FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Baskes, MI AF Baskes, MI TI Properties of a single asperity and the interface between molecular dynamics and continuum mechanics: A commentary SO LANGMUIR LA English DT Editorial Material RP Baskes, MI (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 18 PY 1996 VL 12 IS 19 BP 4535 EP 4536 DI 10.1021/la950892u PG 2 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VH414 UT WOS:A1996VH41400011 ER PT J AU Dabora, JM Pelton, JG Marqusee, S AF Dabora, JM Pelton, JG Marqusee, S TI Structure of the acid state of Escherichia coli ribonuclease HI SO BIOCHEMISTRY LA English DT Article ID MOLTEN GLOBULE STATE; 3-DIMENSIONAL HETERONUCLEAR NMR; HYDROGEN-EXCHANGE; ALPHA-LACTALBUMIN; FOLDING PATHWAY; PROTEINS; SPECTROSCOPY; INTERMEDIATE; SPECTRA; APOMYOGLOBIN AB Under acidic conditions Escherichia coli ribonuclease HI* (RNase H*) adopts a partially folded state with all of the properties of a molten globule. Using amide hydrogen exchange carried out under acid state conditions, followed by quenching and NMR detection on the native state, we have determined the residues that are responsible for the observed structure of the acid state. Although RNase H* is a mixed alpha + beta protein, a helical subdomain (helices A, D, and B) defines the structure of the acid state. This structure correlates with the rare higher energy conformations detected under native conditions and with data for the earliest intermediates populated in the kinetic folding pathway of the protein. C1 UNIV CALIF BERKELEY,DIV BIOCHEM & MOL BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,STRUCT BIOL DIV,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 50945] NR 41 TC 59 Z9 59 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 17 PY 1996 VL 35 IS 37 BP 11951 EP 11958 DI 10.1021/bi9611671 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VH070 UT WOS:A1996VH07000004 PM 8810899 ER PT J AU Radu, NS Buchwald, SL Scott, B Burns, CJ AF Radu, NS Buchwald, SL Scott, B Burns, CJ TI Carbon-hydrogen bond activation of aromatic imines by(Cp*2SmH)(2) SO ORGANOMETALLICS LA English DT Article ID CHIRAL TITANOCENE CATALYST; C-H ACTIVATION; HIGHLY REACTIVE ORGANOLANTHANIDES; RAY CRYSTAL-STRUCTURE; ASYMMETRIC HYDROGENATION; HYDROAMINATION CYCLIZATION; ZIRCONOCENE COMPLEXES; OLEFIN HYDROGENATION; INSERTION CHEMISTRY; MOLECULAR-STRUCTURE AB Treatment of (Cp*2SmH)(2) with 2-phenyl-1-pyrroline forms product 1, via ortho-metalation. Complex 1 was characterized spectroscopically and by single-crystal X-ray diffraction. The C-H bond activation reaction also occurs for acyclic aromatic ketimines and aldimines. C1 MIT,DEPT CHEM,CAMBRIDGE,MA 02139. LOS ALAMOS NATL LAB,INORGAN & STRUCT CHEM GRP,LOS ALAMOS,NM 87545. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 52 TC 26 Z9 26 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP 17 PY 1996 VL 15 IS 19 BP 3913 EP 3915 DI 10.1021/om960371h PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA VH293 UT WOS:A1996VH29300004 ER PT J AU Watson, JM Meyne, J Graves, JAM AF Watson, JM Meyne, J Graves, JAM TI Ordered tandem arrangement of chromosomes in the sperm heads of monotreme mammals SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE chromosome organization; in situ hybridization; platypus ID HUMAN X-CHROMOSOME; INSITU HYBRIDIZATION; NUCLEAR ARCHITECTURE; DNA-SEQUENCES; CELL-LINES; CONSERVATION; MARSUPIALS; EVOLUTION; (TTAGGG)N; MOVEMENT AB A very old unanswered question in classical cytology is whether chromosomes are arranged randomly in sperm or whether they occupy specific positions. Even with modern methods of chromosome painting, it is difficult to resolve this question for the very condensed and almost spherical sperm head of most mammals. We have taken advantage of the unusual fibrillar sperm head of monotreme mammals (echidna and platypus) to examine the position of chromosome landmarks in a two-dimensional array. We used fluorescence and radioactive in situ hybridization to telomeric, rDNA, acid unique sequences to show that chromosomes are arranged tandemly and in a defined order in the sperm nucleus. C1 LA TROBE UNIV,SCH GENET & HUMAN VARIAT,BUNDOORA,VIC 3083,AUSTRALIA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. RI Graves, Jennifer/A-1387-2008 NR 42 TC 25 Z9 25 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 17 PY 1996 VL 93 IS 19 BP 10200 EP 10205 DI 10.1073/pnas.93.19.10200 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VJ203 UT WOS:A1996VJ20300040 PM 8816776 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Gatley, SJ Ding, YS Logan, J Dewey, SL Hitzemann, R Lieberman, J AF Volkow, ND Wang, GJ Fowler, JS Gatley, SJ Ding, YS Logan, J Dewey, SL Hitzemann, R Lieberman, J TI Relationship between psychostimulant-induced ''high'' and dopamine transporter occupancy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE methylphenidate; positron-emission tomography; reinforcement; cocaine treatment ID NONHUMAN-PRIMATES; NUCLEUS-ACCUMBENS; COCAINE ABUSERS; HUMAN BRAIN; METHYLPHENIDATE; BINDING; PET; MAZINDOL; DRUGS AB The ability of cocaine to inhibit the dopamine transporter (DAT) appears to be crucial for its reinforcing properties, The potential use of drugs that produce longlasting inhibition of the DAT as a mean of preventing the ''high'' and reducing drug-seeking behavior has become a major strategy in medication development, However, neither the relation between the high and DAT inhibition nor the ability to block the high by prior DAT blockade have ever been demonstrated, To evaluate if DAT could prevent the high induced by methylphenidate (MP), a drug which like cocaine inhibits the DAT, we compared the responses in eight nondrug-abusing subjects between the first and the second of two MP doses (0.375 mg/kg, i.v.) given 60 min apart. At 60 min the high from MP has returned to baseline, but 75-80% of the drug remains in brain, Positron-emission tomography and [C-11]d-threo-MP were used to estimate DAT occupancies at different times after MP. DAT inhibition by MP did not block or attenuate the high from a second dose of MP given 60 min later, despite a 80% residual transporter occupancy from the first dose, Furthermore some subjects did not perceive a high after single or repeated administration despite significant DAT blockade. These results indicate that DAT occupancy is not sufficient to account for the high, and that for DAT inhibitors to be therapeutically effective, occupancies >80% may be required. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. HILLSIDE HOSP,GLEN OAKS,NY 11004. RP Volkow, ND (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. FU PHS HHS [09490-01] NR 21 TC 98 Z9 102 U1 2 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 17 PY 1996 VL 93 IS 19 BP 10388 EP 10392 DI 10.1073/pnas.93.19.10388 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VJ203 UT WOS:A1996VJ20300073 PM 8816810 ER PT J AU Robertson, J Chen, CW Warren, WL Gutleben, CD AF Robertson, J Chen, CW Warren, WL Gutleben, CD TI Electronic structure of the ferroelectric layered perovskite SrBi2Ta2O9 SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILM CAPACITORS; POLARIZATION FATIGUE; HOLE TRAPS; PB(ZR,TI)O-3; MEMORIES; MODEL AB The band structure of the layered perovskite SrBi2Ta2O9 (SBT) was calculated by tight binding and the valence band density of states was measured by x-ray photoemission spectroscopy. We find both the valence and conduction band edges to consist of states primarily derived from the Bi-O layer rather than the perovskite Sr-Ta-O blocks. The valence band maximum arises from O p and some Bi s states, while the conduction band minimum consists of Bi p states, with a wide band gap of 5.1 eV. It is argued that the Bi-O layers largely control the electronic response whereas the ferroelectric response originates mainly from the perovskite Sr-Ta-O block. Bi and Ta centered traps are calculated to be shallow, which may account in part for its excellent fatigue properties. (C) 1996 American Institute of Physics. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. SONY CORP,RES CTR,HODOGAYA KU,YOKOHAMA,KANAGAWA 240,JAPAN. RP Robertson, J (reprint author), UNIV CAMBRIDGE,DEPT ENGN,CAMBRIDGE CB2 1PZ,ENGLAND. RI Chen, Chun-Wei/L-1889-2015 NR 36 TC 142 Z9 145 U1 0 U2 14 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 SEP 16 PY 1996 VL 69 IS 12 BP 1704 EP 1706 DI 10.1063/1.118003 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400017 ER PT J AU Bhattacharya, A Grupp, DE Goldman, AM Welp, U AF Bhattacharya, A Grupp, DE Goldman, AM Welp, U TI Improvement of the superconducting transition and demagnetization factor in YBa2Cu3O7-delta single crystals by laser cutting SO APPLIED PHYSICS LETTERS LA English DT Article AB Single crystals of YBa2Cu3O7-delta have been cut into disc shapes using an excimer laser. The bulk superconducting transition was found to be sharpened in all cases measured. This is associated with the removal of material at the edges which may be depleted of oxygen or otherwise damaged. The magneto-optical images for one crystal have been correlated with the optical image. The angular dependence of the demagnetizing factor for field applied in the plane was drastically reduced in disc-shaped crystals relative to rectangular ones. The held of first flux entry was also increased. (C) 1996 American Institute of Physics. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Bhattacharya, A (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455, USA. RI Bhattacharya, Anand/G-1645-2011 OI Bhattacharya, Anand/0000-0002-6839-6860 NR 9 TC 1 Z9 1 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 SEP 16 PY 1996 VL 69 IS 12 BP 1792 EP 1794 DI 10.1063/1.117488 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400047 ER PT J AU Goyal, A Norton, DP Budai, JD Paranthaman, M Specht, ED Kroeger, DM Christen, DK He, Q Saffian, B List, FA Lee, DF Martin, PM Klabunde, CE Hartfield, E Sikka, VK AF Goyal, A Norton, DP Budai, JD Paranthaman, M Specht, ED Kroeger, DM Christen, DK He, Q Saffian, B List, FA Lee, DF Martin, PM Klabunde, CE Hartfield, E Sikka, VK TI High critical current density superconducting tapes by epitaxial deposition of YBa2Cu3Ox thick films on biaxially textured metals SO APPLIED PHYSICS LETTERS LA English DT Article ID CU-O SUPERCONDUCTOR; GRAIN-BOUNDARIES; BUFFER LAYERS; TRANSPORT-PROPERTIES; BICRYSTALS AB A method to obtain long lengths of flexible, biaxially oriented substrates with smooth, chemically compatible surfaces for epitaxial growth of high-temperature superconductors is reported. The technique uses well established, industrially scalable, thermomechanical processes to impart a strong biaxial texture to a base metal. This is followed by vapor deposition of epitaxial buffer layers (metal and/or ceramic) to yield chemically compatible surfaces. Epitaxial YBa2Cu3Ox films grown on such substrates have critical current densities exceeding 10(5) A/cm(2) at 77 K in zero field and have field dependencies similar to epitaxial films on single crystal ceramic substrates. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high-J(c) wire capable of carrying high currents in high magnetic fields and at elevated temperatures. (C) 1996 American Institute of Physics. RP Goyal, A (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Christen, David/A-9709-2008; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306 NR 20 TC 771 Z9 798 U1 14 U2 78 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 SEP 16 PY 1996 VL 69 IS 12 BP 1795 EP 1797 DI 10.1063/1.117489 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400048 ER PT J AU Ren, ZF Wang, JH Miller, DJ AF Ren, ZF Wang, JH Miller, DJ TI Structural symmetry of epitaxial Tl2Ba2CuO6+delta thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTING ORDER-PARAMETER; S-WAVE SUPERCONDUCTORS; PI-PHASE-SHIFTS; SINGLE-CRYSTALS; OXYGEN-CONTENT; PAIRING STATE; YBA2CU3O7-DELTA; TC; JUNCTIONS; REVERSAL AB Epitaxial films of Tl2Ba2CuO6+delta (Tl-2201) have been prepared on SrTiO3 by sputtering and postdeposition annealing. The films were deposited onto (100)SrTiO3 single crystal substrates by rf magnetron sputtering and then annealed using a two-step process. The annealed films typically exhibit transition temperatures of about 11 K. Subsequent reannealing to optimize the oxygen doping in the film results in an increase in the transition temperature, and optimally reannealed films exhibit transition temperatures of about 83 K. The crystal structure of these films has been studied by x-ray diffraction and transmission electron microscopy. These results indicate that both the annealed (T-c = 11 K) and optimally reannealed samples (T-c = 83 K) have a tetragonal crystal structure. This structural information is crucial in evaluating recent measurements on these films to determine the electron pairing symmetry (d wave or s wave) in high-T-c superconductors. (C) 1996 American Institute of Physics. C1 SUNY BUFFALO,NEW YORK STATE INST SUPERCONDUCT,BUFFALO,NY 14260. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,SCI TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. RP Ren, ZF (reprint author), SUNY BUFFALO,SUPERCOND MAT LAB,DEPT CHEM,BUFFALO,NY 14260, USA. RI Ren, Zhifeng/B-4275-2014 NR 29 TC 16 Z9 16 U1 1 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 SEP 16 PY 1996 VL 69 IS 12 BP 1798 EP 1800 DI 10.1063/1.117490 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400049 ER PT J AU Wu, CY Cline, D Czosnyka, T Backlin, A Baktash, C Diamond, RM Dracoulis, GD Hasselgren, L Kluge, H Kotlinski, B Leigh, JR Newton, JO Phillips, WR Sie, SH Srebrny, J Stephens, FS AF Wu, CY Cline, D Czosnyka, T Backlin, A Baktash, C Diamond, RM Dracoulis, GD Hasselgren, L Kluge, H Kotlinski, B Leigh, JR Newton, JO Phillips, WR Sie, SH Srebrny, J Stephens, FS TI Quadrupole collectivity and shapes of Os-Pt nuclei SO NUCLEAR PHYSICS A LA English DT Article DE NUCLEAR REACTIONS (186,188,190,192) Os; Pt-194(X,X'), X=Ca-40, Ni-58, Xe-136 and Pb-208; E=3.3-4.8MeV/nucleon; measured E gamma; I gamma following Coulomb excitation; Os-186,Os-188,Os-190,Os-192; Pt-194 deduced levels; E2 and M1 matrix elements ID INTERACTING BOSON MODEL; ELECTROMAGNETIC PROPERTIES; TRANSITIONAL NUCLEI; COULOMB-EXCITATION; OSMIUM ISOTOPES; 15.8-H IR-186; STATES; PT-194; MOMENTS; OS-186 AB E2 collective properties for the low-lying states in Os-186,Os-188,Os-190,Os-192 and Pt-194 have been investigated experimentally by means of Coulomb excitation using 3.3-4.8 MeV/nucleon Ca-40, Ni-58, Xe-136 and (208)pb beams, The deexcitation gamma rays following Coulomb excitation were detected in coincidence with the scattered particles. Levels with excitation energies up to 3-4 MeV of the ground-state, gamma and 4(+) collective bands as well as excited 0(+) states were populated in each nucleus studied. A semiclassical Coulomb-excitation least-squares search code GOSIA was used to extract E2 matrix elements from the measured gamma-ray yields. For each nucleus studied, a unique and almost complete set of E2 matrix elements for the low-lying states has been determined, which includes both the magnitudes and signs of the transitional and diagonal matrix elements. The completeness of the set of measured E2 matrix elements makes it possible to determine the intrinsic quadrupole deformation for the low-lying states in these nuclei via a model-independent method. The results indicate clearly that the E2 properties for the low-lying states in these nuclei are correlated well using only the quadrupole collective degrees of freedom. The extracted E2 matrix elements are compared with the prediction of various collective models such as the asymmetric rigid rotor model, the gamma-soft model of Leander, and the IBA-2 model. These particular models do not reproduce the data satisfactorily, however the general trends of the data are consistent with the descriptions of gamma-soft type collective models through a prolate to oblate shape-transition region. That the enhanced B(E2) values between the I,quasi-K-pi = 4,4(+) state and members of the I,quasi-K-pi = 2,2(+) band are well reproduced by the gamma-soft model is consistent with the interpretation of the I,quasi-K-pi = 4,4(+) state being a two-phonon gamma-vibration excitation. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. AUSTRALIAN NATL UNIV,DEPT PHYS NUCL,CANBERRA,ACT,AUSTRALIA. UNIV WARSAW,HEAVY ION LAB,WARSAW,POLAND. HAHN MEITNER INST BERLIN GMBH,D-14091 BERLIN 39,GERMANY. UNIV MANCHESTER,DEPT PHYS,MANCHESTER M13 9PL,LANCS,ENGLAND. UNIV WARSAW,WARSAW,POLAND. UPPSALA UNIV,INST RADIAT SCI,S-75121 UPPSALA,SWEDEN. RP Wu, CY (reprint author), UNIV ROCHESTER,NUCL STRUCT RES LAB,ROCHESTER,NY 14627, USA. RI Dracoulis, George/A-8123-2008 NR 91 TC 82 Z9 85 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 16 PY 1996 VL 607 IS 2 BP 178 EP 234 DI 10.1016/0375-9474(96)00181-9 PG 57 WC Physics, Nuclear SC Physics GA VJ130 UT WOS:A1996VJ13000005 ER PT J AU Bodwin, GT Sinclair, DK Kim, S AF Bodwin, GT Sinclair, DK Kim, S TI Quarkonium decay matrix elements from quenched lattice QCD SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPECTROSCOPY; CHARMONIUM AB We calculate the long-distance matrix elements for the decays of the lowest-lying S- and P-wave states of charmonium and bottomonium in quenched lattice QCD, using a nonrelativistic formulation for the heavy quarks. (The short-distance coefficients are known from perturbation theory.) In particular, we present the first calculation from QCD first principles of the color-octet contribution to P-wave decay-a contribution that is absent in potential models. We also give the relations between the lattice matrix elements and their continuum counterparts through one-loop order in perturbation theory. RP Bodwin, GT (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 18 TC 64 Z9 64 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 SEP 16 PY 1996 VL 77 IS 12 BP 2376 EP 2379 DI 10.1103/PhysRevLett.77.2376 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400008 ER PT J AU Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Borodin, SV Budagov, J Cao, ZL Cataldi, G Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, EC Durandet, C Elia, V Erwin, AR Evangelista, E Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F HaganIngram, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Jennings, J Judd, D Kononenko, W Kowald, W Lau, K Lawry, T Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, A Misawa, S Mo, G Murphy, CT Nelson, K Panareo, M Pogosian, V Ramachandran, S Recagni, M Rhoades, J Segal, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Tzamouranis, I Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zhang, SN Zou, BT AF Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Borodin, SV Budagov, J Cao, ZL Cataldi, G Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, EC Durandet, C Elia, V Erwin, AR Evangelista, E Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F HaganIngram, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Jennings, J Judd, D Kononenko, W Kowald, W Lau, K Lawry, T Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, A Misawa, S Mo, G Murphy, CT Nelson, K Panareo, M Pogosian, V Ramachandran, S Recagni, M Rhoades, J Segal, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Tzamouranis, I Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zhang, SN Zou, BT TI Search for the flavor changing neutral current decay D-0->mu(+)mu(-) in 800 GeV proton-silicon interactions SO PHYSICAL REVIEW LETTERS LA English DT Article ID LUND MONTE-CARLO; D-MESON PRODUCTION; UPPER LIMIT; PHYSICS AB We have searched for the flavor changing neutral current decay D-0 --> mu(+)mu(-) in the dimuon data obtained by the E771 experiment conducted at Fermilab. No evidence is found. A 90% confidence level upper limit of 4.2 x 10(-6) is obtained for the branching ratio. This new upper limit is about two times lower than the best published result. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. COMENIUS UNIV BRATISLAVA,SQ-84215 BRATISLAVA,SLOVAKIA. DUKE UNIV,DURHAM,NC 27708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV HOUSTON,HOUSTON,TX 77204. JOINT INST NUCL PHYS,RU-141980 DUBNA,RUSSIA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. NANJING UNIV,NANJING 210008,PEOPLES R CHINA. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV PAVIA,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. PRAIRIE VIEW A&M UNIV,PRAIRIE VIEW,TX 77446. SHANDONG UNIV,JINAN 250100,SHANDONG,PEOPLES R CHINA. UNIV S ALABAMA,MOBILE,AL 36688. VANIER COLL,MONTREAL,PQ,CANADA. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22901. RP Alexopoulos, T (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. RI Bonomi, Germano/G-4236-2010; Introzzi, Gianluca/K-2497-2015; Panareo, Marco/Q-4563-2016; Grancagnolo, Francesco/K-2857-2015 OI Bonomi, Germano/0000-0003-1618-9648; Introzzi, Gianluca/0000-0002-1314-2580; Panareo, Marco/0000-0002-7757-5553; Grancagnolo, Francesco/0000-0002-9367-3380 NR 30 TC 12 Z9 13 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 SEP 16 PY 1996 VL 77 IS 12 BP 2380 EP 2383 DI 10.1103/PhysRevLett.77.2380 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400009 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Costa, I Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, B Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Sugano, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Costa, I Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, B Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Sugano, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C TI Search for D-0(D)over-bar(0) mixing in semileptonic decay modes SO PHYSICAL REVIEW LETTERS LA English DT Article ID D0-DBAR0; STANDARD; PHYSICS AB We report the result of a search for D-0 (D) over bar(0) mixing in the data from hadroproduction experiment E791 at Fermilab. We use the charge of the pion from the strong decay D-*+ --> D-0 pi(+) (and charge conjugate) to identify the charm quantum number of the neutral D at production, and the charge of the lepton and the kaon in the semileptonic decays D-0 --> Ke nu and K mu nu to identify the charm at the time of decay. No evidence of mixing is seen. We set a 90% confidence level upper limit on mixing of r < 0.50%, where r = Gamma(D-0 --> (D) over bar(0) --> K(+)l(-)<(nu)over bar>(l))/(D-0 --> K(-)l(+)nu(l)). C1 CTR BRASILEIRO PESQUISAS FIS,RIO JANEIRO,BRAZIL. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. UNIV CINCINNATI,CINCINNATI,OH 45221. CINVESTAV IPN,MEXICO CITY 14000,DF,MEXICO. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IIT,CHICAGO,IL 60616. KANSAS STATE UNIV,MANHATTAN,KS 66506. OHIO STATE UNIV,COLUMBUS,OH 43210. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV AUTONOMA PUEBLA,PUEBLA 72570,MEXICO. UNIV S CAROLINA,COLUMBIA,SC 29208. STANFORD UNIV,STANFORD,CA 94305. TEL AVIV UNIV,IL-69978 TEL AVIV,ISRAEL. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Aitala, EM (reprint author), UNIV MISSISSIPPI,UNIVERSITY,MS 38677, USA. RI Anjos, Joao/C-8335-2013; Santoro, Alberto/E-7932-2014; de Mello Neto, Joao/C-5822-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016; Fernandez Tellez, Arturo/E-9700-2017 OI de Mello Neto, Joao/0000-0002-3234-6634; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Fernandez Tellez, Arturo/0000-0003-0152-4220 NR 20 TC 51 Z9 52 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 SEP 16 PY 1996 VL 77 IS 12 BP 2384 EP 2387 DI 10.1103/PhysRevLett.77.2384 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400010 ER PT J AU Alves, GA Amato, S Anjos, JC Appel, JA Astorga, J Bracker, SB Cremaldi, LM Dagenhart, WD Darling, CL Dixon, RL Errede, D Fenker, HC Gay, C Green, DR Jedicke, R Karchin, PE Kennedy, C Kwan, S Lueking, LH Neto, JRTD Metheny, J Milburn, RH deMiranda, JM daMotta, H Napier, A Passmore, D Rafatian, A dosReis, AC Ross, WR Santoro, AFS Sheaff, M Souza, MHG Spalding, WJ Stoughton, C Streetman, ME Summers, DJ Takach, SF Wallace, A Wu, Z AF Alves, GA Amato, S Anjos, JC Appel, JA Astorga, J Bracker, SB Cremaldi, LM Dagenhart, WD Darling, CL Dixon, RL Errede, D Fenker, HC Gay, C Green, DR Jedicke, R Karchin, PE Kennedy, C Kwan, S Lueking, LH Neto, JRTD Metheny, J Milburn, RH deMiranda, JM daMotta, H Napier, A Passmore, D Rafatian, A dosReis, AC Ross, WR Santoro, AFS Sheaff, M Souza, MHG Spalding, WJ Stoughton, C Streetman, ME Summers, DJ Takach, SF Wallace, A Wu, Z TI Forward cross sections for production of D+, D-0, D-s, D*(+), and Lambda(c) in 250 GeV pi(+/-), Kappa(+/-), and p interactions with nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHARM MESON PRODUCTION; D(0),(D)OVER-BAR(0) PRODUCTION; EMULSION INTERACTIONS; PARTON DISTRIBUTIONS; DRELL-YAN; DEPENDENCE; HADROPRODUCTION; BEAM AB We measure forward cross sections for production of D+, D-0, D-s, D-*+, and Lambda(c) in collisions of pi(+/-), K-+/-, and p on a nuclear target. Production induced by different beam particles is found to be the same within statistics. Strange and baryonic final states are seen to contribute appreciably to the total charm cross section, which our measurements indicate is larger than but consistent with QCD predictions. The energy dependence mapped out by these and previous measurements is consistent with theory. Leading-particle asymmetry measurements for K and p-induced charm production are also presented. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV MISSISSIPPI,UNIVERSITY,MS 38677. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. TUFTS UNIV,MEDFORD,MA 02155. WAYNE STATE UNIV,DETROIT,MI 48202. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Alves, GA (reprint author), CTR BRASILEIRO PESQUISAS FIS,RUA DR XAVIER SIGAUD 150,RIO JANEIRO,BRAZIL. RI Anjos, Joao/C-8335-2013; Alves, Gilvan/C-4007-2013; de Mello Neto, Joao/C-5822-2013 OI de Mello Neto, Joao/0000-0002-3234-6634 NR 26 TC 79 Z9 80 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 SEP 16 PY 1996 VL 77 IS 12 BP 2388 EP 2391 DI 10.1103/PhysRevLett.77.2388 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400011 ER PT J AU Alves, GA Amato, S Anjos, JC Appel, JA Astorga, J Bracker, SB Cremaldi, LM Dagenhart, WD Darling, CL Dixon, RL Errede, D Fenker, HC Gay, C Green, DR Jedicke, R Karchin, PE Kennedy, C Kwan, S Lueking, LH Neto, JRTD Metheny, J Milburn, RH deMiranda, JM daMotta, H Napier, A Passmore, D Rafatian, A dosReis, AC Ross, WR Santoro, AFS Sheaff, M Souza, MHG Spalding, WJ Stoughton, C Streetman, ME Summers, DJ Takach, SF Wallace, A Wu, Z AF Alves, GA Amato, S Anjos, JC Appel, JA Astorga, J Bracker, SB Cremaldi, LM Dagenhart, WD Darling, CL Dixon, RL Errede, D Fenker, HC Gay, C Green, DR Jedicke, R Karchin, PE Kennedy, C Kwan, S Lueking, LH Neto, JRTD Metheny, J Milburn, RH deMiranda, JM daMotta, H Napier, A Passmore, D Rafatian, A dosReis, AC Ross, WR Santoro, AFS Sheaff, M Souza, MHG Spalding, WJ Stoughton, C Streetman, ME Summers, DJ Takach, SF Wallace, A Wu, Z TI Feynman-x and transverse momentum dependence of D meson production in 250 GeV pi, Kappa, and p interactions with nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID D(0),(D)OVER-BAR(0) PRODUCTION; PARTON DISTRIBUTIONS; DRELL-YAN AB We measure the differential cross sections with respect to Feynman x (X(F)) and transverse momentum (p(T)) for pi, K, and p-induced charm meson production using fully reconstructed D+, D-0, and D-s decays. The shapes of these cross sections are compared to the theoretical predictions for charm quark production of next-to-leading order perturbative QCD using modern parametrizations of the pion and nucleon parton distributions. We observe the differences expected in production induced by projectiles with different gluon distributions, harder distributions being indicated for mesons than for protons. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV MISSISSIPPI,UNIVERSITY,MS 38677. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. TUFTS UNIV,MEDFORD,MA 02155. WAYNE STATE UNIV,DETROIT,MI 48202. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Alves, GA (reprint author), CTR BRASILEIRO PESQUISAS FIS,RUA DR XAVIER SIGAUD 150,RIO JANEIRO,BRAZIL. RI Anjos, Joao/C-8335-2013; Alves, Gilvan/C-4007-2013; de Mello Neto, Joao/C-5822-2013 OI de Mello Neto, Joao/0000-0002-3234-6634 NR 13 TC 57 Z9 57 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 SEP 16 PY 1996 VL 77 IS 12 BP 2392 EP 2395 DI 10.1103/PhysRevLett.77.2392 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400012 ER PT J AU Krstic, PS Bent, G Schultz, DR AF Krstic, PS Bent, G Schultz, DR TI New method for treating slow multielectron, multicenter atomic collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-CAPTURE; HYDROGEN-ATOMS; GROUND-STATE; EXCITATION; IONIZATION; RESONANCES; H-2 AB The method of hidden crossings is generalized to treat multielectron systems utilizing molecular Hartree-Fock and configuration interaction methods, extended into the plane of complex internuclear distance. Diabatic promotion of low lying states to the continuum in a two-electron, two-center system via a series of localized transitions is shown for the first time. Excellent agreement with experiments is found regarding single ionization in 50 eV to 1 keV HCH collisions. C1 UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269. RP Krstic, PS (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. NR 20 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1996 VL 77 IS 12 BP 2428 EP 2431 DI 10.1103/PhysRevLett.77.2428 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400021 ER PT J AU Wu, HB Desai, SR Wang, LS AF Wu, HB Desai, SR Wang, LS TI Evolution of the electronic structure of small vanadium clusters from molecular to bulklike SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSITION-METAL CLUSTERS; MAGNETIC-PROPERTIES; CR CLUSTERS; SIZE; SPECTROSCOPY; CHEMISORPTION; DEPENDENCE; SPECTRA; V2 AB The evolution of the electronic structure of V-n clusters is probed by photoelectron spectroscopy (PES) at 3.49, 4.66, and 6.42 eV photon energies. Three regions of spectral evolution are distinctly observed as a function of cluster size: molecularlike behavior for n = 3-12; transition from molecular to bulklike for n = 13-17; gradual convergence to bulk for n > 17, for which a surfacelike feature is observed to slowly merge into the bulk feature near n = 60. The PES spectra provide an atom-by-atom view of the evolution of the electronic structure of the V, clusters from molecular to bulklike. C1 PACIFIC NW NATL LAB,EMSL,RICHLAND,WA 99352. RP Wu, HB (reprint author), WASHINGTON STATE UNIV,DEPT PHYS,RICHLAND,WA 99352, USA. NR 35 TC 62 Z9 63 U1 0 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 SEP 16 PY 1996 VL 77 IS 12 BP 2436 EP 2439 DI 10.1103/PhysRevLett.77.2436 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400023 ER PT J AU Silver, RN Gore, R Greene, J Harlow, F Whitman, R AF Silver, RN Gore, R Greene, J Harlow, F Whitman, R TI Radiographic evidence for k(-5/3) scaling of density power spectra SO PHYSICAL REVIEW LETTERS LA English DT Article ID INTERSTELLAR-MEDIUM; TURBULENCE; FLUCTUATIONS AB Experiments on the explosively driven compression and reexpansion of metal cylinders are reported. Analysis of radiography data taken with a pulsed x-ray source reveals scale invariant density fluctuations. The marginal density spectra are consistent with a k(-8/3) power law, where k is wave number, corresponding to scalar density spectra varying as k(-5/3). Remarkably, the same scaling behavior is observed for a variety of metals with widely different mechanical properties. The relation of these results to fully developed turbulence in both incompressible fluids and compressible fluids with large density variations is discussed. RP Silver, RN (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 16 TC 2 Z9 2 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 SEP 16 PY 1996 VL 77 IS 12 BP 2471 EP 2474 DI 10.1103/PhysRevLett.77.2471 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400032 ER PT J AU Swartzentruber, BS Smith, AP Jonsson, H AF Swartzentruber, BS Smith, AP Jonsson, H TI Experimental and theoretical study of the rotation of Si Ad-dimers on the Si(100) surface SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; CAR-PARRINELLO METHOD; PARALLEL IMPLEMENTATION; SI(001); DIFFUSION; DYNAMICS; SILICON; BINDING; PSEUDOPOTENTIALS; DECOMPOSITION AB Scanning tunneling microscopy measurements and first principles density functional theory calculations are used to study the rate of the rotational transition of Si ad-dimers on top of the surface dimer rows of Si(100). The rotation rate and the relative population of the two stable orientations of the ad-dimers are measured as a function of the applied electric field to extract the zero-field behavior. The measured relative stability of the two configurations is used to test the accuracy of various functionals for density functional theory calculations. C1 UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. TECH UNIV DENMARK, DEPT PHYS, CAMP, DK-2800 LYNGBY, DENMARK. RP Swartzentruber, BS (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Jonsson, Hannes/G-2267-2013 OI Jonsson, Hannes/0000-0001-8285-5421 NR 30 TC 89 Z9 90 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1996 VL 77 IS 12 BP 2518 EP 2521 DI 10.1103/PhysRevLett.77.2518 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400044 ER PT J AU Tromp, RM Theis, W Bartelt, NC AF Tromp, RM Theis, W Bartelt, NC TI Real-time microscopy of two-dimensional critical fluctuations: Disordering of the Si(113)-(3x1) reconstruction SO PHYSICAL REVIEW LETTERS LA English DT Article ID POTTS-MODEL; SPECTROSCOPY; DYNAMICS AB Using low-energy electron microscopy, we have studied the critical fluctuations associated with the disordering of the (3 X 1) reconstruction on Si(113). We not only observe and quantify the increased spatial correlations near T-c, but also the associated slowing down of the relaxation of long wavelength critical fluctuations. The dependence of the slowing down on correlation length is consistent with theories for phase transitions with nonconserved order parameters. In addition, we show that steps limit the size of the correlation length, as is often conjectured. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP Tromp, RM (reprint author), IBM CORP,THOMAS J WATSON RES CTR,POB 218,YORKTOWN HTS,NY 10598, USA. NR 18 TC 11 Z9 11 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 16 PY 1996 VL 77 IS 12 BP 2522 EP 2525 DI 10.1103/PhysRevLett.77.2522 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400045 ER PT J AU Kawakami, RK EscorciaAparicio, EJ Qiu, ZQ AF Kawakami, RK EscorciaAparicio, EJ Qiu, ZQ TI Symmetry-induced magnetic anisotropy in Fe films grown on stepped Ag(001) SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-POLARIZED PHOTOEMISSION; FERROMAGNETIC-RESONANCE; FE(001) FILMS; ULTRATHIN; SURFACE; TRANSITION; AG(100); IRON AB Symmetry breaking at atomic steps of ultrathin Fe films grown on stepped Ag(001) substrates creates a uniaxial magnetic anisotropy with the easy axis parallel to the step edges. The relation between this induced anisotropy and the step density is systematically investigated by magneto-optically scanning films grown on a curved substrate with a vicinal angle range between 0 degrees and 10 degrees. We find that (a) the uniaxial anisotropy depends quadratically on thr step density, and (b) the spin-reorientation transition occurs at a larger thickness for the stepped than for the hat film. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Kawakami, RK (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Qiu, Zi Qiang/O-4421-2016 OI Qiu, Zi Qiang/0000-0003-0680-0714 NR 20 TC 185 Z9 185 U1 0 U2 13 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 SEP 16 PY 1996 VL 77 IS 12 BP 2570 EP 2573 DI 10.1103/PhysRevLett.77.2570 PG 4 WC Physics, Multidisciplinary SC Physics GA VG674 UT WOS:A1996VG67400057 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI The binary hafnium phosphide Hf3P2 SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID CRYSTAL-STRUCTURE AB The structure of trihafnium diphosphide, Hf3P2, has been redetermined by single-crystal analysis. Hf3P2 crystallizes in the orthorhombic space group Pnma (No. 62), with a = 10.128 (2), b = 3.5707 (6), c = 9.868 (2) Angstrom, V = 356.87 (12) Angstrom(3), and the anti-Sb2S3 structure type. The P atoms are situated in singly capped and bicapped trigonal Hf prisms. In contrast to the structure of Zr14P9, no centered Hf cubes as observed in the bcc packing occur in the structure of Hf3P2. RP Kleinke, H (reprint author), IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011, USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP 15 PY 1996 VL 52 BP 2127 EP 2129 DI 10.1107/S0108270196004969 PN 9 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA VJ340 UT WOS:A1996VJ34000004 ER PT J AU Hu, RZ Block, J Hriljac, JA Eylem, C Petrakis, L AF Hu, RZ Block, J Hriljac, JA Eylem, C Petrakis, L TI Use of X-ray powder diffraction for determining low levels of chrysotile asbestos in gypsum-based bulk materials: Sample preparation SO ANALYTICAL CHEMISTRY LA English DT Article AB An X-ray diffraction procedure for quantitative chrysotile asbestos analysis in a gypsum-based matrix is discussed, The procedure includes calibration standards preparation, an EDTA treatment to remove gypsum, sample milling, and X-ray diffraction analysis, The effect of each step is discussed. Morphological and crystal structural changes due to the sample preparation procedure were also characterized using techniques such as SEM, IR, NMR and ICP. Through a statistically designed experiment, it is demonstrated that-X-ray diffraction can be used as a reliable technique in gypsum-based matrices to determine chrysotile concentration from 0.25% to 2.5% with a standard deviation of 0.07%. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. WR GRACE & CO CONN,COLUMBIA,MD 21044. NR 17 TC 11 Z9 11 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1996 VL 68 IS 18 BP 3112 EP 3120 DI 10.1021/ac960179p PG 9 WC Chemistry, Analytical SC Chemistry GA VG141 UT WOS:A1996VG14100006 ER PT J AU Swain, D Winans, RE Dunn, WJ AF Swain, D Winans, RE Dunn, WJ TI Positional isomer differentiation of monoalkylated naphthalenes using principal components analysis and mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID COLLISION-INDUCED DISSOCIATION; SPECTRA; IONS AB Tandem mass spectrometry has been used to differentiate positional isomers of some monoalkylated naphthalenes. The basis of the distinction is the cluster of peaks from m/z 150 to 155. Principal components analysis can extract isomer-specific information that is not obvious from simple visual inspection of the spectra. The analysis led to the observation of similar trends in single-stage electron impact mass spectra. C1 UNIV ILLINOIS,DEPT MED CHEM & PHARMACOGNOSY,CHICAGO,IL 60612. RP Swain, D (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 20 TC 2 Z9 2 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1996 VL 68 IS 18 BP 3244 EP 3249 DI 10.1021/ac9600114 PG 6 WC Chemistry, Analytical SC Chemistry GA VG141 UT WOS:A1996VG14100025 ER PT J AU Nelson, WM Lee, CS AF Nelson, WM Lee, CS TI Mechanistic studies of partial-filling micellar electrokinetic chromatography SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; CAPILLARY ELECTROPHORESIS; DEGRADATION PRODUCTS; S-TRIAZINES AB The need for coupling micellar electrokinetic chromatography (MEKC) with electrospray mass spectrometry initiates the development of partial-filling MEKC. In comparison with conventional MEKC, only a small portion of the capillary is filled with a micellar solution for performing the separation in partial-filling MEKC. Analytes first migrate into the micellar plug, where the separation occurs, and then into the leading electrophoresis buffer, which is free of surfactants, A theoretical model is proposed for predicting the separation behavior of triazine herbicides in partial-filling MEKC. The comparisons between conventional and partial-filling MEKC in terms of separation efficiency and resolution of triazine herbicides are presented and discussed, The optimization techniques, possible applications, and advantages of partial-filling MEKC are similarly addressed. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. NR 11 TC 52 Z9 54 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1996 VL 68 IS 18 BP 3265 EP 3269 DI 10.1021/ac951137o PG 5 WC Chemistry, Analytical SC Chemistry GA VG141 UT WOS:A1996VG14100028 PM 8797385 ER PT J AU Liu, CL Wu, QY Harms, AC Smith, RD AF Liu, CL Wu, QY Harms, AC Smith, RD TI On line microdialysis sample cleanup for electrospray ionization mass-spectrometry of nucleic acid samples SO ANALYTICAL CHEMISTRY LA English DT Article ID ASSISTED LASER-DESORPTION; LIQUID-CHROMATOGRAPHY; DNA; OLIGONUCLEOTIDES; DUPLEX; ONLINE; RAT AB A major limitation of electrospray ionization mass spectrometry (ESI-MS) for oligonucleotide analysis arises due to sodium adduction, a problem that increases with molecular weight. Sodium adduction can preclude useful measurements when-limited sample sizes prevent off-line cleanup. A novel and generally useful on-line microdialysis technique is described for the rapid (similar to 1-5 min) DNA sample cleanup for ESI-MS. Mass spectra of oligonucleotides of different size and sequence showing no significant sodium adduct peaks were obtained using the on-line microdialysis system with sodium chloride concentrations as high as 250 mM. Signal-to-noise ratios were also greatly enhanced compared to direct infusion of the original samples. By using ammonium acetate ga the dialysis buffer, it was also found that the noncovalent association of double-stranded oligonucleotides could be preserved during the microdialysis process, allowing analysis by ESI-MS. C1 PACIFIC NW NATL LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 34 TC 113 Z9 116 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1996 VL 68 IS 18 BP 3295 EP 3299 DI 10.1021/ac960286j PG 5 WC Chemistry, Analytical SC Chemistry GA VG141 UT WOS:A1996VG14100035 PM 8797389 ER PT J AU Ames, BN Gold, LS AF Ames, BN Gold, LS TI Cell proliferation as a major risk factor for cancer: A concept of doubtful validity. SO CANCER RESEARCH LA English DT Letter ID MICE RP Ames, BN (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,CARCINOGEN POTENCY PROJECT,BERKELEY,CA 94720, USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD SEP 15 PY 1996 VL 56 IS 18 BP 4267 EP 4269 PG 3 WC Oncology SC Oncology GA VG370 UT WOS:A1996VG37000035 PM 8797604 ER PT J AU Zhu, YG Zacharia, T AF Zhu, YG Zacharia, T TI A new one-point quadrature, quadrilateral shell element with drilling degrees of freedom SO COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING LA English DT Article ID ASSUMED STRAIN STABILIZATION; INCLUDING VERTEX ROTATIONS; PLANE ELASTICITY ANALYSIS; FINITE-ELEMENT; COMPUTATIONAL ASPECTS; FORMULATION; MODEL; ALGORITHMS; NODE AB In this paper we discuss the development of a new four-node general shell element with single point quadrature used for the analysis of non-linear geometrical and material problems. One of the main features of the present development is the implementation of a rotation component around the shell normal (i.e. drilling rotation) to Belytschko's family of shell elements. Thus, at each node, six degrees of freedom (i.e. three translations and three rotations) make the element easy to connect to space beams, stiffeners or intersecting shells. A projection scheme for warping correction Is proposed so that the element is accurate for both hat and warped configurations. All locking phenomena (such as transverse shear, in-plane shear and membrane locking) are controlled by an assumed strain method. Also, a physical stabilization approach for control of spurious zero-energy modes is proposed without requiring any artificial stabilization parameters. This approach is inexpensive and accurate because it updates and stores hourglass stresses only at the mid-surface rather than at all the integration points through the shell thickness. To demonstrate the features of the new shell element, it was applied to the analysis of large-scale, non-linear, static, dynamic and impact problems using elastic, isotropic/anisotropic elastoplastic and composite damage models. The element performed well for the problems that sometimes cause difficulties for other shell element techniques. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. OI Zacharia, Thomas/0000-0001-6463-5425 NR 55 TC 29 Z9 29 U1 1 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0045-7825 J9 COMPUT METHOD APPL M JI Comput. Meth. Appl. Mech. Eng. PD SEP 15 PY 1996 VL 136 IS 1-2 BP 165 EP 203 DI 10.1016/0045-7825(96)01059-6 PG 39 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA VH092 UT WOS:A1996VH09200009 ER PT J AU Agostoni, E Albertson, D Wittmann, C Hill, F Tobler, H Muller, F AF Agostoni, E Albertson, D Wittmann, C Hill, F Tobler, H Muller, F TI cec-1, a soma-specific chromobox-containing gene in C-Elegans SO DEVELOPMENTAL BIOLOGY LA English DT Article ID POSITION-EFFECT VARIEGATION; HETEROCHROMATIN-ASSOCIATED PROTEIN; NONHISTONE CHROMOSOMAL PROTEIN; DROSOPHILA-MELANOGASTER; CAENORHABDITIS-ELEGANS; POLYCOMB PROTEIN; NUCLEAR-LOCALIZATION; SEQUENCE REVEALS; FISSION YEAST; CELL LINEAGE AB The chrome domain is a phylogenetically conserved sequence motif which was identified as a region of homology between the repressor protein Pc and the heterochromatin constitutive protein HP1 of Drosophila. The specific function of the chromo domain is not yet understood, but it seems to be required for protein-protein interactions in chromatin-associated complexes. Here, we present a new chromobox-containing gene from Caenorhabditis elegans (cec-1). It encodes a nuclear protein that is present in all somatic cells from the 50- to 80-cell stage on throughout development and in adult animals. No cec-1 protein was detected in the cells of early embryos, in germ cells, and in their precursor cells Z2 and Z3. cec-1 mRNA, however, is already present in all the blastomeres of early embryos. Immunolocalization experiments revealed a homogeneous distribution of CEC-1 within interphase nuclei, while during mitosis CEC-1 seems to dissociate from the condensing chromosomes. The expression pattern of the cec-1 gene suggests that it may represent a new regulatory gene in C. elegans. (C) 1996 Academic Press, Inc. C1 UNIV FRIBOURG,INST ZOOL,CH-1700 FRIBOURG,SWITZERLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. MRC,MOL BIOL LAB,CAMBRIDGE CB2 2QH,ENGLAND. NR 59 TC 5 Z9 8 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD SEP 15 PY 1996 VL 178 IS 2 BP 316 EP 326 DI 10.1006/dbio.1996.0221 PG 11 WC Developmental Biology SC Developmental Biology GA VL197 UT WOS:A1996VL19700010 PM 8812132 ER PT J AU Gruszkiewicz, MS Ott, JB AF Gruszkiewicz, MS Ott, JB TI Excess molar enthalpies of (ethane plus ethene), (ethane plus chloromethane), (propane plus chloromethane), and (butane plus chloromethane) calculated from cubic equations of state and the principle of corresponding states - A comparison with experimental results SO FLUID PHASE EQUILIBRIA LA English DT Article DE theory; experiment; equation of state; excess functions; enthalpies; mixtures; polar ID MPA; PRESSURES; VOLUMES AB Excess molar enthalpies H-m(E) are calculated using equations of state and the principle of corresponding states for four binary mixtures: (ethane + ethene), (ethane + chloromethane), (propane + chloromethane), and (butane + chloromethane), at temperatures from 298.15 to 363.15 K and pressures from 5 to 15 MPa, so that a comparison can be made with recently obtained experimental calorimetric results. Four cubic equations of state (van der Waals, Redlich-Kwong, Soave, and Peng-Robinson) and the principle of corresponding states, used together with the van der Waals one-fluid approximation (vdW1), are examined. The only adjustable parameter was the binary interaction parameter k(12) in Berthelot's combining rule. It was adjusted for each type of mixture and set at different values for the equation of state calculations or the principle of corresponding states prediction, but set independent of temperature, pressure, and a particular equation of state. Usually, reasonably good comparisons are obtained between the experimental results and the H-m(E)(p,T) surface calculated from the equations of state and from the principle of corresponding states. (Vapor + liquid) equilibria for (ethane + chloromethane) at p = 5 MPa were also calculated using the k(12) determined from the H-m(E) results, and compared with experimental results. The agreement is best for the Seave and the Peng-Robinson equations, with the other equations and the principle of corresponding states predicting equilibrium mole fractions that are low. C1 BRIGHAM YOUNG UNIV,DEPT CHEM & BIOCHEM,PROVO,UT 84602. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Gruszkiewicz, Miroslaw/L-2389-2016 OI Gruszkiewicz, Miroslaw/0000-0002-6551-6724 NR 20 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD SEP 15 PY 1996 VL 124 IS 1-2 BP 81 EP 98 DI 10.1016/S0378-3812(96)03064-6 PG 18 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA VU557 UT WOS:A1996VU55700006 ER PT J AU Self, S Thordarson, T Keszthelyi, L Walker, GPL Hon, K Murphy, MT Long, P Finnemore, S AF Self, S Thordarson, T Keszthelyi, L Walker, GPL Hon, K Murphy, MT Long, P Finnemore, S TI A new model for the emplacement of Columbia River Basalts as large, inflated pahoehoe lava flow fields SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID KILAUEA VOLCANO; HAWAII; ERUPTION; ORIGIN AB Extensive flows of the Columbia River Basalt (CRB) Group in Washington, Oregon, and Idaho are dominantly inflated compound pahoehoe sheet lavas. Early studies recognized that CRB lavas are compound pahoehoe flows, with textures suggesting low flow velocities, but it was thought that the great thickness and extent of the major flows required very rapid emplacement as turbulent floods of lava over a period of days or weeks. However, small volume (<1 km(3)) compound pahoehoe flows on Kilauea, Hawai'i, demonstrate that such flows can thicken by at least an order of magnitude through gradual inflation and the same mechanism has been proposed for larger (10-20 km(3)) pahoehoe flows in Iceland. The vertical distribution of vesicles and other morphologic features within CRB lava flows indicate that they grew similarly by inflation. Small pahoehoe lobes at the base and top of many CRB pahoehoe lava flows indicate emplacement in a gradual, piecemeal manner rather than as a single flood. We propose that each thick CRB sheet flow was active for months to years and that each group of flows produced by a single eruption (a flow field) was emplaced slowly over many years. C1 UNIV HAWAII, SOEST, DEPT GEOL & GEOPHYS, HONOLULU, HI 96822 USA. INST GEOL & NUCL SCI, WAIRAKEI RES CTR, TAUPO, NEW ZEALAND. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Self, S (reprint author), UNIV HAWAII, SOEST, HAWAII CTR VOLCANOL, HONOLULU, HI 96822 USA. RI Thordarson, Thorvaldur/A-8990-2013; Wright, Dawn/A-4518-2011; Thordarson, Thorvaldur/M-2422-2015 OI Wright, Dawn/0000-0002-2997-7611; Thordarson, Thorvaldur/0000-0003-4011-7185 NR 31 TC 146 Z9 148 U1 2 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1996 VL 23 IS 19 BP 2689 EP 2692 DI 10.1029/96GL02450 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VH169 UT WOS:A1996VH16900029 ER PT J AU Kleinke, H Kleinke, KM Franzen, HF AF Kleinke, H Kleinke, KM Franzen, HF TI Synthesis, oxygen occupation, and properties of the kappa-phases Hf9Mo4SOx and Hf9W4SOx SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE kappa-phases; synthesis; oxygen occupation; properties ID TA-NB-S; CRYSTAL-STRUCTURE; HIGH-TEMPERATURES; LAYERED COMPOUND; SYSTEM; PHOSPHIDES; TANTALUM; SULFIDES; CHAIN; ZRNBP AB Hf9Mo4SOx and Hf9W4SOx have been prepared by are-melting of HfS, Hf and Mo and W respectively and subsequent annealing at 1500 degrees C. Both compounds crystallize in the hexagonal space group P6(3)/mmc (No. 194), with cell dimensions a = 8.6513(5) Angstrom, c = 8.5409(8) Angstrom, V = 557.45(8) Angstrom(3), and a = 8.667(1) Angstrom, c = 8.583(3) Angstrom, V = 555.4(2) Angstrom(3) respectively and belong to the general group of kappa-phases. The metal sublattice consists of chains of Mo/W centered icosahedra, running along [001], which are interconnected by additional Hf atoms and the non-metal atoms. Oxygen is located in a Hf-6 octahedron and sulfur in a Hf-6 trigonal prism. Apparently, the occupation of the interstitial octahedral position with oxygen could not be totally prevented by carrying out all steps of the synthesis in a glove-box under an argon atmosphere, although its presence should not be necessary to form these kappa-phases. Band structure calculations show both materials to be metallic, in agreement with the experimentally determined Pauli paramagnetism. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DOE,AMES,IA 50011. NR 43 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 SEP 15 PY 1996 VL 242 IS 1-2 BP 11 EP 17 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VK819 UT WOS:A1996VK81900006 ER PT J AU Hebner, GA AF Hebner, GA TI Metastable chlorine ion temperature and drift velocity in an inductively coupled plasma SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CYCLOTRON RESONANCE PLASMA; REFERENCE CELL; ELECTRON; DISCHARGES; TRANSPORT AB Laser-induced fluorescence has been used to measure the temperature and radial drift velocity of metastable chlorine ions in inductively coupled Cl-2 and Ar/Cl-2 plasmas. In the center of the plasma, the Cl metastable ion temperature varied between 1500 and 3200 K for rf powers between 200 and 400 W and pressures between 7 and 30 mTorr. Increasing the chlorine fraction in an Ar/Cl-2 gas mixture from 10% to 100% increased the Cl metastable ion temperature from approximately 1500 to 3200 K. Spatially resolved measurements of the ion temperature indicated that the ion temperature increased to between 4500 and 5500 K at the edge of the discharge and increased approximately 700 K moving from the rf source toward the lower electrode. Ion drift velocity in the radial direction was between 6X10(4) and 8x10(4) cm/s at the edge of the plasma. Implications of these measurements on the Ar/Cl-2 chemistry and the energy transport in the plasma are discussed. (C) 1996 American Institute of Physics. RP Hebner, GA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 25 TC 23 Z9 23 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 SEP 15 PY 1996 VL 80 IS 6 BP 3215 EP 3220 DI 10.1063/1.363262 PG 6 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100013 ER PT J AU Benton, JL Stolk, PA Eaglesham, DJ Jacobson, DC Cheng, JY Poate, JM Ha, NT Haynes, TE Myers, SM AF Benton, JL Stolk, PA Eaglesham, DJ Jacobson, DC Cheng, JY Poate, JM Ha, NT Haynes, TE Myers, SM TI Iron gettering mechanisms in silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CZOCHRALSKI-GROWN SILICON; IMPURITIES; SI; DISLOCATIONS; DIFFUSION; LAYERS; COPPER; IMPACT; WAFER; AU AB Boron implantation into silicon offers a unique system for studying the gettering mechanisms of Fe. Using deep level transient spectroscopy to monitor the remaining Fe in the gettered region and secondary-ion-mass spectroscopy to measure the concentration of Fe redistributed to the B region, we show that the gettering mechanisms can be quantitatively described. A combination of Fermi-level-induced Fe+ charge-state stabilization and Fe+-B- pairing acts to lower the free energy of Fe in p+ regions. This can lead to Fe partition coefficients as high as 10(6) at a p+/p interface at temperatures below approximate to 400 degrees C. The dynamic response of the system is diffusion limited during the cooling cycle. B gettering is more effective than gettering produced by Si implantation damage and more effective than trapping by a neutral impurity such as C. These mechanisms also make a large contribution to the effective gettering of Fe by p/p+ epitaxial silicon wafers. The Fermi-level/pairing gettering mechanism is also expected to operate for Cr and Mn. (C) 1996 American Institute of Physics. C1 AT&T BELL LABS,MIDDLETOWN,NJ 07748. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Benton, JL (reprint author), AT&T BELL LABS,LUCENT TECHNOL,600 MT AVE,MURRAY HILL,NJ 07974, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 31 TC 56 Z9 56 U1 0 U2 4 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 SEP 15 PY 1996 VL 80 IS 6 BP 3275 EP 3284 DI 10.1063/1.363236 PG 10 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100022 ER PT J AU Cuevas, A Basore, PA GiroultMatlakowski, G Dubois, C AF Cuevas, A Basore, PA GiroultMatlakowski, G Dubois, C TI Surface recombination velocity of highly doped n-type silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MINORITY-CARRIER TRANSPORT; SATURATION CURRENT; SI-SIO2 INTERFACE; SOLAR-CELLS; EMITTERS; EFFICIENCY; STATES; OXIDES AB New experimental data for the minority-carrier surface recombination velocity of n-type silicon, S-p, are reported. The data, obtained from photoconductance decay measurements of the recombination currents corresponding to different phosphorus diffusions, include oxide-passivated, unpassivated and metal-coated surfaces. For the passivated case, S-p increases linearly with surface dopant density, N-D, for dopant densities higher than 1X10(18) cm(-3), while for unpassivated (bare) and for metal-coated silicon S-p remains essentially constant, at about 2X10(5) cm/s and 3X10(6) cm/s, respectively. The experiments also allow for a determination of the apparent energy bandgap narrowing as a function of dopant density, Delta E(g)(app) = 14 meV [ln(N-D/1.4X10(17) cm(-3))]. These surface recombination velocity and Delta E(g)(app) data form, together with the dependences of minority-carrier lifetime, tau(p), and mobility, mu(p), used in the analysis, a consistent set of parameters that fully characterize highly doped n-type silicon. (C) 1995 American Institute of Physics. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. CNRS, PHYS MAT LAB, URA 358, F-69621 VILLEURBANNE, FRANCE. RP Cuevas, A (reprint author), AUSTRALIAN NATL UNIV, FAC ENGN & INFORMAT TECHNOL, GPO BOX 4, CANBERRA, ACT, AUSTRALIA. RI Cuevas, Andres/K-3499-2014 NR 22 TC 115 Z9 118 U1 4 U2 45 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1996 VL 80 IS 6 BP 3370 EP 3375 DI 10.1063/1.363250 PG 6 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100036 ER PT J AU Chen, H Tong, J Hu, Z Shi, DT Wu, GH Chen, KT George, MA Collins, WE Burger, A James, RB Stahle, CM Bartlett, LM AF Chen, H Tong, J Hu, Z Shi, DT Wu, GH Chen, KT George, MA Collins, WE Burger, A James, RB Stahle, CM Bartlett, LM TI Low-temperature photoluminescence of detector grade Cd1-xZnxTe crystal treated by different chemical etchants SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BULK AB Low-temperature photoluminescence (PL) spectra of detector grade Cd1-xZnxTe (x=0.1) have been measured to obtain information about shallow level defect concentration introduced during mechanical polishing and chemical etching processes. We present here a comparative PL study of Cd0.9Zn0.1Te crystals treated by different chemical solutions used for nuclear detector surface treatment. The results show that the 5% Br-MeOH+2%Br-20% lactic acid in ethylene glycol treatment combines the advantages of bromine and lactic acid for chemical etching and results in the best surface condition, as evidenced by the largest I(D-0,X)/I-def intensity ratio and the narrowest full width at half-maximum of the main peak (D-0,X). Changes in the surface morphology were also analyzed by atomic force microscopy and correlated with the PL results. Current-voltage (I-V) curves and the room-temperature Fe-55 spectral response of the sample etched by the best treatment are also presented and discussed. (C) 1996 American Institute of Physics. C1 SANDIA NATL LABS,ADV ELECT MFG TECHNOL DEPT,LIVERMORE,CA 94550. NASA,GODDARD SPACE FLIGHT CTR,OSC,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,NRC,GREENBELT,MD 20771. RP Chen, H (reprint author), FISK UNIV,CTR PHOTON MAT & DEVICES,DEPT PHYS,NASHVILLE,TN 37208, USA. RI Hu, Zhiyu/J-7742-2013 NR 18 TC 60 Z9 69 U1 2 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 SEP 15 PY 1996 VL 80 IS 6 BP 3509 EP 3512 DI 10.1063/1.363222 PG 4 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100058 ER PT J AU Wen, Q Yu, N Clarke, DR AF Wen, Q Yu, N Clarke, DR TI Epitaxial thin-film ruby as an ion-irradiation damage sensor SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OPTICAL FLUORESCENCE; RESIDUAL-STRESSES; SAPPHIRE; COMPOSITES AB The fluorescence from a thin ruby film, formed by epitaxial growth on a sapphire substrate, is shown to be a sensitive monitor of both the irradiation dose and the strain produced by irradiation of argon ions having an end of range exceeding the thickness of the ruby film. Decreases in fluorescence intensity are detectable for doses in excess of 10(12) cm(2), whereas no damage is detectable by Rutherford backscattering spectrometry/channeling until doses almost two orders of magnitude larger. Using the systematic shift in fluorescence frequency observed with irradiation, it is concluded that lattice strain accumulates rapidly for doses in excess of 10(14) cm(2). (C) 1996 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Wen, Q (reprint author), UNIV CALIF SANTA BARBARA,COLL ENGN,DEPT MAT,SANTA BARBARA,CA 93106, USA. RI Clarke, David/D-2616-2009; Albe, Karsten/F-1139-2011 NR 12 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1996 VL 80 IS 6 BP 3587 EP 3589 DI 10.1063/1.363232 PG 3 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100069 ER PT J AU Bethardy, GA Northrup, FJ Macdonald, RG AF Bethardy, GA Northrup, FJ Macdonald, RG TI The initial vibrational level distribution and relaxation of HCN[(X)over-tilde(1)Sigma(+)(v(1),0,v(3))] in the CN(X(2)Sigma(+))+CH4->HCN+CH3 reaction system SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; ROTATIONAL ENERGY-TRANSFER; QUANTUM SCATTERING CALCULATIONS; RATE CONSTANTS; CHEMICAL-REACTIONS; REACTION DYNAMICS; CN REACTIONS; INFRARED CHEMILUMINESCENCE; STATE DISTRIBUTION; REACTION-PRODUCTS AB The reaction of the cyano radical (CN) with methane was studied by time-resolved infrared absorption spectroscopy by monitoring individual rovibrational states of the HCN and CH3 products. The initial vibrational level distribution of the bendless vibrational levels of HCN(upsilon(1),0,upsilon(3)) was determined by plotting the time dependence of the fractional population of a vibrational level and extrapolating these curves to the origin of time. About 20% of the HCN products were observed to be initially produced in the HCN(upsilon(1),0, upsilon(3)) vibrational levels, with vl and upsilon(3) = 0,1,2. The CN radical was created by laser photolysis of three different precursors. Each photolyte provided a different initial vibrational level distribution of CN; however, similar initial HCN(upsilon(1),0,upsilon(3)) vibrational level distributions were obtained independent of the CN radical precursor. This may indicate that the CN radical does not act as a spectator bond during the course of a reactive encounter for this system. The time dependence of the CH3 (000(0)0) ground state was also followed using time-resolved infrared absorption spectroscopy. Preliminary data indicates that a large fraction, if not all, the CH3 radicals are produced in their ground state in the title reaction. (C) 1996 American Institute of Physics. RP Bethardy, GA (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 73 TC 23 Z9 23 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 SEP 15 PY 1996 VL 105 IS 11 BP 4533 EP 4549 DI 10.1063/1.472537 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VG932 UT WOS:A1996VG93200013 ER PT J AU Treguier, AM Dukowicz, JK Bryan, K AF Treguier, AM Dukowicz, JK Bryan, K TI Properties of nonuniform grids used in ocean general circulation models SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NET DIFFUSIVITY AB Ocean general circulation models frequently use nonuniform grids, especially in the vertical direction. This paper clarifies the implications of using such grids on the consistency and accuracy of numerical schemes. It is emphasized that numerical schemes maintain their order of accuracy on a nonuniform grid provided the grid can be related to a smooth mapping. Additional metric terms appear in the truncation error, which should not be interpreted simply as a numerical diffusion. C1 IFREMER, LAB PHYS OCEANS, F-29280 PLOUZANE, FRANCE. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. PRINCETON UNIV, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08544 USA. RI Treguier, Anne Marie/B-7497-2009 OI Treguier, Anne Marie/0000-0003-4569-845X NR 8 TC 15 Z9 15 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1996 VL 101 IS C9 BP 20877 EP 20881 DI 10.1029/96JC01753 PG 5 WC Oceanography SC Oceanography GA VH015 UT WOS:A1996VH01500028 ER PT J AU Neergaard, LJ Nawaz, MB Tong, Y Jones, M Cesarano, J AF Neergaard, LJ Nawaz, MB Tong, Y Jones, M Cesarano, J TI Silicone-coated alumina powders by the emulsion technique SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB Alumina powders were prepared using an emulsion technique to chemically bond silanol-terminated poly dimethylsiloxane (PDMS or silicone) to the surface of alumina powders. Stable aqueous emulsions of silicone were prepared using Tween-80 surfactant. Transmission optical microscopy was used to measure the oil-droplet and coated-particle sizes. Fourier transform-infrared spectroscopy was used to quantify bonding between the silicone and the Al2O3. Coated powders were dry-pressed, and PDMS was compared to paraffin for dry-pressing behaviour and green strength. Densification studies were made on powders. X-ray diffraction and scanning electron microscopy were used to characterize the sintered ceramic. C1 SANDIA NATL LABS,CERAM PROC SCI DEPT,ALBUQUERQUE,NM 87185. RP Neergaard, LJ (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801, USA. NR 11 TC 8 Z9 8 U1 1 U2 6 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD SEP 15 PY 1996 VL 31 IS 18 BP 4779 EP 4783 DI 10.1007/BF00355861 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA VK397 UT WOS:A1996VK39700007 ER PT J AU Gjertsen, RK Jones, MT Plassmann, PE AF Gjertsen, RK Jones, MT Plassmann, PE TI Parallel heuristics for improved, balanced graph colorings SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID SPARSE MATRICES AB The computation of good, balanced graph colorings is an essential part of many algorithms required in scientific and engineering applications. Motivated by an effective sequential heuristic, we introduce a new parallel heuristic, PLF, and show that this heuristic has the same expected runtime under the PRAM computational model as the scalable coloring heuristic introduced by Jones and Plassmann. We present experimental results performed on the Intel DELTA that demonstrate that this new heuristic consistently generates better colorings and requires only slightly more time than the JP heuristic. In the second part of the paper we introduce two new parallel color-balancing heuristics, PDR(k) and PLF(k). We show that these heuristics have the desirable property that they do not increase the number of colors used by an initial coloring during the balancing process. We present experimental results that show that these heuristics are very effective in obtaining balanced colorings and, in addition, exhibit scalable performance. (C) 1996 Academic Press, Inc. C1 UNIV TENNESSEE, DEPT COMP SCI, KNOXVILLE, TN 37996 USA. ARGONNE NATL LAB, DIV MATH & COMP SCI, ARGONNE, IL 60439 USA. RP Gjertsen, RK (reprint author), UNIV ILLINOIS, DEPT COMP SCI, 1304 W SPRINGFIELD AVE, URBANA, IL 61801 USA. NR 26 TC 9 Z9 9 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 EI 1096-0848 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD SEP 15 PY 1996 VL 37 IS 2 BP 171 EP 186 PG 16 WC Computer Science, Theory & Methods SC Computer Science GA VT720 UT WOS:A1996VT72000005 ER PT J AU Hino, T Song, YH Prausnitz, JM AF Hino, T Song, YH Prausnitz, JM TI Liquid-liquid equilibria and theta temperatures in homopolymer-solvent solutions from a perturbed hard-sphere-chain equation of state SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE equation of state; phase equilibria; polymer solution; lower critical solution temperature; theta temperature ID BINARY COPOLYMER SYSTEMS; CLOUD-POINT CURVES; POLYMER-SOLUTIONS; POLYSTYRENE SOLUTIONS; LIGHT-SCATTERING; POLY(METHYL METHACRYLATE); MOLECULAR-WEIGHT; MIXTURES; BLENDS; THERMODYNAMICS AB The perturbed hard-sphere-chain (PHSC) equation of state is used to calculate liquid-liquid equilibria of binary nonpolar solvent/homopolymer systems exhibiting both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST). Systems studied include polyisobutylene, polyethylene, and polystyrene solutions. Equation-of-state parameters of homopolymers are obtained by regressing the pressure-volume-temperature data of polymer melts, In polymer solutions, however, theory overestimates the equation-of-state effect which causes the LCST at elevated temperature. To correct the overestimated equation-of-state effect, an empirical adjustable parameter is introduced into the perturbation term of the PHSC equation of state. An entropy parameter is also introduced into the Helmholtz energy of the mixture to correlate quantitatively the dependence of critical temperatures on polymer molecular weight. For systems exhibiting a LCST, two adjustable parameters are required to obtain quantitative agreement of theoretical critical temperatures with experiment as a function of polymer molecular weight. For systems exhibiting both an UCST and a LCST, three adjustable parameters may be necessary. The need for so many empirical binary parameters is probably due to the oversimplified perturbation term which is based on the mean-field assumption. (C) 1996 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 44 TC 13 Z9 13 U1 2 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 1996 VL 34 IS 12 BP 1961 EP 1976 PG 16 WC Polymer Science SC Polymer Science GA VC183 UT WOS:A1996VC18300006 ER PT J AU Hino, T Song, YH Prausnitz, JM AF Hino, T Song, YH Prausnitz, JM TI Liquid-liquid equilibria and theta temperatures in binary solvent-copolymer solutions from a perturbed hard-sphere-chain equation of state SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE equation of state; phase equilibria; copolymer solution; lower critical solution temperature; theta temperature ID PHASE-BEHAVIOR; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); POLYMER-SOLUTIONS; MISCIBILITY; BLENDS; POLYSTYRENE; MIXTURES; SYSTEMS; THERMODYNAMICS AB The perturbed hard-sphere-chain (PHSC) equation of state for copolymer systems is used to calculate liquid-liquid equilibria for binary solvent/copolymer systems that exhibit simultaneously an upper critical solution temperature (UCST) and a lower critical solution temperature. The PHSC equation of state for copolymer solutions uses those binary parameters that represent liquid-liquid equilibria for the two parent homopolymer solutions. An additional intersegmental parameter is also required to define the interaction energy between a pair of chemically dissimilar segments comprising the copolymer molecule, Theory is compared with experiment for binary copolymer solutions containing poly(styrene-co-alpha-methylstyrene) random copolymers. Using the same kappa(BC), the intersegmental parameter between styrene and a-methylstyrene segments, theory and experiment show fair agreement for the copolymer-composition dependence of theta temperatures associated with UCST in cyclohexane, methyl cyclohexane, and decalin. A comparison is also made between kappa(BC) obtained from the copolymer-solution data and that obtained from the coexistence curve of homopolymer blends containing polystyrene and poly(alpha-methylstyrene). Data for copolymer solutions require a kappa(BC) that represents interactions more unfavorable than those in homopolymer blends. (C) 1996 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 30 TC 6 Z9 6 U1 1 U2 5 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 1996 VL 34 IS 12 BP 1977 EP 1985 DI 10.1002/(SICI)1099-0488(19960915)34:12<1977::AID-POLB3>3.0.CO;2-N PG 9 WC Polymer Science SC Polymer Science GA VC183 UT WOS:A1996VC18300007 ER PT J AU Burton, H AF Burton, H TI The Cambridge dictionary of scientists - Millar,D SO LIBRARY JOURNAL LA English DT Book Review RP Burton, H (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 SN 0363-0277 J9 LIBR J JI Libr. J. PD SEP 15 PY 1996 VL 121 IS 15 BP 54 EP & PG 2 WC Information Science & Library Science SC Information Science & Library Science GA VR884 UT WOS:A1996VR88400017 ER PT J AU Raj, R AF Raj, R TI A mechanistic basis for high strain rate super-plasticity of aluminum based metal matrix composites SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE high strain rate; superplasticity; aluminium; metal matrix composites ID DIFFUSIONAL CREEP; SUPERPLASTICITY; DUCTILITY; ALLOYS; FLOW; AL AB Aluminum based metal matrix composites exhibit superplasticity at unusually fast strain rates (0.01 to 100s(-1)). An analysis of these data suggests the presence of a superplastic anomaly, characterized by high values of the strain rate sensitivity, and by flow stresses that depend on the grain size, even though the nominal deformation mechanism lies in the power law creep regime. The anomaly is explained in terms of stochastic events of rapid grain boundary sliding. These events are nucleated by stress induced grain boundary migration which, by reducing the amplitude of the boundary shape, accelerate the rate of diffusion accommodated sliding. An equation for the strain rate where such supercritical sliding events are expected is derived. This equation has the same form as the classical equation for diffusional creep except that it is multiplied by an acceleration factor of magnitude 80-38O. In this way relationships between stress, strain rate, temperature, and grain size that quantitatively describe the onset of the anomaly are obtained. RP Raj, R (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MS-K765,LOS ALAMOS,NM 87545, USA. NR 24 TC 2 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1996 VL 215 IS 1-2 BP 1 EP 8 DI 10.1016/0921-5093(96)10216-1 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VU062 UT WOS:A1996VU06200001 ER PT J AU Heidelbach, F Wenk, HR Chen, SR Pospiech, J Wright, SI AF Heidelbach, F Wenk, HR Chen, SR Pospiech, J Wright, SI TI Orientation and misorientation characteristics of annealed, rolled and recrystallized copper SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE copper; orientation ID SINGLE-CRYSTALS; TEXTURES AB The texture and microstructure of annealed, rolled and recrystallized copper (99.99%) were investigated using conventional X-ray diffraction and single-crystal electron backscattering diffraction (EBSP) in a scanning electron microscope. From the EBSP data, misorientation distribution functions for next neighbor orientation relationships were derived, which show that the undeformed (annealed) starting material and the recrystallised sample have primary and secondary twin correlations, whereas in the deformed sample no preferred misorientations are observed. The microtexture of a single grain with twin lamellae in the deformed sample was analysed in detail using automated analysis of electron backscattering diffraction patterns. The twin relationship is transformed continuously into a high angle grain boundary during deformation. Orientation gradients within one grain increase steadily up to 20 degrees. C1 LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. POLISH ACAD SCI,MET RES INST,KRAKOW,POLAND. NR 26 TC 19 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1996 VL 215 IS 1-2 BP 39 EP 49 DI 10.1016/0921-5093(96)10264-1 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VU062 UT WOS:A1996VU06200005 ER PT J AU Hsieh, KC Babu, SS Vitek, JM David, SA AF Hsieh, KC Babu, SS Vitek, JM David, SA TI Calculation of inclusion formation in low-alloy-steel welds SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE thermodynamics; low-alloy-steel-welds; acicular ferrite; inclusions ID ARC WELDS; NUCLEATION; MICROSTRUCTURE; STRENGTH; FERRITE; BAINITE; METALS; PHASES AB Equilibrium thermodynamic calculations were performed to predict the sequential inclusion formation in low-alloy-steel welds. In the calculations the multi-phase equilibrium between oxides and liquid steel was considered. The oxidation sequence was found to be sensitive to small changes in the weld metal composition. The calculations are compared with experimental measurements available in the literature. Calculated aluminum and titanium concentrations in solid solution in the weld correlated well with experimental data. The calculations indicate that the present method can be used as a first approximation to describe the inclusions formation in low-alloy-steel welds. The results are discussed with reference to the acicular ferrite microstructure development. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 20 TC 27 Z9 27 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 1996 VL 215 IS 1-2 BP 84 EP 91 DI 10.1016/0921-5093(96)10370-1 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VU062 UT WOS:A1996VU06200010 ER PT J AU Wu, GW Liu, LZ Buu, VB Chu, B Schneider, DK AF Wu, GW Liu, LZ Buu, VB Chu, B Schneider, DK TI SANS and SAXS studies of pluronic L64 in concentrated solution SO PHYSICA A LA English DT Article; Proceedings Paper CT Workshop on Colloid and Interface Science - Trends and Applications, on the Occasion of the Celebration of the 60th Birthday of Sow-Hsin Chen CY MAY 02-05, 1995 CL GUANICA, PR SP ES, PSCoR NSF, USN, Off Naval Res ID OXIDE) TRIBLOCK-COPOLYMER; COPOLY(OXYETHYLENE OXYPROPYLENE OXYETHYLENE); OSCILLATORY SHEAR MEASUREMENTS; DYNAMIC LIGHT-SCATTERING; AQUEOUS-SOLUTION; BLOCK-COPOLYMER; POLYMERIC MICELLES; PHASE-BEHAVIOR; O-XYLENE; WATER AB The supramolecular structure, formed by a PEO-PPO-PEO copolymer, PEO(13)PPO(30)- PEO(13) or Pluronic L64, in mixtures of xylene/water, was investigated by small-angle X-ray scattering over a temperature range of 25-60 degrees C and by small-angle neutron scattering over a temperature range of 13-29 degrees C. The large aggregates had a hexagonally packed cylindrical structure with the interdomain spacing being in the order of similar to 10 nm. The interdomain spacing increased with increasing amount of solubilized water in the large aggregates. C1 SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT MAT SCI & ENGN,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 33 TC 12 Z9 13 U1 3 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1996 VL 231 IS 1-3 BP 73 EP 81 DI 10.1016/0378-4371(95)00445-9 PG 9 WC Physics, Multidisciplinary SC Physics GA VH367 UT WOS:A1996VH36700006 ER PT J AU Sinha, SK Feng, YP Melendres, CA Lee, DD Russell, TP Satija, SK Sirota, EB Sanyal, MK AF Sinha, SK Feng, YP Melendres, CA Lee, DD Russell, TP Satija, SK Sirota, EB Sanyal, MK TI Off-specular X-ray scattering studies of the morphology of thin films SO PHYSICA A LA English DT Article; Proceedings Paper CT Workshop on Colloid and Interface Science - Trends and Applications, on the Occasion of the Celebration of the 60th Birthday of Sow-Hsin Chen CY MAY 02-05, 1995 CL GUANICA, PR SP ES, PSCoR NSF, USN, Off Naval Res ID DIBLOCK COPOLYMER FILMS; NEUTRON REFLECTIVITY; MULTILAYER FILMS; ROUGH SURFACES; INSITU AB We discuss the scattering of X-rays from thin films at a surface or interface decorated with a morphology of islands and how these effects manifest themselves in the specular reflectivity and the diffuse (off-specular) scattering. We show how this technique has been used to study block copolymer films decorated with islands on the surface and the development of electrochemically induced pitting on a Cu electrode in an electrolyte solution. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. EXXON RES & ENGN CO,CORP RES,ANNANDALE,NJ 08801. SAHA INST NUCL PHYS,CALCUTTA 700009,W BENGAL,INDIA. RP Sinha, SK (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,EXPT FACIL DIV,ARGONNE,IL 60439, USA. RI Sirota, Eric/A-7633-2009; Lee, Daniel/B-5753-2013; sanyal, milan/J-2527-2015 OI sanyal, milan/0000-0002-3847-8793 NR 21 TC 15 Z9 15 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1996 VL 231 IS 1-3 BP 99 EP 110 DI 10.1016/0378-4371(96)00085-4 PG 12 WC Physics, Multidisciplinary SC Physics GA VH367 UT WOS:A1996VH36700008 ER PT J AU Benedek, R Minkoff, M Yang, LH AF Benedek, R Minkoff, M Yang, LH TI Adhesive energy and charge transfer for MgO/Cu heterophase interfaces SO PHYSICAL REVIEW B LA English DT Article ID METAL-CERAMIC INTERFACES; ELECTRON-MICROSCOPY; IMAGE INTERACTIONS; POINT-DEFECTS; PRINCIPLES AB Local-density-functional-theory (LDFT) calculations within the plane-wave pseudopotential framework are performed for two polar (111) and two nonpolar (100) MgO/Cu interfaces. The polar interfaces have larger works of adhesion than nonpolar ones, consistent with field-ion and electron-microscopy observations of (111) interfaces in internally oxidized specimens. Large shifts in the potential of the interface layer relative to the bulk occur in the polar bur not in the nonpolar interfaces. For both polar and nonpolar interfaces, the charge transfer profile is essentially confined to two layers on each side of the interface. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. LAWRENCE LIVERMORE NATL LAB,DEPT CONDENSED MATTER PHYS,LIVERMORE,CA 94551. RP Benedek, R (reprint author), NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. NR 30 TC 90 Z9 90 U1 1 U2 8 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 SEP 15 PY 1996 VL 54 IS 11 BP 7697 EP 7700 DI 10.1103/PhysRevB.54.7697 PG 4 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500028 ER PT J AU Jin, XF Mao, MY Ko, S Shen, YR AF Jin, XF Mao, MY Ko, S Shen, YR TI Adsorption and desorption kinetics of CO on Cu(110) studied by optical differential reflectance SO PHYSICAL REVIEW B LA English DT Article ID SURFACE-DIFFUSION; DIFFRACTION; PARAMETERS; ADSORBATE AB Optical differential reflectance was shown to be a viable technique to study surface adsorption and desorption kinetics. Its application to CO on Cu(110) leads to clearly improved results and better understanding of the system in comparison with earlier thermal desorption measurements. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Jin, XF (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 17 TC 18 Z9 18 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 SEP 15 PY 1996 VL 54 IS 11 BP 7701 EP 7704 DI 10.1103/PhysRevB.54.7701 PG 4 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500029 ER PT J AU Wolverton, C Zunger, A Froyen, S Wei, SH AF Wolverton, C Zunger, A Froyen, S Wei, SH TI Point-charge electrostatics in disordered alloys SO PHYSICAL REVIEW B LA English DT Article ID 1ST-PRINCIPLES STATISTICAL-MECHANICS; RANDOM SUBSTITUTIONAL ALLOYS; SHORT-RANGE ORDER; ELECTRONIC-STRUCTURE; INTERMETALLIC COMPOUNDS; SEMICONDUCTOR ALLOYS; MADELUNG LATTICE; PHASE-DIAGRAMS; CU-AU; METALLIC ALLOYS AB A simple analytic model of point-ion electrostatics has been previously proposed [R. Magri, S. -H. Wei, and A. Zunger, phys. Rev. 42, 11 388 (1990)] in which the magnitude of the net charge qi on each atom in an ordered or random alloy depends linearly on the number N-i((1)) of unlike neighbors in its first coordination shell. Point charges extracted from recent large supercell (256-432 atom) local density approximation (LDA) calculations of Cu1-xZnx random alloys now enable an assessment of the physical validity and accuracy of the simple model. We find that this model accurately describes (i) the trends in q(i) vs N-i((1)), particularly for fee alloys, (ii) the magnitudes of total electrostatic energies in random alloys, (iii) the relationships between constant-occupation-averaged charges [q(i)] and Coulomb shifts [V-i] (i.e., the average over all sites occupied by either A or B atoms) in the random alloy, and (iv) the linear relation between the site charge q(i) and the constant-charge-averaged Coulomb shift <(V)over bar (i)> (i.e., the average over all sites with the same charge) for fcc alloys, However, for bcc alloys the fluctuations predicted by the model in the q(i) vs V-i relation exceed those found in the LDA supercell calculations. We find that (a) the fluctuations present in the model have a vanishing contribution to the electrostatic energy. (b) Generalizing the model to include a dependence of the charge on the atoms in the first three (two) shells in bcc (fee) - rather than the first shell only - removes the fluctuations, in complete agreement with the LDA data. We also demonstrate an efficient way to extract charge transfer parameters of the generalized model from LDA calculations on small unit cells. RP Wolverton, C (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Wolverton, Christopher/B-7542-2009; Zunger, Alex/A-6733-2013 NR 42 TC 23 Z9 23 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1996 VL 54 IS 11 BP 7843 EP 7856 DI 10.1103/PhysRevB.54.7843 PG 14 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500048 ER PT J AU Leung, CM Weinert, M Allen, PB Wentzcovitch, RM AF Leung, CM Weinert, M Allen, PB Wentzcovitch, RM TI First-principles study of titanium oxides SO PHYSICAL REVIEW B LA English DT Article ID ELECTRICAL-RESISTIVITY; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; PSEUDOPOTENTIALS; MONOXIDES; STATE AB Titanium forms a wide range of stoichiometric oxides. The low-temperature monoclinic phase of titanium monoxide Ti5O5 has an ordered array of vacancies in an otherwise simple NaCl structure. Using the variable cell shape method and the local-density approximation, all 12 parameters of the crystal structure are relaxed. Comparisons with other possible structures and other transition-metal monoxides suggest that there is a competition between kinetic- and Madelung-energy contributions and that this low symmetry structure is stabilized in part by the overlap of occupied Ti-ion orbitals via the vacant oxygen site. Resistivities of the low-temperature Ti5O5 phase fitted using the Bloch-Gruneisen formula imply that the monoxide is a borderline quasiparticle gas. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV MINNESOTA,MINNESOTA SUPERCOMP INST,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Leung, CM (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. RI Wentzcovitch, Renata/J-8768-2015 NR 30 TC 41 Z9 42 U1 0 U2 11 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 SEP 15 PY 1996 VL 54 IS 11 BP 7857 EP 7864 DI 10.1103/PhysRevB.54.7857 PG 8 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500049 ER PT J AU vanEk, J Turchi, PEA Sterne, PA AF vanEk, J Turchi, PEA Sterne, PA TI Fe, Ru, and Os disilicides: Electronic structure of ordered compounds SO PHYSICAL REVIEW B LA English DT Article ID IRON DISILICIDE; BAND-GAP; BETA-FESI2; FILMS AB Electronic structure properties of MSi(2), where M=Fe, Ru, or Os, in the orthorhombic beta phase are investigated using the linear muffin-tin orbital method in the atomic sphere approximation. Selective substitution of Fe with Ru, Os, and Cr in beta-FeSi2 is also studied. These compounds are small-gap semiconductors with theoretical energy band gaps ranging from 0.06 to 0.50 eV, with the exception of the metallic Cr-substituted disilicides. Substitution of Ru or Os for Fe in beta P-FeSi2 leads to a reduction of the gap width, an increase in volume of the unit cell, and a bulk modulus similar to or slightly smaller than for beta-FeSi2. Although the theoretical lattice constant of beta-OsSi2 agrees well with experiment, the calculated band gap (0.06 eV) is much smaller than the band gap in beta-FeSi2. This strongly contrasts with experimental observations that suggest a larger band gap in beta-OsSi2 (1.4 - 1.8 eV). Consideration of a proposed metastable monoclinic form of OsSi2 does not remedy this discrepancy, since it is found to be a semimetal. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP vanEk, J (reprint author), LAWRENCE LIVERMORE NATL LAB,L-268,POB 808,LIVERMORE,CA 94551, USA. NR 31 TC 25 Z9 25 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 SEP 15 PY 1996 VL 54 IS 11 BP 7897 EP 7908 DI 10.1103/PhysRevB.54.7897 PG 12 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500054 ER PT J AU Klimov, VI Karavanskii, VA AF Klimov, VI Karavanskii, VA TI Mechanisms for optical nonlinearities and ultrafast carrier dynamics in CuxS nanocrystals SO PHYSICAL REVIEW B LA English DT Article ID SEMICONDUCTOR-DOPED GLASSES; CDSE QUANTUM DOTS; POROUS SILICON; FEMTOSECOND; LUMINESCENCE; TRANSMISSION; RECOMBINATION; ABSORPTION AB Mechanisms for optical nonlinearities and ultrafast carrier dynamics in CuxS nanocrystals (NC's) are studied using femtosecond pump-probe techniques and nanosecond Z-scan measurements. Depending on the copper deficiency, transient absorption is dominated either by state-filling-induce bleaching [for copper sulfide phases with x = 1.8 (digenite), 1.9, and 1.96 (djurleite)] or by photoinduced absorption [x = 2 (chalcosite)]. This difference is explained in terms of the change in the dominant nonlinear-optical mechanism resulting from an indirect-direct-gap transformation accompanying the increase in copper deficiency. Extremely fast signal relaxation (on the time scale from 400 fs to 4 ps) observed in the initial stage after excitation is attributed to carrier trapping. The existence of different types of nonlinearities in CuxS NC's formed by direct- and indirect-gap phases of copper sulfide is confirmed by results of the Z-scan measurements. C1 INST GEN PHYS,MOSCOW 117942,RUSSIA. RP Klimov, VI (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST-6,MS-J585,LOS ALAMOS,NM 87545, USA. NR 30 TC 38 Z9 39 U1 0 U2 16 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 SEP 15 PY 1996 VL 54 IS 11 BP 8087 EP 8094 DI 10.1103/PhysRevB.54.8087 PG 8 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500077 ER PT J AU Shalaev, VM Botet, R Mercer, J Stechel, EB AF Shalaev, VM Botet, R Mercer, J Stechel, EB TI Optical properties of self-affine thin films SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; METAL COLLOID CLUSTERS; LIGHT-SCATTERING; ROUGH SURFACES; EXCITATIONS; ABSORPTION; GRAINS; IMAGES; LIMIT AB Optical properties of self-affine thin films are studied in the quasistatic approximation. The eigenmodes of a self-affine surface manifest strongly inhomogeneous spatial distributions characterized by various degree of localization. On a metal self-affine film, the intensities in areas of high local fields (''hot'' zones) exceed the applied field intensity by approximately three orders of magnitude. The spatial locations of the hot zones are very strong functions of the frequency and polarization of the incident light. C1 UNIV PARIS 11, CTR ORSAY, PHYS SOLIDES LAB, F-91405 ORSAY, FRANCE. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP NEW MEXICO STATE UNIV, DEPT PHYS, LAS CRUCES, NM 88003 USA. RI Stechel, Ellen/B-1253-2012 NR 31 TC 53 Z9 54 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1996 VL 54 IS 11 BP 8235 EP 8242 DI 10.1103/PhysRevB.54.8235 PG 8 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500096 ER PT J AU Chin, RP Huang, JY Shen, YR Chuang, TJ Seki, H AF Chin, RP Huang, JY Shen, YR Chuang, TJ Seki, H TI Interactions of hydrogen and methyl radicals with diamond C(111) studied by sum-frequency vibrational spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; SURFACE; GENERATION; FORMULAS; SPECTRUM; GROWTH; MODES; FILMS; BAND; CH3 AB Methyl-radical and atomic hydrogen adsorption on C(111) have-been studied by infrared-visible sum-frequency vibrational spectroscopy. Methyl iodide, di-tert-butyl-peroxide, and methane passing through a hot filament are used to produce methyl radicals (CH3). Low-energy CH3 from pyrolytic dissociation at similar to 800 degrees C adsorb intact on the surface, but with surface annealing above 350 degrees C, convert to tetrahedrally bonded CH. High-energy CH3 produced at similar to 1800 degrees C convert readily to CH upon adsorption. Go-dosing a high-temperature (similar to 800 degrees C) C(111) substrate with hydrogen and methane via a hot filament at similar to 1800 degrees C yields only the stable tetrahedrally-bonded CH-species on the surface. They appear to stabilize the diamond surface structure. The coverage is not full, leaving sites open for CH3 to adsorb and convert to CH as is necessary for chemical vapor deposition diamond growth. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. ACAD SINICA,INST ATOM & MOL SCI,TAIPEI 115,TAIWAN. IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. NR 39 TC 17 Z9 17 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 SEP 15 PY 1996 VL 54 IS 11 BP 8243 EP 8251 DI 10.1103/PhysRevB.54.8243 PG 9 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500097 ER PT J AU Kolb, EW Riotto, A AF Kolb, EW Riotto, A TI Eternal annihilations of light photinos SO PHYSICAL REVIEW D LA English DT Article ID BIG-BANG NUCLEOSYNTHESIS; DARK-MATTER; PARTICLES; CONSTRAINTS; ABUNDANCE; DEUTERIUM; ELEMENTS; UNIVERSE AB In a class of low-energy supersymmetry models the photino is a natural dark-matter candidate. We investigate the effects of post-freeze-out photino annihilations that generate electromagnetic cascades and lead to photodestruction of He-4 and subsequent overproduction of D and He-3. We also generalize our analysis of electromagnetic showers to include those from a generic dark-matter component whose relic abundance is not determined by the self-annihilation cross section. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Kolb, EW (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 31 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1996 VL 54 IS 6 BP 3722 EP 3726 DI 10.1103/PhysRevD.54.3722 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VK631 UT WOS:A1996VK63100007 ER PT J AU Burakovsky, L Horwitz, LP Schieve, WC AF Burakovsky, L Horwitz, LP Schieve, WC TI New relativistic high-temperature Bose-Einstein condensation SO PHYSICAL REVIEW D LA English DT Article ID 2-BODY BOUND-STATE; SYMMETRY-BREAKING; QUANTUM-MECHANICS; MASS-DISTRIBUTION; FINITE-TEMPERATURE; CURVED SPACETIME; GAUGE-THEORIES; SCALAR FIELDS; D DIMENSIONS; GAS AB We discuss the properties of an ideal relativistic gas of events Possessing Bose-Einstein statistics. We find that the mass spectrum of such a system is bounded by mu less than or equal to m less than or equal to 2M/mu(K), where mu is the usual chemical potential, M is an intrinsic dimensional scale parameter for the motion of an event in space time, and mu(K) is an additional mass potential of the ensemble. For the system including both particles and antiparticles, with a nonzero chemical potential mu, the mass spectrum is shown to be bounded by /mu/ less than or equal to m less than or similar to 2M/mu(K), and a special type of high-temperature Bose-Einstein condensation can occur. We study this Bose-Einstein condensation, and show that it corresponds to a phase transition from the sector of continuous relativistic mass distributions to a sector in which the boson mass distribution becomes sharp at a definite mass M/mu(K). This phenomenon provides a mechanism for the mass distribution of the particles to be sharp at some definite value. C1 INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. UNIV TEXAS,ILYA PRIGOGINE CTR STUDIES STAT MECH,AUSTIN,TX 78712. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 58 TC 23 Z9 24 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 SEP 15 PY 1996 VL 54 IS 6 BP 4029 EP 4038 DI 10.1103/PhysRevD.54.4029 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VK631 UT WOS:A1996VK63100039 ER PT J AU Morningstar, CJ Weinstein, M AF Morningstar, CJ Weinstein, M TI Contractor renormalization group technology and exact Hamiltonian real-space renormalization group transformations SO PHYSICAL REVIEW D LA English DT Article ID EFFECTIVE FIELD-THEORY; VARIATIONAL-METHODS; LATTICE THEORIES; KONDO-LATTICE; HEAVY MESONS; SYSTEMS; SUPERCONDUCTIVITY; FORMULATION; ALGORITHMS; SPECTRUM AB The contractor renormalization group method, a new approach to solving Hamiltonian lattice systems, is presented. The method. defines a systematic and nonperturbative means of implementing Kadanoff-Wilson real-space renormalization group transformations using cluster expansion and contraction techniques. We illustrate the approach and demonstrate its effectiveness using scalar field theory, the Heisenberg antiferromagnetic chain, and the anisotropic Ising chain. Future applications to the Hubbard and t-J models and lattice gauge theory are discussed. C1 STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. RP UNIV CALIF SAN DIEGO, DEPT PHYS, LA JOLLA, CA 92093 USA. RI Morningstar, Colin/N-6925-2014 OI Morningstar, Colin/0000-0002-0607-9923 NR 51 TC 74 Z9 74 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1996 VL 54 IS 6 BP 4131 EP 4151 DI 10.1103/PhysRevD.54.4131 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VK631 UT WOS:A1996VK63100048 ER PT J AU Lykken, JD AF Lykken, JD TI Weak scale superstrings SO PHYSICAL REVIEW D LA English DT Article ID STRING THEORY; 6 DIMENSIONS AB Recent developments in string duality suggest that the string scale may not be irrevocably tied to the Planck scale. Two explicit but unrealistic examples are described where the ratio of the string scale to the Planck scale is arbitrarily small. Solutions that are more realistic may exist in the intermediate coupling or ''truly strong coupling'' region of the heterotic string. Weak scale superstrings have dramatic experimental consequences for both collider physics and cosmology. RP Lykken, JD (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 36 TC 572 Z9 573 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 1996 VL 54 IS 6 BP R3693 EP R3697 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VK631 UT WOS:A1996VK63100004 ER PT J AU Merrill, DW Selvin, S Close, ER Holmes, HH AF Merrill, DW Selvin, S Close, ER Holmes, HH TI Use of density equalizing map projections (DEMP) in the analysis of childhood cancer in four California counties SO STATISTICS IN MEDICINE LA English DT Article; Proceedings Paper CT 5th Symposium on Statistical Methods - Small Area Statistics in Public Health: Design, Analysis, Graphic and Spatial Methods CY 1995 CL ATLANTA, GA SP Ctr Dis Control & Prevent, Agcy Tox Subst & Dis Registry AB In studying geographic disease distributions, one normally compares rates among arbitrarily defined geographic subareas (for example, census tracts), thereby sacrificing the geographic detail of the original data. The sparser the data, the larger the subareas must be in order to calculate stable rates. This dilemma is avoided with he technique of density equalizing map projections (DEMP). Boundaries of geographic subregions are adjusted to equalize population density over the entire study area. Case locations plotted on the transformed map should have a uniform distribution if the underlying disease rates are constant. The present report describes the application of the DEMP technique to 401 childhood cancer cases occurring between 1980 and 1988 in four California counties, with the use of map files and population data for the 262 tracts of the 1980 census. A kth nearest neighbour analysis provides strong evidence for geographic non-uniformity in tract rates (p<10(-4)). No such effect is observed for artificial cases generated under the assumption of constant rates. Work is in progress to repeat the analysis with improved population estimates derived from both 1980 and 1990 census data. Final epidemiologic conclusions will be reported when that analysis is complete. RP Merrill, DW (reprint author), UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,INFORMAT & COMP SCI DIV,BERKELEY,CA 94720, USA. NR 16 TC 9 Z9 9 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0277-6715 J9 STAT MED JI Stat. Med. PD SEP 15 PY 1996 VL 15 IS 17-18 BP 1837 EP 1848 DI 10.1002/(SICI)1097-0258(19960915)15:17<1837::AID-SIM395>3.0.CO;2-E PG 12 WC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Medicine, Research & Experimental; Statistics & Probability SC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Research & Experimental Medicine; Mathematics GA VG312 UT WOS:A1996VG31200003 PM 8888476 ER PT J AU Ducharme, D Vaknin, D Paudler, M Salesse, C Riegler, H Mohwald, H AF Ducharme, D Vaknin, D Paudler, M Salesse, C Riegler, H Mohwald, H TI Surface properties of valine-gramicidin A at the air-water interface SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 7th International Conference on Organized Molecular Films (LB7) CY SEP 10-15, 1995 CL NUMANA, ITALY SP Ist Nazl Biostruct & Biosistemi, Ist Natl Fis Mat, Soc Chim Italiana, Soc Italiana Fis, Univ Ancona DE gramicidin A; monolayers; ellipsometry; X-ray reflectivity ID MONOLAYERS; MIXTURES; COMPLEX AB Fluorescence microscopy, X-ray reflectivity and ellipsometry have been applied to the study of a monolayer of valine-gramicidin A (VGA) at the air-water interface to obtain insight into the conformation and orientation of VGA, and to clarify the shoulder observed in its pi-A curve (12.5-16 mN m(-1), 240-175 Angstrom(2) molecule(-1)). At low molecular areas, the X-ray reflectivities are consistent with formation of a single layer of tubular-shaped dimers. Fluorescence microscopy yielded homogeneous pictures suggesting that on the macroscopic scale the shoulder cannot be attributed to domain formation. Thicknesses calculated from the ellipsometric isotherm are consistent with the X-ray data. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. UNIV MAINZ, INST PHYS CHEM, D-6500 MAINZ, GERMANY. UNIV QUEBEC, CTR RECH PHOTOBIOPHYS, TROIS RIVIERES, PQ, CANADA. RP Ducharme, D (reprint author), COLL SHAWINIGAN, SHAWINIGAN, PQ, CANADA. RI Mohwald, Helmuth/B-8265-2014; Vaknin, David/B-3302-2009 OI Mohwald, Helmuth/0000-0001-7833-3786; Vaknin, David/0000-0002-0899-9248 NR 14 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 15 PY 1996 VL 284 BP 90 EP 93 DI 10.1016/S0040-6090(95)08278-6 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VV928 UT WOS:A1996VV92800024 ER PT J AU Malik, A Durbin, MK Richter, AG Huang, KG Dutta, P AF Malik, A Durbin, MK Richter, AG Huang, KG Dutta, P TI Order in Langmuir-Blodgett films of lead and cadmium stearate: An X-ray diffraction study SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 7th International Conference on Organized Molecular Films (LB7) CY SEP 10-15, 1995 CL NUMANA, ITALY SP Ist Nazl Biostruct & Biosistemi, Ist Natl Fis Mat, Soc Chim Italiana, Soc Italiana Fis, Univ Ancona DE Langmuir-Blodgett films; X-ray diffraction; structural properties; cadmium stearate AB We have studied monolayer and multilayer Langmuir-Blodgett films of lead stearate and cadmium stearate using grazing incidence X-ray diffraction. We find that although these two types of films have similar in-plane structures, lead stearate forms better ordered films: the correlation length increases with the number of layers in lead stearate but levels off at the three-layer value in cadmium stearate. The lattices of adjacent lead ion layers are correlated, but adjacent cadmium layers are not. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP Malik, A (reprint author), NORTHWESTERN UNIV, DEPT PHYS & ASTRON, EVANSTON, IL 60208 USA. NR 7 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 15 PY 1996 VL 284 BP 144 EP 146 DI 10.1016/S0040-6090(95)08292-1 PG 3 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VV928 UT WOS:A1996VV92800038 ER PT J AU Gregory, BW Vaknin, D Cotton, TM Struve, WS AF Gregory, BW Vaknin, D Cotton, TM Struve, WS TI Interfacial complexation of phospholipid Langmuir monolayers with water-soluble porphyrins and phthalocyanines: An X-ray reflectivity study SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 7th International Conference on Organized Molecular Films (LB7) CY SEP 10-15, 1995 CL NUMANA, ITALY SP Ist Nazl Biostruct & Biosistemi, Ist Natl Fis Mat, Soc Chim Italiana, Soc Italiana Fis, Univ Ancona DE X-ray reflectivity; light-harvesting assembly; phthalocyanine; porphyrin AB The use of Coulombic forces to isolate charged, water-soluble macrocycles at the air-water interface (through their interactions with the oppositely charged headgroups of a phospholipid Langmuir monolayer) is currently being exploited in this laboratory as a means to create two-dimensional arrays of pigments. Significant differences have been observed in the surface pressure-molecular area (pi-A) isotherms of dihexadecyl phosphate on subphases containing either copper (II) tetra-(methylaza)-phthalocyanine or tetra-(methylpyridyl)-porphyrin, both of which are cationic. In-situ X-ray specular reflectivity has been employed to determine interfacial organization in these systems and to elucidate the origin of their different phase behavior at the air-water interface. 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. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RI Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 11 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 15 PY 1996 VL 284 BP 849 EP 853 DI 10.1016/S0040-6090(95)08462-2 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VV928 UT WOS:A1996VV92800209 ER PT J AU Branagan, DJ Hyde, TA Sellers, CH McCallum, RW AF Branagan, DJ Hyde, TA Sellers, CH McCallum, RW TI Developing rare earth permanent magnet alloys for gas atomization SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID ELECTRON-MICROSCOPY; B RIBBONS; FE; DOMAINS AB The development of inert gas atomization (IGA) as a primary production route for Nd-Fe-B type magnets has not been commercially successful due to a cooling rate which is much lower than the maximum achievable in melt-spinning (MS). It is further complicated by the fact that powder particles of a range of sizes are produced which solidify at different rates and form significantly different microstructures. The role of the cooling rate is analysed in a general way by processing the same alloy composition by IGA and MS. MS allows a much broader but controlled range of cooling rates to be studied than is possible in IGA. General MS concepts of underquenching and overquenching are applied to IGA to indicate the state of the microstructure. Although the bulk of the IGA powder was formed in an underquenched condition, energy products approaching those obtainable in optimally quenched MS ribbons could be achieved in the finest size fraction (5-10 mu m) of powder. Changes in susceptibility shaw the general trend of improvement in hard magnetic property with decreasing scale of the microstructure. Quenchability diagrams show that TIC additions to the base alloy increase the quenchability and may allow future IGA alloys to be produced in an overquenched condition. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,IOWA CITY,IA. US DOE,AMES LAB,IOWA CITY,IA. RP Branagan, DJ (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 30 TC 12 Z9 12 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD SEP 14 PY 1996 VL 29 IS 9 BP 2376 EP 2385 DI 10.1088/0022-3727/29/9/022 PG 10 WC Physics, Applied SC Physics GA VH755 UT WOS:A1996VH75500023 ER PT J AU Paul, PH Gray, JA Durant, JL Thoman, JW AF Paul, PH Gray, JA Durant, JL Thoman, JW TI Collisional electronic quenching rates for NO A(2)Sigma(+)(upsilon'=0) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NITRIC-OXIDE; PRESSURE FLAMES; SHOCK-TUBE; A2-SIGMA+; LIFETIMES; MODEL; COMBUSTION; NITROGEN; GASES; V'=0 AB We report rate coefficients for electronic quenching of NO A(2) Sigma(+)(upsilon' = 0) by CO, CO2, H-2, H2O, O-2, NO, N2O, NO2, and Ar measured at room temperature and at elevated temperatures behind reproducible shocks. The magnitudes of the rates and the observed temperature dependencies of NO A(2) Sigma(+) quenching by these collision partners are found to be in accord with a charge-transfer (harpoon) collision model for the process. C1 WILLIAMS COLL,DEPT CHEM,WILLIAMSTOWN,MA 01267. RP Paul, PH (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550, USA. NR 31 TC 41 Z9 41 U1 0 U2 7 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 SEP 13 PY 1996 VL 259 IS 5-6 BP 508 EP 514 DI 10.1016/0009-2614(96)00763-4 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VG765 UT WOS:A1996VG76500007 ER PT J AU Feldberg, SW Goldstein, CI Rudolph, M AF Feldberg, SW Goldstein, CI Rudolph, M TI A stability criterion for accurate simulation of electrochemical diffusion-kinetic phenomena at the rotating disk electrode and implications for simulation of diffusion-migration and other problems SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE rotating disk electrode; simulation algorithm; diffusion-kinetics; diffusion-migration ID FINITE-DIFFERENCE ALGORITHM; FULLY IMPLICIT; RICHTMYER MODIFICATION; DIGITAL SIMULATIONS; FIFD ALGORITHM; EXPLICIT AB A stable, accurate, and efficient fully implicit finite difference algorithm is developed for the simulation of electrochemical behavior at a rotating disk electrode (RDE). Convenient expressions are developed for accurate evaluations of the hydrodynamic velocity profile of the solution normal to the disk, of the thickness of the diffusion layer, and of the minimum thickness of solution which must be considered in a simulation. The simulation algorithm uses an exponentially expanding space grid to effect efficient and accurate simulation of systems involving homogeneous chemical reactions with reaction layers that may be much smaller than the RDE diffusion layer. Stability analysis of the RDE simulation in the absence of homogeneous kinetics produces a simple criterion which precisely delimits the values of the parameters which characterize the exponentially expanding space grid (i.e. the density of the volume elements and the rate of expansion) required for stable and accurate simulations. The RDE simulation algorithm was incorporated into a generalized cyclic voltammetric simulator which allowed us to simulate RDE responses for complex systems involving various combinations of heterogeneous and homogeneous (first- and or second-order) reactions: the same stability criterion sufficed. Implications of the analysis for finite difference simulations of diffusion-migration problems are also discussed. C1 UNIV JENA, DEPT INORGAN CHEM, D-6900 JENA, GERMANY. RP Feldberg, SW (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. NR 20 TC 22 Z9 22 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1572-6657 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD SEP 12 PY 1996 VL 413 IS 1-2 BP 25 EP 36 DI 10.1016/0022-0728(96)04625-6 PG 12 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA VL467 UT WOS:A1996VL46700004 ER PT J AU Huang, Z Wang, XN AF Huang, Z Wang, XN TI Dilepton and photon productions from a coherent pion oscillation SO PHYSICS LETTERS B LA English DT Article ID DISORIENTED CHIRAL CONDENSATE; NUCLEUS-NUCLEUS COLLISIONS; QUARK-GLUON PLASMA; EMISSION; DOMAINS AB Since the electromagnetic current for a pion system coincides with the third component of the isovector current, the isospin angular oscillation of a coherent field can be a significant source for the electromagnetic emissions. We study the characteristic dilepton and photon emissions from the classical pion field oscillation in the QCD vacuum. The general analytical solution obtained in the nonlinear sigma model is used to calculate the electromagnetic current density, which exhibits a light-front singularity and decreases rapidly as inverse square of the proper time due to a longitudinal expansion. The momentum and invariant mass spectra of the direct photon and dilepton are calculated using the space-time evolution of the chiral condensate field. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Huang, Z (reprint author), UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721, USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 20 TC 18 Z9 18 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 SEP 12 PY 1996 VL 383 IS 4 BP 457 EP 462 DI 10.1016/0370-2693(96)00814-3 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF933 UT WOS:A1996VF93300016 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Brambilla, E Branson, JG Brigljevic, V Brock, IC Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Castello, R Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R DiBitonto, D Diemoz, M vanDierendonck, D deAsmundis, R DeNotaristefani, F DeBoeck, H Degre, A Deiters, K Denes, P DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hangarter, K Hartmann, B Hasan, A Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Ilyas, MM Innocente, V Janssen, H Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamyshkov, Y Kapinos, P Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Kramer, T Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Lenti, M Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Ludovici, L Luminari, L Lustermann, W Ma, WG Macchiolo, A Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG Mazumdar, K McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Monteleoni, B Moore, R Morganti, S Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Nippe, A Nowak, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Raghavan, R RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Rohner, S Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Schoeneich, B Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Sticozzi, F Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonisch, F Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, YF Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Brambilla, E Branson, JG Brigljevic, V Brock, IC Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Castello, R Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R DiBitonto, D Diemoz, M vanDierendonck, D deAsmundis, R DeNotaristefani, F DeBoeck, H Degre, A Deiters, K Denes, P DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hangarter, K Hartmann, B Hasan, A Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Ilyas, MM Innocente, V Janssen, H Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamyshkov, Y Kapinos, P Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Kramer, T Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Lenti, M Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Ludovici, L Luminari, L Lustermann, W Ma, WG Macchiolo, A Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG Mazumdar, K McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Monteleoni, B Moore, R Morganti, S Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Nippe, A Nowak, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Raghavan, R RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Rohner, S Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Schoeneich, B Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Sticozzi, F Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonisch, F Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, YF Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A TI Measurement of the B-d(0) meson oscillation frequency SO PHYSICS LETTERS B LA English DT Article ID FORWARD-BACKWARD ASYMMETRY; LUND MONTE-CARLO; TIME-DEPENDENCE; JET FRAGMENTATION; MIXING PARAMETER; L3 EXPERIMENT; E+E-PHYSICS; DECAYS; LIFETIME; HADRONS AB Time-dependent B-d(0)-(B) over bar(d)(0) mixing is studied using 1.5 million hadronic Z decays collected by L3. Semileptonic B decays are selected by requiring at least one reconstructed lepton in both thrust hemispheres. Charge correlations between the tagged leptons are studied as a function of proper time. The proper time of the b-hadron decay is measured by reconstructing the production and decay vertices using a silicon microvertex detector: The measured B-d(0) meson oscillation frequency corresponds to a mass difference Delta m(d) between the two B-d(0) mass eigenstates of Delta m(d) = (0.496(-0.051)(+0.053) (stat) +/- 0.043 (syst)) ps(-1). C1 NIKHEF, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. CNRS, LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. UNIV FLORENCE, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. FBLJA, WORLD LAB, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, HEFEI 230029, ANHUI, PEOPLES R CHINA. RES INST HIGH ENERGY PHYS, SEFT, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. UNIV LECCE, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, INST PHYS NUCL LYON, IN2P3, F-69622 VILLEURBANNE, FRANCE. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, UNIVERSITY, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. CIEMAT, E-28040 MADRID, SPAIN. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 2, D-52056 AACHEN, GERMANY. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. RP Acciarri, M (reprint author), IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Ludovici, Lucio/F-5917-2011; Kirkby, Jasper/A-4973-2012; Ferguson, Thomas/O-3444-2014; Servoli, Leonello/E-6766-2012; alpat, ali behcet/G-6290-2013; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; Vogel, Helmut/N-8882-2014; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; OI Ludovici, Lucio/0000-0003-1970-9960; Kirkby, Jasper/0000-0003-2341-9069; Ferguson, Thomas/0000-0001-5822-3731; Servoli, Leonello/0000-0003-1725-9185; alpat, ali behcet/0000-0002-0116-1506; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Goldstein, Joel/0000-0003-1591-6014; Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Filthaut, Frank/0000-0003-3338-2247 NR 29 TC 16 Z9 16 U1 1 U2 8 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 SEP 12 PY 1996 VL 383 IS 4 BP 487 EP 498 DI 10.1016/0370-2693(96)00768-X PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF933 UT WOS:A1996VF93300021 ER PT J AU Andrews, MA Gould, GL Klooster, WT Koenig, KS Voss, EJ AF Andrews, MA Gould, GL Klooster, WT Koenig, KS Voss, EJ TI Syntheses, spectra, and structures of (diphosphine)platinum(II) carbonate complexes SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; PLATINUM(II); REACTIVITY; LIGANDS; HYDROXO; BIS(DIPHENYLPHOSPHINO)METHANE; PARAMETERS; DIOXIDE; VARIETY; BONDS AB A variety of (diphosphine)platinum(II) carbonate complexes, (LL)Pt(CO3), are readily prepared from the corresponding (diphosphine)platinum dichlorides by treatment with silver carbonate in dichoromethane solution provided that water is present. This reaction also permits facile preparation of analogous C-13-labeled complexes. The carbonate ligands in these complexes have been characterized by IR and C-13 NMR spectroscopy. Alternative preparative routes involve conversion of the precursor dichlorides to the corresponding dialkoxides or diphenoxides, followed by treatment with water and carbon dioxide. Various reaction intermediates have been spectroscopically observed in the latter syntheses. Two crystalline modifications of (Ph(2)PCH(2)CH(2)CH(2)PPh(2))Pt(CO3), one with and one without a dichloromethane of solvation, have been studied by single-cgrstal X-ray diffraction. Crystal data for PtP2O3C28H26: P2(1)/c, Z = 4, T = 200 K, a = 10.362(8) Angstrom, b = 14.743(6) Angstrom, c = 19.183(10) Angstrom, beta = 122.69(6)degrees. Crystal data for PtP2O3C28H26. CH2Cl2: P2(1)/c, Z = 4, T approximate to 298 K, a = 11.744(2) Angstrom, b = 15.526(3) Angstrom, c = 15.866(3) Angstrom, beta = 101.58(1)degrees. RP Andrews, MA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 57 TC 41 Z9 41 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 11 PY 1996 VL 35 IS 19 BP 5478 EP 5483 DI 10.1021/ic9603159 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VG416 UT WOS:A1996VG41600011 ER PT J AU Chen, JH Dorhout, PK Ostenson, JE AF Chen, JH Dorhout, PK Ostenson, JE TI A comparative study of two new structure types. Synthesis and structural and electronic characterization of K(RE)P2Se6 (RE=Y,La,Ce,Pr,Gd) SO INORGANIC CHEMISTRY LA English DT Article ID METAL POLYSELENOPHOSPHATE FLUXES; CRYSTAL-STRUCTURE; VIBRATIONAL-SPECTRUM; ION-EXCHANGE; CHEMISTRY; RB; HEXATHIODIPHOSPHATE(IV); REFINEMENT; PHOSPHATE; CLUSTER AB Two polytypes of potassium rare-earth-metal hexaselenodiphosphates(IV), K(RE)P2Se6 (RE = Y, La, Ce, Pr, Gd), have been synthesized from the stoichiometric reaction of RE, P, Se, and K2Se4 at 750 degrees C. Both single-crystal and powder X-ray diffraction analyses showed that the structures of these polytypes vary with the size of the rare earth metals. For the smaller rare-earth metals, Y and Gd, K(RE)P2Se6 crystallized in the orthorhombic space group P2(1)2(1)2(1). The yttrium compound was studied by single-crystal X-ray diffraction with the cell parameters a = 6.7366(5) Angstrom, b = 7.4286(6) Angstrom, c = 21.603(2) Angstrom, and Z = 4. This structure type comprises a layered, square network of yttrium atoms that are bound to four distinct [P2Se6](4-) units through selenium bonding. Each [P2Se6](4-) unit possesses a Se atom that is not bound to any Y atom but is pointing out into the interlayer spacing, into an environment of potassium cations. For larger rare-earth metals, La, Ce, and Pr, K(RE)P2Se6 crystallized in a second, monoclinic polytype, the structure of which has been published. Both of these two different polytypes can be related to each other and several other isoelectronic chalcophosphate structures based on a Parthe valence electron concentration analysis. These structures include Ag4P2S6, K2FeP2S6, and the hexagonal M(II)PS(3) structure types. The magnetic susceptibilities of the title compounds have been studied, and the behavior can been explained based on a simple set of unpaired f-electrons. The diffuse reflectance spectroscopy also showed that these yellow plates are moderately wide band gap (similar to 2.75 eV) semiconductors. C1 COLORADO STATE UNIV,DEPT CHEM,FT COLLINS,CO 80523. US DOE,AMES LAB,AMES,IA 50011. NR 44 TC 64 Z9 66 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 11 PY 1996 VL 35 IS 19 BP 5627 EP 5633 DI 10.1021/ic9516121 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VG416 UT WOS:A1996VG41600033 ER PT J AU Andrews, MA Gould, GL Voss, EJ AF Andrews, MA Gould, GL Voss, EJ TI Evidence for platinum(II) oxo intermediates in reactions of (diphosphine)platinum(II) carbonate complexes SO INORGANIC CHEMISTRY LA English DT Article ID TERTIARY PHOSPHINES; PALLADIUM(II); DIPHOSPHINES; CLEAVAGE; LIGANDS; METALS RP Andrews, MA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 24 TC 21 Z9 21 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 11 PY 1996 VL 35 IS 19 BP 5740 EP 5742 DI 10.1021/ic9601448 PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VG416 UT WOS:A1996VG41600049 ER PT J AU George, GN Garrett, RM Prince, RC Rajagopalan, KV AF George, GN Garrett, RM Prince, RC Rajagopalan, KV TI The molybdenum site of sulfite oxidase: A comparison of wild-type and the cysteine 207 to serine mutant using X-ray absorption spectroscopy SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BOND-VALENCE PARAMETERS; LIGAND K-EDGE; FINE-STRUCTURE; ELECTRON-TRANSFER; CRYSTAL-STRUCTURE; METAL; SPECTRA; OXIDOREDUCTASE; BIOCHEMISTRY; COVALENCY AB X-ray absorption spectroscopy at the molybdenum and sulfur K-edges has been used to probe the active site of wild-type and cysteine 207 --> serine mutant human sulfite oxidases. We compare the active site structures in the Mo(VI) oxidation states: the wild-type enzyme possesses two Mo=O ligands at 1.71 Angstrom and three Mo-S ligands at 2.41 Angstrom. The mutant molybdenum site is a novel trioxo site with Mo=O bond lengths of 1.74 Angstrom, with two Mo-S ligands at 2.47 Angstrom. We conclude that cysteine 207 is a ligand of molybdenum in wild-type human sulfite oxidase, and that, in the mutant, the Mo is ligated to an extra oxo group rather than the hydroxyl of the substituent serine 207. C1 DUKE UNIV, SCH MED, DEPT BIOCHEM, DURHAM, NC 27710 USA. EXXON RES & ENGN CO, ANNANDALE, NJ 08801 USA. RP George, GN (reprint author), STANFORD UNIV, SLAC, STANFORD SYNCHROTRON RADIAT LAB, POB 4349, MS 69, STANFORD, CA 94309 USA. RI George, Graham/E-3290-2013 NR 44 TC 112 Z9 112 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 11 PY 1996 VL 118 IS 36 BP 8588 EP 8592 DI 10.1021/ja961218h PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA VG351 UT WOS:A1996VG35100011 ER PT J AU Laplaza, CE Johnson, MJA Peters, JC Odom, AL Kim, E Cummins, CC George, GN Pickering, IJ AF Laplaza, CE Johnson, MJA Peters, JC Odom, AL Kim, E Cummins, CC George, GN Pickering, IJ TI Dinitrogen cleavage by three-coordinate molybdenum(III) complexes: Mechanistic and structural data SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID TRANSITION-METAL COMPLEXES; RAY CRYSTAL-STRUCTURES; NUCLEAR-MAGNETIC-RESONANCE; ABSORPTION FINE-STRUCTURE; X-RAY; IRON PROTEIN; MOLECULAR-STRUCTURE; NITROGEN-FIXATION; CRYSTALLOGRAPHIC STRUCTURE; CLOSTRIDIUM-PASTEURIANUM AB The synthesis and characterization of the complexes Mo[N(R)Ar](3) (R = C(CD3)(2)CH3, Ar = 3,5-C(6)H(3)Me(2)),(mu-N-2){Mo[N(R)Ar](3)}(2), (mu-N-15(2)){Mo[N(R)Ar](3)}(2), NMo[N(R)Ar](3), (NMo)-N-15[N(R)Ar](3), Mo[N(t-Bu)Ph](3), (mu-N-2){Mo-[N(t-Bu)Ph](3)}(2), and NMo[N(t-Bu)Ph](3) are described. Temperature-dependent magnetic susceptibility data indicate a quartet ground state for Mo[N(R)Ar](3). Single-crystal X-ray diffraction studies for Mo[N(R)Ar](3) and NMo[N(t-Bu)Ph](3) are described. Extended X-ray absorption fine structure (EXAFS) structural studies for Mo[N(R)Ar](3), (mu-N-2){Mo[N(R)Ar](3)}(2), and NMo[N(R)Ar](3) are reported. Temperature-dependent kinetic data are given for the unimolecular fragmentation of (mu-N-2){Mo[N(R)Ar](3)}(2) to 2 equiv of NMo[N(R)Ar](3) and for the fragmentation of (mu-N-2){Mo[N(R)Ar](3)}(2) to 2 equiv of (NMo)-N-15[N(R)Ar](3). The temperature dependence of the N-15(2) isotope effect for the latter N-2 cleavage process was fitted to a simple harmonic model, leading to a prediction for the difference in NN stretching frequencies for the two isotopomers. The latter prediction was consistent with the Raman spectroscopic data for (mu-N-2){Mo[N(R)Ar](3)}(2) and (mu-N-15(2)){Mo[N(R)Ar](3)}(2). The Raman spectroscopic data and EXAFS results are both consistent with an NN bond order of approximately 2 in (mu-N-2){Mo[N(R)Ar](3)}(2). Temperature-dependent magnetic susceptibility data consistent with a triplet ground state are given for (mu-N-2){Mo[N(t-Bu)Ph](3)}(2). C1 MIT,DEPT CHEM,CAMBRIDGE,MA 02139. STANFORD UNIV,SLAC,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RI George, Graham/E-3290-2013; Cummins, Christopher/J-2961-2014; Pickering, Ingrid/A-4547-2013; OI Cummins, Christopher/0000-0003-2568-3269; Odom, Aaron/0000-0001-8530-4561; Pickering, Ingrid/0000-0002-0936-2994 NR 184 TC 278 Z9 278 U1 12 U2 86 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 SEP 11 PY 1996 VL 118 IS 36 BP 8623 EP 8638 DI 10.1021/ja960574x PG 16 WC Chemistry, Multidisciplinary SC Chemistry GA VG351 UT WOS:A1996VG35100014 ER PT J AU Manna, J Whiteford, JA Stang, PJ Muddiman, DC Smith, RD AF Manna, J Whiteford, JA Stang, PJ Muddiman, DC Smith, RD TI Design and self-assembly of nanoscale organoplatinum macrocycles SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CRYSTAL MOLECULAR-STRUCTURE; COMPLEXES; TETRANUCLEAR; CHEMISTRY; RESONANCE; SQUARES; LIGAND; C-13 C1 UNIV UTAH,DEPT CHEM,SALT LAKE CITY,UT 84112. PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 31 TC 78 Z9 78 U1 0 U2 2 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 SEP 11 PY 1996 VL 118 IS 36 BP 8731 EP 8732 DI 10.1021/ja962041u PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VG351 UT WOS:A1996VG35100036 ER PT J AU Back, BB Blumenthal, DJ Davids, CN Henderson, DJ Hermann, RH Jiang, CL Penttila, HT Wuosmaa, AH AF Back, BB Blumenthal, DJ Davids, CN Henderson, DJ Hermann, RH Jiang, CL Penttila, HT Wuosmaa, AH TI Transport efficiency of the Argonne fragment mass analyzer SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SEPARATOR; PRODUCTS; FACILITY AB Absolute transmission efficiencies for the Argonne fragment mass analyzer (FMA) have been measured for ions of W-184, Pb-208, and Th-232 with energies in the range E = 20-45 MeV. These were obtained by Rutherford scattering of S-32 beams of 50, 80 acid 110 MeV into backward angles. Measurements were performed for a range of settings for the FMA in order to determine the acceptance of the instrument as a function of energy and angle of the incident ion. The transport efficiency across the focal plane was also measured. The results are compared with predictions of the transport code GIOS [H. Wollnik et al., Nucl. Instr. and Meth. A 258 (1987) 408], which agree well with the data. With these data we conclude that the transport efficiency of the FMA is sufficiently well known to support measurements of absolute cross sections with an accuracy of +/-10%. RP Back, BB (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. RI Penttila, Heikki/A-4420-2013 NR 9 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 11 PY 1996 VL 379 IS 2 BP 206 EP 211 DI 10.1016/0168-9002(96)00650-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN285 UT WOS:A1996VN28500005 ER PT J AU Hoffman, KD Bortoletto, D Cihangir, S Spalding, J GarciaSciveres, M AF Hoffman, KD Bortoletto, D Cihangir, S Spalding, J GarciaSciveres, M TI Charge collection efficiency in double-sided silicon microstrip detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We present measurements of charge collection efficiency in double-sided silicon microstrip sensors using the signal from a pulsed laser. We compare the efficiency as a function of voltage and position for various strip geometries. The sensors studied here were manufactured as prototypes for the SVXII detector, an upgrade of the CDF silicon vertex detector for run II of the Fermilab Tevatron. Large inefficiencies were observed in prototypes with certain n-side strip geometries. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Hoffman, KD (reprint author), PURDUE UNIV,W LAFAYETTE,IN 47907, USA. NR 16 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 SEP 11 PY 1996 VL 379 IS 2 BP 237 EP 242 DI 10.1016/0168-9002(96)00531-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN285 UT WOS:A1996VN28500010 ER PT J AU Morris, CL Atencio, LG Sondheim, WE Seestrom, SJ RawoolSullivan, MW McGaughey, PL Lee, DM Kinnison, WW Brooks, ML Armijo, V AF Morris, CL Atencio, LG Sondheim, WE Seestrom, SJ RawoolSullivan, MW McGaughey, PL Lee, DM Kinnison, WW Brooks, ML Armijo, V TI Electric discharge etching of thin metallized plastic films SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PROPORTIONAL CHAMBERS AB We describe a technique for etching electrically isolated strips onto metalized Mylar surfaces suitable for strip cathode readout multiwire chambers. Cathode planes created using this technique are much thinner than those made using previously described techniques. RP Morris, CL (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 7 TC 1 Z9 1 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 SEP 11 PY 1996 VL 379 IS 2 BP 243 EP 246 DI 10.1016/0168-9002(96)00434-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN285 UT WOS:A1996VN28500011 ER PT J AU deOliveiraCosta, A Smoot, GF Starobinsky, AA AF deOliveiraCosta, A Smoot, GF Starobinsky, AA TI Can the lack of symmetry in the COBE DMR maps constrain the topology of the universe? SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations; cosmology, theory; large-scale structure of universe ID COSMIC BACKGROUND-RADIATION; MULTIPLY-CONNECTED UNIVERSE; TEMPERATURE-FLUCTUATIONS; ANISOTROPY AB Although the cubic T-3 ''small universe'' has been ruled out by COBE Differential Microwave Radiometer (DMR) results as an interesting cosmological model, we still have the possibility of living in a universe with a more anisotropic topology, such as a rectangular T-3 ''small universe'' with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T-1 and T-2 models; respectively). In order to rule out these anisotropic topologies as well, we apply a new data analysis method that searches for the specific kind of symmetries that these models should produce. We find that the 4 year COBE DMR data place a lower limit on the smallest cell size for T-1 and T-2 models of 3000 h(-1) Mpc, at 95% confidence, for a scale-invariant power spectrum (n = 1). These results imply that all toroidal universes (cubes and rectangles) are ruled out as interesting cosmological models. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. INST NACL PESQUISAS ESPACIAIS,DIV ASTROFIS,BR-12227010 S JOSE CAMPOS,BRAZIL. RUSSIAN ACAD SCI,MOSCOW 117334,RUSSIA. LD LANDAU THEORET PHYS INST,MOSCOW 117334,RUSSIA. RP deOliveiraCosta, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,SPACE SCI LAB,BLDG 50-205,BERKELEY,CA 94720, USA. OI Starobinsky, Alexei/0000-0002-8946-9088 NR 17 TC 68 Z9 68 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 SEP 10 PY 1996 VL 468 IS 2 BP 457 EP & DI 10.1086/177706 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE596 UT WOS:A1996VE59600001 ER PT J AU Mastrodemos, N Morris, M Castor, J AF Mastrodemos, N Morris, M Castor, J TI On the stability of the dust-gas coupling in winds from late-type stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; circumstellar matter; stars, late-type; stars, mass loss; stars, variables, other (long-period variables) ID LONG-PERIOD VARIABLES; CIRCUMSTELLAR ENVELOPES; DRIVEN WINDS; SIZE DISTRIBUTION; KAPPA-MECHANISM; STELLAR WINDS; C-STARS; MODELS; ATMOSPHERES; RADIATION AB We have numerically investigated the dynamical effects of dust drifting on the detailed structure of winds from late-type, pulsating variables. We examine the stability of dust-gas coupling in the presence of luminosity variations, and the assumption of complete momentum coupling, by constructing two-fluid time-dependent wind models. For the range of mass-loss rates and outflow velocities observed in Miras and long-period variables (LPVs), we have found the assumption of complete momentum coupling to be valid to a good degree. In particular, for any given distribution of grain species, small grains appear to always drift slower than larger ones. The detailed thermal balance of the wind, including collisional heating and molecular cooling, is essential in determining its structure on small scales. At large distances from the star, dust streaming and gas-dust viscous heating smooth out the wind. The outer parts of circumstellar envelopes are not subject to growing instabilities. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Mastrodemos, N (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90095, USA. NR 40 TC 12 Z9 13 U1 1 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 SEP 10 PY 1996 VL 468 IS 2 BP 851 EP 860 DI 10.1086/177741 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE596 UT WOS:A1996VE59600036 ER PT J AU Banday, AJ Gorski, KM Bennett, CL Hinshaw, G Kogut, A Smoot, GF AF Banday, AJ Gorski, KM Bennett, CL Hinshaw, G Kogut, A Smoot, GF TI Noncosmological signal contributions to the COBE DMR 4 year sky maps SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; diffuse radiation; intergalactic medium ID NRAO PMN SURVEYS; COSMIC MICROWAVE; SOURCE CATALOG; GALAXIES; ANISOTROPY; SEARCH; GAS AB We limit the possible contributions from noncosmological sources to the COBE Differential Microwave Radiometer (DMR) 4 year sky maps. The DMR data are cross-correlated with maps of rich clusters, extragalactic IRAS sources, HEAO I A-2 X-ray emission, and 5 GHz radio sources using a Fourier space technique. There is no evidence of significant contamination by such sources at an rms level of similar to 8 mu K [95% confidence level (c.l.) at 70 resolution] in the most sensitive 53 GHz sky map. This level is consistent with previous limits set by analysis of earlier DMR data and by simple extrapolations from existing source models. We place a limit on the rms Comptonization parameter averaged over the high-latitude sky of delta gamma < 1 x 10(-6) (95% c.l.). Extragalactic sources have an insignificant effect on the cosmic microwave background power spectrum parameterizations determined from the DMR data. C1 NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,HUGHES STX CORP,GREENBELT,MD 20771. UNIV CALIF BERKELEY,LBL,SSL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,CIPA,BERKELEY,CA 94720. RI Kogut, Alan/D-6293-2012 NR 30 TC 44 Z9 43 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1996 VL 468 IS 2 BP L85 EP L89 DI 10.1086/310235 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE597 UT WOS:A1996VE59700003 ER PT J AU Tanaka, ST Clapp, AC Devlin, MJ Figueiredo, N Gundersen, JO Hanany, S Hristov, VV Lange, AE Lim, MA Lubin, PM Meinhold, PR Richards, PL Smoot, GF Staren, J AF Tanaka, ST Clapp, AC Devlin, MJ Figueiredo, N Gundersen, JO Hanany, S Hristov, VV Lange, AE Lim, MA Lubin, PM Meinhold, PR Richards, PL Smoot, GF Staren, J TI Measurements of anisotropy in the cosmic microwave background radiation at 0 degrees.5 scales near the stars HR 5127 and phi Herculis SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations ID ANGULAR SCALES AB We present measurements of cosmic microwave background (CMB) anisotropy near the stars HR 5127 and phi Herculis from the fifth flight of the Millimeter-wave Anisotropy eXperiment (MAX). We scanned 8 degrees strips of the sky with an approximately Gaussian 0.5 degrees FWHM beam and a 1.4 degrees peak to peak sinusoidal chop. The instrument has four frequency bands centered at 3.5, 6, 9, and 14 cm(-1). The IRAS 100 mu m map predicts that these two regions have low interstellar dust contrast. The HR 5127 data are consistent with CMB anisotropy. The phi Herculis data, which were measured at lower flight altitudes, show time variability at 9 and 14 cm(-1), which we believe to be due to atmospheric emission. However, the phi Herculis data at 3.5 and 6 cm-l are essentially independent of this atmospheric contribution and are consistent with CMB anisotropy. Confusion from Galactic foregrounds is unlikely based on the spectrum and amplitude of the structure at these frequencies. If the observed HR 5127 structure and the atmosphere-independent phi Herculis structure are attributed to CMB anisotropy, then we find Delta T/T = [I(I + 1)C-1/2 pi](1/2) = 1.2(-0.3)(+0.4) x 10(-5) for HR 5127 and 1.9(-0.4)(+0.7) x 10(-5) for phi Herculis in the flat band approximation. The upper and lower limits represent a 68% confidence interval added in quadrature with a 10% calibration uncertainty. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. CALTECH,DIV PHYS MATH & ASTRON,PASADENA,CA 91125. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. ESCOLA FED ENGN ITAJUBA,BR-37500000 ITAJUBA,MG,BRAZIL. INST NACL PESQUISAS ESPACIAIS,BR-12201970 S JOSE CAMPOS,BRAZIL. LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720. RP Tanaka, ST (reprint author), NSF,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720, USA. RI Figueiredo, Newton/F-9976-2011 NR 20 TC 45 Z9 45 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 1996 VL 468 IS 2 BP L81 EP L84 DI 10.1086/310248 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE597 UT WOS:A1996VE59700002 ER PT J AU Sunnerhagen, M Olah, GA Stenflo, J Forsen, S Drakenberg, T Trewhella, J AF Sunnerhagen, M Olah, GA Stenflo, J Forsen, S Drakenberg, T Trewhella, J TI The relative orientation of Gla and EGF domains in coagulation factor X is altered by Ca2+ binding to the first EGF domain. A combined NMR small angle X-ray scattering study SO BIOCHEMISTRY LA English DT Article ID GAMMA-CARBOXYGLUTAMIC ACID; NUCLEAR-MAGNETIC-RESONANCE; HUMAN FACTOR-IX; PROTEIN STRUCTURAL REQUIREMENTS; CALCIUM-DEPENDENT INTERACTION; BETA-HYDROXYASPARTIC ACID; GROWTH-FACTOR PRECURSOR; FACTOR-LIKE MODULES; MEMBRANE-BINDING; NEUTRON-SCATTERING AB Coagulation factor X is a serine protease containing three noncatalytic domains: an N-terminal gamma-carboxyglutamic acid (Gla)(1) domain followed by two epidermal growth factor (EGF)-like domains. The isolated N-terminal EGF domain binds Ca2+ with a K-d of 10(-3) M. When linked to the Gla domain, however, its Ca2+ affinity is increased 10-fold. In this paper, we present the NMR solution structure of the factor X Gla-EGF domain pair with Ca2+ bound to the EGF domain, as well as small angle X-ray scattering (SAXS) data on the Gla-EGF domain pair with and without Ca2+. Our results show that Ca2+ binding to the EGF domain makes the cia and EGF domains fold toward each other using the Ca2+ site as a hinge. Presumably, a similar mechanism may be responsible for alterations in the relative orientation of protein domains in many other extracellular proteins containing EGF domains with the consensus for Ca2+ binding. The results of the NMR and SAXS measurements reported in this paper confirm our previous result that the Gla domain is folded also in its apo state when linked to the EGF domain [Sunnerhagen, M., et al. (1995) Nat. Struct. Biol. 2, 504-509]. Finally, our study clearly demonstrates the powerful combination of NMR and SAXS in the study of modular proteins, since this enables reliable evaluation of both short-range (NMR) and long-range interactions (SAXS). C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. LUND UNIV,MALMO GEN HOSP,WALLENBERG LAB,S-21401 MALMO,SWEDEN. RP Sunnerhagen, M (reprint author), LUND UNIV,CTR CHEM,POB 124,S-22100 LUND,SWEDEN. OI Trewhella, Jill/0000-0002-8555-6766 FU NIGMS NIH HHS [GM40528] NR 84 TC 71 Z9 73 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 10 PY 1996 VL 35 IS 36 BP 11547 EP 11559 DI 10.1021/bi960633j PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VG113 UT WOS:A1996VG11300003 PM 8794734 ER PT J AU Nolan, JP Shen, BH Park, MS Sklar, LA AF Nolan, JP Shen, BH Park, MS Sklar, LA TI Kinetic analysis of human flap endonuclease-1 by flow cytometry SO BIOCHEMISTRY LA English DT Article ID NUCLEOTIDE EXCISION-REPAIR; CELL-SURFACE RECEPTORS; RESTRICTION-ENDONUCLEASE; SACCHAROMYCES-CEREVISIAE; DNA-REPLICATION; SCHIZOSACCHAROMYCES-POMBE; STEADY-STATE; CLEAVAGE; RAD2; BINDING AB Human flap endonuclease-1 (FEN-1) is a structure-specific endonuclease and exonuclease which is essential for DNA replication and repair. We have cloned a human FEN-1 gene, overexpressed it in Escherichia coli, purified the recombinant protein to near homogeneity, and characterized its cleavage of a flap DNA structure using a novel analytical approach based on flow cytometry. With this approach, we were able to measure continuously the kinetics of DNA cleavage by FEN-1 and to separate experimentally the binding and catalysis functions of the enzyme. When the reaction was initiated by the addition of FEN-1, the cleavage kinetics were dependent on enzyme concentration and appeared to saturate at high concentrations. When enzyme and substrate were preincubated in the presence of EDTA and the reaction initiated by the addition of Mg2+, rapid kinetic flow cytometry measurements showed that cleavage is fast (t(1/2) similar to 6s,k = 0.10s(-1)). Using the single-turnover kinetics as a measure of the amount of enzyme-substrate complex present, we estimated the K-d for the FEN-1-flap DNA substrate to be 7.5 nM in the absence of Mg2+ and the rate constant for dissociation of the enzyme-substrate complex to be 0.07 s(-1), Computer fitting of the experimental data to a kinetic model confirms these estimates for the individual steps and suggests some interesting features of enzymology using a surface-bound substrate. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,NATL FLOW CYTOMETRY RESOURCE,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,SCH MED,ALBUQUERQUE,NM 87131. FU NCRR NIH HHS [RR01315] NR 43 TC 58 Z9 60 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 10 PY 1996 VL 35 IS 36 BP 11668 EP 11676 DI 10.1021/bi952840+ PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VG113 UT WOS:A1996VG11300016 PM 8794747 ER PT J AU Luebke, KJ Tinoco, I AF Luebke, KJ Tinoco, I TI Sequence effects on RNA bulge-induced helix bending and a conserved five-nucleotide bulge from the group I introns SO BIOCHEMISTRY LA English DT Article ID CONTAINING DEOXYTRIDECANUCLEOTIDE DUPLEXES; TERTIARY STRUCTURE; DEOXYOLIGONUCLEOTIDE DUPLEX; CONFORMATIONAL TRANSITIONS; TETRAHYMENA RIBOZYME; ENERGY MINIMIZATION; FLANKING SEQUENCE; DNA DUPLEX; NMR; BASES AB Bulge loops introduce bends in RNA double helices. Thus, a role for bulge loops in the tertiary folding of RNA is to orient helical elements. The location, size, and sequence of a five-nucleotide bulge are conserved in many of the self-splicing group I introns. We have used gel electrophoretic analysis of helix bending to test the hypothesis that this bulge loop is conserved to control the angle between the flanking helices. Interruption of an RNA duplex by the five-nucleotide bulge of the group I intron from Tetrahymena thermophila results in an electrophoretically retarded species, indicative of bending by the bulge. However, mutation of conserved bases in the bulge has a small effect on the retardation, suggesting that the average induced bend angle is not strongly dependent on the conserved sequence. Electrophoretic analysis of a mixture of bulged duplexes containing all five-nucleotide bulges reveals that most five-nucleotide bulge sequences induce bends that are similar to the bend induced by the conserved bulge. We have calibrated relative electrophoretic mobilities with bends of known magnitude, and characterized the distribution of bulge sequences among bend angles. Though the entire range of bend angles induced by different five-nucleotide bulges is from approximately 45 degrees to 75 degrees, most (> 85%) five-nucleotide bulge loops induce bends between 65 degrees and 75 degrees. We have identified several of the anomalous five-nucleotide bulge sequences that induce bends of magnitude smaller than 65 degrees. They are generally, though not universally, pyrimidine-rich. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 10840] NR 42 TC 23 Z9 23 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 10 PY 1996 VL 35 IS 36 BP 11677 EP 11684 DI 10.1021/bi960914r PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VG113 UT WOS:A1996VG11300017 PM 8794748 ER PT J AU Romero, LA Yost, FG AF Romero, LA Yost, FG TI Flow in an open channel capillary SO JOURNAL OF FLUID MECHANICS LA English DT Article AB The problem of capillary-driven flow in a V-shaped surface groove is addressed. A nonlinear diffusion equation for the liquid shape is derived from mass conservation and Poiseuille flow conditions. A similarity transformation for this nonlinear equation is obtained and the resulting ordinary differential equation is solved numerically for appropriate boundary conditions. It is shown that the position of the wetting front is proportional to (Dt)(1/2) where D is a diffusion coefficient proportional to the ratio of the liquid-vapour surface tension to viscosity and the groove depth, and a function of the contact angle and the groove angle. For flow into the groove from a sessile drop source it is shown that the groove angle must be greater than the contact angle. Certain arbitrarily shaped grooves are also addressed. RP Romero, LA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 10 TC 83 Z9 84 U1 2 U2 18 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP 10 PY 1996 VL 322 BP 109 EP 129 DI 10.1017/S0022112096002728 PG 21 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA VJ450 UT WOS:A1996VJ45000005 ER PT J AU Lay, T Young, CJ AF Lay, T Young, CJ TI Imaging scattering structures in the lower mantle by migration of long-period S waves SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SHEAR VELOCITY-STRUCTURE; BENEATH NORTHERN SIBERIA; P-WAVE; DISCONTINUITY BENEATH; ISOTROPIC SCATTERERS; SOUTHERN CALIFORNIA; D-REGION; D''; BOUNDARY; REFLECTIONS AB A simplified wave field migration method is applied to long-period tangential component recordings to image lower mantle heterogeneity beneath Alaska. Observed wave field complexities are dominated by coherent arrivals between direct S (or sS) and the core-reflected ScS (or sScS) phases. A relative waveform inversion method is used to objectively extract the time and amplitude of the three main spikes in each wavetrain, removing the effects of source time function, receiver, and instrument responses. The timing of the intermediate arrivals relative to S or ScS is used to define the volumetric position of scattering ellipsoids in the lower mantle, with intersections of ellipsoids illuminating possible regions of isotropic scattering. While a complete waveform migration is not viable due to the very limited ray path coverage and the band-limited data, the kinematics and relative amplitudes of the scattered arrivals are still valuable for assessing the origin of the waveform complexity. In this region, which displays particularly uniform existence of an extra arrival in the data, the simplest interpretation is that a scattering surface with lateral dimensions exceeding 1500 km at a depth near 2600 km in the mantle is responsible for the extra phase. This is consistent with previous interpretations involving a one-dimensional model with a rapid shear velocity increase or discontinuity 240-280 km above the core-mantle,boundary. The proposed methodology can potentially image both heterogeneities or layering in the D-'' region as well as scattering from midmantle structure, although data limitations will continue to be a major obstacle. C1 UNIV CALIF SANTA CRUZ, WM KECK SEISMOL LAB, SANTA CRUZ, CA 95064 USA. SANDIA NATL LABS, DEPT GEOPHYS, ALBUQUERQUE, NM 87185 USA. RP Lay, T (reprint author), UNIV CALIF SANTA CRUZ, EARTH SCI BOARD, INST TECTON, EARTH & MARINE SCI BLDG, SANTA CRUZ, CA 95064 USA. NR 48 TC 26 Z9 26 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1996 VL 101 IS B9 BP 20023 EP 20040 DI 10.1029/96JB01887 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VG396 UT WOS:A1996VG39600001 ER PT J AU Blair, SC Berge, PA Berryman, JG AF Blair, SC Berge, PA Berryman, JG TI Using two-point correlation functions to characterize microgeometry and estimate permeabilities of sandstones and porous glass SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SPATIAL CORRELATION-FUNCTIONS; TRANSPORT-PROPERTIES; FLUID PERMEABILITY; HETEROGENEOUS MATERIALS; PREDICTING PROPERTIES; IMAGE-ANALYSIS; ROCK; CONDUCTIVITY; MODEL; RESISTIVITY AB We have developed an image processing method for characterizing the microstructure of rock and other porous materials and to provide a quantitative means for understanding the dependence of physical properties on the pore structure. Our method is based upon the statistical properties of the microgeometry as observed in scanning electron micrograph (SEM) images of cross sections of porous materials. This method uses a simple statistical measure of microstructure called the spatial correlation function. We formulate a two-point spatial correlation function and Show how it can be used to estimate porosity, specific surface area, and other microstructural features such as pore and grain sizes. The porosity arid specific surface area are of special interest as they can lie used in a Kozeny-Carman relation to predict permeability of porous materials. We explore the Kozeny-Carman relation and show how it incorporates a characteristic microstructural length parameter similar to that used in other analyses of permeability. We analyze SEM images of several different porous glasses and natural sandstones using the two-point correlation function, discuss the importance of image resolution, and show for the sandstones studied here how the appropriate choices of image resolution can be made so the measured parameters are consistent with those used in a simple flow model for computation of permeability. Estimates of permeabilities for several different porous glasses and natural sandstones are presented. Comparison of these estimates to laboratory measurements shows good qualitative agreement and quantitative agreement within about a factor of 2 for most samples and 3 for all samples. RP Blair, SC (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, MS L-201, LIVERMORE, CA 94551 USA. RI Berryman, James/A-9712-2008 NR 50 TC 71 Z9 72 U1 2 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1996 VL 101 IS B9 BP 20359 EP 20375 DI 10.1029/96JB00879 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VG396 UT WOS:A1996VG39600022 ER PT J AU Hur, NH Paranthaman, M Thompson, JR Christen, DK AF Hur, NH Paranthaman, M Thompson, JR Christen, DK TI Superconductivity in the indium-doped Tl-1223 phase: (Tl0.8In0.2)(Sr0.8Ba0.2)(2)Ca2Cu3O9-delta SO PHYSICA C LA English DT Article ID CU-O SYSTEM; 120-K AB We report the synthesis and characterization of a new Tl- and In-based '1223' type cuprate oxide, (Tl0.8In0.2)(Sr0.8Ba0.2)(2)Ca2Cu3O9-delta (Tl,In-1223). The as-synthesized Tl,In-1223 compound becomes superconducting at about 80 K, The T-c increased to 103 K when the sample was annealed under an argon atmosphere, Magnetization studies on polycrystalline samples of Tl,In-1223 reveal that persistent current densities (J(p)) of the indium-doped compound are about 10 times smaller than those of corresponding TI,Bi-1223 and Tl,Pb-1223 with the same structure type, Small substitution of In for Tl in Tl-1223 results in a large reduction of T-c and J(p), A slight change in the electronic configurations of the rock-salt metal sites appears to affect the delicate balance of the metal and oxygen energy levels, which leads to the virtual changes in the superconductivity in Tl,In-1223. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Hur, NH (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 15 TC 3 Z9 3 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 SEP 10 PY 1996 VL 268 IS 3-4 BP 266 EP 270 DI 10.1016/0921-4534(96)00416-9 PG 5 WC Physics, Applied SC Physics GA VH550 UT WOS:A1996VH55000009 ER PT J AU Lindemer, TB Specht, ED AF Lindemer, TB Specht, ED TI Nonstoichiometry and decomposition of Pr1+zBa2-zCu3Oy and comparison with Y123, La123 and Nd123 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID BA-CU-O; CRYSTAL-STRUCTURE; OXYGEN; PR; LA1+ZBA2-ZCU3OY; SUPERCONDUCTOR; PRBA2CU3O7; SYSTEMS AB The temperature (T) and O-2 partial pressure (p[O-2]) dependence of the oxygen content (y) in Pr1+zBa2-zCu3Oy (Pr123) were determined over the entire range of z and the data were represented by chemical thermodynamic models. Comparison of the results with those published previously for Y123, La123 and Nd123, indicated that the La123 system was the most atypical. Thermodynamic arguments suggest the presence of Pr+4 as y approaches its maximum value. The T-z-p[O-2] dependence of high-temperature decomposition was also determined. Resistivity, de magnetization, and susceptibility measurements as low as 5 K revealed only paramagnetic and semiconducting behavior. RP OAK RIDGE NATL LAB, POB 2008, OAK RIDGE, TN 37831 USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 23 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD SEP 10 PY 1996 VL 268 IS 3-4 BP 271 EP 278 DI 10.1016/0921-4534(96)00415-7 PG 8 WC Physics, Applied SC Physics GA VH550 UT WOS:A1996VH55000010 ER PT J AU Kuhn, M Rodriguez, JA Hrbek, J AF Kuhn, M Rodriguez, JA Hrbek, J TI Reaction of S-2 with X/Mo(110) (X=Fe, Pt or Al) surfaces: Admetal-promoted sulfidation of Mo and the behavior of hydrodesulfurization catalysts SO SURFACE SCIENCE LA English DT Article DE aluminum; catalysis; iron; molybdenum; platinum; sulfides; surface chemical reaction; thermal desorption spectroscopy; X-ray photoelectron spectroscopy ID PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC-PROPERTIES; CO CHEMISORPTION; MO(100) SURFACE; PHENYL THIOLATE; MO(110); SULFUR; FILMS; GROWTH; THIOPHENE AB Exposure of a clean Mo(110) surface to S-2 at room temperature or at 700 K results in a chemisorbed layer of sulfur only, without any evidence for the formation of molybdenum sulfides. The effects of Fe, Pt, and Al on the reactivity of Mo(110) toward sulfur have been studied using thermal desorption spectroscopy (TDS), X-ray photoelectron spectroscopy (XPS) and X-ray excited Auger electron spectroscopy (XAES). It is found that at room temperature, the reactivity of S, with multilayers of the admetal follows the order Fe > Al >> Pt. While most of the Fe becomes sulfidized, only a few layers of the Al become sulfidized before passivation, and the least reactive Pt surface is covered by a chemisorbed layer of sulfur. Upon exposure of the Fe/Mo(110) (theta(Fe) <2 ML) surfaces to S-2 at elevated temperatures (700 K) or annealing of FeSy/Mo(110) surfaces (700-1000 K), the formation of MoSx compounds is observed, with FeSy remaining on the surface. High-temperature S-2 exposure of the Pt/Mol(110) system leads to the formation of a small amount of MoS, only in the case where theta(Pt)<1, with only a chemisorbed layer of sulfur observed on top the Pt surface in all other cases. There is no evidence for PtSx formation. High-temperature S-2 exposure of Al/Mo(110) or annealing of the AlSx/Al/Mo(110) system does not lead to formation of molybdenum sulfides. The thin layer AlSx film remains stable to further S, exposure. The effects of Fe, Pt, and Al on the rate of sulfidation of Mo are rationalized by examining the relative stabilities of the metal sulfides, the cohesive energies of the metals involved and electronic interactions in bimetallic bonding. The trends in our results are compared with trends in the activity of Mo-based bimetallic catalysts in hydrodesulfurization processes. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Hrbek, Jan/I-1020-2013 NR 58 TC 10 Z9 10 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 1996 VL 365 IS 1 BP 53 EP 68 DI 10.1016/0039-6028(96)00693-0 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA VF384 UT WOS:A1996VF38400008 ER PT J AU Hanbicki, A Davis, HL Baddorf, AP Poker, DB Plummer, EW AF Hanbicki, A Davis, HL Baddorf, AP Poker, DB Plummer, EW TI Hydrogen-induced structural changes on NiAl(110) SO SURFACE SCIENCE LA English DT Letter DE alloys; atom-solid interactions; hydrogen; low energy electron diffraction (LEED); NiAl; surface relaxation and reconstruction; X-ray scattering, diffraction, and reaction ID ADSORPTION DYNAMICS; RIPPLED RELAXATION; METAL-SURFACES; H-2; CHEMISORPTION AB LEED I-V/analysis and surface X-ray scattering measurements have been used to determine the structural changes induced by the adsorption of atomic hydrogen on NiAl(110) at 130 K. The clean surface, ordered with 50at% Ni-50at%Al, relaxes away from bulk truncation to exhibit a large ripple. At 130 K the rippling (Al out, Ni in) is 0.19 Angstrom, as determined by LEED I-V The adsorption of atomic hydrogen reduces this rippling by 16% at half of saturation coverage and at full saturation by 44%. Saturation coverage was measured to be one hydrogen atom per (1x1)surface unit cell(1 monolayer) using nuclear reaction analysis. This observation contradicts first principles calculations that predict 1 monolayer of H removes the surface rippling. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Hanbicki, A (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. RI Baddorf, Arthur/I-1308-2016 OI Baddorf, Arthur/0000-0001-7023-2382 NR 37 TC 14 Z9 14 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 SEP 10 PY 1996 VL 365 IS 1 BP L639 EP L646 DI 10.1016/0039-6028(96)00851-5 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA VF384 UT WOS:A1996VF38400001 ER PT J AU Meissner, KE Gourley, PL Brennan, TM Hammons, BE McDonald, AE AF Meissner, KE Gourley, PL Brennan, TM Hammons, BE McDonald, AE TI Intracavity spectroscopy in vertical cavity surface-emitting lasers for micro-optical-mechanical systems SO APPLIED PHYSICS LETTERS LA English DT Article AB We demonstrate lasing action in a novel microcavity laser device based on vertical cavity surface-emitting laser technology. This laser can be used for intracavity spectroscopy, high contrast imaging of small (10 mu m) structures, and is well suited for use in micro-optical mechanical systems for analysis of particles or fluids. Here, we investigate spectra of intracavity polystyrene spheres. Lasing threshold, single-mode operation, and multimode operation are all studied. Transverse mode separation in the multimode regime is found to be effective for sizing of the spheres. RP Meissner, KE (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 13 TC 9 Z9 9 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 SEP 9 PY 1996 VL 69 IS 11 BP 1517 EP 1519 DI 10.1063/1.117990 PG 3 WC Physics, Applied SC Physics GA VF485 UT WOS:A1996VF48500006 ER PT J AU Gao, N Ponomarev, IY Xiao, QF Gibson, WM Carpenter, DA AF Gao, N Ponomarev, IY Xiao, QF Gibson, WM Carpenter, DA TI Monolithic polycapillary focusing optics and their applications in microbeam x-ray fluorescence SO APPLIED PHYSICS LETTERS LA English DT Article AB Monolithic polycapillary focusing optics cad collect a large solid angle of x rays from a point source and form intense focused beams for microbeam x-ray fluorescence (MXRF) analysis. Such an optic was tested and characterized in a MXRF setup. For the Cu K-alpha line, the measured focal spot size of the optic was 43 mu m full width at half-maximum (FWHM). With the 16 W microfocusing x-ray source (50 mu mx10 mu m), the average Cu K-alpha intensities over the focal spot was measured to be 8.9x10(4) photons/s/mu m(2). When compared to a straight single channel capillary optic with approximately the same output beam size, an intensity gain of 44 was obtained. ?The optic was applied to the MXRF setup to analyze trace elements in various samples and a minimum detection limit (MDL) of about 2 pg was achieved for the transition elements (V, Cr, Mn, and Fe). The optic was also used to map the distributions of trace elements in various samples. (C) 1996 American Institute of Physics. C1 XRAY OPT SYST INC, ALBANY, NY 12205 USA. OAK RIDGE CTR MFG TECHNOL, OAK RIDGE, TN 37831 USA. RP Gao, N (reprint author), SUNY ALBANY, CTR XRAY OPT, 1400 WASHINGTON AVE, ALBANY, NY 12222 USA. NR 9 TC 37 Z9 38 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 9 PY 1996 VL 69 IS 11 BP 1529 EP 1531 DI 10.1063/1.117994 PG 3 WC Physics, Applied SC Physics GA VF485 UT WOS:A1996VF48500010 ER PT J AU Ruvimov, S LilientalWeber, Z Washburn, J Duxstad, KJ Haller, EE Fan, ZF Mohammad, SN Kim, W Botchkarev, AE Morkoc, H AF Ruvimov, S LilientalWeber, Z Washburn, J Duxstad, KJ Haller, EE Fan, ZF Mohammad, SN Kim, W Botchkarev, AE Morkoc, H TI Microstructure of Ti/Al and Ti/Al/Ni/Au ohmic contacts for n-GaN SO APPLIED PHYSICS LETTERS LA English DT Article AB Transmission electron microscopy has been applied to characterize the structure of Ti/Al and Ti/Al/Ni/Au Ohmic contacts on n-type GaN (similar to 10(17) cm cm(-3)) epitaxial layers. The metals were deposited either by conventional electron-beam or thermal evaporation techniques, and then thermally annealed at 900 degrees C for 30 s in a N-2 atmosphere. Before metal deposition, the GaN surface was treated by reactive ion etching. A thin polycrystalline cubic TiN layer epitaxially matched to the (0001) GaN surface was detected at the interface with the GaN substrate. This layer was studied in detail by electron diffraction and high resolution electron microscopy. The orientation relationship between the cubic TIN and the GaN was found to be: {111}(TiN)//{00.1}(GaN), [110](TiN)//[11.0](GaN), [112](TiN)//[10.0](GaN). The formation of this cubic TiN layer results in an excess of N vacancies in the GaN close to the interface which is considered to be the reason for the low resistance of the contact. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MIN ENGN,BERKELEY,CA 94720. UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL 61810. UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61810. RP Ruvimov, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,MS 62-203,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 11 TC 208 Z9 216 U1 5 U2 45 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 SEP 9 PY 1996 VL 69 IS 11 BP 1556 EP 1558 DI 10.1063/1.117060 PG 3 WC Physics, Applied SC Physics GA VF485 UT WOS:A1996VF48500019 ER PT J AU Findikoglu, AT Foltyn, SR Arendt, PN Groves, JR Jia, QX Peterson, EJ Wu, XD Reagor, DW AF Findikoglu, AT Foltyn, SR Arendt, PN Groves, JR Jia, QX Peterson, EJ Wu, XD Reagor, DW TI Microwave surface resistance of YBa2Cu3Cu3O7-x films on polycrystalline ceramic substrates with textured buffer layers SO APPLIED PHYSICS LETTERS LA English DT Article ID YBA2CU3O7-DELTA THICK-FILMS; YTTRIA-STABILIZED-ZIRCONIA; SAPPHIRE; GROWTH; LOSSES AB We have used a parallel-plate resonator technique to measure the microwave surface resistance R(s) of YBa2Cu3O7-x (YBCO) films on buffered ceramic substrates at around 10 GHz, and studied the correlation between their R(s) and materials properties. A 0.4-mu m-thick YBCO film (with an in-plane mosaic spread of 7 degrees) grown on a polycrystalline alumina substrate with an ion-beam-assisted-deposited yttria-stabilized zirconia buffer layer showed an R(s) of 1.89 m Omega at 76 K and 0.21 m Omega at 4 K. We have observed a strong correlation between the R(s) of the samples and the in-plane mosaic spread of the YBCO films. This correlation can be explained qualitatively in terms of a simple model in which the weak links between the grains of the YBCO film form an electrical network of Josephson junctions. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RI Jia, Q. X./C-5194-2008 NR 15 TC 9 Z9 9 U1 1 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 SEP 9 PY 1996 VL 69 IS 11 BP 1626 EP 1628 DI 10.1063/1.117052 PG 3 WC Physics, Applied SC Physics GA VF485 UT WOS:A1996VF48500043 ER PT J AU Edwards, E Hampton, E Ashby, CR Zhang, JY Wang, RY AF Edwards, E Hampton, E Ashby, CR Zhang, JY Wang, RY TI 5-HT3-like receptors in the rat medial prefrontal cortex: Further pharmacological characterization SO BRAIN RESEARCH LA English DT Article DE medial prefrontal cortex; 5-HT3-like receptor; phosphoinositide hydrolysis; 5-HT3 receptor agonist; PBG chlorinated derivative; SR 57227A ID PHOSPHOINOSITIDE HYDROLYSIS; NUCLEUS-ACCUMBENS; IN-VITRO; AGONIST; RELEASE; BRAIN; SEROTONIN; DOPAMINE; STIMULATION; ANTAGONIST AB The aim of the study was to further characterize the pharmacological properties of 5-hydroxytryptamine (5-HT)(3)-like receptors in the rat medial prefrontal cortex (mPFC) using combinations of biochemical and electrophysiological approaches. Phenylbiguanide (PEG) and three chlorinated derivatives, ortho-chloro-PBG (oCPBG), meta-chloro-PBG (mCPBG) and para-chloro-PBG (pCPBG), dose-dependently stimulated phosphoionositide (PI) turnover in fronto-cingulate cortical slices. All three chloro-isomers of PBG were equipotent in stimulating PI turnover. SR 57227A ((4-amino)-(6-chloro-2-pyridyl) L-piperidine hydrochloride, a novel compound with high affinity and selectivity for peripheral and central 5-HT3 receptors) dose-dependently stimulated PI turnover in fronto-cingulate cortical slices. The rank order of potency of all the 5-HT3 receptor agonists tested in the PI assay as compared to 5-HT was: 5-HT > 2-Me-5-HT > SR57227A > PBG = mCPBG = oCPBG = mCPBG. 5-HT and 5-HT receptor agonists depressed the firing rate of both spontaneously active and glutamate-activated quiescent mPFC cells in a current (dose)-dependent fashion. The rank order of effectiveness of these compounds was: 5-HT > SR57227A = 2-Me-5-HT = mCPBG = oCPBG = pCPBG = PBG. Unlike its action on the 5-HT3 receptors in the periphery or cultured cell Lines, D-tubocurarine chloride appears to be non-specific in blocking the depressant action of 2-Me-5-HT, gamma-aminobutyric acid and dopamine. Our results combined support the view that the pharmacological properties of 5-HT3-like receptors in the mPFC are not identical to those located in peripheral tissues and in cultured cell lines. C1 BROOKHAVEN NATL LABS,DEPT MED,UPTON,NY 11973. SUNY STONY BROOK,DEPT PSYCHIAT & BEHAV SCI,STONY BROOK,NY 11794. RP Edwards, E (reprint author), UNIV MARYLAND,PHARMACOL & TOXICOL PROGRAM,SCH PHARM,DEPT PHARMACEUT SCI,20 N PINE ST,BALTIMORE,MD 21201, USA. FU NIDA NIH HHS [DA 07193, DA 06870]; NIMH NIH HHS [MH 41440] NR 33 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-8993 J9 BRAIN RES JI Brain Res. PD SEP 9 PY 1996 VL 733 IS 1 BP 21 EP 30 DI 10.1016/S0006-8993(96)00529-X PG 10 WC Neurosciences SC Neurosciences & Neurology GA VJ894 UT WOS:A1996VJ89400004 PM 8891244 ER PT J AU Csoto, A Karataglidis, S AF Csoto, A Karataglidis, S TI Low-energy M1 strength in the Li-7(p,gamma o)Be-8 reaction SO NUCLEAR PHYSICS A LA English DT Article DE Li-7(p,gamma o)Be-8; solar neutrinos; cluster model; shell model ID BE-7(P,GAMMA)B-8 CROSS-SECTION; ASTROPHYSICAL S-FACTOR; MICROSCOPIC MODEL; 3-CLUSTER MODEL; S(E) FACTOR; BE-7(P; EXTRAPOLATION; NUCLEI; B-8 AB The Li-7(p, gamma 0)Be-8 reaction is studied in a microscopic cluster model. All relevant subsystem properties are well reproduced. The calculated astrophysical S-factor is in good agreement with the experimental data, although some M1 strength is missing in the 1(+); 1 resonance region, and there is no contribution from the 1(+);0 stare. Our model predicts, in contradiction to experiment, a dominant I = 1 channel spin contribution to the cross section. We estimate an M1 strength of 3.5% at 80 keV. By assuming the experimental resonance parameters and channel spin ratio for the first 1(+) state that M1 strength is 6.3%, in good agreement with an R-matrix analysis, C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Csoto, A (reprint author), MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824, USA. NR 42 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 9 PY 1996 VL 607 IS 1 BP 62 EP 71 DI 10.1016/0375-9474(96)00229-1 PG 10 WC Physics, Nuclear SC Physics GA VH870 UT WOS:A1996VH87000004 ER PT J AU Chu, CS Ho, PM Zumino, B AF Chu, CS Ho, PM Zumino, B TI Non-abelian anomalies and effective actions for a homogeneous space G/H SO NUCLEAR PHYSICS B LA English DT Article DE anomaly; effective action ID CHIRAL ANOMALIES; COHOMOLOGY AB We consider the problem of constructing the fully gauged effective action in 2n-dimensional space-time for Nambu-Goldstone bosons valued in a homogeneous space G/H, with the requirement that the action is a solution of the anomalous Ward identity and that it is invariant under the gauge transformations of H. We show that this can be done whenever the homotopy group pi(2n)(G/H) is trivial, G/H is reductive and H is embedded in G so as to be anomaly free, in particular when H is an anomaly safe group. We construct the necessary generalization of the Bardeen counterterm and give explicit forms for the anomaly and the effective action. When G/H is a symmetric space, the counterterm and the anomaly decompose into a parity-even and a parity-odd part. In this case, for the parity-even part of the action, one does not need the anomaly free embedding of H. RP Chu, CS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. RI Chu, chong-sun/J-8842-2012; OI Ho, Pei-Ming/0000-0002-0466-0351 NR 17 TC 14 Z9 14 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 SEP 9 PY 1996 VL 475 IS 1-2 BP 484 EP 504 DI 10.1016/0550-3213(96)00322-7 PG 21 WC Physics, Particles & Fields SC Physics GA VG583 UT WOS:A1996VG58300021 ER PT J AU Wright, EM Walls, DF Garrison, JC AF Wright, EM Walls, DF Garrison, JC TI Collapses and revivals of Bose-Einstein condensates formed in small atomic samples SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; TRAPPED NEUTRAL ATOMS; GAS; SCATTERING AB The macroscopic wave function for atomic samples composed of a few thousand particles is shown to exhibit collapses and revivals on a few seconds time scale, while Bose-Einstein condensation remains in the form of off-diagonal long-range order in the one-particle reduced density matrix. A recently proposed measurement scheme which is sensitive to Bose-broken gauge symmetry, and hence to the macroscopic wave function, could be used to detect the collapses and revivals experimentally. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV AUCKLAND,DEPT PHYS,AUCKLAND,NEW ZEALAND. RP Wright, EM (reprint author), UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721, USA. RI Wright, Ewan/A-2358-2009 NR 26 TC 181 Z9 183 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 SEP 9 PY 1996 VL 77 IS 11 BP 2158 EP 2161 DI 10.1103/PhysRevLett.77.2158 PG 4 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600003 ER PT J AU Cubaynes, D Diehl, S Journel, L Rouvellou, B Bizau, JM AlMoussalami, S Wuilleumier, FJ Berrah, N VoKy, L Faucher, P Hibbert, A Blancard, C Kennedy, E Morgan, TJ Bozek, J Schlachter, AS AF Cubaynes, D Diehl, S Journel, L Rouvellou, B Bizau, JM AlMoussalami, S Wuilleumier, FJ Berrah, N VoKy, L Faucher, P Hibbert, A Blancard, C Kennedy, E Morgan, TJ Bozek, J Schlachter, AS TI First photoexcitation measurements and R-matrix calculations of even-parity hollow states in laser-excited lithium atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID INNER-SHELL PHOTOIONIZATION; LIFETIMES AB Photoelectron data are reported for the first measurement of even-parity hollow lithium states produced by triple photoexcitation of laser-excited lithium atoms. Calculations using the R-matrix approximation of the energy of these states and partial photoionization cross sections are also reported. Experiment and theory are in excellent agreement on a relative scale. C1 WESTERN MICHIGAN UNIV,KALAMAZOO,MI 49008. OBSERV COTE AZUR,F-06304 NICE,FRANCE. QUEENS UNIV BELFAST,BELFAST,ANTRIM,NORTH IRELAND. CEA LIMEIL VALENTON,F-94195 VILLENEUVE ST GEO,FRANCE. DUBLIN CITY UNIV,DUBLIN 9,IRELAND. WESLEYAN UNIV,MIDDLETOWN,CT 06457. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Cubaynes, D (reprint author), UNIV PARIS 11,LAB SPECT ATOM & ION,CNRS,URA 775,B350,F-91405 ORSAY,FRANCE. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 15 TC 69 Z9 69 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 SEP 9 PY 1996 VL 77 IS 11 BP 2194 EP 2197 DI 10.1103/PhysRevLett.77.2194 PG 4 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600012 ER PT J AU Feibelman, PJ Esch, S Michely, T AF Feibelman, PJ Esch, S Michely, T TI O binding sites on stepped Pt(111) surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID PSEUDOPOTENTIALS; ADSORPTION AB First-principles calculations show that O adatoms are attracted to step edges on Pt(111), gaining 0.2 to 0.3 eV per nearest neighbor step-edge Pt atom, and that they favor ''fee-like'' over ''hcp-like'' sites by similar to 0.4 eV. These preferences account for the different appearances, in scanning tunneling micrographs, of O-saturated, A- and B-type island edges on Pt(111). They imply that O binds in a threefold, fee hollow site behind a B step, while twofold edge bridging is favored for A steps. C1 FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST GRENZFLACHENFORSCH & VAKUUMPHYS, D-52425 JULICH, GERMANY. RP Feibelman, PJ (reprint author), SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 18 TC 108 Z9 108 U1 1 U2 17 PU AMER 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 SEP 9 PY 1996 VL 77 IS 11 BP 2257 EP 2260 DI 10.1103/PhysRevLett.77.2257 PG 4 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600028 ER PT J AU Fehrenbacher, R AF Fehrenbacher, R TI Coupling to optical phonons in the one-dimensional t-J model: Effects on the superconducting fluctuations and phase separation SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; HUBBARD-MODEL; EXACT DIAGONALIZATION; FERMI GAS; SPIN; EXPONENTS; SYSTEMS; DIAGRAM; CHARGE AB The one-dimensional t-J Holstein model is studied by exact diagonalization of finite rings using a variational approximation for the phonon states. Because of renormalization effects induced by the phonons, for intermediate electron-phonon coupling, the phase separation boundary, and with it the region of dominating superconducting fluctuations is shifted substantially to smaller values of J/t as compared to the purl t-J model. Superconducting correlations are weakened through charge density wave interactions mediated by the phonons. Possible consequences for the high-T-c oxides are discussed. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 32 TC 11 Z9 11 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 SEP 9 PY 1996 VL 77 IS 11 BP 2288 EP 2291 DI 10.1103/PhysRevLett.77.2288 PG 4 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600036 ER PT J AU Isgur, N Speth, J AF Isgur, N Speth, J TI Confirmation of the sigma meson - Comment SO PHYSICAL REVIEW LETTERS LA English DT Article RP Isgur, N (reprint author), JEFFERSON LAB,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 6 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 9 PY 1996 VL 77 IS 11 BP 2332 EP 2332 DI 10.1103/PhysRevLett.77.2332 PG 1 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600047 ER PT J AU Hill, JP Feng, Q Birgeneau, RJ AF Hill, JP Feng, Q Birgeneau, RJ TI First-order transition in random-field ising systems - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article ID MODEL C1 MIT,CAMBRIDGE,MA 02139. RP Hill, JP (reprint author), BROOKHAVEN NATL LAB,POB 5000,UPTON,NY 11973, USA. NR 3 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 9 PY 1996 VL 77 IS 11 BP 2339 EP 2339 DI 10.1103/PhysRevLett.77.2339 PG 1 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600054 ER PT J AU Birgeneau, RJ Feng, Q Harris, QJ Hill, JP Ramirez, AP AF Birgeneau, RJ Feng, Q Harris, QJ Hill, JP Ramirez, AP TI X-Ray and neutron scattering, magnetization, and heat capacity study of the 3D random field Ising model - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Birgeneau, RJ (reprint author), MIT,DEPT PHYS,CAMBRIDGE,MA 02139, USA. NR 8 TC 10 Z9 10 U1 0 U2 2 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 SEP 9 PY 1996 VL 77 IS 11 BP 2342 EP 2343 DI 10.1103/PhysRevLett.77.2342 PG 2 WC Physics, Multidisciplinary SC Physics GA VF416 UT WOS:A1996VF41600057 ER PT J AU Hsu, CW Lu, KT Evans, M Chen, YJ Ng, CY Heimann, P AF Hsu, CW Lu, KT Evans, M Chen, YJ Ng, CY Heimann, P TI A high resolution photoionization study of Ne and Ar: Observation of mass analyzed threshold ions using synchrotron radiation and direct current electric fields SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ZEKE PHOTOELECTRON-SPECTROSCOPY; MOLECULAR RYDBERG STATES; ADVANCED LIGHT-SOURCE; AUTOIONIZATION RESONANCES; IONIZATION SPECTROSCOPY; VACUUM-ULTRAVIOLET; CHEMICAL-DYNAMICS; EXCITED-STATES; COHERENT XUV; ENERGY AB Using the high resolution vacuum ultraviolet (vuv) photon source provided by the monochromatized undulator synchrotron radiation of the Chemical Dynamics Beamline at the Advanced Light Source, we have measured the photoionization efficiency (PLE) spectrum for Ne in the energy range of 21.56-21.67 eV at a wavelength resolution of 0.3 meV [full width at half-maximum (FWHM)]. The PIE spectra for Ne obtained using 0.76 and 2.4 V/cm electric fields reveal autoionizing features attributable to the Rydberg slates Ne[2p(5)ns'(1/2)(1); n = 14-29] and Ne[2p(5)nd'(3/2)(1); n = 12-35] converging to the spin-orbit excited Ne+(P-2(1/2)) state. The positions of these Rydberg states are compared to previous experimental results and those calculated using the quantum defects and IE for Ne+(P-2(1/2)) given in Moore [Natl. Stand Ref. Data Ser. Natl. Bur. Stand. 