FN Thomson Reuters Web of Science™ VR 1.0 PT J AU PRICHARD, D THEILER, J AF PRICHARD, D THEILER, J TI GENERATING SURROGATE DATA FOR TIME-SERIES WITH SEVERAL SIMULTANEOUSLY MEASURED VARIABLES SO PHYSICAL REVIEW LETTERS LA English DT Article ID POWER-LAW SPECTRA; CORRELATION DIMENSION; CHAOTIC ATTRACTORS; LYAPUNOV EXPONENTS; FRACTAL DIMENSION; SHALLOW-WATER; NOISE; SYSTEMS; EEG; DYNAMICS AB We propose an extension to multivariate time series of the phase-randomized Fourier-transform algorithm for generating surrogate data. Such surrogate data sets must mimic not only the autocorrelations of each of the variables in the original data set, they must mimic the cross correlations between all the variables as well. The method is applied both to a simulated example (the three components of the Lorenz equations) and to data from a multichannel electroencephalogram. C1 UNIV ALASKA,DEPT PHYS,FAIRBANKS,AK 99775. SANTA FE INST,SANTA FE,NM 87505. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 40 TC 257 Z9 268 U1 2 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 951 EP 954 DI 10.1103/PhysRevLett.73.951 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800010 ER PT J AU KUNG, P LIHN, HC WIEDEMANN, H BOCEK, D AF KUNG, P LIHN, HC WIEDEMANN, H BOCEK, D TI GENERATION AND MEASUREMENT OF 50-FS (RMS) ELECTRON PULSES SO PHYSICAL REVIEW LETTERS LA English DT Article AB An electron source has been developed at the Stanford SUNSHINE facility which can produce electron bunches as short as 50 fs (rms) with (2-4.6) X 10(8)e- per microbunch. This source consists of a 2.6 MeV rf gun with a thermionic cathode and an alpha magnet for bunch compression. Coherent transition radiation emitted at wavelengths equal to the bunch length and longer is used in a Michelson interferometer to determine the bunch length by optical autocorrelation. The experimental setup and results of bunch length measurements are described. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. RP KUNG, P (reprint author), STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305, USA. NR 7 TC 145 Z9 146 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 967 EP 970 DI 10.1103/PhysRevLett.73.967 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800014 ER PT J AU WONG, GCL LUCAS, CA LORETTO, D PAYNE, AP FUOSS, PH AF WONG, GCL LUCAS, CA LORETTO, D PAYNE, AP FUOSS, PH TI PARALLEL ADATOM CHAINS ON SI(111) - A CHEMISORPTION-INDUCED SURFACE RECONSTRUCTION SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIFFRACTION; INTERFACE AB Using surface x-ray scattering, we have studied a (3 x 1) Si(111) reconstruction induced by chemisorption of CaF2. This reconstruction consists of a parallel array of zigzag Si adatom chains oriented along [110BAR]. The orbitals on the Si chain atoms rehybridize into p(x) and p(y) along the surface to form sigma bonds, and parallel sp(z) orbitals perpendicular to the surface to give additional pi bonding. This basic structure, with no dangling bonds at only 1/3 monolayer adsorbate coverage, may explain the occurrence of (3 x 1) reconstructions among a diverse range of Si-adsorbate systems. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP WONG, GCL (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Lucas, Christopher/0000-0001-5743-3868 NR 31 TC 37 Z9 37 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 991 EP 994 DI 10.1103/PhysRevLett.73.991 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800020 ER PT J AU TRANQUADA, JM BUTTREY, DJ SACHAN, V LORENZO, JE AF TRANQUADA, JM BUTTREY, DJ SACHAN, V LORENZO, JE TI SIMULTANEOUS ORDERING OF HOLES AND SPINS IN LA2NIO4.125 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC CORRELATIONS; PHASE-SEPARATION; HUBBARD-MODEL; LA2NIO4+DELTA; OXYGEN; POLARONS AB We report a single-crystal neutron diffraction study of the incommensurate magnetic ordering that occurs in La2NiO4.125 below 110 K. Besides the magnetic first and third harmonic Bragg peaks, we have also observed second harmonic peaks associated with charge ordering. The magnitude of the incommensurate splitting, epsilon, is strongly temperature dependent. Lock-in behavior indicates that epsilon tends to rational fractions, while regions of continuous variation suggest a devil's staircase. Analysis of these features indicates that the holes, induced by the excess oxygen, order in domain walls that form antiphase boundaries between antiferromagnetic domains. C1 UNIV DELAWARE,DEPT CHEM ENGN,NEWARK,DE 19716. 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 20 TC 321 Z9 321 U1 2 U2 27 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 1003 EP 1006 DI 10.1103/PhysRevLett.73.1003 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800023 ER PT J AU WALD, KR KOUWENHOVEN, LP MCEUEN, PL VANDERVAART, NC FOXON, CT AF WALD, KR KOUWENHOVEN, LP MCEUEN, PL VANDERVAART, NC FOXON, CT TI LOCAL DYNAMIC NUCLEAR-POLARIZATION USING QUANTUM POINT CONTACTS SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; RELAXATION AB We have used quantum point contacts (QPCs) to locally create and probe dynamic nuclear polarization (DNP) in GaAs heterostructures in the quantum Hall regime. DNP is created via scattering between spin-polarized Landau level electrons and the Ga and As nuclear spins, and it leads to hysteresis in the dc transport characteristics. The nuclear origin of this hysteresis is demonstrated by nuclear magnetic resonance (NMR). Our results show that QPCs can be used to create and probe local nuclear spin populations, opening up new possibilities for mesoscopic NMR experiments. C1 PHILIPS RES LABS,REDHILL RH1 5HA,SURREY,ENGLAND. LAWRENCE BERKELEY LAB,DIV MED,BERKELEY,CA 94720. DELFT UNIV TECHNOL,DEPT APPL PHYS,2600 GA DELFT,NETHERLANDS. RP WALD, KR (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 13 TC 130 Z9 130 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 1011 EP 1014 DI 10.1103/PhysRevLett.73.1011 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800025 ER PT J AU LIU, SH KLEMM, RA AF LIU, SH KLEMM, RA TI SURFACE-STATE EFFECTS IN HIGH-T(C) SUPERCONDUCTORS SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTOR; ENERGY-GAP STRUCTURE; LAYERED SUPERCONDUCTORS; FERMI-SURFACE; TUNNELING SPECTROSCOPY; OXIDE SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; BI2SR2CACU2O8; ANISOTROPY AB Under appropriate conditions a band of electronic surface states may exist on the topmost CuO2 layer of a high-T(c) superconductor. This layer can then have higher T(c) and energy gap values than the Bulk. The surface band vanishes at the k(x), k(y) points in the Brillouin zone where the bulk bands touch. Such surface states can cause tunneling results to depend upon the method and the geometry, and alter the interpretation of photoemission measurements of the energy gap. Both experiments are consistent with s-wave order parameter symmetry in high-T(c) materials. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP LIU, SH (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. NR 29 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 1019 EP 1022 DI 10.1103/PhysRevLett.73.1019 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800027 ER PT J AU WANG, LW ZUNGER, A AF WANG, LW ZUNGER, A TI DIELECTRIC-CONSTANTS OF SILICON QUANTUM DOTS SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAAS; SI; GE; GAP AB Quantum mechanical pseudopotential calculations of the absorption spectra and static dielectric constant epsilon(s) of Si quantum dots with approximately 100- 1300 atoms are presented. The predicted epsilon(s) is found to be significantly reduced relative to the bulk value, but is considerably larger than the value deduced from currently available model calculations. A convenient parametrization of epsilon(s) vs size R is provided. We find that for quantum dots with R < 20 angstrom the electron-hole pair is confined by the physical dimension of the dot, not by the Coulomb attraction. RP WANG, LW (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 26 TC 275 Z9 279 U1 2 U2 26 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 15 PY 1994 VL 73 IS 7 BP 1039 EP 1042 DI 10.1103/PhysRevLett.73.1039 PG 4 WC Physics, Multidisciplinary SC Physics GA PB988 UT WOS:A1994PB98800032 ER PT J AU SUNWOO, A AF SUNWOO, A TI DIFFUSION BONDING OF ALUMINUM-ALLOY, 8090 SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article RP SUNWOO, A (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 12 TC 10 Z9 10 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD AUG 15 PY 1994 VL 31 IS 4 BP 407 EP 412 DI 10.1016/0956-716X(94)90009-4 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NQ042 UT WOS:A1994NQ04200009 ER PT J AU HAWK, JA ALMAN, DE STOLOFF, NS AF HAWK, JA ALMAN, DE STOLOFF, NS TI ABRASIVE WEAR BEHAVIOR OF MOSI(2)-NB COMPOSITES SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID REINFORCED MOSI2 COMPOSITES C1 RENSSELAER POLYTECH INST,DEPT MAT ENGN,TROY,NY 12180. RP HAWK, JA (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 16 TC 27 Z9 45 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD AUG 15 PY 1994 VL 31 IS 4 BP 473 EP 478 DI 10.1016/0956-716X(94)90021-3 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NQ042 UT WOS:A1994NQ04200021 ER PT J AU ABDALLAH, J CLARK, REH AF ABDALLAH, J CLARK, REH TI COMPARISON OF EXPLICIT AND EFFECTIVE MODELS FOR CALCULATING IONIC POPULATIONS IN ARGON PLASMAS SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID FUSION AB Calculations have been performed to model the state populations of argon plasmas at electron densities at and above those required for the validity of coronal equilibrium. Both effective and explicit models have been used, and both are based on the same set of atomic cross sections. The effective model includes ground and singly excited states explicitly, while the effect of autoionizing states is accounted for by branching factors which describe their depopulation into the various non-autoionizing states. The explicit model considers both autoionizing and non-autoionizing states explicitly. The effective model requires a significantly reduced amount of computer time and memory. Good agreement between the two models can be obtained through moderate densities if the branching factors include electron density dependent terms which describe the collisional stabilization of each autoionizing state. The effective model breaks down as density is increased because the population of individual autoionizing states become significant. Results for both ionization balance and radiated power loss are presented. RP ABDALLAH, J (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD AUG 14 PY 1994 VL 27 IS 15 BP 3589 EP 3602 DI 10.1088/0953-4075/27/15/030 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PC870 UT WOS:A1994PC87000030 ER PT J AU REINHOLD, CO SHAO, H BURGDORFER, J AF REINHOLD, CO SHAO, H BURGDORFER, J TI EVOLUTION OF RYDBERG ANGULAR-MOMENTUM WAVEPACKETS IN HALF-CYCLE PULSES SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID ELECTROMAGNETIC PULSES; IONIZATION; ATOMS AB We study the redistribution of Rydberg states subject to half-cycle electromagnetic pulses as a function of the field strength and the duration of the pulses. It is found that the survival probability exhibits oscillations which are associated with the almost recurrent propagation of the electronic wavepacket in angular momentum space. The classical and quantal origin of the different 'Stark beat' frequencies is discussed. The dependence of the beats on the shape of the pulse and effects due to a non-hydrogenic core are analysed. The momentum transferred by the field is identified as a fundamental variable for the excitation function. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP REINHOLD, CO (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 20 TC 23 Z9 23 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD AUG 14 PY 1994 VL 27 IS 15 BP L469 EP L475 DI 10.1088/0953-4075/27/15/006 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PC870 UT WOS:A1994PC87000006 ER PT J AU MILNE, JC FURLONG, D HANNA, PC WALL, JS COLLIER, RJ AF MILNE, JC FURLONG, D HANNA, PC WALL, JS COLLIER, RJ TI ANTHRAX PROTECTIVE ANTIGEN FORMS OLIGOMERS DURING INTOXICATION OF MAMMALIAN-CELLS SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID DIPHTHERIA-TOXIN; ADENYLATE-CYCLASE; MEMBRANE TRANSLOCATION; EUKARYOTIC CELLS; BOTULINUM TOXIN; LIPID BILAYERS; STREPTOLYSIN-O; TETANUS TOXIN; ALPHA-TOXIN; LOW-PH AB The protective antigen component (PA) of anthrax toxin binds to receptors on target cells and conveys the toxin's edema factor (EF) and lethal factor (LF) components into the cytoplasm. PA (83 kDa) is processed by a cellular protease, yielding a 63-kDa fragment (PA(63)), which binds EF and/or LF. When exposed to acidic pH, PA(63) inserts into membranes and forms ion-conductive channels. By electron microscopy, a significant fraction of purified PA(63), was found to be in the form of a multisubunit ring-shaped oligomer (outer diameter, 10.4 nm). The rings are heptameric, as judged by inspection and by rotational power spectra. Purified PA(63) showed a high M(r) band, apparently corresponding to the oligomer, on SDS-polyacrylamide gels, and oligomer of similar size was formed in cells in a time-dependent manner after addition of full-length PA. Inhibitors of internalization and endosome acidification blocked conversion of cell-associated PA to a high molecular weight species, and medium at pH 5.0 induced oligomer formation in the presence or absence of the inhibitors. These results correlate PA(63) oligomerization with conditions required for translocation of EF and LF across lipid bilayers, implying that the PA(63) oligomer may function in translocation. C1 HARVARD UNIV,SCH MED,DEPT MICROBIOL & MOLEC GENET,BOSTON,MA 02115. HARVARD UNIV,SCH MED,SHIPLEY INST MED,BOSTON,MA 02115. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. OI Collier, R John/0000-0002-2427-4239 FU NCRR NIH HHS [RR01777]; NIAID NIH HHS [AI-22021, AI-22848] NR 42 TC 327 Z9 332 U1 1 U2 4 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 12 PY 1994 VL 269 IS 32 BP 20607 EP 20612 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PB317 UT WOS:A1994PB31700062 PM 8051159 ER PT J AU WHELTON, BD BHATTACHARYYA, MH PETERSON, DP MORETTI, ES TOOMEY, JM WILLIAMS, LL AF WHELTON, BD BHATTACHARYYA, MH PETERSON, DP MORETTI, ES TOOMEY, JM WILLIAMS, LL TI SKELETAL CHANGES IN MULTIPAROUS AND NULLIPAROUS MICE FED A NUTRIENT-DEFICIENT DIET CONTAINING CADMIUM SO TOXICOLOGY LA English DT Article DE CADMIUM; BONE LOSS; PREGNANCY; LACTATION; NUTRIENT-DEFICIENT DIET; ITAI-ITAI DISEASE ID GASTROINTESTINAL ABSORPTION; SUFFICIENT DIET; BONE; RATS; LACTATION; GESTATION; LESIONS; KIDNEY; METALLOTHIONEIN; RETENTION AB Female mice were given nutrient-deficient, purified diets containing either 0.25 (environmental), 5, or 50 ppm Cd; the nutrient quality of each was patterned after deficiencies known to be present in food consumed by Japanese women who contracted Itai-Itai disease. One-half of the mice were bred for six consecutive, 42-day rounds of pregnancy/lactation (PL mice); remaining females were non-pregnant, virgin controls (NP mice). PL and NP mice were sacrificed at the end of rounds 1, 2, 3, 5, or 6. PL mice taken during the first three rounds were successively pregnant; those taken in later rounds experienced gestation/lactation either four (round 5) or three (round 6) non-successive times. No consistent round-by-round decreases in diet consumption or body weight occurred among NP mice during the 252 days of cadmium exposure, however a significant decrease in femur calcium content (11-17%) was observed in virgin groups exposed to 50 vs. 0.25 ppm Cd. Similar femur decalcification (14-20%) was observed in PL mice, however calcium loss at 50 ppm Cd paralleled decreases in food consumption (24%) and body weight (9-17%). Significant but smaller decreases in the calcium/dry weight (Ca/DW) ratio were found for NP and PL groups consuming 50 ppm dietary Cd. Over the 6-round experiment, exposure to cadmium was found to effect smaller decreases in both femur Ca content and Ca/DW ratio than either consumption of nutrient-deficient diet or multiparous experience. Demineralization results for PL mice provide evidence that the combination of chronic ingestion of cadmium in a nutrient-deficient diet and multiparous activity likely played a role in the etiology of Itai-Itai disease; results for NP mice additionally suggest that decalcification may have been initiated in human females at a time prior to the multiparous and menopausal stages of life. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. CORNELL UNIV,SCH VET MED,ITHACA,NY 14850. MICHIGAN STATE UNIV,PESTICIDE RES CTR,E LANSING,MI 48824. RP WHELTON, BD (reprint author), EASTERN WASHINGTON UNIV,DEPT CHEM & BIOCHEM,MS 74,CHENEY,WA 99004, USA. NR 31 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0300-483X J9 TOXICOLOGY JI Toxicology PD AUG 12 PY 1994 VL 91 IS 3 BP 235 EP 251 DI 10.1016/0300-483X(94)90012-4 PG 17 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA PK034 UT WOS:A1994PK03400002 PM 8079363 ER PT J AU COVEY, C AF COVEY, C TI NO TREASON SO NATURE LA English DT Letter RP COVEY, C (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV GLOBAL CLIMATE RES,POB 808,MAIL CODE L-264,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 11 PY 1994 VL 370 IS 6489 BP 408 EP 408 DI 10.1038/370408b0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PB407 UT WOS:A1994PB40700019 ER PT J AU MONCTON, DE FENNER, RB AF MONCTON, DE FENNER, RB TI A STATUS UPDATE ON THE ADVANCED PHOTON SOURCE PROJECT - SUMMER 1993 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID X-RAY UNDULATOR; PERFORMANCE; CHESS AB The Advanced Photon Source Project has passed the mid-point in its construction. The linac and synchrotron booster enclosures are complete. A portion of the experiment hall has been completed and put into use to support accelerator component assembly, test, and installation. Plans for the user lab/office modules and the central laboratory/office complex are well advanced. Installation of the linac injection system has been completed and commissioning is beginning. Installation and commissioning of the positron accumulator ring, the booster synchrotron, the storage ring, and the rf power systems will follow. Accelerator operations capable of supporting the commissioning of the experimental beamlines is planned for the summer of 1995. A strong research program is continuing to produce results supportive of both accelerator and beamline construction and operations. Collaborative Access Teams have been formed to conduct research with the initial set of 32 beamlines that will be available at the completion of the first phase of construction. RP MONCTON, DE (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 39 EP 43 DI 10.1016/0168-9002(94)91850-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900007 ER PT J AU CANTWELL, K AF CANTWELL, K TI THE STANFORD-SYNCHROTRON-RADIATION-LABORATORY - 20 YEARS OF SYNCHROTRON LIGHT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The Stanford Synchrotron Radiation Laboratory (SSRL) is now operating as a fully dedicated light source with low emittance electron optics, delivering high brightness photon beams to 25 experimental stations six to seven months per year. On October 1, 1993 SSRL became a Division of the Stanford Linear Accelerator Center, rather than an independent Laboratory of Stanford University, so that high-energy physics and synchrotron radiation now function under a single DOE contract. The SSRL division of SLAC has responsibility for operating, maintaining and improving the SPEAR accelerator complex, which includes the storage ring and a 3 GeV injector. SSRL has thirteen X-ray stations and twelve VUV/soft X-ray stations serving its 600 users. Recently opened to users is a new spherical grating monochromator (SGM) and a multiundulator beam line. Circularly-polarized X-ray beam capabilities are being exploited on a second SGM line. New YB66 crystals installed in a vacuum double-crystal monochromator line have sparked new interest for Al and Mg edge studies. One of the most heavily-subscribed stations is the rotation camera, which has been recently enhanced with a MAR imaging plate detector system for protein crystallography on a multipole wiggler. Under construction is a new wiggler-based structural molecular biology beam line with experimental stations for crystallography, small-angle scattering and X-ray absorption spectroscopy. Plans for new developments include wiggler beam lines and associated facilities specialized for environmental research and materials processing. RP CANTWELL, K (reprint author), STANFORD SYNCHROTRON RADIAT LAB,MS 69,POB 4349,STANFORD,CA 94309, USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 44 EP 48 DI 10.1016/0168-9002(94)91851-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900008 ER PT J AU DEJUS, RJ AF DEJUS, RJ TI COMPUTER-SIMULATIONS OF THE WIGGLER SPECTRUM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The amount of structure seen in the wiggler spectrum, particularly at energies below the critical energy, depends on several parameters such as the beam emittance, magnetic field errors and the amount of tapering of the device. Simulations will be presented using the proposed Wiggler A at the Advanced Photon Source, which may be operated both in the undulator regime and the wiggler regime. A simple description of the wiggler spectrum is presented that emphasizes the importance of the magnitude of the deflection parameter K in practical computer simulations. Results will be given for the on-axis angular flux density for K between 6 and about 8, and comparison will be made with the bending magnet approximation. It is verified that a small beam emittance will not completely smooth fluctuations in the spectrum, even for energies well above the critical energy, for an otherwise ideal insertion device. It is shown that a small gap-taper dramatically smears the harmonics and provides a bending-magnet-type spectrum well below the critical energy. The importance of being able to simulate random magnetic field errors is addressed. RP DEJUS, RJ (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 56 EP 60 DI 10.1016/0168-9002(94)91854-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900011 ER PT J AU DEJUS, RJ LUCCIO, A AF DEJUS, RJ LUCCIO, A TI PROGRAM UR - GENERAL-PURPOSE CODE FOR SYNCHROTRON-RADIATION CALCULATIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID UNDULATOR AB A computer code for calculating synchrotron radiation emitted by a relativistic particle moving in an arbitrary three-dimensional magnetic field is described. The electric and magnetic fields (Lienard-Wiechert fields) are calculated in the time domain, and a Fourier transform of the radiation field yields the radiation spectrum over a large range of harmonic frequencies. The code is completely general accepting either a measured magnetic field map or a simulated field representing, for example, a tapered undulator. Simple expressions are derived for the fields and the equations of motion using the transverse beam angles as variables. The horizontal and vertical polarized components arc expanded to second order in the beam angles, the observation angles, and the opening angle of radiation (1/gamma), and the three-dimensional equations of motion are solved numerically at each time step, making the code fast and reliable. The beam emittance and the beam energy spread are simulated by either Monte Carlo sampling or deterministic sampling. Comparison with two other codes will be presented. Good agreement was found in both cases. As a practical example, we examined the effect of random magnetic field errors on the on-axis angular flux density for Undulator A at the Advanced Photon Source. It was confirmed that random magnetic field errors play an important role when predicting the spectral performance of real-life insertion devices. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP DEJUS, RJ (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 61 EP 66 DI 10.1016/0168-9002(94)91855-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900012 ER PT J AU WANG, CX SCHLEUTER, R HOYER, E HEIMANN, P AF WANG, CX SCHLEUTER, R HOYER, E HEIMANN, P TI DESIGN OF THE ADVANCED LIGHT-SOURCE ELLIPTIC WIGGLER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The elliptical wiggler is a circularly polarized light source capable of providing very broad spectral coverage and a high degree of circular polarization. The main features of an elliptical wiggler can be understood through analogy to bending magnet radiation. However, some aspects, such as the end structure's influence on the degree of circular polarization, require more elaborate methods to characterize. We present an algorithm based on the stationary-phase method, which allows calculation of radiation properties from an arbitrary electron trajectory, so a non-sinusoidal magnetic field's influence on the radiation performance can be taken into account. We show general radiation properties of an elliptical wiggler and discuss factors affecting the radiation produced. Practical issues encountered during the conceptual design of an elliptical wiggler at the Advanced Light Source are addressed. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 67 EP 72 DI 10.1016/0168-9002(94)91856-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900013 ER PT J AU LIDIA, S CARR, R AF LIDIA, S CARR, R TI AN ELLIPTICALLY-POLARIZING UNDULATOR WITH PHASE ADJUSTABLE ENERGY AND POLARIZATION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID MAGNETS AB We present a planar helical undulator designed to produce elliptically-polarized light. Helical magnetic fields may be produced by a variety of undulators with four parallel cassettes of magnets. In our design, all cassettes are mounted in two planes on slides so that they may be moved parallel to the electron beam. This allows us to produce X-rays of left- or right-handed elliptical or circular polarization as well as horizontal or vertical linear polarization. In model calculations, we have found that by sliding the top pair of rows with respect to the bottom pair, or the left pair with respect to the right pair, we retain the polarization setting but change the magnetic field strength, and hence the X-ray energy. This allows us to select both energy and polarization by independent phase adjustments alone, without changing the gap between the rows. Such a design may be simpler to construct than an adjustable-gap machine. We present calculations that model its operation and its effects on an electron beam. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RP LIDIA, S (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 12 TC 22 Z9 22 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 77 EP 82 DI 10.1016/0168-9002(94)91858-9 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900015 ER PT J AU WANG, CX SCHLEUTER, R AF WANG, CX SCHLEUTER, R TI OPTIMIZATION OF CIRCULARLY-POLARIZED RADIATION FROM AN ELLIPTIC WIGGLER, ASYMMETRIC WIGGLER, OR BENDING MAGNET SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB To collect circularly-polarized radiation from a bending magnet, elliptical wiggler, or asymmetric wiggler source, one must choose operating parameters to optimize their output according to user requirements. The trade-off between flux and degree of circular polarization is a basic feature of such dipole-type sources. In this paper, we discuss how to optimize the output based on two different criteria. The first is to maximize the intensity times the square of circular polarization degree (IP2), a widely used figure of merit in circular-dichroism experiments. The second is to maximize the intensity for a given degree of circular polarization, which is desirable in some cases. The results presented here provide guidelines for the design and operation of dipole-type sources to generate circularly-polarized radiation. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 7 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 92 EP 97 DI 10.1016/0168-9002(94)91861-9 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900018 ER PT J AU XU, S MAINES, J AF XU, S MAINES, J TI TEST OF A NEW MODEL POLE ASSEMBLY FOR AN ADVANCED PHOTON SOURCE UNDULATOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A set of model poles was assembled and tested as part of the design and verification of an Advanced Photon Source undulator. The model pole consists of a half period of a 3.1-cm periodic structure of the undulator. Steel mirror plates are used to set up the magnetic field boundary conditions. The vertical magnetic field component near the midplane of the model has been measured with a Hall probe as a function of gap and transverse position. The results of this study are presented. RP XU, S (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 102 EP 106 DI 10.1016/0168-9002(94)91863-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900020 ER PT J AU SMITH, NV HOWELLS, MR AF SMITH, NV HOWELLS, MR TI WHISPERING GALLERIES FOR THE PRODUCTION OF CIRCULARLY-POLARIZED SYNCHROTRON-RADIATION IN THE XUV REGION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID ULTRAVIOLET; OPTICS; LIGHT AB The physics of the soft-X-ray whispering gallery is outlined with emphasis on the delivery of circularly-polarized radiation in the photon energy range homegaBAR = 10-180 eV. Calculations of the relevant figure of merit TP2 (T = transmission, P = polarization) for candidate materials reveal exceptionally high efficiency for Rh (maximum TP2 = 56% at homegaBAR = 105 eV) and for Ag (44%, 125 eV). The practical implementation of a whispering gallery is discussed and compared with a 4-reflection device. The former offers high efficiency with narrow band pass (approximately 30%); the latter offers reasonable efficiency (TP2 = 4-28%) over an extended homegaBAR range (10-150 eV). C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. AT&T BELL LABS,MURRAY HILL,NJ 07974. NR 8 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 115 EP 118 DI 10.1016/0168-9002(94)91865-1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900022 ER PT J AU SMITH, NV HULBERT, SL JOHNSON, PD ERSKINE, JL AF SMITH, NV HULBERT, SL JOHNSON, PD ERSKINE, JL TI SPHERICAL-GRATING MONOCHROMATOR SYSTEM WITH CIRCULAR-POLARIZATION CAPABILITY FOR THE U5U UNDULATOR AT BROOKHAVEN SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION; LIGHT AB We plan to upgrade the U5U undulator beamline at Brookhaven with a 4-grating 3.5 m SGM (spherical-grating-monochromator) system offering the following enhancements in performance: (1) Improved imaging especially at the sample; (2) Small ''expendable'' gratings; and (3) Circular polarizer of the 4-reflection type. Ray tracing calculations are offered with emphasis on spot-size quality at the sample, and on the relative merits of scanning the exit- or entrance-slit to maintain focus. The excursion of the entrance slit coincides with the length of the undulator image. Calculations of the figure of merit TP2 (T = transmission, P = polarization) are presented for a 4-reflection circular polarizer using the candidate mirror materials Al, Ag, Au and Rh. Ag offers the widest range of coverage, homegaBAR = 10-150 eV, with reasonable throughput, TP2 = 4-18%. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712. RP SMITH, NV (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 119 EP 123 DI 10.1016/0168-9002(94)91866-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900023 ER PT J AU YAHNKE, CJ SRAJER, G HAEFFNER, DR MILLS, DM ASSOUFID, L AF YAHNKE, CJ SRAJER, G HAEFFNER, DR MILLS, DM ASSOUFID, L TI GERMANIUM X-RAY PHASE PLATES FOR THE PRODUCTION OF CIRCULARLY-POLARIZED X-RAYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID DEPENDENT MOMENTUM DISTRIBUTION; SYNCHROTRON RADIATION; IRON AB We have constructed an X-ray phase plate to produce linearly and circularly polarized X-rays at discrete energies between 20 keV and 88 keV. The plate is a monolithic two-crystal design, constructed from germanium. We have measured the degree of circular polarization at 65 keV to be 90% +/- 4%, which is significantly better than that produced by silicon phase plates. This radiation was used to measure the magnetic Compton profile for Fe, which was found to be in good agreement with theory and previous work. The underlying X-ray optics and the characterization of the device between 62 keV and 93 keV at the Cornell High Energy Synchrotron Source are presented. RP YAHNKE, CJ (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 128 EP 133 DI 10.1016/0168-9002(94)91868-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900025 ER PT J AU IDZERDA, YU CHEN, CT LIN, HJ MEIGS, G HO, GH KAO, CC AF IDZERDA, YU CHEN, CT LIN, HJ MEIGS, G HO, GH KAO, CC TI SOFT-X-RAY MAGNETIC CIRCULAR-DICHROISM AND MAGNETIC-FILMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID FE/CR/FE TRILAYERS; ABSORPTION; NICKEL AB Soft X-ray magnetic circular dichroism is the difference in the total absorption cross-section of positive and negative helicity circularly-polarized soft X-rays at the magnetically interesting L2 and L3 absorption edges of 3d tranSition metals or the M4 and M5 absorption edges of the rare earths. The absorption edges can be measured using a variety of techniques including transmission, partial electron yield, total electron yield, partial fluorescence yield, sample current, and reflection. The different measurement schemes represent different probing depths, allowing depth dependent studies, and are complementary to each other. A description of the relative merits of the various measurement schemes is presented. In addition, complications such as beam instability, saturation effect, and incident beam Bragg scattering into the detectors are discussed. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP IDZERDA, YU (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 18 TC 48 Z9 49 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 134 EP 141 DI 10.1016/0168-9002(94)91869-4 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900026 ER PT J AU MCNULTY, I AF MCNULTY, I TI THE FUTURE OF X-RAY HOLOGRAPHY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID MICROSCOPY; RESOLUTION; SPECIMENS; LASER AB X-ray holography is a promising technique for high resolution study of biological, microelectronics and materials science specimens. It offers absorption and phase contrast, it is amenable to flash sources, and it is capable of three-dimensional imaging when coupled with tomography. Soft X-rays are suited to microscopy of thin organic specimens and wet biological objects such as subcellular organelles. Major advances in X-ray sources, optics, and detectors have made possible Gabor and Fourier transform holography with 50 to 60-nm transverse resolution using 350-600 eV photons; 100-nm depth resolution by holographic tomography has recently been demonstrated. X-ray holography at higher energies (1-4 keV) may be feasible soon using third-generation synchrotron sources. These methods might profitably be used to investigate denser objects than are accessible to soft X-rays, for example defects in microcircuits and adsorbates in zeolites. The future is likely to see progress in X-ray holography over an increasing range of photon energies, with elemental and chemical specificity, and with three-dimensional resolution below one micron. RP MCNULTY, I (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 59 TC 22 Z9 22 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 170 EP 176 DI 10.1016/0168-9002(94)91874-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900031 ER PT J AU GLUSKIN, E MCNULTY, I YANG, L RANDALL, KJ XU, Z JOHNSON, ED AF GLUSKIN, E MCNULTY, I YANG, L RANDALL, KJ XU, Z JOHNSON, ED TI INTENSITY INTERFEROMETRY AT THE X13A UNDULATOR BEAMLINE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We are constructing an X-ray intensity interferometer and an undulator beamline to demonstrate intensity interferometry in the soft X-ray region. The 10-period X13 soft X-ray undulator at the National Synchrotron Light Source will provide the coherent flux; the X13A beamline will preserve the brightness of the X-ray beam and provide sufficient temporal coherence with a horizontally deflecting spherical grating monochromator. Using the interferometer, which consists of an array of small slits, a wedge-shaped beamsplitter and two fast microchannel plate detectors, we expect to measure the spatial coherence of the undulator beam and therefore the size of the source. The beamline design and the interferometry experiment are discussed. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP GLUSKIN, E (reprint author), ARGONNE NATL LAB, ARGONNE, IL 60439 USA. NR 13 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 177 EP 181 DI 10.1016/0168-9002(94)91875-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900032 ER PT J AU HOWELLS, MR FRANK, K HUSSAIN, Z MOLER, EJ REICH, T MOLLER, D SHIRLEY, DA AF HOWELLS, MR FRANK, K HUSSAIN, Z MOLER, EJ REICH, T MOLLER, D SHIRLEY, DA TI TOWARD A SOFT-X-RAY FOURIER-TRANSFORM SPECTROMETER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID DOUBLY-EXCITED-STATES; HIGH-RESOLUTION; HELIUM AB The use of Fourier transform spectroscopy in the soft X-ray region is advocated as a possible route to spectral resolution superior to that attainable with a grating system. A technical plan is described for applying Fourier transform spectroscopy to the study of the absorption spectrum of helium in the region of double ionization around 60-80 eV. The proposed scheme includes a Mach-Zehnder interferometer deformed into a rhombus shape to provide grazing-incidence reflections. The path difference between the interfering beams is to be tuned by translation of a table carrying four mirrors over a range +/- 1 cm which, in the absence of errors generating relative tilts of the wave fronts, would provide a resolving power equal to the number of waves of path difference: half a million at 65 eV, for example. The signal-to-noise ratio of the spectrum is analyzed and, for operation on an Advanced Light Source bending magnet beam line, should be about 330. C1 FAIRLEIGH DICKINSON UNIV,DEPT PHYS & ASTRON,TEANECK,NJ 07666. PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802. PENN STATE UNIV,DEPT CHEM,UNIVERSITY PK,PA 16802. RP HOWELLS, MR (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Reich, Tobias/C-7064-2016 OI Reich, Tobias/0000-0002-5600-3951 NR 30 TC 18 Z9 19 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 182 EP 191 DI 10.1016/0168-9002(94)91876-7 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900033 ER PT J AU JOHNSON, ED AF JOHNSON, ED TI CONCEPTS FOR ULTRAVIOLET-FREE ELECTRON LASER OPTICS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB Scientists at Brookhaven National Laboratory have developed a design for an ultra-violet free electron laser (FEL) facility utilizing a seeded-amplifier approach. Since the accelerator is a single-pass device, resonator and outcoupler mirrors (which are a difficult aspect of oscillator FEL designs) are not required. The result is a source of high peak power vacuum ultraviolet radiation with the mode structure, bandwidth and frequency stability of the input seed laser. The accelerator provides pulses of radiation at up to 10 kHz, so to maximize the utilization of the source, novel optical systems to share the radiation had to be developed. These include specialized alignment, beam transport, order sorting, and multiplexing optics. In addition, FEL-on-FEL pump-probe experiments are made possible by a variable optical delay of up to 10 ns operating in the wavelength range of 200 to 75 nm. Some aspects of the FEL design are also described to clarify the constraints and choices for the optical system. RP JOHNSON, ED (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 192 EP 198 DI 10.1016/0168-9002(94)91877-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900034 ER PT J AU WINICK, H BANE, K BOYCE, R COBB, J LOEW, G MORTON, P NUHN, HD PATERSON, J PIANETTA, P RAUBENHEIMER, T SEEMAN, J TATCHYN, R VYLET, V PELLEGRINI, C ROSENZWEIG, J TRAVISH, G PROSNITZ, D SCHARLEMANN, ET HALBACH, K KIM, KJ SCHLUETER, R XIE, M BONIFACIO, R DESALVO, L PIERINI, P AF WINICK, H BANE, K BOYCE, R COBB, J LOEW, G MORTON, P NUHN, HD PATERSON, J PIANETTA, P RAUBENHEIMER, T SEEMAN, J TATCHYN, R VYLET, V PELLEGRINI, C ROSENZWEIG, J TRAVISH, G PROSNITZ, D SCHARLEMANN, ET HALBACH, K KIM, KJ SCHLUETER, R XIE, M BONIFACIO, R DESALVO, L PIERINI, P TI SHORT-WAVELENGTH FELS USING THE SLAC LINAC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID AMPLIFIED SPONTANEOUS EMISSION; FREE-ELECTRON LASERS; GENERATION; DESIGN; BNL AB Recent technological developments have opened the possibility to construct a device which we call a linac coherent light source (LCLS) (C. Pellegrini et al., Nucl. Instr. and Meth. A 331 (1993) 223; H. Winick et al., Proc. IEEE 1993 Particle Accelerator Conf., Washington, DC, May 1993; C. Pellegrini, Nucl. Instr. and Meth. A 341 (1994) 326; J. Seeman, SPIE Meet. on Electron Beam Sources of High Brightness Radiation, San Diego, CA, July 1993 [1-4]); it would be a fourth-generation light source, with brightness, coherence, and peak power far exceeding other sources. Operating on the principle of the free electron laser (FEL), the LCLS would extend the range of FEL operation to much shorter wavelength than the 240 nm that has so far been reached. We report the results of studies of the use of the SLAC linac to drive an LCLS at wavelengths from about 3 to 100 nm initially and possibly even shorter wavelengths in the future. Lasing would be achieved in a single pass of a low emittance, high peak current, high-energy electron beam through a long undulator. Most present FELs use an optical cavity to build up the intensity of the light to achieve lasing action in a low-gain oscillator configuration. By eliminating the optical cavity, which is difficult to make at short wavelengths, laser action can be extended to shorter wavelengths by self-amplified-spontaneous-emission (SASE), or by harmonic generation from a longer wavelength seed laser. Short wavelength, single pass lasers have been extensively studied at several laboratories and at recent workshops (M. Cornacchia and H. Winick (eds.), SLAC Report 92/02; 1. Ben-Zvi and H. Winick (eds.), BNL report 49651 [5,6]). The required low-emittance electron beam can be achieved with recently-developed rf photocathode electron guns (B.E. Carlsten, Nucl. Instr. and Meth. A 285 (1989) 313; J. Rosenzweig and L. Serafini, Proc. IEEE 1993 Particle Accelerator Conf., Washington, DC, 1993 [7,8]). The peak current is increased by about an order of magnitude by compressing the bunch to a length of about 0.2 ps (rms). Techniques for beam transport, acceleration, and compression without emittance dilution have been developed at SLAC as part of the linear-collider project (J. Seeman, Advances of Accelerator Physics and Technologies, ed. H. Schopper (World Scientific, Singapore, 1993 [9]). The undulator length required to saturate the laser varies from about 15 m for a 100 nm FEL to about 60 m at 3 nm. Initial experiments, at wavelengths down to about 50 nm are planned using the 25-m-long Paladin undulator now located at LLNL. In a proposed future LCLS R&D facility the short wavelength light pulses are distributed to multiple end stations using grazing-incidence mirrors. About 10(14) photons per pulse can be produced at a 120 Hz rate, corresponding to average brightness levels of about 10(21) photons/s/mm2/mrad2 Within 0.1% BW and peak brightness levels of about 10(31) photons/S/MM2/Mrad2 within 0.1% BW. Peak power levels are several hundred megawatts to several gigawatts. Electron energies required range from about 500 MeV for the 100 nm FEL to about 7 GeV for 3 nm. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. INFN,I-20133 MILAN,ITALY. RP WINICK, H (reprint author), STANFORD UNIV,CTR LINEAR ACCELERATOR,STANFORD,CA 94309, USA. RI Travish, Gil/H-4937-2011; Pierini, Paolo/J-3555-2012 OI Travish, Gil/0000-0002-4787-0949; Pierini, Paolo/0000-0002-3062-6181 NR 27 TC 33 Z9 33 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 199 EP 205 DI 10.1016/0168-9002(94)91878-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900035 ER PT J AU PADMORE, HA MARTYNOV, V HOLIS, K AF PADMORE, HA MARTYNOV, V HOLIS, K TI THE USE OF DIFFRACTION EFFICIENCY THEORY IN THE DESIGN OF SOFT-X-RAY MONOCHROMATORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB In general, the diffraction efficiency of gratings is limited by the constraints imposed by the type of geometry used to scan the photon energy. In the simplest example, the spherical grating monochromator, the deviation angle, the grating groove width and depth and the groove density are all constrained by considerations of the maximum photon energy and the tuning range for individual gratings. We have examined the case in which these parameters are unconstrained, resulting in predictions of the ultimate performance of lamellar type gratings for groove densities from 300 to 2400 I/mm for gold and nickel coatings. The differential method of Neviere et al. (Nouv. Rev. Opt. 5 (1974) 65) was used for modeling the behavior of the gratings and justification is presented for this by rigorous comparison with measurements. The implications of these results for future monochromators based on a variable-included-angle geometry are discussed. C1 SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. CRC GRAY LAB,NORTHWOOD HA6 2JR,ENGLAND. CHERNOGOLOVKA PROBLEMS MICROELECTR TECHNOL INST,CHERNOGOLOVKA 142432,RUSSIA. RP PADMORE, HA (reprint author), LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720, USA. NR 18 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 206 EP 215 DI 10.1016/0168-9002(94)91879-1 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900036 ER PT J AU VALDES, VS MCKINNEY, WR PALMER, C AF VALDES, VS MCKINNEY, WR PALMER, C TI THE DIFFERENTIAL METHOD FOR GRATING EFFICIENCIES IMPLEMENTED IN MATHEMATICA(TM) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB We have implemented the differential method in Mathematica(TM) for the calculation of diffraction grating efficiencies in the soft X-ray region. The program has been tested by comparison with published theoretical results and by use of the reciprocity theorem. In this report, we describe the design of the program and present the test results. C1 MILTON ROY CO,GRATINGS BUSINESS UNIT,DIV ANALYT PROD,ROCHESTER,NY 14625. RP MCKINNEY, WR (reprint author), LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720, USA. RI McKinney, Wayne/F-2027-2014 OI McKinney, Wayne/0000-0003-2586-3139 NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 216 EP 219 DI 10.1016/0168-9002(94)91880-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900037 ER PT J AU MCKINNEY, WR SHANNON, CL SHULTS, EN AF MCKINNEY, WR SHANNON, CL SHULTS, EN TI WATER-COOLED ION-MILLED DIFFRACTION GRATINGS FOR THE SYNCHROTRON-RADIATION COMMUNITY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID PROFILER AB Key technical and strategic choices are reviewed, leading to the fabrication method of ion-milled grating grooves for the monochromators at the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory (LBL), and for other synchrotrons. Several laboratories and their industrial partners have joined to manufacture gratings with close to theoretical performance. Metrology data and theoretical comparisons are given for square wave profile grating samples ion-milled into electroless nickel surfaces. The extensive capabilities in mirror and grating manufacture and metrology made available in recent years at laboratory and industrial facilities are reviewed. C1 HUGHES AIRCRAFT CO,DIV ELECTROOPT SYST,EL SEGUNDO,CA 90245. RP MCKINNEY, WR (reprint author), LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720, USA. RI McKinney, Wayne/F-2027-2014 OI McKinney, Wayne/0000-0003-2586-3139 NR 13 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 220 EP 225 DI 10.1016/0168-9002(94)91881-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900038 ER PT J AU IRIC, SC AF IRIC, SC TI IMPROVED MEASUREMENT ACCURACY IN A LONG TRACE PROFILER - COMPENSATION FOR LASER POINTING INSTABILITY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SURFACE AB Laser pointing instability adds to the error of slope measurements taken with the long trace profiler. (P.Z. Takacs and S. Qian, United States Patent 4884697, 1989). As with carriage pitch error, this laser pointing error must be accounted for and subtracted from the surface under test slope measurement. In the past, a separate reference beam was used to characterize the component of slope error from carriage pitch. However, the component of slope error from laser pointing manifests itself differently in the surface under test measured slope error and in the reference beam slope error. An analysis of angle error propagation is given, and the effect of these errors on measured slope is determined. A method is proposed for identifying these errors and subtracting them from the measured surface under test slope function. Separate measurements of carriage pitch and laser pointing instability isolate these effects, so that the effectiveness of the error identification algorithm may be demonstrated. RP IRIC, SC (reprint author), LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 5 TC 24 Z9 25 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 226 EP 230 DI 10.1016/0168-9002(94)91882-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900039 ER PT J AU MOSSESSIAN, DA HEIMANN, PA GULLIKSON, E KAZA, RK CHIN, J AKRE, J AF MOSSESSIAN, DA HEIMANN, PA GULLIKSON, E KAZA, RK CHIN, J AKRE, J TI TRANSMISSION GRATING SPECTROMETER FOR CHARACTERIZATION OF UNDULATOR RADIATION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A transmission grating spectrometer has been built to investigate undulator radiation at the Advanced Light Source. The spectrometer covers the spectral range from 10 to 620 angstrom with a spectral resolution from 0.02 to 1 angstrom (depending on the wavelength), and provides the capability to measure the spectral and angular distribution of the undulator radiation. The minimum angular resolution of the spectrometer is 10 murad. The absolute efficiencies of the spectrometer's optical elements have been measured with an accuracy of better than 10%, which will allow measurements of the absolute intensity of the radiation harmonics. The results of the measurements are compared to theoretical calculations of the undulator radiation based on measured magnetic field data. In this paper the design of the spectrometer, the calibration of the optical components, and test measurements with an X-ray tube are described. C1 LAWRENCE BERKELEY LAB,CTR X RAY OPTICS,DIV MAT SCI,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720. RP MOSSESSIAN, DA (reprint author), LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 244 EP 248 DI 10.1016/0168-9002(94)91885-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900042 ER PT J AU HANSEN, RWC WOLSKE, J TAKACS, PZ AF HANSEN, RWC WOLSKE, J TAKACS, PZ TI UV OZONE CLEANING OF A REPLICA GRATING SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION; CARBON; CONTAMINATION AB UV/ozone cleaning was evaluated for cleaning a carbon-contaminated replica grating. Replica optics represent a challenging test of any cleaning process because of the potential for damage to the epoxy layer which can severely degrade the surface figure and finish. A badly contaminated replica grating was divided into three sections for this study. One section was cleaned using a mercury lamp, another section was cleaned using a deuterium lamp, and the third section was left as a control. The results were evaluated using a Ronchi test to determine figure error, a Fotonic sensor to estimate reflectivity, and a microscopic evaluation using a Nomarski objective to look for surface damage. Surface roughness measurements were also performed with a Micromap surface profiler. The results indicated that the surface figure and finish were not significantly degraded, and the surface figure was actually improved compared to the contaminated condition. The visible light reflectivity was fully restored in the areas that were cleaned. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP HANSEN, RWC (reprint author), UNIV WISCONSIN,CTR SYNCHROTRON RADIAT,3731 SCHNEIDER DR,STOUGHTON,WI 53589, USA. NR 9 TC 5 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 254 EP 257 DI 10.1016/0168-9002(94)91887-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900044 ER PT J AU KOIKE, M BEGUIRISTAIN, R UNDERWOOD, JH NAMIOKA, T AF KOIKE, M BEGUIRISTAIN, R UNDERWOOD, JH NAMIOKA, T TI A NEW OPTICAL DESIGN METHOD AND ITS APPLICATION TO AN EXTREME-ULTRAVIOLET VARIED LINE SPACING PLANE GRATING MONOCHROMATOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A new design method has been developed for a double-element optical system. The method incorporates a very simple ray tracing procedure into an analytic merit function that closely represents the variance of an infinite number of ray-traced spots in the image plane. A 174-degrees constant-deviation objective Monk-Gillieson monochromator consisting of a highly demagnifying (approximately 1/10) spherical mirror, varied spacing plane grating, and elliptic cylindrical focusing mirror has been designed for a bending-magnet beamline using the new design method. Ray-tracing results show that the new design can provide higher spectral purity and throughput as compared to a design based on the light path function and that the monochromator design gives slit-width-limited resolutions over a wavelength range of 2-5 nm. C1 UNIV SPACE RES ASSOC,NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP KOIKE, M (reprint author), LAWRENCE BERKELEY LAB,CTR XRAY OPT,BERKELEY,CA 94720, USA. NR 14 TC 24 Z9 25 U1 1 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 273 EP 277 DI 10.1016/0168-9002(94)91891-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900048 ER PT J AU OLSON, CG LYNCH, DW AF OLSON, CG LYNCH, DW TI AN OPTIMIZED UNDULATOR BEAMLINE FOR HIGH-RESOLUTION PHOTOEMISSION VALENCE-BAND SPECTROSCOPY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID FERMI-SURFACE; ELECTRONIC-STRUCTURE; GAP AB A beamline under construction on the storage ring Aladdin is designed for very high performance in the energy range 15 to 30 eV. limiting the scan to this important region allows a very high flux design while minimizing the cost and complexity. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP OLSON, CG (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 9 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 278 EP 281 DI 10.1016/0168-9002(94)91892-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900049 ER PT J AU KOIKE, M HEIMANN, PA KUNG, AH NAMIOKA, T DIGENNARO, R GEE, B YU, N AF KOIKE, M HEIMANN, PA KUNG, AH NAMIOKA, T DIGENNARO, R GEE, B YU, N TI VUV HIGH-RESOLUTION AND HIGH-FLUX BEAMLINE FOR CHEMICAL-DYNAMICS STUDIES AT THE ADVANCED LIGHT-SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SPECTROSCOPIC FACILITY AB An undulator beamline, consisting of VUV high resolution and high flux branch lines, devoted to chemical dynamics experiments has been designed at the Advanced Light Source. The radiation source is an undulator having a 10-cm period, and the fundamental in the energy range from 6 to 30 eV is utilized by the experiments. The higher harmonics of the undulator due to the operation at high K values is suppressed by a novel gas filter. In the first branch, high-flux 2% bandwidth radiation is directed toward an end station for photodissociation. A photon flux calculation predicts 1016 photon/s at this end station. In the second branch, highly monochromatized radiation is sent to an end station for photoelectron spectroscopy and photoionization studies. For this purpose a vertical dispersion 6.65-m off-plane Eagle mounting was chosen for the monochromator in anticipation of achieving a resolving power of approximately 5 X 10(4) with a 1200 grooves/mm grating and 1 X 10(5) to 2 x 10(5) with a 4800 grooves/mm grating. C1 LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV SPACE RES ASSOC,NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP KOIKE, M (reprint author), LAWRENCE BERKELEY LAB,CTR X RAY OPT,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Kung, Andy/F-7909-2012 NR 10 TC 36 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 282 EP 286 DI 10.1016/0168-9002(94)91893-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900050 ER PT J AU SMITHER, RK FERNANDEZ, PB AF SMITHER, RK FERNANDEZ, PB TI ASYMMETRIC-CUT MONOCHROMATOR WITH ADJUSTABLE ASYMMETRY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID GALLIUM AB A variable-incident-angle, asymmetric-cut, double-crystal monochromator with adjustable asymmetry was tested at Argonne National Laboratory to evaluate its possible use on beamlines at the Advanced Photon Source. For both undulator and wiggler beams, the monochromator can expand the area of the footprint of the beam on the surface of the crystals to 50 times the area of the incident beam. This increase in area will reduce the angular distortions of the crystalline planes by a factor of 2500. The asymmetric cut allows one to increase the acceptance angle for incident radiation and obtain a better match to the opening angle of the incident beam. This can increase the intensity of the diffracted beam by a factor of 2 to 5. The monochromator consists of two matched, asymmetric-cut silicon crystals mounted so that they can be rotated independently about three different axes. Rotation around the first axis controls the Bragg angle. Rotation around the second axis controls the angle between the surface of the crystal and the horizontal plane of the beam and can make the footprint a rectangle with minimum length for this footprint area. The third rotation axis is perpendicular to the diffraction planes and carries the asymmetric-cut crystal. Rotation around this axis controls the amount of asymmetry being used and thus the increase of the area of the footprint of the beam on the crystal surface. The asymmetric cut is 18-degrees for the matched pair of crystals, which allows one to expand the footprint area by a factor of 50 for Bragg angles up to 19.15-degrees (6 keV for Si[111] planes). This monochromator, with proper cooling, will be quite useful for analyzing the high intensity X-ray beams produced by both undulators and wigglers at the Advanced Photon Source. RP SMITHER, RK (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 7 TC 14 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 313 EP 319 DI 10.1016/0168-9002(94)91900-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900057 ER PT J AU BLASDELL, RC MACRANDER, AT AF BLASDELL, RC MACRANDER, AT TI MODIFICATIONS TO THE 1989 SHADOW RAY-TRACING CODE FOR GENERAL ASYMMETRIC PERFECT-CRYSTAL OPTICS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The dynamical theory of the diffraction of X-rays from perfect crystals is traditionally expressed in terms of Maxwell's equations using a semi-classical theory originally due to Ewald and Von Laue. Combining the work of Batterman and Cole, Caticha and Caticha-Ellis, and Zachariasen, one can obtain a formalism that treats the general asymmetric, thick and thin crystal, Laue and Bragg cases within the second-order dispersion surface approximation with no assumptions concerning the centro-symmetry of the crystal lattice. We have implemented this formalism with the thick-Bragg-crystal E-field boundary-value conditions in several routines we have added to one of the Advanced Photon Source's modified copies of the 1989 VAX/VMS version of the SHADOW ray-tracing code in order to allow us to ray trace distorted inclined double-crystal monochromators and high-resolution backscattering analyzers. RP BLASDELL, RC (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 320 EP 323 DI 10.1016/0168-9002(94)91901-1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900058 ER PT J AU MACRANDER, AT BLASDELL, RC AF MACRANDER, AT BLASDELL, RC TI WEAK POLARIZATION EFFECTS FOR AN INCLINED CRYSTAL MONOCHROMATOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB We present results of dynamical-diffraction simulations in the inclined geometry. This geometry appears promising for use in a high-heat-load monochromator for undulator radiation at the Advanced Photon Source. In the inclined geometry, the incident-beam wavevector, the reciprocal-lattice vector, and the surface normal are not coplanar. An unusual aspect of the inclined geometry is the lack Of a unique plane of diffraction because different tie points on the dispersion surfaces lead to different diffraction planes. This implies that a unique definition of sigma and pi polarizations cannot be made. We have examined polarization effects using dynamical X-ray diffraction theory cast in matrix form. In recent years, an 8 x 8 matrix theory was developed that treated asymmetric reflections. The polarizations were defined as s or p. That is, polarizations for each beam outside of the crystal were defined with respect to the plane containing the beam wavevector and the surface normal. We have redefined the polarizations to approach the conventional X-ray diffraction definitions of sigma and pi polarizations. Instead of using the surface normal as a reference we used the reciprocal lattice vector as a reference. With these definitions we find only a very weak pi component for pure sigma incident radiation. RP MACRANDER, AT (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 324 EP 326 DI 10.1016/0168-9002(94)91902-X PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900059 ER PT J AU BLASDELL, RC MACRANDER, AT LEE, WK AF BLASDELL, RC MACRANDER, AT LEE, WK TI A RAY-TRACING STUDY OF INCLINED DOUBLE-CRYSTAL MONOCHROMATORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID PERFORMANCE AB Third-generation synchrotron X-ray sources such as the Advanced Photon Source under construction at Argonne National Laboratory will place severe heat load demands on the first beamline optical element. A cooled, inclined double-crystal monochromator is one of the instruments being developed at the APS to handle these high heat loads while retaining the brilliance of the source. Using a modified version of the 1989 VAX/VMS SHADOW code, we examine the properties of the exit beam for two inclined double-crystal monochromator geometries. RP BLASDELL, RC (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 7 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 327 EP 330 DI 10.1016/0168-9002(94)91903-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900060 ER PT J AU KUSHNIR, VI MACRANDER, AT AF KUSHNIR, VI MACRANDER, AT TI A CRITERION FOR THE DYNAMICAL-TO-KINEMATICAL TRANSITION IN X-RAY-DIFFRACTION BY A BENT CRYSTAL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID MONOCHROMATOR AB A criterion is given in answer to the question: ''To what extent is it possible to bend a crystal without loss of X-ray peak reflectivity?'' An expression based on the work of Chulchovskii, Gabrielyan and Petrashen, is formulated that applies to anisotropic cubic crystals and that can be used not only for conventional asymmetric Bragg diffraction, but also for inclined crystal diffraction. The following special cases are treated as examples: an isotropic crystal, a standard symmetrical Bragg diffraction, an extremely asymmetric diffraction, and backscattering with Bragg angles near 90-degrees. In addition, the asymptotic behavior at high energies is discussed. RP KUSHNIR, VI (reprint author), ARGONNE NATL LAB,DIV EXPTL FACIL,9700 S CASS,ARGONNE,IL 60439, USA. NR 8 TC 2 Z9 2 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 331 EP 337 DI 10.1016/0168-9002(94)91904-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900061 ER PT J AU MOONEY, TM TOELLNER, T STURHAHN, W ALP, EE SHASTRI, SD AF MOONEY, TM TOELLNER, T STURHAHN, W ALP, EE SHASTRI, SD TI HIGH-RESOLUTION, LARGE-ANGULAR-ACCEPTANCE MONOCHROMATOR FOR HARD X-RAYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID INCIDENCE ANTIREFLECTION FILMS; SYNCHROTRON RADIATION; DIFFRACTION; SCATTERING; POLARIZATION AB We have constructed the first working model of a novel diffraction geometry for the high-resolution monochromatization of hard (5-30 keV) synchrotron radiation. The monochromator has an energy bandpass of 6.7 meV FWHM and an angular acceptance of 22 murad (4.5 arcseconds) for 14.4 keV X rays - an energy resolution DELTAE/E of 4.6 X 10(-7). With a second set of crystals, an energy bandpass of 23 meV FWHM and an angular acceptance of 7 murad was achieved for 23.8 keV photons. The performance of the monochromator has been verified, in a nearly ideal measurement, using nuclear-fluorescent X rays with an energy bandwidth on the order of 10 neV. C1 CORNELL UNIV,CORNELL HIGH ENERGY SYNCHROTRON SOURCE,ITHACA,NY 14853. CORNELL UNIV,SCH APPL & ENGN PHYS,ITHACA,NY 14853. RP MOONEY, TM (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 20 TC 42 Z9 42 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 348 EP 351 DI 10.1016/0168-9002(94)91907-0 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900064 ER PT J AU SHLEIFER, M DILMANIAN, FA STAICU, FA WOODLE, MH AF SHLEIFER, M DILMANIAN, FA STAICU, FA WOODLE, MH TI MECHANICAL DESIGN OF A HIGH-RESOLUTION TUNABLE CRYSTAL MONOCHROMATOR FOR THE MULTIPLE ENERGY COMPUTED-TOMOGRAPHY PROJECT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION AB We describe the mechanical design of a medical-imaging monochromator for the Multiple Energy Computed Tomography project at the X17B superconducting wiggler beamline at the National Synchrotron Light Source. The monochromator consists of two independent two-crystal Laue-Laue units in tandem, with the option of using a Laue-Bragg/Bragg-Laue configuration. It provides two collinear exit beams of different energies that can be alternatively selected by a shutter. The heart of the design is a mechanically driven spindle with a double-gimbal mechanism for precise angular positioning of each of the four crystals about two orthogonal axes of rotation. An angular resolution of 0.041 arcsec is achieved by using a linear motion of 0.1 mum on a lever arm of 50 cm. The main features of the system include a fixed-exit beam having a 15 mm vertical offset, water-cooled first crystals in both units, a 12 cm beam width, a 3 mm maximum beam height, an energy range of almost-equal-to 25-50 and 75-100 keV, a 2.5 s beam-switching time, and high vacuum compatibility. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP SHLEIFER, M (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 9 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 356 EP 359 DI 10.1016/0168-9002(94)91909-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900066 ER PT J AU KARLIN, BA WOICIK, JC COWAN, PL AF KARLIN, BA WOICIK, JC COWAN, PL TI PERFORMANCE OF INSB/KDP MONOCHROMATOR CRYSTAL PAIR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION AB We report on the performance of an InSb/KDP monochromator mismatched crystal pair in use on beamline X24A at the National Synchrotron Light Source. This crystal pair provides extremely high spectral resolving power and throughput in the photon energy range 1750 to 2100 eV, which is below the physical limit of Si(111). By measuring the back-reflection from a Si(111) single crystal, we determine the resolution of the mismatched pair to be 0.40+/-0.05 eV at 1977 eV. The first Si1s absorption spectrum (1840 eV) recorded with resolution better than the core-hole lifetime is also reported. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ARGONNE NATL LAB,ARGONNE,IL 60439. RP KARLIN, BA (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 10 TC 3 Z9 3 U1 2 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 360 EP 363 DI 10.1016/0168-9002(94)91910-0 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900067 ER PT J AU VOSS, KF KIM, KH STERN, EA BROWN, FC HEALD, SM AF VOSS, KF KIM, KH STERN, EA BROWN, FC HEALD, SM TI A CAPILLARY CONCENTRATOR FOR AN X-RAY MICROPROBE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB Capillary concentrators are examined analytically and by computer simulations for applications in third-generation synchrotron-radiation bean-dines. A comparison is made between them and focusing mirrors for producing a small spot of X rays. Both devices are achromatic and useful for experiments that require an X-ray microprobe which delivers X rays over a broad band of energies. It is shown that the capillary concentrator produces an order of magnitude more intensity than the focusing mirror for spots below micrometer dimensions. The simulations also show that the exact profile of the capillary is not important except for the region near the outlet. C1 UNIV WASHINGTON, DEPT PHYS, FM-15, SEATTLE, WA 98195 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 9 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 390 EP 396 DI 10.1016/0168-9002(94)91915-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900072 ER PT J AU XIAO, QF PONOMAREV, IY KOLOMITSEV, AI GIBSON, DM DILMANIAN, FA NACHALIEL, E AF XIAO, QF PONOMAREV, IY KOLOMITSEV, AI GIBSON, DM DILMANIAN, FA NACHALIEL, E TI GUIDING HARD X-RAYS WITH GLASS POLYCAPILLARY FIBER SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB X rays can be guided through a polycapillary fiber by multiple total reflections from the smooth channel walls of the fiber. Using monochromatic synchrotron radiation at energies of 22 and 44 keV, we measured the efficiency of transmission of X rays through polycapillary fibers with channel diameters of about 13 mum. Efficiencies of 57.3 and 54.5% for 22 and 44 keV X rays, respectively, were obtained with a 120-mm-long straight polycapillary fiber aligned with the incident beam. These values are close to the open fraction of the fiber, which is about 60%. In addition, transmission efficiency was measured as a function of the tilt angle between the incident beam and the axis of the fiber. We also measured the transmission efficiency as a function of the deflection angle for a 114-mm-long curved polycapillary fiber. The measurements are compared with a ray-tracing simulation. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP XIAO, QF (reprint author), X RAY OPT SYST INC,90 FULLER RD,ALBANY,NY 12205, USA. NR 15 TC 1 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 397 EP 400 DI 10.1016/0168-9002(94)91916-X PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900073 ER PT J AU SUTTON, SR RIVERS, ML BAJT, S JONES, K SMITH, JV AF SUTTON, SR RIVERS, ML BAJT, S JONES, K SMITH, JV TI SYNCHROTRON X-RAY-FLUORESCENCE MICROPROBE - A MICROANALYTICAL INSTRUMENT FOR TRACE-ELEMENT STUDIES IN GEOCHEMISTRY, COSMOCHEMISTRY, AND THE SOIL AND ENVIRONMENTAL SCIENCES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID EDGE STRUCTURE; ABSORPTION AB The availability of high-brightness synchrotron radiation sources has permitted the development of X-ray microprobe instrumentation for trace element studies at high spatial resolution based on the X-ray fluorescence technique. The X-ray microprobe at beamline X26A at the National Synchrotron Light Source (Brookhaven National Laboratory) has been applied to a wide variety of problems in the earth, planetary, soil and environmental sciences, including: volatile element contents of micrometeorites, oxidation state heterogeneity of uranium in contaminated sediments, elemental compositions and speciation of flyash particles and the compositions of hydrothermal fluids based on inclusion analyses. C1 UNIV CHICAGO,CTR ADV RADIAT SOURCES,CHICAGO,IL 60637. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP SUTTON, SR (reprint author), UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637, USA. RI Bajt, Sasa/G-2228-2010 NR 16 TC 26 Z9 26 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 412 EP 416 DI 10.1016/0168-9002(94)91919-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900076 ER PT J AU BRENNAN, S TOMPKINS, W TAKAURA, N PIANETTA, P LADERMAN, SS FISCHERCOLBRIE, A KORTRIGHT, JB MADDEN, MC WHERRY, DC AF BRENNAN, S TOMPKINS, W TAKAURA, N PIANETTA, P LADERMAN, SS FISCHERCOLBRIE, A KORTRIGHT, JB MADDEN, MC WHERRY, DC TI WIDE BAND-PASS APPROACHES TO TOTAL-REFLECTION X-RAY-FLUORESCENCE USING SYNCHROTRON-RADIATION SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB Measurement and control of surface and near surface trace impurities on silicon wafers is a critical technology for the development and manufacture of leading-edge silicon VLSI circuits. Among the industry-standard methods for monitoring surface impurities are grazing-incidence X-ray methods employing rotating anode sources. In the semiconductor industry, the X-ray method is referred to as total reflection X-ray fluorescence spectroscopy (TRXRF or TXRF). Conventional-source TRXRF methods are not adequate for future industry needs. Beamline modifications and a special experimental chamber were designed and executed at the Stanford Synchrotron Radiation Laboratory to investigate the performance of synchrotron radiation based approaches to this application. Crystal monochromators, a Mo-C multilayer mirror, and filtered white light were examined as sources for TRXRF. The best experimental configuration surpassed previous attempts in the field. With it, two different semiconductor industry user groups were able to demonstrate significant improvements in the TRXRF detection limits for 3-d transition metals and for aluminum compared to standard conventional equipment. The design goals, equipment configuration and current performance level of this synchrotron-based TRXRF configuration are described in detail. Aspects of the experimental design under further development for even higher performance are discussed. C1 HEWLETT PACKARD CORP,CTR R&D,DIV INTEGRATED CIRCUITS BUSINESS,PALO ALTO,CA 94304. LAWRENCE BERKELEY LAB,CTR X RAY OPT,BERKELEY,CA 94720. INTEL CORP,SANTA CLARA,CA 95052. FISONS INSTRUMENTS,SAN CARLOS,CA 94070. RP BRENNAN, S (reprint author), STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309, USA. NR 5 TC 18 Z9 18 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 417 EP 421 DI 10.1016/0168-9002(94)91920-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900077 ER PT J AU NG, W RAYCHAUDHURI, AK LIANG, S SINGH, S SOLAK, H WELNAK, J CERRINA, F MARGARITONDO, G UNDERWOOD, JH KORTRIGHT, JB PERERA, RCC AF NG, W RAYCHAUDHURI, AK LIANG, S SINGH, S SOLAK, H WELNAK, J CERRINA, F MARGARITONDO, G UNDERWOOD, JH KORTRIGHT, JB PERERA, RCC TI HIGH-RESOLUTION SPECTROMICROSCOPY WITH MAXIMUM - PHOTOEMISSION SPECTROSCOPY REACHES THE 1000-ANGSTROM SCALE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB We present new results from the soft X-ray scanning photoemission microscope: MAXIMUM. The microscope is installed at the U41 undulator at the Synchrotron Radiation Center at the University of Wisconsin. The instrument is based on a multilayer-coated Schwarzchild objective, operating at 95 eV, and it has demonstrated spatial resolution better than 0.1 mum and electron energy resolution of 300 meV. We review the design and the implementation of the microscope. We also present recent results as well as a summary of the research programs that are bei conducted with MAXIMUM. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. ECOLE POLYTECH FED LAUSANNE,DEPT PHYS APPL,CH-1015 LAUSANNE,SWITZERLAND. RP NG, W (reprint author), UNIV WISCONSIN,CTR XRAY LITHOG,3731 SCHNEIDER DR,STOUGHTON,WI 53589, USA. RI Margaritondo, Giorgio/B-1367-2008 NR 16 TC 27 Z9 27 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 422 EP 430 DI 10.1016/0168-9002(94)91921-6 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900078 ER PT J AU ZHANG, X ADE, H JACOBSEN, C KIRZ, J LINDAAS, S WILLIAMS, S WIRICK, S AF ZHANG, X ADE, H JACOBSEN, C KIRZ, J LINDAAS, S WILLIAMS, S WIRICK, S TI MICRO-XANES - CHEMICAL CONTRAST IN THE SCANNING-TRANSMISSION X-RAY MICROSCOPE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The scanning transmission X-ray microscope on the X1A undulator beam line, at the National Synchrotron Light Source, has been used for imaging various biological as well as polymer samples at 55 nm Rayleigh resolution. The microscope is operated mainly in direct imaging mode, where X-rays of fixed energy are diffractively focussed to a microprobe and the sample is scanned in two dimensions. However, by varying the X-ray energy while keeping the beam focussed to one spot on the sample we can also determine the localized chemical composition of the sample from the carbon X-ray absorption near edge spectra in an area smaller than 0.2 mum by 0.2 mum. The spatial distribution of the chemical constituents can be obtained by imaging at absorption maxima of specific chemical bonds, while retaining the 0.05 mum spatial resolution of the microscope. The chemical sensitivity of X-ray-absorption near-edge spectroscopy provides a powerful contrast mechanism for imaging organic systems. The well-known differences in energy among pi* resonances of different chemical bonds have been used to distinguish different polymer phases and have been applied to biological systems. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695. RP ZHANG, X (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. RI Ade, Harald/E-7471-2011; Jacobsen, Chris/E-2827-2015; OI Jacobsen, Chris/0000-0001-8562-0353; Zhang, Xiaodong/0000-0001-9786-7038 NR 9 TC 46 Z9 47 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 431 EP 435 DI 10.1016/0168-9002(94)91922-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900079 ER PT J AU LEE, KD HULBERT, SL KUIPER, P JI, D HANSON, DM AF LEE, KD HULBERT, SL KUIPER, P JI, D HANSON, DM TI AUGER, ZERO-ENERGY PHOTOELECTRON, COINCIDENCE SPECTROSCOPY - CHEMICAL-SITE-SELECTIVE AUGER-ELECTRON SPECTROSCOPY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID POST-COLLISION INTERACTIONS; NITROUS-OXIDE; THRESHOLD; SPECTRA; PHOTOIONIZATION; TRANSITIONS AB The Auger electron spectrum associated with decay of a core-hole on the terminal nitrogen and that associated with the central nitrogen of nitrous oxide, N2O, are obtained individually through the use of a coincidence technique. Specifically, each of the two Auger electron spectra is obtained by detection of Auger electrons in coincidence with near zero energy (threshold) photoelectrons at the respective ionization thresholds. These zero energy electrons serve to identify the core-ionization continuum associated with the different Auger electrons. The salient features of the experimental spectra are in good agreement with theoretical calculations. The low counting rate generally associated with coincidence experiments, especially in the gas phase, is not encountered because the low energy electrons are collected over a 4pi solid angle. Also, velocity discrimination is accomplished by a spatial filter rather than by time-of-flight to utilize the maximum duty cycle of the synchrotron source. These data are believed to be the first examples of chemical-site-selective molecular Auger spectra. C1 SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RI Kuiper, Pieter/A-6806-2012 NR 16 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 446 EP 452 DI 10.1016/0168-9002(94)91925-9 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900082 ER PT J AU DENLINGER, JD ZHANG, J TONNER, BP AF DENLINGER, JD ZHANG, J TONNER, BP TI ANGULAR INSTRUMENT RESPONSE FOR PHOTOELECTRON DIFFRACTION USING FOCUSED, PLANE-POLARIZED SYNCHROTRON BEAMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID HOLOGRAPHY; PARAMETERS; ELECTRON AB The non-diffractive instrument response function for photoelectron diffraction is summarized for various data collection modes and experimental geometries. Plane-polarization and small focused spots from synchrotron X-ray sources produce very different angular response functions compared to those using standard laboratory flood sources and should be considered in optimizing the experimental design. In the case of sample-scanned photoelectron diffraction, use of a polar rotation axis of the sample in the horizontal plane of the synchrotron beam and the photoelectron detector is shown to have several advantages over the more standard vertical polar axis. C1 UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53211. RP DENLINGER, JD (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 475 EP 479 DI 10.1016/0168-9002(94)91931-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900088 ER PT J AU KINNEY, JH HAUPT, DL NICHOLS, MC BREUNIG, TM MARSHALL, GW MARSHALL, SJ AF KINNEY, JH HAUPT, DL NICHOLS, MC BREUNIG, TM MARSHALL, GW MARSHALL, SJ TI THE X-RAY TOMOGRAPHIC MICROSCOPE - 3-DIMENSIONAL PERSPECTIVES OF EVOLVING MICROSTRUCTURES SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION; COMPOSITES; XTM AB Recent advances in X-ray tomography using synchrotron radiation enable three-dimensional microscopic images to be obtained nondestructively from relatively large samples. With both increased sample size and improved spatial resolution, it is now possible to quantify experimentally-induced microstructural and microchemical changes in materials as they occur in situ, in vitr, and even in vivo. With the X-ray tomographic microscope, we have begun to improve our understanding of the processing of ceramic matrix composites, bone loss in osteoporosis, and the development of caries lesions in teeth. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. RP KINNEY, JH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 20 TC 41 Z9 41 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 480 EP 486 DI 10.1016/0168-9002(94)91932-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900089 ER PT J AU SOUTHWORTH, SH MACDONALD, MA LEBRUN, T DESLATTES, RD AF SOUTHWORTH, SH MACDONALD, MA LEBRUN, T DESLATTES, RD TI ELECTRON-ION-X-RAY SPECTROMETER SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION AB We describe a spectrometer system developed for electron, ion, and X-ray spectroscopy of gas-phase atoms and molecules following inner-shell excitation by tunable synchrotron radiation. The instrumentation and experimental methods are discussed, and examples are given of electron spectra and coincidence spectra between electrons and fluorescent X-rays. C1 SERC, DARESBURY LAB, WARRINGTON WA4 4AD, CHESHIRE, ENGLAND. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 12 TC 16 Z9 16 U1 0 U2 0 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 499 EP 503 DI 10.1016/0168-9002(94)91936-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900093 ER PT J AU GUARDALA, NA PRICE, JL LAND, DJ SIMONS, DG LEE, DH JOHNSON, BM GLASS, GA BRENNAN, JG AF GUARDALA, NA PRICE, JL LAND, DJ SIMONS, DG LEE, DH JOHNSON, BM GLASS, GA BRENNAN, JG TI COMPTON-ELECTRON SPECTROSCOPY USING HIGH-ENERGY SYNCHROTRON X-RAYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SCATTERING AB Compton-recoil electron spectra have been measured using high-energy (46 and 56 keV) synchrotron X-rays produced at the National Synchrotron Light Source. Thin foils of C and Al (< 1500 angstrom thick) were used as targets. The emitted electrons were detected at 0-degrees-C with respect to the incident photon beam using an electrostatic analyzer with an overall energy resolution of approximately 3%. C1 USN,CTR SURFACE WARFARE,WHITE OAK LAB,SILVER SPRING,MD 20903. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV SW LOUISIANA,LAFAYETTE,LA 70504. CATHOLIC UNIV AMER,WASHINGTON,DC 20064. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 504 EP 506 DI 10.1016/0168-9002(94)91937-2 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900094 ER PT J AU WIEDEMANN, H BALTAY, M CARR, R HERNANDEZ, M LAVENDER, W AF WIEDEMANN, H BALTAY, M CARR, R HERNANDEZ, M LAVENDER, W TI A COMPACT RADIATION SOURCE FOR DIGITAL SUBTRACTIVE ANGIOGRAPHY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID TRANSVENOUS CORONARY ANGIOGRAPHY; SYNCHROTRON RADIATION; MONOCHROMATOR AB Beam requirements for 33 keV radiation used in digital subtraction angiography have been established through extended experimentation first at Stanford and later at the National Synchrotron Light Source in Brookhaven. So far research and development of this medical procedure to image coronary blood vessels have been undertaken on large high energy electron storage rings. With progress in this diagnostic procedure, it is interesting to look for an optimum concept for providing a 33 keV radiation source which would fit into the environment of a hospital. A variety of competing effects and technologies to produce 33 keV radiation are available, but none of these process provides the combination of sufficient photon flux and monochromaticity except for synchrotron radiation from an electron storage ring. The conceptual design of a compact storage ring optimized to fit into a hospital environment and producing sufficient 33 keV radiation for digital subtraction radiography will be discussed. RP WIEDEMANN, H (reprint author), STANFORD SYNCHROTRON RADIAT LAB,POB 4349,BIN 69,STANFORD,CA 94305, USA. NR 13 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 515 EP 521 DI 10.1016/0168-9002(94)91940-2 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900097 ER PT J AU NADAY, I ROSS, S KANYO, M WESTBROOK, E WESTBROOK, M AF NADAY, I ROSS, S KANYO, M WESTBROOK, E WESTBROOK, M TI CHARACTERIZATION OF CCD-BASED IMAGING X-RAY-DETECTORS FOR DIFFRACTION EXPERIMENTS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB High-resolution CCD-based imaging detectors are successfully used in X-ray diffraction experiments. some detectors are commercially available, others have been developed by research groups around the world. Reliable comparison of the performance must be based on thorough testing of all relevant characteristics of these detectors. We describe methods of measurements of detector parameters such as conversion gain, linearity, uniformity, point spread function, geometrical uniformity, dark current, and detective quantum efficiency. As an example for the characterization, test results of a single module fiberoptic taper/CCD X-ray detector will be presented. The projected performance of a large area, array detector consisting of 9 CCDs and fiberoptic taper modules, will be given. This new detector (the ''Gold'' detector) will be installed on Beamline X8C at the National Synchrotron Light Source at Brookhaven National Laboratory. RP NADAY, I (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 0 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 AUG 11 PY 1994 VL 347 IS 1-3 BP 534 EP 538 DI 10.1016/0168-9002(94)91943-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900100 ER PT J AU THOMPSON, AC LAVENDER, WM CHAPMAN, D GMUR, N THOMLINSON, W ROSSO, V SCHULZE, C RUBENSTEIN, E GIACOMINI, JC GORDON, HJ DERVAN, JP AF THOMPSON, AC LAVENDER, WM CHAPMAN, D GMUR, N THOMLINSON, W ROSSO, V SCHULZE, C RUBENSTEIN, E GIACOMINI, JC GORDON, HJ DERVAN, JP TI A 1200 ELEMENT DETECTOR SYSTEM FOR SYNCHROTRON-BASED CORONARY ANGIOGRAPHY SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A 1200 channel Si(Li) detector system has been developed for transvenous coronary angiography experiments using synchrotron radiation. It is part of the synchrotron medical imaging facility at the National Synchrotron Light Source. The detector is made from a single crystal of lithium-drifted silicon with an active area 150 mm long x 11 mm high x 5 mm thick. The elements are arranged in two parallel rows of 600 elements with a center-to-center spacing of 0.25 mm. All 1200 elements are read out simultaneously every 4 ms. An Intel 80486 based computer with a high speed digital signal processing interface is used to control the beamline hardware and to acquire a series of images. The signal-to-noise, linearity and resolution of the system have been measured. Human images have been taken with this system. C1 STANFORD UNIV,HANSEN EXPTL PHYS LAB,STANFORD,CA 94305. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. UNIV PISA,DIPARTIMENTO FIS,I-56100 PISA,ITALY. EUROPEAN SYNCHROTRON RADIAT FACIL,GRENOBLE,FRANCE. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. SUNY STONY BROOK,DIV CARDIOL,STONY BROOK,NY 11794. RP THOMPSON, AC (reprint author), LAWRENCE BERKELEY LAB,CTR X-RAY OPT,BERKELEY,CA 94720, USA. RI Chapman, Dean/I-6168-2013 OI Chapman, Dean/0000-0001-6590-4156 NR 7 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 545 EP 552 DI 10.1016/0168-9002(94)91945-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900102 ER PT J AU COBB, J TATCHYN, R AF COBB, J TATCHYN, R TI TESTS OF PLANAR PERMANENT-MAGNET MULTIPOLE FOCUSING ELEMENTS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB In recent work, planar configurations of permanent magnets were proposed as substitutes fr conventional current-driven iron quadrupoles in applications limited by small aperture sizes and featuring small beam occupation diameters. Important examples include the configuring of focusing lattices in small-gap insertion devices, and the implementation of compact mini-beta sections on linear or machines. In subsequent analysis, this approach was extended to sextupoles and higher-order multipoles. In this paper we report initial measurements conducted at the Stanford Linear Accelerator Center on recently fabricated planar permanent magnet quadruples and sextupoles configured out of SmCo and NdFe/B. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. NR 10 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 562 EP 567 DI 10.1016/0168-9002(94)91948-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900105 ER PT J AU GREEN, MA MCVEY, BD TRZECIAK, WS TATCHYN, R HANSEN, RWC FILIPPONI, A AF GREEN, MA MCVEY, BD TRZECIAK, WS TATCHYN, R HANSEN, RWC FILIPPONI, A TI MEASUREMENTS AND MODELING OF UNDULATOR RADIATION WITH A FILTER PHOTODIODE DETECTOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID OPERATION; BEAMLINE AB Owing to choherence effects, undulator radiation is energy-angle correlated with a quasi-monochromatic central cone of very small divergence. In correct combination, the energy-dependent responses of a filter and photodiode can aid in spatially resolving this radiation. Experience and measurements with a filter-photodiode monitor, gained over several years of monitoring radiation from the SSRL/LBL undulator on the Aladdin storage ring, are presented. Modeling of the detection process is described together with comparison to the data. