elastic and inertio-elastic instabilities in Taylor-Couette flow SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE Taylor-Couette; viscoelastic instability; non-axisymmetric modes; Boger fluids ID ROTATING CYLINDERS; FLUIDS AB Flow visualization is performed on two highly elastic, non-shear-thinning dilute polymer solutions (polyisobutylene/ polybutene) in a wide gap Couette cell (R-1/R-2=0.827) over a range of shear rates and choices of relative cylinder rotations. Axisymmetric structures of the type found in a narrow gap cell (R-1/R-2=0.912) [B.M Baumert, S.J. Muller, Rheol. Acta 34 (1995) 147-159; B.M. Baumert, S.J. Muller, Phys. Fluids 9 (1997) 566-586] were reproduced. Additionally, helical and nonaxisymmetric standing wave patterns were visualized. In the more viscous, more elastic fluid (epsilon=De/Re=15.0) transitions were found to be purely elastic. At the lowest shear rates at which transitions were observed, extremely slow-growing stationary axisymmetric counter-rotating vortices replace the purely azimuthal base flow. At rates more than twice the critical, axisymmetric oscillatory flow precedes the onset of steady vortices. Non-axisymmetric structures an first observed at rates more than 5 times the critical. The pattern is initially highly regular: two m=1 helices superpose to generate a nonaxisymmetric standing wave pattern ('ribbons'). The ribbons quickly give way to intense merging structures with nearly axisymmetric cores. In the less viscous, less elastic fluid (epsilon=0.0562) the lowest rate transitions are to weak axisymmetric counter-rotating vortices. At progressively higher rates in the presence of centrifugal destabilization several types of axially translating axisymmetric vortices are generated. Go-rotation of the cylinders gives rise to translating vortices at fewer shear rates than rotation of the inner cylinder alone. At somewhat more than twice the critical rate, robust and hysteretic m=1 ribbons are produced. Brief periods of unpaired m=1 helices are also detectable very near the critical rate for the ribbons. The spectrum of spatial and temporal frequencies of the ribbons is found to broaden with further increases of shear rate. At the highest shear rates examined for this fluid, the flow is non-axisymmetric and highly disordered. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Muller, SJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. NR 19 TC 44 Z9 45 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD JUN PY 1999 VL 83 IS 1-2 BP 33 EP 69 DI 10.1016/S0377-0257(98)00132-3 PG 37 WC Mechanics SC Mechanics GA 189RG UT WOS:000079919000003 ER PT J AU Lepeshkin, NN Kim, W Safonov, VP Zhu, JG Armstrong, RL White, CW Zuhr, RA Shalaev, VM AF Lepeshkin, NN Kim, W Safonov, VP Zhu, JG Armstrong, RL White, CW Zuhr, RA Shalaev, VM TI Optical nonlinearities of metal-dielectric composites SO JOURNAL OF NONLINEAR OPTICAL PHYSICS & MATERIALS LA English DT Article ID SMALL-PARTICLE COMPOSITES; SURFACE-ENHANCED RAMAN; FRACTAL CLUSTERS; ION-IMPLANTATION; COLLOIDAL SILVER; GOLD; FILMS; SPECTROSCOPY; SCATTERING; SIZE AB Nonlinear optical properties of metal-dielectric composites, such as fractal colloid aggregates and clusters created by ion implantation, are studied. Strong fluctuations of local fields result in huge enhancements of optical nonlinearities in fractal colloid aggregates. The real and imaginary parts of the cubic susceptibility of silver colloid aggregates are measured. It is found that the coefficient of nonlinear absorption strongly depends on the laser wavelength and intensity. Optical limiting effect in fractal silver colloids is observed. Nondegenerate forward four-wave mixing technique is used to investigate the third-order nonlinear susceptibility for nanocomposite material with Au nanocrystals formed inside a SiO2 glass matrix. The Au nanocrystals are formed by the ion implantation and annealing method that produces very high volume fraction of nanoparticles. The large value \chi((3))\ = 1 3 x 10(-7) esu is measured. Two characteristic relaxation times, 5.3 ps and 0.66 ps, are estimated from the detuning curve of \chi((3))\, as the probe beam wavelength changes. A novel class of optical materials, microcavities doped with nanostructured fractal aggregates, is also studied. In our experiments, lasing at extremely low pump intensities, below 1 mW, and dramatically enhanced Raman scattering was observed in microcavity/fractal composites. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Russian Acad Sci, Inst Automat & Electrometry, Novosibirsk 630090, Russia. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Lepeshkin, NN (reprint author), New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. NR 50 TC 33 Z9 36 U1 1 U2 23 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-1991 J9 J NONLINEAR OPT PHYS JI J. Nonlinear Opt. Phys. Mater. PD JUN PY 1999 VL 8 IS 2 BP 191 EP 210 DI 10.1142/S021886359900014X PG 20 WC Optics; Physics, Applied SC Optics; Physics GA 218KR UT WOS:000081552200002 ER PT J AU Anderl, RA Causey, RA Davis, JW Doerner, RP Federici, G Haasz, AA Longhurst, GR Wampler, WR Wilson, KL AF Anderl, RA Causey, RA Davis, JW Doerner, RP Federici, G Haasz, AA Longhurst, GR Wampler, WR Wilson, KL TI Hydrogen isotope retention in beryllium for tokamak plasma-facing applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Review ID NEUTRON-IRRADIATED BERYLLIUM; ELEVATED-TEMPERATURES; TRITIUM RELEASE; DEUTERIUM RETENTION; COMPREHENSIVE MODEL; CARBON; CODEPOSITION; JET; BEHAVIOR; TUNGSTEN AB Beryllium has been used as a plasma-facing material to effect substantial improvements in plasma performance in the Joint European Torus (JET), and it is planned as a plasma-facing material for the first wall (FW) and other components of the International Thermonuclear Experimental Reactor (ITER). The interaction of hydrogenic ions, and charge-exchange neutral atoms from plasmas, with beryllium has been studied in recent years with widely varying interpretations of results. In this paper we review experimental data regarding hydrogenic atom inventories in experiments pertinent to tokamak applications and show that with some very plausible assumptions, the experimental data appear to exhibit rather predictable trends. A phenomenon observed in high ion-flux experiments is the saturation of the beryllium surface such that inventories of implanted particles become insensitive to increased flux and to continued implantation fluence. Methods for modeling retention and release of implanted hydrogen in beryllium are reviewed and an adaptation is suggested for modeling the saturation effects. The TMAP4 code used with these modifications has succeeded in simulating experimental data taken under saturation conditions where codes without this feature have not. That implementation also works well under more routine conditions where the conventional recombination-limited release model is applicable. Calculations of tritium inventory and permeation in the ITER FW during the basic performance phase (BPP) using both the conventional recombination model and the saturation effects assumptions show a difference of several orders of magnitude in both inventory and permeation rate to the coolant. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Toronto, Inst Aerosp Studies, Toronto, ON, Canada. ITER JWS Garching Coctr, Garching, Germany. RP Longhurst, GR (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 77 TC 58 Z9 59 U1 3 U2 14 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 1999 VL 273 IS 1 BP 1 EP 26 DI 10.1016/S0022-3115(99)00022-7 PG 26 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 203VM UT WOS:000080728900001 ER PT J AU Hashimoto, N Wakai, E Robertson, JP AF Hashimoto, N Wakai, E Robertson, JP TI Relationship between hardening and damage structure in austenitic stainless steel 316LN irradiated at low temperature in the HFIR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID MICROSTRUCTURAL EVOLUTION; NEUTRON-IRRADIATION; DEFORMATION AB An austenitic stainless steel 316LN irradiated to damage levels of about 3 dpa at irradiation temperatures of about 90 degrees C and 250 degrees C has been examined by transmission electron microscopy. The irradiation at 90 degrees C and 250 degrees C induced a dislocation loop density of 3.5 x 10(22) and 5.2 x 10(22) m(-3) and a black dot density of 2.2 x 10(23) and 1.1 x 10(23) m-3 respectively, in the steel. A low density (<1 x 10(19) m(-3)) of radiation-enhanced precipitates was observed in the matrix. No cavities were observed. These features are correlated with the changes in tensile properties. It is concluded that the dislocation loops and the black dots cause irradiation hardening and a decrease in the uniform elongation in the 316LN steel irradiated at low temperatures. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 31911, Japan. RP Hashimoto, N (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012; Wakai, Eiichi/L-1099-2016 NR 28 TC 38 Z9 38 U1 2 U2 13 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 1999 VL 273 IS 1 BP 95 EP 101 DI 10.1016/S0022-3115(99)00009-4 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 203VM UT WOS:000080728900008 ER PT J AU DiStefano, JR De Van, JH Rohrig, DH Chitwood, LD AF DiStefano, JR De Van, JH Rohrig, DH Chitwood, LD TI Reactions of hydrogen with V-Cr-Ti alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB The interest in vanadium alloys for use as a first-wall material in fusion reactor applications has led to a study to determine the effects of hydrogen on the mechanical properties of certain V-Cr-Ti alloys. Hydrogen uptake by the alloys is a function of temperature and pressure. In the absence of increases in oxygen concentration, additions of up to 400 wpm hydrogen to V-4Cr-4Ti did not result in any significant embrittlement. However, when hydrogen approached 500 wppm, rapid embrittlement occurred at 325 degrees C that was suggested to result from formation of a hydride phase upon cooling. When oxygen was added as well, either during or prior to hydrogen exposure, synergistic effects depending on grain size occurred that led to significant embrittlement by 35-130 wppm hydrogen. Because of its synergism with hydrogen and ubiquitous presence in most environments, oxygen pick-up remains as one of the major concerns for use of V-Cr-Ti alloys in fusion reactor applications. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Karlsruhe, D-76000 Karlsruhe, Germany. RP DiStefano, JR (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 13 Z9 15 U1 1 U2 2 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 1999 VL 273 IS 1 BP 102 EP 110 DI 10.1016/S0022-3115(99)00014-8 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 203VM UT WOS:000080728900009 ER PT J AU Crivelli, S Jessup, ER AF Crivelli, S Jessup, ER TI The PMESC programming library for distributed-memory MIMD computers SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID TRIDIAGONAL EIGENVALUE PROBLEM AB Efficient programming of task-parallel problems, where the number and execution times of the computational tasks can vary unpredictably, demands an asynchronous and adaptive approach. In this sort of approach, however, such fundamental programming issues as load sharing, data sharing, and termination detection can present difficult programming problems. This paper presents the PMESC library for managing task-parallel problems on distributed-memory MIMD computers within the context of the SPMD (single program, multiple data) programming model. PMESC offers support for all of the application-independent programming issues involved in SPMD task-parallel computation in a portable and efficient way while still allowing users to customize their codes. Because different problems may require different strategies to achieve good performance, PMESC is based on a straightforward model in which different building blocks can be easily put together and changed to accommodate the particular needs of the different applications. The library provides an interface that allows users to program a virtual machine and thereby ignore the details associated with message passing and machine architecture. These features make PMESC accessible to a wide variety of users. (C) 1999 Academic Press, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC Div, Berkeley, CA 94720 USA. RP Crivelli, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. EM crivelli@global.lbl.gov; jessup@cs.colorado.edu NR 52 TC 5 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD JUN PY 1999 VL 57 IS 3 BP 295 EP 321 DI 10.1006/jpdc.1999.1539 PG 27 WC Computer Science, Theory & Methods SC Computer Science GA 202VQ UT WOS:000080673200002 ER PT J AU McKay, RML La Roche, J Yakunin, AF Durnford, DG Geider, RJ AF McKay, RML La Roche, J Yakunin, AF Durnford, DG Geider, RJ TI Accumulation of ferredoxin and flavodoxin in a marine diatom in response to Fe SO JOURNAL OF PHYCOLOGY LA English DT Article DE diatoms; ferredoxin; flavodoxin; iron; photosynthesis; phytoplankton ID EQUATORIAL PACIFIC-OCEAN; PHAEODACTYLUM-TRICORNUTUM BACILLARIOPHYCEAE; IRON-LIMITATION; PHYTOPLANKTON PHOTOSYNTHESIS; CYANOPHORA-PARADOXA; CHLOROPLAST GENOME; CYANELLE GENOME; ANABAENA SP; THALASSIOSIRA-WEISSFLOGII; PORPHYRA-UMBILICALIS AB Despite recognition that Fe availability is significant in regulating oceanic production in some regions, the biogeochemistry of this trace element is poorly understood. To complement contemporary methods of analytical chemistry, we have used an immunological approach to monitor the Fe nutrition of marine phytoplankton. In prokaryotes and numerous microalgae, the redox catalyst ferredoxin is functionally replaced by flavodoxin during periods of Fe deficiency. In this study, antibodies were raised against ferredoxin purified from a marine diatom, and their utility as a diagnostic indicator was assessed. A species survey demonstrated broad reactivity with both pennate and centric diatoms and additionally with several nondiatom taxa. In batch cultures of the diatom Phaeodactylum tricornutum Bohlin, in which Fe levels were varied, accumulation of ferredoxin varied with the physiological state of the culture; in unimpaired cells (F-v/F-m greater than or equal to 0.65), ferredoxin levels were high, whereas levels dropped markedly in cells experiencing even slight photochemical impairment. Accumulation of flavodoxin varied inversely with that of ferredoxin. An experiment was performed to demonstrate the temporal pattern of accumulation of ferredoxin upon recovery from Fe limitation. Prior to Fe amendment, cells were physiologically impaired (chlorotic, F-v/F-m < 0.3) and contained flavodoxin but no detectable ferredoxin. Following addition of Fe, constraints on photochemistry were relaxed within hours. Coinciding with this, levels of flavodoxin declined, whereas ferredoxin was accumulated to high levels within 8 h. C1 Bowling Green State Univ, Dept Biol Sci, Bowling Green, OH 43403 USA. Brookhaven Natl Lab, Div Oceanog & Atmospher Sci, Upton, NY 11973 USA. Univ Montreal, Dept Microbiol & Immunol, Montreal, PQ, Canada. Univ New Brunswick, Dept Biol, Fredericton, NB E3B 6E1, Canada. Marine Biol Assoc United Kingdom Lab, Plymouth, Devon, England. RP McKay, RML (reprint author), Bowling Green State Univ, Dept Biol Sci, Bowling Green, OH 43403 USA. RI LaRoche, Julie/A-1109-2010; Yakunin, Alexander/J-1519-2014; OI McKay, Robert/0000-0003-2723-5371; Yakunin, Alexander/0000-0003-0813-6490 NR 57 TC 42 Z9 43 U1 0 U2 5 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD JUN PY 1999 VL 35 IS 3 BP 510 EP 519 DI 10.1046/j.1529-8817.1999.3530510.x PG 10 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA 212RD UT WOS:000081229300010 ER PT J AU Su, BJ Olson, GL AF Su, BJ Olson, GL TI Non-grey benchmark results for two temperature non-equilibrium radiative transfer SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID NONEQUILIBRIUM AB Benchmark solutions to time-dependent radiative transfer problems involving non-equilibrium coupling to the material temperature field are crucial for validating time-dependent radiation transport codes. Previous efforts on generating analytical solutions to non-equilibrium radiative transfer problems were all restricted to the one-group grey model. In this paper, a non-grey model, namely the picket-fence model, is considered for a two temperature non-equilibrium radiative transfer problem in an infinite medium. The analytical solutions, as functions of space and time, are constructed in the form of infinite integrals for both the diffusion description and transport description. These expressions are evaluated numerically and the benchmark results are generated. The asymptotic solutions for large and small times are also derived in terms of elementary functions and are compared with the exact results. Comparisons are given between the transport and diffusion solutions and between the grey and non-grey solutions. (C) 1999 Elsevier Science Ltd, All rights reserved. C1 Univ Cincinnati, Dept Mech Ind & Nucl Engn, Cincinnati, OH 45221 USA. Univ Calif Los Alamos Natl Lab, Transport Methods Grp, Los Alamos, NM 87545 USA. RP Su, BJ (reprint author), Univ Cincinnati, Dept Mech Ind & Nucl Engn, Cincinnati, OH 45221 USA. NR 9 TC 17 Z9 18 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUN PY 1999 VL 62 IS 3 BP 279 EP 302 DI 10.1016/S0022-4073(98)00105-8 PG 24 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 187GX UT WOS:000079779700002 ER PT J AU Narayanan, VA Stump, NA Del Cul, GD Vo-Dinh, T AF Narayanan, VA Stump, NA Del Cul, GD Vo-Dinh, T TI Vibrational spectrum of strychnine: Detection at the nanogram level using a Raman microscope SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article ID INDOLE AB The complete vibrational spectra of strychnine is reported. Strychnine, a compound with medicinal value at the proper dosage, is also a potent toxin at certain concentration levels. Down to 5 ng of strychnine were detected from its spectrum using a microscope attached to a Raman spectrophotometer. The complete Raman and Fourier transform IR spectra were also recorded for positive identification. The prominent vibrational band wavenumbers useful as a reference source for the identification of strychnine in an emergency situation are discussed. The Raman spectra of a bulk sample and of a strychnine microcrystal are given to facilitate positive identification. The potential application of the vibrational analysis of strychnine for forensic diagnostics is discussed. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Savannah State Univ, Savannah, GA 31404 USA. Winston Salem State Univ, Winston Salem, NC 27101 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 27 TC 8 Z9 8 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD JUN PY 1999 VL 30 IS 6 BP 435 EP 439 DI 10.1002/(SICI)1097-4555(199906)30:6<435::AID-JRS391>3.0.CO;2-S PG 5 WC Spectroscopy SC Spectroscopy GA 206LE UT WOS:000080879900003 ER PT J AU Phillips, CC Wallace, BC Hamilton, CB Pursley, RT Petty, GC Bayne, CK AF Phillips, CC Wallace, BC Hamilton, CB Pursley, RT Petty, GC Bayne, CK TI The efficacy of material safety data sheets and worker acceptability SO JOURNAL OF SAFETY RESEARCH LA English DT Article DE adoption diffusion; chemicals; chemical safety card; comprehensibility; cognitive theory; efficacy; format; health belief model; laboratory; material safety data sheets; worker education ID HEALTH AB This study quantified how well the Material Safety Data Sheet (MSDS) diffused information to workers, compared the efficacy of an OSHA type form with the Chemical Manufacturer's Association/American National Standards Institute (CMA/ANSI Z400.1) structure and the International Chemical Safety Card (ICSC), and determined worker acceptability and understanding of MSDSs at a large national laboratory. An inventory questionnaire and quantitative testing were used to gather data from 160 union workers employed at the national laboratory Most of the workers in the sample population studied reported favorably on MSDS acceptability, accessibility, and understanding. All three formats significantly diffused information to workers, although approximately one third of the information was not absorbed. The rank order of finish between the three different formats was ICSC, OSHA type format; and CMA/ANSI Z400.1 respectively; however, there were no significant differences in scores. There were significant differences in how well each format answered specific test questions. (C) 1999 National Safety Council and Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Off Safety & Hlth Protect, Oak Ridge, TN 37831 USA. Univ Tennessee, Coll Human Ecol, Dept Hlth Leisure & Safety, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. RP Phillips, CC (reprint author), Oak Ridge Natl Lab, Off Safety & Hlth Protect, Oak Ridge, TN 37831 USA. NR 18 TC 10 Z9 10 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4375 J9 J SAFETY RES JI J. Saf. Res. PD SUM PY 1999 VL 30 IS 2 BP 113 EP 122 DI 10.1016/S0022-4375(99)00005-5 PG 10 WC Ergonomics; Public, Environmental & Occupational Health; Social Sciences, Interdisciplinary; Transportation SC Engineering; Public, Environmental & Occupational Health; Social Sciences - Other Topics; Transportation GA 200ZH UT WOS:000080569800004 ER PT J AU Kresin, VZ Ovchinnikov, YN Wolf, SA AF Kresin, VZ Ovchinnikov, YN Wolf, SA TI Layered superconductors in an external magnetic field SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT International Workshop on Exactly Aligned Magnetic Field Effects in Low-Dimensional Superconductors CY NOV 16-18, 1998 CL KYOTO, JAPAN DE layered superconductors; magnetic field ID CU-O; OXIDES AB Presence of localized magnetic moments and inhomogeneites leads to an unconventional behavior of the upper critical field for layered superconductors. In addition, one can observe a large diamagnetic moment at H tau N-c2 and in the normal resistive state. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. LD Landau Theoret Phys Inst, Moscow 11733V, Russia. USN, Res Lab, Washington, DC 20375 USA. RP Kresin, VZ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 19 TC 2 Z9 2 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 1999 VL 12 IS 3 BP 493 EP 496 DI 10.1023/A:1007719831482 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 215YX UT WOS:000081414000009 ER PT J AU Kadish, A AF Kadish, A TI Static friction threshold effects on hysteresis and frequency spectra in rocks SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Static friction in rocks is modeled as a threshold phenomenon. An inverse problem in ground motion is analyzed for propagation in a medium with an arbitrary number of fractures at which static friction thresholds determine the onset of slippage. It is shown that seismic source dynamics inferred from surface motion is unique. This result is used to show that the threshold property of static friction is not a mechanism for hysteresis in rocks. The coda for the surface motion is shown, in the case of a single fracture and a deep source of finite duration, to be either a periodic function in time, or to asymptote in time to such a function, depending on an algebraic relation between ground and fracture parameters. The fundamental period of the coda is independent of the source time series and is equal to four times the signal transit time between the single fracture and ground surface. Only odd harmonics of the fundamental frequency are present in a Fourier series of these periodic functions. (C) 1999 Acoustical Society of America. [S0001-4966(99)03106-9]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kadish, A (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 7 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1999 VL 105 IS 6 BP 3097 EP 3107 DI 10.1121/1.424640 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 204RN UT WOS:000080778100012 ER PT J AU Candy, JV Chambers, DH AF Candy, JV Chambers, DH TI Model-based dispersive wave processing: A recursive Bayesian solution SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID INTERNAL WAVES; OCEAN; BOREHOLE AB Wave propagation through dispersive media represents a significant problem-in many acoustic applications, especially in ocean acoustics, seismology, and nondestructive evaluation. In this paper we propose a propagation model that can easily represent many classes of dispersive waves and proceed to develop the model-based solution to the wave processing problem. It is shown that the underlying wave system is nonlinear and time-variable requiring a recursive processor. Thus the general solution to the-model-based dispersive wave enhancement problem is developed using a Bayesian maximum a posteriori (MAP) approach and shown to lead to the recursive, nonlinear extended Kalman filter (EKF) processor. The problem of internal wave estimation is cast within this framework. The specific processor is developed and applied to data synthesized by a sophisticated simulator demonstrating the feasibility of this approach. (C) 1999 Acoustical Society of America. [S0001-4966(99)00106-X]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Candy, JV (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-156, Livermore, CA 94551 USA. NR 34 TC 5 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1999 VL 105 IS 6 BP 3364 EP 3374 DI 10.1121/1.424665 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 204RN UT WOS:000080778100037 ER PT J AU Brown, TD Smith, DN Hargis, RA O'Dowd, WJ AF Brown, TD Smith, DN Hargis, RA O'Dowd, WJ TI Mercury measurement and its control: What we know, have learned, and need to further investigate SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article C1 US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Brown, TD (reprint author), US DOE, Fed Energy Technol Ctr, POB 10940, Pittsburgh, PA 15236 USA. NR 21 TC 89 Z9 101 U1 3 U2 13 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JUN PY 1999 VL 49 IS 6 BP 628 EP 640 PG 13 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 203ZA UT WOS:000080737000002 PM 26355369 ER PT J AU Stephenson, JL Schaaff, TG McLuckey, SA AF Stephenson, JL Schaaff, TG McLuckey, SA TI Hydroiodic acid attachment kinetics as a chemical probe of gaseous protein ion structure: Bovine pancreatic trypsin inhibitor SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; MULTIPLY-CHARGED IONS; GAS-PHASE PROTEINS; CYTOCHROME-C; ELECTROSPRAY-IONIZATION; MASS-SPECTROMETRY; MOBILITY MEASUREMENTS; CONFORMATION; BIOMOLECULES; CATIONS AB The kinetics of attachment of hydroiodic acid (HI) to the (M + 6H)(6+) ions of native and reduced forms of bovine pancreatic trypsin inhibitor (BPTI) in the quadrupole ion tray environment are reported. Distinctly nonlinear (pseudo first-order) reaction kinetics are observed for reaction of the native ions, indicating two or more noninterconverting structures in the parent ion population. The reduced form, on the other hand, shows very nearly linear reaction kinetics. Both forms of the parent ion attach a maximum of five molecules of hydroiodic acid. This number is expected based on the amino acid composition of the protein. There is a total of 11 strongly basic sites in the protein (i.e., six arginines, four lysines, and one N-terminus). An ion with protons occupying six of the basic sites has five available for hydroiodic acid attachment. The kinetics of successive attachment of HI to the native and reduced forms of BPTI also differ, particularly for the addition of the fourth and fifth I-II molecules. A very simple kinetic model describes the behavior of the reduced form reasonably well, suggesting that all of the neutral basic sites in the reduced BPTI ions have roughly equal reactivity. However, the behavior of the native ion is not well-described by this simple model. The results are discussed within the context of differences in the three-dimensional structures of the ions that result from the presence or absence of the three disulfide linkages found in native BPTI. The HI reaction kinetics appears to have potential as a chemical probe of protein ion three-dimensional structure in the gas phase. Hydroiodic acid attachment chemistry is significantly different from other chemistries used to probe three-dimensional structure and hence, promises to yield complementary information. (C) 1999 American Society for Mass Spectrometry. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP McLuckey, SA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 FU NIGMS NIH HHS [GM45372] NR 36 TC 18 Z9 18 U1 0 U2 8 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUN PY 1999 VL 10 IS 6 BP 552 EP 556 DI 10.1016/S1044-0305(99)00026-4 PG 5 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 203HM UT WOS:000080702500010 PM 10368949 ER PT J AU Yeung, ES AF Yeung, ES TI Chemical characterization of single cells and single molecules SO JOURNAL OF THE CHINESE CHEMICAL SOCIETY LA English DT Article DE single cell; single molecule; imaging; capillary electrophoresis ID LASER-INDUCED FLUORESCENCE; INDUCED NATIVE FLUORESCENCE; LACTATE-DEHYDROGENASE ISOENZYMES; CAPILLARY ELECTROPHORESIS; HUMAN ERYTHROCYTES; LIQUID-CHROMATOGRAPHY; QUANTITATIVE-DETERMINATION; ELECTROCHEMICAL DETECTION; DNA-MOLECULES; MAST-CELLS AB Advances in sensitive optical measurement schemes have led to the detection and the physical and chemical characterization of single biological cells and individual molecules. These technological achievements are much more than the ultimate milestone in low-level monitoring. Potential applications include DNA sequencing at high speeds, probing microscale environments, monitoring environmental pollution, studying the variability of molecular conformations, detecting disease infection at an early stage, and devising molecular-scale imaging probes. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. NR 66 TC 6 Z9 6 U1 1 U2 1 PU CHINESE CHEM SOC PI TAIPEI PA PO BOX 609, TAIPEI 10099, TAIWAN SN 0009-4536 J9 J CHIN CHEM SOC-TAIP JI J. Chin. Chem. Soc. PD JUN PY 1999 VL 46 IS 3 BP 351 EP 360 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 214HB UT WOS:000081321600011 ER PT J AU Liu, P Zhang, JG Turner, JA Tracy, CE Benson, DK AF Liu, P Zhang, JG Turner, JA Tracy, CE Benson, DK TI Lithium-manganese-oxide thin-film cathodes prepared by plasma-enhanced chemical vapor deposition SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ION BATTERIES; SPINEL PHASE; LIMN2O4; LIMNO2; CELLS AB Lithium-manganese-oxide thin-film electrodes have been fabricated using the plasma-enhanced chemical vapor deposition technique. Process parameters such as flow rates of the reactants, deposition temperature, and RF power have been systematically varied to optimize the charge and discharge properties. The thin films are amorphous as found by X-ray diffraction spectrometry and can be cycled reversibly in the range from 4.5 to 3 V or 4.5 to 2.5 V with maximum capacities of 30 and 39 mu Ah/cm(2) mu m, respectively. The capacity fade of the films is ca, 0.04% per cycle over more than 700 cycles when tested in liquid electrolytes, Films which are optimized for cycling between 4.5 and 3 V demonstrate a near-perfect balance between the charge and discharge capacities during the initial cycle and also show very small capacity fade in the subsequent cycles. Our results indicate that these lithium manganese oxide thin films are good candidates for use as cathodes in thin-film lithium-ion batteries. (C) 1999 The Electrochemical Society. S0013-4651(98)08-070-7. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Liu, P (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Liu, Ping/I-5615-2012 NR 26 TC 26 Z9 29 U1 0 U2 11 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1999 VL 146 IS 6 BP 2001 EP 2005 DI 10.1149/1.1391881 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 207HC UT WOS:000080930500002 ER PT J AU Doeff, MM Georen, P Qiao, J Kerr, J De Jonghe, LC AF Doeff, MM Georen, P Qiao, J Kerr, J De Jonghe, LC TI Transport properties of a high molecular weight poly(propylene oxide)-LiCF3SO3 system SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID POLYMER ELECTROLYTES; MICROPHASE SEPARATION; CONDUCTIVITY BEHAVIOR; TRANSFERENCE NUMBER; SALT ELECTROLYTES; OXIDE); COMPLEXES; LITHIUM; CELLS AB Conductivities (sigma), salt diffusion coefficients (D-S), and cationic transference numbers (t(+)(0)) are reported for a high molecular weight polypropylene oxide (Parel(TM)-LiCF3SO3 polymer electrolyte system at 85 degrees C. Transference numbers were determined as a function of salt concentration using a recently described electrochemical method based on concentrated solution theory. For the Parel-LiCF3SO3 system, t(+)(0) is slightly positive for electrolytes with O:Li ratios of 15 or 12:1 but decreases to negative values for more concentrated solutions. This implies that negatively charged ionic aggregates such as triplets are more mobile than free cations in this concentration range. Such behavior is commonly seen in binary salt/polymer electrolytes, which typically exhibit a high degree of nonideality. The nonunity transference numbers and microphase separation in the Parel-LiCF3SO3 system strongly suggest that salt precipitation or phase separation in operating cells containing these electrolytes due to the development of large concentration gradients during passage of current. (C) 1999 The Electrochemical Society. S0013-4651(98)07-064-5. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Royal Inst Technol, Dept Chem Engn & Technol, Div Appl Electrochem, SE-10044 Stockholm, Sweden. RP Doeff, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Doeff, Marca/G-6722-2013 OI Doeff, Marca/0000-0002-2148-8047 NR 28 TC 37 Z9 39 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1999 VL 146 IS 6 BP 2024 EP 2028 DI 10.1149/1.1391885 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 207HC UT WOS:000080930500006 ER PT J AU Schmuki, P Buchler, M Virtanen, S Isaacs, HS Ryan, MP Bohni, H AF Schmuki, P Buchler, M Virtanen, S Isaacs, HS Ryan, MP Bohni, H TI Passivity of iron in alkaline solutions studied by in situ XANES and a laser reflection technique SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID INSITU FTIR SPECTROSCOPY; CATHODIC REDUCTION; BORATE BUFFER; RING-DISK; FILM; SURFACE; NAOH; ELECTRODES; LAYERS AB Passivity of iron in alkaline solutions was investigated by in situ X-ray absorption near edge spectroscopy (XANES) and with a laser absorption technique. In 0.1 M NaOH, no significant material loss takes place during reduction of the iron passive film, but the ferric passive film is converted completely to a ferrous film. Subsequent anodic polarization leads to growth of a "new" passive film underneath the converted layer; By multiple potential stepping a thin iron film (100 Angstrom) (between reduction and oxidation potential range) can be completely converted from the metallic slate into an oxide. This thick oxide layer remains electrochemically active, i.e., during potential cycles the redox reactions Fe(II) --> Fe (III) and Fe(III) --> Fe (II) take place in the entire layer. The formation of such a porous oxide/hydroxide layer does not take place when ethylenediaminetetraacetic acid (EDTA) is added to electrolyte, as the ferrous layer formed during reduction is dissolved in presence of EDTA. The behavior of the Fe electrode during potential cycling in NaOH + EDTA becomes reversible with respect to oxide formation and reductive dissolution. (C) 1999 The Electrochemical Society. S0013-4651(98)08-118-X. All rights reserved. C1 Ecole Polytech Fed Lausanne, Swiss Fed Inst Technol, Dept Mat Sci, Ecublens, CH-1015 Lausanne, Switzerland. ETH Honggerberg, Inst Mat Chem & Corros, Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland. Brookhaven Natl Lab, Div Sci Mat, Dept Appl Sci, Upton, NY 11973 USA. RP Schmuki, P (reprint author), Ecole Polytech Fed Lausanne, Swiss Fed Inst Technol, Dept Mat Sci, Ecublens, CH-1015 Lausanne, Switzerland. RI Virtanen, Sannakaisa/N-3699-2015 OI Virtanen, Sannakaisa/0000-0002-7179-7593 NR 19 TC 32 Z9 32 U1 1 U2 10 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1999 VL 146 IS 6 BP 2097 EP 2102 DI 10.1149/1.1391897 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 207HC UT WOS:000080930500018 ER PT J AU Mukundan, R Brosha, EL Birdsell, SA Costello, AL Garzon, FH Willms, RS AF Mukundan, R Brosha, EL Birdsell, SA Costello, AL Garzon, FH Willms, RS TI Tritium conductivity and isotope effect in proton-conducting perovskites SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID WATER-VAPOR; HYDROGEN; YB; TEMPERATURE; SRCEO3; BACEO3 AB The tritium ion conductivities of SrZr0.9Yb0.1O2.95 and BaCe0.9Yb0.1O2.95 have been measured by ac impedance analysis. The high tritium conductivity of these perovskites could potentially lead to their application as an electrochemical membrane for the recovery of tritium from tritiated gas streams. The conductivities of these perovskites, along with SrCe0.95Yb0.05O2.975 were also measured in hydrogen- and deuterium-containing atmospheres to illustrate the isotope effect. For the strontium zirconate and barium cerate samples, the impedance plot consists of two clearly resolved arcs, a bulk and a grain boundary are, in the temperature range 50-350 degrees C. However, for the strontium cerate sample, the clear resolution of the bulk conductivity was not possible and only the total conductivity was measurable. Thus, the isotope effect was clearly established only for the strontium zirconate and barium cerate samples. The decrease in bulk conductivity with increasing isotope mass was found to be a result of an increase in the activation energy for conduction accompanied by a decrease in the pre-exponential factor. Since the concentration of the mobile species (H+, D+, or T+) should remain relatively constant at T < 350 degrees C, this increase in activation energy is directly attributable to the increased activation energy for the isotope mobility. (C) 1999 The Electrochemical Society. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Elect & Electrchem Mat & Devices Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Tritium Sci & Engn Grp, Los Alamos, NM 87545 USA. RP Mukundan, R (reprint author), Univ Calif Los Alamos Natl Lab, Elect & Electrchem Mat & Devices Grp, POB 1663, Los Alamos, NM 87545 USA. NR 16 TC 28 Z9 29 U1 3 U2 8 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1999 VL 146 IS 6 BP 2184 EP 2187 DI 10.1149/1.1391911 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 207HC UT WOS:000080930500032 ER PT J AU Richman, EE Jones, CC Lindsley, J AF Richman, EE Jones, CC Lindsley, J TI An empirical data based method for development of lighting energy standards SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article C1 Pacific NW Lab, Richland, WA 99352 USA. RP Richman, EE (reprint author), Pacific NW Lab, Richland, WA 99352 USA. NR 14 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 1999 VL 28 IS 2 BP 81 EP 93 PG 13 WC Optics SC Optics GA 224LR UT WOS:000081901000008 ER PT J AU Clear, R Rubinstein, F AF Clear, R Rubinstein, F TI A cost benefit analysis applied to lumen maintenance controls SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 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 1999 VL 28 IS 2 BP 113 EP 126 PG 14 WC Optics SC Optics GA 224LR UT WOS:000081901000011 ER PT J AU Yi, KS Hong, SP Bae, YN Quinn, JJ AF Yi, KS Hong, SP Bae, YN Quinn, JJ TI Longitudinal spin-charge responses and collective modes in spin-polarized quantum devices SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT 9th Seoul International Symposium on the Physics of Semiconductors and Applications (SEOUL ISPSA-98) CY NOV 06-07, 1998 CL KOREA UNIV, SEOUL, SOUTH KOREA HO KOREA UNIV ID QUASI-2-DIMENSIONAL ELECTRON-GAS; EXCITATIONS; DENSITY; WELL AB The generalized longitudinal charge-spin susceptibility functions and the collective excitations of spin-polarized quantum structures are investigated within the framework of spin;dependent linear response theory. We evaluate the charge response and the longitudinal spin response to a general external disturbance. Exchange-correlation effects between electrons of spin sigma and sigma' are included by using spin-polarization dependent generalized local field factors. Both the collective charge-density and spin-density excitations are examined. The present results are compared with the case of a spin-unpolarized system. In contrast to the result for an unpolarized system, the mixing of charge and spin responses results in coupled charge;spin excitations in the spin polarized system. C1 Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Yi, KS (reprint author), Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea. NR 14 TC 1 Z9 1 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 1999 VL 34 SU S BP S334 EP S338 PG 5 WC Physics, Multidisciplinary SC Physics GA 214BE UT WOS:000081307100026 ER PT J AU Sarma, G Zacharia, T AF Sarma, G Zacharia, T TI Integration algorithm for modeling the elasto-viscoplastic response of polycrystalline materials SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE constitutive behavior; crystal plasticity; elastic-viscoplastic material; polycrystalline material; numerical algorithms ID CRYSTALLOGRAPHIC TEXTURE; FCC METALS; DEFORMATION; PLASTICITY; EVOLUTION; CRYSTALS; SOLIDS; CREEP AB An integration scheme is presented for modeling the texture evolution and stress-strain response of elasto-viscoplastic polycrystalline materials. Single crystal kinematics based on a multiplicative decomposition of the deformation gradient is used to obtain an evolution equation for the crystal elastic deformation gradient. An implicit scheme to integrate this equation is presented which is stable and efficient. The reorientation of the crystal as well as the elastic strain can then be obtained from a polar decomposition of the elastic deformation gradient. Numerical studies are presented using material parameters for aluminum (FCC crystals) and zircaloy (HCP crystals) to demonstrate the general nature of the model. Predictions of the model are also compared with those obtained using a rigid-viscoplastic polycrystal model which neglects the elastic response. Retaining the elastic response makes the model useful for large deformation analyses where both anisotropy due to texture as well as elastic effects such as springback and residual stresses are important. (C) 1999 Elsevier Science Ltd, All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sarma, G (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Zacharia, Thomas/0000-0001-6463-5425 NR 30 TC 31 Z9 44 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD JUN PY 1999 VL 47 IS 6 BP 1219 EP 1238 DI 10.1016/S0022-5096(98)00105-7 PG 20 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 192FD UT WOS:000080067100002 ER PT J AU Rapaport, A Moteau, O Bass, M Boatner, LA Deka, C AF Rapaport, A Moteau, O Bass, M Boatner, LA Deka, C TI Optical spectroscopy and lasing properties of neodymium-doped lutetium orthophosphate SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LASERS AB Studies of the spectroscopic and lasing properties of Nd3+-doped LuPO4, are reported. LuPO4 permits incorporation of lanthanide dopants in high concentration. We report the absorption and luminescence properties of Nd3+ ions doped at 10% in this host. Promising laser performance with diode laser pumping is also described. (C) 1999 Optical Society of America [S0740-3224(99)00806-1] OCIS codes: 140.5680, 160.5690, 300.6280, 140.3480, 140.3380, 160.3380. C1 Univ Cent Florida, Sch Opt, Orlando, FL 32816 USA. Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Orlando, FL 32816 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Beckman Coulter Inc, Miami, FL 33196 USA. RP Rapaport, A (reprint author), Univ Cent Florida, Sch Opt, Orlando, FL 32816 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 11 TC 30 Z9 31 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 1999 VL 16 IS 6 BP 911 EP 916 DI 10.1364/JOSAB.16.000911 PG 6 WC Optics SC Optics GA 202XN UT WOS:000080677600004 ER PT J AU Schultze, AE McEntee, MF Daniel, GB Johnson, DK AF Schultze, AE McEntee, MF Daniel, GB Johnson, DK TI Radiographic, histologic, and cytologic lesions associated with mutations in the Fitness1(4226SB) locus of mice SO LABORATORY ANIMAL SCIENCE LA English DT Article ID BELGRADE RAT RETICULOCYTES; INTESTINAL IRON-ABSORPTION; HEMATOPOIETIC STEM-CELLS; EXPERIMENTAL SCOLIOSIS; MOUSE CHROMOSOME-7; MICROCYTIC ANEMIA; HYPOTRANSFERRINAEMIC MICE; HEMOGLOBIN-DEFICIT; THALASSEMIC MICE; BETA-THALASSEMIA AB Background and Purpose: Previous investigation of fitness1(4226SB) mice revealed growth retardation and microcytic, hypochromic anemia with functional iron deficiency. Serum biochemical analysis suggested protein-losing enteropathy and liver dysfunction, Methods: Radiography was done to assess lumbar bone lesions in mice hemizygous for fitness1 (fit1) [c fit1(4226SB)/Df(c Mod2 sh1)(26DVT)] and age-matched sibling controls [C-ch+/c(ch)+] at 40 or 60 days of age. Macroscopic and microscopic lesions were evaluated at necropsy, Bone marrow was examined cytologically to evaluate hematopoietic lesions. Results: Mice hemizygous for fit1 had radiographically evident lumbar vertebral abnormalities, including various degrees of vertebral body fusion, with loss of intervertebral disk spaces and mild, generalized osteopenia, All mutant mice had scoliosis, Several mutant mice had lordosis and/or kyphosis of variable severity and mild subluxation at the lumbosacral junction. Marked splenomegaly and mild cardiomegaly were evident, and bone marrow color ranged from normal to slightly pale. The spleen had marked extramedullary hematopoiesis; lumbar vertebrae contained microscopic lesions that corresponded to the radiographic Lesions. Cytologic examination of bone marrow revealed normocellular to hypocellular status, with mild to moderate erythroid hypoplasia characterized by mild increase in the myeloid-to-erythroid cell ratio, decreased percentage of erythroid precursors, and slight increase in percentage of myeloid precursor cells. Conclusions: Mutations in fit1 directly or indirectly cause alteration(s) in blood, organs of hematopoiesis (bone marrow spleen, and liver), heart, and vertebral column, and suggest that this mouse may be a good model for study of scoliosis and relationships between iron metabolism and bone growth. C1 Univ Tennessee, Coll Vet Med, Dept Pathol, Knoxville, TN 37901 USA. Univ Tennessee, Coll Vet Med, Dept Small Anim Clin Sci, Knoxville, TN 37901 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN USA. RP Schultze, AE (reprint author), Univ Tennessee, Coll Vet Med, Dept Pathol, POB 1071, Knoxville, TN 37901 USA. RI Daniel, Gregory/I-1597-2016; OI Daniel, Gregory/0000-0002-7313-7425; McEntee, Michael/0000-0002-1616-3715 NR 89 TC 4 Z9 4 U1 0 U2 0 PU AMER ASSOC LABORATORY ANIMAL SCIENCE PI MEMPHIS PA 9190 CRESTWYN HILLS DR, MEMPHIS, TN 38125 USA SN 0023-6764 J9 LAB ANIM SCI JI Lab. Anim. Sci. PD JUN PY 1999 VL 49 IS 3 BP 260 EP 268 PG 9 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA 207QJ UT WOS:000080947300007 PM 10403440 ER PT J AU Kuritz, T AF Kuritz, T TI An easy colorimetric assay for screening and qualitative assessment of deiodination and dehalogenation by bacterial cultures SO LETTERS IN APPLIED MICROBIOLOGY LA English DT Article ID MICROBIAL-DEGRADATION; CLONING AB Halogenated organic substances are among the main environmental concerns. A number of micro-organisms are able to dehalogenate these compounds. However, the methods for the assessment of micro-organismal ability to dehalogenate ale expensive and require complex instrumentation. Here, an easy colorimetric assay for the screening and assessment of the ability of bacterial cultures to deiodinate, and potentially dehalogenate, chemical substances is proposed. The method is based on the oxidation of iodide, released due to biotransformation, to iodine followed by a subsequent detection of iodine by a classical reaction with starch. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kuritz, T (reprint author), Oak Ridge Natl Lab, MS 6194,Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0266-8254 J9 LETT APPL MICROBIOL JI Lett. Appl. Microbiol. PD JUN PY 1999 VL 28 IS 6 BP 445 EP 447 DI 10.1046/j.1365-2672.1999.00538.x PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 206XM UT WOS:000080905700009 PM 10389261 ER PT J AU Androsch, R Blackwell, J Chvalun, SN Wunderlich, B AF Androsch, R Blackwell, J Chvalun, SN Wunderlich, B TI Wide- and small-angle X-ray analysis of poly(ethylene-co-octene) SO MACROMOLECULES LA English DT Article ID ETHYLENE-OCTENE COPOLYMERS; MELTING BEHAVIOR; POLYETHYLENE; CRYSTALS; RADIATION; PARAFFINS; DSC AB Wide-angle X-ray data point to a three-phase structure in isotropic and drawn specimens of a homogeneous poly(ethylene-co-octene) (7.3 mol % 1-octene). In addition to the amorphous halo, the unoriented polymer exhibits Bragg reflections characteristic of the orthorhombic crystalline phase and an additional reflection that is assigned to the hexagonal mesophase. On stretching 800%, the degree of crystallinity increases from similar to 25% to similar to 50%, due mainly to the formation of smaller hexagonal crystallites, while the proportions of the orthorhombic and amorphous phases decline. Small-angle X-ray data reveal a distinct long period, pointing to the existence of lamellae that become oriented perpendicular to the draw direction. On releasing the specimen, there is a considerable permanent set (similar to 350% extension), and the crystallinity declines to similar to 30% as the hexagonal crystallites appear to revert to the amorphous structure. The results suggest that the hexagonal mesophase is formed by chain segments that have octene side chains, once these segments become oriented by deformation. C1 Case Western Reserve Univ, Dept Macromol Sci, Cleveland, OH 44106 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. LY Karpov Phys Chem Res Inst, Moscow 103064, Russia. RP Blackwell, J (reprint author), Case Western Reserve Univ, Dept Macromol Sci, Cleveland, OH 44106 USA. RI chvalun, sergei/E-3924-2014 NR 20 TC 85 Z9 86 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 1 PY 1999 VL 32 IS 11 BP 3735 EP 3740 DI 10.1021/ma9818331 PG 6 WC Polymer Science SC Polymer Science GA 203DA UT WOS:000080691300026 ER PT J AU Christian, AT Garcia, HE Tucker, JD AF Christian, AT Garcia, HE Tucker, JD TI PCR in situ followed by microdissection allows whole chromosome painting probes to be made from single microdissected chromosomes SO MAMMALIAN GENOME LA English DT Article ID DNA-SYNTHESIS PRINS; RAPID GENERATION; IDENTIFICATION; AMPLIFICATION; ORGANIZATION; REGION; FISH AB Whole-chromosome painting probes (WCPs) and chromosome-arm painting probes (CAPs) are an integral part of the cytogenetic analysis of chromosome abnormalities. While these are routinely made by chromosome microdissection, multiple copies of the dissected region have been necessary to achieve a library sufficiently complex to provide adequate painting. Performing multiple dissections of chromosomes or chromosome regions is time consuming and occasionally impossible, such as when working with species whose banded karyotype is not well defined. We have developed a method whereby chromosome paints can be reliably generated by dissecting single chromosomes. The technique consists of performing degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) in situ on the chromosomes, prior to dissection. Enough amplification occurs to enable a single dissected chromosome to be used to create a painting probe sufficiently complex for use in fluorescence in situ hybridization (FISH). The amplification products remain localized on the chromosomes; this allows region-specific chromosome paints to be made. We derail this novel technique and show whole-chromosome, arm-specific, and contiguous region-specific probes for human and rat, each created from single dissected fragments of chromatin. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Tucker, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-452, Livermore, CA 94551 USA. FU NCI NIH HHS [CA55861] NR 17 TC 15 Z9 16 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD JUN PY 1999 VL 10 IS 6 BP 628 EP 631 DI 10.1007/s003359901058 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 197UD UT WOS:000080383300020 PM 10341099 ER PT J AU Wanninkhof, R Lewis, E Feely, RA Millero, FJ AF Wanninkhof, R Lewis, E Feely, RA Millero, FJ TI The optimal carbonate dissociation constants for determining surface water pCO(2) from alkalinity and total inorganic carbon SO MARINE CHEMISTRY LA English DT Article DE oceanography; carbon dioxide; dissociation; alkalinity ID EQUATORIAL PACIFIC; DIOXIDE SYSTEM; SEAWATER; ACID; CO2; CONSISTENCY; FUGACITY; OCEANS AB In many numerical ocean chemistry models, total dissolved inorganic carbon, DIC and total alkalinity, TA are transported between subsurface boxes. The partial pressure pCO(2) is subsequently calculated from TA and DIC in the surface box in order to account for air-sea exchange of carbon dioxide. The conversion is commonly performed by solving the thermodynamic relationships for equilibria between carbonate, bicarbonate, and aqueous CO2 using carbonate dissociation constants. Four independent determinations of the constants have been made for seawater in the past 50 years. These results have been corrected, refit, and combined by others creating a virtual cottage industry of laboratory and field verification, and cross-checks. Here, we show that, based on field observations in three ocean basins, the calculated surface water pCO(2) from TA and DIC corresponds best with the measured pCO(2) if the constants proposed by Mehrbach et al. [Mehrbach, C., Culberson, C.H., Hawley, J.E., Pytkowicz, R.M., 1973. Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure. Limnology and Oceanography 18, 897-907] as refit by Dickson and Millero [Dickson, A.G., Millero, F.J., 1987. A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media. Deep-Sea Res. 34, 1733-1743] are used. This suggests that the K-1/K-2 ratio of Mehrbach et al. for a pCO(2) range of 280-450 mu atm is correct but it does not necessarily imply that the absolute values of K-1 and K-2 are correct or that these constants work as well at higher pCO(2). An independent cross-check with pCO(2) measurements made at constant temperature (20 degrees C) is in agreement with these conclusions. The differences in calculated pCO(2) can be as great as 30 mu atm depending which constants are used. If the models are forced with a prescribed atmospheric pCO(2) they will end up having surface concentration of TA that are up to 20 mu eq kg(-1) too high or DIC concentration up to 20 mu mol kg(-1) too low if constants other than those of Mehrbach et al. are used. This makes comparisons between observation and models problematic. (C) 1999 Published by Elsevier Science B.V. C1 NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Dept Marine & Atmospher Chem, Miami, FL 33149 USA. RP Wanninkhof, R (reprint author), NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. NR 32 TC 63 Z9 67 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD JUN PY 1999 VL 65 IS 3-4 BP 291 EP 301 DI 10.1016/S0304-4203(99)00021-3 PG 11 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 214ZW UT WOS:000081358300012 ER PT J AU Griffith, ML Schlienger, ME Harwell, LD Oliver, MS Baldwin, MD Ensz, MT Essien, M Brooks, J Robino, CV Smugeresky, JE Hofmeister, WH Wert, MJ Nelson, DV AF Griffith, ML Schlienger, ME Harwell, LD Oliver, MS Baldwin, MD Ensz, MT Essien, M Brooks, J Robino, CV Smugeresky, JE Hofmeister, WH Wert, MJ Nelson, DV TI Understanding thermal behavior in the LENS process SO MATERIALS & DESIGN LA English DT Article DE ferrous metals and alloys; lasers; microstructure AB In direct laser metal deposition technologies, such as the laser engineered net shaping (LENS) process, it is important to understand and control the thermal behavior during fabrication. With this control, components can be reliably fabricated with desired material properties. This paper will describe the use of contact and imaging techniques to monitor the thermal signature during LENS processing. Development of an understanding of solidification behavior, residual stress, and microstructural evolution with respect to thermal behavior will be discussed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA USA. Vanderbilt Univ, Nashville, TN USA. Stanford Univ, Stanford, CA 94305 USA. EM mlgriff@sandia.gov OI Hofmeister, William/0000-0002-4145-7061 NR 9 TC 128 Z9 139 U1 6 U2 41 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0261-3069 J9 MATER DESIGN JI Mater. Des. PD JUN PY 1999 VL 20 IS 2-3 BP 107 EP 113 DI 10.1016/S0261-3069(99)00016-3 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 198RG UT WOS:000080437300007 ER PT J AU Luther, GG AF Luther, GG TI Musings on the use of a bifilar suspension in the measurement of G SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on the Gravitational Constant - Theory and Experiment 200 Years After Cavendish CY NOV 23-24, 1998 CL INST PHYS, PORTLAND PLACE, ENGLAND HO INST PHYS DE gravitational constant; bifilar suspension ID NEWTONIAN GRAVITATIONAL CONSTANT AB Torsion balances and torsion pendulums have been associated with the measurement of the Newtonian gravitational constant from Cavendish through Eotvos and Heyl. The usual suspension consists of a single fine fibre supporting the small test mass, ordinarily a dumbbell of some type. Problems with this system an discussed and some of the advantages of using a bifilar suspension are posited. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD JUN PY 1999 VL 10 IS 6 BP 426 EP 429 DI 10.1088/0957-0233/10/6/302 PG 4 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 205AY UT WOS:000080800200004 ER PT J AU Sanders, AJ Alexeev, AD Allison, SW Bronnikov, KA Campbell, JW Cates, MR Corcovilos, TA Earl, DD Gadfort, T Gillies, GT Harris, MJ Kolosnitsyn, NI Konstantinov, MY Melnikov, VN Newby, RJ Schunk, RG Smalley, LL AF Sanders, AJ Alexeev, AD Allison, SW Bronnikov, KA Campbell, JW Cates, MR Corcovilos, TA Earl, DD Gadfort, T Gillies, GT Harris, MJ Kolosnitsyn, NI Konstantinov, MY Melnikov, VN Newby, RJ Schunk, RG Smalley, LL TI Project SEE (Satellite Energy Exchange): proposal for space-based gravitational measurements SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on the Gravitational Constant - Theory and Experiment 200 Years After Cavendish CY NOV 23-24, 1998 CL INST PHYS, PORTLAND PLACE, ENGLAND HO INST PHYS DE gravity; gravitational constant; Cavendish; equivalence principle; inverse-square law ID INTERACTION PARAMETERS; EARTH SATELLITE; CONSTANT-G AB Project SEE (Satellite Energy Exchange) is an international effort to organize a new space mission for fundamental measurements in gravitation, including tests of the equivalence principle (EP) by composition dependence (CD) and inverse-square-law (ISL) violations, determination of G, and a test for non-zero G-dot. The CD tests will be both at intermediate distances (a few metres) and at long distances (radius of the Earth, R-E). Thus, a SEE mission would obtain accurate information self-consistently on a number of distinct gravitational effects. The EP test by CD at distances of a few metres would provide confirmation of earlier, more precise experiments. All other tests would significantly improve our knowledge of gravity. In particular, the error in G is projected to be less than 1 ppm. Project SEE entails launching a dedicated satellite and making detailed observations of free-floating test bodies within its experimental chamber. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Russian Gravitat Soc, Moscow 117313, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35749 USA. Univ Virginia, Beam Phys Lab, Charlottesville, VA 22903 USA. Univ Alabama, Huntsville, AL 35899 USA. RP Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM asanders@utk.edu; w.campbell@msfc.nasa.gov; catesmr@ornl.gov; rgs@com2com.ru RI Corcovilos, Theodore/G-8699-2012; OI Corcovilos, Theodore/0000-0001-5716-1188; Newby, Robert/0000-0003-3571-1067; Allison, Stephen/0000-0002-5887-5403; Bronnikov, Kirill/0000-0001-9392-7558 NR 33 TC 21 Z9 22 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD JUN PY 1999 VL 10 IS 6 BP 514 EP 524 DI 10.1088/0957-0233/10/6/317 PG 11 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 205AY UT WOS:000080800200019 ER PT J AU Chadwick, MB Barschall, HH Caswell, RS DeLuca, PM Hale, GM Jones, DTL MacFarlane, RE Meulders, JP Schuhmacher, H Schrewe, UJ Wambersie, A Young, PG AF Chadwick, MB Barschall, HH Caswell, RS DeLuca, PM Hale, GM Jones, DTL MacFarlane, RE Meulders, JP Schuhmacher, H Schrewe, UJ Wambersie, A Young, PG TI A consistent set of neutron kerma coefficients from thermal to 150 MeV for biologically important materials SO MEDICAL PHYSICS LA English DT Article DE kerma coefficients; cross sections; nuclear data; neutron dosimetry; therapy ID DIFFERENTIAL INCLUSIVE HYDROGEN; SCATTERING CROSS-SECTIONS; PARTICLE PRODUCTION; ENERGY-RANGE; NUCLEAR-DATA; ANGULAR-DISTRIBUTIONS; HELIUM SPECTRA; LIGHT-NUCLEI; CARBON; THERAPY AB Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data far charged-particle production as well as neutron and photon production. Therefore they can be used to determine kerma coefficients for calculations of energy deposition by neutrons in matter. Methods used to evaluate the neutron cross sections above 20 MeV, using nuclear model calculations and experimental data, are described. Below 20 MeV, the evaluated cross sections from the ENDF/B-VI library are adopted. Comparisons are shown between the evaluated charged-particle production cross sections and measured data. Kerma coefficients are derived from the neutron cross sections, for major isotopes of H, C, N, O, Al, Si, P, Ca, Fe, Cu, W, Pb, and for ICRU-muscle, A-150 tissue-equivalent plastic, and other compounds important for treatment planning and dosimetry. Numerous comparisons are made between our kerma coefficients and experimental kerma coefficient data, to validate our results, and agreement is found to be good. An important quantity in neutron dosimetry is the kerma coefficient ratio of ICRU-muscle to A-150 plastic. When this ratio is calculated from our kerma coefficient data, and averaged over the neutron energy spectra for higher-energy clinical therapy beams [three p(68)+ Be beams, and a d(48.5) + Be beam], a value of 0.94+-0.03 is obtained. Kerma ratios for water to A-150 plastic, and carbon to oxygen, are also compared with measurements where available. (C) 1999 American Association of Physicists in Medicine. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Med Phys, Madison, WI 53706 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Natl Accelerator Ctr, Cape Town, South Africa. Catholic Univ Louvain, B-3000 Louvain, Belgium. Phys Tech Bundesanstalt, D-3300 Braunschweig, Germany. RP Chadwick, MB (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 90 TC 59 Z9 61 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 1999 VL 26 IS 6 BP 974 EP 991 DI 10.1118/1.598601 PG 18 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 207WM UT WOS:000080958800016 PM 10436900 ER PT J AU Engler, O AF Engler, O TI On the origin of the R orientation in the recrystallization textures of aluminum alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID CUBE TEXTURE; PURITY ALUMINUM; NUCLEATION; GROWTH; MICROSTRUCTURE; DIFFRACTION; DEFORMATION; GRAINS AB The crystallographic textures of most Al alloys, after rolling and recrystallization, are composed of two components, the cube orientation {001}[100] and a component similar to the former rolling texture, the so-called R orientation {124}[211]. The R orientation can be retained from the rolling texture in cases where the stored dislocation energy is being reduced merely through extended recovery reactions, which is referred to as continuous recrystallization. In addition, R-oriented grains can form through genuine, discontinuous recrystallization by nucleation within S-oriented grains at the grain boundaries between the deformed bands and a subsequent growth selection as caused by orientation pinning. The strength of the R orientation in the recrystallization textures strongly depends on the pretreatment and processing parameters of the material and, in particular, on the alloy investigated. The present article gives a survey of the factors affecting the R orientation and reviews recent results on the formation mechanisms of this orientation, which have been obtained by local texture analysis. The results are discussed with regard to the competition of the Ii orientation with the cube orientation during the evolution of the recrystallization textures in Al alloys. C1 Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. NR 61 TC 54 Z9 59 U1 1 U2 12 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 1999 VL 30 IS 6 BP 1517 EP 1527 DI 10.1007/s11661-999-0088-7 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 208XK UT WOS:000081017100005 ER PT J AU Kailasam, SK Glicksman, ME Mani, SS Fradkov, VE AF Kailasam, SK Glicksman, ME Mani, SS Fradkov, VE TI Investigation of microstructural coarsening in Sn-Pb alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PARTICLE DIFFUSION PROBLEM; VOLUME FRACTION; AL ALLOYS; OSTWALD; DEPENDENCE; KINETICS; GROWTH AB The central theme of this work is to investigate the kinetics of microstructural evolution at high volume fractions of the dispersed phase in a solid-liquid mixture. Until recently, the kinetics of coarsening in the high volume fraction range was not clearly established. A recent study focused on high volume fractions (V-nu > 0.90) revealed that the temporal scaling laws that describe phase coarsening change from the conventional cube root of time behavior to a fourth-power relationship. This work probes the variation of the temporal exponent with volume fraction of the dispersed phase (V-nu greater than or equal to 0.60). An overview of the fundamentals of the physics involved in diffusion-limited coarsening is presented. Also explained is the relevance of phase coarsening in various applications. A succinct review of the attempts to understand the various parameters involved in coarsening is provided, with the Sn-Pb system chosen for this study for reasons apart from its importance as a commercial solder alloy system. Details of the experimental procedures are described, and, following this, the results are outlined and the underlying mechanisms discussed. The findings reveal that the temporal exponent changes as the volume fraction of the dispersed phase changes. C1 Rensselaer Polytech Inst, Troy, NY 12180 USA. Northrop Grumman Corp, Pittsburgh, PA 15235 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kailasam, SK (reprint author), Rensselaer Polytech Inst, Troy, NY 12180 USA. OI Glicksman, Martin/0000-0002-2675-2759 NR 31 TC 16 Z9 16 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1999 VL 30 IS 6 BP 1541 EP 1547 DI 10.1007/s11661-999-0091-z PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 208XK UT WOS:000081017100008 ER PT J AU Lesuer, DR Syn, CK Whittenberger, JD Sherby, OD AF Lesuer, DR Syn, CK Whittenberger, JD Sherby, OD TI Microstructure-property relations in As-extruded ultrahigh-carbon steels SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID TENSILE PROPERTIES; PEARLITE AB The microstructure and mechanical properties of as-extruded ultrahigh-carbon steels (UHCSs) are described. Extrusion ratios of 16:1 reduction were used at extrusion temperatures of 900 degrees C, 1025 degrees C, and 1150 degrees C. Air cooling followed the extrusion process. The compositions of the four UHCSs investigated ranged from 1.2 to 1.8 pet C and contained either aluminum or silicon and/or chromium as the principal alloying elements. The as-extruded microstructures were predominantly pearlitic. Detailed examination of the microstructures allowed determination of the composition and extrusion temperature at which grain-boundary carbide networks and graphite can be avoided. It is shown that the yield strength of the as-extruded bars, for a given UHCS alloy composition, correlates well with the interlamellar spacing, independent of the extrusion temperature. Ultimate tensile strengths ranged from 1000 to 1690 MPa, and elongations to failure ranged from 3 to 12.5 pet. The present results indicate that single-step mechanical working of UHCSs to achieve fully pearlitic structures, with no postworking heat treatment, can lead to a new class of ultrahigh-strength steels. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. RP Lesuer, DR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 20 TC 29 Z9 37 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1999 VL 30 IS 6 BP 1559 EP 1568 DI 10.1007/s11661-999-0093-x PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 208XK UT WOS:000081017100010 ER PT J AU Zhu, JH Liaw, PK Corum, JM McCoy, HE AF Zhu, JH Liaw, PK Corum, JM McCoy, HE TI High-temperature mechanical behavior of Ti-6Al-4V alloy and TiCp/Ti-GAl-4V composite SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID METAL-MATRIX COMPOSITES; FATIGUE BEHAVIOR; CREEP-BEHAVIOR; CRACK-GROWTH; FRACTURE; ROUTE; COST AB Mechanical behaviors at 538 degrees C, including tensile and creep properties, were investigated for both the Ti-6Al-4V alloy and the Ti-6Al-4V composite reinforced with 10 wt pet TiC particulates fabricated by cold and hot isostatic pressing (CHIP). It was shown that the yield strength (YS) and ultimate tensile strength CUTS) of the composite were greater than those of the matrix alloy at the strain rates ranging from approximately 10(-5) to 10(-3) s(-1). However, the elongation of the composite material was substantially lower than that of the matrix alloy. The creep resistance of the composite was superior to that of the matrix alloy. The data of minimum creep strain rate vs applied stress for the composite can be fit to a power-law equation, and the stress exponent values of 5 and 8 were obtained for applied stress ranges of 103 to 232 MPa and 232 to 379 MPa, respectively. The damage mechanisms were different for the matrix alloy and the composite, as demonstrated by the scanning electron microscopy (SEM) observation of fracture surfaces and the optical microscopy examination of the regions adjacent to the fracture surface. The tensile-tested matrix alloy showed dimpled fracture, while the creep-tested matrix alloy exhibited preferentially interlath and intercolony cracking. The failure of the tensile-tested and creep-tested composite material was controlled by the cleavage failure of the particulates, which was followed by the ductile fracture of the matrix. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. RP Zhu, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 30 TC 25 Z9 25 U1 0 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1999 VL 30 IS 6 BP 1569 EP 1578 DI 10.1007/s11661-999-0094-9 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 208XK UT WOS:000081017100011 ER PT J AU Kozeschnik, E Pletenev, V Zolotorevsky, N Buchmayr, B AF Kozeschnik, E Pletenev, V Zolotorevsky, N Buchmayr, B TI Aluminum nitride precipitation and texture development in batch-annealed bake-hardening steel SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID LOW-CARBON STEELS; MODELING RECRYSTALLIZATION; KILLED STEEL; POLYCRYSTALLINE IRON; ROLLING TEXTURES; YIELD STRENGTH; SHEET; KINETICS; SYSTEM AB A model is presented that describes the development of texture during the production process of bake-hardening steel recrystallized in a batch-annealing furnace. Proper conditions are analyzed to generate a pronounced gamma-fiber texture and a "pancake microstructure" that shows superior deep drawability. The gamma-fiber texture is assumed to be caused by the interaction between tertiary precipitating aluminum nitride particles and the recrystallization process during heating in the furnace. Deep drawability is presented in terms of the logarithmic gamma- and alpha-fiber X-ray intensity ratio. The computer simulation of the coupled aluminum nitride precipitation and recrystallization kinetics is based on an iterative procedure. A comparison between simulation results and available experimental data proves the ability of the model to predict the final deep drawability, taking into account the initial aluminum and nitrogen contents, the time/temperature history during slab reheating, hot rolling and coiling, the degree of cold reduction, and the heating rate during batch annealing. C1 Graz Univ Technol, Inst Mat Sci Welding & Forming, A-8010 Graz, Austria. St Petersburg State Tech Univ, Dept Met Phys, St Petersburg 195251, Russia. RP Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 53 TC 23 Z9 25 U1 0 U2 3 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 1999 VL 30 IS 6 BP 1663 EP 1673 DI 10.1007/s11661-999-0104-y PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 208XK UT WOS:000081017100021 ER PT J AU Berman, GP Campbell, DK Doolen, GD Nagaev, KE AF Berman, GP Campbell, DK Doolen, GD Nagaev, KE TI Electron-nuclear spin dynamics in a mesoscopic solid-state quantum computer SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 4th International Symposium on New Phenomena in Mesoscopic Structures CY DEC 07-11, 1998 CL KAUAI, HAWAII SP Japan Soc Promot Sci, 151st Comm Electr Propert Extreme Struct AB We numerically simulate the process of nuclear spin measurement in Kane's quantum computer. For this purpose, we model the quantum dynamics of two coupled nuclear spins on P-31 donors implanted in Si. We estimate the minimum time of measurement necessary for the reliable transfer of quantum information from the nuclear spin subsystem to the electronic subsystem. Wie also calculate the probability of error for typical values of external noise. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Russian Acad Sci, Inst Radioengn & Elect, Moscow 103907, Russia. RP Berman, GP (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-13,MS B213, Los Alamos, NM 87545 USA. RI Nagaev, Kirill/H-6802-2016 OI Nagaev, Kirill/0000-0002-1659-6115 NR 2 TC 3 Z9 3 U1 0 U2 0 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 1999 VL 47 IS 1-4 BP 277 EP 279 DI 10.1016/S0167-9317(99)00213-0 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 215VF UT WOS:000081403600064 ER PT J AU Campbell, DK Alekseev, KN Berman, GP Cannon, EH AF Campbell, DK Alekseev, KN Berman, GP Cannon, EH TI Dissipative chaos and symmetry breaking in ac-driven nanostructures SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 4th International Symposium on New Phenomena in Mesoscopic Structures CY DEC 07-11, 1998 CL KAUAI, HAWAII SP Japan Soc Promot Sci, 151st Comm Electr Propert Extreme Struct ID SEMICONDUCTOR SUPERLATTICES AB We present results of several recent numerical "balance equation" studies of the nonlinear transport and dynamics of electrons in ac-driven nanostructures. Our studies reveal both deterministic chaos and "symmetry-breaking'' (i.e., the development of a dc bias in response to a purely ac applied field) in parameter regimes accessible to present experiments. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. LV Kirensky Phys Inst, Theory Nonlinear Proc Lab, Krasnoyarsk 660036, Russia. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Campbell, DK (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, MS B258, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD JUN PY 1999 VL 47 IS 1-4 BP 337 EP 339 DI 10.1016/S0167-9317(99)00228-2 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 215VF UT WOS:000081403600079 ER PT J AU Aronov, IE Beletskii, NN Berman, GP Campbell, DK Doolen, GD Dudiy, SV AF Aronov, IE Beletskii, NN Berman, GP Campbell, DK Doolen, GD Dudiy, SV TI Modeling AC electronic transport through a two-dimensional quantum point contact SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 4th International Symposium on New Phenomena in Mesoscopic Structures CY DEC 07-11, 1998 CL KAUAI, HAWAII SP Japan Soc Promot Sci, 151st Comm Electr Propert Extreme Struct AB We present new results on the a.c. transport of electrons moving through a two-dimensional (2D) semiconductor quantum point contact (QPC). We concentrate our attention on the characteristic properties of the high frequency admittance (omega approximate to 0 - 50 GHz), and on the oscillations of the admittance in the vicinity of the separatrix (when a channel opens or closes), in presence of the relaxation effects. The experimental verification of these oscillations in the admittance would be a strong confirmation of our semi-classical approach to a.c. transport through a QPC, in the separatrix region. C1 Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Natl Acad Sci Ukraine, Inst Radiophys & Elect, UA-310085 Kharkov, Ukraine. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Aronov, IE (reprint author), Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. NR 4 TC 1 Z9 1 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 1999 VL 47 IS 1-4 BP 357 EP 359 DI 10.1016/S0167-9317(99)00233-6 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 215VF UT WOS:000081403600084 ER PT J AU McEuen, PL Bockrath, M Cobden, DH Lu, JG AF McEuen, PL Bockrath, M Cobden, DH Lu, JG TI One dimensional transport in carbon nanotubes SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 4th International Symposium on New Phenomena in Mesoscopic Structures CY DEC 07-11, 1998 CL KAUAI, HAWAII SP Japan Soc Promot Sci, 151st Comm Electr Propert Extreme Struct ID ROPES AB Single-walled carbon nanotubes - nanometer diameter graphene cylinders - are a new class of one-dimensional (1D) conductors. Recent STM[1] and transport[2-8] experiments have shown that these tubes can be either semiconductors or 1D metals. Here we review our group's recent electrical studies[3-5] of these novel 1D conductors. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP McEuen, PL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, M-S 2-200 LBNL, Berkeley, CA 94720 USA. RI Lu, Jia Grace/I-7435-2015 OI Lu, Jia Grace/0000-0001-9908-4061 NR 15 TC 10 Z9 10 U1 0 U2 2 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 1999 VL 47 IS 1-4 BP 417 EP 420 DI 10.1016/S0167-9317(99)00248-8 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 215VF UT WOS:000081403600099 ER PT J AU Barton, DL Bernhard-Hofer, K Cole, EI AF Barton, DL Bernhard-Hofer, K Cole, EI TI FLIP-chip and "backside" techniques SO MICROELECTRONICS RELIABILITY LA English DT Article; Proceedings Paper CT 10th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis (ESREF 99) CY OCT 05-08, 1999 CL ARCACHON, FRANCE ID SILICON AB State-of-the-art techniques for failure localization and design modification through bulk silicon are essential for multi-level metallization and new, flip chip packaging methods. The tutorial reviews the transmission of light through silicon, sample preparation, and backside defect localization techniques that are both currently available and under development. The techniques covered include emission microscopy, scanning laser microscope based techniques (electrooptic techniques, LIVA and its derivatives), and other non-IR based tools (FIB, e-beam techniques, etc.). (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Infineon Technol AG I Gr, Munich, Germany. RP Barton, DL (reprint author), Sandia Natl Labs, MS 1081, Albuquerque, NM 87185 USA. NR 42 TC 20 Z9 20 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD JUN-JUL PY 1999 VL 39 IS 6-7 BP 721 EP 730 DI 10.1016/S0026-2714(99)00093-1 PG 10 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 240RJ UT WOS:000082838700002 ER PT J AU Cole, EI Tangyunyong, P Benson, DA Barton, DL AF Cole, EI Tangyunyong, P Benson, DA Barton, DL TI TIVA and SEI developments for enhanced front and backside interconnection failure analysis SO MICROELECTRONICS RELIABILITY LA English DT Article; Proceedings Paper CT 10th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis (ESREF 99) CY OCT 05-08, 1999 CL ARCACHON, FRANCE AB Thermally-induced Voltage Alteration (TIVA) and Seebeck Effect Imaging (SEI) are newly developed techniques for localizing shorted and open conductors from the front and backside of an IC. Recent improvements have greatly increased the sensitivity of the TIVA/SEI system, reduced the acquisition times by more than 20X, and localized previously unobserved defects. The system improvements, non-linear response of IC defects to heating, modeling of laser heating and examples using the improved system are presented. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Cole, EI (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, 1515 Eubank SE,MS 1081, Albuquerque, NM 87185 USA. NR 11 TC 23 Z9 23 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD JUN-JUL PY 1999 VL 39 IS 6-7 BP 991 EP 996 DI 10.1016/S0026-2714(99)00136-5 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 240RJ UT WOS:000082838700045 ER PT J AU Copaken, RR Kern, NR Steenhagen, J Kemp, G AF Copaken, RR Kern, NR Steenhagen, J Kemp, G TI Symposium: Policy implications of the price of oil SO MIDDLE EAST POLICY LA English DT Article C1 US DOE, Washington, DC 20585 USA. RP Copaken, RR (reprint author), US DOE, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MIDDLE EAST POLICY COUNCIL PI WASHINGTON PA 1730 M ST, NW, STE 512, WASHINGTON, DC 20036 USA SN 1061-1924 J9 MIDDLE EAST POLICY JI Middle East Policy PD JUN PY 1999 VL 6 IS 4 BP 34 EP 58 PG 25 WC Area Studies; International Relations SC Area Studies; International Relations GA 216DJ UT WOS:000081425700001 ER PT J AU Sen, CK AF Sen, CK TI Glutathione homeostasis in response to exercise training and nutritional supplements SO MOLECULAR AND CELLULAR BIOCHEMISTRY LA English DT Article DE thiols; antioxidant; redox; adaptation; oxidative stress; skeletal muscle; dietary supplement ID ALPHA-LIPOIC ACID; TUMOR-NECROSIS-FACTOR; INDUCED OXIDATIVE STRESS; ANTIOXIDANT ENZYME-ACTIVITY; HUMAN SKELETAL-MUSCLE; PHYSICAL EXERCISE; CANCER CACHEXIA; TISSUE-DAMAGE; EXHAUSTIVE EXERCISE; ORAL GLUTATHIONE AB Glutathione plays a central role in the maintenance of tissue antioxidant defenses and in the regulation of redox sensitive signal transduction. In muscle cells, the level and redox status of GSH regulates activity of the redox sensitive transcription factor NF-kappa B. Physical exercise may cause oxidation of GSH in tissues such as the blood, skeletal muscle and liver. Endurance training strengthened GSH dependent tissue antioxidant defenses in most studies. Although studies investigating the effect of sprint training are few, current results show that sprint training may also have a beneficial effect on tissue GSH homeostasis. Skeletal muscle GSH level appears to be tightly regulated by the state of physical activity. Regular exercise enhances and chronic inactivity decreases the level of GSH in this tissue. N-acetyl-L-cysteine (NAC) and alpha-lipoic acid (LA) are two antioxidant dietary supplements that are able to enhance cellular GSH levels. Because LA can be recycled to its potent dithiol form, dihydrolipoate, by enzymes present in the human cell it has a clear advantage over NAC. Recently an improved form of LA, a positively charged analogue (LA-Plus), has been discovered. LA-Plus has more potent immuno-modulatory activity compared to LA. Both LA and NAC have been shown to have beneficial effects in protecting tissue GSH homeostasis against exercise induced oxidative stress. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energies Technol Div, Biol Technol Sect, Berkeley, CA 94720 USA. Univ Kuopio, Dept Physiol, FIN-70211 Kuopio, Finland. RP Sen, CK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energies Technol Div, Biol Technol Sect, Life Sci Addit,Room 251 C,Mail Stop 3200, Berkeley, CA 94720 USA. RI Sen, Chandan/A-8762-2013 FU NIDDK NIH HHS [DK 50430]; NIGMS NIH HHS [GM 27345] NR 99 TC 74 Z9 84 U1 0 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0300-8177 J9 MOL CELL BIOCHEM JI Mol. Cell. Biochem. PD JUN PY 1999 VL 196 IS 1-2 BP 31 EP 42 DI 10.1023/A:1006910011048 PG 12 WC Cell Biology SC Cell Biology GA 204UL UT WOS:000080782900005 PM 10448900 ER PT J AU Kuklin, A Davis, AP Hecker, KH Gjerde, DT Taylor, PD AF Kuklin, A Davis, AP Hecker, KH Gjerde, DT Taylor, PD TI A novel technique for rapid automated genotyping of DNA polymorphisms in the mouse SO MOLECULAR AND CELLULAR PROBES LA English DT Article DE mice; genotyping; DNA polymorphisms ID CHROMATOGRAPHY; FRAGMENTS AB The ability to rapidly and reliably genotype mice is an important concern. Traditional methods employ labour intensive and time consuming techniques such as test crossing, gel electrophoresis or nucleic acid hybridization. Here we show that a new molecular biology workstation, the WAVE(TM) DNA Fragment Analysis System, can easily resolve polymerase chain reaction (PCR) products that have small differences in their lengths. Analysis is fully automated and takes less than 7 min per sample. Approximately 200 samples can be analysed per day with only minutes of hands-on time after completion of the PCR. Genotyping with the WAVE(TM) DNA Fragment Analysis System is a fast and efficient method with minimal manual intervention. (C) 1999 Academic Press. C1 Trasgen Inc, San Jose, CA 95131 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hecker, KH (reprint author), Trasgen Inc, 2032 Concourse Dr, San Jose, CA 95131 USA. NR 6 TC 15 Z9 15 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0890-8508 J9 MOL CELL PROBE JI Mol. Cell. Probes PD JUN PY 1999 VL 13 IS 3 BP 239 EP 242 DI 10.1006/mcpr.1999.0239 PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Cell Biology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Cell Biology GA 210RG UT WOS:000081118000011 PM 10369750 ER PT J AU Gascard, P Nunomura, W Lee, G Walensky, LD Krauss, SW Takakuwa, Y Chasis, JA Mohandas, N Conboy, JG AF Gascard, P Nunomura, W Lee, G Walensky, LD Krauss, SW Takakuwa, Y Chasis, JA Mohandas, N Conboy, JG TI Deciphering the nuclear import pathway for the cytoskeletal red cell protein 4.1R SO MOLECULAR BIOLOGY OF THE CELL LA English DT Article ID SPECTRIN-ACTIN-BINDING; LARGE T-ANTIGEN; MEMBRANE SKELETAL PROTEIN-4.1; II SITE FLANKING; LOCALIZATION SIGNAL; INTERPHASE NUCLEI; MESSENGER-RNA; TERMINAL DIFFERENTIATION; ERYTHROCYTE PROTEIN-4.1; STRUCTURAL PROTEIN-4.1 AB The erythroid membrane cytoskeletal protein 4.1 is the prototypical member of a genetically and topologically complex family that is generated by combinatorial alternative splicing pathways and is localized at diverse intracellular sites including the nucleus. To explore the molecular determinants for nuclear localization, we transfected COS-7 cells with epitope-tagged versions of natural red cell protein 4.1 (4.1R) isoforms as well as mutagenized and truncated derivatives. Two distant topological sorting signals were required for efficient nuclear import of the 4.1R(80) isoform: a basic peptide, KKKRER, encoded by alternative exon 16 and acting as a weak core nuclear localization signal (4.1R NLS), and an acidic peptide, EED, encoded by alternative exon 5. 4.1R(80) isoforms lacking either of these two exons showed decreased nuclear import. Fusion of various 4.1Rs0 constructs to the cytoplasmic reporter protein pyruvate kinase confirmed a requirement for both motifs for full NLS function. 4.1Rs0 was efficiently imported in the nuclei of digitonin-permeabilized COS-7 cells in the presence of recombinant Rch1 (human importin alpha 2), importin beta, and GTPase Ran. Quantitative analysis of protein-protein interactions using a resonant mirror detection technique showed that 4.1R(80) bound to Rch1 in vitro with high affinity (K-D, 30 nM). The affinity decreased at least 7- and 20-fold, respectively, if the EED motif in exon 5 or if 4.1R NLS in exon 16 was lacking or mutated, confirming that both motifs were required for efficient importin-mediated nuclear import of 4.1Rs0. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Subcellular Struct, Div Life Sci, Berkeley, CA 94720 USA. Tokyo Womens Med Univ, Sch Med, Dept Biochem, Tokyo 162, Japan. Johns Hopkins Univ, Sch Med, Baltimore, MD 21205 USA. RP Gascard, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Subcellular Struct, Div Life Sci, Berkeley, CA 94720 USA. FU NIDDK NIH HHS [P01 DK032094, DK-32094] NR 79 TC 37 Z9 38 U1 1 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA PUBL OFFICE, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD JUN PY 1999 VL 10 IS 6 BP 1783 EP 1798 PG 16 WC Cell Biology SC Cell Biology GA 206NT UT WOS:000080886500008 PM 10359596 ER PT J AU Annamalai, H Slingo, JM Sperber, KR Hodges, K AF Annamalai, H Slingo, JM Sperber, KR Hodges, K TI The mean evolution and variability of the Asian summer monsoon: Comparison of ECMWF and NCEP-NCAR reanalyses SO MONTHLY WEATHER REVIEW LA English DT Article ID SEA-SURFACE-TEMPERATURE; MODEL INTERCOMPARISON PROJECT; LARGE-SCALE MODELS; OBSERVATIONAL ASPECTS; ATMOSPHERIC MOISTURE; TROPICAL PACIFIC; INDIAN-OCEAN; RAINFALL; SENSITIVITY; PREDICTION AB The behavior of the Asian summer monsoon is documented and compared using the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA) and the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) Reanalysis. In terms of seasonal mean climatologies the results suggest that, in several respects, the ERA is superior to the NCEP-NCAR Reanalysis. The overall better simulation of the precipitation and hence the diabatic heating field over the monsoon domain in ERA means that the analyzed circulation is probably nearer reality. In terms of interannual variability, inconsistencies in the definition of weak and strong monsoon years based on typical monsoon indices such as All-India Rainfall (AIR) anomalies and the large-scale wind shear based dynamical monsoon index (DMI) still exist. Two dominant modes of interannual variability have been identified that together explain nearly 50% of the variance. Individually, they have many features in common with the composite flow patterns associated with weak and strong monsoons, when defined in terms of regional AIR anomalies and the large-scale DMI. The reanalyses also show a common dominant mode of intraseasonal variability that describes the latitudinal displacement of the tropical convergence zone from its oceanic-to-continental regime and essentially captures the low-frequency active/break cycles of the monsoon. The relationship between interannual and intraseasonal variability has been investigated by considering the probability density function (PDF) of the principal component of the dominant intraseasonal mode. Based on the DMI, there is an indication that in years with a weaker monsoon circulation, the PDF is skewed toward negative values (i,e., break conditions). Similarly, the PDFs for El Nino and La Nina years suggest that El Nino predisposes the system to more break spells, although the sample size may limit the statistical significance of the results. C1 Univ Reading, Dept Meteorol, Ctr Global Atmospher Modelling, Reading RG6 6BB, Berks, England. Univ Calif Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Livermore, CA USA. Univ Reading, Dept Geog, Environm Syst Sci Ctr, Reading RG6 6BB, Berks, England. RP Slingo, JM (reprint author), Univ Reading, Dept Meteorol, Ctr Global Atmospher Modelling, Earley Gate, Reading RG6 6BB, Berks, England. RI Sperber, Kenneth/H-2333-2012 NR 68 TC 176 Z9 206 U1 0 U2 15 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1999 VL 127 IS 6 BP 1157 EP 1186 DI 10.1175/1520-0493(1999)127<1157:TMEAVO>2.0.CO;2 PN 2 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 207AU UT WOS:000080913800002 ER PT J AU Rawers, J AF Rawers, J TI Comparison of attrition milled, nanostructured, powder-compaction techniques SO NANOSTRUCTURED MATERIALS LA English DT Article DE compaction; nanostructure; Hall-Petch; hardness; grain size ID MECHANICAL-BEHAVIOR; NANOCRYSTALLINE FE; IRON-POWDER; CONSOLIDATION; MICROSTRUCTURE; ALLOYS AB The efficacy of compaction techniques for iron-based nanostructured powders was compared. Compaction processing conditions varied from room temperature to 1000 degrees C; Pressures from 50MPa to 20GPa; and times from a few seconds to three hours. The resulting compact microstructures and grain sizes were dependent upon processing variables, especially temperature, but were independent of the processing technique. The advantages and limitations of each technique are discussed. Published by Elsevier Science Ltd. C1 US Bur Mines, Albany Res Ctr, US DOE, Albany, OR 97321 USA. RP Rawers, J (reprint author), US Bur Mines, Albany Res Ctr, US DOE, Albany, OR 97321 USA. NR 34 TC 22 Z9 23 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JUN PY 1999 VL 11 IS 4 BP 513 EP 522 DI 10.1016/S0965-9773(99)00337-2 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 231FX UT WOS:000082298400010 ER PT J AU Singhal, A Skandan, G Wang, A Glumac, N Kear, BH Hunt, RD AF Singhal, A Skandan, G Wang, A Glumac, N Kear, BH Hunt, RD TI On nanoparticle aggregation during vapor phase synthesis SO NANOSTRUCTURED MATERIALS LA English DT Article ID SPRAY-PYROLYSIS AB A number of techniques have evolved over the past several years for the synthesis of ceramic nanopowders. At issue in each of these processes is the extent of agglomeration (particle adhesion) and aggregation (particle sintering), the latter referring to clusters of primary particles being cemented together by inter-particle necks. While it is virtually impossible to eliminate agglomeration of pristine nanopowders due to the strong van der Waals forces of attraction that keep the particles together, aggregation can be restricted by controlled powder synthesis. We have optimized a vapor phase synthesis method, called Combustion Flame-Chemical Vapor Condensation (CF-CVC), which involves pyrolysis of chemical precursors in a low pressure flat flame. By controlling the time-temperature history of the particles in the hot zone of the flame, we have produced nanopowders of oxides that have an average aggregate (secondary particle) size similar to 100 nm, and an average primary particle size less than 25 nm. (C)1999 Acta Metallurgica Inc. C1 Nanopowder Enterprises Inc, Piscataway, NJ 08854 USA. Rutgers State Univ, Piscataway, NJ 08854 USA. Oak Ridge Natl Lab, Knoxville, TN USA. RP Singhal, A (reprint author), Nanopowder Enterprises Inc, 120 Centennial Ave, Piscataway, NJ 08854 USA. RI Glumac, Nick/C-1730-2015 OI Glumac, Nick/0000-0001-6673-0573 NR 17 TC 43 Z9 46 U1 3 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JUN PY 1999 VL 11 IS 4 BP 545 EP 552 DI 10.1016/S0965-9773(99)00343-8 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 231FX UT WOS:000082298400014 ER PT J AU Liu, XY Dangel, AW Kelley, RI Zhao, W Denny, P Botcherby, M Cattanach, B Peters, J Hunsicker, PR Mallon, AM Strivens, MA Bate, R Miller, W Rhodes, M Brown, SDM Herman, GE AF Liu, XY Dangel, AW Kelley, RI Zhao, W Denny, P Botcherby, M Cattanach, B Peters, J Hunsicker, PR Mallon, AM Strivens, MA Bate, R Miller, W Rhodes, M Brown, SDM Herman, GE TI The gene mutated in bare patches and striated mice encodes a novel 3 beta-hydroxysteroid dehydrogenase SO NATURE GENETICS LA English DT Article ID LEMLI-OPITZ-SYNDROME; STR CRITICAL REGIONS; CHOLESTEROL-BIOSYNTHESIS; STEROL BIOSYNTHESIS; REDUCTASE GENE; HUMAN XQ28; MUTATIONS; MOUSE; 7-DEHYDROCHOLESTEROL; TRANSCRIPTS AB X-linked dominant disorders that are exclusively lethal prenatally in hemizygous males have been described in human and (1). None of the genes responsible has been isolated in mouse either species; The bare patches (Bpa):and striated (Str) mouse mutations were originally identified in female offspring of X-irradiated males(2) (3). Subsequently, additional independent alleles were described. We have previously mapped these X-linked dominant, male-lethal mutations to an overlapping region:of 600 kb that is homologous to human Xq28 (ref. 4) and identified several candidate genes in this: interval(5). Here we report mutations in one of these genes, Nsdhl, encoding an NAD(P)H steroid dehydrogenase-like protein, in two independent Bpa and three independent Str alleles. Quantitative analysis of sterols from tissues of affected Bpa mice support a role for Nsdhl in cholesterol biosynthesis. Our results demonstrate that Bpa and Sfr are allelic mutations and identify the first mammalian locus associated with an X-linked dominant, male-lethal phenotype. They also expand the spectrum of phenotypes associated with abnormalities of cholesterol metabolism. C1 Ohio State Univ, Childrens Hosp Res Fdn, Columbus, OH 43205 USA. Ohio State Univ, Dept Pediat, Columbus, OH 43205 USA. Johns Hopkins Univ, Kennedy Krieger Inst, Baltimore, MD 21205 USA. Johns Hopkins Univ, Dept Pediat, Baltimore, MD 21205 USA. MRC, Mouse Genome Ctr, Didcot OX11 ORD, Oxon, England. MRC, Mammalian Genet Lab, Didcot OX11 ORD, Oxon, England. MRC, Human Genome Mapping Project Resource Ctr, Cambridge, England. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Penn State Univ, Dept Comp Sci, University Pk, PA 16802 USA. RP Herman, GE (reprint author), Ohio State Univ, Childrens Hosp Res Fdn, Columbus, OH 43205 USA. FU NINDS NIH HHS [R01 NS34953]; NLM NIH HHS [R01 LM05110] NR 30 TC 103 Z9 105 U1 0 U2 2 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1061-4036 J9 NAT GENET JI Nature Genet. PD JUN PY 1999 VL 22 IS 2 BP 182 EP 187 PG 6 WC Genetics & Heredity SC Genetics & Heredity GA 202YX UT WOS:000080680900026 PM 10369263 ER PT J AU Williams, PA Blackburn, NJ Sanders, D Bellamy, H Stura, EA Fee, JA McRee, DE AF Williams, PA Blackburn, NJ Sanders, D Bellamy, H Stura, EA Fee, JA McRee, DE TI The Cu-A domain of Thermus thermophilus ba(3)-type cytochrome c oxidase at 1.6 angstrom resolution SO NATURE STRUCTURAL BIOLOGY LA English DT Letter ID ELECTRON-TRANSFER; MIXED-VALENCE; TERMINAL OXIDASE; RESPIRATION; EVOLUTION; COMPLEX; ENZYME; SITE AB The structure of the Cu-A-containing, extracellular domain of Thermus thermophilus ba(3)-type cytochrome c oxidase has been determined to 1.6 Angstrom resolution using multiple X-ray wavelength anomalous dispersion (MAD). The Cu2S2 cluster forms a planar rhombus with a copper-copper distance of 2.51 +/- 0.03 Angstrom, X-ray absorption fine-structure (EXAFS) studies show that this distance is unchanged by crystallization. The Cu, center is asymmetrical; one copper is tetrahedrally coordinated to two bridging cysteine thiolates, one histidine nitrogen and one methionine sulfur, while the other is trigonally coordinated by the two cysteine thiolates and a histidine nitrogen. Combined sequence-structure alignment of amino acid sequences reveals conserved interactions between cytochrome c oxidase subunits I and II. C1 Scripps Res Inst, Dept Mol Biol MB8, La Jolla, CA 92037 USA. Oregon Grad Inst, Dept Biochem & Mol Biol, Portland, OR 97291 USA. Univ Calif San Diego, Dept Biol, La Jolla, CA 92037 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP McRee, DE (reprint author), Scripps Res Inst, Dept Mol Biol MB8, 10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. RI STURA, Enrico/A-2793-2010 OI STURA, Enrico/0000-0001-6718-2118 NR 31 TC 79 Z9 80 U1 1 U2 9 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUN PY 1999 VL 6 IS 6 BP 509 EP 516 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 201HH UT WOS:000080589000008 PM 10360350 ER PT J AU Chanana, AD Capala, J Chadha, M Coderre, JA Diaz, AZ Elowitz, EH Iwai, J Joel, DD Liu, HGB Ma, RM Pendzick, N Peress, NS Shady, MS Slatkin, DN Tyson, GW Wielopolski, L AF Chanana, AD Capala, J Chadha, M Coderre, JA Diaz, AZ Elowitz, EH Iwai, J Joel, DD Liu, HGB Ma, RM Pendzick, N Peress, NS Shady, MS Slatkin, DN Tyson, GW Wielopolski, L TI Boron neutron capture therapy for glioblastoma multiforme: Interim results from the Phase I/II dose-escalation studies SO NEUROSURGERY LA English DT Article DE boron neutron capture therapy; boronophenylalanine; epithermal neutrons; glioblastoma multiforme; malignant glioma ID RECURSIVE PARTITIONING ANALYSIS; MALIGNANT BRAIN-TUMORS; ONCOLOGY GROUP RTOG; RADIATION-THERAPY; P-BORONOPHENYLALANINE; PROGNOSTIC FACTORS; SURVIVAL; GLIOMA; BEAM; BIODISTRIBUTION AB OBJECTIVE: The primary objective of these Phase I/II dose-escalation studies is to evaluate the safety of borono-phenylalanine (BPA) -fructose-mediated boron neutron capture therapy (BNCT) for patients with glioblastoma multiforme (GBM). A secondary purpose is to assess the palliation of GEM by BNCT, if possible. METHODS: Thirty-eight patients with GBM have been treated. Subtotal or gross total resection of GBM was performed for 38 patients (median age, 56 yr) before BNCT. BPA-fructose (250 or 290 mg BPA/kg body weight) was infused intravenously, in 2 hours, approximately 3 to 5 weeks after surgery. Neutron irradiation was begun between 34 and 82 minutes after the end of the BPA infusion and lasted 38 to 65 minutes. RESULTS: Toxicity related to BPA-fructose was not observed. The maximal radiation dose to normal brain varied from 8.9 to 14.8 Gy-Eq. The volume-weighted average radiation dose to normal brain tissues ranged from 1.9 to 6.0 Gy-Eq. No BNCT-related Grade 3 or 4 toxicity was observed, although milder toxicities were seen. Twenty-five of 37 assessable patients are dead, all as a result of progressive GEM. No radiation-induced damage to normal brain tissue was observed in postmortem examinations of seven brains. The minimal tumor volume doses ranged from 18 to 55 Gy-Eq. The median time to tumor progression and the median survival time from diagnosis (from Kaplan-Meier curves) were 31.6 weeks and 13.0 months, respectively. CONCLUSION: The BNCT procedure used has been safe for all patients treated to date. Our limited clinical evaluation suggests that the palliation offered by a single session of BNCT is comparable to that provided by fractionated photon therapy. Additional studies with further escalation of radiation doses are in progress. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Beth Israel Deaconess Med Ctr, Dept Radiat Oncol, New York, NY 10003 USA. Beth Israel Deaconess Med Ctr, Dept Neurosurg, New York, NY 10003 USA. Montefiore Med Ctr, Dept Radiat Oncol, Bronx, NY 10467 USA. Univ Calif Davis, Dept Neurol Surg, Sacramento, CA 95817 USA. McClellan Nucl Radiat Ctr, Mcclellan AFB, CA USA. SUNY Stony Brook, Dept Pathol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Neurol Surg, Stony Brook, NY 11794 USA. RP Chanana, AD (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 36 TC 138 Z9 139 U1 2 U2 6 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0148-396X J9 NEUROSURGERY JI Neurosurgery PD JUN PY 1999 VL 44 IS 6 BP 1182 EP 1192 DI 10.1097/00006123-199906000-00013 PG 11 WC Clinical Neurology; Surgery SC Neurosciences & Neurology; Surgery GA 201HB UT WOS:000080588400011 ER PT J AU Gao, HR Angelici, RJ AF Gao, HR Angelici, RJ TI Rhodium amine complexes tethered on silica-supported metal catalysts. Highly active catalysts for the hydrogenation of arenes SO NEW JOURNAL OF CHEMISTRY LA English DT Article ID HOMOGENEOUS HYDROGENATION; ASYMMETRIC HYDROGENATION; HETEROGENEOUS CATALYSIS; AROMATIC-HYDROCARBONS; SPILLOVER; ZEOLITES; LIGANDS; DERIVATIVES; CHEMISTRY; OLEFINS AB Rhodium amine complexes, RhCl(CO)(2)[Et2N(CH2)(3)Si(OCH3)(3)] (Rh-NEt2), RhCl(CO)(2)[H2N(CH2)(3)Si(OC2H5)(3)] (Rh-NH2) and RhCl(COD)[H2NCH2CH2NH(CH2)(3)Si(OCH3)(3)] (Rh(COD)(N-N)), were tethered to the silica-supported metal heterogeneous catalysts, M-SiO2 (M = Pd, Ni, Au), to give the TCSM (tethered complex on supported metal) catalysts, Rh-NEt2/M-SiO2 (M = Pd, Ni, Au), Rh-NH2/Pd-SiO2 and Rh(COD)(N-N)/Pd-SiO2. These TCSM catalysts exhibit activities, at 40 degrees C and 1 arm of H-2 pressure, for the hydrogenation of arenes that are higher than those of the separate homogeneous rhodium amine complexes, the separate silica-supported metal heterogeneous catalysts or the rhodium complex catalysts tethered on just SiO2. The activities of the TCSM catalysts are strongly affected by both the tethered rhodium amine complex and the SiO2-supported metal. Among these TCSM catalysts, Rh-NEt2/Pd-SiO2 exhibits the highest activity for the hydrogenation of toluene; its maximum TOF is 7.2 mol H-2, (mol Rh min)(-1) while its TO is 1919 mol H-2 (mol Rh)(-1) during a 5 h period. IR(DRIFT) spectral studies of the TCSM catalysts before and after being used for the hydrogenation of toluene show that during the hydrogenation, the two CO ligands of Rh-NEt2/M-SiO2 (M = Pd, Ni, Au) are lost from the rhodium center. After standing in air for one month, Rh-NEt2/Pd-SiO2 becomes more active for the hydrogenation of toluene, but the activity of the air-aged Rh(COD)(N-N)/Pd-SiO2 is lower than that of the fresh catalyst. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 54 TC 28 Z9 28 U1 1 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1144-0546 EI 1369-9261 J9 NEW J CHEM JI New J. Chem. PD JUN PY 1999 VL 23 IS 6 BP 633 EP 640 DI 10.1039/a900250b PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 205AW UT WOS:000080800000013 ER PT J AU McLaughlin, SB Wimmer, R AF McLaughlin, SB Wimmer, R TI Tansley Review No. 104 - Calcium physiology and terrestrial ecosystem processes SO NEW PHYTOLOGIST LA English DT Review DE calcium; forests; ecosystem; physiology; structure; function ID ABIES L KARST; RED SPRUCE SEEDLINGS; CATION-EXCHANGE CAPACITY; SOIL SOLUTION CHEMISTRY; PRIMARY SUCCESSIONAL SEQUENCE; GERMAN FOREST ECOSYSTEMS; TANANA RIVER FLOODPLAIN; WET TROPICAL MOUNTAINS; EASTERN-UNITED-STATES; BEECH FAGUS-SYLVATICA AB Calcium occupies a unique position among plant nutrients both chemically and functionally. Its chemical properties allow it to exist in a wide range of binding states and to serve in both structural and messenger roles. Despite its importance in many plant processes, Ca mobility is low, making Ca uptake and distribution rate a limiting process for many key plant functions. Ca plays an essential role in regulating many physiological processes that influence both growth and responses to environmental stresses. Included among these are: water and solute movement, influenced through effects on membrane structure and stomatal function; cell division and cell wall synthesis; direct or signaling roles in systems involved in plant defense and repair of damage from biotic and abiotic stress; rates of respiratory metabolism and translocation; and structural chemistry and function of woody support tissues. Forest trees, because of their size and age capacity, have been examined for evidence of limitations imposed by the timing and level of Ca supply. Examination of Ca physiology and biogeochemical cycling for forested systems reveals many indications that Ca supply places important limitations on forest structure and function. These limitations are likely to be most significant with older trees, later successional stages, high levels of soil acidity and/or high canopy Ca leaching losses, or under conditions vc here plant competition is high or transpiration is limited by high humidity or low soil moisture. Evidence of structural and physiological adaptations of forests to limited Ca supply; indicators of system dysfunction at many levels under reduced Ca supply; and the positive responses of diverse indicators of forest vitality in liming experiments indicate that Ca is more important to forest function and structure than has generally been recognized. Lack of recognition of Ca limitations is due in part to that fact some important plant functions are controlled by changes in very small physiologically active pools within the cytoplasm, and whole-leaf Ca levels may not reflect these limitations. An additional aspect is the fact that Ca availability has declined significantly for man!, forests in just the past few decades. Additional research on the role of Ca supply in resistance of forests to disease, changes in structural integrity of woody tissues, restrictions on rooting patterns and function, and uptake of other nutrients, notably N, is needed. Increased understanding of the physiological ecology of Ca supply can be anticipated to provide important insights that will aid in future protection and management of both natural and commercial forest systems. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Austrian Agr Univ, Vienna, Austria. RP McLaughlin, SB (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 296 TC 230 Z9 249 U1 12 U2 82 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD JUN PY 1999 VL 142 IS 3 BP 373 EP 417 DI 10.1046/j.1469-8137.1999.00420.x PG 45 WC Plant Sciences SC Plant Sciences GA 221TD UT WOS:000081741600001 ER PT J AU Sovinec, CR Prager, SC AF Sovinec, CR Prager, SC TI Magnetohydrodynamic effects of current profile control in reversed field pinches SO NUCLEAR FUSION LA English DT Article ID POLOIDAL CURRENT DRIVE; IMPROVED CONFINEMENT; ENERGY CONFINEMENT; MAGNETIC SHEAR; HEAT-TRANSPORT; TORE-SUPRA; FLUCTUATION; TOKAMAK; DYNAMO; CONFIGURATIONS AB Linear and non-linear MHD computations are used to investigate reversed field pinch configurations with magnetic fluctuations reduced through current profile control. Simulations with reduced ohmic drive and moderate auxiliary current drive, represented generically with an electron force term, applied locally in radius near the plasma edge show magnetic fluctuation energies that are orders of magnitude smaller than those in simulations without profile control. The core of the improved configurations has reduced magnetic shear and closed flux surfaces in some cases, and reversal is sustained through the auxiliary current drive. Modes resonant near the edge may become unstable with auxiliary drive, but their saturation levels can be controlled. The space of auxiliary drive parameters is explored, and the ill effects of deviating far from optimal conditions is demonstrated in non-linear simulations. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Madison, WI USA. RP Sovinec, CR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 40 TC 31 Z9 31 U1 0 U2 9 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 1999 VL 39 IS 6 BP 777 EP 790 DI 10.1088/0029-5515/39/6/306 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 216QY UT WOS:000081454400006 ER PT J AU Van Scyoc, JM Brunett, BA Yoon, H Gilbert, TS Hilton, NR Lund, JC James, RB AF Van Scyoc, JM Brunett, BA Yoon, H Gilbert, TS Hilton, NR Lund, JC James, RB TI Spatial mapping of cadmium zinc telluride materials properties and electrical response to improve device yield and performance SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE cadmium zinc telluride; CZT; uniformity; electrical characterization AB Cadmium zinc telluride has experienced tremendous growth in its application to various radiation sensing problems over the last five years. However, there are still issues with yield, particularly of the large volume devices needed for imaging and sensitivity-critical applications. Inhomogeneities of various types and on various length scales currently prevent the fabrication of large devices of high spectral performance. This paper discusses the development of a set of characterization tools for quantifying these inhomogeneities, in order to develop improvement strategies to achieve the desired cadmium zinc telluride crystals for detector fabrication. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. RP Van Scyoc, JM (reprint author), Sandia Natl Labs, POB 969,MS 9671, Livermore, CA 94550 USA. NR 7 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 1 EP 7 DI 10.1016/S0168-9002(98)01573-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500002 ER PT J AU James, RB Siffert, P Eisen, Y Schlesinger, TE Cuzin, M Franks, LA Trombka, J Campiotti, M Schieber, M AF James, RB Siffert, P Eisen, Y Schlesinger, TE Cuzin, M Franks, LA Trombka, J Campiotti, M Schieber, M TI Proceedings of the Conference on Room Temperature Semiconductor Detectors for Remote, Portable and In-situ Radiation Measurement Systems, Jerusalem, Israel, July 26-29, 1998 - Preface SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Editorial Material C1 Sandia Natl Labs, Livermore, CA 94550 USA. CNRS, Lab PHASE, F-75700 Paris, France. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. CEA, LETI, Grenoble, France. NASA Goddard, Greenbelt, MD USA. Hebrew Univ Jerusalem, IL-91905 Jerusalem, Israel. RP James, RB (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP VII EP VIII PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500001 ER PT J AU Burger, A Chen, H Chattopadhyay, K Shi, D Morgan, SH Collins, WE James, RB AF Burger, A Chen, H Chattopadhyay, K Shi, D Morgan, SH Collins, WE James, RB TI Characterization of metal contacts on and surfaces of cadmium zinc telluride SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE cadmium zinc telluride; electrical contacts; surface passivation; photoconductivity; surface recombination ID NUCLEAR RADIATION DETECTORS; CDZNTE STRIP DETECTORS; CDTE SURFACES; PERFORMANCE; ETCHANTS AB In the past several years significant progress has been made in building a database of physical properties for detector quality CdxZn1-xTe (CZT) (x = 0.1-0.2) crystal material. CZT's high efficiency combined with its room temperature operation make the material an excellent choice for imaging and spectroscopy in the 10-200 keV energy range. For detector grade material, superior crystallinity and high bulk resistivity are required. The surface preparation during the detector fabrication plays a vital role in determining the contact characteristics and the surface leakage current, which are often the dominant factors influencing its performance. This paper presents a surface and contact characterization study aimed at establishing the effects of the surface preparation steps prior to contacting (polishing and chemical etching), the choice of the metal and contact deposition technique; and the surface oxidation process. A photoconductivity mapping technique is used for studying the effects of different surface treatments on the surface recombination. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. Sandia Natl Labs, Adv Mat Proc Dept, Livermore, CA 94551 USA. RP Burger, A (reprint author), Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. NR 28 TC 32 Z9 34 U1 2 U2 14 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 1999 VL 428 IS 1 BP 8 EP 13 DI 10.1016/S0168-9002(98)01574-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500003 ER PT J AU Toney, JE Schlesinger, TE James, RB AF Toney, JE Schlesinger, TE James, RB TI Optimal bandgap variants of Cd1-xZnxTe for high-resolution X-ray and gamma-ray spectroscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE optimal band gap; X-rays; gamma rays; simulation; band gap ID RADIATION DETECTORS; V COMPOUNDS; SPECTROMETERS; CRYSTALS; CD0.8ZN0.2TE; MOBILITY AB We show that the trade-off between noise and charge generation statistics in Cd1-xZnxTe leads to an optimal band gap of approximately 2.0 eV at room temperature. This implies a ZnTe fraction of approximately 0.7-0.8. We show that for X-rays and relatively low energy gamma-rays Cd0.2Zn0.8Te theoretically offers a significant potential improvement in energy resolution over Cd0.9Zn0.1Te even if compensation of shallow levels is less complete and carrier lifetimes are an order of magnitude lower for the higher x variant. We also show that these calculations are consistent with observed detector performance reported by many workers over a large period of time. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Toney, JE (reprint author), Spire Corp, 1 Patriots Pk, Bedford, MA 01730 USA. NR 24 TC 45 Z9 48 U1 0 U2 3 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 1999 VL 428 IS 1 BP 14 EP 24 DI 10.1016/S0168-9002(98)01575-7 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500004 ER PT J AU Schieber, M Zuck, A Sanguinetti, S Montalti, M Braiman, M Melekhov, L Nissenbaum, J Grilli, E Guzzi, M Turchetta, R Dulinski, W Husson, D Riester, JL AF Schieber, M Zuck, A Sanguinetti, S Montalti, M Braiman, M Melekhov, L Nissenbaum, J Grilli, E Guzzi, M Turchetta, R Dulinski, W Husson, D Riester, JL TI Characterization studies of purified HgI2 precursors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE mercuric iodide growth; optical spectroscopy; purification methods ID MERCURIC IODIDE; DETECTOR PERFORMANCE; GAMMA AB The ability of HgI2 powders, used as precursors in mercuric iodide crystal growth, to produce high-quality detectors may be predicted by non-destructive methods like photoluminescence. In fact, it is possible to correlate the presence and the intensity ratio of specific bands in the photoluminescence spectrum of a HgI2 crystal to its impurity content and stoichiometry. These quantities determine the detector grade that may be achieved using that starting material. Nine different HgI2 precursors, obtained by different purification methods, have been characterized. The lowest impurity content is achieved via poly-ethylene treatment, which gives also a powder of relatively good stoichiometric quality. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Hebrew Univ Jerusalem, Grad Sch Appl Sci, IL-91904 Jerusalem, Israel. Sandia Natl Labs, Livermore, CA 94550 USA. Univ Milan, INFM, I-20126 Milan, Italy. Univ Milan, Dipartimento Sci Mat, I-20126 Milan, Italy. Univ Strasbourg 1, IN2P3, LEPSI, Strasbourg, France. RP Schieber, M (reprint author), Hebrew Univ Jerusalem, Grad Sch Appl Sci, IL-91904 Jerusalem, Israel. RI Sanguinetti, Stefano/D-9488-2011 OI Sanguinetti, Stefano/0000-0002-4025-2080 NR 16 TC 18 Z9 24 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 25 EP 29 DI 10.1016/S0168-9002(98)01576-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500005 ER PT J AU Hermon, H Schieber, M James, RB Antolak, AJ Morse, DH Brunett, B Hackett, C Tarver, E Komar, V Goorsky, MS Yoon, H Kolesnikov, NN Toney, J Schlesinger, TE AF Hermon, H Schieber, M James, RB Antolak, AJ Morse, DH Brunett, B Hackett, C Tarver, E Komar, V Goorsky, MS Yoon, H Kolesnikov, NN Toney, J Schlesinger, TE TI Evaluation of CZT crystals from the former Soviet Union SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE cadmium zinc telluride (CZT); room-temperature radiation detectors; photoluminescence (PL); X-ray diffraction (XRD); particle-induced X-ray emission (PIXE); crystal growth; elemental analysis; vertical high-pressure Bridgman (VHPB); transient charge technique (TCT) ID GAMMA-RAY; X-RAY; DETECTORS; CD0.8ZN0.2TE AB Vertical high-pressure Bridgman (VHPB) Cd1-xZnxTe (0.04 < x < 0.24) detector crystals grown in the Ukraine and Russia have been evaluated and compared to US-grown materials. Various analytical techniques were used to study the materials for trace impurities, precipitates, crystallinity, and electrical transport properties. Relatively, high concentrations of carbon and trace impurities such as Se, Nd and Si have been detected in the crystals. In most cases, the crystals showed lower resistivity than US-grown CZT. However, recent crystals grown in Russia exhibited better detector performance than those grown previously, and a good response to an Am-241 radioactive source was found. Electron lifetimes below 1 mu s were measured in crystals having significant numbers of micro-defects, compared to lifetimes of 5-15 mu s found in spectrometer grade materials produced in the US. Furthermore, the zinc composition along the growth axis showed better homogeneity in comparison with the US material. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Hebrew Univ Jerusalem, IL-91904 Jerusalem, Israel. Natl Acad Sci Ukraine, Inst Single Crystals, UA-310001 Kharkov, Ukraine. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RP Hermon, H (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 14 TC 16 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 30 EP 37 DI 10.1016/S0168-9002(98)01577-0 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500006 ER PT J AU Lee, EY James, RB AF Lee, EY James, RB TI Device simulation and optimization of laterally-contacted-unipolar-nuclear detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE CdZnTe; CZT; semiconductor radiation detector; device simulation AB Unipolar gamma-ray detectors offer the possibility of enhanced energy resolution and detection sensitivity over the conventional planar detectors. However, these detectors are difficult to understand and to fabricate, due to their three-dimensional geometry and multiple electrodes. Computer simulation offers a powerful way to design and to optimize these detectors, by giving the internal electric fields, weighting potentials, and spatially resolved detector responses. Simulation and optimization of an unipolar gamma-ray detector called laterally-contacted-unipolar-nuclear detector (LUND) are shown. For 662 keV gamma-rays from a Cs-137 source, the simulation and optimization of LUND resulted in improvement in the energy resolution from 1.6% to 1.3% and improvement in the active detector volume from 4% to 38% of the total detector volume. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Adv Mat Dept, Livermore, CA 94551 USA. RP Lee, EY (reprint author), Sandia Natl Labs, Adv Mat Dept, Livermore, CA 94551 USA. NR 7 TC 6 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 66 EP 71 DI 10.1016/S0168-9002(98)01581-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500010 ER PT J AU Prettyman, TH AF Prettyman, TH TI Theoretical framework for mapping pulse shapes in semiconductor radiation detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE semiconductor; CdZnTe; detector; modeling; Monte Carlo; Green's function ID CDZNTE DETECTORS; CHARGE-TRANSPORT; GENERATION; CDTE AB An efficient method for calculating of charge pulses produced by semiconductor detectors is presented. The method is based on a quasi-steady-state model for semiconductor detector operation. A complete description of the model and underlying assumptions is given. Mapping of charge pulses is accomplished by solving an adjoint carrier continuity equation. The solution of the adjoint equation yields Green's function, a time- and position-dependent map that contains all possible charge pulses that can be produced by the detector for charge generated at discrete locations (e.g., by gamma-ray interactions). Because the map is generated by solving a single, time-dependent problem, the potential for reduction in computational effort over direct mapping methods is significant, particularly for detectors with complex electrode structures. In this paper, the adjoint equation is presented and the mapping method is validated for a benchmark problem. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Safeguards Sci & Technol Grp, Los Alamos, NM 87545 USA. RP Prettyman, TH (reprint author), Univ Calif Los Alamos Natl Lab, Safeguards Sci & Technol Grp, NIS-5,Mail Stop E540, Los Alamos, NM 87545 USA. OI Prettyman, Thomas/0000-0003-0072-2831 NR 14 TC 29 Z9 29 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 72 EP 80 DI 10.1016/S0168-9002(98)01582-4 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500011 ER PT J AU Turchetta, R Dulinski, W Husson, D Riester, JL Schieber, M Zuck, A Melekhov, L Saado, Y Hermon, H Nissenbaum, J AF Turchetta, R Dulinski, W Husson, D Riester, JL Schieber, M Zuck, A Melekhov, L Saado, Y Hermon, H Nissenbaum, J TI Imaging with polycrystalline mercuric iodide detectors using VLSI readout SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE room temperature detector; imaging; single-photon counting; polycrystalline HgI2 ID PARTICLE COUNTERS AB Potentially low cost and large area polycrystalline mercuric iodide room-temperature radiation detectors, with thickness of 100-600 mu m have been successfully tested with dedicated low-noise, low-power mixed signal VLSI electronics which can be used for compact, imaging solutions. The detectors are fabricated by depositing HgI2 directly on an insulating substrate having electrodes in the form of microstrips and pixels with an upper continuous electrode. The deposition is made either by direct evaporation or by screen printing HgI2 mixed with glue such as Poly-Vinyl-Butiral. The properties of these first-generation detectors are quite uniform from one detector to another. Also for each single detector the response is quite uniform and no charge loss in the inter-electrode space have been detected. Because of the low cost and of the polycrystallinity, detectors can be potentially fabricated in any size and shape, using standard ceramic technology equipment, which is an attractive feature where low cost and large area applications are needed. The detectors which act as radiation counters have been tested with a beta source as well as in a high-energy beam of 100 GeV muons at CERN,connected to VLSI, low noise electronics. Charge collection efficiency and uniformity have been studied. The charge is efficiently collected even in the space between strips indicating that fill factors of 100% could be reached in imaging applications with direct detection of radiation. Single photon counting capability is reached with VLSI electronics. These results show the potential of this material for applications demanding position sensitive, radiation resistant, room-temperature operating radiation detectors, where position resolution is essential, as it can be found in some applications in high-energy physics, nuclear medicine and astrophysics. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Strasbourg, CNRS, IN2P3, LEPSI, F-67037 Strasbourg 02, France. Hebrew Univ Jerusalem, Sch Appl Sci, IL-91904 Jerusalem, Israel. Sandia Natl Labs, Livermore, CA 94550 USA. RP Turchetta, R (reprint author), Univ Strasbourg, CNRS, IN2P3, LEPSI, 23 Ave Loess,BP 20, F-67037 Strasbourg 02, France. NR 12 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 1999 VL 428 IS 1 BP 88 EP 94 DI 10.1016/S0168-9002(98)01584-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500013 ER PT J AU Franks, LA Brunett, BA Olsen, RW Walsh, DS Vizkelethy, G Trombka, JI Doyle, BL James, RB AF Franks, LA Brunett, BA Olsen, RW Walsh, DS Vizkelethy, G Trombka, JI Doyle, BL James, RB TI Radiation damage measurements in room-temperature semiconductor radiation detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Room Temperature Semiconductor Detectors for Remote, Portable and In-Situ Radiation Measurement Systems CY JUL 26-29, 1998 CL JERUSALEM, ISRAEL DE cadmium zinc telluride; cadmium telluride; mercuric iodide; radiation damage; neutron damage; charged particle damage; gamma-ray spectrometers ID X-RAY-DETECTORS; RESISTANCE; CDZNTE AB The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10(10) p/cm(2) and significant bulk leakage after 10(12) p/cm(2). CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 x 10(9) p/cm(2) in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from a moderated fission spectrum of neutrons after fluences up to 1010 n/cm(2), although activation was evident. Exposures of CZT to 5 MeV alpha particles at fluences up to 1.5 x 10(10) alpha/cm(2) produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 x 10(9) alpha/cm(2), CT detectors show resolution losses after fluences of 3 x 10(9) p/cm(2) at 33 MeV for chlorine-doped detectors. Indium-doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 x 10(10) n/cm(2). Mercuric iodide has been studied with intermediate energy protons (10-33 MeV) at fluences up to 10(12) p/cm(2) and with 1.5 GeV protons at fluences up to 1.2 x 10(8) p/cm(2). Neutron exposures at 8 MeV have been reported at fluences up to 10(15) n/cm(2). No radiation damage was reported under these irradiation conditions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Carnegie Mellon Univ, ECE Dept, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Idaho State Univ, Pocatello, ID 83209 USA. RP Franks, LA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 11 TC 31 Z9 31 U1 1 U2 11 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 1999 VL 428 IS 1 BP 95 EP 101 DI 10.1016/S0168-9002(98)01585-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 204MF UT WOS:000080767500014 ER PT J AU Ovchinnikov, SY Macek, JH AF Ovchinnikov, SY Macek, JH TI Rapid oscillation of electron distributions in low-energy ion-atom collisions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Workshop on Fast Ion-Atom Collisions CY SEP 09-11, 1998 CL DEBRECEN, HUNGARY SP BIOGAL Pharmaceut Factory, Chamber of Commerce & Ind Hajdu-Bihar County, City Council Debrecen, County Council Hadju-Bihar, Hungarian Acad Sci, Budapest, Hungarian Sci Res Fdn, Budapest, Natl Comm Tech Dev, Budapest, Paks Nuclear Power Plant Co, Pfeiffer Vacuum Austria, univ Fdn, Debrecen ID IONIZATION AB The Sturmian theory with only a few Sturmian functions gives a complete ab initio description of electron distributions in ion atom collisions. The interference of the contribution from sigma and pi Sturmian functions gives rise to rapid oscillation of electron angular distributions with impact velocity v. These rapid oscillations measure the real part of the adiabatic eigenvalues in the harmonic oscillator region, which occurs only at complex R. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Ovchinnikov, SY (reprint author), AF Ioffe Phys Tech Inst, Politekhnicheskaya 26, St Petersburg 194021, Russia. RI Ovchinnikov, Serguei/C-4994-2014 NR 9 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 154 IS 1-4 BP 41 EP 45 DI 10.1016/S0168-583X(99)00027-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 215TQ UT WOS:000081399600007 ER PT J AU Abdallah, MA Landers, A Singh, M Wolff, W Wolf, HE Kamber, EY Stockli, M Cocke, CL AF Abdallah, MA Landers, A Singh, M Wolff, W Wolf, HE Kamber, EY Stockli, M Cocke, CL TI Capture and ionization processes studied with COLTRIMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Workshop on Fast Ion-Atom Collisions CY SEP 09-11, 1998 CL DEBRECEN, HUNGARY SP BIOGAL Pharmaceut Factory, Chamber of Commerce & Ind Hajdu-Bihar County, City Council Debrecen, County Council Hadju-Bihar, Hungarian Acad Sci, Budapest, Hungarian Sci Res Fdn, Budapest, Natl Comm Tech Dev, Budapest, Paks Nuclear Power Plant Co, Pfeiffer Vacuum Austria, univ Fdn, Debrecen DE electron ionization; COLTRIMS; electron capture; rotational coupling ID ION-MOMENTUM SPECTROSCOPY; HIGHLY-CHARGED IONS; SELECTIVE ELECTRON-CAPTURE; ATOM COLLISIONS; RECOIL; HE; SINGLE; SLOW; DISTRIBUTIONS; PROJECTILE AB A review of some basic features of the COLTRIMS technique is presented. Examples of recent work on low-energy electron capture and ionization collisions and for high-velocity ionization from Kansas State University are given. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RP Cocke, CL (reprint author), Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA. RI Landers, Allen/C-1213-2013; Wolff, Wania/O-5556-2015 NR 37 TC 5 Z9 5 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 154 IS 1-4 BP 73 EP 82 DI 10.1016/S0168-583X(99)00185-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 215TQ UT WOS:000081399600011 ER PT J AU Briand, JP Le Roux, V Bechu, N Dreuil, S Machicoane, G Prior, M Xie, Z AF Briand, JP Le Roux, V Bechu, N Dreuil, S Machicoane, G Prior, M Xie, Z TI The hollow atoms SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Workshop on Fast Ion-Atom Collisions CY SEP 09-11, 1998 CL DEBRECEN, HUNGARY SP BIOGAL Pharmaceut Factory, Chamber of Commerce & Ind Hajdu-Bihar County, City Council Debrecen, County Council Hadju-Bihar, Hungarian Acad Sci, Budapest, Hungarian Sci Res Fdn, Budapest, Natl Comm Tech Dev, Budapest, Paks Nuclear Power Plant Co, Pfeiffer Vacuum Austria, univ Fdn, Debrecen DE hollow atoms; ions-surfaces ID HIGHLY CHARGED IONS; ELECTRON-EMISSION; SURFACE; SLOW; NEUTRALIZATION; ACCELERATION; CASCADE; TARGET; DECAY AB This talk briefly reviews the atomic properties of the hollow atoms and presents recent results on the interaction of highly charged ions with surfaces. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Paris 06, Equipe Rech Ions Surfaces, F-75252 Paris 05, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Briand, JP (reprint author), Univ Paris 06, Equipe Rech Ions Surfaces, F-75252 Paris 05, France. NR 27 TC 9 Z9 10 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 154 IS 1-4 BP 166 EP 173 DI 10.1016/S0168-583X(99)00192-5 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 215TQ UT WOS:000081399600021 ER PT J AU Ludziejewski, T Stohlker, T Beyer, H Bosch, F Fritzsche, S Ionescu, DC Kozhuharov, C Kramer, A Liesen, D Mokler, P Rymuza, P Stachura, Z Swiat, P Warczak, A AF Ludziejewski, T Stohlker, T Beyer, H Bosch, F Fritzsche, S Ionescu, DC Kozhuharov, C Kramer, A Liesen, D Mokler, P Rymuza, P Stachura, Z Swiat, P Warczak, A TI Excitation of high-Z one- and two-electron ions in relativistic collisions with gaseous targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Workshop on Fast Ion-Atom Collisions CY SEP 09-11, 1998 CL DEBRECEN, HUNGARY SP BIOGAL Pharmaceut Factory, Chamber of Commerce & Ind Hajdu-Bihar County, City Council Debrecen, County Council Hadju-Bihar, Hungarian Acad Sci, Budapest, Hungarian Sci Res Fdn, Budapest, Natl Comm Tech Dev, Budapest, Paks Nuclear Power Plant Co, Pfeiffer Vacuum Austria, univ Fdn, Debrecen DE relativistic ion-atom collisions; electron excitation ID URANIUM IONS AB Progress in the studies of ground state excitation of heavy hydrogen-like and helium-like ions in relativistic collisions with atoms is reported. Tn particular the recent results obtained in experiments carried out at the internal gas-jet target of the ESR Storage Ring at GSI-Darmstadt are presented. Special emphasis is given to the sensitivity of the measured state selective cross sections to the magnetic effects occurring in relativistic heavy-ion-atom collisions, (C) 1999 Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Frankfurt, D-60486 Frankfurt, Germany. Univ Kassel, D-34132 Kassel, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Soltan Inst Nucl Studies, PL-05400 Otwock, Poland. Inst Nucl Phys, PL-31342 Krakow, Poland. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Ludziejewski, T (reprint author), Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. NR 5 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 154 IS 1-4 BP 204 EP 208 DI 10.1016/S0168-583X(99)00187-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 215TQ UT WOS:000081399600025 ER PT J AU Almazouzi, A Caturla, MJ Alurralde, M de la Rubia, TD Victoria, M AF Almazouzi, A Caturla, MJ Alurralde, M de la Rubia, TD Victoria, M TI Defect production and damage evolution in Al: a molecular dynamics and Monte Carlo computer simulation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 4th International Conference on Computer Simulation of Radiation Effects in Solids (COSIRES 98) CY SEP 15-19, 1998 CL OKAYAMA, JAPAN SP Japan Soc Appl Phys, Phys Soc Japan, Japan Inst Met, Iron & Steel Inst Japan, Kajima Fdn, Okayama Fdn Sci & Technol, Res Fdn Mat Sci, Asahi Glass Fdn, Inque Fdn Sci, Federat Electr Power Co, Japan Elect Mfg Assoc, Japan Soc Plasma Sci & Nuclear Fus Res, Electr Technol Res Fdn Chugoku, Commemorative Assoc Japan World Exposit (1970), Okayama Univ Sci, Atom Energy Soc Japan, Japan MRS Soc, Japan Atom Ind Forum, Mitsubishi Chem Corp, Kinokuniya Corp Ltd, Kawahara Shoten, Japan Iron & Steel Federat, Elsevier Sci BV ID EMBEDDED-ATOM-METHOD; DISPLACEMENT CASCADES; BCC METALS; IRRADIATION; ALLOYS AB Predicting microstructure evolution of metals under irradiation requires an in depth understanding of the production and properties of point defects and their clusters. Although, analytical descriptions based on the production bias model have recently been applied successfully to explain the behaviour of metals under different irradiation conditions, they still lack an important ingredient, namely that of the diffusion mechanism of the defects produced. In the present investigation, a hierarchical computer simulation model which takes into account spatial and temporal correlation in the production and diffusion of the defects is used to investigate the production of freely migrating defects in irradiated aluminium. The approach uses classical molecular dynamics with the embedded atom method potential to investigate the primary damage state from displacement cascades and a kinetic Monte Carlo simulation to follow defect kinetics over macroscopic time scales. In the present paper, Re have used this approach to investigate the primary damage state and the fraction of freely migrating defects in pure Al as a function of irradiation particle energy and crystal temperature. The results ale compared to other FCC metals and to the experiments when available. (C) 1999 Elsevier Science B.V, All rights reserved. C1 Ecole Polytech Fed Lausanne, Ctr Rech Phys Plasmas, EURATOM Assoc, CH-5232 Villigen, Switzerland. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Comis Nacl Energia Atom, Ctr Atom Constituyentes, Dept Mat, RA-1429 Buenos Aires, DF, Argentina. RP Almazouzi, A (reprint author), Ecole Polytech Fed Lausanne, Ctr Rech Phys Plasmas, EURATOM Assoc, CH-5232 Villigen, Switzerland. RI Caturla, Maria /D-6241-2012 OI Caturla, Maria /0000-0002-4809-6553 NR 30 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 153 IS 1-4 BP 105 EP 115 DI 10.1016/S0168-583X(98)00989-6 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 207LY UT WOS:000080939400018 ER PT J AU Beardmore, KM Gronbech-Jensen, N AF Beardmore, KM Gronbech-Jensen, N TI An efficient molecular dynamics scheme for predicting dopant implant profiles in semiconductors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 4th International Conference on Computer Simulation of Radiation Effects in Solids (COSIRES 98) CY SEP 15-19, 1998 CL OKAYAMA, JAPAN SP Japan Soc Appl Phys, Phys Soc Japan, Japan Inst Met, Iron & Steel Inst Japan, Kajima Fdn, Okayama Fdn Sci & Technol, Res Fdn Mat Sci, Asahi Glass Fdn, Inque Fdn Sci, Federat Electr Power Co, Japan Elect Mfg Assoc, Japan Soc Plasma Sci & Nuclear Fus Res, Electr Technol Res Fdn Chugoku, Commemorative Assoc Japan World Exposit (1970), Okayama Univ Sci, Atom Energy Soc Japan, Japan MRS Soc, Japan Atom Ind Forum, Mitsubishi Chem Corp, Kinokuniya Corp Ltd, Kawahara Shoten, Japan Iron & Steel Federat, Elsevier Sci BV DE molecular dynamics; ion implant; binary collision; SIMS; semiconductors ID STOPPING-POWER MODEL; ION-IMPLANTATION; SILICON; SIMULATION AB We present a highly efficient molecular dynamics scheme for calculating the concentration profile of dopants implanted in group-IV alloy, and III-V zinc blende structure materials. Our program incorporates methods for reducing computational overhead, plus a rare event algorithm to give statistical accuracy over several orders of magnitude change in the dopant concentration. The code uses a molecular dynamics (MD) model, instead of the binary collision approximation (BCA) used in implant simulators such as TRIM and Marlowe, to describe ion-target interactions. Atomic interactions are described by a combination of 'many-body' and screened Coulomb potentials. Inelastic energy loss is accounted for using a Firsov model, and electronic stopping is described by a Brandt-Kitagawa model which contains the single adjustable parameter for the entire scheme. Thus, the program is easily extensible to new ion-target combinations with the minimum of tuning, and is predictive over a wide range of implant energies and angles. The scheme is especially suited for calculating profiles due to low energy, large angle implants, and for situations where a predictive capability is required with the minimum of experimental validation. We give examples of using our code to calculate concentration profiles and 2D 'point response' profiles of dopants in crystalline silicon, silicon-germanium blends, and gallium-arsenide. We can predict the experimental profile over five orders of magnitude for [100] and [110] channeling and for non-channeling implants at energies up to hundreds of keV. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Computat Mat Grp MS B285, Motorola Computat Technol Lab, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Beardmore, KM (reprint author), Univ Calif Los Alamos Natl Lab, Computat Mat Grp MS B285, Motorola Computat Technol Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 1999 VL 153 IS 1-4 BP 391 EP 397 DI 10.1016/S0168-583X(99)00203-7 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 207LY UT WOS:000080939400065 ER PT J AU Favorite, JA Stacey, WM AF Favorite, JA Stacey, WM TI A variational synthesis nodal discrete ordinates method SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID DIFFUSION AB A self-consistent nodal approximation method for computing discrete ordinates neutron flux distributions has been developed from a variational functional for neutron transport theory. The advantage of the new nodal method formulation is that it is self-consistent in its definition of the homogenized nodal parameters, the construction of the global nodal equations, and the reconstruction of the detailed flux distribution. The efficacy of the method is demonstrated by two-dimensional test problems. C1 Georgia Inst Technol, Nucl & Radiol Engn Program, Atlanta, GA 30332 USA. RP Favorite, JA (reprint author), Univ Calif Los Alamos Natl Lab, X Div, Code Integrat Grp, MS F663, Los Alamos, NM 87545 USA. NR 21 TC 1 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 1999 VL 132 IS 2 BP 181 EP 193 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 199XD UT WOS:000080508600002 ER PT J AU Cramer, SN AF Cramer, SN TI Derivations of the solid angle subtended at a point by first- and second-order surfaces and volumes as a function of elliptic integrals SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID CARLO AB An analytic study of the solid angle subtended at a point by objects of first and second algebraic order has been made. It is shown that the derived solid angle for all such objects is in the form of a general elliptic integral, which can be written as a linear combination of elliptic integrals of the first and third kind and elementary functions. Many common surfaces and volumes have been investigated, including the conic sections and their volumes of revolution. The principal feature of the study is the manipulation of solid-angle equations into integral forms that can be matched with those found in handbook tables. These integrals are amenable to computer special function library routine analysis requiring no direct interaction with elliptic integrals by the user The general case requires the solution of a fourth-order equation before specific solid-angle formulations can be made, but for many common geometric objects this equation can be solved by elementary means. Methods for the testing and application of solid-angle equations with Monte Carlo rejection and estimation techniques are presented. Approximate and degenerate forms of the equations are shown, and methods for the evaluation of the solid angle of a torus are outlined. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Cramer, SN (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 1999 VL 132 IS 2 BP 217 EP 258 PG 42 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 199XD UT WOS:000080508600005 ER PT J AU Ahluwalia, R Hua, TQ Geyer, HK AF Ahluwalia, R Hua, TQ Geyer, HK TI Behavior of uranium and zirconium in direct transport tests with irradiated EBR-II fuel SO NUCLEAR TECHNOLOGY LA English DT Article DE electrochemical; spent nuclear fuels; EBR-II AB A theoretical model is used to analyze the transport of U and Zr in electrorefining of irradiated binary Experimental Breeder Reactor-II fuel, A limiting-current hypothesis is advanced to explain the observed dissolution of Zr in the presence of U at high, intermediate, and low cell voltages. The internal diffusion model predicts the existence of a critical current and a critical voltage for Zr oxidation. Experimental results are presented for a test designed and run based on optimum conditions determined from the model to dissolve U expediently while retaining Zr in the anode baskets. A simple model of kinetic exchange reactions between salt-phase U and Cd-phase Zr is formulated to explain the measured electrodeposition of Zr on the solid cathode. It is shown that the Zr content of the deposit is overpredicted if the pool is considered isolated and grossly underpredicted if the salt phase is equilibrated instantaneously with the Cd pool. Finally, the aspects of anodic current efficiency and cathodic collection efficiency are discussed taking into account shorting between the dissolution baskets and the Cd pool, multiple oxidation stares of Zr, and the exchange reactions between the fuel and UCl3 prior to electrotransport. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RP Ahluwalia, R (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 19 Z9 19 U1 0 U2 5 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUN PY 1999 VL 126 IS 3 BP 289 EP 302 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 196TA UT WOS:000080322600004 ER PT J AU Howell, LH Pember, RB Colella, P Jessee, JP Fiveland, WA AF Howell, LH Pember, RB Colella, P Jessee, JP Fiveland, WA TI A conservative adaptive-mesh algorithm for unsteady, combined-mode heat transfer using the discrete ordinates method SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID RADIATIVE TRANSPORT-EQUATION; NAVIER-STOKES EQUATIONS; LAMINAR FLAMES; REFINEMENT; PROJECTION; LAWS AB Adaptive mesh refinement (AMR) permits a computational algorithm to allocate additional grid resolution when and where it is most needed. A block-structured AMR scheme provides this capability without sacrificing the numerical and computational efficiencies associated with regular meshes. In this article we describe an AMR implementation of the discrete ordinates method for radiative transfer, coupled with an existing projection method for low-Mach-number flows. The complete algorithm constitutes a conservative scheme for unsteady combined-mode heat transfer. Results for two- and three-dimensional examples are shown. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. Lawrence Berkeley Lab, Appl Numer Algorithms Grp, Berkeley, CA 94720 USA. McDermott Technol Inc, Div Res & Dev, Alliance, OH 44601 USA. RP Howell, LH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808, Livermore, CA 94550 USA. NR 26 TC 23 Z9 23 U1 0 U2 4 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 USA SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD JUN PY 1999 VL 35 IS 4 BP 407 EP 430 PG 24 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 208AW UT WOS:000080968900002 ER PT J AU Knoll, DA Kothe, DB Lally, B AF Knoll, DA Kothe, DB Lally, B TI A new nonlinear solution method for phase-change problems SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID KRYLOV METHODS; SOLIDIFICATION; DIFFUSION; SYSTEMS AB We present a new nonlinear algorithm for the efficient and accurate solution of isothermal and nonisothermal phase-change problems. The method correctly evolves latent heat release in isothermal and nonisothermal phase change, and more important, it provides a means for the efficient and accurate coupling between temperature and concentration fields in multispecies nonisothermal phase change. Newton-like superlinear convergence is achieved in the global nonlinear iteration, without the complexity of forming or inverting the Jacobian matrix. This "Jacobian-free" method is a combination of an outer Newton-based iteration and an inner conjugate gradient-like (Krylov) iteration. The effects of the Jacobian are probed only through approximate matrix-vector products required in the conjugate gradient-like iteration. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knoll, DA (reprint author), Univ Calif Los Alamos Natl Lab, M-S D413, Los Alamos, NM 87545 USA. NR 14 TC 24 Z9 24 U1 0 U2 3 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 USA SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD JUN PY 1999 VL 35 IS 4 BP 439 EP 459 PG 21 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 208AW UT WOS:000080968900004 ER PT J AU Miller, SP Bever, JD AF Miller, SP Bever, JD TI Distribution of arbuscular mycorrhizal fungi in stands of the wetland grass Panicum hemitomon along a wide hydrologic gradient SO OECOLOGIA LA English DT Article DE arbuscular mycorrhizal fungi; depressional wetlands; spores; species distribution; gradient ID COMMUNITY STRUCTURE; PLANTS; COLONIZATION; DIVERSITY; DYNAMICS; CAROLINA; PATTERNS AB Although wetland plant species usually aggregate into zones that correspond with their water depth/dryness tolerances, it is not known whether associated arbuscular mycorrhizal (AM) fungi show a similar zonation. We assessed the distribution of AM fungi in two similar depressional wetlands dominated by the semi-aquatic grass Panicum hemitomon by sampling soil in plots along dry-to-wet gradients that spanned 80 cm in relative elevation, and identifying/counting viable AM fungal spores. We found that eight of nine AM fungal species were common to both of the wetlands. Within each wetland, there were significant differences in species composition related to relative water depth. The zonation patterns were not identical between wetlands but revealed that certain species were relegated to the drier portions of the gradient in both. No species were relegated to only the wet portions of the wetlands; those that dominated there were also present in the drier areas. Our data show that water depth is an important factor determining the distribution of the AM fungi, even when, as in our study wetlands, the host plant remains constant along a dry-to-wet gradient. This suggests that the fungi are not physiologically equivalent in their tolerance to wetland conditions. C1 Univ Georgia, Inst Ecol, Athens, GA 30605 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Calif Irvine, Dept Ecol & Evolutionary Biol, Irvine, CA 92696 USA. RP Miller, SP (reprint author), W Virginia Univ, Dept Biol, POB 6057, Morgantown, WV 26506 USA. NR 35 TC 56 Z9 61 U1 1 U2 18 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD JUN PY 1999 VL 119 IS 4 BP 586 EP 592 DI 10.1007/s004420050823 PG 7 WC Ecology SC Environmental Sciences & Ecology GA 210WU UT WOS:000081128300015 PM 28307718 ER PT J AU List, EJW Markart, P Graupner, W Leising, G Partee, J Shinar, J Smith, R Gin, D AF List, EJW Markart, P Graupner, W Leising, G Partee, J Shinar, J Smith, R Gin, D TI Optically detected magnetic resonance studies of nanostructured PPV-composites SO OPTICAL MATERIALS LA English DT Article; Proceedings Paper CT Symposium M on Molecular Photonics for Optical Telecommunications - Materials, Physics and Device Technology of the 1998 E-MRS Spring Conference CY JUN 15-19, 1998 CL STRASBOURG, FRANCE SP European Mat Res Soc DE organic semiconductors; magnetic resonance; nano composites ID CONJUGATED POLYMERS; POLARONS AB We used the spectroscopic technique of photoluminescence detected magnetic resonance (PLDMR) to monitor the dynamics of singlet excitons as well as polarons of isolated poly(p-phenylenevinylene) (PPV) chains incorporated into a self-assembled matrix, ordered at a nanometer scale, and compare it with the results obtained for bulk PPV. The isolation of the PPV chains in the inorganic matrix which is of hexagonal structure is confirmed by a blue shift of the photoluminescence (PL) spectrum and the increase of the PL quantum yield. The effect on the photo physical properties due to the isolation of the polymer chains is further proved by the difference in the PLDMR linewidth and the observation of a strong difference in the exponent in power-law dependence of Delta PL/PL on the laser power. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Graz Tech Univ, Inst Festkorperphys, A-8010 Graz, Austria. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP List, EJW (reprint author), Graz Tech Univ, Inst Festkorperphys, Petersgasse 16, A-8010 Graz, Austria. RI List-Kratochvil, Emil/M-5312-2013; OI GIN, DOUGLAS/0000-0002-6215-668X NR 9 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-3467 J9 OPT MATER JI Opt. Mater. PD JUN PY 1999 VL 12 IS 2-3 BP 369 EP 372 DI 10.1016/S0925-3467(99)00067-1 PG 4 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA 211BP UT WOS:000081140300035 ER PT J AU Downey, TR Meriaudeau, F Passian, A Wig, A Ferrell, TL AF Downey, TR Meriaudeau, F Passian, A Wig, A Ferrell, TL TI Guided propagation in a step-index, multi-mode fiber: effect of index difference variation on allowable TM propagation constants SO OPTICS AND LASER TECHNOLOGY LA English DT Article DE dielectric waveguide; guided mode propagation; fiber optic sensor; refractive index variation AB The effect of variation of core and cladding index difference, Delta n = n(core) - n(cladding), on allowable values for the guided mode transverse magnetic propagation constants within a step-index, multi-mode optical fiber is investigated. We use a iterative computational technique to calculate the propagation constants for modes inside and outside the core that satisfy the boundary conditions contained within the characteristic eigen-equation for the TM field components. Evidence of a strong dependence of the allowable propagation constants on changes of Delta n is shown. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. IUT Le Creusot, Lab Electron Informat & Image, F-71200 Le Creusot, France. Oak Ridge Natl Lab, Div Life Sci, Photometr Grp, Oak Ridge, TN 37830 USA. RP Downey, TR (reprint author), Univ Tennessee, Dept Phys & Astron, 401 AH Nielsen Phys Bldg, Knoxville, TN 37996 USA. EM tdowney@utk.edu NR 18 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0030-3992 J9 OPT LASER TECHNOL JI Opt. Laser Technol. PD JUN PY 1999 VL 31 IS 4 BP 273 EP 277 DI 10.1016/S0030-3992(99)00056-0 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA 254ED UT WOS:000083598200017 ER PT J AU Shaulov, G Gabitov, I Haus, JW AF Shaulov, G Gabitov, I Haus, JW TI Pulse dynamics in absorber dominated optical cavities SO OPTICS COMMUNICATIONS LA English DT Article DE modelocked lasers; optical fibers; nonlinear waves ID EQUATIONS; FRONTS AB We investigate optical field dynamics in lasers cavities dominated by a saturable absorber. We found that for a specific parameter range the solitary wave-type solutions exist and can be expressed in analytic form, including a new gray-pulse solution. Stability of these solitary waves is discussed and numerically examined. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Haus, JW (reprint author), Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUN 1 PY 1999 VL 164 IS 1-3 BP 39 EP 45 DI 10.1016/S0030-4018(99)00158-3 PG 7 WC Optics SC Optics GA 206RD UT WOS:000080892200007 ER PT J AU Bennett, CV Kolner, BH AF Bennett, CV Kolner, BH TI Upconversion time microscope demonstrating 103x magnification of femtosecond waveforms SO OPTICS LETTERS LA English DT Article ID UP-CONVERSION; SPACE; COMPRESSION; DISPERSION; DUALITY; PULSES; LENSES AB We present the operational principles and results of a temporal imaging system, configured as a time microscope, that achieves 103x magnification of waveforms with 300-fs resolution and a 5.7-ps field of view. The quadratic-phase time-lens element is realized by upconversion of the dispersed input waveform with a linearly chirped 5-THz bandwidth pump. The system allows expansion of ultrafast optical waveforms to a time scale that is directly accessible with slower conventional technology, in real time, on a single-shot basis. (C) 1999 Optical Society of America. C1 Univ Calif Los Angeles, Dept Elect Engn, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Bennett, CV (reprint author), Univ Calif Los Angeles, Dept Elect Engn, POB 808,L-174, Livermore, CA 94551 USA. RI Bennett, Corey/C-2403-2009 OI Bennett, Corey/0000-0003-4365-5739 NR 21 TC 103 Z9 106 U1 2 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 1999 VL 24 IS 11 BP 783 EP 785 DI 10.1364/OL.24.000783 PG 3 WC Optics SC Optics GA 201GZ UT WOS:000080588200027 PM 18073854 ER PT J AU Park, Y Butt, DP AF Park, Y Butt, DP TI Composition dependence of the kinetics and mechanisms of thermal oxidation of titanium-tantalum alloys SO OXIDATION OF METALS LA English DT Article DE titanium; tantalum; titanium-tantalum alloys; oxidation mechanism; oxidation kinetics AB The oxidation behavior of titanium-tantalum alloys was investigated with respective concentrations of each element ranging from 0 to 100 wt.%. Alloys were exposed to argon-20% oxygen at 800 to 1400 degrees C. The slowest oxidation rates were observed in alloys with 5-20% Ta, The oxidation kinetics of alloys containing less than approximately 40% Ta were approximately parabolic. Pure Ta exhibited nearly, linear kinetics. Alloys containing 50% or more Ta exhibited paralinear kinetics. The activation energies for oxidation ranged between 232 kJ/mole for pure Ti and 119 kJ/mole for pure Ta, with the activation energies of the alloys falling between these values and generally decreasing with increasing Ta content. The activation energies for oxidative of the end members, Ti and Ta, agree well with published values for the activation energies for diffusion of oxygen in alpha-Ti and Ta. Scale formation in the alloys was found to be complex exhibiting various layers of Ti-, Ta-, and TiTa-oxides. The outermost layer of the oxidized alloys was predominately rutile (TiO2) Beneath the TiO2 grew a variety of other oxides with the Ta content generally increasing with proximity to the metal-oxide interface. It was found that the most osidation-resistant alloys had compositions falling between Ti-5Ta and Ti-15Ta. Although Ta stabilizes the beta-phase of Ti, the kinetics of oxidation appeared to be rate limited bl, oxygen transport through the oxygen-stabilized a-phase. However, the kinetics are complicated by the formation of a complex oxide, which cracks periodically. Tantalum appears to increase the compositional range of oxygen-stabilized alpha-phase and I educes both the solubility of oxygen and diffusivity of Ti in the alpha- and beta-phases. C1 Univ Calif Los Alamos Natl Lab, Mat Corros & Environm Effects Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Park, Y (reprint author), Univ Calif Los Alamos Natl Lab, Mat Corros & Environm Effects Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 17 TC 13 Z9 13 U1 0 U2 11 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD JUN PY 1999 VL 51 IS 5-6 BP 383 EP 402 DI 10.1023/A:1018883009343 PG 20 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 185TQ UT WOS:000079686800003 ER PT J AU Brady, MP Verink, ED Smith, JW AF Brady, MP Verink, ED Smith, JW TI Oxidation behavior of two-phase gamma+sigma Nb-Ti-Al alloys SO OXIDATION OF METALS LA English DT Article DE internal oxidation; niobium aluminides; titanium aluminides; sigma phase; gamma phase ID HIGH-TEMPERATURE; SYSTEM; EQUILIBRIA; NITROGEN; ALUMINA AB The oxidation behavior of a series of single- and two-phase Nb-Ti-Al alloys, selected from the same extended gamma + sigma tie-line, was investigated at 1200 degrees C in air. The single-phase sigma alloy suffered from extensive internal oxidation and oxidized at a much higher rate than the single-phase gamma alloy. In a two-phase gamma + sigma microstructure, the gamma phase was preferentially attacked to form "internal" alumina and Ti-rich nitride. This preferential attack of gamma limited the extent to which the sigma phase was internally oxidized, but also interrupted the formation of a continuous alumina scale. The single-phase gamma alloy also did not form a continuous alumina scale. The inability of the gamma phase to form continuous alumina as attributed to a combination of nitride formation and internal oxidation. The oxidation behavior of the two-phase gamma + sigma Nb-Ti-Al alloys is discussed in terms of mechanisms developed for the oxidation of binary two-phase alloys. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Brady, MP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Brady, Michael/A-8122-2008 OI Brady, Michael/0000-0003-1338-4747 NR 18 TC 11 Z9 11 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD JUN PY 1999 VL 51 IS 5-6 BP 539 EP 556 DI 10.1023/A:1018899412977 PG 18 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 185TQ UT WOS:000079686800011 ER PT J AU Misra, A Chu, F Mitchell, TE AF Misra, A Chu, F Mitchell, TE TI Incommensuration and other structural anomalies in rhenium disilicide SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID RESI2; SILICIDES; CRYSTALS; ALLOYS AB The structure of solidification-processed rhenium disilicide is investigated by X-ray diffraction and transmission electron microscopy. It is usually reported to have the tetragonal C11(b) MoSi2 structure and the stoichiometry of ReSi2. In the present study it is found that rhenium disilicide exhibits an off-stoichiometric Si-deficient composition of Re4Si7. In addition, several structural instabilities are observed by electron microscopy including firstly an orthorhombic distortion of about 0.6% from the tetragonal C11(b) MoSi2 structure with spot splitting across the {110} twin plane, secondly an incommensuration along the a axis with a periodicity of 1.3 nm, thirdly another longer period modulation along the c axis, fourthly a weak monoclinic distortion (beta approximate to 90.4 degrees) in some specimens, as revealed by spot splitting in the high-order Laue zone reflections of [100] diffraction patterns, accompanied by twinning on the (001) planes, and fifthly much larger distortions in some [010] patterns plus a chevron structure in the image which may result from a displacive transformation. These structural anomalies are probably related to the stoichiometry of Re4Si7 which may result in a composite modulated structure where the Si sublattice has a larger average periodicity along the a axis than the Re sublattice, as is the case with manganese silicides. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Misra, A (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Misra, Amit/H-1087-2012 NR 21 TC 14 Z9 14 U1 3 U2 7 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUN PY 1999 VL 79 IS 6 BP 1411 EP 1422 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 203BR UT WOS:000080687900010 ER PT J AU Han, K Yu-Zhang, K AF Han, K Yu-Zhang, K TI Transmission electron microscopy study of epitaxial lanthanum-manganite thin films on SrTiO3 SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID CA-MN-O; MAGNETORESISTANCE; PEROVSKITE; LAMNO3 AB The microstructure of lanthanum manganite (La1-xMnO3-delta) thin film on strontium titanate (SrTiO3) substrate fabricated by liquid chemical vapour deposition has been studied by transmission electron microscopy. Both La1-xMnO3-delta and SrTiO3 have a perovskite structure with lattice misfit about 1% but there is no evidence for correlation of the density of the misfit dislocation and misfit. In the vicinity of the interface between La1-xMnO3-delta and SrTiO3, the misfit is accommodated by a distortion of the lattice of La1-xMnO3-delta. At the areas not adjacent to the interface of La1-xMnO3-delta-SrTiO3, small particles, which can be identified as MnO, are found to be associated with the misfit between La1-xMnO3-delta and SrTiO3. The MnO phase is unstable with respect to La1-xMnO3-delta. The growth of a thin film of La1-xMnO3-delta on SrTiO3 is epitaxial and an orientation relationship is (100)La1-xMnO3-delta//(100)SrTiO3//(100)(MnO) and [010]La1-xMnO3-delta//[010]SrTiO3//[010](MnO). The Interface of La1-xMnO3-delta-SrTiO3 is composed of Ti and Mn atoms plus oxygen. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Univ Marne La Vallee, Dept Phys, LPMDI, F-77454 Marne La Vallee 2, France. RP Han, K (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Mail Stop 765, Los Alamos, NM 87545 USA. NR 28 TC 6 Z9 6 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD JUN PY 1999 VL 79 IS 6 BP 897 EP 909 DI 10.1080/13642819908214848 PG 13 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 203BN UT WOS:000080687600006 ER PT J AU Xie, JJ Chen, SP de Gironcoli, S Baroni, S AF Xie, JJ Chen, SP de Gironcoli, S Baroni, S TI Thermodynamic properties and lattice dynamics of silver at high pressure: a first-principles study SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID THERMAL-EXPANSION; DIAMOND; SEMICONDUCTORS; METALS; PSEUDOPOTENTIALS; TRANSITION; SOLIDS; STATE AB The pressure dependence of the thermodynamic properties of silver is calculated in the quasiharmonic approximation using the ab initio pseudopotential plane-wave method and the density-functional perturbation theory. At a given temperature and pressure, the thermodynamic equilibrium volume of the crystal is obtained from the first-principles P-V-T equation of state which is constructed from the Helmholtz free energy. The calculated thermal quantities such as the equilibrium volume, thermal expansion coefficient, bulk modulus, and heat capacity are in good agreement with available experimental data in a wide range of temperatures and pressures. We also present the phonon dispersion and the phonon density of states under different pressures. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. Ist Nazl Fis Mat, I-34014 Trieste, Italy. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI de Gironcoli, Stefano/G-7236-2011; Baroni, Stefano/F-2982-2011 OI de Gironcoli, Stefano/0000-0002-2307-0998; Baroni, Stefano/0000-0002-3508-6663 NR 39 TC 16 Z9 16 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 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 1999 VL 79 IS 6 BP 911 EP 919 DI 10.1080/13642819908214849 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 203BN UT WOS:000080687600007 ER PT J AU Kumar, M Sriram, S Schwartz, AJ Vasudevan, VK AF Kumar, M Sriram, S Schwartz, AJ Vasudevan, VK TI Weak-beam analysis of dissociated 1/2 [112] superdislocations in gamma-TiAl SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; DEFORMATION CHARACTERISTICS; FAULT ENERGIES; DISLOCATIONS; ANOMALIES; TEMPERATURE; TEM AB Among the problems encountered in the characterization of 1/2[112] super-dislocations in gamma-TiAl intermetallic alloy, one arises from asymmetric or abnormal contrast observed during transmission electron microscopy (TEM) experiments. The diffraction contrast from the core of these superdislocations does not always follow the rules of diffraction contrast established for analyzing partial dislocations bounding stacking faults. In particular,the configuration involving three similar Shockley partials on adjacent planes has often been ruled out owing to the absence of fringes indicating the presence of stacking faults. In order to determine the dissociated configuration, weak-beam TEM observations of edge-oriented 1/2[112] superdislocations have been correlated with computer-simulated images. Dissociation of these superdislocations into similar 1/6[112] Shockley partial dislocations bounding a superlattice extrinsic and intrinsic stacking-fault pair has been consequently determined from these analyses. Comparison of experimental and simulated images confirms that the formation of an antiphase boundary or complex stacking-fault-linked dissociation or locking by stair rod dislocations can be ruled out. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Novellus Syst Inc, San Jose, CA 95134 USA. Univ Cincinnati, Dept Mat Sci & Engn, Cincinnati, OH 45221 USA. RP Kumar, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave,L-370, Livermore, CA 94550 USA. NR 29 TC 9 Z9 9 U1 2 U2 7 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD JUN PY 1999 VL 79 IS 6 BP 315 EP 325 DI 10.1080/095008399177156 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 203YG UT WOS:000080735300002 ER PT J AU Savikhin, S Xu, W Chitnis, P Struve, WS AF Savikhin, S Xu, W Chitnis, P Struve, WS TI Primary processes in photosystem I: Mutageneses, ultrafast kinetics, and reality-based simulations. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem & Biochem, Ames, IA 50011 USA. Iowa State Univ, Dept Biophys, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 13S EP 13S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200039 ER PT J AU Sutherland, JC Sutherland, BM AF Sutherland, JC Sutherland, BM TI Medical and environmental effects of UVA and visible light, an overview. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 14S EP 14S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200043 ER PT J AU Wishart, JF AF Wishart, JF TI Picosecond radiolysis at the Brookhaven Laser-Electron Radiolysis Facility. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 14S EP 14S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200042 ER PT J AU Dylla, HF AF Dylla, HF TI The free electron laser: An advanced high intensity UV-visible light source for photobiology. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Thomas Jefferson Natl Accelerator Fac, Newport News, VA 23606 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 16S EP 16S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200048 ER PT J AU Setlow, RB AF Setlow, RB TI Animal models for carcinogenesis and other deleterious effects. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 16S EP 17S PG 2 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200049 ER PT J AU Maness, PC Huang, Z Smolinski, S Jacoby, W Blake, D Wolfrum, E AF Maness, PC Huang, Z Smolinski, S Jacoby, W Blake, D Wolfrum, E TI Photosterilization and photominerization of microbial cells with titanium dioxide. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 5 Z9 6 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 64S EP 65S PG 2 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200194 ER PT J AU Hidema, J Sutherland, JC Sutherland, BM Kumagai, T AF Hidema, J Sutherland, JC Sutherland, BM Kumagai, T TI Cultivar difference in CPD photorepair between UV-resistant and UV-sensitive rice. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Tohoku Univ, Inst Genet Ecol, Sendai, Miyagi 9808577, Japan. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 86S EP 86S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200260 ER PT J AU Sutherland, JC AF Sutherland, JC TI Quantification of DNA damage by gel electrophoresis and the method-of-moments: Evaluation of accuracy using calculated lane profiles. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 86S EP 86S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200259 ER PT J AU Leander, MV Trunk, J Sutherland, JC Sutherland, BM AF Leander, MV Trunk, J Sutherland, JC Sutherland, BM TI Illumination conditions determine detection of photorepair. SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 1999 VL 69 SI SI BP 87S EP 87S PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 220KB UT WOS:000081663200262 ER PT J AU Felcher, GP AF Felcher, GP TI Polarized neutron reflectometry - a historical perspective SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE neutron reflectivity; polarized neutrons ID ANNEALED NI80FE20/AG MULTILAYERS; FE/CR(001) SUPERLATTICES; MAGNETIC-STRUCTURES; PENETRATION DEPTH; FE/SI MULTILAYERS; THIN-FILMS; X-RAY; REFLECTION; GD/FE; MAGNETOMETRY AB Born in the early 1980s to study magnetic films, polarized neutron reflectometry (PNR) has enjoyed growing popularity as witnessed by the number of instruments assembled at neutron research centers. PNR has proved its usefulness by providing information as diverse as the penetration depth of the magnetic field in superconductors and the absolute value of the magnetic moments in ultrathin ferromagnetic layers; yet its widest application has become the study of the magnetic configurations in multilayers. Two types of reflectometers have been constructed: time of flight and crystal analyzer. The relative merits of the two types are discussed in the light of present and future applications, (C) 1999 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Felcher, GP (reprint author), Argonne Natl Lab, Bldg 223, Argonne, IL 60439 USA. EM felcher@anl.gov NR 60 TC 17 Z9 17 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 1999 VL 267 BP 154 EP 161 DI 10.1016/S0921-4526(99)00053-8 PG 8 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100028 ER PT J AU Blume, M AF Blume, M TI Neutron polarization phenomena in scattering processes SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE polarization dependence; polarization of scattered beam; correlation functions; generalized susceptibility; magnetisation density ID DIFFRACTION; CRYSTALS AB The theory of polarization-dependent cross sections and of the polarization of the scattered beam in terms of the nuclear and magnetic correlation functions will be reviewed and extended. It is possible, using three-dimensional polarization analysis, to separate different correlation functions and static expectation values. Expressions which are useful for this purpose are given. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Amer Phys Soc, Ridge, NY 11961 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Blume, M (reprint author), Amer Phys Soc, Ridge, NY 11961 USA. EM blume@aps.org NR 11 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 1999 VL 267 BP 211 EP 214 DI 10.1016/S0921-4526(99)00076-9 PG 4 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100039 ER PT J AU Semadeni, F Boni, P Endoh, Y Roessli, B Shirane, G AF Semadeni, F Boni, P Endoh, Y Roessli, B Shirane, G TI Direct observation of spin-flip excitations in MnSi SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE itinerant ferromagnets; Stoner excitations; polarized neutrons ID FLUCTUATIONS AB Using inelastic neutron scattering with polarization analysis, the magnetic excitations in the field induced Ferromagnetic state of MnSi have been measured. The spin-hip cross-section displays well defined spin waves with E(q) = Dq(2) + Delta at low-energy transfers. Above E similar or equal to 3 meV, the excitations broaden significantly and their intensity becomes small. In addition, the slope of the dispersion curve becomes very steep indicating the transition from coherent magnetic excitations to single-particle excitations. The polarized beam experiments prove directly that the Stoner excitations are spin-flip. The non spin-flip excitations are only well defined at low E, whereas at higher E they are barely visible. They have a similar q-dependence as the parallel fluctuations delta S\\M in other ferromagnets like Ni or EuS. (C) 1999 Elsevier Science B.V. All rights reserved. C1 ETH Zurich, Labor Neutronenstreuung, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 980, Japan. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Semadeni, F (reprint author), ETH Zurich, Labor Neutronenstreuung, CH-5232 Villigen, Switzerland. EM fabrizio.semadeni@psi.ch NR 7 TC 8 Z9 8 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 1999 VL 267 BP 248 EP 251 DI 10.1016/S0921-4526(99)00077-0 PG 4 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100045 ER PT J AU Boni, P Lorenzo, JE Roessli, B Shirane, G Werner, SA Wildes, A AF Boni, P Lorenzo, JE Roessli, B Shirane, G Werner, SA Wildes, A TI Polarization analysis of low-energy excitations in single-domain Cr SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE spin-density waves; antiferromagnetism; incommensurate; itinerant; polarized neutrons ID MAGNETIC EXCITATIONS; CHROMIUM; DYNAMICS; ALLOYS AB The longitudinal and transverse spin fluctuations in single-domain Cr have been investigated in the transverse spin-density-wave phase using constant energy scans with 4 less than or equal to E less than or equal to 25 meV and polarization analysis. The transverse excitations show well-defined peaks centered at the incommensurate satellite positions (1 +/- delta 0 0) and a broad peak at the commensurate (1 0 0) position. The longitudinal fluctuations exhibit a much more complicated structure due to the additional appearance of magnetic excitations below 9 meV (Fincher-Burke modes). The fluctuations with longitudinal polarization show a pronounced renormalization between 136 and 230 K raising the possibility that the Fincher-Burke modes are responsible for the phase transition at T(N). Above E similar or equal to 18 meV, the longitudinal fluctuations decrease with increasing E at T = 230 K in contrast to the transverse fluctuations. Our results indicate that unpolarized beam data is not really useful for making comparisons with existing theories. There is an urgent need to extend polarization analysis to higher neutron energies. (C) 1999 Elsevier Science B.V. All rights reserved. C1 ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. CNRS, Crystallog Lab, F-38042 Grenoble, France. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Missouri, Dept Phys, Columbia, MO 65211 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. RP Boni, P (reprint author), ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. EM boni@psi.ch NR 14 TC 1 Z9 1 U1 1 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 1999 VL 267 BP 255 EP 258 DI 10.1016/S0921-4526(99)00019-8 PG 4 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100047 ER PT J AU Pappas, C Kali, G Boni, P Kischnik, R Mertens, LA Granz, P Mezei, F AF Pappas, C Kali, G Boni, P Kischnik, R Mertens, LA Granz, P Mezei, F TI Performance of the multidetector NSE spectrometer SPAN at BENSC SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE polarized neutrons; neutron spin-echo spectroscopy; quasielastic neutron scattering AB The neutron spin-echo spectroscopy (NSE) precession field, which is created by three pairs of coils with diameters 1, 3 and 4.8 m, respectively, is the peculiarity in the design of SPAN. Each pair is mounted in a Helmholtz-like fashion, with the electric currents oriented oppositely to each other, one coil above and one coil below the horizontal scattering plane. The centers of all coils are placed on the same vertical axis, which crosses the sample position. The NSE field is horizontal with axial symmetry. Particular care has been taken to shape the magnetic field around the sample, which is weak, vertical and very homogeneous. We present a first series of NSE measurements, which show that only little held adjustment is required to satisfy the exact echo condition (phase) simultaneously for a range of scattering angles and confirm the high axial symmetry of the precession field. The results show that the new magnetic field configuration of SPAN allows for multidetector NSE over a wide angular range. (C) 1999 Elsevier Science B.V. All rights reserved. C1 HMI Berlin, BENSC, D-14109 Berlin, Germany. ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. PSI, CH-5232 Villigen, Switzerland. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Pappas, C (reprint author), HMI Berlin, BENSC, Glienicker Str 100, D-14109 Berlin, Germany. EM pappas@hmi.de RI Kali, Gyorgy/C-2070-2008 NR 5 TC 12 Z9 13 U1 1 U2 9 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 1999 VL 267 BP 285 EP 288 DI 10.1016/S0921-4526(99)00083-6 PG 4 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100053 ER PT J AU Lohstroh, W Felcher, GP Goyette, R Munzenberg, M Felsch, W AF Lohstroh, W Felcher, GP Goyette, R Munzenberg, M Felsch, W TI Imprinted spiral structures as neutron polarizers SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 2nd Workshop on Polarised Neutrons for Condensed Matter Investigations (PNCMI'98) CY SEP 21-23, 1998 CL INST LAUE LANGEVIN, CHADWICK AMPHITHEATER, GRENOBLE, FRANCE SP CEN Grenoble, Inst Laue Langevin, CNRS HO INST LAUE LANGEVIN, CHADWICK AMPHITHEATER DE neutron reflectometry; neutron polarizer AB Neutron diffraction from magnetic spiral structures is governed by strong selection rules for the polarization of the outgoing beam. When the sample is entirely of one chirality - for instance a right-handed spiral - the neutrons diffracted by some Bragg reflections are fully polarized. While the scattering theory has been formulated long ago, attempts to controllably modify the population of left-handed and right-handed spiral domains in natural magnetic structures (which for instance occur in some rare-earth metals) have been largely unsuccessful. In contrast, we have been able to imprint helical magnetic structures in La/Fe multilayers (each layer approximately 30 Angstrom thick) simply by rotating the growing sample in a weak external held (3 Oe). A first estimate is given of the efficiency of these multilayers as polarizers of neutron beams. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Gottingen, Inst Phys 1, D-37073 Gottingen, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. RP Lohstroh, W (reprint author), Univ Gottingen, Inst Phys 1, Bunsenstr 9, D-37073 Gottingen, Germany. EM wlohstr@gwdg.de RI Munzenberg, Markus/B-1251-2010 OI Munzenberg, Markus/0000-0002-1332-5678 NR 9 TC 4 Z9 4 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 1999 VL 267 BP 352 EP 354 DI 10.1016/S0921-4526(99)00025-3 PG 3 WC Physics, Condensed Matter SC Physics GA 194AZ UT WOS:000080171100066 ER PT J AU Gilbert, EP Reynolds, PA Thiyagarajan, P Wozniak, DG White, JW AF Gilbert, EP Reynolds, PA Thiyagarajan, P Wozniak, DG White, JW TI Microphase separation kinetics in n-alkane mixtures SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID PARAFFIN SOLID-SOLUTIONS; RELAXATION-TIME MEASUREMENTS; PHASE-SEPARATION; INFRARED-SPECTROSCOPY; COMPUTER-SIMULATION; CRYSTAL-STRUCTURE; DILUTE SYSTEMS; BINARY; DYNAMICS; ISOTOPE AB Using time-resolved small-angle neutron scattering, the kinetics of microphase separation at various quench temperatures between 10 and 43 degrees C in metastable, binary paraffin mixtures C(30)H(D)(62)-C(36)D(H)(74) of 4 : 1, 1 : 1 and 1 : 4 composition, and 1 : 1 mixtures of C(n)H(2n+2)-C(36)D(74) for 28 less than or equal to n less than or equal to 31, both in the bulk and doped into an exfoliated graphite, have been investigated for up to 6000 minutes at 15 min resolution. The data were fitted to a single exponential relaxation function. Graphite adsorption generally has little effect on the rates, with explicable exceptions. The Q-dependent relaxation times, except for 1 :4 C(30)H(62)-C(36)D(74), all peak at Q ca. 0.07 Angstrom(-1), which together with the shape of the structure function, and the relative trends in the relaxation times, indicate a single demixing process to alternating lamellae. The relaxation time decreases with increasing C(36) concentration and has a noticeable H/D isotopic dependence. Increasing chain length mismatch strongly decreases the relaxation times. These observations are all explained by a combination of the interplay of C(36) conformational defects and screw motion in the individual alkane chains, together with a void mechanism for mobility. Power-law behaviour of the kinetics is shown to occur over usefully large time domains. The range over which this behaviour is observed increases with decreasing C(36) concentration. Our analysis suggests that three broad regions of scattering development can be defined corresponding to linear, power-law and logarithmic growth. C1 Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Gilbert, EP (reprint author), Australian Natl Univ, Res Sch Chem, GPO Box 4, Canberra, ACT 0200, Australia. RI Gilbert, Elliot/A-5566-2010 OI Gilbert, Elliot/0000-0001-6413-7813 NR 47 TC 25 Z9 25 U1 0 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PD JUN 1 PY 1999 VL 1 IS 11 BP 2715 EP 2724 DI 10.1039/a900695h PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 205AK UT WOS:000080798900011 ER PT J AU Benioff, P AF Benioff, P TI Simple example of definitions of truth, validity, consistency, and completeness in quantum mechanics SO PHYSICAL REVIEW A LA English DT Article ID COMPUTATIONAL POWER; ERROR-CORRECTION; TRAPPED IONS; LOGIC GATE; SET-THEORY; AUTOMATA; SYSTEMS; ROBOTS; CODE AB Besides their use for efficient computation, quantum computers and quantum robots form a base for studying quantum systems that create valid physical theories using mathematics and physics. If quantum mechanics is universally applicable, then quantum mechanics must describe its own validation by these quantum systems. An essential part of this process is the development of a coherent theory of mathematics and quantum-mechanics together. It is expected that such a theory will include a coherent combination of mathematical logical concepts with quantum mechanics. That this might be possible is shown here by defining truth, validity, consistency, and completeness for a quantum-mechanical version of a simple (classical) expression enumeration machine described by Smullyan. Some of the expressions are chosen as sentences denoting the presence or absence of other expressions in the enumeration. Two of the sentences are self-referential. It is seen that, for an interpretation based on a Feynman path sum over expression paths, truth, consistency, and completeness for the quantum system have different properties than for the classical system. For instance, the truth of a sentence S is defined only on those paths containing S. It is undefined elsewhere. Also S and its negation can both be true provided they appear on separate paths. This satisfies the definition of consistency. The definitions of validity and completeness connect the dynamics of the system to the truth of the sentences. It is proved that validity implies consistency. It is seen that the requirements of validity and maximal completeness strongly restrict the allowable dynamics for the quantum system. Aspects of the existence of a valid, maximally complete dynamics are discussed. An exponentially efficient quantum computer is described that is also valid and complete for the set of sentences considered here. [S1050-2947(99)02506-8]. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Benioff, P (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 51 TC 5 Z9 5 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4223 EP 4237 DI 10.1103/PhysRevA.59.4223 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600017 ER PT J AU Milonni, PW Schaden, M Spruch, L AF Milonni, PW Schaden, M Spruch, L TI Lamb shift of an atom in a dielectric medium SO PHYSICAL REVIEW A LA English DT Article ID CASIMIR AB Adapting an approach used by Feynman for the Lamb shift of an isolated atom, we obtain a nonperturbative expression for the Lamb shift of an atom in a dielectric medium, previously calculated perturbatively [P. W. Milonni, J. Mod. Opt. 42, 1191 (1995)]. The separation of the Lamb and Casimir components of the field energy is greatly simplified, and previous nonperturbative results for the Lamb shift [M. Schaden, L. Spruch, and F. Zhou, Phys. Rev. A 57, 1108 (1998)], based on the generalized argument theorem, are obtained much more easily and directly. [S1050-2947(99)12205-4]. C1 Univ Calif Los Alamos Natl Lab, Theoret Div T4, Los Alamos, NM 87545 USA. NYU, Dept Phys, New York, NY 10003 USA. RP Milonni, PW (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Div T4, Los Alamos, NM 87545 USA. NR 8 TC 15 Z9 15 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4259 EP 4263 DI 10.1103/PhysRevA.59.4259 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600021 ER PT J AU Cohen, JS AF Cohen, JS TI Negative pion capture in HD gas and in H-2+D-2 gas mixtures: Resolution of the isotope puzzle SO PHYSICAL REVIEW A LA English DT Article ID EFFECTIVE HAMILTONIAN-STRUCTURE; KINETIC-ENERGY DISTRIBUTION; FERMION MOLECULAR-DYNAMICS; HYDROGEN-ATOMS; DEUTERIUM; MUONS AB The cross sections. initial quantum numbers, and kinetic energies For pionic atoms formed by negative pion capture in mixtures of isotopic hydrogen molecules are calculated using the fe:rmion-molecular-dynamics (FMD) method. With these cross sections, the reduced capture ratio for a H-2 + D-2 mixture is found to be (P-p((H2+D2))/P-d((H2+D2)))/(c(p)/c(d))= 1.204, and the capture ratio for HD is found to be P-p((HD))/P-d((HD)) - 0.875. In light of these results, the p-to-d pion transfer probabilities Q are reevaluated using prior experimental data and determined to be larger than previously thought: Q = 0.28 at deuterium fraction C-d= 0.5 and Q = 0.42 as c(d), -->. The puzzling relationship of the experimental data for HD to that for H-2 + D-2, mixtures is explained. [S1050-2947(99)06806-7]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Cohen, JS (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 28 TC 11 Z9 11 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4300 EP 4308 DI 10.1103/PhysRevA.59.4300 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600027 ER PT J AU Czarnecki, A Melnikov, K Yelkhovsky, A AF Czarnecki, A Melnikov, K Yelkhovsky, A TI Positronium S-state spectrum: Analytic results at O(m alpha(6)) SO PHYSICAL REVIEW A LA English DT Article ID HYPERFINE INTERVAL; ENERGY-LEVELS; BOUND-STATE; RECOIL CORRECTIONS; ORDER M-ALPHA(6); GROUND-STATE; MUONIUM; HYDROGEN; SYSTEMS; QCD AB We present an analytic calculation of the O(m alpha(6))recoil and radiative recoil corrections to energy levels of positronium nS states and their hyperfine splitting. A complete analytic formula valid to O(,m alpha(6)) is given for the spectrum of S states. Technical aspects of the calculation are discussed in detail. Theoretical predictions are given for various energy intervals and compared with experimental results. [S1050-2947(99)09206-9]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Karlsruhe, Inst Theoret Teilchenphys, D-76128 Karlsruhe, Germany. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Czarnecki, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 45 TC 73 Z9 73 U1 1 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 1999 VL 59 IS 6 BP 4316 EP 4330 DI 10.1103/PhysRevA.59.4316 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600029 ER PT J AU Ward, SJ Macek, JH Ovchinnikov, SY AF Ward, SJ Macek, JH Ovchinnikov, SY TI Application of the hidden-crossing method to positronium formation SO PHYSICAL REVIEW A LA English DT Article ID CLOSE-COUPLING CALCULATION; SPLINE COLLOCATION METHOD; S-WAVE POSITRON; HYDROGEN SCATTERING; THRESHOLD IONIZATION; LOW ENERGIES; COLLISIONS; SECTIONS; SYSTEMS; IMPACT AB We have applied the hidden-crossing method to compute S-, P-, and D-wave cross sections for Ps formation in positron-hydrogen collisions in the Ore gap. The hidden-crossing method has provided a physical explanation of why the S-wave cross section is so small and why the D wave is significant. The one-Sturmian theory is used to correct the hidden-crossing theory to take into account the factor ( + (1/4)/R-2). We have considered this correction term in computing the P- and D-wave cross sections. The hidden-crossing results are compared with accurate results from other methods. This comparison helps assess the accuracy of the hidden-crossing method in describing three-body collisions. [S1050-2947(99)06506-3]. C1 Univ N Texas, Dept Phys, Denton, TX 76203 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ward, SJ (reprint author), Univ N Texas, Dept Phys, Denton, TX 76203 USA. RI Ovchinnikov, Serguei/C-4994-2014 NR 54 TC 24 Z9 24 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 1999 VL 59 IS 6 BP 4418 EP 4427 DI 10.1103/PhysRevA.59.4418 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600040 ER PT J AU Ritchie, B AF Ritchie, B TI Reaction-field-induced interatomic forces between atoms in the presence of a strong magnetic field SO PHYSICAL REVIEW A LA English DT Article ID HYDROGEN MOLECULES; ABSORPTION AB It is shown that the reaction field induced in an atom by a strong magnetic field is of order B alpha(2) in atomic units (for magnetic-field strength B and fine structure constant alpha). The reaction field causes a dipole-dipole interatomic potential energy to exist between a pair of atoms of order B(3/2)alpha(7/2), such that B must be of order alpha-(7/3) for the interatomic energy to be of order 1 a.u. B of this order corresponds to a field strength of 1.66 x 10(12) G, which is within the regime of field strengths considered in recent studies of atoms and molecules in the presence of a strong magnetic field. [S1050-2947(99)04606-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ritchie, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP 4571 EP 4573 DI 10.1103/PhysRevA.59.4571 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600057 ER PT J AU Yoshida, S Reinhold, CO Kristofel, P Burgdorfer, J Watanabe, S Dunning, FB AF Yoshida, S Reinhold, CO Kristofel, P Burgdorfer, J Watanabe, S Dunning, FB TI Floquet analysis of the dynamical stabilization of the kicked hydrogen atom SO PHYSICAL REVIEW A LA English DT Article ID HALF-CYCLE PULSES; RYDBERG ATOM; QUANTUM CHAOS; IONIZATION; FIELD AB We analyze the quantum dynamics of the one-dimensional periodically kicked Rydberg atom. The time-dependent Schrodinger equation is solved by employing a nonunitary representation of the period-one evolution operator in a finite basis set that accounts for the outbound probability flux. We find a direct correspondence between stable classical islands in phase space and the quantum Husimi distributions of stable Floquet states. These results explain the pronounced peak recently found experimentally in the frequency-dependent survival probability of Rydberg states subject to a sequence of half-cycle pulses. [S1050-2947 (99)50605-9]. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Vienna Tech Univ, Inst Theoret Phys, A-1040 Vienna, Austria. Univ Electrocommun, Dept Appl Phys, Chofu, Tokyo 1828585, Japan. Rice Univ, Dept Phys, Houston, TX 77005 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. RP Yoshida, S (reprint author), Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 20 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1999 VL 59 IS 6 BP R4121 EP R4124 DI 10.1103/PhysRevA.59.R4121 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 204RH UT WOS:000080777600004 ER PT J AU Cornelius, AL Arko, AJ Sarrao, JL Harrison, N AF Cornelius, AL Arko, AJ Sarrao, JL Harrison, N TI de Haas-van Alphen effect, magnetic transitions, and specific heat in the heavy-fermion system UCd11 SO PHYSICAL REVIEW B LA English DT Article ID METAMAGNETIC TRANSITION; FIELDS; TEMPERATURE; UPT3 AB We have used high pulsed magnetic fields to 50 T to observe de Haas-van Alphen oscillations in the heavy fermion antiferromagnet UCd11, which has a strongly enhanced value of the electronic specific-heat coefficient (gamma = 803 mJ/mol K-2). The low-temperature magnetization shows the existence of two magnetic phase transitions. The presence of quantum oscillations above the first transition indicates that UCd11 has a coherent Fermi liquid, although there is little or no change in the Fermi-surface topology on passing through the second transition. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cornelius, AL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Cornelius, Andrew/A-9837-2008 NR 23 TC 8 Z9 8 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 21 BP 13542 EP 13545 DI 10.1103/PhysRevB.59.13542 PG 4 WC Physics, Condensed Matter SC Physics GA 204RV UT WOS:000080778700015 ER PT J AU Anderson, CR Andersen, KH Bossy, J Stirling, WG Dimeo, RM Sokol, PE Cook, JC Brown, DW AF Anderson, CR Andersen, KH Bossy, J Stirling, WG Dimeo, RM Sokol, PE Cook, JC Brown, DW TI High-resolution neutron-scattering study of the roton in confined superfluid He-4 SO PHYSICAL REVIEW B LA English DT Article ID COLLECTIVE EXCITATIONS; AEROGEL AB We report high-resolution neutron inelastic-scattering measurements of the roton energy and linewidth of superfluid He-4 confined in 95% porosity aerogel glass far temperatures 0.08 infinity, T-IC(N) is independent of the Fe-Cr coupling strength. We find that T-IC(infinity) is always larger than the bulk Neel transition temperature and increases with the strain on the Cr spacer. These results explain the very high IC transition temperature of about 600 K extrapolated from measurements on Fe/Cr/Fe wedges. Model II assumes that the I SDW nodes lie precisely at the Fe-Cr interfaces. This condition may be enforced by the interfacial roughness of sputtered Fe/Cr multilayers. As a result, the C phase is never stable and the transition temperature T-N(N) takes on a seesaw pattern as n greater than or equal to 2 increases with thickness. In agreement with measurements on both sputtered and epitaxially grown multilayers, model II predicts the I phase to be unstable above the bulk Neel temperature. Model II also predicts that the I SDW may undergo a single phase transition from n = m to m-1 before disappearing above TN(N). This behavior has recently been confirmed by neutron-scattering measurements on CrMn/Cr multilayers. While model I very successfully predicts the behavior of Fe/Cr/Fe wedges, a refined version of model II describes some properties of sputtered Fe/Cr multilayers. [S0163-1829(99)03021-0]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Read Rite Corp, R&D Div, Milpitas, CA 95035 USA. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013 NR 44 TC 30 Z9 30 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 21 BP 13849 EP 13860 DI 10.1103/PhysRevB.59.13849 PG 12 WC Physics, Condensed Matter SC Physics GA 204RV UT WOS:000080778700065 ER PT J AU Sandvik, AW AF Sandvik, AW TI Stochastic series expansion method with operator-loop update SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM MONTE-CARLO; SPIN SYSTEMS; HEISENBERG-MODEL; FINITE-SIZE; SIMULATIONS; TEMPERATURE; STATISTICS; LATTICES; SQUARE; TIME AB A cluster update (the "operator loop") is developed within the framework of a numerically exact quantum Monte Carlo method based on the power series expansion of exp(-beta H) (stochastic series expansion). The method is generally applicable to a wide class of lattice Hamiltonians for which the expansion is positive definite. For some important models the operator-loop algorithm is more efficient than loop updates previously developed for "worldline'' simulations. The method is here tested on a two-dimensional anisotropic Heisenberg antiferromagnet in a magnetic field. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Sandvik, AW (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. NR 26 TC 399 Z9 399 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14157 EP 14160 PG 4 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700005 ER PT J AU Asta, M Morgan, D Hoyt, JJ Sadigh, B Althoff, JD de Fontaine, D Foiles, SM AF Asta, M Morgan, D Hoyt, JJ Sadigh, B Althoff, JD de Fontaine, D Foiles, SM TI Embedded-atom-method study of structural, thermodynamic, and atomic-transport properties of liquid Ni-Al alloys SO PHYSICAL REVIEW B LA English DT Article ID SHORT-RANGE ORDER; MOLECULAR-DYNAMICS; FCC METALS; TRANSITION-METALS; GLASS-TRANSITION; RAPID SOLIDIFICATION; COMPUTER-SIMULATION; AMORPHOUS COPPER; PHASE-DIAGRAM; ALUMINUM AB Structural, thermodynamic, and atomic-transport properties of liquid Ni-Al alloys have been studied by Monte Carlo and molecular-dynamics simulations based upon three different embedded-atom method (EAM) interatomic potentials, namely those due to Foiles and Daw (FD) [J. Mater. Res. 2, 5 (1987)], Voter and Chen (VC) [in Characterization of Defects in Materials, edited by R. W. Siegel et al. MRS Symposia Proceedings. No. 82 (Materials Research Society, Pittsburgh, 1987), p.175] and Ludwig and Gumbsch (LG) [Model. Simul. Mater. Sci. Eng. 3, 533 (1995)]. We present detailed comparisons between calculated results and experimental data for structure factors, atomic volumes, enthalpies of mixing, activities, and viscosities. Calculated partial structure factors are found to be in semiquantitative agreement with published neutron scattering measurements for Ni20Al80 alloys, indicating that short-range order in the liquid phase is qualitatively well described. Calculated thermodynamic properties of mixing are found to agree very well with experimental data for Ni compositions greater than 75 atomic %, while for alloys richer in Al the magnitudes of the enthalpies and entropies of mixing are significantly underestimated. The VC and LG potentials give atomic densities and viscosities in good agreement with experiment for Ni-rich compositions, while FD potentials consistently underestimate both properties at all concentrations. The results of this study demonstrate that VC and LG potentials provide a realistic description of the thermodynamic and atomic transport properties for NixAl1-x liquid alloys with x greater than or equal to 0.75, and point to the limitations of EAM potentials for alloys richer in Al. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Morgan, D (reprint author), Sandia Natl Labs, MS 9161,POB 969, Livermore, CA 94551 USA. OI Foiles, Stephen/0000-0002-1907-454X NR 69 TC 77 Z9 78 U1 4 U2 22 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14271 EP 14281 DI 10.1103/PhysRevB.59.14271 PG 11 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700021 ER PT J AU Gramsch, E Lynn, KG Throwe, J Kanazawa, I AF Gramsch, E Lynn, KG Throwe, J Kanazawa, I TI Positron diffusion in solid and liquid metals SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-PROPERTIES; NONTHERMAL POSITRONS; POLYVALENT ELEMENTS; SLOW POSITRONS; SURFACES; EMISSION; ANNIHILATION; VACANCIES; LIFETIME; ENERGIES AB We made a systematic study of the diffusion of positrons in several liquid and solid metals with a vertical positron beam. Several interesting effects have been observed by studying the line shape parameter S, the fraction of positronium formed at the surface, and the diffusion length of positrons in liquids. The S parameter and the fraction of positronium created and released at the surface (F parameter) were measured as a function of temperature in the solid and liquid phases of Ga, Bi, Na, Sn, In, and Pb. An appreciable change just below or across the melting point in the S parameter was measured in metals where positron trapping has not been observed (Ga, Bi, and Sn). In metals where positron trapping occurs in the solid phase. there is a small change or none in the S parameter (Pb and In), which indicates that there is only a small change in the nature of the traps. Positron trapping was seen in all the liquid metals, indicating that they have a high density of defect like sites that trap positrons. The diffusion length of positrons in the Liquid was extracted from the experimental data. In Ga, Bi, and Sn, there is a large drop in the diffusion length upon melting, in Pb and Int only a small change or none is seen. In all liquid metals the diffusion length increases as the temperature increases, suggesting that diffusion is related to trapping in temporary fluctuations in the liquid's structure. The positron moves from fluctuation to fluctuation. The size of the traps strongly depends on temperature, and so when it increases, the positron's hopping motion increases. We also measured the reemitted energy spectra of positrons from liquid and solid surfaces. No appreciable change was seen with increasing temperature or when the metals melted. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Gramsch, E (reprint author), Univ Santiago, Dept Phys, Santiago, Chile. EM egramsch@lauca.usach.cl OI Gramsch, Ernesto/0000-0002-6787-7355 NR 72 TC 7 Z9 7 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14282 EP 14301 DI 10.1103/PhysRevB.59.14282 PG 20 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700022 ER PT J AU Radaelli, PG Cox, DE Capogna, L Cheong, SW Marezio, M AF Radaelli, PG Cox, DE Capogna, L Cheong, SW Marezio, M TI Wigner-crystal and bi-stripe models for the magnetic and crystallographic superstructures of La0.333Ca0.667MnO3 SO PHYSICAL REVIEW B LA English DT Article ID CHARGE-ORDERED STRIPES; DIFFRACTION; LA1-XCAXMNO3 AB The crystallographic (charge-ordered) and magnetic superstructures of La0.333Ca0.667MnO3 were studied by high-resolution synchrotron x-ray and neutron powder diffraction. In the antiferromagnetic structure, which was refined using a noncollinear model, the a lattice parameter is trifled and the c lattice parameter is doubled with respect to the average crystallographic unit cell (Pnma setting). The crystallographic structure below the charge-ordering temperature (T(CO)similar to 260 K) is characterized by ordering of the d(z2) orbitals of the Jahn-Teller-distorted Mn3+O6 octahedra in the orthorhombic ne plane, and the appearance of superlattice peaks in the x-ray patterns corresponding to a tripling of the a axis lattice parameter. The intensities of the superlattice peaks can be accounted for satisfactorily in terms of ordering of the Mn3+ cations in sites as far apart as possible in the ac plane ("Wigner-crystal" model) and transverse displacements of the Mn4+O6 octahedra in the c direction. These results are not consistent with a recently proposed model based on transmission electron microscopy (TEM) data in which the Mn3+O6 octahedra are arranged in a bi-stripe pattern ("bi-stripe" model). In particular, the large longitudinal stripe modulation revealed by TEM is not observed, suggesting that the TEM data may not be representative of the bulk sample. Within the framework of the Wigner-crystal model, the magnetic structure at 1.5 K and the charge-ordered superstructures at 160 and 1.5 K were refined from the neutron data. [S0163-1829(99)04421-5]. C1 Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. INFM, Genoa, Italy. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. CNR, MASPEC, I-43100 Parma, Italy. RP Radaelli, PG (reprint author), Rutherford Appleton Lab, ISIS Facil, Bldg R3, Didcot OX11 0QX, Oxon, England. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 16 TC 178 Z9 184 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14440 EP 14450 DI 10.1103/PhysRevB.59.14440 PG 11 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700037 ER PT J AU Cornelius, AL Arko, AJ Sarrao, JL Thompson, JD Hundley, MF Booth, CH Harrison, N Oppeneer, PM AF Cornelius, AL Arko, AJ Sarrao, JL Thompson, JD Hundley, MF Booth, CH Harrison, N Oppeneer, PM TI Electronic properties of UX3 (X = Ga, Al, and Sn) compounds in high magnetic fields: Transport, specific heat, magnetization, and quantum oscillations SO PHYSICAL REVIEW B LA English DT Article ID FERMION SYSTEMS; METAMAGNETIC TRANSITION; URANIUM-COMPOUNDS; SINGLE-CRYSTALS; QUASI-PARTICLE; UGA3; UPT3; HYBRIDIZATION; RESISTIVITY; CERU2SI2 AB We have performed measurements of the specific heat and resistivity in static magnetic fields up to 12 T, as well as magnetic measurements in a static field of 0.1 T and in pulsed fields up to 50 T on high-quality UX3 (X= Ga, Al, and Sn) single crystals. The behavior of the electronic specific heat coefficients in applied field gamma(B) either remains nearly constant or increases as B increases and is inconsistent with the expectations of the single-impurity model. For UGa3, different de Haas-van Alphen (dHvA) frequencies are observed above and below a magnetic transition at a field B(M)similar to 12 T at T similar to 0.5 K, indicating that a major reconstruction of the Fermi surface occurs. Neither USn3 nor UAl3 exhibited a magnetic transition in fields to 50 T, and only a single weak dHvA frequency was observed in these compounds. The difference between the behavior of the UX3 compounds can be attributed to the degree of hybridization of the 5f orbitals with the conduction electron orbitals. UGa3 behaves as an itinerant Sf-electron system, while UAl3 has a tendency to localization, but is still relatively delocalized. USn3 is a heavy fermion compound. Concurrent to our experimental investigations we have performed calculations of the energy band structures of the three compounds. Owing to the delocalized 5f behavior of UGa3, and also of UAl3, we find that an itinerant, energy band approach explains the dHvA frequencies of antiferromagnetic UGa3 and paramagnetic UAl3 reasonably well. For UGa3 an unusual sensitivity of the magnetic moment to the magnetic structure and the lattice parameter occurs, providing evidence that UGa3 is an unique example of an itinerant uranium-based antiferromagnet. [S0163-1829(99)04321-0]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Dresden Univ Technol, Inst Theoret Phys, D-01062 Dresden, Germany. RP Cornelius, AL (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Cornelius, Andrew/A-9837-2008; Booth, Corwin/A-7877-2008 NR 55 TC 42 Z9 42 U1 4 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14473 EP 14483 DI 10.1103/PhysRevB.59.14473 PG 11 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700041 ER PT J AU Antonov, VN Antropov, VP Harmon, BN Yaresko, AN Perlov, AY AF Antonov, VN Antropov, VP Harmon, BN Yaresko, AN Perlov, AY TI Fully relativistic spin-polarized LMTO calculations of the magneto-optical Kerr effect of d and f ferromagnetic materials. I. Chromium spinel chalcogenides SO PHYSICAL REVIEW B LA English DT Article ID HALF-METALLIC FERROMAGNETS; HEUSLER ALLOYS; SPECTRA; ROTATION; PTMNSB; CESB; FEPT AB CuCr2Se4 is one of the few compounds that exhibits a magneto-optical (MO) Kerr angle of greater than one degree at room temperature. To better understand the origin of this effect, the MO properties of ferromagnetic CuCr2X4 (X=S, Se, Te) spinel chalcogenides are evaluated using fully relativistic local-density electronic structure calculations. Treating the 3d electronic states within the standard hand description, excellent agreement with the measured MO spectra is obtained. The calculations are analyzed to further elucidate aspects of the Ken rotation. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. RP Antonov, VN (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 69 TC 35 Z9 35 U1 2 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14552 EP 14560 DI 10.1103/PhysRevB.59.14552 PG 9 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700051 ER PT J AU Antonov, VN Harmon, BN Perlov, AY Yaresko, AN AF Antonov, VN Harmon, BN Perlov, AY Yaresko, AN TI Fully relativistic spin-polarized LMTO calculations of the magneto-optical Kerr effect of d and f ferromagnetic materials. II. Neodymium chalcogenides SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; BAND THEORY; ROTATION; SYSTEMS; METALS; CERIUM; CESB AB The optical and magneto-optical spectra of neodymium NaCl-type compounds NdX (X = S, Se, and Te) and Nd3S4 With Th3P4 crystal structure are investigated theoretically using an energy-band approach in combination with the linear-response formalism. The energy band structure is obtained within the local spin-density approximation (LSDA), and within its extension Which explicitly takes into account the onsite 4f Coulomb interaction U (LSDA + U). Although the LSDA predicts a large Kerr rotation in the compounds under consideration, we find that the LSDA + U gives a better description of the Kerr spectra of NdS and Nd3S4 The origin of the Kerr rotation realized in the compounds is examined. [S0163-1829(99)08721-4]. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. RP Antonov, VN (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 28 TC 18 Z9 19 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14561 EP 14570 DI 10.1103/PhysRevB.59.14561 PG 10 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700052 ER PT J AU Antonov, VN Harmon, BN Yaresko, AN Perlov, AY AF Antonov, VN Harmon, BN Yaresko, AN Perlov, AY TI Fully relativistic spin-polarized LMTO calculations of the magneto-optical Kerr effect of d and f ferromagnetic materials. III. Uranium chalcogenides and pnictides SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; ORBITAL POLARIZATION; CRYSTAL-STRUCTURE; ACTINIDE METALS; 5F ELECTRONS; BAND THEORY; SPECTROSCOPY; SPECTRA; U3P4; U3AS4 AB The optical and magneto-optical (MO) spectra of binary uranium compounds U3X4 (X=P, As, Sb, Bi, Se, and Te) with the Th3P4 crystal structure, and the ternary UCu2P2 compound are investigated from first principles, using the fully relativistic Dirac LMTO band structure method and density-functional theory in the local spin-density approximation (LSDA). The electronic structure is obtained with the LSDA, as well as with the so-called LSDA+U approach which contains an explicit Coulomb interaction U for localized orbitals. Within a bandlike description of the 5f electrons, excellent agreement with the measured MO spectra is obtained for U3P4, U3As4, and UCu2P2. The origin of the Kerr rotation in the compounds is examined. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Kiev Met Phys Inst, UA-252142 Kiev, Ukraine. RP Antonov, VN (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 57 TC 17 Z9 17 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14571 EP 14582 DI 10.1103/PhysRevB.59.14571 PG 12 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700053 ER PT J AU Kastner, MA Aharony, A Birgeneau, RJ Chou, FC Entin-Wohlman, O Greven, M Harris, AB Kim, YJ Lee, YS Parks, ME Zhu, Q AF Kastner, MA Aharony, A Birgeneau, RJ Chou, FC Entin-Wohlman, O Greven, M Harris, AB Kim, YJ Lee, YS Parks, ME Zhu, Q TI Field-dependent antiferromagnetism and ferromagnetism of the two copper sublattices in Sr2Cu3O4Cl2 SO PHYSICAL REVIEW B LA English DT Article ID HEISENBERG-ANTIFERROMAGNET; MAGNETIC-PROPERTIES; SPIN-ORBIT; EXCHANGE AB The Cu3O4 layer in Sr2CU3O4Cl2 is a variant of the square CuO2 lattice of the high-temperature superconductors, in which the center of every second plaquette contains an extra Cu2+ ion, The ions that make up the conventional CuO2 network, called CuI, have CuI-CuI exchange energy approximate to 130 meV, and order antiferromagnetically at about 380 K; the Cull-Cull exchange is only approximate to 10 meV, and the Cull's order at approximate to 40 K. A study is reported here of the dependence of the magnetization on held, temperature, and crystallographic orientation for this interesting system. We show that the small permanent ferromagnetic moment, that appears when the CuI spins order, and the unusual spin rotation transitions seen most clearly for one particular direction of the magnetic field, are the result of several small bond-dependent anisotropic terms in the spin Hamiltonian that are revealed because of the frustration of the isotropic Heisenberg interaction between CuI and Cull spins. These include a term which favors collinearity of the CuI and CuII spins, which originates from quantum fluctuations, and also the pseudodipolar interaction. Some of these small interactions also come into play in other lamellar cuprates, connected with the high-T-c superconductivity materials, and in many spin-chain and spin-ladder compounds. [S0163-1829(99)03218-X]. C1 MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Kastner, MA (reprint author), MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RI Kim, Young-June /G-7196-2011; ENTIN, ORA/F-1114-2012; harris, A Brooks/C-8640-2013 OI Kim, Young-June /0000-0002-1172-8895; NR 25 TC 13 Z9 13 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14702 EP 14711 DI 10.1103/PhysRevB.59.14702 PG 10 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700072 ER PT J AU Tranquada, JM Ichikawa, N Uchida, S AF Tranquada, JM Ichikawa, N Uchida, S TI Glassy nature of stripe ordering in La1.6-xNd0.4SrxCuO4 SO PHYSICAL REVIEW B LA English DT Article ID COPPER-OXIDE SUPERCONDUCTORS; STRUCTURAL PHASE-TRANSITION; EARTH-DOPED LA2-XSRXCUO4; MUON-SPIN-RELAXATION; X-RAY-DIFFRACTION; LOW-TEMPERATURE; QUANTUM ANTIFERROMAGNETS; MAGNETIC FLUCTUATIONS; TRANSPORT-PROPERTIES; NEUTRON-SCATTERING AB We present the results of neutron-scattering studies on various aspects of crystalline and magnetic structure in single crystals of La1.6-xNd0.4SrxCuO4 with x = 0.12 and 0.15. In particular, we have reexamined the degree of stripe order in an x = 0.12 sample. Measurements of the width for an elastic magnetic peak show that it saturates at a finite value below 30 K, corresponding to a spin-spin correlation length of 200 Angstrom. A model calculation indicates that the differing widths of magnetic and (previously reported) charge-order peaks, together with the lack of commensurability, can be consistently explained by disorder in the stripe spacing. Above 30 K (i.e., above the point at which a recent muon spin-rotation study has found a loss of static magnetic order), the width of the nominally elastic signal begins to increase. Interpreting the signal as critical scattering from slowly fluctuating spins, the temperature dependence of the width is consistent with renormalized classical behavior of a two-dimensional anisotropic Heisenberg antiferromagnet. Inelastic scattering measurements show that incommensurate spin excitations survive at and above 50 K, where the elastic signal is negligible. Given that the stripe order is believed to be pinned by the low-temperature tetragonal (LIT) crystal structure, we have also investigated the transition near 70 K from the low-temperature orthorhombic (LTO) structure. We show that our x = 0.12 crystal passes through an intervening less-orthorhombic phase, before reaching the LTT at similar to 40 K, whereas the x = 0.15 crystal goes directly from LTO to LTT, with coexistence of the two phases over a range of similar to 7 K. Sharp Bragg peaks in the LTT phase of the x = 0.15 crystal indicate a domain size of greater than or similar to 1000 Angstrom, with no obvious evidence for LTO domains: hence, the coexistence of stripe order and superconductivity in this sample cannot be explained by a mixture of crystalline phases. Finally, Lye present scattering evidence for small LTT-like domains in the LTO phase of the x = 0.15 sample. A correlation between the volume fraction of such domains and deviations of in-plane resistivity from linens T dependence suggest that charge stripes interact with these domains within the LTO matrix. [S0163-1829(99)1142-8]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 113, Japan. RP Tranquada, JM (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 59 TC 130 Z9 131 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 1999 VL 59 IS 22 BP 14712 EP 14722 DI 10.1103/PhysRevB.59.14712 PG 11 WC Physics, Condensed Matter SC Physics GA 204TN UT WOS:000080780700073 ER PT J AU Stoks, VGJ Rijken, TA AF Stoks, VGJ Rijken, TA TI Soft-core baryon-baryon potentials for the complete baryon octet SO PHYSICAL REVIEW C LA English DT Article ID NUCLEON-NUCLEON POTENTIALS; PP SCATTERING DATA; HYPERON-NUCLEON; MATTER; MODELS; PARTICLE AB SU(3) symmetry relations on the recently constructed hyperon-nucleon potentials are used to develop potential models for all possible baryon-baryon interaction channels. The main focus is on the interaction channels with total strangeness S = -2, -3, and -4, for which no experimental data exist yet. The potential models for these channels are based on SU(3) extensions of potential models for the S = 0 and S = - 1 sectors, which are fitted to experimental data. Although the SU(3) symmetry is not taken to be exact, the S = 0 and S = -1 sectors still provide the necessary constraints to fix all free parameters. The potentials for the S = -2, -3, and -4 sectors, therefore, do not contain any additional free parameters, which makes them among the first models of this kind. Various properties of the potentials are illustrated by giving results for scattering lengths, bound states, and total cross sections. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Adelaide, Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. Univ Nijmegen, Inst Theoret Phys, Nijmegen, Netherlands. RP Stoks, VGJ (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 28 TC 265 Z9 269 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 1999 VL 59 IS 6 BP 3009 EP 3020 DI 10.1103/PhysRevC.59.3009 PG 12 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200009 ER PT J AU Witala, H Kamada, H Nogga, A Glockle, W Elster, C Huber, D AF Witala, H Kamada, H Nogga, A Glockle, W Elster, C Huber, D TI Modern NN force predictions for the total nd cross section up to 300 MeV SO PHYSICAL REVIEW C LA English DT Article ID 3-NUCLEON FORCE AB For several modern nucleon-nucleon potentials state-of-the-art Faddeev calculations are carried out for the nd total cross section between 10 and 300 MeV projectile energy and compared to new high precision measurements. The agreement between theory and data is rather good, with an exception at higher energies when a 10% discrepancy builds up. In addition the convergence of the multiple scattering series incorporated in the Faddeev scheme is studied numerically with the result that rescattering corrections remain important. Based on this multiple scattering series the high energy limit of the total nd cross section is also investigated analytically. In contrast to the naive expectation that the total nd cross section is the sum of the np and nn total cross sections we find additional effects resulting from the rescattering processes, which have different signs and a different behavior as a function of the energy. A shadowing effect in the high energy limit only occurs for energies higher than 300 MeV. The expressions in the high energy limit have qualitatively a similar behavior as the exactly calculated expressions, but can be expected to be valid quantitatively only at much higher energies. C1 Ruhr Univ Bochum, Inst Theoret Phys 2, D-44780 Bochum, Germany. Ohio Univ, Inst Nucl & Particle Phys, Athens, OH 45701 USA. Ohio Univ, Dept Phys, Athens, OH 45701 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Witala, H (reprint author), Ruhr Univ Bochum, Inst Theoret Phys 2, D-44780 Bochum, Germany. RI Nogga, Andreas/A-3354-2008; Elster, Charlotte/N-9845-2015 OI Nogga, Andreas/0000-0003-2156-748X; NR 18 TC 37 Z9 37 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 1999 VL 59 IS 6 BP 3035 EP 3046 DI 10.1103/PhysRevC.59.3035 PG 12 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200011 ER PT J AU Daly, PJ Bhattacharyya, P Zhang, CT Grabowski, ZW Broda, R Fornal, B Ahmad, I Lauritsen, T Morss, LR Urban, W Phillips, WR Durell, JL Leddy, MJ Smith, AG Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J AF Daly, PJ Bhattacharyya, P Zhang, CT Grabowski, ZW Broda, R Fornal, B Ahmad, I Lauritsen, T Morss, LR Urban, W Phillips, WR Durell, JL Leddy, MJ Smith, AG Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J TI Yrast spectroscopy of N=82,83 isotopes Xe-136 and Xe-137 from Cm-248 fission SO PHYSICAL REVIEW C LA English DT Article ID PRODUCT GAMMA-RAY; NUCLEI; TRANSITIONS; SN-132; CF-252; CHARGE AB Prompt gamma-ray cascades in neutron-rich nuclei around doubly magic Sn-132 have been studied at Eurogam II using a Cm-248 fission source. Here we report results for the f our-valence-proton N = 82 nucleus Xe-136 and for its N = 83 neighbor Xe-137. For both nuclei, the yrast level spectra have been considerably extended, and empirical nucleon-nucleon interactions have been used to assign probable shell model configurations. The Xe-136 level energies are compared with those calculated using different sets of proton-proton interaction matrix elements, both diagonal and nondiagonal, obtained by fitting experimental data for other N = 82 isotones. C1 Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Univ Manchester, Dept Phys, Manchester M13 9PL, Lancs, England. Univ Manchester, Dept Astron, Manchester M13 9PL, Lancs, England. Univ Strasbourg 1, Inst Rech Subatom, F-67037 Strasbourg, France. Royal Inst Technol, Dept Phys Frescati, S-10405 Stockholm, Sweden. RP Daly, PJ (reprint author), Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. NR 16 TC 32 Z9 34 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 1999 VL 59 IS 6 BP 3066 EP 3070 DI 10.1103/PhysRevC.59.3066 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200015 ER PT J AU Broda, R Fornal, B Daly, PJ Zhang, CT Bhattacharyya, P Grabowski, ZW Cocks, JFC Butler, PA Greenlees, PT Jones, GD Jones, PM Julin, R Lee, IY Macchiavelli, AO Blomqvist, J AF Broda, R Fornal, B Daly, PJ Zhang, CT Bhattacharyya, P Grabowski, ZW Cocks, JFC Butler, PA Greenlees, PT Jones, GD Jones, PM Julin, R Lee, IY Macchiavelli, AO Blomqvist, J TI Five-valence-proton N=82 isotone Cs-137 SO PHYSICAL REVIEW C LA English DT Article ID SN-132 AB Yrast excitations in the N = 82 isotone Cs-137 have been identified for the first time in thick-target gamma-ray coincidence measurements for the system Th-232+Xe-136 using the Gammasphere array. The Cs-137 nuclei were produced in deep inelastic one-proton-transfer reactions. By-products of the main investigation were two well-developed rotational bands which were identified in heavy reaction partner products complementary to Cs-137 and are tentatively assigned to the little studied nucleus Ac-231. There was no difficulty in placing the 11 observed Cs-137 transitions in a yrast level scheme extending to an I-pi = (31/2(-)) level at 5494 keV. Interpretation was also straightforward, since the experimental level energies are in close agreement with results of shell model calculations performed earlier using empirical single particle energies and interaction matrix elements derived from experimental data for other N = 82 isotones. C1 Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Jyvaskyla, Dept Phys, Accelerator Lab, FIN-40351 Jyvaskyla, Finland. Lawrence Berkeley Natl Lab, Berkeley, CA 95720 USA. Royal Inst Technol, Dept Phys Frescati, S-10405 Stockholm, Sweden. RP Broda, R (reprint author), Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. OI Butler, Peter/0000-0001-6080-9205 NR 10 TC 23 Z9 23 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 1999 VL 59 IS 6 BP 3071 EP 3075 DI 10.1103/PhysRevC.59.3071 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200016 ER PT J AU Kondev, FG Riley, MA Hartley, DJ Brown, TB Laird, RW Lively, M Pfohl, J Sheline, RK Clark, RM Fallon, P Sarantites, DG Devlin, M LaFosse, DR Lerma, F Wadsworth, R Hibbert, IM O'Brien, NJ Paul, ES Joss, DT Nolan, PJ Shepherd, SL Archer, DE Simpson, J AF Kondev, FG Riley, MA Hartley, DJ Brown, TB Laird, RW Lively, M Pfohl, J Sheline, RK Clark, RM Fallon, P Sarantites, DG Devlin, M LaFosse, DR Lerma, F Wadsworth, R Hibbert, IM O'Brien, NJ Paul, ES Joss, DT Nolan, PJ Shepherd, SL Archer, DE Simpson, J TI Relative quadrupole deformations for decoupled structures in the odd-odd Pr-130 and Pr-132 nuclei SO PHYSICAL REVIEW C LA English DT Article ID DEFORMED ROTATIONAL BANDS; QUASI-PARTICLE STATES; LIFETIME MEASUREMENTS; SUPERDEFORMED BANDS; HIGH-SPIN; REGION; VI(13/2); MOMENT AB The quadrupole moments of three decoupled bands in the odd-odd nuclei Pr-130 and Pr-132 were measured using the Doppler shift attenuation method in the bombardment of Pd-105 with Cl-35 at 173 MeV. The pi h(11/2) x v(f(7/2), h(9/2)) configuration was assigned to these structures on the basis of the observed in-band properties and relative deformations. New information is presented on the shape-driving behavior of the 1/2(-) [541] (f(7/2), h(9/2)) intruder neutron orbital, whose involvement in a particular configuration leads to quadrupole deformation values which are intermediate between those known for normally deformed and so-called superdeformed bands in this mass region. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. CLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. RP Kondev, FG (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 48 TC 14 Z9 14 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 1999 VL 59 IS 6 BP 3076 EP 3085 DI 10.1103/PhysRevC.59.3076 PG 10 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200017 ER PT J AU Laue, CA Gregorich, KE Sudowe, R Hendricks, MB Adams, JL Lane, MR Lee, DM McGrath, CA Shaughnessy, DA Strellis, DA Sylwester, ER Wilk, PA Hoffman, DC AF Laue, CA Gregorich, KE Sudowe, R Hendricks, MB Adams, JL Lane, MR Lee, DM McGrath, CA Shaughnessy, DA Strellis, DA Sylwester, ER Wilk, PA Hoffman, DC TI New plutonium isotope: Pu-231 SO PHYSICAL REVIEW C LA English DT Article ID DECAY AB The new plutonium isotope, Pu-231, was produced by the U-233(He-3,5n)Pu-231 reaction. After chemical separation, the Pu-231 decay modes were studied using alpha-spectrometry. The isotope,Pu-231, was unequivocally identified by the alpha-decay of the chain members from its alpha- and electron-capture daughters using the alpha-alpha-correlation technique. The half-life of Pu-231 was determined to be (8.6+/-0.5) min. An cu-group with an energy of (6.72+/-0.03) MeV was assigned to Pu-231. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Laue, CA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd,MS 70A-3307, Berkeley, CA 94720 USA. RI Wilk, Philip/B-5954-2008; McGrath, Christopher/E-8995-2013 NR 20 TC 6 Z9 6 U1 0 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 1999 VL 59 IS 6 BP 3086 EP 3092 DI 10.1103/PhysRevC.59.3086 PG 7 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200018 ER PT J AU Esbensen, H Bertsch, GF AF Esbensen, H Bertsch, GF TI Nuclear induced breakup of halo nuclei SO PHYSICAL REVIEW C LA English DT Article ID B-8; FRAGMENTATION; COULOMB; LI-11 AB We investigate the validity of approximations that are sometimes made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled-channels calculations, in which the nuclear couplings between continuum states are ignored, gives almost the same result as a first-order calculation. However, the couplings are much too strong to justify these approximations. This is demonstrated in the frozen limit of a semiclassical description, where one can compare to exact results. We find in this limit that the one-neutron removal cross section of Be-11 obtained in the approximate treatment is much larger than the exact result. This trend is also indicated at low energy by comparing a perturbative calculation of the breakup of B-8 to the result of a more realistic treatment, which evolves the wave function of the valence proton essentially to all orders in the target fields. [S0556-2813(99)01406-5]. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. RP Esbensen, H (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 13 TC 71 Z9 71 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 1999 VL 59 IS 6 BP 3240 EP 3245 DI 10.1103/PhysRevC.59.3240 PG 6 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200035 ER PT J AU Ayala, A Jeon, SY Kapusta, J AF Ayala, A Jeon, SY Kapusta, J TI Size of fireballs created in high energy heavy ion collisions as inferred from Coulomb distortions of pion spectra SO PHYSICAL REVIEW C LA English DT Article ID SINGLE-PARTICLE; DISTRIBUTIONS; NA49 AB We compute the Coulomb effects produced by an expanding highly charged fireball on the momentum distribution of pions. We compare our results to data on Au + Au at 11.6A GeV from E866 at the BNL AGS and to data on Pb + Pb at 158A GeV from NA44 at the CERN SPS. We conclude that the distortion of the spectra at low transverse momentum and midrapidity can be explained in both experiments by the effect of the large amount of participating charge in the central rapidity region. By adjusting the fireball expansion velocity to match the average transverse momentum of protons, we find a best fit when the fireball radius is about 10 fm, as determined by the moment when the pions undergo their last scattering. This value is common to both the AGS and CERN experiments. [S0556-2813(99)04406-4]. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Ayala, A (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Apartado Postal 70-543, Mexico City 04510, DF, Mexico. NR 17 TC 9 Z9 9 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 1999 VL 59 IS 6 BP 3324 EP 3328 DI 10.1103/PhysRevC.59.3324 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200045 ER PT J AU Schaffner-Bielich, J Randrup, J AF Schaffner-Bielich, J Randrup, J TI Disoriented chiral condensate dynamics with the SU(3) linear sigma model SO PHYSICAL REVIEW C LA English DT Article ID HIGH-ENERGY COLLISIONS; HEAVY-ION COLLISIONS; PHASE-TRANSITION; QCD; FIELD; CONFIRMATION; ENHANCEMENT; EVOLUTION; DOMAINS; PLASMA AB The SU(3) extension of the linear sigma model is employed to elucidate the effect of including strangeness on the formation of disoriented chiral condensates. By means of a Hartree factorization, approximate dispersion relations for the 18 scalar and pseudoscalar meson species are derived and their self-consistent solution makes it possible to trace out the thermal path of the two order parameters as well as delineate the region of instability within which spontaneous pair creation becomes possible. The results depend significantly on the employed sigma mass, with the highest values yielding the largest regions of instability. An approximate solution of the equations of motion for the order parameter in scenarios emulating uniform scaling expansions show that even with a rapid quench only the pionic modes grow unstable. Nevertheless, the rapid and oscillatory relaxation of the order parameters leads to enhanced production of both pions and (to a lesser degree) kaons. [S0556-2813(99)00506-3]. C1 Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Schaffner-Bielich, J (reprint author), Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. NR 60 TC 23 Z9 23 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 1999 VL 59 IS 6 BP 3329 EP 3342 DI 10.1103/PhysRevC.59.3329 PG 14 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200046 ER PT J AU Zaerpoor, K Chan, YD Dragowsky, MR Issac, MCP Krane, KS Larimer, RM Macchiavelli, AO Macleod, RW Norman, EB AF Zaerpoor, K Chan, YD Dragowsky, MR Issac, MCP Krane, KS Larimer, RM Macchiavelli, AO Macleod, RW Norman, EB TI Cosmic-ray half-life of Ni-56 SO PHYSICAL REVIEW C LA English DT Article AB The positron decay partial half-life of Ni-56 is needed to employ this isotope as a cosmic-ray chronometer. We conducted an experiment by counting a purified 2.8-mu Ci source of Ni-56 in GAMMASPHERE in order to search for the beta(+)-decay branch of this isotope. A plastic scintillator was used to measure the energy of positrons in coincidence with the positron-annihilation gamma rays and the characteristic 158-keV gamma ray line. A careful analysis of 96 h of source counting shows no net signal and results in an upper limit of 77 counts of 511-511-158 keV plus scintillator coincident events. From this result we establish a 1 sigma upper limit on the branch for this decay mode to be (6.3 x 10(-5))%. The discrepancy between the outcome of this experiment and previous measurements of this branch and the implications of this result for the Ni-56 cosmic-ray chronometer problem are discussed. [S0556-2813(99)01306-0]. C1 Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Zaerpoor, K (reprint author), Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. NR 9 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 1999 VL 59 IS 6 BP 3393 EP 3396 DI 10.1103/PhysRevC.59.3393 PG 4 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200053 ER PT J AU Sinyukov, YM Akkelin, SV Xu, N AF Sinyukov, YM Akkelin, SV Xu, N TI Final conditions in high energy heavy ion collisions SO PHYSICAL REVIEW C LA English DT Article ID RELATIVISTIC NUCLEAR COLLISIONS; PION INTERFEROMETRY; 200A GEV; RADII; GAS AB Motivated by recent experimental observations, we discuss the freeze-out properties of the fireball created in central heavy ion collisions. We find that the freeze-out parameters, temperature T, and velocity gradient near the center of the fireball are similar for different colliding systems and beam energies. This means that the transverse flow is stronger in collisions of heavy nuclei than that of light ones. [S0556-2813(99)06205-6]. C1 Bogolyubov Inst Theoret Phys, UA-252143 Kiev, Ukraine. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Sinyukov, YM (reprint author), Bogolyubov Inst Theoret Phys, UA-252143 Kiev, Ukraine. NR 23 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 1999 VL 59 IS 6 BP 3437 EP 3440 DI 10.1103/PhysRevC.59.3437 PG 4 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200061 ER PT J AU Bingham, CR Batchelder, JC Rykaczewski, K Toth, KS Yu, CH Ginter, TN Gross, CJ Grzywacz, R Karny, M Kim, SH MacDonald, BD Mas, J McConnell, JW Semmes, PB Szerypo, J Weintraub, W Zganjar, EF AF Bingham, CR Batchelder, JC Rykaczewski, K Toth, KS Yu, CH Ginter, TN Gross, CJ Grzywacz, R Karny, M Kim, SH MacDonald, BD Mas, J McConnell, JW Semmes, PB Szerypo, J Weintraub, W Zganjar, EF TI Identification of a proton-emitting isomer in Lu-151 SO PHYSICAL REVIEW C LA English DT Article ID DRIP-LINE; NUCLEI; RADIOACTIVITY; ENERGIES; DECAY AB An isomer of Lu-151 was identified by its direct proton radioactivity. It was produced by bombardment of Ru-96 With 266-MeV Ni-58 from the Holifield Radioactive-Ion Beam Facility, mass separated with a recoil separator and implanted in a double-sided silicon strip detector, which provided signals to correlate each proton decay with a particular implant. The proton energy and half-life of Lu-151(m) were measured to be 1310(10) keV and 16(1) mu s, respectively. The half-life of the previously known hll, ground state was observed to be 80(2) ms in agreement with the previously adopted value of 88(10) ms. Comparison of the half-life of Lu-151(m) with WKB barrier-penetration calculations leads to the conclusion that the isomer is a d(3/2) proton state. A two-potential approach predicts a half-life of 5.5(-1.1)(+1.4) mu s which yields an experimental spectroscopic factor of 0.34(-0.08)(+0.12). C1 Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Vanderbilt Univ, Nashville, TN 37235 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Tennessee Technol Univ, Cookeville, TN 38505 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. RP Bingham, CR (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 24 TC 43 Z9 46 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 1999 VL 59 IS 6 BP R2984 EP R2988 DI 10.1103/PhysRevC.59.R2984 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200003 ER PT J AU Capstick, S Lee, TSH Roberts, W Svarc, A AF Capstick, S Lee, TSH Roberts, W Svarc, A TI Evidence for the fourth P-11 resonance predicted by the constituent quark model SO PHYSICAL REVIEW C LA English DT Article ID PARTICLE PHYSICS; BARYONS; CHROMODYNAMICS; 3-CHANNEL; AMPLITUDE; DECAYS AB It is pointed out that the third of five low-lying P-11 states predicted by a constituent quark model can be identified with the third of four states in a solution From a three-channel analysis by the Zagreb group. This is one of the so-called "missing" resonances, predicted at 1880 MeV. The fit of the Zagreb group to the pi N --> eta N data is the crucial element in finding this fourth resonance in the P-11 partial wave. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Natl Sci Fdn, Arlington, VA 22230 USA. Rudjer Boskovic Inst, Zagreb, Croatia. RP Capstick, S (reprint author), Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. NR 18 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 1999 VL 59 IS 6 BP R3002 EP R3004 DI 10.1103/PhysRevC.59.R3002 PG 3 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200007 ER PT J AU Poli, GL Davids, CN Woods, PJ Seweryniak, D Batchelder, JC Brown, LT Bingham, CR Carpenter, MP Conticchio, LF Davinson, T DeBoer, J Hamada, S Henderson, DJ Irvine, RJ Janssens, RVF Maier, HJ Muller, L Soramel, F Toth, KS Walters, WB Wauters, J AF Poli, GL Davids, CN Woods, PJ Seweryniak, D Batchelder, JC Brown, LT Bingham, CR Carpenter, MP Conticchio, LF Davinson, T DeBoer, J Hamada, S Henderson, DJ Irvine, RJ Janssens, RVF Maier, HJ Muller, L Soramel, F Toth, KS Walters, WB Wauters, J TI Proton and alpha radioactivity below the Z=82 shell closure SO PHYSICAL REVIEW C LA English DT Article ID INTRUDER STATES; DRIP-LINE; NUCLEI; ISOTOPES; MASS; DECAY AB Ground and isomeric proton and alpha decay branches are reported for the new isotope Tl-177, produced by bombarding a Pd-102 target with a 370 MeV beam of Kr-78 ions, The ground state is assigned as a pi s(1/2) configuration and the high spin isomer is assigned as a (pi h(11/2))(-1) configuration. The ground-state proton decay of Au-171 has been identified for the first time, produced by bombarding a Ru-96 target with Kr-78 ions. The Au-171 ground state is also assigned as a pi s(1/2) configuration. Spectroscopic factors, masses, and proton separation energies are derived using these new proton decay measurements. New ground-state cr decays for Ir-169 and (173)A are also reported. C1 Univ Milan, Ist Fis Gen Appl, I-20133 Milan, Italy. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Munich, Sekt Phys, D-85748 Garching, Germany. Adv Sci Res Ctr, Japan Atom Energy Res Inst, Oarai, Ibaraki 31911, Japan. Ist Nazl Fis Nucl, Sez Padova, I-35133 Padua, Italy. Univ Udine, Dipartimento Fis, I-33100 Udine, Italy. Univ Udine, Ist Nazl Fis Nucl, I-33100 Udine, Italy. RP Poli, GL (reprint author), Univ Milan, Ist Fis Gen Appl, I-20133 Milan, Italy. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 16 TC 57 Z9 57 U1 0 U2 7 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 1999 VL 59 IS 6 BP R2979 EP R2983 DI 10.1103/PhysRevC.59.R2979 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200002 ER PT J AU Titov, AI Lee, TSH Toki, H AF Titov, AI Lee, TSH Toki, H TI Isotopic effect in phi photoproduction at a few GeV SO PHYSICAL REVIEW C LA English DT Article ID NEAR-THRESHOLD; VECTOR-MESONS; SCATTERING; NUCLEON; STRANGENESS; PROTON AB A distinct isotopic pi - eta interference effect in cp photoproduction at root s similar to 2-5 GeV region is identified by examining the Pomeron- and meson-exchange amplitudes. This isotopic interference effect is a consequence of the SU(3) symmetry and the isotopic structure of the gamma NN coupling in the direct phi-radiation amplitude. It can be tested experimentally by measuring differences in the polarization observables between the gamma p --> phi p and gamma n --> phi n reactions. C1 Osaka Univ, Nucl Phys Res Ctr, Ibaraki, Osaka 5670047, Japan. Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Russia. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Titov, AI (reprint author), Osaka Univ, Nucl Phys Res Ctr, Ibaraki, Osaka 5670047, Japan. NR 27 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 1999 VL 59 IS 6 BP R2993 EP R2997 DI 10.1103/PhysRevC.59.R2993 PG 5 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200005 ER PT J AU Uusitalo, J Davids, CN Woods, PJ Seweryniak, D Sonzogni, AA Batchelder, JC Bingham, CR Davinson, T deBoer, J Henderson, DJ Maier, HJ Ressler, JJ Slinger, R Walters, WB AF Uusitalo, J Davids, CN Woods, PJ Seweryniak, D Sonzogni, AA Batchelder, JC Bingham, CR Davinson, T deBoer, J Henderson, DJ Maier, HJ Ressler, JJ Slinger, R Walters, WB TI Proton emission from the closed neutron shell nucleus Ta-155 SO PHYSICAL REVIEW C LA English DT Article ID DRIP-LINE; RADIOACTIVITY; EMITTERS AB Proton radioactivity from the closed neutron shell nucleus Ta-155 has been observed. It was produced via the p4n fusion evaporation channel using a Ni-58 beam on a Pd-102 target. The measured decay properties are E-p = 1765(10) keV and t(1/2) = 12(-3)(+4) mu s. Spin and parity J(pi) = 11/2(-) and a spectroscopic factor S-p(exp) = 0.58(-0.15)(+0.20) characterize the decaying state. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Munich, Sekt Phys, D-85748 Garching, Germany. RP Uusitalo, J (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Ressler, Jennifer Jo/F-2279-2010 NR 18 TC 16 Z9 16 U1 0 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 1999 VL 59 IS 6 BP R2975 EP R2978 DI 10.1103/PhysRevC.59.R2975 PG 4 WC Physics, Nuclear SC Physics GA 204RP UT WOS:000080778200001 ER PT J AU Balazs, C Yuan, CP AF Balazs, C Yuan, CP TI Higgs boson production at hadron colliders with soft gluon effects: Backgrounds SO PHYSICAL REVIEW D LA English DT Article ID TRANSVERSE-MOMENTUM DISTRIBUTION; DOUBLE-PHOTON PRODUCTION; TO-BACK JETS; QCD CORRECTIONS; PROTON COLLIDERS; PAIR PRODUCTION; RADIATIVE-CORRECTIONS; INELASTIC-SCATTERING; PERTURBATION-THEORY; COLLISIONS AB The gold-plated discovery mode of a standard model like Higgs boson at the CERN Large Hadron Collider (LHC) is the H-->Z(0)Z(0) decay mode. To find and then measure the properties of the Higgs boson, it is crucial to have the most precise theoretical prediction both for the signal and the QCD background in this mode. In this work we calculate the effects of the initial-state multiple soft-gluon emission on the kinematic distributions of Z(0) boson and photon pairs produced in hadron collisions. The Collins-Soper-Sterman formalism is extended to resum the large logarithmic terms due to soft gluons. The resummed total rates, the invariant mass, transverse momentum, and rapidity distributions of the Z(0) and photon pairs, and the transverse momentum distributions of the individual vector bosons are presented and compared to the fixed order predictions in the whole kinematic range, for the LHC energies and for the upgraded Fermilab Tevatron. Our conclusion is that the resummed predictions should be used when extracting the Higgs signal at the LHC. [S0556-2821(99)05709-4]. C1 Michigan State Univ, E Lansing, MI 48824 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Balazs, C (reprint author), Michigan State Univ, E Lansing, MI 48824 USA. EM balazs@pa.msu/edu; yuan@pa.msu.edu NR 59 TC 30 Z9 30 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 1999 VL 59 IS 11 AR 114007 DI 10.1103/PhysRevD.59.114007 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900026 ER PT J AU Benayoun, M DelBuono, L Eidelman, S Ivanchenko, VN O'Connell, HB AF Benayoun, M DelBuono, L Eidelman, S Ivanchenko, VN O'Connell, HB TI Radiative decays, nonet symmetry, and SU(3) breaking SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PERTURBATION-THEORY; PION FORM-FACTOR; HIDDEN LOCAL SYMMETRIES; DYNAMICAL GAUGE BOSONS; VECTOR-MESONS; MOMENTUM DEPENDENCE; ETA-GAMMA; QUARK; PHYSICS; MODEL AB We reexamine the problem of simultaneously describing in a consistent way all radiative and leptonic decays of light mesons (V --> P gamma, P --> V gamma, P --> gamma gamma, V --> e(+)e(-)). For this purpose, we rely on the hidden local symmetry model in both its anomalous and non-anomalous sectors. We show that the SU(3) symmetry breaking scheme proposed by Bando, Kugo and Yamawaki, supplemented with nonet symmetry breaking in the pseudoscalar sector, allows one to reach a nice agreement with all data, except for the K*(+/-) radiative decay. An extension of this breaking pattern allows one to account for this particular decay mode too. Considered together, the whole set of radiative decays provides a pseudoscalar mixing angle theta(P) similar or equal to 11 degrees and a value for theta(V) which is similar or equal to 3 degrees from that of ideal mixing. We also show that it is impossible, in a practical sense, to disentangle the effects of nonet symmetry breaking and those of glue inside the eta', using only light meson decays. [S0556-2821(99)01013-9]. C1 Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, IN2P3, Paris, France. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Benayoun, M (reprint author), Univ Paris 06, LPNHE, Paris, France. OI O'Connell, Heath/0000-0002-1895-5310 NR 75 TC 62 Z9 62 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 1999 VL 59 IS 11 AR 114027 DI 10.1103/PhysRevD.59.114027 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900046 ER PT J AU Buttimore, NH Kopeliovich, BZ Leader, E Soffer, J Trueman, TL AF Buttimore, NH Kopeliovich, BZ Leader, E Soffer, J Trueman, TL TI Spin dependence of high energy proton scattering SO PHYSICAL REVIEW D LA English DT Review ID TOTAL CROSS-SECTION; COULOMB-NUCLEAR INTERFERENCE; PP ELASTIC-SCATTERING; POLARIZATION MEASUREMENTS; HADRONIC INTERFERENCE; REGGE PHENOMENOLOGY; ODDERON INTERCEPT; PERTURBATIVE QCD; IMPACT-PICTURE; GEV-C AB Motivated by the need for an absolute polarimeter to determine the beam polarization for the forthcoming BNL RHIC spin program, we study the spin dependence of the proton-proton elastic scattering amplitudes at high energy and small momentum transfer. In particular, we examine experimental evidence for the existence of an asymptotic part of the helicity-flip amplitude phi(5) which is not negligible relative to the largely imaginary average nonflip amplitude phi(+) = 1/2(phi(1) + phi(3)) We discuss theoretical estimates of r(5) = m phi(5)/root-t Im phi(+) based upon several approaches: exuapolation of low and medium energy Regge phenomenological results to high energies, models based on a hybrid of perturbative QCD and nonrelativistic quark models, and models based on eikonalization techniques. We also apply the rigorous, model-independent methods of analyticity and unitarity. We find the preponderence of evidence at currently available energy indicates that r(5) is small, probably less than 10%. The best available experimental limit comes from Fermilab E704: combined with rather weak theoretical assumptions those data indicate that \r(5)\ < 15%. These bounds are important because rigorous methods allow much larger values. Furthermore, in contradiction to a widely held prejudice that r(5) decreases with energy, general principles allow it to grow as fast as Ins asymptotically, and some of the models we consider show an even faster growth in the RHIC range. One needs a more precise measurement of r(5) or to bound it to be smaller than 5% in order to use the classical Coulomb-nuclear interference technique for RHIC polarimetry. Our results show how important the measurements of spin dependence at RHIC will be to our understanding of proton structure and scattering dynamics. As part of this study, we demonstrate the surprising result that proton-proton elastic scattering is self-analyzing, in the sense that all the helicity amplitudes can, in principle, be determined experimentally at small momentum transfer without a knowledge of the magnitude of the beam and target polarization. [S0556-2821(99)09109-2]. C1 Univ Dublin Trinity Coll, Sch Math, Dublin 2, Ireland. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ London Birkbeck Coll, London WC1E 7HX, England. CNRS Marseille Luminy, Ctr Phys Theor, F-13288 Marseille 09, France. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Buttimore, NH (reprint author), Univ Dublin Trinity Coll, Sch Math, Dublin 2, Ireland. NR 112 TC 84 Z9 84 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 1999 VL 59 IS 11 AR 114010 DI 10.1103/PhysRevD.59.114010 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900029 ER PT J AU Carlson, CE Carone, CD Goity, JL Lebed, RF AF Carlson, CE Carone, CD Goity, JL Lebed, RF TI Operator analysis of l=1 baryon masses in large N-c QCD SO PHYSICAL REVIEW D LA English DT Article ID 1/N-C EXPANSION; QUARK-MODEL; 1/N(C) EXPANSION; MAGNETIC-MOMENTS; EXCITED BARYONS; FLAVOR SYMMETRY; SPLITTINGS; BREAKING AB We consider in detail the mass operator analysis for the nonstrange l=1 excited baryons in large N-c QCD. We present a straightforward procedure for constructing the large N-c baryon wave functions, and provide complete analytic expressions for the matrix elements of all the independent isosinglet mass operators. We discuss the relationship between the old-fashioned operator analyses based on nonrelativistic SU(6) symmetry and the modern large N-c approach, which has a firmer theoretical foundation. We then suggest a possible dynamical interpretation for the subset of operators preferred strongly by the data. [S0556-2821 (49)07809-1]. C1 Coll William & Mary, Dept Phys, Nucl & Particle Theory Grp, Williamsburg, VA 23187 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Carlson, CE (reprint author), Coll William & Mary, Dept Phys, Nucl & Particle Theory Grp, Williamsburg, VA 23187 USA. NR 33 TC 125 Z9 125 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 1999 VL 59 IS 11 AR 114008 DI 10.1103/PhysRevD.59.114008 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900027 ER PT J AU Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Dambasuren, E Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Titov, A Viehhauser, G Wang, JC Bartelt, J Csorna, SE McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chan, S Eigen, G Lipeles, E Miller, JS Schmidtler, M Shapiro, A Sun, WM Urheim, J Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, J Sharma, V Asner, DM Gronberg, J Hill, TS Korte, CM Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Tajima, H Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Warburton, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Sahu, SK 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 Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Schwarthoff, H Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Bishai, M Chen, S Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X AF Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Dambasuren, E Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Titov, A Viehhauser, G Wang, JC Bartelt, J Csorna, SE McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chan, S Eigen, G Lipeles, E Miller, JS Schmidtler, M Shapiro, A Sun, WM Urheim, J Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, J Sharma, V Asner, DM Gronberg, J Hill, TS Korte, CM Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Tajima, H Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Warburton, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Sahu, SK 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 Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Schwarthoff, H Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Bishai, M Chen, S Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X CA CLEO Collaboration TI Search for exclusive rare baryonic decays of B mesons SO PHYSICAL REVIEW D LA English DT Article ID CP-VIOLATION; ANTIBARYON; DETECTOR AB We report the results of a search for the rare baryonic decay modes B0-->Lambda<(Lambda)over bar>, B+--><(Lambda)over bar>p, B-0--><(Lambda)over bar>Kp pi(-), and B-0-->p (p) over bar (and their charge conjugate states) using 5.8X10(6) B (B) over bar pairs collected with the CLEO detector. We see no statistically significant signals in any of these modes and set 90% confidence level upper limits on their branching fractions, B(B-0-->Lambda<(Lambda)over bar>)<3.9X10(-6), B(B+--><(Lambda)over bar>p)<2.6X10(-6), B(B-0--><(Lambda)over bar>p pi(-))<1.3X10(-5), and B(B-0-->p (p) over bar)<7.0X10(-6). [S0556-2821(99)50311-1]. C1 So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Texas, Austin, TX 78712 USA. Yonsei Univ, Seoul 120749, South Korea. RP Coan, TE (reprint author), So Methodist Univ, Dallas, TX 75275 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014; OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039; Poling, Ronald/0000-0001-7305-4702 NR 18 TC 19 Z9 19 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 1999 VL 59 IS 11 AR 111101 DI 10.1103/PhysRevD.59.111101 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900001 ER PT J AU Gronau, M Rosner, JL AF Gronau, M Rosner, JL TI Combining CP asymmetries in B -> K pi decays SO PHYSICAL REVIEW D LA English DT Article ID WEAK PHASE-GAMMA; RARE B-DECAYS; ELECTROWEAK PENGUIN; ISOSPIN ANALYSIS; ANGLE-GAMMA; VIOLATION; DIAGRAMS; PSEUDOSCALARS; AMPLITUDES; MESONS AB We prove an approximate relation, to leading order in dominant terms, between CP-violating rate differences in B-0/(B) over bar(0)-->K+/- pi(-/+) and B+/--->K+/- pi(0). We show how data from these two processes may be combined in order to enhance the significance of a nonzero result. [S0556-2821(99)05909-3]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. RP Gronau, M (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 42 TC 65 Z9 65 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 1999 VL 59 IS 11 AR 113002 DI 10.1103/PhysRevD.59.113002 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900005 ER PT J AU Hall, LJ Smith, D AF Hall, LJ Smith, D TI Leading order textures for lepton mass matrices SO PHYSICAL REVIEW D LA English DT Article ID NEUTRINO MASS; ATMOSPHERIC NEUTRINOS; SOLAR NEUTRINOS; OSCILLATIONS; MATTER; QUARK; HIERARCHY AB In theories with three light neutrinos, certain simplicity assumptions allow the construction of a complete list of leading order lepton mass matrices. These matrices are consistent with m(tau)not equal 0,Delta m(12)(2)much less than Delta m(23)(2),theta(23)similar to O(1) and theta(13)=0, as suggested by measurements of atmospheric and solar neutrino fluxes. The list contains twelve generic cases: two have three degenerate neutrinos, eight have two neutrinos forming a Dirac state, and in only two cases is one neutrino much heavier than the other two. For each of these twelve generic cases the possible forms for the perturbations which yield m(mu) are given. Ten special textures are also found. [S0556-2821(99)06011-7]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys, Berkeley, CA 94720 USA. NR 33 TC 7 Z9 7 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 1999 VL 59 IS 11 AR 113013 DI 10.1103/PhysRevD.59.113013 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900016 ER PT J AU Rizzo, TG AF Rizzo, TG TI Distinguishing indirect signatures of new physics at the NLC : Z ' versus R-parity violation SO PHYSICAL REVIEW D LA English DT Article ID LEPTON NUMBERS; BREAKING; MODELS; SUPERSYMMETRY; LEPTOQUARKS; COLLIDERS; RESONANCE; COUPLINGS; LEP2 AB R-parity violation and extensions of the standard model gauge structure offer two nonminimal realizations of supersymmetry at low energies that can lead to simiIar new physics signatures at existing and future colliders. We discuss techniques that can be employed at the NLC below direct production threshold to distinguish these two new physics scenarios. [S0556-2821(99)07309-9]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Rizzo, TG (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 39 TC 25 Z9 25 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 1999 VL 59 IS 11 AR 113004 DI 10.1103/PhysRevD.59.113004 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900007 ER PT J AU Rizzo, TG AF Rizzo, TG TI More and more indirect signals for extra dimensions at more and more colliders SO PHYSICAL REVIEW D LA English DT Article ID E(-)E(-) COLLISIONS; TEV; MILLIMETER; SCATTERING AB It has been recently suggested by Arkani-Ramed,Dimopoulos and Dvali that gravity may become strong at energies not far above the electroweak scale and thus remove the hierarchy problem. Such a scenario can be tested at both-present and future accelerators since towers of Kaluza-Klein gravitons and associated scalar fields now play an important phenomenological role. In this paper we examine several processes for their sensitivity to a low scale for quantum gravity including deep inelastic ep scattering at DESY HERA, high precision low energy nu N scattering, Bhabha and Moller scattering at linear colliders and both fermion and gluon pair production at gamma gamma colliders. [S0556-2821(99)00413-0]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Rizzo, TG (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 47 TC 125 Z9 125 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 1999 VL 59 IS 11 AR 115010 DI 10.1103/PhysRevD.59.115010 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 204RX UT WOS:000080778900060 ER PT J AU Jarzynski, C Mazonka, O AF Jarzynski, C Mazonka, O TI Feynman's ratchet and pawl: An exactly solvable model SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR MOTORS; THERMAL RATCHET; PARTICLES; MOTION AB We introduce a simple, discrete model of Feynman's ratchet and pawl, operating between two heat reservoirs. We solve exactly for the steady-state directed motion and heat Flows produced, first in the absence and then in the presence of an external load. We show that the model can act both as a heat engine and as a refrigerator. We finally investigate the behavior of the system near equilibrium and use our model to confirm general predictions based on linear-response theory. [S1063-651X(99)07506-6]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Inst Nucl Studies, Otwock, Poland. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM chrisj@lanl.gov; maz@iriss.ipj.gov.pl RI Jarzynski, Christopher/B-4490-2009 OI Jarzynski, Christopher/0000-0002-3464-2920 NR 25 TC 56 Z9 58 U1 3 U2 17 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 1999 VL 59 IS 6 BP 6448 EP 6459 DI 10.1103/PhysRevE.59.6448 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 210YY UT WOS:000081134200033 PM 11969630 ER EF