35 (1971)]. We have also observed mass analyzed threshold ions (MATI) for Ne formed in the Ne+(P-2(3/2,1/2)), states. For Ar, only the MATI peak for Ar+(P-2(3/2)) is observed. The failure tu observe the MATI peak for Ar+(P-2(1/2)) is attributed to shorter lifetimes of high-n Ar[3p(5)ns'(1/2)(1)] and Ar[3p(5)nd'(3/2)(1)] Rydberg stales compared to the minimum time required for separating the prompt Ar+ ions from the field ionized Ar+ ions in this experiment. The MATI peaks for Ne+(P-2(3/2,1/2)) achieves a resolution of 0.7 meV (FWHM). These MATI spectra for Ne and Ar reported here represent the first such studies made using a cw vuv Light source and de electric fields. (C) 1996 American Institute of Physics. C1 US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV ACCELERATOR & FUS RES, ADV LIGHT SOURCE, BERKELEY, CA 94720 USA. RI Chen, Yu-Ju/E-9481-2015 NR 60 TC 73 Z9 75 U1 3 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1996 VL 105 IS 10 BP 3950 EP 3961 DI 10.1063/1.472268 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VF657 UT WOS:A1996VF65700007 ER PT J AU GuanSajonz, H Guiochon, G AF GuanSajonz, H Guiochon, G TI Effect of the packing pressure on the performance of C-18 reversed-phase liquid chromatographic columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE packing pressure; stationary phases, LC; preparative chromatography; porosity; band profiles; isotherms; phenylpropanol ID EXCLUSION CHROMATOGRAPHY; PREPARATIVE CHROMATOGRAPHY; STATIONARY PHASES; EQUILIBRIUM; ADSORPTION; ISOTHERMS; SOLIDS AB Early evidence has shown that HPLC columns packed with a given ODS phase give different performance, related to differences in their packing densities and external porosities. This effect was systematically studied on two groups of ten analytical (10X0.46 cm) columns packed with Kromasil and Zorbax 10 mu m spherical C-18, respectively, using chloroform as the slurry solvent and methanol as the pushing solvent. The packing pressure used for column j in each group was 1000j p.s.i. The mass of packing material inside each column increased with increasing packing pressure. The column external porosity, determined by inverse size-exclusion chromatography method, decreased as the packing pressure increased, while the internal porosity remained constant. With a methanol-water (45:55, v/v) solution as the mobile phase, the retention factors and column efficiencies were measured at infinite dilution for acetone, benzyl acetate, benzyl alcohol, m-cresol, 2,6-dimethyl phenol, methyl benzoate, 3-phenyl-1-propanol, and uracil (also used as non-retained compound to determine the hold-up times). The retention factor and the column efficiency of each compound increased linearly with increasing packing pressure. The isotherm of 5-phenyl-1-propanol was determined on each column by elution by characteristic points and frontal analysis methods. These data were normalized by the column geometrical volume (V-k: ml), by the stationary phase volume (V-p: ml), and by the mass of packing (W-p: g). The parameters obtained from the isotherm normalized by V-k cannot predict the band profile accurately. Better results were obtained with the parameters obtained from the isotherm normalized by V-p. Close agreement was obtained between the parameters obtained by mass normalization. This allowed a reasonable prediction of the band profiles recorded on one column using isotherm data measured on another column. Considering the difficulties encountered in volume determinations, normalization of isotherm data by the packing weight seems to be the most practical solution. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 35 TC 15 Z9 16 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD SEP 6 PY 1996 VL 743 IS 2 BP 247 EP 259 DI 10.1016/0021-9673(96)00300-7 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VJ563 UT WOS:A1996VJ56300002 ER PT J AU Chen, LL Hodgson, KO Doniach, S AF Chen, LL Hodgson, KO Doniach, S TI A lysozyme folding intermediate revealed by solution X-ray scattering SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE lysozyme; protein folding; X-ray solution scattering; folding intermediate; singular value decomposition ID EGG-WHITE LYSOZYME; PARTIALLY FOLDED STATE; SMALL-ANGLE SCATTERING; STRUCTURAL CHARACTERIZATION; DENATURED STATES; MOLTEN GLOBULE; PROTEIN; COMPONENTS; TITRATION; UREA AB Equilibrium unfolding of hen egg lysozyme as a function of urea concentration at pH 2.9 has been studied by solution X-ray scattering. Differences in the unfolding transition are observed as monitored by the radius of gyration R(g), and by far and near UV CD (circular dichroism) at 222 nm and 298 nm, respectively. This suggests the existence of a third unfolding species, in addition to the native and the unfolded states. A singular value decomposition (SVD) analysis was made of the scattering curves at different urea concentrations. This analysis shows clear evidence of a third basis component in the X-ray scattering curves, thus supporting the results of the R(g) and CD measurements. The denaturant binding model was employed to estimate the thermodynamic parameters of denaturation for the intermediate and unfolded states. Use of these parameters to refine the SVD analysis allows us to reconstruct a scattering profile for the pure intermediate state. Simplified partially folded models, based on the crystal structure of hen lysozyme, support a working model for the intermediate, whose structure may be correlated with that of the kinetic intermediate found in the refolding pathway studied by Dobson and coworkers. (C) 1996 Academic Press Limited C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. FU NCRR NIH HHS [RR-01209] NR 46 TC 119 Z9 120 U1 1 U2 10 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 SEP 6 PY 1996 VL 261 IS 5 BP 658 EP 671 DI 10.1006/jmbi.1996.0491 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VF296 UT WOS:A1996VF29600007 PM 8800214 ER PT J AU Chen, JB Day, CL Jacobson, RA Angelici, RJ AF Chen, JB Day, CL Jacobson, RA Angelici, RJ TI Unexpected products resulting from reactions of Cp(*) Ir(eta(5)-2,5-Me(2)T)(2+) (Me(2)T=2,5-dimethylthiophene) with (mu-S)(2)Fe-2(CO)(6)(2-) and (mu-CO)(mu-RS) Fe-2(CO)(6)(-) SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE iridium; iron; thiophene; sulfur; hydrodesulfurization; pentamethylcyclopentadienyl ID TRANSITION-METAL COMPLEXES; SULFUR BOND-CLEAVAGE; C-S-BONDS; THIOPHENE HYDRODESULFURIZATION; COORDINATED THIOPHENE; <(MU-CO)(MU-RS)FE2(CO)6> COMPLEXES; 2,5-DIMETHYLTHIOPHENE COORDINATION; FE2(CO)6 COMPLEXES; REACTIVITY; IRIDIUM AB The reactions of Cp*Ir(eta(5)-2,5-Me(2)T)(2+) (1) with (mu-S)(2)Fe-2(CO)(6)(2-) and (mu-Co)(mu-n-BuS)Fe-2(CO)(6)(-), which are expected to result in either reduction of 1 or nucleophilic attack on the eta(5)-2,5-dimethylthiophene ring, yield products that contain the reduced Cp*Ir(eta(4)-2,5-Me(2)T) (2) ligand. X-ray diffraction studies of the products Cp*Ir(eta(4)-2,5-Me(2)T . Fe-2(CO)(5)(mu-S-2)) (6) and Cp*Ir(eta(4)-2,5-Me(2)T . Fe-2(CO)(5)(mu-S(n)Bu)(2)) (9) show that the Cp*Ir(eta(4)-2,5-Me(2)T) is coordinated through its sulfur atom to an Fe atom of the Fe-2(mu-S)(2)(CO)(4) dimer core. Reaction of 2 with (mu-S-2)Fe-2(CO)(6) (4) leads to a completely different product 7 in which the two bridging sulfur atoms of the Fe-2(mu-S)(2)(CO)(4) core are bonded at two carbons of a rearranged 2,5-Me(2)T ligand. Characterization and mechanisms of formation of the new compounds are discussed. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. CHINESE ACAD SCI,SHANGHAI INST ORGAN CHEM,SHANGHAI 200032,PEOPLES R CHINA. NR 49 TC 9 Z9 9 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 SEP 6 PY 1996 VL 522 IS 1 BP 21 EP 32 DI 10.1016/0022-328X(96)06242-0 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA VH577 UT WOS:A1996VH57700003 ER PT J AU Rose, TP Davisson, ML AF Rose, TP Davisson, ML TI Radiocarbon in hydrologic systems containing dissolved magmatic carbon dioxide SO SCIENCE LA English DT Article ID CO2; EMISSIONS; INDONESIA; ISLAND; CYCLE; DIENG; ETNA; SOIL; NYOS AB In regions of active volcanism, the presence of magmatic carbon dioxide (CO2) in regional hydrologic systems provides a radiocarbon-depleted tracer for delineating ground-water transport and mixing processes and provides a means of assessing regional magmatic carbon fluxes, Variations in the stable carbon isotopic composition (delta(13)C) and carbon-14 values of springs and surface waters from the southern Cascade Range show consistent patterns of carbon isotopic mixing between magmatic, biogenic, and atmospheric CO2 reservoirs. Radiocarbon measurements of waters from the Lassen region in northern California were used to construct a ground-water carbon-14 contour map, revealing principal subsurface flow paths and a broad region of diffuse magmatic CO2 flux. RP Rose, TP (reprint author), LAWRENCE LIVERMORE NATL LAB,ISOTOPE SCI DIV,L-231,LIVERMORE,CA 94550, USA. NR 24 TC 30 Z9 31 U1 3 U2 9 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD SEP 6 PY 1996 VL 273 IS 5280 BP 1367 EP 1370 DI 10.1126/science.273.5280.1367 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VF610 UT WOS:A1996VF61000035 ER PT J AU Sherwood, JL Petersen, JN Skeen, RS Valentine, NB AF Sherwood, JL Petersen, JN Skeen, RS Valentine, NB TI Effects of nitrate and acetate availability on chloroform production during carbon tetrachloride destruction SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE denitrify; carbon tetrachloride; chloroform; acetate; nitrate; bioremediation ID SP STRAIN-KC; DENITRIFICATION CONDITIONS; BIOLOGICAL DESTRUCTION; TRANSFORMATION; KINETICS; CCL4 AB Fed batch experiments were performed to test the effects of electron donor and electron acceptor availability on the production of chloroform (CF) during carbon tetrachloride (CT) destruction by a denitrifying bacterial consortium. In one series of tests, acetate (electron donor) was present in excess while nitrate and nitrite (electron acceptor) were limiting. In the other series of tests, acetate was the limiting nutrient, and nitrate and nitrite were in excess. Under nitrate limiting conditions, 50% (+/-17%) of the CT transformed by the microorganisms was converted to CF. However, under acetate limiting conditions, only 4% (+/-4%) of the CT that was degraded appeared as CF. Previous research had suggested that denitrifying bacteria can degrade CT via two competing pathways. One of these pathways produces CF as the predominant end product. The second pathway produces CO2 as the primary end product, The results shown here suggest that the first pathway is dominant when nitrate and nitrite are depleted while the second pathway, which produces little CF, dominates when nitrate or nitrite are available. (C) 1996 John Wiley & Sons, Inc. C1 WASHINGTON STATE UNIV, DEPT CHEM ENGN, PULLMAN, WA 99164 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Petersen, James/B-8924-2008 NR 25 TC 9 Z9 9 U1 1 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD SEP 5 PY 1996 VL 51 IS 5 BP 551 EP 557 DI 10.1002/(SICI)1097-0290(19960905)51:5<551::AID-BIT7>3.0.CO;2-B PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA UZ749 UT WOS:A1996UZ74900007 PM 18629819 ER PT J AU Reynolds, J AF Reynolds, J TI Catalytic conversion of polycyclic aromatic hydrocarbons: An introduction SO CATALYSIS TODAY LA English DT Editorial Material C1 UNIV DELAWARE,DEPT CHEM ENGN,NEWARK,DE 19716. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Reynolds, J (reprint author), PENN STATE UNIV,FUEL SCI PROGRAM,UNIVERSITY PK,PA 16802, 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 0920-5861 J9 CATAL TODAY JI Catal. Today PD SEP 5 PY 1996 VL 31 IS 1-2 BP 1 EP 2 PG 2 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VJ364 UT WOS:A1996VJ36400001 ER PT J AU Autrey, T Linehan, JC Camaioni, DM Kaune, LE Watrob, HM Franz, JA AF Autrey, T Linehan, JC Camaioni, DM Kaune, LE Watrob, HM Franz, JA TI Mechanistic investigations of iron/sulfur-catalyzed bond scission in aromatic hydrocarbons. A catalytic hydrogen atom transfer step involving a late transition state SO CATALYSIS TODAY LA English DT Article; Proceedings Paper CT American-Chemical-Society Symposiun on Catalytic Conversion of Polycyclic Aromatic Hydrocarbons, at the 210th ACS National Meeting CY AUG 20-24, 1995 CL CHICAGO, IL SP Amer Chem Soc DE catalysis; hydrogen transfer; iron; model compounds ID DIPHENYLMETHANE HYDROCRACKING; COAL-LIQUEFACTION; MODEL; CLEAVAGE; PHASE; FES2 AB The mechanism of carbon-carbon bond scission by 'iron sulfide' catalysts is explored through the use of substituted diphenylmethane model compounds. The reaction kinetics are shown to be first order in model compound with the methylene-arene carbon-carbon bond adjacent to the most substituted arene being selectively cleaved. These results are consistent with the catalyst acting as a hydrogen atom transfer agent. RP Autrey, T (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 26 TC 13 Z9 14 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD SEP 5 PY 1996 VL 31 IS 1-2 BP 105 EP 111 DI 10.1016/0920-5861(96)00037-5 PG 7 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VJ364 UT WOS:A1996VJ36400011 ER PT J AU Herzenberg, CL AF Herzenberg, CL TI Pseuds' corner SO NATURE LA English DT Letter RP Herzenberg, CL (reprint author), ARGONNE NATL LAB,DECIS & INFORMAT SCI DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD SEP 5 PY 1996 VL 383 IS 6595 BP 17 EP 17 DI 10.1038/383017d0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VF295 UT WOS:A1996VF29500022 ER PT J AU Ramakrishnan, E Azhari, A Beene, JR Charity, RJ Halbert, ML Hua, PF Kryger, RA Mueller, PE Pfaff, R Sarantites, DG Sobotka, LG Thoennessen, M VanBuren, G Varner, RL Yokoyama, S AF Ramakrishnan, E Azhari, A Beene, JR Charity, RJ Halbert, ML Hua, PF Kryger, RA Mueller, PE Pfaff, R Sarantites, DG Sobotka, LG Thoennessen, M VanBuren, G Varner, RL Yokoyama, S TI Temperature dependence of the giant dipole resonance width in Pb-208 SO PHYSICS LETTERS B LA English DT Article DE giant dipole resonance; hot nuclei; statistical model; shell effects ID HOT NUCLEI; INELASTIC-SCATTERING; ROTATING NUCLEI; EXCITATION; CONTINUUM; DECAY AB The evolution of the giant dipole resonance (GDR) in hot Pb-208 nuclei was studied by measuring high energy gamma-rays from the decay of the resonance built on excited states. Nuclei in the excitation energy range of 40-110 MeV were populated by inelastic scattering of 40 MeV/nucleon alpha-particles. The GDR width was observed to increase systematically from 4 MeV at the ground state to similar to 8 MeV at the highest excitation energy. C1 MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. NR 34 TC 45 Z9 45 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 SEP 5 PY 1996 VL 383 IS 3 BP 252 EP 257 DI 10.1016/0370-2693(96)00746-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VE187 UT WOS:A1996VE18700003 ER PT J AU Kawasaki, M Moroi, T Yanagida, T AF Kawasaki, M Moroi, T Yanagida, T TI Can decaying particles raise the upperbound on the Peccei-Quinn scale? SO PHYSICS LETTERS B LA English DT Article ID INVISIBLE AXION; SUPERSTRING MODELS; HARMLESS AXION; CP INVARIANCE; SUPERGRAVITY; POLONYI; BARYOGENESIS; GRAVITINO; BREAKING AB We reexamine the effect of entropy production on the cosmic axion density and find that the Peccei-Quinn scale F-a larger than about 10(15) GeV is not allowed even if large entropy is produced by the decays of coherent oscillations or non-relativistic massive particles. We also argue that the Polonyi field in supergravity models is a natural candidate for an entropy-producing source. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. UNIV TOKYO,DEPT PHYS,TOKYO 113,JAPAN. RP Kawasaki, M (reprint author), UNIV TOKYO,INST COSM RAY RES,TANASHI,TOKYO 188,JAPAN. RI Yanagida, Tsutomu/A-4394-2011 NR 25 TC 68 Z9 68 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 SEP 5 PY 1996 VL 383 IS 3 BP 313 EP 316 DI 10.1016/0370-2693(96)00743-5 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VE187 UT WOS:A1996VE18700012 ER PT J AU Dikanov, SA Xun, LY Karpiel, AB Tyryshkin, AM Bowman, MK AF Dikanov, SA Xun, LY Karpiel, AB Tyryshkin, AM Bowman, MK TI Orientationally-selected two-dimensional ESEEM spectroscopy of the Rieske-type iron-sulfur cluster in 2,4,5-trichlorophenoxyacetate monooxygenase from Burkholderia cepacia AC1100 SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ECHO ENVELOPE MODULATION; Q-BAND ENDOR; MITOCHONDRIAL-MEMBRANES; PHTHALATE DIOXYGENASE; 2-DIMENSIONAL ESEEM; FUMARATE REDUCTASE; ESCHERICHIA-COLI; 2 HISTIDINES; ELECTRON; N-14 AB Burkholderia cepacia AC1100 is able to use the chlorinated compound 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as the sole source of carbon and energy. CW EPR and one-dimensional ESEEM spectroscopy studies performed earlier indicate the presence of a Rieske-type [2Fe-2S] cluster with two coordinated histidine residues in 2,4,5-T monooxygenase from B. cepacia. This paper describes the application of two-dimensional ESEEM (called HYSCORE) spectroscopy for further characterization of the nitrogens surrounding the reduced Rieske-type cluster. The HYSCORE spectra measured at field positions in the neighborhood of the principal directions of the g tensor contain major contributions from cross-peaks correlating the two double-quantum transitions from each histidine nitrogen. These allow the estimation of the diagonal components of the hyperfine tensors along the principal axes of the g tensor: 4.05, 3.88, and 4.01 MHz (N1) and 4.71, 5.07, and 5.02 MHz (N2). Other spectral features from the histidine nitrogens usually have a much weaker intensity and are occasionally observed in the spectra. HYSCORE measurements have been also performed with the reduced [2Fe-2S] plant ferredoxin-type cluster with four cysteine ligands in a ferredoxin from Porphira umbilicalis, and spectral features produced by the peptide nitrogen are observed. Similar features also appear in the HYSCORE spectra of the Rieske cluster. Systematic differences are observed between 2,4,5-T monooxygenase and published results from related benzene and phthalate dioxygenases that may reflect structural and functional differences in histidine ligation and the nitrogens of nearby amino acids in Rieske-type [2Fe-2S] clusters. C1 RUSSIAN ACAD SCI, INST CHEM KINET & COMBUST, NOVOSIBIRSK 630090, RUSSIA. WASHINGTON STATE UNIV, DEPT MICROBIOL & IMMUNOL, RICHLAND, WA 99352 USA. RP Dikanov, SA (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. RI Tyryshkin, Alexei/A-5219-2008; Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 37 TC 73 Z9 73 U1 2 U2 9 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 SEP 4 PY 1996 VL 118 IS 35 BP 8408 EP 8416 DI 10.1021/ja960781x PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA VF378 UT WOS:A1996VF37800026 ER PT J AU Loy, DA Carpenter, JP Myers, SA Assink, RA Small, JH Greaves, J Shea, KJ AF Loy, DA Carpenter, JP Myers, SA Assink, RA Small, JH Greaves, J Shea, KJ TI Intramolecular condensation reactions of alpha,omega-bis(triethoxysilyl)alkanes. Formation of cyclic disilsesquioxanes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ORGANIC-INORGANIC MATERIALS; BRIDGED POLYSILSESQUIOXANES; POLYMERIZATION C1 UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92717. RP Loy, DA (reprint author), SANDIA NATL LABS,DEPT PROPERTIES ORGAN MAT,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 18 TC 28 Z9 30 U1 0 U2 14 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 SEP 4 PY 1996 VL 118 IS 35 BP 8501 EP 8502 DI 10.1021/ja961409k PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VF378 UT WOS:A1996VF37800043 ER PT J AU Pohl, PI Faulon, JL Smith, DM AF Pohl, PI Faulon, JL Smith, DM TI Pore structure of imogolite computer models SO LANGMUIR LA English DT Article ID ADSORPTION; VPI-5 AB This study analyzes computer models of the microporous material imogolite. The purpose of this work is to validate computational methods developed for extracting pore size, pore volume, and surface area measurement of molecular level computer models. We accomplished this by comparing model properties with experimental data derived from N-2 adsorption isotherms and by simulating CH4 and N-2 adsorption and He/SF6 diffusion. Pore volume and pore size are easily determined and fit experimental data within reason for validation purposes. Surface area calculations are at first greater than those determined experimentally. Correcting for the curvature of the pore enables duplication of experimental data within the combined error of both methods. Simulations of adsorption and diffusion fit available experimental results reasonably well and along with previous conclusions allow identification of the most probable model structures. The computer-based method studied should be adequate for analyzing other silicate models such as sol-gel derived microporous membranes, aerogels, and zeolites. C1 UNIV NEW MEXICO,NSF,CTR MICROENGINEERED CERAM,ALBUQUERQUE,NM 87131. NANOPORE CORP,ALBUQUERQUE,NM 87106. RP Pohl, PI (reprint author), SANDIA NATL LABS,DIV ENERGY & ENVIRONM,POB 5800,MAIL STOP 0720,ALBUQUERQUE,NM 87185, USA. NR 24 TC 27 Z9 27 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 4 PY 1996 VL 12 IS 18 BP 4463 EP 4468 DI 10.1021/la9600715 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VF861 UT WOS:A1996VF86100025 ER PT J AU Hoberg, JO Jennings, PW AF Hoberg, JO Jennings, PW TI Platinum(II)-catalyzed isomerization of alkoxycyclopropanes to alkylated ketones SO ORGANOMETALLICS LA English DT Article ID PLATINACYCLOBUTANE CHEMISTRY; PLATINA(IV)CYCLOBUTANE COMPLEXES; DIASTEREOSELECTIVE SYNTHESIS; STEREOSELECTIVE SYNTHESIS; ORGANIC-SYNTHESIS; CARBON CARBON; 1ST EXAMPLE; ZEISE DIMER; DERIVATIVES; CYCLOPROPANES AB Conversion of alkoxycyclopropanes to 2-methyl Ketones has been accomplished using catalytic platinum. Mechanistic studies revealed that the conversion involves platinum insertion into the cyclopropane followed by rearrangement to produce the methyl ketone. C1 MONTANA STATE UNIV,DEPT CHEM,BOZEMAN,MT 59717. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 35 TC 19 Z9 19 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP 3 PY 1996 VL 15 IS 18 BP 3902 EP 3904 DI 10.1021/om960157t PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA VF418 UT WOS:A1996VF41800023 ER PT J AU Malladi, R Sethian, JA AF Malladi, R Sethian, JA TI An O(N log N) algorithm for shape modeling SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE Hamilton-Jacobi equation; Eikonal equation; shape recovery; medical image analysis; level sets ID CURVATURE; FRONTS AB We present a shape-recovery technique in two dimensions and three dimensions with specific applications in modeling anatomical shapes from medical images. This algorithm models extremely corrugated structures like the brain, is topologically adaptable, and runs in O(N log N) time, where N is the total number of points in the domain. Our technique is based on a level set shape-recovery scheme recently introduced by the authors and the fast marching method for computing solutions to static Hamilton-Jacobi equations. C1 UNIV CALIF BERKELEY, DEPT MATH, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 16 TC 58 Z9 60 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 3 PY 1996 VL 93 IS 18 BP 9389 EP 9392 DI 10.1073/pnas.93.18.9389 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VF614 UT WOS:A1996VF61400015 PM 8790339 ER PT J AU Mutz, MW McLendon, GL Wishart, JF Gaillard, ER Corin, AF AF Mutz, MW McLendon, GL Wishart, JF Gaillard, ER Corin, AF TI Conformational dependence of electron transfer across de novo designed metalloproteins SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BUNDLE PROTEIN; PEPTIDE; COMPLEXES; HELIX AB Flash photolysis and pulse radiolysis measurements demonstrate a conformational dependence of electron transfer rates across a 16-mer helical bundle (three-helix metalloprotein) modified with a capping Co-III(bipyridine)(3) electron acceptor at the N terminus and a 1-ethyl-1'-ethyl-4,4'-bipyridinium donor at the C terminus. For the Co-III(peptide)(3)-1-ethyl-1'-ethyl-4,4'-bipyridinium maquettes, the observed transfer is a first order, intramolecular process, independent of peptide concentration or laser pulse energy. In the presence of 6 M urea, the random coil bundle (approximate to 0% helicity) has an observed electron transfer rate constant of k(obs) = 900 +/- 100 s(-1). In the presence of 25% trifluoroethanol (TFE), the helicity of the peptide is 80% and the k(obs) increases to 2000 +/- 200 s(-1). Moreover, the increase in the rate constant in TFE is consistent with the observed decrease in donor-acceptor distance in this solvent, Such bifunctional systems provide a class of molecules for testing the effects of conformation on electron transfer in proteins and peptides. C1 PRINCETON UNIV, DEPT CHEM, PRINCETON, NJ 08544 USA. BROOKHAVEN NATL LABS, DEPT CHEM, UPTON, NY 11973 USA. UNIV ROCHESTER, DEPT CHEM, ROCHESTER, NY 14627 USA. SCRIPPGEN PHARMACEUT INC, MEDFORD, MA 02155 USA. RI Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 FU NIGMS NIH HHS [GM50019] NR 23 TC 48 Z9 48 U1 0 U2 3 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 3 PY 1996 VL 93 IS 18 BP 9521 EP 9526 DI 10.1073/pnas.93.18.9521 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VF614 UT WOS:A1996VF61400039 PM 8790363 ER PT J AU Cline, HT Witte, S Jones, KW AF Cline, HT Witte, S Jones, KW TI Low lead levels stunt neuronal growth in a reversible manner SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE retinal axons; lead toxicity; visual system development ID PROTEIN-KINASE-C; RECEPTOR ANTAGONISTS DISRUPT; CELL DENDRITIC DEVELOPMENT; NEURITE OUTGROWTH; NMDA RECEPTOR; BLOOD LEAD; EXPOSURE; RAT; BRAIN; INTOXICATION AB The developing brain is particularly susceptible to lead toxicity; however, the cellular effects of lead on neuronal development are not well understood. The effect of exposure to nanomolar concentrations of lead on several parameters of the developing retinotectal system of frog tadpoles was tested. Lead severely reduced the area and branchtip number of retinal ganglion cell axon arborizations within the optic tectum at submicromolar concentrations. These effects of lead on neuronal growth are more dramatic and occur at lower exposure levels than previously reported. Lead exposure did not interfere with the development of retinotectal topography. The deficient neuronal growth does not appear to be secondary to impaired synaptic transmission, because concentrations of lead that stunted neuronal growth were lower than those required to block synaptic transmission. Subsequent treatment of lead-exposed animals with the chelating agent 2,3-dimercaptosuccinic acid completely reversed the effect of lead on neuronal growth. These studies indicate that impaired neuronal growth may be responsible in part for lead-induced cognitive deficits and that chelator treatment counteracts this effect. C1 UNIV IOWA,DEPT PHYSIOL & BIOPHYS,IOWA CITY,IA 52245. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 58 TC 30 Z9 30 U1 1 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 3 PY 1996 VL 93 IS 18 BP 9915 EP 9920 DI 10.1073/pnas.93.18.9915 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VF614 UT WOS:A1996VF61400107 PM 8790431 ER PT J AU Haynes, TE Eaglesham, DJ Stolk, PA Gossmann, HJ Jacobson, DC Poate, JM AF Haynes, TE Eaglesham, DJ Stolk, PA Gossmann, HJ Jacobson, DC Poate, JM TI Interactions of ion-implantation-induced interstitials with boron at high concentrations in silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID TRANSIENT ENHANCED DIFFUSION; DOPANTS; SI AB Ion implantation of Si (60 keV, 1x10(14)/cm(2)) has been used to introduce excess interstitials into silicon predoped with high background concentrations of B, which were varied between 1x10(18) and 1x10(19)/cm(3). Following post-implantation annealing at 740 degrees C for 15 min to allow agglomeration of the available interstitials into elongated {311} defects, the density of the agglomerated interstitials was determined by plan-view transmission electron microscopy observation of the defects. We report a significant reduction in the fraction of excess interstitials trapped in {311} defects as a function of boron concentration up to nearly complete disappearance of the {311} defects at boron concentrations of 1x10(19)/cm(3). The reduction of the excess interstitial concentration is interpreted in terms of boron-interstitial clustering, and implications for transient-enhanced diffusion of B at high concentrations are discussed. (C) 1996 American Institute of Physics. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. PHILIPS RES LABS,NL-5656 AA EINDHOVEN,NETHERLANDS. RP Haynes, TE (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 19 TC 72 Z9 72 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 2 PY 1996 VL 69 IS 10 BP 1376 EP 1378 DI 10.1063/1.117441 PG 3 WC Physics, Applied SC Physics GA VE530 UT WOS:A1996VE53000012 ER PT J AU Choquette, KD Geib, KM Chui, HC Hammons, BE Hou, HQ Drummond, TJ AF Choquette, KD Geib, KM Chui, HC Hammons, BE Hou, HQ Drummond, TJ TI Selective oxidation of buried AlGaAs versus AlAs layers SO APPLIED PHYSICS LETTERS LA English DT Article ID VERTICAL-CAVITY LASERS; SURFACE-EMITTING LASERS AB We report significant differences between the properties of buried oxides converted from AlGaAs and AlAs layers using selective wet oxidation. Layers of AlxGa1-xAs with x greater than or equal to 0.96 exhibit crystallographic dependent oxidation rates, while for layers with x less than or equal to 0.92 the oxidation rate is isotropic. Mesas containing partially oxidized layers of AlAs are unstable to rapid thermal cycling and exhibit excessive strain at the oxide terminus, while mesas containing partially oxidized layers of AlGaAs are robust and lack evidence of strain, Finally, the oxidation of AlGaAs layers, rather than AlAs, is found to provide robust oxide apertures for reliable vertical-cavity surface emitting lasers. (C) 1996 American Institute of Physics. C1 UNIV VIRGINIA,DEPT MAT SCI,CHARLOTTESVILLE,VA 22903. RP Choquette, KD (reprint author), SANDIA NATL LABS,DEPT PHOTON RES,ALBUQUERQUE,NM 87185, USA. NR 17 TC 57 Z9 59 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 2 PY 1996 VL 69 IS 10 BP 1385 EP 1387 DI 10.1063/1.117589 PG 3 WC Physics, Applied SC Physics GA VE530 UT WOS:A1996VE53000015 ER PT J AU Vartuli, CB Pearton, SJ Lee, JW Hong, J MacKenzie, JD Abernathy, CR Shul, RJ AF Vartuli, CB Pearton, SJ Lee, JW Hong, J MacKenzie, JD Abernathy, CR Shul, RJ TI ICl/Ar electron cyclotron resonance plasma etching of III-V nitrides SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GALLIUM NITRIDE; GAN; GAAS; INN; GROWTH; CH3I; ALN AB Electron cyclotron resonance plasma etch rates for GaN, InN, InAlN, AlN, and InGaN were measured for a new plasma chemistry, ICl/Ar. The effects of gas chemistry, microwave and rf power on the etch rates for these materials were examined. InN proved to be the most sensitive to the plasma composition and ion density. The GaN, InN, and InGaN etch rates reached similar to 13 000, 11 500, and similar to 7000 Angstrom/min, respectively, at 250 W rf (-275 V dc) and 1000 W microwave power. The etched surface of GaN was found to be smooth, with no significant preferential loss of N from the surface at low rf powers, and no significant residue on the surface after etching. (C) 1996 American Institute of Physics. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Vartuli, CB (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 29 TC 43 Z9 43 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 SEP 2 PY 1996 VL 69 IS 10 BP 1426 EP 1428 DI 10.1063/1.117603 PG 3 WC Physics, Applied SC Physics GA VE530 UT WOS:A1996VE53000029 ER PT J AU Guzelian, AA Banin, U Kadavanich, AV Peng, X Alivisatos, AP AF Guzelian, AA Banin, U Kadavanich, AV Peng, X Alivisatos, AP TI Colloidal chemical synthesis and characterization of InAs nanocrystal quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID ISLANDS; GAAS; SURFACES AB InAs nanocrystal quantum dots have been prepared via colloidal chemical synthesis using the reaction of InCl3 and AS[Si(CH3)(3)](3) Sizes ranging from 25 to 60 Angstrom in diameter are produced and isolated with size distributions of +/-10%-15% in diameter, The nanocrystals are crystalline and generally spherical with surfaces passivated by trioctylphosphine giving them solubility in common organic solvents. The dots have been structurally characterized by transmission electron microscopy (TEM) and powder x-ray diffraction (XRD) and the optical absorption and emission have been examined. Quantum confinement effects are evident with absorption onsets well to the blue of the bulk band gap and size dependent absorption and emission features. The emission is dominated by band edge luminescence. These quantum dots are particularly interesting as they provide an opportunity to make important comparisons with comparably sized InAs quantum dots synthesized by molecular beam epitaxy techniques. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Alivisatos , Paul /N-8863-2015; peng, xiaogang/R-6184-2016 OI Alivisatos , Paul /0000-0001-6895-9048; peng, xiaogang/0000-0002-5606-8472 NR 21 TC 345 Z9 346 U1 2 U2 75 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 SEP 2 PY 1996 VL 69 IS 10 BP 1432 EP 1434 DI 10.1063/1.117605 PG 3 WC Physics, Applied SC Physics GA VE530 UT WOS:A1996VE53000031 ER PT J AU Warren, WL SimmonsPotter, K Potter, BG Ruffner, JA AF Warren, WL SimmonsPotter, K Potter, BG Ruffner, JA TI Charge trapping, isolated Ge defects, and photosensitivity in sputter deposited GeO2:SiO2 thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON NITRIDE FILMS; COLOR-CENTERS; DIOXIDE; FIBERS; GLASS; BAND; UV AB The nature of the defects in sputter-deposited GeO2:SiO2 thin films and their relationship to charge trapping and enhanced photosensitivity have been studied using electron paramagnetic resonance, capacitance-voltage, and optical bleaching and absorption spectroscopies. We find a good qualitative agreement between the density of isolated Ge dangling bonds measured magnetically, the density of charge trapping sites measured electrically, and the density of absorbing centers measured optically. Collectively, all observations can be modeled by assuming that a change in spin state and charge state of isolated paramagnetic neutral Ge dangling bonds, to form either diamagnetic positively or negatively charged Ge sites, are largely responsible for the charge trapping and photosensitivity in these thin films. (C) 1996 American Institute of Physics. RP Warren, WL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 13 Z9 13 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 2 PY 1996 VL 69 IS 10 BP 1453 EP 1455 DI 10.1063/1.117612 PG 3 WC Physics, Applied SC Physics GA VE530 UT WOS:A1996VE53000038 ER PT J AU Stubenrauch, J Brosha, E Vohs, JM AF Stubenrauch, J Brosha, E Vohs, JM TI Reaction of carboxylic acids on CeO2(111) and CeO2(100) SO CATALYSIS TODAY LA English DT Article ID ENERGY-LOSS SPECTROSCOPY; X-RAY PHOTOELECTRON; FORMIC-ACID; CARBON-MONOXIDE; BASE PROPERTIES; CERIUM DIOXIDE; SURFACES; DECOMPOSITION; ADSORPTION; HREELS AB The reactions of HCOOH and CH3COOH on CeO2(111) and CeO2(100) were studied using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The carboxylic acids were found to dissociate on both surfaces to form carboxylates. Adsorbed formates and acetates decomposed near 600 K to produce primarily the dehydration products CO and CH2CO, respectively. This result is consistent with previous studies which have indicated that the ease of reduction of the oxide is the primary factor in determining the selectivity for dehydration versus dehydrogenation during carboxylate decomposition. In addition to CO and CO2, small amounts of formaldehyde were produced during formate decomposition on both CeO2(111) and CeO2(100). In contrast, acetone was observed as a product during acetate decomposition only on the CeO2(111) surface. C1 UNIV PENN,DEPT CHEM ENGN,PHILADELPHIA,PA 19104. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 39 TC 72 Z9 72 U1 3 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD SEP 2 PY 1996 VL 28 IS 4 BP 431 EP 441 DI 10.1016/S0920-5861(96)00251-9 PG 11 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA WQ264 UT WOS:A1996WQ26400014 ER PT J AU ArkaniHamed, N Cheng, HC Feng, JL Hall, LJ AF ArkaniHamed, N Cheng, HC Feng, JL Hall, LJ TI Probing lepton flavor violation at future colliders SO PHYSICAL REVIEW LETTERS LA English DT Article AB Supersymmetric theories with significant lepton flavor violation have (e) over tilde and <(mu) over tilde> nearly degenerate. In this case, pair production of (e) over tilde(+)(e) over tilde(-) and <(mu)over tilde>(+)<(mu)over tilde>(-) at LEP n and at the Next Linear Collider (NLC) leads to the phenomenon of slepton oscillations, which is analogous to neutrino oscillations. The reach in Delta m(2) and sin(2) 2 theta gives a probe of lepton flavor violation which is significantly more powerful than the current bounds from rare processes, such as mu --> e gamma. Polarizable e(-) beams and the e(-)e(-) mode at the NLC are found to be promising options. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP ArkaniHamed, N (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 14 TC 104 Z9 104 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 SEP 2 PY 1996 VL 77 IS 10 BP 1937 EP 1940 DI 10.1103/PhysRevLett.77.1937 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100007 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, H Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Cunningham, JD Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Scarpine, V Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonnison, J deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, H Vucinic, D Wagner, RG Wagner, RL Wahl, J Wang, C Wang, CH Wang, G Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Wolinski, D Wolinski, J Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S TI Measurement of the lifetime of the B-s(0) meson using the exclusive decay mode B-s(0)->J/psi phi SO PHYSICAL REVIEW LETTERS LA English DT Article ID DETECTOR; B+ AB The lifetime of the B-s(0) meson is measured using the exclusive decay mode B-s(0) --> J/psi phi, where J/psi --> mu(+)mu(-) and phi --> K+K-. The data sample consists of 110 pb(-1) of collisions at root S = 1.8 TeV, collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We find 58 +/- 12 signal events, and the B-s(0) meson lifetime is determined to be tau(Bs0) = 1.34(-0.19)(+0.23)(stat) +/- 0.05(syst) ps. This result is consistent with previous measurements of the B-s(0), B+, and B-d(0) meson lifetimes and with theoretical predictions. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60637. DUKE UNIV,DURHAM,NC 27708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,NAZL FRASCATI LAB,I-00044 FRASCATI,ITALY. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. ERNEST ORLAND LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,SEZ PADOVA,I-35131 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15260. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11529,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. RI Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 19 TC 18 Z9 18 U1 0 U2 2 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 SEP 2 PY 1996 VL 77 IS 10 BP 1945 EP 1949 DI 10.1103/PhysRevLett.77.1945 PG 5 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100009 ER PT J AU Grimsditch, M Mattson, JE Sowers, CH Bader, SD Peters, MJ AF Grimsditch, M Mattson, JE Sowers, CH Bader, SD Peters, MJ TI Confined phonons in metallic superlattices: Raman study of Co/Ru SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAAS-ALAS SUPERLATTICES; SCATTERING; LATTICE; TC AB The Raman-active transverse-optic (TO) phonon mode of Ru was measured in a series of Co/Ru superlattices. The changes in the frequency of the TO vibration, interpreted within the framework of confined phonons, are in excellent agreement with published dispersion curves for bulk Ru obtained from inelastic neutron-scattering experiments. Interpretations of the frequency shifts of the Ru TO mode as due to phonon-folding or lattice-strain effects are ruled out by the data. C1 APPALACHIAN STATE UNIV,DEPT PHYS & ASTRON,BOONE,NC 28607. RP Grimsditch, M (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 14 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 2025 EP 2028 DI 10.1103/PhysRevLett.77.2025 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100029 ER PT J AU Graupner, W Partee, J Shinar, J Leising, G Scherf, U AF Graupner, W Partee, J Shinar, J Leising, G Scherf, U TI Dynamics of long-lived polarons in poly(para-phenylene)-type ladder polymers SO PHYSICAL REVIEW LETTERS LA English DT Article ID DETECTED MAGNETIC-RESONANCE; ALPHA-SI-H; CONJUGATED POLYMERS; PHOTOINDUCED ABSORPTION; ELECTROLUMINESCENCE; PHOTOLUMINESCENCE; SPECTROSCOPY; RECOMBINATION; LUMINESCENCE; EMISSION AB The X-band spin-1/2 photoluminescence-detected magnetic resonance of poly(para-phenylene)-type ladder polymer films and solutions are described. The photoluminescence-enhancing resonances are assigned to enhanced nonradiative recombination of long-lived polaron pairs, which are singlet exciton quenching centers. Their behavior is consistent with two distinct polaron lifetimes or a very broad distribution of lifetimes; in solutions they are approximate to 10 longer than in films. Distinct lifetimes are discussed in relation to longer-lived intrachain interconjugation segment and shorter-lived interchain pairs. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. MAX PLANCK INST POLYMER RES,D-55128 MAINZ,GERMANY. RP Graupner, W (reprint author), GRAZ TECH UNIV,INST FESTKORPERPHYS,PETERSGASSE 16,A-8010 GRAZ,AUSTRIA. RI Scherf, Ullrich/G-1552-2012 NR 31 TC 49 Z9 50 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 2033 EP 2036 DI 10.1103/PhysRevLett.77.2033 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100031 ER PT J AU Wu, Y Stephen, JT Han, DX Rutland, JM Crandall, RS Mahan, AH AF Wu, Y Stephen, JT Han, DX Rutland, JM Crandall, RS Mahan, AH TI New hydrogen distribution in a-Si:H: An NMR study SO PHYSICAL REVIEW LETTERS LA English DT Article ID AMORPHOUS-SILICON; MAGNETIC-RESONANCE; MICROSTRUCTURE AB Hot-filament-assisted CVD deposited a-Si:H with low H concentration and low defect density has been examined by H-1 NMR. It is demonstrated for the first time that H microstructures can be altered significantly in device quality a-Si:H films. In the present films, large H clusters account for 90% of the 2-3 at.% H atoms, with the remaining H more dispersed, but still aggregated in a small volume fraction of the material. These results suggest that an ideal a-Si:H network with low defect density and high structural stability may not necessarily be homogeneous. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Wu, Y (reprint author), UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599, USA. NR 17 TC 87 Z9 87 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 2049 EP 2052 DI 10.1103/PhysRevLett.77.2049 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100035 ER PT J AU Yoshinari, Y Hammel, PC Martindale, JA Moshopoulou, E Thompson, JD Sarrao, JL Fisk, Z AF Yoshinari, Y Hammel, PC Martindale, JA Moshopoulou, E Thompson, JD Sarrao, JL Fisk, Z TI Magnetic excitations of the doped-hole state in diamagnetic La2Cu0.5Li0.5O4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-LATTICE RELAXATION; LA2CU1-XLIXO4; TC AB Substitution of Li for Cu in La2Cu1-xLixO4 donates holes; at x = 0.5 the Li ions form an ordered superlattice which isolates individual CuO4 plaquettes from one another, and the number of doped holes is sufficient that each plaquette is occupied. Above 170 K, an activated temperature dependence of the Cu nuclear spin relaxation rate reveals a magnetic excitation of the doped-hole state with an energy of similar to 130 meV. Below 170 K relaxation is primarily due to fluctuations of the electric field gradient; the temperature dependence of this rate is anomalously slow: T-1(-1) proportional to root T. C1 NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. RP Yoshinari, Y (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 20 TC 27 Z9 27 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 2069 EP 2072 DI 10.1103/PhysRevLett.77.2069 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100040 ER PT J AU Fendrich, JA Welp, U Kwok, WK Koshelev, AE Crabtree, GW Veal, BW AF Fendrich, JA Welp, U Kwok, WK Koshelev, AE Crabtree, GW Veal, BW TI Static and dynamic vortex phases in YBa2Cu3O7-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID LATTICE-MELTING TRANSITION; FLUX-LINE-LATTICE; II SUPERCONDUCTORS; BOSON LOCALIZATION; 1ST-ORDER; DISORDER; CRYSTAL AB Simultaneous magnetization, resistivity, and I-V measurements on YBa2Cu3O7-delta show the relationship of the thermodynamic and dynamic behavior near the vortex lattice melting line. We find a coexistence region of solid and liquid at melting, with a first order magnetization jump which is independent of the vortex velocity. Sudden jumps and time dependent hysteresis of the I-V curve in the vortex solid phase are interpreted as a relaxation-pinning effect. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Fendrich, JA (reprint author), ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439, USA. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 35 TC 92 Z9 92 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 2073 EP 2076 DI 10.1103/PhysRevLett.77.2073 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100041 ER PT J AU AsokaKumar, P Alatalo, M Ghosh, VJ Kruseman, AC Nielsen, B Lynn, KG AF AsokaKumar, P Alatalo, M Ghosh, VJ Kruseman, AC Nielsen, B Lynn, KG TI Increased elemental specificity of positron annihilation spectra SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACES AB Positron annihilation spectroscopy (PAS) is a sensitive probe for studying the electronic structure of defects in solids. We show that the high-momentum part of the Doppler-broadened annihilation spectra can be used to distinguish different elements. This is achieved by using a new two-detector coincidence system to examine the line shape variations originating from high-momentum core electrons. Because the core electrons retain their atomic character even when atoms form a solid, these results can be directly compared to simple theoretical predictions. The new approach adds increased elemental specificity to the PAS technique, and is useful in studying the elemental variations around a defect site. C1 DELFT UNIV TECHNOL,INTERFAC REACTOR INST,NL-2629 JB DELFT,NETHERLANDS. RP AsokaKumar, P (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 8 TC 370 Z9 378 U1 5 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 SEP 2 PY 1996 VL 77 IS 10 BP 2097 EP 2100 DI 10.1103/PhysRevLett.77.2097 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100047 ER PT J AU Kozyrev, AN Zheng, G Zhu, CF Dougherty, TJ Smith, KM Pandey, RK AF Kozyrev, AN Zheng, G Zhu, CF Dougherty, TJ Smith, KM Pandey, RK TI Syntheses of stable bacteriochlorophyll-a derivatives as potential photosensitizers for photodynamic therapy SO TETRAHEDRON LETTERS LA English DT Article AB New methods for conversion of unstable bacteriochlorophyll-a present in Rb. sphaeroides into stable bacteriochlorins are presented. Cyclic imide derivatives from related cyclic isoimide or amide analogs are obtained by intramolecular base catalyzed cyclization. Most of the new bacteriochlorins have long wavelength absorptions in the range of 796-822 nm In preliminary screening, the isoimide analogs have shown promising in vivo photosensitizing activity for the treament of cancer by photodynamic therapy. Copyright (C) 1996 Elsevier Science Ltd C1 ROSWELL PK CANC INST, DEPT RADIAT BIOL, DIV CHEM, DIV RADIAT MED, BUFFALO, NY 14263 USA. LAWRENCE LIVERMORE NATL LAB, DEPT CHEM, DAVIS, CA 95616 USA. RI Smith, Kevin/G-1453-2011 OI Smith, Kevin/0000-0002-6736-4779 NR 13 TC 48 Z9 52 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD SEP 2 PY 1996 VL 37 IS 36 BP 6431 EP 6434 DI 10.1016/0040-4039(96)01346-9 PG 4 WC Chemistry, Organic SC Chemistry GA VE831 UT WOS:A1996VE83100003 ER PT J AU Terwilliger, TC Berendzen, J AF Terwilliger, TC Berendzen, J TI Bayesian difference refinement SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID MACROMOLECULAR STRUCTURES; X-RAY; HEMOGLOBIN; CONSEQUENCES; BINDING; PROTEIN; ERRORS; SITE AB Interest in a pair of highly isomorphous structures often focuses on the differences between them. In cases where substantial correlated model errors exist or where there are differences in the quality of the two experimental data sets (cases quite common in macromolecular crystallography), independent refinement of the two structures does not lead to the most accurate estimate of the differences between them. An alternative procedure that has proven effective in some such cases is difference refinement, in which the residual between observed and calculated differences in structure-factor amplitudes between the two structures is minimized. A Bayesian approach has been used to extend the range of applicability of difference refinement to cases where there is only partial correlation in model errors and where the overlap between the data sets is limited. The resulting method, Bayesian difference refinement, uses residuals to be minimized that vary smoothly between difference refinement and independent refinement. When the errors in the two structural models are very similar, difference refinement is used; when they are very different, independent refinement is used; and when they are partially correlated, a combination of the two is used. The procedure is very simple to apply and does not significantly increase the computational demands of refinement. C1 LOS ALAMOS NATL LAB,BIOPHYS GRP,LOS ALAMOS,NM 87545. RP Terwilliger, TC (reprint author), LOS ALAMOS NATL LAB,STRUCT BIOL GRP,MAIL STOP M888,LOS ALAMOS,NM 87545, USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 21 TC 8 Z9 9 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP 1 PY 1996 VL 52 BP 1004 EP 1011 DI 10.1107/S0907444996006725 PN 5 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA VM251 UT WOS:A1996VM25100015 PM 15299610 ER PT J AU Huang, L Jancarik, J Kim, SH Hofer, F Martin, GS AF Huang, L Jancarik, J Kim, SH Hofer, F Martin, GS TI Crystallization and preliminary crystallographic analysis of the Ras binding domain of RalGDS, a guanine nucleotide dissociation stimulator of the Ral protein SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID IDENTIFICATION; GTPASE; TARGET AB The RalGDS is a guanine nucleotide dissociation stimulator which activates the Ral protein, a Ras-like small GTPase. The C-terminal domain of the RalGDS (C-RalGDS) binds tightly to the effector loop of Ras suggesting that the RalGDS may be a crossing point of two signal tranduction pathways associated with the Ras and Ral proteins. C-RalGDS has been purified and crystallized in space group C2, with unit-cell dimensions a=108.8, b=30.7, c=51.3 Angstrom, beta=91.7 degrees at 277 K and a=103.8, b=30.55, c=51.4 Angstrom, beta=94.9 degrees for data collected at 100 K. The crystals diffract to 1.8 Angstrom at a synchrotron radiation source. To use the multiple-wavelength anomalous diffraction method for phasing, a selenomethionine derivative of the protein has also been crystallized. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MOL & CELL BIOL,BERKELEY,CA 94720. RP Huang, L (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720, USA. NR 20 TC 2 Z9 2 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP 1 PY 1996 VL 52 BP 1033 EP 1035 DI 10.1107/S0907444996003228 PN 5 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA VM251 UT WOS:A1996VM25100023 PM 15299618 ER PT J AU Chan, KS Munson, DE Bodner, SR Fossum, AF AF Chan, KS Munson, DE Bodner, SR Fossum, AF TI Cleavage and creep fracture of rock salt SO ACTA MATERIALIA LA English DT Article ID INELASTIC FLOW; TRIAXIAL COMPRESSION; CONSTITUTIVE MODEL; DAMAGE EVOLUTION; CRACK EXTENSION; BRITTLE SOLIDS; FAILURE; MAPS AB The dominant Failure mechanism in rock salt at ambient temperature is either cleavage or creep fracture. Since the transition of creep fracture to cleavage in a compressive stress field is not well understood, failure of rock salt by cleavage and creep Fracture is analyzed in this paper to elucidate the effect of stress state on the competition between these two fracture mechanisms. For cleavage Fracture, a shear crack is assumed to cause the formation and growth of a symmetric pair of wing cracks in a predominantly compressive stress field. The conditions for wing-crack instability are derived and presented as the cleavage fracture boundary in the Fracture mechanism map. Using an existing creep fracture model, stress conditions for the onset of creep Fracture and isochronous Failure curves of specified times-to-rupture are calculated and incorporated into the fracture mechanism map, The regimes of dominance by cleavage and creep fracture are established and compared with experimental data. The result indicates that unstable propagation of cleavage cracks occurs only in the presence of tensile stress. The onset of creep Fracture is promoted by a tensile stress, but can be totally suppressed by a high confining pressure. Transition of creep Fracture to cleavage occurs when critical conditions of stress difference and tensile stress For crack instability are exceeded. Copyright (C) 1996 Acta Metallurgica Inc. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. TECHNION ISRAEL INST TECHNOL,DEPT MECH ENGN,IL-32000 HAIFA,ISRAEL. SPEC INC,RE,RAPID CITY,SD 57709. RP Chan, KS (reprint author), SW RES INST,SAN ANTONIO,TX 78238, USA. NR 35 TC 16 Z9 26 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP PY 1996 VL 44 IS 9 BP 3553 EP 3565 DI 10.1016/1359-6454(96)00004-3 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VD016 UT WOS:A1996VD01600011 ER PT J AU Nieh, TG Luo, P Nellis, W Lesuer, D Benson, D AF Nieh, TG Luo, P Nellis, W Lesuer, D Benson, D TI Dynamic compaction of aluminum nanocrystals SO ACTA MATERIALIA LA English DT Article ID COPPER-POWDER; DEPOSITION AB We investigated shock-compaction behavior of nanocrystalline aluminum (n-Al) powder with an average particle size of about 50-70 nm. The starting powders were analyzed using various analytical tools, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The initial Al particles were found to be coated naturally by a uniform, thin (similar to 5 nm) near-stoichiometric, amorphous oxide layer. Shock compaction was carried out at 2-3 GPa (20-30 kbars) to obtain high-density disks. The microstructure of samples prior to and after consolidation were both examined. Despite substantial deformation during dynamic compaction, the surface oxide remained intact at the pressures employed and prevented a metallurgical bond between the nano-sized particles. Theoretical simulations of the dynamic compaction of n-Al were also carried out using an Eulerian hydrocode. The results were in good agreement with experimental observations. Copyright (C) 1996 Acta Metallurgica Inc. C1 UNIV CALIF SAN DIEGO,DEPT APPL MECH & ENGN SCI,LA JOLLA,CA 92093. RP Nieh, TG (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 16 TC 43 Z9 43 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP PY 1996 VL 44 IS 9 BP 3781 EP 3788 DI 10.1016/1359-6454(96)83816-X PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VD016 UT WOS:A1996VD01600031 ER PT J AU Wen, SJ Chen, LQ AF Wen, SJ Chen, LQ TI A possible way to measure lithium ion diffusion coefficient for Li insertion thin film with unknown Li composition: Application to Li alpha CoO2 and WO3 SO ACTA PHYSICA SINICA-OVERSEAS EDITION LA English DT Article AB In this paper, a new experimental method of lithium ion diffusion coefficient measurement for lithium intercalation thin film material is presented. This experimental method is feasible and can be applied to thin films with unknown lithium composition such as LialphaCoO2 etc. To check its validity, we used the impedance spectroscopy method to make a verification on the WO3 thin film sample with known lithium composition. RP Wen, SJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 7 TC 0 Z9 0 U1 1 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1004-423X J9 ACTA PHYS SIN-OV ED JI Acta Phys. Sin.