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. UNIV AQUILA,I-67010 COPPITO,ITALY. RP GREEN, MA (reprint author), UNIV WISCONSIN,CTR SYNCHROTRON RADIAT,3731 SCHNEIDER DR,STOUGHTON,WI 53589, USA. RI Filipponi, Adriano/P-7796-2015 OI Filipponi, Adriano/0000-0002-3870-5853 NR 16 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 568 EP 572 DI 10.1016/0168-9002(94)91949-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900106 ER PT J AU SHU, D COLLINS, JT BARRAZA, J KUZAY, TM AF SHU, D COLLINS, JT BARRAZA, J KUZAY, TM TI THE ADVANCED PHOTON SOURCE-X-RAY TRANSMITTING BEAM-POSITION-MONITOR TESTS AT THE NATIONAL SYNCHROTRON LIGHT-SOURCE X-25 BEAMLINE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A synthetic-diamond-based X-ray transmitting beam-position monitor has been studied using focused white beam at the National Synchrotron Light Source X-25 wiggler beamline. of particular interest are the possibilities to design an integral window and filter/photon beam-position monitor for the Advanced Photon Source high-heat-flux insertion-device beamlines. The preliminary measurements were taken using two synthetic-diamond blade samples with different thicknesses and cooling configurations. The monitor (consisting of a vacuum vessel, an ion pump, a water-cooling base, a blade mounting block, and electric feedthroughs) was mounted on a three-dimensional (x, y, phi) stepping-motor-driven stage with a 0.064-mum stepping size and a 0.1-mum linear encoder resolution. An infrared camera system was used to monitor and record the diamond blade surface temperature field through a sapphire window and test results are presented. RP SHU, D (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 5 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 577 EP 580 DI 10.1016/0168-9002(94)91951-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900108 ER PT J AU SHU, DM KUZAY, TM AF SHU, DM KUZAY, TM TI GENERAL LAYOUT DESIGN FOR THE ADVANCED-PHOTON-SOURCE BEAMLINE FRONT-ENDS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB In the first phase of construction, sixteen insertion-device beamline front ends and sixteen bending-magnet beamline front ends will be built by 1995 for the Advanced Photon Source (APS). Designs for these front ends have been completed. In this paper, the particular designs and specifications as well as the optical and bremsstrahlung ray-tracing analysis for the APS front ends are presented. RP SHU, DM (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 584 EP 590 DI 10.1016/0168-9002(94)91953-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900110 ER PT J AU BARRAZA, J SHU, D KUZAY, TM AF BARRAZA, J SHU, D KUZAY, TM TI FRONT-END SUPPORT SYSTEMS FOR THE ADVANCED-PHOTON-SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The support-system designs for the Advanced Photon Source (APS) front ends are complete and will be installed in 1994. These designs satisfy the positioning and alignment requirements of the front-end components to be installed inside the storage-ring tunnel, including the photon beam position monitors, fixed masks, photon and safety shutters, fitters, windows, and differential pumps. Other components include beam transport pipes and ion pumps. The designs comprise 3-point kinematic mounts and single-axis supports to satisfy various multi-direction positioning requirements from coarse to ultra-precise. The confined space inside the storage-ring tunnel has posed engineering challenges in the design of these devices, in view of the fact that some components weigh as much as 500 kg. These challenges include designing for mobility during commissioning and initial alignment, mechanical and thermal stability, and precise low-profile vertical and horizontal positioning. As a result, novel stages and kinematic mounts have been constructed using modular and standard designs. This paper will discuss the diverse group of support systems, including specifications and performance data of the prototypes. RP BARRAZA, J (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 591 EP 597 DI 10.1016/0168-9002(94)91954-2 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900111 ER PT J AU FENGBERMAN, SK SIDDONS, DP BERMAN, L AF FENGBERMAN, SK SIDDONS, DP BERMAN, L TI NATIONAL-SYNCHROTRON-LIGHT-SOURCE BEAM LINE DATA-ACQUISITION AND ANALYSIS COMPUTER-SYSTEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB A versatile computer environment to manage instrumentation alignment and experimental control at the National Synchrotron Light Source beam lines has been developed. The system is based on a 386/486 personal computer running under a UNIX operating system with X11 Windows. It offers an ideal combination of capability, flexibility, compatibility, and cost- With a single personal computer, the beam line user can run a wide range of scattering and spectroscopy experiments using a multi-tasking data-collection program which can interact with CAMAC, GPEB and AT-Bus interfaces, and simultaneously examine and analyze data and communicate with remote network nodes. RP FENGBERMAN, SK (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 603 EP 606 DI 10.1016/0168-9002(94)91956-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900113 ER PT J AU BERMAN, LE AF BERMAN, LE TI HIGH-HEAT-LOAD CRYSTAL OPTICS EXPERIMENTS AT THE NSLS X25 X-RAY WIGGLER BEAM LINE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID POWER-DENSITY; PERFORMANCE; MONOCHROMATORS RP BERMAN, LE (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 607 EP 608 DI 10.1016/0168-9002(94)91957-7 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900114 ER PT J AU LEE, WK MILLS, DM AF LEE, WK MILLS, DM TI HIGH HEAT LOAD X-RAY OPTICS RESEARCH-AND-DEVELOPMENT AT THE ADVANCED-PHOTON-SOURCE - AN OVERVIEW SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID SYNCHROTRON RADIATION; POWER-DENSITY; CRYSTAL MONOCHROMATOR; SILICON; PERFORMANCE; BEAMS AB Insertion devices at third-generation synchrotron radiation sources are capable of producting X-ray beams with total power in excess of 7 kW or power densities of 150 W/mm2 at a typical location of the optical components. Optical elements subjected to these heat fluxes will suffer considerably unless carefully designed to withstand such unprecedented power loadings. At the Advanced Photon Source (APS), we have an aggressive program aimed at investigating possible methods to mitigate thermal distortions. The approaches being studied include improved heat exchangers, use of liquid gallium and liquid nitrogen as coolants, novel crystal geometries, power filtering, and replacement of silicon with diamond for crystal monochromators. This paper provides an overview of the high heat load X-ray optics program at the APS. RP LEE, WK (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 28 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 618 EP 626 DI 10.1016/0168-9002(94)91960-7 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900117 ER PT J AU WANG, ZB KUZAY, TM SHARMA, SK AF WANG, ZB KUZAY, TM SHARMA, SK TI POSTBUCKLING BEHAVIOR OF WINDOWS SUBJECTED TO SYNCHROTRON-RADIATION X-RAYS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID BERYLLIUM AB To fully understand the behavior of windows after buckling so as to precisely predict failure, this paper first reviews test data and then examines the postbuckling behavior of thin-shell structures under thermal or mechanical load. The paper presents postbuckling analyses of beryllium windows subjected to X-ray thermal loads and investigates the possibility of incorporating elastic buckling into window designs. RP WANG, ZB (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 627 EP 630 DI 10.1016/0168-9002(94)91961-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900118 ER PT J AU WANG, ZB KUZAY, TM HAHN, U SHU, DM DEJUS, R BRITE, C AF WANG, ZB KUZAY, TM HAHN, U SHU, DM DEJUS, R BRITE, C TI FILTER AND WINDOW BEHAVIOR FOR THE ADVANCED PHOTON SOURCE BEAMLINE FRONT-ENDS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB Cooling methods and thickness selection of filters and windows are investigated. Safety criteria previously proposed are used to design the filter and window parameters at the Advanced Photon Source. Results are presented on power absorption as well as analytical results from thermal and structural analyses. RP WANG, ZB (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 631 EP 639 DI 10.1016/0168-9002(94)91962-3 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900119 ER PT J AU SMITHER, RK FERNANDEZ, PB AF SMITHER, RK FERNANDEZ, PB TI APPARENT TEMPERATURE VERSES TRUE TEMPERATURE OF SILICON-CRYSTALS AS A FUNCTION OF THEIR THICKNESS USING INFRARED MEASUREMENTS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST ID GALLIUM AB Viewing the surface of objects subjected to high heat fluxes with an infrared camera or infrared sensor has proven to be a very effective method for monitoring the magnitude and distribution of surface temperatures On an object. This approach has been quite useful in studies of cooling silicon crystals in monochromators subject to high heat loads. The main drawback is that single crystals of silicon are partially transparent to infrared radiation as monitored in most infrared cameras. This means that the infrared radiation emitted from the surface contains a component that comes from the interior of the crystal, and that the intensity of the emitted radiation and thus the apparent temperature of the surface of the crystal depends on the thickness of the crystal and the kind of coating on the back (and/or the front) of the crystal. The apparent temperature of the crystal increases as the crystal is made thicker. A series of experiments was performed at Argonne National Laboratory to calibrate the apparent temperature of the crystal as measured with an infrared camera as a function of the crystal thickness and the type of coating (if any) on the back of the crystal. A good reflecting surface on the back of the crystal increases the apparent temperature of the crystal and simulates the response of a crystal twice the thickness. These measurements make it possible to interpret infrared signals from cooled silicon crystals used in earlier high-heat-load experiments. A number of examples are given for data taken in synchrotron experiments with high intensity X-ray beams. RP SMITHER, RK (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 640 EP 643 DI 10.1016/0168-9002(94)91963-1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900120 ER PT J AU KUZAY, TM AF KUZAY, TM TI A REVIEW OF THERMOMECHANICAL CONSIDERATIONS OF HIGH-TEMPERATURE MATERIALS FOR SYNCHROTRON APPLICATIONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The third generation synchrotron facilities such as the 7-GeV Advanced Photon Source generate X-ray beams with very high heat load and heat flux levels. Certain front end and beamline components will be required to sustain total heat loads of 3.8 to 15 kW and heat flux levels exceeding 400 W/mm2 even during the first phase of this project. Grazing geometry and enhanced heat transfer techniques in the design of such components reduce the heat flux levels below the 30 W/mm2 level, which is sustainable by the special copper materials routinely used in the component design. Although the resulting maximum surface temperatures are sustainable, structural stresses and fatigue issues remain important concerns. Cyclic thermal loads have a propensity to cause spallation and thermal striping. As such, the steady-state part of the problem is much easier to understand and handle than the time-dependent part. Ease of bonding as well as ultrahigh vacuum and radiation compatibility are additional constraints on material selection for these components. The two copper materials, which are very commonly used in synchrotron components, are the traditional oxygen-free high-conductivity copper (OFHC) and the newer dispersion-strengthened copper, Glidcop. New materials are also appearing in heat sinks or heat spreaders that are bonded to the base copper in some fashion. These are either partially transparent to X-rays and have engineered volumetric heating and/or are very thermally conductive to spread the thermal load in a preferred way. These materials are reviewed critically for high-heat-load or high-heat-flux applications in synchrotrons. RP KUZAY, TM (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 1 Z9 1 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 644 EP 650 DI 10.1016/0168-9002(94)91964-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900121 ER PT J AU WANG, ZB NIAN, T RYDING, D KUZAY, TM AF WANG, ZB NIAN, T RYDING, D KUZAY, TM TI LOW-CYCLE-FATIGUE BEHAVIOR OF COPPER MATERIALS AND THEIR USE IN SYNCHROTRON BEAMLINE COMPONENTS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB Analyses and evaluation of the life cycle number and crack propagation rate were performed on oxygen-free high-conductivity copper X-ray beamline components based on data available in the literature. Recommendations are made with respect to the safe use of materials in high-heat-load beamline component design. The available literature is critically reviewed for low-cycle fatigue properties at the elevated temperatures typically found in synchrotron operations. RP WANG, ZB (reprint author), ARGONNE NATL LAB,DIV EXPTL FACILITIES,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 651 EP 656 DI 10.1016/0168-9002(94)91965-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900122 ER PT J AU NIAN, HLT SHU, D SHENG, ICA KUZAY, TM AF NIAN, HLT SHU, D SHENG, ICA KUZAY, TM TI THERMOMECHANICAL ANALYSIS OF FIXED MASK-1 FOR THE ADVANCED PHOTON SOURCE INSERTION DEVICE FRONT-ENDS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th National Conference on Synchrotron Radiation Instrumentation CY AUG 23-26, 1993 CL NIST, GAITHERSBURG, MD HO NIST AB The first fixed mask is one of the critical elements on the insertion device front ends of the beamlines at the Advanced Photon Source now under construction at Argonne National Laboratory. The heat flux from the undulators will be very large. We simulated the X-ray beam at several locations to ensure that the worst possible case was considered. The maximum temperature (about 180-degrees-C) occurs when the beam hits the center of the horizontal surface. The maximum effective stress (about 313 MPa) occurs when the X-ray beam hits at or near the corners. RP NIAN, HLT (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1994 VL 347 IS 1-3 BP 657 EP 663 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD429 UT WOS:A1994PD42900123 ER PT J AU OZAWA, A KOBAYASHI, T SATO, H HIRATA, D TANIHATA, I YAMAKAWA, O OMATA, K SUGIMOTO, K OLSON, D CHRISTIE, W WIEMAN, H AF OZAWA, A KOBAYASHI, T SATO, H HIRATA, D TANIHATA, I YAMAKAWA, O OMATA, K SUGIMOTO, K OLSON, D CHRISTIE, W WIEMAN, H TI INTERACTION CROSS-SECTIONS AND RADII OF THE MASS-NUMBER A=17 ISOBAR (N-17, 17F, AND NE-17) SO PHYSICS LETTERS B LA English DT Article ID NUCLEAR RADII; PROTON HALO; LI-11; DECAY AB Interaction cross sections of mass number A = 17 isobar (N-17(7)10, F-17(9)8, and Ne-17(10)7) have been measured at around 700 MeV/nucleon. Effective root-mean-square (RMS) radii of the nucleon distribution of these nuclei have been deduced using Glauber-model calculation. A strong isospin dependence of the radii has been observed in the A = 17 isobar, which shows an increase of the radii on the proton rich side from F-17 to Ne-17. The radius of Ne-17 is also found to be larger than that of its mirror nucleus N-17. The increase of the radius in Ne-17 suggests its anomalous structure. One of the possibilities is that an inversion of the s and d orbitals occurs in this nucleus. The role of the centrifugal barrier in the formation of a halo is also discussed. C1 FUKUI UNIV,FAC EDUC,FUKUI 910,JAPAN. UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN. OSAKA UNIV,FAC SCI,TOYONAKA,OSAKA 560,JAPAN. LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP OZAWA, A (reprint author), INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. RI Hirata, Daisy/F-3199-2013 NR 21 TC 128 Z9 129 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 11 PY 1994 VL 334 IS 1-2 BP 18 EP 22 DI 10.1016/0370-2693(94)90585-1 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB598 UT WOS:A1994PB59800004 ER PT J AU WHITE, AR AF WHITE, AR TI THE O(G(4)) LIPATOV KERNELS SO PHYSICS LETTERS B LA English DT Article ID HIGH-ENERGY BEHAVIOR; ABELIAN GAUGE-THEORY; S APPROXIMATION; AMPLITUDES; QCD; POMERON AB Leading plus next-to leading log results for the Regge limit of massless Yang-Mills theories are reproduced by reggeon diagrams in which the Regge slope alpha' --> 0 and reggeon amplitudes satisfy Ward identity constraints at zero transverse momentum. Using reggeon unitarity together with multiple discontinuity theory a complete set of such diagrams can be constructed. The resulting two-two, one-three and two-four kernels which generalise the Lipatov equation at O(g4) are determined uniquely. RP WHITE, AR (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 20 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 11 PY 1994 VL 334 IS 1-2 BP 87 EP 96 DI 10.1016/0370-2693(94)90595-9 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB598 UT WOS:A1994PB59800014 ER PT J AU HINSHAW, G KOGUT, A GORSKI, KM BANDAY, AJ BENNETT, CL LINEWEAVER, C LUBIN, P SMOOT, GF WRIGHT, EL AF HINSHAW, G KOGUT, A GORSKI, KM BANDAY, AJ BENNETT, CL LINEWEAVER, C LUBIN, P SMOOT, GF WRIGHT, EL TI LIMITS ON 3-POINT CORRELATIONS IN THE COBE DMR 1ST-YEAR ANISOTROPY MAPS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMIC MICROWAVE BACKGROUND; COSMOLOGY, OBSERVATIONS ID DIFFERENTIAL MICROWAVE RADIOMETERS AB We compute the three-point temperature correlation function of the COBE Differential Microwave Radiometer (DMR) first-year sky maps to search for non-Gaussian temperature fluctuations. The level of fluctuations seen in the computed correlation function are too large to be attributable solely to instrument noise. However the fluctuations are consistent with the level expected to result from a superposition of instrument noise and sky signal arising from a Gaussian power-law model of initial fluctuations, with a quadrupole normalized amplitude of 17 muK and a power-law spectral index n = 1. We place limits on the amplitude of intrinsic three-point correlations with a variety of predicted functional forms. C1 NASA, GODDARD SPACE FLIGHT CTR, GSFC, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. UNIV CALIF BERKELEY, LBL, SSL, BERKELEY, CA 94720 USA. UCSB, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV CALIF LOS ANGELES, DEPT ASTRN, LOS ANGELES, CA 90024 USA. RP HINSHAW, G (reprint author), HUGHES STX CORP, NASA, GSFC, CODE 685 9, GREENBELT, MD 20771 USA. RI Kogut, Alan/D-6293-2012 NR 15 TC 30 Z9 30 U1 0 U2 0 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 AUG 10 PY 1994 VL 431 IS 1 BP 1 EP 5 DI 10.1086/174462 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NZ977 UT WOS:A1994NZ97700001 ER PT J AU FRIEMAN, J SCOCCIMARRO, R AF FRIEMAN, J SCOCCIMARRO, R TI CAN MACHOS PROBE THE SHAPE OF THE GALAXY HALO SO ASTROPHYSICAL JOURNAL LA English DT Article DE DARK MATTER; GRAVITATIONAL LENSING; MAGELLANIC CLOUDS ID GALACTIC HALO; DARK MATTER; OBJECTS; STAR AB Microlensing searches in our galaxy have recently discovered several candidates in the direction of the Large Magellanic Cloud (LMC). We study the prospects for such searches to yield useful information about the flattening of the Galaxy dark matter halo, using a self-consistent oblate halo model and allowing for the possibility of misalignment between the disk and halo symmetry axes. The microlensing optical depth for the LMC, tau(LMC), depends sensitively on the disk-halo tilt angle in the Milky Way, as does the ratio tau(SMC)/tau(LMC). If the tilt angle is as large as 30-degrees, a much larger spread in values for tau(LMC) is consistent with rotation curve constraints than previously thought. Disk-halo tilt and halo flattening do not significantly affect the MACHO masses inferred from event durations. C1 UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP FRIEMAN, J (reprint author), NASA,CTR ASTROPHYS,FERMILAB,FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 29 TC 19 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1994 VL 431 IS 1 BP L23 EP L26 DI 10.1086/187463 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NZ979 UT WOS:A1994NZ97900006 ER PT J AU RANSOM, SM FAZIO, GG EIKENBERRY, SS MIDDLEDITCH, J KRISTIAN, J HAYS, K PENNYPACKER, CR AF RANSOM, SM FAZIO, GG EIKENBERRY, SS MIDDLEDITCH, J KRISTIAN, J HAYS, K PENNYPACKER, CR TI HIGH TIME RESOLUTION INFRARED OBSERVATIONS OF THE CRAB-NEBULA PULSAR SO ASTROPHYSICAL JOURNAL LA English DT Article DE INSTRUMENTATION, DETECTORS; PULSARS, INDIVIDUAL (PSR 0531+21); STARS, NEUTRON ID RAPIDLY SPINNING PULSARS; ENERGETIC RADIATION; ULTRAVIOLET; VELA AB The Crab Nebula pulsar (PSR 0531+21) was observed in the infrared in J (1.2 mum), H (1.6 mum), K (2.2 mum), and a 0.9-2.5 mum band on the Las Campanas 2.5 m and Mount Hopkins 1.2 m telescopes. A new detector was used, called the Solid State Photomultiplier (SSPM), which allowed measurements of unprecedented time resolution (approximately 20-50 mus) in these bands. The infrared pulse profiles are shown to be qualitatively similar to those at ultraviolet and optical wavelengths, but the main pulse widths and the pulse/interpulse separations increase from the ultraviolet to the infrared. These observations are consistent with the predictions of the outer magnetospheric gap models of high-energy pulsar emission. No evidence was found of the infrared ''shoulder'' of the main pulse or the excess infrared flux after the interpulse previously reported. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CARNEGIE INST WASHINGTON OBSERV,PASADENA,CA 91101. ROCKWELL INT CORP,CTR SCI,ANAHEIM,CA 92803. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. RP RANSOM, SM (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA. OI Ransom, Scott/0000-0001-5799-9714 NR 15 TC 12 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1994 VL 431 IS 1 BP L43 EP L46 DI 10.1086/187468 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NZ979 UT WOS:A1994NZ97900011 ER PT J AU ERSKINE, D NELLIS, WJ WEIR, ST AF ERSKINE, D NELLIS, WJ WEIR, ST TI SHOCK-WAVE PROFILE STUDY OF TUFF FROM THE NEVADA TEST SITE SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ORIENTED GRAPHITE; TRANSFORMATION; DEFORMATION; DIAMOND; QUARTZ AB Shock wave equation of state and release behavior of tuff from the Nevada Test Site were measured in the range 8 to 107 GPa by recording shock wave profiles produced by impact of projectiles accelerated by a two-stage light-gas gun. Shock wave profiles were measured with a fast optical interferometer. Hugoniot, sound speed, and effective Gruneisen parameter data were determined from the profiles. The specimen geometry allows direct observation of the shape of the leading edge of the shock, in which complex compressive dynamics caused by pore crushing or phase transitions can manifest themselves. The tuff specimens were tested in both a water-saturated and semidry state. Hydration of the rock increases both the shock and sound speeds for a given compression. The U(s)-U(p) relation for our water-saturated tuff is slightly nonlinear and can be approximated as U(s)=2.00 + 1.42 U(p) for 0*) most likely arises from increased spin-orbit coupling caused by the nonplanarity of the macrocycle. These results demonstrate that structural perturbations of porphyrin macrocycles, imposed by peripheral substitution in vitro or the protein environment in vivo, can result in significant changes in electronic properties, including the rates and yields of the fundamental excited state deactivation processes. C1 WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RI Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 47 TC 177 Z9 189 U1 5 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 10 PY 1994 VL 116 IS 16 BP 7363 EP 7368 DI 10.1021/ja00095a046 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA PB764 UT WOS:A1994PB76400046 ER PT J AU SCHULTZ, RH BENGALI, AA TAUBER, MJ WEILLER, BH WASSERMAN, EP KYLE, KR MOORE, CB BERGMAN, RG AF SCHULTZ, RH BENGALI, AA TAUBER, MJ WEILLER, BH WASSERMAN, EP KYLE, KR MOORE, CB BERGMAN, RG TI IR FLASH KINETIC SPECTROSCOPY OF C-H BOND ACTIVATION OF CYCLOHEXANE-D(0) AND CYCLOHEXANE-D(12) BY CP(ASTERISK)RH(CO)(2) IN LIQUID RARE-GASES - KINETICS, THERMODYNAMICS, AND AN UNUSUAL ISOTOPE EFFECT SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID FEMTOSECOND TRANSIENT ABSORPTION; UNSATURATED METAL CENTERS; OXIDATIVE ADDITION; SUBSTITUTION-REACTIONS; TETRAHYDROFURAN SOLUTION; SATURATED-HYDROCARBONS; REDUCTIVE ELIMINATION; INFRARED-SPECTROSCOPY; SUPERCRITICAL FLUIDS; CARBONYL-COMPLEXES AB Flash kinetic spectroscopy with infrared detection is used to probe C-H activation of cyclohexane-d(0) and -d(12) by intermediates generated upon ultraviolet irradiation of Cp*Rh(CO)(2) (Cp* = C-5(CH3)5) in liquid rare gas (Rg = Kr or Xe) solution at low temperature (163-193 K). Upon UV photolysis, a new C-O stretching band (at 1946.5 cm(-1) in Kr and at 1941.5 cm(-1) in Xe) appears promptly, which we attribute to Cp*Rh(CO)(Rg), In the presence of hydrocarbon a second C-O stretching band (2002.5 cm(-1) in Kr and 1998 cm(-1) in Xe) grows in at the same observed rate as the disappearance of the 1946.5-cm(-1) band. We attribute this second band to the alkyl hydride product, Cp*Rh(CO)(H)(C6H11). The concentration dependence of the observed reaction rate in Kr solution shows behavior consistent with a preequilibrium mechanism in which the initial Cp*Rh(CO)(Rg) complex equilibrates with a weakly bound Cp*Rh(CO)(alkane) complex (which has an IR carbonyl frequency unresolvable from that of the rare gas complex) followed by C-H activation of the latter. We observe a large normal kinetic isotope effect (k(2)(H)/k(2)(D) approximate to 10) on the C-H activation step k(2), but, most unusually, a large inverse isotope effect on the preequilibrium constant (K-eq(H)/K-eq(D) approximate to 0.1), implying that C6D12 binds more strongly to the rhodium center than does C6H12 From the temperature dependence of k(2), we derive Eyring activation energies of 4.2 +/- 0.5 kcal/mol for k(2)(H) and 5.3 +/- 0.5 kcal/mol for k(2)(D). C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 95 TC 135 Z9 135 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 10 PY 1994 VL 116 IS 16 BP 7369 EP 7377 DI 10.1021/ja00095a047 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA PB764 UT WOS:A1994PB76400047 ER PT J AU SAUTET, P DUNPHY, JC OGLETREE, DF JOACHIM, C SALMERON, M AF SAUTET, P DUNPHY, JC OGLETREE, DF JOACHIM, C SALMERON, M TI IMAGING A P(2X2) LAYER OF SULFUR ON RE(0001) WITH THE SCANNING TUNNELING MICROSCOPE - AN EXPERIMENTAL AND THEORETICAL-STUDY OF THE EFFECT OF ADSORPTION SITE AND TIP STRUCTURE SO SURFACE SCIENCE LA English DT Article ID METAL-SURFACES; STM IMAGES; ATOM; BENZENE AB A combined experimental and theoretical study of the STM images of p(2 x 2)-S on Re(0001) is presented. STM images were calculated with the electron scattering quantum chemistry (ESQC) method in order to study the effect on the images of the structure of the tip, the site and binding height of the adsorbate, and the tunneling gap resistance. It was found that only sulfur adsorption in the hollow site yields calculated images in agreement with the experimental data. While the STM images were found to depend strongly on the tip structure, the calculations indicate that three basic types of tip terminations (S and Pt single atom terminations and multiple Pt atom terminations) can explain the most frequently observed types of images. Additionally, the calculations show that the contrast of STM images is highly sensitive to the height of the S adatom with respect to the surface, but not strongly sensitive to the tunneling gap resistance except at very small gaps. Calculations of a less dense sulfur structure indicate that the variation of the shape and contrast of the image with tip and surface structure is a specific property of dense overlayers and is absent in the case of isolated or well separated adsorbates. These variations are explained as a result of interferences between several tunneling channels produced by the simultaneous overlap of the tip wavefunction with that of several adsorbates. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. INST RECH CATALYSE,F-69626 VILLEURBANNE,FRANCE. ECOLE NORMALE SUPER,F-69364 LYON 07,FRANCE. CEMES,LOE,F-31055 TOULOUSE,FRANCE. RI Sautet, Philippe/G-3710-2014; Ogletree, D Frank/D-9833-2016 OI Sautet, Philippe/0000-0002-8444-3348; Ogletree, D Frank/0000-0002-8159-0182 NR 28 TC 46 Z9 46 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 10 PY 1994 VL 315 IS 1-2 BP 127 EP 142 DI 10.1016/0039-6028(94)90549-5 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA PC311 UT WOS:A1994PC31100028 ER PT J AU BAGLEY, KA VANGARDEREN, CJ CHEN, M DUIN, EC ALBRACHT, SPJ WOODRUFF, WH AF BAGLEY, KA VANGARDEREN, CJ CHEN, M DUIN, EC ALBRACHT, SPJ WOODRUFF, WH TI INFRARED STUDIES ON THE INTERACTION OF CARBON-MONOXIDE WITH DIVALENT NICKEL IN HYDROGENASE FROM CHROMATIUM-VINOSUM SO BIOCHEMISTRY LA English DT Article ID DESULFOVIBRIO-GIGAS HYDROGENASE; IRON-SULFUR CLUSTER; NIFE HYDROGENASE; REDOX PROPERTIES; EPR; ACTIVATION; CENTERS; SITE; MOSSBAUER; COMPLEXES AB Infrared spectra of a carbon monoxy-bound form of the EPR silent Ni(II) species of hydrogenase isolated from Chromatium vinosum are presented. These spectra show a band at 2060 cm(-1) due to nu(CO) for a metal-CO complex. This absorbance shifts to 2017 cm(-1) upon exposure of the enzyme to (CO)-C-13. This band is attributed to nu(CO) from a Ni(II)-CO species. It is shown that the CO on this species is photolabile at cryogenic temperatures but rebinds to form the original carbon monoxy species at temperatures above 200 K. In addition to the nu(CO) band, infrared lines are detected at 2082, 2069, and 1929 cm(-1), which shift slightly higher in frequency upon photolysis of the CO from the Ni. These infrared bands do not arise from CO itself on the basis of the fact that the frequency of these bands is unaffected by exposure of the enzyme to (CO)-C-13. Experiments in D2O show that these bands do not arise from an exchangeable hydrogen species. It is concluded that these non-CO bands arise from species near or coordinated to the Ni active site. The possible nature of these bands is discussed. C1 LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545. UNIV AMSTERDAM,BIOCENTRUM,EC SLATER INST BIOCHEM RES,1018 TV AMSTERDAM,NETHERLANDS. FU NIDDK NIH HHS [DK 36263] NR 45 TC 116 Z9 118 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 9 PY 1994 VL 33 IS 31 BP 9229 EP 9236 DI 10.1021/bi00197a026 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PB763 UT WOS:A1994PB76300026 PM 8049224 ER PT J AU LOWACK, RH VOLLHARDT, KPC AF LOWACK, RH VOLLHARDT, KPC TI DECASUBSTITUTED DECAPHENYLMETALLOCENES SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE METALLOCENES; CYCLOPENTADIENYL; TIN; LEAD ID MOLECULAR-STRUCTURE; COMPLEXES; CRYSTAL; DECAPHENYLSTANNOCENE; THALLIUM(I); IRON(II); LIGANDS; ISOMER; SODIUM AB Pentaphenylcyclopentadienes that are para-substituted at each phenyl group prove to be valuable new ligands. They are easily prepared in good yield and high purity from pentaphenylcyclopentadiene by acetylation and subsequent acetalation. Owing to the ease with which the electronic properties of these ligands can be modified and due to the solubility and the facile characterization of their complexes it is now possible to explore the whole field of decaarylmetallocenes. The first soluble decaarylmetallocenes with tin and lead as the metal atom are described. C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP LOWACK, RH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 17 TC 21 Z9 21 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD AUG 9 PY 1994 VL 476 IS 1 BP 25 EP 32 DI 10.1016/0022-328X(94)84136-5 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA PA312 UT WOS:A1994PA31200005 ER PT J AU BACA, AG ZIPPERIAN, TE HOWARD, AJ KLEM, JF TIGGES, CP AF BACA, AG ZIPPERIAN, TE HOWARD, AJ KLEM, JF TIGGES, CP TI THERMODYNAMICALLY STABLE P-CHANNEL STRAINED-LAYER ALGAAS/INGAAS/GAAS HETEROSTRUCTURE FIELD-EFFECT TRANSISTOR SO APPLIED PHYSICS LETTERS LA English DT Article ID HIGH-TRANSCONDUCTANCE; QUANTUM-WELL AB Device characteristics of a thermodynamically stable p-channel, strained quantum-well heterostructure field effect transistor (HFET) are reported. The AlGaAs/InGaAs/GaAs material system was used to fabricate the p-channel HFETs with Al and In mole fractions of 0.20 and 0.18, respectively. Transconductances of 32 and 94 mS/mm were achieved at 300 and 77 K, respectively, for devices with 1.2 mum recessed gates. These numbers are comparable to InGaAs quantum-well, recessed gate pHFETs whose quantum-well thicknesses exceed the thermodynamic stability limit. These results have important implications for high performance self-aligned devices which require high-temperature processing. RP BACA, AG (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 8 PY 1994 VL 65 IS 6 BP 752 EP 754 DI 10.1063/1.112220 PG 3 WC Physics, Applied SC Physics GA PA919 UT WOS:A1994PA91900034 ER PT J AU BAI, GR CHANG, HLM FOSTER, CM AF BAI, GR CHANG, HLM FOSTER, CM TI PREPARATION OF SINGLE-CRYSTAL Y3AL5O12 THIN-FILM BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION, (VOL 64, PG 1777, 1994) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition RP BAI, GR (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 1 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 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 8 PY 1994 VL 65 IS 6 BP 790 EP 790 DI 10.1063/1.113088 PG 1 WC Physics, Applied SC Physics GA PA919 UT WOS:A1994PA91900047 ER PT J AU ZHENG, ZF SALMERON, MB WEBER, ER AF ZHENG, ZF SALMERON, MB WEBER, ER TI EMPTY STATE AND FILLED STATE IMAGE OF ZNGA ACCEPTOR IN GAAS STUDIED BY SCANNING-TUNNELING-MICROSCOPY, (VOL 64, PG 1836, 1994) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition C1 UNIV CALIF BERKELEY,DEPT MAT SCI,BERKELEY,CA 94720. RP ZHENG, ZF (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 1 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 8 PY 1994 VL 65 IS 6 BP 790 EP 790 DI 10.1063/1.113089 PG 1 WC Physics, Applied SC Physics GA PA919 UT WOS:A1994PA91900048 ER PT J AU SZPAK, S MOSIERBOSS, PA BOSS, RD SMITH, JJ AF SZPAK, S MOSIERBOSS, PA BOSS, RD SMITH, JJ TI COMMENTS ON THE ANALYSIS OF TRITIUM CONTENT IN ELECTROCHEMICAL-CELLS SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article AB Expressions are given for the tritium distribution between gas and liquid phases arising from prolonged electrolysis of D2O on Pd electrodes saturated with absorbed deuterium. Errors associated with commonly employed experimental procedures and their interpretation using a simple model for the distribution between the gas and liquid phases are evaluated. With regard to tritium production, an unambiguous resolution requires a complete mass balance. Conclusions based on partial data, such as the measurement of the tritium content in a single cell component (e.g. electrode, electrolyte or ''electrolytic'' gas phase), may be misleading, particularly if production rates are either low or intermittent. C1 US DOE,WASHINGTON,DC 20585. RP SZPAK, S (reprint author), USN,CTR CONTROL & OCEAN SURVEILLENCE,DIV RDT & E,SAN DIEGO,CA 92152, USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD AUG 8 PY 1994 VL 373 IS 1-2 BP 1 EP 9 DI 10.1016/0022-0728(94)03302-1 PG 9 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA PB510 UT WOS:A1994PB51000001 ER PT J AU MCBREEN, J SANSONE, M AF MCBREEN, J SANSONE, M TI IN-SITU X-RAY-ABSORPTION SPECTROSCOPIC STUDY OF ADSORBED PB ON CARBON-SUPPORTED PT SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article ID ELECTRODES; PLATINUM; MONOLAYER; GOLD AB In situ X-ray absorption spectroscopy (XAS) was used to study the structure of adsorbed Pb on carbon-supported Pt in 1 M HClO4 + 5 x 10(-3) M Pb2+, in the potential range -0.24 to 1.15 V vs. SCE. The XAS measurements were done using a Canberra 13-element germanium detector. X-ray absorption near-edge structure (XANES) measurements indicated that, in the undepotential deposition (UPD) region, the Pb species are essentially neutral Pb atoms. At all potentials positive to the main UPD peak in the cyclic voltammogram the Pb is in the Pb(II) state. Analysis of the extended X-ray absorption fine structure (EXAFS) data for potentials more negative than 0.0 V vs. SCE required a two-shell fit involving Pb-Pb and Pb-Pt interactions. At more positive potentials, in the UPD region, the data could be fitted to a single Pb-Pt shell, indicating a high degree of lateral disorder in the layer. There is no evidence of Pb interaction with oxygenated species in the UPD region. On stripping the UPD layer the Pb was present as hydrated Pb2+ ions. At more positive potentials there was clear evidence of incorporation of Pb into the platinum oxide layer. Repeated cycling changes the nature of the UPD layer. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. RP MCBREEN, J (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 13 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD AUG 8 PY 1994 VL 373 IS 1-2 BP 227 EP 233 DI 10.1016/0022-0728(94)03330-7 PG 7 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA PB510 UT WOS:A1994PB51000027 ER PT J AU HENRY, RG LAURITSEN, T KHOO, TL AHMAD, I CARPENTER, MP CROWELL, B DOSSING, T JANSSENS, RVF HANNACHI, F KORICHI, A SCHUCK, C AZAIEZ, F BEAUSANG, CW BERAUD, R BOURGEOIS, C CLARK, RM DELONCLE, I DUPRAT, J GALL, B HUBEL, H JOYCE, MJ KACI, M LECOZ, Y MEYER, M PAUL, ES PERRIN, N POFFE, N PORQUET, MG REDON, N SERGOLLE, H SHARPEYSCHAFER, JF SIMPSON, J SMITH, AG WADSWORTH, R WILLSAU, P AF HENRY, RG LAURITSEN, T KHOO, TL AHMAD, I CARPENTER, MP CROWELL, B DOSSING, T JANSSENS, RVF HANNACHI, F KORICHI, A SCHUCK, C AZAIEZ, F BEAUSANG, CW BERAUD, R BOURGEOIS, C CLARK, RM DELONCLE, I DUPRAT, J GALL, B HUBEL, H JOYCE, MJ KACI, M LECOZ, Y MEYER, M PAUL, ES PERRIN, N POFFE, N PORQUET, MG REDON, N SERGOLLE, H SHARPEYSCHAFER, JF SIMPSON, J SMITH, AG WADSWORTH, R WILLSAU, P TI SPECTRUM OF GAMMA-RAYS CONNECTING SUPERDEFORMED AND NORMAL STATES IN HG-192 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY; BAND AB The complete spectrum of gamma rays following the decay of superdeformed (SD) states in Hg-192 has been extracted. The spectrum, which comprises a quasicontinuous component and sharp lines, reveals the decay mechanism and defines the excitation energies of the SD band. The decay of SD states results from the coupling between a cold, ordered SD system with a hot, chaotic one with normal deformation. C1 CNRS,INST NATL PHYS NUCL & PHYS PARTICULES,CTR SPECTROMETRIE NUCL,F-91405 ORSAY,FRANCE. CNRS,INST NATL PHYS NUCL & PHYS PARTICLES,INST PHYS NUCL,F-91405 ORSAY,FRANCE. UNIV LIVERPOOL,LIVERPOOL L69 3BX,ENGLAND. CNRS,INST NATL PHYS NUCL & PHYS PARTICULES,INST PHYS NUCL LYON,F-69622 VILLEURBANNE,FRANCE. UNIV YORK,YORK YO1 5DD,N YORKSHIRE,ENGLAND. UNIV BONN,INST STRAHLEN & KERNPHYS,D-53115 BONN,GERMANY. SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. UNIV OXFORD,OXFORD,ENGLAND. RP HENRY, RG (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 23 TC 57 Z9 57 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 8 PY 1994 VL 73 IS 6 BP 777 EP 781 DI 10.1103/PhysRevLett.73.777 PG 5 WC Physics, Multidisciplinary SC Physics GA PA371 UT WOS:A1994PA37100001 ER PT J AU FALLON, P BEAUSANG, CW CLARKE, S TWIN, PJ BECK, FA BYRSKI, T CURIEN, D DAGNALL, PJ DEFRANCE, G DUCHENE, G FORSYTH, PD HAAS, B JOYCE, MJ MACCHIAVELLI, AO PAUL, ES SHARPEYSCHAFER, JF SIMPSON, J VIVIEN, JP ABERG, S NAZAREWICZ, W AF FALLON, P BEAUSANG, CW CLARKE, S TWIN, PJ BECK, FA BYRSKI, T CURIEN, D DAGNALL, PJ DEFRANCE, G DUCHENE, G FORSYTH, PD HAAS, B JOYCE, MJ MACCHIAVELLI, AO PAUL, ES SHARPEYSCHAFER, JF SIMPSON, J VIVIEN, JP ABERG, S NAZAREWICZ, W TI PAIR EXCITATIONS AND A PROTON BAND CROSSING IN SUPERDEFORMED GD-150 SO PHYSICAL REVIEW LETTERS LA English DT Article ID IDENTICAL BANDS; REGION; STATES; NUCLEI; DY-152 AB An excited superdeformed (SD) band in 150Gd is associated with a two-particle-two-hole proton excitation and provides the first evidence for collective proton pair excitations in a SD nucleus. This band is seen to exhibit a discontinuity in the gamma-ray transition energies (backbending), which is interpreted as a band crossing associated with the alignment of a pair of N = 6 protons. There is further evidence that this excited SD band decays into the yrast SD band. C1 UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,ENGLAND. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. LUND INST TECHNOL,DEPT MATH PHYS,S-22100 LUND,SWEDEN. OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. WARSAW INST TECHNOL,INST PHYS,WARSAW,POLAND. RP FALLON, P (reprint author), LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. RI CURIEN, Dominique/B-6718-2013 NR 20 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 8 PY 1994 VL 73 IS 6 BP 782 EP 785 DI 10.1103/PhysRevLett.73.782 PG 4 WC Physics, Multidisciplinary SC Physics GA PA371 UT WOS:A1994PA37100002 ER PT J AU DEYOREO, JJ LAND, TA DAIR, B AF DEYOREO, JJ LAND, TA DAIR, B TI GROWTH-MORPHOLOGY OF VICINAL HILLOCKS ON THE (101) FACE OF KH2PO4 - FROM STEP-FLOW TO LAYER-BY-LAYER GROWTH SO PHYSICAL REVIEW LETTERS LA English DT Article ID ADP FACE; MICROSCOPY AB The growth morphologies of vicinal hillocks on KH2PO4 {101} surfaces have been investigated using atomic force microscopy. Growth occurs on monomolecular steps both by step-flow and through layer-by-layer growth on both dislocation induced steps and 2D nuclei. Dislocation induced hillocks exhibit hollow cores. The circular cross sections of these cores are consistent with an isotropic step edge energy and the core radii are in good agreement with theoretical predictions. From the interisland spacing we estimate the surface diffusion length to be 200 to 300 nm at 300 K. RP DEYOREO, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 97 Z9 97 U1 1 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 8 PY 1994 VL 73 IS 6 BP 838 EP 841 DI 10.1103/PhysRevLett.73.838 PG 4 WC Physics, Multidisciplinary SC Physics GA PA371 UT WOS:A1994PA37100016 ER PT J AU GAULIN, BD GIBBS, D ISAACS, ED LUSSIER, JG REIMERS, JN SCHRODER, A TAILLEFER, L ZSCHACK, P AF GAULIN, BD GIBBS, D ISAACS, ED LUSSIER, JG REIMERS, JN SCHRODER, A TAILLEFER, L ZSCHACK, P TI RESONANT MAGNETIC-X-RAY SCATTERING STUDY OF PHASE-TRANSITIONS IN UPD2AL3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMION SUPERCONDUCTOR UPD2AL3; RANGE ANTIFERROMAGNETIC ORDER; EXCHANGE SCATTERING; URU2SI2; UPT3; POLARIZATION; COEXISTENCE; DIAGRAM; HOLMIUM AB Resonant magnetic x-ray scattering measurements were performed on a single microcrystallite at the surface of a polycrystalline boule of the antiferromagnetic, heavy fermion superconductor UPd2Al3. These measurements show a strong anomaly in the order parameter at 11.8 K, below T(N) is similar to 14.5 K, indicating at least two antiferromagnetically ordered phases which share a common periodicity. Measurements performed near and below T(c) = 2.0 K show the antiferromagnetic order parameter to be unaffected on passing into the superconducting phase, to +/-2%. C1 BROOKHAVEN NATL LAB,OAK RIDGE INST SCI & EDUC,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. AT&T BELL LABS,MURRAY HILL,NJ 07973. CNRS,LAB LOUIS NEEL,F-38042 GRENOBLE,FRANCE. RP GAULIN, BD (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON L8S 4M1,ONTARIO,CANADA. RI Piper, Walter/B-7908-2009 NR 28 TC 20 Z9 20 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 8 PY 1994 VL 73 IS 6 BP 890 EP 893 DI 10.1103/PhysRevLett.73.890 PG 4 WC Physics, Multidisciplinary SC Physics GA PA371 UT WOS:A1994PA37100029 ER PT J AU GRONBECHJENSEN, N SAMUELSEN, MR AF GRONBECHJENSEN, N SAMUELSEN, MR TI PHASE-LOCKING OF AN OVERDAMPED PENDULUM SO PHYSICS LETTERS A LA English DT Article ID DRIVEN PENDULUM; CHAOS; JUNCTIONS AB We analyze phase-locking of an overdamped pendulum in the general case of all harmonics of the driving field and all frequencies. The results show that to first order in the ac amplitude, no harmonic phase-locking exists. The range of phase-locking for fundamental phase-locking is calculated and comparisons to numerical experiments show excellent agreement for all frequencies. C1 TECH UNIV DENMARK,DEPT PHYS,DK-2800 LYNGBY,DENMARK. RP GRONBECHJENSEN, N (reprint author), LOS ALAMOS NATL LAB,DIV COMMUNITY MED,LOS ALAMOS,NM 87545, USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD AUG 8 PY 1994 VL 191 IS 1-2 BP 57 EP 60 DI 10.1016/0375-9601(94)90559-2 PG 4 WC Physics, Multidisciplinary SC Physics GA PB133 UT WOS:A1994PB13300009 ER PT J AU LAMBLE, G MOEN, A NICHOLSON, DG AF LAMBLE, G MOEN, A NICHOLSON, DG TI STRUCTURE OF THE DIAMMINECOPPER(I) ION IN SOLUTION - AN X-RAY-ABSORPTION SPECTROSCOPIC STUDY SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID COPPER(I) AB X-Ray absorption spectroscopy (XAS) using synchrotron radiation has been used to probe the structure of copper(I) species in an aqueous ammonia solution that contains hydrazine to prevent any oxidation to copper(II) species. Combining a characteristic copper(I) pre-edge feature with the extended X-ray absorption fine structure (EXAFS) of the XAS enabled the stereochemistry and bond distances to be extracted for the predominant species, which is shown to be the diamminecopper(I) ion. The structure is linear with Cu-N bond lengths of 1.88 +/- 0.02 angstrom. C1 UNIV TRONDHEIM,AVH,DEPT CHEM,N-7055 DRAGVOLL,NORWAY. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RI Nicholson, David/I-3749-2013 NR 19 TC 32 Z9 32 U1 1 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD AUG 7 PY 1994 VL 90 IS 15 BP 2211 EP 2213 DI 10.1039/ft9949002211 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NZ748 UT WOS:A1994NZ74800006 ER PT J AU KALUZA, M MUCKERMAN, JT RABITZ, H AF KALUZA, M MUCKERMAN, JT RABITZ, H TI THE ROLE OF LASER-PULSE PHASES IN THE SUBPICOSECOND OPTIMAL INFRARED MULTIPHOTON DISSOCIATION OF HF SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SELECTIVITY; DYNAMICS; DF AB In a simulation of the five-pulse, subpicosecond, optimal infrared multiphoton dissociation of an HF molecule (M. Kaluza J.T. Muckerman, P. Gross and H. Rabitz, J. Chem. Phys. 100 (1994) 4211), randomizing phases of an optimal pulse reduced the dissociation yield by nearly a factor of two. Here we simulate the response of an HF molecule to ten five-laser pulses which lack shot-to-shot phase reproducibility. We optimize the timings and carrier frequencies of the five pulses to achieve the maximal average dissociation yield over the ensemble of shots, and provide an estimate for the yield in an experiment in which phases of the laser pulses are not controllable. C1 PRINCETON UNIV,DEPT CHEM,PRINCETON,NJ 08544. RP KALUZA, M (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Muckerman, James/D-8752-2013 NR 13 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 5 PY 1994 VL 225 IS 4-6 BP 335 EP 339 DI 10.1016/0009-2614(94)87090-X PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA PB644 UT WOS:A1994PB64400007 ER PT J AU NORCUM, MT WILKINSON, DA CARLSON, MC HAINFELD, JF CARLSON, GM AF NORCUM, MT WILKINSON, DA CARLSON, MC HAINFELD, JF CARLSON, GM TI STRUCTURE OF PHOSPHORYLASE-KINASE - A 3-DIMENSIONAL MODEL DERIVED FROM STAINED AND UNSTAINED ELECTRON-MICROGRAPHS SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE PHOSPHORYLASE KINASE; ELECTRON MICROSCOPY; STRUCTURE ID SCANNING TUNNELING MICROSCOPY; DEPENDENT PROTEIN-KINASE; SKELETAL-MUSCLE; GAMMA-SUBUNIT; MOLECULAR-BASIS; CDNA CLONING; B KINASE; IDENTIFICATION; ACTIVATION; CALMODULIN AB Phosphorylase kinase, the first protein kinase discovered, is a key regulatory enzyme in glycogen metabolism. Although its biochemical properties are well characterized, details of its three-dimensional structure and subunit topology are yet to be elucidated. This study describes four characteristic views of the hexadecameric holoenzyme (alpha(4) beta(4) gamma(4) delta(4)) as observed in both negatively stained and unstained electron micrographs. The predominant views are the widely reported ''butterfly'' with two wing-like lobes connected by thin bridges, and the previously described ''chalice'', composed of ''cup'' and ''stem'' segments. Two additional views, a ''cube'', similar to the previously reported ''tetrad'', and a ''cross'' or ''X'' are less common. but illustrate the overall geometry of the particle. Based on these images, the first three-dimensional model of the enzyme has been constructed, It is composed of four identical protomers that associate with D, symmetry to form the two major structural elements (the two lobes). Two protomers in a head to head arrangement make up each symmetrical lobe; to complete the holoenzyme, one lobe is inverted and placed perpendicular to the other. Thus, the overall structure has three 2-fold axes of symmetry, and the arrangement of the four protomers approximates a tetrahedron. Each lobe of the model corresponds to a wing of the butterfly projection. Two projections form the chalice: in the intra-lobe orientation, one lobe forms the cup and the other forms the stem, and in the inter-lobe view, one-half of each lobe contributes to each segment of the image. The cube and cross projections result from 90 degrees rotations from the butterfly orientation. In the cube, the distal portions of each lobe are projected separately. In the cross, one lobe is crossed over and is above the other. This model both accounts for and predicts all of the observed microscopic images. C1 UNIV TENNESSEE,CTR HLTH SCI,DEPT BIOCHEM,MEMPHIS,TN 38163. UNIV MISSISSIPPI,MED CTR,DEPT BIOCHEM,JACKSON,MS 39216. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NIDDK NIH HHS [DK32953] NR 43 TC 28 Z9 28 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD AUG 5 PY 1994 VL 241 IS 1 BP 94 EP 102 DI 10.1006/jmbi.1994.1476 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PA947 UT WOS:A1994PA94700010 PM 8051711 ER PT J AU MAKHOV, AM HANNAH, JH BRENNAN, MJ TRUS, BL KOCSIS, E CONWAY, JF WINGFIELD, PT SIMON, MN STEVEN, AC AF MAKHOV, AM HANNAH, JH BRENNAN, MJ TRUS, BL KOCSIS, E CONWAY, JF WINGFIELD, PT SIMON, MN STEVEN, AC TI FILAMENTOUS HEMAGGLUTININ OF BORDETELLA-PERTUSSIS - A BACTERIAL ADHESIN FORMED AS A 50-NM MONOMERIC RIGID-ROD BASED ON A 19-RESIDUE REPEAT MOTIF RICH IN BETA-STRANDS AND BETA-TURNS SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE PERTUSSIS; FILAMENTOUS HEMAGGLUTININ; ADHESIN; LEUCINE-RICH REPEATS; BETA-HELIX PROTEINS ID RESPIRATORY-EPITHELIAL-CELLS; MONOCLONAL-ANTIBODIES; ELECTRON-MICROSCOPY; SECONDARY STRUCTURE; TAIL-FIBER; MOLECULAR-STRUCTURE; ESCHERICHIA-COLI; ADENOVIRUS FIBER; PROMOTING FACTOR; SHEET STRUCTURE AB The filamentous hemagglutinin (FHA) of Bordetella pertussis is an adhesin that binds the bacteria to cells of the respiratory epithelium in whooping-cough infections. Mature FNA is a 220 kDa secretory protein that is highly immunogenic and has been included in acellular vaccines. We have investigated its structure by combining electron microscopy and circular dichroism spectroscopy (CD) with computational analysis of its amino acid sequence. The FHA molecule is 50 nm in length and has the shape of a horseshoe nail: it has a globular head that appears to consist of two domains; a 35 nm-long shaft that averages 4 nm in width, but tapers slightly from the head end; and a small, flexible, tail. Mass measurements by scanning transmission electron microscopy establish that FHA is a monomer. Its sequence contains two regions of tandem 19-residue pseudo-repeats: the first, of 38 cycles, starts at residue 344; the second, of 13 cycles, starts at residue 1440. The repeat motifs are predicted to consist of short beta-strands separated by beta-turns, and secondary structure measurements by CD support this prediction. We propose a hairpin model for FHA in which the head is composed of the terminal domains; the shaft consists mainly of the repeat regions conformed as amphipathic, hyper-elongated beta-sheets, with their hydrophobic faces apposed and the tail is composed of the intervening sequence. Further support for the model was obtained by immuno-labeling electron microscopy. The 19-residue repeats of FHA have features in common with the leucine-rich repeats (LRRs) that are present in many eukaryotic proteins, including some adhesion factors. The model is also compared with the two other classes of filamentous proteins that are rich in beta-structure, i.e. viral adhesins and two beta-helical secretory proteins. Our proposed structure implies how the functionally important adhesion sites and epitopes of PHB are distributed: its tripeptide (RGD) integrin-binding site is assigned to the tail; the putative hemagglutination site forms part of the head. and two classes of immunodominant epitopes are assigned to opposite ends of the molecule. Possible mechanisms are discussed for two modes of FHA-mediated adhesion. C1 NIH,US FDA,DIV BACTERIAL PROD,BETHESDA,MD 20892. NIH,DIV COMP RES & TECHNOL,COMPUTAT BIOL & ENGN LAB,BETHESDA,MD 20892. NIH,OFF DIRECTOR,PROT EXPRESS LAB,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NIAMSD,STRUCT BIOL RES LAB,BETHESDA,MD 20892. RI Conway, James/A-2296-2010 OI Conway, James/0000-0002-6581-4748 NR 78 TC 79 Z9 81 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD AUG 5 PY 1994 VL 241 IS 1 BP 110 EP 124 DI 10.1006/jmbi.1994.1478 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PA947 UT WOS:A1994PA94700012 PM 7519681 ER PT J AU GONG, EL TAN, CS SHOUKRY, MI RUBIN, EM NICHOLS, AV AF GONG, EL TAN, CS SHOUKRY, MI RUBIN, EM NICHOLS, AV TI STRUCTURAL AND FUNCTIONAL-PROPERTIES OF HUMAN AND MOUSE APOLIPOPROTEIN-A-I SO BIOCHIMICA ET BIOPHYSICA ACTA-LIPIDS AND LIPID METABOLISM LA English DT Article DE DISCOIDAL COMPLEX; GUANIDINE HYDROCHLORIDE DENATURATION; FLUORESCENCE PROPERTY; LDL INTERACTION; APO A-I; (HUMAN); (MOUSE) ID HIGH-DENSITY-LIPOPROTEIN; LECITHIN-CHOLESTEROL ACYLTRANSFERASE; TRANSGENIC MICE; DISCOIDAL COMPLEXES; SELF-ASSOCIATION; PHOSPHATIDYLCHOLINE; GENE; EXPRESSION; SUBCLASSES; PROTEINS AB Mouse and human plasma apolipoprotein A-I (apo A-I-m and apo A-I-h, respectively) were investigated to compare their molecular properties in solution, their incorporation into palmitoyloleoylphosphatidylcholine-apo A-I (POPC-apo A-I) discoidal complexes, their structural stability in discoidal complexes and high-density lipoproteins (HDL), and their effect on structural rearrangement of discoidal complexes upon interaction with low-density lipoproteins (LDL). Unlike apo A-I-h, only minimal concentration-dependent self-association was observed for apo A-I-m. While both apo A-I-m and apo A-I-h formed discoidal complexes of distinct composition and size that reflected reassembly molar ratios of POPC/apo A-I, apo A-I-m demonstrated specific deficiencies in formation of larger-sized complexes. Denaturation of both apo A-I-m or apo A-I-h-containing complexes and HDL with guanidine hydrochloride (GuHCl) indicated significantly reduced stabilization of apo A-I-m by lipid in these particles. Interaction of apo A-I-m- or apo A-I-h-containing discoidal complexes with human plasma LDL revealed a more extensive conversion of apo A-I-m-complexes to smaller species. Mean hydrophobicities and mean hydrophobic moments of amphipathic helical segments in apo A-I-m and apo A-I-h were compared; differences potentially contributing to differential lipid-binding properties between apo A-I-m and apo A-I-h were identified. Our results demonstrate differences between apo A-I-m and apo A-I-h that may contribute to the major changes in plasma HDL distribution and function observed in apo A-I-h transgenic mice. RP GONG, EL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL-4681-03, HL 182574] NR 31 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2760 J9 BBA-LIPID LIPID MET JI Biochim. Biophys. Acta-Lipids Lipid Metab. PD AUG 4 PY 1994 VL 1213 IS 3 BP 335 EP 342 DI 10.1016/0005-2760(94)00062-X PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PB435 UT WOS:A1994PB43500010 PM 8049247 ER PT J AU MENYUK, CR RUBENCHIK, AM AF MENYUK, CR RUBENCHIK, AM TI EFFECT OF BRILLOUIN-SCATTERING ON OPTICAL-FIBER COMMUNICATION USING SOLITONS SO ELECTRONICS LETTERS LA English DT Article DE SOLITON TRANSMISSION; BRILLOUIN SCATTERING ID DARK-SOLITON; FIBERS AB The limitation imposed by the Brillouin effect on both bright and dark solitons is examined. Bit rates in excess of 100Gbit/s are allowed, although WDM or sliding filters must be used with bright solitons. C1 LAWRENCE LIVERMORE NATL LAB,PLASMA PHYS RES INST,LIVERMORE,CA 94550. RP MENYUK, CR (reprint author), UNIV MARYLAND,DEPT ELECT ENGN,CATONSVILLE,MD 21228, USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD AUG 4 PY 1994 VL 30 IS 16 BP 1324 EP 1326 DI 10.1049/el:19940864 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA PC862 UT WOS:A1994PC86200047 ER PT J AU GROVER, JR CHENG, BM HERRON, WJ COOLBAUGH, MT PEIFER, WR GARVEY, JF AF GROVER, JR CHENG, BM HERRON, WJ COOLBAUGH, MT PEIFER, WR GARVEY, JF TI PHOTOIONIZATION-INDUCED INTRACLUSTER REACTIONS OF CHLOROBENZENE/AMMONIA MIXED COMPLEXES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RESONANT 2-PHOTON IONIZATION; NUCLEOPHILIC-SUBSTITUTION REACTIONS; INTRAMOLECULAR PENNING IONIZATION; ION-MOLECULE REACTIONS; CLUSTERS FOLLOWING PHOTOIONIZATION; RARE-GAS CLUSTERS; VANDERWAALS COMPLEXES; CHEMICAL-REACTIONS; PHOTO-IONIZATION; DISSOCIATIVE PHOTOIONIZATION AB Complexes of chlorobenzene and ammonia, C6H5Cl.NH3, C6H5Cl(NH3)(2), and C6H5Cl(NH3)(3), were studied by single-photon ionization. The ionization potentials of these three complexes were measured to be 8.744 +/- 0.022, 8.652 +/- 0.013, and 8.555 +/- 0.012 eV, respectively. The appearance potential of C6H5NH3+ from C6H5Cl.NH3 was found at 8.935 +/- 0.004 eV, which, with the known heat of formation of anilinium ion, gives the dissociation energy D(C6H5Cl.NH3) = 2.9 +/- 0.5 kcal mol(-1) (12.0 +/- 2.2 kJ mol(-1)). Then, from its onset energy from C6H5Cl.NH3, the dissociation energy of (C6H5Cl.NH3)+ is calculated to be D[(C6H5Cl.NH3)(+)] = 10.4 +/- 0.7 kcal mol(-1) (43.5 +/- 2.9 kJ mol(-1)), unusually large for a heterodimer ion. No production of C6H5NH3+ from trimers could be detected in the onset region. The ion C6H5NH2+ has onsets of 8.849 +/- 0.009 and 8.855 +/- 0.029 eV from C6H5Cl.NH3 and C6H5Cl(NH3)(2), respectively. These energies are below the onset for C6H5NH3+ but far above the thermochemical thresholds for aniline ion, which are near 7.6 eV. Evidently, C6H5NH2+ is not produced by dissociative ionization of the excited neutral complex. Instead, the complex must first be ionized and excited to at least 0.1 eV. Since the onsets for (C6H5Cl.NH3)(+) and C6H5NH2+ are lower than for C6H5NH3+, then (C(6)H5(C)l.NH3)(+) in its ground state does not spontaneously form C6H5NH3+. Kinetic energy release distributions measured for C6H5NH2+ and C6H5NH3+ indicate that the formation of both ions is consistent with statistical processes; i.e., no evidence for nonstatistical mechanisms was found, even for photon energies as large as 17.7 eV. C1 SYNCHROTRON RADIAT RES CTR,HSINCHU 30077,TAIWAN. SUNY BUFFALO,DEPT CHEM,BUFFALO,NY 14214. RP GROVER, JR (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 65 TC 15 Z9 15 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 4 PY 1994 VL 98 IS 31 BP 7479 EP 7487 DI 10.1021/j100082a016 PG 9 WC Chemistry, Physical SC Chemistry GA PA689 UT WOS:A1994PA68900016 ER PT J AU CHANG, HC JANKOWIAK, R YOCUM, CF PICOREL, R ALFONSO, M SEIBERT, M SMALL, GJ AF CHANG, HC JANKOWIAK, R YOCUM, CF PICOREL, R ALFONSO, M SEIBERT, M SMALL, GJ TI EXCITON LEVEL STRUCTURE AND DYNAMICS IN THE CP47 ANTENNA COMPLEX OF PHOTOSYSTEM-II SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ENERGY-TRANSFER DYNAMICS; HOLE-BURNING SPECTROSCOPY; STATE STRUCTURE; RHODOBACTER-SPHAEROIDES; DISPERSIVE KINETICS; POLYVINYL-ALCOHOL; REACTION CENTERS; PROTEIN; TEMPERATURE; GLASSES AB Persistent nonphotochemical and population bottleneck hole-burning results obtained as a function of burn wavelength are reported for the CP47 proximal antenna protein complex of photosystem II. Attention is focused on the lower energy chlorophyll alpha Q(y) states. Results are presented for the CP47 complex from two preparations. The Chl alpha content per CP47 complex was determined, spectroscopically, to be 14 +/- 2. On the basis of the analysis of the hole spectra and the 4.2 K static fluorescence spectrum, the lowest energy state of CP47 lies at 690 nm (fluorescence origin at 691 nm). The width of the weak 690-nm absorption band from inhomogeneous broadening is 100 cm(-1). The linear electron-phonon coupling of the 690-nm state is weak with a Huang-Rhys factor (S) of about 0.2 and a mean phonon frequency (omega(m)) of 20 cm(-1), which explains why the Stokes shift (2S omega(m)) is so small. The 690-nm state is found to be excitonically correlated with a, hitherto, unobserved state at 687 nm. However, the combined absorption intensity of the 690- and 687-nm states was determined to be equivalent to only 1 Chl alpha molecule. Results are presented which illustrate that these two states are fragile (i.e., their associated chlorophyll a molecules are readily disrupted). Thus, it is possible that the correct number of Chl alpha molecules is 2, not 1. Indeed, the simplest interpretation consistent with the hole-burning data has the 687- and 690-nm states being associated with a Chl alpha dimer with the latter close to forbidden in absorption. The results indicate that the 687-nm state relaxes to the 690-nm state in about 70 fs. The zero-phonon hole widths for the higher integrity CP47 samples are used to determine the energy-transfer times for the higher energy absorbing states at 4.2 K. The absorption intensity of a previously identified state at 684 nm is found to vary from preparation to preparation. Diminution of the intensity of the 684-nm band is accompanied by increased absorption at similar to 670 nm. This speaks to the fragility of the 684-nm absorbing Chl alpha. Consideration of the nature of the 684-nm-absorbing Chl alpha of CP47 is mainly reserved for the accompanying paper on the D1-D2-cyt b(559) reaction center and CP47-D1-D2-cyt b(559) complexes. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. UNIV MICHIGAN,DEPT BIOL & CHEM,ANN ARBOR,MI 48109. CSIC,EE AULA DEI,E-50080 ZARAGOZA,SPAIN. NATL RENEWABLE ENERGY LAB,DIV BASIC SCI,GOLDEN,CO 80401. RI PICOREL, RAFAEL/K-7930-2014; Alfonso, Miguel/L-6970-2014 OI PICOREL, RAFAEL/0000-0003-3791-129X; Alfonso, Miguel/0000-0002-8190-5156 NR 53 TC 55 Z9 63 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 4 PY 1994 VL 98 IS 31 BP 7717 EP 7724 DI 10.1021/j100082a050 PG 8 WC Chemistry, Physical SC Chemistry GA PA689 UT WOS:A1994PA68900050 ER PT J AU CHANG, HC JANKOWIAK, R REDDY, NRS YOCUM, CF PICOREL, R SEIBERT, M SMALL, GJ AF CHANG, HC JANKOWIAK, R REDDY, NRS YOCUM, CF PICOREL, R SEIBERT, M SMALL, GJ TI ON THE QUESTION OF THE CHLOROPHYLL-A CONTENT OF THE PHOTOSYSTEM-II REACTION-CENTER SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; PRIMARY ELECTRON-DONOR; REACTION CENTER COMPLEX; HOLE-BURNING SPECTROSCOPY; EXCITED-STATE STRUCTURE; CHARGE SEPARATION RATE; RED ABSORPTION-BAND; RHODOPSEUDOMONAS-VIRIDIS; RHODOBACTER-SPHAEROIDES; ENERGY-TRANSFER AB Isolation procedures have led to chlorophyll alpha (Chl alpha) contents of the photosystem II reaction center (RC) that range between about 4 and 6. Since this content for the bacterial RC is 4 (with two of those being associated with the special pair), the nature of the ''extra'' Chl alpha in RC preparations of photosystem II containing more than 4 Chl alpha molecules is currently of much interest. So too are the dynamics of primary charge separation in the RC which are triggered by excitation of the primary electron donor state, P680* (where P680 indicates that the lowest energy ground-state absorption band of the primary donor lies at 680 nm; the asterisk indicates lowest lying (1) pi pi* (Q(y)) state). We report absorption and triplet-state bottleneck hole spectra (4.2 K) for RC preparations of photosystem II containing 4, 5, and 6 Chl alpha molecules. The spectra reveal that the extra Chl alpha are due to 684-nm-absorbing Chl alpha, some contamination by the proximal antenna protein complex CP47, and, probably, also nonnative (disrupted) Chl alpha absorbing near 670 nm. The 684-nm Chl alpha were found to be easily disrupted by the ionic detergent Triton X-100 (much more so than P680). The results are inconsistent with the model that has the 684-nm band being the dimer (special pair) partner of P680. Nor can they be satisfactorily interpreted within the model that has the 684-nm band being P684 of a structurally very distinct subset of the RC ensemble. This ''mixture'' model has the ensemble comprised of P680 and P684 RC subsets. Importantly, the intensities of the 684-nm band observed for the CP47 complex and the CP47-RC complex were also found to vary from preparation to preparation adn be sensitive to Triton C-100. Two possibilities are considered: that the 684-nm Chl alpha are associated with the CP47-RC complex as a whole or that both CP47 and the RC possess 684-nm-absorbing Chl alpha or, equivalently, an intrinsic (fragile) 684-nm state. Irrespective of which of these two is correct, it is concluded that the number of Chl alpha in the hydrophobic interior of the RC of photosystem II is 4 and that the 684-nm Chl alpha are located in the exterior region of the RC protein complex. The of P680* of the 4 Chl alpha-RC preparation, which contains very little 684-nm Chl alpha (5% on a Chl alpha basis), was determined to be 1.9 ps at 4.2 K. This is identical to our previous determination for higher Chl alpha content RC and CP47-RC samples. Thus, the 684-nm Chl alpha do not affect the lifetime of P680* at low temperatures, i.e., do not serve as an efficient trap for P680*. A theoretical analysis of the burn wavelength dependence of the P680 hole spectra of the 4 Chl alpha preparation is given. In agreement with our previous work, the electron-phonon (protein) coupling is as strong (S = 2) as that observed for P870 and P960 of the bacterial RC Rhodobacter sphaeroides and Rhodopseudomonas viridis, respectively. However, the special pair marker mode (125/145 cm(-1)) progression of P870 and P960 is essentially silent in P680. This, together with the observation that the weakly absorbing, upper dimer partner of P680* lies only 300 cm(-1) higher in energy, further establishes that the special pair of the PS II RC has a structure which is significantly different than in the bacterial RC. Structural models for the special pair are reviewed and discussed. C1 IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. UNIV MICHIGAN, DEPT BIOL & CHEM, ANN ARBOR, MI 48109 USA. CSIC, EE AULA DEI, E-50080 ZARAGOZA, SPAIN. NATL RENEWABLE ENERGY LAB, DIV BASIC SCI, GOLDEN, CO 80401 USA. RI PICOREL, RAFAEL/K-7930-2014 OI PICOREL, RAFAEL/0000-0003-3791-129X NR 73 TC 62 Z9 65 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 4 PY 1994 VL 98 IS 31 BP 7725 EP 7735 DI 10.1021/j100082a051 PG 11 WC Chemistry, Physical SC Chemistry GA PA689 UT WOS:A1994PA68900051 ER PT J AU SOLEM, JC AF SOLEM, JC TI DENSITY AND SIZE OF COMET SHOEMAKER-LEVY-9 DEDUCED FROM A TIDAL BREAKUP MODEL SO NATURE LA English DT Article AB Although comets have been studied throughout most of recorded history, a detailed understanding of their internal properties is still lacking. Recent observations' of the split comet Shoemaker-Levy 9-actually a spectacular string of cometary fragments that resulted from the tidal disruption of a single parent body as it passed close to Jupiter(2-5)-have therefore stimulated much interest, as they provide an unprecedented opportunity to Investigate the physical properties of comets more generally(6-8). I report here simulations of the tidal breakup of the parent comet, which I assume to have been an assemblage of a large number of spherical components bound together only by gravity. Following the initial tidal disruption of the assemblage, the particles coalesce rapidly by mutual gravitation into a chain of larger fragments, the morphology of which depends critically on the density of the components. By comparing the size, number and distribution of the stimulated fragments with observations of Shoemaker-Levy 9, I determine an average comet density of about 0.5 g cm(-3) and a parent comet diameter of about 1.8 km. RP SOLEM, JC (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 16 TC 50 Z9 50 U1 1 U2 2 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 4 PY 1994 VL 370 IS 6488 BP 349 EP 351 DI 10.1038/370349a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PA304 UT WOS:A1994PA30400048 ER PT J AU ZHANG, H WANG, YY ZHANG, H DRAVID, VP MARKS, LD HAN, PD PAYNE, DA RADAELLI, PG JORGENSEN, JD AF ZHANG, H WANG, YY ZHANG, H DRAVID, VP MARKS, LD HAN, PD PAYNE, DA RADAELLI, PG JORGENSEN, JD TI IDENTITY OF PLANAR DEFECTS IN THE INFINITE-LAYER COPPER-OXIDE SUPERCONDUCTOR SO NATURE LA English DT Article ID HIGH-PRESSURE AB The 'infinite-layer' compound(1-3) ACuO(2) (where A stands for cations such as strontium or calcium), has the simplest structure of all superconducting copper oxides, with only bare cations separating the CuO2 planes. Accordingly, an understanding of the doping mechanism(s) that lead to superconductivity in this compound may facilitate the elucidation of the same phenomenon in the other copper oxide superconductors. Recently, Azuma and co-workers(2,4) observed planar defects in an infinite-layer phase synthesized at high oxygen pressure, and proposed that the defects are A-cation deficient, and lead to superconductivity (with transition temperature T-c approximate to 100-110 K) in this compound. Here, based on quantitative X-ray and high-resolution electron-microscopic analysis of the planar defects in (Sr, Ca)CuO2, we propose that the defects consist of a corrugated Sr-O layer substituted for a CuO2 layer, with the incorporation of apical oxygen atoms (which are absent in the parent structure) at roughly half the available sites in the neighbouring Sr layers. This is equivalent to an insertion of a Sr3O2+/-x block in an otherwise infinite-layer sequence. The variable oxygen stoichiometry of our defect model can account for the occurrence of p-type superconductivity (following high-pressure oxygenation), n-type superconductivity (high-pressure reduction) or lack of superconductivity (high-pressure neutral-atmosphere annealing) in this system, depending on the synthesis conditions(4). C1 NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCONDUCT,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. UNIV ILLINOIS,DEPT MAT SCI & ENGN,URBANA,IL 61801. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Dravid, Vinayak/B-6688-2009; Marks, Laurence/B-7527-2009; Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 11 TC 32 Z9 35 U1 1 U2 10 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 4 PY 1994 VL 370 IS 6488 BP 352 EP 354 DI 10.1038/370352a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PA304 UT WOS:A1994PA30400049 ER PT J AU COLVIN, VL SCHLAMP, MC ALIVISATOS, AP AF COLVIN, VL SCHLAMP, MC ALIVISATOS, AP TI LIGHT-EMITTING-DIODES MADE FROM CADMIUM SELENIDE NANOCRYSTALS AND A SEMICONDUCTING POLYMER SO NATURE LA English DT Article ID ELECTROLUMINESCENCE; EMISSION AB Electroluminescent devices have been developed recently that are based on new materials such as porous silicon and semiconducting polymers(2,3). By taking advantage of developments in the preparation and characterization of direct-gap semiconductor nanocrystals(4-6), and of electroluminescent polymers', we have now constructed a hybrid organic/inorganic electroluminescent device. Light emission arises from the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV)(8-10) with electrons injected into a multilayer film of cadmium selenide nanocrystals. Close matching of the emitting layer of nanocrystals with the work function of the metal contact leads to an operating voltage(11) of only 4 V. At low voltages emission from the CdSe layer occurs. Because of the quantum size effect(19-24) the colour of this emission can be varied from red to yellow by changing the nanocrystal size. At higher voltages green emission from the polymer layer predominates. Thus this device has a degree of voltage tunability of colour. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP COLVIN, VL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 26 TC 2843 Z9 2926 U1 76 U2 578 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD AUG 4 PY 1994 VL 370 IS 6488 BP 354 EP 357 DI 10.1038/370354a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA PA304 UT WOS:A1994PA30400050 ER PT J AU WERNER, TR SHEIKH, JA NAZAREWICZ, W STRAYER, MR UMAR, AS MISU, M AF WERNER, TR SHEIKH, JA NAZAREWICZ, W STRAYER, MR UMAR, AS MISU, M TI SHAPE COEXISTENCE AROUND S-44(16)28 - THE DEFORMED N=28 REGION SO PHYSICS LETTERS B LA English DT Article ID EXOTIC NUCLEI; BETA-DECAY; NEUTRON; ISOTOPES; STATES AB Masses, deformations, radii, and single-particle properties of the very neutron-rich Sulfur isotopes are investigated in the framework of the selfconsistent mean-field theory. Tle stability of the N = 28 magic gap around 44S is discussed. C1 JOINT INST HEAVY ION,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. RI Umar, Ahmet/J-4125-2013 OI Umar, Ahmet/0000-0002-9267-5253 NR 37 TC 61 Z9 61 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 4 PY 1994 VL 333 IS 3-4 BP 303 EP 309 DI 10.1016/0370-2693(94)90146-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB134 UT WOS:A1994PB13400005 ER PT J AU CROWELL, B JANSSENS, RVF CARPENTER, MP AHMAD, I HARFENIST, S HENRY, RG KHOO, TL LAURITSEN, T NISIUS, D WILSON, AN SHARPEYSCHAFER, JF SKALSKI, J AF CROWELL, B JANSSENS, RVF CARPENTER, MP AHMAD, I HARFENIST, S HENRY, RG KHOO, TL LAURITSEN, T NISIUS, D WILSON, AN SHARPEYSCHAFER, JF SKALSKI, J TI SUPERDEFORMED BAND WITH A UNIQUE DECAY PATTERN - POSSIBLE EVIDENCE FOR OCTUPOLE VIBRATION IN HG-160 SO PHYSICS LETTERS B LA English DT Article ID NUCLEI; STATES AB An excited superdeformed (SD) band has been observed in 190Hg which decays to the lowest-energy (yrast) SD band rather than to the less deformed states as observed in most known SD bands in the A approximately 150 and A approximately 190 regions. The most plausible interpretation of this very unusual decay pattern associates this band with a collective structure built on an octupole-vibrational phonon in the SD well. C1 UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,ENGLAND. SOLTAN INST NUCL STUDIES,PL-00681 WARSAW,POLAND. RP CROWELL, B (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015; OI Carpenter, Michael/0000-0002-3237-5734; Wilson, Anna/0000-0001-6928-1689 NR 25 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 4 PY 1994 VL 333 IS 3-4 BP 320 EP 325 DI 10.1016/0370-2693(94)90149-X PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB134 UT WOS:A1994PB13400008 ER PT J AU ESKOLA, KJ HOYER, P VANTTINGEN, M VOGT, R AF ESKOLA, KJ HOYER, P VANTTINGEN, M VOGT, R TI HIGHER-TWIST EFFECTS IN THE DRELL-YAN ANGULAR-DISTRIBUTION SO PHYSICS LETTERS B LA English DT Article ID EXCLUSIVE PROCESSES; QUANTUM CHROMODYNAMICS; PERTURBATIVE QCD; SCATTERING; PAIRS AB We study the Drell-Yan process piN --> mu+mu-X at large x(F) using perturbative QCD. A higher-twist mechanism suggested by Berger and Brodsky is known to qualitatively explain the observed x(F) dependence of the muon angular distribution, but the predicted large x(F) behavior differs quantitatively from observations. We have repeated the model calculation taking into account the effects of nonasymptotic kinematics. At fixed-target energies we find important corrections which improve the agreement with data. The asymptotic result of Berger and Brodsky is recovered only at much higher energies. We discuss the generic reasons for the large corrections at high x(F). A proper understanding of the x(F) --> 1 data would give important information on the pion distribution amplitude and exclusive form factor. C1 UNIV HELSINKI,THEORET PHYS RES INST,SF-00014 HELSINKI,FINLAND. LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP ESKOLA, KJ (reprint author), UNIV HELSINKI,HIGH ENERGY PHYS LAB,POB 9,SF-00014 HELSINKI,FINLAND. NR 16 TC 40 Z9 40 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 4 PY 1994 VL 333 IS 3-4 BP 526 EP 530 DI 10.1016/0370-2693(94)90178-3 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB134 UT WOS:A1994PB13400037 ER PT J AU DONG, ZH MUNCZEK, HJ ROBERTS, CD AF DONG, ZH MUNCZEK, HJ ROBERTS, CD TI GAUGE COVARIANT FERMION PROPAGATOR IN QUENCHED, CHIRALLY SYMMETRICAL QUANTUM ELECTRODYNAMICS SO PHYSICS LETTERS B LA English DT Article ID SCHWINGER-DYSON EQUATIONS; MULTIPLICATIVE RENORMALIZABILITY; BREAKING; VERTEX AB We discuss the chirally symmetric solution of the massless, quenched, Dyson-Schwinger equation for the fermion propagator in three and four dimensions. The solutions are manifestly gauge covariant. We consider a gauge covariance constraint on the fermion-gauge-boson vertex, which motivates a vertex Ansatz that both satisfies the Ward identity when the fermion self-mass is zero and ensures gauge covariance of the fermion propagator. C1 ARGONNE NATL LAB, DEPT PHYS, ARGONNE, IL 60439 USA. RP UNIV KANSAS, DEPT PHYS & ASTRON, LAWRENCE, KS 66045 USA. NR 17 TC 54 Z9 54 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD AUG 4 PY 1994 VL 333 IS 3-4 BP 536 EP 544 DI 10.1016/0370-2693(94)90180-5 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB134 UT WOS:A1994PB13400039 ER PT J AU BRAATEN, E DONCHESKI, MA FLEMING, S MANGANO, ML AF BRAATEN, E DONCHESKI, MA FLEMING, S MANGANO, ML TI FRAGMENTATION PRODUCTION OF PSI/PSI AND PSI' AT THE TEVATRON SO PHYSICS LETTERS B LA English DT Article ID HEAVY-QUARK PRODUCTION; HADRON-COLLISIONS; Z(0) DECAY; J/PSI; QCD; CHARMONIUM; COLLIDER; JETS AB We present a calculation of the charm and gluon fragmentation contributions to inclusive J/psi and psi' production at large transverse momentum at the Tevatron. For psi production, we include both fragmentation directly into psi and fragmentation into chi(c) followed by the radiative decay chi(c) --> psi + gamma. We find that fragmentation overwhelms the leading-order mechanisms for prompt psi production at large p(T), and that the dominant contributions come from fragmentation into chi(c). Our results are consistent with recent data on psi production from the CDF and D0 experiments. In the case of prompt psi' production, the dominant mechanism at large p(T) is charm fragmentation into psi'. We find serious disagreement between our theoretical predictions and recent psi' data from the Tevatron. C1 NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. INFN,SCUOLA NORMALE SUPER,PISA,ITALY. CARLETON UNIV,DEPT PHYS,OTTAWA K1S 5B6,ONTARIO,CANADA. DIPARTIMENTO FIS,PISA,ITALY. RP BRAATEN, E (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Fleming, Sean/C-3677-2015 OI Fleming, Sean/0000-0002-9553-7198 NR 31 TC 131 Z9 131 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 4 PY 1994 VL 333 IS 3-4 BP 548 EP 554 DI 10.1016/0370-2693(94)90182-1 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB134 UT WOS:A1994PB13400041 ER PT J AU BARNHART, DM CLARK, DL GORDON, JC HUFFMAN, JC VINCENT, RL WATKIN, JG ZWICK, BD AF BARNHART, DM CLARK, DL GORDON, JC HUFFMAN, JC VINCENT, RL WATKIN, JG ZWICK, BD TI SYNTHESIS, PROPERTIES, AND X-RAY STRUCTURES OF THE LANTHANIDE ETA-6-ARENE-BRIDGED ARYLOXIDE DIMERS LN2(O-2,6-I-PR2C6H3)6 AND THEIR LEWIS BASE ADDUCTS LN(O-2,6-I-PR2C6H3)3(THF)2 (LN=PR, ND, SM, GD, ER, YB, LU) SO INORGANIC CHEMISTRY LA English DT Article ID THF = TETRAHYDROFURAN; CRYSTAL-STRUCTURE; MOLECULAR-STRUCTURE; LIGAND ENVIRONMENT; ALKOXIDE COMPLEXES; YTTRIUM; CHEMISTRY; REACTIVITY; NEODYMIUM; OXYGEN AB Reaction of 3 equiv of 2,6-diisopropylphenol with Ln[N(SiMe3)2]3 (Ln = Nd, Sm, Er) in refluxing toluene and subsequent crystallization yield pale blue (Nd), deep yellow (Sm), or light pink (Er) crystals of the tris(aryloxide) complexes Ln2(O-2,6-i-Pr2C6H3)6 (Ln = Nd (1), Sm (2), Er (3)) in good yield. X-ray crystallographic studies of 1 and 2 reveal centrosymmetric, dimeric units bridged by eta6-pi-arene interactions of a unique aryloxide ligand. Ln-O bond lengths average 2.122(9) (1, Nd) and 2.101(6) angstrom (2, Sm) for terminal ligands and 2.211(8) (1) and 2.198(5) angstrom (2) for bridging aryloxide ligands. Eta6-Arene bridges hold the dimeric units together with an average Ln-C distance of 3.035 angstrom for 1 and 2.986 and 3.016 angstrom for the two independent molecules in the asymmetric unit of 2. Compounds 1-3 react with THF in toluene solution to give the THF bisadducts Ln(O-2,6-i-Pr2C6H3)3(THF)2 (Ln = Nd (4), Sm (5), Er (6)) in essentially quantitative yield. In a related fashion, Lu(O-2,6-i-Pr2C6H3)3(THF)2 (7) was prepared following the reaction of Lu[N(SiMe3)2]3 with 3 equiv of diisopropylphenol in the presence of THF. The anhydrous trichlorides of Sm, Pr, Gd, and Yb react with 3 equiv of potassium 2,6-diisopropylphenoxide in THF solution to give the 5-coordinate THF bisadducts Ln(O-2,6-i-Pr2C6H3)3(THF)2 (Ln = Sm (5), Pr (8), Gd (9), Yb (10)). X-ray crystal structures have been obtained for Ln(O-2,6-i-Pr2C6H3)3(THF)2 (Ln = Er (6), Lu (7), Pr (8), Gd(9)), The four compounds are isostructural, and the molecular structure consists of a distorted trigonal bipyramidal lanthanide metal center with two axial THF and three equatorial aryloxide ligands. Ln-O distances for the aryloxide ligands average 2.078 (6, Er), 2.044 (7, Lu), 2.172 (8, Pr), and 2.130 (9, Gd) while Ln-O distances for the THF ligands average 2.346 (6), 2.296 (7), 2.482 (8), and 2.394 angstrom (9). Solution H-1 and C-13 NMR data, together with solution IR data, strongly support the proposal that the pi-arene-bridged dimeric structures of 1-3 are maintained in both benzene and toluene solutions at room temperature. Crystal data for 1 (at -162-degrees-C): monoclinic space group P2(1)/a, a = 9.536(2) angstrom, b = 21.219(6) angstrom, c = 17.162(5) angstrom, beta = 104.43(1)-degrees, V = 3363.0 angstrom3, Z = 2, d(calc) = 1.335 g cm-3, R(F) = 0.0518, R(w)(F) = 0.0522. Crystal data for 2 (at -70-degrees-C): monoclinic space group P2(1)/c, a = 9.555(2) angstrom, b = 21.301(2) angstrom, c = 33.220(4) angstrom, beta = 91.50(3)-degrees, V = 6759 angstrom3, Z = 2 (2 molecules per asymmetric unit), d(calc) = 1.341 g cm-3, R(F) = 0.0447, R(w)(F) = 0.0640. Crystal data for 6 (at -170-degrees-C): monoclinic space group P2(1), a = 9.693(1) angstrom, b = 19.141(3) angstrom, c = 12.083(l) angstrom, beta = 109.48(1)-degrees, V = 2113.50 angstrom3, d(calc) = 1.325 g cm-3, Z = 2, R(F) = 0.047, R(w)(F) = 0.063. Crystal data for 7 (at -70-degrees-C): monoclinic space group P2(1), a = 9.632(1) angstrom, b = 19.269(2) angstrom, c = 12.164(1) angstrom, beta = 109.52(1)-degrees, V = 2127.9 angstrom3, d(calc) = 1.328 g cm-3, Z = 2, R(f) = 0.021, R(w)(F) = 0.031. Crystal data for 8 (at -70-degrees-C): monoclinic space group P2(1), a = 9.857(2) k, b = 19.408(4) angstrom, c = 12.085(3) angstrom, beta = 109.81(2)-degrees, V = 2175.1 angstrom3, d(calc) = 1.247 g cm-3, Z = 2, R(F) = 0.045, R(w)(F) = 0.061. Crystal data for 9 (at -70-degrees-C): monoclinic space group P2(1), a = 9.755(1) angstrom, b = 19.377(2) angstrom, c = 12.184(1) angstrom, beta = 109.65(1)-degrees, V = 2168.1 angstrom3, d(calc) = 1.276 g cm-3, Z = 2, R(F) = 0.054, R(F) = 0.073. C1 INDIANA UNIV,CTR MOLEC STRUCT,BLOOMINGTON,IN 47405. LOS ALAMOS NATL LAB,ACTINIDE MAT CHEM GRP NMT6,LOS ALAMOS,NM 87545. RP CLARK, DL (reprint author), LOS ALAMOS NATL LAB,INORGAN STRUCT & APPL CHEM GRP CST3,LOS ALAMOS,NM 87545, USA. RI Clark, David/A-9729-2011 NR 59 TC 98 Z9 98 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD AUG 3 PY 1994 VL 33 IS 16 BP 3487 EP 3497 DI 10.1021/ic00094a009 PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PB222 UT WOS:A1994PB22200009 ER PT J AU MIASKIEWICZ, K MILLER, J OSMAN, R AF MIASKIEWICZ, K MILLER, J OSMAN, R TI ENERGETIC BASIS FOR STRUCTURAL PREFERENCES IN 5/6-HYDROXY-5,6-DIHYDROPYRIMIDINES - PRODUCTS OF IONIZING AND ULTRAVIOLET-RADIATION ACTION ON DNA BASES SO BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION LA English DT Article DE DNA DAMAGE; PYRIMIDINE BASE; STRUCTURE-FUNCTION RELATIONSHIP ID THYMINE GLYCOL LESIONS; THYMIDINE GLYCOL; POLYMERASE-I; GLYCOSYLASE ACTIVITIES; AQUEOUS-SOLUTIONS; DAMAGE; DIHYDROTHYMIDINE; MONOPHOSPHATE; BACTERIAL; STABILITY AB The structures of all diastereoisomers of 5/6-hydroxy-5,6-dihydropyrimidines have been optimized with ab initio quantum chemical calculations using a 6-31G basis set. The energies of the optimized structures were calculated at the MP2/6-31G* level. The hydroxyl group prefers an equatorial over an axial orientation at the C(5) position of pyrimidines by 3-4 kcal/mol. At the C(6) position, the axial orientation of hydroxyl is preferred by 3-4 kcal/mol. The factors responsible for the different preferences result from dipolar intramolecular interactions between the hydroxyl and C(4)=O(4) on the one hand, and the N(1)-H(1) on the other hand. As a consequence of these structural preferences, the pseudo axial positions at C(5) and C(6), which are perpendicular to the molecular plane, can be occupied by different substituents. These pseudo axial groups are expected to be a major source of distortions to DNA structure with more bulky groups having a greater effect. This may constitute a structural basis for interpretation of experimental results on the biological consequences of pyrimidine lesions. The conclusions drawn from the calculations correlate well with experimental observations on the biological activities of thymine lesions. C1 CUNY MT SINAI SCH MED, DEPT PHYSIOL & BIOPHYS, NEW YORK, NY 10029 USA. PACIFIC NW LAB, DEPT BIOL & CHEM, RICHLAND, WA 99352 USA. NR 32 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-4781 J9 BBA-GENE STRUCT EXPR JI Biochim. Biophys. Acta-Gene Struct. Expression PD AUG 2 PY 1994 VL 1218 IS 3 BP 283 EP 291 DI 10.1016/0167-4781(94)90179-1 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PB554 UT WOS:A1994PB55400004 PM 8049253 ER PT J AU MIAOU, SP AF MIAOU, SP TI THE RELATIONSHIP BETWEEN TRUCK ACCIDENTS AND GEOMETRIC DESIGN OF ROAD SECTIONS - POISSON VERSUS NEGATIVE BINOMIAL REGRESSIONS SO ACCIDENT ANALYSIS AND PREVENTION LA English DT Article DE TRUCK ACCIDENTS; GEOMETRIC DESIGN; POISSON; ZERO-INFLATED POISSON; NEGATIVE BINOMIAL ID OVERDISPERSION; MODELS; TESTS AB This paper evaluates the performance of Poisson and negative binomial (NB) regression models in establishing the relationship between truck accidents and geometric design of road sections. Three types of models are considered: Poisson regression, zero-inflated Poisson (ZIP) regression, and NB regression. Maximum likelihood (ML) method is used to estimate the unknown parameters of these models. Two other feasible estimators for estimating the dispersion parameter in the NB regression model are also examined: a moment estimator and a regression-based estimator. These models and estimators are evaluated based on their (i) estimated regression parameters, (ii) overall goodness-of-fit, (iii) estimated relative frequency of truck accident involvements across road sections, (iv) sensitivity to the inclusion of short road sections, and (v) estimated total number of truck accident involvements. Data from the Highway Safety Information System are employed to examine the performance of these models in developing such relationships. The evaluation results suggest that the NB regression model estimated using the moment and regression-based methods should be used with caution. Also, under the ML method, the estimated regression parameters from all three models are quite consistent and no particular model outperforms the other two models in terms of the estimated relative frequencies of truck accident involvements across road sections. It is recommended that the Poisson regression model be used as an intial model for developing the relationship. If the overdispersion of accident data is found to be moderate or high, both the NB and ZIP regression models could be explored. Overall, the ZIP regression model appears to be a serious candidate model when data exhibit excess zeros, e.g. due to underreporting. However, the interpretation of the ZIP model can be difficult. RP MIAOU, SP (reprint author), OAK RIDGE NATL LAB,CTR TRANSPORTAT ANAL,DIV ENERGY,POB 2008,MS 6366,BLDG 5500A,OAK RIDGE,TN 37831, USA. NR 29 TC 255 Z9 265 U1 5 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0001-4575 J9 ACCIDENT ANAL PREV JI Accid. Anal. Prev. PD AUG PY 1994 VL 26 IS 4 BP 471 EP 482 DI 10.1016/0001-4575(94)90038-8 PG 12 WC Ergonomics; Public, Environmental & Occupational Health; Social Sciences, Interdisciplinary; Transportation SC Engineering; Public, Environmental & Occupational Health; Social Sciences - Other Topics; Transportation GA NT639 UT WOS:A1994NT63900006 PM 7916855 ER PT J AU RUCKMAN, MW STRONGIN, M AF RUCKMAN, MW STRONGIN, M TI MONOLAYER METAL-FILMS ON METALLIC SURFACES - CORRELATION BETWEEN ELECTRONIC-STRUCTURE AND MOLECULAR CHEMISORPTION SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID ULTRATHIN PD FILMS; BIMETALLIC SURFACES; HYDROGEN-UPTAKE; PHOTOELECTRON-SPECTROSCOPY; CARBON-MONOXIDE; TIGHT-BINDING; UPTAKE RATES; THIN-FILMS; CO; ADSORPTION RP RUCKMAN, MW (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 69 TC 57 Z9 57 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD AUG PY 1994 VL 27 IS 8 BP 250 EP 256 DI 10.1021/ar00044a006 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA PC150 UT WOS:A1994PC15000006 ER PT J AU GRANGE, AO SANTOSHAM, M AYODELE, AK LESI, FEA STALLINGS, RY BROWN, KH AF GRANGE, AO SANTOSHAM, M AYODELE, AK LESI, FEA STALLINGS, RY BROWN, KH TI EVALUATION OF A MAIZE-COWPEA-PALM OIL DIET FOR THE DIETARY-MANAGEMENT OF NIGERIAN CHILDREN WITH ACUTE, WATERY DIARRHEA SO ACTA PAEDIATRICA LA English DT Article DE DIARRHEA; MALNUTRITION; NUTRITIONAL THERAPY; ORAL REHYDRATION THERAPY; WEANING FOODS ID ACUTE CHILDHOOD DIARRHEA; CLINICAL-TRIAL; ENERGY-INTAKE; KWARA STATE; INFANTS; FORMULA; BEANS AB A randomized clinical trial was carried out to compare a locally available maize-cowpea-palm oil diet (group MCP) with a commercially produced lactose-free, soy protein isolate formula (group SF) for the dietary management of 69 Nigerian boys, 6-24 months of age, hospitalized for acute, watery diarrhea. Although the treatment groups were generally similar initially, the children in group SF had slightly lower mean weight-for-age z scores (p = 0.08), lower serum bicarbonate levels (p = 0.04) and greater stool outputs during the period of rehydration before the diets were initiated (p = 0.01). Rates of treatment failure in group MCP (5.7%) and group SF (8.8%) were similar (p = 0.67). There were no significant differences in the adjusted mean stool outputs by study group on days 1-5, but the children in group SF had slightly lower fecal weights on day 6 (p = 0.05). Children in group MCP had a substantially reduced duration of liquid stool excretion (estimated median duration 42 h versus 140 h; p < 0.001). On the other hand, children in group SF consumed considerably more of their diet, had greater net absorption of macronutrients and greater rates of weight gain than those in group MCP. We conclude that children can safely consume the MCP diet during acute, watery diarrhea without increasing their risk of treatment failure or augmenting stool output. However, the diet may not be adequate as a sole source of nutrients beyond the period of acute illness. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT NUTR,PROGRAM INT NUTR,DAVIS,CA 95616. UNIV LAGOS,TEACHING HOSP,COLL MED,DEPT PEDIAT,LAGOS,NIGERIA. JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,DEPT INT HLTH,BALTIMORE,MD. NR 30 TC 8 Z9 8 U1 0 U2 0 PU SCANDINAVIAN UNIVERSITY PRESS PI OSLO PA PO BOX 2959 TOYEN, JOURNAL DIVISION CUSTOMER SERVICE, N-0608 OSLO, NORWAY SN 0803-5253 J9 ACTA PAEDIATR JI Acta Paediatr. PD AUG PY 1994 VL 83 IS 8 BP 825 EP 832 DI 10.1111/j.1651-2227.1994.tb13153.x PG 8 WC Pediatrics SC Pediatrics GA PF112 UT WOS:A1994PF11200007 PM 7981559 ER PT J AU GUDOWSKANOWAK, E AF GUDOWSKANOWAK, E TI COMMENTS ON LIMITED USE OF SMOLUCHOWSKI EQUATION IN KINETIC-ANALYSIS OF ELECTRON-TRANSFER PROCESSES SO ACTA PHYSICA POLONICA B LA English DT Article ID ACTIVATED RATE-PROCESSES; GENERALIZED LANGEVIN EQUATION; FREQUENCY-DEPENDENT FRICTION; TRANSITION-STATE THEORY; NON-MARKOVIAN SYSTEMS; ISOMERIZATION DYNAMICS; CHARGE-TRANSFER; SOLVENT; RELAXATION; ESCAPE AB The rate of barrier crossing in a cusped potential serves as a model for electron transfer processes in the presence of dissipation. The spatial diffusion limit for the rate constant is known for this case in the strong damping limit when the Smoluchowski equation is valid. The paper discusses comparison of different approximation schemes in derivation of a one dimensional Smoluchowski equation for a linear kinetic model derived by a non-Markovian dynamics. Differences in calculated short- and longtime limit properties of the systems resulting from various method of elimination of fast variables question validity of use of a Smoluchowski equation in the kinetic rate approach. To calculate the rate, the standard definition in the integrated form of the correlation function is used and the results are shown to be consistent with the predictions of numerical analysis presented in literature. RP GUDOWSKANOWAK, E (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. RI Gudowska-Nowak, Ewa/A-7622-2014 OI Gudowska-Nowak, Ewa/0000-0001-5604-094X NR 56 TC 2 Z9 2 U1 0 U2 0 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD AUG PY 1994 VL 25 IS 8 BP 1161 EP 1181 PG 21 WC Physics, Multidisciplinary SC Physics GA PB925 UT WOS:A1994PB92500001 ER PT J AU PAUL, PH GRAY, JA DURANT, JL THOMAN, JW AF PAUL, PH GRAY, JA DURANT, JL THOMAN, JW TI COLLISIONAL QUENCHING CORRECTIONS FOR LASER-INDUCED FLUORESCENCE MEASUREMENTS OF NO A2-SIGMA+ SO AIAA JOURNAL LA English DT Article ID NITRIC-OXIDE; VIBRATIONAL-RELAXATION; RAMAN-SCATTERING; PRESSURE FLAMES; TEMPERATURE; BAND; LIFETIMES; METHANE; STATES; MODEL AB Quantitative combustion diagnostics using laser-induced fluorescence require a knowledge of energy transfer and quenching rates at elevated temperatures. Such information is critical both for experimental design and for subsequent reduction of measured signals to measurements of temperature and species concentrations. We present the results of a study of electronic energy transfer in NO A2SIGMA+. These results are cast in the form of empirical correlations which have been developed to facilitate the practical applications of quenching corrections. The choice of particular functional forms for these correlations is based on a classical collisional model of the process. This model has been calibrated against an extensive set of measured cross sections. Results are presented for a number of species of interest in combustion and aerothermodynamic applications. C1 WILLIAMS COLL,WILLIAMSTOWN,MA 01267. RP PAUL, PH (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 34 TC 62 Z9 62 U1 1 U2 9 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD AUG PY 1994 VL 32 IS 8 BP 1670 EP 1675 DI 10.2514/3.12158 PG 6 WC Engineering, Aerospace SC Engineering GA NZ342 UT WOS:A1994NZ34200015 ER PT J AU REITZ, M VERONESE, FD LOUIE, A WATKINS, B GUPTA, G LUSSO, P GALLO, RC ROBERTGUROFF, M AF REITZ, M VERONESE, FD LOUIE, A WATKINS, B GUPTA, G LUSSO, P GALLO, RC ROBERTGUROFF, M TI CONFORMATIONAL ASPECTS OF V3 IN HIV-1 NEUTRALIZATION SO AIDS RESEARCH AND HUMAN RETROVIRUSES LA English DT Meeting Abstract C1 NCI,TUMOR CELL BIOL LAB,BETHESDA,MD 20892. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 0889-2229 J9 AIDS RES HUM RETROV JI Aids Res. Hum. Retrovir. PD AUG PY 1994 VL 10 SU 1 BP S39 EP S39 PG 1 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA PF066 UT WOS:A1994PF06600076 ER PT J AU GOLUB, MS TAKEUCHI, PT KEEN, CL GERSHWIN, ME HENDRICKX, AG LONNERDAL, B AF GOLUB, MS TAKEUCHI, PT KEEN, CL GERSHWIN, ME HENDRICKX, AG LONNERDAL, B TI MODULATION OF BEHAVIORAL PERFORMANCE OF PREPUBERTAL MONKEYS BY MODERATE DIETARY ZINC DEPRIVATION SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE MONKEYS; ZINC DEPRIVATION; GROWTH; BEHAVIOR; PREPUBERTY; CHILDHOOD; TASTE; COGNITION; SUPPLEMENTS ID PERIURBAN GUATEMALAN CHILDREN; NEUTRAL AMINO-ACIDS; RHESUS-MONKEYS; BODY-COMPOSITION; GROWTH; DEFICIENCY; BRAIN; VITAMIN AB Young rhesus monkeys (Macaca mulatta, n = 14) 25-30 mo of age were fed a zinc-deficient (ZD) diet (2 mu g Zn/g diet) (moderate zinc deprivation) over 15 week. The ZD diet period was compared with a zinc-adequate (ZA) diet period (50 mu g Zn/g diet) of the same duration, which either preceded or followed it (crossover design). Plasma zinc was lower at the end of the ZD than after the ZA period. There were no overt signs of zinc deficiency or effects on growth rate. Spontaneous motor activity was lower and performance of a visual-attention task and short-term-memory task were poorer during the ZD period than during the ZA period. Behavioral effects were detected as changes from individual baseline values, and often represented a failure to improve. The results suggests that dietary zinc deprivation can modulate behavior in prepubertal monkeys without affecting growth. C1 UNIV CALIF DAVIS,SCH MED,DEPT INTERNAL MED,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT NUTR,DAVIS,CA 95616. RP GOLUB, MS (reprint author), LAWRENCE LIVERMORE NATL LAB,CALIF PRIMATE RES CTR,DAVIS,CA 95616, USA. FU NCRR NIH HHS [RR00169]; NICHD NIH HHS [HD 14388] NR 40 TC 49 Z9 50 U1 0 U2 3 PU AMER SOC CLINICAL NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, SUBSCRIPTIONS, RM L-2310, BETHESDA, MD 20814-3998 SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD AUG PY 1994 VL 60 IS 2 BP 238 EP 243 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA NY101 UT WOS:A1994NY10100014 PM 8030602 ER PT J AU BUNYARATVEJ, A FUCHAROEN, S GREENBAUM, A MOHANDAS, N AF BUNYARATVEJ, A FUCHAROEN, S GREENBAUM, A MOHANDAS, N TI HYDRATION OF RED-CELLS IN ALPHA-THALASSEMIA AND BETA-THALASSEMIA DIFFERS - A USEFUL APPROACH TO DISTINGUISH BETWEEN THESE RED-CELL PHENOTYPES SO AMERICAN JOURNAL OF CLINICAL PATHOLOGY LA English DT Article DE CELL HEMOGLOBIN CONCENTRATION; CELL VOLUME; HEMOGLOBINOPATHIES; RED CELL INDEXES; RED CELLS; THALASSEMIA ID HEMOGLOBIN CONCENTRATION; MEMBRANE-PROPERTIES; LIGHT-SCATTERING; IRON-DEFICIENCY; VOLUME AB Differences in the pathobiologic features of alpha and beta thalassemic red cells include differing derangements in the ability of these cells to regulate their volume. To explore differences in cell hydration in these two red cell phenotypes, heterogeneity in hemoglobin concentration of individual red cells was quantitated. Red cells from 91 patients with alpha thalassemia (hemoglobin H disease) and 69 patients with beta thalassemia of the genotype beta-thal zero/Hb E were analyzed. Marked differences between these thalassemias were noted in the heterogeneity of hemoglobin concentration among individual cells. Decreased cell hemoglobin concentration and increased cell hydration were features of alpha-thalassemic blood samples, whereas both decreased and increased cell hemoglobin concentration as a result of cell hydration and dehydration, respectively, were features of beta-thalassemic blood samples. The documented differences in the hemoglobin concentration distributions should prove useful in distinguishing between the two thalassemic phenotypes. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. MAHIDOL UNIV,RAMATHIBODI HOSP,DEPT PATHOL,BANGKOK 10700,THAILAND. MAHIDOL UNIV,FAC MED,CTR THALALASSEMIA,BANGKOK,THAILAND. MILES DIAGNOST,TARRYTOWN,NY. FU NHLBI NIH HHS [HL31579]; NIDDK NIH HHS [DK26263] NR 16 TC 16 Z9 16 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0002-9173 J9 AM J CLIN PATHOL JI Am. J. Clin. Pathol. PD AUG PY 1994 VL 102 IS 2 BP 217 EP 222 PG 6 WC Pathology SC Pathology GA PA500 UT WOS:A1994PA50000016 PM 8042592 ER PT J AU JOHNSON, VP ALTHERR, MR BLAKE, JM KEPPEN, LD AF JOHNSON, VP ALTHERR, MR BLAKE, JM KEPPEN, LD TI FISH DETECTION OF WOLF-HIRSCHHORN SYNDROME - EXCLUSION OF D4F26 AS CRITICAL SITE SO AMERICAN JOURNAL OF MEDICAL GENETICS LA English DT Article DE WOLF-HIRSCHHORN SYNDROME; 4P DELETION; FISH; DNA DELETION MAPPING; CONTIGUOUS GENE SYNDROME ID HUNTINGTON DISEASE GENE; DISTAL CHROMOSOME 4P; PATERNAL ORIGIN; SHORT ARM; DELETION; LOCUS; PCR AB Wolf-Hirschhorn syndrome (WHS) is due to a deletion in the terminal band of 4p16.3. Among loci that have been involved in deletions are D4S98, D4S95, D4S125, D4F26, as shown by PCR typing, Southern blot hybridization, and/or fluorescent in situ hybridization (FISH). Currently, FISH detection of WHS is predicated upon the deletion of the D4F26 locus with failure to hybridize to pC847.351, a commercially available cosmid probe. A WHS patient is shown to have an interstitial deletion, by hemizygosity at D4S98 and D4S95 but not at D4F26. This suggests that the tip of 4p, specifically D4F26, is not a critical deletion site for WHS. (C) 1994 Wiley-Liss, Inc. C1 UNIV S DAKOTA,SCH MED,SIOUX FALLS,SD. UNIV S DAKOTA,SCH MED,DEPT PEDIAT,SIOUX FALLS,SD. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. NR 19 TC 22 Z9 22 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0148-7299 J9 AM J MED GENET JI Am. J. Med. Genet. PD AUG 1 PY 1994 VL 52 IS 1 BP 70 EP 74 DI 10.1002/ajmg.1320520114 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA NY099 UT WOS:A1994NY09900013 PM 7977466 ER PT J AU GODFREY, VL ROUSE, BT WILKINSON, JE AF GODFREY, VL ROUSE, BT WILKINSON, JE TI TRANSPLANTATION OF T-CELL-MEDIATED, LYMPHORETICULAR DISEASE FROM THE SCURFY (SF) MOUSE SO AMERICAN JOURNAL OF PATHOLOGY LA English DT Note ID VERSUS-HOST DISEASE; MINOR HISTOCOMPATIBILITY ANTIGENS; TRANSGENIC MICE; LPR; LYMPHOPROLIFERATION; MODEL AB The X-linked mutation, scurfy (sf), causes a fatal lymphoreticular disease characterized by runting, lymphadenopathy, splenomegaly, hypergammaglobulinemia, exfoliative dermatitis, Coombs'-positive anemia, and death by 24 days of age. T lymphocytes are required to mediate this syndrome as shown by a total absence of disease in mice bred to be scurfy and nude (sf/Y; nu/nu). The scurfy phenotype is not transmitted by sf/Y bone marrow transplants, though cells of scurfy origin do reconstitute all lymphoid organs in the recipient mouse. These data suggest that scurfy disease results from an abnormal T cell development process and not from an intrinsic stem cell defect. We therefore tested the ability of transplanted scurfy thymuses to transmit scurfy disease to congenic euthymic mice, to athymic (nude) mice, and to severe combined immunodeficiency (SCID) mice. Euthymic recipients of sf/Y thymic grafts remained clinically normal as did all SCID and nude recipients of normal thymus transplants. Morphological lesions similar to those found in scurfy mice occurred in all H-2- compatible nude and SCID recipients of sf/Y thymic grafts. Intraperitoneal injections of scurfy thymocytes, splenocytes, and lymph node cells also transmitted the scurfy phenotype to H-2-compatible nude mice and SCID mice. Our findings indicate that scurfy, disease cas be transmitted to T cell-deficient mice by engraftment of scurfy T cells, but that pathogenic scurfy T cell activities can be inhibited (or prevented)) ill immunocompetent recipient mice. C1 UNIV TENNESSEE,COLL VET MED,KNOXVILLE,TN. RP GODFREY, VL (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. NR 16 TC 57 Z9 57 U1 0 U2 2 PU AMER SOC INVESTIGATIVE PATHOLOGY, INC PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202-3993 SN 0002-9440 J9 AM J PATHOL JI Am. J. Pathol. PD AUG PY 1994 VL 145 IS 2 BP 281 EP 286 PG 6 WC Pathology SC Pathology GA PB283 UT WOS:A1994PB28300006 PM 8053488 ER PT J AU GHIO, AJ QUIGLEY, DR AF GHIO, AJ QUIGLEY, DR TI COMPLEXATION OF IRON BY HUMIC-LIKE SUBSTANCES IN LUNG-TISSUE - ROLE IN COAL-WORKERS PNEUMOCONIOSIS SO AMERICAN JOURNAL OF PHYSIOLOGY LA English DT Article DE IRON CHELATES; FREE RADICALS ID LIPID-PEROXIDATION; FIBROSIS; COLLAGEN; HAMSTERS; INFLAMMATION; HYDROXYLASE AB Deposition of coal dust in the lungs during the mining of this energy resource can cause an inappropriate fibrosis. Those characteristics of the coal responsible for lung injury are not known. The hypothesis was tested that 1) humic-like substances (HLS) in coal complex iron cations, which subsequently catalyze oxidant generation; and 2) the accumulation of this metal in the lungs of coal miners is associated with collagen deposition. In vitro measurements of ionizable ferric ion concentration ([Fe3+]) and oxidant generation by 10 standard coal dusts increased with the concentration of HLS. Dust mass, nonheme [Fe3+], and hydroxyproline concentrations in lung tissue were significantly higher in the lungs of coal miners, relative to matched controls. Although hydroxyproline concentrations increased with both dust mass and tissue nonheme [Fe3+], the association with the latter appeared greater. HLS in coal dusts sequestered in human lungs may be associated with injury as a result of their capacity to complex metals, which catalyze oxidant generation. C1 DUKE UNIV,MED CTR,DEPT MED,DIV ALLERGY CRIT CARE & RESP MED,DURHAM,NC 27710. IDAHO NATL ENGN LAB,DEPT ENGN RES & APPLICAT,IDAHO FALLS,ID 83415. RP GHIO, AJ (reprint author), DUKE UNIV,MED CTR,DEPT VET AFFAIRS MED CTR,BOX 3177,DURHAM,NC 27710, USA. FU NHLBI NIH HHS [HL-02655]; NIDCR NIH HHS [DE-AC07-76ID01570] NR 39 TC 13 Z9 14 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0002-9513 J9 AM J PHYSIOL JI Am. J. Physiol. PD AUG PY 1994 VL 267 IS 2 BP L173 EP L179 PN 1 PG 7 WC Physiology SC Physiology GA PC439 UT WOS:A1994PC43900092 PM 8074240 ER PT J AU THOMAS, EV AF THOMAS, EV TI A PRIMER ON MULTIVARIATE CALIBRATION SO ANALYTICAL CHEMISTRY LA English DT Article ID PARTIAL LEAST-SQUARES; NEAR-INFRARED SPECTROSCOPY; PRINCIPAL COMPONENTS; REGRESSION; GLUCOSE; CHEMOMETRICS; SELECTION; EXAMPLE RP THOMAS, EV (reprint author), SANDIA NATL LABS,DEPT STAT & HUMAN FACTORS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 30 TC 154 Z9 158 U1 2 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1994 VL 66 IS 15 BP A795 EP A804 DI 10.1021/ac00087a002 PG 10 WC Chemistry, Analytical SC Chemistry GA PA170 UT WOS:A1994PA17000003 ER PT J AU VOLKOW, ND FOWLER, JS WANG, GJ LOGAN, J SCHLYER, D MACGREGOR, R HITZEMANN, R WOLF, AP AF VOLKOW, ND FOWLER, JS WANG, GJ LOGAN, J SCHLYER, D MACGREGOR, R HITZEMANN, R WOLF, AP TI DECREASED DOPAMINE TRANSPORTERS WITH AGE IN HEALTHY-HUMAN SUBJECTS SO ANNALS OF NEUROLOGY LA English DT Note ID POSITRON EMISSION TOMOGRAPHY; HUMAN-BRAIN; PARKINSONS-DISEASE; SUBSTANTIA-NIGRA; C-11 RACLOPRIDE; BINDING-SITES; RECEPTORS; DENSITY; INVIVO; BABOON AB The effects of aging on brain dopamine transporters was evaluated in 26 healthy male volunteers (age range, 21-63 years) using positron emission tomography and [C-11]cocaine. The ratio of the distribution volume for [C-11]cocaine in basal ganglia to that in cerebellum was used as a model parameter for dopamine transporter availability and showed a significant negative correlation with age (r = 0.65, p < 0.0005). This results document an age-related decline in dopamine transporters in healthy individuals. C1 SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. RP VOLKOW, ND (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. FU NIDA NIH HHS [NIDA 5RO1-DA06891] NR 19 TC 127 Z9 127 U1 0 U2 0 PU LITTLE BROWN CO PI BOSTON PA 34 BEACON STREET, BOSTON, MA 02108-1493 SN 0364-5134 J9 ANN NEUROL JI Ann. Neurol. PD AUG PY 1994 VL 36 IS 2 BP 237 EP 239 DI 10.1002/ana.410360218 PG 3 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA PB260 UT WOS:A1994PB26000017 PM 8053661 ER PT J AU LIN, Y SCHILL, J WANG, RW AF LIN, Y SCHILL, J WANG, RW TI INSTRUMENTAL NOISE EFFECT IN AN OPTICAL HETERODYNE PROFILER SO APPLIED OPTICS LA English DT Article DE HETERODYNE; PROFILER; SURFACE ROUGHNESS; PHASE MEASUREMENT; COMMON-PATH INTERFEROMETER ID STATISTICAL PROPERTIES; SURFACES AB An optical heterodyne profiler has been developed for measuring surface roughness at Brookhaven National Laboratory. The height measurement sensitivity and lateral resolution are 1.1 angstrom and 4 mum, respectively, when a 40x objective is used. A Zeeman-split He-Ne laser is the light source. A noncontact measurement system is designed as an optical common-path interferometer. Optical and electronic common-mode rejection techniques are employed to minimize the effects of environmental conditions. The effect of the system noise is analyzed in detail. The effect of varying the number of samples at each sampling point is shown. The comparisons of the system noises with different objectives, 5x, 10x, 20x, and 40x, are presented. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP LIN, Y (reprint author), CHINESE ACAD SCI, SHANGHAI INST OPT & FINE MECH, SHANGHAI, PEOPLES R CHINA. NR 15 TC 8 Z9 8 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1994 VL 33 IS 22 BP 5005 EP 5010 PG 6 WC Optics SC Optics GA PD324 UT WOS:A1994PD32400007 PM 20935879 ER PT J AU HARRISON, L MICHALSKY, J BERNDT, J AF HARRISON, L MICHALSKY, J BERNDT, J TI AUTOMATED MULTIFILTER ROTATING SHADOW-BAND RADIOMETER - AN INSTRUMENT FOR OPTICAL DEPTH AND RADIATION MEASUREMENTS SO APPLIED OPTICS LA English DT Article DE ATMOSPHERIC RADIOMETRY; TURBIDITY; OPTICAL DEPTH; LANGLEY REGRESSION AB The multifilter rotating shadow-band radiometer is a ground-based instrument that uses independent interference-filter-photodiode detectors and the automated rotating shadow-band technique to make spectrally resolved measurements at seven wavelength passbands (chosen at the time of manufacture between 350 nm and 1.7 mum) of direct-normal, total-horizontal, and diffuse-horizontal irradiances. This instrument achieves an accuracy in direct-normal spectral irradiance comparable with that of tracking radiometers, and it is more accurate than conventional instruments for the determination of the diffuse and total-horizontal spectral irradiances because the angular acceptance function of the instrument closely approximates the ideal cosine response, and because the measured direct-normal component can be corrected for the remaining angular acceptance error. The three irradiance components are measured with the same detector for a given wavelength. Together with the automated shadow-band technique, this guarantees that the calibration coefficients are identical for each, thus reducing errors when one compares them (as opposed to measurements made with independent instruments). One can use the direct-normal component observations for Langley analysis to obtain depths and to provide an ongoing calibration against the solar constant by extrapolation to zero air mass. Thus the long-term stability of all three measured components can be tied to the solar constant by an analysis of the routinely collected data. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP HARRISON, L (reprint author), SUNY ALBANY, ATMOSPHER SCI RES CTR, 100 FULLER RD, ALBANY, NY 12205 USA. NR 12 TC 333 Z9 336 U1 4 U2 17 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1994 VL 33 IS 22 BP 5118 EP 5125 PG 8 WC Optics SC Optics GA PD324 UT WOS:A1994PD32400023 PM 20935895 ER PT J AU MOROSIN, B HENDERSON, C SCHIRBER, JE AF MOROSIN, B HENDERSON, C SCHIRBER, JE TI STOICHIOMETRICALLY CONTROLLED DIRECT SOLID-STATE SYNTHESIS OF C60H2 SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID BUCKMINSTERFULLERENE AB The direct solid-state synthesis of C60H2 has been demonstrated by controlling the amount of hydrogen introduced into the reaction with C60. Palladium hydride has been used as the source of hydrogen. The main product 1,2-C60 is the isomer predicted to have the lowest energy of the possible 23 isomers; in addition, small amounts of the thermodynamically most stable isomer of C60H4, 1,2,3,4-C60H4, have also been obtained. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP MOROSIN, B (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 13 TC 12 Z9 12 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD AUG PY 1994 VL 59 IS 2 BP 179 EP 180 DI 10.1007/BF00332213 PG 2 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA PB826 UT WOS:A1994PB82600015 ER PT J AU ZIMMER, K STENNER, J KLUGE, HJ LANTZSCH, J MONZ, L OTTEN, EW PASSLER, G SCHWALBACH, R SCHWARZ, M STEVENS, H WENDT, K HERRMANN, G NIESS, S TRAUTMANN, N WALTER, K BUSHAW, BA AF ZIMMER, K STENNER, J KLUGE, HJ LANTZSCH, J MONZ, L OTTEN, EW PASSLER, G SCHWALBACH, R SCHWARZ, M STEVENS, H WENDT, K HERRMANN, G NIESS, S TRAUTMANN, N WALTER, K BUSHAW, BA TI DETERMINATION OF SR-90 IN ENVIRONMENTAL-SAMPLES WITH RESONANCE IONIZATION SPECTROSCOPY IN COLLINEAR GEOMETRY SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID SEPARATION; STRONTIUM; EXTRACTION; ACCIDENT; FALLOUT AB A new, fast technique for trace analysis of the radioactive isotopes Sr-89 and Sr-90 in environmental samples has been developed. Conventional mass separation is combined with resonance ionization spectroscopy in collinear geometry, which provides high selectivity and sensitivity. In addition, a chemical separation procedure for sample preparation has been developed. The described technique was used to determine the Sr-90 content in almost-equal-to 870 m3 air samples collected near Munich during and shortly after the Chernobyl reactor accident in April 1986. The content of Sr-90 was measured to be 1.4 mBq per m3, corresponding to 1.6 x 10(9) atoms of Sr-90 per sample. This value is in good agreement with the results of radiochemical measurements. C1 UNIV MAINZ, INST KERNCHEM, D-550099 MAINZ, GERMANY. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP ZIMMER, K (reprint author), UNIV MAINZ, INST PHYS, D-55099 MAINZ, GERMANY. RI Wendt, Klaus/D-7306-2011 OI Wendt, Klaus/0000-0002-9033-9336 NR 23 TC 12 Z9 13 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD AUG PY 1994 VL 59 IS 2 BP 117 EP 121 DI 10.1007/BF01081161 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA PB825 UT WOS:A1994PB82500004 ER PT J AU KAMEI, M SHIGESATO, Y TAKAKI, S HAYASHI, Y SASAKI, M HAYNES, TE AF KAMEI, M SHIGESATO, Y TAKAKI, S HAYASHI, Y SASAKI, M HAYNES, TE TI ELECTRON-MICROSCOPIC AND ION-SCATTERING STUDIES OF HETEROEPITAXIAL TIN-DOPED INDIUM OXIDE-FILMS SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL-PROPERTIES AB The microstructure of heteroepitaxial tin-doped indium oxide (ITO) films were studied in detail.The surface morphology of the heteroepitaxial ITO film consisted of square-shaped, in-plane oriented subgrains (approximately 300 angstrom) in contrast to that of the polycrystalline film (characteristic grain-subgrain structure). The subgrain boundaries were predominantly formed along the {110} planes in the ITO film and dislocations were observed primarily along the subgrain boundaries. Ion channeling measurements showed the dislocation density of this film to be approximately 3 x 10(10)/cm2, and the angular distribution of the ion channeling yield showed that the subgrains are aligned to within better than 0.3-degrees (standard deviation). C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP KAMEI, M (reprint author), ASAHI GLASS CO LTD,RES CTR,1150 HAZAWA CHO,KANAGAWA KU,YOKOHAMA,KANAGAWA 221,JAPAN. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 11 TC 16 Z9 16 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 1 PY 1994 VL 65 IS 5 BP 546 EP 548 DI 10.1063/1.112292 PG 3 WC Physics, Applied SC Physics GA PA153 UT WOS:A1994PA15300011 ER PT J AU CHEN, Y LIU, X WEBER, E BOURRET, ED LILIENTALWEBER, Z HALLER, EE WASHBURN, J OLEGO, DJ DORMAN, DR GAINES, JM TASKER, NR AF CHEN, Y LIU, X WEBER, E BOURRET, ED LILIENTALWEBER, Z HALLER, EE WASHBURN, J OLEGO, DJ DORMAN, DR GAINES, JM TASKER, NR TI STRUCTURES AND ELECTRONIC-PROPERTIES OF MISFIT DISLOCATIONS IN ZNSE/GAAS(001) HETEROJUNCTIONS SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; GROWTH MODE; ZNSE; SYSTEM AB The structures and electronic properties of misfit dislocations in ZnSe/GaAs(001) heterojunctions have been studied by transmission electron microscopy, cathodoluminescence (CL), and photoluminescence. In undoped ZnSe epilayers, irregular dislocation segments tending to lie roughly along [100] and [010] directions were observed as well as long straight 60-degrees dislocations along [110] and [110BAR] directions. In N-doped ([N]>l X 10(18) cm-3) ZnSe epilayers, the misfit dislocations were predominantly dissociated into partial dislocations which makes cross slip and formation of irregular dislocations more difficult; only the straight dislocations along [110] and [110BAR] were observed. The CL observations suggest that the irregular dislocations trap carriers more efficiently than the dislocations along [110]. C1 PHILIPS LABS,BRIARCLIFF MANOR,NY 10510. RP CHEN, Y (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 9 TC 12 Z9 13 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 1 PY 1994 VL 65 IS 5 BP 549 EP 551 DI 10.1063/1.112293 PG 3 WC Physics, Applied SC Physics GA PA153 UT WOS:A1994PA15300012 ER PT J AU SCHNEIDER, RP JONES, ED FOLLSTAEDT, DM AF SCHNEIDER, RP JONES, ED FOLLSTAEDT, DM TI GROWTH AND CHARACTERIZATION OF GAINP UNICOMPOSITIONAL DISORDER-ORDER-DISORDER QUANTUM-WELLS SO APPLIED PHYSICS LETTERS LA English DT Article ID VAPOR-PHASE EPITAXY; BAND-GAP ENERGY; PHOTOLUMINESCENCE-EXCITATION-SPECTROSCOPY; GA0.5IN0.5P; ALLOYS AB Metalorganic vapor phase epitaxy (MOVPE) is used to grow unicompositional quantum-well (QW) structures, in which the QW and barrier layers are composed of ordered and disordered GaInP, respectively. Transmission electron dark-field micrographs reveal abrupt interfaces between highly ordered QWs and disordered barriers, with no evidence of defect formation. Low-temperature photoluminescence from the structures exhibits relatively broad emission peaks, with emission energy increasing with decreasing QW thickness. The dependence of emission energy on well thickness can be described by a finite square well model only when a type-II band alignment is taken for the heterostructure, in which the conduction band edge of the ordered GaInP QW lies about 135-150 meV below that of the disordered barrier material. These results demonstrate a high degree of control over the ordering process in MOVPE, such that quantum size effects can be realized solely through disorder-order phenomena. Further, the data provide strong support for a type-II (spatially indirect) recombination transition between ordered and disordered GaInP. RP SCHNEIDER, RP (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 24 TC 39 Z9 41 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 1 PY 1994 VL 65 IS 5 BP 587 EP 589 DI 10.1063/1.112307 PG 3 WC Physics, Applied SC Physics GA PA153 UT WOS:A1994PA15300025 ER PT J AU SELVAMANICKAM, V GOYAL, A KROEGER, DM AF SELVAMANICKAM, V GOYAL, A KROEGER, DM TI GRAIN ALIGNMENT IN BULK YBA2CU3OX SUPERCONDUCTOR BY A LOW-TEMPERATURE PHASE-TRANSFORMATION METHOD SO APPLIED PHYSICS LETTERS LA English DT Article ID CURRENT-DENSITY; MICROSTRUCTURE AB A quench and directional phase transformation process has been developed to achieve grain alignment in bulk YBa2CU3Ox Superconductors at temperatures about 100-degrees-C below the peritectic temperature. Isothermal phase transformation of quenched precursors at 890-degrees-C for 3 min is found to result in the formation of more than 75% of YBa2CU3Ox phase without any formation of Y2BaCuO5. Phase transformation at higher temperatures leads to rapid formation Of Y2BaCuO5 in addition to YBa2CU3Ox. A well-aligned microstructure is achieved by directional phase transformation of the quenched compacts as a rate of 10 mm/h. The magnetic field dependence of the critical current density at 77 K of the directionally phase transformed material compares well with that of melt-textured YBCO and is superior to that of magnetically aligned and sintered YBCO. RP SELVAMANICKAM, V (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 1 PY 1994 VL 65 IS 5 BP 639 EP 641 DI 10.1063/1.112256 PG 3 WC Physics, Applied SC Physics GA PA153 UT WOS:A1994PA15300043 ER PT J AU SMITH, DR SCHULTZ, S KROLL, N SIGALAS, M HO, KM SOUKOULIS, CM AF SMITH, DR SCHULTZ, S KROLL, N SIGALAS, M HO, KM SOUKOULIS, CM TI EXPERIMENTAL AND THEORETICAL RESULTS FOR A 2-DIMENSIONAL METAL PHOTONIC BAND-GAP CAVITY SO APPLIED PHYSICS LETTERS LA English DT Article ID 2 DIMENSIONS; DEFECTS AB We demonstrate, by both microwave experiments and numerical simulation, that a two-dimensional lattice of metal cylinders can from a complete photonic band-gap (PBG) structure. The band structure exhibits a single broad PBG extending from zero frequency to a threshold frequency, above which all modes may propagate in some direction. A single cylinder removed from the lattice produces a defect mode localized about the defect site, with an energy density attenuation rate of 30 dB per lattice constant. The frequency dependence of the transmission through a finite thickness of this structure is also calculated in good agreement with the measurements. We suggest that the defect mode resonant cavity when formed by appropriate low loss metals may be advantageous for use in PBG high energy accelerator structures that we are evaluating. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP SMITH, DR (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,9500 GILMAN DR,LA JOLLA,CA 92093, USA. RI Soukoulis, Costas/A-5295-2008; Smith, David/E-4710-2012 NR 7 TC 163 Z9 170 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 1 PY 1994 VL 65 IS 5 BP 645 EP 647 DI 10.1063/1.112258 PG 3 WC Physics, Applied SC Physics GA PA153 UT WOS:A1994PA15300045 ER PT J AU MINCHER, BJ ARBON, RE KNIGHTON, WB MEIKRANTZ, DH AF MINCHER, BJ ARBON, RE KNIGHTON, WB MEIKRANTZ, DH TI GAMMA-RAY-INDUCED DEGRADATION OF PCBS IN NEUTRAL ISOPROPANOL USING SPENT REACTOR-FUEL SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID POLYCHLORINATED-BIPHENYLS; DECHLORINATION; REDUCTION; RADICALS AB In this study we report new results concerning the gamma-radiolysis of the PCB octachlorobiphenyl. The radiolytic decomposition rate of octachlorobiphenyl (8CB) in neutral isopropanol was studied as a function of dose using spent nuclear fuel as a gamma-ray source. The G-values measured were small (approx. 0.01 mumol J-1), however the easy access to very high gamma-ray doses and dose rates has allowed for the investigation of a process not constrained to deaerated, alkaline conditions. The G-value was suppressed by the addition of a solvated electron and solvent radical scavenger, but not by the addition of hydrogen atom and hydroxyl radical scavengers, suggesting that in neutral alcoholic solvent the solvated electron and possibly solvent radicals are the primary species responsible for PCB decomposition. C1 MONTANA STATE UNIV,BOZEMAN,MT 59717. RP MINCHER, BJ (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. RI Mincher, Bruce/C-7758-2017 NR 20 TC 22 Z9 23 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD AUG PY 1994 VL 45 IS 8 BP 879 EP 887 DI 10.1016/0969-8043(94)90219-4 PG 9 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA PB426 UT WOS:A1994PB42600008 ER PT J AU STUMP, NA SCHWEITZER, GK GIBSON, JK HAIRE, RG PETERSON, JR AF STUMP, NA SCHWEITZER, GK GIBSON, JK HAIRE, RG PETERSON, JR TI LUMINESCENCE STUDY OF THE THERMAL-DECOMPOSITION OF EUROPIUM TRICHLORIDE HEXAHYDRATE, EUCL3.6H2O SO APPLIED SPECTROSCOPY LA English DT Article DE LUMINESCENCE; THERMAL DECOMPOSITION; EUCL3.6H2O; EUCL3.3H2O; EUCL3.2H2O; EUCL3.H2O; EU(OH)CL2 ID PRESSURE; EU-3+ AB We have studied the thermal decomposition of EuCl3.6H2O using in situ measurements of the Eu3+ ion luminescence spectrum. The luminescence spectrum proved to be extremely sensitive to structural and compositional changes undergone by the title compound during the decomposition process. There appeared to be no change in the oxidation state of the europium throughout the decomposition process. Four differently hydrated species of EuCl3.nH2O(n=6,3,2, or 1) were identified via luminescence spectroscopy. We also observed another intermediate compound formed from the monohydrate prior to the final product EuOCl. Our analysis of this intermediate's spectrum indicates a single Eu3+ ion site, which is consistent with a formulation of Eu(OH)Cl2 rather than a mixed EuOCl.2EuCl3 product, both of which have been postulated by others on the basis of their thermogravimetric measurements. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,TRANSURANIUM RES LAB,OAK RIDGE,TN 37831. RP STUMP, NA (reprint author), WINSTON SALEM STATE UNIV,DEPT PHYS SCI,WINSTON SALEM,NC 27110, USA. NR 21 TC 19 Z9 19 U1 2 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1994 VL 48 IS 8 BP 937 EP 944 DI 10.1366/0003702944029712 PG 8 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA PJ210 UT WOS:A1994PJ21000006 ER PT J AU IIDA, Y YEUNG, ES AF IIDA, Y YEUNG, ES TI OPTICAL MONITORING OF LASER-INDUCED PLASMA-DERIVED FROM GRAPHITE AND CHARACTERIZATION OF THE DEPOSITED CARBON-FILM SO APPLIED SPECTROSCOPY LA English DT Article ID AMORPHOUS-CARBON; INDUCED FLUORESCENCE; CLUSTER SOURCE; DIAMOND FILMS; VAPORIZATION; EMISSION; BUCKMINSTERFULLERENE; SPECTROSCOPY; CONSTANTS AB Mechanisms of the deposition of carbon thin films by the laser ablation of graphite were investigated by monitoring the plasma emission. Parameters such as electron density, ionization temperature, and vibrational temperature during plasma growth were evaluated as a function of the laser power density and the surrounding atmosphere. Also, Raman spectra of the deposited films were measured so that the particle size can be estimated from the intensity ratio of the Raman bands around 1360 and 1580 cm-1. The increase in power density caused an increase in ionization temperature and vibrational temperature of carbon species in the plasma but a decrease of particle size of the deposited thin films. The existence of 10 Torr of helium as a surrounding atmosphere caused drastic changes in the plasma parameters. The films deposited with helium atmosphere showed a low optical band gap, which indicates heat restructuring of ablated graphite particles in the hot plasma. The results can be explained with a simple model of laser ablation and the subsequent interaction of ablated particles with the laser-induced plasma. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP IIDA, Y (reprint author), MINIST INT TRADE & IND,AGCY IND SCI & TECHNOL,NATL IND RES INST NAGOYA,HIRATE CHO,KITA KU,NAGOYA 462,JAPAN. NR 31 TC 50 Z9 50 U1 2 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1994 VL 48 IS 8 BP 945 EP 950 DI 10.1366/0003702944029596 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA PJ210 UT WOS:A1994PJ21000007 ER PT J AU SHELTON, RD HAAS, JW WACHTER, EA AF SHELTON, RD HAAS, JW WACHTER, EA TI SURFACE-ENHANCED RAMAN DETECTION OF AQUEOUS CYANIDE SO APPLIED SPECTROSCOPY LA English DT Article DE SERS; CYANIDE; ELECTROCHEMICAL; GROUNDWATER; PROCESS MONITORING ID SILVER ELECTRODE; AG ELECTRODES; SCATTERING; SPECTRA; SPECTROSCOPY; FILMS; SERS AB Cyanide ion (CN-) has been the subject of numerous studies probing the mechanisms underlying the surface-enhanced Raman scattering (SERS) phenomenon. This work examines various aspects critical to application of SERS for direct detection of trace cyanide in groundwater and in wastewater streams. A new method for direct quantitation of cyanide in aqueous electrolyte has been developed that uses an ex situ oxidation-reduction cycle to precondition a planar silver electrode. Cyanide ion can be detected in 0.1 M KCl with a linear response between 100 ppm and 10 ppb. The estimated limit of detection is approximately 8 ppb. The effects of pH, electrolyte level, and two common background ions, nitrate (NO3-) and sulfate (SO42-), have been characterized. Cyanide response was found to be sensitive to pH, with optimal performance observed at neutral to basic pH. Electrolyte concentrations of 0.001 M reduced response to cyanide by a factor of five, while levels above 0.1 M had no significant effect. The addition of 10-ppm sulfate ion decreased response approximately 40%, while the presence of nitrate ion at concentrations up to 100 ppm had a negligible effect on SERS response. These results suggest that cyanide ion can be detected directly in high-ionic-strength aqueous solutions, such as groundwater. C1 OAK RIDGE NATL LAB,DIV HLTH SCI RES,OAK RIDGE,TN 37831. NR 16 TC 17 Z9 17 U1 1 U2 6 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1994 VL 48 IS 8 BP 1007 EP 1010 DI 10.1366/0003702944029677 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA PJ210 UT WOS:A1994PJ21000017 ER PT J AU CHEN, G WANG, SH HAIRE, RG PETERSON, JR AF CHEN, G WANG, SH HAIRE, RG PETERSON, JR TI PRESSURE-INDUCED D-ORBITAL TO F-ORBITAL ENERGY CROSSOVER IN SM2+ ION IN CSSMI3 - A LUMINESCENCE STUDY SO APPLIED SPECTROSCOPY LA English DT Note DE ORBITAL ENERGY CROSSOVER; PRESSURE; LUMINESCENCE; CSSMI3 ID FLUORESCENCE C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. BEIJING NORMAL UNIV,DEPT CHEM,BEIJING 100875,PEOPLES R CHINA. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,TRANSURANIUM RES LAB,OAK RIDGE,TN 37831. NR 8 TC 3 Z9 3 U1 1 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1994 VL 48 IS 8 BP 1026 EP 1028 DI 10.1366/0003702944029622 PG 3 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA PJ210 UT WOS:A1994PJ21000021 ER PT J AU EVANS, BR MARGALIT, R WOODWARD, J AF EVANS, BR MARGALIT, R WOODWARD, J TI VERATRYL ALCOHOL OXIDASE ACTIVITY OF A CHEMICALLY-MODIFIED CELLULASE PROTEIN SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article ID SPERM WHALE MYOGLOBIN; LIGNIN-PEROXIDASE; PHANEROCHAETE-CHRYSOSPORIUM; TRICHODERMA-REESEI; ELECTRON-TRANSFER; CATALYTIC ACTIVITY; FUNGAL CELLULASES; CYTOCHROME-C; OXALIC-ACID; OXIDATION AB A cellulase, cellobiohydrolase I (CBH I) from Trichoderma reesei was chemically modified by covalent attachment of pentaammine ruthenium (III) without loss in hydrolytic activity. Data suggest that such a modification endowed CBH I with oxidoreductase activity. The modified enzyme was able to carry out hydrogen peroxide-dependent oxidation of veratryl alcohol, a substrate for lignin peroxidase, at a rate of 0.148 mu mol substrate oxidized min(-1) mu mol(-1) enzyme. The effects of pH, temperature, and substrate concentration on the oxidation reaction were examined. The optimal temperature was determined to be 45 degrees C, and the optimal pH was 4.3. The K-m and V-max for veratryl alcohol were determined to be 3.519 mM and 52.27 mu M min(-1), respectively. Tartrate at concentrations as low as 0.10 mM was found to inhibit the reaction. (C) 1994 Academic Press, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. CALTECH,JET PROP LAB,PASADENA,CA 91109. NR 36 TC 12 Z9 12 U1 2 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD AUG 1 PY 1994 VL 312 IS 2 BP 459 EP 466 DI 10.1006/abbi.1994.1332 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA NX805 UT WOS:A1994NX80500018 PM 8037459 ER PT J AU SCHNEIDER, JS MOORE, DH SAGEBIEL, RW AF SCHNEIDER, JS MOORE, DH SAGEBIEL, RW TI RISK-FACTORS FOR MELANOMA INCIDENCE IN PROSPECTIVE FOLLOW-UP - THE IMPORTANCE OF ATYPICAL (DYSPLASTIC) NEVI SO ARCHIVES OF DERMATOLOGY LA English DT Article ID CUTANEOUS MALIGNANT-MELANOMA; MELANOCYTIC NEVI; NAEVI AB Background and Design: Assessment of melanoma risk factors can help identify individuals at greatest risk for melanoma. Previous studies were retrospective case-control or prospective without control groups. A prospective group of 3889 employees without previous melanoma or family history of multiple melanoma at the Lawrence Livermore (Calif) National Laboratory were examined as part of a melanoma screening program. Their subsequent incidence of melanoma in relationship to potential melanoma risk factors, which were recorded at the first examination, was determined. Results: Nine invasive melanomas developed after initial examination among the studied population over an 8-year period with an average follow-up of 5 years. The presence of an easily recognized pattern of definite clinically atypical (dysplastic) nevi was present in 7% of employees and was associated with a cumulative melanoma risk of 1.9%. It was the strongest risk factor, with a relative risk of 47 compared with the 0.04% cumulative melanoma risk in the 64% of employees with no atypical (dysplastic) moles (chi(2) for equal risk, P=7 X 10(-8)). Significant, but less marked associations with melanoma risk were found for the total number of moles and for a history of many moles in other family members, with a maximal relative risk of 11.6 and 10.4, respectively. Conclusion: A small subgroup of the population with easily recognizable definite atypical (dysplastic) nevi have a marked increased risk of melanoma. Smaller significant melanoma risks were found for a total number of moles and a family history of many moles. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA. UNIV CALIF SAN FRANCISCO,DEPT PATHOL,SAN FRANCISCO,CA. UNIV CALIF SAN FRANCISCO,DEPT DERMATOL,SAN FRANCISCO,CA 94143. RP SCHNEIDER, JS (reprint author), KAISER PERMANENTE,9 MONTICELLO RD,SAN RAFAEL,CA 94903, USA. NR 25 TC 54 Z9 54 U1 0 U2 3 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0003-987X J9 ARCH DERMATOL JI Arch. Dermatol. PD AUG PY 1994 VL 130 IS 8 BP 1002 EP 1007 DI 10.1001/archderm.130.8.1002 PG 6 WC Dermatology SC Dermatology GA PC020 UT WOS:A1994PC02000006 PM 8053695 ER PT J AU BOOPATHY, R AF BOOPATHY, R TI TRANSFORMATION OF NITROAROMATIC COMPOUNDS BY A METHANOGENIC BACTERIUM, METHANOCOCCUS SP (STRAIN-B) SO ARCHIVES OF MICROBIOLOGY LA English DT Article DE NITROAROMATIC COMPOUNDS; METHANOGENS; BIOTRANSFORMATION; ANAEROBIC PROCESS; SULFATE-REDUCERS ID MICROBIAL TRANSFORMATION; 2,4,6-TRINITROTOLUENE TNT; PHANEROCHAETE-CHRYSOSPORIUM; ANAEROBIC BIODEGRADATION; PARA-NITROPHENOL; NITROGEN-SOURCE; REDUCTION; SLUDGE; PURIFICATION; DEGRADATION AB The transformation of several nitroaromatic compounds by a newly isolated methanogenic bacterium, Methanococcus sp. (strain B) was studied. The presence of nitroaromatic compounds (0.5 mM) viz., nitrobenzene, 2,4-dinitrobenzene, 2,4,6-trinitrobenzene, 2,4-dinitrophenol, 2,4-dinitrotoluene, and 2,6-dinitrotoluene in the culture medium did not inhibit growth of the isolate. The bacteria grew rapidly and reached stationary phase within seven days of incubation. All the nitroaromatic compounds tested were 80 to 100% transformed by the bacterium to amino compounds by a reduction process. The isolate did not use the nitroaromatic compounds as the sole source of carbon or nitrogen. The transformation of nitroaromatic compounds by this isolate was compared to that of other methanogenic bacteria, Out of five methanogens studied, only Methanococcus deltae and Methanococcus thermolithotrophicus could transform the nitroaromatic compounds; however, the transformation rates were significantly less than that of the new isolate Methanococcus sp. (strain B). The nitroaromatic compounds were not transformed by Methanosarcina barkeri, Methanobacterium thermoautotrophicum, and Methanobrevibacter ruminantium. RP BOOPATHY, R (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,BLDG 203,ARGONNE,IL 60439, USA. NR 39 TC 23 Z9 23 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0302-8933 J9 ARCH MICROBIOL JI Arch. Microbiol. PD AUG PY 1994 VL 162 IS 3 BP 167 EP 172 DI 10.1007/BF00314470 PG 6 WC Microbiology SC Microbiology GA PF297 UT WOS:A1994PF29700003 ER PT J AU ARASTEH, DK BECK, FA DUPONT, WC MATHIS, RC AF ARASTEH, DK BECK, FA DUPONT, WC MATHIS, RC TI RATING THE THERMAL PERFORMANCE OF FENESTRATION SYSTEMS SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Article RP ARASTEH, DK (reprint author), LAWRENCE BERKELEY LAB,WINDOWS & DAYLIGHTING GRP,BERKELEY,CA 94720, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD AUG PY 1994 VL 36 IS 8 BP 16 EP 20 PG 5 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA PC776 UT WOS:A1994PC77600008 ER PT J AU SMECKERHANE, TA STETSON, PB HESSER, JE LEHNERT, MD AF SMECKERHANE, TA STETSON, PB HESSER, JE LEHNERT, MD TI THE STELLAR POPULATIONS OF THE CARINA DWARF SPHEROIDAL GALAXY .1. A NEW COLOR MAGNITUDE DIAGRAM FOR THE GIANT AND HORIZONTAL BRANCHES SO ASTRONOMICAL JOURNAL LA English DT Article ID ELLIPTICAL GALAXY; STANDARD STARS; DRACO; EVOLUTION; CLUSTERS; ORIGIN; DARK AB We report on the first in a series of studies of the Carina dwarf spheroidal galaxy, a nearby satellite of our Galaxy. Our two major results are: (1) precise BI photometry (sigma(B-I) less than or similar 0.05 for V less tha or similar 22) for 11 489 stars in the Carina field, and (2) the detection of two, morphologically distinct, horizontal branches in Carina, which confirms that star formation occurred in two well separated episodes. The old horizontal branch and RR Lyrae instability strip belong to a greater than or similar to 10 Gyr stellar population, while the populous red-clump horizontal branch belongs, presumably, to a approximately 6 Gyr stellar population. We derive a distance modulus (m - M)0=20.09+/-0.06 for Carina from the apparent magnitudes of the old horizontal branch and the tip of the red giant branch (RGB), and discuss modifications to the previously estimated distance, total magnitude, and stellar ages of Carina. Using the color of the RGB, we estimate the metallicities of the younger and older populations to be [Fe/H] congruent-to -2.0 and -2.2, respectively. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP SMECKERHANE, TA (reprint author), NATL RES COUNCIL CANADA,HERZBERG INST ASTROPHYS,DOMINION ASTROPHYS OBSERV,5071 W SAANICH RD,RR 5,VICTORIA V8X 4M6,BC,CANADA. NR 38 TC 164 Z9 164 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 1994 VL 108 IS 2 BP 507 EP & DI 10.1086/117087 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA NZ059 UT WOS:A1994NZ05900014 ER PT J AU INTZAND, JJM HEISE, J JAGER, R AF INTZAND, JJM HEISE, J JAGER, R TI THE OPTIMUM OPEN FRACTION OF CODED APERTURES - WITH AN APPLICATION TO THE WIDE-FIELD X-RAY CAMERAS OF SAX SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE INSTRUMENTATION, DETECTORS; TECHNIQUES, IMAGE PROCESSING; TELESCOPES; X-RAY, GENERAL ID UNIFORMLY REDUNDANT ARRAYS; ASTRONOMY; DESIGN; MASKS AB We consider issues that concern the mathematical description of coded aperture patterns. Primarily this involves the relation between the open fraction of such patterns and the signal-to-noise ratio of imaged point sources. A refinement of the corresponding theory is introduced, taking into account the spatial response of the coded aperture camera. From this we predict that patterns with an open fraction of less than 0.5 can enhance the performance of coded aperture cameras to bright point sources, as opposed to what was previously thought. As an application of the refined theory, we tested candidate open fractions in the instrumental configuration of two identical, wide field, coded aperture X-ray cameras (1.8-30 keV), that will be part of the X-ray satellite SAX (to be launched in late 1995). These tests consisted of numerical simulations of several types of observations, and show that open fractions between 0.25 and 0.33 are to be favored for the SAX cameras. The improvement in signal-to-noise ratio with respect to the commonly used open fraction of 0.5 is up to 30%. Whenever telemetry limits the data coverage, this profit may well be larger. We also address additional aperture constraints as applied to the SAX cameras, such as the aperture geometry and pattern. From this analysis we propose a new type of coded aperture pattern for the SAX cameras with an open fraction equal to 0.33, which possesses near-ideal intrinsic mathematical properties. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP INTZAND, JJM (reprint author), SRON, SPACE RES LAB, SORBONNELAAN 2, 3584 CA UTRECHT, NETHERLANDS. NR 21 TC 24 Z9 24 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 1994 VL 288 IS 2 BP 665 EP 674 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PB634 UT WOS:A1994PB63400035 ER PT J AU LEE, IY PARK, HM AF LEE, IY PARK, HM TI PARAMETERIZATION OF THE POLLUTANT TRANSPORT AND DISPERSION IN URBAN STREET CANYONS SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE STREET CANYON; TRANSPORT AND DIFFUSION; TIME CONSTANT ID SIMULATION; MODEL AB A two-dimensional, time-dependent flow model has been applied to the evaluation of pollutant dispersion properties in urban street canyons. The processes by which pollutants emitted at street level are transported and diffused from street canyons are examined to determine the exchange rates of pollutants between street canyons and the upper air under variable flow conditions and different aspect ratios (the ratio of the building height to the street width). The time constant, defined as the time required for the average pollutant concentration in the street canyon to be reduced to e(-1), is parameterized as a function of canyon cross-sectional area, influx strength, Reynolds number, Peclet number, and aspect ratio. Time constants may be applied directly to urban air quality models for better estimation of emission rates. C1 SOGANG UNIV,DEPT CHEM ENGN,SEOUL,SOUTH KOREA. RP LEE, IY (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 16 TC 94 Z9 107 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD AUG PY 1994 VL 28 IS 14 BP 2343 EP 2349 DI 10.1016/1352-2310(94)90488-X PG 7 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA PE566 UT WOS:A1994PE56600008 ER PT J AU PAGE, RE ROBINSON, GE AF PAGE, RE ROBINSON, GE TI REPRODUCTIVE COMPETITION IN QUEENLESS HONEY-BEE COLONIES (APIS-MELLIFERA L) SO BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY LA English DT Article DE APIS MELLIFERA; GENETICS; DRONE PRODUCTION; ALLOZYMES; REPRODUCTIVE CONFLICT ID OVARIAN DEVELOPMENT; KIN DISCRIMINATION; RECOGNITION; WORKERS; POPULATION; NEPOTISM; KINSHIP; SISTERS; FULL AB Previously we reported that there are subfamily differences in drone production in queenless honey bee colonies, but these biases are not always explained by subfamily differences in oviposition behavior. Here we determine whether these puzzling results are best explained by either inadequate sampling of the laying worker population or reproductive conflict among workers resulting in differential treatment of eggs and larvae. Using colonies composed of workers from electrophoretically distinct subfamilies, we collected samples of adult bees engaged in the following behavior: ''true'' egg laying, ''false'' egg laying, indeterminate egg laying, egg cannibalism, or nursing (contact with larvae). We also collected samples of drone brood at four different ages: 0 to 2.5-h-old eggs, 0 to 24-h-old eggs, 3 to 8-day-old larvae, and 9 to 14-day-old larvae and pupae. Allozyme analyses revealed significant subfamily differences in the likelihood of exhibiting egg laying, egg cannibalism, and nursing behavior, as well as significant subfamily differences in drone production. There were no subfamily differences among the different types of laying workers collected from each colony, suggesting that discrepancies between subfamily biases in egg-laying behavior and drone production are not due to inadequate sampling of the laying worker population. Subfamily biases in drone brood production within a colony changed significantly with brood age. Laying workers had significantly more developed ovaries than either egg cannibals or nurses, establishing a physiological correlate for the observed behavioral genetic differences. These results suggest there is reproductive conflict among subfamilies and individuals within queenless colonies of honey bees. The implications of these results for the evolution of reproductive conflict, in both queenright and queenless contexts, are discussed. C1 UNIV ILLINOIS,DEPT ENTOMOL,URBANA,IL 61801. RP PAGE, RE (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ENTOMOL,DAVIS,CA 95616, USA. NR 49 TC 43 Z9 43 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-5443 J9 BEHAV ECOL SOCIOBIOL JI Behav. Ecol. Sociobiol. PD AUG PY 1994 VL 35 IS 2 BP 99 EP 107 DI 10.1007/BF00171499 PG 9 WC Behavioral Sciences; Ecology; Zoology SC Behavioral Sciences; Environmental Sciences & Ecology; Zoology GA PF203 UT WOS:A1994PF20300004 ER PT J AU PRATT, LR HUMMER, G GARCIA, AE AF PRATT, LR HUMMER, G GARCIA, AE TI ION-PAIR POTENTIALS-OF-MEAN-FORCE IN WATER SO BIOPHYSICAL CHEMISTRY LA English DT Review DE ION PAIR POTENTIALS-OF-MEAN FORCE; ALKALI HALIDE; WATER ID BOUNDARY ELEMENT METHOD; BORN MODEL; ELECTROSTATIC INTERACTION; INTEGRAL-EQUATIONS; MOLECULAR-DYNAMICS; EXTENDED RISM; SITE THEORY; HYDRATION; ENERGY; CONTINUUM AB Motivated by the surprising dielectric model predictions of alkali-halide ion pair potentials-of-mean-force in water due to Rashin, we reanalyze the theoretical bases of that comparison. We discuss recent, pertinent molecular simulation and integral equation results that have appeared for these systems. We implement dielectric model calculations to check the basic features of Rashin's calculations. We confirm that the characteristic structure of contact and solvent-separated minima does appear in the dielectric model results for the pair potentials-of-mean-force for oppositely charged ions in water under physiological thermodynamic conditions. Comparison of the dielectric model results with the most current molecular level information indicates that the dielectric model does not, however, provide an accurate description of these potentials-of-mean-force. Since literature results indicate that dielectric models can be helpfully accurate on a coarse, or chemical energy scale, we consider how they might be based more firmly on molecular theory. The objective is a parameterization better controlled by molecular principles and thus better adapted to the prediction of quantities of physical interest. Such a result might be expected to describe better the thermal-level energy changes associated with simple molecular rearrangements, i.e. ion pair potentials-of-mean-force. We note that linear dielectric models correspond to modelistic implementations of second-order thermodynamic perturbation theory for the excess chemical potential of a distinguished solute molecule at infinite dilution. Therefore, the molecular theory corresponding to the dielectric models is second-order thermodynamic perturbation theory for that excess chemical potential. Examination of the required formulae indicate that this corresponding molecular theory should be quite amenable to computational implementation. The second-order, or fluctuation, term raises a technical computational issue of treatment of long-ranged interactions similar to the one which arises in calculation of the dielectric constant of the solvent. Satisfactory calculation of that term will require additional theoretical consideration of those issues. It is contended that the most important step for further development of dielectric models would be a separate assessment of the first-order perturbative term (equivalently the potential at zero charge) which Vanishes in the dielectric models but is generally nonzero. Parameterization of radii and molecular volumes should then be based on the second-order perturbative term alone. Illustrative initial calculations are presented and discussed. RP PRATT, LR (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Pratt, Lawrence/H-7955-2012; Hummer, Gerhard/A-2546-2013 OI Pratt, Lawrence/0000-0003-2351-7451; Hummer, Gerhard/0000-0001-7768-746X NR 46 TC 111 Z9 111 U1 1 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD AUG PY 1994 VL 51 IS 2-3 BP 147 EP 165 DI 10.1016/0301-4622(94)00057-3 PG 19 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA PA335 UT WOS:A1994PA33500005 ER PT J AU GRUJIC, D STREZOSKA, Z CRKVENJAKOV, R AF GRUJIC, D STREZOSKA, Z CRKVENJAKOV, R TI HIGH-THROUGHPUT PCR PROCEDURE FOR UP TO 6-KB LENGTHS OF DNA SO BIOTECHNIQUES LA English DT Note ID HYBRIDIZATION C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 7 TC 3 Z9 3 U1 0 U2 0 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD AUG PY 1994 VL 17 IS 2 BP 291 EP & PG 0 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PA948 UT WOS:A1994PA94800022 PM 7980930 ER PT J AU DRMANAC, S DRMANAC, R AF DRMANAC, S DRMANAC, R TI PROCESSING OF CDNA AND GENOMIC KILOBASE-SIZE CLONES FOR MASSIVE SCREENING, MAPPING AND SEQUENCING BY HYBRIDIZATION SO BIOTECHNIQUES LA English DT Article ID POLYMERASE CHAIN-REACTION; LARGE-SCALE; COMPLEX GENOMES; DNA; LIBRARIES; STRATEGY; PCR; AMPLIFICATION; CONSTRUCTION; PLAQUES AB Efficient procedures for managing a large number of M13 or plasmid clones have been developed. In addition to picking, clones are directly arrayed in multiwell plates by dispensing diluted transfor mation mixtures. Metal pin arrays are used for fast inoculations of preparative plates filled by medium or by PCR mixture. Growth of M13 clones in multiwell plates is optimized to obtain a consistently high yield, and a PCR protocol is defined for reliable amplification of several thousand M13 ol plasmid inserts per day in BioOvens. Over 80000 cDNA inserts have been amplified. The phages or amplified inserts are spotted on nylon filters using an array of pins having a flat bottom, 0.3 mm in diameter The procedures are suitable for an automated processing of hundreds of thousands of short clones from representative cDNA and genomic libraries. Hybridization of arrayed clones with oligonucleotide and complex probes can simplify the search for new genes and accelerate large-scale sequencing. C1 ARGONNE NATL LAB,INTEGRAL GENET GRP,ARGONNE,IL 60439. NR 44 TC 27 Z9 28 U1 0 U2 6 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD AUG PY 1994 VL 17 IS 2 BP 328 EP & PG 0 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PA948 UT WOS:A1994PA94800029 PM 7980937 ER PT J AU SOUTHWORTH, GR PETERSON, MJ ADAMS, SM BLAYLOCK, BG AF SOUTHWORTH, GR PETERSON, MJ ADAMS, SM BLAYLOCK, BG TI ESTIMATION OF APPROPRIATE BACKGROUND CONCENTRATIONS FOR ASSESSING MERCURY CONTAMINATION IN FISH SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID LARGEMOUTH BASS; LAKES; RIVER RP SOUTHWORTH, GR (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,BLDG 1505,MS 6036,OAK RIDGE,TN 37831, USA. NR 16 TC 10 Z9 10 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD AUG PY 1994 VL 53 IS 2 BP 211 EP 218 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA NQ337 UT WOS:A1994NQ33700007 PM 8086702 ER PT J AU HUTCHINGS, L AF HUTCHINGS, L TI KINEMATIC EARTHQUAKE MODELS AND SYNTHESIZED GROUND MOTION USING EMPIRICAL GREENS-FUNCTIONS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-FERNANDO EARTHQUAKE; HIGH-FREQUENCY RADIATION; RUPTURE; FAULT; WAVE; SIMULATION; SPECTRA; STRESS AB In order to improve computer simulations of earthquakes and computations of ground motions, the primary goals of this study are to: (1) examine the effect of a range of kinematic rupture models and rupture parameters on synthesized seismograms, (2) examine the theoretical relationship between rupture models and synthesized seismograms, and (3) demonstrate that simple kinematic earthquake models, used with empirical Green's functions, can be used to predict very realistic seismograms. Earthquake models and synthesized seismograms are examined by computing ground motion for the 1971 San Fernando earthquake (M(L) = 6.4) and for two aftershocks (M(L) = 3.3 and 3.5). Well-constrained source parameters and Green's functions allow a controlled examination of rupture models and rupture parameters. Seismograms are synthesized for the full wave train on three components and for frequencies of 0.5 to 25.0 Hz and are compared to observed seismograms as a guide to indicate whether the models are realistic. The examination of rupture models and rupture parameters show that: (1) variations in modeled rupture velocity and rise times most greatly affect the waveforms and amplitudes of synthesized waveforms; (2) the shape of the slip function is not critical to match observed seismograms; (3) only a narrow range of rupture parameters result in realistic synthetic seismograms; (4) simple source models are sufficient to provide good matches to observed seismograms; (5) a simple interpolation scheme for empirical Green's functions is sufficient to match observed seismograms; and (6) the best rupture model for simulating earthquakes is a Kostrov slip model with healing that results in a smooth variation of slip amplitudes, and a distribution of rise times that results in a constant stress drop for most of the fault surface; randomly distributed areas of shortened rise times, resulting in higher stress drops, improve synthesis above 10 Hz. Theoretical and numerical solutions for the representation relation show that: (1) spectral fall-off of the synthesized seismograms is controlled by the phase delays resulting from rupture parameters; (2) moderately complicated source pulse shapes result from simple rupture models, and the high complexity of synthesized seismograms is primarily a result of the empirical Green's functions; (3) high-frequency arrivals are generated by simple fault rupture models that violate accepted hypotheses that require spatial variations in either stress drop, rupture velocity, or slip rate; and (4) only Haskell rupture models are subject to previously published results that the empirical Green's function synthesis method leads to deficiencies of the Fourier amplitude spectra. RP HUTCHINGS, L (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 55 TC 45 Z9 47 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1994 VL 84 IS 4 BP 1028 EP 1050 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800005 ER PT J AU HARRIS, DB DSPAIN, G GOLDNER, A AF HARRIS, DB DSPAIN, G GOLDNER, A TI REGIONAL OBSERVATION OF A NUCLEAR TEST FROM A VERTICLE HYDROPHONE ARRAY SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID DEPTH DEPENDENCE; AMBIENT NOISE; FIELD AB In order to evaluate the potential of water-column vertical hydrophone arrays for the measurement of continental events at regional distances, ocean acoustic data bases were examined for arrivals from these types of events. In 1987, the nuclear test LOCKNEY (m(b) 5.7, 37.28-degrees-N 116.38-degrees-W) was observed in the deep-ocean water column at a range of 900 km by the Vertical Line Array (VLA) at 35-degrees-N 126-degrees-W. Although the hydrophone data were contaminated below 10 Hz by array suspension noise and ocean acoustic noise, adaptive array processing allows us to extract the P and T phases. The root-mean-square (rms) direct P-wave amplitude in the water column is 100.6 dB referenced to 1 muPa in the 4- to 8-Hz band in a 20-sec window, which suggests a detection threshold of m(b) 5.2 in a deep oceanic environment at this range for a single hydrophone. The arrival time of the T phase [i.e., the portion of seismic energy that has somehow coupled into, and propagated within, the deep ocean sound channel (Aki and Richards, 1980)] is consistent with a P-wave conversion at the continental margin, assuming a velocity of 6 km/sec from NTS to the continental margin and acoustic propagation at 1.5 km/sec in the water column from the continent to the array. C1 UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92106. RP HARRIS, DB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 2 Z9 3 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD AUG PY 1994 VL 84 IS 4 BP 1148 EP 1153 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PC608 UT WOS:A1994PC60800014 ER PT J AU GARTEN, CT VANMIEGROET, H AF GARTEN, CT VANMIEGROET, H TI RELATIONSHIPS BETWEEN SOIL-NITROGEN DYNAMICS AND NATURAL N-15 ABUNDANCE IN PLANT FOLIAGE FROM GREAT SMOKY MOUNTAINS NATIONAL-PARK SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Article ID RED SPRUCE; SOLUTION CHEMISTRY; FOREST ECOSYSTEMS; NITRIFICATION; SATURATION; DENITRIFICATION; FRACTIONATION; AVAILABILITY; VARIABILITY; DEPOSITION AB We tested the hypothesis that naturally occurring nitrogen (N) isotope ratios in foliage (from plants that do not symbiotically fix atmospheric N-2) are an indicator of soil N dynamics in forests. Replicate plots were established at eight locations ranging in elevation from 615 to 1670 m in Great Smoky Mountains National Park in eastern Tennessee, U.S.A. The locations selected ranged from N-poor (low-elevation) to N-rich (high-elevation) forest stands. Soils were sampled in June 1992; plants, forest floors, and upper mineral soils were sampled in August 1992. Net N mineralization and net nitrification potentials for surface mineral soils and organic matter layers at each site were determined by aerobic laboratory incubations. Soils and organic layers from high-elevation sites had greater net N mineralization and nitrification potentials than soils from low-elevation sites. There were significant (P less than or equal to 0.05) differences between study sites in soil N-15 abundance. Therefore, we examined correlations between measures of soil N availability and both mean foliar delta(15)N values and mean enrichment factors (epsilon(p-s) = delta(15)N(leaf) - delta(15)N(soil)). In evergreens, maples, and ferns, mean foliar delta(15)N values and mean enrichment factors were positively correlated with net N mineralization and net nitrification potentials in soil. The observed relationships between natural N-15 abundance in plant leaves and soil N availability were explained by a simple model of soil N dynamics. The model predicts how the isotopic composition of plant N is affected by the following factors: (i) varying uptake of soil NH4-N and NO3-N, (ii) the isotopic composition of different soil N pools, and (iii) relative rates of soil N transformations. C1 UTAH STATE UNIV,DEPT FOREST RESOURCES,LOGAN,UT 84322. RP GARTEN, CT (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Van Miegroet, Helga/A-1925-2012 NR 37 TC 130 Z9 137 U1 1 U2 28 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0045-5067 J9 CAN J FOREST RES JI Can. J. For. Res.-Rev. Can. Rech. For. PD AUG PY 1994 VL 24 IS 8 BP 1636 EP 1645 DI 10.1139/x94-212 PG 10 WC Forestry SC Forestry GA QA527 UT WOS:A1994QA52700014 ER PT J AU MEZZINA, M EVENO, E CHEVALLIERLAGENTE, O BENOIT, A CARREAU, M VERMEULEN, W HOEIJMAKERS, JHJ STEFANINI, M LEHMANN, AR WEBER, CA SARASIN, A AF MEZZINA, M EVENO, E CHEVALLIERLAGENTE, O BENOIT, A CARREAU, M VERMEULEN, W HOEIJMAKERS, JHJ STEFANINI, M LEHMANN, AR WEBER, CA SARASIN, A TI CORRECTION BY THE ERCC2 GENE OF UV SENSITIVITY AND REPAIR DEFICIENCY PHENOTYPE IN A SUBSET OF TRICHOTHIODYSTROPHY CELLS SO CARCINOGENESIS LA English DT Article ID COMPLEMENTATION GROUP-D; CHLORAMPHENICOL ACETYLTRANSFERASE GENE; XERODERMA-PIGMENTOSUM; DNA-REPAIR; COCKAYNES-SYNDROME; EUKARYOTIC CELLS; EXPRESSION; HELICASE; DEFECT; ASSAY AB Trichothiodystrophy (TTD) is a rare genetic disease with heterogeneous clinical features associated with specific deficiencies in nucleotide excision repair. Patients have brittle hair due to a reduced content of cysteine-rich matrix proteins, About 50% of the cases reported in the literature are photosensitive. In these patients an altered cellular response to UV, due to a specific deficiency in nucleotide excision repair, has been observed. The majority of repair-defective TTD patients have been assigned by complementation analysis to group D of xeroderma pigmentosum (XP). Recently, the human excision repair gene ERCC2 has been shown to correct the UV sensitivity of XP-D fibroblasts. In this work we describe the effect of ERCC2 on the DNA repair deficient phenotype of XP-D and on two repair-defective TTD cell strains (TTD1VI and TTD2VI) assigned by complementation analysis to group D of XP. ERCC2 cDNA, cloned into a mammalian expression vector, was introduced into TTD and XP fibroblasts via DNA-mediated transfection or microneedle injection. UV sensitivity and cellular DNA repair properties, including unscheduled DNA synthesis and reactivation of a UV-irradiated plasmid;containing the chloramphenicol acetyltransferase reporter gene (pRSVCat), were corrected to wild-type level in both TTD and XP-D cells. These data show that a functional ERCC2 gene is sufficient to reestablish a wild-type DNA repair phenotype in TTD1VI and TTD2VI cells, confirming the genetic relationship between TTD and XP-D. Furthermore, our findings suggest that mutations at the ERCC2 locus are responsible for causing a similar phenotype in TTD and XP-D cells in response to UV irradiation, but produce quite different clinical symptoms. C1 ERASMUS UNIV ROTTERDAM, DEPT CELL BIOL & GENET, 3000 DR ROTTERDAM, NETHERLANDS. CNR, IST GENET BIOCHIM & EVOLUZIONIST, I-27100 PAVIA, ITALY. UNIV SUSSEX, MRC, CELL MUTAT UNIT, BRIGHTON BN1 9RR, ENGLAND. LAWRENCE LIVERMORE NATL LAB, BIOL & BIOTECHNOL RES PROGRAM, LIVERMORE, CA 94550 USA. RP MEZZINA, M (reprint author), LAB MOLEC GENET, CNRS, UPR 42, IFC H01, BP 8, F-94801 VILLEJUIF, FRANCE. NR 39 TC 21 Z9 21 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD AUG PY 1994 VL 15 IS 8 BP 1493 EP 1498 DI 10.1093/carcin/15.8.1493 PG 6 WC Oncology SC Oncology GA PC325 UT WOS:A1994PC32500004 PM 8055625 ER PT J AU DECOLSTOUN, FB KHITROVA, G FEDOROV, AV NELSON, TR LOWRY, C BRENNAN, TM HAMMONS, BG MAKER, PD AF DECOLSTOUN, FB KHITROVA, G FEDOROV, AV NELSON, TR LOWRY, C BRENNAN, TM HAMMONS, BG MAKER, PD TI TRANSVERSE-MODES, VORTICES AND VERTICAL-CAVITY SURFACE-EMITTING LASERS SO CHAOS SOLITONS & FRACTALS LA English DT Article ID OPTICAL VORTEX SOLITONS; SPATIOTEMPORAL STRUCTURES; PHASE SINGULARITIES; PATTERNS; POLARIZATION; STABILITY; CO2-LASER; EMISSION; BEAMS AB Injection locking dramatically modifies the phase and transverse output intensity profile of vertical-cavity surface-emitting lasers (VCSELs). Injection can induce a VCSEL to emit a high-order transverse mode. Vortices are generated by three different methods: insertion of a helicoidal phase mask, interference of two Gaussian beams, and injection locking of the TEM(01) and TEM(01) modes of a VCSEL to form the TEM*(01) donut mode. The first two methods stem from geometrical optics; the third method involves nonlinear mode competition in the laser cavity. C1 SANDIA NATL LABS,DEPT 1311,ALBUQUERQUE,NM 87185. CALTECH,JET PROP LAB,PASADENA,CA 91109. SI VAVILOV STATE OPT INST,ST PETERSBURG 199034,RUSSIA. DIRNSA,FORT GG MEADE,MD 20755. RP DECOLSTOUN, FB (reprint author), UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721, USA. NR 39 TC 40 Z9 40 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD AUG-SEP PY 1994 VL 4 IS 8-9 BP 1575 EP 1596 DI 10.1016/0960-0779(94)90098-1 PG 22 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA PV522 UT WOS:A1994PV52200019 ER PT J AU WRIGHT, EM CHIAO, RY GARRISON, JC AF WRIGHT, EM CHIAO, RY GARRISON, JC TI OPTICAL ANYONS - ATOMS TRAPPED ON ELECTROMAGNETIC VORTICES SO CHAOS SOLITONS & FRACTALS LA English DT Article ID TWO-DIMENSIONAL SUPERFLUIDS; COLD CESIUM ATOMS; FRACTIONAL STATISTICS; QUANTUM-MECHANICS; ANGULAR-MOMENTUM; QUANTIZED MOTION; MAGNETIC-FLUX; SPIN; PARTICLES; DYNAMICS AB We study composite particles consisting of an atom trapped on an electromagnetic vortex. The vortex core acts as a guiding center for the atom, so that the atom-vortex composite will be maintained under sufficiently gentle motions of the vortex center. We show that the adiabatic exchange of two identical atom-vortex composites generates a nontrivial geometric phase factor, and conclude that these quasiparticles should obey fractional statistics. C1 UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP WRIGHT, EM (reprint author), UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721, USA. RI Wright, Ewan/A-2358-2009 NR 32 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD AUG-SEP PY 1994 VL 4 IS 8-9 BP 1797 EP 1803 DI 10.1016/0960-0779(94)90112-0 PG 7 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA PV522 UT WOS:A1994PV52200033 ER PT J AU COX, R BUTTRY, DA BONNESEN, P RAYMOND, KN AF COX, R BUTTRY, DA BONNESEN, P RAYMOND, KN TI MEASURING TRACE URANIUM SO CHEMTECH LA English DT Article ID QUARTZ CRYSTAL MICROBALANCE; LIGANDS; URANYL C1 UNIV CALIF BERKELEY, BERKELEY, CA 94720 USA. LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, SEPARAT SCI GRP, OAK RIDGE, TN 37831 USA. RP UNIV WYOMING, DEPT CHEM, LARAMIE, WY 82071 USA. RI Bonnesen, Peter/A-1889-2016 OI Bonnesen, Peter/0000-0002-1397-8281 NR 13 TC 6 Z9 6 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 AUG PY 1994 VL 24 IS 8 BP 18 EP 21 PG 4 WC Chemistry, Applied SC Chemistry GA PC589 UT WOS:A1994PC58900004 ER PT J AU SUPERKO, HR KRAUSS, RM AF SUPERKO, HR KRAUSS, RM TI CORONARY-ARTERY DISEASE REGRESSION - CONVINCING EVIDENCE FOR THE BENEFIT OF AGGRESSIVE LIPOPROTEIN MANAGEMENT SO CIRCULATION LA English DT Article DE CHOLESTEROL; LIPOPROTEINS; CORONARY DISEASE; ANGIOGRAPHY ID LOW-DENSITY-LIPOPROTEIN; COLESTIPOL-NIACIN THERAPY; HEART-DISEASE; RISK FACTOR; ATHEROSCLEROSIS-REGRESSION; CARDIOVASCULAR-DISEASE; MYOCARDIAL-INFARCTION; SUBCLASS PATTERNS; BYPASS-SURGERY; STUDY STARS AB Background Numerous reports suggest that coronary artery disease can regress with lipoprotein manipulation. Many of these reports lack control groups and contain relatively small numbers. Methods and Results Ten randomized controlled clinical trials using coronary arteriography to assess the effect of lipoprotein manipulation on the rate of progression and regression of atherosclerosis have been either published or reported as an abstract at a national meeting. These studies were critically reviewed for individual differences and combined clinically applicable lessons. These trials involved a total of 2095 subjects and have consistently reported reduction in the percentage of patients arteriographically defined as progressing (mean, 23.6%) and an increase in the percentage regressing (mean, 20.0%) compared with control groups. Compared with large clinical trials using clinical end points, lipoprotein change was greater, achieving on average a 28% reduction in low-density lipoprotein cholesterol, 11% reduction in triglycerides, and 11% increase in high-density lipoprotein cholesterol compared with control groups. Four investigations used a nonpharmacological approach, and seven used single and multiple drug therapy combined with diet. Despite the relatively brief treatment time of often 2 to 4 years, clinical events were fewer in the treatment groups; within some studies, this reached statistical significance. Side effects from the different therapies were tolerated by most patients, and severe adverse clinical events were few. Conclusions These trials present convincing evidence that aggressive lipoprotein manipulation can result in improved arteriographic measurements and fewer cardiovascular events in a relatively short period of time of 2 to 4 years. Extrapolation of this information to the larger population with known coronary artery disease suggests that directed lipoprotein manipulation can reduce clinical events in a cost-effective manner. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. OI Superko, H. Robert/0000-0002-3542-0393 FU NHLBI NIH HHS [HL-18574] NR 74 TC 138 Z9 141 U1 0 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD AUG PY 1994 VL 90 IS 2 BP 1056 EP 1069 PG 14 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA PA963 UT WOS:A1994PA96300055 PM 8044919 ER PT J AU ESPOSITO, G MIELE, G ROSA, L AF ESPOSITO, G MIELE, G ROSA, L TI ONE-LOOP EFFECTIVE POTENTIAL FOR SO(10) GUT THEORIES IN DESITTER SPACE SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID LEFT-RIGHT SYMMETRY; DE-SITTER SPACE; UNIFICATION; UNIVERSE; BREAKING; BROKEN; MODELS AB Zeta-function regularization is applied to the evaluation of the one-loop effective potential for SO(10) grand unified theories in de Sitter cosmologies. When the Higgs scalar field belongs to the 210-dimensional irreducible representation of SO(10), attention is focused on the mass matrix relevant for the SU(3) X SU(2) X U(1) symmetry-breaking direction, to agree with the low-energy phenomenology of the standard model of particle physics. The analysis is restricted to those values of the tree-level potential parameters for which the absolute minimum of the classical potential has been evaluated. As shown in the recent literature, such minima turn out to be SO(6) X SO(4) or SU(3) X SU(2) X U(1) invariant. Electroweak phenomenology is more naturally derived, however, from the former minima. Hence the values of the parameters leading to the alternative set of minima have been discarded. Within this framework, the flat-space limit and the general form of the one-loop effective potential are studied in detail by using analytic and numerical methods. It turns out that, as far as the absolute-minimum direction is concerned, the flat-space limit of the one-loop calculation with a de Sitter background does not change the results previously obtained in the literature, where the tree-level potential in flat spacetime was studied. Moreover, even when curvature effects are no longer negligible in the one-loop potential, it is found that the early universe can only reach the SO(6) X SO(4) absolute minimum. C1 DIPARTIMENTO SCI FIS,I-80125 NAPLES,ITALY. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP ESPOSITO, G (reprint author), IST NAZL FIS NUCL,MOSTRA OLTREMARE PADIGL 20,I-80125 NAPLES,ITALY. RI Miele, Gennaro/F-3628-2010; Rosa, Luigi/K-3869-2015; Esposito, Giampiero/H-3405-2012 OI Miele, Gennaro/0000-0002-2028-0578; Rosa, Luigi/0000-0002-5595-5037; Esposito, Giampiero/0000-0001-5930-8366 NR 18 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD AUG PY 1994 VL 11 IS 8 BP 2031 EP 2044 DI 10.1088/0264-9381/11/8/010 PG 14 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PE557 UT WOS:A1994PE55700010 ER PT J AU GOIX, PJ EDWARDS, CF CESSOU, A DUNSKY, CM STEPOWSKI, D AF GOIX, PJ EDWARDS, CF CESSOU, A DUNSKY, CM STEPOWSKI, D TI STRUCTURE OF A METHANOL AIR COAXIAL REACTING SPRAY NEAR THE STABILIZATION REGION SO COMBUSTION AND FLAME LA English DT Article ID DROPLET VAPORIZATION; COMBUSTION; VELOCITY; ANALYZER; SIZE AB Planar laser Mie scattering, planar laser-induced fluorescence and two component phase-doppler interferometry have been used to study the reaction zone structure near the stabilization region of a coaxial methanol/air spray flame. The configuration of the experiment was chosen to approximate the atomizer geometry, surface tension and Weber number of a single coaxial rocket injector. The measurements are made in a water-cooled, optically accessible confinement chamber at a pressure of 1 atm. Data are reported for two atomizing air velocity conditions. One yields a flame length of approximately 1 m, the other, half that value. Both the Weber number (characterizing the atomization process) and the Reynolds number (characterizing the gas-phase mixing process) vary between the cases, but the data suggest that it is the Weber number which has the dominant effect. In both cases OH imaging shows that the reaction zone is confined to a narrow region, with the OH field being similar in appearance to that of a single-phase turbulent mixing-controlled (diffusion) flame. Size-classified mean velocity vectors derived from the phase-doppler data show striking differences in the flow pattern for low and high Stokes number droplets. Droplets 5 mum in diameter and below (Stokes number less than 3) appear to follow the recirculating eddies that provide flame stabilization while droplets of large Stokes number travel ballistically through the flow. Increasing the Weber number by a factor of 2.5 decreased the Sauter mean diameter of the spray by as much as one-third, and the arithmetic mean diameter by as much as one-half. We believe that it is this decrease in the spray droplet diameter that is primarily responsible for the very different flame lengths in the two cases. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. CORIA,CNRS,URA 230,F-76134 MONT ST AIGNAN,FRANCE. NR 23 TC 16 Z9 16 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD AUG PY 1994 VL 98 IS 3 BP 205 EP 219 DI 10.1016/0010-2180(94)90236-4 PG 15 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA PA048 UT WOS:A1994PA04800004 ER PT J AU LAIRD, G KENNEDY, TC AF LAIRD, G KENNEDY, TC TI MICROMECHANICS OF IMPERFECT INTERFACES IN HETEROGENEOUS MATERIALS SO COMPOSITES LA English DT Article; Proceedings Paper CT 3rd International Conference on Interfacial Phenomena in Composite Materials CY SEP 13-16, 1993 CL CAMBRIDGE, ENGLAND SP UNIV CAMBRIDGE, ROBINSON COLL DE MICROMECHANICS; INTERFACES; HETEROGENEOUS MATERIALS ID SILICON-CARBIDE WHISKERS; MATRIX COMPOSITES; INCLUSION; TEMPERATURE; PARTICLES; BEHAVIOR; CERAMICS AB In the design of strong engineered materials containing fibres or particulates to be used for impact and abrasive wear, one important problem is the magnitude of the stress concentration around these second-phase constituents. Analytical solutions for cylindrical and spherical inclusions embedded within infinite matrices are reviewed and assessed for their value in predicting the constitutive behaviour of heterogeneous materials. Solutions for two distinct interfacial behaviours are found in the literature: (1 ) radial displacement and stress continuity with zero shear stress across the interface (i.e. frictionless); and (2) an elastic interface (modelled as a very thin interfacial elastic layer) capable of supporting both normal and tangential displacements and stresses. However, both of these approaches incorporate constitutive behaviour that would be considered incompatible for real materials (e.g. interpenetration between reinforcement and matrix). In this study, finite element models are developed without these limitations and their results (stress concentration factors) are compared with analytically derived solutions. It is shown that for certain load cases analytical solutions inadequately model the idealized micromechanical behaviour of heterogeneous materials. C1 OREGON STATE UNIV,DEPT MECH ENGN,CORVALLIS,OR 97331. RP LAIRD, G (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 30 TC 6 Z9 6 U1 2 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0010-4361 J9 COMPOSITES JI Composites PD AUG PY 1994 VL 25 IS 7 BP 593 EP 603 DI 10.1016/0010-4361(94)90189-9 PG 11 WC Materials Science, Composites SC Materials Science GA NW025 UT WOS:A1994NW02500021 ER PT J AU YANG, KT XIA, Q NICOLETTE, VF AF YANG, KT XIA, Q NICOLETTE, VF TI SIMULATION OF STRONG TURBULENT BUOYANT FLOW IN A VENTED COMPLEX ENCLOSURE SO COMPUTATIONAL MECHANICS LA English DT Article AB A three-dimensional field model for turbulent flow in an arbitrary compartment, taking into account strong buoyancy, full compressibility, turbulence, surface-surface radiation exchange, and wall heat losses is utilized to simulate a full-scale fire test in a fire room with open doorways located in a decommissioned nuclear reactor containment vessel in Germany. Results show that reasonable agreement in the numerical and test data in the unsteady temperature field at three locations inside the fire room was obtained, even though the numerical simulation underestimated the doorway instantaneous exit velocities by as much as 40%. The discrepancies are discussed in terms of both test uncertainties and adequacy of the physical submodels utilized in the field model. C1 SANDIA NATL LABS,THERMAL & FLUID ENGN,ALBUQUERQUE,NM 87185. RP YANG, KT (reprint author), UNIV NOTRE DAME,DEPT AEROSP & MECH ENGN,NOTRE DAME,IN 46556, USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD AUG PY 1994 VL 14 IS 5 BP 468 EP 479 DI 10.1007/BF00377599 PG 12 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA PC719 UT WOS:A1994PC71900007 ER PT J AU TABORMORRIS, AE RUPP, B AF TABORMORRIS, AE RUPP, B TI SEXIE 3.0 - AN UPDATED COMPUTER-PROGRAM FOR THE CALCULATION OF COORDINATION SHELLS AND GEOMETRIES SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID ABSORPTION FINE-STRUCTURE; SCATTERING AB We report a new version of our FORTRAN program SEXIE (ACBV). New features permit interfacing to related programs for EXAFS calculations (FEFF by J.J. Rehr et al.) and structure visualization (SCHAKAL by E. Keller). The code has been refined and the basis transformation matrix from fractional to cartesian coordinates has been corrected and made compatible with IUCr (International Union for Crystallography) standards. We discuss how to determine the correct space group setting and atom position input. New examples for Unix script files are provided. C1 LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550. UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. OI Tabor-Morris, Anne/0000-0002-1395-5717 NR 13 TC 1 Z9 1 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 AUG PY 1994 VL 82 IS 1 BP 23 EP 29 DI 10.1016/0010-4655(94)90128-7 PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PC320 UT WOS:A1994PC32000003 ER PT J AU JONES, MT PLASSMANN, PE AF JONES, MT PLASSMANN, PE TI COMPUTATIONAL RESULTS FOR PARALLEL UNSTRUCTURED MESH COMPUTATIONS SO COMPUTING SYSTEMS IN ENGINEERING LA English DT Article; Proceedings Paper CT 3rd National Symposium on Large-Scale Structural Analysis for High-Performance Computers and Workstations CY NOV 08-11, 1994 CL NORFOLK, VA ID NONUNIFORM AB The majority of finite element models in structural engineering are composed of unstructured meshes. These unstructured meshes are often very large and require significant computation resources; hence they are excellent candidates for massively parallel computation. Parallel solution of the sparse matrices that arise from such meshes has been studied heavily, and many good algorithms have been developed. Unfortunately, many of the other aspects of parallel unstructured mesh computation have gone largely ignored. We present a set of algorithms that all the entire unstructured mesh computation process to execute in parallel-including adaptive mesh refinement, equation reordering, mesh partitioning, and sparse linear system solution. We briefly describe these algorithms and state results regarding their running-time and performance. We then give results from the 512-processor Intel DELTA for a large-scale structural analysis problem. The results demonstrate that the new algorithms are scalable and efficient. The algorithms are able to achieve up to 2.2 gigaflops for this unstructured mesh problem. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. RP JONES, MT (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. NR 25 TC 30 Z9 30 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-0521 J9 COMPUT SYST ENG JI Comput. Syst. Eng. PD AUG-DEC PY 1994 VL 5 IS 4-6 BP 297 EP 309 DI 10.1016/0956-0521(94)90013-2 PG 13 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA RA471 UT WOS:A1994RA47100002 ER PT J AU MAKER, BN QIN, JN NGUYEN, DT AF MAKER, BN QIN, JN NGUYEN, DT TI PERFORMANCE OF NIKE3D WITH PVSOLVE ON VECTOR AND PARALLEL COMPUTERS SO COMPUTING SYSTEMS IN ENGINEERING LA English DT Article; Proceedings Paper CT 3rd National Symposium on Large-Scale Structural Analysis for High-Performance Computers and Workstations CY NOV 08-11, 1994 CL NORFOLK, VA AB The cost of large implicit finite element calculations is dominated by the linear equation solver. In this work, several versions of the direct linear equation solver PVSOLVE were implemented in the general purpose, nonlinear finite element code NIKE3D. Timing studies were performed on Sun and IBM workstations, CRAY Y/MP and C90 supercomputers, and the distributed memory MEIKO CS-2 parallel computer. Cost breakdowns and efficiency curves are presented for a benchmark problem with several mesh densities. The distributed memory implementation is shown to be most efficient for large problems, where MEIKO performance is comparable to that of a single CRAY processor. C1 OLD DOMINION UNIV,CTR MULTIDISCIPLINARY PARALLEL VECTOR COMPUTAT,NORFOLK,VA 23529. RP MAKER, BN (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-0521 J9 COMPUT SYST ENG JI Comput. Syst. Eng. PD AUG-DEC PY 1994 VL 5 IS 4-6 BP 363 EP 368 DI 10.1016/0956-0521(94)90018-3 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA RA471 UT WOS:A1994RA47100007 ER PT J AU TURNER, MG WU, YA WALLACE, LL ROMME, WH BRENKERT, A AF TURNER, MG WU, YA WALLACE, LL ROMME, WH BRENKERT, A TI SIMULATING WINTER INTERACTIONS AMONG UNGULATES, VEGETATION, AND FIRE IN NORTHERN YELLOWSTONE PARK SO ECOLOGICAL APPLICATIONS LA English DT Article DE BISON; BISON BISON; CERVUS-ELAPHUS; ELK; FIRE; LANDSCAPE ECOLOGY; SIMULATION MODELING; SNOW; SPATIAL SCALE OR PATTERN; UNGULATES; WINTER SEVERITY; YELLOWSTONE-NATIONAL-PARK ID MULE DEER; ENERGY EXPENDITURES; TALLGRASS PRAIRIE; NATIONAL-PARK; LARGE MAMMALS; ELK; BISON; GRASS; ECOLOGY; SNOW AB The interaction of large-scale fire, vegetation, and ungulates is an important management issue in Yellowstone National Park. A spatially explicit individual-based simulation model was developed to explore the effects of fire scale and pattern on the winter foraging dynamics and survival of free-ranging elk (Cervus elaphus) and bison (Bison bison) in northern Yellowstone National Park. The Northern Yellowstone Park (NOYELP) model simulates the search, movement, and foraging activities of individuals or small groups of elk 'and bison. The 77 020-ha landscape is represented as a gridded irregular polygon with a spatial resolution of 1 ha. Forage intake is a function of an animal's initial body mass, the absolute amount of forage available on a site, and the depth and density of snow. When the energy expenditures of an animal exceed the energy gained during a day, the animal's endogenous reserves are reduced to offset the deficits. Simulations are conducted with a 1-d time step for a duration of 180 d, almost-equal-to 1 November through the end of April. Simulated elk survival for three winters (1987-1988; 1988-1989; 1990-199 1) agreed with observed data. A factorial simulation experiment was conducted to explore the effects on ungulate survival of fire size, fire pattern, and winter severity during an initial postfire winter (when no forage is available in burned areas) and a later postfire winter (when forage is enhanced in burned areas). Initial ungulate population sizes were held constant at 18 000 elk and 600 bison. Winter severity played a dominant role in ungulate survival. When winter conditions were extremely mild, even fires that affected 60% of the landscape had no effect on ungulate-survival during the initial postfire winter. The effects of fire on ungulate survival become important when winter conditions were average to severe, and effects were apparent in both the initial and later postfire winters. The spatial patterning of fire influenced ungulate survival if fires covered small to moderate proportions of the landscape (e.g., 15% or 30%) and if winter snow conditions were moderate to severe. Ungulate survival was higher with a clumped than with a fragmented fire pattern, suggesting that a single, large fire is not equivalent to a group of smaller disconnected fires. The interaction between fire scale and spatial pattern suggests that knowledge of fire size alone is not always sufficient to predict ungulate survival. C1 UNIV OKLAHOMA,DEPT BOT & MICROBIOL,NORMAN,OK. FT LEWIS COLL,DEPT BIOL,DURANGO,CO 81301. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP TURNER, MG (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Turner, Monica/B-2099-2010; Romme, William/C-7317-2016 NR 79 TC 108 Z9 111 U1 4 U2 37 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1994 VL 4 IS 3 BP 472 EP 486 DI 10.2307/1941951 PG 15 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA NZ308 UT WOS:A1994NZ30800007 ER PT J AU JONES, RH SHARITZ, RR DIXON, PM SEGAL, DS SCHNEIDER, RL AF JONES, RH SHARITZ, RR DIXON, PM SEGAL, DS SCHNEIDER, RL TI WOODY PLANT-REGENERATION IN 4 FLOODPLAIN FORESTS SO ECOLOGICAL MONOGRAPHS LA English DT Article DE ACER-RUBRUM; BOTTOMLAND HARDWOOD FOREST; DEMOGRAPHY; FLOODPLAIN FORESTS; FOREST REGENERATION; LIFE HISTORY TRAITS; LIQUIDAMBAR-STYRACIFLUA; NYSSA-SYLVATICA VAR BIFLORA; POPULATION DYNAMICS; QUERCUS SPP; SEED SIZE; SEEDLING RECRUITMENT; SHADE TOLERANCE ID OLD-FIELD SUCCESSION; TREE ESTABLISHMENT; SEEDLING SURVIVAL; TROPICAL FORESTS; TUPELO SWAMP; DYNAMICS; MAINTENANCE; MECHANISMS; VEGETATION; EMERGENCE AB Between 1987 and 1990, we estimated seedfall and recorded age, growth, and survival of 10 933 tree and vine seedlings growing in the understories of four bottomland hardwood forests in South Carolina. The forests differed in flood frequency, soils, and vegetation structure but had a number of woody plant species in common. Several demographic processes were consistent for all four forests as well as for floodplain forests described in other published studies. Smaller seeded species had larger numbers of seeds dispersed, germinants, and established seedlings. Seed size, however, was not clearly related to seedling survival. Published rankings of shade and flood tolerances were also unrelated to survival, at least during the first growing season after germination. Seedling survival rates were least during the first growing season and greater in subsequent years. Within a growing season, early germinants had greater survival. For some species, survival was negatively related to basal area of neighboring conspecific adult trees. Some aspects of the regeneration process were more site specific. Within species, seedfall densities relative to adult tree abundance differed across forests by an order of magnitude. First-year seedling mortality rates were significantly affected by site and site x species interactions. Mortality in subsequent years was also significantly affected by site. Although the role of flooding in site-specific mortality was not clear, small elevation changes within flooded sites were correlated with changes in germination and survival for some species. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. UNIV GEORGIA,DEPT BOT,ATHENS,GA 30602. KBN ENGN & APPL SCI,GAINESVILLE,FL 32605. CORNELL UNIV,DEPT ECOL,ITHACA,NY 14853. RP JONES, RH (reprint author), AUBURN UNIV,SCH FORESTRY,AUBURN,AL 36849, USA. NR 61 TC 131 Z9 142 U1 1 U2 24 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9615 J9 ECOL MONOGR JI Ecol. Monogr. PD AUG PY 1994 VL 64 IS 3 BP 345 EP 367 DI 10.2307/2937166 PG 23 WC Ecology SC Environmental Sciences & Ecology GA NX850 UT WOS:A1994NX85000004 ER PT J AU VALLET, CE WHITE, CW AF VALLET, CE WHITE, CW TI ELECTROCATALYST SURFACES MODELED BY ION-IMPLANTATION SO ELECTROCHIMICA ACTA LA English DT Article; Proceedings Paper CT International Symposium on Progress in Electrocatalysis: Theory and Practice CY SEP 13-15, 1993 CL FERRARA, ITALY DE CATALYTIC ACTIVITY; CHLORINE EVOLUTION; DSA ANODES; ION IMPLANTATION; REACTION MECHANISMS ID OXIDE-FILMS; TITANIUM ELECTRODES; CHLORINE EVOLUTION; OXYGEN EVOLUTION; ANODIC-OXIDATION; CORROSION; IR; SPECTROSCOPY; ADSORPTION; BEHAVIOR AB A critical parameter in the evaluation of the activity of different catalysts toward one reaction is the estimate of the active sites concentration at the electrode surface. A preparation scheme of models of the dimensionally stable anodes (DSA) is presented which comprises ion-implantation of Ru (Ir) into titanium followed by electrochemical oxidation of the near-surface alloys. Results pertinent to DSA like anodes include the determination of the mechanisms of the Cl-2 evolution reaction and the specific catalytic activities of Ru and Ir. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN. RP VALLET, CE (reprint author), OAK RIDGE NATL LAB,DIV CHEM,POB 2008,OAK RIDGE,TN 37831, USA. NR 51 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD AUG PY 1994 VL 39 IS 11-12 BP 1537 EP 1543 DI 10.1016/0013-4686(94)85132-8 PG 7 WC Electrochemistry SC Electrochemistry GA PC034 UT WOS:A1994PC03400011 ER PT J AU MULLER, S STRIEBEL, K HAAS, O AF MULLER, S STRIEBEL, K HAAS, O TI LA0.6CA0.4COO3 - A STABLE AND POWERFUL CATALYST FOR BIFUNCTIONAL AIR ELECTRODES SO ELECTROCHIMICA ACTA LA English DT Article; Proceedings Paper CT International Symposium on Progress in Electrocatalysis: Theory and Practice CY SEP 13-15, 1993 CL FERRARA, ITALY DE BIFUNCTIONAL AIR ELECTRODE; OXYGEN EVOLUTION; OXYGEN REDUCTION; PEROVSKITE; ELECTROCATALYSIS ID OXYGEN EVOLUTION; PEROVSKITES AB High-surface-area La0.6Ca0.4CoO3 perovskite-type oxides were prepared by the citric and malic acid precursor method. The oxide catalyst was homogeneously dispersed on corrosion-resistant graphitized Vulcan XC 72 carbon powder. A manufacturing process for preparing two-layer Teflon(R)-bonded bifunctional O-2 diffusion electrodes in practical sizes for battery applications was developed. The microstructure and the performance of the electrodes were studied experimentally using electrochemical, physical (mercury porosimetry, BET analyses) and imaging (SEM and EDX) techniques. A cycle life of about 1400h of alternating operation as cathodes and anodes was determined for the bifunctional electrodes. Catalyst dissolution due to erosion of the active surface by-oxygen evolution and partial destruction of the perovskite catalyst appear to be the dominant life-limiting processes. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP MULLER, S (reprint author), PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. NR 12 TC 88 Z9 95 U1 2 U2 29 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD AUG PY 1994 VL 39 IS 11-12 BP 1661 EP 1668 DI 10.1016/0013-4686(94)85151-4 PG 8 WC Electrochemistry SC Electrochemistry GA PC034 UT WOS:A1994PC03400030 ER PT J AU GASTEIGER, HA MARKOVIC, N ROSS, PN CAIRNS, EJ AF GASTEIGER, HA MARKOVIC, N ROSS, PN CAIRNS, EJ TI ELECTROOXIDATION OF SMALL ORGANIC-MOLECULES ON WELL-CHARACTERIZED PT-RU ALLOYS SO ELECTROCHIMICA ACTA LA English DT Article; Proceedings Paper CT International Symposium on Progress in Electrocatalysis: Theory and Practice CY SEP 13-15, 1993 CL FERRARA, ITALY DE ELECTROCATALYSIS; PT-RU ALLOYS; METHANOL; FORMIC ACID; CARBON MONOXIDE ID NOBLE-METAL ELECTRODES; FORMIC-ACID ADSORBATES; ELECTROCATALYTIC OXIDATION; PLATINUM-ELECTRODE; REACTION-PRODUCTS; ANODIC-OXIDATION; METHANOL; ELECTROOXIDATION; CH3OH; HCOOH AB The electro-oxidation of methanol, formic acid, and carbon monoxide in sulfuric acid electrolyte was studied using uhv-prepared polycrystalline Pt-Ru alloy electrodes. The alloys were sputter-cleaned in uhv and the surface composition was determined definitively with low energy ion scattering (LEIS) prior to clean transfer to an electrochemical cell. At the optimum surface composition, the alloys increase the oxidation kinetics of all three molecules by a factor of 5-30 at 25 degrees C. The optimum composition for methanol oxidation was different from that for the other two molecules, 7 at.% and 46 at.% Ru, respectively. The effect of Ru in the Pt surface on the catalysis of oxidation of all three molecules could be rationalized by a bifunctional mechanism. Ru sites nucleate oxygen-containing species at 0.2-0.3 V lower potentials than on the pure Pt surface; the adsorbed carbonaceous species are preferentially oxidized at these sites by surface diffusion from sites where adsorption occurs. Pt-Ru pair sites nucleate a more active form of oxygen-containing species than Ru-Ru pairs or Ru clusters. The optimum surface composition of Ru maximizes the Pt-Ru pair sites within the constraints of the optimum ensemble for adsorption of the molecule. In the case of CO and HCOOH, adsorption is equally facile at Pt-Pt, Ru-Ru and Pt-Ru sites, and the optimum surface composition is 50 at.% Ru. For methanol, the optimum adsorption site is a C-3v Pt ensemble, and the composition which simultaneously maximizes the number of these ensembles and Pt-Ru pairs is approximate to 10 at.% Ru. RP GASTEIGER, HA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM ENGN,BERKELEY,CA 94720, USA. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 27 TC 220 Z9 223 U1 3 U2 33 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD AUG PY 1994 VL 39 IS 11-12 BP 1825 EP 1832 DI 10.1016/0013-4686(94)85171-9 PG 8 WC Electrochemistry SC Electrochemistry GA PC034 UT WOS:A1994PC03400050 ER PT J AU MEYERS, S SALAYF, J SCHIPPER, L AF MEYERS, S SALAYF, J SCHIPPER, L TI ENERGY USE IN A TRANSITIONAL ECONOMY - THE CASE OF POLAND SO ENERGY POLICY LA English DT Article DE ENERGY DEMAND; ENERGY EFFICIENCY; EASTERN EUROPE AB This paper provides a sectoral analysis of how energy use has changed in Poland since the 1970s, with particular emphasis on changes since the country began its transition from a centrally planned to a market economy in 1990. Total final energy use in 1991 was 25% below that in 1988 and the lowest since the mid-1970s. The most important factors behind the large decline in Polish energy use in 1990 were a sharp fall in industrial output and a huge drop in residential coal use driven by higher prices. Energy use declined by only 2% in 1991, which was less than the fail in GDP of 8%. Key factors that lessened the decrease in energy use after 1989 were a rise in energy intensity in many heavy industries and a shift toward greater use of cars and trucks in passenger and freight transport. Higher energy prices have had an evident impact on residential coal use, but in industry there was relatively little sign of energy conservation in 1991. C1 LUND UNIV,DEPT ENVIRONM & ENERGY SYST STUDIES,S-22362 LUND,SWEDEN. RP MEYERS, S (reprint author), LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. NR 23 TC 8 Z9 8 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD AUG PY 1994 VL 22 IS 8 BP 699 EP 713 DI 10.1016/0301-4215(94)90062-0 PG 15 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA PL139 UT WOS:A1994PL13900006 ER PT J AU SKEEN, RS TRUEX, MJ PETERSEN, JN HILL, JS AF SKEEN, RS TRUEX, MJ PETERSEN, JN HILL, JS TI A BATCH REACTOR FOR MONITORING PROCESS DYNAMICS DURING BIODEGRADATION OF VOLATILE ORGANICS SO ENVIRONMENTAL PROGRESS LA English DT Article AB Data are presented that demonstrate a batch reactor that allows accurate monitoring of process dynamics during biodegradation of volatile organics. Using this system, many samples can be removed in a aseptic fashion, allowing frequent measurements of the concentrations of biomass, electron donors, electron acceptors, and volatile compounds. Additionally, the reactor is well instrumented, allowing the continuous monitoring of pH, oxidation/reduction potential, pressure, and temperature. The reactor is constructed entirely of materials which have minimal interaction with volatile organic compounds. It is also demonstrated that sample removal does not cause losses of volatile compounds since the sampling ports are double sealed, making use of both gas-tight stainless steel ball valves and Teflon-lined septa. RP SKEEN, RS (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Petersen, James/B-8924-2008 NR 0 TC 9 Z9 9 U1 0 U2 0 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD AUG PY 1994 VL 13 IS 3 BP 174 EP 177 DI 10.1002/ep.670130312 PG 4 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PC369 UT WOS:A1994PC36900007 ER PT J AU WOLSKY, AM DANIELS, EJ JODY, BJ AF WOLSKY, AM DANIELS, EJ JODY, BJ TI CO2 CAPTURE FROM THE FLUE-GAS OF CONVENTIONAL FOSSIL-FUEL-FIRED POWER-PLANTS SO ENVIRONMENTAL PROGRESS LA English DT Article AB Research has been conducted at Argonne National Laboratory to identify and evaluate the advantages and deficiencies of several technologies, both commercially available and alternative technologies, for capturing CO2 from the flue gas of utility boilers that use air as an oxidant (the current universal practice). The technologies include chemical solvent, cryogenic, membrane, physical absorption, and physical adsorption methods. In general, technologies for capturing CO2 are expensive and energy-intensive. Therefore, they result in a substantial overall increase in the cost of power generation. Research to improve the performance and economics of these technologies is discussed. RP WOLSKY, AM (reprint author), ARGONNE NATL LAB,DIV ENERGY SYST,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 61 Z9 64 U1 0 U2 3 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD AUG PY 1994 VL 13 IS 3 BP 214 EP 219 DI 10.1002/ep.670130318 PG 6 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PC369 UT WOS:A1994PC36900013 ER PT J AU GROSSL, PR SPARKS, DL AINSWORTH, CC AF GROSSL, PR SPARKS, DL AINSWORTH, CC TI RAPID KINETICS OF CU(II) ADSORPTION-DESORPTION ON GOETHITE SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID OXIDE-WATER INTERFACE; SURFACE-IONIZATION; METAL-IONS; COMPLEXATION; DESORPTION; IRON; CU; PB; ZN; CD AB The kinetics of Cu2+ adsorption/desorption on goethite (alpha-FeOOH) was evaluated using the pressure-jump (p-jump) relaxation technique. This technique provides kinetic and mechanistic information for reactions occurring on millisecond time scales. A double relaxation event was observed for Cu2+ adsorption/desorption on goethite. The rate of these relaxations (r) decreased with an increase in pH, along the adsorption edge. The mechanism ascribed to the relaxations is the formation of a monodentate inner-sphere Cu2+/goethite surface complex. The calculated intrinsic rate constant for adsorption (k1'int) was 10(6.81) L mol-1 s-1 and was about 2 orders of magnitude larger than the intrinsic rate constant for desorption (k-1'int = 10(4.88) L mol-1 s-1). Using results from this study and others, it was established that the rate of adsorption of divalent metal cations on goethite was directly related to the rate of removal of a water molecule from the primary hydration sphere of a particular divalent metal cation. C1 UNIV DELAWARE, DEPT PLANT & SOIL SCI, NEWARK, DE 19717 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 31 TC 72 Z9 74 U1 2 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD AUG PY 1994 VL 28 IS 8 BP 1422 EP 1429 DI 10.1021/es00057a008 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PA221 UT WOS:A1994PA22100013 PM 22165924 ER PT J AU BAYNE, CK SCHMOYER, DD JENKINS, RA AF BAYNE, CK SCHMOYER, DD JENKINS, RA TI PRACTICAL REPORTING TIMES FOR ENVIRONMENTAL-SAMPLES SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID WATER AB A new preanalytical holding-time approach called ''Practical reporting time'' (PRI) has been developed that depends on the probability of an analyte measurement being below a critical concentration. This new approach has been applied to 19 volatile organic compounds and four explosives in both water and soil matrices. Practical reporting times for these analytes are used to develop a nomograph to show the consequences of chemically analyzing environmental samples past their PRT. This nomograph can be applied to a large class of analytes that uses zero-order or first-order kinetic models to approximate the degradation of analyte concentrations. C1 OAK RIDGE NATL LAB,DIV ANALYT SCI,OAK RIDGE,TN 37831. RP BAYNE, CK (reprint author), OAK RIDGE NATL LAB,DIV COMP APPLICAT,POB 2008,OAK RIDGE,TN 37831, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD AUG PY 1994 VL 28 IS 8 BP 1430 EP 1436 DI 10.1021/es00057a009 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA PA221 UT WOS:A1994PA22100014 PM 22165925 ER PT J AU LIN, HH SHINPOCK, SG KERLEY, MK POPP, DM POPP, RA MUCENSKI, ML AF LIN, HH SHINPOCK, SG KERLEY, MK POPP, DM POPP, RA MUCENSKI, ML TI HEMATOPOIETIC ANALYSES OF C-MYB MUTANT MICE SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DIV BIOL,OAK RIDGE,TN. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1994 VL 22 IS 8 BP 708 EP 708 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA PB368 UT WOS:A1994PB36800114 ER PT J AU HROMAS, R AMEMIYA, C MOHRENWEISER, H HOFFMAN, S AF HROMAS, R AMEMIYA, C MOHRENWEISER, H HOFFMAN, S TI THE MZF FAMILY - A CLUSTER OF MYELOID-SPECIFIC ZINC-FINGER GENES LOCATED AT THE TELOMERE OF CHROMOSOME 19Q SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 INDIANA UNIV,MED CTR,INDIANAPOLIS,IN 46204. WALTHER ONCOL CTR,INDIANAPOLIS,IN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1994 VL 22 IS 8 BP 721 EP 721 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA PB368 UT WOS:A1994PB36800162 ER PT J AU MIGLIACCIO, AR JIANG, Y WINARDI, R MIGLIACCIO, G ADAMSON, JW AF MIGLIACCIO, AR JIANG, Y WINARDI, R MIGLIACCIO, G ADAMSON, JW TI COORDINATE REGULATION OF THE BETA-CHAIN OF THE IL-3 RECEPTOR (BETA(IL-3)) AND ID GENE-EXPRESSION DURING ERYTHROID-DIFFERENTIATION SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 NEW YORK BLOOD CTR,NEW YORK,NY 10021. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1994 VL 22 IS 8 BP 722 EP 722 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA PB368 UT WOS:A1994PB36800164 ER PT J AU SEED, TM GOLTRY, K GREENBERGER, JS AF SEED, TM GOLTRY, K GREENBERGER, JS TI LEUKEMIC-CELL TRANSFORMATION UNDER CHRONIC RADIATION IN-VITRO SO EXPERIMENTAL HEMATOLOGY LA English DT Meeting Abstract C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV PITTSBURGH,PITTSBURGH,PA 15213. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD AUG PY 1994 VL 22 IS 8 BP 762 EP 762 PG 1 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA PB368 UT WOS:A1994PB36800316 ER PT J AU GARTEN, CT HUSTON, MA THOMS, CA AF GARTEN, CT HUSTON, MA THOMS, CA TI TOPOGRAPHIC VARIATION OF SOIL-NITROGEN DYNAMICS AT WALKER BRANCH WATERSHED, TENNESSEE SO FOREST SCIENCE LA English DT Article DE N-MINERALIZATION; NITRIFICATION; N-CYCLING; LEAF FALL; TOPOGRAPHIC INDEX ID NORTHERN LOWER MICHIGAN; FOREST ECOSYSTEMS; UREASE ACTIVITY; NITRIFICATION; MINERALIZATION; NITRATE; VARIABILITY; GRADIENT; BIOMASS; USA AB Understanding the spatial and temporal variability of soil nitrogen (N) transformations is central to quantifying the N dynamics and productivity of ecosystems. The objectives of this work were to examine spatial and temporal variation of soil N dynamics and to identify factors correlated with topographic variation in soil N dynamics in a forest watershed. Net N mineralization and net nitrification potential were measured by aerobic laboratory incubations of surface (0-7 cm) mineral soils. Principal components analysis was used to describe sampling sites across the watershed based on 13 site characterization variables. A topographic index used in hydrologic modeling, In (alpha/tan beta), was calculated for each site as the natural logarithm of the ratio of the upslope drainage area per unit contour length (a) to the local slope angle (tan beta). Soils from valley floors had greater total N concentrations, lower carbon-to-nitrogen (C:N) ratios, greater potential net nitrification, and greater microbial activity (as indicated by short-term urease assays) than soils from ridges. Mean net nitrification potential was 0.59 mug N g-1 d-1 in surface soils from valley floors and was < 0.01 on ridges and slopes. The first principal component was related to the N and C properties of soils, leaf litter, and leaf fall at a site. The second principal component was related to forest stand composition. The topographic index was significantly correlated with important variables related to soil N dynamics. Once calibration data are derived, this index may be useful as a first approximation to total soil N concentrations and soil C:N ratios in forest watersheds because In (alpha/tan beta) can be calculated from geographic information systems that contain topographic data. C1 UNIV WISCONSIN,COLL NAT RESOURCES,STEVENS POINT,WI 54481. RP GARTEN, CT (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,ECOSYST STUDIES SECT,POB 2008,MAIL STOP 6038,OAK RIDGE,TN 37831, USA. RI Huston, Michael/B-1434-2009 OI Huston, Michael/0000-0001-9513-1166 NR 26 TC 76 Z9 78 U1 0 U2 17 PU SOC AMER FORESTERS PI BETHESDA PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 SN 0015-749X J9 FOREST SCI JI For. Sci. PD AUG PY 1994 VL 40 IS 3 BP 497 EP 512 PG 16 WC Forestry SC Forestry GA PC659 UT WOS:A1994PC65900007 ER PT J AU GRUBER, RP MATTHEWS, SM AF GRUBER, RP MATTHEWS, SM TI IS THERE A UNIVERSAL SCALE OF TIME SO FOUNDATIONS OF PHYSICS LETTERS LA English DT Article DE TIME; MASS VARIATION; CLOCK ASYNCHRONY; IDEAL CLOCKS; SYNCHRONIZATION; GEOMETRODYNAMIC CLOCK AB The assumption that the same universal scale of time applies for different physical laws depends upon the hypothesis that there is a unique universal scale of time in the universe. Intrinsic to that hypothesis is the assumption that if extraneous factors that affect physical clocks and processes that run on different physical principles could be removed, all clocks are synchronizable with one another. The consequences of that hypothesis not being true are considered. It was found that clock asynchrony implies that: (1) a mass variation theory is probable; (2) there is a need for multiple clocks; and (3) t in the equations of physics is referring to clocks rather than time such that the properties of time are reduced to its direction (as characterized by thermodynamics and cosmology). C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP GRUBER, RP (reprint author), STANFORD UNIV,STANFORD,CA 94305, USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0894-9875 J9 FOUND PHYS LETT JI Found. Phys. Lett. PD AUG PY 1994 VL 7 IS 4 BP 385 EP 392 DI 10.1007/BF02186689 PG 8 WC Physics, Multidisciplinary SC Physics GA PE300 UT WOS:A1994PE30000008 ER PT J AU BENSON, SA STEADMAN, EN MEHTA, AK SCHMIDT, CE AF BENSON, SA STEADMAN, EN MEHTA, AK SCHMIDT, CE TI TRACE-ELEMENT TRANSFORMATIONS IN COAL-FIRED POWER-SYSTEMS, SCOTTSDALE, AZ, 19-22 APRIL 1993 - PREFACE SO FUEL PROCESSING TECHNOLOGY LA English DT Editorial Material C1 ELECT POWER RES INST,PALO ALTO,CA 94303. US DOE,PITTSBURGH ENERGY TECHNOL CTR,PITTSBURGH,PA 15236. RP BENSON, SA (reprint author), UNIV N DAKOTA,ENERGY & ENVIRONM RES CTR,POB 9018,GRAND FORKS,ND 58202, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD AUG PY 1994 VL 39 IS 1-3 BP 1 EP 3 DI 10.1016/0378-3820(94)90167-8 PG 3 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA PG937 UT WOS:A1994PG93700001 ER PT J AU FLOWER, WL PENG, LW BONIN, MP FRENCH, NB JOHNSEN, HA OTTESEN, DK RENZI, RF WESTBROOK, LV AF FLOWER, WL PENG, LW BONIN, MP FRENCH, NB JOHNSEN, HA OTTESEN, DK RENZI, RF WESTBROOK, LV TI A LASER-BASED TECHNIQUE TO CONTINUOUSLY MONITOR METAL AEROSOL EMISSIONS SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Workshop on Trace Element Transformations in Coat-Fired Power Systems CY APR 19-22, 1993 CL SCOTTSDALE, AZ AB We are developing an instrument to continuously monitor metal aerosol emissions in applications including industrial process vents (e.g., exhaust stacks from electroplating baths), waste treatment processes (incinerators), and boilers and industrial furnaces (coal-fired power plants). The monitoring technique is based on laser spark spectroscopy (LASS; also known as laser-induced breakdown spectroscopy - LIBS), in which a pulsed laser is used to rapidly heat a particle and produce a plasma (or laser 'spark'). The light emission from the spark is spectrally resolved and analyzed to identify the elemental constituents of the particle and quantify the abundance of the measured species. One feature of LASS is that it can measure atomic species embedded in either solid particles or fine liquid droplets, which account for a large percentage of metal emissions from applications of interest. In the initial work described here, we have focused on the application of the LASS technique for measuring chromium emissions from electroplating baths. This paper describes the approach used for measuring the total chromium concentration in laboratory simulations of electroplating aerosols. Chromium concentrations less than 1 mg/scm can be measured. This work forms the basis for future applications to incineration and fossil power plants. C1 INSITEC MEASUREMENT SYST,SAN RAMON,CA. RP FLOWER, WL (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 4 TC 24 Z9 24 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD AUG PY 1994 VL 39 IS 1-3 BP 277 EP 284 DI 10.1016/0378-3820(94)90186-4 PG 8 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA PG937 UT WOS:A1994PG93700020 ER PT J AU WITH, KA AF WITH, KA TI ONTOGENIC SHIFTS IN HOW GRASSHOPPERS INTERACT WITH LANDSCAPE STRUCTURE - AN ANALYSIS OF MOVEMENT PATTERNS SO FUNCTIONAL ECOLOGY LA English DT Article DE FRACTAL ANALYSIS; HETEROGENEITY; LANDSCAPE ECOLOGY; SCALE AB 1. Patterns of animal movement provide a spatial record of how organisms interact with landscape structure. 2. Although species may differ in absolute measures of movement (e.g. net displacement), they may nevertheless interact with landscape structure in similar ways. Fractal analysis affords a scale-independent measure that assesses pattern structure across a range of spatial scales. Similarities in the fractal geometry of movement pathways therefore indicate that species are interacting with landscape structure in similar ways. 3. Within a species, different life stages may possess different perceptions of landscape structure. To test this idea, I examined how developmental stages of a gomphocerine grasshopper (Orthoptera, Acrididae), Opeia obscura, interacted with microlandscape structure in a grassland mosaic. 4. Adults moved two to six times farther and were more strongly influenced by microlandscape structure than were nymphs. The fractal dimensions of movement pathways (an index of pattern complexity) differed significantly between life stages, indicating that adults and nymphs interacted with landscape structure in different ways. 5. Nymphs traverse the landscape in a different manner to adults: nymphs leap between discrete vegetative structures (e.g. grass blades), whereas adults move across the plane of the landscape. Nymphs thus possess a finer perceptual grain of landscape structure; nymphs move at slower rates and can resolve small-scale details. Adults move at faster rates across the mosaic, and may operate at a greater spatial extent than nymphs. RP WITH, KA (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. RI With, Kimberly/J-5124-2014 OI With, Kimberly/0000-0001-5570-1515 NR 0 TC 71 Z9 71 U1 0 U2 8 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0269-8463 J9 FUNCT ECOL JI Funct. Ecol. PD AUG PY 1994 VL 8 IS 4 BP 477 EP 485 DI 10.2307/2390072 PG 9 WC Ecology SC Environmental Sciences & Ecology GA PA056 UT WOS:A1994PA05600008 ER PT J AU TILLACK, M SHARAFAT, S YOUSSEF, M HERRING, S MALANG, S SZE, DK AF TILLACK, M SHARAFAT, S YOUSSEF, M HERRING, S MALANG, S SZE, DK TI FUSION NUCLEAR TECHNOLOGY AND MATERIALS - STATUS AND RESEARCH-AND-DEVELOPMENT NEEDS SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology CY SEP 13-17, 1993 CL LOS ANGELES, CA SP INT ATOM ENERGY AGCY AB The importance of fusion nuclear technology has grown in recent years due to advances in large tokamaks and a strong international movement towards a ''next step'' device such as ITER. Programs around the world have made major advances in the development of in-vessel reactor components. However, much further R&D will be required in order to develop attractive DEMO components. The realization that testing in a next-step fusion test reactor may be required in as little as 10 years has provided a new sense of urgency. In this paper, the current status and R&D needs are surveyed for the key in-vessel components, including blankets, plasma-facing components, and tritium systems. Special needs in the areas of neutronics, materials development and safety are highlighted. C1 IDAHO NATL ENGN LAB,FUS SAFETY PROGRAM,POB 1625,IDAHO FALLS,ID 83415. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,INST ANGEW THERMO & FLUIDDYNAM,W-7500 KARLSRUHE 1,GERMANY. ARGONNE NATL LAB,FUS POWER PROGRAM,ARGONNE,IL 60439. NR 22 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1994 VL 25 IS 1-3 BP 21 EP 34 DI 10.1016/0920-3796(94)90051-5 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PC633 UT WOS:A1994PC63300005 ER PT J AU LYON, JF GULEC, K MILLER, RL ELGUEBALY, L AF LYON, JF GULEC, K MILLER, RL ELGUEBALY, L TI STATUS OF THE UNITED-STATES STELLARATOR REACTOR STUDY SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology CY SEP 13-17, 1993 CL LOS ANGELES, CA SP INT ATOM ENERGY AGCY ID CONFINEMENT AB Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors. This scoping study, which uses an integrated cost-minimization code that incorporates costing and reactor component models self-consistently with a one-dimensional energy transport calculation, shows that a torsatron reactor could also be economically competitive with a tokamak reactor. The projected cost of electricity (COE) estimated using the Advanced Reactor Innovation and Evaluation Studies (ARIES) costing algorithms is 65.6 mill per kWe h in constant 1992 dollars for a reference 1 GWe compact torsatron reactor. The COE is relatively insensitive (less than 10% variation) over a wide range of assumptions, including variations in the maximum field allowed on the coils, the coil elongation, the shape of the density profile, the beta limit, the confinement multiplier, and the presence of a large loss region for alpha particles. The largest variations in the COE occur for variations in the electrical power output demanded and the plasma-coil separation ratio. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV WISCONSIN,MADISON,WI 53706. RP LYON, JF (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 23 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1994 VL 25 IS 1-3 BP 85 EP 103 DI 10.1016/0920-3796(94)90056-6 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PC633 UT WOS:A1994PC63300010 ER PT J AU HERRING, JS MCCARTHY, KA DOLAN, TJ AF HERRING, JS MCCARTHY, KA DOLAN, TJ TI SAFETY ANALYSES OF THE ARIES TOKAMAK REACTOR DESIGNS SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology CY SEP 13-17, 1993 CL LOS ANGELES, CA SP INT ATOM ENERGY AGCY ID FUSION AB The ARIES design effort has sought to maximize the environmental and safety advantages of fusion through careful selection of materials and careful design. Three goals are that the reactor achieve inherent or passive safety, that no public evacuation plan be necessary, and that the waste be disposable as 10CFR61 class C waste. The ARIES-I tokamak reactor design consists of an SiC composite structure for the first wall and blanket, cooled by 10 MPa helium. The breeder is Li2ZrO3, although Li2O and Li4SiO4 were also considered. The divertor consists of SiC composite tubes coated with 2 mm tungsten. Owing to the minimal afterheat of this blanket design loss-of-cooling accident (LOCA) calculations indicate maximum temperatures will not cause damage if the plasma is promptly extinguished. The ARIES-II design includes liquid lithium and vanadium, both of which have low activation, multiple barriers between the lithium and air and an inert cover gas to prevent lithium-air reactions. The ARIES-II reactor is passively safe with a total 1 km early dose of about 88 rem (0.88 Sv). This dose is the result of a full-scale lithium fire resulting from a LOCA with air ingress. ARIES-III was an extensive examination of the viability of a D-He-3 fueled tokamak power reactor. Because neutrons are produced only through side reactions (D + D --> He-3 + n, and D + D --> T + p followed by D + T --> He-4 + n), the reactor has the significant advantages of reduced activation of the first wall and shield, low afterheat and class A or C low level waste disposal. Since no tritium is required for operation, no lithium-containing breeding blanket is necessary. We modeled a LOCA in which the organic coolant was burning in order to estimate the amount of radionuclides released from the first wall. Because the maximum temperature is low, below 600-degrees-C, release fractions are small. We analyzed the disposition of the 20 g per day of tritium that is produced by D-D reactions and removed by the vacuum pumps. The ARIES-IV reactor has been designed for low activation and low stored energy. The coolant is helium and the breeder is lithium oxide. The structure is silicon carbide. Since the neutron multiplier, beryllium metal, is combustible, releasing about 60 MJ kg-1, beryllium is the chief source of chemical energy. Less than 10% of the Na-24 inventory is likely to diffuse out of the SiC during a fire in which the beryllium is consumed. Therefore, the offsite dose would be less than 200 rem. RP HERRING, JS (reprint author), IDAHO NATL ENGN LAB,FUS SAFETY PROGRAM,POB 1625,MS 3815,IDAHL FALLS,ID 83415, USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1994 VL 25 IS 1-3 BP 193 EP 204 DI 10.1016/0920-3796(94)90064-7 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PC633 UT WOS:A1994PC63300018 ER PT J AU MAU, TK EHST, DA MANDREKAS, J AF MAU, TK EHST, DA MANDREKAS, J TI CURRENT DRIVE STUDIES FOR THE ARIES STEADY-STATE TOKAMAK REACTORS SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology CY SEP 13-17, 1993 CL LOS ANGELES, CA SP INT ATOM ENERGY AGCY ID PLASMAS AB Steady-state plasma operating scenarios are designed for three versions of the ARIES reactor, using non-inductive current drive techniques that have an established database. R.f. waves, including fast and lower hybrid waves, are the reference drivers for the D-T burning ARIES-I and ARIES-II/IV, while neutral beam injection is employed for ARIES-III which burns D-He-3. Plasma equilibria with a high bootstrap-current component have been used, in order to minimize the recirculating power fraction and cost of electricity. To maintain plasma stability, the driven current profile has been aligned with that of equilibrium by proper choices of the plasma profiles and power launch parameters. Except for ARIES-III, the current-drive power requirements and the relevant technology developments are found to be quite reasonable. The wave-power spectrum and launch requirements are also considered achievable with a modest development effort. Issues such as an improved database for fast-wave current drive, lower-hybrid power coupling to the plasma edge, profile control in the plasma core, and access to the design point of operation remain to be addressed. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. GEORGIA INST TECHNOL,ATLANTA,GA 30332. RP MAU, TK (reprint author), UNIV CALIF LOS ANGELES,INST PLASMA & FUS RES,LOS ANGELES,CA 90024, USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1994 VL 25 IS 1-3 BP 205 EP 214 DI 10.1016/0920-3796(94)90065-5 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PC633 UT WOS:A1994PC63300019 ER PT J AU JARDIN, SC KESSEL, CE POMPHREY, N AF JARDIN, SC KESSEL, CE POMPHREY, N TI MAGNETOHYDRODYNAMIC STABILITY REGIMES FOR STEADY-STATE AND PULSED REACTORS SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design and Technology CY SEP 13-17, 1993 CL LOS ANGELES, CA SP INT ATOM ENERGY AGCY ID BALLOONING MODES; BETA; TOKAMAK; PLASMAS; REGION; LIMIT; SHEAR AB A tokamak reactor will operate at the maximum value of beta = 2mu0[p]/B2 that is compatible with magnetohydrodynamic (MHD) stability. This value depends on the plasma current and pressure profiles, the plasma shape and aspect ratio, and the location of nearby conducting structures. In addition, a steady state reactor will minimize its external current drive requirements and thus achieve its maximum economic benefit with a bootstrap fraction near unity, I(BS)/I(P) almost-equal-to 1, which constrains the product of the inverse aspect ratio and the plasma poloidal beta to be near unity, eisplonbeta(P) almost-equal-to 1. An inductively driven pulsed reactor has different constraints set by the steady-state Ohm's law which relates the plasma temperature and density profiles to the parallel current density. We present the results obtained during ARIES I, II/IV, and III and PULSAR reactor studies where these quantities were optimized subject to different design philosophies. The ARIES-II/IV and ARIES-III designs are both in the second stability regime, but differ in requirements in the form of the profiles at the plasma edge, and in the location of the conducting wall. The relation between these, as well as new attractive MHD regimes not utilized in the ARIES or PULSAR studies, is also discussed. RP JARDIN, SC (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Jardin, Stephen/E-9392-2010; pomphrey, neil/G-4405-2010 NR 19 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1994 VL 25 IS 1-3 BP 215 EP 225 DI 10.1016/0920-3796(94)90066-3 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PC633 UT WOS:A1994PC63300020 ER PT J AU LEE, JD AF LEE, JD TI WASTE-DISPOSAL ASSESSMENT OF HYLIFE-II STRUCTURE SO FUSION TECHNOLOGY LA English DT Article DE WASTE DISPOSAL; ICF; HYLIFE-II AB Initial scoping analysis indicates that by using Type 304 stainless steel (SS), most of the vacuum vessel's structural mass in the HYLIFE-II inertial fusion energy power plant conceptual design could be disposed of by shallow burial. And, if all the structural components are mixed together and treated as one solid entity, all of it could be disposed of by shallow burial Two other types of SS assessed, manganese-modified Type 316 SS and prime candidate alloy (PCA), were found to require disposal by deep geologic burial of most of the structural mass. The presence of niobium and molybdenum in manganese-modified Type 316 SS and PCA was found to dominate the generation of long-term wastes that contribute to the shallow burial index, and their presence should be avoided. RP LEE, JD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 11 TC 38 Z9 38 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD AUG PY 1994 VL 26 IS 1 BP 74 EP 78 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA NY713 UT WOS:A1994NY71300006 ER PT J AU SUGG, DW CHESSER, RK AF SUGG, DW CHESSER, RK TI EFFECTIVE POPULATION SIZES WITH MULTIPLE PATERNITY SO GENETICS LA English DT Article ID NATURAL-POPULATIONS; GENETIC-VARIABILITY; MOSQUITOFISH; INSEMINATION; DIVERSITY AB While the concept of effective population size is of obvious applicability to many questions in population genetics and conservation biology, its utility has suffered due to a lack of agreement among its various formulations. Often, mathematical formulations for effective sizes apply restrictive assumptions that limit their applicability. Herein, expressions for effective sizes of populations that account for mating tactics, biases in sex ratios, and differential dispersal rates (among other parameters) are developed. Of primary interest is the influence of multiple paternity on the maintenance of genetic variation in a population. In addition to the standard inbreeding and variance effective sizes, intragroup (coancestral) and intergroup effective sizes also are developed. Expressions for effective sizes are developed for the beginning of nonrandom gene exchanges (initial effective sizes), the transition of gene correlations (instantaneous effective sizes), and the steady-state (asymptotic effective size). Results indicate that systems of mating that incorporate more than one male mate per female increase all effective sizes above those expected from polygyny and monogamy. Instantaneous and asymptotic sizes can be expressed relative to the fixation indices. The parameters presented herein can be utilized in models of effective sizes for the study of evolutionary biology and conservation genetics. C1 UNIV GEORGIA,DEPT GENET,ATHENS,GA 30602. UNIV GEORGIA,INST ECOL,ATHENS,GA 30602. RP SUGG, DW (reprint author), SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802, USA. NR 25 TC 153 Z9 157 U1 1 U2 13 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 SN 0016-6731 J9 GENETICS JI Genetics PD AUG PY 1994 VL 137 IS 4 BP 1147 EP 1155 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA NX912 UT WOS:A1994NX91200025 PM 7982568 ER PT J AU FJELLSTROM, RG PARFITT, DE AF FJELLSTROM, RG PARFITT, DE TI WALNUT (JUGLANS SPP) GENETIC DIVERSITY DETERMINED BY RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS SO GENOME LA English DT Article DE JUGLANS; RFLP; GENETIC DIVERSITY; WALNUT ID PHYLOGENETIC-RELATIONSHIPS; RFLP LOCI; ISOZYME; MARKERS; INHERITANCE; POPULATIONS; DISTANCE; LACTUCA; ORIGIN AB The genetic diversity of 13 Juglans species was characterized using nuclear RFLPs. Allelic frequencies among 41 Juglans populations were determined at 19 RFLP loci by hybridizing single locus probes to walnut DNAs digested with the restriction endonuclease EcoRI or HindIII. A 10-fold difference in species heterozygosity levels was seen among species in different sections of the genus. Differentiation among conspecific populations varied over threefold between species. Genetic differentiation among conspecific east Asian populations was larger than that seen among east Asian species, while the opposite trend was seen for Western Hemisphere species. Taxonomic affinities were also indicated by these results, suggesting that J. cinerea should be included as part of section Cardiocaryon rather than as a unique section, Trachycaryon. Juglans hindsii is classified as a distinct species and not a subspecies of J. californica. Strategies for germplasm preservation and species requiring marked collection efforts are given. RP FJELLSTROM, RG (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT POMOL,DAVIS,CA 95616, USA. NR 39 TC 36 Z9 42 U1 0 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0831-2796 J9 GENOME JI Genome PD AUG PY 1994 VL 37 IS 4 BP 690 EP 700 DI 10.1139/g94-097 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA PE349 UT WOS:A1994PE34900024 PM 18470111 ER PT J AU LAI, F STUBBS, L ARTZT, K AF LAI, F STUBBS, L ARTZT, K TI MOLECULAR ANALYSIS OF MOUSE RAB11B - A NEW-TYPE OF MAMMALIAN YPT/RAB PROTEIN SO GENOMICS LA English DT Article ID GTP-BINDING-PROTEINS; RAS-LIKE GENES; ACTIVATING PROTEIN; CODING SEQUENCES; SCHIZOSACCHAROMYCES-POMBE; TRANSFORMING PROPERTIES; H-2K REGION; CELL-LINE; YPT1 GENE; YEAST AB Since the realization that the vesicular transport machinery is conserved from yeast to vertebrate neurons, much interest in the proteins involved has been generated. Here we describe a new type of mammalian YPT/Rab protein, named Rab11b, that is most abundantly expressed in brain, heart, and testis. It has all the hallmarks of a YPT3/Rab11 protein, but is more closely related to a ypt3-related gene isolated from fish (97% homology) than to the previously described four mammalian Rab11 genes (89% homology). The mammalian Rab11 genes discovered previously are, by contrast, 100% identical to each other. The genomic structure of a mammalian Rab11 protein is described for the first time. It is surprisingly asymmetrical, with 96% of the coding sequence contained in one-third of the transcription unit. Two copies of this gene are mapped to mouse chromosomes 1 and 17. The fine structural analysis of Rab11b and the protein sequence comparison provides a close look at all YPT3/Rab11-related genes cloned so far and clues to their possible relationship. (C) 1994 Academic Press, Inc. C1 UNIV TEXAS,DEPT ZOOL,AUSTIN,TX 78712. OAK RIDGE NATL LAB,MAMMALIAN GENET LAB,BIOL SECT,OAK RIDGE,TN 37831. OI Stubbs, Lisa/0000-0002-9556-1972 FU NICHD NIH HHS [HD30658, HD10668] NR 41 TC 41 Z9 43 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD AUG PY 1994 VL 22 IS 3 BP 610 EP 616 DI 10.1006/geno.1994.1434 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA PC816 UT WOS:A1994PC81600013 PM 8001972 ER PT J AU RITSON, PI ESSER, BK NIEMEYER, S FLEGAL, AR AF RITSON, PI ESSER, BK NIEMEYER, S FLEGAL, AR TI LEAD ISOTOPIC DETERMINATION OF HISTORICAL SOURCES OF LEAD TO LAKE ERIE, NORTH-AMERICA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article; Proceedings Paper CT Symposium on Topics in Global Geochemistry, in Honor of Clair C Patterson CY DEC 03-04, 1993 CL PASADENA, CA ID ATMOSPHERIC LEAD; GREAT-LAKES; SEDIMENTS; PB-210; POLLUTION; CS-137; CONTAMINATION; DIAGENESIS; TRANSPORT; MONTEREY AB Measurements of lead concentrations and stable lead isotopic compositions (Pb-204, Pb-206, Pb-207, Pb-208) in sediment cores from Lake Erie document both temporal and spatial variations in lead sources to the lake. These analyses track the history of lead contamination in the lake, as well as the transport of particulate matter which governs the redistribution of particle-reactive contaminants within the lake. The isotopic compositions of the sediments reveal two sources of natural lead (fluvial and shoreline bluff erosion) and three primary sources of anthropogenic lead (coal combustion, gasoline additives, and municipal waste water discharges) to the lake. Lead concentrations and isotopic compositions of Pb-210-dated sediment cores record historical variations in the inputs from these sources. The heterogeneous isotopic composition of the three basins of Lake Erie indicates that lead from municipal effluent is most prominent in the urbanized western region of the lake and that atmospheric deposition is most prominent in the more rural eastern areas. Calculations based on a Pb-207/Pb-206 vs. Pb-208/Pb-206 linear mixing model show that as much as 70% of sediment in the Central Basin and 25% in the East Basin originates from the West Basin of Lake Erie. These calculations attest to the interbasinal redistribution of particle-reactive contaminants within the lake. C1 LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,LIVERMORE,CA 94551. RP RITSON, PI (reprint author), UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064, USA. RI Esser, Bradley/G-4283-2010 OI Esser, Bradley/0000-0002-3219-4298 NR 39 TC 53 Z9 53 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1994 VL 58 IS 15 BP 3297 EP 3305 DI 10.1016/0016-7037(94)90058-2 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB991 UT WOS:A1994PB99100019 ER PT J AU HORITA, J WESOLOWSKI, DJ AF HORITA, J WESOLOWSKI, DJ TI LIQUID-VAPOR FRACTIONATION OF OXYGEN AND HYDROGEN ISOTOPES OF WATER FROM THE FREEZING TO THE CRITICAL-TEMPERATURE SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID AQUEOUS SALT-SOLUTIONS; DEUTERIUM FRACTIONATION; O-18 AB The equilibrium fractionation factors of oxygen and hydrogen isotopes between liquid water and water vapor have been precisely determined from 25 to 350-degrees-C on the VSMOW-SLAP scale, using three different types of apparatus with static or dynamic techniques for the sampling of water vapor. Our results for both oxygen and hydrogen isotope fractionation factors between 2 5 and 100-degrees-C are in excellent agreement with the literature (e.g., MAJOUBE, 1971 ). Our results for the hydrogen isotope fractionation factor above 100-degrees-C also agree quantitatively with the literature values of MERLIVAT et al. ( 1963) and BOTTINGA ( 1968). The results for the hydrogen isotope fractionation factor obtained in this study and from most of the literature were regressed to the equation, 10(3) ln alpha1-v(D) = 1158.8(T3/10(9)) - 1620.1(T2/10(6)) + 794.84(T/10(3)) - 161.04 + 2.9992(10(9)/T3), from 0-degrees-C to the critical temperature of water (374.1-degrees-C) within +/-1.2(1sigma) (n = 157); T(K). The crossover temperature is 229 +/- 13-degrees-C (1sigma). Our values for the oxygen isotope fractionation factor between liquid water and water vapor are, however, at notable variance with the only dataset available above 100-degrees-C in the literature (BOTTINGA, 1968), which is systematically higher (av. + 0.15 in 103 ln alpha1-v(O-18)) with large errors (+/- 0.23 in 1sigma). Our results and most of the literature data below 100-degrees-C were regressed to the equation, 10(3) ln alpha1-v(O-18) = -7.685 + 6.7123(10(3)/T) - 1.6664(10(6)/T2) + 0.35041(10(9)/T3), from 0 to 374. 1-degrees-C within +/- 0.11 (1sigma) (n = 112); T(K). A third water-steam isotope geothermometer, using the ratio of DELTAdeltaD/DELTAdeltaO-18 given by water and steam samples, is readily obtained from the above equations. This geothermometer is less affected by incomplete separation of water and steam, and partial condensation of steam than those employing the oxygen and hydrogen isotopic compositions alone. RP HORITA, J (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 26 TC 288 Z9 303 U1 15 U2 83 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1994 VL 58 IS 16 BP 3425 EP 3437 DI 10.1016/0016-7037(94)90096-5 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PE613 UT WOS:A1994PE61300009 ER PT J AU RATTANAWANGCHAROEN, N DATTA, SK SHAH, AH AF RATTANAWANGCHAROEN, N DATTA, SK SHAH, AH TI NON-AXISYMMETRICAL GUIDED-WAVES IN A COMPOSITE CYLINDER WITH TRANSVERSELY ISOTROPIC CORE SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE COMPOSITE CYLINDER; GUIDED WAVE; INTERFACE DISPERSION; TRANSVERSELY ISOTROPIC ID HEXAGONAL CRYSTAL SYMMETRY; CLADDED ACOUSTIC FIBERS AB Ultrasonic guided waves in a composite cylinder have been studied by using a Rayleigh-Ritz-type finite-element representation. Although the method can be applied to general anisotropic cylinders, the analysis has been confined here to the case of a narrow transversely isotropic solid cylindrical core surrounded by a thick coaxial isotropic cylinder. Numerical results are presented for the dispersion of the first two modes when the circumferential wavenumber n = 1 and 3. It is found that, for the particular case of a graphite core in a magnesium cylinder, the two modal branches approach very closely (pinch) at the Rayleigh wave speed of magnesium. In the presence of a soft interface material, the pinch frequency is found to shift downwards. The effect of this interface material on the dispersion is also discussed. C1 US DOE,OFF BASIC ENERGY SCI,DIV ENGN & GEOSCI,WASHINGTON,DC 20595. UNIV MANITOBA,DEPT CIVIL & GEOL ENGN,WINNIPEG R3T 2N2,MANITOBA,CANADA. UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309. RP RATTANAWANGCHAROEN, N (reprint author), CHIANG MAI UNIV,FAC ENGN,DEPT CIVIL ENGN,CHIANG MAI 50002,THAILAND. NR 5 TC 2 Z9 2 U1 1 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD AUG PY 1994 VL 118 IS 2 BP 317 EP 324 DI 10.1111/j.1365-246X.1994.tb03963.x PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA PB912 UT WOS:A1994PB91200007 ER PT J AU MILLER, KM SHEBELL, P KLEMIC, GA AF MILLER, KM SHEBELL, P KLEMIC, GA TI IN-SITU GAMMA-RAY SPECTROMETRY FOR THE MEASUREMENT OF URANIUM IN SURFACE SOILS SO HEALTH PHYSICS LA English DT Article DE SPECTROMETRY, GAMMA; URANIUM; SOIL; CONTAMINATION AB The application of the technique of in situ gamma-ray Spectrometry to the measurement of uranium isotopes in surface soils is described. A basic review of the in situ methodology using high resolution germanium gamma-ray spectrometers is given and specifics on calculated fluences, dose rates in air, and calibration factors are provided for relevant uranium isotopes and their progeny. The influence of the uranium depth distribution on measured concentrations is examined as it pertains to the comparison of in situ results with those obtained with soil sampling. Results from the analysis of spectra collected in the vicinity of the Fernald Environmental Management Project are presented as an example of the application of the technique. RP MILLER, KM (reprint author), US DOE, ENVIRONM MEASUREMENTS LAB, 376 HUDSON ST, NEW YORK, NY 10014 USA. NR 16 TC 32 Z9 32 U1 1 U2 8 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1994 VL 67 IS 2 BP 140 EP 150 DI 10.1097/00004032-199408000-00004 PG 11 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 NX651 UT WOS:A1994NX65100004 PM 8026967 ER PT J AU BIRCHALL, A JAMES, AC AF BIRCHALL, A JAMES, AC TI A RAPID METHOD FOR MODELING THE KINETICS OF RADIOACTIVE PROGENY APPLIED TO THORIUM IN THE LUNGS SO HEALTH PHYSICS LA English DT Article DE RADON PROGENY; THORIUM; KINETICS; LUNGS, HUMAN ID SOLVING COMPARTMENTAL-MODELS; MICROCOMPUTER ALGORITHM AB A general method for solving first-order compartmental models (recycling and nonrecycling) with any number of radioactive progeny is described and a heuristic proof of the method is provided. The method can be applied to any system where the progeny are assumed to behave isokinetically with the parent, as is the case with the biokinetic models currently recommended by the ICRP. The method is simple to apply, and its application to the modeling of radioactive progeny in the lungs following inhalation of thorium oxides is illustrated. The new ICRP respiratory tract model is used for this illustration. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP BIRCHALL, A (reprint author), NATL RADIOL PROTECT BOARD, DIDCOT OX11 0RQ, OXON, ENGLAND. FU NCI NIH HHS [FI3PCT920064A] NR 24 TC 1 Z9 1 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1994 VL 67 IS 2 BP 162 EP 169 DI 10.1097/00004032-199408000-00007 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA NX651 UT WOS:A1994NX65100007 PM 8026970 ER PT J AU MORRIS, MD JONES, TD YOUNG, RW AF MORRIS, MD JONES, TD YOUNG, RW TI BONE-MARROW EQUIVALENT PROMPT DOSE FROM 2 COMMON FALLOUT SCENARIOS SO HEALTH PHYSICS LA English DT Note DE FALLOUT; BONE MARROW; DOSIMETRY; MODELING, DOSE ASSESSMENT ID RADIATION-INDUCED MYELOPOIESIS; CELL-KINETICS; IRRADIATIONS; EXPOSURE; MODELS; DEATH; MICE AB A cell-kinetics model for radiation-induced myelopoiesis has been derived for mice, rats, dogs, sheep, swine, and burros. The model was extended to humans after extensive comparisons with molecular and cellular data from biological experiments and an assortment of predictive/validation tests on animal mortality, cell survival, and cellular repopulation following irradiations. One advantage of the model is that any complex pattern of protracted irradiation can be equated to its equivalent prompt dose. Severity of biological response depends upon target-organ dose, dose rate, and dose fractionation. Epidemiological and animal data are best suited for exposures given in brief periods of time. To use those data to assess risk from protracted human exposures, it is obligatory to model molecular repair and compensatory proliferation in terms of prompt dose. Although the model is somewhat complex both mathematically and biologically, this note describes simple numerical approximations for two common exposure scenarios. Both approximations are easily evaluated on a simple pocket calculator by a health physicist or emergency management officer. C1 OAK RIDGE NATL LAB, HLTH & SAFETY RES DIV,DIV ENGN PHYS & MATH, BLDG 4500-S,MS 6101, OAK RIDGE, TN 37831 USA. DEF NUCL AGCY, WASHINGTON, DC 20305 USA. NR 12 TC 2 Z9 2 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 AUG PY 1994 VL 67 IS 2 BP 183 EP 186 DI 10.1097/00004032-199408000-00011 PG 4 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 NX651 UT WOS:A1994NX65100011 PM 8026974 ER PT J AU GILBERT, ES AF GILBERT, ES TI SMOKING AS AN EXPLANATION FOR THE NEGATIVE RELATIONSHIP BETWEEN EXPOSURE TO RADON AND CERTAIN TYPES OF CANCER SO HEALTH PHYSICS LA English DT Letter RP GILBERT, ES (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 6 TC 3 Z9 3 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 AUG PY 1994 VL 67 IS 2 BP 197 EP 197 PG 1 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 NX651 UT WOS:A1994NX65100014 PM 8026976 ER PT J AU JOHNSON, JR AF JOHNSON, JR TI SCIENTIST VERSION-2.0 SO HEALTH PHYSICS LA English DT Software Review RP JOHNSON, JR (reprint author), PACIFIC NW LAB, BATTELLE BLVD, RICHLAND, WA 99352 USA. NR 0 TC 0 Z9 0 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 AUG PY 1994 VL 67 IS 2 BP 199 EP 200 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA NX651 UT WOS:A1994NX65100017 ER PT J AU PAXSON, V AF PAXSON, V TI EMPIRICALLY DERIVED ANALYTIC MODELS OF WIDE-AREA TCP CONNECTIONS SO IEEE-ACM TRANSACTIONS ON NETWORKING LA English DT Article AB We analyze 3 million TCP connections that occurred during 15 wide-area traffic traces. The traces were gathered at five ''stub'' networks and two internetwork gateways, providing a diverse look at wide-area traffic. We derive analytic models describing the random variables associated with TELNET, NNTP, SMTP, and FTP connections. To assess these models we present a quantitative methodology for comparing their effectiveness with that of empirical models such as Tcplib [7]. Our methodology also allows us to determine which random variables show significant variation from site to site, over time, or between stub networks and internetwork gateways. Overall we find that the analytic models provide good descriptions, and generally model the various distributions as well as empirical models. C1 UNIV CALIF BERKELEY,DIV EECS,BERKELEY,CA 94720. RP PAXSON, V (reprint author), LAWRENCE BERKELEY LAB,NETWORK RES GRP,BERKELEY,CA 94720, USA. NR 32 TC 228 Z9 238 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1063-6692 J9 IEEE ACM T NETWORK JI IEEE-ACM Trans. Netw. PD AUG PY 1994 VL 2 IS 4 BP 316 EP 336 DI 10.1109/90.330413 PG 21 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA PY100 UT WOS:A1994PY10000001 ER PT J AU HOFMANN, M KOCH, M FELDMANN, J ELSASSER, W GOBEL, EO CHOW, WW KOCH, SW AF HOFMANN, M KOCH, M FELDMANN, J ELSASSER, W GOBEL, EO CHOW, WW KOCH, SW TI PICOSECOND GAIN DYNAMICS OF AN ACTIVELY MODE-LOCKED EXTERNAL-CAVITY LASER-DIODE SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID QUANTUM-WELL LASER; SEMICONDUCTOR-LASERS; PULSE GENERATION; OPTICAL PULSES; LOCKING; MODELOCKING; COMPRESSION; AMPLIFIERS; PS AB We report a new experimental approach to study the temporal gain dynamics of an actively mode-locked external-cavity laser diode. The experiment can be viewed as an electrical pump-optical probe technique. Picosecond time resolution is achieved by synchronizing the actively mode-locked semiconductor laser to a mode-locked Ti:sapphire laser. The transmission of the Ti:sapphire pulses through the active region of the laser diode is then measured as a function of photon energy and delay time. Our experiment allows to investigate the dynamics of the entire gain spectrum with picosecond time resolution since the Ti:sapphire laser is wavelength tunable. On the basis of these data we are able to determine directly the wavelength dependence of the differential gain. The results compare well with microscopic calculations. The implication for the mode-locking behavior of the diode laser is discussed. C1 PHILIPPS UNIV MARBURG,ZENTRUM MAT WISSENSCH,D-35032 MARBURG,GERMANY. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP HOFMANN, M (reprint author), PHILIPPS UNIV MARBURG,FACHBEREICH PHYS,D-35032 MARBURG,GERMANY. NR 26 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1994 VL 30 IS 8 BP 1756 EP 1762 DI 10.1109/3.301639 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA PC197 UT WOS:A1994PC19700010 ER PT J AU SENNAROGLU, A POLLOCK, CR NATHEL, H AF SENNAROGLU, A POLLOCK, CR NATHEL, H TI GENERATION OF TUNABLE FEMTOSECOND PULSES IN THE 1.21-1.27-MU-M AND 605-635 NM WAVELENGTH REGION BY USING A REGENERATIVELY INITIATED SELF-MODE-LOCKED CRFORSTERITE LASER SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID TI-SAPPHIRE LASER; CHROMIUM-DOPED FORSTERITE; 2ND-HARMONIC GENERATION; INTRACAVITY DISPERSION; NEGATIVE DISPERSION; ADDITIVE-PULSE; OPTICAL PULSES; OPERATION; LOCKING; CW AB A detailed description of the design and operational characteristics of a regeneratively initiated, self-mode-locked Cr:forsterite laser pumped by a continuous-wave Nd:YAG laser is given. Without compensating for the intracavity positive group velocity dispersion, regenerative acoustooptic modulation produced pulses of between 41 and 6.5 ps (FWHM) at 1.23 mum with average output powers of between 280 and 380 mW, respectively. Using intracavity negative group-velocity-dispersion compensation, nearly transform-limited femtosecond pulses of 48 fs (FWHM) duration were generated with average TEM00 output powers of 380 mW at 1.23 mum. By tuning the output of the mode-locked laser from 1.211 to 1.264 mum, the dispersion (second and third order) of the Cr:forsterite gain medium has been measured. The operational wavelength range of the laser was extended to the visible region from 605 to 635 nm by external frequency doubling in a LiIO3 nonlinear crystal. With approximately 250 mW of fundamental pump power at 1.23 mum, red pulses of 116 fs (FWHM) duration at 615 nm were obtained with conversion efficiencies approaching 10 percent. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP SENNAROGLU, A (reprint author), CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853, USA. NR 57 TC 37 Z9 37 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1994 VL 30 IS 8 BP 1851 EP 1861 DI 10.1109/3.301649 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA PC197 UT WOS:A1994PC19700020 ER PT J AU DANE, CB NEUMAN, WA HACKEL, LA AF DANE, CB NEUMAN, WA HACKEL, LA TI HIGH-ENERGY SBS PULSE-COMPRESSION SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING AB An efficient two-cell stimulated Brillouin scattering (SBS) pulse-compressor design that can be scaled to large laser-pulse energies is described and a numerical model has been developed that accurately predicts the performance of this pulse-compressor system over a wide range of operating parameters. The compression of a 2.5 J input pulse from a width of 15.8 to 1.7 ns is experimentally demonstrated with 80 percent energy efficiency. A design of an SBS pulse compressor to compress a 25 J pulse to a pulse width less than 1 ns with 80 percent energy efficiency is presented. RP DANE, CB (reprint author), LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,LIVERMORE,CA 94550, USA. NR 13 TC 63 Z9 73 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1994 VL 30 IS 8 BP 1907 EP 1915 DI 10.1109/3.301654 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA PC197 UT WOS:A1994PC19700025 ER PT J AU WEBB, M AF WEBB, M TI TEMPERATURE SENSITIVITY OF KDP FOR PHASE-MATCHED FREQUENCY-CONVERSION OF 1-MU-M LASER-LIGHT SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID HARMONIC-GENERATION; 2ND-HARMONIC GENERATION; CRYSTAL AB The magnitudes of the derivatives of the phase-matching angles with respect to temperature \partial derivative theta(pm)/partial derivative T\ (milliradians/degree Celsius), for critically phase-matched frequency conversion using KDP (KH2PO4) have been directly measured for the five most interesting processes to inertial confinement fusion (ICF) laser-system designers: 2omega I, 2omega II, 3omega I, 3omega II, and 4omega I. These measurements span an approximate temperature range of 25 to 90-degrees-C, and were performed at a fundamental (1omega) wavelength of lambda = 1.064 mum. The results are used to calculate the phase-matching thermal-sensitivity parameter \beta(T)\ (centimeter-1/milliradian), for each conversion process. RP WEBB, M (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 13 TC 10 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1994 VL 30 IS 8 BP 1934 EP 1942 DI 10.1109/3.301657 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA PC197 UT WOS:A1994PC19700028 ER PT J AU GOURLEY, PL LEAR, KL SCHNEIDER, RP AF GOURLEY, PL LEAR, KL SCHNEIDER, RP TI A DIFFERENT MIRROR SO IEEE SPECTRUM LA English DT Article C1 SANDIA NATL LABS,SEMICOND MAT RES DEPT,TECH STAFF,ALBUQUERQUE,NM 87185. RP GOURLEY, PL (reprint author), SANDIA NATL LABS,DEPT SEMICOND,ALBUQUERQUE,NM 87185, USA. NR 4 TC 10 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD AUG PY 1994 VL 31 IS 8 BP 31 EP & DI 10.1109/6.299535 PG 0 WC Engineering, Electrical & Electronic SC Engineering GA NY860 UT WOS:A1994NY86000017 ER PT J AU SCHOENWALD, DA OZGUNER, U AF SCHOENWALD, DA OZGUNER, U TI ROBUST STABILIZATION OF NONLINEAR-SYSTEMS WITH PARAMETRIC UNCERTAINTY SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Note ID ADAPTIVE-CONTROL AB We present a result on the robust stabilization of a class of nonlinear systems exhibiting parametric uncertainty. We consider feedback linearizable nonlinear systems with a vector of unknown constant parameters perturbed about a known value. A Taylor series of the system about the nominal parameter vector coupled with a feedback linearizing control law yields a linear system plus nonlinear perturbations. Via a structure matching condition, a Lyapunov-based control law is shown to exponentially stabilize the full system. The novelty of the result is that the linearizing coordinates are completely known since they are defined about the nominal parameter vector, and fewer restrictions are imposed on the nonlinear perturbations than elsewhere in the literature. C1 OHIO STATE UNIV,DEPT ELECT ENGN,COLUMBUS,OH 43210. RP SCHOENWALD, DA (reprint author), OAK RIDGE NATL LAB,DIV INSTRUMENTAT & CONTROLS,OAK RIDGE,TN 37831, USA. RI Ozguner, Umit/A-4523-2008 NR 14 TC 10 Z9 13 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD AUG PY 1994 VL 39 IS 8 BP 1751 EP 1755 DI 10.1109/9.310067 PG 5 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA PC488 UT WOS:A1994PC48800041 ER PT J AU KLAISNER, LA AF KLAISNER, LA TI THE NUCLEUS - A REPORT FROM THE GUEST EDITOR OF THE 1993 NSS MIC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material RP KLAISNER, LA (reprint author), STANFORD LINEAR ACCELERATOR CTR,DIV TECH,POB 4349,BIN 30,PALO ALTO,CA 94509, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 665 EP 665 PN 1 PG 1 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800002 ER PT J AU ZHANG, JG LUND, JC CIRIGNANO, L SHAH, KS SQUILLANTE, MR AF ZHANG, JG LUND, JC CIRIGNANO, L SHAH, KS SQUILLANTE, MR TI LEAD SULFATE SCINTILLATOR CRYSTAL-GROWTH FOR PET APPLICATIONS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB It has recently been shown that lead sulfate (PbSO4) is a promising scintillator material for use in PET detector systems. However, for lead sulfate scintillators to be useful in such an application, a technique must be developed to grow large optical quality crystals of this material. This paper describes our research into the high-temperature solution growth of PbSO4 crystals. We report on the systematic selection of solvent materials including KCl, LiCl, PbCl2, Na2SO4 and Li2SO4. Our studies indicate that Na2SO4 is the best solvent. With Na2SO4 as the flux, we obtained PbSO4 single crystals of several millimeters in size by Bridgman crystal growth method. We employed ACRT (Accelerated Crucible Rotation Technique), to resolve the constitutional supercooling problem, thus increased the crystal yield and reduced the number of grains. Finally, we compared the scintillation properties of synthetic PbSO4 crystals we grew with previous measurements on natural anglesite and other synthetic crystals, and found them nearly identical. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP ZHANG, JG (reprint author), RAIDAT MONITORING DEVICES INC,WATERTOWN,MA 02172, USA. NR 18 TC 6 Z9 6 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 669 EP 674 DI 10.1109/23.322786 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800003 ER PT J AU WOODY, CL KIERSTEAD, JA LEVY, PW STOLL, SP AF WOODY, CL KIERSTEAD, JA LEVY, PW STOLL, SP TI RADIATION-DAMAGE IN UNDOPED AND BARIUM DOPED CERIUM FLUORIDE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID SCINTILLATOR; CRYSTALS AB Radiation damage has been measured in undoped and barium doped cerium fluoride using Co-60 gamma rays. The effects of damage are mainly seen as the formation of absorption bands in the 300-350 nm and 500-600 nm regions. The bands produced at 300-350 nm result in a significant loss in detectable light output from all crystals. Recovery has been measured as a function of time at room temperature, along with the recovery induced by thermal and optical annealing. Measurements were made shortly after irradiation in order to study the effects of short term recovery. Thermoluminescence glow curves for both the doped and undoped material are also presented. Finally, it was found that neither material exhibits any significant phosphorescence after irradiation. RP WOODY, CL (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 14 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 675 EP 680 DI 10.1109/23.322787 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800004 ER PT J AU BLANKESPOOR, SC DERENZO, SE MOSES, WW ROSSINGTON, CS ITO, M OBA, K AF BLANKESPOOR, SC DERENZO, SE MOSES, WW ROSSINGTON, CS ITO, M OBA, K TI CHARACTERIZATION OF A PULSED X-RAY SOURCE FOR FLUORESCENT LIFETIME MEASUREMENTS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB To search for new, fast, inorganic scintillators, we have developed a bench-top pulsed x-ray source for determining fluorescent lifetimes and wavelengths of compounds in crystal or powdered form. This source uses a light-excited x-ray tube which produces x-rays when light from a laser diode strikes its photocathode. The x-ray tube has a tungsten anode, a beryllium exit window, a 30 kV maximum tube bias, and a 50 muA maximum average cathode current. The laser produces 3x10(7) photons at 650 nm per approximately 100 ps pulse, with up to 10(7) pulses/sec. The time spread for the laser diode, x-ray tube, and a microchannel plate photomultiplier tube is less than 120 ps fwhm. The mean x-ray energy at tube biases of 20, 25, and 30 kV is 9.4, 10.3, and 11.1 keV, respectively. We measured 140, 230, and 330 x-ray photons per laser diode pulse per steradian, at tube biases of 20, 25 and 30 kV, respectively. Background x-rays due to dark current occur at a rate of 1x10(6) and 3x10(6) photons/sec/steradian at biases of 25 and 30 kV, respectively. Data characterizing the x-ray output with an aluminum filter in the x-ray beam are also presented. C1 HAMAMATSU PHOTON KK,HAMAMATSU,JAPAN. RP BLANKESPOOR, SC (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 TC 24 Z9 26 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 698 EP 702 DI 10.1109/23.322791 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800008 ER PT J AU WOJTOWICZ, AJ BALCERZYK, M WISNIEWSKI, D LEMPICKI, A WOODY, CL LEVY, PW KIERSTEAD, JA STOLL, S AF WOJTOWICZ, AJ BALCERZYK, M WISNIEWSKI, D LEMPICKI, A WOODY, CL LEVY, PW KIERSTEAD, JA STOLL, S TI SCINTILLATION LIGHT TRAPPING AND RADIATION-DAMAGE IN CEF(3) SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID CERIUM FLUORIDE; ENERGY-TRANSFER; CRYSTALS AB In this paper we review solved and some of remaining problems in development of CeF3 scintillator. CeF3 emerges as a dense (6.16 g/cc), fast (23 ns), and reasonably efficient (2400 photons/MeV) material with potential applications in high energy and nuclear physics experiments. Despite significant progress in technology the level of uncontrolled impurities and defects in present crystals is still too high, posing problems like scintillation light trapping and radiation damage. We speculate about the possibility of electron self-trapping and nonradiative recombination at Ce sites leading to limited light output and intrinsic radiation hardness of CeF3. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP WOJTOWICZ, AJ (reprint author), BOSTON UNIV,DEPT CHEM,590 COMMONWEALTH AVE,BOSTON,MA 02215, USA. RI Wojtowicz, Andrzej/D-7418-2014; Balcerzyk, Marcin/H-4071-2011 OI Wojtowicz, Andrzej/0000-0001-5788-5987; Balcerzyk, Marcin/0000-0001-6030-7416 NR 25 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 713 EP 718 DI 10.1109/23.322794 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800011 ER PT J AU JOHNSON, JD ALLANDER, KS BOUNDS, JA GARNER, SE JOHNSON, JP MACARTHUR, DW AF JOHNSON, JD ALLANDER, KS BOUNDS, JA GARNER, SE JOHNSON, JP MACARTHUR, DW TI LONG-RANGE ALPHA DETECTOR (LRAD) SENSITIVITY TO BETA-CONTAMINATION AND SOIL-MOISTURE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB Long-range alpha detector (LRAD) systems are designed to monitor alpha contamination by measuring the ionization in air formed by the alphas. Recent tests have been performed to determine the sensitivity of LRAD systems to beta contamination and soil moisture levels. These results and the general technology are discussed in this paper. RP JOHNSON, JD (reprint author), 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 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 755 EP 757 DI 10.1109/23.322801 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800020 ER PT J AU ADAM, A AHLEN, S AMBROSI, G BABUCCI, E BASCHIROTTI, A BATTISTON, R BAYJ, A LBENCZE, GY BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOSETTI, M BROOKS, ML BUSENITZ, J BURGER, WJ CAMPS, C CARIA, M CASTELLINI, G CHECCUCCI, B CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DUINKER, P EASO, S EXTERMANN, P FIANDRINI, E GOUGAS, A HANGARTNE, RK HAUVILLER, C HERVE, A HOU, S JOSA, I KAPUSTINSKY, JS KIM, D KINNISON, WW KORNIS, J KRASTEV, VR LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LEJEUNE, E LIN, WT LOHMANN, W MARIN, A MASSETTI, R MILLS, GB NOWAK, H PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S PERRIN, E RANCOITA, PG RATTAGI, M SANTOCCHIA, A SACHWITZ, M SCHMITZ, P SCHOENIECH, B SERVOLI, L SUSINNO, GF TERZI, G THOMPSON, TC TONISCH, F TOTH, J TROWITZSCH, G VIERTEL, GM VOGT, H WALDMEIER, S WEILL, R YEH, SC ZHOU, B AF ADAM, A AHLEN, S AMBROSI, G BABUCCI, E BASCHIROTTI, A BATTISTON, R BAYJ, A LBENCZE, GY BERTUCCI, B BIASINI, M BILEI, GM BOBBINK, GJ BOSETTI, M BROOKS, ML BUSENITZ, J BURGER, WJ CAMPS, C CARIA, M CASTELLINI, G CHECCUCCI, B CHEN, A COAN, TE COMMICHAU, V DIBITONTO, D DUINKER, P EASO, S EXTERMANN, P FIANDRINI, E GOUGAS, A HANGARTNE, RK HAUVILLER, C HERVE, A HOU, S JOSA, I KAPUSTINSKY, JS KIM, D KINNISON, WW KORNIS, J KRASTEV, VR LANDI, G LEBEAU, M LECOMTE, P LEE, DM LEISTE, R LEJEUNE, E LIN, WT LOHMANN, W MARIN, A MASSETTI, R MILLS, GB NOWAK, H PASSALEVA, G PAUL, T PAULUZZI, M PENSOTTI, S PERRIN, E RANCOITA, PG RATTAGI, M SANTOCCHIA, A SACHWITZ, M SCHMITZ, P SCHOENIECH, B SERVOLI, L SUSINNO, GF TERZI, G THOMPSON, TC TONISCH, F TOTH, J TROWITZSCH, G VIERTEL, GM VOGT, H WALDMEIER, S WEILL, R YEH, SC ZHOU, B TI THE DESIGN AND CONSTRUCTION OF A DOUBLE-SIDED SILICON MICROVERTEX DETECTOR FOR THE L3 EXPERIMENT AT CERN SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB A Silicon Microvertex Detector (SMD) has been commissioned for the L3 experiment at the Large Electron-Positron colliding-beam accelerator (LEP) at the European Center for Nuclear Physics, (CERN). The SMD is a 72,672 channel, two layer barrel tracker that is comprised of 96 accoupled, double-sided silicon detectors. Details of the design and construction are presented. C1 UNIV ALABAMA,TUSCALOOSA,AL 35401. BOSTON UNIV,BOSTON,MA 02215. TECH UNIV BUDAPEST,INST PHYS,H-1521 BUDAPEST,HUNGARY. CERN,CH-1211 GENEVA 23,SWITZERLAND. KFKI,PARTICLE & NUCL PHYS RES INST,BUDAPEST,HUNGARY. SWISS FED INST TECHNOL,CH-8092 ZURICH,SWITZERLAND. UNIV FLORENCE,INFN,I-50121 FLORENCE,ITALY. IROE,INFN,FLORENCE,ITALY. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. UNIV LAUSANNE,CH-1000 LAUSANNE 17,SWITZERLAND. UNIV MILAN,I-20122 MILAN,ITALY. NIKHEF,AMSTERDAM,NETHERLANDS. UNIV PERUGIA,INFN,I-06100 PERUGIA,ITALY. NCU,CHUNGLI,TAIWAN. NATL TSING HUA UNIV,HSINCHU 300,TAIWAN. DESY,IFH,ZEUTHEN,GERMANY. LAPP,ANNECY,FRANCE. RP ADAM, A (reprint author), RHEIN WESTFAL TH AACHEN,INST PHYS 3,W-5100 AACHEN,GERMANY. RI Fiandrini, Emanuele/C-4549-2008; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Josa, Isabel/K-5184-2014; Rancoita, Pier Giorgio/J-9896-2015; OI Servoli, Leonello/0000-0003-1725-9185; Rancoita, Pier Giorgio/0000-0002-1990-4283; Ambrosi, Giovanni/0000-0001-6977-9559 NR 8 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 772 EP 778 DI 10.1109/23.322805 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800024 ER PT J AU ARRINGTON, K KEFFORD, D KENNEDY, J PISANI, R SANZENI, C SEGALL, K WALL, D WINN, DR CAREY, R DYE, S MILLER, J SULAK, L WORSTELL, W EFREMENKO, Y KAMYSHKOV, Y SAVIN, A SHMAKOV, K TARKOVSKY, E AF ARRINGTON, K KEFFORD, D KENNEDY, J PISANI, R SANZENI, C SEGALL, K WALL, D WINN, DR CAREY, R DYE, S MILLER, J SULAK, L WORSTELL, W EFREMENKO, Y KAMYSHKOV, Y SAVIN, A SHMAKOV, K TARKOVSKY, E TI CERENKOV FIBER SAMPLING CALORIMETERS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID SPAGHETTI CALORIMETER AB Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1-degree-7-degrees). The 7 lambda deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented. C1 BOSTON UNIV,BOSTON,MA 02215. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP ARRINGTON, K (reprint author), FAIRFIELD UNIV,FAIRFIELD,CT 06430, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 840 EP 844 DI 10.1109/23.322817 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800036 ER PT J AU ABE, K ANTILOGUS, P ASTON, D BAIRD, K BEAN, A BENDAVID, R BIENZ, T BIRD, F CALDWELL, DO CAVALLISFORZA, M COLLER, J COYLE, P COYNE, D DASU, S DOLINSKY, S DOLIVEIRA, A DUBOSCQ, J DUNWOODIE, W HALLEWELL, G HASEGAWA, K HASEGAWA, Y HUBER, J IWASAKI, Y JACQUES, P JOHNSON, RA KALELKAR, M KAWAHARA, H KWON, Y LEITH, DWGS LIU, X LU, A MANLY, S MARTINEZ, J MATHYS, L MCHUGH, S MEADOWS, B MULLER, G MULLER, D NAGAMINE, T NUSSBAUM, M PAVEL, TJ PLANO, R RATCLIFF, B RESNING, P SANTHA, AKS SCHULTZ, D SHANK, JT SHAPIRO, S SIMOPOULOS, C SNYDER, J SOKOLOFF, MD SOLODOV, E STAMER, P STOCKDALE, I SUEKANE, F TOGE, N TURK, J VAVRA, J WHITAKER, JS WILLIAMS, DA WILLIAMS, SH WILLOCQ, S WILSON, RJ WORD, G YELLIN, S YUTA, H AF ABE, K ANTILOGUS, P ASTON, D BAIRD, K BEAN, A BENDAVID, R BIENZ, T BIRD, F CALDWELL, DO CAVALLISFORZA, M COLLER, J COYLE, P COYNE, D DASU, S DOLINSKY, S DOLIVEIRA, A DUBOSCQ, J DUNWOODIE, W HALLEWELL, G HASEGAWA, K HASEGAWA, Y HUBER, J IWASAKI, Y JACQUES, P JOHNSON, RA KALELKAR, M KAWAHARA, H KWON, Y LEITH, DWGS LIU, X LU, A MANLY, S MARTINEZ, J MATHYS, L MCHUGH, S MEADOWS, B MULLER, G MULLER, D NAGAMINE, T NUSSBAUM, M PAVEL, TJ PLANO, R RATCLIFF, B RESNING, P SANTHA, AKS SCHULTZ, D SHANK, JT SHAPIRO, S SIMOPOULOS, C SNYDER, J SOKOLOFF, MD SOLODOV, E STAMER, P STOCKDALE, I SUEKANE, F TOGE, N TURK, J VAVRA, J WHITAKER, JS WILLIAMS, DA WILLIAMS, SH WILLOCQ, S WILSON, RJ WORD, G YELLIN, S YUTA, H TI RESULTS FROM THE SLD BARREL CRID DETECTOR SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID RING IMAGING DETECTOR; PERFORMANCE AB We report on operational experience with an experimental performance of the SLD barrel Cherenkov Ring Imaging Detector from the 1992 and 1993 physics runs. The liquid (C6F14) and gas (C5F12) radiator recirculation systems have performed well, and the drift gas supply system has operated successfully with TMAE for three years. Cherenkov rings have been observed from both the liquid and gas radiators. The number and angular resolution of Cherenkov photons have been measured, and found to be close to design specifications. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RUTGERS STATE UNIV,SERIN PHYS LAB,PISCATAWAY,NJ 08855. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. YALE UNIV,DEPT PHYS,NEW HAVEN,CT 06511. UNIV CALIF SANTA CRUZ,SANTA CRUZ INST PARTICLE PHYS,SANTA CRUZ,CA 95064. BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523. NOVOSIBIRSK NUCL PHYS INST,NOVOSIBIRSK 630090,RUSSIA. UNIV ESTADUAL PAULISTA,BR-15054000 SAO PAULO,BRAZIL. RP ABE, K (reprint author), TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 980,JAPAN. RI Cavalli-Sforza, Matteo/H-7102-2015; OI Dolinsky, Sergei/0000-0002-2789-453X; Bean, Alice/0000-0001-5967-8674; Wilson, Robert/0000-0002-8184-4103 NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 862 EP 865 DI 10.1109/23.322821 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800040 ER PT J AU GONG, WG WIEMAN, H HARRIS, JW MITCHELL, JT HONG, WS PEREZMENDEZ, V AF GONG, WG WIEMAN, H HARRIS, JW MITCHELL, JT HONG, WS PEREZMENDEZ, V TI MICROSTRIP GAS-CHAMBERS ON GLASS AND CERAMIC SUBSTRATES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID ELECTRONIC CONDUCTIVITY; PROPORTIONAL COUNTER; PERFORMANCE; DETECTOR; ANODE AB We report developments of Microstrip Gas Chambers (MSGC) fabricated on glass and ceramic substrates with various resistivities. Low resistivity of the substrate is found to be critical for achieving stable operation of microstrip gas chambers. The microstrip pattern consists of 10 mum wide anodes and 90 mum wide cathodes with a 200 mum anode-to-anode pitch. High-quality microstrips are fabricated using the dry etch after UV-photolithography. Our chambers are tested in an Ar(90)-CH4(10) gas mixture at atmospheric pressure with a 100 muCi Fe-55 source. An energy resolution (FWHM) of 15% has been achieved for 6 keV soft X-rays. At a rate of 5 x 10(4) photons/sec/mm2, gas gains are stable within a few percent. C1 LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. RP GONG, WG (reprint author), LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 890 EP 897 DI 10.1109/23.322827 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800046 ER PT J AU JING, T GOODMAN, CA DREWERY, J CHO, G HONG, WS LEE, H KAPLAN, SN MIRESHGHI, A PEREZMENDEZ, V WILDERMUTH, D AF JING, T GOODMAN, CA DREWERY, J CHO, G HONG, WS LEE, H KAPLAN, SN MIRESHGHI, A PEREZMENDEZ, V WILDERMUTH, D TI AMORPHOUS-SILICON PIXEL LAYERS WITH CESIUM IODIDE CONVERTERS FOR MEDICAL RADIOGRAPHY SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID RADIATION-DAMAGE; X-RAY; CSI(TL) CRYSTALS; CSI; SCINTILLATORS; DETECTORS; READOUT; ARRAYS; YIELD; CCD AB We describe the properties of evaporated layers of Cesium Iodide (Thallium activated) deposited on substrates that enable easy coupling to amorphous silicon pixel arrays. The CsI(Tl) layers range in thickness from 65 to 220mum. We used the two-boat evaporator system to deposit CsI(Tl) layers. This system ensures the formation of the scintillator film with homogenous thallium concentration which is essential for optimizing the scintillation light emission efficiency. The Tl concentration was kept to 0.1 -0.2 mole percent for the highest light output. Temperature annealing can affect the microstructure as well as light output of the CsI(Tl) film. 200-300-degrees-C temperature annealing can increase the light output by a factor of two. The amorphous silicon pixel arrays are p-in diodes approximately 1 mum thick with transparent electrodes to enable them to detect the scintillation light produced by X-rays incident on the CsI(Tl). Digital radiography requires a good spatial resolution. This is accomplished by making the detector pixel size less than 50mum. The light emission from the CsI(Tl) is collimated by techniques involving the deposition process on patterned substrates. We have measured MTF of greater than 12 line pairs per mm at the 10% level. C1 AIR TECH INC,HICKSVILLE,NY 11802. RP JING, T (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Cho, Gyuseong/C-1527-2011 NR 23 TC 33 Z9 35 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 903 EP 909 DI 10.1109/23.322829 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800048 ER PT J AU MIRESHGHI, A CHO, G DREWERY, JS HONG, WS JING, T LEE, H KAPLAN, SN PEREZMENDEZ, V AF MIRESHGHI, A CHO, G DREWERY, JS HONG, WS JING, T LEE, H KAPLAN, SN PEREZMENDEZ, V TI HIGH-EFFICIENCY NEUTRON SENSITIVE AMORPHOUS-SILICON PIXEL DETECTORS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB A multi-layer a-Si:H based thermal neutron detector was designed, fabricated and simulated by Monte Carlo method. The detector consists of two a-Si:H pin detectors prepared by plasma enhanced chemical vapor deposition (PECVD) and interfaced with coated layers of Gd, as a thermal neutron coverter. Simulation results indicate that a detector consisting of 2 Gd films with thicknesses of 2 and 4 mum, sandwiched properly with two layers of sufficiently thick (approximately 30mum) amorphous silicon diodes, has the optimum parameters. The detectors have an intrinsic efficiency of about 42% at a threshold setting of 7000 electrons, with an expected average signal size of approximately 12000 electrons which is well above the noise. This efficiency will be further increased to nearly 63%, if we use Gd with 50% enrichment in Gd-157. We can fabricate position sensitive detectors with spatial resolution of 300 mum with gamma sensitivity of approximately 1x10(-5). These detectors are highly radiation resistant and are good candidates for use in various application, where high efficiency, high resolution, gamma insensitive position sensitive neutron detectors are needed. RP MIRESHGHI, A (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Cho, Gyuseong/C-1527-2011 NR 12 TC 40 Z9 40 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 915 EP 921 DI 10.1109/23.322831 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800050 ER PT J AU FEHLAU, PE AF FEHLAU, PE TI INTEGRATED NEUTRON GAMMA-RAY PORTAL MONITORS FOR NUCLEAR SAFEGUARDS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. We compared the influence of the two methods of integration on detecting neutrons and gamma rays, and we examined the effectiveness of other design factors and the methods for signal detection as well. RP FEHLAU, PE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 922 EP 926 DI 10.1109/23.322832 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800051 ER PT J AU HSU, HH ALVAR, KR VASILIK, DG AF HSU, HH ALVAR, KR VASILIK, DG TI A NEW BONNER-SPHERE SET FOR HIGH-ENERGY NEUTRON MEASUREMENTS - MONTE-CARLO SIMULATION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB The usual Bonner sphere set consists of six to eight high density polyethylene spheres with diameters varying from 3 to 12 inches. Either a BF3 counter, LiI scintillator, or He-3 detector is located at the center of each sphere to detect the moderated neutrons. The responses of these spheres for high energy neutrons are very low even for the largest 12 inch sphere. To increase the response for high energy neutrons, high Z material such as Pb, W, Tl, or Au can be added to the sphere to utilize the (n,xn) reaction of these materials. Monte Carlo Simulations for the Pb-added case with a He-3 detector as an example will be presented. The response at high energy for this case is enhanced by a factor of 5 to 8 depending upon the sphere diameter. RP HSU, HH (reprint author), LOS ALAMOS NATL LAB,POB 1663,MS G761,LOS ALAMOS,NM 87545, USA. NR 5 TC 29 Z9 29 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 938 EP 940 DI 10.1109/23.322835 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800054 ER PT J AU CHEN, W KRANER, HW LI, Z REHAK, P HESS, F AF CHEN, W KRANER, HW LI, Z REHAK, P HESS, F TI FABRICATION OF LARGE-AREA SI CYLINDRICAL DRIFT DETECTORS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID CHAMBERS AB The processing of an advanced silicon detector, a large area cylindrical drift detector (CDD), was carried out in the BNL Instrumentation Division Fabrication Facility. The double-sided planar process technique was developed for the fabrication of the CDD. Important improvements of the double-sided planar process in this fabrication include the introduction of an A1 implantation protection mask and implantation of boron through an 1000 angstrom oxide layer in the step of opening the p-window. Another important aspect of the design of the CDD is the structure called ''river,'' which allows the current generated on the Si-SiO2 interface to ''flow'' into the guard anode, and thus minimize the leakage current at the signal anode. The test result showed that for the best detector most of the signal anodes have leakage currents of about 0.3 nA/cm2. C1 MAX PLANCK INST NUCL PHYS, W-6900 HEIDELBERG 1, GERMANY. RP BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. NR 10 TC 6 Z9 7 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 AUG PY 1994 VL 41 IS 4 BP 941 EP 947 DI 10.1109/23.322836 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800055 ER PT J AU LI, Z AF LI, Z TI MODELING OF THE FREQUENCY-DEPENDENT C-V CHARACTERISTICS OF NEUTRON-IRRADIATED P(+)-N SILICON DETECTORS AFTER THE TYPE INVERSION IN THE SPACE-CHARGE REGION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID RESISTIVITY AB The modeling of the frequency dependent C-V characteristics of neutron irradiated p+-n silicon detectors is extended to the case of high neutron fluences (PHI n>8x10(12)n/cm2) where the effective doping concentration N(eff) in the space charge region (SCR) exhibits a net acceptor state (or ''p'' type), while the resistivity in the electrical neutral bulk (ENB) approaches intrinsic due to the perfect compensation of all deep levels in the condition of no band bending (or no field) and therefore no Fermi level crossing for any deep levels. The C-V characteristics are still frequency dependent, but the deep level that is responsible for it may be different from the one before the type inversion in the SCR. N(eff) in the SCR may be dominated by an acceptor level, such as V-V-, whose concentration is proportional to the neutron fluence. The contribution of the high resistivity ENB to the frequency dependence have also been discussed. RP LI, Z (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 8 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 948 EP 956 DI 10.1109/23.322837 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800056 ER PT J AU BIGGERI, U BORCHI, E BRUZZI, M LI, Z LAZANU, S AF BIGGERI, U BORCHI, E BRUZZI, M LI, Z LAZANU, S TI STUDIES OF DEEP LEVELS IN HIGH-RESISTIVITY SILICON DETECTORS IRRADIATED BY HIGH FLUENCE FAST-NEUTRONS USING A THERMALLY STIMULATED CURRENT SPECTROMETER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID TRANSIENT SPECTROSCOPY; TRAPS AB Measurements of deep level spectra for high resistivity silicon detectors irradiated by high fluence fast neutrons (up to 10(14) n/cm2) have been performed using a Thermally Stimulated Current (TSC) spectrometer. Nine new defect levels, with peaking temperatures of respectively 26K, 34K, 41K, 47K, 90K, 110K, 135K, 147K and 155K begin to appear for flunces over 10(13) n/cm2. All peaks are strongly dependent on the filling forward voltage. V(fill), or injection current, especially for high fluences of irradiations. Energy levels inside the band gap and trap concentrations corresponding to each of the TSC peaks, totaling at most 18, have been studied systematically and possible relations to lattice defects have been discussed. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV BUCHAREST,BUCHAREST,ROMANIA. INST ATOM PHYS,BUCHAREST,ROMANIA. RP BIGGERI, U (reprint author), UNIV FLORENCE,DIPARTIMENTO ENERGET,I-50139 FLORENCE,ITALY. RI Lazanu, Sorina/B-7819-2012; Bruzzi, Mara/K-1326-2015 OI Lazanu, Sorina/0000-0003-0390-0779; Bruzzi, Mara/0000-0001-7344-8365 NR 20 TC 23 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 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 964 EP 970 DI 10.1109/23.322840 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800059 ER PT J AU LUKE, PN PEHL, RH DILMANIAN, FA AF LUKE, PN PEHL, RH DILMANIAN, FA TI A 140-ELEMENT GE DETECTOR FABRICATED WITH AMORPHOUS-GE BLOCKING CONTACTS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB A 140-element position-sensitive Ge detector has been fabricated as the prototype detector for the development of a monochromatic computed tomography system using synchroton radiation. The detector was made in very few processing steps that included the use of amorphous Ge blocking contacts. The fabrication process and the results of testing the detector are described. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP LUKE, PN (reprint author), LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720, USA. NR 3 TC 24 Z9 24 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 976 EP 978 DI 10.1109/23.322842 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800061 ER PT J AU DERHACOBIAN, N FINE, P WALTON, JT WONG, YK ROSSINGTON, CS LUKE, PN AF DERHACOBIAN, N FINE, P WALTON, JT WONG, YK ROSSINGTON, CS LUKE, PN TI DETERMINATION OF SURFACE RECOMBINATION VELOCITY AND BULK LIFETIME IN DETECTOR-GRADE SILICON AND GERMANIUM-CRYSTALS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID WAFER; AIR; SI AB The utility of a noncontact photoconductive decay (PCD) technique is demonstrated in measuring the bulk lifetime, tau(B), and surface recombination velocity, S, in detector grade silicon and germanium crystals. We show that the simple analytical equations which relate the observed effective lifetimes in PCD transients to tau(B) and S have a limited range of applicability. The noncontact PCD technique is used to determine the effect of several surface treatments on the observed effective lifetimes in Si and Ge. A degradation of the effective lifetime in Si is reported as a result of the growth of a thin layer of native oxide at room temperature under atmospheric conditions. RP DERHACOBIAN, N (reprint author), LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720, USA. NR 14 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 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1026 EP 1030 DI 10.1109/23.322852 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800071 ER PT J AU WALTON, JT WONG, YK DERHACOBIAN, N HALLER, EE AF WALTON, JT WONG, YK DERHACOBIAN, N HALLER, EE TI LITHIUM DRIFTED SILICON DETECTOR FABRICATION ON GETTERED FLOATING-ZONE SILICON SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID DEFECTS AB A gettering procedure using phosphorous doped glass is shown to remove lithium-ion precipitation sites from p-type Floating-Zone (FZ) silicon. A model involving interaction between grown-in vacancies and oxidation-injected silicon interstitials is proposed to explain the gettering procedure. Examples of silicon lithium-drifted detectors fabricated on ungettered and gettered FZ silicons are presented. C1 LAWRENCE BERKELEY LAB,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP WALTON, JT (reprint author), LAWRENCE BERKELEY LAB,DIV ENGN,BERKELEY,CA 94720, USA. NR 22 TC 3 Z9 3 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1031 EP 1036 DI 10.1109/23.322853 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800072 ER PT J AU LUDEWIGT, B JAKLEVIC, J KIPNIS, I ROSSINGTON, C SPIELER, H AF LUDEWIGT, B JAKLEVIC, J KIPNIS, I ROSSINGTON, C SPIELER, H TI A HIGH-RATE, LOW-NOISE, X-RAY SILICON STRIP DETECTOR SYSTEM SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID HIGH-RESISTIVITY SILICON AB An x-ray detector system, based on a silicon strip detector wire-bonded to a low noise charge-sensitive amplifier integrated circuit, has been developed for synchrotron radiation experiments which require very high count rates and good energy resolution. Noise measurements and x-ray spectra were taken using a 6 mm long, 55 mum pitch strip detector in conjunction with a prototype 16-channel charge-sensitive preamplifier, both fabricated using standard 1.2 mum CMOS technology. The detector system currently achieves an energy resolution of 350 eV FWHM at 5.9 keV, 2 mus peaking time, when cooled to -5-degrees-C. RP LUDEWIGT, B (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 12 TC 26 Z9 26 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1037 EP 1041 DI 10.1109/23.322854 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800073 ER PT J AU JALAS, P NIEMELA, A CHEN, W REHAK, P CASTOLDI, A LONGONI, A AF JALAS, P NIEMELA, A CHEN, W REHAK, P CASTOLDI, A LONGONI, A TI NEW RESULTS WITH SEMICONDUCTOR DRIFT CHAMBERS FOR X-RAY SPECTROSCOPY SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID ELECTRONICS; DETECTORS AB Silicon Drift Detectors have been tested for X-ray Spectroscopy applications. By optimizing the detector-FET connection and using a very low leakage current detector manufacturing process, it has been possible to achieve a very good energy resolution. The resolution and leakage current have been studied as a function of temperature, from room temperature down to -30-degrees-C, and as function of active area. Also the effects influencing the peak to background ratio have been outlined. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. POLITECN MILAN, I-20133 MILAN, ITALY. RP OUTOKUMPU INSTRUMENTS OY, RIIHITONTUNTIE 7C, SF-02200 ESPOO, FINLAND. NR 10 TC 11 Z9 11 U1 0 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 AUG PY 1994 VL 41 IS 4 BP 1048 EP 1053 DI 10.1109/23.322856 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800075 ER PT J AU LUKE, PN ROSSINGTON, CS WESELA, MF AF LUKE, PN ROSSINGTON, CS WESELA, MF TI LOW-ENERGY X-RAY RESPONSE OF GE DETECTORS WITH AMORPHOUS-GE ENTRANCE CONTACTS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID MONTE-CARLO SIMULATION; SI(LI) DETECTORS AB The low energy x-ray response of Ge detectors with amorphous Ge entrance contacts has been evaluated. The spectral background due to near contact incomplete charge collection was found to consist of two components: a low level component which is insensitive to applied voltage and a high level step-like component which is voltage dependent. At high operating voltages, the high level component can be completely suppressed, resulting in background levels which are much lower than those previously observed using Ge detectors with Pd surface barrier or B ion implanted contacts, and which also compare favorably to those obtained with Si(Li) x-ray detectors. The response of these detectors to Fe-55 and 1.77 keV x-rays is shown. A qualitative explanation of the origins of the observed background components is presented. RP LUKE, PN (reprint author), LAWRENCE BERKELEY LAB,FAC ENGN,BERKELEY,CA 94720, USA. NR 11 TC 26 Z9 26 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1074 EP 1079 DI 10.1109/23.322861 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800080 ER PT J AU VANSTEVENINCK, W AF VANSTEVENINCK, W TI A PRESSURIZED ION-CHAMBER MONITORING-SYSTEM FOR ENVIRONMENTAL RADIATION MEASUREMENTS UTILIZING A WIDE-RANGE TEMPERATURE-COMPENSATED ELECTROMETER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to +/- 3 . 10(-16) A over the environmental range of temperature (-40 to +40-degrees-C). Using a single 10(11) OMEGA feed-back resistor, the electrometer accurately measures currents over a range from 3 . 10(-15) A to 3 . 10(-11) A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 muR h-1), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically approximately 27 pA at 1 mR h-1. A data recorder and system controller was designed using the Tattletale(TM) Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards. RP VANSTEVENINCK, W (reprint author), US DOE,ENVIRONM MEASUREMENTS LAB,376 HUDSON ST,NEW YORK,NY 10014, USA. NR 10 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1080 EP 1085 DI 10.1109/23.322862 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800081 ER PT J AU KIPNIS, I SPIELER, H COLLINS, T AF KIPNIS, I SPIELER, H COLLINS, T TI AN ANALOG FRONT-END BIPOLAR-TRANSISTOR INTEGRATED-CIRCUIT FOR THE SDC SILICON TRACKER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID STRIP DETECTORS AB A low-noise, low-power, high-bandwidth, radiation hard, silicon bipolar-transistor full-custom integrated circuit (IC) containing 64 channels of analog signal processing has been developed for the SDC silicon tracker. The IC was designed and tested at LBL and was fabricated using AT&T's CBIC-U2, 4 GHz f(T) complementary bipolar technology. Each channel contains the following functions: low-noise preamplification, pulse shaping and threshold discrimination. This is the first iteration of the production analog IC for the SDC silicon tracker. The IC is laid out to directly match the 50 mum pitch double-sided silicon strip detector. The chip measures 6.8 mm x 3.1 mm and contains 3,600 transistors. Three stages of amplification provide 180 mV/fC of gain with a 35 nsec peaking time at the comparator input. For a 14 pF detector capacitance, the equivalent noise charge is 1300 el. rms at a power consumption of 1 mW/channel from a single 3.5 V supply. With the discriminator threshold set to 4 times the noise level, a 16 nsec time-walk for 1.25 to 10 fC signals is achieved using a time-walk compensation network. Irradiation tests at TRIUMF to a PHI=10(14) protons/cm2 have been performed on the IC, demonstrating the radiation hardness of the complementary bipolar process. RP KIPNIS, I (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 9 TC 20 Z9 20 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1095 EP 1103 DI 10.1109/23.322865 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800084 ER PT J AU GOULDING, FS LANDIS, DA MADDEN, N MAIER, M YAVER, H AF GOULDING, FS LANDIS, DA MADDEN, N MAIER, M YAVER, H TI GAMMASPHERE - TIMING AND SIGNAL-PROCESSING ASPECTS OF THE BGO COMPTON SHIELD SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB We describe the design of the signal processing system and considerations involved in the timing performance of the BGO scintillator Compton shield that surrounds each of the 110 large germanium detectors used in a geodesic array covering the complete sphere surrounding the target in GAMMASPHERE. It is shown that the main timing limitation results from the statistics of photoelectron emission from the photocathode of the photomultiplier tubes (PMTs) that observe the light from the scintillators and that achieving the required timing demands triggering on the first photoelectron. The circuits to do this for a single detector assembly must be able to deal with signals from 14 PMTs associated with the 7 elements of the scintillator shield surrounding each germanium detector. RP GOULDING, FS (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 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 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1135 EP 1139 DI 10.1109/23.322871 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800090 ER PT J AU GOULDING, FS LANDIS, DA MADDEN, N MAIER, M YAVER, H AF GOULDING, FS LANDIS, DA MADDEN, N MAIER, M YAVER, H TI GAMMASPHERE - ELIMINATION OF BALLISTIC DEFICIT BY USING A QUASI-TRAPEZOIDAL PULSE SHAPER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB Gammasphere uses an spherical array of very large (7.2cm dia.) germanium detectors and only high-multiplicity events are studied. To achieve a reasonable coincidence rate, the individual detector channels must handle high rates with minimum pile-up losses. Ten microseconds was chosen as the total processing time for a signal which means that the shaped signal peaks in about 4us. The combination of short pulse shaping and the fluctuating long charge collection times (up to 400ns) in the detectors exaggerates the energy resolution degradation due to ballistic deficit effects. We describe a method of producing a flat-topped pulse with a simple time-invariant network that satisfies GAMMASPHERE requirements and eliminates ballistic deficit effects. RP GOULDING, FS (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 TC 8 Z9 9 U1 2 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1140 EP 1144 DI 10.1109/23.322872 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800091 ER PT J AU GOULDING, FS LANDIS, DA AF GOULDING, FS LANDIS, DA TI GAMMASPHERE - CORRECTION TECHNIQUE FOR DETECTOR CHARGE TRAPPING SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID BALLISTIC DEFICIT; SPECTROMETERS AB GAMMASPHERE uses 110 very large germanium detectors. Such detectors exhibit charge trapping effects on energy resolution initially due to a native electron trap that is present in virtually all germanium. Furthermore, radiation damage is a serious problem in GAMMASPHERE experiments, producing hole traps that degrade resolution and eventually require annealing to restore the original performance. The technique discussed here uses the current pulse shape from a detector to develop a parameter related to the radius of the largest interaction in the ''track'' of a gamma ray in the detector. Since the charge trapping loss in a signal can be related to the distance carriers travel, the ''radius'' parameter can be used by software to apply a trap correction to the signal. RP GOULDING, FS (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 TC 12 Z9 12 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1145 EP 1149 DI 10.1109/23.322873 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800092 ER PT J AU TURKO, BT ALBRIGHT, KL KING, NSP YATES, GJ AF TURKO, BT ALBRIGHT, KL KING, NSP YATES, GJ TI A/D PROCESSING OF VIDEO SIGNALS AT VERY HIGH PIXEL RATES SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB Video wave-form of CCD photocharge, clocked out at very high pixel rates, is a sequence of narrow voltage pulses. Pulse height is proportional to the recovered charge. A method and circuits are described for digitizing such waveforms in a 10-bit range at rates exceeding 75 MHz. Signal processing includes a wide-band clamping amplifier, a self-clocked peak detector, a very fast track/hold amplifier and a 75 MSPS, 10-bit flash converter. Digital data can be stored either in a local high speed RAM or transferred by a fast fiber-optic link to the remote digital storage. Test results (such as linearity, dynamic range and signal/noise ratio) are also given. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. RP TURKO, BT (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1159 EP 1162 DI 10.1109/23.322876 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800095 ER PT J AU HEARN, WE WRIGHT, ME AF HEARN, WE WRIGHT, ME TI A FULLY INTEGRATED 16 CHANNEL DIGITALLY TRIMMED PULSE SHAPING AMPLIFIER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID CAPACITOR AB A fully integrated CMOS pulse shaping amplifier has been developed at LBL. All frequency dependent networks are included on the chip. Provision is made for tuning to compensate for process variations. The overall architecture and details of the circuitry are discussed. Test results are presented. RP HEARN, WE (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1163 EP 1168 DI 10.1109/23.322877 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800096 ER PT J AU CRAWLEY, HB MCKAY, R MEYER, WT ROSENBERG, EI THOMAS, WD AF CRAWLEY, HB MCKAY, R MEYER, WT ROSENBERG, EI THOMAS, WD TI RECENT RESULTS FROM TEST OF FAST ANALOG-TO-DIGITAL CONVERTERS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID FLASH ADCS; PERFORMANCE; RANGE AB We present results from tests of eight, ten, and twelve bit ADCs that operate in the range of 10 to 120 megasamples per second. We use a test bench and software we have developed to perform the tests on as wide a range of devices as possible. By testing devices with the same input signals, the same software, and the same parameter definitions, we make possible direct comparisons between competing devices. Important parameters measured include integral and differential nonlinearity, effective number of bits, and word error rate. While the tests are intended primarily to benefit the design of high rate physics experiments, the results are also useful to workers in other fields. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. RP CRAWLEY, HB (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1181 EP 1186 DI 10.1109/23.322880 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800099 ER PT J AU NUTTER, S TARLE, G CRAWLEY, HB MCKAY, R MEYER, WT ROSENBERG, EI THOMAS, WD AF NUTTER, S TARLE, G CRAWLEY, HB MCKAY, R MEYER, WT ROSENBERG, EI THOMAS, WD TI RESULTS OF RADIATION HARDNESS TESTS AND PERFORMANCE TESTS OF THE HS9008RH FLASH ADC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID RANGE AB Results from tests characterizing the performance and radiation hardness of the HS9008RH flash analog to digital convertor (FADC) are presented. These tests were performed primarily to evaluate the suitability of this device for use in the GEM Central Tracker at the SSC experiment. Basic performance characteristics and susceptibility of these characteristics to radiation were examined. Performance test results indicate that the device integral nonlinearity is sampling rate dependent and worsens rapidly above a sampling rate of 15 megasamples per second (MSPS). No degradation in performance of the device was observed after its exposure of up to 81 Mrad of 1.25 MeV gamma radiation from a Co-60 source. Exposure of the device to a reactor fast neutron fluence (E > 100keV) of 5 x 10(14)/cm2 resulted in no significant observed performance degradation as well. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. RP NUTTER, S (reprint author), UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1197 EP 1202 DI 10.1109/23.322883 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800102 ER PT J AU HALLER, GM WOOLEY, BA AF HALLER, GM WOOLEY, BA TI AN ANALOG MEMORY INTEGRATED-CIRCUITS FOR WAVE-FORM SAMPLING UP TO 900 MHZ SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID LARGE DETECTOR; CALORIMETER; ELECTRONICS AB The design and implementation of a switched-capacitor memory suitable for capturing high-speed analog waveforms is described. Highlights of the presented circuit are a 900 MHz sampling frequency (generated on chip), input signal independent cell pedestals and sampling instances, and cell gains that are insensitive to component sizes. A two-channel version of the memory with 32 cells for each channel has been integrated in a 2-mum complementary metal oxide semiconductor (CMOS) process with polysilicon-to-polysilicon capacitors. The measured rms cell response variation in a channel after cell pedestal subtraction is less than 0.3 mV across the full input signal range. The cell-to-cell gain matching is better than 0.01% rms, and the nonlinearity is less than 0.03% for a 2.5-V input range. The dynamic range of the memory exceeds 13 bits, and the peak signal-to-(noise+distortion) ratio for a 21.4 MHz sine wave sampled at 900 MHz is 59 dB. C1 STANFORD UNIV,CTR INTEGRATED SYST,STANFORD,CA 94309. RP HALLER, GM (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 20 TC 14 Z9 15 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1203 EP 1207 DI 10.1109/23.322884 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800103 ER PT J AU TODD, RA KENNEDY, EJ BRITTON, CL BERRIDGE, SC BUGG, WM DU, YC ALLEY, GT BRASHEAR, HR BAUER, ML EMERY, MS WINTENBERG, AL AF TODD, RA KENNEDY, EJ BRITTON, CL BERRIDGE, SC BUGG, WM DU, YC ALLEY, GT BRASHEAR, HR BAUER, ML EMERY, MS WINTENBERG, AL TI MONOLITHIC SYSTEMS-DESIGN FOR THE SILICON ELECTROMAGNETIC CALORIMETRY COLLABORATION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB A series of monolithic bipolar charge-sensitive preamplifiers and a companion monolithic 50-ns CMOS shaping amplifier have been designed, fabricated, and characterized for use with silicon calorimeters. The preamplifier topologies evaluated were current-mode, folded cascode, and differential. These three topologies were fabricated in the Harris Semiconductor VHF process and were characterized for noise, transient response, power dissipation and radiation hardness. Versions of each preamplifier have been designed to operate over a range of detector pad capacitance from 20-500 pF. The CMOS shaping amplifier specifications and test results are presented with emphasis on the system integration requirements for beam tests. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP TODD, RA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1212 EP 1216 DI 10.1109/23.322886 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800105 ER PT J AU ERICSON, MN TURNER, GW MCMILLAN, DE HOFFHEINS, BS TODD, RA HILLER, JM AF ERICSON, MN TURNER, GW MCMILLAN, DE HOFFHEINS, BS TODD, RA HILLER, JM TI A MINIATURIZED ASIC-BASED MULTICHANNEL SCALER INSTRUMENT SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID SYSTEM AB A miniaturized multichannel scaler instrument has been developed to address size and operational constraints for data acquisition in a portable laser-induced luminescence system. The multichannel scaling (MCS) function is implemented as a programmable application specific integrated circuit (ASIC) with standard interfaces for control and data acquisition. The instrument is microcontroller-based with sufficient computing power for data manipulation and algorithmic processing. The unit includes electronics for laser control and amplification and pulse height discrimination of PMT pulses. Modification of the instrument should allow use in nuclear, chemical, and spectroscopy-related applications including Mossbauer experiments[1,2]. Interfaces are incorporated allowing both computer-controlled and stand-alone operation. Implementation of the MCS function as an ASIC and comparison with conventional implementations are discussed. Full characterization of the MCS is presented including differential non-linearity (DNL), bin dead time, and bandwidth measurements. C1 OAK RIDGE Y-12 PLANT,OAK RIDGE,TN 37831. RP ERICSON, MN (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, 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 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1217 EP 1220 DI 10.1109/23.322887 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800106 ER PT J AU BECKERSZENDY, R BRIGGS, D HALLER, G HOEFLICH, J INNES, W AF BECKERSZENDY, R BRIGGS, D HALLER, G HOEFLICH, J INNES, W TI DESIGN OF A TRIGGER AND DATA-ACQUISITION SYSTEM FOR A DETECTOR AT PEP-II SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB This paper proposes a design of a trigger and data acquisition system for a detector at the PEP-II B Factory. The system is asynchronous, data-driven, and scalable. Design goals include orthogonal tracking and calorimetric triggers, minimal dead time, graceful degradation, high efficiency, and useful performance in the face of backgrounds so high as to overwhelm reconstruction. Also described are instrumentation of the Drift Chamber, based on 8-bit FADCs, and of the Calorimeter, based on a new custom integrated circuit, the Charge Amplifier with Range Encoding (CARE), and 10-bit ADCs. This design employs commercial embedded CPUs in VME and VXI crates. RP BECKERSZENDY, R (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1289 EP 1293 DI 10.1109/23.322901 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800120 ER PT J AU ANDRESEN, J ARETI, H BLACK, D CHRAMOWICZ, J FOSTER, G JOSHI, U TREPTOW, K WALSH, D VANCONANT, R ZIMMERMANN, S ZMUDA, T AF ANDRESEN, J ARETI, H BLACK, D CHRAMOWICZ, J FOSTER, G JOSHI, U TREPTOW, K WALSH, D VANCONANT, R ZIMMERMANN, S ZMUDA, T TI FASTBUS READOUT SYSTEM FOR THE CDF DAQ UPGRADE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB The Data Acquisition System (DAQ) at the Collider Detector at Fermilab is currently being upgraded to handle a minimum of 100 events/sec for an aggregate bandwidth which is at least 25 Mbytes/sec. The DAQ System is based on a commercial switching network which has interfaces to VME bus. The modules that read out the front end crates (FASTBUS and RABBIT) have to deliver the data to the VME bus based host adapters of the switch. This paper describes a read out system that has the required bandwidth while keeping the experiment deadtime due to the read out to a minimum. RP ANDRESEN, J (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1300 EP 1303 DI 10.1109/23.322903 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800122 ER PT J AU MOSS, CE CASPERSON, DE ECHAVE, MA EDWARDS, BC MILLER, JR SAYLOR, WW SWEET, MR VALENCIA, JE AF MOSS, CE CASPERSON, DE ECHAVE, MA EDWARDS, BC MILLER, JR SAYLOR, WW SWEET, MR VALENCIA, JE TI A SPACE FIBEROPTIC X-RAY BURST DETECTOR SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB We describe a novel, lightweight x-ray burst detector that can be embedded in a satellite structure, thus forming a ''smart skin,'' which has minimal impact on the host satellite. The design is based on two types of optical fibers coupled to photodiodes. The first is a scintillating fiber, which gives a fast signal for timing. The second is a germanium-doped silica fiber, which darkens for a few milliseconds when irradiated with a burst of x rays. The resulting slow signal is used to discriminate against electrostatic discharges. The coincidence of a fast signal from the scintillating fiber with a slow signal from the darkening fiber is the signature of an x-ray burst. The response is linear at low doses and becomes nonlinear at high doses. We have two techniques to test the instrument in a space experiment scheduled for 1994. First, a small, space-qualified flash x-ray unit can illuminate the fibers. Second, we can detect space background radiation. The cumulative dose will be monitored by RADFET dosimeters. Future work on embedding the fibers and the electronics as Application Specific Integrated Circuits (ASICs) in the spacecraft skin could lead to use of these detectors on many satellites. RP MOSS, CE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544, USA. NR 9 TC 0 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1328 EP 1332 DI 10.1109/23.322908 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800127 ER PT J AU HUBBARD, GS MCMURRAY, RE KELLER, RG WERCINSKI, PF WALTON, JT WONG, YK AF HUBBARD, GS MCMURRAY, RE KELLER, RG WERCINSKI, PF WALTON, JT WONG, YK TI VARIABLE-TEMPERATURE PERFORMANCE OF A SI(LI) DETECTOR STACK SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB New experimental data is presented which displays Cs-137 resolution of both single Si(Li) devices and a detector stack 2 cm in height as a function of temperature (85 K less-than-or-equal-to T less-than-or-equal-to 245 K). We also discuss variations in photopeak shape which indicate that detector charge collection may be temperature dependent over the range of interest. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP HUBBARD, GS (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1338 EP 1342 DI 10.1109/23.322910 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800129 ER PT J AU SMEDLEY, K JAYASURIYA, A CHRISTIANSEN, C SHAFER, R AF SMEDLEY, K JAYASURIYA, A CHRISTIANSEN, C SHAFER, R TI RIPPLE DISTRIBUTION IN MAGNET STRINGS OF SUPER COLLIDER SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB The voltage ripple in the power supplies of the Collider generate ripple current in the magnet coil that, in turn, generates ripple in the magnetic field of dipoles and quadrupoles. The ripple in the magnetic field will be a function of time and space due to the transmission line effect. The work reported in this paper gives a thorough analysis the frequency spectrum and the spatial propagation pattern of the differential mode ripple in the magnet strings for the injection mode and the collider mode. C1 SO METHODIST UNIV,DALLAS,TX 75275. SUPERCONDUCTING SUPER COLLIDER LAB,DALLAS,TX 75237. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP SMEDLEY, K (reprint author), UNIV CALIF IRVINE,IRVINE,CA 92717, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1364 EP 1370 DI 10.1109/23.322914 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800133 ER PT J AU CAVALLISFORZA, M KELLEY, LA KLEIN, SR ANTHONY, P BECKERSZENDY, R ERICKSON, R GEARHART, RA KELLER, LP NIEMI, G PERL, ML ROCHESTER, LS STANEK, M TRUHER, JB BOSTED, PE WHITE, J AF CAVALLISFORZA, M KELLEY, LA KLEIN, SR ANTHONY, P BECKERSZENDY, R ERICKSON, R GEARHART, RA KELLER, LP NIEMI, G PERL, ML ROCHESTER, LS STANEK, M TRUHER, JB BOSTED, PE WHITE, J TI A METHOD OF OBTAINING PARASITIC E(+) OR E(-) BEAMS DURING SLAC LINEAR COLLIDER OPERATION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB We have developed a technique that allows SLAC to provide parasitic low-intensity secondary e+ and e- beams up to 25 GeV to End Stations A and B and to the FFTB during SLC operation. This beam was successfully used for a one-month-long experimental run in End Station A by the SLAC E-146 collaboration. The experiment used 400 MeV to 25 GeV electron beams at intensities averaging one electron per pulse and 120 pulses per second. The method for producing such a beam without the need for dedicated beam time was to operate parasitically from SLC: photons produced in the SLC beam scrapers in linac sectors 28, 29 and 30 were converted to positrons and electrons in a target downstream from the SLC splitter magnet. The secondary electrons or positrons were then transported to ESA with the A-line. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. AMERICAN UNIV,WASHINGTON,DC 20016. RP CAVALLISFORZA, M (reprint author), UNIV CALIF SANTA CRUZ,SANTA CRUZ INST PARTICLE PHYS,SANTA CRUZ,CA 95064, USA. RI Cavalli-Sforza, Matteo/H-7102-2015 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1371 EP 1373 DI 10.1109/23.322915 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800134 ER PT J AU STOCK, D VESELY, W SAMANTA, P AF STOCK, D VESELY, W SAMANTA, P TI MODELING THE DEGRADATION OF NUCLEAR-COMPONENTS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB This paper describes component level reliability models that use information on degradation to predict component reliability, and which have been used to evaluate different maintenance and testing policies. The models are based on continuous time Markov processes, and are a generalization of reliability models currently used in Probabilistic Risk Assessment. An explanation of the models, the model parameters, and an example of how these models can be used to evaluate maintenance policies are discussed. C1 SCI APPLICAT INT CORP,DUBLIN,OH 43017. RP STOCK, D (reprint author), BROOKHAVEN NATL LAB,POB 5000,UPTON,NY 11973, USA. NR 5 TC 3 Z9 3 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1405 EP 1407 DI 10.1109/23.322923 PN 1 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800141 ER PT J AU MOSES, WW DERENZO, SE AF MOSES, WW DERENZO, SE TI DESIGN STUDIES FOR A PET DETECTOR MODULE USING A PIN PHOTODIODE TO MEASURE DEPTH OF INTERACTION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE ID EFFICIENT; SYSTEM AB We present design studies of a multi-layer PET detector module that uses an 8x8 array of 3 mm square PIN photodiodes to both identify the crystal of interaction and measure the depth of interaction. Each photodiode is coupled to one end of a 3x3x30 mm BGO crystal, with the opposite ends of 64 such crystals attached to a single 1'' square photomultiplier tube that provides a timing signal and energy discrimination. Each BGO crystal is coated with a lossy reflector, so the ratio of light detected in the photodiode and photomultiplier tube depends on the interaction depth in the crystal, and is used to determine this depth of interaction on an event by event basis. A test module with one 3x3x30 mm BGO crystal, one 3 mm square PIN photodiode, and one photomultiplier tube is operated at -20-degrees-C with an amplifier peaking time of 4 mus, and a depth of interaction resolution of 5 to 8 mm fwhm measured. Simulations predict that this virtually eliminates radial elongation in a 60 cm diameter BGO tomograph. The photodiode signal corresponding to 511 keV energy deposit varies linearly with excitation position, ranging from 1250 electrons (e-) at the end closest to the photodiode to 520 e- at the opposite end. The electronic noise is a position independent 330 e- fwhm, so the signal to noise ratio is sufficient to reliably identify the crystal of interaction in a 64 element module. RP MOSES, WW (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 14 TC 106 Z9 108 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1441 EP 1445 DI 10.1109/23.322929 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800147 ER PT J AU MOSES, WW KIPNIS, I HO, MH AF MOSES, WW KIPNIS, I HO, MH TI A 16-CHANNEL CHARGE SENSITIVE AMPLIFIER IC FOR A PIN PHOTODIODE-ARRAY BASED PET DETECTOR MODULE SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium and Medical Imaging Conference (NSS-MIC 93) CY OCT 30-NOV 06, 1993 CL SAN FRANCISCO, CA SP IEEE AB A 16-channel integrated circuit charge sensitive preamplifier has been developed for a PET detector module that uses an 8x8 array of PIN photodiodes to identify the crystal of interaction. The amplifier, which is made using 1.2 mum CMOS technology, produces an output of 100 mV per 1000 e- input, and its noise performance is optimized for 10 pF detector capacitance. The rise time, fall time, bias current through the first FET, and detector current compensation are each controlled by a dc current applied to the 2 mm square chip. The Johnson noise (e- fwhm at 1 mus peaking time) is 173 + 13C, where C is the input capacitance in pF, and the shot noise (e- fwhm) is 16.4 square-root IT, where I is the detector dark current in pA and T is the amplifier shaping time in mus. With this amplifier, the target noise of 300 e- fwhm can nearly be met with 300 mum depletion thickness photodiodes (3 pF, 200 pA per 3x3 mm element). RP MOSES, WW (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 9 TC 23 Z9 23 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1994 VL 41 IS 4 BP 1469 EP 1472 DI 10.1109/23.322933 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA PE028 UT WOS:A1994PE02800152 ER PT J AU HALLOCK, GA HICKOK, RL HORNADY, RS AF HALLOCK, GA HICKOK, RL HORNADY, RS TI THE TMX HEAVY-ION BEAM PROBE SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID TANDEM MIRROR; CONFINEMENT AB A heavy ion beam probe has been used to measure the radial space potential distribution in the central cell of TMX. This was the first beam probe system to utilize computer control, CAMAC instrumentation, and fast time response for broadband fluctuation capabilities. The fast time response was obtained using off-line processing of the energy analyzer detector signals and wideband transimpedance amplifiers. The on-axis space potential was found to be 300-400 V, with phi(e)/T-ec similar to 8. The radial potential profile is parabolic when gas box fueling is used. The frequency of observed fluctuations was found to agree with the E x B plasma rotation frequency during the discharge. The measured Tl++ secondary ion current level is consistent with calculations, given reasonable assumptions for beam attenuation. C1 RENSSELAER POLYTECH INST,DEPT ELECT COMP & SYST ENGN,TROY,NY 12180. LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550. RP HALLOCK, GA (reprint author), UNIV TEXAS,DEPT ELECT & COMP ENGN,AUSTIN,TX 78712, USA. NR 20 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 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1994 VL 22 IS 4 BP 341 EP 349 DI 10.1109/27.310639 PG 9 WC Physics, Fluids & Plasmas SC Physics GA PE336 UT WOS:A1994PE33600006 ER PT J AU WINSKE, D JONES, ME AF WINSKE, D JONES, ME TI PARTICULATE DYNAMICS AT THE PLASMA-SHEATH BOUNDARY IN DC GLOW-DISCHARGES SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID LOW-PRESSURE DISCHARGES; CONTAMINATION PARTICLE TRAPS; RADIO-FREQUENCY DISCHARGES; LASER-LIGHT SCATTERING; MONTE-CARLO SIMULATION; FLUID HYBRID MODEL; SELF-CONSISTENT; RADIOFREQUENCY DISCHARGES; DUST PARTICLES; RF DISCHARGES AB The forces on and resulting dynamics of particulate contaminants near the plasma-sheath boundary in a one-dimensional, steady-state glow discharge are examined. Various expressions for the electric force, including the effects of nonneutrality and particulate spacing on the charge state, are considered, and several different ways to compute the ion drag force are compared. The properties of the particulate traps that result from the interplay of these forces are studied. The effects of the gravitational, neutral drag, and polarization forces are also considered. Time-dependent motion of the particulates, including the effects of a temporally varying, spatially localized particulate density, is also investigated. While some uncertainties exist in the individual expressions for the various forces and in the properties of the discharge, the particulate traps are fairly well defined and consistent with experiments and other analyses. RP WINSKE, D (reprint author), LOS ALAMOS NATL LAB,DIV APPL THEORET PHYS,INERTIAL FUS & PLASMA THEORY GRP,LOS ALAMOS,NM 87545, USA. NR 85 TC 51 Z9 51 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1994 VL 22 IS 4 BP 454 EP 464 DI 10.1109/27.310655 PG 11 WC Physics, Fluids & Plasmas SC Physics GA PE336 UT WOS:A1994PE33600022 ER PT J AU PIN, FG KILLOUGH, SM AF PIN, FG KILLOUGH, SM TI A NEW FAMILY OF OMNIDIRECTIONAL AND HOLONOMIC WHEELED PLATFORMS FOR MOBILE ROBOTS SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article AB This paper presents the concepts for a new family of holonomic wheeled platforms that feature full omnidirectionality with simultaneous and independently controlled rotational and translational motion capabilities. We first present the ''orthogonal-wheels'' concept and the two major wheel assemblies on which these platforms are based. We then describe how a combination of these assemblies with appropriate control can be used to generate an omnidirectional capability for mobile robot platforms. Several alternative designs are considered, and their respective characteristics with respect to rotational and translational motion control are discussed. The design and control of a prototype platform developed to test and demonstrate the proposed concepts is then described, and experimental results illustrating the full omnidirectionality of the platform with decoupled rotational and translational degrees of freedom are presented. C1 OAK RIDGE NATL LAB,CESAR,OAK RIDGE,TN 37831. RP PIN, FG (reprint author), OAK RIDGE NATL LAB,DIV ROBOT & PROC SYST,AUTONOMOUS ROBOT SYST GRP,OAK RIDGE,TN 37831, USA. NR 22 TC 147 Z9 151 U1 1 U2 19 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD AUG PY 1994 VL 10 IS 4 BP 480 EP 489 DI 10.1109/70.313098 PG 10 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA PC662 UT WOS:A1994PC66200007 ER PT J AU PARKS, HG SCHRIMPF, RD CRAIGIN, B JONES, R RESNICK, P AF PARKS, HG SCHRIMPF, RD CRAIGIN, B JONES, R RESNICK, P TI QUANTIFYING THE IMPACT OF HOMOGENEOUS METAL CONTAMINATION USING TEST STRUCTURE METROLOGY AND DEVICE MODELING SO IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING LA English DT Article; Proceedings Paper CT International Conference on Microelectronic Test Structures (ICMTS) CY MAR 22-25, 1993 CL SITGES, SPAIN SP IEEE, ELECTRON DEVICES SOC AB Deposition of metallic impurities from HF process solutions has been investigated experimentally and explained theoretically in a qualitative manner. The depositions are shown to be electrochemical in nature in that an oxidation reduction reaction results in metal ions in solution depositing on the wafer as elements with an oxidation state of 0. The theory is only qualitative in that it can only predict which metals will deposit, not how much. Experimentally, simple transmission equations can be determined which relate metallic contamination levels on Si wafer surfaces (atoms/cm2) to metal concentration in the solution (ppb). Simple test structures have been fabricated with known amounts of iron and copper contamination in the pregate oxide clean of a 1.25 mum CMOS process. Device measurements indicate device degradation in the case of copper, confirming deposition studies that copper deposits from HF solutions. Iron contaminated wafers show no contamination related device effects, in support of theoretical predictions and deposition studies indicating iron does not deposit from HF solutions. The importance and potential usefulness of test structures as homogeneous contamination monitors is illustrated through device modeling of the contamination effects observed in the test structures that can then be used to estimate the effects of such contamination on ULSI circuit performance. C1 SANDIA NATL LABS,MICROELECTR DEV LAB,ALBUQUERQUE,NM 87185. UNIV ARIZONA,DEPT ELECT & COMP ENGN,SEMATECH ELECT EFFECTS CONTAMINAT GRP,TUCSON,AZ 85721. RP PARKS, HG (reprint author), UNIV ARIZONA,DEPT ELECT & COMP ENGN,TUCSON,AZ 85721, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 21 TC 17 Z9 17 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0894-6507 J9 IEEE T SEMICONDUCT M JI IEEE Trans. Semicond. Manuf. PD AUG PY 1994 VL 7 IS 3 BP 249 EP 258 DI 10.1109/66.311326 PG 10 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA PE203 UT WOS:A1994PE20300003 ER PT J AU HAWLEY, RW GALLAGHER, NC AF HAWLEY, RW GALLAGHER, NC TI ON EDGEWORTHS METHOD FOR MINIMUM ABSOLUTE ERROR LINEAR-REGRESSION SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Article AB The Edgeworth algorithm for minimizing absolute error is known to suffer from convergence problems when the data contains degeneracies. In this paper, it is shown that for the particular problem of fitting a line to a set of uniformly sampled data, the problem of degeneracy may be easily avoided by utilizing a stable sorter for the weighted median operation needed in Edgeworth's method. Proof of convergence is based on establishing an equivalence between the use of a stable sorting routine and perturbing the original data in such a way that no degeneracies exist. In addition, it will be shown that the data set size may be selected so that the minimum error fit is unique. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87123. UNIV DELAWARE,DEPT ELECT ENGN,NEWARK,DE 19718. RP HAWLEY, RW (reprint author), PURDUE UNIV,SCH ELECT ENGN,W LAFAYETTE,IN 47907, USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD AUG PY 1994 VL 42 IS 8 BP 2045 EP 2054 DI 10.1109/78.301827 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA PB601 UT WOS:A1994PB60100012 ER PT J AU HASHIMOTO, S MOHRENWEISER, HW GREGERSEN, PK CHIORAZZI, N AF HASHIMOTO, S MOHRENWEISER, HW GREGERSEN, PK CHIORAZZI, N TI CHROMOSOMAL LOCALIZATION, GENOMIC STRUCTURE, AND ALLELIC POLYMORPHISM OF THE HUMAN CD79A (IG-ALPHA/MB-1) GENE SO IMMUNOGENETICS LA English DT Article ID CHRONIC LYMPHOCYTIC-LEUKEMIA; CELL ANTIGEN RECEPTOR; FLUORESCENCE INSITU HYBRIDIZATION; MURINE MB-1 GENE; PRE-B; TRANSCRIPTION FACTOR; CONSERVED SEQUENCE; MOLECULAR-CLONING; B29 GENE; IMMUNOGLOBULIN AB The germline DNA sequence of the human CD79a (Ig-alpha/mb-1) gene was determined by polymerase chain reaction sequencing of a cosmid clone derived from an arrayed human chromosome 19 library. The CD79a gene was localized to chromosome 19q13.2; this localization places the gene within the CEA-like gene cluster with the following gene order: -CEA-CGM1-CD79a-RPS11-ATP1A3-BGP-CGM9-. The genomic organization of the human CD79a gene resembles the mouse counterpart with five exons interrupted by four introns. Computer analyses suggest the presence of transcription regulatory elements known to be important in the regulation of mouse CD79a (AP-1, EBF, AP-2, MUF2, and SP-1 sites), as well as elements not found in the mouse gene (an NF-kappa B binding site and a series of E-box motifs). Similar to the mouse gene, the 5' flanking region of human CD79n lacks a TATA box; however, unlike mouse CD79a, a classical octamer motif could not be identified in the human gene. Finally, a new Rsa I restriction fragment length polymorphism was defined in the non-coding regions of the human gene. C1 N SHORE UNIV HOSP,DEPT MED,MANHASSET,NY 11030. CORNELL UNIV,COLL MED,NEW YORK,NY 10021. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. FU NIAID NIH HHS [NIAID AI 35984, NIAID AI 10811] NR 62 TC 14 Z9 15 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0093-7711 J9 IMMUNOGENETICS JI Immunogenetics PD AUG PY 1994 VL 40 IS 4 BP 287 EP 295 PG 9 WC Genetics & Heredity; Immunology SC Genetics & Heredity; Immunology GA PE479 UT WOS:A1994PE47900006 PM 7916003 ER PT J AU BURNS, JH SACHLEBEN, RA DAVIS, MC AF BURNS, JH SACHLEBEN, RA DAVIS, MC TI STRUCTURES OF ISOMERIC SUBSTITUTED 14-CROWN-4 ETHERS AND THEIR LISCN COMPLEXES SO INORGANICA CHIMICA ACTA LA English DT Article DE CRYSTAL STRUCTURES; CROWN ETHER COMPLEXES; LITHIUM COMPLEXES ID LITHIUM IONS; DERIVATIVES; DIBENZO-14-CROWN-4; EXTRACTION; SELECTIVITY; IONOPHORES; BEARING; ALKALI AB Crystal structures of methyleno,tetracyclopentyl-14-crown-4 (1), methyl,tetracyclopentyl-14-crown-4 (2), methyleno,didecalino-14-crown-4 (3), methyl,didecalino-14-crown-4 (4), 2.LiSCN and 4.LiSCN were determined by X-ray diffraction methods. The free ligands, 2 and 4, have their rings collapsed, but on complexation open up to accommodate an Li+ ion. It is bonded to all four O atoms of the crown in each case and to an apical SCN- ion to form a rectangular pyramid. The methyl group is pseudoaxial in 2.LiSCN and pseudoequatorial in 4.LiSCN. In 2 and 4 the bridging propylene groups are disordered over two sites. RP BURNS, JH (reprint author), OAK RIDGE NATL LAB,DIV CHEM ZP ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD AUG PY 1994 VL 223 IS 1-2 BP 125 EP 130 DI 10.1016/0020-1693(94)04006-0 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA PF173 UT WOS:A1994PF17300019 ER PT J AU NGUYEN, HD PAIK, S AF NGUYEN, HD PAIK, S TI UNSTEADY MIXED CONVECTION FROM A SPHERE IN WATER-SATURATED POROUS-MEDIA WITH VARIABLE SURFACE-TEMPERATURE HEAT-FLUX SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID CYLINDER AB Mixed convection about a sphere buried in a porous medium saturated with water is numerically investigated using a Chebyshev-Legendre spectral method. Both Darcy's law and the Boussinesq approximation together with effects due to nonlinear dependence of density on temperature are used to formulate the governing equations. Two types of surface condition are considered including variable surface temperature and surface heat flux which are modeled by Legendre expansions. Calculated results for the nonuniform heating and the nonuniform surface temperature cases demonstrate that the flow structures are not much different from the non-porous medium except for the recirculation zones which appear when the direction of the free stream velocity is opposite to the direction of the buoyancy force. Effects of nonuniform surface temperature are seen to dictate the heat flux distribution along the sphere surface and vice versa. RP NGUYEN, HD (reprint author), IDAHO NATL ENGN LAB, POB 1625, IDAHO FALLS, ID 83415 USA. NR 13 TC 9 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 EI 1879-2189 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD AUG PY 1994 VL 37 IS 12 BP 1783 EP 1793 DI 10.1016/0017-9310(94)90067-1 PG 11 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA NZ770 UT WOS:A1994NZ77000009 ER PT J AU STEINBERG, M AF STEINBERG, M TI FOSSIL-FUEL AND GREENHOUSE-GAS MITIGATION TECHNOLOGIES SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB The world has become highly alerted to the global warming problem. The major greenhouse gas is CO2, large quantities of which are produced by combustion of fossil fuels; coal being a major contributor. Whereas a great deal of effort is being expended on the science of climate change, very little work has gone into mitigation technologies. This is now changing. The options include improved energy utilization efficiency, fuel switching, non-fossil energy sources, and pre- and post-combustion removal and disposal of CO2 from central power stations. Another approach is the pre-combustion conversion of fossil fuel to a carbon-rich fraction and a hydrogen-rich fraction; storing the carbon-rich and only utilizing the hydrogen-rich fraction. By coprocessing with the biomass, the CO2 emission from fossil fuel can be reduced to negligible values. Assessment of these systems is discussed. RP STEINBERG, M (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 9 TC 2 Z9 2 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD AUG PY 1994 VL 19 IS 8 BP 659 EP 665 DI 10.1016/0360-3199(94)90150-3 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA NU518 UT WOS:A1994NU51800002 ER PT J AU YEW, CH TAYLOR, PA AF YEW, CH TAYLOR, PA TI A THERMODYNAMIC THEORY OF DYNAMIC FRAGMENTATION SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article ID SPALL AB We present a theory of dynamic fragmentation of brittle materials based on thermodynamic arguments. We recover the expressions for average fragment size and number as originally derived by Grady. We extend the previous work by obtaining descriptions of fragment size distribution and compressibility change due to the fragmentation process. The size distribution is assumed to be proportional to the spectral power of the strain history, and a sample distribution is presented for a fragmentation process corresponding to a constant rate strain history. The description of compressibility change should be useful in computational studies of fragmentation. These results should provide insight into the process of fragmentation of brittle materials from hypervelocity impact. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP YEW, CH (reprint author), UNIV TEXAS,AUSTIN,TX 78712, USA. NR 10 TC 13 Z9 15 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD AUG PY 1994 VL 15 IS 4 BP 385 EP 394 DI 10.1016/0734-743X(94)80023-3 PG 10 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA NX410 UT WOS:A1994NX41000005 ER PT J AU FORRESTAL, MJ ALTMAN, BS CARGILE, JD HANCHAK, SJ AF FORRESTAL, MJ ALTMAN, BS CARGILE, JD HANCHAK, SJ TI AN EMPIRICAL-EQUATION FOR PENETRATION DEPTH OF OGIVE-NOSE PROJECTILES INTO CONCRETE TARGETS SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article ID RODS AB We conducted depth of penetration experiments with ogive-nose projectiles and concrete targets with unconfined compressive strengths of nominally 14 MPa (2 ksi), 35 MPa (5 ksi), and 97 MPa (14 ksi). From our data and the data presented by Canfield and Clator [J. A. CANFIELD and I. G. CLATOR, Development of a scaling law and techniques to investigate penetration in concrete. NWL Report No. 2057, U.S. Naval Weapons Laboratory, Dahlgren, VA (1966)] [1], we developed an empirical equation for penetration depth of ogive-nose projectiles penetrating concrete targets at normal impact. Our penetration equation contains a single, dimensionless empirical constant that depends only on the unconfined compressive strength of the target. We determine the empirical constant from penetration depth versus striking velocity data with six sets of penetration data for striking velocities between 250 and 800 m/s. Predictions are in good agreement with all six data sets. C1 WATERWAYS EXPT STN,VICKSBURG,MS 39180. UNIV DAYTON,RES INST,DAYTON,OH 45469. RP FORRESTAL, MJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 5 TC 163 Z9 250 U1 5 U2 42 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD AUG PY 1994 VL 15 IS 4 BP 395 EP 405 DI 10.1016/0734-743X(94)80024-4 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA NX410 UT WOS:A1994NX41000006 ER PT J AU SILVER, RN RODER, H AF SILVER, RN RODER, H TI DENSITIES OF STATES OF MEGA-DIMENSIONAL HAMILTONIAN MATRICES SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C-PHYSICS AND COMPUTERS LA English DT Article DE DENSITIES OF STATES; STATISTICAL MECHANICS; EXACT DIAGONALIZATION; STATISTICAL METHODS; LARGE MATRICES AB We propose a statistical method to estimate densities of states (DOS) and thermodynamic functions of very large Hamiltonian matrices. Orthogonal polynomials are defined on the interval between lower and upper energy bounds. The DOS is represented by a kernel polynomial constructed out of polynomial moments of the DOS and modified to damp the Gibbs phenomenon. The moments are stochastically evaluated using matrix-vector multiplications on Gaussian random vectors and the polynomial recurrence relations, The resulting kernel estimate is a controlled approximation to the true DOS, because it also provides estimates of statistical and systematic errors. For a given fractional energy resolution and statistical accuracy, the required cpu time and memory scale linearly in the number of states for sparse Hamiltonians. The method is demonstrated for the two-dimensional Heisenberg anti-ferromagnet with the number of states as large as 2(26). Results are compared to exact diagonalization where available. C1 UNIV BAYREUTH,DEPT PHYS,W-8850 BAYREUTH,GERMANY. RP SILVER, RN (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. NR 15 TC 67 Z9 67 U1 0 U2 4 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C-Phys. Comput. PD AUG PY 1994 VL 5 IS 4 BP 735 EP 753 DI 10.1142/S0129183194000842 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA PG233 UT WOS:A1994PG23300007 ER PT J AU ZHAO, JT CORBETT, JD AF ZHAO, JT CORBETT, JD TI R5GA3 COMPOUNDS OF SELECTED RARE-EARTH METALS-R - STRUCTURES AND PROPERTIES SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article AB The phases La5Ga3, Gd5Ga3, Y5Ga3, Ho5Ga3 and Er5Ga3 were synthesized from the elements in Ta or by arc melting. La5Ga3 and Y5Ga3 were shown to be line phases. The structures of the first three were established by single-crystal X-ray diffraction refinements to be Ba5Si3 type (P4/ncc), a deformation of the Cr5B3-type structure (I4/mcm) that decreases in magnitude in the order listed. (La5Si3 is also Ba5Si3 type). The structures of the last two listed above were presumed to be the same although the two structure types cannot be distinguished for these elements by Guinier powder diffraction. Samples of Y5Ga3, Ho5Ga3 and Er5Ga3 quenched from about 1175-degrees-C or higher have an evidently slightly deformed Mn5Si3-type Structure which transforms somewhat slowly to the low temperature Ba5Si3 form on annealing at about 800-degrees-C. This transformation has evidently not been seen in prior thermal analysis of these as well as of the analogous Tm, Lu, Sc systems, all of which have been reported to contain only Mn5Si3-type R5Ga3. The law temperature forms of La5Ga3 and Y5Ga3 exhibit Pauli-like paramagnetism and rho273 almost-equal-to 125 muOMEGA cm with metal-like temperature dependences. On the contrary, Mn5Si3-type Y5Ga3 exhibits significantly larger temperature-independent paramagnetism (about 3.5 x 10(-3) e.m.u. mol-1) and rho273 approximately 75 muOMEGA cm with a temperature dependence of 0.07% K-1, so its description as a simple Zintl phase with filled gallium orbitals-valence band is not appropriate. Gd5Ga3 (Ba5Si3) and Ho5Ga3 (low and high temperature types) exhibit Curie-Weiss behavior with mu(eff) almost-equal-to 8.9 mu(B), 10.8 mu(B) and 10.7 mu(B), per lanthanide respectively and metal-like resistivities of 50-100 muOMEGA cm. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 24 TC 22 Z9 22 U1 0 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD AUG PY 1994 VL 210 IS 1-2 BP 1 EP 7 DI 10.1016/0925-8388(94)90105-8 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA PA713 UT WOS:A1994PA71300002 ER PT J AU GOREN, SD KORN, C ROSSLER, E VIETH, HM LUDERS, K GAVRA, Z JOHNSON, JR REILLY, JJ AF GOREN, SD KORN, C ROSSLER, E VIETH, HM LUDERS, K GAVRA, Z JOHNSON, JR REILLY, JJ TI ON THE DEUTERIUM QUADRUPOLE COUPLING-CONSTANT OF H-DOPED Y-BA-CU-O SYSTEMS SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article ID HYDROGEN; O-17; ICE AB The H-2 quadrupole coupling constant e2qQ/h and asymmetry parameter eta were measured for deuterium-doped Y2BaCuO5 (green phase) where x = 0.31 and 0.61 in HxY2BaCuO5 and at temperatures of 180, 300 and 360 K. The values are e2qQ/h = 235 +/- 20 kHz and eta = 0.05 +/- 0.05, independent of x and the temperature. These results, together with previously measured quadrupole coupling constants of other hydrogen-doped Y-Ba-Cu-O compounds, are correlated with IR stretching frequencies of these compounds and support the model that the hydrogen C1 FREE UNIV BERLIN,FACHBEREICH PHYS,W-1000 BERLIN 33,GERMANY. NUCL RES CTR NEGEV,IL-84190 BEER SHEVA,ISRAEL. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP GOREN, SD (reprint author), BEN GURION UNIV NEGEV,DEPT PHYS,POB 653,IL-84105 BEER SHEVA,ISRAEL. OI Vieth, Hans-Martin/0000-0002-6552-9381 NR 19 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD AUG PY 1994 VL 210 IS 1-2 BP 9 EP 11 DI 10.1016/0925-8388(94)90106-6 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA PA713 UT WOS:A1994PA71300003 ER PT J AU STAHL, K HANSON, J AF STAHL, K HANSON, J TI REAL-TIME X-RAY SYNCHROTRON POWDER DIFFRACTION STUDIES OF THE DEHYDRATION PROCESSES IN SCOLECITE AND MESOLITE SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID POSITION-SENSITIVE DETECTOR; NEUTRON-DIFFRACTION; STRUCTURE REFINEMENT; NATROLITE; 20-K AB The high intensity of an X-ray synchrotron source in combination with a curved position-sensitive detector covering 120-degrees (CPS120 by INEL) has been used to collect complete powder diffraction patterns, suitable for Rietveld analyses, within minutes. From consecutive patterns (DELTAT congruent-to 5 K), detailed information was obtained on water expulsion and phase transitions induced by dehydration of the natural zeolites scolecite and mesolite. Scolecite, Ca8Al16Si24O80 . 24H2O, shows an initial gradual loss of half O(2W). At approximately 480 K, scolecite goes through a phase transition already described by Rinne [Neues Jahrb. MineraL Beil. (1923), 48, 240-249]. The crystal symmetry changes from F1d1 to Fd11 when half the Ca ions move by approximately 1/2c and the remaining O(2W) is expelled. Metascolecite: Ca8Al16Si24O80.16H2O, Fd11, Z = 1, T = 489 K, a = 18.1465 (7), b = 18.8604 (7), c = 6.5396 (3) angstrom, alpha = 88.986 (2)-degrees, R(p) = 5.42%, R(B) = 2.51% from 3620 observations, 802 Bragg reflections and 79 refined parameters. Continued heating to 615 K did not further reduce the water content. The dehydration process in mesolite starts with a loss of half the same Ca-coordinated water as in scolecite. The initial water loss is followed by an order/disorder transition, where the Na and Ca ions become randomly distributed over the cation sites. Consequently, the b axis of metamesolite is reduced to 1/3 of b(mes) and the k not-equal 3n reflections disappear. Metamesolite is very similar to natrolite, with equal numbers of Na atoms, Ca atoms and vacancies in the natrolite Na-atom site and with n(H2O) varying between 16 and 10.67. Metamesolite: Ca5.33Na5.33Al16Si24O80.n(H2O), Fdd2, Z = 1, n(H2O) = 10.6 (2), T = 582 K, a = 18.1039 (6), b = 18.5763 (6), c = 6.5589 (2) angstrom, R(p) = 4.85%, R(B) = 2.01 % from 3620 observations, 424 Bragg reflections and 54 refined parameters. Both scolecite and mesolite have one AlO4 tetrahedron with only one O atom coordinated by a cation. The initially expelled waters are in both cases hydrogen bonded to an O atom in those AlO4 tetrahedra. The initial water expulsions thus worsen the underbonding and trigger the cation rearrangements. The resulting cation distributions in metascolecite and metamesolite are the most even with respect to the AlO4 tetrahedra and are considered the driving force of both phase transitions. The cation rearrangement in mesolite requires cross-channel diffusion and is considerably slower than the in-channel rearrangement taking place in scolecite. In both zeolites, the lower limit in the calcium coordination number was found to be six. The ICDD Powder Diffraction File Nos. are: 45-1489 for Ca8Al16Si24O80.16H2O; 45-1490 for Ca8Al16Si24O80 . 18.9H2O; 45-1491 for Ca5.33Na5.33Al16Si24O80 . 12.8H2O; 45-1492 for Ca5.33Na5.33Al16Si24O80 . 16.7H2O. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP STAHL, K (reprint author), LUND UNIV,POB 124,S-22100 LUND,SWEDEN. RI Hanson, jonathan/E-3517-2010; OI Stahl, Kenny/0000-0002-4459-3026 NR 20 TC 72 Z9 72 U1 0 U2 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1994 VL 27 BP 543 EP 550 DI 10.1107/S002188989301235X PN 4 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PB265 UT WOS:A1994PB26500014 ER PT J AU PARTIN, DE OKEEFFE, M VONDREELE, RB AF PARTIN, DE OKEEFFE, M VONDREELE, RB TI CRYSTAL-STRUCTURE AND PROFILE FITTING OF MG(OD)2 BY TIME-OF-FLIGHT NEUTRON-DIFFRACTION SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID RIETVELD REFINEMENT AB The crystal structure of Mg(OD)2 has been refined from time-of-flight (TOF) neutron diffraction data. M(r) = 60.304, trigonal, P3m1BAR, a = 3.1455 (1), c = 4.7646(3) angstrom, Y = 40.831(4) angstrom, Z = 4, D(x) = 2.453 g cm-3, neutron time of flight, Rietveld refinement, R(wp) = 3.84%, R(p) = 2.83%, reduced chi2 = 2.98 for 70 variables, data collected at 305 K. The O-D bond length is 0.937 (1) angstrom (0.956 angstrom corrected for 'riding' motion). The use of a pseudo-Voigt profile function to allow for strain and particle-size broadening in TOF neutron diffraction of fine anisotropic powders is described. C1 LOS ALAMOS NATL LAB,LANSCE,LOS ALAMOS,NM 87545. RP PARTIN, DE (reprint author), ARIZONA STATE UNIV,DEPT CHEM,TEMPE,AZ 85287, USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1994 VL 27 BP 581 EP 584 DI 10.1107/S0021889893008672 PN 4 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA PB265 UT WOS:A1994PB26500020 ER PT J AU MATHEWS, M HAHN, K THOMPSON, J GADEKEN, L MADIGAN, W AF MATHEWS, M HAHN, K THOMPSON, J GADEKEN, L MADIGAN, W TI SUBSURFACE RADIONUCLIDE INVESTIGATION OF A NUCLEAR TEST SO JOURNAL OF APPLIED GEOPHYSICS LA English DT Article AB This paper reports on an environmental investigation into the vertical distribution of radionuclides from a nuclear test. Dalhart is the name of an underground nuclear test that was executed at the Nevada Test Site at a depth of 2100 ft on October 13, 1988. The test occurred below the static water level of 1667 ft and created multiple radioactive isotopes or fission products. These radioactive isotopes penetrated the surrounding formations and chimney region above the test and were retained there. A 19-degrees 9-7/8-inch diameter slant hole was drilled to sample the geologic material in the chimney region above the Dalhart test for the purpose of assessing the distribution of radioactivity in and around the shot site. A 30-ft core recovered from a vertical depth of 1628 ft in the collapsed zone or chimney region and above the original static water level was found to be free of radionuclides. Drilling was completed to a vertical depth of 2156 ft with the present static water level at a vertical depth of 1644 ft. Gamma-ray spectroscopy log measurements, made within the drill pipe while drilling fluid was pumped through this pipe, indicate that radioactive material produced by the test was present from the vertical depth interval of 1746-2156 ft. Side-wall samples acquired from the vertical depth interval of 1721-2089 ft and analyzed in the field contained radionuclides such as Cs-137, Sb-125, Ru-106, plus the natural radioactive background of potassium, uranium, and thorium. These samples were sent to Los Alamos to determine the complete radionuclide content at each depth. These analyses were used with the gamma-ray spectroscopy logging data to determine the subsurface vertical radionuclide distribution at the Dalhart site. C1 HALLIBURTON ENERGY SERV INC,HOUSTON,TX 77242. RP MATHEWS, M (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-9851 J9 J APPL GEOPHYS JI J. Appl. Geophys. PD AUG PY 1994 VL 32 IS 2-3 BP 279 EP 291 DI 10.1016/0926-9851(94)90028-0 PG 13 WC Geosciences, Multidisciplinary; Mining & Mineral Processing SC Geology; Mining & Mineral Processing GA PD474 UT WOS:A1994PD47400016 ER PT J AU DATTOLI, G GALLARDO, JC OTTAVIANI, PL AF DATTOLI, G GALLARDO, JC OTTAVIANI, PL TI FREE-ELECTRON LASER INTRACAVITY LIGHT AS A SOURCE OF HARD X-RAY-PRODUCTION BY COMPTON BACKSCATTERING SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BEAMS AB In this paper we consider the x-ray production by Compton backscattering of intracavity visible free-electron laser (FEL) radiation. We discuss the interplay between the build-up of the laser in the cavity and the backscattered signal including the effects of the e-beam degradation (energy spread) induced by the FEL interaction. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. CTR RIC ENERGIA E CLEMENTEL,ENEA,DIPARTIMENTO INNOVAZ,SETTORE ELETTROOTT & LASER,I-40138 BOLOGNA,ITALY. RP DATTOLI, G (reprint author), CTR RIC ENERGIA FRASCATI,ENEA,DIPARTIMENTO INNOVAZ,SETTORE ELETTROOTT & LASER,POB 65,I-00044 FRASCATI,ITALY. OI Gallardo, Juan C/0000-0002-5191-3067 NR 29 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1399 EP 1404 DI 10.1063/1.357786 PG 6 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500002 ER PT J AU ANDERS, A ANDERS, S GUNDERSEN, MA AF ANDERS, A ANDERS, S GUNDERSEN, MA TI ELECTRON-EMISSION FROM PSEUDOSPARK CATHODES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SOURCE ION-IMPLANTATION; ATMOSPHERIC-PRESSURE ARCS; VACUUM-ARC; SUPERDENSE GLOW; SPOTS; THYRATRON; EROSION; IONIZATION; SIMULATION; DISCHARGE AB The pseudospark cathode has the remarkable property of macroscopically homogeneous electron emission at very high current density (>1 kA/cm2) over a large area (some cm2). The model of electron emission presented here is based on the assumption that the pseudospark microscopically utilizes explosive arc processes, as distinct from earlier models of ''anomalous emission in superdense glow discharges.'' Explosive emission similar to vacuum are cathode spots occurs rapidly. when the field strength is sufficiently high. The plasma remains macroscopically homogeneous since the virtual plasma anode adapts to the cathode morphology so that the current is carried by a large number of homogeneously distributed cathode spots which are similar to ''type 1'' and ''type 2'' spots of vacuum arc discharges. The net cathode erosion is greatly reduced relative to ''spark gap-type'' emission. At very high current levels, a transition to highly erosive spot types occurs, and this ''arcing'' leads to a significant reduction in device lifetime. Assuming vacuum-arc-like cathode spots, the observed current density and time constants can be easily explained. The observed cathode erosion rate and pattern, recent fast-camera data, laser-induced fluorescence, and spectroscopic measurements support this approach. A new hypothesis is presented explaining current quenching at relatively low currents. From the point of view of electron emission, the ''superdense glow'' or ''superemissive phase'' of pseudosparks represents an arc and not a glow discharge even if no filamentation or ''arcing'' is observed. C1 UNIV SO CALIF,DEPT PHYS,LOS ANGELES,CA 90089. RP ANDERS, A (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016 OI Anders, Andre/0000-0002-5313-6505; NR 65 TC 29 Z9 29 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1494 EP 1502 DI 10.1063/1.357724 PG 9 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500016 ER PT J AU MAYER, TM CHASON, E HOWARD, AJ AF MAYER, TM CHASON, E HOWARD, AJ TI ROUGHENING INSTABILITY AND ION-INDUCED VISCOUS RELAXATION OF SIO2 SURFACES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THERMAL SIO2; BOMBARDMENT; SILICA; TOPOGRAPHY; MICROSCOPY; GROWTH; FLOW; GE AB We characterize the development of nanometer scale topography (roughness) on SiO2 surfaces as a result of low energy, off-normal ion bombardment, using in situ energy dispersive x-ray reflectivity and atomic force microscopy. Surfaces roughen during sputtering by heavy ions (Xe), with roughness increasing approximately linearly with ion fluence up to 10(17) cm-2. A highly coherent ripple structure with wavelength of 30 nm and oriented with the wave vector parallel to the direction of incidence is observed after Xe sputtering at 1 keV. Lower frequency, random texture is also observed. Subsequent light ion (H, He) bombardment smoothens preroughened surfaces. The smoothing kinetics are first order with ion fluence and strongly dependent on ion energy in the range 0.2-1 eV. We present a linear model to account for the experimental observations which includes roughening both by random stochastic processes and by development of a periodic surface instability due to sputter yield variations with surface curvature which leads to ripple development. Smoothing occurs via ion bombardment induced viscous flow and surface diffusion. From the smoothing kinetics with H and He irradiation we measure the radiation enhanced ViScoSitY of SiO2 and find values on the order of 1-20 X 10(12) N s m-2. The viscous relaxation per ion scales as the square root of the ion induced displacements in the film over the range of the ion penetration, suggesting short-lived defects with a bimolecular annihilation mechanism. The surface instability mechanism accounts for the ripple formation, while inclusion of stochastic roughening produces the random texture and reproduces the observed linear roughening kinetics and the magnitude of the overall roughness. RP MAYER, TM (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 37 TC 263 Z9 263 U1 1 U2 31 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1633 EP 1643 DI 10.1063/1.357748 PG 11 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500037 ER PT J AU KOMVOPOULOS, K WEI, B ANDERS, S ANDERS, A BROWN, IG AF KOMVOPOULOS, K WEI, B ANDERS, S ANDERS, A BROWN, IG TI SURFACE MODIFICATION OF MAGNETIC RECORDING-HEADS BY PLASMA IMMERSION ION-IMPLANTATION AND DEPOSITION SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID METALS; MICROSTRUCTURE; WEAR AB Plasma immersion ion implantation and deposition is a novel process for surface modification. By combining plasma deposition and ion implantation and using filtered vacuum arc plasmas, thin film formation, direct and recoil ion implantation, and ion-beam-assisted intermixing of the film and substrate can be accomplished simultaneously. The implications of this technique in tribology of magnetic recording media have been investigated experimentally. SurfaceS of Al2O3-TiC heads were modified with silver, carbon, and titanium ions at doses of 3 x 10(16) ions/cm2 and mean implantation energies between 2.0 and 4.2 keV. Simulation results indicated that the modified regions exhibited high concentrations -of implanted species in the top 2-3 nm, atomically mixed interfaces, and thicknesses between 10 and 25 nm. Surface imaging with an atomic force microscope and nanoindentation testing revealed that the modified heads possessed smoother topographies and increased hardnesses. Contact start-stop and continuous sliding experiments with modified heads and carbon-coated magnetic rigid disks and microscopy observations demonstrated that significant enhancement of the friction and wear characteristics can be achieved with the present surface modification technique. The possible reasons for the improved tribological behavior and the predominant mechanisms during contact start-stop and continuous sliding are interpreted in light of the obtained experimental results. C1 LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP KOMVOPOULOS, K (reprint author), UNIV CALIF BERKELEY, DEPT MECH ENGN, BERKELEY, CA 94720 USA. RI Anders, Andre/B-8580-2009; Raoux, Simone/G-3920-2016 OI Anders, Andre/0000-0002-5313-6505; NR 21 TC 18 Z9 18 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1656 EP 1664 DI 10.1063/1.358516 PG 9 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500039 ER PT J AU XIAO, Y MCMAHON, TJ PANKOVE, JI TSUO, YS AF XIAO, Y MCMAHON, TJ PANKOVE, JI TSUO, YS TI EXISTENCE OF A P-B1-LIKE DEFECT CENTER IN POROUS SILICON SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-SPIN-RESONANCE; VISIBLE-LIGHT EMISSION; DANGLING-BOND; PARAMAGNETIC-RESONANCE; SI; INTERFACE; PHOTOLUMINESCENCE; WAFERS AB We performed a detailed study of electron spin resonance (ESR) spectra of porous silicon (PS) samples at different stages of treatment and with different porosities. In addition to the commonly observed P(b0)-like dangling bond, results of curve fitting to our ESR spectra show that a P(b1)-like center, similar to the P(b1) center observed at the (100) crystalline-Si/Si02 interface, appears in the PS nanostructure. The ratio of the number of P(b1)-like centers to that of P(b0)-like centers is related to the PS porosity. Remote hydrogen plasma processing of the annealed PS does not change the ratio significantly, although the total numbers Of P(b0)-like and P(b1)-like centers are reduced and photoluminescence efficiency is improved. C1 UNIV COLORADO,DEPT ELECT & COMP ENGN,BOULDER,CO 80309. RP XIAO, Y (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE AVE,GOLDEN,CO 80401, USA. NR 21 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1759 EP 1763 DI 10.1063/1.358433 PG 5 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500057 ER PT J AU MAHAN, GD LYON, HB AF MAHAN, GD LYON, HB TI THERMOELECTRIC DEVICES USING SEMICONDUCTOR QUANTUM-WELLS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SUPERLATTICES; CONVERSION AB The efficiency of thermoelectric devices are analyzed for a superlattice of semiconductor quantum wells. It is assumed that the quantum wells are the thermoelectric active elements, and the layers between conduct only heat. It is shown that the efficiency of the device depends on the property of both layers. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. MARLOW IND,DALLAS,TX 75238. RP MAHAN, GD (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 16 TC 33 Z9 34 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1994 VL 76 IS 3 BP 1899 EP 1901 DI 10.1063/1.357715 PG 3 WC Physics, Applied SC Physics GA PA305 UT WOS:A1994PA30500077 ER PT J AU SETLIK, RF MEYER, DJ SHIBATA, M ROSKWITALSKI, R ORNSTEIN, RL REIN, R AF SETLIK, RF MEYER, DJ SHIBATA, M ROSKWITALSKI, R ORNSTEIN, RL REIN, R TI A FULL-COORDINATE MODEL OF THE POLYMERASE DOMAIN OF HIV-I REVERSE-TRANSCRIPTASE AND ITS INTERACTION WITH A NUCLEIC-ACID SUBSTRATE SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID DNA-POLYMERASE; CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; STEREOCHEMICAL COURSE; ANGSTROM RESOLUTION; VIRUS; RNA; MECHANISM; CONFORMATION; TRIPHOSPHATE AB We present a full-coordinate model of residues 1 - 319 of the polymerase domain of HIV-I reverse transcriptase. This model was constructed from the x-ray crystallographic structure of Jacobo-Molina et al. (Jacobo-Molina et al., P.N.A.S. USA 90, 6320-6324 (1993)) which is currently available to the degree of C-coordinates. The backbone and side-chain atoms were constructed using the MAXSPROUT suite of programs (L. Holm and C. Sander, J. Mol. Biol. 218, 183-194 (1991)) and refined through molecular modeling. A seven base pair A-form dsDNA was positioned in the nucleic acid binding cleft to represent the template-primer complex. The orientation of the template-primer complex in the nucleic acid binding cleft was guided by the positions of phosphorus atoms in the crystal structure. C1 ROSWELL PK CANC INST, DEPT BIOPHYS, BUFFALO, NY 14263 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. NR 44 TC 3 Z9 3 U1 0 U2 0 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD AUG PY 1994 VL 12 IS 1 BP 37 EP 60 PG 24 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PJ683 UT WOS:A1994PJ68300003 PM 7531452 ER PT J AU SZKLARZ, GD ORNSTEIN, RL HALPERT, JR AF SZKLARZ, GD ORNSTEIN, RL HALPERT, JR TI APPLICATION OF 3-DIMENSIONAL HOMOLOGY MODELING OF CYTOCHROME-P450 2B1 FOR INTERPRETATION OF SITE-DIRECTED MUTAGENESIS RESULTS SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID SUBSTRATE-SPECIFICITY; AMINO-ACID; CRYSTAL-STRUCTURE; STRUCTURE PREDICTION; HUMAN AROMATASE; SEQUENCE; REGIOSELECTIVITY; HYDROXYLATION; LIVER; 15-ALPHA-HYDROXYLASE AB Three-dimensional structures of cytochrome P450 2B1 were modeled based on the crystallographic structure of P450(cam). The effect of the alignment, loop choice, and minimization with or without water was assessed. Although final models were similar in overall structure, the identity of active site residues depended upon the alignment. An example is Phe-206, which may or may not form part of the active site. The choice of the loop conformation had a lesser effect, while including water in the final minimization step was essential for preserving the shape and size of the active site. The best model (model 2) was in good agreement with the data from site-directed mutagenesis studies, and correctly predicted the effect of substitutions at 9 out of 10 amino acid positions. Thus, residues important for P450 2B1 activity, such as Ile-114, Phe-206, Ile-290, Thr-302, Val-363, and Gly-478, constitute part of the active site and are able to interact with the substrate androstenedione through hydrophobic interactions. On the other hand, Ser-303, Ser-360 and Lys-473 are far from the active site and/or cannot interact with the substrate, in agreement with experimental data. The model indicates other residues likely to be important for enzyme function, such as Tyr-111, Leu-209, Ile-477, and Ile-480, which can be tested experimentally. The substrate may assume numerous binding orientations consistent with observed patterns of hydroxylation at C-15 and C-16. The replacement in the model of certain amino acid residues to mimic residue substitutions from site-directed mutagenesis studies and docking of the substrate into the modified active site allowed a plausible explanation for alterations in regio- and stereospecificities of some mutants of P450 2B1, such as Gly-478 --> Ala or Val-363 --> Ala. C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RP SZKLARZ, GD (reprint author), UNIV ARIZONA, COLL PHARM, DEPT PHARMACOL & TOXICOL, TUCSON, AZ 85721 USA. FU NIEHS NIH HHS [ES03619] NR 47 TC 62 Z9 62 U1 0 U2 1 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD AUG PY 1994 VL 12 IS 1 BP 61 EP 78 PG 18 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PJ683 UT WOS:A1994PJ68300004 PM 7848559 ER PT J AU YANG, LQ DEPRISTO, AE AF YANG, LQ DEPRISTO, AE TI SURFACE SEGREGATION IN BIMETALLIC CLUSTERS - STATISTICAL-MECHANICAL MODELING USING CLUSTER SITE ENERGIES SO JOURNAL OF CATALYSIS LA English DT Article ID CORRECTED EFFECTIVE-MEDIUM; MONTE-CARLO SIMULATIONS; MOLECULAR-DYNAMICS; BODY FORMULATION; NANOSTRUCTURES; CATALYSTS; CHEMISORPTION; ALLOYS AB A five-state statistical-mechanical model is employed in the present study of surface segregation in 201-atom bimetallic clusters having truncated cubo-octahedral shape. The model uses ideal entropy of mixing and assumes zero heat of mixing. Surface segregation is studied via direct minimization of the free energy without performing Monte Carlo simulations. The effects of size mismatch between atoms of different type are included via a new empirical formula, based upon dimensional scaling arguments, leading to an increase in the surface fraction of larger atoms. We used the corrected effective medium potentials to generate the site energies (interaction energy per atom) used in the model. A complete list of site energies for nine fcc metals is presented for 201-, 586-, 1289-atom clusters and semi-infinite surfaces. In particular, the corner and edge site energies are found to be independent of cluster size. The model reproduced qualitatively the surface and edge-comer segregation results for 11 50%-50% bimetallic clusters generated by atomistic simulations at 600 K that we reported earlier. The remaining difference in results between the model and the simulations is attributed to the effect of nonzero heats of mixing. For systems with very large (> 12%) lattice-size mismatch such as Ni-Ag and Cu-Ag, the distortion from the perfect lattice structure is significant according to the simulations; thus, simple modeling involving a few well-defined states is problematic. (C) 1994 Academic Press, Inc. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP YANG, LQ (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 28 TC 40 Z9 40 U1 1 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD AUG PY 1994 VL 148 IS 2 BP 575 EP 586 DI 10.1006/jcat.1994.1244 PG 12 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA NZ026 UT WOS:A1994NZ02600017 ER PT J AU LEE, YK EMSLEY, L LARSEN, RG SCHMIDT-ROHR, K HONG, M FRYDMAN, L CHINGAS, GC PINES, A AF LEE, YK EMSLEY, L LARSEN, RG SCHMIDT-ROHR, K HONG, M FRYDMAN, L CHINGAS, GC PINES, A TI 3-DIMENSIONAL VARIABLE-ANGLE NUCLEAR-MAGNETIC-RESONANCE EXCHANGE SPECTROSCOPY WITHOUT ROTOR AXIS HOPPING SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CHEMICAL-SHIFT; MAGIC-ANGLE; NMR-SPECTROSCOPY; SPINNING NMR; ISOTACTIC POLYPROPYLENE; ROTATING SOLIDS; POWDER SAMPLES; LINE-SHAPES; MOTION; DISTRIBUTIONS AB Slow, large-amplitude chain motions play an important role in determining the macroscopic mechanical properties of polymers. Although such motions have been studied quantitatively by two-dimensional (2D) nuclear: magnetic resonance (NMR) exchange experiments, overlapping anisotropic patterns hamper spectral analysis, and limit applications. Variable angle correlation spectroscopy (VACSY) has proven useful in resolving such problems for rapidly spinning samples by separating anisotropic spectral patterns according to isotropic chemical shifts. In a previous study [J. Am. Chem. Sec. 115, 4825 (1993)], we described a three-dimensional (3D) NMR experiment that incorporates; the VACSY method and a hop of the rotor axis to correlate the isotropic chemical shifts to 2D anisotropic exchange patterns. The hop of the rotor axis, however, presents experimental difficulties and limits the range of motional rates that may be studied. We present in this paper a new 3D VACSY exchange experiment that obtains the same correlations without the need for the rotor axis hop. A series of 2D exchange spectra are recorded with the sample spinning at different rotation axis angles.' Then using the scaling of the anisotropic frequency at the different angles, we construct the data onto a 3D matrix so that a Fourier transformation directly yields the desired correlations. The technique is applied to C-13 exchange NMR to study the slow molecular motion of ordered isotactic polypropylene. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RI Emsley, Lyndon/C-6108-2008; larsen, russell/H-3443-2013 OI Emsley, Lyndon/0000-0003-1360-2572; NR 48 TC 13 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 1852 EP 1864 DI 10.1063/1.467696 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200011 ER PT J AU KIM, HL WICKRAMAARATCHI, MA ZHENG, XN HALL, GE AF KIM, HL WICKRAMAARATCHI, MA ZHENG, XN HALL, GE TI REACTIONS OF VELOCITY-ALIGNED ATOMS PROBED BY DOPPLER PROFILES - H+O-2-]OH+O SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; ROTATIONALLY INELASTIC-COLLISIONS; PHOTOFRAGMENT VECTOR CORRELATIONS; INDUCED FLUORESCENCE SPECTROSCOPY; ANGULAR-MOMENTUM POLARIZATION; POTENTIAL-ENERGY SURFACE; PHOTODISSOCIATION DYNAMICS; SUB-DOPPLER; REACTION H+O2->OH+O; EXCHANGE-REACTION AB Final state resolved vector properties of the reaction H (S-2)+O-2((3) Sigma(g)(-))-->OH((II)-I-2)+O(P-3) have been measured using Doppler spectroscopy. Velocity-aligned H atoms were generated by photodissociation of H2S with linearly polarized ArF excimer laser light. The correlated velocity and angular momentum distribution of nascent OH reaction products was probed by laser induced fluorescence. Techniques are described for analyzing the line shapes, modeling the bipolar moments of the OH velocity and angular momentum distribution as parametric functions of the scattering angle. Distinctive Doppler-broadened lineshapes indicate scattering angle distributions with a strong forward and a weaker backward maximum. A qualitatively different angular momentum polarization for the two lambda doublet components of the OH product is required to explain the Doppler profiles. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RI Hall, Gregory/D-4883-2013 OI Hall, Gregory/0000-0002-8534-9783 NR 78 TC 100 Z9 101 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 2033 EP 2050 DI 10.1063/1.467712 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200029 ER PT J AU CLAY, JT WALTERS, EA GROVER, JR WILLCOX, MV AF CLAY, JT WALTERS, EA GROVER, JR WILLCOX, MV TI PHOTOIONIZATION OF GAS-PHASE BROMOTRIFLUOROMETHANE AND ITS COMPLEXES WITH METHANOL - STATE DEPENDENCE OF INTRACLUSTER REACTIONS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CLUSTER BEAM ANALYSIS; ENERGY; DISSOCIATION; THERMOCHEMISTRY; ABSORPTION; CHEMISTRY; SPECTRA; CF3BR; IONS AB Weakly bound complexes of CF3Br molecules or of CF3Br and CH3OH were prepared in supersonic jet expansions and studied by photoionization mass spectrometry. Argon was present in the jet expansion to promote cooling of the complexes. Measured ionization potentials are CF3Br, 11.404+/-0.014 eV; (CF3Br)(2), 11.10+/-0.02 eV; (CF3Br.CH3OH), 10.76+/-0.05 eV. The appearance potential of CF3+ from CF3Br was found to be 11.56+/-0.02 eV, and evidence is presented that this value is adiabatic. From this appearance potential, Delta H-f0(0)(CF3+)=86.6+/-1.1 kcal mol(-1) The magnitude of the spin-orbit splitting in ($) over bar X (2)E CF3Br+ into E(1/2) and E(3/2) states dominates any Jahn-Teller distortion. The effects of these phenomena on the stability of ($) over bar X (2)E CF3Br+ are discussed. The following dissociation channels were observed: CF3+ from ($) over bar X (2)E CF3Br+, CF2Br+ from ($) over bar A (2)A(1) CF3Br+, Br+ from ($) over bar B (2)A(2) CF3Br+, and CF2+ from ($) over bar D (2)E CF3Br+.(CF3.CH3OH)(+) is not produced from neutral dimers, but is created when a CF3Br moiety embedded in a trimer or larger cluster is ionized to ($) over bar A (2)A(1) CF3Br+. In contrast, (Br.CH3OH)(+) does come from dimers as well as larger clusters. The cross sections for the production of (CF3Br)(2)(+) and (CF3Br.CH3OH)(+) from trimers or larger progenitors are enhanced when intracluster CF3Br is ionized to CF3Br+ in the ($) over bar B or higher electronic states. Possible reasons for these state-specific reactions are given. Finally, a new method is presented for determining neutral cluster distributions in a molecular beam, and the method is shown to be in quantitative agreement with the near-threshold technique previously published by Grover et al. [J. Phys. Chem. 95, 6473 (1991)]. C1 UNIV NEW MEXICO,CTR GLOBAL ENVIRONM TECHNOL,ALBUQUERQUE,NM 87131. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP CLAY, JT (reprint author), UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131, USA. NR 39 TC 17 Z9 17 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 2069 EP 2080 DI 10.1063/1.467714 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200031 ER PT J AU SUN, JQ RUEDENBERG, K AF SUN, JQ RUEDENBERG, K TI LOCATING TRANSITION-STATES BY QUADRATIC IMAGE GRADIENT DESCENT ON POTENTIAL-ENERGY SURFACES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SADDLE-POINTS; STEEPEST DESCENT; ALGORITHM; WALKING; PATH; OPTIMIZATION; MINIMIZATION; EXTREMALS; LINES AB An analysis is given of the so-called ''image function'' approach to finding transition states; It is demonstrated that, in fact, such functions do not exist for general potential energy surfaces so that a plain minimum search is inappropriate. Nonconservative image gradient fields do exist, however, and their field lines, defined by Euler's equation, can lead to transition states as exemplified by quantitative integrations of these equations for the Muller-Brown surface. As do gradient fields, image gradient fields contain streambeds and ridges, but their global structure is considerably more complex than that of gradient fields. In particular, they contain certain singular points where the image gradients change sign without passing through zero. They are the points where the two lowest eigenvalues of the Hessian are degenerate. Some of them can act as singular attractors for the image gradient descent and any algorithm must contain safeguards for avoiding them. (Such regions are equally troublesome for quasi-Newton-type transition-state searches.) Image gradient fields appear to have considerably larger catchment basins around transition states than do quasi-Newton-type or gradient-norm-type transition-state searches. A quantitative quadratic image-gradient-following algorithm is formulated and, through applications to the Muller-Brown surface, shown to be effective in finding transition states. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP SUN, JQ (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 42 TC 32 Z9 33 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 2157 EP 2167 DI 10.1063/1.467721 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200039 ER PT J AU RUEDENBERG, K SUN, JQ AF RUEDENBERG, K SUN, JQ TI A SIMPLE PREDICTION OF APPROXIMATE TRANSITION-STATES ON POTENTIAL-ENERGY SURFACES SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POINTS AB Given the locations, the energies, and the force constants of a reactant minimum and a product minimum and assuming that no other information is available, an analytical algorithm is formulated for determining the optimal conjecture for a surmized transition state between them. It is based on a model surface obtained by combining the two quadratic basin approximations. The method is illustrated by applications to transition states on an analytical surface and on an ab initio surface. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP RUEDENBERG, K (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 7 TC 9 Z9 9 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 2168 EP 2174 DI 10.1063/1.467722 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200040 ER PT J AU DAVIS, MJ BETHARDY, GA LEHMANN, KK AF DAVIS, MJ BETHARDY, GA LEHMANN, KK TI HIERARCHICAL STRUCTURE IN THE 3-NU(1) BAND OF PROPYNE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Note ID INFRARED DOUBLE-RESONANCE; FREE-JET C1 PRINCETON UNIV, DEPT CHEM, PRINCETON, NJ 08542 USA. RP ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 10 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1994 VL 101 IS 3 BP 2642 EP 2643 DI 10.1063/1.467639 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA NY002 UT WOS:A1994NY00200096 ER PT J AU MARSHALL, S ROADS, JO GLATZMAIER, G AF MARSHALL, S ROADS, JO GLATZMAIER, G TI SNOW HYDROLOGY IN A GENERAL-CIRCULATION MODEL SO JOURNAL OF CLIMATE LA English DT Article ID COMMUNITY CLIMATE MODEL; SIMPLE BIOSPHERE MODEL; PRECIPITATION FORECASTS; ATMOSPHERIC MODELS; CO2 CLIMATE; COVER; SENSITIVITY; ICE; TEMPERATURE; CYCLE AB A snow hydrology has been implemented in an atmospheric general circulation model (GCM). The snow hydrology consists of parameterizations of snowfall and snow cover fraction, a prognostic calculation of snow temperature, and a model of the snow mass and hydrologic budgets. Previously, only snow albedo had been included by a specified snow line. A 3-year GCM simulation with this now more complete surface hydrology is compared to a previous GCM control run with the specified snow line, as well as with observations. In particular, the authors discuss comparisons of the atmospheric and surface hydrologic budgets and the surface energy budget for U.S. and Canadian areas. The new snow hydrology changes the annual cycle of the surface moisture and energy budgets in the model. There is a noticeable shift in the runoff maximum from winter in the control run to spring in the snow hydrology run. A substantial amount of GCM winter precipitation is now stored in the seasonal snowpack. Snow cover also acts as an important insulating layer between the atmosphere and the ground. Wintertime soil temperatures are much higher in the snow hydrology experiment than in the control experiment. Seasonal snow cover is important for dampening large fluctuations in GCM continental skin temperature during the Northern Hemisphere winter. Snow depths and snow extent show good agreement with observations over North America. The geographic distribution of maximum depths is not as well simulated by the model due, in part, to the coarse resolution of the model. The patterns of runoff are qualitatively and quantitatively similar to observed patterns of streamflow averaged over the continental United States. The seasonal cycles of precipitation and evaporation are also reasonably well simulated by the model, although their magnitudes are larger than is observed. This is due, in part, to a cold bias in this model, which results in a dry model atmosphere and enhances the hydrologic cycle everywhere. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. LOS ALAMOS NATL LAB,INST GEOPHYS & PLANETARY PHYS,LOS ALAMOS,NM 87544. RP MARSHALL, S (reprint author), UNIV N CAROLINA,DEPT GEOG & EARTH SCI,CHARLOTTE,NC 28223, USA. NR 52 TC 47 Z9 48 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD AUG PY 1994 VL 7 IS 8 BP 1251 EP 1269 DI 10.1175/1520-0442(1994)007<1251:SHIAGC>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA PD451 UT WOS:A1994PD45100006 ER PT J AU PASZTY, C MAEDA, N VERSTUYFT, J RUBIN, EM AF PASZTY, C MAEDA, N VERSTUYFT, J RUBIN, EM TI APOLIPOPROTEIN AI TRANSGENE CORRECTS APOLIPOPROTEIN-E DEFICIENCY-INDUCED ATHEROSCLEROSIS IN MICE SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article DE ATHEROGENESIS; TRANSGENIC MICE; HIGH DENSITY LIPOPROTEINS; LIPOPROTEINS ID DENSITY LIPOPROTEIN LEVELS; ESTER TRANSFER PROTEIN; PLASMA-LEVELS; GENE; ATHEROGENESIS; CHOLESTEROL; EXPRESSION; HYPERCHOLESTEROLEMIA; SUSCEPTIBILITY; SUBCLASSES AB Apolipoprotein E (apo E)-deficient mice are severely hypercholesterolemic and develop advanced atheromas independent of diet. The C57BL/6 strain differs from most inbred strains by having lower HDL concentrations and a high risk of developing early atherosclerotic lesions when fed an atherogenic diet. The relative HDL deficiency and atherosclerosis susceptibility of the C57BL/6 strain are corrected with the expression of a human apolipoprotein AI (ape AI) transgene in this genetic background. To examine if increases in apo AI and HDL are also effective in minimizing apo E deficiency-induced atherosclerosis, we introduced the human apo AI transgene into the hypercholesterolemic apo E knockout background. Similar elevations of total plasma cholesterol occurred in both the apo E knockout and apo E knockout mice also expressing the human apo AI transgene. The latter animals, however, also showed a two- to threefold increase in HDL and a sixfold decrease in susceptibility to atherosclerosis. This study demonstrates that elevating the concentration of apo AI reduces atherosclerosis in apo E deficient-mice and suggests that elevation of apo AI and HDL may prove to be a useful approach for treating unrelated causes of heightened atherosclerosis susceptibility. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. UNIV N CAROLINA, DEPT PATHOL, CHAPEL HILL, NC 27599 USA. FU NHLBI NIH HHS [HL-18574, HL-42630] NR 28 TC 296 Z9 301 U1 0 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 SN 0021-9738 J9 J CLIN INVEST JI J. Clin. Invest. PD AUG PY 1994 VL 94 IS 2 BP 899 EP 903 DI 10.1172/JCI117412 PG 5 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA PA250 UT WOS:A1994PA25000058 PM 8040345 ER PT J AU ALMGREN, AS BUTTKE, T COLELLA, P AF ALMGREN, AS BUTTKE, T COLELLA, P TI A FAST ADAPTIVE VORTEX METHOD IN 3 DIMENSIONS SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PARTICLE SIMULATIONS; CONVERGENCE; ALGORITHM AB The method of local corrections (MLC) developed by Anderson for two spatial dimensions is a particle-particle particle-mesh method, in which the calculation of the velocity field induced by a collection of vortices is split into two parts: (i) a finite difference velocity field calculation using a fast Poisson solver, the results of which are used to represent the velocity field induced by vortices far from the evaluation point; and (ii) an N-body calculation to compute the velocity field at a vortex induced by nearby vortices. We present a fast vortex method for incompressible flow in three dimensions, based on the extension of the MLC algorithm from two to three spatial dimensions and the use of adaptive mesh refinement in the finite difference calculation of the MLC. Calculations with a vortex ring in three dimensions show that the break-even point between the MLC with AMR and the direct method is at N almost-equal-to 3000 on a Cray Y-MP; for N almost-equal-to 64,000 MLC with AMR can be 12 times faster than the direct method. Results from calculations of two colliding inviscid vortex rings demonstrate the increased resolution which can be obtained using fast methods. (C) 1994 Academic Press, Inc. C1 NYU,COURANT INST MATH SCI,NEW YORK,NY 10003. UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP ALMGREN, AS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 28 TC 31 Z9 32 U1 0 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD AUG PY 1994 VL 113 IS 2 BP 177 EP 200 DI 10.1006/jcph.1994.1129 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA NW811 UT WOS:A1994NW81100003 ER PT J AU PAULSEN, MD ORNSTEIN, RL AF PAULSEN, MD ORNSTEIN, RL TI ACTIVE-SITE MOBILITY INHIBITS REDUCTIVE DEHALOGENATION OF 1,1,1-TRICHLOROETHANE BY CYTOCHROME P450CAM SO JOURNAL OF COMPUTER-AIDED MOLECULAR DESIGN LA English DT Article DE HEXACHLOROETHANE; BIODEGRADATION; MOLECULAR DYNAMICS; ENZYME SIMULATION; PROTEIN DYNAMICS ID MOLECULAR-DYNAMICS SIMULATION; TRANSITION-METAL COENZYMES; ABSOLUTE STEREOCHEMISTRY; SUBSTRATE MOBILITY; PROTEIN; METABOLISM; PRODUCT; HYDROXYLATION; BIODEHALOGENATION; TRICHLOROETHYLENE AB Recent studies by Wackett and co-workers have shown that cytochrome P450cam is capable of reductively dehalogenating hexachloroethane at a significant rate, but that no appreciable dehalogenation of 1,1,1-trichloroethane is observed. A growing body of evidence indicates that differences in intrinsic reactivity can not completely explain this observation. We therefore explored the possible role of differences in preferred binding orientation and in active-site mobility. A detailed analysis of molecular dynamics trajectories with each of these substrates bound at the active site of P450cam is presented. While the dynamics and overall time-average structure calculated for the protein are similar in the two trajectories, the two substrates behave quite differently. The smaller substrate, 1,1,1-trichloroethane, is significantly more mobile than hexachloroethane and has a preferred orientation in which the substituted carbon is generally far from the heme iron. In contrast, for hexachloroethane, one of the chlorine atoms is nearly always in van der Waals contact with the heme iron, which should favor the initial electron transfer step. C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. NR 49 TC 8 Z9 8 U1 0 U2 0 PU ESCOM SCI PUBL BV PI LEIDEN PA PO BOX 214, 2300 AE LEIDEN, NETHERLANDS SN 0920-654X J9 J COMPUT AID MOL DES JI J. Comput.-Aided Mol. Des. PD AUG PY 1994 VL 8 IS 4 BP 389 EP 404 DI 10.1007/BF00125374 PG 16 WC Biochemistry & Molecular Biology; Biophysics; Computer Science, Interdisciplinary Applications SC Biochemistry & Molecular Biology; Biophysics; Computer Science GA PE353 UT WOS:A1994PE35300003 PM 7815091 ER PT J AU JIN, S FREAR, DR MORRIS, JW AF JIN, S FREAR, DR MORRIS, JW TI UNTITLED SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Editorial Material C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP JIN, S (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 691 EP 691 PG 1 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600001 ER PT J AU VIANCO, PT ERICKSON, KL HOPKINS, PL AF VIANCO, PT ERICKSON, KL HOPKINS, PL TI SOLID-STATE INTERMETALLIC COMPOUND GROWTH BETWEEN COPPER AND HIGH-TEMPERATURE, TIN-RICH SOLDERS .1. EXPERIMENTAL-ANALYSIS SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Substitutes for Pb-Containing Solders for Microelectronic Applications, at the 1994 TMS Annual Meeting CY FEB 28-MAR 03, 1994 CL SAN FRANCISCO, CA SP MINERALS MET & MAT SOC DE INTERFACIAL REACTION; INTERMETALLIC COMPOUND; SOLDER AB An experimental study was performed which examined the solid state growth kinetics of the interfacial intermetallic compound layers formed between copper and the high temperature, tin-rich solders 96.5Sn-3.5Ag (wt.%) and 95Sn-5Sb. These results were compared with baseline data from the 100Sn/copper system. Both the 96.5Sn-3.5Ag and 95Sn-5Sb solders exhibited the individual Cu3Sn and Cu6Sn5 layers at the interface; the thickness of the Cu3Sn layer being a function of the aging time and temperature. The total thickness of the intermetallic compound layer formed in the 96.5Sn-3.5Ag solder/copper couple showed a mixture of linear and square-root t dependencies at the lower temperatures of 70, 100, and 135-degrees-C, and a t0.42 dependence at 170 and 205-degrees-C. The combined apparent activation energy was 59 kJ/mol, the Arrhenius plot showed a knee between the low and high temperature data. The total layer thickness of the 95Sn-5Sb/copper system exhibited square-root t dependence at the three lower temperatures and t0.42 growth kinetics at 170 and 205-degrees-C. The combined apparent activation energy was 61 kJ/mol. C1 SANDIA NATL LABS,CTR ENGN SCI,ALBUQUERQUE,NM 87185. RP VIANCO, PT (reprint author), SANDIA NATL LABS,CTR SOLDER SCI & TECHNOL,ALBUQUERQUE,NM 87185, USA. NR 7 TC 105 Z9 107 U1 0 U2 8 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 721 EP 727 DI 10.1007/BF02651365 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600006 ER PT J AU ERICKSON, KL HOPKINS, PL VIANCO, PT AF ERICKSON, KL HOPKINS, PL VIANCO, PT TI SOLID-STATE INTERMETALLIC COMPOUND GROWTH BETWEEN COPPER AND HIGH-TEMPERATURE, TIN-RICH SOLDERS .2. MODELING SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Substitutes for Pb-Containing Solders for Microelectronic Applications, at the 1994 TMS Annual Meeting CY FEB 28-MAR 03, 1994 CL SAN FRANCISCO, CA SP MINERALS MET & MAT SOC DE INTERFACIAL DIFFUSION; INTERMETALLIC GROWTH; SOLDER AB The solder/base metal interfacial chemistry characterizing solder joints impacts the manufacturability and reliability of electronic components. A model was developed to predict the long-term diffusion-controlled growth of interfacial intermetallic compound layers using short-term experimental data. The model included terms for both constant and variable diffusion coefficients. Application of the model was demonstrated using parameter values for 100Sn/Cu system and comparing calculated layer thicknesses with the experimentally observed values. The early time data for the 100Sn/Cu system that were used to predict growth at longer times were characterized using a variable diffusion coefficient that was an empirical function of layer thickness. C1 SANDIA NATL LABS,CTR SOLDER SCI & TECHNOL,ALBUQUERQUE,NM 87185. RP ERICKSON, KL (reprint author), SANDIA NATL LABS,CTR ENGN SCI,ALBUQUERQUE,NM 87185, USA. NR 7 TC 22 Z9 22 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 729 EP 734 DI 10.1007/BF02651366 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600007 ER PT J AU ARTAKI, I JACKSON, AM VIANCO, PT AF ARTAKI, I JACKSON, AM VIANCO, PT TI EVALUATION OF LEAD-FREE SOLDER JOINTS IN ELECTRONIC ASSEMBLIES SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Substitutes for Pb-Containing Solders for Microelectronic Applications, at the 1994 TMS Annual Meeting CY FEB 28-MAR 03, 1994 CL SAN FRANCISCO, CA SP MINERALS MET & MAT SOC DE ELECTRONIC ASSEMBLY; LEAD-FREE; SOLDER; SOLDERABILITY AB The feasibility of printed circuit board assembly with lead-free solder alloys was investigated. Studies were conducted with two baseline eutectic binary alloys, SnBi and SnAg, and three new lead-free solder formulations: (1) 91.8Sn-4.8Bi-3.4Ag (wt%) developed at Sandia Laboratories, (2) 77.2Sn-20In-2.8Ag developed at Indium Corp. of America, and (3) 96.2Sn-2.5Ag-0.8Cu-0.5Sb provided by AIM Inc. The basic physical properties (melting temperature, wetting, mechanical strength) pertinent to each of the newly developed alloys are described. The feasibility of 0.4 mm pitch assembly was established with each of the lead-free solder alloys investigated, although the processing windows were generally found to be narrower. All solder joints exhibited good fillets, in accordance with the workmanship standards. Wetting of the lead-free solders was significantly improved on immersion tin vs imidazole finished circuit boards. The laminates did not suffer thermal degradation effects, such as warpage, delamination, or severe discoloration (reflow was performed under an inert atmosphere). It is thus concluded that the manufacturability performance of the new solder formulations is adequate for surface mount applications. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP ARTAKI, I (reprint author), AT&T BELL LABS,PRINCETON,NJ 08542, USA. NR 21 TC 49 Z9 49 U1 1 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 757 EP 764 DI 10.1007/BF02651370 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600011 ER PT J AU RAY, U ARTAKI, I GORDON, HM VIANCO, PT AF RAY, U ARTAKI, I GORDON, HM VIANCO, PT TI THE INFLUENCE OF TEMPERATURE AND HUMIDITY ON PRINTED WIRING BOARD SURFACE FINISHES - IMMERSION TIN VS ORGANIC AZOLES SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Substitutes for Pb-Containing Solders for Microelectronic Applications, at the 1994 TMS Annual Meeting CY FEB 28-MAR 03, 1994 CL SAN FRANCISCO, CA SP MINERALS MET & MAT SOC DE AZOLES; IMMERSION TIN; SOLDERABILITY; SURFACE FINISH; WETTING AB Substitution of lead-free solders in electronic assemblies requires changes in the conventional Sn:Pb finishes on substrates and component leads to prevent contamination of the candidate lead-free solder. Options for solderability preservative coatings on the printed wiring board include organic (azole or rosin/resin based) films and tin-based plated metallic coatings. This paper compares the solderability performance and corrosion protection effectiveness of electroless tin coatings vs organic azole films after exposure to a series of humidity and thermal cycling conditions. The solderability of immersion tin is directly related to the tin oxide growth on the surface and is not affected by the formation of Sn-Cu intermetallic phases as long as the intermetallic phase is underneath a protective Sn layer. Thin azole films decompose upon heating in the presence of oxygen and lead to solderability degradation. Evaluations of lead-free solder pastes for surface mount assembly applications indicate that immersion tin significantly improves the spreading of Sn:Ag and Sn:Bi alloys as compared to azole surface finishes. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP RAY, U (reprint author), AT&T BELL LABS,PRINCETON,NJ 08540, USA. NR 13 TC 8 Z9 8 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 779 EP 785 DI 10.1007/BF02651373 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600014 ER PT J AU BARTELS, F MORRIS, JW DALKE, G GUST, W AF BARTELS, F MORRIS, JW DALKE, G GUST, W TI INTERMETALLIC PHASE-FORMATION IN THIN SOLID-LIQUID DIFFUSION COUPLES SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Substitutes for Pb-Containing Solders for Microelectronic Applications, at the 1994 TMS Annual Meeting CY FEB 28-MAR 03, 1994 CL SAN FRANCISCO, CA SP MINERALS MET & MAT SOC DE DIFFUSION; INTERMETALLIC COMPOUND; SOLDER AB Conducting joints with low fabrication temperatures and high thermal stability are useful in modern electronics. This paper discusses the potential use of intermetallic phases in making such joints. Thin interconnection layers that consist entirely of intermetallic phases have been produced by joining planar Cu substrates that are coated with thin films of Sn. Thin layers (1-5 mum) of intermetallic phase are produced at temperatures slightly above the melting temperature of Sn in a process similar to reflow soldering. Metallography and x-ray analysis are used to characterize the formation mechanism of the intermetallic. Cu dissolves into the liquid Sn by diffusion along narrow channels between grains of the growing eta-Cu6Sn5 intermetallic phase. Tensile tests were used to measure mechanical properties. The joint strength increased with reaction time. The joint fails in a ductile mode as long as unreacted Sn is present, but fractures along interphase boundaries when the joint is completely intermetallic. C1 MAX PLANCK INST MET RES,D-70156 STUTTGART,GERMANY. RP BARTELS, F (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 6 TC 78 Z9 80 U1 2 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 787 EP 790 DI 10.1007/BF02651374 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600015 ER PT J AU SHERWIN, ME ZOLPER, JC BACA, AG DRUMMOND, TJ SHUL, RJ HOWARD, AJ RIEGER, DJ SCHNEIDER, RP KLEM, JF AF SHERWIN, ME ZOLPER, JC BACA, AG DRUMMOND, TJ SHUL, RJ HOWARD, AJ RIEGER, DJ SCHNEIDER, RP KLEM, JF TI COMPARISON OF MG AND ZN GATE IMPLANTS FOR GAAS N-CHANNEL JUNCTION FIELD-EFFECT TRANSISTORS SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE GAAS; JUNCTION FIELD EFFECT TRANSISTOR (JFET); MG IMPLANTS; ZN IMPLANTS ID ANNEALING BEHAVIOR; ATOMIC PROFILES; DIFFUSION; ACTIVATION; ZINC; PERFORMANCE; ZN-64; LAYER; MODEL AB Zinc and magnesium implants into GaAs were profiled with secondary ion mass spectroscopy and etching capacitance-voltage to measure the as-implanted and annealed profiles for the eventual formation of shallow p+/n junction gates for junction field effect transistors (JFETs). The larger mass of the zinc ions results in shorter projected range with significantly less tailing than magnesium implants. High dose, shallow zinc implants annealed under tungsten gate metal showed good activation with negligible diffusion. The improved profile of the zinc implant, as compared to a similar magnesium implant, allowed a tighter JFET design with increased performance. Zn gated n-channel enhancement mode GaAs JFETs with 0.9 mum gate lengths showed transconductances up to 200 mS/mm with a f(t) of 18 GHZ and a f(max) of 37 GHz. The performance of these self-aligned fully implanted JFETs compare favorably with comparably sized implanted MESFETs. RP SHERWIN, ME (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 32 TC 6 Z9 6 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD AUG PY 1994 VL 23 IS 8 BP 809 EP 818 DI 10.1007/BF02651377 PG 10 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA PA946 UT WOS:A1994PA94600018 ER PT J AU CAI, Y CHEN, SS AF CAI, Y CHEN, SS TI DYNAMICS OF ELASTIC CABLE UNDER PARAMETRIC AND EXTERNAL RESONANCES SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID LINEAR FREE-VIBRATIONS; NONLINEAR RESPONSE; EXCITATION AB Nonlinear dynamics of a heavy clastic suspended cable were investigated for application to a stack/wire system. Small oscillations of the cable at the support attached to the stack. the result of bending motion of the stack due to vortex shedding, lead to parametric and external excitation. Numerical analysis was used to predict the parametric and external resonances of the elastic suspended cable, which contained cubic nonlinearities due to cable stretching and quadratic nonlinearities due to equilibrium cable curvature in a tilted configuration. Numerical results agree well with the original stack/wire response. Additional para metric analyses were pursued to distinguish between parametric and external resonances and their couplings. It was found that excitation amplitudes and tilted angles play very important roles in parametric and external resonances. RP CAI, Y (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,TECH STAFF,ARGONNE,IL 60439, USA. NR 11 TC 21 Z9 22 U1 2 U2 5 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD AUG PY 1994 VL 120 IS 8 BP 1786 EP 1802 DI 10.1061/(ASCE)0733-9399(1994)120:8(1786) PG 17 WC Engineering, Mechanical SC Engineering GA NY326 UT WOS:A1994NY32600011 ER PT J AU SCIME, EE PHILLIPS, JL BAME, SJ AF SCIME, EE PHILLIPS, JL BAME, SJ TI EFFECTS OF SPACECRAFT POTENTIAL ON 3-DIMENSIONAL ELECTRON MEASUREMENTS IN THE SOLAR-WIND SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA-EXPERIMENT; COLLECTION; SURFACES AB Using the three-dimensional, low-energy electron spectrometer aboard the Ulysses spacecraft, we have measured the gyrotropicity of electron distributions in the solar wind. In order to make these observations, we have developed a new technique for correcting spacecraft charging effects in three-dimensional, low-energy particle measurements. Comparisons of ion and electron number and current densities, and the alignment of electron temperature anisotropies with the local magnetic field, are presented as evidence of the improvement in the accuracy of the electron moments resulting from the spacecraft charging corrections. The implications of our charging correction technique go beyond simple scalar corrections to the Ulysses measurements. We discuss the effects of our charging correction upon the measurements of temporal and radial gradients in a plasma environment and for two-dimensionally obtained low-energy particle data. RP SCIME, EE (reprint author), LOS ALAMOS NATL LAB,DIV NONPRLIFERAT & INT SECUR,SPACE & ATMOSPHER SCI GRP,GRP NIS-1,LOS ALAMOS,NM 87545, USA. NR 17 TC 32 Z9 32 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14769 EP 14776 DI 10.1029/94JA00489 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500007 ER PT J AU SCURRY, L RUSSELL, CT GOSLING, JT AF SCURRY, L RUSSELL, CT GOSLING, JT TI GEOMAGNETIC-ACTIVITY AND THE BETA-DEPENDENCE OF THE DAYSIDE RECONNECTION RATE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERE; SUBSTORMS; STORMS AB In previous work we have used geomagnetic activity as a proxy measure of the reconnection rate to determine how die upstream solar wind parameters control reconnection. Herein we extend that work to show how the solar wind magnetosonic Mach number, upstream solar wind beta, and the cone angle of the interplanetary magnetic field are correlated with a proxy measure of the efficiency of the reconnection process. Each of these three parameters controls the plasma beta in the magnetosheath downstream of die Earth's bow shock. The dependence of die efficiency of reconnection on the above parameters is in agreement with the expectation that large magnetosheath betas reduce the rate of or hinder the onset of dayside reconnection. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP SCURRY, L (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,6877 SLICHTER HALL,LOS ANGELES,CA 90024, USA. NR 16 TC 35 Z9 35 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14811 EP 14814 DI 10.1029/94JA00794 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500013 ER PT J AU SCURRY, L RUSSELL, CT GOSLING, JT AF SCURRY, L RUSSELL, CT GOSLING, JT TI A STATISTICAL STUDY OF ACCELERATED FLOW EVENTS AT THE DAYSIDE MAGNETOPAUSE SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FLUX-TRANSFER EVENTS; EARTHS MAGNETOPAUSE; ANISOTROPIC PLASMA; ISEE OBSERVATIONS; MAGNETIC SHEAR; SOLAR-WIND; RECONNECTION; DISCONTINUITIES AB Accelerated plasma flows in the magnetopause current layer and low-latitude boundary layer are examined using the ISEE 2 spacecraft. Accelerated flow of magnetosheath plasma inside the magnetopause is an indication that reconnection is occurring or has recently occurred. Over 180 inbound and outbound magnetopause crossings of the ISEE 2 spacecraft have been examined for such evidence of reconnection. Of those orbits for which a good determination could be made, a total of 58 statistically independent accelerated flow events were found where only one event is chosen per inbound or outbound magnetopause traversal. Upstream solar wind data are available for 42 of these 58 events. These 42 traversals are examined in relation to the upstream solar wind and magnetosheath parameters. The occurrence of accelerated flows is found to be dependent upon the direction of the upstream interplanetary magnetic field and the local magnetic shear across the magnetopause. The occurrence rate of accelerated flows is greatest when the interplanetary magnetic field has a southward component in solar magnetospheric coordinates and the local magnetic shear across the magnetopause is large. As the magnetosheath beta increases, the occurrence of accelerated flows decreases. Events in which the magnetic shear is small occur only when the beta is low. This study also provides a statistical estimate of the length and tilt of the merging line. The location and direction of the accelerated flows indicate that merging occurs most often near the subsolar point along a line of length approximately 6 R(E) that tilts in response to the direction of the interplanetary magnetic field. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP SCURRY, L (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,6877 SLICHTER HALL,LOS ANGELES,CA 90024, USA. NR 33 TC 47 Z9 47 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14815 EP 14829 DI 10.1029/94JA00793 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500014 ER PT J AU BIRN, J SCHINDLER, K JANICKE, L HESSE, M AF BIRN, J SCHINDLER, K JANICKE, L HESSE, M TI MAGNETOTAIL DYNAMICS UNDER ISOBARIC CONSTRAINTS SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CENTRAL PLASMA SHEET; FIELD-ALIGNED CURRENTS; SUBSTORM CURRENT WEDGE; MAGNETOSPHERIC SUBSTORMS; GROWTH-PHASE; EARTHS MAGNETOTAIL; CURRENT DIVERSION; GEOMAGNETIC TAIL; MAGNETIC-FIELD; NEUTRAL SHEET AB Using linear theory and nonlinear MHD simulations, we investigate the resistive and ideal MHD stability of two-dimensional plasma configurations under the isobaric constraint dP/dt = 0, which in ideal MHD is equivalent to conserving the pressure function P = P(A), where A denotes the magnetic flux. This constraint is satisfied for incompressible modes, such as Alfven waves, and for systems undergoing energy losses. The linear stability analysis leads to a Schrodinger equation, which can be investigated by standard quantum mechanics procedures. We present an application to a typical stretched magnetotail configuration. For a one-dimensional sheet equilibrium characteristic properties of tearing instability are rediscovered. However, the maximum growth rate scales with the 1/7 power of the resistivity, which implies much faster growth than for the standard tearing mode (assuming that the resistivity is small). The same basic eigen-mode is found also for weakly two-dimensional equilibria, even in the ideal MHD limit. In this case the growth rate scales with the 1/4 power of the normal magnetic field. The results of the linear stability analysis are confirmed qualitatively by nonlinear dynamic MHD simulations. These results suggest the interesting possibility that substorm onset, or the thinning in the late growth phase, is caused by the release of a thermodynamic constraint without the (immediate) necessity of releasing the ideal MHD constraint. In the nonlinear regime the resistive and ideal developments differ in that the ideal mode does not lead to neutral line formation without the further release of the ideal MHD constraint; instead a thin current sheet forms. The isobaric constraint is critically discussed. Under perhaps more realistic adiabatic conditions the ideal mode appears to be stable but could be driven by external perturbations and thus generate the thin current sheet in the late growth phase, before a nonideal instability sets in. C1 NASA,GODDARD SPACE FLIGHT CTR,ELECTRODYNAM BRANCH,GREENBELT,MD 20771. RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. RP BIRN, J (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MS D466,LOS ALAMOS,NM 87545, USA. RI Hesse, Michael/D-2031-2012 NR 48 TC 11 Z9 11 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14863 EP 14875 DI 10.1029/94JA00862 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500017 ER PT J AU FUSELIER, SA ANDERSON, BJ GARY, SP DENTON, RE AF FUSELIER, SA ANDERSON, BJ GARY, SP DENTON, RE TI INVERSE CORRELATIONS BETWEEN THE ION TEMPERATURE ANISOTROPY AND PLASMA-BETA IN THE EARTHS QUASI-PARALLEL MAGNETOSHEATH SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID DEPLETION LAYER; CYCLOTRON WAVES; ENERGETIC IONS; SHOCKS; FIELD; INSTABILITIES; MAGNETOPAUSE AB Average proton parameters in the magnetosheath downstream from the quasi-perpendicular shock (the quasi-perpendicular magnetosheath) for high solar wind dynamic pressure conditions are observed to vary continuously from high-beta, low-temperature anisotropy to low-beta, high-temperature anisotropy. Observations and theory have shown that this inverse correlation is a direct consequence of pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves, which regulate the anisotropy, restoring the plasma toward marginal stability. Although the previously documented spectral characteristics of EMIC waves are not evident downstream of the quasi-parallel bow shock, the inverse anisotropy-beta relation found in the quasi-perpendicular magnetosheath also holds in the quasi-parallel magnetosheath. This indicates that the EMIC instability regulates the ion anisotropy regardless of the shock geometry. C1 JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723. DARTMOUTH COLL,DEPT PHYS & ASTRON,HANOVER,NH 03755. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP FUSELIER, SA (reprint author), LOCKHEED PALO ALTO RES LABS,DEPT 9120,BLDG 255,3251 HANOVER ST,PALO ALTO,CA 94304, USA. RI Anderson, Brian/I-8615-2012 NR 23 TC 59 Z9 59 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14931 EP 14936 DI 10.1029/94JA00865 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500021 ER PT J AU BOROVSKY, JE NEMZEK, RJ AF BOROVSKY, JE NEMZEK, RJ TI THE EARTHS MAGNETOSPHERE UNDER CONTINUED FORCING - SUBSTORM ACTIVITY DURING THE PASSAGE OF AN INTERPLANETARY CLOUD - COMMENT SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note ID MODEL; MAGNETOTAIL; PLASMA RP BOROVSKY, JE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 32 TC 9 Z9 9 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 14937 EP 14940 DI 10.1029/94JA00363 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500022 ER PT J AU DUBOIS, DF AF DUBOIS, DF TI SPACE AND TIME DISTRIBUTION OF HF EXCITED LANGMUIR TURBULENCE IN THE IONOSPHERE - COMPARISON OF THEORY AND EXPERIMENT - REPLY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note ID INDUCED PLASMA-WAVES; ARECIBO RP DUBOIS, DF (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B-213,LOS ALAMOS,NM 87545, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1994 VL 99 IS A8 BP 15093 EP 15095 DI 10.1029/94JA00836 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA PA015 UT WOS:A1994PA01500036 ER PT J AU ZENG, SQ HUNT, AJ CAO, W GREIF, R AF ZENG, SQ HUNT, AJ CAO, W GREIF, R TI PORE-SIZE DISTRIBUTION AND APPARENT GAS THERMAL-CONDUCTIVITY OF SILICA AEROGEL SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Note DE MODELING AND SCALING; POROUS MEDIA; THERMOPHYSICAL PROPERTIES C1 UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. RP ZENG, SQ (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 8 TC 24 Z9 24 U1 3 U2 16 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD AUG PY 1994 VL 116 IS 3 BP 756 EP 759 DI 10.1115/1.2910933 PG 4 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA PD421 UT WOS:A1994PD42100031 ER PT J AU BARTON, JC PATTON, MA EDWARDS, CQ GRIFFEN, LM KUSHNER, JP MEEKS, RG LEGGETT, RW AF BARTON, JC PATTON, MA EDWARDS, CQ GRIFFEN, LM KUSHNER, JP MEEKS, RG LEGGETT, RW TI BLOOD LEAD CONCENTRATIONS IN HEREDITARY HEMOCHROMATOSIS SO JOURNAL OF LABORATORY AND CLINICAL MEDICINE LA English DT Article ID ABSORPTION; RETENTION; IRON AB We postulated that patients with hereditary hemochromatosis (HH) absorb increased quantities of lead, as do iron-deficient subjects. To test this hypothesis, whole blood lead concentration ([blood Pb]) was quantified by atomic absorption spectrometry in HH homozygotes (n = 44), obligate heterozygotes (n = 19), normal control subjects (n = 33), and abnormal controls with transfusion-induced iron overload (n = 8). HH homozygotes had higher [blood Pb] than did normal control subjects (5.6 +/- 0.6 mu g/dl vs 3.6 +/- 0.5 mu g/dl; p < 0.005); significantly increased mean [blood Pb] was observed in bath male and female homozygotes. In heterozygotes, the mean [blood Pb] (4.1 +/- 0.5 mu g/dl) was intermediate between that of homozygotes and normal control subjects. The mean [blood Pb] of subjects with transfusion-induced iron overload (2.2 +/- 0.6 mu g/dl) did not differ significantly from that of normal controls. The findings in homozygotes could not be related to age, serum ferritin concentration, presence or absence of iron loading, or the extent of therapeutic phlebotomy. Lead exposure in all of our subjects was due primarily to ambient sources. Analysis of our data, when using a mathematical biokinetic model of human lead metabolism, suggests that the most likely explanation for our findings is that homozygotes (and, to a lesser extent, heterozygotes) absorb increased quantities of lead, a conclusion that corresponds to the increased absorption of iron and cobalt previously documented in homozygotes C1 VET ADM MED CTR,DEPT MED,BIRMINGHAM,AL. UNIV ALABAMA,DEPT MED,BIRMINGHAM,AL 35294. UNIV ALABAMA,DEPT ENVIRONM TOXICOL,BIRMINGHAM,AL. UNIV ALABAMA,SCH PUBL HLTH,BIRMINGHAM,AL 35294. UNIV UTAH,COLL MED,DEPT MED,SALT LAKE CITY,UT. LDS HOSP,SALT LAKE CITY,UT. OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,METAB & DOSIMETRY RES GRP,OAK RIDGE,TN. BROOKWOOD MED CTR,BIRMINGHAM,AL. FU NCRR NIH HHS [RR-00064]; NIADDK NIH HHS [AM-20630] NR 35 TC 36 Z9 38 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0022-2143 J9 J LAB CLIN MED JI J. Lab. Clin. Med. PD AUG PY 1994 VL 124 IS 2 BP 193 EP 198 PG 6 WC Medical Laboratory Technology; Medicine, General & Internal; Medicine, Research & Experimental SC Medical Laboratory Technology; General & Internal Medicine; Research & Experimental Medicine GA PB204 UT WOS:A1994PB20400012 PM 8051482 ER PT J AU ROCHFORD, KB DAY, GW FORMAN, PR AF ROCHFORD, KB DAY, GW FORMAN, PR TI POLARIZATION DEPENDENCE OF RESPONSE FUNCTIONS IN 3X3 SAGNAC OPTICAL-FIBER CURRENT SENSORS SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article AB We show theoretically that the response functions of a lossless Sagnac optical fiber current sensor based on a 3 x 3 coupler fundamentally depend on the polarization state of light entering the coupler, even for systems with no linear birefringence. For a lossless, zero-birefringence system the desired response functions, sinusoids separated by 120 degrees phase shifts, are obtained only for circularly polarized input light. The response functions for linearly polarized and depolarized inputs are sinusoids separated by 180 degrees and yield zero-slope small signal responses; in addition, two outputs are degenerate, so the responses are similar to those observed in 2 x 2 systems. Thus, 3 x 3 Sagnac systems offer no advantage over 2 x 2 systems for linearly polarized input light. The predicted polarization dependence of 3 x 3 Sagnac response functions is experimentally confirmed. This result establishes the need for increased system complexity in 3 x 3 Sagnac current sensors since polarization control optics are required to provide the proper input polarization. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP ROCHFORD, KB (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 14 TC 10 Z9 12 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD AUG PY 1994 VL 12 IS 8 BP 1504 EP 1509 DI 10.1109/50.317541 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA PH086 UT WOS:A1994PH08600027 ER PT J AU ARNOLD, KS BALESTRA, ME KRAUSS, RM CURTISS, LK YOUNG, SG INNERARITY, TL AF ARNOLD, KS BALESTRA, ME KRAUSS, RM CURTISS, LK YOUNG, SG INNERARITY, TL TI ISOLATION OF ALLELE-SPECIFIC, RECEPTOR-BINDING-DEFECTIVE LOW-DENSITY LIPOPROTEINS FROM FAMILIAL DEFECTIVE APOLIPOPROTEIN B-100 SUBJECTS SO JOURNAL OF LIPID RESEARCH LA English DT Article DE LDL; APO-B; AFFINITY CHROMATOGRAPHY; MONOCLONAL ANTIBODIES; ALLELES ID CAUSES HYPERCHOLESTEROLEMIA; MUTATION; HYPOBETALIPOPROTEINEMIA; DISEASE; PLASMA AB Familial defective apolipoprotein B-100 (FDB) is a genetic disorder apparently caused by a single amino acid substitution (Arg(3500)-->Gln) that disrupts the binding of low density lipoproteins (LDL) to the LDL receptor. The plasma of FDB heterozygotes contains a mixture of normal LDL and LDL that is defective in binding to the LDL receptor. In this study, the monoclonal antibody MB19 (which recognizes an immunogenetic polymorphism in apolipoprotein B-100) was used to determine the percentage of defective LDL in the plasma of FDB heterozygotes and to isolate allele-specific receptor-binding-defective LDL. Several FDB heterozygotes were identified who were heterozygous for the MB19 polymorphism: one apolipoprotein B allotype in each of these individuals bound with low affinity to MB19 and possessed the ARG(3500)--> Gln mutation, whereas the other apolipoprotein B allotype bound with high affinity to MB19 and normally to the LDL receptor. Using MB19 radio-immunoassay, we determined that an average of 73% (range 65-87) of the total LDL from FDB heterozygotes contained the Arg(3500)-->Gln mutation. Antibody MB19-Sepharose immunoaffinity chromatography was used to separate the receptor-binding-defective LDL from the normal LDL. The isolated LDL contained primarily the Arg(3500)-->Gln mutation and had only about 9% of normal LDL receptor-binding ability. Finally, the MB19-Sepharose chromatography procedure may be useful for isolating other allele-specific LDL that have functionally significant mutations. C1 UNIV CALIF SAN FRANCISCO, CARDIOVASC RES INST, SAN FRANCISCO, CA 94141 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. Scripps Res Inst, DEPT IMMUNOL, LA JOLLA, CA 92037 USA. RP ARNOLD, KS (reprint author), UNIV CALIF SAN FRANCISCO, GLADSTONE INST CARDIOVASC DIS, POB 419100, SAN FRANCISCO, CA 94141 USA. FU NHLBI NIH HHS [HL 18574, HL 41633] NR 26 TC 15 Z9 15 U1 0 U2 0 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD AUG PY 1994 VL 35 IS 8 BP 1469 EP 1476 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA PA008 UT WOS:A1994PA00800015 PM 7989871 ER PT J AU WOELK, K RATHKE, JW KLINGLER, RJ AF WOELK, K RATHKE, JW KLINGLER, RJ TI THE TOROID CAVITY NMR DETECTOR SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID SUPERCRITICAL CARBON-DIOXIDE; COMPOSITE PULSES; COMPENSATION; SENSITIVITY; MICROSCOPY; RESONANCE; SEQUENCES; SAMPLE; COILS AB A cylindrical toroid cavity has been developed as an NMR detector for investigations at high temperature and high pressure in metal vessel probes. With toroid cavity detectors, resonance frequencies up to 400 MHz can easily be attained, which makes them particularly useful for high-field H-1 and F-19 spectroscopy. Typically, static half-height linewidths of 1.5 Hz are achieved, as measured on H-1 with standard solutions in cylindrical pressure vessels. Based on the radial dependency of the B-1 field inside a toroid detector, a mathematical equation was derived that precisely predicts the signal intensity as a function of the pulse width. Inversion-recovery measurements of the T-1 relaxation time of compressed gases (methane and hydrogen) were conducted by using composite inversion pulses. The results demonstrated the utility of toroid cavities for quantitative measurements in pressure probes. Pressures up to 300 bar have been used successfully. Because of the strength and regularity of the B-1 gradient, the toroid cavity detector is also suitable for one dimensional rotating-frame NMR microscopy. A spatial resolution down to a few micrometers can be achieved. The spin concentration and spatial distribution of a chloroform solution were accurately reconstructed from two-dimensional H-1 NMR data. Another similarly accurate but even stronger B-1 gradient evolves as a result of the skin effect during high-frequency current transmission inside the central conductor. This gradient makes it possible to perform rotating-frame microscopy inside the central conductor, as demonstrated with Cu-63 NMR spectroscopy. (C) 1994 Academic Press, Inc. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. NR 36 TC 40 Z9 40 U1 0 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD AUG PY 1994 VL 109 IS 2 BP 137 EP 146 DI 10.1006/jmra.1994.1147 PG 10 WC Physics, Atomic, Molecular & Chemical SC Physics GA PB546 UT WOS:A1994PB54600001 ER PT J AU SUN, BQ PINES, A AF SUN, BQ PINES, A TI THEORY AND EXACT-SOLUTIONS FOR TYCKOS ZERO-FIELD NMR IN HIGH-FIELD SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; SOLID-STATE NMR AB A theory of zero-field NMR in high field (ZFHF-NMR) is described in terms of coherent averaging and irreducible tensors. The theory is used to determine analytical solutions for the parameters of the trajectory proposed and used by Tycko. A new pulse sequence is presented, and optimized solutions for dynamic-angle spinning, dynamic-angle hopping, and double-rotation versions of ZFHF-NMR are discussed. (C) 1994 Academic Press, Inc. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RP SUN, BQ (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 27 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 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD AUG PY 1994 VL 109 IS 2 BP 157 EP 165 DI 10.1006/jmra.1994.1149 PG 9 WC Physics, Atomic, Molecular & Chemical SC Physics GA PB546 UT WOS:A1994PB54600003 ER PT J AU EHRENBERG, H WLTSCHEK, G TROUW, F KROENER, T WEITZEL, H FUESS, H AF EHRENBERG, H WLTSCHEK, G TROUW, F KROENER, T WEITZEL, H FUESS, H TI MAGNETIC-STRUCTURES OF ALPHA-FEMOO4 AND ALPHA-COMOO4 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article AB The crystallographic and magnetic structures of alpha-FeMoO4 and alpha-CoMoO4 were determined by elastic neutron scattering. Both compounds were prepared by subsolidus reaction and crystallize in space group C2/m. For the first compound the magnetic unit cell has doubled b- and c-axes with respect to the crystallographic cell, i.e. k = (0, 1/2, 1/2) and the magnetic space group is P2'. The magnetic moments are collinear within each sublattice for the two different crystallographic sites and aligned along [010] for the ions on screw axes and along [100] for the other site. The absolute values at T = 1.5 K are \mu(Fe2+)\ = 2.1(2)mu(B), and 2.0(2)mu(B),. In a specific heat measurement with a powder sample of alpha-CoMoO4 two phase transitions at T-1 = 6 K and T-2=12 K are observed. We have determined the low temperature phase with the magnetic cell doubled along the a- and c-axes, i.e. k = (1/2, 0, 1/2) and the magnetic space group is Pm', The magnetic moments are collinear aligned along [001] for both sites and the absolute values at T = 1.5 K are \mu(Co2+)\ = 1.50(20)mu(B) and 1.35(20)mu(B) for the two different crystallographic sites. C1 ARGONNE NATL LAB,DIV IPNS,ARGONNE,IL 60439. KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,INST TECH PHYS,D-76021 KARLSRUHE,GERMANY. RP EHRENBERG, H (reprint author), TH DARMSTADT,FACHBEREICH MAT WISSENSCH,FACHGEBIET STRUKTRUFORSCH,D-64287 DARMSTADT,GERMANY. RI Ehrenberg, Helmut/M-7090-2013 OI Ehrenberg, Helmut/0000-0002-5134-7130 NR 3 TC 10 Z9 10 U1 0 U2 15 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 AUG PY 1994 VL 135 IS 3 BP 355 EP 360 DI 10.1016/0304-8853(94)90367-0 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA PD987 UT WOS:A1994PD98700014 ER PT J AU HUGHES, DA DAWSON, DB KORELLIS, JS WEINGARTEN, LI AF HUGHES, DA DAWSON, DB KORELLIS, JS WEINGARTEN, LI TI NEAR-SURFACE MICROSTRUCTURES DEVELOPING UNDER LARGE SLIDING LOADS SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE CONTACT MECHANICS; COPPER; DEFORMATION; DISLOCATION STRUCTURE; FRICTION; WEAR; GRAIN REFINEMENT; METALS; MICROSTRUCTURE; RECRYSTALLIZATION; STRAIN-HARDENING; TRIBOLOGY ID ENERGY DISLOCATION-STRUCTURES; DEFORMATION STRUCTURES; PLASTIC-DEFORMATION; LARGE STRAINS; FRICTION; EVOLUTION; WEAR; COPPER; CELL; RESISTANCE AB The subsurface zones of copper developed during the application of large sliding loads were observed using TEM and SEM, Differences in microstructural development as a function of load and sliding velocity are assessed, The observed microstructural changes, such as the development of a dislocation substructure and a mechanically mixed layer, are used to estimate the stress and strain-state of the near surface zone during sliding, These estimates of local stress and strain were compared to the applied stresses to show that large stress concentrations develop at and below a sliding interface, Thus, the stresses which develop locally within the near surface zone can be many times larger than those predicted from the applied load and the friction coefficient, It is postdated that these stress concentrations arise from two sources: 1) asperity interactions and 2) local and momentary bonding between the two surfaces, These results are compared to various friction models. RP SANDIA NATL LABS, CTR MAT & APPL MECH, LIVERMORE, CA 94550 USA. NR 48 TC 48 Z9 48 U1 0 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1059-9495 EI 1544-1024 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD AUG PY 1994 VL 3 IS 4 BP 459 EP 475 DI 10.1007/BF02645312 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA QE402 UT WOS:A1994QE40200003 ER PT J AU NIEH, TG WADSWORTH, J AF NIEH, TG WADSWORTH, J TI BIAXIAL GAS-PRESSURE FORMING OF A SUPERPLASTIC AL2O3/YTZP SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE CERAMIC COMPOSITE; FINE-GRAINED SIZE; FORMING; SUPERPLASTICITY; ZIRCONIA ID DEFORMATION; COMPOSITE; SHEET; BEHAVIOR; CERAMICS AB The superplastic deformation behavior of fine-grained, 20 wt% alumina/yttria-stabilized tetragonal zirconia (20 wt% Al2O3/YTZP) under conditions of biaxial gas-pressure deformation is described. Sheet specimens were deformed into hemispherical caps at temperatures ranging from 1450 to 1600 degrees C and at imposed gas pressures of 345 and 690 kPa. For the conditions examined, hemispherical caps were formed at times ranging from 10(3) to 2.1 x 10(4) s. The correlation between data obtained in uniaxial tensile testing and the behavior observed during the biaxial deformation experiments of this study is discussed. RP NIEH, TG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L350,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 20 TC 2 Z9 2 U1 0 U2 3 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD AUG PY 1994 VL 3 IS 4 BP 496 EP 500 DI 10.1007/BF02645316 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA QE402 UT WOS:A1994QE40200007 ER PT J AU HOU, SY PHILLIPS, JM WERDER, DJ TIEFEL, TH MARSHALL, JH SIEGAL, MP AF HOU, SY PHILLIPS, JM WERDER, DJ TIEFEL, TH MARSHALL, JH SIEGAL, MP TI SYSTEMATIC TRENDS OF YBA2CU3O7-DELTA THIN-FILMS POST ANNEALED IN LOW-OXYGEN PARTIAL PRESSURES SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID VAPOR-DEPOSITION; GROWN INSITU; SUPERCONDUCTORS; BA2YCU3O7-DELTA; DECOMPOSITION; LAALO3(100); RESISTIVITY; DEPENDENCE; STABILITY; YBA2CU4O8 AB Systematic studies have been performed on 1000 angstrom YBa2Cu3O7-delta films produced by the BaF2 process and annealed in an oxygen partial pressure (p(O2)) range from 740 Torr to 10 mTorr as well as a temperature range from 600 to 1050-degrees-C. The results show that while high quality films can be annealed in a wide range of oxygen partial pressure, they have different characteristics. In general, crystalline quality and T(c) are optimized at high p(O2) and high annealing temperature, while strong flux pinning and low normal state resistivity are achieved at lower values of both variables. Under optimized low p(O2) conditions, an ion channeling chi(min) of 6% is obtained on films as thick as 5000 angstrom. This study will serve as a useful guide to tailoring film properties to the application at hand. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP HOU, SY (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 37 TC 8 Z9 8 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1994 VL 9 IS 8 BP 1936 EP 1945 DI 10.1557/JMR.1994.1936 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA NY070 UT WOS:A1994NY07000004 ER PT J AU WENGSIEH, Z KRULEVITCH, P GRONSKY, R JOHNSON, GC AF WENGSIEH, Z KRULEVITCH, P GRONSKY, R JOHNSON, GC TI STRESS-INDUCED FORMATION OF STRUCTURAL DEFECTS ON THE (311) PLANES OF SILICON SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ROD-LIKE DEFECTS; ISOLATION TRENCHES; SILICON; TRANSFORMATION; DEFORMATION; GERMANIUM AB Structural defects occurring on the {311} planes of single crystal silicon have been observed near the bottom oxide corner in silicon-on-insulator structures formed by selective epitaxial growth. These {311} defects exhibit a preferential orientation and are clustered near the silicon/silicon dioxide interface. This new observation provides an opportunity to study the mechanism of {311} defect generation in a system with discernible microstructure and stress state. High resolution electron microscopy combined with analytical and numerical three-dimensional stress modeling are used to show the dependence of these {311} defects on the local stress field, and to establish their origin in terms of a homogeneous dislocation nucleation model. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. RP WENGSIEH, Z (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 36 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1994 VL 9 IS 8 BP 2057 EP 2065 DI 10.1557/JMR.1994.2057 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA NY070 UT WOS:A1994NY07000018 ER PT J AU FENG, Z KOMVOPOULOS, K BROWN, IG BOGY, DB AF FENG, Z KOMVOPOULOS, K BROWN, IG BOGY, DB TI A PRETREATMENT PROCESS FOR ENHANCED DIAMOND NUCLEATION ON SMOOTH SILICON SUBSTRATES COATED WITH HARD CARBON-FILMS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; AMORPHOUS-CARBON; THIN-FILMS; GROWTH AB Diamond nucleation on unscratched silicon substrates coated with thin films of hard carbon was investigated experimentally with a microwave plasma-assisted chemical vapor deposition system. A new pretreatment process was used to enhance the nucleation of diamond. Relatively high diamond nucleation densities of approximately 10(8) cm-2 were achieved by pretreating the carbon-coated silicon substrates with a methane-rich hydrogen plasma at a relatively low temperature for an hour. Scanning electron microscopy and laser Raman spectroscopy studies revealed that diamond nucleation occurred from nanometer-sized spherical particles of amorphous carbon produced during the pretreatment. The nanoparticles possessed a structure different from that of the original hard carbon film, with a broad non-diamond Raman peak centered at approximately 1500 cm-1, and a high etching resistance in pure hydrogen plasma. The high diamond nucleation density is attributed to the significant percentage of tetrahedrally bonded (sp3) atomic carbon configurations in the nanoparticles and the presence of sufficient high-surface free-energy sites on the pretreated surfaces. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP FENG, Z (reprint author), UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720, USA. NR 18 TC 23 Z9 23 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1994 VL 9 IS 8 BP 2148 EP 2153 DI 10.1557/JMR.1994.2148 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA NY070 UT WOS:A1994NY07000031 ER PT J AU MOYA, JS TOMSIA, AP PAZO, A SANTOS, C GUITIAN, F AF MOYA, JS TOMSIA, AP PAZO, A SANTOS, C GUITIAN, F TI IN-VITRO FORMATION OF HYDROXYLAPATITE LAYER IN A MGO-CONTAINING GLASS SO JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE LA English DT Article AB In the present article, the behaviour of a biologically active glass (BAG) belonging to the system SiO2-CaO-MgO-Na2O-K2O-P2O5, soaked in simulated body fluids (SBF(s)), is studied. The amount of Ca, Mg and K leached from the glass, as well as variations in P concentration and pH of the solution were measured versus time. The formation of a hydroxylapatite (HA) layer on the glass surface was determined by XRD and SEM-EDX. The article reports the influence of pH variation of the medium on the crystallinity of the HA formed. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,LBL,BERKELEY,CA 94720. UNIV SANTIAGO DE COMPOSTELA,INST CERAM,SANTIAGO,SPAIN. RP MOYA, JS (reprint author), CSIC,INST CERAM & VIDRIO,MADRID 6,SPAIN. RI Moya, Jose/I-5841-2013 NR 6 TC 18 Z9 18 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0957-4530 J9 J MATER SCI-MATER M JI J. Mater. Sci.-Mater. Med. PD AUG PY 1994 VL 5 IS 8 BP 529 EP 532 DI 10.1007/BF00124885 PG 4 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA PR241 UT WOS:A1994PR24100005 ER PT J AU TARANTAL, AF OTIANGAOWITI, G HENDRICKX, AG AF TARANTAL, AF OTIANGAOWITI, G HENDRICKX, AG TI HOLOPROSENCEPHALY IN A LONG-TAILED MACAQUE (MACACA-FASCICULARIS) - A CASE-REPORT SO JOURNAL OF MEDICAL PRIMATOLOGY LA English DT Article DE MONKEY; CRANIOFACIAL MALFORMATIONS; HOLOPROSENCEPHALY; ULTRASONOGRAPHY; RU 486 ID NONHUMAN-PRIMATES; PRENATAL GROWTH; EARLY-PREGNANCY; EMBRYOTOXICITY; CYNOMOLGUS; ANOMALIES; MULATTA; DEFECTS; ULTRASOUND; CYCLOPIA AB A long-tailed macaque fetus with ethmocephaly, alobar holoprosencephaly, and arhinia is reported. This fetus was exposed to an antiprogestational agent, RU 486 (2.5 mg/kg intramuscular, once daily), during gestational days 15-18. Three hypotheses are proposed to explain these malformations: (1) they are a direct result of drug exposure, (2) they are a secondary effect of treatment and the result of decreased blood supply to the developing embryo due to an incomplete abortion, and (3) they represent a spontaneous occurrence. C1 UNIV NAIROBI,DEPT VET ANAT,NAIROBI,KENYA. RP TARANTAL, AF (reprint author), LAWRENCE LIVERMORE NATL LAB,CALIF REG PRIMATE RES CTR,DAVIS,CA 95616, USA. NR 24 TC 6 Z9 7 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0047-2565 J9 J MED PRIMATOL JI J. Med. Primatol. PD AUG PY 1994 VL 23 IS 6 BP 319 EP 324 PG 6 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA PX473 UT WOS:A1994PX47300001 PM 7897638 ER PT J AU BLACKBOURN, DJ CHUANG, LF KILLAM, KF CHUANG, RY AF BLACKBOURN, DJ CHUANG, LF KILLAM, KF CHUANG, RY TI INHIBITION OF SIMIAN IMMUNODEFICIENCY VIRUS (SIV) REPLICATION BY CD8(+) CELLS OF SIV-INFECTED RHESUS MACAQUES - IMPLICATIONS FOR IMMUNOPATHOGENESIS SO JOURNAL OF MEDICAL PRIMATOLOGY LA English DT Article DE CD8(+) SUPPRESSOR; SIVMAC INFECTION; TARGET CELL LYSIS; MACACA MULATTA ID TOXIC LYMPHOCYTES-T; PERIPHERAL-BLOOD LYMPHOCYTES; SEROPOSITIVE INDIVIDUALS; CD8+ LYMPHOCYTES; HIV REPLICATION; CD4+ CELLS; CYTO-TOXICITY; AIDS; INVITRO; MECHANISM AB The ability of the CD8+ cells from simian immunodeficiency virus (SIV)-infected rhesus macaques to inhibit SIV replication was investigated. Inhibition was produced by a heat-stable soluble factor of molecular size greater than 10kDa. CD8+ supernatants from some macaques were found not only to suppress SIV growth but also to be cytolytic toward both infected and uninfected CD4+ cells. Such indiscriminate CD8+ cell-mediated cell killing may therefore account for DC4+ cell depletion in certain SIV-infected macaques. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT MED PHARMACOL & TOXICOL,DAVIS,CA 95616. FU PHS HHS [05901] NR 47 TC 15 Z9 15 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0047-2565 J9 J MED PRIMATOL JI J. Med. Primatol. PD AUG PY 1994 VL 23 IS 6 BP 343 EP 354 PG 12 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA PX473 UT WOS:A1994PX47300005 PM 7534828 ER PT J AU SRIVASTAVA, RK LUUTHE, V MARRONE, BL SRIDARAN, R AF SRIVASTAVA, RK LUUTHE, V MARRONE, BL SRIDARAN, R TI SUPPRESSION OF LUTEAL STEROIDOGENESIS BY AN LHRH ANTAGONIST (NAL-LYS-ANTAGONIST-ANTIDE) IN-VITRO DURING EARLY-PREGNANCY IN THE RAT SO JOURNAL OF MOLECULAR ENDOCRINOLOGY LA English DT Article ID GONADOTROPIN-RELEASING-HORMONE; HUMAN CHORIONIC-GONADOTROPIN; OVARIAN-STEROID PRODUCTION; GRANULOSA-CELLS; ESTRADIOL RECEPTORS; INHIBITORY ACTIONS; FEMALE RAT; AGONIST; PROGESTERONE; MECHANISM AB LHRH and its analogues are known to exert direct effects on the ovary. Herein we have described a direct inhibitory effect of an LHRH antagonist (Nal-Lys antagonist: antide) on the basal progesterone (P-4) and pregnenolone (P-5) production by luteal cells obtained from the day-8 pregnant rat. Luteal cells incubated with two doses of antide (10(-4) and 10(-7) M) for 24 or 48 h showed suppression of P-4 production. P-5 production was suppressed by both doses of antide within 12 h of incubation. Neither dose of antide interfered with P-5 production when the duration of incubation was extended beyond 12 h. The 20 alpha-dihydroprogesterone yield from the luteal cells treated with these doses of antide remained unaffected. We estimated the activities of the cholesterol side-chain cleavage (P450scc) enzyme (which is a key enzyme involved in the conversion of cholesterol to P-5) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) (which catalyses the conversion of P-5 to P-4) in the luteal cells treated with different doses of antide. Both doses of antide suppressed the activity of the P450scc enzyme after 12 h of incubation and the 3 beta-HSD content of the luteal cells after 48 h of incubation. These observations indicate that antide exerts a direct inhibitory effect at the level of the corpus luteum, that differential suppression of P-5 and P-4 during different periods of incubation with antide is due to a defect in either the P450scc or the 3 beta-HSD enzyme system, or both.- C1 MOREHOUSE SCH MED,DEPT PHYSIOL,ATLANTA,GA 30310. CHU LAVAL,RES CTR,MRC,MOLEC ENDOCRINOL GRP,QUEBEC CITY G1V 4G2,PQ,CANADA. UNIV LAVAL,QUEBEC CITY G1V 4G2,PQ,CANADA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NICHD NIH HHS [HD-17867, N01-HD-2-2824] NR 47 TC 6 Z9 6 U1 0 U2 0 PU J ENDOCRINOLOGY LTD PI BRISTOL PA 17/18 THE COURTYARD, WOODLANDS, ALMONDSBURY, BRISTOL, ENGLAND BS12 4NQ SN 0952-5041 J9 J MOL ENDOCRINOL JI J. Mol. Endocrinol. PD AUG PY 1994 VL 13 IS 1 BP 87 EP 94 PG 8 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA PC880 UT WOS:A1994PC88000009 PM 7999257 ER PT J AU POMAR, G MULLER, SJ DENN, MM AF POMAR, G MULLER, SJ DENN, MM TI EXTRUDATE DISTORTIONS IN LINEAR LOW-DENSITY POLYETHYLENE SOLUTIONS AND MELT SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE EXTRUDATE DISTORTIONS; MELT FRACTURE; POLYETHYLENE; SHARKSKIN; STABILITY ID WALL SLIP AB The onset of sharkskin and wavy extrudate distortions was studied in a linear low-density polyethylene which was diluted up to 40 wt.% with octadecane in order to vary the plateau modulus. The ratio of critical wall stress to plateau modulus remained constant for the onset of sharkskin. The transition to wavy flow occurred at a constant wall stress, independent of plateau modulus for dilutions up to 30 wt.%, after which the discontinuity in the flow curve and the transition to the wavy instability did not occur. The different behavior for the two transitions suggests different mechanisms. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. NR 11 TC 27 Z9 27 U1 1 U2 3 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 AUG PY 1994 VL 54 BP 143 EP 151 DI 10.1016/0377-0257(94)80019-7 PG 9 WC Mechanics SC Mechanics GA PF630 UT WOS:A1994PF63000009 ER PT J AU GIBSON, JK HAIRE, RG BEAHM, EC GENSINI, MM MAEDA, A OGAWA, T AF GIBSON, JK HAIRE, RG BEAHM, EC GENSINI, MM MAEDA, A OGAWA, T TI THE NEPTUNIUM-IRON PHASE-DIAGRAM SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB The phase relations in the Np-Fe alloy system have been elucidated using differential thermal analysis. A phase diagram for this system is postulated based upon the experimental results, regular-solution model calculations, and an expected correspondence to the U-Fe and Pu-Fe diagrams. The postulated Np-Fe diagram is characterized by limited terminal solid solubilities, two intermetallic solid phases, NpFe2, and Np6Fe, and two eutectics. C1 JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. RP GIBSON, JK (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 21 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 1994 VL 211 IS 3 BP 215 EP 222 DI 10.1016/0022-3115(94)90349-2 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA PE843 UT WOS:A1994PE84300005 ER PT J AU STABIN, MG ECKERMAN, KF RYMAN, JC WILLIAMS, LE AF STABIN, MG ECKERMAN, KF RYMAN, JC WILLIAMS, LE TI BREMSSTRAHLUNG RADIATION-DOSE IN Y-90 THERAPY APPLICATIONS SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE INTERNAL DOSIMETRY; BREMSSTRAHLUNG RADIATION; THERAPY AB The bremsstrahlung component of the decay scheme of beta emitters has been traditionally ignored in internal dosimetry calculations. Methods: We have estimated the radiation dose from the bremsstrahlung component of the decay scheme of Y-90 as a function of distance from a point source in a liquid medium and to body organs from distributed sources of Y-90 in the liver and spleen. Results: These estimates agree with measurements of bremsstrahlung dose measured in a Rando phantom, and give an estimate of the importance of this contribution to the overall dosimetry. Conclusions: The bremsstrahlung radiation absorbed dose contribution from an organ to itself is very small compared to that from the beta dose, but the contribution to other organs is not always negligible, especially when large amounts of Y-90 may be involved, as in therapy applications. C1 CITY HOPE NATL MED CTR,DIV RADIOL,DUARTE,CA 91010. RP STABIN, MG (reprint author), OAK RIDGE NATL LAB,OAK RIDGE INST SCI & EDUC,CTR RADIAT INTERNAL DOSE INFORMAT,DIV MED SCI,OAK RIDGE,TN 37831, USA. FU FDA HHS [FDA 224-75-3016]; NCI NIH HHS [CA 43904]; PHS HHS [33572] NR 12 TC 15 Z9 15 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD AUG PY 1994 VL 35 IS 8 BP 1377 EP 1380 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA PA676 UT WOS:A1994PA67600027 PM 8046497 ER PT J AU CHIBA, S SMITH, DL AF CHIBA, S SMITH, DL TI IMPACTS OF DATA TRANSFORMATIONS ON LEAST-SQUARES SOLUTIONS AND THEIR SIGNIFICANCE IN DATA-ANALYSIS AND EVALUATION SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE LEAST-SQUARES METHOD; LEAST SQUARE FIT; ANOMALY; PEELLES PERTINENT PUZZLE; NONLINEAR DATA TRANSFORMATION; INVARIANT SOLUTION; CORAVARIANCE MATRIX; SENSITIVITY MATRIX; TRUNCATION; APPROXIMATION AB anomaly known as Peelle's Pertinent Puzzle is introduced which appears in obtaining a least-squares average of two strongly-correlated data. This anomaly is then generalized as a change of least-squares solution when data and associated covariance matrix are transformed by non-linear functions. Reason of the change of the least-squares solution with respect to such data transformations is explained by the inconsistency in transforming the data covariance and sensitivity matrices. General criteria which can resolve this anomaly are derived. It is shown that if either one of these criteria is satisfied, the least-squares method gives the correct answer even if the data are discrepant, strongly correlated and the number of data points is small. Effects of data truncations are illustrated by a numerical example, which give an explanation on another aspect of Peelle's Puzzle. An approximate method is also proposed which should be applied when the correct method derived in this paper is not feasible. C1 ARGONNE NATL LAB, DIV ENGN PHYS, ARGONNE, IL 60439 USA. RP JAPAN ATOM ENERGY RES INST, CTR NUCL DATA, TOKAI, IBARAKI 31911, JAPAN. NR 10 TC 10 Z9 10 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD AUG PY 1994 VL 31 IS 8 BP 770 EP 781 DI 10.1080/18811248.1994.9735223 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA PG772 UT WOS:A1994PG77200002 ER PT J AU POLEWSKI, K ZINGER, D TRUNK, J MONTELEONE, DC SUTHERLAND, JC AF POLEWSKI, K ZINGER, D TRUNK, J MONTELEONE, DC SUTHERLAND, JC TI FLUORESCENCE OF MATRIX-ISOLATED GUANINE AND 7-METHYLGUANINE SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY LA English DT Article DE FLUORESCENCE; PHOSPHORESCENCE; ABSORPTION; MATRIX ISOLATION; TIME-RESOLVED FLUORESCENCE; ELECTRONIC EXCITED STATES ID MAGNETIC CIRCULAR-DICHROISM; DEOXYRIBONUCLEIC ACID; MOLECULAR-STRUCTURE; ELECTRONIC-SPECTRA; PYRIMIDINE-BASES; INFRARED-SPECTRA; NUCLEIC-ACIDS; IR-SPECTRA; ABSORPTION; MONOMERS AB We have prepared argon and nitrogen matrices containing guanine and 7-methylguanine, and measured their absorption, fluorescence excitation and fluorescence emission spectra. The fluorescence excitation spectrum of guanine shows four well-resolved bands in the range from 170 to 290 nm; excitation at the wavelengths of each of these bands results in a fluorescence emission with maximum intensity near 350 nm and a single-exponential decay with a lifetime of about 10 ns. There are significant differences between the fluorescent excitation and emission spectra of guanine and of 7-methylguanine, suggesting that the fluorescence observed from the guanine sample does not arise from a minority tautomer. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. AGR UNIV,DEPT PHYS,PL-60637 POZNAN,POLAND. FU NIGMS NIH HHS [GM35662] NR 47 TC 11 Z9 11 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 1011-1344 J9 J PHOTOCH PHOTOBIO B JI J. Photochem. Photobiol. B-Biol. PD AUG PY 1994 VL 24 IS 3 BP 169 EP 177 DI 10.1016/1011-1344(94)07018-0 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA PH778 UT WOS:A1994PH77800004 PM 7965413 ER PT J AU SCHNEIDER, JC ROESSLER, P AF SCHNEIDER, JC ROESSLER, P TI RADIOLABELING STUDIES OF LIPIDS AND FATTY-ACIDS IN NANNOCHLOROPSIS (EUSTIGMATOPHYCEAE), AN OLEAGINOUS MARINE ALGA SO JOURNAL OF PHYCOLOGY LA English DT Article DE ARACHIDONIC ACID; EICOSAPENTAENOIC ACID; EUSTIGMATOPHYCEAE; FISH OIL; NANNOCHLOROPSIS; PULSE CHASE ID BETAINE LIPIDS; OLEOYL-PHOSPHATIDYLCHOLINE; MICROSOMAL PREPARATIONS; EICOSAPENTAENOIC ACID; LOWER PLANTS; BIOSYNTHESIS; DGTA; METABOLISM; MICROALGAE; COTYLEDONS AB The synthesis of fatty acids and lipids in Nannochloropsis sp. was investigated by labeling cells in vivo with [C-14]-bicarbonate or [C-14]-acetate. [C-14]-bicarbonate was incorporated to the greatest extent into 16:0, 16:1, and 14:0 fatty acids, which are the predominant fatty acids of triacylglycerols. However, more than half of the [C-14]-acetate was incorporated into longer and more desaturated fatty acids, which are constituents of membrane lipids. [C-14]-acetate was incorporated most strongly into phosphatidylcholine, which rapidly lost label during a 5-h chase period. The label associated with phosphatidylethanolamine also decreased during the chase period, whereas label in other membrane lipids and triacylglycerol increased. The dynamics of labeling, along with information regarding the acyl compositions of various lipids, suggests that 1) the primary products of chloroplast fatty acid synthesis are 14:0, 16:0, and 16:1; 2) C-20 fatty acids are formed by an elongation reaction that can utilize externally supplied acetate; 3) phosphatidylcholine is a site for desaturation of C-18 fatty acids; and 4) phosphatidylethanolamine may be a site for desaturation of C-20 fatty acids. RP SCHNEIDER, JC (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 22 TC 45 Z9 48 U1 4 U2 16 PU PHYCOLOGICAL SOC AMER INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0022-3646 J9 J PHYCOL JI J. Phycol. PD AUG PY 1994 VL 30 IS 4 BP 594 EP 598 DI 10.1111/j.0022-3646.1994.00594.x PG 5 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA PE430 UT WOS:A1994PE43000004 ER PT J AU HAMILTON, JH RAMAYYA, AV KORMICKI, J MA, WC LU, Q SHI, D DENG, JK ZHU, SJ SANDULESCU, A GREINER, W TERAKOPIAN, GM OGANESSIAN, YT POPEKO, GS DANIEL, AV KLIMAN, J POLHORSKY, V MORHAC, M COLE, JD ARYAEINEJAD, R LEE, IY JOHNSON, NR MCGOWAN, FK AF HAMILTON, JH RAMAYYA, AV KORMICKI, J MA, WC LU, Q SHI, D DENG, JK ZHU, SJ SANDULESCU, A GREINER, W TERAKOPIAN, GM OGANESSIAN, YT POPEKO, GS DANIEL, AV KLIMAN, J POLHORSKY, V MORHAC, M COLE, JD ARYAEINEJAD, R LEE, IY JOHNSON, NR MCGOWAN, FK TI ZERO NEUTRON EMISSION IN SPONTANEOUS FISSION OF CF-252 - A FORM OF CLUSTER RADIOACTIVITY SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Letter ID COLD FRAGMENTATION; KINETIC ENERGIES; CHARGE; YIELDS; ELEMENTS; PRODUCTS; U-233; MASS AB By using the triple gamma coincidence technique with 20 Ge detectors at the Holifield Laboratory in the spontaneous fission of Cf-252, neutronless fragmentations, like 104Mo-148Ba, 106Mo-146Ba, 108Mo-144Ba and 104Zr-148Ce, are experimentally observed directly for the first time. When zero neutron emission spontaneous fission occurs, essentially all the available energy goes into the total kinetic energy of the fragments (cold fission). This process is seen theoretically to be an extension of cluster radioactivity, which involves the emission of one light fragment like C-14, O-20, Ne-24 or Mg-28 to nearly equal fragments. In the neutronless spontaneous fission reported here, double fine structures (i.e. decays to the excited states of both fragments) are observed experimentally in contrast to fine structure in only the heavy partner populated by the light partner in earlier cluster radioactivity work. Neutronless spontaneous fission is discussed in the framework of cluster radioactivity. C1 TSING HUA UNIV,DEPT PHYS,BEIJING,PEOPLES R CHINA. JW GOETHE UNIV,INST THEORET PHYS,D-60054 FRANKFURT,GERMANY. ORNL,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. JOINT INST NUCL RES,DUBNA,RUSSIA. SASC,INST PHYS,BRATISLAVA,SLOVAKIA. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. RP HAMILTON, JH (reprint author), VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235, USA. NR 27 TC 79 Z9 80 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD AUG PY 1994 VL 20 IS 8 BP L85 EP L89 DI 10.1088/0954-3899/20/8/003 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA PA634 UT WOS:A1994PA63400003 ER PT J AU MCBREEN, J AF MCBREEN, J TI NICKEL ZINC BATTERIES SO JOURNAL OF POWER SOURCES LA English DT Article ID OXIDE CELLS; ALKALINE ELECTROLYTES; CURRENT-MODULATION; CALCIUM HYDROXIDE; ZN/NIOOH CELLS; SHAPE CHANGE; ELECTRODES; DEPOSITION; MECHANISM; KINETICS AB The nickel/zinc battery is very attractive for electric vehicle applications. Development is slow because of problems related to the solubility of the zinc electrode discharge products and the disparity in charging efficiencies between the nickel and zinc electrodes. Recent advances in solving these problems are reviewed. RP MCBREEN, J (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 53 TC 25 Z9 27 U1 3 U2 15 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD AUG-SEP PY 1994 VL 51 IS 1-2 BP 37 EP 44 DI 10.1016/0378-7753(94)01954-1 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA PQ800 UT WOS:A1994PQ80000005 ER PT J AU HENRIKSEN, GL VISSERS, DR AF HENRIKSEN, GL VISSERS, DR TI LITHIUM ALUMINUM IRON SULFIDE BATTERIES SO JOURNAL OF POWER SOURCES LA English DT Article ID TEMPERATURE AB Lithium-alloy/metal sulfide batteries have been under development at Argonne National Laboratory since 1972. ANL's technology employs a two-phase Li alloy negative electrode, low-melting point LiCl-rich LiCl-LiBr-KBr molten salt electrolyte, and either an FeS or an upper-plateau (UP) FeS2 positive electrode. These components are assembled in an 'electrolyte-starved' bipolar cell configuration. Use of the multi-phase Li alloy ((alpha + beta)-Li-Al and Li5Al5Fe2) negative electrode provides in situ overcharge tolerance that renders the bipolar design viable. Employing LiCl-rich LiCl-LiBr-KBr electrolyte in 'electrolyte-starved' cells achieves low-burdened cells that possess low area-specific impedance, comparable with that of flooded cells using LiCl-LiBr-KBr eutectic electrolyte. The combination of dense UP FeS2 electrodes and low-melting electrolyte produces a stable and reversible couple, achieving over 1000 cycles in flooded cells, with high power capabilities. In addition, a new class of stable chalcogenide ceramic/sealant materials was developed. These materials produce high-strength bonds between a variety of metals and ceramics, which make fabrication of lithium/iron sulfide bipolar stacks practical. Bipolar Li-Al/FeS and Li-Al/FeS2 cells and four-cell stacks using these seals have been built and tested for electric vehicle (EV) applications. When cell performance characteristics are used to model full-scale EV and hybrid vehicle (HV) batteries, they are projected to meet or exceed the performance requirements for a large variety of EV and HV applications. In 1992, the US Advanced Battery Consortium awarded contracts to ANL and SAFT America to continue the development of the bipolar Li-Al/FeS2 battery to meet their long-term criteria. Both ANL and SAFT are working together to refine this technology for EV applications and scale it up to larger stacks and fully integrated battery modules. RP HENRIKSEN, GL (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,ELECTROCHEM TECHNOL PROGRAM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 23 TC 21 Z9 23 U1 5 U2 34 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD AUG-SEP PY 1994 VL 51 IS 1-2 BP 115 EP 128 DI 10.1016/0378-7753(94)01965-7 PG 14 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA PQ800 UT WOS:A1994PQ80000010 ER PT J AU PHILLIPS, JH ATWOOD, CL MAGLEBY, HL KHERICHA, ST AF PHILLIPS, JH ATWOOD, CL MAGLEBY, HL KHERICHA, ST TI INTERPRETATION OF PROBABILISTIC STRUCTURAL-ANALYSIS OF AN AGING PASSIVE COMPONENT SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB This article describes a technique to calculate the risk from failure of passive components over time, and demonstrates the technique by applying it to a weld in the auxiliary feedwater (AFW) system. It uses a modified version of the PRAISE computer code to perform a probabilistic structural analysis to calculate the probability that crack growth due to aging would cause the weld to rupture. It then uses the weld rupture probability as input to a modified existing PRA to calculate the change in plant risk with time. The results show an insignificant effect on plant risk because of the low calculated rupture rate of the weld in this particular calculation over 48 yr of service. A decreasing yearly rupture rate for this weld is calculated. This results from infant mortality; that is, most of those initial flaws that will eventually lead to rupture will do so early in life. C1 EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP PHILLIPS, JH (reprint author), TENERA LP,IDAHO FALLS,ID 83402, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 1994 VL 116 IS 3 BP 295 EP 301 DI 10.1115/1.2929591 PG 7 WC Engineering, Mechanical SC Engineering GA PE104 UT WOS:A1994PE10400009 ER PT J AU PAPP, L CHEN, SS AF PAPP, L CHEN, SS TI TURBULENCE-INDUCED VIBRATION OF TUBE ARRAYS IN 2-PHASE FLOW SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Two-phase flow exists in many engineering systems and is a dominant type of flow in heat exchangers, steam generators, and condensers. A flowing two-phase fluid is a source of energy that can cause vibration of tube bundles of these systems. A simple correlation is presented to predict the response of tube bundles in two-phase flow. The model correlates with experimental data reasonably well and is a useful tool in the prediction of tube response. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP PAPP, L (reprint author), RES INST VITKOVICE,VITKOVICE,CZECHOSLOVAKIA. NR 13 TC 10 Z9 10 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 1994 VL 116 IS 3 BP 312 EP 316 DI 10.1115/1.2929594 PG 5 WC Engineering, Mechanical SC Engineering GA PE104 UT WOS:A1994PE10400012 ER PT J AU IGLESIAS, CA WILSON, BG AF IGLESIAS, CA WILSON, BG TI STATISTICAL SIMULATION OF ATOMIC DATA IN OPACITY CALCULATIONS SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID ABSORPTION-MEASUREMENTS; SPECTRA; PLASMA; IRON AB The most significant improvement in radiative opacity codes in recent years has been advances in the atomic data incorporated in the models. In particular, the configuration term structure, which significantly increases the amount of atomic data in the calculations, is now explicitly included for elements with low atomic number. For large atomic number, where explicit calculations are impractical, clever methods have been developed that conserve a few properties of the transition arrays rather than attempt to reproduce the detailed spectrum. There are, however, conditions where neglecting the resolved character of the transition arrays leads to large errors, but for which explicit calculations are either costly or impractical. Here, we test recently developed methods for statistically simulating resolved transition arrays. When possible, the results are compared to explicit calculations and experiments. RP IGLESIAS, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 22 TC 15 Z9 15 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD AUG PY 1994 VL 52 IS 2 BP 127 EP 136 DI 10.1016/0022-4073(94)90001-9 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA PF389 UT WOS:A1994PF38900001 ER PT J AU SMITH, DC RUSH, EE MATTHEWS, CW CHAVEZ, JM BATOR, PA AF SMITH, DC RUSH, EE MATTHEWS, CW CHAVEZ, JM BATOR, PA TI OPERATION OF LARGE-SCALE PUMPS AND VALVES IN MOLTEN-SALT SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The molten salt pump and valve (P&V) test loops at Sandia National Laboratories (SNL) National Solar Thermal Test Facility (NSTTF) operated between Jan. 1988 and Oct. 1990. The purpose of the P&V test was to demonstrate the performance, reliability, and service life of full-scale hot and cold salt pumps and valves for use in commercial central receiver solar power plants. The P&V test hardware consists of two pumped loops; the ''Hot Loop'' to simulate the hot (565-degrees-C) side of the receiver and the ''Cold Loop'' to simulate the receiver's cold (285-degrees-C) side. Each loop contains a pump and five valves sized to be representative of a conceptual 60-MW(e) commercial solar power plant design. The hot loop accumulated over 6700 hours of operation and the cold loop over 2500 hours of operation. This project has demonstrated that standard commercial scale pump and valve designs will work in molten salt. The test also exposed some pitfalls that must be avoided in specifying such equipment. Although certainly not all of the pitfalls were discovered, careful design and specification should result in reliable or at least workable equipment. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. BABCOCK & WILCOX CO,BARBERTON,OH 44203. RP SMITH, DC (reprint author), SCI APPLICAT INT,ALBUQUERQUE,NM 87106, USA. NR 9 TC 1 Z9 1 U1 0 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD AUG PY 1994 VL 116 IS 3 BP 137 EP 141 DI 10.1115/1.2930072 PG 5 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA PD468 UT WOS:A1994PD46800003 ER PT J AU CHEN, G PETERSON, JR BRISTER, KE AF CHEN, G PETERSON, JR BRISTER, KE TI AN ENERGY-DISPERSIVE X-RAY-DIFFRACTION STUDY OF MONOCLINIC EU2O3 UNDER PRESSURE SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Letter AB The phase behavior of monoclinic (B-type) Eu2O3 under pressure in a diamond anvil cell was studied at room temperature by energy-dispersive X-ray diffraction at the Cornell High Energy Synchrotron Source. The bulk modulus (B0) of B-type Eu2O3, derived from the compression curve obtained, was 140 GPa. A pressure-induced phase transition from the monoclinic to the hexagonal (A-type) crystal structure was observed at about 4.7 GPa. The fractional volume change, DELTAV/V, under this transition pressure was approximately -2%. (C) 1994 Academic Press, Inc. C1 OAK RIDGE NATL LAB,TRANSURANIUM RES LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. CORNELL UNIV,CORNELL HIGH ENERGY SYNCHROTRON SOURCE,ITHACA,NY 14853. RP CHEN, G (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 15 TC 19 Z9 20 U1 2 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD AUG PY 1994 VL 111 IS 2 BP 437 EP 439 DI 10.1006/jssc.1994.1250 PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA PC615 UT WOS:A1994PC61500031 ER PT J AU NARKHEDE, MR NGUYENTRUNG, C PALMER, DA AF NARKHEDE, MR NGUYENTRUNG, C PALMER, DA TI DISSOCIATION QUOTIENTS OF D-GALACTURONIC ACID IN AQUEOUS-SOLUTION AT 0.1 MPA TO 1 MOLAL IONIC-STRENGTH AND 100-DEGREES-C SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE POTENTIOMETRY; D-GALACTURONIC ACID; DISSOCIATION CONSTANTS; THERMODYNAMICS ID CHLORIDE; 300-DEGREES-C; IONIZATION; WATER; MEDIA; ZINC AB The molal dissociation quotients of D-galacturonic acid were measured potentiometrically in a newly-designed, hydrogen-electrode concentration cell from 5 to 100-degree-C at four ionic strengths ranging from 0.1 to 1.0 mol-kg-1 using sodium trifluoromethanesulfonate (NaF3CSO3) as the supporting electrolyte. These quotients were fitted in the all anionic (isocoulombic) form by an empirical equation incorporating three adjustable parameters. When combined with the known dissociation quotient for water in the same medium, this treatment yielded the following thermodynamic quantities for the acid dissociation equilibrium at 25-degrees-C and infinite dilution: log K(H) = -3.490+/-0.011, DELTAH(H)degrees = 0.4+/-0.2 kJ-mol-1, DELTAS(H)degrees = -65+/-1 J-mol-1-K-1, and DELTAC(p,H)degrees = -231+/-8 J-mol-1-K-1. Comparisons are made with the corresponding results of a limited number of previous studies carried out near ambient conditions. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,BLDG 4500S,OAK RIDGE,TN 37831. CREGU,F-54501 VANDOEUVRE NANCY,FRANCE. NR 27 TC 3 Z9 3 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD AUG PY 1994 VL 23 IS 8 BP 877 EP 888 DI 10.1007/BF00972751 PG 12 WC Chemistry, Physical SC Chemistry GA PG310 UT WOS:A1994PG31000002 ER PT J AU BARTELT, MC EVANS, JW AF BARTELT, MC EVANS, JW TI SCALING OF SPATIAL CORRELATIONS IN COOPERATIVE SEQUENTIAL ADSORPTION WITH CLUSTERING SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE COOPERATIVE SEQUENTIAL ADSORPTION; NEAREST-NEIGHBOR EXCLUSION; CLUSTERING; PAIR CORRELATIONS ID DIFFRACTED INTENSITY; LATTICE AB We examine solvable cooperative sequential adsorption models on a linear lattice where adsorption rates produce strong clustering or island formation. We show that the spatial pair correlations in this regime assume a scaled form for separations comparable to a characteristic length (which diverges in the strong clustering limit). This scaled form is also determined directly from consideration of appropriate solvable continuum grain growth models. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MATH,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP BARTELT, MC (reprint author), IOWA STATE UNIV SCI & TECHNOL,IPRT,AMES,IA 50011, USA. NR 20 TC 7 Z9 7 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD AUG PY 1994 VL 76 IS 3-4 BP 867 EP 876 DI 10.1007/BF02188690 PG 10 WC Physics, Mathematical SC Physics GA PL384 UT WOS:A1994PL38400006 ER PT J AU KUM, O HOOVER, WG AF KUM, O HOOVER, WG TI TIME-REVERSIBLE CONTINUUM-MECHANICS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE TIME-REVERSIBLE; SMOOTHED-PARTICLE; CONTINUUM MECHANICS; CHAOTIC AB Levesque and Verlet developed a time-reversible and ''bit-reversible'' computational leapfrog algorithm. Their algorithm uses integer arithmetic and is exactly time reversible to the last computational bit describing the particle coordinates. We generalize their idea, developed for atomistic molecular dynamics, to smoothed-particle continuum mechanics. In the special case of a two-dimensional isentropic ideal gas, these two approaches, one microscopic and the other macroscopic, are isomorphic. In the more general nonadiabatic case, but still without dissipative terms, our continuum extension of the leapfrog scheme remains stable and also exhibits the exact time and bit reversibility associated with Levesque and Verlet's atomistic approach. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP KUM, O (reprint author), UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616, USA. NR 9 TC 21 Z9 21 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD AUG PY 1994 VL 76 IS 3-4 BP 1075 EP 1081 DI 10.1007/BF02188699 PG 7 WC Physics, Mathematical SC Physics GA PL384 UT WOS:A1994PL38400015 ER PT J AU JONESOLIVEIRA, JB HARTEN, LP AF JONESOLIVEIRA, JB HARTEN, LP TI TRANSIENT FLUID-SOLID INTERACTION OF SUBMERGED SPHERICAL-SHELLS REVISITED - PROLIFERATION OF FREQUENCIES AND ACOUSTIC RADIATION EFFECTS SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The exact series solutions for the transient shell displacement and fluid pressure fields resulting from the axisymmetric acoustic loading of a submerged, thin elastic, spherical shell are well known. Plots of the shell displacements, velocities, accelerations, strains, and strain rates have been published previously Further investigation for the more general prolate spheroidal geometry has elucidated a complex exchange of energy between the structure and the fluid through the kinematic boundary conditions, which is presented herein for the simpler spherical geometry. The importance of the time evolution of the acoustic radiation coupling to the structure is discussed, including phase information. A comparison of the unloaded versus fluid-loaded frequencies for an example problem demonstrates the ''softening'' effect of the fluid on the structural response and reveals it to be more complex than simple damping. The reloading of the shell due to radiation in the fluid introduces a proliferation of frequencies in the structural response which is characteristic of fluid-solid interaction problems. The computer algebra system PARAMACS is used to perform the analytical and numerical calculations. C1 PARADIGM ASSOC INC,CAMBRIDGE,MA 02139. RP JONESOLIVEIRA, JB (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 8 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD AUG PY 1994 VL 96 IS 2 BP 918 EP 925 DI 10.1121/1.410266 PN 1 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA PB503 UT WOS:A1994PB50300034 ER PT J AU RANKIN, J BOATNER, LA AF RANKIN, J BOATNER, LA TI UNSTABLE NECK FORMATION DURING INITIAL-STAGE SINTERING SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PARTICLES; MGO AB By observing pairs of single-crystal cubic-faceted small particles of MgO in contact along faces, edges, and corners, it was possible to determine the effects of contact geometry on the stability of neck regions formed during the initial stages of sintering. Changes in the neck morphology were monitored during the sintering process by continuous TEM/video observations of particles heated in situ between 1100-degrees and 1260-degrees-C. Particles in face-to-face contact were found to coalesce in the classic manner to form a single particle. Particles in contact along either cube corners or edges, however, developed unstable necks that initially grew, then shrunk, and eventually broke so that such particle pairs effectively ''de-sintered.'' C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 18 TC 26 Z9 26 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 1994 VL 77 IS 8 BP 1987 EP 1990 DI 10.1111/j.1151-2916.1994.tb07088.x PG 4 WC Materials Science, Ceramics SC Materials Science GA PC509 UT WOS:A1994PC50900001 ER PT J AU ROGERS, KA TRUMBLE, KP DALGLEISH, BJ REIMANIS, IE AF ROGERS, KA TRUMBLE, KP DALGLEISH, BJ REIMANIS, IE TI ROLE OF OXYGEN IN MICROSTRUCTURE DEVELOPMENT AT SOLID-STATE DIFFUSION-BONDED CU/ALPHA-AL2O3 INTERFACES SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COPPER; ALUMINA; SYSTEM; THERMODYNAMICS; CUALO2 AB Microstructure development at solid-state diffusion-bonded Cu/alpha-Al2O3 interfaces has been studied using optical and electron microscopy. High-purity Cu foil was bonded between basal-oriented alpha-Al2O3 single-crystal plates at 1040-degrees-C for 24 h in a vacuum of approximately 1.3 X 10(-4) Pa (1 X 10(-6) torr). Optical microscopy of as-bonded specimens revealed a large Cu grain size, fine pores, and long needles of Cu2O at the interface. Bulk specimens were annealed at 1000-degrees-C for various times under controlled oxygen partial pressures in CO/CO2 mixtures. Consistent with a thermochemical analysis, CuAlO2 could be formed at the interfaces. The CuAlO2 was acicular and discontinuous, but occurred in a uniform distribution over the bulk specimen interfaces. C1 LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. RP ROGERS, KA (reprint author), PURDUE UNIV,SCH MAT ENGN,W LAFAYETTE,IN 47907, USA. NR 26 TC 32 Z9 32 U1 1 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD AUG PY 1994 VL 77 IS 8 BP 2036 EP 2042 DI 10.1111/j.1151-2916.1994.tb07094.x PG 7 WC Materials Science, Ceramics SC Materials Science GA PC509 UT WOS:A1994PC50900007 ER PT J AU MCLUCKEY, SA HABIBIGOUDARZI, S AF MCLUCKEY, SA HABIBIGOUDARZI, S TI ION-TRAP TANDEM MASS-SPECTROMETRY APPLIED TO SMALL MULTIPLY-CHARGED OLIGONUCLEOTIDES WITH A MODIFIED BASE SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID NUCLEIC-ACID CONSTITUENTS; ELECTROSPRAY IONIZATION; RANDOM NOISE; LASER; ADDUCTS AB Two isomeric oligodeoxynucleotide hexamers, 5'-d(N-6meATGCAT)-3' and 5'-d(ATG5meCAT)-3', were subjected to analysis by electrospray and ion trap mass spectrometry. In the case of the isomer with a modified adenine, location of the modified base in the sequence was straightforward and a triple mass spectrometry experiment provided information on the identify of the modification. In contrast, the isomer with the methylated cytosine did not yield definitive information on the location or identity of the modification. Tandem mass spectrometry data in this case could indicate that the modification was present on either the third or fourth nucleoside. The two isomers represent extremes in the facility with which modified bases can be identified and located in a small oligonucleotide via multiple mass spectrometry of multiply charged anions. A preference for loss of particular bases strongly influences which structurally diagnostic ions are formed upon collisional activation. The likelihood for locating and identifying a modified base is dependent, therefore, upon the likelihood that the base is lost directly from the parent ion. RP MCLUCKEY, SA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 31 TC 77 Z9 77 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD AUG PY 1994 VL 5 IS 8 BP 740 EP 747 DI 10.1016/1044-0305(94)80006-5 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA PD435 UT WOS:A1994PD43500006 PM 24222001 ER PT J AU SHORT, RT TODD, PJ AF SHORT, RT TODD, PJ TI IMPROVED ENERGY COMPENSATION FOR TIME-OF-FLIGHT MASS-SPECTROMETRY SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ASSISTED LASER DESORPTION; IMPROVED RESOLUTION; ION MIRROR; IONIZATION; PERFORMANCE; DESIGN AB A model for improved energy compensation in time-of-flight (TOF) mass spectrometry has been developed and tested. This model includes effects of both the acceleration and drift region on mass resolution for surface desorption TOF mass spectrometers that employ ion mirrors to improve mass resolution. Appropriate placement of an additional stage onto the conventional one- and two-stage mirrors provides compensation for flight time spreads, caused by initial ion kinetic energy distributions, in both regions. Experimental results that validate the model calculations are presented for a modified commercial two-stage ion mirror. For example, m/DELTAm for Na+ was improved from approximately 100 to approximately 200 using only a 200-eV drift energy and a 58-cm drift path. RP SHORT, RT (reprint author), OAK RIDGE NATL LAB,POB 2008,BLDG 5510,MS-6365,OAK RIDGE,TN 37831, USA. NR 36 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD AUG PY 1994 VL 5 IS 8 BP 779 EP 787 DI 10.1016/1044-0305(94)80011-1 PG 9 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA PD435 UT WOS:A1994PD43500011 PM 24222006 ER PT J AU FOLTA, JA HUNT, CE FARRENS, SN AF FOLTA, JA HUNT, CE FARRENS, SN TI LOW-TEMPERATURE WAFER BONDING OF SURFACES USING A REACTIVE SPUTTERED OXIDE SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT Meeting of the Electrochemical-Society CY MAY 16-21, 1993 CL HONOLULU, HI SP ELECTROCHEM SOC ID SILICON-ON-INSULATOR AB A low-temperature silicon wafer bonding technique has been demonstrated to give bond strengths as high as 2.4 MPa for anneal temperatures as low as 400-degrees-C. The technique involves RF magnetron reactive sputter deposition of nonstoichiometric SiOx(x < 2) films on one or both surfaces prior to contacting at room temperature. Surfaces investigated include bare silicon, thermally grown silicon dioxide, and low pressure chemical vapor deposited silicon nitride. Experimental results provide new evidence that removal of oxygen or water from the bonding interface during annealing is critical to the formation of strong interfacial bonds. C1 UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616. RP FOLTA, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV ENGN RES,LIVERMORE,CA 94550, USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD AUG PY 1994 VL 141 IS 8 BP 2157 EP 2160 DI 10.1149/1.2055078 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA PA463 UT WOS:A1994PA46300037 ER PT J AU PAU, S DIXIT, SN EIMERL, D AF PAU, S DIXIT, SN EIMERL, D TI ELECTROOPTIC CONTROL OF CORRELATIONS IN SPECKLE STATISTICS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LASER AB We describe an experiment in which the statistical properties of speckle are modified reproducibly through the use of the electro-optic effect in a birefringent liquid crystal. By adjustment of the voltage applied to a specifically designed liquid-crystal cell, the correlation between the ordinary and the extraordinary waves (which are orthogonally polarized) is varied from almost complete correlation to almost complete decorrelation. The correlation's statistics vary smoothly between the limits of single-speckle-pattern statistics (complete correlation) and the statistics for the intensity addition of two uncorrelated speckle patterns (complete decorrelation). The combined speckle pattern is observed and compared with theory. RP PAU, S (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 6 TC 10 Z9 10 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD AUG PY 1994 VL 11 IS 8 BP 1498 EP 1503 DI 10.1364/JOSAB.11.001498 PG 6 WC Optics SC Optics GA PB777 UT WOS:A1994PB77700025 ER PT J AU BOLLER, A JIN, Y WUNDERLICH, B AF BOLLER, A JIN, Y WUNDERLICH, B TI HEAT-CAPACITY MEASUREMENT BY MODULATED DSC AT CONSTANT-TEMPERATURE SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE HEAT CAPACITY; MODULATED DSC AB The mathematical equations for step-wise measurement of heat capacity (C(p)) by modulated differential scanning calorimetry (MDSC) are discussed for the conditions of negligible temperature gradients within sample and reference. Using a commercial MDSC, applications are evaluated and the limits explored. This new technique permits the determination of C(p) by keeping the sample continually close to equilibrium, a condition conventional DSC is unable to meet. Heat capacity is measured at 'practically isothermal condition' (often changing not more than +/-1 K). The method provides data with good precision. The effects of sample mass, amplitude and frequency of temperature modulation were studied and methods for optimizing the instrument are proposed. The correction for the differences in sample and reference heating rates, needed for high-precision data by standard DSC, do not apply for this method. C1 OAK RIDGE NATL LAB,DIV ANALYT SCI,OAK RIDGE,TN 37831. RP BOLLER, A (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 23 TC 196 Z9 196 U1 2 U2 18 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PD AUG-SEP PY 1994 VL 42 IS 2-3 BP 307 EP 330 DI 10.1007/BF02548519 PG 24 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA PQ123 UT WOS:A1994PQ12300004 ER PT J AU GERLACH, TM WESTRICH, HR CASADEVALL, TJ FINNEGAN, DL AF GERLACH, TM WESTRICH, HR CASADEVALL, TJ FINNEGAN, DL TI VAPOR SATURATION AND ACCUMULATION IN MAGMAS OF THE 1989-1990 ERUPTION OF REDOUBT VOLCANO, ALASKA SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID CARBON-DIOXIDE; SULFUR; INCLUSIONS; SOLUBILITY; MELT; EMISSIONS; CHLORINE; WATER; ATMOSPHERE; GLASSES AB The 1989-1990 eruption of Redoubt Volcano, Alaska, provided an opportunity to compare petrologic estimates of SO2 and Cl emissions with estimates of SO2 emissions based on remote sensing data and estimates of Cl emissions based on plume sampling. In this study, we measure the sulfur and chlorine contents of melt inclusions and matrix glasses in the eruption products to determine petrologic estimates of SO2 and Cl emissions. We compare the results with emission estimates based on COSPEC and TOMS data for SO2 and data for Cl/SO2 in plume samples. For the explosive vent clearing period (December 14-22, 1989), the petrologic estimate for SO2 emission is 21,000 tons, or similar to 12% of a TOMS estimate of 175,000 tons. For the dome growth period (December 22, 1989 to mid-June 1990), the petrologic estimate for SO2 emission is 18,000 tons, or similar to 3% of COSPEC-based estimates of 572,000-680,000 tons. The petrologic estimates give a total SO2 emission of only 39,000 tons compared to an integrated TOMS/COSPEC emission estimate of similar to 1,000,000 tons for the whole eruption, including quiescent degassing after mid-June 1990. Petrologic estimates also appear to underestimate Cl emissions, but apparent HCl scavenging in the plume complicates Cl emission comparisons. Several potential sources of 'excess sulfur' often invoked to explain petrologic SO2 deficits are concluded to be unlikely for the 1989-1990 Redoubt eruption - e.g., breakdown of sulfides, breakdown of anhydrite, release of SO2 from a hydrothermal system, degassing of commingled infusions of basalt in the magma chamber, and syn-eruptive degassing of sulfur from melt present in non-erupted magma. Leakage and/or diffusion of sulfur from melt inclusions do not provide convincing explanations for the petrologic SO2 deficits either. The main cause of low petrologic estimates for SO2 is that melt inclusions do not represent the total sulfur content of the Redoubt magmas, which were vapor-saturated magmas carrying most of their sulfur in an accumulated vapor phase. Almost all the sulfur of the SO2 emissions was present prior to emission as accumulated magmatic vapor at 6-10 km depth in the magma that supplied the eruption; whole-rock normalized concentrations of gaseous excess S in these magmas remained at similar to 0.2 wt.% throughout the eruption, equivalent to similar to 0.7 vol.% at depth. Data for CO2 emissions during the eruption indicate that CO2 at whole-rock concentrations of similar to 0.6 wt.% in the erupted magma was a key factor in creating the vapor saturation and accumulation condition making a vapor phase source of excess sulfur possible at depth. When explosive volcanism involves magma with accumulated vapor, melt inclusions do not provide a sufficient basis for predicting SO2 emissions. Thus, petrologic estimates made for SO2 emissions during explosive eruptions of the past may be too low and may significantly underestimate impacts on climate and the chemistry of the atmosphere. C1 SANDIA NATL LABS,DEPT GEOCHEM 6118,ALBUQUERQUE,NM 87185. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP GERLACH, TM (reprint author), US GEOL SURVEY,CASCADES VOLCANO OBSERV,500 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 48 TC 87 Z9 89 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD AUG PY 1994 VL 62 IS 1-4 BP 317 EP 337 DI 10.1016/0377-0273(94)90039-6 PG 21 WC Geosciences, Multidisciplinary SC Geology GA PH198 UT WOS:A1994PH19800016 ER PT J AU PEKOW, CA WELLER, RE KIMSEY, BB ALLEN, MK AF PEKOW, CA WELLER, RE KIMSEY, BB ALLEN, MK TI ULTRASOUND-GUIDED CHOLECYSTOCENTESIS IN THE OWL MONKEY SO LABORATORY ANIMAL SCIENCE LA English DT Article ID PERCUTANEOUS CHOLECYSTOSTOMY; GALLBLADDER; AOTUS AB Bile samples were obtained from adult owl monkeys by ultrasound-guided percutaneous cholecystocentesis, using a transhepatic approach. Sampling frequency was once weekly over a B-week period. Clinical recovery from each procedure was rapid. Animal body weights fluctuated within 22% of baseline over the study period, but maximal weight loss in any animal was less than 3% at the study's end. At necropsy, gross lesions in the liver and gallbladder were minimal. Histologic examination revealed mild focal cholecystitis in the gallbladder of four of six animals, focal pericholecystitis in three of six animals, and foci of gallbladder fibrosis in two animals. Changes were consistent with repeated trauma from the centesis procedure. Gallbladder mucosa was judged normal in all animals. Body weight fluctuations were attributed to a change in diet, part of a concurrent study, rather than to the centesis procedure. Ultrasound-guided cholecystocentesis provides a rapid, minimally traumatic, and safe method for repeated bile sampling in a small nonhuman primate. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP PEKOW, CA (reprint author), VET ADM MED CTR, 1660 S COLUMBIAN WAY, SEATTLE, WA 98108 USA. NR 11 TC 3 Z9 3 U1 2 U2 3 PU AMER ASSOC LABORATORY ANIMAL SCIENCE PI CORDOVA PA 70 TIMBERCREEK DR, SUITE 5, CORDOVA, TN 38018 SN 0023-6764 J9 LAB ANIM SCI JI Lab. Anim. Sci. PD AUG PY 1994 VL 44 IS 4 BP 365 EP 368 PG 4 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA PD469 UT WOS:A1994PD46900013 PM 7983850 ER PT J AU SMITH, DH JOHNSON, GK WANG, YHC LIM, KH AF SMITH, DH JOHNSON, GK WANG, YHC LIM, KH TI ELECTRICAL CONDUCTIVITIES OF 3-PHASE EMULSIONS .1. STRONGLY WETTING MIDDLE PHASE SO LANGMUIR LA English DT Article ID DISPERSION MORPHOLOGY DIAGRAM; NONPOLAR-SOLVENTS; WATER; MICROEMULSION; MIXTURES; AMPHIPHILES; INVERSION; LIQUIDS; SYSTEM AB Electrical conductivities of steady-state, three-phase (macro)emulsions formed by the top (T), middle (M), and bottom (B) phases of the amphiphile/oil/''water'' (i.e., aqueous 10 mM NaCl) system C4H9OC2H40H/n-decane/water have been measured and compared with the predictions of equations from the literature or that we have proposed. In all cases the continuous phase could be deduced from the combination of experiment and theory, but less information was obtained about dispersed-phase structures. Three new conductivity equations and two new three-phase dispersion morphologies have been proposed. C1 WASC INC,EG&G,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. UNIV OKLAHOMA,SCH CHEM ENGN & MAT SCI,NORMAN,OK 73019. UNIV OKLAHOMA,INST APPL SURFACTANT RES,NORMAN,OK 73019. CHUNG ANG UNIV,DEPT CHEM ENGN,SEOUL 156756,SOUTH KOREA. RP SMITH, DH (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. NR 31 TC 13 Z9 13 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG PY 1994 VL 10 IS 8 BP 2516 EP 2522 DI 10.1021/la00020a006 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA PC650 UT WOS:A1994PC65000006 ER PT J AU JOHNSON, GK DADYBURJOR, DB SMITH, DH AF JOHNSON, GK DADYBURJOR, DB SMITH, DH TI ELECTRICAL CONDUCTIVITIES OF 3-PHASE EMULSIONS .2. C6H13(OC2H4)2OH N-TETRADECANE WATER WITH WETTING AND NONWETTING MIDDLE PHASES SO LANGMUIR LA English DT Article ID WATER; MICROEMULSION; SYSTEM; MORPHOLOGIES; MIXTURES AB Electrical conductivities of steady-state, three-phase (macro)emulsions formed by the top (T), middle (i.e, microemulsion, M), and bottom (B) phases of the amphiphile/oil/''water'' (i.e., aqueous 10 mM NaCl) system C6H13(OC2H4)2OH/n-tetradecane/water have been measured and compared with conductivities predicted by equations for different emulsion morphologies. Two temperatures were used, one above and one below the temperature of the middle-phase wetting transition. The appropriate conductivity equations, and thus the emulsion morphologies, appeared to depend on the wettability of the T-B interface by the middle phase. C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. W VIRGINIA UNIV,DEPT CHEM ENGN,MORGANTOWN,WV 26506. UNIV OKLAHOMA,DEPT CHEM ENGN & MAT SCI,NORMAN,OK 73019. UNIV OKLAHOMA,INST APPL SURFACTANT RES,NORMAN,OK 73019. NR 18 TC 7 Z9 7 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG PY 1994 VL 10 IS 8 BP 2523 EP 2527 DI 10.1021/la00020a007 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA PC650 UT WOS:A1994PC65000007 ER PT J AU GHAREHBAGHI, K BURGESS, GS COLLART, FR LITZJACKSON, S HUBERMAN, E JAYARAM, HN BOSWELL, HS AF GHAREHBAGHI, K BURGESS, GS COLLART, FR LITZJACKSON, S HUBERMAN, E JAYARAM, HN BOSWELL, HS TI P210-BCR-ABL CONFERS OVEREXPRESSION OF INOSINE MONOPHOSPHATE DEHYDROGENASE - AN INTRINSIC PATHWAY TO DRUG-RESISTANCE MEDIATED BY ONCOGENE SO LEUKEMIA LA English DT Article ID CHINESE-HAMSTER CELLS; IMP DEHYDROGENASE; MESSENGER-RNA; GENE-EXPRESSION; TIAZOFURIN; RAS; PROLIFERATION; LEUKEMIA; 2-BETA-D-RIBOFURANOSYLTHIAZOLE-4-CARBOXAMIDE; INHIBITION AB The p210 bcr-abl fusion protein tyrosine kinase oncogene has been implicated in the pathogenesis of chronic granulocytic leukemia (CGL). Specific intracellular functions performed by p210 bcr-abl have recently been delineated. We considerd the possibility that p210 bcr-abl may also regulate the abundance of inosine 5'-monophosphate dehydrogenase (IMPDH) which is a rate-limiting enzyme for de novo guanylate synthesis. We performed studies of the inhibition of IMPDH by tiazofurin, which acts as a competitive inhibitor through its active species that mimics nicotinamide adenine dinucleotide (NAD), i.e. thiazole-4-carboxamide adenine dinucleotide (TAD). The mean inhibitory concentration (IC50) of tiazofurin for cellular proliferation inhibition was 2.3-2.8-fold greater in cells expressing p210 bcr-abl than in their corresponding parent cells proliferating under the influence of growth factors or in growth factor-independent derivative cells not expressing detectable p210 bcr-abl. IMPDH activity was 1.5-2.3-fold greater within cells expressing p210 bcr-abl than in their parent cells. This increase in enzyme activity was a result of 2-fold increased IMPDH protein as determined by immunoblotting. In addition, an increase in the K-m value for NAD utilization by IMPDH was observed in p210 bcr-abl transformed cells, but this increase was within the range of resident NAD concentrations observed in the cells. Increased IMPDH protein in p210 bcr-abl transformed cells was traced to an increased level of IMP dehydrogenase II messenger RNA. Thus, regulation of IMPDH gene expression is mediated at least in part by the bcr-abl gene product and may therefore be indicative of a specific mechanism of intrinsic resistance to tiazofurin. C1 INDIANA UNIV,SCH MED,DEPT MED,EXPTL ONCOL LAB,INDIANAPOLIS,IN. INDIANA UNIV,SCH MED,DEPT MED,DIV HEMATOL ONCOL,INDIANAPOLIS,IN. INDIANA UNIV,SCH MED,VET ADM MED CTR,INDIANAPOLIS,IN. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. OI Collart, Frank/0000-0001-6942-4483 FU NCI NIH HHS [CA 51770] NR 27 TC 12 Z9 12 U1 0 U2 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0887-6924 J9 LEUKEMIA JI Leukemia PD AUG PY 1994 VL 8 IS 8 BP 1257 EP 1263 PG 7 WC Oncology; Hematology SC Oncology; Hematology GA PD379 UT WOS:A1994PD37900001 PM 7520100 ER PT J AU ODELL, WG SCHOENIGER, JS BLACKBAND, SJ MCVEIGH, ER AF ODELL, WG SCHOENIGER, JS BLACKBAND, SJ MCVEIGH, ER TI A MODIFIED QUADRUPOLE GRADIENT SET FOR USE IN HIGH-RESOLUTION MRI TAGGING SO MAGNETIC RESONANCE IN MEDICINE LA English DT Note DE GRADIENT SETS; CARDIAC MRI; QUADRUPOLE; HIGH RESOLUTION AB A special purpose gradient set with a Cos(2 theta) current distribution has been constructed for high resolution MR imaging of small samples in a clinical Signa 1.5 T scanner using the existing gradient amplifiers. The X, Y,and Z gradient coils can attain gradient field strengths of 11.3, 4.7, and 15.2 G/cm at 100 amps current, respectively, with a slew rate of 20 G/cm/ms and usable ramp time of 150 mu s. Field distortions are less than 2% over the central 8 cm of the bore, suitable for high resolution tagging of isolated canine hearts. C1 JOHNS HOPKINS UNIV,SCH MED,DEPT BIOMED ENGN,BALTIMORE,MD 21205. JOHNS HOPKINS UNIV,SCH MED,DEPT RADIOL,BALTIMORE,MD 21205. SANDIA NATL LABS,CTR COMPUTAT ENGN,LIVERMORE,CA. HULL ROYAL INFIRM,CTR MRI,KINGSTON HULL HU3 2JZ,N HUMBERSIDE,ENGLAND. FU Intramural NIH HHS [Z01 HL004608-08]; NHLBI NIH HHS [HL45683] NR 12 TC 10 Z9 10 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0740-3194 J9 MAGNET RESON MED JI Magn.Reson.Med. PD AUG PY 1994 VL 32 IS 2 BP 246 EP 250 DI 10.1002/mrm.1910320215 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA NZ793 UT WOS:A1994NZ79300014 PM 7968449 ER PT J AU TERRELL, JB HARVEY, DP SUDARSHAN, TS LOUTHAN, MR AF TERRELL, JB HARVEY, DP SUDARSHAN, TS LOUTHAN, MR TI PARTICIPATION OF HYDROGEN IN SLOW BENDING BEHAVIOR OF 304L STAINLESS-STEEL SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID EMBRITTLEMENT; CRACKING AB Three point bending test studies on 304L austenitic stainless steel at 293 and 77 K demonstrated that hydrogen charging promoted the formation of brittle fracture features at 293 K; promoted the formation of larger and shallower microvoids at 77 K; and reduced the energy absorbed by the material at both temperatures, although to a greater degree at 77 K. These observations suggest that although hydrogen redistribution during testing can affect the failure mode of this material, it is not a necessary requirement for hydrogen induced degradation. Furthermore, the observation that embrittlement is more severe at liquid nitrogen temperatures indicates that the effects of low temperatures and hydrogen may interact synergistically. The data presented in this paper are consistent with a model in which the embrittlement process is affected by local hydrogen concentrations. C1 USN,RES LAB,MECH & MAT BRANCH,WASHINGTON,DC 20375. MAT MODIFICAT INC,FAIRFAX,VA. E I DUPONT NEMOURS INC,SAVANNAH RIVER LAB,AIKEN,SC. RP TERRELL, JB (reprint author), REYNOLDS MET CO,RICHMOND,VA, USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON, ENGLAND SW1Y 5DB SN 0267-0836 J9 MATER SCI TECH SER JI Mater. Sci. Technol. PD AUG PY 1994 VL 10 IS 8 BP 738 EP 740 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PR617 UT WOS:A1994PR61700010 ER PT J AU THRESHER, RW HOCK, SM AF THRESHER, RW HOCK, SM TI WIND SYSTEMS FOR ELECTRICAL-POWER PRODUCTION SO MECHANICAL ENGINEERING LA English DT Article RP THRESHER, RW (reprint author), NATL RENEWABLE ENERGY LAB,DIV WIND TECHNOL,GOLDEN,CO, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD AUG PY 1994 VL 116 IS 8 BP 68 EP 72 PG 5 WC Engineering, Mechanical SC Engineering GA PC176 UT WOS:A1994PC17600019 ER PT J AU MANCINI, TR CHAVEZ, JM KOLB, GJ AF MANCINI, TR CHAVEZ, JM KOLB, GJ TI SOLAR THERMAL POWER TODAY AND TOMORROW SO MECHANICAL ENGINEERING LA English DT Article RP MANCINI, TR (reprint author), SANDIA NATL LABS,DEPT SOLAR THERMAL TECHNOL,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD AUG PY 1994 VL 116 IS 8 BP 74 EP 79 PG 6 WC Engineering, Mechanical SC Engineering GA PC176 UT WOS:A1994PC17600020 ER PT J AU HILL, R AF HILL, R TI COMMERCIALIZING PHOTOVOLTAIC TECHNOLOGY SO MECHANICAL ENGINEERING LA English DT Article RP HILL, R (reprint author), SANDIA NATL LABS,DEPT PHOTOVOLTAIC SYST APPLICAT,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0025-6501 J9 MECH ENG JI Mech. Eng. PD AUG PY 1994 VL 116 IS 8 BP 80 EP 83 PG 4 WC Engineering, Mechanical SC Engineering GA PC176 UT WOS:A1994PC17600021 ER PT J AU SILLIMAN, K SHORE, V FORTE, TM AF SILLIMAN, K SHORE, V FORTE, TM TI HYPERTRIGLYCERIDEMIA DURING LATE PREGNANCY IS ASSOCIATED WITH THE FORMATION OF SMALL DENSE LOW-DENSITY LIPOPROTEINS AND THE PRESENCE OF LARGE BUOYANT HIGH-DENSITY-LIPOPROTEINS SO METABOLISM-CLINICAL AND EXPERIMENTAL LA English DT Article ID LDL PARTICLE-SIZE; MYOCARDIAL-INFARCTION; SUBCLASS PATTERNS; LP(A) LIPOPROTEIN; RISK FACTOR; PLASMA; CHOLESTEROL; METABOLISM; HYPERLIPIDEMIA; TRIGLYCERIDES C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT MOLEC & NUCL MED,DIV LIFE SCI,DONNER LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT NUTR SCI,BERKELEY,CA. FU NHLBI NIH HHS [HL 18574]; NICHD NIH HHS [HD 07266] NR 52 TC 52 Z9 52 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0026-0495 J9 METABOLISM JI Metab.-Clin. Exp. PD AUG PY 1994 VL 43 IS 8 BP 1035 EP 1041 DI 10.1016/0026-0495(94)90186-4 PG 7 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA PB588 UT WOS:A1994PB58800018 PM 8052144 ER PT J AU RIZZO, HF ZOCCO, T MASSALSKI, TB NASTASI, M ECHEVERRIA, A AF RIZZO, HF ZOCCO, T MASSALSKI, TB NASTASI, M ECHEVERRIA, A TI FORMATION AND STABILITY OF METASTABLE STRUCTURES AND AMORPHOUS PHASES IN PU-V, PU-TA, AND PU-YB SYSTEMS WITH POSITIVE HEATS OF MIXING SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID SPUTTERING TECHNIQUE; ALLOYS; MODEL AB The triode sputtering technique with a 'split-target' arrangement was used to obtain metastable crystalline and amorphous phases in the Pu-V, Pu-Ta, and Pu-Yb systems. The proposed phase diagrams for these systems all exhibit liquid immiscibility. The heats of mixing are estimated to be highly positive, and the atomic radii of the component atoms differ by at least 10 pct. Extended amorphous and body-centered cubic (bcc) solid-solution regions were observed in the Pu-V and Pu-Ta systems. The corresponding lattice parameters appear to follow in each case an assumed Vegard's Law extension. In the Pu-Yb system, no amorphous phase was obtained, but an extended face-centered cubic (fcc) solid-solution region (24 to 78 at. pct Yb) was observed with a large positive deviation of the lattice parameter (approximately 9 pct at 40 at. pct Yb) from a linear Vegard's Law between the pure fcc components. The observed ranges of amorphous and metastable solid-solution phases have been interpreted in terms of predicated heats of formation for these phases using Miedema's thermodynamic approximations that include chemical, elastic, and structural contributions. The effect of the high deposition rates on the formation of amorphous and metastable phases has also been considered. Thermal annealing of Pu-Ta amorphous alloys brings about a rapid diffusion of Pu to the free surface of the amorphous phase without crystallization of the remaining Ta-rich amorphous phase. Microhardness measurements indicate that amorphous Pu-V and Pu-Ta alloys are softer than the crystalline bcc solid-solution alloys in the same composition range. Several similarities in the formation of mixed phase regions (amorphous and solid solutions), microhardness, and resistance to decomposition on heating were noted between the Pu-Ta and Pu-V systems and the Cu-W system studied previously. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. RP RIZZO, HF (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 28 TC 9 Z9 9 U1 1 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1994 VL 25 IS 8 BP 1579 EP 1590 DI 10.1007/BF02668524 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NY717 UT WOS:A1994NY71700003 ER PT J AU KEISER, DD DAYANANDA, MA AF KEISER, DD DAYANANDA, MA TI INTERDIFFUSION BETWEEN U-ZR FUEL VS SELECTED CLADDING STEELS SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID II DRIVER FUEL AB To better understand fuel-cladding compatibility issues as affected by diffusion processes in Argonne National Laboratory's Integral Fast Reactors, interdiffusion studies were carried out with solid-solid diffusion couples assembled with a U-23 at. pct Zr alloy and cladding steels, such as 316, D9, and HT9. All diffusion couples were annealed at 700-degrees-C and examined metallographically and by scanning electron microscopy-energy-dispersive spectroscopy analysis for diffusion structure development. The development of diffusion layers in the couples for various cladding steels is compared and discussed in light of the relative diffusion behavior of the individual elements, intermetallic formation, and experimental diffusion paths. In the context of fuel-cladding compatibility, HT9 is considered superior to 316 and D9, as it develops the smallest diffusion zone with the fewest number of phases. C1 PURDUE UNIV,SCH MAT ENGN,W LAFAYETTE,IN 47907. RP KEISER, DD (reprint author), ANL W,IDAHO FALLS,ID 83402, USA. NR 8 TC 16 Z9 16 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD AUG PY 1994 VL 25 IS 8 BP 1649 EP 1653 DI 10.1007/BF02668530 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NY717 UT WOS:A1994NY71700009 ER PT J AU HAAS, PA ADCOCK, PW CORONEOS, AC HENDRIX, DE AF HAAS, PA ADCOCK, PW CORONEOS, AC HENDRIX, DE TI SMALL-CELL EXPERIMENTS FOR ELECTROLYTIC REDUCTION OF URANIUM-OXIDES TO URANIUM METAL USING FLUORIDE SALTS SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article AB Electrolytic reduction of uranium oxide was proposed for the preparation of uranium metal feed for the atomic vapor laser isotope separation (AVLIS) process. A laboratory cell of 25-cm ID was operated to obtain additional information in areas important to design and operation of a pilot plant cell. Reproducible test results and useful operating and control procedures were demonstrated. About 20 kg of uranium metal of acceptable purity were prepared. A good supply of dissolved UO2 feed at the anode is the most important controlling requirement for efficient cell operation. A large fraction of the cell current is ''nonproductive'' in that it does not produce a metal product nor consume carbon anodes. All useful test conditions gave some reduction of UF4 to produce CF4 in addition to the reduction of UO2, but the fraction of metal from the reduction of UF4 can be decreased by increasing the concentration of dissolved UO2. Operation of large continuous cells would probably be limited to current efficiencies of less than 60 pct, and more than 20 pct of the metal would result from the reduction of UF4. C1 OAK RIDGE NATL LAB, TECH ANAL OPERAT, K25 PLANT, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, DIV ENERGY, OAK RIDGE, TN 37831 USA. RP HAAS, PA (reprint author), OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD AUG PY 1994 VL 25 IS 4 BP 505 EP 518 DI 10.1007/BF02650072 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PA275 UT WOS:A1994PA27500005 ER PT J AU NELSON, LS DUDA, PM HYNDMAN, DA AF NELSON, LS DUDA, PM HYNDMAN, DA TI INTERACTIONS BETWEEN DROPS OF A MOLTEN ALUMINUM-LITHIUM ALLOY AND LIQUID WATER SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Note ID HYDROGEN C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP NELSON, LS (reprint author), UNIV WISCONSIN, DEPT NUCL ENGN & ENGN PHYS, MADISON, WI 53706 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD AUG PY 1994 VL 25 IS 4 BP 623 EP 625 DI 10.1007/BF02650083 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA PA275 UT WOS:A1994PA27500016 ER PT J AU BRADLEY, SA COHN, MJ PENNYCOOK, SJ AF BRADLEY, SA COHN, MJ PENNYCOOK, SJ TI Z-CONTRAST IMAGING OF SUPPORTED PT AND PD CLUSTERS SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Article DE STEM; Z-CONTRAST MICROSCOPY; IMPREGNATED METAL; CATALYSTS ID ELECTRON-MICROSCOPY; CATALYSTS AB High-angle annular dark-field or Z-contrast microscopy was used to demonstrate that well dispersed metal supported catalysts consist of nanometer sized clusters. Depending upon the impregnated metal, different cluster sizes were observed. Grouping of Pd clusters could also be confirmed by analytical electron microscopy. (C) 1994 Wiley-Liss, Inc. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP BRADLEY, SA (reprint author), UOP RES CTR,DES PLAINES,IL 60017, USA. NR 8 TC 2 Z9 2 U1 0 U2 4 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1059-910X J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD AUG 1 PY 1994 VL 28 IS 5 BP 427 EP 429 DI 10.1002/jemt.1070280509 PG 3 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA NU578 UT WOS:A1994NU57800008 PM 7919530 ER PT J AU PRICE, C RIND, D AF PRICE, C RIND, D TI MODELING GLOBAL LIGHTNING DISTRIBUTIONS IN A GENERAL-CIRCULATION MODEL SO MONTHLY WEATHER REVIEW LA English DT Article ID THUNDERSTORMS; THUNDERCLOUDS; CONVECTION; WATER AB A general circulation model (GCM) is used to model global lightning distributions and frequencies. Both total and cloud-to-ground lightning frequencies are modeled using parameterizations that relate the depth of convective clouds to lightning frequencies. The model's simulations of lightning distributions in time and space show good agreement with available observations. The model's annual mean climatology shows a global lightning frequency of 77 flashes per second, with cloud-to-ground lightning making up 25% of the total. The maximum lightning activity in the GCM occurs during the Northern Hemisphere summer, with approximately 91% of all lightning occurring over continental and coastal regions. C1 NASA, GODDARD SPACE FLIGHT CTR, GODDARD INST SPACE STUDIES, GREENBELT, MD 20771 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. RP PRICE, C (reprint author), LAWRENCE LIVERMORE NATL LAB, GLOBAL CLIMATE RES DIV, L-262, POB 808, LIVERMORE, CA 94550 USA. NR 33 TC 102 Z9 105 U1 1 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD AUG PY 1994 VL 122 IS 8 BP 1930 EP 1939 DI 10.1175/1520-0493(1994)122<1930:MGLDIA>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA NY973 UT WOS:A1994NY97300019 ER PT J AU WILEY, LM RAABE, OG KHAN, R STRAUME, T AF WILEY, LM RAABE, OG KHAN, R STRAUME, T TI RADIOSENSITIVE TARGET IN THE EARLY MOUSE EMBRYO EXPOSED TO VERY-LOW DOSES OF IONIZING-RADIATION SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE PREIMPLANTATION EMBRYO; CHIMERA; CELL PROLIFERATION; TRITIUM; GAMMA-RADIATION ID PREIMPLANTATION EMBRYOS; DEVELOPMENT INVITRO; IMMATURE OOCYTES; TRITIATED-WATER; HAMSTER OOCYTES; GAMMA-RADIATION; MALE-MICE; IN-VITRO; ASSAY; AGGREGATION AB We exposed mouse preimplantation embryos in vitro to either tritiated water (HTO) or tritiated thymidine (TdR) to determine whether the radiosensitive target was nuclear or extranuclear for embryonic cell proliferation disadvantage in the mouse embryo chimera assay. 8-cell embryos were incubated in either HTO or TdR for 2 h and paired with non-irradiated control embryos to form chimeras. Chimeras were cultured for an average of 20.2 h to allow for 2-3 cell cycles and then partially dissociated to obtain the number of progeny cells contributed by the two partner embryos for each chimera. These values were expressed as a ''proliferation ratio'' (number of cells from the irradiated embryo: total number of cells in the chimera). A ratio significantly less than 0.50 indicates that the experimental embryo expressed an embryonic cell proliferation disadvantage, which is the endpoint of this assay. The activity concentrations of HTO and TdR were adjusted so that both would deliver comparable mean absorbed nuclear doses during the combined initial 2-h irradiation incubation and subsequent 20.2 h chimera incubation periods. Although nuclear doses were comparable under these conditions, the extranuclear dose delivered by the uniformly distributed HTO was about 100 times greater than the extranuclear dose delivered by TdR for each given nuclear dose. Consequently, obtaining mean TdR proliferation ratios less than or equal to mean HTO proliferation ratios would be evidence for a nuclear target while obtaining mean HTO proliferation ratios < mean TdR proliferation ratios would be evidence for an extranuclear target. TdR consistently produced lower mean proliferation ratios over a range of doses from 0.14 Gy to 0.43 Gy. Therefore, we conclude that the radiosensitive target for this endpoint is nuclear. C1 UNIV CALIF DAVIS,INST TOXICOL & ENVIRONM HLTH,DAVIS,CA 95616. UNIV CALIF DAVIS,SCH VET MED,DEPT MOLEC BIOSCI,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT CIVIL & ENVIRONM ENGN,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DIV HLTH & ECOL ASSESSMENT,LIVERMORE,CA 94551. RP WILEY, LM (reprint author), UNIV CALIF DAVIS,SCH MED,DIV REPRODUCT BIOL & MED,DAVIS,CA, USA. FU NIEHS NIH HHS [R01ES05409] NR 31 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD AUG 1 PY 1994 VL 309 IS 1 BP 83 EP 92 DI 10.1016/0027-5107(94)90045-0 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA PM079 UT WOS:A1994PM07900010 PM 7519736 ER PT J AU MCFEE, AF ABBOTT, MG GULATI, DK SHELBY, MD AF MCFEE, AF ABBOTT, MG GULATI, DK SHELBY, MD TI RESULTS OF MOUSE BONE-MARROW MICRONUCLEUS STUDIES ON 1,4-DIOXANE SO MUTATION RESEARCH-GENETIC TOXICOLOGY LA English DT Note DE 1,4-DIOXANE; MOUSE; BONE MARROW; CLASTOGENICITY; MICRONUCLEI ID SALMONELLA MUTAGENICITY; CHEMICAL-STRUCTURE; CARCINOGENICITY; RODENTS C1 ENVIRONM HLTH RES & TESTING INC,LEXINGTON,KY 40503. NIEHS,RES TRIANGLE PK,NC 27709. RP MCFEE, AF (reprint author), OAK RIDGE INST SCI EDUC,DIV MED SCI,POB 117,OAK RIDGE,TN 37831, USA. NR 11 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-1218 J9 MUTAT RES-GENET TOX JI Mutat. Res.-Genet. Toxicol. PD AUG PY 1994 VL 322 IS 2 BP 145 EP 148 DI 10.1016/0165-1218(94)90096-5 PG 4 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA PM070 UT WOS:A1994PM07000010 PM 7519323 ER PT J AU WEBER, CA KIRCHNER, JM SALAZAR, EP TAKAYAMA, K AF WEBER, CA KIRCHNER, JM SALAZAR, EP TAKAYAMA, K TI MOLECULAR ANALYSIS OF CXPD MUTATIONS IN THE REPAIR-DEFICIENT HAMSTER MUTANTS UV5 AND UVL-13 SO MUTATION RESEARCH LETTERS LA English DT Article DE DNA REPAIR; CXPD; MUTATION ANALYSIS; HAMSTER; XPD; XERODERMA PIGMENTOSUM ID NUCLEOTIDE EXCISION REPAIR; OVARY CELLS; CHO CELLS; DNA; GENE; REPLICATION; INDUCTION; HELICASE; LESIONS; DEFECT AB The cDNA sequence of the Chinese hamster xeroderma pigmentosum group D (CXPD) nucleotide excision repair gene was analyzed from three Chinese hamster ovary (CHO) cell lines: repair proficient strain AA8 and repair deficient, UV complementation group 2 strains UV5 and UVL-13. CXPD encodes a presumed ATP-dependent DNA helicase and is single copy in CHO lines due to the hemizygosity of chromosome 9. Comparison of the deduced wild-type AA8 CXPD protein sequence with that of the Chinese hamster V79 lung-derived cell line revealed two amino acid polymorphisms. Position 285 is glutamine in AA8 and arginine in V79, and position 298 is alanine in AA8 and threonine in V79. Comparison with the human XPD, Saccharomyces cerevisiae RAD3, and Schizosaccharomyces pombe rad15 homologs shows variability at these positions. Analysis of the CXPD sequence in the repair deficient CHO lines UV5 and UVL-13 revealed, in each case, a single base substitution resulting in an amino acid substitution. Position 116 is tyrosine in UV5 and cysteine in AA8, and the corresponding positions of XPD, RADS, and rad15 are cysteine. Position 615 is glutamic acid in UVL-13 and glycine in AA8, and the corresponding positions of XPD, RAD3, and rad15 are glycine. In both UV5 and UVL-13, positions 285 and 298 are glutamine and alanine, respectively, as seen in AA8. These results suggest that cysteine 116 and glycine 615 are critical to the repair function of CXPD. RP WEBER, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,POB 808,L-452,LIVERMORE,CA 94551, USA. FU NCI NIH HHS [CA52679] NR 29 TC 12 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7992 J9 MUTAT RES LETT JI Mutat. Res. Lett. PD AUG PY 1994 VL 324 IS 4 BP 147 EP 152 DI 10.1016/0165-7992(94)90012-4 PG 6 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA PM083 UT WOS:A1994PM08300002 PM 8052270 ER PT J AU HAGSTROM, JN HAGSTROM, R OVERBEEK, R PRICE, M SCHRAGE, L AF HAGSTROM, JN HAGSTROM, R OVERBEEK, R PRICE, M SCHRAGE, L TI MAXIMUM-LIKELIHOOD GENETIC SEQUENCE RECONSTRUCTION FROM OLIGO CONTENT SO NETWORKS LA English DT Article ID DNA AB One promising technique for determining long genetic sequences is sequencing by oligonucleotide content. This technique involves probing a segment of the unknown multimillion ''character'' genetic sequence for the presence or absence of known short subsequences. The information obtained from such hybridization experiments may be represented in network form. Network optimization methods may then be applied to identify the most likely forms of the unknown target sequence. (C) 1994 John Wiley & Sons, Inc. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. UNIV CHICAGO,GRAD SCH BUSINESS,CHICAGO,IL 60637. RP HAGSTROM, JN (reprint author), UNIV ILLINOIS,DEPT INFORMAT & DECIS SCI,POB 4348,CHICAGO,IL 60680, USA. OI Price, Morgan/0000-0002-4251-0362 NR 15 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0028-3045 J9 NETWORKS JI Networks PD AUG PY 1994 VL 24 IS 5 BP 297 EP 302 DI 10.1002/net.3230240506 PG 6 WC Computer Science, Hardware & Architecture; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA NY118 UT WOS:A1994NY11800005 ER PT J AU FITZNER, RE GRAY, RH AF FITZNER, RE GRAY, RH TI WINTER DIET AND WEIGHTS OF BARROWS AND COMMON GOLDENEYE IN SOUTH-CENTRAL WASHINGTON SO NORTHWEST SCIENCE LA English DT Article AB Little data are available relative to diets and body weight dynamics of wintering Barrow's and common goldeneyes in freshwater habitats, and no data exist for subadults. Diets of these birds were studied on the Columbia and Yakima Rivers in southcentral Washington from October through May 1955-1956 and 1956-1957. Trichopteran larvae accounted for more than 67% of common goldeneye and 81% of Barrow's goldeneye food biomass. Mollusc and aquatic plant achenes were other important food items. Average weights of common goldeneye ranged from 599.3 +/- 39.86 g for subadult females to 1060.2 +/- 33.36 g for adult males. Average weights of Barrow's goldeneye ranged from 736.0 +/- 44.73 g for subadult females to 1330.5 +/- 18.69 g for adult males. Body-weight dynamics of birds may reflect resource availability, competition, and bioenergetics, all of which may influence winter distribution, differential migration and habitat use by sexes. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 0 TC 3 Z9 3 U1 4 U2 6 PU WASHINGTON STATE UNIV PI PULLMAN PA PO BOX 645910, PULLMAN, WA 99164-5910 SN 0029-344X J9 NORTHWEST SCI JI Northwest Sci. PD AUG PY 1994 VL 68 IS 3 BP 172 EP 177 PG 6 WC Ecology SC Environmental Sciences & Ecology GA PJ430 UT WOS:A1994PJ43000002 ER PT J AU HO, DDM LINDL, JD TABAK, M AF HO, DDM LINDL, JD TABAK, M TI RADIATION CONVERTER PHYSICS AND A METHOD FOR OBTAINING THE UPPER LIMIT FOR GAIN IN HEAVY-ION FUSION SO NUCLEAR FUSION LA English DT Article ID THERMAL-RADIATION; INERTIAL FUSION; BEAM ENERGY; CONVERSION; DRIVEN; POWER; MODEL AB Converting the kinetic energy of heavy ion beams into radiation energy at high efficiency is important for heavy ion fusion. High conversion efficienty can be achieved if the radiating material consists mainly of a low Z element, for example, beryllium, mixed with a small amount of high Z element, for example, lead. For stopping incoming beams with a given energy, low Z material has higher stopping power and hence has less total internal energy than a high Z material. A high Z material is used for efficient radiation; the exact amount used is determined by the requirement that the Planck mean free path is approximately equal to the dimension of the radiation converter. Too much high Z material would hence prevent radiation from escaping from the interior region of the radiating material. To reduce the hydrodynamic loss in the radial direction, the radiating material is placed inside a casing made of high Z material. Calculations show that the energy absorbed by the casing is tolerable and that the interface between the casing and the radiating material is almost stationary. Various scaling laws for the converter are developed. Simulations with the LASNEX hydrodynamic code show that carefully designed converters can have conversion efficiencies as high as 70% (80%) for incoming beams with 10 GeV (5 GeV) energy. Because the converters have high efficiency and ion range shortening in beryllium is not substantial, range shortening is not a major issue. Once the diagram for the conversion efficiency versus the converter radius is obtained for various beam ion energies, the trajectory is located on this diagram that gives the upper limit for conversion efficiency (and hence for gain) while satisfying the engineering limit of the quadrupole pole-tip magnetic fields of the final-focusing system for heavy ion beams (for ballistic transport through a hard-vacuum reactor chamber). Finally, converter configurations are presented that can deflect the direction of radiation, thereby eliminating the need for ion beam bending. RP HO, DDM (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 26 TC 35 Z9 35 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD AUG PY 1994 VL 34 IS 8 BP 1081 EP 1095 DI 10.1088/0029-5515/34/8/I03 PG 15 WC Physics, Fluids & Plasmas SC Physics GA PM460 UT WOS:A1994PM46000003 ER PT J AU JARDIN, SC KESSEL, CE POMPHREY, N AF JARDIN, SC KESSEL, CE POMPHREY, N TI POLOIDAL FLUX LINKAGE REQUIREMENTS FOR THE INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR SO NUCLEAR FUSION LA English DT Article ID TOKAMAKS AB Two computational models have been applied to calculate the poloidal flux linkage requirements for the current ramp-up and for the flat-top phase of the proposed International Thermonuclear Experimental Reactor (ITER). For the current ramp-up phase, the TSC code has been used to simulate the entire current ramp-up period as described in the TAC-3 Report. The time of the simulation has been extended to cover the full current penetration time, that is, until the loop voltage is a constant throughout the plasma. Sensitivity studies have been performed with respect to current ramp-up time, impurity concentration and to the time of onset of auxiliary heating. A steady state plasma equilibrium code has been used that has the constant loop voltage constraint built in to survey the dependence of the steady state loop voltage on the density and temperature profiles. This calculation takes into account the plasma bootstrap current contribution, including non-circular and collisional corrections. The results can be displayed as contours of the loop voltage on a POPCON-like diagram. RP JARDIN, SC (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. RI Jardin, Stephen/E-9392-2010; pomphrey, neil/G-4405-2010 NR 12 TC 14 Z9 20 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD AUG PY 1994 VL 34 IS 8 BP 1145 EP 1160 DI 10.1088/0029-5515/34/8/I07 PG 16 WC Physics, Fluids & Plasmas SC Physics GA PM460 UT WOS:A1994PM46000007 ER PT J AU WANG, CB AF WANG, CB TI SIMULATION ANALYSIS OF THE EFFECT OF BEAM PIPES AND MULTIMODE COMPETITION IN THE STANDING-WAVE FREE-ELECTRON LASER 2-BEAM ACCELERATOR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID RELATIVISTIC KLYSTRON AB In this paper, we present simulation results of an array of standing-wave free-electron lasers (SWFELs) in the standing-wave free-electron laser two-beam accelerator (SWFEL/TBA) configuration. The influence of betatron motion on the stability of rf output energy is analyzed. The effects of beam pipes and finite emittance on rf output power are examined, and an investigation is made of a possible mode competition. It is shown that for an array of SWFELs with 9 cavities and a 100.6-ns, 0.5-kA, 7.98-MeV, 2.0 X 10(-4) pi m normalized-emittance electron beam, prebunched at 17.1 GHz, an averaged energy output of 12.3 J/m can be obtained with a fluctuation of less than 6.5%. It is also shown that potential competitive longitudinal modes can be suppressed by inserting irises along the electric field direction at some node points of the electric field of the operating mode. C1 LAWRENCE BERKELEY LAB,CTR BEAM PHYS,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV ELECTR SCI & TECHNOL CHINA,HIGH ENERGY ELECTR RES INST,CHENGDU 610054,PEOPLES R CHINA. OI Wang, Changbiao/0000-0001-7891-7079 NR 21 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 1994 VL 346 IS 3 BP 416 EP 425 DI 10.1016/0168-9002(94)90577-0 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NY696 UT WOS:A1994NY69600003 ER PT J AU NOSOCHKOV, Y SEN, T COURANT, E GARREN, A RITSON, DM STIENING, R SYPHERS, MJ AF NOSOCHKOV, Y SEN, T COURANT, E GARREN, A RITSON, DM STIENING, R SYPHERS, MJ TI PRINCIPLES OF INTERACTION REGION DESIGN IN HADRON COLLIDERS AND THEIR APPLICATION TO THE SSC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The high luminosity interaction regions (IRs) are an important part of the lattice in colliding beam machines. The performance of the collider may depend significantly on the particular design of the IRs. In this paper we discuss the general principles of IR design and apply these principles to the design of the Superconducting Super Collider interaction regions. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP NOSOCHKOV, Y (reprint author), SUPERCOND SUPER COLLIDER LAB,2550 BECKLEYMEADE AVE,DALLAS,TX 75237, USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 1994 VL 346 IS 3 BP 448 EP 460 DI 10.1016/0168-9002(94)90581-9 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NY696 UT WOS:A1994NY69600007 ER PT J AU BOYERS, D HO, A LI, Q PIESTRUP, M RICE, M TATCHYN, R AF BOYERS, D HO, A LI, Q PIESTRUP, M RICE, M TATCHYN, R TI TESTS OF VARIABLE-BAND MULTILAYERS DESIGNED FOR INVESTIGATING OPTIMAL SIGNAL-TO-NOISE VERSUS ARTIFACT SIGNAL RATIOS IN DUAL-ENERGY DIGITAL SUBTRACTION ANGIOGRAPHY (DDSA) IMAGING-SYSTEMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID X-RAY-DETECTOR; SYNCHROTRON RADIATION; CORONARY ANGIOGRAPHY; PERFORMANCE; OPTICS AB In recent work, various design techniques were applied to investigate the feasibility of controlling the bandwidth and bandshape profiles of tungsten/boron-carbon (W/B4C) and tungsten/silicon (W/Si) multilayers for optimizing their performance in synchrotron radiation based angiographical imaging systems at 33 keV. Varied parameters included alternative spacing geometries, material thickness ratios, and numbers of layer pairs. Planar optics with nominal design reflectivities of 30-94% and bandwidths ranging from 0.6-10% were designed at the Stanford Synchrotron Radiation Laboratory, fabricated by the Ovonic Synthetic Materials Company, and characterized on Beam Line 4-3 at the Stanford Synchrotron Radiation Laboratory. In this paper we report selected results of these tests and review the possible use of the multilayers for determining optimal signal to noise vs artifact signal ratios in practical dual-energy digital subtraction angiography systems. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. ADELPHI TECHNOL INC,PALO ALTO,CA 94306. NR 28 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 1 PY 1994 VL 346 IS 3 BP 565 EP 570 DI 10.1016/0168-9002(94)90593-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NY696 UT WOS:A1994NY69600019 ER PT J AU MURPHY, JB KRINSKY, S AF MURPHY, JB KRINSKY, S TI MILLIMETER-WAVE COHERENT SYNCHROTRON-RADIATION IN THE SXLS PHASE-I ELECTRON STORAGE-RING SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID INFRARED REGION AB Installation of a 2856 MHz RF system into the phase I SXLS electron storage ring would allow the generation of millimeter wave coherent synchrotron radiation. Operating at 150 MeV, one could produce bunches containing on the order of 2 X 10(7) electrons with a bunch length sigma(L0) = 0.3 mm, resulting in coherent emission at wavelengths above 0.8 mm. The characteristics of the source and the emitted radiation are discussed. In the case of 100 mrad horizontal collection angle, the average power radiated in the wavelength band 1 mm less-than-or-equal-to lambda less-than-or-equal-to 2 mm is 0.3 mW for single bunch operation and 24 mW for 80 bunch operation and the peak power in a single pulse of a few picosecond duration is on the order of 1 W. RP MURPHY, JB (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 34 TC 14 Z9 15 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 AUG 1 PY 1994 VL 346 IS 3 BP 571 EP 577 DI 10.1016/0168-9002(94)90594-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA NY696 UT WOS:A1994NY69600020 ER PT J AU KODAMA, K USHIDA, N MOKHTARANI, A PAOLONE, VS FOLK, JT WILCOX, JO YGER, PM EDELSTEIN, RM FREYBERGER, AP GIBAUT, DB LIPTON, RJ NICHOLS, WR POTTER, DM RUSS, JS ZHANG, C ZHANG JANG, HI KIM, HY KIM, TI LIM, IT PAC, MY BALLER, BR STEFANSKI, RJ NAKAZAWA, K CHUNG, KS CHUNG, SH KIM, DC PARK, IG PARK, MS SONG, JS YOON, CS KURAMATA, S CHIKAWA, M AOKI, S HARA, T TAKAHASHI, Y TARUMA, K CHANG, SD CHEON, DG CHO, JH KANG, JS KIM, CO KIM, KY KIM, TY LEE, JC LEE, SB LIM, GY NAM, SW SHIN, TS SIM, KS WOO, JK GAUTHIER, A HOSHINO, K ISHIKAWA, S KAWAI, T KITAMUR, AH KOBAYASHI, K MIYANISHI, M NAKAMURA, K NAKAMURA, M NAKAMURA, Y NAKANISHI, S NIWA, K NOMURA, M SASAKI, H TAJIMA, H TOMITA, Y YOSHIDA, S ARYAL, M DUNLEA, JM FREDERIKSEN, SG LUNDBERG, BG OLEYNIK, GA REAY, NW REIBEL, K SIDWELL, RA STANTON, NR KALBFLEISCH, GR SKUBIC, P SNOW, JM WILLIS, SE NAKAMURA, K OHASHI, S KUSAWA, T TERANAKA, M TOMINAGA, T YOSHIDA, T OKABE, H YOKOTA, J ADACHI, M IKEGAMI, S KAZUNO, M KOYA, T NIU, E SHIBUYA, H WATANABE, S SATO, Y TEZUKA, I BAHK, SY KIM, SK AF KODAMA, K USHIDA, N MOKHTARANI, A PAOLONE, VS FOLK, JT WILCOX, JO YGER, PM EDELSTEIN, RM FREYBERGER, AP GIBAUT, DB LIPTON, RJ NICHOLS, WR POTTER, DM RUSS, JS ZHANG, C ZHANG JANG, HI KIM, HY KIM, TI LIM, IT PAC, MY BALLER, BR STEFANSKI, RJ NAKAZAWA, K CHUNG, KS CHUNG, SH KIM, DC PARK, IG PARK, MS SONG, JS YOON, CS KURAMATA, S CHIKAWA, M AOKI, S HARA, T TAKAHASHI, Y TARUMA, K CHANG, SD CHEON, DG CHO, JH KANG, JS KIM, CO KIM, KY KIM, TY LEE, JC LEE, SB LIM, GY NAM, SW SHIN, TS SIM, KS WOO, JK GAUTHIER, A HOSHINO, K ISHIKAWA, S KAWAI, T KITAMUR, AH KOBAYASHI, K MIYANISHI, M NAKAMURA, K NAKAMURA, M NAKAMURA, Y NAKANISHI, S NIWA, K NOMURA, M SASAKI, H TAJIMA, H TOMITA, Y YOSHIDA, S ARYAL, M DUNLEA, JM FREDERIKSEN, SG LUNDBERG, BG OLEYNIK, GA REAY, NW REIBEL, K SIDWELL, RA STANTON, NR KALBFLEISCH, GR SKUBIC, P SNOW, JM WILLIS, SE NAKAMURA, K OHASHI, S KUSAWA, T TERANAKA, M TOMINAGA, T YOSHIDA, T OKABE, H YOKOTA, J ADACHI, M IKEGAMI, S KAZUNO, M KOYA, T NIU, E SHIBUYA, H WATANABE, S SATO, Y TEZUKA, I BAHK, SY KIM, SK TI NEW TECHNIQUES FOR EMULSION ANALYSIS IN A HYBRID EXPERIMENT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID CHARMED PARTICLES; BEAUTY PARTICLES; ANALYSIS SYSTEM; CROSS-SECTIONS; SPECTROMETER; LIFETIMES; NEUTRINOS; DECAY AB A new method, called graphic scanning, was developed by the Nagoya University Group for emulsion analysis in a hybrid experiment. This method enhances both speed and reliability of emulsion analysis. Details of the application of this technique to the analysis of Fermilab experiment E653 are described. C1 UNIV CALIF DAVIS,DAVIS,CA 95616. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CHONNAM NATL UNIV,KWANGJU 500757,SOUTH KOREA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. GYEONGSANG NATL UNIV,JINJU 660300,SOUTH KOREA. KOREA UNIV,SEOUL 136701,SOUTH KOREA. NAGOYA UNIV,NAGOYA 46401,JAPAN. HIROSAKI UNIV,HIROSAKI,AOMORI 036,JAPAN. KINKI UNIV,OSAKA,OSAKA 577,JAPAN. KOBE UNIV,KOBE 657,JAPAN. GIFU UNIV,GIFU 50111,JAPAN. UNIV OKLAHOMA,NORMAN,OK 73019. OSAKA CITY UNIV,OSAKA 558,JAPAN. SCI EDUC INST OSAKA PREFECTURE,OSAKA 558,JAPAN. TOHO UNIV,FUNABASHI,CHIBA 274,JAPAN. UTSUNOMIYA UNIV,UTSUNOMIYA,TOCHIGI 321,JAPAN. WONKWANG UNIV,IRI 570749,SOUTH KOREA. RP KODAMA, K (reprint author), AICHI UNIV EDUC,KARIYA 448,JAPAN. RI Russ, James/P-3092-2014; Aoki, Shigeki/L-6044-2015; Yger, Pierre/F-2755-2017 OI Russ, James/0000-0001-9856-9155; NR 26 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 1994 VL 93 IS 3 BP 340 EP 354 DI 10.1016/0168-583X(94)95486-0 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA PD420 UT WOS:A1994PD42000020 ER PT J AU QUINN, HR AF QUINN, HR TI CP VIOLATION IN B-DECAYS SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 3rd KEK Topical Conference on CP Violation, its Implications to Particle Physics and Cosmology CY NOV 16-18, 1993 CL NATL LAB HIGH ENERGY PHYS, TSUKUBA, JAPAN SP NATL LAB HIGH ENERGY PHYS HO NATL LAB HIGH ENERGY PHYS ID QUARK EFFECTIVE THEORY; ASYMMETRIES AB I review how one can test the Standard Model predictions for CP violation. This test requires sufficient independent measurements to overconstrain the model parameters and thus be sensitive to possible beyond Standard Model contributions. I address the challenges for theory as well as for experiment to achieve such a test. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. NR 17 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG PY 1994 SU 37A BP 21 EP 28 DI 10.1016/S0920-5632(94)00581-8 PG 8 WC Physics, Particles & Fields SC Physics GA PE194 UT WOS:A1994PE19400004 ER PT J AU ATWOOD, D SONI, A AF ATWOOD, D SONI, A TI INFLUENCE OF KAONIC RESONANCES ON THE CP VIOLATION IN B-]K-ASTERISK-GAMMA LIKE PROCESSES SO NUCLEAR PHYSICS B LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. STANFORD UNIV,SLAC,DEPT PHYS,STANFORD,CA 94309. 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 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG PY 1994 SU 37A BP 67 EP 67 PG 1 WC Physics, Particles & Fields SC Physics GA PE194 UT WOS:A1994PE19400010 ER PT J AU TSCHIRHART, RS AF TSCHIRHART, RS TI THE SEARCH FOR DIRECT CP VIOLATION IN THE NEUTRAL KAON SYSTEM SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 3rd KEK Topical Conference on CP Violation, its Implications to Particle Physics and Cosmology CY NOV 16-18, 1993 CL NATL LAB HIGH ENERGY PHYS, TSUKUBA, JAPAN SP NATL LAB HIGH ENERGY PHYS HO NATL LAB HIGH ENERGY PHYS ID BRANCHING RATIO; LIMIT AB The status and prospects of neutral Kaon experiments searching for evidence of direct CP violation will be reviewed. The recent results and prospects of experiments measuring \epsilon'/epsilon\ will be emphasized. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. NR 18 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG PY 1994 SU 37A BP 99 EP 104 PG 6 WC Physics, Particles & Fields SC Physics GA PE194 UT WOS:A1994PE19400014 ER PT J AU MURAYAMA, H YANAGIDA, T YOKOYAMA, J AF MURAYAMA, H YANAGIDA, T YOKOYAMA, J TI CHAOTIC SNEUTRINO INFLATION AND BARYOGENESIS IN SUPERGRAVITY SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 3rd KEK Topical Conference on CP Violation, its Implications to Particle Physics and Cosmology CY NOV 16-18, 1993 CL NATL LAB HIGH ENERGY PHYS, TSUKUBA, JAPAN SP NATL LAB HIGH ENERGY PHYS HO NATL LAB HIGH ENERGY PHYS ID PHASE-TRANSITION; SUPERSYMMETRY BREAKING; COSMOLOGICAL BARYON; NUMBER VIOLATION; DARK MATTER; UNIVERSE; FLUCTUATIONS; CONSTRAINTS; GRAVITINOS; RENORMALIZATION AB We present in the framework of supergravity a natural model of chaotic inflation and baryogenesis, which are driven by a right-handed sneutrino. Its mass of M approximately 10(13) GeV is consistent with both the COBE data and the Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem. In this model the supersymmetry is easily broken by adding a constant term in the superpotential but with a vanishing cosmological constant. In addition, the model prefers the material ingredients appropriate for the mixed dark matter scenario. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. KYOTO UNIV,YUKAWA INST THEORET PHYS,UJI RES CTR,UJI,KYOTO 611,JAPAN. TOHOKU UNIV,FAC SCI,DEPT PHYS,SENDAI,MIYAGI 980,JAPAN. RI Yanagida, Tsutomu/A-4394-2011; Murayama, Hitoshi/A-4286-2011 NR 53 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG PY 1994 SU 37A BP 137 EP 145 PG 9 WC Physics, Particles & Fields SC Physics GA PE194 UT WOS:A1994PE19400018 ER PT J AU HALL, LJ AF HALL, LJ TI TESTING THEORIES OF QUARK AND LEPTON MASSES VIA B-MESON PHYSICS SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 3rd KEK Topical Conference on CP Violation, its Implications to Particle Physics and Cosmology CY NOV 16-18, 1993 CL NATL LAB HIGH ENERGY PHYS, TSUKUBA, JAPAN SP NATL LAB HIGH ENERGY PHYS HO NATL LAB HIGH ENERGY PHYS ID GRAND UNIFIED THEORIES; FERMION MASSES; MIXING-ANGLE; TOP-QUARK; PREDICTIONS; SUPERSYMMETRY; UNIFICATION; SU(5) AB Grand unified theories of quark and lepton masses are used to Predict tan beta, m(t), V(cb), m(s), m(s)/m(d), m(u)/m(d), V(ub) and the amount of CP violation J. These predictions are presented, together with experiments which will test them. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. NR 30 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG PY 1994 SU 37A BP 151 EP 159 PG 9 WC Physics, Particles & Fields SC Physics GA PE194 UT WOS:A1994PE19400020 ER PT J AU PALMIOTTI, G SALVATORES, M HILL, RN AF PALMIOTTI, G SALVATORES, M HILL, RN TI SENSITIVITY, UNCERTAINTY ASSESSMENT, AND TARGET ACCURACIES RELATED TO RADIOTOXICITY EVALUATION SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Time-dependent sensitivity techniques, which have been used in the past for standard reactor applications, are adapted to calculate the impact of data uncertainties and to estimate target data accuracies in radiotoxicity evaluations. The methodology is applied to different strategies of radioactive waste management connected with the European Fast Reactor and the Integral Fast Reactor fuel cycles. Results are provided in terms of sensitivity coefficients of basic data (cross sections and decay constants), uncertainties of global radiotoxicity at different times of storing after discharge, and target data accuracies needed to satisfy maximum uncertainty limits. C1 CEN CADARACHE,CEA,NUCL REACTOR DIRECT,F-13108 ST PAUL DURANCE,FRANCE. RP PALMIOTTI, G (reprint author), ARGONNE NATL LAB,DIV REACTOR ANAL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 10 Z9 10 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD AUG PY 1994 VL 117 IS 4 BP 239 EP 250 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA NZ429 UT WOS:A1994NZ42900003 ER PT J AU MARTENS, SN BOYD, RS AF MARTENS, SN BOYD, RS TI THE ECOLOGICAL SIGNIFICANCE OF NICKEL HYPERACCUMULATION - A PLANT-CHEMICAL DEFENSE SO OECOLOGIA LA English DT Article DE SERPENTINE; STREPTANTHUS; HERBIVORY; HEAVY METALS ID SERPENTINE; ACCUMULATION; CRUCIFERAE; TOLERANCE AB Nickel hyperaccumulating plants have more than 1000 mg Ni kg(-1) dry weight when grown on nickel-bearing soils. We hypothesized that Ni hyperaccumulation could serve as a chemical defense against herbivores. In feeding experiments with potential insect herbivores and Ni hyperaccumulating plants, only those insects fed leaves from plants grown on non-nickel-bearing soil survived or showed a weight gain. Among chemical parameters measured, only Ni content of plants was sufficient to explain this result. When subjected to herbivory by lepidopteran larvae, plants grown on Ni-amended soil showed greater survival and yield than plants on unamended soil. Ni hyperaccumulation may be an effective plant chemical defense against herbivores because of its high lethality, apparent low cost, and broad spectrum of toxicity. C1 UNIV CALIF DAVIS,DEPT BOT,DAVIS,CA 95616. AUBURN UNIV,DEPT BOT & MICROBIOL,AUBURN,AL 36849. AUBURN UNIV,ALABAMA AGR EXPT STN,AUBURN,AL 36849. RP MARTENS, SN (reprint author), LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,EES-15,MS J495,LOS ALAMOS,NM 87545, USA. NR 33 TC 129 Z9 131 U1 1 U2 18 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0029-8549 J9 OECOLOGIA JI Oecologia PD AUG PY 1994 VL 98 IS 3-4 BP 379 EP 384 DI 10.1007/BF00324227 PG 6 WC Ecology SC Environmental Sciences & Ecology GA PE432 UT WOS:A1994PE43200018 PM 28313915 ER PT J AU NILSEN, J MACGOWAN, BJ DASILVA, LB MORENO, JC KOCH, JA SCOFIELD, JH AF NILSEN, J MACGOWAN, BJ DASILVA, LB MORENO, JC KOCH, JA SCOFIELD, JH TI REINTERPRETATION OF THE NEON-LIKE TITANIUM LASER EXPERIMENTS SO OPTICAL ENGINEERING LA English DT Article DE X-RAY LASERS; LASER-PLASMA INTERACTION ID X-RAY LASER AB We present results that show lasing on the 3p --> 3s (J = 0 --> 1) transition in neon-like chromium (Z = 24), iron (Z = 26), and nickel (Z = 28) at 28.5, 25.5, and 23.1 nm, respectively. These results destroy the uniqueness of the lasing observed several years ago in neon-like titanium (Z = 22) at 32.6 nm on the same transition and makes highly unlikely the hypothesis that resonant photopumping is playing a significant role in the titanium laser. The titanium, chromium, iron, and nickel experiments all require a prepulse in order to lase, and our calculations suggest that the prepulse is an exciting new way to create a uniform low-density plasma that allows the proper conditions for gain and laser propagation for low-Z neon-like ions when illuminating a thick slab target. We also present an observation of hyperfine splitting in neon-like niobium at 14.6 nm and offer an explanation as to how the hyperfine effect is reducing the gain of neon-like ions with odd Z. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP NILSEN, J (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, LIVERMORE, CA 94550 USA. NR 10 TC 10 Z9 10 U1 0 U2 2 PU SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 EI 1560-2303 J9 OPT ENG JI Opt. Eng. PD AUG PY 1994 VL 33 IS 8 BP 2687 EP 2691 DI 10.1117/12.173558 PG 5 WC Optics SC Optics GA PB299 UT WOS:A1994PB29900028 ER PT J AU NILSEN, J MORENO, JC AF NILSEN, J MORENO, JC TI USE OF THE PREPULSE TECHNIQUE TO ENHANCE THE WEAK 1,-2-NM LASER LINE IN NEON-LIKE SELENIUM SO OPTICS LETTERS LA English DT Article ID X-RAY LASER AB We report strong lasing in selenium on the neonlike 3p --> 38, J = 0 --> 1 transition at 18.2 nm when the prepulse technique of using a low-intensity prepulse before the main optical drive pulse is used to illuminate the selenium target. Without the use of the prepulse, this line is 2 orders of magnitude weaker. The usual J = 2 --> 1 lines at 20.6 and 20.9 nm are observed to dominate the spectra both with and without the use of the prepulse. These experiments may provide important clues to help our understanding of why the 18.2-nm line, which was predicted to dominate the laser output, was always observed weakly in previous experiments. RP NILSEN, J (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 15 TC 19 Z9 19 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 1 PY 1994 VL 19 IS 15 BP 1137 EP 1139 PG 3 WC Optics SC Optics GA NZ757 UT WOS:A1994NZ75700013 PM 19844555 ER PT J AU RODRIGUEZ, G ROBERTS, JP TAYLOR, AJ AF RODRIGUEZ, G ROBERTS, JP TAYLOR, AJ TI ULTRAVIOLET ULTRAFAST PUMP-PROBE LASER-BASED ON A TI-SAPPHIRE LASER SYSTEM SO OPTICS LETTERS LA English DT Article ID ABSORPTION-SPECTROSCOPY; FEMTOSECOND; GENERATION AB An ultrafast spectroscopic pump-probe apparatus for detection of ultraviolet time-resolved spectra is described. Frequency doubling of an 810-nm 0.3-TW Ti:sapphire laser system yields 15-mJ 165-fs pulses at 405 nm. We obtain pulse energies of 0.8 mJ by frequency tripling to 270 nm. An ultraviolet supercontinuum extending from 200 to 600 nm is also generated in water by use of the frequency-doubled 405-nm light. The system operates at a 5-Hz repetition rate and is useful for applications in deep-ultraviolet pump-probe subpicoseeond spectroscopy. RP RODRIGUEZ, G (reprint author), LOS ALAMOS NATL LAB,GRP CST-5,MS E543,LOS ALAMOS,NM 87545, USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 12 TC 20 Z9 21 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 1 PY 1994 VL 19 IS 15 BP 1146 EP 1148 PG 3 WC Optics SC Optics GA NZ757 UT WOS:A1994NZ75700016 PM 19844558 ER PT J AU OZBAY, E MICHEL, E TUTTLE, G BISWAS, R HO, KM BOSTAK, J BLOOM, DM AF OZBAY, E MICHEL, E TUTTLE, G BISWAS, R HO, KM BOSTAK, J BLOOM, DM TI TERAHERZ SPECTROSCOPY OF 3-DIMENSIONAL PHOTONIC BAND-GAP CRYSTALS SO OPTICS LETTERS LA English DT Article AB We have fabricated and built three-dimensional photonic band-gap crystals with band-gap frequencies larger than 500 GHz. We built the crystals by stacking micromachined (110) silicon wafers. The transmission and dispersion characteristics of the structures were measured by an all-electronic terahertz spectroscopy setup. The experimental results were in good agreement with theoretical calculations. To our knowledge, our new crystal has the highest reported photonic band-gap frequency. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP OZBAY, E (reprint author), IOWA STATE UNIV SCI & TECHNOL,MICROELECTR RES CTR,AMES,IA 50011, USA. RI Ozbay, Ekmel/B-9495-2008 NR 11 TC 91 Z9 93 U1 2 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 1 PY 1994 VL 19 IS 15 BP 1155 EP 1157 PG 3 WC Optics SC Optics GA NZ757 UT WOS:A1994NZ75700019 PM 19844561 ER PT J AU BURNHAM, AK AF BURNHAM, AK TI THE EFFECTS OF THE MINERAL MATRIX ON THE DETERMINATION OF KINETIC-PARAMETERS USING MODIFIED ROCK-EVAL PYROLYSIS - COMMENTS SO ORGANIC GEOCHEMISTRY LA English DT Letter RP BURNHAM, AK (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 4 TC 13 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD AUG-SEP PY 1994 VL 21 IS 8-9 BP 985 EP 986 DI 10.1016/0146-6380(94)90058-2 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA NX461 UT WOS:A1994NX46100018 ER PT J AU LANGRY, KC AF LANGRY, KC TI SYNTHESIS OF IMIDAZOQUINOLINES AND IMIDAZOISOQUINOLINES FROM AZANAPHTHALENE CARBOXYLIC-ACIDS SO ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL LA English DT Article ID INHIBITORS RP LANGRY, KC (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV HLTH & ECOL ASSESSMENT,POB 808,L-524,LIVERMORE,CA 94550, USA. NR 27 TC 7 Z9 8 U1 0 U2 0 PU ORGANIC PREP PROCEDURES INC PI NEWTON HIGHLANDS PA PO BOX 9, NEWTON HIGHLANDS, MA 02161 SN 0030-4948 J9 ORG PREP PROCED INT JI Org. Prep. Proced. Int. PD AUG PY 1994 VL 26 IS 4 BP 429 EP 438 PG 10 WC Chemistry, Organic SC Chemistry GA NY940 UT WOS:A1994NY94000003 ER PT J AU GOLDMAN, M BURMESTER, CP WILLE, LT GRONSKY, R AF GOLDMAN, M BURMESTER, CP WILLE, LT GRONSKY, R TI STRAIN AND DOMAIN EVOLUTION IN YBA2CU3OZ SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID NONSTOICHIOMETRIC YBA2CU3O6+DELTA; SCATTERING; SUPERCONDUCTORS; DIFFRACTION AB A Monte Carlo study of the time evolution of atomic positions and occupancies within the basal plane of YBa2Cu3Oz is performed. The simulations are based upon an anisotropic Ising model, and, for the first time, include elastic interactions associated with continuous displacements of atoms within the basal plane. Samples quenched to temperatures below the disorder-order transition curve from the disordered tetragonal state rapidly form orthorhombic domains separated by twin boundaries' The resulting microstructure is observed to coarsen and eventually to anneal into a single domain that exhibits the experimentally observed 2 1/2 a0 X 2 1/2 a0 superlattice reflections. Strain maps are used to elucidate and interpret these observations. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. FLORIDA ATLANTIC UNIV,DEPT PHYS,BOCA RATON,FL 33431. RP GOLDMAN, M (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 22 TC 5 Z9 5 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD AUG PY 1994 VL 70 IS 2 BP 65 EP 73 DI 10.1080/09500839408241274 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA NZ513 UT WOS:A1994NZ51300001 ER PT J AU OLAIZOLA, M LAROCHE, J KOLBER, Z FALKOWSKI, PG AF OLAIZOLA, M LAROCHE, J KOLBER, Z FALKOWSKI, PG TI NONPHOTOCHEMICAL FLUORESCENCE QUENCHING AND THE DIADINOXANTHIN CYCLE IN A MARINE DIATOM SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE DIADINOXANTHIN; DIATOXANTHIN; FLUORESCENCE-QUENCHING; PHOTOPROTECTION; PHYTOPLANKTON; PROTEIN TURNOVER; XANTHOPHYLL-CYCLE ID II REACTION CENTERS; PHOTOSYSTEM-II; XANTHOPHYLL-CYCLE; CHLOROPHYLL FLUORESCENCE; PHAEODACTYLUM-TRICORNUTUM; ZEAXANTHIN FORMATION; NITROGEN LIMITATION; THYLAKOID MEMBRANES; ABSORBANCE CHANGES; PHOTOSYNTHESIS AB The diadinoxanthin cycle (DD-cycle) in chromophyte algae involves the interconversion of two carotenoids, diadinoxanthin (DD) and diatoxanthin (DT). We investigated the kinetics of light-induced DD-cycling in the marine diatom Phaeodactylum tricornutum and its role in dissipating excess excitation energy in PS II. Within 15 min following an increase in irradiance, DT increased and was accompanied by a stoichiometric decrease in DD. This reaction was completely blocked by dithiothreitol (DTT). A second, time-dependent, increase in DT was detected similar to 20 min after the light shift without a concomitant decrease in DD. DT accumulation from both processes was correlated with increases in non-photochemical quenching of chlorophyll fluorescence. Stern-Volmer analyses suggests that changes in non-photochemical quenching resulted from changes in thermal dissipation in the PS II antenna and in the reaction center. The increase in non-photochemical quenching was correlated with a small decrease in the effective absorption cross section of PS II. Model calculations suggest however that the changes in cross section are not sufficiently large to significantly reduce multiple excitation of the reaction center within the turnover time of steady-state photosynthetic electron transport at light saturation. In DTT poisoned cells, the change in nan-photochemical quenching appears to result from energy dissipation in the reaction center and was associated with decreased photochemical efficiency. D1 protein degradation was slightly higher in samples poisoned with DTT than in control samples. These results suggest that while DD-cycling may dynamically alter the photosynthesis-irradiance response curve, it offers limited protection against photodamage of PS II reaction centers at irradiance levels sufficient to saturate steady-state photosynthesis. C1 SUNY STONY BROOK, MARINE SCI RES CTR, STONY BROOK, NY 11794 USA. BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI LaRoche, Julie/A-1109-2010 NR 53 TC 176 Z9 179 U1 4 U2 24 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0166-8595 EI 1573-5079 J9 PHOTOSYNTH RES JI Photosynth. Res. PD AUG PY 1994 VL 41 IS 2 BP 357 EP 370 DI 10.1007/BF00019413 PG 14 WC Plant Sciences SC Plant Sciences GA PE916 UT WOS:A1994PE91600007 PM 24310118 ER PT J AU REN, ZF WANG, JH MILLER, DJ GORETTA, KC AF REN, ZF WANG, JH MILLER, DJ GORETTA, KC TI RELATIONSHIP BETWEEN GRAIN CONNECTIVITY, ALIGNMENT, AND CRITICAL-CURRENT DENSITY IN HIGH-TEMPERATURE SUPERCONDUCTING BULK MATERIALS SO PHYSICA C LA English DT Article ID TAPE; ENHANCEMENT; PHASE; TL AB Uniaxial hydraulic pressure was successfully employed to partially reorient the c-axes of the highly anisotropic superconducting grains in bulk Ti0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9-delta samples. The partial reorientation was confirmed by X-ray diffraction pattern, rocking curves, and SQUID magnetization measurements. Samples made from the superconducting powder with partial alignment in c-axis direction and samples made from reaction mixture (in-situ synthesis method) with random orientation should have a similar grain connectivity since both were made by the same fabrication procedure. Both types of samples were found to exhibit about the same J(c) value of 15 000-17 000 A/cm2 at 77 K. By contrast, another pair of samples with the same c-axis alignment as shown by X-ray diffraction, rocking curve, and SEM measurements, but with different grain connectivity due to the different compression and heat treatment procedure used, showed a significant difference in J(c). The just rolled tape had a J(c) of 13 300 A/cm2, whereas the rolled and subsequently compressed tape had a J(c) of 19 500 A/cm2 at 77 K. Based on the results of these and other related experiments, we have to conclude that grain connectivity, not lattice alignment, is the decisive factor in determining the J(c) of Tl based 1223 bulk superconducting materials and silver-sheathed superconducting tapes made by the powder-in-tube method. C1 SUNY BUFFALO,SUPERCOND MAT LAB,ACHESON HALL,BUFFALO,NY 14214. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RI Ren, Zhifeng/B-4275-2014 NR 12 TC 30 Z9 30 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD AUG 1 PY 1994 VL 229 IS 1-2 BP 137 EP 144 DI 10.1016/0921-4534(94)90822-2 PG 8 WC Physics, Applied SC Physics GA PF495 UT WOS:A1994PF49500018 ER PT J AU BHATTACHARYA, RN DUDA, A GINLEY, DS DELUCA, JA REN, ZF WANG, CA WANG, JH AF BHATTACHARYA, RN DUDA, A GINLEY, DS DELUCA, JA REN, ZF WANG, CA WANG, JH TI SUPERCONDUCTING THALLIUM OXIDE-FILMS VIA AN ELECTRO-DEPOSITED PRECURSOR SO PHYSICA C LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BA-CU-OXIDE; ELECTRODEPOSITION PROCESS; THIN-FILMS; ELECTROCHEMICAL SYNTHESIS; YBACUO; TLBACACUO; VAPOR AB Electro-deposited precursor films of BaCaCuO (BCCO) doped with Ag were prepared on Ag foil. The electrodeposited films were processed using a two-zone anneal, which employs a Tl source zone and a separate sample zone, both within an O2 ambient. The annealed films showed c-axis oriented 1223 as the major phase. At 77 K and no magnetic field, the critical current density was 4.42 x 10(4) A/cm2 using the field criterion of 1 muV/cm. The field dependence for the Tl-1223 film was equally impressive, showing 8.2 x 10(3) A/cm2 at 5.5 T (77 K) for the field oriented parallel to the ab plane (H(parallel-to) ab) and parallel to the applied current. C1 GE CO,CORP RES & DEV,SCHENECTADY,NY 12301. SUNY BUFFALO,BUFFALO,NY 14214. RP BHATTACHARYA, RN (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. RI Ren, Zhifeng/B-4275-2014 NR 18 TC 23 Z9 23 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD AUG 1 PY 1994 VL 229 IS 1-2 BP 145 EP 151 DI 10.1016/0921-4534(94)90823-0 PG 7 WC Physics, Applied SC Physics GA PF495 UT WOS:A1994PF49500019 ER PT J AU KHAKHALIN, SY FAENOV, AY SKOBELEV, IY PIKUZ, SA NILSEN, J OSTERHELD, A AF KHAKHALIN, SY FAENOV, AY SKOBELEV, IY PIKUZ, SA NILSEN, J OSTERHELD, A TI THE OBSERVATION OF THE NE-LIKE ION RESONANCE LINE SATELLITES FOR CR-XV...NI-XIX CO2-LASER PRODUCED PLASMA SO PHYSICA SCRIPTA LA English DT Article AB We present an analysis of dielectronic satellite spectra of Ne-like ion resonance lines for elements from Cr to Ni. For these low-Z elements, we use spectra from strongly underionized CO2-laser produced plasma to minimize the emission from open L-shell ions. This simplifies the spectra and allows the identification of satellite lines caused by radiative transitions from autoionizing states of sodium like ions. Good agreement between the satellite structure calculations and the experimental emission spectra is obtained. C1 PN LEBEDEV PHYS INST,MOSCOW,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP KHAKHALIN, SY (reprint author), NPO VNIIFTRI,141570 MISDC,MENDELEYEVSK,RUSSIA. RI Pikuz, Sergey/M-8231-2015 NR 9 TC 12 Z9 12 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG PY 1994 VL 50 IS 2 BP 102 EP 105 DI 10.1088/0031-8949/50/2/002 PG 4 WC Physics, Multidisciplinary SC Physics GA PB080 UT WOS:A1994PB08000002 ER PT J AU KHAKHALIN, SY DYAKIN, VM FAENOV, AY FIEDOROWICZ, H BARTNIK, A PARYS, P NILSEN, J OSTERHELD, A AF KHAKHALIN, SY DYAKIN, VM FAENOV, AY FIEDOROWICZ, H BARTNIK, A PARYS, P NILSEN, J OSTERHELD, A TI THE DIELECTRONIC SATELLITES TO THE 2S-3P NE-LIKE KRYPTON RESONANCE LINES SO PHYSICA SCRIPTA LA English DT Article ID X-RAY-SPECTRA; SEQUENCES; IONS AB We present an analysis of dielectronic satellite spectra of 2p6-2s2p(6)3p Ne-like krypton resonance lines. The satellite structure was registered with high (better than lambda/DELTAlambda > 3500) spectral resolution in the emission of a laser irradiated ps puff target. We perform an unambiguous identification of satellite fines caused by radiative transitions from autoionizing states of sodium-like krypton ions. A total of about 20 spectral features are identified, most of them for the first time. Very good agreement between the satellite structure calculations and experimental emission spectra is obtained. C1 INST OPTOELECTR,PL-00908 WARSAW 49,POLAND. INST PLASMA PHYS & LASER MICROFUS,PL-00908 WARSAW 49,POLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP KHAKHALIN, SY (reprint author), NPO VNIIFTRI,141570 MISDC,MENDELEYEVSK,RUSSIA. NR 12 TC 20 Z9 21 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD AUG PY 1994 VL 50 IS 2 BP 106 EP 109 DI 10.1088/0031-8949/50/2/003 PG 4 WC Physics, Multidisciplinary SC Physics GA PB080 UT WOS:A1994PB08000003 ER PT J AU WHITFIELD, SB KRAUSE, MO VANDERMEULEN, P CALDWELL, CD AF WHITFIELD, SB KRAUSE, MO VANDERMEULEN, P CALDWELL, CD TI HIGH-RESOLUTION PHOTOELECTRON SPECTROMETRY OF ATOMIC MANGANESE FROM THE REGION OF THE 3P-]3D GIANT-RESONANCE TO 120 EV SO PHYSICAL REVIEW A LA English DT Article ID CROSS-SECTIONS; ANGULAR-DISTRIBUTION; 3P PHOTOABSORPTION; METAL ATOMS; MN; PHOTOIONIZATION; DECAY; PHOTOIONISATION; EXCITATION; CR AB Partial photoionization cross sections sigma of the 3d and the 4s main lines and the major satellite lines following the photoionization of atomic manganese in the vicinity of the 3p --> 3d giant resonance are studied in detail using the constant-ionic-state technique. Previously unresolved features are seen, revealing the complex structure of this transition-metal atom. Evidence for seven excited states hidden in the giant-resonance region is uncovered. Widths of most of the observed excited states are deduced. The width of the dominant [Ne]3s(2)3p(5)3(d)64s2(6P) state is found to be at most 1.5 eV. The origin of a pronounced dip in the partial cross section of the primary 3d photoionization line, which also appears in absorption, is identified. More than 15 resonance features converging to the [Ne]3s(2)3p(5)3d(5)4s2(P-7(4,3,2)) limits are observed, and tentative assignments are given. In addition, nonresonant photoelectron spectra recorded from 80 to 120 eV photon energy are examined to determine the behavior of the strongest photoelectron satellite lines and very-high-lying binding energy satellites, which, until now have not been investigated. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. UNIV AMSTERDAM, DEPT PHYS CHEM, 1018 WS AMSTERDAM, NETHERLANDS. UNIV CENT FLORIDA, DEPT PHYS, ORLANDO, FL 32816 USA. RP WHITFIELD, SB (reprint author), MAX PLANCK GESELL, FRITZ HABER INST, FARADAYWEG 4-6, D-14195 BERLIN, GERMANY. NR 53 TC 23 Z9 23 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1269 EP 1286 DI 10.1103/PhysRevA.50.1269 PN A PG 18 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB592 UT WOS:A1994PB59200050 ER PT J AU SCHULTZ, DR BOTTCHER, C MADISON, DH PEACHER, JL BUFFINGTON, G PINDZOLA, MS GORCZYCA, TW GAVRAS, P GRIFFIN, DC AF SCHULTZ, DR BOTTCHER, C MADISON, DH PEACHER, JL BUFFINGTON, G PINDZOLA, MS GORCZYCA, TW GAVRAS, P GRIFFIN, DC TI TIME-DEPENDENT APPROACH TO ATOMIC AUTOIONIZATION SO PHYSICAL REVIEW A LA English DT Article ID PERTURBATION-THEORY; 2-ELECTRON ATOMS; STATES; SCATTERING; IONIZATION; THRESHOLD; HYDROGEN; ROTATION; LATTICE AB A time-dependent approach to the study of atomic autoionization in two-electron systems is formulated. In the first step a two-dimensional (2D) model ''He'' atom is constructed by replacing the full 3D electrostatic interaction with a 1D soft-core interaction. The autoionization decay of doubly excited states constructed within the model is calculated by both standard perturbation theory and direct solution of the time-dependent Schrodinger equation. Configuration-interaction theory is invoked to obtain correlated resonance states, and strong laser fields are found to alter the decay rates. In the second step the full 6D wave function for the He atom is expanded in coupled spherical harmonics using a procedure as described by C. Bottcher, D. R. Schultz, and D. H. Madison [Phys. Rev. A 49, 1714 (1994)]. Solution of the time-dependent Schrodinger equation reduces to solving the propagator equations for the 3D expansion coefficients on a B-spline collocation lattice. Autoionizing decay rate calculations using product resonance states are found to be in qualitative agreement with the 2D model results. C1 UNIV MISSOURI,DEPT PHYS,ROLLA,MO 65401. AUBURN UNIV,DEPT PHYS,AUBURN,AL 36849. ROLLINS COLL,DEPT PHYS,WINTER PK,FL 32789. RP SCHULTZ, DR (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. NR 26 TC 29 Z9 29 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1348 EP 1358 DI 10.1103/PhysRevA.50.1348 PN A PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB592 UT WOS:A1994PB59200059 ER PT J AU WANG, HH WOICIK, JC ABERG, T MAU, HC HERRERAGOMEZ, A KENDELEWICZ, T MANTYKENTTA, A MIYANO, KE SOUTHWORTH, S CRASEMANN, B AF WANG, HH WOICIK, JC ABERG, T MAU, HC HERRERAGOMEZ, A KENDELEWICZ, T MANTYKENTTA, A MIYANO, KE SOUTHWORTH, S CRASEMANN, B TI THRESHOLD K-LL AUGER-SPECTRA OF P IN INP SO PHYSICAL REVIEW A LA English DT Article ID X-RAY-EMISSION; SYNCHROTRON RADIATION BEAMLINE; EXTRA-ATOMIC RELAXATION; HIGH-ENERGY-RESOLUTION; CORE-LEVEL SHIFTS; PHOSPHORUS-COMPOUNDS; TRANSITION-PROBABILITIES; FLUORESCENCE YIELDS; MADELUNG ENERGY; BINDING-ENERGY AB The evolution of K-L2,3L2,3 1D2 radiationless resonant Raman scattering into Auger-electron emission was studied by tuning synchrotron radiation across the K edge of P in InP. The spectrum can be interpreted in terms of a two-component model that involves excitation of a photoelectron (1) into a discrete excitonlike state and (2) into the continuum; extra-atomic relaxation is taken into account. Auxiliary studies of above-threshold Auger and photoelectron spectra arising from K photoionization were used to identify the dominantly atomic features of these spectra. C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. HELSINKI UNIV TECHNOL,PHYS LAB,SF-02150 ESPOO 15,FINLAND. LAWRENCE LIVERMORE NATL LAB,DIV HIGH ENERGY PHYS,LIVERMORE,CA 94550. STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305. UNIV OULU,DEPT PHYS,SF-90570 OULU,FINLAND. CUNY BROOKLYN COLL,DEPT PHYS,BROOKLYN,NY 11210. NIST,PHYS LAB,GAITHERSBURG,MD 20899. RP WANG, HH (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. NR 89 TC 29 Z9 29 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 AUG PY 1994 VL 50 IS 2 BP 1359 EP 1371 DI 10.1103/PhysRevA.50.1359 PN A PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB592 UT WOS:A1994PB59200060 ER PT J AU THOMPSON, JS GREGORY, DC AF THOMPSON, JS GREGORY, DC TI ABSOLUTE CROSS-SECTION MEASUREMENTS FOR ELECTRON-IMPACT SINGLE IONIZATION OF SI4+ AND SI5+ SO PHYSICAL REVIEW A LA English DT Article ID IRON IONS AB Experimental measurements of absolute cross sections are presented for electron-impact single ionization of Si4+ and Si5+. The incident electron energies range from below threshold to 1500 eV. The measurements were performed using the crossed ion-electron beams apparatus at the Oak Ridge National Laboratory Electron-Cyclotron Resonance Ion-Source Facility. The data are in reasonable agreement with cross sections calculated using the Lotz semiempirical formula. Reduced cross sections for the isoelectronic targets, Si4+ and Ar8+, are compared in order to test classical scaling for direct electron-impact single ionization. C1 UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. OI Thompson, Jeffrey/0000-0001-9699-5767 NR 20 TC 13 Z9 13 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1377 EP 1381 DI 10.1103/PhysRevA.50.1377 PN A PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB592 UT WOS:A1994PB59200062 ER PT J AU RESCIGNO, TN AF RESCIGNO, TN TI LOW-ENERGY ELECTRON-COLLISION PROCESSES IN MOLECULAR CHLORINE SO PHYSICAL REVIEW A LA English DT Article ID KOHN VARIATIONAL METHOD; SEPARABLE APPROXIMATION; EXCHANGE APPROXIMATION; POLYATOMIC-MOLECULES; METHANE SCATTERING; IMPACT EXCITATION; INTEGRALS; ABINITIO; PLASMA AB The results of close-coupling calculations using the complex Kohn variational method are reported for a variety of low-energy electron-collision processes involving molecular chlorine. We report cross sections for elastic scattering and momentum transfer, as well as dissociative excitation of the five lowest electronically excited states (1,3PI(u), 1,3PI(g), 3SIGMA(u)+) which are formed by promoting an occupied valence electron into an antibonding (5sigma(u)) orbital. We also report cross sections for the excitation of the lowest bound optically allowed states in Cl2. The cross sections, especially at very low energies, are found to depend sensitively on both target polarization and a proper balance of correlation effects in the N- and (N + 1)-electron systems. Comparison is made between the results of this study and the limited body of experimental results available for this system. RP RESCIGNO, TN (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 33 TC 41 Z9 41 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1382 EP 1389 DI 10.1103/PhysRevA.50.1382 PN A PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB592 UT WOS:A1994PB59200063 ER PT J AU LOPEZ, MJ JELLINEK, J AF LOPEZ, MJ JELLINEK, J TI FRAGMENTATION OF ATOMIC CLUSTERS - A THEORETICAL-STUDY SO PHYSICAL REVIEW A LA English DT Article ID COLLISION-INDUCED DISSOCIATION; TRANSITION-METAL CLUSTERS; LENNARD-JONES CLUSTERS; RARE-GAS CLUSTERS; MOLECULAR-DYNAMICS; PHASE-CHANGES; IONS; MICROCLUSTERS; SURFACE; STATES AB Collisionless fragmentation of nonrotating model n-atom metal clusters (n = 12, 13, and 14) is studied using isoergic molecular-dynamics simulations. Minimum-energy paths for fragmentation are mapped out as functions of the distance between the centers of mass of the fragments. These paths provide information on the fragmentation energies for the different fragmentation channels. Fragmentation patterns (distributions of the fragmentation channel probabilities) and global and channel-specific fragmentation rate constants are computed and analyzed as functions of the internal energy and of the size of the clusters. The trends derived from the dynamics are compared with those obtained using the RRK and TST statistical approaches. The dynamics of the fragmentation process is analyzed in terms of characteristic quantities such as the distance between the centers of mass of the fragments, their relative translational energy, and their interaction energy, all considered as functions of time. RP LOPEZ, MJ (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Lopez, Maria/H-2492-2013 OI Lopez, Maria/0000-0001-7698-9327 NR 71 TC 74 Z9 74 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1445 EP 1458 DI 10.1103/PhysRevA.50.1445 PN B PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB594 UT WOS:A1994PB59400003 ER PT J AU KOCH, JA MACGOWAN, BJ DASILVA, LB MATTHEWS, DL UNDERWOOD, JH BATSON, PJ LEE, RW LONDON, RA MROWKA, S AF KOCH, JA MACGOWAN, BJ DASILVA, LB MATTHEWS, DL UNDERWOOD, JH BATSON, PJ LEE, RW LONDON, RA MROWKA, S TI EXPERIMENTAL AND THEORETICAL INVESTIGATION OF NEON-LIKE SELENIUM X-RAY LASER SPECTRAL LINEWIDTHS AND THEIR VARIATION WITH AMPLIFICATION SO PHYSICAL REVIEW A LA English DT Article ID CARBON K-EDGE; LINE-PROFILES; COLLISIONAL-EXCITATION; EXTREME ULTRAVIOLET; RADIATIVE PROCESSES; HIGH-GAIN; EMISSION; DOPPLER; AMPLIFIERS; MICROSCOPY AB This paper describes our recent x-ray laser spectral linewidth measurements and discusses the consequences of these measurements. The experiments observed the 206.38- and 182.45-angstrom laser transitions in neonlike selenium using an extremely high-resolution soft-x-ray spectrometer, and measured the spectral linewidths and relative spectral intensities of the laser lines from amplifiers of varying lengths. The data allow the intrinsic (unamplified) linewidths of the 206- and 182-angstrom lasers to be extrapolated as 50 and 35 mangstrom, respectively. The intrinsic spectral width of the 206-angstrom laser is somewhat greater than the predicted 43-mangstrom Voigt-profile width based on calculated transition rates and on the expected ion temperature in the plasma, and while the number of data points obtained with the 182-angstrom laser is small and a conclusive comparison with calculations is not possible, the extrapolated intrinsic linewidth of this laser is clearly consistent with the predicted 37-mangstrom Voigt-profile width and is not significantly broader or narrower than expected. The data also show significant gain narrowing of both lines with increasing amplifier length and show no significant rebroadening of the 206-angstrom laser in long, saturated amplifiers. We discuss line broadening and line transfer calculations we have performed which show that the saturated 206-angstrom laser line transfer behavior can be treated homogeneously due to non-negligible homogeneous lifetime broadening contributions, which significantly reduce inhomogeneous Doppler saturation rebroadening, and due to collisional redistribution rates which are large enough in any case to homogenize the otherwise inhomogeneous Doppler contributions. We also discuss the implications of these results with regard to earlier suggestions that Dicke narrowing effects could play a significant role in determining the intrinsic line profiles of these laser transitions, and we conclude that Dicke narrowing effects are not likely to be significant for either laser. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP KOCH, JA (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808,L-059, LIVERMORE, CA 94550 USA. NR 87 TC 67 Z9 67 U1 2 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 EI 1094-1622 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 1994 VL 50 IS 2 BP 1877 EP 1898 DI 10.1103/PhysRevA.50.1877 PN B PG 22 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA PB594 UT WOS:A1994PB59400048 ER PT J AU HELGESEN, G HILL, JP THURSTON, TR GIBBS, D KWO, J HONG, M AF HELGESEN, G HILL, JP THURSTON, TR GIBBS, D KWO, J HONG, M TI TEMPERATURE-DEPENDENCE OF RESONANT X-RAY MAGNETIC SCATTERING IN HOLMIUM SO PHYSICAL REVIEW B LA English DT Article ID 2 LENGTH SCALES; ER THIN-FILMS; CRITICAL FLUCTUATIONS; EXCHANGE SCATTERING; RESOLUTION FUNCTION; CRITICAL-BEHAVIOR; DEVILS STAIRCASE; LIQUID-CRYSTALS; SUPERLATTICES; PHASE AB We report the results of resonant x-ray magnetic scattering experiments on bulk and thin-film single crystals of holmium. The scattering at the principal magnetic reflection has been characterized as a function of the temperature in the spiral phases near and below their respective Neel temperatures. The integrated intensity of the principal magnetic peak in both samples shows power-law behavior versus reduced temperature with nearly equal exponents. The exponents for the scattering at the resonant second and third harmonics in the bulk sample are not simple integer multiples of the first, and motivate the consideration of simple scaling corrections to mean-field theory. We also present and compare the results of high-resolution measurements of the temperature dependence of the magnetic wave vectors, c-axis lattice constants, and correlation lengths of the magnetic scattering of the two samples in their. spiral phases. Although the qualitative behavior is similar, systematic differences are found, including uniformly larger magnetic wave vectors and the suppression of the 1/6 phase in the film. The spiral magnetic structure of the film forms a domain state at all temperatures in the ordered phase. The magnetic correlation lengths of both samples are greatest near the Neel temperature, where that of the film appears to exceed the translational correlation lengths of the lattice. As the temperature decreases, the magnetic correlation lengths also decrease. These results are discussed in terms of the strain present in the samples. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. AT&T BELL LABS,MURRAY HILL,NJ 07974. RI Hong, Minghwei/C-1433-2010; Hill, John/F-6549-2011 NR 68 TC 47 Z9 47 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 2990 EP 3004 DI 10.1103/PhysRevB.50.2990 PG 15 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200030 ER PT J AU ASAI, K YOKOKURA, O NISHIMORI, N CHOU, H TRANQUADA, JM SHIRANE, G HIGUCHI, S OKAJIMA, Y KOHN, K AF ASAI, K YOKOKURA, O NISHIMORI, N CHOU, H TRANQUADA, JM SHIRANE, G HIGUCHI, S OKAJIMA, Y KOHN, K TI NEUTRON-SCATTERING STUDY OF THE SPIN-STATE TRANSITION AND MAGNETIC CORRELATIONS IN LA1-XSRXCOO3 (X=0 AND 0.08) SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; METAL TRANSITION; LACOO3; SEMICONDUCTOR; SPECTROSCOPY; EQUILIBRIA AB LaCoO3 exhibits two magnetic-electronic transitions, one near 90 K and a second near 500 K. A previous study of the paramagnetic scattering using polarized neutrons demonstrated that the low-temperature transition is associated with the thermal excitation of Co3+ ions from the low-spin to the high-spin state. In the present work, we extend the paramagnetic-scattering measurements up to a temperature of 700 K. We find that the magnetic-scattering intensity decreases monotonically for temperatures above 300 K, indicating that the high-temperature transition is not dominantly magnetic in origin. Furthermore, the anomalous thermal expansion associated with the low-temperature transition is measured and shown to be consistent with a simple theoretical model for the spin-state transition. For comparison, paramagnetic-scattering measurements for La0.92Sr0.08CoO3 are also presented. In this material the ferromagnetic correlations are substantially stronger than in the undoped compound, and no transition to the low-spin state is observed. Instead, the paramagnetic scattering increases steadily with decreasing temperature until saturating below 24 K, the same temperature at which the magnetization of the zero-field-cooled specimen shows a sharp cusp. These results suggest that the magnetic moments in the doped compound freeze into a spin-glass state at low temperature. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. WASEDA UNIV,DEPT PHYS,TOKYO 169,JAPAN. RP ASAI, K (reprint author), UNIV ELECTROCOMMUN,DEPT APPL PHYS & CHEM,CHOFU,TOKYO 182,JAPAN. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 35 TC 249 Z9 253 U1 3 U2 22 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3025 EP 3032 DI 10.1103/PhysRevB.50.3025 PG 8 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200034 ER PT J AU RIERA, J DAGOTTO, E AF RIERA, J DAGOTTO, E TI SUPERCONDUCTIVITY IN THE MULTIBAND HUBBARD-MODEL WITH LONG-RANGE COULOMB REPULSION SO PHYSICAL REVIEW B LA English DT Article ID T-J MODEL; HIGH-TEMPERATURE SUPERCONDUCTORS; O-BASED SUPERCONDUCTORS; CHARGE-TRANSFER; PHASE-SEPARATION; MONTE-CARLO; EXCITATIONS; OXIDES; STATE; LIMIT AB A multiband CuO Hubbard model is studied which incorporates long-range (LR) repulsive Coulomb interactions. In the atomic limit, it is shown that a charge transfer from copper to oxygen ions occurs as the strength of the LR interaction is increased. The regime of phase separation is replaced by a uniform state with doubly occupied oxygens. As the holes become mobile a superfluid condensate is formed, as suggested by a numerical analysis of pairing correlations and flux quantization on one-dimensional chains. The competition between charge-density wave and superconductivity is also analyzed. It is argued that the results are also applicable to two dimensions. C1 FLORIDA STATE UNIV,DEPT PHYS,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. FLORIDA STATE UNIV,MARTECH,TALLAHASSEE,FL 32306. FAC CIENCIAS EXACTAS & INGN,DEPT FIS,RA-2000 ROSARIO,ARGENTINA. RP RIERA, J (reprint author), OAK RIDGE NATL LAB,DIV PHYS,CTR COMPUTAT INTENS PHYS,OAK RIDGE,TN 37831, USA. RI Riera, Jose/A-1234-2008 OI Riera, Jose/0000-0003-4546-1137 NR 30 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3215 EP 3220 DI 10.1103/PhysRevB.50.3215 PG 6 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200058 ER PT J AU TAKAHASHI, H SHAKED, H HUNTER, BA RADAELLI, PG HITTERMAN, RL HINKS, DG JORGENSEN, JD AF TAKAHASHI, H SHAKED, H HUNTER, BA RADAELLI, PG HITTERMAN, RL HINKS, DG JORGENSEN, JD TI STRUCTURAL EFFECTS OF HYDROSTATIC-PRESSURE IN ORTHORHOMBIC LA2-XSRCUO4 SO PHYSICAL REVIEW B LA English DT Article ID PHASE-TRANSITION; SUPERCONDUCTIVITY; TEMPERATURE; DEPENDENCE; LA2-XSRXCUO4-Y; DIAGRAM; LA2CUO4 AB We have investigated the effect of hydrostatic pressure on the structure of orthorhombic La2-xSrxCuO4 between 1 atm and 0.6 GPa, using neutron powder diffraction. Increasing pressure causes the tilt angle of CuO6 octahedra to decrease, leading to a transition to tetragonal symmetry. There is a strong compressibility anisotropy for the orthorhombic structure. Order parameters for the transition versus pressure are consistent with Landau theory for a second-order transition. It is shown that this transition can be universally scaled over (x, T, P) space in the context of Landau theory. We conclude that T(c) varies inversely with the tilt angle and is maximum for the tetragonal structure, i.e., for flat and square CuO2 planes, for this compound. C1 NUCL RES CTR NEGEV,DEPT PHYS,IL-84190 BEER SHEVA,ISRAEL. BEN GURION UNIV NEGEV,DEPT PHYS,IL-84105 BEER SHEVA,ISRAEL. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP TAKAHASHI, H (reprint author), UNIV TOKYO,INST SOLID STATE PHYS,7-22-1 ROPPONGI,TOKYO 106,JAPAN. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 27 TC 63 Z9 65 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3221 EP 3229 DI 10.1103/PhysRevB.50.3221 PG 9 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200059 ER PT J AU SUN, YR THOMPSON, JR KERCHNER, HR CHRISTEN, DK PARANTHAMAN, M BRYNESTAD, J AF SUN, YR THOMPSON, JR KERCHNER, HR CHRISTEN, DK PARANTHAMAN, M BRYNESTAD, J TI STRONG SURFACE-PINNING EFFECTS IN POLYCRYSTALLINE HGBA2CUO4+DELTA SUPERCONDUCTORS SO PHYSICAL REVIEW B LA English DT Article ID VORTEX FLUCTUATIONS; BARRIERS; RELAXATION; CRYSTALS; FIELD; MAGNETIZATION; PENETRATION; CROSSOVER AB Magnetic studies on polycrystalline HgCa2CuO4+delta superconductors reveal pronounced pinning by the grain surfaces at low temperatures over a wide range of magnetic fields. The response to sm ac fields shows that up to 80% of the width of the dc magnetic hysteresis loop in high fields originates from shielding supercurrent flowing in the surface sheath, a vortex-free region with thickness of approximately 10 nm. At 10 K and 15 kG, the observed persistent surface current has a density of approximately 5 x 10(7) A/cm2 when averaged over the barrier thickness. The study suggests that a high current density may be achieved in very thin films by surface pinning. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP SUN, YR (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 26 TC 35 Z9 35 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3330 EP 3336 DI 10.1103/PhysRevB.50.3330 PG 7 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200073 ER PT J AU LEE, JY PAGET, KM LEMBERGER, TR FOLTYN, SR WU, XD AF LEE, JY PAGET, KM LEMBERGER, TR FOLTYN, SR WU, XD TI CROSSOVER IN TEMPERATURE-DEPENDENCE OF PENETRATION DEPTH LAMBDA(T) IN SUPERCONDUCTING YBA2CU3O7-DELTA FILMS SO PHYSICAL REVIEW B LA English DT Article ID IMPURITY SCATTERING; YBA2CU3O6.95 AB The ab-plane penetration depth lambda(T) in twinned YBa2Cu3O7-delta films exhibits a crossover in its T dependence at 25 K. Below 25 K, deltalambda = lambda(T) - lambda(0) is-proportional-to T2. This differs from recent measurements on a crystal which find deltalambda is-proportional-to T below 40 K. Above 25 K, the normalized data lambda(T/T(c))/lambda(0) vs T/T(c) for our films agree extremely well with the crystal data, including quasilinear behavior between 25 and 40 K. Differences and similarities of films and crystals agree well with a theory of slightly disordered d-wave superconductors. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP LEE, JY (reprint author), OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210, USA. NR 22 TC 34 Z9 34 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3337 EP 3341 DI 10.1103/PhysRevB.50.3337 PG 5 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200074 ER PT J AU LI, GG DELEON, JM CONRADSON, SD LOVATO, MV SUBRAMANIAN, MA AF LI, GG DELEON, JM CONRADSON, SD LOVATO, MV SUBRAMANIAN, MA TI LOCAL DISTORTIONS OF THE TL-O LAYERS IN TL-BASED HIGH-TEMPERATURE SUPERCONDUCTORS SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; PULSED-NEUTRON-SCATTERING; FINE-STRUCTURE; CRYSTAL-STRUCTURE; SINGLE-CRYSTALS; DIFFRACTION; TL2BA2CACU2O8; TL2BA2CUO6; THALLIUM AB Local distortions of Tl and O(3) atoms from the high-symmetry crystallographic sites in Tl2Ba2CuO6 and Tl2Ba2Ca2CuO8 have been observed by x-ray-absorption fine structure at the Tl L(III)-edge. The interlayer Tl-Tl distance around R = 3.50 angstrom remains, but the intralayer Tl-Tl distance around R = 3.87 angstrom is not found. The Tl-O(3) distances (in the Tl-O layers) are R = 2.31 angstrom in Tl-2201 and R = 2.35 angstrom in TI-2212. These results show that both Tl and O atoms are shifted from their ideal crystallographic positions. The differences in the near-edge features of the x-ray-absorption spectra of these materials are consistent with this result. A negative edge shift of 1.2 eV at the Tl L(III)-edge compared to that of Tl2O3 indicates that the valence state of the Tl ion is less than 3+, which is consistent with charge-transfer models. C1 LOS ALAMOS NATL LAB,ELECTR SECT,LOS ALAMOS,NM 87545. CINVESTAV MERIDA,DEPT APPL PHYS,MERIDA 97310,YUCATAN,MEXICO. DUPONT CO INC,CENT RES & DEV,EXPTL STN,WILMINGTON,DE 19880. NR 30 TC 10 Z9 10 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3356 EP 3362 DI 10.1103/PhysRevB.50.3356 PG 7 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200077 ER PT J AU SIGALAS, MM ECONOMOU, EN KAFESAKI, M AF SIGALAS, MM ECONOMOU, EN KAFESAKI, M TI SPECTRAL GAPS FOR ELECTROMAGNETIC AND SCALAR WAVES - POSSIBLE EXPLANATION FOR CERTAIN DIFFERENCES SO PHYSICAL REVIEW B LA English DT Note ID PHOTONIC BAND-GAPS; PERIODIC DIELECTRIC STRUCTURES; PROPAGATION; LOCALIZATION AB We study two different scalar wave equations. One of them exhibits the main gross features of the simple scalar and elastic wave propagation in periodic composite media. The other behaves similarly to the electromagnetic waves in preferring the network topology and the higher volume fractions for developing spectral gaps. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RES CTR CRETE FORTH,GR-71110 IRAKLION,GREECE. UNIV CRETE,DEPT PHYS,GR-71409 IRAKLION,GREECE. RP SIGALAS, MM (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Kafesaki, Maria/E-6843-2012; Economou, Eleftherios /E-6374-2010 OI Kafesaki, Maria/0000-0002-9524-2576; NR 18 TC 38 Z9 38 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3393 EP 3396 DI 10.1103/PhysRevB.50.3393 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200082 ER PT J AU BONCA, J RODRIGUEZ, JP FERRER, J BEDELL, KS AF BONCA, J RODRIGUEZ, JP FERRER, J BEDELL, KS TI DIRECT CALCULATION OF SPIN STIFFNESS FOR SPIN-1/2 HEISENBERG MODELS SO PHYSICAL REVIEW B LA English DT Note ID SQUARE LATTICE; T-J; ANTIFERROMAGNET; TEMPERATURE AB The spin stiffness of frustrated spin-1/2 Heisenberg models in one and two dimensions is computed by exact diagonalizations on small clusters that implement spin-dependent twisted boundary conditions. Finite-size extrapolation to the thermodynamic limit yields a value of 0.14 +/- 0.01 for the spin stiffness of the unfrustrated planar antiferromagnet. We also present a general discussion of the linear-response theory for spin twists, which ultimately leads to the moment sum rule. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. CALIF STATE UNIV LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90032. UNIV LJUBLJANA,J STEFAN INST,61111 LJUBLJANA,SLOVENIA. UNIV AUTONOMA MADRID,DEPT FIS MAT CONDENSADA,CANTO BLANCO,SPAIN. RP BONCA, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Ferrer, Jaime/G-3888-2011 OI Ferrer, Jaime/0000-0002-4067-2325 NR 17 TC 25 Z9 25 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3415 EP 3418 DI 10.1103/PhysRevB.50.3415 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200088 ER PT J AU FEHRENBACHER, R NORMAN, MR AF FEHRENBACHER, R NORMAN, MR TI GAP RENORMALIZATION IN DIRTY ANISOTROPIC SUPERCONDUCTORS - IMPLICATIONS FOR THE ORDER-PARAMETER OF THE CUPRATES SO PHYSICAL REVIEW B LA English DT Note ID PENETRATION DEPTH; SCATTERING AB We contrast the effects of nonmagnetic impurities on the properties of superconductors having a d(x2-y2) order parameter, and a highly anisotropic s-wave (ASW) gap with the same nodal structure. The nonvanishing, impurity-induced, off-diagonal self-energy in the ASW state is shown to inhibit the low-energy excitations present in the clean system, leading to a qualitatively different impurity response of the single-particle density of states compared to the d(x2-y2) state. We discuss how this behavior can be employed to distinguish one state from the other by an analysis of high-resolution angle-resolved photoemission spectra. RP FEHRENBACHER, R (reprint author), ARGONNE NATL LAB,DIV MAT SCI,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439, USA. RI Norman, Michael/C-3644-2013 NR 24 TC 127 Z9 128 U1 2 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3495 EP 3498 DI 10.1103/PhysRevB.50.3495 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200109 ER PT J AU BUDHANI, RC WEAVER, BD HOLSTEIN, WL AF BUDHANI, RC WEAVER, BD HOLSTEIN, WL TI DISORDER-INDUCED REDUCTION OF THE ANOMALOUS HALL VOLTAGE IN PROTON-IRRADIATED AND AG21+-ION-IRRADIATED TL2BA2CACU2O8 EPITAXIAL-FILMS SO PHYSICAL REVIEW B LA English DT Note ID HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTALS; VORTEX MOTION; SIGN REVERSAL; YBA2CU3O7-DELTA; RESISTANCE; BEHAVIOR; DENSITY; TC AB The effects of structural disorder introduced by proton and heavy-ion irradiation on the mixed-state Hall resistivity (rho(xy)) of Tl2Ba2CaCu2O8 films are reported. The rho(xy) attains a peak negative value at a temperature T* where the vortex mobility is a rapidly varying function of temperature. At T* it also shows a universal inverse scaling with the normal-state resistivity of the material, which increases on irradiation. Our data suggest that a stronger downstream contribution to vortex velocity from the drift of the normal carriers in the core, dictates the sign of the Hall voltage as the overall carrier concentration in the materials is reduced by irradiation. C1 BROOKHAVEN NATL LAB, DIV MAT SCI, UPTON, NY 11973 USA. USN, RES LAB, WASHINGTON, DC 20375 USA. DUPONT CO INC, CENT RES & DEV, WILMINGTON, DE 19880 USA. NR 26 TC 4 Z9 4 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3499 EP 3502 DI 10.1103/PhysRevB.50.3499 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200110 ER PT J AU BULAEVSKII, LN CHO, JH MALEY, MP KES, P LI, Q SUENAGA, M LEDVIJ, M AF BULAEVSKII, LN CHO, JH MALEY, MP KES, P LI, Q SUENAGA, M LEDVIJ, M TI EFFECT OF QUANTUM FLUCTUATIONS OF VORTICES ON REVERSIBLE MAGNETIZATION IN HIGH-T(C) SUPERCONDUCTORS SO PHYSICAL REVIEW B LA English DT Note ID HIGH-TC SUPERCONDUCTORS; II SUPERCONDUCTORS; VORTEX LATTICE; FIELD; STATE; MODEL AB The field (B) and temperature dependence of reversible magnetization M in Bi (2:2:1:2) single crystals is measured for the orientation of the field along the c axis. The slope of the curve M vs lnB decreases remarkably with field below 70 K. In the mean-field approach this slope should be almost B independent. We explain this change of slope by the quantum fluctuations of vortices. We show that for magnetization quantum fluctuations are important at all temperatures except in a narrow region near T(c). C1 LEIDEN UNIV,KAMERLINGH ONNES LAB,2312 AV LEIDEN,NETHERLANDS. BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP BULAEVSKII, LN (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 27 TC 24 Z9 24 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3507 EP 3510 DI 10.1103/PhysRevB.50.3507 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200112 ER PT J AU BASOV, DN TIMUSK, T DABROWSKI, B JORGENSEN, JD AF BASOV, DN TIMUSK, T DABROWSKI, B JORGENSEN, JD TI C-AXIS RESPONSE OF YBA2CU4O8 - A PSEUDOGAP AND POSSIBILITY OF JOSEPHSON COUPLING OF CUO2 PLANES SO PHYSICAL REVIEW B LA English DT Note ID BI2SR2CACU2O8 SINGLE-CRYSTALS; SUPERCONDUCTING STATES; CHARGE DYNAMICS; ANISOTROPY; LA2-XSRXCUO4; REFLECTANCE; GAP AB We report on the temperature dependence of the far-infrared conductivity of YBa2Cu4O8 single crystals for E parallel-to c. With decreasing temperature, the conductivity shows a transition from a Drude-like behavior to a pseudogap at 180 cm-1 which grows deeper below 180 K without any abrupt changes at the superconducting transition at T(c) = 80 K. In the superconducting state the formation of the superfluid condensate can be seen. We show that in a variety of high-T(c) superconductors the value of the London penetration depth for E parallel-to c correlates with the conductivity along the c direction. With respect to this correlation we discuss the possibility of Josephson coupling between the CuO2 layers. C1 NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP BASOV, DN (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON L8S 4M1,ONTARIO,CANADA. NR 33 TC 210 Z9 210 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 5 BP 3511 EP 3514 DI 10.1103/PhysRevB.50.3511 PG 4 WC Physics, Condensed Matter SC Physics GA PB182 UT WOS:A1994PB18200113 ER PT J AU ONODERA, A TSUNODA, Y KUNITOMI, N PRINGLE, OA NICKLOW, RM MOON, RM AF ONODERA, A TSUNODA, Y KUNITOMI, N PRINGLE, OA NICKLOW, RM MOON, RM TI NEUTRON-DIFFRACTION STUDY OF GAMMA-FE AT HIGH-PRESSURE SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL PHASE-TRANSITION; CENTERED-CUBIC IRON; FCC IRON; CU; ANTIFERROMAGNETISM; FERROMAGNETISM AB Face-centered-cubic iron (gamma-Fe) coherently precipitated in a single crystal of Cu has been studied by neutron diffraction at high pressures up to 0.9 GPa and in the temperature range from about 5 to 110 K. It undergoes antiferromagnetic ordering at 67 +/- 2 K at ambient pressure. The ordering temperature T(N) monotonically decreases with increasing pressure following a relation T(N)(K) = 67 - 12.8p - 11.1p2 -6.17p3, where p is in units of GPa. The change of T(N) in gamma-Fe is discussed in terms of the volume change caused by pressurization or by alloying. C1 OSAKA UNIV,FAC SCI,TOYONAKA,OSAKA 560,JAPAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP ONODERA, A (reprint author), OSAKA UNIV,FAC ENGN SCI,TOYONAKA,OSAKA 560,JAPAN. NR 27 TC 19 Z9 19 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 3532 EP 3535 DI 10.1103/PhysRevB.50.3532 PG 4 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900002 ER PT J AU CIVALE, L KRUSINELBAUM, L THOMPSON, JR WHEELER, R MARWICK, AD KIRK, MA SUN, YR HOLTZBERG, F FEILD, C AF CIVALE, L KRUSINELBAUM, L THOMPSON, JR WHEELER, R MARWICK, AD KIRK, MA SUN, YR HOLTZBERG, F FEILD, C TI REDUCING VORTEX MOTION IN YBA2CU3O7 CRYSTALS WITH SPLAY IN COLUMNAR DEFECTS SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BOSON LOCALIZATION; ION IRRADIATION; LINEAR DEFECTS AB A strategy to boost the current-carrying capacity of cuprate superconductors beyond the levels attainable with parallel columnar defects was recently proposed. It consists of the enforcement of vortex entanglement by controlled splay of columns. We demonstrate the validity of this suggestion in YBa2Cu3O2 single crystals using the difference in splay naturally occurring in irradiations with two ions differing in mass and energy. The terminal dispersion of the columns produced by 0.58-GeV Sn-116(30+) is about 10-degrees, as compared with 1-degrees for 1.08-GeV Au-197(23+). At high temperatures, this large splay results in a persistent current density one order of magnitude larger and a creep rate one order of magnitude smaller. C1 IBM RES,YORKTOWN HTS,NY 10598. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 17 TC 90 Z9 90 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 4102 EP 4109 DI 10.1103/PhysRevB.50.4102 PG 8 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900066 ER PT J AU TRYGG, J WILLS, JM JOHANSSON, B ERIKSSON, O AF TRYGG, J WILLS, JM JOHANSSON, B ERIKSSON, O TI 1ST-PRINCIPLES STUDY OF THE MAGNETIZATION DENSITY IN CEFE2 SO PHYSICAL REVIEW B LA English DT Note ID TRANSITION-METAL INTERMETALLICS; LAVES PHASE-COMPOUNDS; 3D-5D BAND MAGNETISM; BRILLOUIN-ZONE; SPECIAL POINTS; SYSTEMS; LUFE2 AB We present first-principles calculations of the magnetization density and its resolution into spin and orbital moments in CeFe2. The calculations do not rely on any shape assumptions concerning the density or potential and verify that the total moment on the Ce and Fe sites are coupled antiparallel. This is due to the fact that the Fe and Ce spin moments are coupled antiparallel and that the orbital moment on the Ce site is smaller than the spin moment. We argue that this is in sharp contrast to the expected behavior for a 4f local moment system, where essentially the free-ion behavior of the Ce magnetism is expected, with an orbital moment larger and antiparallel to the spin moment. The recent suggestion of a large nonspherical moment density in CeFe2 is specifically addressed and the calculations are found to support such a behavior. The calculated individual moments are approximately 50% larger than the moments deduced from neutron-scattering experiments. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP TRYGG, J (reprint author), UNIV UPPSALA,DEPT PHYS,CONDENSED MATTER THEORY GRP,BOX 530,S-75105 UPPSALA,SWEDEN. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 20 TC 23 Z9 23 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 4200 EP 4203 DI 10.1103/PhysRevB.50.4200 PG 4 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900083 ER PT J AU SHASTRI, A BORSA, F TORGESON, DR GOLDMAN, AI AF SHASTRI, A BORSA, F TORGESON, DR GOLDMAN, AI TI DISTRIBUTION OF NONEQUIVALENT ALUMINUM SITES REVEALED IN AL-CU-RU AND AL-CU-FE QUASI-CRYSTALS BY AL-27 NQR SO PHYSICAL REVIEW B LA English DT Note ID ICOSAHEDRAL QUASI-CRYSTAL; NMR; MAGNETISM; ORDER; PD; MN AB The distribution of nonequivalent aluminum sites was studied in Al-Cu-Fe and Al-Cu-Ru stable icosahedral quasicrystalline phases using Al-27 NQR spectra taken at 4.2 K. The observed spectra-which give directly the distribution of nonequivalent aluminum sites-were broad, asymmetric, and structureless. A simple electric-field-gradient model calculation accounted for the spectral width in terms of a wide distribution of local atomic environments, and an estimate for the lower limit on the number of nonequivalent aluminum sites was found. C1 UNIV PAVIA,DIPARTIMENTO FIS,I-27100 PAVIA,ITALY. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP SHASTRI, A (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 23 TC 12 Z9 12 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 4224 EP 4227 DI 10.1103/PhysRevB.50.4224 PG 4 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900089 ER PT J AU FISHMAN, RS LIU, SH AF FISHMAN, RS LIU, SH TI DYNAMICS OF COMMENSURATE CHROMIUM-ALLOYS SO PHYSICAL REVIEW B LA English DT Note ID SPIN-DENSITY-WAVE; AMPLITUDE COLLECTIVE MODES; MAGNETIC EXCITATIONS; SCATTERING; NICKEL; PHASE AB The dynamics of commensurate chromium alloys are produced by the fluctuations of a spin-density wave consisting of bound electron-hole pairs. For a commensurate alloy at any temperature, we find a transverse spin-wave (SW) mode with frequency omega = cq and a longitudinal amplitude mode with dispersion omega = 2 square-root DELTA2 + (cq)2/4, where c = upsilon(F)/square-root 3 is the SW mode velocity and 2DELTA is the energy required to break apart an electron-hole pair. Unlike in an itinerant ferromagnet, the SW and amplitude modes never intersect. Other fluctuations below the SW mode and above the amplitude mode are intrinsically damped in an itinerant antiferromagnet. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP FISHMAN, RS (reprint author), N DAKOTA STATE UNIV,DEPT PHYS,FARGO,ND 58105, USA. RI Fishman, Randy/C-8639-2013 NR 28 TC 7 Z9 7 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 4240 EP 4243 DI 10.1103/PhysRevB.50.4240 PG 4 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900093 ER PT J AU LI, Q WIESMANN, HJ SUENAGA, M MOTOWIDLOW, L HALDAR, P AF LI, Q WIESMANN, HJ SUENAGA, M MOTOWIDLOW, L HALDAR, P TI OBSERVATION OF VORTEX-GLASS-TO-LIQUID TRANSITION IN THE HIGH-T(C) SUPERCONDUCTOR BI2SR2CA2CU3O10 SO PHYSICAL REVIEW B LA English DT Note ID TRANSPORT; CRYSTALS; DEFECTS AB We report a series of measurements of I-V curves for a c-axis-oriented Bi2Sr2Ca2Cu3O10/Ag tape immersed in liquid oxygen. By applying the critical scaling analysis to the I-V characteristics measured in various magnetic fields, a vortex-glass-liquid phase-transition line was identified in the mixed state of this system for H less-than-or-equal-to 1.2 T, with critical exponents nu = 1.25 +/- 0.15 and z = 8.5 +/- 1.5. We also show that this transition boundary in the H-T plane defines the upper limit of useful current carrying capacities for the Bi2Sr2Ca2Cu3O10/Ag tapes at a given temperature and magnetic field. C1 IGC,ADV SUPERCOND INC,WATERBURY,CT 06704. INTERMAGNET GEN CORP,GUILDERLAND,NY 12084. RP LI, Q (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 18 TC 75 Z9 75 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD AUG 1 PY 1994 VL 50 IS 6 BP 4256 EP 4259 DI 10.1103/PhysRevB.50.4256 PG 4 WC Physics, Condensed Matter SC Physics GA PB629 UT WOS:A1994PB62900097 ER PT J AU RAMAN, S JURNEY, ET STARNER, JW KURONEN, A KEINONEN, J NORDLUND, K MILLENER, DJ AF RAMAN, S JURNEY, ET STARNER, JW KURONEN, A KEINONEN, J NORDLUND, K MILLENER, DJ TI LIFETIMES IN N-15 FROM GAMMA-RAY LINE-SHAPES PRODUCED IN THE H-2(N-14,P-GAMMA) AND N-14(THERMAL N,GAMMA) REACTIONS SO PHYSICAL REVIEW C LA English DT Article ID THERMAL-NEUTRON REACTION; HIGH-EXITATION LEVELS; EXCITED-STATES; NUCLEAR LIFETIMES; HYDROGEN; STRENGTHS; ENERGIES; SOLIDS; C-13; TA AB Mean lifetimes of bound states in N-15 were inferred from the Doppler-shift-attenuation (DSA) of gamma rays produced in the inverse reaction H-2(N-14, pgamma) and from the primary gamma-ray-induced Doppler broadening (GRID) of secondary gamma rays iu the thermal-neutron capture reaction N-14(n, gamma). Targets for the DSA measurements were prepared by implanting first neon into a gold backing and then deuterium into the same region such that deuterium was trapped at the neon precipitates. To find out experimentally the initial velocity distributions of the recoiling N-15 nuclei, another target was prepared by implanting deuterium into silicon, which is a slow stopping-power medium. Computer simulations with the Monte Carlo method and experimental stopping powers were used in the DSA analysis of the gamma-ray line shapes. This analysis yielded the following lifetimes for eight bound levels in N-15: 43 +/- 4 fs (5.30 MeV), < 12 fs (6.32 MeV), 11 +/- 2 fs (7.16 MeV), < 3 fs (7.30 MeV), 129 +/- 6 fs (7.57 MeV), < 3 fs (8.31 MeV), < 10 fs (8.57 MeV), and < 4 fs (9.05 MeV). GRID measurements were made with melamine (C3H6N6) and with silicon nitride (Si3N4) as both targets and slowing-down media. Measurements were also made with air (80% nitrogen). The Doppler-broadened gamma-ray line shapes were analyzed by molecular-dynamics simulations of the slowing-down process to obtain the lifetime values of 40 +/- 3 fs (5.30 MeV), < 2 fs (6.32 MeV), < 3 fs (7.30 MeV), and < 3 fs (8.31 MeV) for levels in N-15. The extent to which the mirror symmetry of levels in N-15 and O-15 is valid is examined in some detail. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV HELSINKI,ACCELERATOR LAB,SF-00014 HELSINKI,FINLAND. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP RAMAN, S (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Keinonen, Juhani/D-4347-2013; Nordlund, Kai/L-8275-2014 OI Nordlund, Kai/0000-0001-6244-1942 NR 61 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 682 EP 697 DI 10.1103/PhysRevC.50.682 PG 16 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000023 ER PT J AU HINDI, MM CHAMPAGNE, AE DACRUZ, MTF LARIMER, RM LESKO, KT NORMAN, EB SUR, B AF HINDI, MM CHAMPAGNE, AE DACRUZ, MTF LARIMER, RM LESKO, KT NORMAN, EB SUR, B TI BETA+-DECAY AND COSMIC-RAY HALF-LIVES OF PM-143 AND PM-144 SO PHYSICAL REVIEW C LA English DT Article AB The positron decay partial half-lives of Pm-143 and Pm-144 are needed to assess the viability of elemental Pm as a cosmic-ray clock. We have conducted experiments to measure the beta+ branches of these isotopes; we find beta+ branches of < 5.7 x 10(-6)% for Pm-143 and < 8 X 10(-5)% for Pm-144. Although these branches are a factor of 20 lower than the previous experimental limits, the resulting partial half-lives are still too uncertain to permit any firm conclusions. C1 DUKE UNIV,TRIANGLE UNIV NUCL LAB,DURHAM,NC 27706. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599. RP HINDI, MM (reprint author), TENNESSEE TECHNOL UNIV,DEPT PHYS,COOKEVILLE,TN 38505, USA. NR 6 TC 5 Z9 5 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 728 EP 732 DI 10.1103/PhysRevC.50.728 PG 5 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000027 ER PT J AU HOROI, M CLAUSNITZER, G BROWN, BA WARBURTON, EK AF HOROI, M CLAUSNITZER, G BROWN, BA WARBURTON, EK TI NEW CALCULATIONS OF THE PARITY NONCONSERVATION MATRIX ELEMENT FOR THE J-PI-T 0+1, 0-1 DOUBLET IN N-14 SO PHYSICAL REVIEW C LA English DT Article ID RESONANCES; NUCLEI; O-16 AB A new calculation of the predominantly isoscalar PNC matrix element between the J(pi)T 0+1, 0-1 (E(x) almost-equal-to 8.7 MeV) states in N-14 has been carried out in a (0+1+2+3+4)HBARomega model space with the Warburton-Brown interaction. The magnitude of the PNC matrix element of 0.22 to 0.54 eV obtained with the DDH PNC interaction is substantially suppressed compared with previous calculations in smaller model spaces but shows agreement with the preliminary Seattle experimental data. The calculated sign is opposite to that obtained experimentally, and the implications of this are discussed. C1 MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP HOROI, M (reprint author), JUSTUS LIEBIG UNIV,STRAHLENZENTRUM,D-35392 GIESSEN,GERMANY. NR 28 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 AUG PY 1994 VL 50 IS 2 BP 775 EP 783 DI 10.1103/PhysRevC.50.775 PG 9 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000033 ER PT J AU YEN, YF BRINKMOLLER, B DEHNHARD, D FRANEY, MA STERBENZ, SM YU, YJ BERMAN, B BURLESON, GR CRANSTON, K KLEIN, A KYLE, GS ALARCON, R AVERETT, T COMFORT, JR GORGEN, JJ RITCHIE, BG TINSLEY, JR BARLETT, M HOFFMANN, GW JOHNSON, K MOORE, CF PURCELL, M WARD, H WILLIAMS, A FAUCETT, JA GREENE, SJ JARMER, JJ MCGILL, JA MORRIS, CL PENTTILA, SI TANAKA, N FORTUNE, HT INSKO, E IVIE, R ODONNELL, JM SMITH, D KHANDAKER, MA CHAKRAVARTI, S AF YEN, YF BRINKMOLLER, B DEHNHARD, D FRANEY, MA STERBENZ, SM YU, YJ BERMAN, B BURLESON, GR CRANSTON, K KLEIN, A KYLE, GS ALARCON, R AVERETT, T COMFORT, JR GORGEN, JJ RITCHIE, BG TINSLEY, JR BARLETT, M HOFFMANN, GW JOHNSON, K MOORE, CF PURCELL, M WARD, H WILLIAMS, A FAUCETT, JA GREENE, SJ JARMER, JJ MCGILL, JA MORRIS, CL PENTTILA, SI TANAKA, N FORTUNE, HT INSKO, E IVIE, R ODONNELL, JM SMITH, D KHANDAKER, MA CHAKRAVARTI, S TI PION ELASTIC-SCATTERING FROM POLARIZED C-13 IN THE ENERGY REGION OF THE P-33 RESONANCE SO PHYSICAL REVIEW C LA English DT Article ID CHARGE-EXCHANGE; INELASTIC-SCATTERING; ANALYZING POWERS; DELTA-RESONANCE; PHOTOPRODUCTION; NUCLEON; SUPPRESSION AB Analyzing powers A(y) were measured for pi+ and pi- elastic scattering from polarized C-13 at incident pion energies T(pi) near the P-33 pi-nucleon resonance. At T(pi) = 130 MeV, the values of A(y) are significantly different from zero for pi- scattering. For pi+ at T(pi) = 130 MeV and for both pi- and pi+ at all other energies, the A(y) are mostly consistent with zero. Blastic differential cross sections were measured using an unpolarized C-13 target. Both the analyzing-power and cross-section data were compared with predictions using a variety of nuclear structure and reaction models. The analyzing power was found to be strongly sensitive to the quadrupole spin-flip part of the transition. The data of this work complement measurements of the magnetic form factor by electron scattering. The pion A(y) data are not reproduced by calculations using wave functions that fit the magnetic form factor at low momentum transfers. C1 UNIV MINNESOTA,MINNEAPOLIS,MN 55455. NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. ARIZONA STATE UNIV,TEMPE,AZ 85287. UNIV TEXAS,AUSTIN,TX 78712. UNIV PENN,PHILADELPHIA,PA 19104. UNIV MARYLAND,COLLEGE PK,MD 20742. CALIF STATE POLYTECH UNIV POMONA,POMONA,CA 91768. RP YEN, YF (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Averett, Todd/A-2969-2011 NR 47 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 897 EP 908 DI 10.1103/PhysRevC.50.897 PG 12 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000048 ER PT J AU KNUDSON, JN BOWMAN, JD PENTTILA, SI COMFORT, JR TINSLEY, J RITCHIE, BG GORGEN, J MATHIS, D HANNA, SS KING, B POCANIC, D LOVEMAN, RA FRITZ, LS DIXON, NS AF KNUDSON, JN BOWMAN, JD PENTTILA, SI COMFORT, JR TINSLEY, J RITCHIE, BG GORGEN, J MATHIS, D HANNA, SS KING, B POCANIC, D LOVEMAN, RA FRITZ, LS DIXON, NS TI NEUTRON DEFORMATION IN HO-165 SO PHYSICAL REVIEW C LA English DT Article ID SINGLE-CHARGE-EXCHANGE; INELASTIC-SCATTERING; DEFORMED-NUCLEI; ALIGNED HO-165; REGION AB We report asymmetries in the forward-angle differential cross sections for pion single-charge-exchange scattering from oriented and unoriented Ho-165 nuclei. These asymmetries are directly related to the neutron deformation of a nucleus that has a large charge quadrupole moment. The measured asymmetry extrapolated to 0-degrees is -0.020 +/- 0.024. In the model of Chiang and Johnson, this value implies a quadrupole deformation ratio beta2n/beta2p = 0.84+/-0.08, indicating that the excess neutrons are less deformed than the protons. This result conflicts with the predictions of the best available Hartree-Fock models based on Skyrme interactions. We also report on asymmetries of the nonresonant continuum and of the giant dipole resonances. C1 ARIZONA STATE UNIV,DEPT PHYS,TEMPE,AZ 85287. STANFORD UNIV,DEPT PHYS,PALO ALTO,CA 94305. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. FRANKLIN & MARSHALL COLL,DEPT PHYS,LANCASTER,PA 17604. RP KNUDSON, JN (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 50 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 909 EP 917 DI 10.1103/PhysRevC.50.909 PG 9 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000049 ER PT J AU SALEMVASCONCELOS, S TAKAGUI, EM BECHARA, MJ KOIDE, K DIETZSCH, O NUEVO, AB TAKAI, H AF SALEMVASCONCELOS, S TAKAGUI, EM BECHARA, MJ KOIDE, K DIETZSCH, O NUEVO, AB TAKAI, H TI ELASTIC AND INELASTIC-SCATTERING OF O-16 AND O-18 IONS FROM ZN-64 AT ENERGIES NEAR THE COULOMB BARRIER SO PHYSICAL REVIEW C LA English DT Article ID COUPLED-CHANNELS CALCULATIONS; MICROSCOPIC ANALYSIS; STATE AB Coulomb-nuclear interference effects were investigated in the inelastic scattering of O-16 and O-18 by Zn-64. Measurements of elastic and inelastic angular distributions of O-18 were performed at a laboratory energy of 49 MeV, over the angular range from theta(lab) approximately 30-degrees to 85-degrees. The excitation functions of O-16 and O-18 ions were measured at incident energies between 29 and 46 MeV at theta(lab) = 174-degrees. The experimental angular distributions show structures which are more pronounced for projectile excitation than for target excitation. The interference minimum for the excitation of the O-18 first 2+ state was found to be shifted towards forward angles by approximately 5-degrees(c.m.) with respect to the distorted-wave Born approximation calculations and by approximately 3.5-degrees(c.m.) with respect to the coupled-channels calculations. A pronounced Coulomb-nuclear interference minimum was seen in the excitation of Zn-64(2+) state by inelastic scattering of O-16 projectiles, whereas no pronounced minimum was observed in target excitation by O-18 projectiles. The elastic scattering data were analyzed with the optical model. The inelastic differential cross sections for the excitation of the first 2+ states in the target and in the O-18 projectile were analyzed using the distorted-wave Born approximation and also the coupled-channels approach with collective form factors. C1 UNIV FED RIO DE JANEIRO,INST FIS,RIO JANEIRO,BRAZIL. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP SALEMVASCONCELOS, S (reprint author), UNIV SAO PAULO,INST FIS,SAO PAULO,BRAZIL. RI Takai, Helio/C-3301-2012 OI Takai, Helio/0000-0001-9253-8307 NR 28 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 AUG PY 1994 VL 50 IS 2 BP 927 EP 933 DI 10.1103/PhysRevC.50.927 PG 7 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000051 ER PT J AU CHADWICK, MB YOUNG, PG GEORGE, DC WATANABE, Y AF CHADWICK, MB YOUNG, PG GEORGE, DC WATANABE, Y TI MULTIPLE PREEQUILIBRIUM EMISSION IN FESHBACH-KERMAN-KOONIN ANALYSES SO PHYSICAL REVIEW C LA English DT Article ID COINCIDENT PROTON EMISSION; MULTISTEP DIRECT REACTIONS; NEUTRON EMISSION; STATISTICAL-THEORY; CROSS-SECTIONS; COMPOUND; ENERGY; CONTINUUM; MODEL; BOMBARDMENT AB We describe how multiple preequilibrium emission can be included in the Feshbach-Kerman-Koonin (FKK) theory. By analyzing (p, xn) and (p, xp) reactions on zirconium, at incident energies of 80 and 160 MeV, the importance of multiple preequilibrium emission can be clearly seen. This mechanism accounts for much of the emission spectra and its importance extends to relatively high emission energies. We show that multiple preequilibrium must be included in FKK analyses at these incident energies in order to simultaneously satisfy unitarity and account for inclusive nucleon emission spectra. The importance of multistep processes is reduced in comparison to analyses which omit multiple preequilibrium. Our calculated angular distributions account for measurements except at the highest backward angles, where we underpredict the data. We compare our results with other analyses at these energies. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. KYUSHU UNIV,DEPT ENERGY CONVERS ENGN,KASUGA,FUKUOKA 816,JAPAN. RP CHADWICK, MB (reprint author), LAWRENCE LIVERMORE NATL LAB,NUCL DATA GRP,LIVERMORE,CA 94550, USA. NR 55 TC 55 Z9 55 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 996 EP 1005 DI 10.1103/PhysRevC.50.996 PG 10 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000059 ER PT J AU BENESH, CJ QIU, JW VARY, JP AF BENESH, CJ QIU, JW VARY, JP TI J/PSI SUPPRESSION IN HADRON-NUCLEUS COLLISIONS SO PHYSICAL REVIEW C LA English DT Article ID INELASTIC ELECTRON-SCATTERING; QUARK DISTRIBUTIONS; COLOR TRANSPARENCY; SMALL VALUES; RECOMBINATION; DEPENDENCE; DEUTERIUM; SINGLET; QCD AB We examine the production of J/psi mesons in high-energy hadron-nucleus collisions using models that account for both the initial state modification of parton distributions in nuclei and the final state interaction of the produced ccBAR pairs. We show that, at the energies of current fixed target experiments, J/psi production through quark-antiquark annihilation gives the largest contribution at x(F) > 0.5, while gluon-gluon fusion dominates the production at smaller x(F). The observed J/psi suppression at large x(F) is directly connected to nuclear shadowing in deeply inelastic scattering. We find that a 6-8 mb ccBAR-nucleon cross section is needed to explain the data on J/psi suppression if a simple incoherent multiple scattering formalism is used for the final state interactions. We then provide a more complete model to incorporate the effects of final state multiple soft scatterings. With only one parameter, this model can fit both the normalization and A dependence of the data for a variety of nuclei. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. UNIV HEIDELBERG, INST THEORET PHYS, D-69120 HEIDELBERG, GERMANY. RP RICE UNIV, BONNER NUCL LAB, HOUSTON, TX 77251 USA. NR 33 TC 35 Z9 35 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 1015 EP 1023 DI 10.1103/PhysRevC.50.1015 PG 9 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000061 ER PT J AU ABBOTT, T AKIBA, Y BEAVIS, D BLOOMER, MA BOND, PD CHASMAN, C CHEN, Z CHU, YY COLE, BA COSTALES, JB CRAWFORD, HJ CUMMING, JB DEBBE, R ENGELAGE, J FUNG, SY GONIN, M GUSHUE, S HAMAGAKI, H HANSEN, O HAYANO, R HAYASHI, S HOMMA, S HUANG, HZ IKEDA, Y JURICIC, I KANG, J KATCOFF, S KAUFMAN, S KIMURA, K KITAMURA, K KURITA, K LEDOUX, RJ LEVINE, MJ MIAKE, Y MORSE, RJ MOSKOWITZ, B NAGAMIYA, S OLNESS, J PARSONS, CG REMSBERG, LP SAKURAI, H SARABURA, M STANKUS, P STEADMAN, SG STEPHANS, GSF SUGITATE, T TANNENBAUM, MJ TANAKA, Y VANDIJK, JH VIDEBAEK, F VIENT, M VINCENT, P VUTSADAKIS, V WEGNER, HE WOODRUFF, DS WU, YD ZAJC, WA AF ABBOTT, T AKIBA, Y BEAVIS, D BLOOMER, MA BOND, PD CHASMAN, C CHEN, Z CHU, YY COLE, BA COSTALES, JB CRAWFORD, HJ CUMMING, JB DEBBE, R ENGELAGE, J FUNG, SY GONIN, M GUSHUE, S HAMAGAKI, H HANSEN, O HAYANO, R HAYASHI, S HOMMA, S HUANG, HZ IKEDA, Y JURICIC, I KANG, J KATCOFF, S KAUFMAN, S KIMURA, K KITAMURA, K KURITA, K LEDOUX, RJ LEVINE, MJ MIAKE, Y MORSE, RJ MOSKOWITZ, B NAGAMIYA, S OLNESS, J PARSONS, CG REMSBERG, LP SAKURAI, H SARABURA, M STANKUS, P STEADMAN, SG STEPHANS, GSF SUGITATE, T TANNENBAUM, MJ TANAKA, Y VANDIJK, JH VIDEBAEK, F VIENT, M VINCENT, P VUTSADAKIS, V WEGNER, HE WOODRUFF, DS WU, YD ZAJC, WA TI CHARGED HADRON DISTRIBUTIONS IN CENTRAL AND PERIPHERAL SI+A COLLISIONS AT 14.6A GEV/C SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; QUARK-GLUON PLASMA; PARTICLE-PRODUCTION; TRANSPARENCY; BROOKHAVEN; PROTONS; SYSTEM; PIONS; PI AB The AGS spectrometer experiment E-802 has measured transverse mass spectra for charged hadrons over a wide rapidity interval in Si+Au, Si+Cu, and Si+Al reactions at 14.6A GeV/c. These results are compared for two different trigger conditions: central collisions corresponding to 7% of the inelastic cross section selected on multiplicity of charged particles and peripheral collisions corresponding to roughly 50% of the inelastic cross section selected on high kinetic energy at zero degrees. The invariant spectra are well described by exponentials in transverse mass allowing the extraction of rapidity distributions and inverse slope parameters for each specie emitted in the different reactions. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT CHEM,ALTERNATING GRADIENT SYNCHROTRON,UPTON,NY 11973. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92507. NEVIS LABS,IRVINGTON,NY 10533. HIROSHIMA UNIV,DEPT PHYS,HIROSHIMA 730,JAPAN. UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN. KYUSHU UNIV,FUKUOKA 812,JAPAN. MIT,CAMBRIDGE,MA 02139. UNIV TOKYO,DEPT PHYS,TOKYO 113,JAPAN. RI Cumming, James/I-3358-2013; SAKURAI, HIROYOSHI/G-5085-2014; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014; OI Cumming, James/0000-0001-6930-0958; Hayano, Ryugo/0000-0002-1214-7806; Tannenbaum, Michael/0000-0002-8840-5314 NR 41 TC 96 Z9 96 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 1024 EP 1047 DI 10.1103/PhysRevC.50.1024 PG 24 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000062 ER PT J AU ALBRECHT, R ANTONENKO, A AWES, TC BERGER, F BLOOMER, MA BOCK, D BOCK, R CLAESSON, G CLEWING, G DRAGON, L EKLUND, A FOKIN, S FRANZ, A GARPMAN, S GLASOW, R GUSTAFSSON, HA GUTBROD, HH HARTIG, M HE, X HOLKER, G IDH, J IPPOLITOV, M JACOBS, P KAMPERT, KH KARADJEV, K KOLB, BW LEBEDEV, A LOHNER, H LUND, I MANKO, V NIKOLAEV, S NYSTRAND, J OBENSHAIN, FE OSKARSSON, A OTTERLUND, I PEITZMANN, T PLASIL, F POSKANZER, AM PURSCHKE, M RITTER, HG ROTERS, B SAINI, S SANTO, R SCHMIDT, HR SODERSTROM, K SORENSEN, SP STEFFENS, K STEINHAUSER, P STENLUND, E STUKEN, D VINOGRADOV, A YOUNG, GR AF ALBRECHT, R ANTONENKO, A AWES, TC BERGER, F BLOOMER, MA BOCK, D BOCK, R CLAESSON, G CLEWING, G DRAGON, L EKLUND, A FOKIN, S FRANZ, A GARPMAN, S GLASOW, R GUSTAFSSON, HA GUTBROD, HH HARTIG, M HE, X HOLKER, G IDH, J IPPOLITOV, M JACOBS, P KAMPERT, KH KARADJEV, K KOLB, BW LEBEDEV, A LOHNER, H LUND, I MANKO, V NIKOLAEV, S NYSTRAND, J OBENSHAIN, FE OSKARSSON, A OTTERLUND, I PEITZMANN, T PLASIL, F POSKANZER, AM PURSCHKE, M RITTER, HG ROTERS, B SAINI, S SANTO, R SCHMIDT, HR SODERSTROM, K SORENSEN, SP STEFFENS, K STEINHAUSER, P STENLUND, E STUKEN, D VINOGRADOV, A YOUNG, GR TI INTERMITTENCY AND CORRELATIONS IN 200 GEV/NUCLEON S+S AND S+AU COLLISIONS SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; HIGH-ENERGY COLLISIONS; NUCLEAR COLLISIONS; FACTORIAL MOMENTS; MONTE-CARLO; FLUCTUATIONS; DISTRIBUTIONS; MULTIPLICITY; BEHAVIOR; DECAYS AB We have studied one- and two-dimensional scaled factorial moments in S-32+S and S-32+Au collisions at 200 GeV/nucleon in a high statistics electronic measurement at the CERN SPS using pad-readout streamer tubes. We observe no intermittency signal beyond that produced by folding the FRITIOF event generator with a detailed model of our detector. The systematic effects of detector response, two-track separation, and finite statistics in a factorial moment analysis are discussed in detail. Even though the observed signal contains measurable distortions due to these experimental effects, we show that we are sensitive to intermittency. As an alternative method, a two-particle correlation function analysis was applied to the same data to measure correlated particle production at small scales. We show that this method does not suffer as much as the factorial moment analysis does from distortions due to the limited two-track resolution of the detector. The correlation functions also agree with the predictions of FRITIOF filtered through our detector simulation, down to the limit of the two-track resolution. Since FRITIOF models nucleus-nucleus collisions by the superposition of nucleon-nucleon collisions, we conclude that there is no evidence in our data of the kinds of collective behavior predicted to give strong intermittency in heavy ion collisions. C1 KURCHATOV INST,123182 MOSCOW,RUSSIA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV MUNSTER,D-48149 MUNSTER,GERMANY. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. LUND UNIV,S-22362 LUND,SWEDEN. UNIV TENNESSEE,KNOXVILLE,TN 37996. UNIV GRONINGEN,KERNFYS VERSNELLER INST,9747 AA GRONINGEN,NETHERLANDS. RP ALBRECHT, R (reprint author), GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. RI Peitzmann, Thomas/K-2206-2012; Lohner, Herbert/B-2397-2014; OI Peitzmann, Thomas/0000-0002-7116-899X; Lohner, Herbert/0000-0002-7441-739X; Kampert, Karl-Heinz/0000-0002-2805-0195 NR 62 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 AUG PY 1994 VL 50 IS 2 BP 1048 EP 1064 DI 10.1103/PhysRevC.50.1048 PG 17 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000063 ER PT J AU BARRETTE, J BELLWIED, R BRAUNMUNZINGER, P CLELAND, WE CORMIER, TM DAVID, G DEE, J DIEBOLD, GE DIETZSCH, O GERMANI, JV GILBERT, S GREENE, SV HALL, JR HEMMICK, TK HERRMANN, N HONG, B JAYANANDA, K KRAUS, D KUMAR, BS LACASSE, R LISSAUER, D LLOPE, WJ LUDLAM, TW MCCORKLE, S MAJKA, R MARK, SK MITCHELL, JT MUTHUSWAMY, M OBRIEN, E PRUNEAU, C ROTONDO, FS SANDWEISS, J DASILVA, NC SONNADARA, U STACHEL, J TAKAI, H TAKAGUI, EM THROWE, TG WOLFE, D WOODY, CL XU, N ZHANG, Y ZHANG, Z ZOU, C AF BARRETTE, J BELLWIED, R BRAUNMUNZINGER, P CLELAND, WE CORMIER, TM DAVID, G DEE, J DIEBOLD, GE DIETZSCH, O GERMANI, JV GILBERT, S GREENE, SV HALL, JR HEMMICK, TK HERRMANN, N HONG, B JAYANANDA, K KRAUS, D KUMAR, BS LACASSE, R LISSAUER, D LLOPE, WJ LUDLAM, TW MCCORKLE, S MAJKA, R MARK, SK MITCHELL, JT MUTHUSWAMY, M OBRIEN, E PRUNEAU, C ROTONDO, FS SANDWEISS, J DASILVA, NC SONNADARA, U STACHEL, J TAKAI, H TAKAGUI, EM THROWE, TG WOLFE, D WOODY, CL XU, N ZHANG, Y ZHANG, Z ZOU, C TI PRODUCTION OF LIGHT-NUCLEI IN RELATIVISTIC HEAVY-ION COLLISIONS SO PHYSICAL REVIEW C LA English DT Article ID HADRONIC MATTER; STRANGE MATTER; ENERGY; ENTROPY; FRAGMENTS; PARTICLE; STATE; MODEL; PIONS AB We have measured cross sections for the synthesis of nuclei of mass A less-than-or-equal-to 4 in collisions of 14.6A GeV/c Si-28 nuclei with targets of Pb, Cu, and Al. The data are measured at close to center-of-mass rapidities, and are unique in their exploration of the centrality dependence of nucleosynthesis. Simple coalescence models that were used to study nucleosynthesis at lower energies are inadequate for the description of our measurements. Our data and improved models are used to extract parameters related to the size of the interaction volume at freeze-out. C1 GESELL SCHWERIONENFORSCH MBH, W-6100 DARMSTADT 11, GERMANY. MCGILL UNIV, MONTREAL H3A 2T8, QUEBEC, CANADA. UNIV PITTSBURGH, PITTSBURGH, PA 15260 USA. SUNY STONY BROOK, STONY BROOK, NY 11794 USA. UNIV NEW MEXICO, ALBUQUERQUE, NM 87131 USA. UNIV SAO PAULO, SAO PAULO, BRAZIL. WAYNE STATE UNIV, DETROIT, MI 48202 USA. YALE UNIV, NEW HAVEN, CT 06520 USA. RP BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Sonnadara, Upul/E-6359-2010; Takai, Helio/C-3301-2012; OI Takai, Helio/0000-0001-9253-8307; Sonnadara, Upul/0000-0001-7862-2537 NR 45 TC 46 Z9 46 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 1077 EP 1084 DI 10.1103/PhysRevC.50.1077 PG 8 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000065 ER PT J AU MALTMAN, K AF MALTMAN, K TI PI-0 ELECTROMAGNETIC SELF-ENERGY AND ITS IMPLICATIONS FOR INCORPORATING ELECTROMAGNETISM IN FEW-BODY SYSTEMS SO PHYSICAL REVIEW C LA English DT Note ID NUCLEAR-CHARGE ASYMMETRY; DASHEN THEOREM; QUARKS; MESONS; MASS AB By investigating the electromagnetic (EM) chiral series for the pseudoscalar mesons at next-to-leading order, it is shown that the pi0 EM self-energy is O(alpha(EM)m(u,d)), and hence small. This observation completes the crucial step in an earlier argument, which employed previously the vanishing of the pi0 EM self-energy in the chiral limit, and which demonstrates that the effects of not only one-photon-exchange- but also one-photon-loop graphs must be included in order to incorporate the effects of electromagnetism in hadronic systems. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP MALTMAN, K (reprint author), YORK UNIV,DEPT MATH & STAT,4700 KEELE ST,N YORK M3J 1P3,ON,CANADA. NR 16 TC 3 Z9 3 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP 1237 EP 1239 DI 10.1103/PhysRevC.50.1237 PG 3 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000085 ER PT J AU BRADY, FP CHRISTIE, WB ROMERO, JL TULL, CE CHANCE, JL GRIM, GP YOUNG, JC CRAWFORD, HJ KOBAYASHI, T LINDSTROM, PJ OLSON, DL SYMONS, TJM TANIHATA, I WIEMAN, H MULLER, WFJ SANN, H LYNEN, U AF BRADY, FP CHRISTIE, WB ROMERO, JL TULL, CE CHANCE, JL GRIM, GP YOUNG, JC CRAWFORD, HJ KOBAYASHI, T LINDSTROM, PJ OLSON, DL SYMONS, TJM TANIHATA, I WIEMAN, H MULLER, WFJ SANN, H LYNEN, U TI FRAGMENT MASS DEPENDENCE OF P(T) AT GEV PER NUCLEON ENERGIES SO PHYSICAL REVIEW C LA English DT Note ID HEAVY-ION COLLISIONS; 200-980 MEV NUCLEON; TRANSVERSE-MOMENTA; GOLD PROJECTILES; CHARGE YIELDS; SHOCK-WAVES; COLLECTIVE FLOW; MATTER; DISTRIBUTIONS AB Measurements of the transverse momenta (p(T)) of medium and heavy mass projectile fragments for a range of projectile nuclei (Ar-40, Nb-93, La-139, Au-197) have been carried out. It is found that the width of the traverse momentum distributions increases more rapidly with projectile and fragment mass than predicted by models based on nucleon momenta in the projectile nuclei. The distributions can be fit by including an additional transverse momentum, p(B) (for Bounce). The extracted values of p(B)/A(F) increase with decreasing A(F), and extrapolations to small A(F) appear to be consistent with the mean values of reaction-plane-projected p(T) per nucleon for light particle (e.g., nucleon) ''bounce-off.'' C1 UNIV CALIF DAVIS,CROCKER NUCL LAB,DAVIS,CA 95616. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. GESELL SCHWERIONENFORSCH MBH,W-6100 DARMSTADT 11,GERMANY. RP BRADY, FP (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 41 TC 8 Z9 8 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP R525 EP R529 DI 10.1103/PhysRevC.50.R525 PG 5 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000001 ER PT J AU DEGTYARENKO, PV BUTTONSHAFER, J ELOUADRHIRI, L MISKIMEN, RA PETERSON, GA WANG, K GAVRILOV, VB KOSSOV, MV LEKSIN, GA SHUVALOV, SM DIETRICH, FS MELNIKOFF, SO MOLITORIS, JD VANBIBBER, K AF DEGTYARENKO, PV BUTTONSHAFER, J ELOUADRHIRI, L MISKIMEN, RA PETERSON, GA WANG, K GAVRILOV, VB KOSSOV, MV LEKSIN, GA SHUVALOV, SM DIETRICH, FS MELNIKOFF, SO MOLITORIS, JD VANBIBBER, K TI MULTIPLE HADRON-PRODUCTION BY 14.5 GEV ELECTRON AND POSITRON SCATTERING FROM NUCLEAR TARGETS SO PHYSICAL REVIEW C LA English DT Note ID MATTER AB Multiple proton and pion electroproduction from nuclei are studied. Final states including at least two protons produced by the interaction of 14.5 GeV electrons and positrons with light nuclei (mainly C-12 and O-16) have been measured, and compared with analogous data from Ar-40. Scattered electrons and positrons were detected in the energy transfer range from 0.2 to 12.5 GeV, and four-momentum transfer squared range from 0.1 to 5.0 GeV2/c2. Phenomenological characteristics of the secondary hadron production cross sections such as temperature and velocity of the effective source of hadrons were found to be dependent on energy transfer to the nucleus and independent on the four-momentum transfer squared at energy transfers greater than 2 GeV. C1 INST THEORET & EXPTL PHYS,MOSCOW 117259,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP DEGTYARENKO, PV (reprint author), UNIV MASSACHUSETTS,DEPT PHYS & ASTRON,AMHERST,MA 01003, USA. NR 15 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 AUG PY 1994 VL 50 IS 2 BP R541 EP R545 DI 10.1103/PhysRevC.50.R541 PG 5 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000005 ER PT J AU GAO, H ARRINGTON, J BEISE, EJ BRAY, B CARR, RW FILIPPONE, BW LUNG, A MCKEOWN, RD MUELLER, B PITT, ML JONES, CE DESCHEPPER, D DODSON, G DOW, K ENT, R FARKHONDEH, M HANSEN, JO KORSCH, W KRAMER, LH LEE, K MAKINS, N MILNER, RG TIEGER, DR WELCH, TP CANDELL, E NAPOLITANO, J WOJTSEKHOWSKI, BB TRIPP, C LORENZON, W AF GAO, H ARRINGTON, J BEISE, EJ BRAY, B CARR, RW FILIPPONE, BW LUNG, A MCKEOWN, RD MUELLER, B PITT, ML JONES, CE DESCHEPPER, D DODSON, G DOW, K ENT, R FARKHONDEH, M HANSEN, JO KORSCH, W KRAMER, LH LEE, K MAKINS, N MILNER, RG TIEGER, DR WELCH, TP CANDELL, E NAPOLITANO, J WOJTSEKHOWSKI, BB TRIPP, C LORENZON, W TI MEASUREMENT OF THE NEUTRON MAGNETIC FORM-FACTOR FROM INCLUSIVE QUASI-ELASTIC SCATTERING OF POLARIZED ELECTRONS FROM POLARIZED HE-3 SO PHYSICAL REVIEW C LA English DT Note ID QUASI-ELASTIC SCATTERING; ASYMMETRY; NUCLEON AB We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized He-3 target. The neutron magnetic form factor G(M)n has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. Our determination of G(M)n at Q2 = 0.19 (GeV/c)2 agrees with the dipole parametrization. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering. C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. MIT, BATES LINEAR ACCELERATOR CTR, NUCL SCI LAB, CAMBRIDGE, MA 02139 USA. MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. RENSSELAER POLYTECH INST, TROY, NY 12180 USA. TRIUMF, VANCOUVER V6T 2A3, BC, CANADA. RP CALTECH, PASADENA, CA 91125 USA. RI Gao, Haiyan/G-2589-2011; Arrington, John/D-1116-2012 OI Arrington, John/0000-0002-0702-1328 NR 36 TC 111 Z9 112 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1994 VL 50 IS 2 BP R546 EP R549 DI 10.1103/PhysRevC.50.R546 PG 4 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000006 ER PT J AU JOHNSON, CW GINOCCHIO, JN AF JOHNSON, CW GINOCCHIO, JN TI HERMITIAN BOSON MAPPING AND FINITE TRUNCATION SO PHYSICAL REVIEW C LA English DT Note ID LIE-ALGEBRAS; EXPANSION; NUCLEI; MODEL AB Starting from a general, microscopic fermion-to-boson mapping that preserves Hermitian conjugation, we discuss truncations of the boson Fock space basis. We give conditions under which the exact boson images of finite fermion operators are also finite [e.g., a (1+2)-body fermion Hamiltonian is mapped to a (1+2)-body boson Hamiltonian] in the truncated basis. For the most general case, where the image is not necessarily exactly finite, we discuss how to make practical and controlled approximations. RP JOHNSON, CW (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 18 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 AUG PY 1994 VL 50 IS 2 BP R571 EP R575 DI 10.1103/PhysRevC.50.R571 PG 5 WC Physics, Nuclear SC Physics GA PC470 UT WOS:A1994PC47000012 ER PT J AU MONTANET, L BARNETT, RM GROOM, DE TRIPPE, TG WOHL, CG ARMSTRONG, B WAGMAN, GS MURAYAMA, H STONE, J HERNANDEZ, JJ PORTER, FC MORRISON, RJ MANOHAR, A AGUILARBENITEZ, M CASO, C LANTERO, P CRAWFORD, RL ROOS, M TORNQVIST, NA HAYES, KG HOHLER, G KAWABATA, S MANLEY, DM OLIVE, K SHROCK, RE EIDELMAN, S SCHINDLER, RH GURTU, A HIKASA, K CONFORTO, G WORKMAN, RL GRAB, C AF MONTANET, L BARNETT, RM GROOM, DE TRIPPE, TG WOHL, CG ARMSTRONG, B WAGMAN, GS MURAYAMA, H STONE, J HERNANDEZ, JJ PORTER, FC MORRISON, RJ MANOHAR, A AGUILARBENITEZ, M CASO, C LANTERO, P CRAWFORD, RL ROOS, M TORNQVIST, NA HAYES, KG HOHLER, G KAWABATA, S MANLEY, DM OLIVE, K SHROCK, RE EIDELMAN, S SCHINDLER, RH GURTU, A HIKASA, K CONFORTO, G WORKMAN, RL GRAB, C TI REVIEW OF PARTICLE PROPERTIES SO PHYSICAL REVIEW D LA English DT Review ID ELECTROWEAK RADIATIVE-CORRECTIONS; INELASTIC MUON SCATTERING; KOBAYASHI-MASKAWA MATRIX; STRONG-COUPLING-CONSTANT; HADRONIC-Z-DECAYS; NUCLEON STRUCTURE FUNCTIONS; PROMPT PHOTON PRODUCTION; B-MESON DECAYS; SEMILEPTONIC NEUTRINO SCATTERING; SUPERSYMMETRIC STANDARD MODEL AB This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 2300 new measurements from 700 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, monopoles, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. C1 LAWRENCE BERKELEY LAB, DIV PHYS, BERKELEY, CA 94720 USA. TOHOKU UNIV, DEPT PHYS, SENDAI, MIYAGI 980, JAPAN. BOSTON UNIV, DEPT PHYS, BOSTON, MA 02215 USA. UNIV VALENCIA, CSIC, INST FIS CORPUSCULAR, E-46100 BURJASSOT, SPAIN. CALTECH, DEPT PHYS, PASADENA, CA 91125 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV CALIF SAN DIEGO, DEPT PHYS, LA JOLLA, CA 92093 USA. CIEMAT, E-08040 MADRID, SPAIN. UNIV GENOA, DIPARTIMENTO FIS, I-6146 GENOA, ITALY. UNIV GENOA, INFN, I-16146 GENOA, ITALY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, SCOTLAND. UNIV HELSINKI, DEPT PHYS, SF-00100 HELSINKI 10, FINLAND. IST NAZL FIS NUCL, SEZ FIRENZE, I-50125 FLORENCE, ITALY. UNIV HELSINKI, HIGH ENERGY PHYS RES INST, SF-00014 HELSINKI, FINLAND. HILLSDALE COLL, DEPT PHYS, HILLSDALE, MI 49242 USA. UNIV KARLSRUHE, INST THEORET TEILCHENPHYS, D-76128 KARLSRUHE, GERMANY. NATL LAB HIGH ENERGY PHYS, KEK, OHO, IBARAKI 305, JAPAN. KENT STATE UNIV, DEPT PHYS, KENT, OH 44242 USA. UNIV MINNESOTA, SCH PHYS & ASTRON, MINNEAPOLIS, MN 55455 USA. SUNY STONY BROOK, INST THEORET PHYS, STONY BROOK, NY 11794 USA. NOVOSIBIRSK NUCL PHYS INST, NOVOSIBIRSK 630090, RUSSIA. STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. TATA INST FUNDAMENTAL RES, BOMBAY 400005, INDIA. TOHOKU UNIV, DEPT PHYS, AOBA KU, SENDAI 98077, JAPAN. UNIV URBINO, I-61029 URBINO, ITALY. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. SWISS FED INST TECHNOL, INST HIGH ENERGY PHYS, CH-8093 ZURICH, SWITZERLAND. RP MONTANET, L (reprint author), CERN, PARTICLE PHYS LAB, CH-1211 GENEVA 23, SWITZERLAND. RI Murayama, Hitoshi/A-4286-2011; Hernandez-Rey, Juan Jose/N-5955-2014 OI Hernandez-Rey, Juan Jose/0000-0002-1527-7200 NR 760 TC 1043 Z9 1044 U1 0 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 1173 EP + DI 10.1103/PhysRevD.50.1173 PN 1 PG 0 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB614 UT WOS:A1994PB61400001 ER PT J AU ADAMS, MR AID, S ANTHONY, PL BAKER, MD BARTLETT, J BHATTI, AA BRAUN, HM BUSZA, W CARROLL, T CONRAD, JM COUTRAKON, G DAVISSON, R DERADO, I DHAWAN, SK DOUGHERTY, W DREYER, T DZIUNIKOWSKA, K ECKARD, V ECKER, U ERDMANN, M ESKREYS, A FIGIEL, J GEBAUER, HJ GEESAMAN, DF GILMAN, R GREEN, MC HAAS, J HALLIWELL, C HANLON, J HANTKE, D HUGHES, VW JACKSON, HE JAFFE, DE JANSCO, G JANSEN, DM KAUFMAN, S KENNEDY, RD KIRK, T KOBRAK, HGE KRZYWDZINSKI, S KUNORI, S LORD, JJ LUBATTI, HJ MCLEOD, D MAGILL, S MALECKI, P MANZ, A MELANSON, H MICHAEL, DG MOHR, W MONTGOMERY, HE MORFIN, JG NICKERSON, RB ODAY, S OLKIEWICZ, K OSBORNE, I PAPAVASSILIOU, V PAWLIK, B PIPKIN, FM RAMBERG, EJ ROSER, A RYAN, JJ SALVARANI, A SCHELLMAN, H SCHMITT, M SCHMITZ, N SCHULER, KP SEYERLEIN, HJ SKUJA, A SNOW, GA SOLDNERREMBOLD, S STEINBERG, PH STIER, HE STOPA, P SWANSON, RA TALAGA, R TENTINDOREPOND, S TROST, HJ VENKATARAMANIA, H VIDAL, M WILHELM, M WILKES, J WILSON, R WITTEK, W WOLBERS, SA ZHAO, T AF ADAMS, MR AID, S ANTHONY, PL BAKER, MD BARTLETT, J BHATTI, AA BRAUN, HM BUSZA, W CARROLL, T CONRAD, JM COUTRAKON, G DAVISSON, R DERADO, I DHAWAN, SK DOUGHERTY, W DREYER, T DZIUNIKOWSKA, K ECKARD, V ECKER, U ERDMANN, M ESKREYS, A FIGIEL, J GEBAUER, HJ GEESAMAN, DF GILMAN, R GREEN, MC HAAS, J HALLIWELL, C HANLON, J HANTKE, D HUGHES, VW JACKSON, HE JAFFE, DE JANSCO, G JANSEN, DM KAUFMAN, S KENNEDY, RD KIRK, T KOBRAK, HGE KRZYWDZINSKI, S KUNORI, S LORD, JJ LUBATTI, HJ MCLEOD, D MAGILL, S MALECKI, P MANZ, A MELANSON, H MICHAEL, DG MOHR, W MONTGOMERY, HE MORFIN, JG NICKERSON, RB ODAY, S OLKIEWICZ, K OSBORNE, I PAPAVASSILIOU, V PAWLIK, B PIPKIN, FM RAMBERG, EJ ROSER, A RYAN, JJ SALVARANI, A SCHELLMAN, H SCHMITT, M SCHMITZ, N SCHULER, KP SEYERLEIN, HJ SKUJA, A SNOW, GA SOLDNERREMBOLD, S STEINBERG, PH STIER, HE STOPA, P SWANSON, RA TALAGA, R TENTINDOREPOND, S TROST, HJ VENKATARAMANIA, H VIDAL, M WILHELM, M WILKES, J WILSON, R WITTEK, W WOLBERS, SA ZHAO, T TI SCALED ENERGY (Z) DISTRIBUTIONS OF CHARGED HADRONS OBSERVED IN DEEP-NELASTIC MUON SCATTERING AT 490 GEV FROM XENON AND DEUTERIUM TARGETS SO PHYSICAL REVIEW D LA English DT Article ID NUCLEAR TARGETS; CROSS-SECTION; LEPTOPRODUCTION; FRAGMENTATION; MESONS; JETS AB Fermilab Experiment-665 measured deep-inelastic scattering of 490 GeV muons off deuterium and xenon targets. Events were selected with a range of energy exchange nu from 100 GeV to 500 GeV and with large ranges of Q2 and x(Bj): 0.1 GeV2/C2 < Q2 < 150 GeV2/C2 and 0.001 < x(Bj) < 0.5. The fractional energy (z) distributions of forward-produced hadrons from the two targets have been compared as a function of the kinematics of the scattering; specifically, the kinematic region of ''shadowing'' has been compared to that of nonshadowing. The dependence of the distributions upon the order of the hadrons, determined by the fractional energies, has been examined as well; a strong degree of similarity has been observed in the shapes of the distributions of the different order hadrons. These z distributions, however, show no nuclear dependence, even in the kinematic region of shadowing. C1 MIT, BM 24-508, CAMBRIDGE, MA 02139 USA. INST NUCL PHYS, KRAKOW, POLAND. AGH UNIV SCI & TECHNOL, INST NUCL PHYS, KRAKOW, POLAND. MAX PLANCK INST PHYS & ASTROPHYS, D-80805 MUNICH, GERMANY. NORTHWESTERN UNIV, EVANSTON, IL 60208 USA. UNIV WUPPERTAL, W-5600 WUPPERTAL, GERMANY. YALE UNIV, NEW HAVEN, CT 06511 USA. UNIV MARYLAND, COLLEGE PK, MD 20742 USA. UNIV FREIBURG, W-7800 FREIBURG, GERMANY. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. UNIV ILLINOIS, CHICAGO, IL 60680 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. MIT, CAMBRIDGE, MA 02139 USA. RI Carroll, Timothy/B-6934-2009 NR 41 TC 31 Z9 31 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 1836 EP 1873 DI 10.1103/PhysRevD.50.1836 PN 2 PG 38 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB616 UT WOS:A1994PB61600003 ER PT J AU ROBERTS, D ARISAKA, K KUBIC, J SLATER, W WEAVER, M BRIERE, RA CHEU, E HARRIS, DA MCFARLAND, KS ROIODMAN, A SCHWINGENHEUER, B SOMALWAR, SV WAHL, YW WINSTEIN, B WINSTON, R BARKER, AR SWALLOW, EC BOCK, GJ COLEMAN, R CRISLER, M ENAGONIO, J FORD, R HSIUNG, YB JENSEN, DA RAMBERG, E TSCHIRHART, R COLLINS, EM GOLLIN, GD NAKAYA, T YAMANAKA, T GU, P HAAS, P HOGAN, WP KIM, SK MATTHEWS, JN MYUNG, SS SCHNETZER, S THOMSON, GB ZOU, Y AF ROBERTS, D ARISAKA, K KUBIC, J SLATER, W WEAVER, M BRIERE, RA CHEU, E HARRIS, DA MCFARLAND, KS ROIODMAN, A SCHWINGENHEUER, B SOMALWAR, SV WAHL, YW WINSTEIN, B WINSTON, R BARKER, AR SWALLOW, EC BOCK, GJ COLEMAN, R CRISLER, M ENAGONIO, J FORD, R HSIUNG, YB JENSEN, DA RAMBERG, E TSCHIRHART, R COLLINS, EM GOLLIN, GD NAKAYA, T YAMANAKA, T GU, P HAAS, P HOGAN, WP KIM, SK MATTHEWS, JN MYUNG, SS SCHNETZER, S THOMSON, GB ZOU, Y TI SEARCH FOR THE DECAY K(L)(0)-]PI-0-PI-GAMMA SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PERTURBATION-THEORY; BRANCHING RATIO AB We report the results of a search for the decay K(L)0 --> pi0pi0gamma conducted by the E799 Collaboration at Fermilab. The amplitude for this process vanishes to O(p4) in chiral perturbation theory, so a measurement of the decay would directly probe O(p) effects. This is the first published search for this decay mode and we set a 90% confidence level upper limit on the branching ratio of B(K(L)0 --> pi0pi0gamma) < 2.3 X 10(-4). C1 UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV ILLINOIS,URBANA,IL 61801. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV COLORADO,BOULDER,CO 80309. OSAKA UNIV,DEPT PHYS,TOYONAKA,OSAKA 560,JAPAN. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. ELMHURST COLL,ELMHURST,IL 60126. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. RI Briere, Roy/N-7819-2014; Kim, Sun Kee/G-2042-2015 OI Briere, Roy/0000-0001-5229-1039; Kim, Sun Kee/0000-0002-0013-0775 NR 15 TC 3 Z9 3 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 1874 EP 1878 DI 10.1103/PhysRevD.50.1874 PN 2 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB616 UT WOS:A1994PB61600004 ER PT J AU RIZZO, TG AF RIZZO, TG TI A(LR), NEGATIVE-S, AND EXTENDED GAUGE-MODELS SO PHYSICAL REVIEW D LA English DT Article ID ATOMIC PARITY VIOLATION; STANDARD MODEL; PHENOMENOLOGICAL ASPECTS; ELECTROWEAK DATA; BOSONS; CESIUM AB The implications of the recent measurement of the left-right asymmetry A(LR) by the SLD Collaboration for theories with extended gauge sectors are examined. We show that it is possible to arrange for large, negative values of S, based on an analysis of leptonic data, without serious side effects for other observables in certain classes of models. The implications of such scenarios for future measurements on the Z peak, at the Fermilab Tevatron, and for atomic parity violation experiments are examined. RP RIZZO, TG (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 34 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 2256 EP 2264 DI 10.1103/PhysRevD.50.2256 PN 2 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB616 UT WOS:A1994PB61600036 ER PT J AU HUANG, Z SUZUKI, M WANG, XN AF HUANG, Z SUZUKI, M WANG, XN TI SIGNALS OF A DISORIENTED CHIRAL CONDENSATE SO PHYSICAL REVIEW D LA English DT Article ID HEAVY-ION COLLISIONS; HIGH-ENERGY; SEARCH; COLLIDER; EVENTS; FIELD; QCD AB If a disoriented chiral condensate is created over an extended space-time region following a rapid cooling in hadronic or nuclear collisions, the misalignment of the condensate with the electroweak symmetry breaking can generate observable effects in the processes which involve both strong and electromagnetic interactions. We point out the relevance of the dilepton decay of light vector mesons as a signal for the formation of the disoriented condensate. We predict that the decay rho0 --> l+l- will be suppressed and/or the rho resonance peak widens, while the decay omega --> l+l- will not be affected by the condensate. C1 LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP HUANG, Z (reprint author), LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 23 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 2277 EP 2281 DI 10.1103/PhysRevD.50.2277 PN 2 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB616 UT WOS:A1994PB61600038 ER PT J AU CREUTZ, M HORVATH, I AF CREUTZ, M HORVATH, I TI SURFACE-STATES AND CHIRAL-SYMMETRY ON THE LATTICE SO PHYSICAL REVIEW D LA English DT Article ID FERMIONS; ANOMALIES; NEUTRINOS; ABSENCE; PROOF; MODEL AB In a Hamiltonian formalism we study chiral symmetry for lattice fermions formulated in terms of Shockley surface states bound to a wall in an extra spatial dimension. For hadronic physics this provides a natural scheme for taking quark masses to zero without requiring a precise tuning of parameters. We illustrate the chiral anomaly as a flow of states in this extra dimension. We discuss two alternatives for extending the picture to a chiral coupling of gauge fields to such fermions: one with a small explicit breaking of gauge symmetry and one with heavy mirror fermions. RP BROOKHAVEN NATL LAB, DEPT PHYS, POB 5000, UPTON, NY 11973 USA. NR 36 TC 50 Z9 50 U1 1 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 1 PY 1994 VL 50 IS 3 BP 2297 EP 2308 DI 10.1103/PhysRevD.50.2297 PN 2 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA PB616 UT WOS:A1994PB61600041 ER PT J AU KERSTEIN, AR ASHURST, WT AF KERSTEIN, AR ASHURST, WT TI PASSAGE RATES OF PROPAGATING INTERFACES IN RANDOMLY ADVECTED MEDIA AND HETEROGENEOUS MEDIA SO PHYSICAL REVIEW E LA English DT Article ID GROWING INTERFACES; PERCOLATION THEORY; TURBULENT; VELOCITY; EQUATION; FIELD AB The mean passage rate of a propagating interface, subject to random advection or random variation of the local propagation speed, is investigated analytically and computationally. A model representing the longitudinal propagation of two points of the interface separated by a fixed transverse distance is formulated and analyzed. In the limit of weak random perturbations, the model predicts several parameter dependences of the mean passage rate. These predictions are evaluated by performing two-dimensional and three-dimensional numerical simulations of interface propagation. The analysis addresses broadband (i.e., multiscale, as in turbulent flow) as well as narrow-band perturbations. In the broadband case, scaling laws governing transient as well as statistically steady propagation are derived. The numerical simulations span a sufficient range of perturbation amplitudes to exhibit the complete amplitude dependence of the mean passage rate, including scaling behaviors governing the weak and strong perturbation limits. RP KERSTEIN, AR (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 28 TC 23 Z9 23 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP 1100 EP 1113 DI 10.1103/PhysRevE.50.1100 PN A PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD425 UT WOS:A1994PD42500059 ER PT J AU HAMMERBERG, JE HOLIAN, BL RAVELO, R AF HAMMERBERG, JE HOLIAN, BL RAVELO, R TI NUCLEATION OF LONG-RANGE ORDER IN QUENCHED YUKAWA PLASMAS SO PHYSICAL REVIEW E LA English DT Article ID MONTE-CARLO CALCULATIONS; ONE-COMPONENT PLASMAS; MOLECULAR-DYNAMICS; CRYSTAL NUCLEATION; HOMOGENEOUS NUCLEATION; PHASE-DIAGRAM; GLASS-TRANSITION; LIQUID RUBIDIUM; SIMULATIONS; SYSTEM AB We discuss the nucleation from glassy to crystalline order in quenched one-component Yukawa plasmas as studied by molecular dynamics. Rapid quenches from T greater-than-or-equal-to 4T(melt) to T less-than-or-equal-to 0.5T(melt) were studied and a range of Yukawa exponents were considered for systems with up to 10 000 particles. We report on the effect of system size on nucleation and the relevance of classical nucleation theory to the observed nonequilibrium dynamics. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV TEXAS,DEPT PHYS,EL PASO,TX 79968. RP HAMMERBERG, JE (reprint author), LOS ALAMOS NATL LAB,DIV APPL THEORET PHYS,LOS ALAMOS,NM 87545, USA. NR 26 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 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP 1372 EP 1375 DI 10.1103/PhysRevE.50.1372 PN B PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD426 UT WOS:A1994PD42600005 ER PT J AU OKAMOTO, H JIANG, SC GLUCKSTERN, RL AF OKAMOTO, H JIANG, SC GLUCKSTERN, RL TI LONGITUDINAL AND TRANSVERSE IMPEDANCE OF AN IRIS IN A BEAM PIPE SO PHYSICAL REVIEW E LA English DT Article ID COUPLING IMPEDANCE AB The use of iris loaded cavities to accelerate high current bunched beams makes it important to understand the impedance and wake fields caused by an iris in a beam pipe. In this paper we present a method to calculate both the longitudinal and transverse impedance of a circular iris of radius b and thickness g in a circular beam pipe of radius a for ultrarelativistic particles. An integral equation is derived for the transverse electric field at the junction between the iris and the beam pipe and a variational expression is obtained for the impedance, using the transverse field as a trial function. Accurate numerical results are obtained for the longitudinal and transverse impedances using a trial function with only a few adjustable parameters. By invoking causality we confirm the analytic behavior of the impedances in the complex frequency plane and obtain the corresponding wake functions. We particularly explore the limit b --> infinity to compare with previous studies of the impedance of a circular hole in a transverse metallic plane. C1 UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. RP OKAMOTO, H (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 7 TC 2 Z9 2 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP 1501 EP 1515 DI 10.1103/PhysRevE.50.1501 PN B PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD426 UT WOS:A1994PD42600021 ER PT J AU BOHN, CL DELAYEN, JR AF BOHN, CL DELAYEN, JR TI FOKKER-PLANCK APPROACH TO THE DYNAMICS OF MISMATCHED CHARGED-PARTICLE BEAMS SO PHYSICAL REVIEW E LA English DT Article ID RELAXATION; SIMULATION; WAVES AB A semianalytic formalism is constructed for investigating the transverse dynamics of intense, mismatched charged-particle beams which are centered on, and propagate through, focusing channels. It uses the Fokker-Planck equation to account for the rapid evolution of the coarse-grained distribution function in the phase space of a single beam particle. It also incorporates the space-charge potential, which is calculated from Poisson's equation using the coarse-grained density. A simple phenomenological model of dynamical friction and diffusion represents the effects of turbulence triggered by charge redistribution. Sheet beams and fully two-dimensional beams are both considered in detail. In addition, closed-form solutions are presented for beams in which the space charge is negligible and noise arises from other stochastic processes. RP BOHN, CL (reprint author), ARGONNE NATL LAB,DIV TECHNOL DEV,ARGONNE,IL 60439, USA. NR 36 TC 12 Z9 12 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP 1516 EP 1534 DI 10.1103/PhysRevE.50.1516 PN B PG 19 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD426 UT WOS:A1994PD42600022 ER PT J AU HOLIAN, BL PERCUS, OE WARNOCK, TT WHITLOCK, PA AF HOLIAN, BL PERCUS, OE WARNOCK, TT WHITLOCK, PA TI PSEUDORANDOM NUMBER GENERATOR FOR MASSIVELY-PARALLEL MOLECULAR-DYNAMICS SIMULATIONS SO PHYSICAL REVIEW E LA English DT Article AB A class of uniform pseudorandom number generators is proposed for modeling and simulations on massively parallel computers. The algorithm is simple, nonrecursive, and is easily transported to serial or vector computers. We have tested the procedure for uniformity, independence, and correlations by several methods. Related, less complex sequences passed some of these tests well enough; however, inadequacies were revealed by tests for correlations and in an interesting application, namely, annealing from an initial lattice that is mechanically unstable. In the latter case, initial velocities chosen by a random number generator that is not sufficiently random lead quickly to unphysical regularity in grain structure. The new class of generators passes this dynamical diagnostic for unwanted correlations. C1 NYU,COURANT INST MATH SCI,NEW YORK,NY 10012. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. CUNY BROOKLYN COLL,DEPT COMP & INFORMAT SCI,BROOKLYN,NY 11210. RP HOLIAN, BL (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 20 TC 27 Z9 29 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP 1607 EP 1615 DI 10.1103/PhysRevE.50.1607 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD426 UT WOS:A1994PD42600033 ER PT J AU CAI, D BISHOP, AR GRONBECHJENSEN, N MALOMED, BA AF CAI, D BISHOP, AR GRONBECHJENSEN, N MALOMED, BA TI MOVING SOLITONS IN THE DAMPED ABLOWITZ-LADIK MODEL-DRIVEN BY A STANDING-WAVE SO PHYSICAL REVIEW E LA English DT Note ID INTRINSIC LOCALIZED MODES; SINE-GORDON SYSTEM; ANHARMONICITY; EXCITATIONS AB We predict theoretically that, via a resonance mechanism, stable moving solitons exist in a discrete (1 + 1)-dimensional nonlinear Schrodinger (Ablowitz-Ladik) equation with dissipation and an ac driving term in the form of a standing wave. Agreement between the predicted threshold (minimum) values of the strength of the drive which is able to sustain the moving solitons and those measured in direct numerical simulations is excellent. Our results show an example of multistability in damped, standing-wave-driven systems. The dynamical instability for the motion of solitons in the unstable regimes is also analyzed. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. TEL AVIV UNIV,SCH MATH SCI,DEPT APPL MATH,IL-69978 TEL AVIV,ISRAEL. RP CAI, D (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 17 TC 8 Z9 8 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP R694 EP R697 DI 10.1103/PhysRevE.50.R694 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD425 UT WOS:A1994PD42500017 ER PT J AU MASLOV, S PACZUSKI, M AF MASLOV, S PACZUSKI, M TI SCALING THEORY OF DEPINNING IN THE SNEPPEN MODEL SO PHYSICAL REVIEW E LA English DT Note ID SELF-ORGANIZED CRITICALITY; INTERFACE MOTION; POROUS-MEDIA; GROWTH; PERCOLATION; DYNAMICS; AFFINE AB We develop a scaling theory for the critical depinning behavior of the Sneppen interface model [Phys. Rev. Lett. 69, 3539 (1992)]. This theory is based on a ''gap'' equation that describes the self-organization process to a critical state of the depinning transition. All of the critical exponents can be expressed in terms of two independent exponents, nu(parallel-t0)(d) and nu(perpendicular-to)(d), characterizing the divergence of the parallel and perpendicular correlation lengths as the interface approaches its dynamical attractor. C1 SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11790. ISAAC NEWTON INST MATH SCI,CAMBRIDGE CB4 0EH,ENGLAND. RP MASLOV, S (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 25 TC 23 Z9 23 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP R643 EP R646 DI 10.1103/PhysRevE.50.R643 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD425 UT WOS:A1994PD42500004 ER PT J AU RITCHIE, B AF RITCHIE, B TI RELATIVISTIC SELF-FOCUSING AND CHANNEL FORMATION IN LASER-PLASMA INTERACTIONS SO PHYSICAL REVIEW E LA English DT Note ID WAVE-PACKET THEORY; PULSES; SCATTERING; ACCELERATION; ABSORPTION; RADIATION; ELECTRONS; BEAMS AB Nonparaxial wave propagation theory is used to study relativistic self-focusing and channel formation in the propagation of an intense, short-pulse laser through an underdense plasma. The stable on-axis channel predicted by paraxial theory is found to break up into on-axis channel remnants and off-axis rings. RP RITCHIE, B (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 17 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD AUG PY 1994 VL 50 IS 2 BP R687 EP R689 DI 10.1103/PhysRevE.50.R687 PN A PG 3 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA PD425 UT WOS:A1994PD42500015 ER PT J AU GAMBINO, P SIRLIN, A AF GAMBINO, P SIRLIN, A TI EVIDENCE FOR BOSONIC ELECTROWEAK CORRECTIONS IN THE STANDARD MODEL SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATIVE-CORRECTIONS; GAUGE-THEORIES AB We present strong indirect evidence for the contribution of bosonic electroweak corrections in the standard model. Although important conceptually, these corrections give subleading contributions in current high energy experiments, and it was previously thought that they are difficult to detect. We also discuss the separate contribution of the Higgs boson. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP GAMBINO, P (reprint author), NYU,DEPT PHYS,4 WASHINGTON PL,NEW YORK,NY 10003, USA. OI Gambino, Paolo/0000-0002-7433-4914 NR 17 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 1 PY 1994 VL 73 IS 5 BP 621 EP 623 DI 10.1103/PhysRevLett.73.621 PG 3 WC Physics, Multidisciplinary SC Physics GA NZ549 UT WOS:A1994NZ54900003 ER PT J AU LAZAREV, YA LOBANOV, YV OGANESSIAN, YT UTYONKOV, VK ABDULLIN, FS BUKLANOV, GV GIKAL, BN ILIEV, S MEZENTSEV, AN POLYAKOV, AN SEDYKH, IM SHIROKOVSKY, IV SUBBOTIN, VG SUKHOV, AM TSYGANOV, YS ZHUCHKO, VE LOUGHEED, RW MOODY, KJ WILD, JF HULET, EK MCQUAID, JH AF LAZAREV, YA LOBANOV, YV OGANESSIAN, YT UTYONKOV, VK ABDULLIN, FS BUKLANOV, GV GIKAL, BN ILIEV, S MEZENTSEV, AN POLYAKOV, AN SEDYKH, IM SHIROKOVSKY, IV SUBBOTIN, VG SUKHOV, AM TSYGANOV, YS ZHUCHKO, VE LOUGHEED, RW MOODY, KJ WILD, JF HULET, EK MCQUAID, JH TI DISCOVERY OF ENHANCED NUCLEAR-STABILITY NEAR THE DEFORMED SHELLS N=162 AND Z=108 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPONTANEOUS-FISSION; ELEMENT 106; ISOTOPES; HEAVY; BARRIERS AB In bombardments of Cm-248 with Ne-22 we discovered two new isotopes, (265)106 and (266)106, by establishing genetic links between their a decays and spontaneous fussion (SF) or alpha decays of the daughter nuclides. We measured E(alpha) = 8.63 +/- 0.05 MeV for (266)106 and a half-life of 1.2 s for its daughter (262)104. For (265)106 we measured E(alpha) = 8.71 to 8.91 MeV. From these a energies we estimated alpha half-lives of 10-30 s for (266)106 and 2-30 s for (265)106. We estimated SF branches of 50% or less for both isotopes. The decay properties of (266)106 establish the existence of enhanced nuclear stability near the predicted deformed shells N = 162 and Z = 108. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP LAZAREV, YA (reprint author), JOINT INST NUCL RES,141980 DUBNA,RUSSIA. NR 18 TC 165 Z9 167 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 1 PY 1994 VL 73 IS 5 BP 624 EP 627 DI 10.1103/PhysRevLett.73.624 PG 4 WC Physics, Multidisciplinary SC Physics GA NZ549 UT WOS:A1994NZ54900004 ER PT J AU COLLINS, GW LETTS, SA FEARON, EM MCEACHERN, RL BERNAT, TP AF COLLINS, GW LETTS, SA FEARON, EM MCEACHERN, RL BERNAT, TP TI SURFACE-ROUGHNESS SCALING OF PLASMA POLYMER-FILMS SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; BALLISTIC DEPOSITION MODEL; INTERFACE GROWTH; EPITAXIAL-GROWTH; KINETIC GROWTH; GOLD-FILMS; DIFFUSION; CONTINUUM; INSTABILITY AB Atomic force microscopy data reveal self-affine scaling of plasma polymer films. The rms surface roughness sigma increases with film thickness tau as sigma(f < xi-1) is similar to tau(beta), and with measurement length L as sigma(f > L-1 > xi-1) is similar to L(alpha), where xi is the surface roughness correlation length. At the deposition rate R = 2 mum/h, the scaling exponents alpha and beta are 0.9 and 0.7, both increasing to 1 at R = 1 mum/h. A competition between surface relaxation and deposition rate determine sigma and xi, which increase rapidly with R or inverse temperature. RP COLLINS, GW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 32 TC 91 Z9 93 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 1 PY 1994 VL 73 IS 5 BP 708 EP 711 DI 10.1103/PhysRevLett.73.708 PG 4 WC Physics, Multidisciplinary SC Physics GA NZ549 UT WOS:A1994NZ54900025 ER PT J AU BALATSKY, AV ROSENGREN, A ALTSHULER, BL AF BALATSKY, AV ROSENGREN, A ALTSHULER, BL TI IMPURITIES AND QUASI-ONE-DIMENSIONAL TRANSPORT IN A D-WAVE SUPERCONDUCTOR SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANISOTROPY; SCATTERING; YBA2CU3O7; OXIDES; TC AB Impurity scattering in the unitary limit produces low-energy quasiparticles with an anisotropic spectrum in a two-dimensional d-wave superconductor. We describe a new quasi-one-dimensional limit of the quasiparticle scattering, which might occur in a superconductor with short coherence length and with finite impurity potential range. The dc conductivity in a d-wave superconductor is predicted to be proportional to the normal state scattering time and is impurity dependent. The quasi-one-dimensional regime will occur in high-T(c) superconductors above critical impurity concentration. We argue that the impurities produce weak orthogonal localization of the quasiparticles. C1 LOS ALAMOS NATL LAB,CTR SUPERCOND TECHNOL,LOS ALAMOS,NM 87545. ROYAL INST TECHNOL,DEPT THEORET PHYS,S-10044 STOCKHOLM 70,SWEDEN. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. LANDAU INST THEORET PHYS,MOSCOW,RUSSIA. RP BALATSKY, AV (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 24 TC 43 Z9 43 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 1 PY 1994 VL 73 IS 5 BP 720 EP 723 DI 10.1103/PhysRevLett.73.720 PG 4 WC Physics, Multidisciplinary SC Physics GA NZ549 UT WOS:A1994NZ54900028 ER PT J AU HIROTA, K COX, DE LORENZO, JE SHIRANE, G TRANQUADA, JM HASE, M UCHINOKURA, K KOJIMA, H SHIBUYA, Y TANAKA, I AF HIROTA, K COX, DE LORENZO, JE SHIRANE, G TRANQUADA, JM HASE, M UCHINOKURA, K KOJIMA, H SHIBUYA, Y TANAKA, I TI DIMERIZATION OF CUGEO3 IN THE SPIN-PEIERLS STATE SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSITION; CUPRATE AB The dimerization of the Cu ions in the spin-Peierls state of CuGeO3 below 14 K has been determined by neutron-diffraction measurements. In addition to superlattice reflections with indices h/2kl/2 (h, k, l, all odd) recently observed in electron and x-ray diffraction studies, we also found peaks for which k = even. Oxygen displacements in the a-b plane of about 0.01 angstrom, accompanied by comparable shifts of the Cu ions along the chain direction c, can be related to the dimerized spin state in a natural fashion. C1 UNIV TOKYO,DEPT APPL PHYS,BUNKYO KU,TOKYO 113,JAPAN. YAMANASHI UNIV,INST INORGAN SYNTH,KOFU,YAMANASHI 400,JAPAN. RP HIROTA, K (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Hirota, Kazuma/C-6797-2008; Tranquada, John/A-9832-2009; Tanaka, Isao/D-1519-2012; Hase, Masashi/B-8900-2008 OI Tranquada, John/0000-0003-4984-8857; Hase, Masashi/0000-0003-2717-461X NR 15 TC 246 Z9 246 U1 1 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 1 PY 1994 VL 73 IS 5 BP 736 EP 739 DI 10.1103/PhysRevLett.73.736 PG 4 WC Physics, Multidisciplinary SC Physics GA NZ549 UT WOS:A1994NZ54900032 ER PT J AU DABOUL, J NIETO, MM AF DABOUL, J NIETO, MM TI QUANTUM BOUND-STATES WITH ZERO BINDING-ENERGY SO PHYSICS LETTERS A LA English DT Article ID OSTROVSKY ATOMIC MODEL; DYNAMICAL SYMMETRY AB After reviewing the general properties of zero-energy quantum states, we give the explicit solutions of the Schrodinger equation with E = 0 for the class of potentials V = -\gamma\/r(nu), where -infinity < nu < infinity. For nu > 2, these solutions are normalizable and correspond to bound states, if the angular momentum quantum number l > 0. (These states are normalizable, even for l = 0, if we increase the space dimension, D, beyond 4; i.e. for D > 4.) For nu < -2 the above solutions, although unbound, are normalizable. This is true even though the corresponding potentials are repulsive for all r. We discuss the physics of these unusual effects. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP DABOUL, J (reprint author), BEN GURION UNIV NEGEV,DEPT PHYS,IL-84120 BEER SHEVA,ISRAEL. NR 17 TC 25 Z9 25 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD AUG 1 PY 1994 VL 190 IS 5-6 BP 357 EP 362 DI 10.1016/0375-9601(94)90714-5 PG 6 WC Physics, Multidisciplinary SC Physics GA NZ946 UT WOS:A1994NZ94600003 ER PT J AU BRIZARD, A AF BRIZARD, A TI EULERIAN ACTION PRINCIPLES FOR LINEARIZED REDUCED DYNAMICAL EQUATIONS SO PHYSICS OF PLASMAS LA English DT Article ID GUIDING-CENTER THEORIES; LIE PERTURBATION EQUATIONS; VLASOV EQUATION; MAXWELL-VLASOV; CONSERVATION-LAWS; VARIATIONAL-PRINCIPLES; EQUILIBRIA; PLASMAS; ENERGY; STABILITY AB New Eulerian action principles for the linearized gyrokinetic Maxwell-Valsov equations and the linearized kinetic-magnetohydrodynamic (kinetic-MHD) equations are presented. The variational fields for the linearized gyrokinetic Vlasov-Maxwell equations are the perturbed electromagnetic potentials (phi1,A1) and the gyroangle-independent gyrocenter (gy) function S(gy), while the variational fields for the linearized kinetic-MHD equations are the ideal MHD fluid displacement xi and the gyroangle-independent drift-kinetic (dk) function S(dk) (defined as the drift-kinetic limit of S(gy)). According to the Lie-transform approach to Vlasov perturbation theory, S(gy) generates first-order perturbations in the gyrocenter distribution F1={S(gy), F0}gc, where F1 satisfies the linearized gyrokinetic Vlasov equation and { , }gc denotes the unperturbed guiding-center (gc) Poisson bracket. Previous quadratic variational forms were constructed ad hoc from the linearized equations, and required the linearized gyrokinetic (or drift-kinetic) Vlasov equation to be solved a priori (e.g., by integration along an unperturbed guiding-center orbit) through the use of the normal-mode and ballooning-mode representations. The presented action principles ignore these requirements and, thus, apply to more general perturbations. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. OI Brizard, Alain/0000-0002-0192-6273 NR 57 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2460 EP 2472 DI 10.1063/1.870574 PG 13 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400006 ER PT J AU BRIZARD, A AF BRIZARD, A TI QUADRATIC FREE-ENERGY FOR THE LINEARIZED GYROKINETIC VLASOV-MAXWELL EQUATIONS SO PHYSICS OF PLASMAS LA English DT Article ID EQUILIBRIA; PLASMAS AB The motivation for the present work resides in the search for a new formalism for investigating the stability of plasma equilibria perturbed by low-frequency electromagnetic field fluctuations. In this context, the free-energy method of Morrison and Pfirsch [Phys. Fluids B 2, 1105 (1990)] has been extended by deriving an expression for the gyrokinetic free energy. As a check on the gyrokinetic free-energy method, known formulas previously obtained in the electrostatic limit are recovered, while recent (drift-kinetic) formulas obtained by Betti and Freidberg [Phys. Fluids B 4, 1465 (1992)] in the electromagnetic limit are generalized. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. OI Brizard, Alain/0000-0002-0192-6273 NR 19 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2473 EP 2479 DI 10.1063/1.870575 PG 7 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400007 ER PT J AU WANG, JG PAYNE, GL DUBOIS, DF ROSE, HA AF WANG, JG PAYNE, GL DUBOIS, DF ROSE, HA TI ONE-DIMENSIONAL SIMULATIONS OF LANGMUIR COLLAPSE IN A RADIATION-DRIVEN PLASMA SO PHYSICS OF PLASMAS LA English DT Article ID CAVITON TURBULENCE; WAVE COLLAPSE; FIELD AB Langmuir collapse in a radiation-driven plasma is simulated in one dimension using both the hybrid Vlasov model and the modified Zakharov model. In the hybrid model, the electrons are described by the Vlasov equation and the ions are described by the fluid equations. Two numerical runs with different parameters are performed: (a) a weakly driven case, and (b) a strongly driven case. The comparisons of the results between the two models for each case are carried out in detail. It is found that the dynamic behavior of the plasma can be changed dramatically by varying the external driving field. The electron temperature increases only approximately 10% in the weakly driven case, while it increases approximately 200% in the strongly driven case during a single Langmuir collapse. The two models agree with each other during the first collapse after the saturation of modulational instability. Dynamic differences appear after the first collapse, caused by the electron heating in the hybrid model, which is not accounted for in the standard isothermal Zakharov model. C1 UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 25 TC 24 Z9 24 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2531 EP 2546 DI 10.1063/1.870581 PG 16 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400013 ER PT J AU TESSAROTTO, M WHITE, RB ZHENG, LJ AF TESSAROTTO, M WHITE, RB ZHENG, LJ TI PROBABILISTIC APPROACH TO MONTE-CARLO OPERATORS SO PHYSICS OF PLASMAS LA English DT Article ID TRANSPORT-THEORY; PLASMAS AB A general method for constructing Monte Carlo collision operators is formulated based on the introduction of a stochastic Liouville equation. The approach is applied to the investigation of a suitable discretized gyrokinetic equation describing the dynamics of a strongly rotating multispecies plasma, in a toroidally axisymmetric configuration. Improved expressions are obtained for the Monte Carlo collision operators for general non-normal (in v space) coordinate systems. As an application, the important case of the bounce-averaged gyrokinetic equation is discussed, in various cases of interest. Finally, using an approximate collision operator, the friction coefficients are evaluated and expressed in terms of energy and momentum restoring coefficients, thus yielding for the Monte Carlo operators a representation convenient for their numerical implementation. C1 PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP TESSAROTTO, M (reprint author), UNIV TRIESTE,DIPARTIMENTO SCI MATEMAT,CONSORZIO MAGNETOFLUIDODINAM,I-34100 TRIESTE,ITALY. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 10 TC 5 Z9 5 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2591 EP 2602 DI 10.1063/1.870586 PG 12 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400019 ER PT J AU ARTUN, M TANG, WM AF ARTUN, M TANG, WM TI NONLINEAR ELECTROMAGNETIC GYROKINETIC EQUATIONS FOR ROTATING AXISYMMETRICAL PLASMAS SO PHYSICS OF PLASMAS LA English DT Article ID PARTICLE SIMULATION; ION-TRANSPORT; TOKAMAK; MODES; FLOWS AB The influence of sheared equilibrium flows on the confinement properties of tokamak plasmas is a topic of much current interest. A proper theoretical foundation for the systematic kinetic analysis of this important problem has been provided here by presenting the derivation of a set of nonlinear electromagnetic gyrokinetic equations applicable to low-frequency microinstabilities in a rotating axisymmetric plasma. The subsonic rotation velocity considered is in the direction of symmetry, with the angular rotation frequency being a function of the equilibrium magnetic flux surface. In accordance with experimental observations, the rotation profile is chosen to scale with the ion temperature. The results obtained represent the shear flow generalization of the earlier analysis by Frieman and Chen [Phys. Fluids 25, 502 (1982)], where such flows were not taken into account. In order to make it readily applicable to gyrokinetic particle simulations, this set of equations is cast in a phase-space-conserving continuity equation form. RP ARTUN, M (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 24 TC 45 Z9 45 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2682 EP 2692 DI 10.1063/1.870595 PG 11 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400029 ER PT J AU CHARLTON, LA CARRERAS, BA LYNCH, VE SIDIKMAN, KL DIAMOND, PH AF CHARLTON, LA CARRERAS, BA LYNCH, VE SIDIKMAN, KL DIAMOND, PH TI BIFURCATIONS AND MODULATIONAL INTERACTION IN NEGATIVE COMPRESSIBILITY TURBULENCE SO PHYSICS OF PLASMAS LA English DT Article ID DRIFT-WAVE TURBULENCE; GENERATION AB The results of detailed numerical studies of phenomena in negative compressibility turbulence with sheared perpendicular (i.e., poloidal) flow are presented. The turbulence model is based on the parallel ion flow gradient instability, a representative paradigm for ion drift waves. Studies of coupled turbulence and mean flow evolution indicate the existence of two distinct nonlinear states. In the first state, saturation occurs via nonlinear transfer to damped high-k modes and sheared flow is heavily damped. In the second state, the turbulence level is controlled by the self-consistently generated sheared flow. Transition between these states is determined by the competition between instability growth and damping of rotation. The dynamics of the observed transition is well described and consistent with a simple set of coupled envelope equations. Modulational interaction between small scale turbulence and large scale m not-equal 0 shear flows is observed, as well. C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. RP CHARLTON, LA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Lynch, Vickie/J-4647-2012 OI Lynch, Vickie/0000-0002-5836-7636 NR 11 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2700 EP 2710 DI 10.1063/1.870597 PG 11 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400031 ER PT J AU WU, YL WHITE, RB AF WU, YL WHITE, RB TI SELF-CONSISTENT STUDY OF THE ALPHA-PARTICLE-DRIVEN TOROIDICITY-INDUCED ALFVEN EIGENMODE SO PHYSICS OF PLASMAS LA English DT Article ID TOROIDAL PLASMAS; TOKAMAKS AB The interaction of high energy particles with an Alfven eigenmode is investigated self-consistently by using a kinetic dispersion relation. All important poloidal mode numbers and their radial mode profiles as calculated with the NOVA-K code [C. Z. Cheng, Phys. Rep. 211, 1 (1992)] are included. A Hamiltonian guiding center code is used to simulate the alpha particle motion. The numerical simulations include particle orbit width, nonlinear particle dynamics, and the effects of the modes on the particles. Modification of the particle distribution leading to mode saturation is observed. Particle loss depends on the radial extent of the mode and the ratio of the alpha particle gyroradius to the minor radius. RP WU, YL (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08544, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 17 TC 18 Z9 18 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2733 EP 2740 DI 10.1063/1.870508 PG 8 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400034 ER PT J AU WARE, AS DIAMOND, PH CARRERAS, BA AF WARE, AS DIAMOND, PH CARRERAS, BA TI CRITIQUE OF ATOMIC PHYSICS INSTABILITY MECHANISMS - IONIZATION-DRIVEN AND RADIATIVE MICROINSTABILITIES IN THE TOKAMAK EDGE PLASMA - COMMENT SO PHYSICS OF PLASMAS LA English DT Note ID DRIFT WAVE C1 UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. RP WARE, AS (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD AUG PY 1994 VL 1 IS 8 BP 2806 EP 2807 DI 10.1063/1.870517 PG 2 WC Physics, Fluids & Plasmas SC Physics GA PA194 UT WOS:A1994PA19400044 ER PT J AU INGLESE, P ISRAEL, AA NOBEL, PS AF INGLESE, P ISRAEL, AA NOBEL, PS TI GROWTH AND CO2 UPTAKE FOR CLADODES AND FRUIT OF THE CRASSULACEAN ACID METABOLISM SPECIES OPUNTIA-FICUS-INDICA DURING FRUIT-DEVELOPMENT SO PHYSIOLOGIA PLANTARUM LA English DT Article DE CHLOROPHYLL; CO2 EXCHANGE; CRASSULACEAN ACID METABOLISM; PEPCASE; RUBISCO; SINK STRENGTH ID PRUNUS-PERSICA FRUITS; DRY-MATTER PRODUCTION; WATER RELATIONS; APPLE-TREES; PHOTOSYNTHESIS; EXCHANGE; CARBON; PLANT; CACTUS; LEAVES AB Growth and daily net CO2 uptake were measured for fruit of Opuntia ficus-indica and for its cladodes with 0, 5, 10 and 15 fruit and for cladodes after fruit removal. Growth of individual fruit decreased but fruit dry weight per cladode increased as the number of fruit per cladode increased. Removal of fruit decreased the total daily net CO2 uptake of the bearing cladode by about 10%. From 15 to 45 days after flowering, nocturnal CO2 uptake per unit area of the fruit averaged 19 of that of cladodes and then declined, as did the chlorophyll content and the activity of the CO2-fixing enzymes. Fruit growth for O. ficus-indica was supported by the bearing cladode as well as other cladodes, especially for cladodes with more than 5 fruit. C1 UNIV CALIF LOS ANGELES,DEPT BIOL,LOS ANGELES,CA 90024. UNIV REGGIO CALABRIA,ICLAF,I-89061 REGGIO CALABRIA,ITALY. UNIV CALIF LOS ANGELES,UCLA DOE LAB,LOS ANGELES,CA 90024. OI Inglese, Paolo/0000-0001-7394-4633 NR 31 TC 30 Z9 31 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0031-9317 J9 PHYSIOL PLANTARUM JI Physiol. Plant. PD AUG PY 1994 VL 91 IS 4 BP 708 EP 714 DI 10.1034/j.1399-3054.1994.910423.x PG 7 WC Plant Sciences SC Plant Sciences GA PB337 UT WOS:A1994PB33700023 ER PT J AU CHENG, J MOSS, SC EISNER, M ZSCHACK, P AF CHENG, J MOSS, SC EISNER, M ZSCHACK, P TI X-RAY CHARACTERIZATION OF MELANINS .1. SO PIGMENT CELL RESEARCH LA English DT Article DE X-RAY DIFFRACTION; COMPTON SCATTERING; ELASTIC SCATTERING; MULTIPLE SCATTERING; ATOMIC SCATTERING FACTOR; SCATTERING WAVE VECTOR; STRUCTURE FACTOR; RADIAL DISTRIBUTION FUNCTION AB The intrinsic local structure characterization of natural sepia melanin and L-dopa and tyrosine synthetic melanin powder has been carried out by X-ray diffraction using synchrotron radiation. The derived structure factor, S(q), shows six significant diffuse peaks within the q-range from 0.3 Angstrom(-1) to 16 Angstrom(-1) in the reciprocal space (q = (4 pi sin theta)/lambda, 2 theta is the scattering angle). The Fourier transform of S(q), which yields the radial distribution function (RDF), gives us information in real space of a 1.42 Angstrom distance averaged over the C-C, C-O and C-N bond lengths as well as peaks at 2.40-2.41 Angstrom, 3.67-3.71 Angstrom and 4.67-4.70 Angstrom discrete neighbor distances. There is a great similarity in the scattering intensity profiles of the natural and synthetic melanins indicating that the synthetically prepared material may be essentially similar to ''real'' melanin in its local atomic arrangements. An evidence of a prepeak at q similar or equal to 0.45 Angstrom(-1) has been confirmed which indicates a preferred length scale of similar to 13-20 Angstrom that corresponds to the initial particle size in colloidal melanin solutions. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. BROOKHAVEN NATL LAB,ORAU,NSLS,UPTON,NY 11973. NR 26 TC 72 Z9 74 U1 1 U2 12 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0893-5785 J9 PIGM CELL RES JI Pigm. Cell. Res. PD AUG PY 1994 VL 7 IS 4 BP 255 EP 262 DI 10.1111/j.1600-0749.1994.tb00060.x PG 8 WC Cell Biology; Dermatology SC Cell Biology; Dermatology GA PL618 UT WOS:A1994PL61800012 PM 7855074 ER PT J AU GAL, S RAIKHEL, NV AF GAL, S RAIKHEL, NV TI A CARBOXY-TERMINAL PLANT VACUOLAR TARGETING SIGNAL IS NOT RECOGNIZED BY YEAST SO PLANT JOURNAL LA English DT Note ID BARLEY LECTIN; SACCHAROMYCES-CEREVISIAE; ENDOPLASMIC-RETICULUM; PROTEIN SECRETION; XENOPUS-LAEVIS; PROPEPTIDE; TOBACCO; CELLS; LOCALIZATION; TRANSPORT AB Three different classes of signals for plant vacuolar targeting have been defined. Previous work has demonstrated that the carboxyl-terminal propeptide (CTPP) of barley lectin (BL) is a vacuolar targeting signal in tobacco plants. When a mutant BL protein lacking the CTPP is expressed in tobacco, the protein is secreted. In an effort to determine the universality of this signal, the CTPP was tested for its ability to target proteins to the vacuole of Saccharomyces cerevisiae. Genes encoding fusion proteins between the yeast secreted protein invertase and BL domains were synthesized and transformed into an invertase deletion mutant of yeast. Invertase assays on intact and detergent-solubilized cells demonstrated that invertase+CTPP was secreted, while nearly 90% of the invertase::BL+CTPP (fusion protein between invertase and BL containing the CTPP) and invertase::BL-CTPP proteins (fusion between invertase and BL lacking the CTPP) were retained intracellularly. These fusions were secreted in a mutant of yeast that normally secretes proteins targeted to the vacuole. With this and previous work, proteins representing all three classes of plant vacuolar targeting signals have now been tested in yeast, and in all cases, the experiments indicate that the plant proteins are directed to the yeast vacuole using signals other than those recognized by plants. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 50 TC 18 Z9 18 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0960-7412 J9 PLANT J JI Plant J. PD AUG PY 1994 VL 6 IS 2 BP 235 EP 240 DI 10.1046/j.1365-313X.1994.6020235.x PG 6 WC Plant Sciences SC Plant Sciences GA PB718 UT WOS:A1994PB71800010 PM 7920713 ER PT J AU LAROCHE, J WYMAN, K FALKOWSKI, PG AF LAROCHE, J WYMAN, K FALKOWSKI, PG TI A CDNA FOR DUNALIELLA-TERTIOLECTA CYTOSOL RIBOSOMAL-PROTEIN S11 SO PLANT PHYSIOLOGY LA English DT Note RP LAROCHE, J (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. RI LaRoche, Julie/A-1109-2010 NR 5 TC 0 Z9 2 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD AUG PY 1994 VL 105 IS 4 BP 1447 EP 1448 DI 10.1104/pp.105.4.1447 PG 2 WC Plant Sciences SC Plant Sciences GA PC568 UT WOS:A1994PC56800055 PM 7972505 ER PT J AU KALLENBACH, A FUSSMANN, G MAYER, HM PITCHER, S AF KALLENBACH, A FUSSMANN, G MAYER, HM PITCHER, S TI THE INFLUENCE OF SPATIALLY AND TEMPORALLY VARYING EDGE CONDITIONS ON THE INTERPRETATION OF SPECTROSCOPIC FLUX MEASUREMENTS SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID ASDEX; TURBULENCE; TRANSPORT; TOKAMAKS AB The influence of plasma parameter variations on the interpretation of spectroscopic flux measurements in terms of particle fluxes is investigated by analytical and numerical methods. In addition to the temperature and density dependence of the local photon efficiencies, transport processes and spatial shifts of the source distribution result in variations of the effective photon yields which are used to interpret measurements. Parameter studies for typical variations of edge conditions of the ASDEX Upgrade tokamak reveal changes by a factor of 3 for the ratio of the particle influx and corresponding photon flux. If fast temporal changes of the plasma density occur, the photon emission basically follows the density fluctuations for frequencies higher than the inverse ionization time, while the fluctuating part of the photon flux is damped for lower frequencies. C1 PPPL,PRINCETON,NJ. CFFTP,TORONTO,ON,CANADA. RP KALLENBACH, A (reprint author), MAX PLANCK INST PLASMA PHYS,EURATOM ASSOC,D-85748 GARCHING,GERMANY. NR 12 TC 4 Z9 4 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD AUG PY 1994 VL 36 IS 8 BP 1299 EP 1306 DI 10.1088/0741-3335/36/8/005 PG 8 WC Physics, Fluids & Plasmas SC Physics GA PC284 UT WOS:A1994PC28400005 ER PT J AU Buss, RJ Hareland, WA AF Buss, Richard J. Hareland, Willard A. TI Gas phase particulate formation in radiofrequency fluorocarbon plasmas SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article AB The production, suspension and transport of fluorocarbon particulates in capacitively coupled radiofrequency discharges are studied using in situ laser light scattering and ex situ chemical analysis. The time evolution of the spatial distribution of suspended palticles is obtained by two-dimensional imaging of the scattered light. The chemistry of the discharge is varied by use of a range of pure fluorocarbon gases and mixtures with argon, oxygen and hydrogen-containing molecules. Addition of hydrogen to a fluorocarbon discharge increases the rate of formation of particles although these powders are found by Fourier transform infrared measurements to contain negligible amounts of hydrogen. Particle formation rates correlate with polymer deposition rates and are independent of apparatus history. It is proposed that this is a, clear example of gas phase rather than surface processes leading to particle nucleation and growth. C1 [Buss, Richard J.; Hareland, Willard A.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Buss, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 16 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD AUG PY 1994 VL 3 IS 3 BP 268 EP 272 DI 10.1088/0963-0252/3/3/005 PG 5 WC Physics, Fluids & Plasmas SC Physics GA V10QD UT WOS:000207477600005 ER PT J AU Anderson, HM Radovanov, S Mock, JL Resnick, PJ AF Anderson, Harold M. Radovanov, Svetlana Mock, Joseph L. Resnick, Paul J. TI Particulates in C(2)F(6)-CHF(3) and CF(4)-CHF(3) etching plasmas SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article AB Particulate generation has been studied during reactive-ion etching of oxide wafers in C(2)F(6)-CHF(3) and CF(4)-HF(3) plasmas using both a commercial etch tool and the GEC reference cell modified to resemble the commercial tool. Under certain discharge process conditions, copious amounts of submicrometre-sized particles are shown to form due to plasma interactions with the oxide substrate. In the commercial tool. particles were detected only by a downstream particle flux monitor, whereas in the reference cell, particles were observed by both in situ laser light scattering and downstream monitoring. in the commercial tool, wafers etched to end-point were shown by post-process surface analysis to be contaminated by submicrometre-sized columnar structures. Previous reports of similar such columnar structures formed during reactive-ion etching of oxide films have attributed the phenomenon to polymer micromasking. However, the results of this study clearly contradict this conclusion and suggest that the presence of columnar oxide etch residues is linked to process-induced particulate contamination. Laser light scattering measurements were made in the reference cell during reactive-ion etching of blanket oxide wafers and used to help clarify the complex processes of particulate nucleation, growth and deposition during oxide etching. Polarization coagulation of spherical particles formed in the reference cell is shown to occur, presumably in the high-field regions of the sheath, forming filamentous rod-like particle aggregates. The implications of this observation for wafer contamination are explored. C1 [Anderson, Harold M.; Radovanov, Svetlana; Mock, Joseph L.] Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. [Resnick, Paul J.] Sandia Natl Labs, Silicon Technol Dept, Albuquerque, NM 87185 USA. RP Anderson, HM (reprint author), Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. NR 15 TC 22 Z9 22 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD AUG PY 1994 VL 3 IS 3 BP 302 EP 309 DI 10.1088/0963-0252/3/3/010 PG 8 WC Physics, Fluids & Plasmas SC Physics GA V10QD UT WOS:000207477600010 ER PT J AU Blain, MG Tipton, GD Holber, WM Selwyn, GS Westerfield, PL Maxwell, KL AF Blain, M. G. Tipton, G. D. Holber, W. M. Selwyn, G. S. Westerfield, P. L. Maxwell, K. L. TI Particle behavior in an electron cyclotron resonance plasma etch tool SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article AB Sources of particles in a closed-coupled electron cyclotron resonance plasma source used for polysilicon etch included flaking of a residual film deposited on chamber surfaces and shedding of material from the electrostatic wafer chuck. A large. episodic increase in the number of particles added to a wafer in a clean system is observed more frequently for a plasma-on than for a gas-only source condition. For film-forming process conditions, particles were added to wafers by a residual film, which was observed to fracture and flake away from chamber surfaces. The presence of a plasma, especially when radiofrequency bias is applied to the wafer, caused more particles to be ejected from the walls and added to wafers than the microwave powers. A study of the effect of electrode temperatures on particles added showed that thermophoretic and gravitational forces are not significant for this electron cyclotron resonance operating configuration. Particles originating from the electrostatic chuck were observed to be deposited on wafers in much larger numbers in the presence of the plasma as compared with gas-only conditions, implying the existence of a large ion drag force. C1 [Blain, M. G.; Tipton, G. D.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Holber, W. M.; Selwyn, G. S.] IBM Corp, Div Res, Yorktown Hts, NY 10598 USA. [Westerfield, P. L.; Maxwell, K. L.] SEMATECH, Austin, TX 78741 USA. RP Blain, MG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 11 Z9 11 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD AUG PY 1994 VL 3 IS 3 BP 325 EP 333 DI 10.1088/0963-0252/3/3/014 PG 9 WC Physics, Fluids & Plasmas SC Physics GA V10QD UT WOS:000207477600014 ER PT J AU Rader, DJ Geller, AS AF Rader, Daniel J. Geller, Anthony S. TI Particle transport modelling in semiconductor process environments SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article AB We review our recent efforts to develop and apply computational models that can predict fluid, thermal and particle transport in semiconductor process equipment such as that used for chemical vapour deposition or plasma etching. The purpose of this work is to supply equipment designers and operators with models that allow them to optimize process conditions and to develop tool designs that reduce panicle contamination levels. The algorithms for predicting particle transport are briefly described. A Lagrangian approach is used in this work when both particle inertia and applied forces are important, while a Eulerian approach is sed when both particle Brownian motion and applied forces are important. As an example, a commercial finite-element code is used to calculate the fluid and thermal fields : in a simple geometry representative of real single-wafer processing tools, namely axisymmetric flow between a showerhead and a parallel plate separated by a small gap. Using the calculated velocity field, both Lagrangian and Eulerian particle transport formulations give the same panicle collection efficiency for terminal-velocity-dominated deposition when particle inertia can be neglected. Although plasma-induced forces on the particles are not Treated in detail, we discuss how models for these forces can be incorporated into the Lagrangian and Euler: an framework as they become available. C1 [Rader, Daniel J.; Geller, Anthony S.] Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP Rader, DJ (reprint author), Sandia Natl Labs, Engn Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 27 Z9 27 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD AUG PY 1994 VL 3 IS 3 BP 426 EP 432 DI 10.1088/0963-0252/3/3/028 PG 7 WC Physics, Fluids & Plasmas SC Physics GA V10QD UT WOS:000207477600028 ER PT J AU SIMPSON, RL PAGORIA, PF MITCHELL, AR COON, CL AF SIMPSON, RL PAGORIA, PF MITCHELL, AR COON, CL TI SYNTHESIS, PROPERTIES AND PERFORMANCE OF THE HIGH EXPLOSIVE ANTA SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB 3-Amino-5-nitro-1,2,4-triazole (ANTA) was prepared and evaluated in terms of insensitivity and performance. The material is very insensitive to impact and moderately so to thermal stimuli. Performance was found to be inferior to 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). The best synthesis of ANTA is a three-step route using commercially available 3,5-diamino-1,2,4-triazole. RP SIMPSON, RL (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 11 TC 39 Z9 41 U1 3 U2 13 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD AUG PY 1994 VL 19 IS 4 BP 174 EP 179 DI 10.1002/prep.19940190405 PG 6 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA QD844 UT WOS:A1994QD84400004 ER PT J AU VONHOLTZ, E ORNELLAS, D FOLTZ, MF CLARKSON, JE AF VONHOLTZ, E ORNELLAS, D FOLTZ, MF CLARKSON, JE TI THE SOLUBILITY OF EPSILON-CL-20 IN SELECTED MATERIALS SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB The solubiliy of the epsilon polymorph of CL-20 was determined in thirteen liquids over the temperature range of ambient to 74 degrees C using high performance liquid chromatography. The experiments included epsilon-CL-20 produced by two different synthesis routes; one lot contained a higher level of polymorphic impurity, the other lot contained a higher level of non-CL-20 impurity. In general, the epsilon-CL-20 was found to be highly soluble in the solvents with carbonyl groups, and relatively insoluble in hydrocarbons and materials containing ether linkages. The amount of phase conversion to gamma-CL-20 which occurred during the solubility testing was measured using FTIR, and ranged from essentially zero to similar to 10% conversion. It appears that the presence of beta-CL-20 in the virgin epsilon-CL-20 lots will affect the amount of gamma-phase present in the final residue. RP VONHOLTZ, E (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 10 TC 19 Z9 21 U1 0 U2 4 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD AUG PY 1994 VL 19 IS 4 BP 206 EP 212 DI 10.1002/prep.19940190410 PG 7 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA QD844 UT WOS:A1994QD84400009 ER PT J AU LIU, HC CHOU, P LIN, KN WANG, SJ FUH, JL LIN, HC LIU, CY WU, GS LARSON, EB WHITE, LR GRAVES, AB TENG, EL AF LIU, HC CHOU, P LIN, KN WANG, SJ FUH, JL LIN, HC LIU, CY WU, GS LARSON, EB WHITE, LR GRAVES, AB TENG, EL TI ASSESSING COGNITIVE-ABILITIES AND DEMENTIA IN A PREDOMINANTLY ILLITERATE POPULATION OF OLDER INDIVIDUALS IN KINMEN SO PSYCHOLOGICAL MEDICINE LA English DT Article ID MINI-MENTAL STATE; ALZHEIMERS-DISEASE; EDUCATION; PREVALENCE; SHANGHAI; SCALE AB A community survey of dementia was conducted on a Chinese islet. A total of 221 men and 234 women in the age range of 50-92 were assessed. The Cognitive Abilities Screening Instrument (CASI), a 100-point cognitive test designed for cross-cultural studies and adapted in Chinese for individuals with little or no formal education, was administered twice by trained field workers with a retest interval of 3 to 4 weeks. In addition, all participants were assessed by physicians who did not know the CASI scores. The physicians' assessment included a complete neurological examination, plus semi-structured tests and interviews covering cognitive abilities, daily activities, depression, cerebrovascular disease, and Parkinson's disease. Dementia was diagnosed by consensus among the physicians according to the DSM-III-R criteria. Among the 455 participants, 16 cases of dementia were identified, including 13 with probable Alzheimer's disease and 1 each with vascular dementia, Parkinson's disease, and alcoholism. The rates of dementia were 0, 3.9 and 11.5% for the age groups of 50-69, 70-79 and 80-92; and 4.4, 2.0 and 0% for the education groups of 0-1, 2-6 and 7-15 years of schooling. No sex difference was found after controlling for education. The Chinese version of the CASI had an intraclass retest reliability of 0.90. Using a cut-off score of less than or equal to 50 for dementia, the sensitivity was 0.88 and the specificity was 0.94. The preliminary study suggests that the CASI can be used in Chinese populations with generally low education levels and that Alzheimer's disease was the most common type of dementia in this population. C1 NATL YANG MING MED COLL,INST PUBL HLTH,TAIPEI 11221,TAIWAN. CHANG GUNG MEM HOSP,DEPT PSYCHIAT,TAIPEI 10591,TAIWAN. BUR PUBL HLTH & ENVIRONM PROTECT,KINMEN,PEOPLES R CHINA. UNIV WASHINGTON,DEPT MED EPIDEMIOL & HLTH SERV,SEATTLE,WA. BATTELLE SEATTLE RES CTR,SEATTLE,WA. NIA,HONOLULU ASIA AGING STUDY,HONOLULU,HI. UNIV SO CALIF,SCH MED,DEPT NEUROL,LOS ANGELES,CA 90033. RP LIU, HC (reprint author), VET GEN HOSP,INST NEUROL,TAIPEI,TAIWAN. OI Fuh, Jong-Ling/0000-0001-9135-3351 NR 24 TC 88 Z9 92 U1 1 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0033-2917 J9 PSYCHOL MED JI Psychol. Med. PD AUG PY 1994 VL 24 IS 3 BP 763 EP 770 PG 8 WC Psychology, Clinical; Psychiatry; Psychology SC Psychology; Psychiatry GA PE052 UT WOS:A1994PE05200023 PM 7991758 ER PT J AU WILKINSON, SR SMITH, AV AF WILKINSON, SR SMITH, AV TI GAIN WITHOUT INVERSION IN 4 LEVEL ATOMS USING PULSED LASERS SO QUANTUM OPTICS LA English DT Article AB We present results of a numerical calculation of gain without inversion in the transient regime. We show that atomic coherence and gain without population inversion can be induced on time scales short compared to atomic radiative lifetimes. We also describe the process in terms of transient dressed states. RP WILKINSON, SR (reprint author), SANDIA NATL LABS,DEPT OPT & REMOTE SENSING,ALBUQUERQUE,NM 87185, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-8998 J9 QUANTUM OPT PD AUG PY 1994 VL 6 IS 4 BP 317 EP 325 DI 10.1088/0954-8998/6/4/009 PG 9 WC Optics; Physics, Applied SC Optics; Physics GA PD672 UT WOS:A1994PD67200010 ER PT J AU RYDBERG, B LOBRICH, M COOPER, PK AF RYDBERG, B LOBRICH, M COOPER, PK TI DNA DOUBLE-STRAND BREAKS INDUCED BY HIGH-ENERGY NEON AND IRON IONS IN HUMAN FIBROBLASTS .1. PULSED-FIELD GEL-ELECTROPHORESIS METHOD SO RADIATION RESEARCH LA English DT Article ID RADIATION-SENSITIVE PHENOTYPE; INDUCED SINGLE-STRAND; HAMSTER CELL MUTANT; IONIZING-RADIATION; ALPHA-PARTICLES; MAMMALIAN-CELLS; X-RAYS; RELATIVE CONTRIBUTIONS; CHEF ELECTROPHORESIS; FILTER ELUTION AB The relative effectiveness of high-energy neon and iron ions for the production of DNA double-strand breaks was measured in one transformed and one nontransformed human fibroblast cell line using pulsed-field.gel electrophoresis. The DNA released from the gel plug (fraction of activity released: FAR) as well as the size distribution of the DNA entering the gel were used to compare the effects of the heavy-ion exposure with X-ray exposure. Both methods gave similar results, indicating similar distributions of breaks over megabase-pair distances for the heavy ions and the X rays. The relative biological effectiveness (RBE) compared to 225 kVp X rays of initially induced DNA double-strand breaks was found to be 0.85 for 425 MeV/u neon ions (LET 32 keV/mu m) and 0.42-0.55 for 250-600 MeV/u iron ions (LET 190-350 keV/mu m). Postirradiation incubation showed less efficient repair of breaks induced by the neon ions and the 600 MeV/u iron ions compared to X rays. Survival experiments demonstrated RBE values larger than one for cell killing by the heavy ions in parallel experiments (neon: RBE = 1.2, iron: RBE = 2.3-3.0, based on D-10 values). It is concluded that either the initial yield of DNA double-strand breaks induced by the high-energy particles is lower than the yield for X rays, or the breaks induced by heavy ions are present in clusters that cannot be resolved with the technique used. These results are confirmed in the accompanying paper (M. Lobrich, B. Rydberg and P. Cooper, Radiat. Res. 139, 142-151, 1994). RP RYDBERG, B (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BLDG 934,BERKELEY,CA 94720, USA. NR 47 TC 90 Z9 99 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1994 VL 139 IS 2 BP 133 EP 141 DI 10.2307/3578657 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA NZ316 UT WOS:A1994NZ31600001 PM 8052688 ER PT J AU LOBRICH, M RYDBERG, B COOPER, PK AF LOBRICH, M RYDBERG, B COOPER, PK TI DNA DOUBLE-STRAND BREAKS INDUCED BY HIGH-ENERGY NEON AND IRON IONS IN HUMAN FIBROBLASTS .2. PROBING INDIVIDUAL NOTI FRAGMENTS BY HYBRIDIZATION SO RADIATION RESEARCH LA English DT Article ID FIELD GEL-ELECTROPHORESIS; IONIZING-RADIATION; HUMAN CHROMOSOME-21; ALPHA-PARTICLES; CHEF ELECTROPHORESIS; V(D)J RECOMBINATION; MAMMALIAN-CELLS; PULSED-FIELD; REPAIR; MUTANTS AB The initial yields of DNA double-strand breaks induced by energetic heavy ions (425 MeV/u neon and 250, 400 and 600 MeV/u iron) in comparison to X rays were measured in normal human diploid fibroblast cells within three small areas of the genome, defined by NotI fragments of 3.2, 2.0 and 1.2 Mbp. The methodology involves NotI restriction endonuclease digestion of DNA from irradiated cells, followed by pulsed-field gel electrophoresis, Southern blotting and hybridization;with probes recognizing single-copy sequences within the three NotI fragments. The gradual disappearance of the full-size NotI fragment with dose and the appearance of a smear of broken DNA molecules are quantified. Assuming Poisson statistics for the number of double-strand breaks induced per NotI fragment of known size, absolute yields of DNA double-strand breaks were calculated and determined to be linear with dose in all cases, with the neon ion (LET 32 keV/mu m) producing 4.4 x 10(-3) breaks/Mbp/Gy and all three ironion beams (LETs from 190 to 350 keV/mu m) producing 2.8 x 10(-3) breaks/Mbp/Gy, giving RBE values for production of double-strand breaks of 0.76 for neon and 0.48 for iron in comparison to our previously determined X-ray induction rate of 5.8 x 10(-3) breaks/Mbp/Gy. These RBE values are in good agreement with results of measurements over the whole genome as reported in the accompanying paper (B. Rydberg, M. Lobrich and P. Cooper, Radiat. Res. 139, 133-141, 1994). The distribution of broken DNA molecules was similar for the various radiations, supporting a random distribution of double-strand breaks induced by the heavy ions over Mbp distances; however, correlated breaks (clusters) over much smaller distances are not ruled out. Reconstitution of the 3.2 Mbp NotI fragment was studied during postirradiation incubation of the cells as a measure of rejoining of correct DNA ends. The proportion of breaks repaired decreased with increasing LET. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. NR 41 TC 45 Z9 45 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD AUG PY 1994 VL 139 IS 2 BP 142 EP 151 DI 10.2307/3578658 PG 10 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA NZ316 UT WOS:A1994NZ31600002 PM 8052689 ER PT J AU MORRIS, GM CODERRE, JA HOPEWELL, JW MICCA, PL REZVANI, M AF MORRIS, GM CODERRE, JA HOPEWELL, JW MICCA, PL REZVANI, M TI RESPONSE OF RAT SKIN TO BORON NEUTRON-CAPTURE THERAPY WITH P-BORONOPHENYLALANINE OR BOROCAPTATE SODIUM SO RADIOTHERAPY AND ONCOLOGY LA English DT Article DE BNCT; BORON PHARMACOKINETICS; SKIN TOLERANCE; RBE; COMPOUND BIOLOGICAL EFFECTIVENESS FACTOR ID RELATIVE BIOLOGICAL EFFECTIVENESS; MURINE MELANOMA; TUMORS; GLIOSARCOMAS; BRAIN AB The effects of boron neutron capture irradiation employing either BPA or BSH as neutron capture agents has been assessed using the dorsal skin of Fischer 344 rats. Pharmacokinetic studies, using prompt gamma spectrometry, revealed comparable levels of boron-10 (B-10) in blood and skin after the intravenous infusion of BSH (100 mg/kg body wt.). The B-10 content of blood (12.0 +/- 0.5 mu g/g) was slightly hig her than that of skin (10.0 +/- 0.5 mu g/g) after oral dosing with BPA. Biphasic skin reactions were observed after irradiation with the thermal neutron beam alone or in combination with BPA or BSH. The time of onset of the first phase of the skin reaction, moist desquamation, was similar to 2 weeks. The time at which the second-wave skin reaction, dermal necrosis, became evident was dose-related and occurred after a latent interval of greater than or equal to 24 weeks, well after the acute epithelial reaction had healed. The incidence of both phases of skin damage was also dose-related. The radiation doses required to produce skin damage in 50% of skin sites (ED(50) values) were calculated from dose-effect curves and these values were used to determine relative biological effectiveness (RBE) and compound biological effectiveness (CBE) factors for both moist desquamation and dermal necrosis. It was concluded on the basis of these calculations that the microdistribution of the two neutron capture agents had a critical bearing on the overall biological effect after thermal neutron activation. BSH, which was possibly excluded from the cytoplasm of epidermal cells, had a low CBE factor value (0.56 +/- 0.06) while BPA, which may be selectively accumulated in epidermal cells had a very high CBE factor (3.74 +/- 0.7). For the dermal reaction, where vascular endothelial cells represent the likely target cell population, the CBE factor values were comparable, at 0.73 +/- 0.42 and 0.86 +/- 0.08 for BPA ad BSH, respectively. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP MORRIS, GM (reprint author), UNIV OXFORD,CHURCHILL HOSP,RES INST,CRC,NORMAL TISSUE RADIOBIOL RES GRP,S PARKS RD,OXFORD OX3 7LJ,ENGLAND. NR 37 TC 37 Z9 39 U1 0 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0167-8140 J9 RADIOTHER ONCOL JI Radiother. Oncol. PD AUG PY 1994 VL 32 IS 2 BP 144 EP 153 DI 10.1016/0167-8140(94)90101-5 PG 10 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA PJ735 UT WOS:A1994PJ73500008 PM 7972908 ER PT J AU KAZMERSKI, LL AF KAZMERSKI, LL TI ARRAYS TO ATOMS - THE RANGE, EVOLUTION, AND FRONTIERS OF CHARACTERIZATION SO RENEWABLE ENERGY LA English DT Article; Proceedings Paper CT World Renewable Energy Congress - Climate Change, Energy and the Environment CY SEP 11-16, 1994 CL READING, ENGLAND DE PHOTOVOLTAICS; MEASUREMENTS; CHARACTERIZATION; PERFORMANCE; MICROANALYSIS; NANOCHARACTERIZATION ID SCANNING TUNNELING MICROSCOPY; SURFACES; SCALE; STM AB Characterization is one important component in the ensemble of photovoltaics research and development efforts. It has supported the evolution of the technology, and measurement techniques have themselves evolved in response to the technology's needs. This paper highlights some important evaluation and verification techniques, covering macroscale through nanooscale characterization methods. Some emphasis is placed upon the lower spatial resolution regimes, in which the characterization and processing of semiconductors are leading to areas of atomic engineering of materials. RP KAZMERSKI, LL (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD AUG PY 1994 VL 5 IS 1-4 BP 107 EP 117 DI 10.1016/0960-1481(94)90360-3 PG 11 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA PU945 UT WOS:A1994PU94500014 ER PT J AU KAZMERSKI, LL EMERY, KA DEBLASIO, R AF KAZMERSKI, LL EMERY, KA DEBLASIO, R TI EVALUATION AND DIRECTIONS OF THE PHOTOVOLTAIC TECHNOLOGIES SO RENEWABLE ENERGY LA English DT Article; Proceedings Paper CT World Renewable Energy Congress - Climate Change, Energy and the Environment CY SEP 11-16, 1994 CL READING, ENGLAND DE PHOTOVOLTAICS; CELLS; MODULE; PERFORMANCE; EFFICIENCY; RESEARCH; COMMERCIALIZATION ID SOLAR-CELLS AB The status of, directions, and expectations for the photovoltaic technologies are discussed and updated, with emphasis on the performances of cells and modules used in various research and commercial solar cell approaches. Current and projected research and development directions are indicated. Special aspects of the current evolution of photovoltaics from the research laboratory to the commercial arena are discussed, including new programs directed to make this energy resource a viable electricity choice for users worldwide. RP KAZMERSKI, LL (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 42 TC 4 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD AUG PY 1994 VL 5 IS 1-4 BP 252 EP 267 DI 10.1016/0960-1481(94)90381-6 PG 16 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA PU945 UT WOS:A1994PU94500035 ER PT J AU WINSTON, R JENKINS, D OGALLAGHER, J LANDO, M BERNSTEIN, H LEWANDOWSKI, A AF WINSTON, R JENKINS, D OGALLAGHER, J LANDO, M BERNSTEIN, H LEWANDOWSKI, A TI APPLICATIONS OF ULTRA-HIGH SOLAR FLUX SO RENEWABLE ENERGY LA English DT Article; Proceedings Paper CT World Renewable Energy Congress - Climate Change, Energy and the Environment CY SEP 11-16, 1994 CL READING, ENGLAND DE NONIMAGING OPTICS; SOLAR LASERS; HIGH FLUX; FULLERENES AB Nonimaging optics provides a means of concentrating light to intensities approaching the theoretical limit. In experiments at the University of Chicago, we measured a concentration of 84,000 using a sapphire concentrator. We are currently scaling up our experiments at the National Renewable Energy Laboratory in Golden, Colorado. Our goals include a) measuring 50,000 suns using a borosilicate concentrator with total power collected approaching one kW, b) producing fullerenes by vaporizing carbon, and c) pumping solid state lasers using a side-pumping arrangement. Preliminary results indicate that we have delivered 50,000 suns through an aperture using a concentrator of unique design. In this paper, we report on this measurement and current designs for fullerene production and laser pumping. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP WINSTON, R (reprint author), UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637, USA. NR 0 TC 0 Z9 0 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD AUG PY 1994 VL 5 IS 1-4 BP 368 EP 372 DI 10.1016/0960-1481(94)90398-0 PG 5 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA PU945 UT WOS:A1994PU94500052 ER PT J AU BULL, SR AF BULL, SR TI RENEWABLE ALTERNATIVE FUELS - ALCOHOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS SO RENEWABLE ENERGY LA English DT Article; Proceedings Paper CT World Renewable Energy Congress III - Climate Change, Energy and the Environment CY SEP 11-16, 1994 CL READING, ENGLAND DE RENEWABLE FUELS; ALTERNATIVE FUELS; ALCOHOL PRODUCTION; LIGNOCELLULOSE; BIOMASS ENERGY AB Advances in renewable alternative biomass-based fuel technologies make their commercialization likely within a decade. Substituting fuels derived from biomass for fossil fuels can reduce dependence on petroleum use, improve air quality, mitigate global warming, and strengthen a weak farm economy. Implementation of the Clean Air Act Amendments of 1990 increased the oxygenate content in gasoline, providing greater market opportunities for alcohols-as direct blends and to produce ethers such as ETBE and MTBE. Alcohol production from lignocellulosic biomass is promising, leading to renewable, alternative transportation fuels that are projected to be competitive as pure fuels with fuels derived from petroleum at $20-$25/bbl ($0.13-$0.16/liter) within the next 5 to 10 years. However, the timeframe for deployment depends not only on the development of technologies, but also on the active involvement of appropriate industries. Industrial partnerships have been formed, and commericalization strategy is well under way; process development units at the pilot scale are both operating and under construction in the United States. Alliances between industry and the government include agreements to proceed with scale-up to engineering development units and eventually to commercial-scale plants. RP BULL, SR (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 3 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD AUG PY 1994 VL 5 IS 5-8 BP 799 EP 806 DI 10.1016/0960-1481(94)90091-4 PG 8 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA PU947 UT WOS:A1994PU94700013 ER PT J AU CHEN, GY WARMACK, RJ THUNDAT, T ALLISON, DP HUANG, A AF CHEN, GY WARMACK, RJ THUNDAT, T ALLISON, DP HUANG, A TI RESONANCE RESPONSE OF SCANNING FORCE MICROSCOPY CANTILEVERS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A variational method is used to calculate the deflection and the fundamental and harmonic resonance frequencies of commercial V-shaped and rectangular atomic force microscopy cantilevers. The effective mass of V-shaped cantilevers is roughly half that calculated for the equivalent rectangular cantilevers. Damping by environmental gases, including air, nitrogen, argon, and helium, affects the frequency of maximum response and to a much greater degree the quality factor Q. Helium has the lowest viscosity, resulting in the highest Q, and thus provides the best sensitivity in noncontact force microscopy. Damping in liquids is dominated by an increase in effective mass of the cantilever due to an added mass of the liquid being dragged with that cantilever. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP CHEN, GY (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 15 TC 220 Z9 226 U1 2 U2 26 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1994 VL 65 IS 8 BP 2532 EP 2537 DI 10.1063/1.1144647 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC319 UT WOS:A1994PC31900016 ER PT J AU POLEWSKI, K KRAMER, SL KOLBER, ZS TRUNK, JG MONTELEONE, DC SUTHERLAND, JC AF POLEWSKI, K KRAMER, SL KOLBER, ZS TRUNK, JG MONTELEONE, DC SUTHERLAND, JC TI TIME-RESOLVED FLUORESCENCE USING SYNCHROTRON-RADIATION EXCITATION - A POWERED 4TH-HARMONIC CAVITY IMPROVES PULSE STABILITY SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ROSE-BENGAL; SPECTROSCOPY; FLUOROMETER; LIFETIMES; PHOTON; STATE AB The pulsed nature or ''time structure'' of synchrotron radiation from electron storage rings is used to measure the kinetics of the decay of electronically excited states and is particularly useful because the wavelength of excitation can be chosen at will. However, changes in the length of the pulses of radiation from a storage ring resulting from the gradual decrease of current circulating in the ring during the course of a ''fill'' limit the duration of data collection, and hence photometric sensitivity. A fourth-harmonic cavity that was recently added to the vacuum ultraviolet (VUV) storage ring at the National Synchrotron Light Source slows the loss of current during a fill, and thus increases the total number of photons produced. When operated in a passive (unpowered) mode, however, the fourth-harmonic cavity increases both the average width of the photon pulses and the changes in width that occur during a fill, thus reducing the usefulness of the VUV ring in timing experiments. We demonstrate that operating the fourth-harmonic cavity in an active (powered) mode, while further increasing pulse duration, can stabilize pulse width, thereby restoring timing capabilities. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. AGR UNIV,INST PHYS,POZNAN,POLAND. NR 21 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1994 VL 65 IS 8 BP 2562 EP 2567 DI 10.1063/1.1144651 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC319 UT WOS:A1994PC31900021 ER PT J AU WATT, RG OERTEL, J ARCHELUTA, T AF WATT, RG OERTEL, J ARCHELUTA, T TI GATED X-RAY IMAGER GAIN CORRECTION USING A TAPERED MICROCHANNEL-PLATE STRIPLINE SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Gated imagers used to record x-ray emission in the 1-5 keV range in laser-plasma interaction experiments have suffered from resistive gain degradation between voltage drive pulse input and output ends of a microchannel-plate stripline. The reduction in gain as the pulse travels down the strip results in a lower signal-to-background ratio in the last image on a strip than in the first image. Compensation for this gain nonuniformity using a tapered stripline in place of the normally straight striplines is discussed. RP WATT, RG (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 5 TC 10 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD AUG PY 1994 VL 65 IS 8 BP 2585 EP 2586 DI 10.1063/1.1144655 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA PC319 UT WOS:A1994PC31900025 ER PT J AU BOGEN, KT AF BOGEN, KT TI A NOTE ON COMPOUNDED CONSERVATISM SO RISK ANALYSIS LA English DT Note DE UNCERTAINTY; CONSERVATISM; SAFETY; LOGNORMAL; PROBABILITY ID RISK ASSESSMENT AB Compounded conservatism (or ''creeping safety'') describes the impact of using conservative, upper-bound estimates of the values of multiple input variates to obtain a conservative estimate of risk modeled as an increasing function of those variates. In a simple multiplicative model of risk, for example, if upper p-fractile (100pth percentile) values are used for each of several statistically independent input variates, the resulting risk estimate will be the upper p'-fractile of risk predicted according to that multiplicative model, where p' > p. The amount of compounded conservativism reflected by the difference between p' and p may be substantial, depending on the number of inputs, their relative uncertainties, and the value of p selected. Particular numerical examples of compounded conservatism are often cited, but an analytic approach may better serve to conceptualize and communicate its potential quantitative impact. This note briefly outlines such an approach and illustrates its application to the case of risk modeled as a product of lognormally distributed inputs. RP BOGEN, KT (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV HLTH & ECOL ASSESSMENT L-453,7000 E AVE,LIVERMORE,CA 94550, USA. NR 11 TC 26 Z9 27 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 379 EP 381 DI 10.1111/j.1539-6924.1994.tb00255.x PG 3 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100001 ER PT J AU MACINTOSH, DL SUTER, GW HOFFMAN, FO AF MACINTOSH, DL SUTER, GW HOFFMAN, FO TI USES OF PROBABILISTIC EXPOSURE MODELS IN ECOLOGICAL RISK ASSESSMENT OF CONTAMINATED SITES SO RISK ANALYSIS LA English DT Article DE UNCERTAINTY; ECOLOGICAL RISKS; FOOD WEB MODEL; MINK; HERON ID POLYCHLORINATED-BIPHENYLS; MINK; METHYLMERCURY; COMBINATION AB Food web models have two uses in assessments of environmental contaminants. First, they are used to determine whether remediation is needed by estimating exposure of end-point species and subsequent effects. Second, they are used to establish cleanup goals by estimating concentrations of contaminants in ambient media that will not cause significant effects. This paper demonstrates how achievement of these goals can be enhanced by the use of stochastic food web models. The models simulate the dynamics of PCBs and mercury in the food webs of mink and great blue herons. All parameters of the models are treated as having knowledge uncertainty, due to imperfect knowledge of the actual parameter values for the site, chemicals, and species of interest. This uncertainty is an indicator of the potential value of additional measurements. In addition, those parameters that are responsible for variance among individual organisms are assigned stochastic uncertainty. This uncertainty indicates the range of body burdens that are expected when the end-point species are monitored. These two types of uncertainty are separately accounted for in Monte Carlo simulations of the models. Preliminary monitoring results indicate that the models give reasonably good estimates of heron egg and nestling body burdens and of variance among individuals. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. SENES OAK RIDGE INC,CTR RISK ANAL,OAK RIDGE,TN. RP MACINTOSH, DL (reprint author), HARVARD UNIV,SCH PUBL HLTH,DEPT ENVIRONM HLTH,665 HUNTINGTON AVE,ROOM 1310,BOSTON,MA 02115, USA. NR 20 TC 41 Z9 44 U1 2 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 405 EP 419 DI 10.1111/j.1539-6924.1994.tb00259.x PG 15 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100005 ER PT J AU MCKONE, TE AF MCKONE, TE TI UNCERTAINTY AND VARIABILITY IN HUMAN EXPOSURES TO SOIL CONTAMINANTS THROUGH HOME-GROWN FOOD - A MONTE-CARLO ASSESSMENT SO RISK ANALYSIS LA English DT Article DE EXPOSURE; FOOD CHAINS; MONTE-CARLO; UNCERTAINTY; VARIABILITY; HOMEGROWN FOODS; MILK; MEAT; EGGS; VEGETABLES; FRUITS; GRAINS ID NON-IONIZED CHEMICALS; ORGANIC-CHEMICALS; PLANT-SURFACES; BIOCONCENTRATION; LIPOPHILICITY; BARLEY; BEEF AB This paper presents a general model for exposure to homegrown foods that is used with a Monte Carlo analysis to determine the relative contributions of variability (Type A uncertainty) and true uncertainty (Type B uncertainty) to the overall variance in prediction of the dose-to-concentration ratio. Although classification of exposure inputs as uncertain or variable is somewhat subjective, food consumption rates and exposure duration are judged to have a predicted variance that is dominated by variability among individuals by age, income, culture, and geographical region. Whereas, biotransfer factors and partition factors are inputs that, to a large extent, involve uncertainty. Using ingestion of fruits, vegetables, grains, dairy products, and meat and soils assumed to be contaminated by hexachlorbenzene (HCB) and benzo(a)pyrene (BaP) as cases studies, a Monte Carlo analysis is used to explore the relative contribution of uncertainty and variability to overall variance in the estimated distribution of potential dose within the population that consumes home-grown foods. It is found that, when soil concentrations are specified, variances in ratios of dose-to-concentration for HCB are equally attributable to uncertainty and variability, whereas for BaP, variance in these ratios is dominated by true uncertainty. C1 LAWRENCE LIVERMORE NATL LAB,RISK SCI PROGRAM,LIVERMORE,CA 94551. RP MCKONE, TE (reprint author), UNIV CALIF DAVIS,POB 808,L-453,LIVERMORE,CA 94551, USA. NR 43 TC 62 Z9 65 U1 3 U2 14 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 449 EP 463 DI 10.1111/j.1539-6924.1994.tb00263.x PG 15 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100009 PM 7972954 ER PT J AU HELTON, JC AF HELTON, JC TI TREATMENT OF UNCERTAINTY IN PERFORMANCE ASSESSMENTS FOR COMPLEX-SYSTEMS SO RISK ANALYSIS LA English DT Article DE LATIN HYPERCUBE SAMPLING; MONTE-CARLO ANALYSIS; PERFORMANCE ASSESSMENT; PROBABILISTIC RISK ASSESSMENT; SENSITIVITY ANALYSIS; STOCHASTIC UNCERTAINTY; SUBJECTIVE UNCERTAINTY; UNCERTAINTY ANALYSIS ID PROBABILISTIC RISK ASSESSMENTS; RADIOACTIVE-WASTE DISPOSAL; EPA RELEASE LIMITS; SENSITIVITY ANALYSIS; NUREG-1150; METHODOLOGY AB When viewed at a high level, performance assessments (PAs) for complex systems involve two types of uncertainty: stochastic uncertainty, which arises because the system under study can behave in many different ways, and subjective uncertainty, which arises from a lack of knowledge about quantities required within the computational implementation of the PA. Stochastic uncertainty is typically incorporated into a PA with an experimental design based on importance sampling and leads to the final results of the PA being expressed as a complementary cumulative distribution function (CCDF). Subjective uncertainty is usually treated with Monte Carlo techniques and leads to a distribution of CCDFs. This presentation discusses the use of the Kaplan/Garrick ordered triple representation for risk in maintaining a distinction between stochastic and subjective uncertainty in PAs for complex systems. The topics discussed include (1) the definition of scenarios and the calculation of scenario probabilities and consequences, (2) the separation of subjective and stochastic uncertainties, (3) the construction of CCDFs required in comparisons with regulatory standards (e.g., 40 CFR Part 191, Subpart B for the disposal of radioactive waste), and (4) the performance of uncertainty and sensitivity studies. Results obtained in a preliminary PA for the Waste Isolation Pilot Plant, an uncertainty and sensitivity analysis of the MACCS reactor accident consequence analysis model, and the NUREG-1150 probabilistic risk assessments are used for illustration. RP HELTON, JC (reprint author), SANDIA NATL LABS,DEPT 6342,ALBUQUERQUE,NM 87185, USA. NR 69 TC 138 Z9 140 U1 2 U2 11 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 483 EP 511 DI 10.1111/j.1539-6924.1994.tb00266.x PG 29 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100012 ER PT J AU NANSTAD, LD KRAMEL, RC AF NANSTAD, LD KRAMEL, RC TI ECOLOGY OF ENVIRONMENTAL PROFESSIONALS - HOWELL,DJ SO RISK ANALYSIS LA English DT Book Review RP NANSTAD, LD (reprint author), OAK RIDGE NATL LAB,DIV HLTH SCI RES,RISK ANAL SECT,POB 2008,105 MITCHELL RD,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 659 EP 660 PG 2 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100026 ER PT J AU WILBERT, KA AF WILBERT, KA TI ELEMENT OF RISK - THE POLITICS OF RADON - COLE,LA SO RISK ANALYSIS LA English DT Book Review C1 UNIV TENNESSEE,KNOXVILLE,TN 37916. RP WILBERT, KA (reprint author), OAK RIDGE NATL LAB,CTR RISK MANAGEMENT,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD AUG PY 1994 VL 14 IS 4 BP 659 EP 659 PG 1 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA PK031 UT WOS:A1994PK03100025 ER PT J AU CLARKE, J AF CLARKE, J TI SQUIDS SO SCIENTIFIC AMERICAN LA English DT Article C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. RP CLARKE, J (reprint author), UNIV CALIF BERKELEY,BERKELEY,CA, USA. NR 5 TC 22 Z9 23 U1 1 U2 9 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 SN 0036-8733 J9 SCI AM JI Sci.Am. PD AUG PY 1994 VL 271 IS 2 BP 46 EP 53 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA NX270 UT WOS:A1994NX27000018 ER PT J AU ALMAN, DE DOGAN, CP AF ALMAN, DE DOGAN, CP TI MICROSTRUCTURAL OBSERVATIONS OF MOSI2/SIC COMPOSITES FORMED IN-SITU FROM REACTIONS BETWEEN ELEMENTAL MO,SI POWDERS AND C-FIBERS SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID REINFORCED MOSI2; MOLYBDENUM RP ALMAN, DE (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 9 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD AUG 1 PY 1994 VL 31 IS 3 BP 273 EP 278 DI 10.1016/0956-716X(94)90282-8 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA NM940 UT WOS:A1994NM94000008 ER EF