-Overseas Ed. PD SEP PY 1996 VL 5 IS 9 BP 692 EP 699 PG 8 WC Physics, Multidisciplinary SC Physics GA WT167 UT WOS:A1996WT16700007 ER PT J AU Hawrylycz, M AF Hawrylycz, M TI Arguesian identities in invariant theory SO ADVANCES IN MATHEMATICS LA English DT Article ID FACTORIZATION AB Having been motivated by an example of Doubilet, Rota, and Stein [Stud. Appl. Math. 56 (1976), 185-216], we present a technique for constructing geometric identities in a Grassmann-Cayley algebra. Each identity represents a projective invariant closely related to the Theorem of Desargues in the plane and its generalizations to higher dimensional projective space. The construction employs certain combinatorial properties of matchings in bipartite graphs. We also prove a dimension independence result for Arguesian identities, thereby connecting the identities With lattice theory. (C) 1996 Academic Press, Inc. RP Hawrylycz, M (reprint author), LOS ALAMOS NATL LAB,COMP RES & APPLICAT GRP,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0001-8708 J9 ADV MATH JI Adv. Math. PD SEP 1 PY 1996 VL 122 IS 1 BP 1 EP 48 DI 10.1006/aima.1996.0056 PG 48 WC Mathematics SC Mathematics GA VF886 UT WOS:A1996VF88600001 ER PT J AU Eggleston, CM Ehrhardt, JJ Stumm, W AF Eggleston, CM Ehrhardt, JJ Stumm, W TI Surface structural controls on pyrite oxidation kinetics: An XPS-UPS, STM, and modeling study SO AMERICAN MINERALOGIST LA English DT Article ID X-RAY PHOTOELECTRON; SCANNING TUNNELING MICROSCOPY; RATE-DETERMINING STEP; ACID-MINE DRAINAGE; ELECTRONIC-STRUCTURE; ORGANIC-MOLECULES; AUGER-ELECTRON; FERRIC IRON; SPECTROSCOPY; WATER AB X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS, respectively) and scanning tunneling microscopy (STM) were used. to observe the initial oxidation of pyrite surfaces in air. The results show the growth of oxide-like oxidation products, with minor contributions from sulfate, UPS shows a decrease in the density of electronic slates in the uppermost valence band of pyrite, corresponding to oxidation of surface Fe2+. This allows reliable interpretation of STM images, which show that initial surface oxidation of Fe2+ proceeds by growth of oxidized patches. The borders of oxidized patches contain small segments oriented in the [110] and [100] directions. STM of as-received pyrite cube surfaces, oxidized in air for years, also show the importance of the [110] crystallographic directions, on the surface, in controlling reaction progress. A model in which oxidation probabilities for Fe2+ surface sites are proportional to the number of nearest-neighbor oxidized (Fe3+) sites was tested using a Monte Carlo approach and reproduces the surface patterns observed in STM. An oxidation mechanism consistent with the XPS, UPS, STM, and Monte Carlo results is proposed. The rate constant for electron transfer from surface-exposed pyrite Fe2+ to O-2 is small. Electron transfer is more rapid from pyrite Fe2+ to Fe3+ present on the surface as an oxidation product, such as in the patches we observed. Fe2+ in oxide is a better reductant than Fe2+ in pyrite, so electron transfer to O-2 from the oxide is also fast. However, this two-step mechanism is faster overall only if electron transfer to the surface oxide patches is irreversible (e.g., because of S-2 oxidation or electron hopping within the surface oxide patches). Cycling of Fe between the Fe2+ and Fe3+ forms, particularly along borders between oxidized and unoxidized areas, is thus a key feature of the pyrite oxidation mechanism. An understanding of the surface electronic and band structure aids definition of the redox potentials of electrons in various surface states. Rates of electron transfer from these states to O-2 are estimated using a kinetic theory of elementary heterogeneous electron transfer. C1 LAWRENCE LIVERMORE NATL LAB, DIV EARTH SCI, LIVERMORE, CA 94550 USA. UNIV NANCY 1, LAB CHIM PHYS ENVIRONM, CNRS, UMR 9992, F-54013 NANCY, FRANCE. SWISS FED INST TECHNOL, INST ENVIRONM SCI & TECHNOL, EAWAG, CH-8600 DUBENDORF, SWITZERLAND. NR 73 TC 141 Z9 142 U1 7 U2 35 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1996 VL 81 IS 9-10 BP 1036 EP 1056 PG 21 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA VN940 UT WOS:A1996VN94000002 ER PT J AU Lager, GA VonDreele, RB AF Lager, GA VonDreele, RB TI Neutron powder diffraction study of hydrogarnet to 9.0 GPa SO AMERICAN MINERALOGIST LA English DT Article ID CRYSTAL-CHEMISTRY; ICE-VIII; 10 GPA; X-RAY; GARNETS; PRESSURE; CA3AL2(O4H4)3; BRUCITE; PYROPE; OH AB The crystal structure of synthetic, deuterated katoite [Ca3Al2(O4D4)(3)] has been refined at 0.0001, 0.78, 3.6, 6.1, 7.9, and 9.0 GPa using the opposed-anvil Paris-Edinburgh cell and the POLARIS powder diffractometer at the U.K. pulsed spallation source, ISIS. A constrained Birch-Murnaghan fit to the unit-cell volume yields K-0 = 52(1) GPa for K'(0) = 4.0. The lower bulk modulus of katoite relative to anhydrous Ca-bearing garnets (K-0 = 159-179 GPa) is due to the greater compressibility of the Ca dodecahedron and O4D4 tetrahedron. At high pressure, corner-sharing tetrahedra and octahedra undergo a rigid-body rotation, which causes a shift in the O position. This rotation, coupled with the large compression of the two tetrahedral edges shared with the dodecahedron, changes the relative lengths of the Ca-O bonds at high pressure, such that Ca2-O < Ca1-O for P > 6 GPa. With increasing pressure, the O-D ... O angles widen slightly, as the O-D vector rotates toward the tetrahedral face. Both O-D and O ... D bond lengths decrease as a function of pressure, which was unexpected in view of the results of recent high-pressure studies. Comparison of crystallographic and spectroscopic data collected at high pressure for hydrogarnets suggests that empirical relationships derived for hydrogen-bond systems at ambient conditions, where a relaxed, equilibrium state is attained, may not always apply to O-D ... O hydrogen bonds under compression. C1 LOS ALAMOS NATL LAB,LANSCE,LOS ALAMOS,NM 87545. RP Lager, GA (reprint author), UNIV LOUISVILLE,DEPT GEOG & GEOSCI,LOUISVILLE,KY 40292, USA. NR 31 TC 42 Z9 42 U1 0 U2 6 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP-OCT PY 1996 VL 81 IS 9-10 BP 1097 EP 1104 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA VN940 UT WOS:A1996VN94000006 ER PT J AU Yan, C Dadoo, R Zare, RN Rakestraw, DJ Anex, DS AF Yan, C Dadoo, R Zare, RN Rakestraw, DJ Anex, DS TI Gradient elution in capillary electrochromatography SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; DYNAMIC PH GRADIENT; ZONE ELECTROPHORESIS; PACKED CAPILLARIES; GENERATION; SYSTEM; COLUMN AB In analogy to pressure-driven gradient, techniques in high-performance liquid chromatography, a system has been developed for delivering electroosmotically driven solvent gradients for capillary electrochromatograph (CEC). Dynamic gradients with submicroliter per minute now rates are generated by merging two electroosmotic flows that are regulated by computer-controlled voltages, These flows are delivered by two fused-silica capillary arms attached to a T-connector, where they mix and then now into a capillary column that has been electrokinetically packed with 3-mu m reversed-phase particles. The inlet of one capillary arm is placed in a solution reservoir containing one mobile phase, and the inlet of the other is placed in a second reservoir containing a second mobile phase. Two independent computer-controlled, programmable, high-voltage power supplies (0-50 kV)-one providing an increasing ramp and the other providing a decreasing ramp-are used to apply variable high-voltage potentials to the mobile phase reservoirs to regulate the electroosmotic now in each arm. The ratio of the electroosmotic flow rates between the two arms is changed with time according to the computer-controlled voltages to deliver the required gradient profile to the separation column, Experiments were performed to confirm the composition of the mobile phase during a gradient run and to determine the change of the composition in response to the programmed voltage profile. To demonstrate the performance of electroosmotically driven gradient elution in CEC, a mixture of 16 polycyclic aromatic hydrocarbons was separated in less than 90 min, This gradient technique is expected to be well-suited for generating not only solvent gradients II CEC but also other types of gradients, such as pH and ionic strength gradients, in capillary electrokinetic separations and analyses. C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. SANDIA NATL LABS,LIVERMORE,CA 94551. RI Zare, Richard/A-8410-2009 NR 29 TC 129 Z9 138 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2726 EP 2730 DI 10.1021/ac960020c PG 5 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800009 PM 21619344 ER PT J AU Borgerding, AJ Wilkerson, CW AF Borgerding, AJ Wilkerson, CW TI A comparison of cryofocusing injectors for gas sampling and analysis in fast GC SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTRON-CAPTURE DETECTION; VOLATILE ORGANIC-COMPOUNDS; TRAP INLET SYSTEM; PURGE GASES; CHROMATOGRAPHY; SPEED; COLLECTION; WATER; INSTRUMENTATION; STRATEGIES AB The performance of two cryofocusing injectors for fast gas chromatography has been studied, The first system traps analytes onto bare metal tubes and rapidly vaporizes them upon ballistically heating the tube using a capacitance discharge, The second is a microloop injector in which analytes are cryotrapped onto short lengths of narrow-bore fused silica tubing with various coatings, The ballistically heated injector is capable of sampling and injecting compounds from air faster than the microloop system, because the metal tube can be heated and cooled more rapidly. Both systems are capable of cryotrapping compounds as volatile as butane at -90 degrees C, and the microloop system can trap ethane when a section of a porous layer open-tubular (PLOT) column is used as the sample loop, In addition, the microloop injector can be used without cryointegration to analyze compounds regardless of their volatility, as long as they are present in the samples at detectable concentrations. Because the ballistically heated injector is flushed prior to injection, it can introduce only compounds that are adsorbed onto its metal trap. Comparison of chromatograms obtained using the two injectors show similar chromatographic resolution, Both traps are susceptible to freezing during the cryotrapping step, but the use of an inline Nafion dryer allows air saturated with water vapor to be sampled using both systems for 3 min without plugging the trap. Thermal decomposition during the injection step can occur for labile species in the ballistically heated trap, but even the highly unstable compound ethyl diazoacetate may be injected without breakdown in the microloop system. C1 LOS ALAMOS NATL LAB,DEPT CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 20 TC 21 Z9 21 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2874 EP 2878 DI 10.1021/ac9601876 PG 5 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800030 PM 21619356 ER PT J AU Preisler, J Yeung, ES AF Preisler, J Yeung, ES TI Characterization of nonbonded poly(ethylene oxide) coating for capillary electrophoresis via continuous monitoring of electroosmotic flow SO ANALYTICAL CHEMISTRY LA English DT Article ID ZONE ELECTROPHORESIS; ONLINE DETERMINATION; DNA; SEPARATIONS AB We examined changes in a poly(ethylene oxide) (PEG) coating by continuously monitoring the electroosmotic now (EOF) in a fused-silica capillary during electrophoresis. An imaging CCD camera was used to follow the motion of a fluorescent neutral marker zone along the length of the capillary. The PEO coating was shown to reduce the velocity of EOF by more than 1 order of magnitude compared to a bare capillary at pH 7.0. However, it did not reduce EOF efficiently at pH 8.2. The coating protocol was important, especially at an intermediate pH of 7.7. Capillary reconditioning with an acidified solution of PEO was necessary in order to create a stable and efficient coating. In all cases we observed a gradual increase of EOF during extended runs, suggesting that the coating is slowly being degraded. The increase of pH in the cathodic (detection-end) buffer reservoir beyond pH similar to 8.0, e.g., as a result of electrolysis, had a large impact on the stability of the coating. This phenomenon may be used for the efficient and fast regeneration of the column surface and provides a simpler and more reliable alternative to pressure flushing of the capillary. C1 IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RI Preisler, Jan/B-2005-2009 OI Preisler, Jan/0000-0002-9819-1284 NR 18 TC 102 Z9 105 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2885 EP 2889 DI 10.1021/ac960260s PG 5 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800032 PM 21619358 ER PT J AU Kuhn, KJ Dyke, JT AF Kuhn, KJ Dyke, JT TI A renewable-reagent fiber-optic sensor for measurement of high acidities SO ANALYTICAL CHEMISTRY LA English DT Article ID DONNAN DIALYSIS; POLYMERS AB A renewable-reagent fiber-optic HNO3 sensor was developed for HNO3 measurement in the 0.1-10.0 M range. The HNO3 sensor employs a tubular Nafion cation-exchange membrane to extract acid species from an external HNO3 sample into an internal flowing reagent solution. In high-concentration HNO3 samples, incomplete HNO3 dissociation results in a significant concentration of neutral HNO3 species hi addition to protons. As both neutrals and protons are potentially membrane-permeable species, various reagent compositions were tested to examine the contributions of both acid transfer mechanisms. Continuous reagent flow limited internal acid accumulation rind transferred reagent to the sensor optical detection cell. All reagent compositions included cresol red as a colorimetric indicator, which was measured within the sensor detection cell. Careful fiber-optic alignment provided sufficient light throughput in a back-scatter Illumination mode to allow use of a photodiode array detector for visible spectral acquisition. The use of Ca2+ as a reagent countercation produced notable reductions in HNO3 sensor response to interferent cations and temperature changes. Sensor measurement of HNO3 samples in the tested concentration range produced average relative standard deviations of less than 0.4%, Control over reagent now rate should allow for extension of the HNO3 sensor measurement range to 16.0 M HNO3. RP Kuhn, KJ (reprint author), LOS ALAMOS NATL LAB,CST-15,LOS ALAMOS,NM 87545, USA. NR 18 TC 21 Z9 21 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2890 EP 2896 DI 10.1021/ac960242a PG 7 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800033 PM 21619359 ER PT J AU Lillard, SJ Yeung, ES McCloskey, MA AF Lillard, SJ Yeung, ES McCloskey, MA TI Monitoring exocytosis and release from individual mast cells by capillary electrophoresis with laser-induced native fluorescence detection SO ANALYTICAL CHEMISTRY LA English DT Article ID MICROCOLUMN SEPARATIONS; ELECTROCHEMICAL DETECTION; RECEPTOR SUBTYPES; SINGLE CELLS; SEROTONIN; MEDIATORS; HISTAMINE; COMPOUND; FUSION AB The complex temporal evolution of on-column exocytotic release of serotonin and proteins from individual rat peritoneal mast cells (RPMCs) was monitored by using capillary electrophoresis. Laser-induced native fluorescence detection with 275-nm excitation was used, and a detection limit of 1.7 amol (S/N = 3; rms) was obtained for serotonin. A physiological rurning buffer was used to ensure that the cell remained viable throughout. The secretagogue was polymyxin B sulfate (Pmx). Following the injection of a single mast cell into the capillary, electromigration of Pmx toward and past the cell induced degranulation and release of serotonin. The time course of release was registered in the electropherograms with subsecond resolution. Subsequent introduction of SDS caused the cell to lyse completely and allowed the residual serotonin to be quantified. The average amount of serotonin observed per RPMC was 1.6 +/- 0.6 fmol; the average percentage of serotonin released was 28 +/- 14%. Events that are consistent with released serotonin from single submicrometer granules (250 at each) were evident, each of which contained an average amount of 5.9 +/- 3 amol. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT ZOOL & GENET,AMES,IA 50011. FU NIGMS NIH HHS [GM48144] NR 35 TC 80 Z9 82 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2897 EP 2904 DI 10.1021/ac960412j PG 8 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800034 PM 8794924 ER PT J AU Zhang, NY Yeung, ES AF Zhang, NY Yeung, ES TI Genetic typing by capillary electrophoresis with the allelic ladder as an absolute standard SO ANALYTICAL CHEMISTRY LA English DT Article ID CHAIN-REACTION PRODUCTS; ZONE ELECTROPHORESIS; HIGH-RESOLUTION; TANDEM REPEATS; DNA; PCR; INJECTION AB We demonstrate a genetic typing method based on capillary electrophoresis/laser-induced fluorescence (CE-LIF). VNTR polymorphism in the human D1S80 locus was studied. A pooled allelic ladder, which contains the 27 most common human alleles, was used as the absolute standard. Extracted genomic DNA from an individual was amplified by polymerase chain reaction (PCR). Typing can be accomplished by co-injection of the PCR product and the D1S80 ladder and then running CE. Separation by a polymer solution of poly(ethylene oxide) in uncoated fused-silica capillaries allows high-resolution, repeated runs in the same capillary. Sensitive detection with minimal sample preparation is possible by using ethidium bromide as the intercalating dye. Statistical analysis of the data indicates a high level of confidence in matching the bands despite variations in the injection process or in the CE system. Future adaptation to a multiple-capillary array system should allow high-speed, high throughput operation. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 20 TC 40 Z9 41 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 1996 VL 68 IS 17 BP 2927 EP 2931 DI 10.1021/ac960346l PG 5 WC Chemistry, Analytical SC Chemistry GA VE598 UT WOS:A1996VE59800038 PM 8794927 ER PT J AU Anderson, KM Seed, T Jajeh, A Dudeja, P Byun, T Meng, J Ou, D Bonomi, P Harris, JE AF Anderson, KM Seed, T Jajeh, A Dudeja, P Byun, T Meng, J Ou, D Bonomi, P Harris, JE TI An in vivo inhibitor of 5-lipoxygenase, MK886, at micromolar concentration induces apoptosis in U937 and CML cells SO ANTICANCER RESEARCH LA English DT Article DE experimental apoptosis; leukemia; lipoxygenase inhibitors ID LEUKOTRIENE BIOSYNTHESIS INHIBITOR; CHRONIC MYELOGENOUS LEUKEMIA; ARACHIDONIC-ACID METABOLISM; DNA-SYNTHESIS; GENERATION; MK-886 AB MK886 (Merck Frosst) is a selective in vivo inhibitor of 5-lipoxygenase, active at nanomolar concentrations. At micromolar concentrations, it inhibited the proliferation of U937 monoblastoid cells and of cultured malignant cells from patients with chronic myelogenous leukemia. These cells became morphologically apoptotic, a form of physiologic cell death. U937 cell apoptosis was assessed by flow cytometry, ultrastructure, DNA laddering and immuno-histology for free 3'OH-DNA. MK886-induced apoptosis developed over time as cells were recruited in concert with reduction in their numbers. Some CML cells exhibited cytoplasmic changes of apoptosis without typical nuclear changes. Under conditions used for measuring Ca2+ with Fura 2, 10 micromolar MK886 increased U937 intracellular Ca2+ 4-fold or more over the 8 minute period of measurement. Since MK886 inhibits the association of arachidonic acid with the 5-lipoxygenase activating protein, altered arachidonic acid metabolism may have contributed to these results. C1 RUSH MED COLL,DEPT BIOCHEM,CHICAGO,IL 60612. ARGONNE NATL LAB,DIV MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. COOK CTY HOSP,DEPT MED,CHICAGO,IL 60612. W SIDE VET ADM MED CTR,CHICAGO,IL 60612. UNIV ILLINOIS,CHICAGO,IL 60612. RP Anderson, KM (reprint author), RUSH MED COLL,DEPT MED,CHICAGO,IL 60612, USA. NR 32 TC 46 Z9 46 U1 0 U2 1 PU INT INST ANTICANCER RESEARCH PI ATHENS PA EDITORIAL OFFICE 1ST KM KAPANDNTIOU-KALAMOU RD KAPANDRITI, POB 22, ATHENS 19014, GREECE SN 0250-7005 J9 ANTICANCER RES JI Anticancer Res. PD SEP-OCT PY 1996 VL 16 IS 5A BP 2589 EP 2599 PG 11 WC Oncology SC Oncology GA VQ152 UT WOS:A1996VQ15200020 PM 8917356 ER PT J AU Boopathy, R AF Boopathy, R TI Methanogenic transformation of methylfurfural compounds to furfural SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID STRICTLY ANAEROBIC BACTERIUM; SP STRAIN-B; METHANOSARCINA-BARKERI; 2-FUROIC ACID; GROWTH; SUBSTRATE; BIOTRANSFORMATION; DEGRADATION; PYRUVATE; SULFATE AB The metabolic conversion of 5-methylfurfural and 2-methylfurfural to furfural by a methanogenic bacterium, Methanococcus sp. strain B, was studied. This bacterium was found to use methylfurfural compounds as a growth substrate and to convert them stoichiometrically to furfural. For every mole of methylfurfurals metabolized, almost 1 mol of furfural and 0.7 mol of methane were produced. Several methanogenic bacteria did not carry out this conversion. The metabolic conversion of methylfurfurals is likely to be of value in the anaerobic treatment of methylfurfural-containing wastewaters such as those produced by the paper and pulp industries and oatmeal processing industries. This study adds to the list of the limited number of compounds that are known to serve as electron donors for methanogenesis. RP Boopathy, R (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,BLDG 203,ARGONNE,IL 60439, USA. NR 27 TC 9 Z9 9 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD SEP PY 1996 VL 62 IS 9 BP 3483 EP 3485 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA VF616 UT WOS:A1996VF61600067 PM 16535410 ER PT J AU Reed, NE Gini, M Johnson, PE AF Reed, NE Gini, M Johnson, PE TI Robust strategies for diagnosing manufacturing defects SO APPLIED ARTIFICIAL INTELLIGENCE LA English DT Article ID INSPECTION AB We describe several strategies used by expert troubleshooters performing a manufacturing screening task, the diagnosis of defects on a computer board. These strategies use ''inexact models'' of the components and connections on the board. A prototype expert system has been implemented that uses the strategies and models. The strategies and models are robust because they are applicable to a wide range of problems, including problems not previously encountered. The system saves useful data acquired during problem solving to assist in future problems. We also describe how the above strategies and models can be used in a sensor-based system that acquires information about the board through a vision camera and other sensing devices. This will further increase the productivity of human troubleshooters. C1 UNIV MINNESOTA,DEPT COMP SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT INFORMAT & DECIS SCI,MINNEAPOLIS,MN 55455. RP Reed, NE (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT COMP SCI,2063 ENGN 2,DAVIS,CA 95616, USA. OI Gini, Maria/0000-0001-8841-1055 NR 17 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0883-9514 J9 APPL ARTIF INTELL JI Appl. Artif. Intell. PD SEP-OCT PY 1996 VL 10 IS 5 BP 387 EP 406 DI 10.1080/088395196118470 PG 20 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA VM981 UT WOS:A1996VM98100001 ER PT J AU Chow, R Tsujimoto, N AF Chow, R Tsujimoto, N TI Silicon dioxide and hafnium dioxide evaporation characteristics from a high-frequency sweep e-beam system SO APPLIED OPTICS LA English DT Article DE hafnium dioxide; silicon dioxide; e-beam evaporation; experimental design strategy ID DEFECT AB Reactive oxygen evaporation characteristics were determined as a function of the front-panel control parameters provided by a programmable, high-frequency sweep e-beam system. An experimental design strategy used deposition rate, beam speed, pattern, azimuthal rotation speed, and dwell time as the variables. The optimal settings for obtaining a broad thickness distribution, efficient silicon dioxide boule consumption, and minimal hafnium dioxide defect density were generated. design analysis showed the compromises involved with evaporating these oxides. (C) 1996 Optical Society of America C1 MDC VACUUM PROD CORP,HAYWARD,CA 94545. RP Chow, R (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 6 TC 6 Z9 7 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 1996 VL 35 IS 25 BP 5095 EP 5101 DI 10.1364/AO.35.005095 PG 7 WC Optics SC Optics GA VE604 UT WOS:A1996VE60400022 PM 21102942 ER PT J AU Inn, KGW Lin, ZV Liggett, WS Schima, FJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA McCurdy, D Germain, P Yamamoto, M Handl, J Popplewell, DS Woods, MJ Jerome, S Bates, TH Holms, A Harvey, BR Odell, KJ Warren, BB Young, P AF Inn, KGW Lin, ZV Liggett, WS Schima, FJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA McCurdy, D Germain, P Yamamoto, M Handl, J Popplewell, DS Woods, MJ Jerome, S Bates, TH Holms, A Harvey, BR Odell, KJ Warren, BB Young, P TI Low-level radioactivity ocean sediment standard reference material SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT International-Committee-for-Radionuclide-Metrology Conference on Low-Level Measurement Techniques CY OCT 02-06, 1995 CL SEVILLE, SPAIN SP Int Comm Radionuclide Metrol AB The National Institute of Standards and Technology (NIST), in cooperation with experienced international laboratories, will issue a low-level radioactivity Ocean Sediment Standard Reference Material (SRM) 4357 in 1996. The Ocean Sediment joins the NIST suite of six other 'natural matrix' environmental radioactivity Standard Reference Materials. This family of natural matrix materials have already been used: (1) to develop radiochemical procedures; (2) to test radiochemical procedures already in use for environmental and biokinetic evaluations; (3) to calibrate instruments; (4) to intercompare and evaluate radiochemical methods; (5) to test competency of technicians to do radiochemical assays; and (6) to demonstrate that data output is reliable. The participating laboratories provided data for the following 25 radionuclides: K-40, Sr-90, (TC)-T-99, I-129, (CS)-C-137, Eu-155, Pb-210, Po-210, Pb-212, Bi-214, Ra-226, Ra-228, Ac-228, Th-228, Th-230, Th-232, U-234, U-235, Np-237, U-238, Pu-238, Pu-239+Pu-240, Pu-241, and Am-241. The data for many of these radionuclides are of sufficient quality to establish certified values and reasonable uncertainty limits given the relatively low concentrations of the radionuclides. The uncertainties for a number of certified radionuclides are non-symmetrical and large because of the non-normal distribution of reported values. Copyright (C) 1996 Elsevier Science Ltd. C1 NATL INST STAND & TECHNOL,STAT ENGN DIV,COMP & APPL MATH LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899. US EPA,LAS VEGAS,NV 89193. US DOE,ENVIRONM MEASUREMENTS LAB,NEW YORK,NY 10014. INT TECHNOL CORP,OAK RIDGE,TN. MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. OREGON STATE UNIV,NEWPORT,OR. YANKEE ATOM ELECT CO,BOLTON,ENGLAND. CEA,CTR STUDIES NUCL,LAB RADIOECOL MARINE,FONTENAY ROSES,FRANCE. KANAZAWA UNIV,KANAZAWA,ISHIKAWA 920,JAPAN. NIEDERSACHS INST RADIOOKOL,HANNOVER,GERMANY. NATL RADIOL PROTECT BOARD,OXFORD,ENGLAND. NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. BRITISH NUCL FUELS PLC,SELLAFIELD,ENGLAND. LAB GOVT CHEMIST,TEDDINGTON TW11 0LY,MIDDX,ENGLAND. MAFF,LOWESTOFT NR33 OHT,SUFFOLK,ENGLAND. NUCL ELECT,GRAVESEND,ENGLAND. ATOM WEAPONS ESTAB,ALDERMASTON,ENGLAND. S SCOTLAND ELECT BOARD,HUNTERSTON,SCOTLAND. RP Inn, KGW (reprint author), NATL INST STAND & TECHNOL,IONIZING RADIAT DIV,PHYS LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. RI Huh, Chih-An/N-4610-2013 NR 1 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-OCT PY 1996 VL 47 IS 9-10 BP 967 EP 970 DI 10.1016/S0969-8043(96)00094-2 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VX653 UT WOS:A1996VX65300027 ER PT J AU Kuperman, RG AF Kuperman, RG TI Relationships between soil properties and community structure of soil macroinvertebrates in oak-hickory forests along an acidic deposition gradient SO APPLIED SOIL ECOLOGY LA English DT Article DE soil fauna; acidic deposition; soil organic matter; oak-hickory forests; midwest ID CONIFEROUS FOREST; AIR-POLLUTANTS; PINE FOREST; COLLEMBOLA; RAIN; ACIDIFICATION; DECOMPOSITION AB Soil macroinvertebrate communities were studied in ecologically analogous oak-hickory forests across a three-state atmospheric pollution gradient in Illinois, Indiana, and Ohio. The goal was to investigate changes in the community structure of soil fauna in study sites receiving different amounts of acidic deposition for several decades and the possible relationships between these changes and physico-chemical properties of soil. The study revealed significant differences in the numbers of soil animals among the three study sites. The sharply differentiated pattern of soil macroinvertebrate fauna seems closely linked to soil chemistry. Significant correlations of the abundance of soil macroinvertebrates with soil parameters suggest that their populations could have been affected by acidic deposition in the region. Abundance of total soil macroinvertebrates decreased with the increased cumulative loading of acidic deposition. Among the groups most sensitive to deposition were: earthworms, gastropods, dipteran larvae, termites, and predatory beetles. The results of the study support the hypothesis that chronic long-term acidic deposition could adversely affect the soil decomposer community which could cause lower organic matter turnover rates leading to an increase in soil organic matter content in high deposition sites. RP Kuperman, RG (reprint author), ARGONNE NATL LAB,ENVIRONM ASSESSMENT DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kuperman, Roman/D-4297-2009 NR 45 TC 27 Z9 38 U1 5 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0929-1393 J9 APPL SOIL ECOL JI Appl. Soil Ecol. PD SEP PY 1996 VL 4 IS 2 BP 125 EP 137 DI 10.1016/0929-1393(96)00108-4 PG 13 WC Soil Science SC Agriculture GA VU805 UT WOS:A1996VU80500004 ER PT J AU Eppler, AS Cremers, DA Hickmott, DD Ferris, MJ Koskelo, AC AF Eppler, AS Cremers, DA Hickmott, DD Ferris, MJ Koskelo, AC TI Matrix effects in the detection of Pb and Ba in soils using laser-induced breakdown spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE laser-induced breakdown spectroscopy; LIBS; laser microprobe; atomic emission spectroscopy; soil analysis ID ELEMENTAL ANALYSIS; SPECTROMETRY; SPARK AB With the use of laser-induced breakdown spectroscopy (LIBS), the effects of chemical speciation and matrix composition on ph and Ba measurements have been investigated by using sand and soil matrices. A cylindrical lens was used to focus the laser pulses on the samples because it yielded higher measurement precision than a spherical lens for the experimental conditions used here. The detection limits for Pb and Ba spiked in a sand matrix were 17 and 76 ppm (w/w), respectively. In spiked soil, the detection limits were 57 and 42 ppm (w/w) for Pb and Ba, respectively. Measurement precision for five replicate measurements was typically 10% RSD or less. Two factors were found to influence emissions from Pb and Ba present in sand and soil matrices as crystalline compounds: (1) compound speciation, where Ba emission intensities varied in the order carbonate > oxide > sulfate > chloride > nitrate, and where Ph emission intensities varied in the order oxide > carbonate > chloride > sulfate > nitrate; and (2) the composition of the bulk sample matrix. Emissions from Ba(II) correlated inversely with the plasma electron density, which in turn was dependent upon the percent sand in a sand/soil mixture. The analytical results obtained here show that a field-screening instrument based on LIBS would be useful for the initial screening of soils contaminated with Pb and Ba. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. RI Hickmott, Donald/C-2886-2011 NR 25 TC 165 Z9 173 U1 3 U2 33 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 1996 VL 50 IS 9 BP 1175 EP 1181 DI 10.1366/0003702963905123 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA VK589 UT WOS:A1996VK58900014 ER PT J AU Deelman, PW Thundat, T Schowalter, LJ AF Deelman, PW Thundat, T Schowalter, LJ TI AFM and RHEED study of Ge islanding on Si(111) and Si(100) SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 5th International Conference on Formation of Semiconductor Interfaces (ICFSI-5) CY JUN 26-30, 1995 CL PRINCETON, NJ SP Princeton Univ, Adv Technol Ctr Photon & Optoelectr Mat, David Sarnoff Res Ctr, Epitaxx, Evans East, IBM, Int Rectifier Corp, US, Off Naval Res, Oxford Instruments Inc, Princeton Univ, Princeton Mat Inst, Princeton Univ, Sch Engn & Appl Sci, Sensors Unlimited, W Windsor Plainsboro H S German Club ID MOLECULAR-BEAM EPITAXY; TUNNELING-MICROSCOPY; GROWTH; MORPHOLOGY; SURFACES; STRAIN; INGAAS; FILMS AB Strain relaxation and clustering of Ge thin films grown on Si(111) and Si(100) by molecular beam epitaxy (MBE) have been studied in situ with reflection high energy electron diffraction (RHEED) and analyzed by atomic force microscopy (AFM) and Rutherford backscattering spectrometry (RES). At low temperature, growth is dominated by island nucleation and by strain relief through island formation, The cluster size distribution (measured by AFM) just after the 2D-3D growth mode transition is broader than that for 'late-stage' growth (when diffusion gradients dominate cluster growth) and is well fit by a model in which the surface diffusion of adatoms is described by a random walk. At high temperature, growth is dominated by dislocation formation acid the aspect ratio of the islands changes, The barrier to dislocation formation is reduced at step bunches; thus, islands nucleate preferentially at the step bunches and grow along them. By understanding Ge island nucleation and evolution, we hope to grow a population of uniformly-sized nanocrystals exhibiting quantum confinement effects. C1 RENSSELAER POLYTECH INST,DEPT PHYS,TROY,NY 12180. RENSSELAER POLYTECH INST,CTR INTEGRATED ELECT & ELECT MFG,TROY,NY 12180. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 15 TC 33 Z9 33 U1 3 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD SEP PY 1996 VL 104 BP 510 EP 515 DI 10.1016/S0169-4332(96)00195-X PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VR573 UT WOS:A1996VR57300082 ER PT J AU Batsford, S Mihatsch, M Dunn, J AF Batsford, S Mihatsch, M Dunn, J TI Outer surface lipoprotein A of Borrelia burgdorferi is a potent mediator of inflammation in vivo. SO ARTHRITIS AND RHEUMATISM LA English DT Meeting Abstract C1 DEPT PATHOL,CH-4056 BASEL,SWITZERLAND. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0004-3591 J9 ARTHRITIS RHEUM JI Arthritis Rheum. PD SEP PY 1996 VL 39 IS 9 SU S BP 534 EP 534 PG 1 WC Rheumatology SC Rheumatology GA VH883 UT WOS:A1996VH88300534 ER PT J AU Terasawa, N Hattori, M AF Terasawa, N Hattori, M TI Effect of kick velocity on the distribution of gamma-ray bursters SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars, neutron; galaxy, halo; galaxy, formation; dark matter; gamma rays, bursts ID ABSORPTION; FEATURES; SPECTRUM; PULSAR AB The effect of kick velocity to newly born pulsars on the distribution of gamma-ray bursters is examined in the context of a disk origin model and a halo model of gamma-ray bursters. The conversion formula from a two-dimensional velocity distribution function to a three-dimensional distribution function is derived and applied to reproduce the distribution function of the kick velocity of radio pulsars. Monte Carlo simulations of the kicked neutron stars show that the disk neutron star model of gamma-ray bursters still needs unnatural assumptions if the velocity distribution of the gamma-ray bursters is the same as that of neutron stars - only neutron stars with very high kick velocities can become gamma-ray bursters and there are silent majorities, On the other hand, the core radius of gamma-ray bursters is not found to be extended by the kick velocity if the core-halo structure similar to the Galactic dark matter distribution is based on the initial distribution of the halo neutron stars, Thus the introduction of a kick velocity to neutron stars do not improve the statistics of neither the disk model nor the halo model. Two possibilities to save Galactic models are suggested: (1) The gamma-ray bursters are old neutron stars which were accelerated to velocities faster than 750 km s(-1) by jet propulsion and passed the death line for pulsars due to spin down from the rotational energy loss by jet ejection, (2) The initial distribution of neutron stars is fairly uniform and the extent of the halo is large enough for the halo model to be consistent with the observations, It implies that the initial star formation burst of the Galaxy occurred fairly uniformly in the extended halo region. C1 NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. TOUHOKU UNIV, INST ASTRON, SENDAI, MIYAGI 98077, JAPAN. MAX PLANCK INST EXTRATERR PHYS, D-85740 GARCHING, GERMANY. RP Terasawa, N (reprint author), INST PHYS & CHEM RES, HIROSAWA 2-1, WAKO, SAITAMA 35101, JAPAN. NR 19 TC 0 Z9 0 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP 1 PY 1996 VL 313 IS 1 BP 197 EP 203 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VG169 UT WOS:A1996VG16900020 ER PT J AU Meixner, M Skinner, CJ Keto, E Zijlstra, A Hoare, MG AF Meixner, M Skinner, CJ Keto, E Zijlstra, A Hoare, MG TI Mid-IR and radio images of IC 418: Dust in a young planetary nebula SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM, dust; planetary nebulae, individual, IC 418; stars, mass loss; infrared, ISM, lines and bands ID CIRCUMNEBULAR NEUTRAL HYDROGEN; EMISSION FEATURE; IC-418; EVOLUTION; STARS; SPECTRA; GRAINS; CO AB We present three new images of the young, carbon rich planetary nebula, IC 418: 11.3 mu m dust emission, a [Ne II] 12.8 mu m line emission and 6 cm free-free continuum. All three images show different morphologies. In order to investigate these spatial differences and the mechanisms of dust emission in IC 418, we compare our data to two radiative transfer models with different radial density distributions. Model 1 has a thin shell that drops off as r(-3), resulting in a high density ionized region surrounded by an ionized halo. While, model 2 has a thicker shell that drops off as r(-2) resulting in the ionization front stopping in the thick shell and a high density ionized region immediately surrounded by a neutral shell. Both models use a mixture of silicon carbide (SiC) and amorphous carbon (AC) dust grains with dust to gas ratios of similar to 2 x 10(-5) and similar to 6 x 10(-4), respectively and the standard power law distribution in sizes (a(-3.5); 0.005 mu m < a < 0.25 mu m). Both models reproduce our mid-IR images and mid-IR spectra well suggesting that, while IC 418 has emission features attributed to polycyclic aromatic hydrocarbons (PAHs), the SiC feature and not the PAH feature probably dominates the 11.3 mu m emission. Comparison of our images with broad-band J, H and K images of IC 418 by Hora et al. (1993), suggest that dust emission processes may contribute more near-IR emission than previously thought and that this near-IR ''dust'' emission is contained within the ionized gas region. Both models reproduce the observed spatial distributions of the 11.3 mu m, [Ne II], and 6 cm emissions which differ because they have different radial excitation gradients in the nebula. However, model 1 better explains all of the many previous observations of IC 418 at different wavelengths. We suggest a three layer onion model for IC 418: a similar to 6'' radius high density ionized region surrounded by a similar to 20'' radius low density ionized halo, enclosed by a completely photodissociated neutral halo extended beyond a similar to 80'' radius. This structure may suggest a mass loss history for IC 418 in which its progenitor AGE star experienced a superwind (M over dot similar to 4 x 10(-5) M. yr(-1), v similar to 11 km s(-1)) just before departing the AGB. C1 UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. LAWRENCE LIVERMORE NATL LAB, EXPT ASTROPHYS LAB, LIVERMORE, CA 94551 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94551 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. EUROPEAN SO OBSERV, D-85748 HEIDELBERG, GERMANY. MAX PLANCK INST ASTRON, D-69117 HEIDELBERG, GERMANY. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. RP Meixner, M (reprint author), UNIV ILLINOIS, DEPT ASTRON, MC 221, URBANA, IL 61801 USA. NR 48 TC 10 Z9 10 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP 1 PY 1996 VL 313 IS 1 BP 234 EP 242 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VG169 UT WOS:A1996VG16900025 ER PT J AU Loveday, J Efstathiou, G Maddox, SJ Peterson, BA AF Loveday, J Efstathiou, G Maddox, SJ Peterson, BA TI The Stromlo-APM redshift survey .3. Redshift space distortions, omega, and bias SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, distances and redshifts; large-scale structure of universe; surveys ID LARGE-SCALE STRUCTURE; GALAXY SURVEY; PECULIAR VELOCITIES; LUMINOSITY FUNCTION; DARK-MATTER; DENSITY; UNIVERSE; MASS AB Galaxy redshift surveys provide a distorted picture of the universe due to the non-Hubble component of galaxy motions. By measuring such distortions in the linear regime one can constrain the quantity beta = Omega(0.6)/b where Omega is the cosmological density parameter and b is the (linear) bias factor for optically selected galaxies. In this paper we apply two techniques for estimating beta from the Stromlo-APM redshift survey: (1) measuring the anisotropy of the redshift space correlation function in spherical harmonics, and (2) comparing the amplitude of the direction-averaged redshift space correlation function to the real space correlation function. We test the validity of these techniques, particularly whether the assumption of linear theory is justified, using two sets of large N-body simulations. We find that the first technique is affected by nonlinearities on scales up to similar to 30 h(-1) Mpc. The second technique is less sensitive to nonlinear effects and so is more useful for existing redshift surveys. The Stromlo-APM survey data favours a low value for beta, which beta less than or similar to 0.6. A bias parameter b approximate to 2 is thus required if Omega = 1. However, higher-order correlations measured from the APM galaxy survey indicate a low value for the bias parameter b approximate to 1,; requiring that Omega less than or similar to 0.5. We also measure the relative bias for samples of galaxies of various luminosity and morphological type and find that low-luminosity galaxies are roughly three times less biased than L* galaxies. For the galaxy population as a whole, we measure a real space variance of galaxy counts in 8 h(-1) Mpc spheres of (sigma(8)(2))(g) = 0.89 +/- 0.05. C1 UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. ROYAL GREENWICH OBSERV,CAMBRIDGE CB3 0EZ,ENGLAND. MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. RP Loveday, J (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. OI Maddox, Stephen/0000-0001-5549-195X NR 29 TC 38 Z9 38 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 1996 VL 468 IS 1 BP 1 EP 16 DI 10.1086/177665 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE592 UT WOS:A1996VE59200001 ER PT J AU Bradley, PA AF Bradley, PA TI Theoretical models for asteroseismology of DA white dwarf stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, evolution; stars, interiors; stars, oscillations; white dwarfs ID WHOLE EARTH TELESCOPE; COOLING DEGENERATE DWARF; CETI INSTABILITY STRIP; ZZ-CETI; COMPOSITION GRADIENTS; EVOLUTIONARY MODELS; THICK HYDROGEN; PULSATIONS; LAYER; MASS AB Because white dwarfs are the most common end state of stellar evolution, determining their internal structure will yield many clues about the final stages of stellar evolution and the physics of matter under extreme conditions. We present the results of our parametric survey of evolutionary models of compositionally stratified white dwarfs with hydrogen surface layers (DA white dwarfs) and provide a comprehensive set of theoretical g-mode pulsation periods for comparison to observations of pulsating DA white dwarfs. This survey complements the previous survey of helium atmosphere (DB) white dwarf periods of Bradley, Winget, & Wood. We show how to use the periods of low-overtone and/or trapped modes to constrain the internal structure of pulsating DA white dwarfs by utilizing their sensitivity to the total stellar mass and the location of the hydrogen/helium transition zone. We use G117-B15A as an example to demonstrate the potential of our models for asteroseismology; we suggest that G117-B15A has a mass of 0.55 M. and a hydrogen layer mass of approximate to 1.5 x 10(-4) M*. RP Bradley, PA (reprint author), LOS ALAMOS NATL LAB, XTA, MS B220, LOS ALAMOS, NM 87545 USA. NR 56 TC 70 Z9 70 U1 1 U2 1 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 SEP 1 PY 1996 VL 468 IS 1 BP 350 EP 368 DI 10.1086/177696 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE592 UT WOS:A1996VE59200032 ER PT J AU Liedahl, DA Paerels, F AF Liedahl, DA Paerels, F TI Photoionization-driven X-ray line emission in Cygnus X-3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; stars, individual (Cygnus X-3); techniques, spectroscopic; X-rays, stars ID ELEMENTS AB The ASCA SIS spectrum of the X-ray binary Cygnus X-3 is shown to contain a narrow recombination continuum of hydrogenic sulfur near 3.5 keV, which indicates that the temperature of the X-ray emission-line region is far below the coronal equilibrium temperature required to support S15+. The presence of this feature immediately confirms that X-ray photoionization produces extreme overionization in the circumsource medium, and that the X-ray emission features are energized by the hard X-ray continuum. Therefore, we conclude that spectral analyses of Cygnus X-3 and, most likely, other accretion-powered X-ray sources must be conducted in the context of plasma emission models that account for population kinetics dominated by recombination. Furthermore, the temperature dependence of the shapes of recombination continua provides a simple diagnostic of the electron temperature. We reanalyze the SIS data using a spectral model developed to account for recombination cascades, and, using these diagnostics, derive constraints on the temperatures in the S15+, Si13+, and Mg11+ ionization zones. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. RP Liedahl, DA (reprint author), LAWRENCE LIVERMORE NATL LAB,ASTROPHYS GRP,DIV 5,POB 808,L-41,LIVERMORE,CA 94550, USA. NR 20 TC 80 Z9 80 U1 1 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 SEP 1 PY 1996 VL 468 IS 1 BP L33 EP L36 DI 10.1086/310217 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VE594 UT WOS:A1996VE59400009 ER PT J AU Edwards, CF Marx, KD AF Edwards, CF Marx, KD TI Single-point statistics of ideal sprays .1. Fundamental descriptions and derived quantities SO ATOMIZATION AND SPRAYS LA English DT Article AB In this work we explore the nature of single-point statistical descriptions of sprays and the quantities derived therefrom. Specifically, we introduce the concept of what constitutes a complete and fundamental single-point description, and show how this can be developed in each of two basic forms: concentration-based anf flux-based statistics. The results of this development show that a complete single-point description of a spray has two components: The first is the spray intensity-expressing the quantity of spray present in a suitable form. The second is the well-known spray distribution function-expressing how the droplets of the spray are partitioned over their characteristics. Transformation expressions between the two descriptions are developed, as are derivations of the various quantities that depend on these descriptions. Specifically, quantities such as marginal distribution functions, droplet-dependent expected values, and various property flux rates and concentrations are defined and derived in each of the basic forms. These latter developments are included both for the sake of completeness and to rectify common misconceptions about the definition and interpretation of these derived quantities. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Edwards, CF (reprint author), STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305, USA. NR 11 TC 14 Z9 14 U1 0 U2 1 PU BEGELL HOUSE INC PI NEW YORK PA 79 MADISON AVE, SUITE 1205, NEW YORK, NY 10016-7892 SN 1044-5110 J9 ATOMIZATION SPRAY JI Atom. Sprays PD SEP-OCT PY 1996 VL 6 IS 5 BP 499 EP 536 PG 38 WC Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VP735 UT WOS:A1996VP73500001 ER PT J AU Willoughby, CE Mazur, P Peter, AT Critser, JK AF Willoughby, CE Mazur, P Peter, AT Critser, JK TI Osmotic tolerance limits and properties of murine spermatozoa SO BIOLOGY OF REPRODUCTION LA English DT Article ID MOUSE SPERMATOZOA; MITOCHONDRIAL-FUNCTION; WATER PERMEABILITY; ACROSOME REACTION; FLOW-CYTOMETRY; COOLING RATE; WARMING RATE; CRYOPRESERVATION; GLYCEROL; EMBRYOS AB Osmotic tolerance of spermatozoa is a critical determinant of functional survival after cryopreservation. This study first tested the hypothesis that mouse spermatozoa behave as linear osmometers, using an electronic particle counter to measure the change in sperm volume in response to anisosmotic solutions. The resulting Boyle-van't Hoff plot was linear (r(2) = 0.99) from 75 to 1200 mOsmolal and indicates that 60.7% of the total cell volume is osmotically inactive. Next, mouse sperm tolerance to osmotic stress was determined by assessment of plasma membrane integrity, mitochondrial viability, and motility, Each functional endpoint was measured after exposure to anisosmotic solutions and again after return to isosmolality. The dual fluorescent stains-carboxyfluorescein diacetate with propidium iodide and Rhodamine 123 with propidium iodide-were used to determine membrane integrity and functional mitochondria, respectively. Motility was measured by video microscopy in the range of 1-2400 mOsmolal and was further analyzed from 140 to 600 mOsmolal using computer-assisted semen analysis. The data indicate that motility is substantially more sensitive to osmotic stress than either mitochondrial viability or membrane integrity and that mouse spermatozoa should be maintained within 76-124% of their isosmotic volume during cryopreservation in order to maintain > 80% of pretreatment motility. C1 METHODIST HOSP INDIANA INC,CRYOBIOL RES INST,INDIANAPOLIS,IN 46202. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. PURDUE UNIV,SCH VET MED,DEPT VET CLIN SCI,W LAFAYETTE,IN 47907. FU NICHD NIH HHS [K04-HD00980, R01-HD30274] NR 38 TC 107 Z9 108 U1 0 U2 4 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD SEP PY 1996 VL 55 IS 3 BP 715 EP 727 DI 10.1095/biolreprod55.3.715 PG 13 WC Reproductive Biology SC Reproductive Biology GA VE876 UT WOS:A1996VE87600029 PM 8862792 ER PT J AU Bennett, PV Gange, RW Hacham, H Hejmadi, VS Moran, M Ray, S Sutherland, BM AF Bennett, PV Gange, RW Hacham, H Hejmadi, VS Moran, M Ray, S Sutherland, BM TI Isolation of high-molecular-length DNA from human skin SO BIOTECHNIQUES LA English DT Article ID PYRIMIDINE DIMER FORMATION; GENOMIC DNA; STRAND BREAKS; WHOLE-BLOOD; ELECTROPHORESIS; GELS; EXTRACTION; FRAGMENTS AB An agarose plug method for isolating high-molecular-length DNA from mammalian tissues has been developed , including from those that are difficult, such as skin. It gives high yields of DNA that contain a minimum of single-strand breaks and is readily digested by restriction and other nucleases. The method requires only simple equipment and is readily adaptable to field or clinical studies. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. HARVARD UNIV,SCH MED,WELLMAN LABS PHOTOMED,BOSTON,MA. FU NCI NIH HHS [CA 23096]; NIAMS NIH HHS [R29-AR3529] NR 16 TC 8 Z9 8 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 SEP PY 1996 VL 21 IS 3 BP 458 EP & PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VG212 UT WOS:A1996VG21200024 PM 8879585 ER PT J AU Lynch, NJ Cherry, RS AF Lynch, NJ Cherry, RS TI Design of passively aerated compost piles: Vertical air velocities between the pipes SO BIOTECHNOLOGY PROGRESS LA English DT Article AB Passively aerated compost piles are built on a base of porous materials, such as straw or wood chips, in which perforated air supply pipes are distributed. The piles are not turned during composting, nor is forced-aeration equipment used, which significantly reduces the operating and capital expenses associated with these piles. Currently, pile configurations and materials are worked out by trial and error. Fundamentally based design procedures are difficult to develop because the natural convection air flow rate is not explicitly known, but rather is closely coupled with the pile temperature. This paper develops a mathematical model to analytically determine the maximum upward air flow velocity over an air supply pipe and the drop in vertical velocity away from the pipe. This model has one dimensionless number, dependent on the pile and base properties, which fully characterizes the velocity profile between the pipes. C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. NR 9 TC 20 Z9 21 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 1996 VL 12 IS 5 BP 624 EP 629 DI 10.1021/bp960048+ PG 6 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA VL170 UT WOS:A1996VL17000007 ER PT J AU Felinger, A Guiochon, G AF Felinger, A Guiochon, G TI Optimizing experimental conditions in overloaded gradient elution chromatography SO BIOTECHNOLOGY PROGRESS LA English DT Article ID MAXIMUM PRODUCTION-RATES; LIQUID-CHROMATOGRAPHY; DISPLACEMENT CHROMATOGRAPHY; DESIGN PARAMETERS; SAMPLE-SIZE; OPTIMIZATION; PROPAGATION; ENANTIOMERS; SIMULATION; BAND AB The optimization of preparative separations by overloaded gradient elution chromatography was studied on a theoretical basis. Band profiles of binary mixtures were calculated as numerical solutions of the equilibrium-dispersive model. A nonlinear simplex method allowed the determination of the optimum experimental conditions. The product of the production rate and the recovery yield was used as an objective function. The optimum experimental conditions are very different depending on whether the purification of the first or second component is being optimized. Similarities can be observed with the optimum conditions observed when the same separation is carried out in isocratic elution. The recovery yield is very high for the more retained component, moderate for the less retained one. Since the initial retention factor is much higher in gradient elution than the optimum found in isocratic elution, the optimum plate number is rather small in gradient elution. When the two solutes are convergent, very flat gradient steepness should be used, preventing a reversal of the elution order. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV VESZPREM,DEPT ANALYT CHEM,H-8200 VESZPREM,HUNGARY. RI Felinger, Attila/A-1595-2008 OI Felinger, Attila/0000-0001-7130-1968 NR 21 TC 29 Z9 29 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 1996 VL 12 IS 5 BP 638 EP 644 DI 10.1021/bp960057i PG 7 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA VL170 UT WOS:A1996VL17000009 ER PT J AU Shields, MJ Brady, PV AF Shields, MJ Brady, PV TI Mass balance and fluid flow constraints on regional-scale dolomitization, Late Devonian, Western Canada Sedimentary Basin - Reply SO BULLETIN OF CANADIAN PETROLEUM GEOLOGY LA English DT Editorial Material C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. SO METHODIST UNIV,DEPT GEOL SCI,DALLAS,TX 75275. RP Shields, MJ (reprint author), IMPERIAL OIL RESOURCES LTD,CALGARY,AB T2P 3M9,CANADA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU CANADIAN SOC PETROL GEOLOGISTS PI CALGARY PA 505, 206 - 7TH AVE SW, CALGARY AB T2P 0W7, CANADA SN 0007-4802 J9 B CAN PETROL GEOL JI Bull. Can. Pet. Geol. PD SEP PY 1996 VL 44 IS 3 BP 572 EP 573 PG 2 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA VJ893 UT WOS:A1996VJ89300011 ER PT J AU Knezovich, JP Steichen, DJ Jelinski, JA Anderson, SL AF Knezovich, JP Steichen, DJ Jelinski, JA Anderson, SL TI Sulfide tolerance of four marine species used to evaluate sediment and pore-water toxicity SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP Knezovich, JP (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,LIVERMORE,CA 94550, USA. NR 8 TC 36 Z9 37 U1 0 U2 4 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 SEP PY 1996 VL 57 IS 3 BP 450 EP 457 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UY477 UT WOS:A1996UY47700016 PM 8672072 ER PT J AU Avery, SK Try, PD Anthes, RA Hallgren, RE Seitz, F Santer, BD Bolin, B Houghton, J Meira, LG AF Avery, SK Try, PD Anthes, RA Hallgren, RE Seitz, F Santer, BD Bolin, B Houghton, J Meira, LG TI Open letter to Ben Santer SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 AMER METEOROL SOC, BOSTON, MA 02108 USA. ROCKEFELLER UNIV, NEW YORK, NY 10021 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. INTERGOVT PANEL CLIMATE CHANGE, WORKING GRP 1, BRACKNELL, BERKS, ENGLAND. RP Avery, SK (reprint author), UNIV CORP ATMOSPHER RES, BOARD TRUSTEES, BOULDER, CO 80303 USA. NR 0 TC 5 Z9 5 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1996 VL 77 IS 9 BP 1961 EP 1966 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL660 UT WOS:A1996VL66000001 ER PT J AU Bailey, K AF Bailey, K TI So what? SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Article RP Bailey, K (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR SECUR & TECHNOL STUDIES,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD SEP-OCT PY 1996 VL 52 IS 5 BP 46 EP 47 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA VD708 UT WOS:A1996VD70800020 ER PT J AU BurkhartSchultz, KJ Thompson, CL Jones, IM AF BurkhartSchultz, KJ Thompson, CL Jones, IM TI Spectrum of somatic mutation at the hypoxanthine phosphoribosyltransferase (hprt) gene of healthy people SO CARCINOGENESIS LA English DT Article ID HUMAN LYMPHOCYTES-T; MUTANT FREQUENCY; GUANINE PHOSPHORIBOSYLTRANSFERASE; HUMAN-POPULATION; MISMATCH RECOGNITION; MOLECULAR ANALYSES; CLONING ASSAY; CODING REGION; BLOOD-CELLS; SKIN-CANCER AB Understanding the significance of somatic mutations requires knowledge of the mutations that occur in vivo in healthy people, The molecular characterization of mutations in the hypoxanthine phosphoribosyltransferase (hprt) gene in 217 independent T-lymphocyte mutants from 172 donors, including smoking and non-smoking males and females, reveals a broad spectrum of in vivo somatic mutation occurring in a population of healthy people, Identification of the DNA alteration in individual mutant clones was accomplished using either one or a combination of multiplex polymerase chain reaction analysis of genomic DNA, sequencing of cDNA, and genomic DNA sequencing, The total spectrum consists of 59% (128/217) base substitutions: 126 simple and two tandem CC>TT base substitutions; 39% (85/217) deletion/insertion type mutations: 30 frameshifts, 26 small (3-200 basepairs) and 27 large deletions, and two duplications; and the remaining 2% (4/217) complex mutations involving the deletion of one to 11 basepairs which are replaced by 1 to 10 basepairs, No significant difference was detected between the base substitution spectra for the smokers and the non-smokers, Analysis of the number of mutations occurring at any one base position led to the identification of three hotspots for mutations at basepairs 197, 508 and 617, in the hprt gene coding region, Spontaneous deamination of CpG may be implicated in the creation of basepair 508 as a hotspot since all mutations detected are C>T transitions resulting in the nonsense mutation, TAG, At basepairs 197 and 617 both G>T transversions and G>A transitions were found indicating that at least two mechanisms were involved in creating mutations at these positions, Comparison of the mutation spectra from two populations can provide insight into the origin of the mutations, This study provides an excellent base for comparison of mutation spectra in other human populations. C1 NIEHS,DIV BIOMETRY & RISK ASSESSMENT,RES TRIANGLE PK,NC 27709. RP BurkhartSchultz, KJ (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,POB 808,L-452,LIVERMORE,CA 94551, USA. FU NIEHS NIH HHS [Y01-ES-80171] NR 54 TC 45 Z9 45 U1 1 U2 2 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD SEP PY 1996 VL 17 IS 9 BP 1871 EP 1883 DI 10.1093/carcin/17.9.1871 PG 13 WC Oncology SC Oncology GA VH728 UT WOS:A1996VH72800013 PM 8824508 ER PT J AU Benkadda, S Sen, A Shklyar, DR AF Benkadda, S Sen, A Shklyar, DR TI Chaotic dynamics of charged particles in the field of two monochromatic waves in a magnetized plasma SO CHAOS LA English DT Article ID LOWER HYBRID WAVE AB We study the dynamics of charged particles in the presence of two electrostatic waves propagating obliquely to an ambient magnetic field. The presence of a second wave makes the problem a two-dimensional and time-dependent one with a complicated phase space behavior. We derive a set of difference equations (maps) for the nonrelativistic particle motion limit and numerically study them to elucidate the various aspects of the phase space dynamics. For the general case of oblique propagation, we observe synergistic effects leading to the lowering of the stochasticity threshold and the concomitant reduction in electric field amplitudes for particle heating applications. These results can be understood in terms of the resonance structures associated with the two waves and we obtain approximate analytic expressions for the thresholds. For the degenerate case of omega(1)=n Omega,omega(2)=m Omega (where omega(1),omega(2) are the frequencies of the two waves, Omega is the cyclotron frequency and n,m are integers) and strictly perpendicular propagation, the problem simplifies to a one-and-one-half-dimensional one. We observe the presence of stochastic webs in this situation. (C) 1996 American Institute of Physics. C1 INST PLASMA RES,BHAT,GANDHINAGAR,INDIA. IZMIRAN,TROITSK 142092,RUSSIA. UNIV AIX MARSEILLE 1,IMT,EQUIPE TURBULENCE PLASMA,CNRS URA 733,F-13451 MARSEILLE 20,FRANCE. RP Benkadda, S (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Sen, Ashoke/B-1570-2009 NR 17 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1054-1500 J9 CHAOS JI Chaos PD SEP PY 1996 VL 6 IS 3 BP 451 EP 460 DI 10.1063/1.166187 PG 10 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA VK304 UT WOS:A1996VK30400022 ER PT J AU Zhong, GM Guiochon, G AF Zhong, GM Guiochon, G TI Analytical solution for the linear ideal model of simulated moving bed chromatography SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE simulated moving bed; chromatography; analytical solution; asymptotic solution; linear chromatography; ideal chromatography ID ADSORPTION SEPARATION PROCESSES; ROBUST DESIGN; COUNTERCURRENT AB An analytical solution for linear ideal simulated moving bed (SMB) chromatography is derived. This solution is a set of algebraic equations which allows the calculation of the concentration profiles along the columns and of the concentration histories at the raffinate and extract ports. Using this solution, the operations of SMB under steady-state conditions and during the transition from start-up to steady state are examined. An asymptotic property is found for the steady state. A comparison between SMB and true moving bed (TMB) illustrates their similarities and differences. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 11 TC 74 Z9 80 U1 2 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD SEP PY 1996 VL 51 IS 18 BP 4307 EP 4319 DI 10.1016/0009-2509(96)00262-X PG 13 WC Engineering, Chemical SC Engineering GA VC612 UT WOS:A1996VC61200010 ER PT J AU Alam, TM Assink, RA Loy, DA AF Alam, TM Assink, RA Loy, DA TI Hydrolysis and esterification in organically modified alkoxysilanes: A Si-29 NMR investigation of methyltrimethoxysilane SO CHEMISTRY OF MATERIALS LA English DT Article ID SOL-GEL KINETICS; SILICON ALKOXIDES; CONDENSATION PROCESS; POLYCONDENSATION; POLYMERIZATION; TETRAETHOXYSILANE; ALCOHOL; SYSTEM; TEOS AB High-resolution Si-29 NR IR was used to investigate the acid-catalyzed hydrolysis and esterification reactions of methyltrimethoxysilane (MTMS) in methanol, The INEPT experiment, adapted for spin systems with multiple heteronuclear coupling constants, was used to assign the closely spaced resonances of the MTMS hydrolysis products. Due to the rapid reaction rates, only the pseudoequilibrium concentration distribution for the resulting hydrolysis products could be determined, Models based on thermodynamically statistical distributions, irreversible hydrolysis reactions, and reversible hydrolysis reactions were nearly equally successful in accounting for the concentration distributions over a wide range of H2O/Si ratios (R(w)) and temperatures, However, preparation of hydrolyzed MTMS in a nonpseudoequilibrium state unequivocally demonstrated the reversibility of hydrolysis reactions on a short time scale, By measuring the extent of reaction of MTMS systems at high water concentrations, the ratio of the hydrolysis to esterification rate constant was determined to be approximately 100. RP Alam, TM (reprint author), SANDIA NATL LABS,PROPERTIES ORGAN MAT DEPT,ALBUQUERQUE,NM 87185, USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 35 TC 53 Z9 53 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP PY 1996 VL 8 IS 9 BP 2366 EP 2374 DI 10.1021/cm960183h PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VG774 UT WOS:A1996VG77400025 ER PT J AU Charych, D Nagy, JO AF Charych, D Nagy, JO TI Artificial cell membranes for diagnostics and therapeutics SO CHEMTECH LA English DT Article ID INFLUENZA-VIRUS; SIALIC-ACID; POLYDIACETYLENES; POLYMERIZATION; MULTILAYERS; LIPOSOMES RP Charych, D (reprint author), LAWRENCE BERKELEY NATL LAB,DIV SCI MAT,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 17 TC 12 Z9 13 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2703 J9 CHEMTECH JI Chemtech PD SEP PY 1996 VL 26 IS 9 BP 24 EP 28 PG 5 WC Chemistry, Applied SC Chemistry GA VF842 UT WOS:A1996VF84200010 ER PT J AU Tieszen, SR Stamps, DW OHern, TJ AF Tieszen, SR Stamps, DW OHern, TJ TI A heuristic model of turbulent mixing applied to blowout of turbulent jet diffusion flames SO COMBUSTION AND FLAME LA English DT Article ID BURNING VELOCITIES; SCHMIDT-NUMBER; STABILIZATION; STABILITY; LIFTOFF; REGION; FIELD; AIR AB A phenomenological study has been conducted on jet flames near blowout for the purpose of determining the blowout mechanism. The authors show the successful blowout correlation of Broadwell et al. [Twentieth Symposium (International) on Combustion, 1984, p. 303] can be derived from the assumptions of Vanquickenborne and van Tigglen [Combust. Flame 10:59 (1966)], namely, that blowout is a competition between the local premixed turbulent flame speed and the local flow velocity. The authors argue that the role of coherent, large-scale, rotational structures found in jet turbulence is to enhance the turbulent flame speed near blowout. Experiments were conducted which show that nearly the entire cross-section of the jet is combusting in a premixed flame near blowout. This is distinct from a lifted flame that combusts only near the outer edge of the jet. The length and time scales used in the derivation of the blowout mechanism are compared with those observed in the experiments and found to be consistent with the data. RP Tieszen, SR (reprint author), SANDIA NATL LABS,UNSTEADY & REACT FLUID MECH ORG,POB 5800,9116-MS0836,ALBUQUERQUE,NM 87185, USA. NR 47 TC 38 Z9 38 U1 2 U2 3 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 SEP PY 1996 VL 106 IS 4 BP 442 EP & DI 10.1016/0010-2180(96)00008-9 PG 28 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VE509 UT WOS:A1996VE50900006 ER PT J AU Aro, CJ AF Aro, CJ TI CHEMSODE: A stiff ODE solver for the equations of chemical kinetics SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE atmospheric chemistry; preconditioning; Stiff ODEs ID MODEL AB The ODEs describing a chemical kinetics system can be very stiff and are the most computationally costly part of most reactive flow simulations. Research areas ranging from combustion to climate modeling are often limited by their ability to solve these chemical ODE systems both accurately and efficiently, These problems are commonly treated with an implicit numerical method due to the stiffness that is usually present, The implicit solution technique introduces a large amount of computational overhead necessary to solve the nonlinear algebraic system derived from the implicit time-stepping method. in this paper, a code is presented that avoids much of the usual overhead by preconditioning the implicit method with an iterative technique. This results in a class of time-stepping method that is explicit and very stable for chemical kinetics problems. C1 UNIV CALIF DAVIS, DEPT APPL SCI, LIVERMORE, CA 94550 USA. RP Aro, CJ (reprint author), LAWRENCE LIVERMORE NATL LAB, COMP RES GRP, POB 808, L-794, LIVERMORE, CA 94550 USA. NR 26 TC 12 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP PY 1996 VL 97 IS 3 BP 304 EP 314 DI 10.1016/0010-4655(96)00071-9 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VF029 UT WOS:A1996VF02900004 ER PT J AU Choi, J Dongarra, JJ Walker, DW AF Choi, J Dongarra, JJ Walker, DW TI PB-BLAS: A set of parallel block basic linear algebra subprograms SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB We propose a new software package which would be very useful for implementing dense linear algebra algorithms on block-partitioned matrices. The routines are referred to as block basic linear algebra subprograms (BLAS), and their use is restricted to computations in which one or more of the matrices involved consists of a single row or column of blocks, and in which no more than one of the matrices consists of an unrestricted two-dimensional array of blocks. The functionality of the block BLAS routines can also be provided by Level 2 and 3 BLAS routines. However, for non-uniform memory access machines the use of the block BLAS permits certain optimizations in memory access to be taken advantage of. This is particularly true for distributed memory machines, for which the block BLAS are referred to as the parallel block basic linear algebra subprograms (PB-BLAS). The PB-BLAS are the main focus of this paper, and for a block-cyclic data distribution, a single row or column of blocks lies in a single row or column of the processor template. The PB-BLAS consist of calls to the sequential BLAS for local computations, and calls to the BLACS for communication. The PB-BLAS are the building blocks for implementing ScaLAPACK, the distributed-memory version of LAPACK, and provide the same ease-of-use and portability for ScaLAPACK that the BLAS provide for LAPACK. The PB-BLAS consist of an Level 2 and 3 BLAS routines for dense matrix computations (not for banded matrix) and four auxiliary routines for transposing and copying of a vector and/or a block vector. The PB-BLAS are currently available for all numeric data types, i.e., single and double precision, real and complex. C1 SOONGSIL UNIV,SCH COMP,DONGJAK KU,SEOUL 156743,SOUTH KOREA. UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RI Walker, David/B-7978-2010; Dongarra, Jack/E-3987-2014; OI Walker, David/0000-0002-1360-6330 NR 23 TC 6 Z9 6 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD SEP PY 1996 VL 8 IS 7 BP 517 EP 535 DI 10.1002/(SICI)1096-9128(199609)8:7<517::AID-CPE226>3.0.CO;2-W PG 19 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VD442 UT WOS:A1996VD44200002 ER PT J AU Chen, CH DePaolo, DJ Lan, CY AF Chen, CH DePaolo, DJ Lan, CY TI Rb-Sr microchrons in the Manaslu granite: Implications for Himalayan thermochronology SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE geochronology; geochemical methods; Himalayas; erosion; strontium ID RUTHERFORD BACKSCATTERING SPECTROSCOPY; EPISODIC TECTONIC DENUDATION; STRONTIUM DIFFUSION; SOUTHERN TIBET; K-FELDSPAR; AGE; LEUCOGRANITE; LEUKOGRANITE; CONSTRAINTS; EVOLUTION AB Samples of minerals from the Manaslu leucogranite in the central Himalaya were microsampled and measured for Rb-Sr mineral ages. The ages obtained are used in conjunction with models for Rb-Sr closure temperatures, to reconstruct the thermochronological history of the Manaslu granite. The Rb-Sr results indicate a rapid change in temperature between 21 Ma and 17 Ma of 60-70 degrees C/million yr, which, in turn, indicates unroofing at 2 mm/yr, The temperature-time curve inferred from Rb-Sr data is in excellent agreement with existing Ar-Ar data on the Manaslu granite and its thermal aureole. The results confirm that parts of the Himalaya, in addition to the Gangdese belt, were eroded rapidly in the 20-17 Ma time period, and this erosion could account for the observed rapid increase in seawater Sr-87/Sr-86. A tourmaline-whole rock age of 29.5 Ma was obtained on a sample from the Chokkang Arm, but may be unreliable because of post-crystallization alteration of feldspar. Microsampling approaches are demonstrated that allow high precision isotopic data to be obtained on minerals sampled at scales of 100 0 mu m or less. Microanalysis, combined with models for Sr redistribution, can be a useful thermochronological tool that can augment the Ar-40-Ar-39 approach. C1 UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,CTR ISOTOPE GEOCHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. ACAD SINICA,INST EARTH SCI,TAIPEI 115,TAIWAN. NR 31 TC 16 Z9 19 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP PY 1996 VL 143 IS 1-4 BP 125 EP 135 DI 10.1016/0012-821X(96)00122-7 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VN030 UT WOS:A1996VN03000010 ER PT J AU Loehle, C LeBlanc, D AF Loehle, C LeBlanc, D TI Model-based assessments of climate change effects on forests: A critical review SO ECOLOGICAL MODELLING LA English DT Review DE carbon; climate; forest ecosystems; gap models; paleoclimatic reconstructions ID MIDWESTERN UNITED-STATES; EASTERN NORTH-AMERICA; TERRESTRIAL ECOSYSTEM COMPLEXES; BROAD-SCALE DISTRIBUTION; VEGETATION RESPONSE; ECOLOGICAL RESPONSE; GENETIC-VARIATION; BOREAL FORESTS; SEED STERILITY; RADIAL GROWTH AB While current projections of future climate change associated with increases in atmospheric greenhouse gases have a high degree of uncertainty, the potential effects of climate change on forests are of increasing concern. A number of studies based on forest simulation models predict substantial alteration of forest composition, forest dieback, or even loss of forest cover in response to increased temperatures associated with increasing atmospheric carbon dioxide concentrations. However, the structure of these computer models may cause them to overemphasize the role of climate in controlling tree growth and mortality. Model functions that represent the influence of climate on tree growth are based on the geographic range limits of a species, predicting maximal growth in the center of the range and zero growth (100% mortality) at the range limits and beyond. This modeling approach ignores the fact that the geographic range of a species reflects the influence of both climate and other environmental factors, including competition with other tree species, soil characteristics, barriers to dispersal, and distributions of pests and pathogens. These climate-response functions in forest simulation models implicitly assume that tree species occur in all environments where it is possible for them to survive (their fundamental niche or potential habitat) and that these potential habitats are entirely defined by climate. Hence, any alteration of climate must result in a fairly rapid decline of species near their range limits and rapid alteration of forest composition and structure. The climate-response functions that lead to these unrealistic conclusions have no basis in plant physiology or actual measurements of tree responses to climate stressors. Rather, these functions were chosen as a necessary expedient for modeling the climatic responses of many tree species for which there were limited or no ecophysiological data. There is substantial evidence, however, that some tree species can survive, and even thrive, in climatic conditions outside their present range limits. This evidence suggests that nonclimatic factors exclude some species from natural forests beyond their present range limits and that climate may not be the only determinant of these limits. Hence, there is reason to suspect that published projections of forest responses to climate change based on forest simulation models may exaggerate the direct impact of climate on tree growth and mortality. We propose that forest simulation models be reformulated with more realistic representations of growth responses to temperature, moisture, mortality, and dispersal. We believe that only when these models more accurately reflect the physiological bases of the responses of tree species to climate variables can they be used to simulate responses of forests to rapid changes in climate. We argue that direct forest responses to climate change projected by such a reformulated model may be less traumatic and more gradual than those projected by current models. However, the indirect effects of climate change on forests, mediated by alterations of disturbance regimes or the actions of pests and pathogens, may accelerate climate-induced change in forests, and they deserve further study and inclusion within forest simulation models. C1 BALL STATE UNIV,DEPT BIOL,MUNCIE,IN 47306. RP Loehle, C (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,BLDG 203,ROOM E-149,ARGONNE,IL 60439, USA. NR 129 TC 217 Z9 227 U1 7 U2 115 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD SEP PY 1996 VL 90 IS 1 BP 1 EP 31 DI 10.1016/0304-3800(96)83709-4 PG 31 WC Ecology SC Environmental Sciences & Ecology GA VA857 UT WOS:A1996VA85700001 ER PT J AU Gabor, AJ Leach, RR Dowla, FU AF Gabor, AJ Leach, RR Dowla, FU TI Automated seizure detection using a self-organizing neural network SO ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY LA English DT Article DE seizure detection; self-organizing map; neural network; wavelet transform ID EPILEPTIFORM DISCHARGES; EEG; RECOGNITION AB An algorithm for automated seizure detection using the self-organizing map (SOM) neural network (NN), with unsupervised training, was used to detect seizures in 24 long-term EEG recordings. The detection paradigm was tested on a constant 8 channel subset of 18 channel scalp EEG recordings. The NN was trained to recognize seizures using 98 training examples. A strategy was devised using wavelet transform to construct a filter that was 'matched' to the frequency features of examples used to train the NN. Four second epochs of training examples and EEGs being tested were transformed into time-independent representations of spectrograms resulting in a time-frequency representation of the time-series. Rule-based long and short term contextual features were used for detection in association with the NN. Fifty-six seizures were detected from a possible 62 (90%) associated with an average 0.71 +/- 0.79 false-positive errors per hour using the same 'population' detection parameters. When the sensitivity for detection was increased, all but one of the 62 seizures were detected (98%). Less than 1.0 false-positive error per hour occurred in all but 5 records when using the 'population' parameters. The combination of rule-based detection criteria employing contextual parameters and unsupervised training of NNs to recognize time-frequency patterns is a promising direction for automated seizure detection. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Gabor, AJ (reprint author), UNIV CALIF DAVIS,MED CTR,DEPT NEUROL,2315 STOCKTON BLVD,SACRAMENTO,CA 95817, USA. NR 21 TC 77 Z9 82 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0013-4694 J9 ELECTROEN CLIN NEURO JI Electroencephalogr. Clin. Neurophysiol. PD SEP PY 1996 VL 99 IS 3 BP 257 EP 266 PG 10 WC Engineering, Biomedical; Clinical Neurology SC Engineering; Neurosciences & Neurology GA VL669 UT WOS:A1996VL66900006 PM 8862115 ER PT J AU Visco, S AF Visco, S TI Fuel cells get 100% power boost SO ELECTRONICS WORLD LA English DT Editorial Material RP Visco, S (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU REED BUSINESS PUBLISHING LTD PI SUTTON PA QUADRANT HOUSE THE QUADRANT, SUTTON, SURREY, ENGLAND SM2 5AS SN 0959-8332 J9 ELECTRON WORLD JI Electron. World PD SEP PY 1996 IS 1725 BP 643 EP 643 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA VA517 UT WOS:A1996VA51700015 ER PT J AU White, CM Jensen, KL Rohar, PC Tamilia, JP Shaw, LJ Hickey, RF AF White, CM Jensen, KL Rohar, PC Tamilia, JP Shaw, LJ Hickey, RF TI Separation of Fischer-Tropsch catalyst/wax mixtures using dense-gas and liquid extraction SO ENERGY & FUELS LA English DT Article AB This paper describes a catalyst/wax separation technique based on dense-gas and/or liquid extraction of the soluble hydrocarbon components from the insoluble inorganic catalyst particles. The separation by extraction can also be performed in conjunction with magnetic separation of iron catalyst particles. Extractions of 4.91 wt % catalyst in wax were performed with n-butane, n-pentane, and n-hexane. Up to 91 wt % of the catalyst/wax feed mixture to the extractor could be recovered as a catalyst-free wax (combined yield of the second- and third-stage separators). High-temperature gel permeation chromatography was used to measure the average molecular weight of the extraction fractions. The extraction process separates the wax according to molecular weight. The lower molecular weight wax components are extracted from the catalyst/wax mixture and accumulate in the second-stage separator, while the higher molecular weight wax components remain in the first-stage separator. The low molecular weight wax fraction can be remixed with the catalyst and pumped back into the slurry reactor, reducing the average molecular weight, reducing the viscosity, and improving the transport properties of the reaction media while minimizing the chances of reactor gelation due to buildup of high molecular weight waxes. RP White, CM (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,PITTSBURGH,PA 15236, USA. NR 12 TC 11 Z9 13 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 1996 VL 10 IS 5 BP 1067 EP 1073 DI 10.1021/ef960027x PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA VH332 UT WOS:A1996VH33200006 ER PT J AU McCold, LN Saulsbury, JW AF McCold, LN Saulsbury, JW TI Including past and present impacts in cumulative impact assessments SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE cumulative impacts; environmental impact assessment; National Environmental Policy Act; significance; mitigation AB Environmental concerns such as loss of biological diversity and stratospheric ozone depletion have heightened awareness of the need to assess cumulative impacts in environmental documents. More than 20 years of experience with the National Environmental Policy Act (NEPA) have provided analysts in the United States with opportunities for developing successful techniques to assess site-specific impacts of proposed actions. Methods for analyzing a proposed action's incremental contribution to cumulative impacts are generally less advanced than those for project-specific impacts. The President's Council on Environmental Quality (CEQ) defines cumulative impact to include the impacts of ''past, present and reasonably foreseeable future actions'' regardless of who undertakes the action. Court decisions have helped clarify the distinction between reasonably foreseeable future actions and other possible future actions. This paper seeks to clarify how past acid present impacts should be included in cumulative impact analyses. The definition of cumulative impacts implies that cumulative impact analyses should include the effects of all past and present actions on a particular resource. Including past and present impacts in cumulative impact assessments increases the likelihood of identifying significant impacts. NEPA requires agencies to give more consideration to alternatives and mitigation and to provide more opportunities for public involvement for actions that would have significant impacts than for actions that would not cause or contribute to significant impacts. For an action that would contribute to significant cumulative impacts, the additional cost and effort involved in increased consideration of alternatives and mitigation and in additional public involvement may be avoided if the action can be modified so that its contributions to significant cumulative impacts are eliminated. RP McCold, LN (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,POB 2008,MS 6206,OAK RIDGE,TN 37831, USA. NR 18 TC 28 Z9 32 U1 4 U2 20 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD SEP-OCT PY 1996 VL 20 IS 5 BP 767 EP 776 DI 10.1007/BF01204147 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA VD303 UT WOS:A1996VD30300015 ER PT J AU Shi, Y Littlejohn, D Kettler, PB Chang, SG AF Shi, Y Littlejohn, D Kettler, PB Chang, SG TI Removal of nitric oxide from flue gas with iron thiochelate aqueous solution in a turbulent contact absorber SO ENVIRONMENTAL PROGRESS LA English DT Article ID REDUCTION; NO AB An iron(II) thiochelate has been developed for use as an additive in a wet flue gas scrubber for simultaneous removal of SO2 and NOx from flue gas. The additive enhances the solubility of NO in scrubbing liquor by binding NO to form an iron nitrosyl thiochelate. The effect of oxygen on NO absorption in iron(II) thiochelate aqueous solutions, as well as in iron(II)(EDTA) solutions, has been studied. The results showed that the iron(II) thiochelate is more resistant to oxidation by oxygen than the conventional iron(II)(EDTA) additive. Parametric studies of the absorption efficiency of NO were performed in a bench-scale Turbulent Contact Absorber (TCR). Based on the bench-scale test results, a prediction of the performance of a full-scale spray absorber has been made. RP Shi, Y (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. NR 15 TC 9 Z9 20 U1 2 U2 11 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 FAL PY 1996 VL 15 IS 3 BP 153 EP 158 DI 10.1002/ep.670150313 PG 6 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VG541 UT WOS:A1996VG54100006 ER PT J AU Foy, BR Waldthausen, K Sedillo, MA Buelow, SJ AF Foy, BR Waldthausen, K Sedillo, MA Buelow, SJ TI Hydrothermal processing of chlorinated hydrocarbons in a titanium reactor SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SUPERCRITICAL WATER; OXIDATION; TRICHLOROETHYLENE; PYROLYSIS; HYDROGEN; VAPOR AB Experiments are reported on the oxidative hydrothermal destruction of chlorinated organics in a corrosion-resistant titanium reactor. Oxidation reaction conditions were 250-500 degrees C near 650 bar and reaction times of 30-100 s in a continuous-Row reactor. Trichloroacetic acid; trichloroethylene, and 1,1,1-trichloroethane behaved similarly. The organic concentration was similar to 1.5 wt %; hydrogen peroxide was the oxidizer; sodium bicarbonate was added to achieve neutral pH. Hydrolysis occurs at low temperature, producing chloride ion and secondary organics. Carbon dioxide is the sole carbon product at 500 degrees C. Sodium nitrate and sodium nitrite were also found to be effective oxidizers. Corrosion of the titanium was found to be slight (<0.038 mm/yr). The reaction mixture is likely not a single phase at these conditions. The destruction efficiency for trichloroethylene was estimated as 99.96% at 450 degrees C and 60 s, with <0.02% conversion to volatile chlorinated organic byproducts. RP Foy, BR (reprint author), LOS ALAMOS NATL LAB, CHEM SCI & TECHNOL DIV CST6, MS J567, LOS ALAMOS, NM 87545 USA. NR 32 TC 41 Z9 42 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD SEP PY 1996 VL 30 IS 9 BP 2790 EP 2799 DI 10.1021/es960041o PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VE883 UT WOS:A1996VE88300030 ER PT J AU Kirchstetter, TW Harley, RA Littlejohn, D AF Kirchstetter, TW Harley, RA Littlejohn, D TI Measurement of nitrous acid in motor vehicle exhaust SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID COAST AIR BASIN; ANNULAR DENUDER; WATER-VAPOR; INDOOR AIR; URBAN AIR; ATMOSPHERE; DIOXIDE; IDENTIFICATION; POLLUTANTS; KINETICS AB Nitrous acid (HONO) is an important tropospheric air pollutant. Photolysis of HONO produces hydroxy] radicals that promote ozone formation. HONO may also adversely affect human health. Sources of HONO include both direct emission from combustion processes and secondary atmospheric formation from nitrogen oxides (NOx). The relative contribution of these sources to ambient HONO concentrations is not well known. In this study, HONO and NOx emissions from on-road vehicles were measured at the Caldecott Tunnel during summer 1995. The Caldecott Tunnel is located on a heavily used highway in the San Francisco Bay area. The mean and median model years of vehicles observed during this study were 1989.3 and 1990, respectively. Nitrous acid was collected on sodium carbonate-coated glass annular denuders; NOx concentrations were measured using chemiluminescent analyzers. Average HONO concentrations in the tunnel exhaust and background air were 6.9 +/- 1.4 and 0.7 +/- 0.3 ppb, respectively. The average HONO/NOx ratio in motor vehicle exhaust was (2.9 +/- 0.5) x 10(-3). The HONO/NOx ratio in vehicle exhaust measured at the Caldecott Tunnel was higher than that reported previously for well-maintained, catalyst-equipped vehicles, but was lower than that for older vehicles with limited emission controls. Nighttime ambient HONO/NOx ratios are typically much larger than the HONO/NOx ratio measured at the Caldecott Tunnel, which suggests that ambient HONO concentrations are governed mainly by secondary formation. C1 UNIV CALIF BERKELEY,DEPT CIVIL & ENVIRONM ENGN,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RI Harley, Robert/C-9177-2016 OI Harley, Robert/0000-0002-0559-1917 NR 40 TC 104 Z9 107 U1 6 U2 30 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 SEP PY 1996 VL 30 IS 9 BP 2843 EP 2849 DI 10.1021/es960135y PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VE883 UT WOS:A1996VE88300037 ER PT J AU LeBlanc, MM Lassila, DH AF LeBlanc, MM Lassila, DH TI A hybrid technique for compression testing at intermediate strain rates SO EXPERIMENTAL TECHNIQUES LA English DT Article RP LeBlanc, MM (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, L-170, LIVERMORE, CA 94551 USA. NR 9 TC 8 Z9 9 U1 1 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0732-8818 EI 1747-1567 J9 EXP TECHNIQUES JI Exp. Tech. PD SEP-OCT PY 1996 VL 20 IS 5 BP 21 EP 24 DI 10.1111/j.1747-1567.1996.tb00459.x PG 4 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA VK350 UT WOS:A1996VK35000005 ER PT J AU Frankel, EN AF Frankel, EN TI Antioxidants in lipid foods and their impact on food quality SO FOOD CHEMISTRY LA English DT Article; Proceedings Paper CT 2nd International Food Data Base Conference on Food Composition Research - The Broader Context CY AUG 28-30, 1995 CL LAHTI, FINLAND ID VITAMIN-E; OXIDATIVE STABILITY; NATURAL ANTIOXIDANTS; BULK OILS; TOCOPHEROLS; EMULSIONS; ACID; INHIBITION AB This paper reviews the antioxidant properties of tocopherols and ascorbic acid in edible oils, and the impact of interfacial phenomena on their activities in emulsions and the effects of edible oil processing. Tocopherols are the most important natural antioxidants found in vegetable oil-derived foods, These antioxidants can interrupt lipid autoxidation by interfering with either the chain propagation or the decomposition processes. alpha-Tocopherol at high concentrations inhibits hydroperoxide decomposition but promotes hydroperoxide formation. The effect of antioxidants in inhibiting hydroperoxide decomposition may thus be critical in preserving food quality by reducing rancidity due to aldehyde formation. Ascorbic acid can regenerate alpha-tocopherol, inactivate metal initiators and reduce hydroperoxides. The activity of natural antioxidants is greatly affected by complex interfacial phenomena in emulsions and multicomponent foods. In an oil-in-water emulsion system, the lipophilic antioxidants alpha-tocopherol and ascorbyl palmitate are more effective than in bulk oil, while the opposite trend is found for the hydrophilic antioxidants Trolox and ascorbic acid. The methodology to evaluate natural antioxidants must be carefully interpreted depending on whether oxidation is carried out in bulk oils or in emulsions, and what method is used to measure lipid oxidation. Copyright (C) 1996 Elsevier Science Ltd RP Frankel, EN (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT FOOD SCI & TECHNOL,DAVIS,CA 95616, USA. NR 31 TC 215 Z9 224 U1 10 U2 60 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0308-8146 J9 FOOD CHEM JI Food Chem. PD SEP PY 1996 VL 57 IS 1 BP 51 EP 55 DI 10.1016/0308-8146(96)00067-2 PG 5 WC Chemistry, Applied; Food Science & Technology; Nutrition & Dietetics SC Chemistry; Food Science & Technology; Nutrition & Dietetics GA VR298 UT WOS:A1996VR29800010 ER PT J AU Freeman, GB Dill, JA Johnson, JD Kurtz, PJ Parham, F Mathews, HB AF Freeman, GB Dill, JA Johnson, JD Kurtz, PJ Parham, F Mathews, HB TI Comparative absorption of lead from contaminated soil and lead salts by weanling fischer 344 rats SO FUNDAMENTAL AND APPLIED TOXICOLOGY LA English DT Article ID PHYSIOLOGICALLY-BASED MODELS; BONE-SEEKING ELEMENTS; LOW DIETARY CALCIUM; BIOAVAILABILITY; BLOOD; DISPOSITION; TOXICITY; KINETICS; ACETATE AB A 44-day dosed feed study was performed to compare the bioavailability of lead from contaminated soil versus two lead salts and the effect of soil on gastrointestinal absorption of ingested lead. Male Fischer rats (approximately 4 weeks of age) received lead, 17, 42, or 127 ppm, in the form of lead acetate, lead sulfide, lead-contaminated soil, or combinations thereof in the diet for 7, 15, or 44 days, Control soil was added to the diets of some animals to determine how it might alter lead bioavailability, Blood Delta-aminolevulinic acid dehydratase (Delta-ALAD) and blood, bone, kidney, and liver lead were determined in groups of animals at each time-point, Blood Delta-ALAD was inhibited in a dose-dependent manner and to the greatest degree in the lead acetate and lead acetate/control soil groups, followed by the lead sulfide and lead-contaminated soil groups, Bone and tissue lead levels increased in a dose-dependent manner and were greatest in animals receiving lead acetate and significantly less in animals receiving lead sulfide and lead-contaminated soil. Blood lead levels were generally greatest by 7 days and stabilized at lower levels thereafter, Bone lead concentration-time patterns did not demonstrate the biphasic change seen with tissues and continued to increase in most treatment groups through the course of the study, The presence of soil in the diet clearly attenuated the absorption of lead acetate, but had little effect on the absorption of lead sulfide. Results of these studies confirm previous observations that lead absorption is highly dependent on the form of lead ingested and the matrix in which it is ingested, More important, these studies demonstrate that lead in soil may be significantly less available than estimated by current default assumptions and that the presence of soil may decrease the availability of lead from lead salts on which the default assumptions are based. Results presented here also demonstrate that the weanling rat may represent an appropriate model that could be used to obtain relatively rapid and economical estimates of the availability of lead in complex matrices such as soil. (C) 1996 Society of Toxicology. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NIEHS, RES TRIANGLE PK, NC 27709 USA. RP Freeman, GB (reprint author), BATTELLE MEM INST, 505 KING AVE, COLUMBUS, OH 43210 USA. NR 41 TC 34 Z9 37 U1 0 U2 10 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0272-0590 J9 FUND APPL TOXICOL JI Fundam. Appl. Toxicol. PD SEP PY 1996 VL 33 IS 1 BP 109 EP 119 DI 10.1006/faat.1996.0148 PG 11 WC Toxicology SC Toxicology GA VF995 UT WOS:A1996VF99500013 PM 8812247 ER PT J AU Thomas, CE Harris, JH Haste, GR Klepper, CC Hogan, JT Tobin, S Baity, FW Isler, RC Uckan, T Batchelor, DB Carter, MD Ryan, PM Hoffman, DJ Saoutic, B Beaumont, B Becoulet, A Kuus, H Fraboulet, D Grosman, A Guilhem, D Hess, W Walter, J Loarer, T Chatelier, M AF Thomas, CE Harris, JH Haste, GR Klepper, CC Hogan, JT Tobin, S Baity, FW Isler, RC Uckan, T Batchelor, DB Carter, MD Ryan, PM Hoffman, DJ Saoutic, B Beaumont, B Becoulet, A Kuus, H Fraboulet, D Grosman, A Guilhem, D Hess, W Walter, J Loarer, T Chatelier, M TI ICRF/edge interaction guidelines for ICRF antenna design and initial ICRF/edge interaction experiments on the tore supra tokamak SO FUSION TECHNOLOGY LA English DT Editorial Material DE scrape-off-layer plasma; ICRF antenna; magnetic fusion ID DC ELECTRIC-FIELDS; SCRAPE-OFF LAYER; EDGE PLASMA; FARADAY SHIELD; IMPURITY PRODUCTION; JET; TEXTOR; SHEATH; RF; BOUNDARY AB Understanding ion cyclotron range of frequency (ICRF) antenna interaction with the edge/scrape-off-layer (SOL) plasma is crucial to building antennas that can survive long-pulse or Steady-state high-power operation in plasmas. The global effects of ICRF/edge interactions are discussed. The present knowledge of ICRF-induced sheath interactions with the edge and SOL plasmas in magnetic fusion experiments is quantitatively reviewed and added to. The design principles and equations governing plasma heat loading and the sputtering of Faraday shields and the bumper limiters of ICRF antennas for long-pulse and steady-state devices are presented. Electrostatic sheaths on Faraday shields and bumper limiters are discussed, and an analytic estimate of the induced direct-current (de) plasma potential at the lateral protection (bumper limiters) of ICRF antennas is given. This is a new result. This estimated de voltage is used to give the total power flow to the lateral protection, and an expression for the power flux is given-also with new results. Equations to use in estimating impurity production (sputtering) and principles for minimizing im purity production are reviewed. Similar equations and estimates for electromotive radio-frequency sheaths are given, and new scaling laws for the de voltage and power flow to the ICRF antenna lateral protection due to electromotive sheaths are proposed, The initial results from the ICRF/edge interaction experiments on Tore Supra are presented and discussed in light of the theoretical and heuristic results given. C1 CEA,CEN CADARACHE,DEPT RECH FUS CONTROLEE,EURATOM ASSOC,F-13108 ST PAUL DURANCE,FRANCE. RP Thomas, CE (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. OI Isler, Ralph/0000-0002-5368-7200 NR 77 TC 13 Z9 14 U1 0 U2 3 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 SEP PY 1996 VL 30 IS 1 BP 1 EP 39 PG 39 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VF994 UT WOS:A1996VF99400002 ER PT J AU Barnes, CW Larson, AR Roquemore, AL AF Barnes, CW Larson, AR Roquemore, AL TI Calculations of neutron activation response for the tokamak fusion test reactor and absolute calibrations of neutron yield SO FUSION TECHNOLOGY LA English DT Article ID JOINT EUROPEAN TORUS; CROSS CALIBRATION; SYSTEM; TFTR; DEUTERIUM; TRANSPORT; OPERATION; DETECTOR; PLASMAS; TRITIUM AB The most accurate determination of neutron yields from fusion reactors may be obtained from neutron activation measurements of elemental foils, On the Tokamak Fusion Test Reactor (TFTR), a re-entrant irradiation end has been installed to provide a low-scattering environment close to the plasma for neutron activation measurements. The ratio of energy-dependent fluence to total fusion yield is calculated using a fully three-dimensional Monte Carlo calculation with the Monte Carlo code for neutron and photon transport (MCNP), Corrections to the ''virgin'' fluence from attenuation and scattering are only 10 to 20% for deuterium-tritium (D-T) reactions and 30 to 40% for deuterium-deuterium reactions. A total I-sigma accuracy of +/-8% is achieved for D-T neutron yields over a wide dynamic range. This paper documents the response coefficients (hits per source neutron, where hits are activated nuclei per target nuclei)for use by the neutron activation system on TFTR; describes the possible systematic corrections needed (such as major radial variations or the impact of ion temperature on reactions with high-energy thresholds); and estimates uncertainties in the response coefficients. Results from in situ use of a D-T neutron generator are also analyzed using the MCNP modeling as an approximate benchmarking experiment; only 20% accuracy in the comparison is possible because of poor counting statistics in the calibration experiment. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Barnes, CW (reprint author), LOS ALAMOS NATL LAB,P-24 MAIL STOP E526,LOS ALAMOS,NM 87545, USA. NR 21 TC 11 Z9 11 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 SEP PY 1996 VL 30 IS 1 BP 63 EP 72 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VF994 UT WOS:A1996VF99400005 ER PT J AU Petzoldt, RW Moir, RW AF Petzoldt, RW Moir, RW TI Membrane support of accelerated fuel capsules for inertial fusion energy SO FUSION TECHNOLOGY LA English DT Article AB The use of thin membranes to suspend art inertial fusion energy fuel capsule in a holder or hohlraum for injection into a reaction chamber is investigated. Also discussed is the stress that occurs in the fuel within a capsule during acceleration. To determine the maximum target acceleration, capsule displacement and membrane deformation angle are calculated for an axisymmetric geometry for a range of membrane strain and capsule size. Membranes must be thin (perhaps <1 mu m) to minimize their effect on capsule implosion symmetry. Typical target injection scenarios prefer accelerations in excess of 1000 m/s(2). Acceleration in excess of 1600 m/s(2) for a 2.4-mm-radius 30-mg capsule is possible with two 0.1-mu m-thick membranes. Added stress from vibrations could cause a factor of 2 decrease in the allowed acceleration unless the acceleration profile is modified to mitigate this effect However if the acceleration is gradually increased and then decreased, over a few membrane oscillation periods (i.e., a few milliseconds), the membrane stress due to oscillation overshoot and the final capsule oscillation amplitude is minimal. Compared with a single membrane, a dual membrane geometry allows several times greater acceleration with reduced capsule displacement. RP Petzoldt, RW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 7 TC 5 Z9 5 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 SEP PY 1996 VL 30 IS 1 BP 73 EP 82 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VF994 UT WOS:A1996VF99400006 ER PT J AU Sheliak, JD Hoffer, JK Foreman, LR Mapoles, ER AF Sheliak, JD Hoffer, JK Foreman, LR Mapoles, ER TI High-resolution optical measurements of surface roughness for beta-layered deuterium-tritium solid inside a re-entrant copper cylinder SO FUSION TECHNOLOGY LA English DT Article ID RADIOACTIVELY INDUCED SUBLIMATION; FUEL AB A high-resolution optical imaging system and custom-designed image analysis software are used to make surface roughness measurements for deuterium-tritium (D-T) solid layers, equilibrated inside a 2-mm-inside-diameter re-entrant copper cylinder Several experiments are performed that yield D-T layer thicknesses of between 75 and 139 mu m, with equilibration temperatures between 17.4 and 18.8 K. A 1024- x 1024-pixel charge-coupled-device imaging camera, coupled with a Maksutov-Cassegrain long-range microscope, produces a 2.5-mu m (single-pixel) image resolution, The error function fitting of the image analysis data produces submicron resolution of the layer interior surface finish. The length scale for the cylinder inner bore is just over 6 mm, and the final layer surface roughness for this length ranges from 3- to 1.7-mu m root-mean-square. The feasibility is being explored of using these highly uniform and smooth D-T solid layers inside future targets for inertial confinement fusion reactors to produce surface finishes that will meet target design requirements for the National Ignition Facility. Techniques for improving the D-T solid layer surface finish are examined, limitations of the current D-T cell configuration and fuel mix are discussed, and cell configurations for future experiments are described. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Sheliak, JD (reprint author), LOS ALAMOS NATL LAB,GEN ATOM INC,POB 1663,MAIL STOP K764,LOS ALAMOS,NM 87545, USA. NR 10 TC 7 Z9 7 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 SEP PY 1996 VL 30 IS 1 BP 83 EP 94 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VF994 UT WOS:A1996VF99400007 ER PT J AU Bonaldo, MDF Lennon, G Soares, MB AF Bonaldo, MDF Lennon, G Soares, MB TI Normalization and subtraction: Two approaches to facilitate gene discovery SO GENOME RESEARCH LA English DT Article ID EXPRESSED SEQUENCE TAGS; HUMAN BRAIN; MESSENGER-RNA; CDNA LIBRARY; HUMAN GENOME; DNA; DIVERSITY; MAP AB Large-scale sequencing of cDNAs randomly picked From libraries has proven to be a very powerful approach to discover (putatively) expressed sequences that, in turn, once mapped, may greatly expedite the process involved in the identification and cloning of human disease genes. However, the integrity of the data and the pace at which novel sequences can be identified depends to a great extent on the cDNA libraries that are used. Because altogether, in a typical cell, the mRNAs of the prevalent and intermediate frequency classes comprise as much as 50-65% of the total mRNA mass, but represent no more than 1000-2000 different mRNAs, redundant identification of mRNAs of these two frequency classes is destined to become overwhelming relatively early in any such random gene discovery programs, thus seriously compromising their cost-effectiveness. With the goal of facilitating such efforts, previously we developed a method to construct directionally cloned normalized cDNA libraries and applied it to generate infant brain (1NIB) and fetal liver/spleen [1NFLS] libraries, from which a total of 45,192 and 86,088 expressed sequence tags, respectively, have been derived. While improving the representation of the longest cDNAs in our libraries, we developed three additional methods to normalize cDNA libraries and generated over 35 libraries, most of which have been contributed to our integrated Molecular Analysis of Genomes and Their Expression (IMAGE) Consortium and thus distributed widely and used for sequencing and mapping. In an attempt to facilitate the process of gene discovery further, we have also developed a subtractive hybridization approach designed specifically to eliminate for reduce significantly the representation of) large pools of arrayed and (mostly) sequenced clones from normalized libraries yet to be (or just partly) surveyed. Here we present a detailed description and a comparative analysis of Four methods that we developed and used to generate normalize cDNA libraries from human (15), mouse (3), rat (2), as well as the parasite Schistosoma mansoni (1). In addition, we describe the construction and preliminary characterization of a subtracted liver/spleen library (1NFLS-S1) that resulted from the elimination (or reduction of representation] of similar to 5000 1NFLS-IMAGE clones from the 1NFLS library. C1 COLUMBIA UNIV,COLL PHYS & SURG,DEPT PSYCHIAT,NEW YORK,NY 10032. NEW YORK STATE PSYCHIAT INST & HOSP,NEW YORK,NY 10032. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94551. FU NHGRI NIH HHS [R01 HG00980] NR 21 TC 416 Z9 462 U1 0 U2 11 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD SEP PY 1996 VL 6 IS 9 BP 791 EP 806 DI 10.1101/gr.6.9.791 PG 16 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VJ575 UT WOS:A1996VJ57500004 PM 8889548 ER PT J AU Hillier, L Lennon, G Becker, M Bonaldo, MF Chiapelli, B Chissoe, S Dietrich, N DuBuque, T Favello, A Gish, W Hawkins, M Hultman, M Kucaba, T Lacy, M Le, M Le, N Mardis, E Moore, B Morris, M Parsons, J Prange, C Rifkin, L Rohlfing, T Schellenberg, K Soares, MB Tan, F ThierryMeg, J Trevaskis, E Underwood, K Wohldman, P Waterston, R Wilson, R Marra, M AF Hillier, L Lennon, G Becker, M Bonaldo, MF Chiapelli, B Chissoe, S Dietrich, N DuBuque, T Favello, A Gish, W Hawkins, M Hultman, M Kucaba, T Lacy, M Le, M Le, N Mardis, E Moore, B Morris, M Parsons, J Prange, C Rifkin, L Rohlfing, T Schellenberg, K Soares, MB Tan, F ThierryMeg, J Trevaskis, E Underwood, K Wohldman, P Waterston, R Wilson, R Marra, M TI Generation and analysis of 280,000 human expressed sequence tags SO GENOME RESEARCH LA English DT Article ID HUMAN GENOME PROJECT; CDNA LIBRARY; CAENORHABDITIS-ELEGANS; C-ELEGANS; GENES; DNA; MAP; CLONES; BRAIN AB We report the generation of 319,311 single-pass sequencing reactions (known as expressed sequence taps, or ESTs) obtained from the 5' and 3' ends of 194,031 human cDNA clones. Our goal has been to obtain tag sequences From many different genes and to deposit these in the publicly accessible Data Base for Expressed Sequence Taps. Highly efficient automatic screening of the data allows deposition of the annotated sequences without delay. Sequences have been generated From 26 oligo(dT) primed directionally cloned libraries, of which 18 were normalized. The libraries were constructed using mRNA isolated From 17 different tissues representing three developmental states. Comparisons of a subset of our data with nonredundant human mRNA and protein data bases show that the ESTs represent many known sequences and contain many that are novel. Analysis of protein families using Hidden Markov Models confirms this observation and supports the contention that although normalization reduces significantly the relative abundance of redundant cDNA clones, it does not result in the complete removal of members of gene families. C1 LAWRENCE LIVERMORE NATL LAB, CTR HUMAN GENOME, LIVERMORE, CA 94550 USA. COLUMBIA UNIV, COLL PHYS & SURG, DEPT PSYCHIAT, NEW YORK, NY 10032 USA. NEW YORK STATE PSYCHIAT INST & HOSP, NEW YORK, NY 10032 USA. RP WASHINGTON UNIV, SCH MED, GENOME SEQUENCING CTR, ST LOUIS, MO 63108 USA. RI Gish, Warren/C-8123-2012; Marra, Marco/B-5987-2008 NR 38 TC 370 Z9 391 U1 0 U2 11 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI COLD SPRING HARBOR PA 1 BUNGTOWN RD, COLD SPRING HARBOR, NY 11724 USA SN 1088-9051 EI 1549-5469 J9 GENOME RES JI Genome Res. PD SEP PY 1996 VL 6 IS 9 BP 807 EP 828 DI 10.1101/gr.6.9.807 PG 22 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VJ575 UT WOS:A1996VJ57500005 PM 8889549 ER PT J AU Shen, ZY PardingtonPurtymun, PE Comeaux, JC Moyzis, RK Chen, DJ AF Shen, ZY PardingtonPurtymun, PE Comeaux, JC Moyzis, RK Chen, DJ TI UBL1, a human ubiquitin-like protein associating with human RAD51/RAD52 proteins SO GENOMICS LA English DT Article ID SACCHAROMYCES-CEREVISIAE; DNA-REPAIR; INSITU HYBRIDIZATION; NUCLEOTIDE-SEQUENCE; RECOMBINATION GENES; CONJUGATING ENZYME; CENTROMERE PROTEIN; RAD51 PROTEIN; YEAST RAD23; S-PHASE AB The RAD51/RAD52-dependent DNA repair pathway is involved in DNA recombination and DNA double-strand break repair in yeast. Although many proteins in the RAD51/RAD52-dependent DNA repair pathway have been identified in yeast, a novel protein(s) that functions with RAD51/RAD52 may also exist in humans. Using a yeast two-hybrid system, we have identified a 12-kDa protein that associates with the human RAD51 and RAD52 proteins. This protein shares significant amino acid homology with the yeast protein SMT3, which functionally associates with the yeast mitosis fidelity protein MIF2. It also shares moderate homology with ubiquitin and several other proteins, including the N-terminus of the RAD23 protein and a ubiquitin cross reacting protein. Therefore, the gene is tentatively designated UBL1 for ubiquitin-like 1. The UBL1 mRNA is expressed in many human tissues, most highly in testis. The UBL1 gene is mapped to chromosome 2q32.2-q33, and a related sequence may be located on chromosome 1q23-q25. (C) 1996 Academic Press, Inc. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,DNA DAMAGE & REPAIR GRP,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. FU NCI NIH HHS [CA50519] NR 52 TC 150 Z9 152 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD SEP 1 PY 1996 VL 36 IS 2 BP 271 EP 279 DI 10.1006/geno.1996.0462 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA VH187 UT WOS:A1996VH18700006 PM 8812453 ER PT J AU Cooper, RF Fanselow, JB Poker, DB AF Cooper, RF Fanselow, JB Poker, DB TI The mechanism of oxidation of a basaltic glass: Chemical diffusion of network-modifying cations SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SILICATE MELTS; OXYGEN DIFFUSION; REDOX EQUILIBRIA; TRACER DIFFUSION; STRUCTURAL ROLE; SOLID-SOLUTIONS; OXIDE GLASSES; FERROUS IRON; LIQUIDS; PRESSURE AB Rutherford backscattering spectroscopy, in conjunction with optical and scanning electron microscopy, has been used to characterize the oxidation process in a homogeneous, well-annealed glass prepared from a nepheline-normative olivine basalt. Initially melted and annealed at an oxygen fugacity substantially below the quartz-fayalite-magnetite (QFM) buffer, the glasses were oxidized in air under the time and temperature ranges 1-100 h and 550-600 degrees C, respectively. Oxidation causes (1) formation of crystalline CaO and MgO that partially covers the free surface of the glass and (2) an internal reaction zone that is depleted of Ca2+ and Mg2+ but enriched in Na+. The reaction morphology is uniquely consistent with a model in which oxidation occurs by the outward diffusion (to the free surface) of Ca2+ and Mg2+ that is charge compensated by an inward flux of electron holes (polarons): oxidation of the glass occurs as the oxygen/cation ratio increases, not by addition of oxygen, but rather by removal of cations. The flux of Na+ from depth in the glass to the oxidizing region, which is also charge compensated by a counterflux of electron holes, is a response to the thermodynamic driving force seeking to stabilize Fe3+ as a network former, consistent with equilibrium thermodynamic and spectroscopic studies. Growth of the oxidized/transformed glass follows parabolic (chemical-diffusion-limited) kinetics. Using a first-order, Wagnerian approach, the diffusion coefficient and driving force terms of the parabolic reaction-rate constant are separated, giving an average divalent cation diffusion coefficient of <(D)over bar (A2+)(cm(2) . s(-1))> = 9.9 x 10(-2) exp(-210 kJ . mol(-1)/RT). The oxidation mechanism seen for the glass, that is, one dominated by diffusion of network modifying cations and not an oxygen species, is anticipated to also occur in iron-bearing aluminosilicate melts: the discrepancy between the kinetics of redox reactions and of oxygen tracer diffusion noted in the literature for melts is most likely explained in this way. C1 UNIV WISCONSIN,DEPT GEOL & GEOPHYS,MADISON,WI 53706. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Cooper, RF (reprint author), UNIV WISCONSIN,DEPT MAT SCI & ENGN,1509 UNIV AVE,MADISON,WI 53706, USA. NR 51 TC 83 Z9 83 U1 1 U2 13 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 SEP PY 1996 VL 60 IS 17 BP 3253 EP 3265 DI 10.1016/0016-7037(96)00160-3 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VG642 UT WOS:A1996VG64200007 ER PT J AU Turner, GD Zachara, JM McKinley, JP Smith, SC AF Turner, GD Zachara, JM McKinley, JP Smith, SC TI Surface-charge properties and UO22+ adsorption of a subsurface smectite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID AMORPHOUS IRON OXYHYDROXIDE; SOLID-SOLUTION INTERFACE; OXIDE-WATER INTERFACE; ALUMINUM-OXIDE; BINDING-SITES; METAL-IONS; COMPLEXATION; MONTMORILLONITE; SORPTION; URANYL AB Surface charge and UO22+ adsorption were measured on a clay-sized, subsurface mineral isolate whose mineralogy was dominated by a ferrogenous beidellite. Experiments were performed in batch at 25 degrees C with N-2(g) atmosphere and sorbent suspensions (9.46 g clay/kg suspension) that had been adjusted in pH between 4 and 9. Surface charge was defined by measurements of adsorbed Na by isotopic exchange and of proton adsorption by potentiometric titration in NaClO4 (I = 0.1, 0.01, 0.001). Extraction of the clay with La(NO3)(3) and aqueous-phase analyses were necessary to establish the contributions of Al and Si dissolution to the proton balance and the total adsorbed cation charge (i.e., Na-ads(+) + 3Al(ads)(3+)). The adsorption of UO22+ (7.5 x 10(-6) mol L(-1)) was determined in Na+ (0.1, 0.01, 0.001 mol L(-1)) and Ca2+ (0.05 and 0.005 mol L(-1)) electrolytes. Adsorption of UO22+ showed contributions of ion exchange and edge complexation reactions in Na+ electrolyte, but by only edge complexation reactions in Ca2+ electrolyte. A multiple-site surface-complexation model containing fixed-(X(-)) and variable-charge sites (SiOH, AlOH) was fit to adsorbed cation charge data between pH 4 and 10, with the concentrations of AlOH, SiOH, and X(-) as the adjustable parameters. Surface acidity and ion-pair formation constants for gibbsite and silica were used to describe the ionization and electrolyte binding of the AlOH and SiOH sites. The model provided an excellent description of the surface-charge characteristics of the clay as measured by sodium isotopic exchange and potentiometric titration. A composite model was formulated to predict UO22+ adsorption by incorporating UO22+ aqueous speciation, competitive ion exchange with background electrolyte cations, and UO22+ complexation with AlOH and SiOH sites. UO22+ complexation with AlOH and SiOH was parameterized by UO22+ sorption on alpha-Al(OH)(3)(s) and alpha-SiO2(s), respectively. The composite model overpredicted UO22+ sorption across the entire pH range in both electrolytes. Acceptable predictions could be obtained if the UO22+ affinity for edge AlOH sites were adjusted 2.03 log units below that of gibbsite. Changes in chemical affinity arising from lattice substitutions and edge site morphology are, therefore, concluded to contribute significantly to adsorption, although the potential competitive effects of dissolved Al3+ and H4SiO4 could not be discounted. The adsorption of UO22+ On the subsurface smectite was similar to that of the reference montmorillonite, SWy-1, with the exception that Al dissolution contributed significantly to adsorbed cation charge. C1 ENVIRONM & ENERGY SCI DIV, PACIFIC NW NATL LAB, RICHLAND, WA 99352 USA. NR 60 TC 137 Z9 137 U1 1 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1996 VL 60 IS 18 BP 3399 EP 3414 DI 10.1016/0016-7037(96)00169-X PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VH190 UT WOS:A1996VH19000004 ER PT J AU Bargar, JR Towle, SN Brown, GE Parks, GA AF Bargar, JR Towle, SN Brown, GE Parks, GA TI Outer-sphere Pb(II) adsorbed at specific surface sites on single crystal alpha-alumina SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Letter ID X-RAY-ABSORPTION; SOLID-SOLUTION INTERFACE; FINE-STRUCTURE; SAPPHIRE ALPHA-AL2O3; MULTIPLE-SCATTERING; ADSORPTION; SPECTROSCOPY; EXAFS AB Solvated Pb(II) ions were found to adsorb as structurally well-defined outer-sphere complexes at specific sites on the alpha-Al2O3 (0001) single crystal surface, as determined by grazing-incidence X-ray absorption fine structure (GI-XAFS) measurements. The XAFS results suggest that the distance between Pb(II) adions and the alumina surface is approximately 4.2 Angstrom. In contrast, Pb(II) adsorbs as more strongly bound inner-sphere complexes on alpha-Al2O3 (1 (1) over bar 02) The difference in reactivities of the two alumina surfaces has implications for modeling surface complexation reactions of contaminants in natural environments, catalysis, and compositional sector zoning of oxide crystals. C1 STANFORD UNIV, DEPT GEOL & ENVIRONM SCI, STANFORD, CA 94305 USA. STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94309 USA. NR 28 TC 120 Z9 120 U1 2 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 1996 VL 60 IS 18 BP 3541 EP 3547 DI 10.1016/0016-7037(96)00222-0 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VH190 UT WOS:A1996VH19000016 ER PT J AU Dypvik, H Gudlaugsson, ST Tsikalas, F Attrep, M Ferrell, RE Krinsley, DH Mork, A Faleide, JI Nagy, J AF Dypvik, H Gudlaugsson, ST Tsikalas, F Attrep, M Ferrell, RE Krinsley, DH Mork, A Faleide, JI Nagy, J TI Mjolnir structure: An impact crater in the Barents sea SO GEOLOGY LA English DT Article ID SPITSBERGEN; EXTINCTION; QUARTZ; ORIGIN AB A systematic search for impact indicators was conducted on a core of Late Jurassic-Early Cretaceous sedimentary strata from the vicinity of the proposed Mjolnir impact structure, Barents Sea, A 0.8-m-thick section of the core was found to contain unequivocal indicators of meteoritic impact: shocked quartz grains and a strong enrichment in iridium, The ejecta-bearing strata were discovered only 30 km north-northeast of the structure, within a stratigraphic interval corresponding to the seismically defined deformation event at Mjolnir. Further study of this unusually well preserved impact-crater-ejecta-layer pair may help constrain poorly understood aspects of large-magnitude meteorite impacts into the oceans. C1 LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545. LOUISIANA STATE UNIV,DEPT GEOL & GEOPHYS,BATON ROUGE,LA 70803. UNIV OREGON,DEPT GEOL SCI,EUGENE,OR 97403. IKU PETR RES,N-7034 TRONDHEIM,NORWAY. RP Dypvik, H (reprint author), UNIV OSLO,DEPT GEOL,POB 1047,N-0316 OSLO,NORWAY. NR 14 TC 84 Z9 85 U1 0 U2 7 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 1996 VL 24 IS 9 BP 779 EP 782 DI 10.1130/0091-7613(1996)024<0779:MLSAIC>2.3.CO;2 PG 4 WC Geology SC Geology GA VG002 UT WOS:A1996VG00200003 ER PT J AU Shiokawa, K Yumoto, K Meng, CI Reeves, G AF Shiokawa, K Yumoto, K Meng, CI Reeves, G TI Broadband electrons observed by the DMSP satellites during storm-time substorms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GREAT MAGNETIC STORM AB Electrons that have intense broadband spectra, are found to precipitate in the equatorward part of the auroral oval. The electrons are observed by the DMSP satellites in association with particular substorms during the main phase of magnetic storms. Electron fluxes are drastically enhanced after the substorm onset at all the energies measured (32 eV to 30 keV) at magnetic latitudes lower than 60 degrees (L < 4). The energy flux of the electrons exceeds 1.0 x 10(13) eV cm(-2) s(-1) sr(-1). The intense electron precipitation lasts less than 1 h. These characteristics are significantly different from those seen in the central plasma sheet region. We suggest that an unknown energization mechanism of these electrons exists at the inner part of the plasma. sheet at L < 4 during these particular storm-time substorms. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. KYUSHU UNIV,FAC SCI,FUKUOKA 812,JAPAN. JOHNS HOPKINS UNIV,APPL PHYS LAB,BALTIMORE,MD 20723. RP Shiokawa, K (reprint author), NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA 442,JAPAN. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 8 TC 18 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1996 VL 23 IS 18 BP 2529 EP 2532 DI 10.1029/96GL01955 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VG005 UT WOS:A1996VG00500030 ER PT J AU Andres, RJ Marland, G Fung, I Matthews, E AF Andres, RJ Marland, G Fung, I Matthews, E TI A 1 degrees x1 degrees distribution of carbon dioxide emissions from fossil fuel consumption and cement manufacture, 1950-1990 SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID CO2 AB One degree latitude by one degree longitude (1 degrees x 1 degrees) data sets of carbon dioxide emissions from fossil fuel consumption and cement manufacture were produced for 1950, 1960, 1970, 1980, and 1990. National estimates of carbon emissions were combined with 1 degrees x 1 degrees data sets of political units and human population density to create the new 1 degrees x 1 degrees carbon emissions data sets. The human population density data set has an effective resolution of the country/state level. This resolution translates to the 1 degrees x 1 degrees carbon emissions data set. Latitudinal distribution of emissions have also been calculated. The data show continual growth with time over most of the world, with increased growth rates in major urban areas. A slow southerly shift in the bulk of the emissions is apparent as Asian countries increase their energy consumption to support their growing economies and populations. The digital data sets are available by anonymous ftp. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NASA,GODDARD SPACE FLIGHT CTR,INST SPACE STUDIES,NEW YORK,NY 10025. RI ANDRES, ROBERT/B-9786-2012; OI ANDRES, ROBERT/0000-0001-8781-4979 NR 22 TC 190 Z9 199 U1 3 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP PY 1996 VL 10 IS 3 BP 419 EP 429 DI 10.1029/96GB01523 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA VD604 UT WOS:A1996VD60400005 ER PT J AU Seaman, JC Bertsch, PM Korom, SF Miller, WP AF Seaman, JC Bertsch, PM Korom, SF Miller, WP TI Physicochemical controls on nonconservative anion migration in coarse-textured alluvial sediments SO GROUND WATER LA English DT Article ID SCALE DISPERSION; SANDY AQUIFER; ADSORPTION; TRANSPORT; CHARGE; SOILS AB Three sandy subsurface materials and a sandy surface soil (Orangeburg Series) from the Upper Coastal Plain, were used to assess the influence of mineralogy and surface chemistry on the determination of physical transport parameters using ionic tracers, The clay mineralogy of the surface soil consisted primarily of kaolinite, hydroxy-interlayered vermiculite, and gibbsite, while the dominant clay mineralogy of the subsurface materials consisted of kaolinite, goethite, and mica (illite), Repacked columns of the four differing strata were leached with tritiated (approximate to 200 pCi mL(-1)) Bromide solutions, either MgBr2 or KBr, of varying ionic strengths (0.1-0.001 N), Pore-water velocities estimated by bulk density and mass flux were consistent with those estimated from tritium breakthrough, In contrast, Br- breakthrough differed drastically within the four materials and was altered by experimental conditions (sample drying, carrier cation, etc.), The retardation for 0.001 N KBr varied from 0.94 for the surface soil to 2.15 for the subsurface materials and increased with increasing Fe oxide content, For the subsurface samples, Br- was retarded to a greater degree in the presence of Mg2+ compared to K+. In contrast, oven drying the sample reduced the degree of Br- retardation observed for the subsurface materials, These results indicate that retardation can vary dramatically within materials of similar texture, mineralogy, and origin. The apparent conservative behavior of an ionic species under a given set of conditions (mineralogy, pH, ionic strength, scale size, predominant counter ion) does not automatically ensure that transport will remain conservative as those conditions are altered by changes in experimental design or unforeseen circumstances encountered at the field scale. C1 UNIV N DAKOTA,DEPT GEOL & GEOL ENGN,GRAND FORKS,ND 58202. UNIV GEORGIA,DEPT ENVIRONM SOIL SCI,ATHENS,GA 30602. RP Seaman, JC (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,BIOGEOCHEM DIV,DRAWER E,AIKEN,SC 29802, USA. NR 23 TC 25 Z9 25 U1 0 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 778 EP 783 DI 10.1111/j.1745-6584.1996.tb02070.x PG 6 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900005 ER PT J AU Gwo, JP Toran, LE Morris, MD Wilson, GV AF Gwo, JP Toran, LE Morris, MD Wilson, GV TI Subsurface stormflow modeling with sensitivity analysis using a Latin-hypercube sampling technique SO GROUND WATER LA English DT Article ID FLOW; SOIL AB During storm events, the shallow disposal facilities at Oak Ridge National Laboratory become inundated, and subsurface stormflow may intermittently extract radionuclides from the surrounding soils and the wastes themselves, It is estimated that 90% of the rain water infiltrating the soil horizons becomes subsurface stormflow, yet stormflow is a poorly understood process, The objectives of this research are to model stormflow: (1) to identify important parameters for waste site monitoring and data collections; (2) to evaluate remediation designs; and (3) to investigate the effect of local heterogeneities on stormflow paths, Numerical models of a proposed waste disposal site were developed, and a Latin-hypercube simulation technique was used to study the uncertainty of model parameters, Sensitivity analyses of model parameters suggested that hydraulic conductivity was the most influential parameter. However, local heterogeneities may alter flow patterns and result in complex recharge and discharge processes. Hydraulic conductivity, therefore, may not be used as the only reference for subsurface flow monitoring and engineering designs. Neither of two engineering designs, capping and French drains, was found to be effective in hydrologically Isolating downslope waste trenches. However, combinations of both designs may prove more effective than either one alone. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV MATH & COMP SCI,OAK RIDGE,TN 37831. DESERT RES INST,WATER RESOURCES CTR,LAS VEGAS,NV 89132. NR 20 TC 23 Z9 23 U1 1 U2 5 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 811 EP 818 DI 10.1111/j.1745-6584.1996.tb02075.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900010 ER PT J AU Rautman, CA Istok, JD AF Rautman, CA Istok, JD TI Probabilistic assessment of ground-water contamination .1. Geostatistical framework SO GROUND WATER LA English DT Article ID WASTE SITE DATA; CONDITIONAL SIMULATION; FLOW AB Characterizing the extent and severity of ground-water contamination at waste sites is expensive and time-consuming. A probabilistic approach, based on the acceptance of uncertainty and a finite probability of making classification errors (contaminated relative to a regulatory threshold vs, uncontaminated), is presented as an alternative to traditional site characterization methodology, The approach utilizes geostatistical techniques to identify and model the spatial continuity of contamination at a site (variography) and to develop alternate plausible simulations of contamination fields (conditional simulation). Probabilistic summaries of many simulations provide tools for (a) estimating the range of plausible contaminant concentrations at unsampled locations, (b) identifying the locations of boundaries between contaminated and uncontaminated portions of the site and the degree of certainty in those locations, and (c) estimating the range of plausible values for total contaminant mass. The first paper in the series presents the geostatistical framework and illustrates the approach using synthetic data for a hypothetical site. The second paper presents an application of the proposed methodology to the probabilistic assessment of ground-water contamination at a site involving ground-water contamination by nitrate and herbicide in a shallow, unconfined alluvial aquifer in an agricultural area in eastern Oregon. C1 OREGON STATE UNIV,DEPT CIVIL ENGN,CORVALLIS,OR 97331. RP Rautman, CA (reprint author), SANDIA NATL LABS,GEOHYDROL DEPT,POB 5800,MS-1324,ALBUQUERQUE,NM 87185, USA. NR 28 TC 18 Z9 19 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 899 EP 909 DI 10.1111/j.1745-6584.1996.tb02084.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900019 ER PT J AU Fountain, JC Starr, RC Middleton, T Beikirch, M Taylor, C Hodge, D AF Fountain, JC Starr, RC Middleton, T Beikirch, M Taylor, C Hodge, D TI A controlled field test of surfactant-enhanced aquifer remediation SO GROUND WATER LA English DT Article ID SOLUBILIZATION AB The presence of dense nonaqueous phase liquids is one of the principal problems associated with current ground-water remediation efforts. Standard pump-and-treat methods are ineffective largely because of the low aqueous solubilities of DNAPL components. Surfactants can increase DNAPL solubility and hence have the potential for increasing the rate of DNAPL dissolution in pump-and-treat systems. To test the effectiveness of surfactants under field conditions, a controlled field test at Canadian Forces Base Borden was undertaken. Results indicate surfactant-enhanced aquifer remediation can rapidly remove the majority of DNAPL using simple modifications of a pump-and-treat system, As in all pump-and-treat systems, the efficiency is a function of the hydraulic conductivity. The persistence of high DNAPL concentrations at specific elevations within the aquifer throughout the test indicates that little vertical movement of DNAPL occurred as a result of the introduction of the surfactant, Since the test was stopped when small amounts of DNAPL still remained, the limit of removal was not investigated. C1 EG&G IDAHO INC,IDAHO FALLS,ID 83415. RP Fountain, JC (reprint author), SUNY BUFFALO,DEPT GEOL,BUFFALO,NY 14260, USA. NR 22 TC 102 Z9 103 U1 2 U2 7 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 910 EP 916 DI 10.1111/j.1745-6584.1996.tb02085.x PG 7 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900020 ER PT J AU Spane, FA Thorne, PD Swanson, LC AF Spane, FA Thorne, PD Swanson, LC TI Applicability of slug interference tests for hydraulic characterization of unconfined aquifers .2. Field test examples SO GROUND WATER LA English DT Article AB Slug interference testing may be particularly useful for characterizing hydraulic properties of aquifer sites where disposal of contaminated ground water makes pumping tests undesirable, The design, performance, and analysis of slug interference tests for two field test examples are presented, Results were compared with standard constant-rate pumping tests, The comparison indicates that slug interference tests provide estimates comparable to those obtained from short duration pumping tests for the determination of transmissivity, storativity, and vertical anisotropy. The close agreement in hydraulic property values obtained using the two test methods suggests that slug interference testing, under favorable test conditions (for example, observation well distances less than or equal to 30 m), can provide representative aquifer characterization results. The quality and extent of test data obtained also indicate the potential use of slug interference testing for three-dimensional hydrologic characterization investigations, when conducted using multilevel monitoring facilities. C1 INT TECHNOL HANFORD, RICHLAND, WA 99352 USA. RP Spane, FA (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 15 TC 14 Z9 14 U1 0 U2 6 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 925 EP 933 DI 10.1111/j.1745-6584.1996.tb02087.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900022 ER PT J AU Clement, TP Hooker, BS Skeen, RS AF Clement, TP Hooker, BS Skeen, RS TI Macroscopic models for predicting changes in saturated porous media properties caused by microbial growth SO GROUND WATER LA English DT Article ID CAPILLARY RETENTION CHARACTERISTICS; HYDRAULIC CONDUCTIVITY; PHYSICAL-PROPERTIES; BIOFILM GROWTH; UNSATURATED SOILS; SIZE DISTRIBUTION; SAND COLUMNS; TRANSPORT; BIODEGRADATION; PERMEABILITY AB Analytical equations are developed to model changes in porosity, specific surface area, and permeability caused by biomass accumulation in porous media. The proposed equations do not assume any specific pattern for microbial growth but instead are based on macroscopic estimates of average biomass concentrations. For porous media with a pore-size distribution index value (lambda) equal to 3, the macroscopic model predictions of porosity, specific surface area, and permeability changes are in exact agreement with biofilm-model predictions, At other values of lambda between 2 and 5, simulated porosity profiles are identical and relative specific surface area and permeability profiles show minor deviations, In comparison to biofilm-based models, the macroscopic models are relatively simple to implement and are computationally more efficient. Simulations of biologically reactive flow in a one-dimensional column shaw that the macroscopic and biofilm approach based transport codes predict almost identical porosity and permeability profiles, The macroscopic models are simple and useful tools for estimating changes in various porous media properties during bioremediation of contaminated aquifers. RP Clement, TP (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 33 TC 115 Z9 120 U1 0 U2 20 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 1996 VL 34 IS 5 BP 934 EP 942 DI 10.1111/j.1745-6584.1996.tb02088.x PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VF569 UT WOS:A1996VF56900023 ER PT J AU Wahl, LE AF Wahl, LE TI Evaluation of the NESHAP radiological risk assessment SO HEALTH PHYSICS LA English DT Review DE risk analysis; risk estimates; radiation risk; emissions; atmosphere AB The Environmental Protection Agency performed a risk assessment as a basis for the National Emission Standards for Hazardous Air Pollutants. This paper compares the Environmental Protection Agency's risk assessment with the models used by the National Research Council's fifth Committee on the Biological Effects of Ionizing Radiations, the United Nations Scientific Committee on the Effects of Atomic Radiation, and the International Commission on Radiological Protection. Comparison of the parameters used by each organization suggests that the Environmental Protection Agency could improve its own risk assessment by adopting one of the assessments done by the BEIR V Committee, the United Nations Scientific Committee on the Effects of Atomic Radiation, and the International Commission on Radiological Protection. RP Wahl, LE (reprint author), LOS ALAMOS NATL LAB, AIR QUAL GRP, ESH 17, MS J987, LOS ALAMOS, NM 87545 USA. NR 11 TC 1 Z9 1 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1996 VL 71 IS 3 BP 279 EP 283 DI 10.1097/00004032-199609000-00002 PG 5 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 VC462 UT WOS:A1996VC46200002 PM 8698567 ER PT J AU Carlton, WH Murphy, CE Evans, AG AF Carlton, WH Murphy, CE Evans, AG TI Plutonium in the Savannah River Site environment SO HEALTH PHYSICS LA English DT Article DE plutonium; contamination, environmental; dose; water AB The Savannah River Site has produced plutonium, tritium, and other special nuclear materials for national defense, other government programs, and some civilian purposes. Plutonium has been released to the environment during the operation of five reactors, two radiochemical processing facilities, and other supporting facilities. During the period 1954-1989, 140 GBq of plutonium were released to the atmosphere and 23 GBq were released to site streams and ponds, The maximum individual effective dose equivalent at the site boundary was estimated to be 120 mu Sv from atmospheric releases and 2.4 mu Sv from liquid releases. The 80-km population dose was 7.1 person-Sv. RP Carlton, WH (reprint author), WESTINGHOUSE SAVANNAH RIVER CO, SAVANNAH RIVER TECHNOL CTR, AIKEN, SC 29808 USA. NR 18 TC 7 Z9 8 U1 0 U2 6 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1996 VL 71 IS 3 BP 290 EP 299 DI 10.1097/00004032-199609000-00004 PG 10 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 VC462 UT WOS:A1996VC46200005 PM 8698569 ER PT J AU Poston, JW Kodimer, KA Bolch, WE Poston, JW AF Poston, JW Kodimer, KA Bolch, WE Poston, JW TI Calculation of absorbed energy in the gastrointestinal tract SO HEALTH PHYSICS LA English DT Article DE dosimetry; Monte Carlo; photons; dose AB One goal of this research was to reproduce the photon specific absorbed fraction calculations of Cristy and Eckerman using their gastrointestinal (GI) tract model. A second goal was to calculate photon specific absorbed fraction values for their GI tract model using electron tracking techniques. A final goal was to calculate electron absorbed fraction values for their GI tract model. This paper summarizes the work performed using the currently accepted model of the GI tract provided by Cristy and Eckerman. Their model was coded into the Electron Gamma Shower 4 (EGS4) computational package for calculation of photon specific absorbed fraction values. To benchmark the initial code, the EGS4 program was run so that all secondary particles deposited their energy at the site of the primary photon interaction (i.e., without electron tracking). The results obtained from these preliminary calculations were compared to those provided by Cristy and Eckerman to verify and benchmark the program. Next, specific absorbed fraction values were calculated for twelve discrete photon energies using the electron tracking capabilities of EGS4. These photon specific absorbed fraction values were compared to those calculated without electron tracking, Finally, absorbed fraction values were calculated for twelve discrete electron energies. The electron absorbed fraction values were compared to the ICRP ''one-half assumption'' for electron energy deposition in the wall of the GI tract. C1 TEXAS A&M UNIV, DEPT NUCL ENGN, COLLEGE STN, TX 77843 USA. UNIV FLORIDA, DEPT NUCL ENGN SCI, GAINESVILLE, FL 32611 USA. RP Poston, JW (reprint author), ARGONNE NATL LAB W, POB 2528, IDAHO FALLS, ID 83403 USA. NR 15 TC 6 Z9 6 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 SEP PY 1996 VL 71 IS 3 BP 300 EP 306 DI 10.1097/00004032-199609000-00005 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VC462 UT WOS:A1996VC46200006 PM 8698570 ER PT J AU Poston, JW Kodimer, KA Bolch, WE Poston, JW AF Poston, JW Kodimer, KA Bolch, WE Poston, JW TI A revised model for the calculation of absorbed energy in the gastrointestinal tract SO HEALTH PHYSICS LA English DT Article DE dosimetry; gastrointestinal tract; Monte Carlo; ingestion AB The goal of this research was to develop a more complete gastrointestinal (GI) tract model for use in internal dose assessment. This paper summarizes the development of a revised mathematical model of the GI tract. The current GI tract model assumes the wall can be represented as a single soft tissue layer without regard to the radiosensitivity of the cells. The goal of the GI tract revision was to develop geometric regions that separate the radiosensitive cells from the less radiosensitive cells. Once the model was revised, it was coded into the Electron Gamma Shower 4 (EGS4) computational package for calculation of photon and electron absorbed fraction values. Photon absorbed fraction values were calculated for twelve discrete energies. For the photon absorbed fraction calculations, the EGS4 program was run so that secondary particles created in photon interactions were followed using the electron tracking capabilities of EGS4. The results of the photon absorbed fraction calculations provided better estimates of the energy deposited in the radiosensitive cells when the target organ was the source, In cases where the target organ was not the source, the photon absorbed fraction values did not provide better estimates than those obtained using the current GI tract model. An increase in the number of photon histories should provide better estimates of the photon absorbed fraction for these cases. Electron absorbed fraction values also were calculated for twelve discrete electron energies. The results of these calculations provided the expected pattern of energy deposition and better estimates than those currently available. The annual limit on intake was recalculated for a single radionuclide to demonstrate the affect of these improved absorbed fraction values on internal dose assessment. The radionuclide was selected for two reasons: 1) it was a beta emitting radionuclide; and 2) the annual limit on intake for ingestion was based on the non-stochastic committed dose equivalent limit to the lower large intestine. The calculated annual limit on intake was found to be three times greater than the annual limit on intake provided in ICRP Publication 30. There are many radionuclides that have a section of the GI tract as the limiting organ for ingestion. It is expected that the annual limit on intake value for these radionuclides would increase when the revised GI tract model is employed for internal dose assessment. C1 TEXAS A&M UNIV, DEPT NUCL ENGN, COLLEGE STN, TX 77843 USA. UNIV FLORIDA, DEPT NUCL ENGN SCI, GAINESVILLE, FL 32611 USA. RP Poston, JW (reprint author), ARGONNE NATL LAB, POB 2528, IDAHO FALLS, ID 83403 USA. NR 14 TC 13 Z9 13 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 1996 VL 71 IS 3 BP 307 EP 314 DI 10.1097/00004032-199609000-00006 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 VC462 UT WOS:A1996VC46200007 PM 8698571 ER PT J AU Cossairt, JD AF Cossairt, JD TI On residual dose rate within particle accelerator enclosures SO HEALTH PHYSICS LA English DT Article DE accelerators; radiation, gamma; photons; radiation protection ID CONCRETE AB A mathematical proof of a theorem concerning the flux density of particles at any point interior to a simple closed convex surface in which the surface emits such particles uniformly and isotropically is presented. The relationship of this theorem, which is of rather general validity, to related observations of other workers is discussed. The ramifications of the theorem are considered with particular attention devoted to conditions commonly found at particle accelerators. It is concluded that results of this theorem are directly applicable to efforts to apply the principle of maintaining dose equivalents received by personnel as low as reasonably achievable. RP Cossairt, JD (reprint author), FERMILAB NATL ACCELERATOR LAB, POB 500, BATAVIA, IL 60510 USA. NR 13 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 SEP PY 1996 VL 71 IS 3 BP 315 EP 319 DI 10.1097/00004032-199609000-00007 PG 5 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 VC462 UT WOS:A1996VC46200008 PM 8698572 ER PT J AU Barnett, TP Santer, BD Jones, PD Bradley, RS Briffa, KR AF Barnett, TP Santer, BD Jones, PD Bradley, RS Briffa, KR TI Estimates of low frequency natural variability in near-surface air temperature SO HOLOCENE LA English DT Article DE air temperature; natural variability; anthropogenic effects; climatic change; general circulation models; GCM; global climate ID OCEAN-ATMOSPHERE MODEL; WESTERN NORTH-AMERICA; CLIMATE VARIABILITY; RECONSTRUCTION; PACIFIC; RECORD; CHINA; CORE AB Estimates of the spectrum of natural variability are critical to the problem of detecting an anthropogenic signal in global climate observations. Without such information it is impossible to say that current climate change is different or unique from changes that have happened in the past and, therefore, potentially due to man-induced causes. We have estimated the spectrum of natural variability from a globally distributed set of palaeo-temperature proxies and compared it with comparable estimates from two long control integrations of coupled general circulation models - the type used to predict anthropogenic change due to greenhouse gases. None of the three estimates of the natural variability spectrum agree with each other on the low-frequency, near-global time/space scales. Until this dichotomy is resolved, it will be hard to say, with confidence, that an anthropogenic climate signal has or has not been detected. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV E ANGLIA,NORWICH NR4 7TJ,NORFOLK,ENGLAND. UNIV MASSACHUSETTS,AMHERST,MA 01003. RP Barnett, TP (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. RI Briffa, Keith/C-8834-2009; Jones, Philip/C-8718-2009; Santer, Benjamin/F-9781-2011; OI Jones, Philip/0000-0001-5032-5493; Briffa, Keith/0000-0003-3323-3639 NR 52 TC 48 Z9 49 U1 1 U2 5 PU EDWARD ARNOLD PUBL LTD PI LONDON PA 338 EUSTON ROAD, LONDON, ENGLAND NW1 3BH SN 0959-6836 J9 HOLOCENE JI Holocene PD SEP PY 1996 VL 6 IS 3 BP 255 EP 263 DI 10.1177/095968369600600301 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA VH189 UT WOS:A1996VH18900001 ER PT J AU Ahumada, MH Mitcham, EJ Moore, DG AF Ahumada, MH Mitcham, EJ Moore, DG TI Postharvest quality of 'Thompson Seedless' grapes after insecticidal controlled-atmosphere treatments SO HORTSCIENCE LA English DT Article DE Vitis vinifera; insect quarantine; carbon dioxide ID CARBON-DIOXIDE ATMOSPHERES; GOLDEN DELICIOUS APPLES; LOW-OXYGEN ATMOSPHERES; POST-HARVEST QUALITY; PHYSIOLOGICAL-RESPONSES; FRUIT; ATTRIBUTES; METABOLISM; TOLERANCE; STORAGE AB Non-SO2-fumigated 'Thompson Seedless' table grapes (Vitis vinifera L.) were stored at 5 or 20 degrees C for 6 and 4.5 days, respectively, in air or one of four insecticidal controlled atmospheres (ICA); 0.5% O-2 + 35% CO2; 0.5% O-2 + 45% CO2; 0.5% O-2 + 55% CO2; or 100% CO2. The fruit were evaluated for weight loss, berry firmness, soluble solids concentration (SSC), titratable acidity, berry shattering, rachis browning, berry browning, and volatiles (acetaldehyde and ethanol). Fruit quality was not affected at 5 degrees C with the exception of greater rachis browning in fruit treated with 0.5% O-2 + 45% CO2. At 20 degrees C, ICA treatments maintained greener rachis compared to the air control; however, SSC was reduced in the fruit treated with 55% and 100% CO2. At both temperatures, ICA induced the production of high levels of acetaldehyde and ethanol. Ethanol concentrations were two-thirds lower at 5 degrees C than at 20 degrees C. Consumer preference was negatively affected by some ICA treatments for grapes kept at 20 degrees C, but not by any of the treatments at 5 degrees C. Preliminary data for mortality of omnivorous leafroller pupae (Platynota stultana Walshingham), western flower thrips (Frankliniella occidentalis Pergande) adults and larvae, and pacific spider mite (Tetranychus pacificus McGregor) adults and larvae indicate that many of the ICA treatments would provide significant insect control. C1 LAWRENCE LIVERMORE NATL LAB,DEPT POMOL,DAVIS,CA 95616. NR 36 TC 26 Z9 27 U1 0 U2 2 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 701 NORTH SAINT ASAPH STREET, ALEXANDRIA, VA 22314-1998 SN 0018-5345 J9 HORTSCIENCE JI Hortscience PD SEP PY 1996 VL 31 IS 5 BP 833 EP 836 PG 4 WC Horticulture SC Agriculture GA VK649 UT WOS:A1996VK64900026 ER PT J AU Ghosh, D Sengupta, J Hendrickx, AG AF Ghosh, D Sengupta, J Hendrickx, AG TI Effect of single-dose early luteal phase administration of mifepristone (RU486) on implantation stage endometrium in the rhesus monkey SO HUMAN REPRODUCTION LA English DT Article DE endometrium; monkey; preimplantation stage; RU486; TEM ID NORMAL MENSTRUAL-CYCLE; PROGESTERONE ANTAGONIST RU-486; DECIDUOGENIC STIMULUS; PREIMPLANTATION EMBRYO; MACACA-MULATTA; ESTROGEN; RECEPTOR; GESTATION; ESTRADIOL; ANTIPROGESTERONE AB The characteristics of implantation stage endometrium following a single-dose, early luteal phase application of mifepristone (RU486) in proven conception cycles has been examined in the rhesus monkey ill an attempt to understand the physiological basis of the anti-implantation activity of the drug, Endometrial samples were collected from monkeys subjected to vehicle (group 1, n = 14) and RU486 (2 mg/kg body weight; group 2, n = 12) on day 2 after the presumed day of ovulation of successfully mated cycles, The average diameter of glands (P < 0.05), number of vacuolated cells (P < 0.01), number of supranuclear vacuolated cells (P < 0.05) in glandular epithelium and amount of glandular secretion (P < 0.05) were significantly lower in RU486-treated endometrium compared with control tissues samples. Additionally, 18% of glandular epithelial cells showed apoptotic and degenerative features in RU486-treated tissue samples, These data, together with the obsewed significant decreases in precipitate area (P < 0.02) and in the optical absorbance of alkaline phosphatase reaction end-product (P < 0.05), confirm that retardation in glandular differentiation in the upper functionalis is a likely target of antiprogestin action in implantation stage endometrium. An increased frequency of mitosis in stromal cells (P < 0.05) and a greater degree of extravasation (P < 0.05) were also observed after RU486 exposure, Despite an apparent indication of constriction and regression in few RU486-exposed endometria compared with controls, morphometric analyses did not show any changes in capillary structure, Whether endometrial vasculature in progesterone-exposed uterus is a target of antiprogestin action during the peri-implantation stage remains to be determined. Further studies are required to explain the observed increase (P < 0.02) In the area of precipitate of roll Willebrand (vW) factor with no change in vW Factor-positive vessels, and the apparent increase In collagen IV immunostain in subepithelial and perivascular basement membrane in implantation stage endometrium after early luteal phase RU486 treatment in monkeys. C1 ALL INDIA INST MED SCI, DEPT PHYSIOL, NEW DELHI 110029, INDIA. LAWRENCE LIVERMORE NATL LAB, CALIF REG PRIMATE RES CTR, DAVIS, CA 95616 USA. FU NCRR NIH HHS [RR00169] NR 71 TC 41 Z9 42 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0268-1161 J9 HUM REPROD JI Hum. Reprod. PD SEP PY 1996 VL 11 IS 9 BP 2026 EP 2035 PG 10 WC Obstetrics & Gynecology; Reproductive Biology SC Obstetrics & Gynecology; Reproductive Biology GA VL972 UT WOS:A1996VL97200047 PM 8921085 ER PT J AU Bischof, C Khademi, P Mauer, A Carle, A AF Bischof, C Khademi, P Mauer, A Carle, A TI Adifor 2.0: Automatic differentiation of Fortran 77 programs SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Article C1 RICE UNIV, CTR RES PARALLEL COMPUTAT, HOUSTON, TX 77251 USA. RP Bischof, C (reprint author), ARGONNE NATL LAB, DIV MATH & COMP SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Bischof, Christian/D-2897-2009 NR 27 TC 188 Z9 190 U1 1 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD FAL PY 1996 VL 3 IS 3 BP 18 EP 32 DI 10.1109/99.537089 PG 15 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA VH235 UT WOS:A1996VH23500005 ER PT J AU Hong, MY Chang, YH Dienes, A Heritage, JP Delfyett, PJ Dijaili, S Patterson, FG AF Hong, MY Chang, YH Dienes, A Heritage, JP Delfyett, PJ Dijaili, S Patterson, FG TI Femtosecond self- and cross-phase modulation in semiconductor laser amplifiers SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article ID INGAASP OPTICAL AMPLIFIERS; TRAVELING-WAVE AMPLIFIERS; INDEX NONLINEARITIES; SUBPICOSECOND GAIN; DYNAMICS; PULSES; ALGAAS; AMPLIFICATION; DIODES AB We present detailed derivation of our new model for femtosecond pulse amplification in semiconductor laser amplifiers. The various dynamic nonlinear terms of gain compression and associated self-phase modulation are derived semiphenomenologically, and are discussed physically. Included are the effects of carrier depletion, carrier heating and spectral hole-burning, as well as linear and two photon absorption and the instantaneous nonlinear index. Additionally, we account for dynamically changing gain curvature and slope. We apply the theory to strong signal cross-phase-cross-gain modulation experiments with similar to 500 fs pulses in a broad area GaAs amplifier and show that the model accurately describes the observed complex phenomena. We also present experimental results on single beam strong signal amplification in two different quantum-well amplifiers using 150-200 fs duration pulses. For such pulse lengths, carrier heating becomes an integrating nonlinearity and its self-phase modulation is similar to that due to carrier depletion. Additionally, since the pulse spectrum is broad, the gain slope and curvature shift and narrow it. The resultant spectral distortions are very different than observed (and modeled) earlier for the similar to 500 fs pulses. The model is again able to correctly describe the evolution of these ultrashort pulses, indicating that it remains valid, even though purse durations approach the intraband relaxation time. C1 UNIV CENT FLORIDA,CREOL,ORLANDO,FL 32826. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Hong, MY (reprint author), UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. NR 36 TC 89 Z9 93 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD SEP PY 1996 VL 2 IS 3 BP 523 EP 539 DI 10.1109/2944.571753 PG 17 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WX097 UT WOS:A1996WX09700012 ER PT J AU Taft, G Rundquist, A Murnane, MM Christov, IP Kapteyn, HC DeLong, KW Fittinghoff, DN Krumbugel, MA Sweetser, JN Trebino, R AF Taft, G Rundquist, A Murnane, MM Christov, IP Kapteyn, HC DeLong, KW Fittinghoff, DN Krumbugel, MA Sweetser, JN Trebino, R TI Measurement of 10-fs laser pulses SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article ID AUTO-CORRELATION MEASUREMENTS; TI-SAPPHIRE LASER; FEMTOSECOND PULSES; GENERATION AB We report full characterization of the intensity and phase of similar to 10-fs optical purses using second-harmonic-generation frequency-resolved-optical-gating (SHG FROG). We summarize the subtleties in such measurements, compare these measurements with predicted pulse shapes, and describe the implications of these measurements for the creation of even shorter pulses. We also discuss the problem of validating these measurements. Previous measurements of such short pulses using techniques such as autocorrelation have been difficult to validate because at best incomplete information is obtained and internal self-consistency checks are lacking. FROG measurements of these pulses, in contrast, can be validated, for several reasons. First, the complete pulse-shape information provided by FROG allows significantly better comparison of experimental data with theoretical models than do measurements of the autocorrelation trace of a pulse. Second, there exist internal self-consistency checks in FROG that are not present in other pulse-measurement techniques. Indeed, we show how to correct a FROG trace with systematic error using one of these checks. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550. RP Taft, G (reprint author), UNIV MICHIGAN,CTR ULTRAFAST OPT SCI,ANN ARBOR,MI 48109, USA. RI Kapteyn, Henry/H-6559-2011; Christov, Ivan/D-4446-2014 OI Kapteyn, Henry/0000-0001-8386-6317; Christov, Ivan/0000-0002-9146-6708 NR 25 TC 76 Z9 77 U1 4 U2 13 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD SEP PY 1996 VL 2 IS 3 BP 575 EP 585 DI 10.1109/2944.571757 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WX097 UT WOS:A1996WX09700016 ER PT J AU Wang, HH Grenier, P Whitaker, JF Fujioka, H Jasinski, J LilientalWeber, Z AF Wang, HH Grenier, P Whitaker, JF Fujioka, H Jasinski, J LilientalWeber, Z TI Ultrafast response of As-implanted GaAs photoconductors SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SUBPICOSECOND CARRIER LIFETIMES; TEMPERATURE-GROWN GAAS; ION-IMPLANTATION; DYNAMICS; LAYERS AB The photoconductive response of an optoelectronic switch fabricated from GaAs implanted with arsenic ions is measured to have a duration as short as 0.7 ps and a relaxation time as fast as 0.5 ps. The switching efficiency and relaxation time of the photoswitches using the As-implanted GaAs substrates are determined to be comparable to photoconductive devices employing GaAs grown by low-temperature molecular-beam epitaxy (LT-GaAs). For high de-bias values, persistent photocurrent tails from transient leakage currents are found to be very prominent in bulk GaAs devices that were implanted with 10(16) cm(-2) arsenic ions at 200 keV. This behavior has been determined to arise from substrate leakage current underneath the thin implanted layer, which recrystallizes and exhibits, as does LT-GaAs, arsenic-precipitate formation after annealing. In order to reduce this leakage current, multiple ion dosages with various implantation energies have been implemented. An epitaxial GaAs layer has also been implanted with arsenic ions, isolated from its semi insulating substrate, and bonded onto a fused silica wafer in order to verify that the persistent tail response from the photoconductive switches was not actually due to the implanted region of the GaAs. C1 UNIV CALIF BERKELEY, DEPT MAT & MIN ENGN, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV MICHIGAN, CTR ULTRAFAST OPT SCI, ANN ARBOR, MI 48109 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 23 TC 7 Z9 7 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1077-260X EI 1558-4542 J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD SEP PY 1996 VL 2 IS 3 BP 630 EP 635 DI 10.1109/2944.571761 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WX097 UT WOS:A1996WX09700020 ER PT J AU Soden, JM Hawkins, CF Miller, AC AF Soden, JM Hawkins, CF Miller, AC TI Identifying defects in deep-submicron CMOS ICs SO IEEE SPECTRUM LA English DT Article C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. INTEL CORP,CHANDLER,AZ 85226. RP Soden, JM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 4 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 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD SEP PY 1996 VL 33 IS 9 BP 66 EP 71 DI 10.1109/6.535396 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA VF588 UT WOS:A1996VF58800015 ER PT J AU Hsu, JS Sorenson, PL AF Hsu, JS Sorenson, PL TI Field assessment of induction motor efficiency through air-gap torque SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article; Proceedings Paper CT 1996 IEEE/PES Winter Meeting CY JAN 21-25, 1996 CL BALTIMORE, MD SP IEEE PES AB Induction motors are the most popular motors used in industry. This paper further suggests the use of air-gap torque method [1] to evaluate their efficiency and load changes, The fundamental difference between Method E and the air-gap torque method is discussed. Efficiency assessments conducted on induction motors under various conditions show the accuracy and potential of the air-gap torque method. RP Hsu, JS (reprint author), OAK RIDGE NATL LAB,POB 2003,K-1008-F,MS 7258,OAK RIDGE,TN 37831, USA. NR 12 TC 11 Z9 11 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 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD SEP PY 1996 VL 11 IS 3 BP 489 EP 494 DI 10.1109/60.536998 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA VK804 UT WOS:A1996VK80400003 ER PT J AU Key, TS Lai, JS AF Key, TS Lai, JS TI Costs and benefits of harmonic current reduction for switch-mode power supplies in a commercial office building SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT 1995 IEEE Industry Applications Conference/30th IAS Annual Meeting CY OCT 08-12, 1995 CL LAKE BUENA VISTA, FL SP IEEE, Ind Applicat Soc ID SYSTEMS AB Harmonic currents generated by modern office equipment cause power system heating and add to user power bills. By looking at the harmonic-related losses in a specific electrical system--representing a commercial building--energy costs are quantified. The analysis shows that building wiring losses related to powering nonlinear electronic load equipment may be more than double the losses for linear load equipment. Current-related power losses such as I(2)R, proximity of conductors, and transformer winding eddy currents (I(2)h(2)) are considered. The cost of these losses is compared to the cost of reducing harmonics in the equipment design. Results show that an active-type harmonic-elimination circuit, built into the common electronic equipment switch-mode-power supply, is cost-effective based on energy loss considerations alone. C1 OAK RIDGE NATL LAB,LOCKHEED MARTIN ENERGY RES CORP,OAK RIDGE,TN 37831. RP Key, TS (reprint author), POWER ELECT APPL CTR,KNOXVILLE,TN 37932, USA. OI Lai, Jihsheng/0000-0003-2315-8460 NR 9 TC 22 Z9 22 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 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 1996 VL 32 IS 5 BP 1017 EP 1025 DI 10.1109/28.536860 PG 9 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA VJ560 UT WOS:A1996VJ56000006 ER PT J AU Peng, FZ Lai, JS McKeever, JW VanCoevering, J AF Peng, FZ Lai, JS McKeever, JW VanCoevering, J TI A multilevel voltage-source inverter with separate DC sources for static var generation SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT 1995 IEEE Industry Applications Conference/30th IAS Annual Meeting CY OCT 08-12, 1995 CL LAKE BUENA VISTA, FL SP IEEE, Ind Applicat Soc ID REACTIVE-POWER; COMPENSATION AB A new multilevel voltage-source inverter with separate de sources is proposed for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS) including static var generation (SVG), power-line conditioning, series compensation, phase shifting, voltage balancing, fuel cell, and photovoltaic utility systems interfacing, etc. The new M-level inverter consists of (M - 1)/2 single-phase full bridges in which each bridge has its own separate de source. This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle as the number of levels increases. It can solve the size-and-weight problems of conventional transformer-based multipulse inverters and the component-counts problems of multilevel diode-clamp and flying-capacitor inverters. To demonstrate the superiority of the new inverter, an SVG system using the new inverter topology is discussed through analysis, simulation, and experiment. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Peng, FZ (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 16 TC 437 Z9 545 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 1996 VL 32 IS 5 BP 1130 EP 1138 PG 9 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA VJ560 UT WOS:A1996VJ56000022 ER PT J AU Boenig, HJ Ferner, JA Bogdan, F Rumrill, RS Morris, GC AF Boenig, HJ Ferner, JA Bogdan, F Rumrill, RS Morris, GC TI Design and operation of a 40-MW, highly stabilized power supply SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT 1995 IEEE Industry Applications Conference/30th IAS Annual Meeting CY OCT 08-12, 1995 CL LAKE BUENA VISTA, FL SP IEEE, Ind Applicat Soc AB Four 10-MW highly stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled resistive high-field research magnets. The power supply modules achieve a long-term current stability of 10 ppm over a 12-h period with a short-term ripple and noise variation of <10 ppm over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three, or four modules can operate in parallel. Each power supply module consists of a 12.5-kV vacuum circuit breaker, two three-winding step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated de supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload capability of 20 kA. The isolated output terminals of each power supply module are connected to a reversing switch. An extensive high current bus system allows the modules to be connected to 16 magnet cells. This paper presents the detailed design of the power supply components. Various test results taken during the commissioning phase with a 10-MW resistive load and results taken with the research magnets are shown. The effects of the modules on the electrical supply system and the operational behavior of the power factor correction/harmonic filters are described. Also included are results of a power supply module feeding a superconducting magnet during quench propagation tests. Problems with the power supply design and solutions are presented. Some suggestions on how to improve the performance of these supplies are outlined. C1 NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. ABB IND SYST INC,NEW BERLIN,WI 53151. ALPHA SCI ELECT INC,HAYWARD,CA 94545. RP Boenig, HJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 7 TC 9 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 1996 VL 32 IS 5 BP 1146 EP 1157 DI 10.1109/28.536877 PG 12 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA VJ560 UT WOS:A1996VJ56000024 ER PT J AU Varga, L Doyle, WD Klemmer, T Flanders, PJ Kozaczek, KJ AF Varga, L Doyle, WD Klemmer, T Flanders, PJ Kozaczek, KJ TI Magnetostriction constants of sputtered FeTaN single crystal thin films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB FeTaN single crystal thin films were grown to investigate the dependence of the magnetostriction constants, lambda(100) and lambda(111) on nitrogen content. Films with 5 wt% Ta and different nitrogen contents were prepared by de sputtering on MgO (100) substrates at elevated temperatures. The films' principal orientation with respect to the substrate were (100) // (100) and [100] // [110] with a small fraction of (221) // (100) due to twinning. The values of \lambda(100)\ and \lambda(111)\ relative to pure Fe decreased by a factor of similar to 2 to a minimum near 2 at% nitrogen and then slowly increased at higher nitrogen content. The saturation magnetostriction calculated for a polycrystalline material using the measured values of lambda(100) and lambda(111) shows a considerable discrepancy at higher nitrogen content with published experimental data. C1 UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,DIFFRACT & THERMOPHYS PROPERTIES GRP,OAK RIDGE,TN 37831. RP Varga, L (reprint author), UNIV ALABAMA,DEPT PHYS & ASTRON,CTR MAT INFORMAT TECHNOL,POB 870202,TUSCALOOSA,AL 35487, USA. NR 13 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 3542 EP 3544 DI 10.1109/20.538684 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM258 UT WOS:A1996VM25800060 ER PT J AU Lewis, LH Sellers, CH Panchanathan, V AF Lewis, LH Sellers, CH Panchanathan, V TI Annealing-induced property improvements in 2-14-1 powders produced by inert gas atomization SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB The effects of vacuum annealing on the phase constitution and magnetic properties of various size fractions of 3 alloy compositions produced by inert-gas atomization (IGA) are examined, Annealing results in the oxidation of properitectic alpha-Fe formed during cooling of the melt, producing considerable improvement in the hard magnetic properties of the powders largely via the removal of lower-anisotropy magnetic reversal regions. C1 LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. MAGNEQUENCH INT INC,ANDERSON,IN 46013. RP Lewis, LH (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 5 TC 4 Z9 5 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4371 EP 4373 DI 10.1109/20.538872 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900032 ER PT J AU Horton, JA Wright, JL Herchenroeder, JW AF Horton, JA Wright, JL Herchenroeder, JW TI Fracture toughness of commercial magnets SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID PERMANENT-MAGNETS; FE; ND AB Nd2Fe14B is currently the best (highest energy product) hard magnet available, Like most permanent magnetic materials, it is rather brittle, The fracture toughness of specimens of commercially available hard magnets were measured using a chevron notch, three-point bend test, Values for Nd2Fe14B magnets ranged from 2.5 to 5.5 MPa root m. In comparison, SmCo5 was measured to have a fracture toughness of 1.9 MPa root m. It appears that this testing technique will allow differences in fracture toughness to be measured between alloys with different compositions and fabricated by different production methods and should be able to track the fracture toughness as improvements are made to a particular alloy. C1 MAGNEQUENCH INT INC,ANDERSON,IN 46013. RP Horton, JA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 9 TC 29 Z9 30 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 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4374 EP 4376 DI 10.1109/20.538873 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900033 ER PT J AU Lemke, H Echer, C Thomas, G AF Lemke, H Echer, C Thomas, G TI Electron microscopy of thin films prepared by laser ablation SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID FE-B FILMS; MAGNETS AB A simple processing method has been developed for studying model Nd-Fe-B magnets. The grain structure of these samples is comparable to that of melt-spun magnets. The samples are prepared by depositing films on a carbon foil TEM grid by laser ablation. The influence of temperature on the grain structure is emphasized. Deposition at room temperature yields amorphous films. Crystallinity is obtained at substrate temperatures above 600 degrees C during deposition. The size of the grains is about 20 nm. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP Lemke, H (reprint author), UNIV CALIF BERKELEY,DEPT MSME,BERKELEY,CA 94720, USA. NR 11 TC 19 Z9 19 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4404 EP 4406 DI 10.1109/20.538883 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900043 ER PT J AU Fullerton, EE Sowers, CH Wu, XZ Bader, SD AF Fullerton, EE Sowers, CH Wu, XZ Bader, SD TI Growth or oriented rare-earth-transition-metal thin films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID EPITAXIAL-GROWTH; SUPERLATTICES AB Rare-earth-transition-metal thin films are successfully grown by magnetron sputtering onto single-crystal MgO substrates with epitaxial W buffer layers, The use of epitaxial W buffer layers allows oriented single-phase films to be grown. Sm-Co films grown onto W(100), have strong in-plane anisotropy and coercivities exceeding 5 T at 5 K whereas Fe-Sm films have strong perpendicular anisotropy and are magnetically soft. C1 NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP Fullerton, EE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 8 TC 4 Z9 4 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4434 EP 4436 DI 10.1109/20.538892 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900052 ER PT J AU Keavney, DJ Fullerton, EE Pearson, JE Bader, SD AF Keavney, DJ Fullerton, EE Pearson, JE Bader, SD TI Magnetic properties of c-axis textured Nd2Fe14B thin films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID ND-FE-B; PERMANENT-MAGNETS; ENERGY PRODUCT AB Thin films of Nd2Fe14B (similar to 30-60 nm) were grown with c-axis texture by means of molecular beam epitaxy. A two-phase structure is observed in both the x-ray diffraction and the hysteresis loops, due to an interfacial reaction during the initial growth. Coercivities are 1-2 T at 20 K, and the anisotropy fields are bulk-like. Microstructural analysis by atomic and magnetic force microscopies reveal lateral grain sizes of similar to 200 nm, which could explain the hard magnetic properties. RP Keavney, DJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 10 TC 20 Z9 20 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4440 EP 4442 DI 10.1109/20.538894 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900054 ER PT J AU Fernandez, A Bedrossian, PJ Baker, SL Vernon, SP Kania, DR AF Fernandez, A Bedrossian, PJ Baker, SL Vernon, SP Kania, DR TI Magnetic force microscopy of single-domain cobalt dots patterned using interference lithography SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID TRANSMISSION GRATINGS; ISLANDS AB We have fabricated arrays of Co dots having diameters of 100 nm and 70 nm using interference lithography. The density of these arrays is 7.2x10(9)/in(2). Magnetic force microscopy measurements indicate that the Co dots are single-domain with moments that can be controlled to point either in-plane or out-of-plane. Interference lithography is a process that is easily scaled to large areas and is potentially capable of high throughput. Large, uniform arrays of single-domain structures are potentially useful for high-density, low-noise data storage. RP Fernandez, A (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 13 TC 81 Z9 81 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4472 EP 4474 DI 10.1109/20.538901 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900061 ER PT J AU Li, DQ Bader, SD AF Li, DQ Bader, SD TI Magnetic quantum well states in ultrathin film and wedge structures SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID OSCILLATORY EXCHANGE; THIN-FILMS; MULTILAYERS; MAGNETORESISTANCE; PHOTOEMISSION; CONFINEMENT; SUBSTRATE AB Magnetic quantum-well (QW) states are probed with angle- and spin-resolved photoemission to address critical issues pertaining to the origin of the giant magnetoresistance (GMR) optimization and oscillatory coupling of magnetic multilayers. Two epitaxial systems are highlighted: Cu/Co(wedge)/Cu(100) and Cr/Fe(100)-whisker. The confinement of Cu sp-QW states by a Co barrier requires a characteristic Co thickness of 2.2+/-2.06 Angstrom, which is consistent with the interfacial Co thickness reported to optimize the GMR of permalloy-Cu structures. The controversial k-space origin of the 18-Angstrom long period oscillation in Fe/Cr multilayers is identified by the vector that spans the d-derived ''lens'' feature of the Cr Fermi surface, based on the emergence of QW states with 17+/-2 Angstrom periodicity in this region. RP Li, DQ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 22 TC 1 Z9 1 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4556 EP 4560 DI 10.1109/20.539079 PN 2 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900089 ER PT J AU Michel, RP Chaiken, A Kim, YK Johnson, LE AF Michel, RP Chaiken, A Kim, YK Johnson, LE TI NiO exchange bias layers grown by direct ion beam sputtering of a nickel oxide target SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID STRUCTURAL CHARACTERIZATION; THIN-FILMS; ANISOTROPY AB A new processes for fabricating NiO exchange bias layers has been developed, The process involves the direct ion beam sputtering (IBS) of a NiO target. The process is simpler than other deposition techniques for producing NiO buffer layers, and facilitates the deposition of an entire spin-valve layered structure using IBS without breaking vacuum. The layer thickness and temperature dependence of the exchange field for NiO/NiFe films produced using IBS are presented and are similar to those reported for similar films deposited using reactive magnetron sputtering. The magnetic properties of highly textured exchange couples deposited on single crystal substrates are compared to those of simultaneously deposited polycrystalline films, and both show comparable exchange fields. These results are compared to current theories describing the exchange coupling at the NiO/NiFe interface. C1 QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Michel, RP (reprint author), LAWRENCE LIVERMORE NATL LAB,MAILSTOP L-350,LIVERMORE,CA 94550, USA. NR 13 TC 37 Z9 38 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 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4651 EP 4653 DI 10.1109/20.539107 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900117 ER PT J AU Sechovsky, V Havela, L Nakotte, H Bruck, E AF Sechovsky, V Havela, L Nakotte, H Bruck, E TI Giant magnetoresistance in intermetallics SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID MAGNETIC PHASE-TRANSITIONS; METAMAGNETIC TRANSITIONS; ELECTRICAL-RESISTIVITY; INTERLAYER EXCHANGE; SINGLE-CRYSTALS; FERH; SUPERLATTICES; SMMN2GE2; ALLOYS; UNIGA AB Some typical examples of large magnetoresistance effects observed in intermetallic compounds are reviewed and briefly compared with the giant magnetoresistance (GMR) of magnetic multilayers. Basically, the large magnetoresistance changes are observed at metamagnetic transitions in two classes of intermetallics, antiferromagnets and spin fluctuators. In the former case, a metamagnetic-transition is connected with the suppression of the antiferromagnetic coupling between magnetic moments as discussed with several examples of f-electron materials (NdGu(2), UNiGa and other UTX antiferromagnets). The latter class is represented by the RCo(2) compounds in which a large resistivity drop is connected with the formation and ferromagnetic ordering of Co magnetic moments, which leads to the suppression of the spin fluctuation scattering of conduction electrons. In FeRh based alloys we observe combination of both phenomena, the suppression of antiferromagnetic coupling in the Fe sublattice and the formation of Rh moments. The possibilities of tuning the material parameters desired for applications are discussed with several examples of SmMn2Ge2, Ce(Fe,T)(2), Ce(Fe,X)(2), (Mn,T)(2)Sb and MnPtAl. C1 LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545. UNIV AMSTERDAM,VAN DER WAALS ZEEMAN INST,NL-1018 XE AMSTERDAM,NETHERLANDS. RP Sechovsky, V (reprint author), CHARLES UNIV,DEPT MET PHYS,KE KARLOVU 5,CR-12116 PRAGUE 2,CZECH REPUBLIC. RI Bruck, Ekkes/E-3365-2014; Sechovsky, Vladimir/A-5256-2008 OI Sechovsky, Vladimir/0000-0003-1298-2120 NR 41 TC 13 Z9 13 U1 2 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4687 EP 4691 DI 10.1109/20.539119 PN 2 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900129 ER PT J AU Spallas, JP Huai, Y Vernon, S Fuchs, B Law, B Kania, DR Kroes, D Thomas, M OKane, D Tan, ZCH AF Spallas, JP Huai, Y Vernon, S Fuchs, B Law, B Kania, DR Kroes, D Thomas, M OKane, D Tan, ZCH TI Perpendicular current giant magnetoresistance in 0.4 mu m diameter Co-Cu multilayer sensors SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID MICROSTRUCTURES AB We have fabricated a novel giant magnetoresistive (GMR) multilayer (ML) flux sensor that is designed to operate in the current perpendicular to the plane (CPP) mode. The CPP-GMR sensor is a 0.4 mu m diameter, 0.09 mu m tall Co-Cu ML pedestal. The sensors are patterned using electron beam lithography. The Al2O3-TiC substrate is coated with a sputter deposited Al2O3 film that is polished to <0.2 nm root mean square (RMS) roughness. Contact to the bottom of the CPP-GMR sensor is made by depositing the Co-Cu multilayers onto a smooth 0.45 mu m thick Mo-Si ML stack. The top contact is self-aligned to the CPP-GMR sensor. This is accomplished, in part, by chemical mechanical polishing (CMP). The top and bottom contacts are electrically isolated by a plasma enhanced chemical vapor deposited (PECVD) Si3N4 film. The configuration of the contacts allows four point probe resistance measurements. The CPP-GMR coefficient for these 0.4 mu m diameter sensors is 13%. C1 READ RITE CORP,FREMONT,CA 94539. ETEC SYST INC,HAYWARD,CA 94545. RP Spallas, JP (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 5 TC 7 Z9 7 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4710 EP 4712 DI 10.1109/20.539126 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900136 ER PT J AU Devine, MK Jiles, DC AF Devine, MK Jiles, DC TI Composition dependence of the magnetomechanical effect and magnetostriction SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB Magnetomechanical and magnetostriction measurements were performed on a series of plain carbon steels, with carbon contents ranging from 0.1 to 0.9 wt%. The microstructures in all specimens were similar, being a mixture of ferrite and pearlite, with the pearlite volume fraction increasing with increasing carbon. The magnetomechanical effect was found to vary with carbon content. Specifically, the change in magnetization with stress was proportional to the remanent magnetization for a given carbon level. Also, the sign of the magnetization change upon removal of compressive stress reversed at 0.6 wt% carbon. The results were explained by the increased number of domain wall pinning sites produced by the increase in carbon content. RP Devine, MK (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Jiles, David/H-9548-2012 NR 4 TC 7 Z9 7 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4740 EP 4742 DI 10.1109/20.539136 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900146 ER PT J AU Pulvirenti, PP Jiles, DC AF Pulvirenti, PP Jiles, DC TI Magnetostriction and magnetic Gruneisen parameters in pseudo-binary rare earth-transition metal alloys SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB A magnetoelastic Gruneisen parameter has been derived from thermodynamic equations of state. It has been found that the magnetoelastic Gruneisen parameter is proportional to the magnetomechanical coupling coefficient, k. This relates directly the energy conversion efficiency to the the anharmonicity in the crystal lattice. It therefore provides a way of predicting the field dependence of the energy conversion efficiency in magnetostrictive materials. RP Pulvirenti, PP (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Jiles, David/H-9548-2012 NR 5 TC 0 Z9 0 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4785 EP 4787 DI 10.1109/20.539151 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900161 ER PT J AU Branagan, DJ Hyde, TA Sellers, CH Lewis, LH AF Branagan, DJ Hyde, TA Sellers, CH Lewis, LH TI A new generation of gas atomized powder with improved levels of energy product and processability SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID MAGNETIC-PROPERTIES AB New alloy compositions have been developed which allow commercially significant levels of hard magnetic properties (>10 MGOe) to be produced by inert gas atomization (IGA). Improvements in magnetic properties are a result of altering the quenching characteristics of the liquid melt by alloying with simultaneous additions of Ti and C. IGA of previous alloy compositions produced powders in an underquenched condition which resulted in inferior hard magnetic properties. In this new generation of IGA alloys, powders are produced in an overquenched condition which results in a nanocrystalline grain structure after crystallization. This extremely fine structure allows the development of a domain structure which is very similar to optimally quenched melt-spun ribbons. Amorphous or partially crystalline structures were verified in powder particles up to 100 mu m by magnetic, thermal, and structural experimental methods. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP Branagan, DJ (reprint author), LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 6 TC 10 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 5097 EP 5099 DI 10.1109/20.539502 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900263 ER PT J AU Dryagin, YA Parshin, VV Krupnov, AF Gopalsami, N Raptis, AC AF Dryagin, YA Parshin, VV Krupnov, AF Gopalsami, N Raptis, AC TI Precision broadband wavemeter for millimeter and submillimeter range SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB A precise, broadband, Fabry-Perot wavemeter has been designed and built to measure wavelengths in the millimeter and submillimeter range. The design of the wavemeter is novel in that it enhances the fundamental mode over a wide band and permits determination of the exact longitudinal index of the mode. With the use of an exact mode number in wavelength calculations, high measurement accuracies, to the extent permissible by the quality factor of the resonator, can be obtained. The wavemeter was tested by measuring well-known spectral lines of the OCS molecule in the frequency range of 72-607 GHz. Measurement of 24 OCS lines demonstrated an accuracy of better than 2 x 10(-5) in relative units and 0.87 x 10(-5) in rms units for frequency/wavelength. A discussion of further development and automation of the wavemeter is included. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Dryagin, YA (reprint author), RUSSIAN ACAD SCI,INST APPL PHYS,GSP-120,NIZHNII NOVGOROD 603600,RUSSIA. NR 12 TC 6 Z9 6 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD SEP PY 1996 VL 44 IS 9 BP 1610 EP 1613 DI 10.1109/22.536616 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA VH032 UT WOS:A1996VH03200018 ER PT J AU Lee, TY Raghavendra, CS Nicholas, JB AF Lee, TY Raghavendra, CS Nicholas, JB TI Image composition schemes for sort-last polygon rendering on 2D mesh multicomputers SO IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS LA English DT Article DE sort-last-full; sort-last-sparse; polygon rendering; image composition; message-passing multicomputer system ID PARALLEL AB In a sort-last polygon rendering system, the efficiency of image composition is very important for achieving fast rendering. In this paper, the implementation of a sort-last rendering system on a general purpose multicomputer system is described. A two-phase sort-last-full image composition scheme is described first, acid then many variants of it are presented for 2D mesh message-passing multicomputers, such as the Intel Delta and Paragon. All the proposed schemes are analyzed and experimentally evaluated on Caltech's Inter Delta machine for our sort-last parallel polygon renderer. Experimental results show that sort-last-sparse strategies are better suited than sort-last-full schemes for software implementation on a general purpose multicomputer system. Further, interleaved composition regions perform better than coherent regions. In a large multicomputer system, performance can be improved by carefully scheduling the tasks of rendering and communication. Using 512 processors to render our test scenes, the peak rendering rate achieved on a 262,144 triangle dataset is close to 4.6 million triangles per second which is comparable to the speed of current state-of-the-art graphics workstations. C1 WASHINGTON STATE UNIV, SCH ELECT ENGN & COMP SCI, PULLMAN, WA 99164 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Lee, TY (reprint author), NANTAI COLL, DEPT INFORMAT MANAGEMENT, TAINAN, TAIWAN. NR 32 TC 33 Z9 34 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1077-2626 J9 IEEE T VIS COMPUT GR JI IEEE Trans. Vis. Comput. Graph. PD SEP PY 1996 VL 2 IS 3 BP 202 EP 217 DI 10.1109/2945.537304 PG 16 WC Computer Science, Software Engineering SC Computer Science GA VL564 UT WOS:A1996VL56400003 ER PT J AU Cline, CF AF Cline, CF TI Dynamic compaction of ceramic powders SO INDUSTRIAL CERAMICS LA English DT Article AB Dynamic consolidation is a technique for densifying powder ensembles to near theoretical with or without external application of heat. The technique itself is simple: the confined powder, initially at a green density of similar to 50%, encounters a high pressure shock wave which exceeds the yield strength and densifies as the wave proceeds through the compact. The time scales and pressure range from 1-10's of microseconds and 10-100's of kilobars (10 Kb = 1 GPa). The short time scale of the pressure pulse during the compaction stage inhibits kinetic processes which have longer time constants. The pressure pulse can be delivered to the green compact by a number of techniques, i. e. high explosive, projectile. The methods differ in the degree that one can control the amplitude, duration, and nature of the pressure pulse. The paper will compare powders compacted by explosive and light gas guns and when possible characterize their resulting structures and properties. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. NR 29 TC 1 Z9 1 U1 2 U2 2 PU TECHNA SRL PI FAENZA PA PO BOX 174, 48018 FAENZA, ITALY SN 1121-7588 J9 IND CERAM JI Ind. Ceram. PD SEP-DEC PY 1996 VL 16 IS 3 BP 189 EP 194 PG 6 WC Materials Science, Ceramics SC Materials Science GA WC972 UT WOS:A1996WC97200008 ER PT J AU Bunz, AP Barron, AE Prausnitz, JM Blanch, HW AF Bunz, AP Barron, AE Prausnitz, JM Blanch, HW TI Capillary electrophoretic separation of DNA restriction fragments in mixtures of low- and high-molecular-weight hydroxyethylcellulose SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID CROSS-LINKED POLYACRYLAMIDE; ENTANGLED POLYMER-SOLUTIONS; FREE-ZONE ELECTROPHORESIS; GEL-ELECTROPHORESIS; HIGH-RESOLUTION; CELLULOSE; REPTATION; MOBILITY AB Previous studies (Barren et al., 1993, 1994) have shown that dilute aqueous solutions of hydroxyethylcellulose (HEC) polymers provide an excellent alternative to gel-based DNA separation media for capillary electrophoresis (CE) of DNA restriction fragments (72-23 130 base pairs). DNA separation by CE in HEC solutions is strongly influenced by the average HEC molecular weight as well as by the HEC concentration in the electrophoresis buffer. Here we describe a systematic investigation of the effects of a mixture of low- and high-molecular weight HEC polymers, over a range of concentrations, to form a DNA separation medium with a broad range of polymer chain lengths. Our results show that, relative to separation media containing solely low-molecular-weight or high-molecular-weight HEC polymers, the mixed polymer solutions provide superior separation over the DNA size range of interest, while providing a five-fold viscosity reduction. The addition of a very small amount of high-molecular-weight HEC to a solution of low-molecular-weight HEC leads to a significant improvement in the separation of larger DNA fragments (>603 base pairs), while retaining resolution of smaller DNA fragments. The consequences of these results on the proposed mechanism of DNA separation in un-cross-linked polymer solutions are discussed. C1 UNIV CALIF BERKELEY,DIV CHEM SCI,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RI Barron, Annelise/B-7639-2009 NR 44 TC 22 Z9 22 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD SEP PY 1996 VL 35 IS 9 BP 2900 EP 2908 DI 10.1021/ie950699v PG 9 WC Engineering, Chemical SC Engineering GA VF785 UT WOS:A1996VF78500011 ER PT J AU Guell, DC Brenner, H AF Guell, DC Brenner, H TI Physical mechanism of membrane osmotic phenomena SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID OSMOSIS; DIFFUSION; PRESSURE AB The microscale, physicomechanical cause of osmosis and osmotic pressure in systems involving permeable and semipermeable membranes is not well understood, and no fully satisfactory mechanism has been offered to explain these phenomena. A general theory, albeit limited to dilute systems of inert, noninteracting solute particles, is presented which demonstrates that short-range forces exerted by the membrane on the dispersed solute particles constitute the origin of osmotic phenomena. At equilibrium, the greater total force exerted by the membrane on those solute particles present in the reservior containing the more concentrated of the two solutions bathing the membrane is balanced by a macroscopically observable pressure difference between the two reservoirs. The latter constitutes the so-called osmotic pressure difference. Under nonequilibrium conditions, the membrane-solute force is transmitted to the solvent, thus driving the convective flow of solvent observed macroscopically as osmosis. While elements of these ideas have been proposed previously in various forms, the general demonstration offered here of the physicomechanical source of osmotic phenomena is novel. Beyond the purely academic interest that exists in establishing a mechanical understanding of osmotic pressure, our analysis lays the foundation underlying a quantitative theory of osmosis in dilute, nonequilibrium systems outlined in a companion paper. C1 MIT,DEPT CHEM ENGN,CAMBRIDGE,MA 02139. RP Guell, DC (reprint author), LOS ALAMOS NATL LAB,MS G755,POB 1663,LOS ALAMOS,NM 87545, USA. NR 56 TC 9 Z9 10 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD SEP PY 1996 VL 35 IS 9 BP 3004 EP 3014 DI 10.1021/ie950787f PG 11 WC Engineering, Chemical SC Engineering GA VF785 UT WOS:A1996VF78500025 ER PT J AU Buczak, AL Uhrig, RE AF Buczak, AL Uhrig, RE TI Hybrid fuzzy - Genetic technique for multisensor fusion SO INFORMATION SCIENCES LA English DT Article ID DECISION-MAKING AB This paper describes a novel hierarchical fuzzy-genetic information fusion technique. The reasoning takes place by means of fuzzy aggregation functions, capable of combining information by compensatory connectives that better mimic the human reasoning process than union and intersection, employed in traditional set theories. The parameters of the connectives are found by genetic algorithms. The distinctive feature of the algorithm developed is its capability of fusing data in a near optimal manner when no information about the reliability of the information sources, the degree of redundancy/complementarity of the information sources, and the structure of the hierarchy exists. C1 UNIV TENNESSEE,KNOXVILLE,TN 37916. OAK RIDGE NATL LAB,KNOXVILLE,TN 37916. RP Buczak, AL (reprint author), ALLIED SIGNAL INC,RES & TECHNOL,MORRISTOWN,NJ 07962, USA. NR 14 TC 15 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0020-0255 J9 INFORM SCIENCES JI Inf. Sci. PD SEP PY 1996 VL 93 IS 3-4 BP 265 EP 281 DI 10.1016/0020-0255(96)00078-3 PG 17 WC Computer Science, Information Systems SC Computer Science GA VD400 UT WOS:A1996VD40000005 ER PT J AU Richardson, TB Koetzle, TF Crabtree, RH AF Richardson, TB Koetzle, TF Crabtree, RH TI An M-H center dot center dot center dot H-C hydrogen bonding interaction SO INORGANICA CHIMICA ACTA LA English DT Article DE metal hydride complexes; aryl phosphine complexes; metal hydrogen carbon hydrogen interaction ID RAY CRYSTAL-STRUCTURE; MOLECULAR-STRUCTURE; NEUTRON-DIFFRACTION; OXIDATIVE ADDITION; METAL-COMPLEXES; DIHYDROGEN; IRIDIUM(I); ACTIVATION; REACTIVITY; HYDRIDES AB Study of several X-ray and neutron diffraction crystal structures of aryl phosphine hydride complexes shows that abnormally close CH...HM contacts (1.6-2.1 Angstrom) commonly occur between the arene CH bonds and the hydride. The data suggest that weak CH...HM hydrogen bonds are involved, resembling those we have previously characterized for the NH...HM case. Based on these results, a new mechanism is suggested for cyclometallation. C1 YALE UNIV,DEPT CHEM,NEW HAVEN,CT 06520. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. NR 33 TC 54 Z9 54 U1 2 U2 5 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 SEP PY 1996 VL 250 IS 1-2 BP 69 EP 73 DI 10.1016/S0020-1693(96)05212-7 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VV296 UT WOS:A1996VV29600010 ER PT J AU Belikov, SV White, S Gutnikov, YE Denisov, AG Dyachkov, AI Zharkov, VV Kistenev, EP Kochetkov, VI Makeev, AV Makeev, VV Melnikov, EA Usachev, AP AF Belikov, SV White, S Gutnikov, YE Denisov, AG Dyachkov, AI Zharkov, VV Kistenev, EP Kochetkov, VI Makeev, AV Makeev, VV Melnikov, EA Usachev, AP TI Characteristics of wavelength-shifting fibers for the electromagnetic calorimeter of the PHENIX system SO INSTRUMENTS AND EXPERIMENTAL TECHNIQUES LA English DT Article AB We studied the characteristics of some domestically-produced wavelength-shifting fibers, featuring various re-emitting additives and various core materials (polystyrene and polymethyl metacrylate). Characteristics of BCF-92, BCF-99(29A), and BCF-99(29B) by Bicron were also measured. Absorption and scintillation spectra of the fibers are shown. Values of the Light yield, the attenuation length and the scintillation decay time of the fibers are presented. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. AO POLIMERSINTEZ,VLADIMIR,RUSSIA. RP Belikov, SV (reprint author), INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 0020-4412 J9 INSTRUM EXP TECH+ JI Instrum. Exp. Tech. PD SEP-OCT PY 1996 VL 39 IS 5 BP 665 EP 673 PG 9 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA VY526 UT WOS:A1996VY52600007 ER PT J AU Mebel, AM Lin, MC Morokuma, K Melius, CF AF Mebel, AM Lin, MC Morokuma, K Melius, CF TI Theoretical study of reactions of N2O with NO and OH radicals SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID DENSITY-FUNCTIONAL THERMOCHEMISTRY; POTENTIAL-ENERGY SURFACE; MOLECULAR-ENERGIES; NITROUS-OXIDE; 2ND-ROW COMPOUNDS; GAUSSIAN-1 THEORY; DECOMPOSITION; FREQUENCIES; COMBUSTION; KINETICS AB The reactions of N2O with NO and OH radicals have been studied using ab initio molecular orbital theory. The energetics and molecular parameters, calculated by the modified Gaussian-2 method (G2M), have been used to compute the reaction rate constants on the basis of the TST and RRKM theories. The reaction N2O + NO --> N-2 + NO2 (1) was found to proceed by direct oxygen abstraction and to have a barrier of 47 kcal/mol. The theoretical rate constant, k(1) = 8.74 x 10(-19) x T-2 23 exp (-23,292/T) cm(3) molecule(-1) s(-1), is in close agreement with earlier estimates, The reaction of N2O with OH at low temperatures and atmospheric pressure is slow and dominated by association, resulting in the HONNO intermediate. The calculated rate constant for 300 K less than or equal to T less than or equal to 500 K is lower by a few orders than the upper limits previously reported in the literature. At temperatures higher than 1000 K, the N2O + OH reaction is dominated by the N-2 + O2H channel, while the HNO + NO channel is slower by 2-3 orders of magnitude. The calculated rate constants at the temperature range of 1000-5000 K for N2O + OH --> N-2 + O2H (2A) and N2O + CH --> HNO + NO (2B) are fitted by the following expressions: k(2A) = 2.15 x 10(-26) x T-4 72 x exp(-18,400/T), k(2B) = 1.96 x 10(-28) x T-4 33 x exp(-12,623/T), in units of cm(3) molecule(-1) s(-1) enhance, albeit inefficiently the N2O decomposition by reducing its activation energy. (C) 1996 John Wiley & Sons, Inc. C1 EMORY UNIV, DEPT CHEM, ATLANTA, GA 30322 USA. EMORY UNIV, CHERRY L EMERSON CTR SCI COMP, ATLANTA, GA 30322 USA. SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94550 USA. RI Mebel, Alexander/A-5234-2009 NR 40 TC 19 Z9 19 U1 0 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD SEP PY 1996 VL 28 IS 9 BP 693 EP 703 PG 11 WC Chemistry, Physical SC Chemistry GA VB770 UT WOS:A1996VB77000008 ER PT J AU Xiong, DM Marble, DF AF Xiong, DM Marble, DF TI Strategies for real-time spatial analysis using massively parallel SIMD computers: An application to urban traffic flow analysis SO INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SYSTEMS LA English DT Article AB The current research focuses upon the development of a methodology for undertaking real-time spatial analysis in a supercomputing environment, specifically using massively parallel SIMD computers. Several approaches that can be used to explore the parallelization characteristics of spatial problems are introduced. Within the focus of a methodology directed toward spatial data parallelism, strategies based on both location-based data decomposition and object-based data decomposition are proposed and a programming logic for spatial operations at local, neighborhood and global levels is also recommended. An empirical study of real-time traffic flow analysis shows the utility of the suggested approach for a complex, spatial analysis situation. The empirical example demonstrates that the proposed methodology, especially when combined with appropriate programming strategies, is preferable in situations where critical, real-time, spatial analysis computations are required. The implementation of this example in a parallel environment also points out some interesting theoretical questions with respect to the theoretical basis underlying the analysis of large networks. C1 OHIO STATE UNIV, DEPT GEOG, COLUMBUS, OH 43210 USA. RP OAK RIDGE NATL LAB, CTR TRANSPORTAT ANAL, OAK RIDGE, TN 37831 USA. NR 26 TC 15 Z9 15 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0269-3798 J9 INT J GEOGR INF SYST JI Int. J. Geogr. Inf. Syst. PD SEP PY 1996 VL 10 IS 6 BP 769 EP 789 DI 10.1080/02693799608902109 PG 21 WC Geography; Information Science & Library Science SC Geography; Information Science & Library Science GA VD543 UT WOS:A1996VD54300007 ER PT J AU Palmer, BJ Drost, MK Welty, JR AF Palmer, BJ Drost, MK Welty, JR TI Monte Carlo simulation of radiative heat transfer in arrays of fixed discrete surfaces using cell-to-cell photon transport SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article AB An accurate simulation of radiative heat transfer in arrays of fixed discrete surfaces is challenging because of the complicated geometries that can shade and block many surfaces. This paper presents an innovative Monte Carlo scheme using cell-to-cell photon transport developed to simulate monochromatic radiation impinging on an array of fixed discrete elements. Results of the study show that cell-to-cell photon transport is an efficient method of simulating radiation heat transfer in complicated geometries. Sample calculations demonstrate the dependence of radiation heat transfer in the array on the geometry of the array elements. Copyright (C) 1996 Elsevier Science Ltd. C1 PACIFIC NW LAB, DIV ENERGY, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENERGY & ENVIRONM SCI DIV, RICHLAND, WA 99352 USA. OREGON STATE UNIV, CORVALLIS, OR 97331 USA. NR 10 TC 6 Z9 6 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 1996 VL 39 IS 13 BP 2811 EP 2819 DI 10.1016/0017-9310(95)00340-1 PG 9 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA UN180 UT WOS:A1996UN18000017 ER PT J AU Forsythe, C AF Forsythe, C TI Cognition in the wild - Hutchins,E SO INTERNATIONAL JOURNAL OF HUMAN FACTORS IN MANUFACTURING LA English DT Book Review RP Forsythe, C (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1045-2699 J9 INT J HUM FACTOR MAN JI Int. J. Hum. Factor Manuf. PD FAL PY 1996 VL 6 IS 4 BP 399 EP 400 PG 2 WC Engineering, Manufacturing; Ergonomics SC Engineering GA VJ519 UT WOS:A1996VJ51900007 ER PT J AU Sim, A Parvin, B Keagy, P AF Sim, A Parvin, B Keagy, P TI Invariant representation and hierarchical network for inspection of nuts from X-ray images SO INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY LA English DT Article ID ARTIFICIAL NEURAL NETWORKS; WHEAT RADIOGRAPHS; SCALE; RESOLUTION AB An X-ray based system for the inspection of pistachio nuts and wheat kernels for internal insect infestation is presented. The novelty of this system is twofold. First, we construct an invariant representation of infested nuts from X-ray images that is rich, robust, and compact. Insect infestation creates a tunnel, in the X-ray image, with reduced density of the natural material. The tunneling effect is encoded by linking troughs on the image and constructing a joint curvature-proximity distribution table for each nut. The latter step is designed to accentuate separation of those tunneling effects that are due to the natural structure of the nut. Second, since the representation is sparse, we partition the joint distribution table into several regions, where each region is used independently to train a backpropagation (BP) network. The outputs of these subnets are then collectively trained with another BP network. We show that the resulting hierarchical network has the advantage of reduced dimensionality while maintaining a performance similar to the standard BP network. (C) 1996 John Wiley & Sons, Ind. C1 USDA ARS, WESTERN REG RES CTR, ALBANY, CA 94710 USA. RP Sim, A (reprint author), LAWRENCE BERKELEY LAB, ICSD, IMAGING TECHNOL GRP, MS 50B-2239, BERKELEY, CA 94720 USA. NR 24 TC 2 Z9 2 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0899-9457 J9 INT J IMAG SYST TECH JI Int. J. Imaging Syst. Technol. PD FAL PY 1996 VL 7 IS 3 BP 231 EP 237 DI 10.1002/(SICI)1098-1098(199623)7:3<231::AID-IMA11>3.0.CO;2-1 PG 7 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA VK198 UT WOS:A1996VK19800012 ER PT J AU Chaturvedi, L Babu, BRS Hamilton, JH Ramayya, AV Ma, WC Zhu, SJ Kormicki, J Petrovici, A Schmid, KW Faessler, A Johnson, NR Lee, IY Baktash, C McGowan, FK Halbert, ML Riley, M Cole, JD AF Chaturvedi, L Babu, BRS Hamilton, JH Ramayya, AV Ma, WC Zhu, SJ Kormicki, J Petrovici, A Schmid, KW Faessler, A Johnson, NR Lee, IY Baktash, C McGowan, FK Halbert, ML Riley, M Cole, JD TI Negative parity states in Ge-68: Experiment and theory SO INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS LA English DT Article ID MULTIPLE BAND STRUCTURES; SHAPE COEXISTENCE; NUCLEI; SE-72 AB High spin hegative parity states have been studied in Ge-68 via in-beam gamma-ray spectroscopy at HHIRF. Several close-lying 7(-), 9(-), and 11(-) states are observed with a 13(-) to tentatively 17(-) cascade feeding them. Numerous E1 crossing transitions between the negative and positive parity levels are observed, along with possible M1 connecting transitions between the low lying negative parity bands. Previous microscopic calculations of the shape coexisting positive parity levels have been extended to the negative parity levels. The calculations used the EXCITED VAMPIR model based on complex HFB transformations with neutron-proton correlations and parity mixing in the mean field. The complex decay pattern and multiple high spin negative parity bands can be explained by a variable strength of mixing of the different deformed configurations which are bunched in small excitation intervals. C1 VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. BANARAS HINDU UNIV,DEPT PHYS,VARANASI 221005,UTTAR PRADESH,INDIA. JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. ORISE,UNISOR,OAK RIDGE,TN 37831. INST PHYS & NUCL ENGN,BUCHAREST,ROMANIA. UNIV TUBINGEN,INST THEORET PHYS,D-72076 TUBINGEN,GERMANY. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. IDAHO NUCL ENGN LAB,IDAHO FALLS,ID. NR 9 TC 2 Z9 2 U1 2 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-3013 J9 INT J MOD PHYS E JI Int. J. Mod. Phys. E-Nucl. Phys. PD SEP PY 1996 VL 5 IS 3 BP 565 EP 574 DI 10.1142/S021830139600030X PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VQ294 UT WOS:A1996VQ29400010 ER PT J AU Asay, BW Son, SF Bdzil, JB AF Asay, BW Son, SF Bdzil, JB TI The role of gas permeation in convective burning SO INTERNATIONAL JOURNAL OF MULTIPHASE FLOW LA English DT Article DE gas permeation in porous beds; convective burning; explosives; energetic materials; combustion; deflagration-to-detonation transition (DDT) ID FLOW AB Convective burning is commonly identified in the literature as the key step in deflagration-to-detonation transition (DDT) of granular explosives. The prevalent physical picture of convective burning is of rapid and deep penetration of hot gases which controls the propagation rate via convective heat transfer. This investigation includes a review of relevant literature, new transient measurements of permeability at high pressures, and analysis of the experimental results. Results presented here show that deep penetration (many particle diameters) of gas at high velocities is not physically plausible for the low porosity granular beds of interest. The measured permeabilities are consistent with measurements made at lower pressures in similar materials, but are significantly lower than predictions based on beds of spherical particles. The important time and space scales of this experiment are identified. The interface region between the reservoir and porous bed is analysed. The wave hierarchy of the permeation experiment is studied, and short- and long-time limits are investigated using simplified asymptotic analysis. The low-speed flow approximation is also considered for flow within the bed. It is shown that drag dissipation terms in the energy equation cannot be neglected under adiabatic conditions as is commonly done. These results indicate that compaction processes play a larger role than commonly thought, and motivate the consideration of an asymptotic large drag limit of two-phase, two-velocity models. Published by Elsevier Science Ltd. RP Asay, BW (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. OI Son, Steven/0000-0001-7498-2922 NR 44 TC 45 Z9 46 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0301-9322 J9 INT J MULTIPHAS FLOW JI Int. J. Multiph. Flow PD SEP PY 1996 VL 22 IS 5 BP 923 EP 952 DI 10.1016/0301-9322(96)00041-9 PG 30 WC Mechanics SC Mechanics GA VJ847 UT WOS:A1996VJ84700008 ER PT J AU Kimmel, R Kiryati, N AF Kimmel, R Kiryati, N TI Finding the shortest paths on surfaces by fast global approximation and precise local refinement SO INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE LA English DT Article DE shortest paths; minimal geodesic; graph search; curve evolution; path planning; geodesic curvature flow ID LEVEL SET APPROACH; PROPAGATING INTERFACES; 3-DIMENSIONAL CURVES; POLYHEDRAL SURFACES; MINIMAL DISTANCES; ALGORITHMS; FLOW AB Finding the shortest path between points on a surface is a challenging global optimization problem. It is difficult to devise an algorithm that is computationally efficient, locally accurate and guarantees to converge to the globally shortest path. In this paper a two stage coarse-to-fine approach for finding the shortest paths is suggested. In the first stage the algorithm of Ref. 10 that combines a 3D length estimator with graph search is used to rapidly obtain an approximation to the globally shortest path. In the second stage the approximation is refined to become a shorter geodesic curve, i.e., a locally optimal path. This is achieved by using an algorithm that deforms an arbitrary initial curve ending at two given surface points via geodesic curvature shortening flow. The 3D curve shortening how is transformed into an equivalent 2D one that is implemented using an efficient numerical algorithm for curve evolution with fixed end points, introduced in Ref. 9. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. TECHNION ISRAEL INST TECHNOL,DEPT ELECT ENGN,IL-32000 HAIFA,ISRAEL. NR 20 TC 18 Z9 18 U1 2 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-0014 J9 INT J PATTERN RECOGN JI Int. J. Pattern Recognit. Artif. Intell. PD SEP PY 1996 VL 10 IS 6 BP 643 EP 656 DI 10.1142/S0218001496000384 PG 14 WC Computer Science, Artificial Intelligence SC Computer Science GA WR244 UT WOS:A1996WR24400002 ER PT J AU Lucas, JN Hill, FS Burk, CE Cox, AB Straume, T AF Lucas, JN Hill, FS Burk, CE Cox, AB Straume, T TI Stability of the translocation frequency following whole-body irradiation measured in rhesus monkeys SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID IN-SITU HYBRIDIZATION; CHROMOSOME TRANSLOCATIONS; BLOOD-LYMPHOCYTES; RADIATION; PRIMATES; ABERRATIONS; LIBRARIES; DOSIMETRY; YIELDS; PROBES AB Chromosome translocations are persistent indicators of prior exposure to ionizing radiation and the development of 'chromosome painting' to efficiently detect translocations has resulted in a powerful biological dosimetry tool for radiation dose reconstruction. However, the actual stability of the translocation frequency with time after exposure must be measured before it can be used reliably to obtain doses for individuals exposed years or decades previously. Human chromosome painting probes were used here to measure reciprocal translocation frequencies in cells from two tissues of 8 rhesus monkeys (Macaca mulatta) irradiated almost three decades previously. Six of the monkeys were exposed in 1965 to whole-body (fully penetrating) radiation and two were unexposed controls. The primates were irradiated as juveniles to single doses of 0.56, 1.13, 2.00, or 2.25 Gy. Blood lymphocytes (and skin fibroblasts from one individual) were obtained for cytogenetic analysis in 1993, near the end of the animals' lifespans. Results show identical dose-response relationships 28 y after exposure in vivo and immediately after exposure in vitro. Because chromosome aberrations are induced with identical frequencies in vivo and in vitro, these results demonstrate that the translocation frequencies induced in 1965 have not changed significantly during the almost three decades since exposure. Finally, our emerging biodosimetry data for individual radiation workers are now confirming the utility of reciprocal translocations measured by FISH in radiation dose reconstruction. C1 ARMSTRONG LAB,OERT,BROOKS AFB,TX 78235. RP Lucas, JN (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 806,LIVERMORE,CA 94551, USA. NR 35 TC 60 Z9 63 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD SEP PY 1996 VL 70 IS 3 BP 309 EP 318 DI 10.1080/095530096145049 PG 10 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VG310 UT WOS:A1996VG31000008 PM 8800202 ER PT J AU Roff, A Phillips, WS Brown, DW AF Roff, A Phillips, WS Brown, DW TI Joint structures determined by clustering microearthquakes using waveform amplitude ratios SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article ID NEW-MEXICO; STRESS; EARTHQUAKES; LOCATIONS; PATTERNS; PLANES; SLIP; ROCK AB A new method of clustering seismic events has been developed to identify features within a large cloud of microearthquakes induced by the pressurization of a 3.5-km deep, jointed region of granitic rock. The relative amplitudes of shear- and compressional-waves were taken as an expression of the source mechanism for each microearthquake. Then, the events were clustered according to their similarity in S/P ratio and a second criterion, their spatial proximity to each other. Thus, each cluster contains events with closely spaced hypocenters and similar S/P ratios, and therefore a high probability of the same (or very similar)focal mechanism. This method was applied to a data set of 8000 microearthquakes recorded during hydraulic stimulation of the Hot Dry Rock geothermal reservoir at Fenton Hill, New Mexico, located on the western flank of the Valles Caldera. Over 50 clusters of more than 10 events each were identified as planar features and over 20 such clusters were identified as linear features, together containing 15% of the usable events. Two predominant sets of planar features strike north to N45 degrees W, roughly tangent to the ring fault system circling the caldera and dip 60 degrees in either direction. These planes represent joints that may be associated with stress fields accompanying caldera formation. Most observed planes contain significant resolved shear within the current stress field. However, wide ranges of equally probable orientations are not observed, indicating a relatively unbiased sampling of the actual range of joint orientations. Most linear features are oriented parallel to one or both sets of planar features and may be associated with joint intersections or terminations. These results support a reservoir flow model composed of water storage within aseismic joints oriented perpendicular to the minimum stress direction and of limited dimension, connected by high impedance paths along joints striking north to N45 degrees W as defined by the cluster results. Copyright (C) 1996 Elsevier Science Ltd RP Roff, A (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545, USA. NR 14 TC 12 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD SEP PY 1996 VL 33 IS 6 BP 627 EP 639 DI 10.1016/0148-9062(95)00077-1 PG 13 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA VJ664 UT WOS:A1996VJ66400007 ER PT J AU Thapa, BB Goodman, RE AF Thapa, BB Goodman, RE TI Induced wedge test for field measurement of joint friction SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS LA English DT Article RP Thapa, BB (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD SEP PY 1996 VL 33 IS 6 BP 655 EP 657 DI 10.1016/0148-9062(96)00001-0 PG 3 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA VJ664 UT WOS:A1996VJ66400010 ER PT J AU Hosono, M Hosono, MN Haberberger, T Zamora, PO Guhlke, S Bender, H Knapp, FFR Biersack, HJ AF Hosono, M Hosono, MN Haberberger, T Zamora, PO Guhlke, S Bender, H Knapp, FFR Biersack, HJ TI Localization of small-cell lung cancer xenografts with iodine-125-, indium-111-, and rhenium-188-somatostatin analogs SO JAPANESE JOURNAL OF CANCER RESEARCH LA English DT Article DE small-cell lung cancer; octreotide; rhenium-188; xenograft ID RADIOIODINATED SOMATOSTATIN ANALOG; MONOCLONAL-ANTIBODY; RECEPTOR SCINTIGRAPHY; CARCINOMA; OCTREOTIDE; MICE AB We examined the potential of radiolabeled somatostatin analogs, I-125-Tyr-3-octreotide (I-125-octreotide), In-111-DTPA(diethylenetriaminepentaacetatic acid)-D-Phe-1-octreotide (In-111-octreotide), and Re-188-octreotide for targeting small-cell lung cancer (SCLC) in a mouse model, Tyr-3-octreotide was labeled with I-125 by the chloramine T method, and In-111-octreotide was obtained as a kit, while Re-188 was eluted from a W-188/Re-188 generator, and octreotide was directly labeled with Re-188 by reducing disulfide bonds. The I-125-, In-111- and Re-188-octreotides were injected i.v. into athymic mice bearing NCI-H69 tumors, and the biodistributions were determined at 15 min, and 2, 4, 8, and 24 h. Tumor uptakes were 0.5 +/- 0.2, 0.3 +/- 0.1, 0.3 +/- 0.1 %ID/g, and tumor-to-blood ratios were 1.8, 11.9, 1.2 at 8 h for I-125-, In-111-, and Re-188-octreotides, respectively. Accumulations of In-111-octreotide in normal tissues were lower than those of I-125- and Re-188-octreotides. Re-188-octreotide can be used to localize SCLC lesions as efficiently as radioiodinated octreotide. However, In-111-octreotide was the most suitable agent to obtain high tumor-to-normal tissue contrast for localizing SCLC. C1 OSAKA CITY UNIV,SCH MED,DEPT RADIOL,ABENO KU,OSAKA 545,JAPAN. UNIV BONN,DEPT NUCL MED,D-53127 BONN,GERMANY. RHOMED INC,ALBUQUERQUE,NM. OAK RIDGE NATL LAB,DIV HLTH SCI RES,OAK RIDGE,TN 37831. RP Hosono, M (reprint author), SAITAMA MED SCH,SAITAMA MED CTR,DEPT RADIOL,KAWAGOE,SAITAMA 350,JAPAN. NR 21 TC 12 Z9 13 U1 0 U2 0 PU JAPANESE CANCER ASSOCIATION PI TOKYO PA EDITORIAL OFFICE 7TH FLOOR, JOHKOH BLDG 2-23-11, KOISHIKAWA, TOKYO 112, JAPAN SN 0910-5050 J9 JPN J CANCER RES JI Jpn. J. Cancer Res. PD SEP PY 1996 VL 87 IS 9 BP 995 EP 1000 PG 6 WC Oncology SC Oncology GA VL789 UT WOS:A1996VL78900019 PM 8878464 ER PT J AU Mendelsohn, ML AF Mendelsohn, ML TI Somatic cell mutation as a radiation biodosimeter and predictor of cancer risk and aging SO JAPANESE JOURNAL OF CANCER RESEARCH LA English DT Editorial Material ID ATOMIC-BOMB SURVIVORS; GLYCOPHORIN-A LOCUS; PERIPHERAL-BLOOD LYMPHOCYTES; TUMOR SUPPRESSOR GENES; CHROMOSOME-ABERRATIONS; FREQUENCY; ERYTHROCYTES; ASSAY RP Mendelsohn, ML (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550, USA. NR 28 TC 0 Z9 0 U1 0 U2 1 PU JAPANESE CANCER ASSOCIATION PI TOKYO PA EDITORIAL OFFICE 7TH FLOOR, JOHKOH BLDG 2-23-11, KOISHIKAWA, TOKYO 112, JAPAN SN 0910-5050 J9 JPN J CANCER RES JI Jpn. J. Cancer Res. PD SEP PY 1996 VL 87 IS 9 BP COV2 EP COV2 PG 1 WC Oncology SC Oncology GA VL789 UT WOS:A1996VL78900001 ER PT J AU Miller, MK Russell, KF Martin, PM Busch, R Johnson, WL AF Miller, MK Russell, KF Martin, PM Busch, R Johnson, WL TI Characterization of bulk metallic glasses with the atom probe SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID STATISTICAL-ANALYSIS; ALLOYS; NI AB An atom probe field ion microscopy survey of several bulk metallic glasses including the zirconium-based glasses Zr55Al10Ni5Cu30, Zr46.25Ti8.75Ni10Be27.5, Zr41.2Ti13.8Cu12.5Ni10Be22.5, Zr57Nb5Al10Cu15.4Ni12.6, and Zr52.5Ti5Al10Cu17.9Ni14.6, together with two non-zirconium-based glasses Ti34Zr11Cu47Ni8, and Mg65Cu25Y10, is presented. Non random distribution of solute was observed in all these glasses and crystalline regions were observed in the Ti34Zr11Cu47Ni8 and Zr55Al10Ni5Cu30 materials. C1 CALTECH,WM KECK LAB ENGN MAT,PASADENA,CA 91125. RP Miller, MK (reprint author), OAK RIDGE NATL LAB,MICROSCOPY & MICROANALYT SCI GRP,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 11 TC 14 Z9 14 U1 1 U2 5 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 217 EP 222 DI 10.1051/jp4:1996535 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000038 ER PT J AU Miller, MK Horton, JA Cao, WD Kennedy, RL AF Miller, MK Horton, JA Cao, WD Kennedy, RL TI Characterization of the effects of boron and phosphorus additions to the nickel-based superalloy 718 SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID GRAIN-BOUNDARY MICROCHEMISTRY; ATOM-PROBE; SEGREGATION; ASTROLOY AB The effects of controlled additions of boron and phosphorus to Alloy IN-718 have been investigated by atom probe field ion microscopy and transmission electron microscopy. Boron and phosphorous additions are known to improve the creep rupture properties of IN-718. Significant enrichments of boron, phosphorus and carbon were measured at the grain boundaries. Some fine phosphide precipitates were also observed at the grain boundaries. No enrichment of boron or phosphorus was observed at gamma' or gamma '' interfaces. However, the boron and phosphorus additions did slightly increase the stability of the gamma '' precipitates after long term ageing at 704 degrees C. C1 TELEDYNE ALLVAC,MONROE,NC 28110. RP Miller, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 11 TC 17 Z9 17 U1 1 U2 6 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 241 EP 246 DI 10.1051/jp4:1996539 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000042 ER PT J AU Babu, SS David, SA Vitek, JM Miller, MK AF Babu, SS David, SA Vitek, JM Miller, MK TI Atom-probe field-ion microscopy investigation of CMSX-4 Ni-base superalloy laser beam welds SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID NI3AL ALLOYS; CRACKING AB CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy(APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped gamma' precipitates (0.65 to 0.75 volume fraction) within the gamma matrix. APFIM compositions of the gamma and gamma' phases were found to be different from those in the base metal. Concentration profiles across the gamma and gamma' phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the gamma phase. Calculated lattice misfits near the gamma/gamma' interface in the welds are positive values compared to the negative values for base metal. RP Babu, SS (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 17 TC 17 Z9 17 U1 1 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 253 EP 258 DI 10.1051/jp4:1996541 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000044 ER PT J AU Thomson, RC Russell, KF Miller, MK AF Thomson, RC Russell, KF Miller, MK TI An atom probe field ion microscope study of model Ni-Al superalloys containing Be SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID BERYLLIUM; BEHAVIOR AB Atom probe field ion microscopy and transmission electron microscopy have been used to characterise the phases present, and their compositions, in four model NI-AI superalloys containing Be. In agreement with the limited information available on phase stability within the ternary Ni-Al-Be system, atom probe results indicated that these alloys were in the three phase, gamma-Ni, gamma-Ni3Al and beta-NiBe, region of the ternary diagram. Beryllium was found to substitute on the 'Al' sites within the gamma', consistent with previous results from Be-doped NiAl. The experimental results have shown that the Be additions have resulted in the precipitation of phases enriched in Be within the gamma' phase. The morphology of the phases enriched in Be ranged from monatomically thick plates to lenticular precipitates. Hardness measurements indicate significant hardening resulting from the addition of Be to model Ni-Al alloys. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Thomson, RC (reprint author), LOUGHBOROUGH UNIV TECHNOL,INST POLYMER TECHNOL & MAT ENGN,LOUGHBOROUGH LE11 3TU,LEICS,ENGLAND. RI Thomson, Rachel/B-4217-2011 OI Thomson, Rachel/0000-0002-3681-0107 NR 11 TC 3 Z9 3 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 259 EP 264 DI 10.1051/jp4:1996542 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000045 ER PT J AU Miller, MK Kurishita, H AF Miller, MK Kurishita, H TI APFIM characterization of grain boundary segregation in titanium carbide-doped molybdenum SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID ATOM PROBE AB The grain boundary segregation behavior of titanium and carbon have been characterized in two titanium carbide-doped molybdenum alloys. The matrix of these alloys was found to be significantly depleted in titanium, carbon, oxygen, and nitrogen. Both titanium oxycarbide and molydenum carbide precipitates were observed. The Gibbsian Interfacial Excess, Gamma(i) determined from atom probe analyses revealed significant enrichments of carbon and nitrogen at the grain boundaries in both alloys. In atom probe analyses where the carbon level was high at the grain boundary, the oxygen level was below the detection level and conversely, in analyses where the carbon level was low, some oxygen was detected and suggests that carbon has a beneficial effect of displacing the oxygen from the grain boundary. C1 TOHOKU UNIV, MAT RES INST, OARAI, IBARAKI 31113, JAPAN. RP Miller, MK (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, MICROSCOPY & MICROANALYT SCI GRP, POB 2008, OAK RIDGE, TN 37831 USA. NR 12 TC 1 Z9 1 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 265 EP 270 DI 10.1051/jp4:1996543 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000046 ER PT J AU Larson, DJ Camus, PP Vargas, JL Kelly, TF Miller, MK AF Larson, DJ Camus, PP Vargas, JL Kelly, TF Miller, MK TI Specimen preparation and atom probe field ion microscopy of BSCCO-2212 superconductors SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res ID GRAIN-BOUNDARIES; MASS-SPECTROSCOPY; YBA2CU3O7-X; BICRYSTALS; WIRES AB Field ion specimens of Bi2Sr2CaCu2Ox (BSCCO) high temperature superconductor (HTS) materials have been prepared using a combination of three different preparation techniques: the method of sharp shards, electropolishing and ion milling. Field ion microscopy (FIM) has demonstrated that samples which exhibit the ''striped''-image contrast characteristic of HTS materials can be successfully fabricated using this combination. FIM images have been obtained which show the striped-image contrast much clearer than any previously published images of Pb-free BSCCO. Preliminary atom probe (AP) chemical analysis of the material was also performed. Analytical electron microscopy was used to confirm the existence of both the correct crystallographic structure and nominal composition in the near-apex region of the specimen after preparation and FIM. C1 UNIV WISCONSIN,MAT SCI PROGRAM,MADISON,WI 53706. UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. UNIV WISCONSIN,DEPT MAT SCI & ENGN,MADISON,WI 53706. RP Larson, DJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 26 TC 5 Z9 5 U1 0 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 271 EP 276 DI 10.1051/jp4:1996544 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000047 ER PT J AU Miller, MK Thomson, RC AF Miller, MK Thomson, RC TI Characterization of precipitates with the atom probe SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 43rd International Field Emission Symposium (IFES96) CY JUL 14-19, 1996 CL MOSCOW, RUSSIA SP Assoc Ultramicroscopy Sci & Technol, Ctr Anal Subst, Moscow Govt, Moscow Phys Soc, US DOE, Oak Ridge Natl Lab, Basic Energy Sci, Russian Fund Fundamental Res AB The parameters that can be measured from atom probe random area analyses of small spherical precipitates and platelets have been examined with a combination of simulation and geometrical models. The results indicate that the probe aperture should be less than 50% of the diameter of the precipitate in order to reliable measure the true composition in a significant proportion of precipiates. C1 LOUGHBOROUGH UNIV TECHNOL,LOUGHBOROUGH LE11 3TU,LEICS,ENGLAND. RP Miller, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,MICROSCOPY & MICROANALYT SCI GRP,POB 2008,OAK RIDGE,TN 37831, USA. RI Thomson, Rachel/B-4217-2011 OI Thomson, Rachel/0000-0002-3681-0107 NR 3 TC 2 Z9 2 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 1996 VL 6 IS C5 BP 277 EP 282 DI 10.1051/jp4:1996545 PG 6 WC Physics, Multidisciplinary SC Physics GA WF800 UT WOS:A1996WF80000048 ER PT J AU Wayne, DM Yoshida, TM Vance, DE AF Wayne, DM Yoshida, TM Vance, DE TI Analysis of trace impurities in palladium metal powders by glow discharge mass spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT 1996 Winter Conference on Plasma Spectrochemistry CY JAN 08-13, 1996 CL FT LAUDERDALE, FL DE glow discharge mass spectrometry; inductively coupled plasma mass spectrometry; combustion analysis; palladium; carbon; relative sensitivity factor ID RESOLUTION; SOLIDS; PLASMA AB Metals are often analysed for trace impurities using a combination of techniques (i.e., ICP-MS, ICP-AES, combustion, etc.) which offer accurate and precise results for some elements, but not for others. High-resolution glow discharge mass spectrometry (GDMS) offers nearly complete coverage of the periodic table, thus avoiding the necessity of combining results from several techniques to quantitate a wide range of elements in a single sample. GDMS is a direct solids analytical technique, which provides an additional advantage as samples do not have to be dissolved prior to analysis. However, the application of GDMS to the analysis of many important materials, notably the noble metals, is hampered somewhat by a lack of standard reference materials. Reliable standards can be fabricated in-house, but these lack the necessary tracking and certification. The analysis of powdered metals provides additional challenges due to the presence of surface-adsorbed species (H2O, CO2, etc), occluded atmospheric gases, and the remnants of chemical processing. However, GDMS analysis of Pd powders for a wide range of trace impurities (C, Al, Si, Fe, Ni, Co, Zn, Rh, Ag, Cd, Ir, Pt, Au and Pb) provided comparable results to analyses of the same materials by combustion (C), ICP-AES (Si, Fe) and quadrupole ICP-MS (Al, Ni, Cu, Zn, Rh, Ag, Cd, Ir, Pt, An and Pb). RP Wayne, DM (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MAIL STOP G740,LOS ALAMOS,NM 87545, USA. NR 30 TC 12 Z9 15 U1 2 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 1996 VL 11 IS 9 BP 861 EP 869 DI 10.1039/ja9961100861 PG 9 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA VG928 UT WOS:A1996VG92800035 ER PT J AU Yamane, K Takasugi, S Lee, KH AF Yamane, K Takasugi, S Lee, KH TI A new magnetotelluric inversion scheme using generalized RRI method SO JOURNAL OF APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Recent Advances in Exploration Geophysics (RAEG '95) CY NOV 13-14, 1995 CL KYOTO, JAPAN AB A new two-dimensional (2-D) magnetotelluric (MT) inversion scheme is proposed in this paper. This scheme is based on a locally 2-D analysis in order to minimize computational time and computer memory. The MT governing equation is linearized in terms of the magnetic field and electrical conductivity for the perturbation analysis. The perturbed equation is then multiplied by a test function and integrated over the cross-section. Integrating by parts and then substituting this test function with local magnetic fields, a new equation is obtained that is a 2-D variational integral for the electrical conductivity. The new equation is general in the sense that it can explicitly include the horizontal derivative of the magnetic field. If the horizontal derivative term is eliminated, the new equation becomes identical to the Rapid Relaxation Inversion (RRI) scheme proposed by Smith and Booker (J. Geophys. Res., 96: 3905-3922, 1991). C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Yamane, K (reprint author), GEOTHERMAL ENERGY & RES & DEV CO LTD,TOKYO 103,JAPAN. NR 2 TC 6 Z9 7 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 SEP PY 1996 VL 35 IS 2-3 BP 209 EP 213 DI 10.1016/0926-9851(96)00023-7 PG 5 WC Geosciences, Multidisciplinary; Mining & Mineral Processing SC Geology; Mining & Mineral Processing GA WC475 UT WOS:A1996WC47500016 ER PT J AU Rhoades, RL Gorbatkin, SM AF Rhoades, RL Gorbatkin, SM TI Characterization of Ar/Cu electron-cyclotron-resonance plasmas using optical emission spectroscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ION; DEPOSITION AB Optical emission spectroscopy is used to investigate trends with changes in processing parameters for Ar/Cu plasmas in an electron-cyclotron-resonance (ECR) plasma deposition system. The primary motivation for this work is to monitor trends in ionization fractions for copper deposition plasmas using a noninterfering diagnostic tool. The system, which consists of a solid copper sputter target coupled to a permanent magnet ECR microwave plasma system, is operated in the range of 1-6 mTorr argon with net microwave input power of 500-1500 W. Emission from the following excited states is monitored: Ar neutrals (696.5 nm); Ar ions (488 nm); Cu neutrals (521.8 and 216.5 nm); and Cu ions (213.6 nm). Cu ion emission and Cu neutral emission monotonically increase with net microwave input power but at slightly different rates for different pressures, while argon-ion emission as a function of pressure shows a broad peak around 4 mTorr. The ratio of Cu ion emission to Cu neutral emission is used as an indicator of the relative ionization efficiency for Cu and peaks neat 5 mTorr. Spectroscopic estimates of electron temperature differences between pure Ar and Ar/Cu plasmas are also presented. RP Rhoades, RL (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 21 TC 10 Z9 10 U1 0 U2 4 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 SEP 1 PY 1996 VL 80 IS 5 BP 2605 EP 2613 DI 10.1063/1.363177 PG 9 WC Physics, Applied SC Physics GA VE246 UT WOS:A1996VE24600008 ER PT J AU Bukowski, JD Graves, DB Vitello, P AF Bukowski, JD Graves, DB Vitello, P TI Two-dimensional fluid model of an inductively coupled plasma with comparison to experimental spatial profiles SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CYCLOTRON RESONANCE PLASMA; ELECTRON-DISTRIBUTION FUNCTION; ION VELOCITY DISTRIBUTIONS; CROSS-SECTIONS; REFERENCE CELL; CHLORINE; DENSITY; TRANSPORT; DISCHARGE; FIELD AB A key need for the development and testing of models suitable for chemically active, low pressure plasmas is detailed comparisons between model predictions and experimental measurements. In this paper, a two-dimensional, axisymmetric fluid model of an inductively coupled plasma is described, and model predictions are compared to the experimental measurements of P. A. Miller, G. A. Hebner, K. E. Greenberg, P. D. Pochan, and B. P. Aragon [J. Res. Natl. Inst. Stand. Technol. 100, 427 (1995)] of electron density, electron temperature, and plasma potential. Comparisons between model predictions and experimental measurements were made in argon and chlorine discharges. Qualitative to semiquantitative agreement between the model predictions and experimental diagnostics was observed, suggesting that assumptions made in the model are reasonably accurate. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. NR 39 TC 120 Z9 124 U1 3 U2 15 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 SEP 1 PY 1996 VL 80 IS 5 BP 2614 EP 2623 DI 10.1063/1.363169 PG 10 WC Physics, Applied SC Physics GA VE246 UT WOS:A1996VE24600009 ER PT J AU Hebner, GA AF Hebner, GA TI Spatially resolved, excited state densities and neutral and ion temperatures in inductively coupled argon plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CYCLOTRON RESONANCE PLASMA; ELECTROMAGNETIC-FIELDS; ENERGY-DISTRIBUTIONS; REFERENCE CELL; RF DISCHARGE; ELECTRON; EMISSION AB Spatially resolved, line integrated, excited state densities, and neutral and ion temperatures have been measured in inductively coupled argon plasmas. Absorption spectroscopy was used to measure the line integrated density and temperature of the argon 1s(5), 1s(4), 1s(3), and 1s(2) energy levels. Laser-induced fluorescence was used to confirm the neutral temperatures and to measure argon metastable ion temperatures. For rf powers between 50 and 300 W and pressures of 4-50 mTorr, the line integrated density of the 1s(5) energy level varied between 1x10(16) and 2X10(16) m(-2). The densities of the 1s(4), 1s(3), and 1s(2) levels were approximately 4-10 times smaller. In the center of the plasma, the ion and neutral temperatures were identical, between 550 and 1000 K for plasma powers between 30 and 240 W and pressures between 4 and 50 mTorr. The neutral temperature had a maximum in the center of the discharge and decreased towards the edge of the discharge. However, the ion temperature increased to between 3000 and 4000 K at the edge of the discharge. Ion drift velocity in the radial direction was between 1x10(5) and 2x10(5) cm/s at the edge of the plasma. No significant changes in the spatial density distribution or temperature were observed when either a rf bias was applied to the lower electrode or when the stainless-steel lower electrode was covered with a bare silicon wafer. The addition of nitrogen to the argon discharge resulted in the density of the 1s(5) state decreasing by a factor of 2 and the density of the 1s(4) state decreasing by a factor of 10. Implications of these measurements on the radial electric fields, radiation trapping, and the energy transport in the plasma are discussed. RP Hebner, GA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 43 TC 124 Z9 124 U1 2 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1996 VL 80 IS 5 BP 2624 EP 2636 DI 10.1063/1.363178 PG 13 WC Physics, Applied SC Physics GA VE246 UT WOS:A1996VE24600010 ER PT J AU Romana, LJ Rankin, J Brewster, JR Boatner, LA Williams, AM AF Romana, LJ Rankin, J Brewster, JR Boatner, LA Williams, AM TI Stability of ion-implanted layers on MgO under ultrasonic cavitation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RADIATION-DAMAGE; SINGLE-CRYSTALS; AMORPHIZATION; POTASSIUM AB The effects of ion implantation and ultrasonic cavitation on the near-surface region of MgO single crystals were investigated. For 150 keV, room-temperature implantations of Ar+ or K+ at 5x10(16)-10(17) ions cm(-2) into a (100)-oriented surface of MgO, a dilatometric swelling of the implanted layer is observed perpendicular to the implanted surface. When these strained Surface layers are then subjected to an ultrasonic (similar to 20 kHz) cavitation treatment, uniform layers (similar to 100-200 nm) can be removed from the MgO surface in a controlled manner. The thickness of the removed layer is directly related to the duration of the ultrasonic irradiation, but does not exceed the depth of the implanted species. When MgO implanted with Ar+ or Kr+ at fluences of 5x10(16)-10(17) ions cm(-2) is subsequently irradiated with 2 MeV He+ ions at 10(16)-10(17) ions cm(-2), the region exposed to the He+ beam is effectively ''stabilized'' and is not removed by the ultrasonic treatment. K+ or Ar+ implantations at <5x10(16) ions cm(-2) produced no swelling of the layer, and subsequent ultrasonic irradiation with an energy flux of similar to 120 W cm(-2) did not remove the crystal surface as determined by profilometry, For MgO implanted with >2x10(17) ions cm(-2), the implanted layer is highly strained and detaches from the underlying crystal without exposure to ultrasonic-cavitation effects. These findings are discussed in terms of the stressed states of the implanted layers, and their potential applications to the mechanical ''etching'' of ceramics are considered. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 33 TC 2 Z9 2 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 SEP 1 PY 1996 VL 80 IS 5 BP 2781 EP 2787 DI 10.1063/1.363195 PG 7 WC Physics, Applied SC Physics GA VE246 UT WOS:A1996VE24600031 ER PT J AU Joswick, MD Campbell, IH Barashkov, NN Ferraris, JP AF Joswick, MD Campbell, IH Barashkov, NN Ferraris, JP TI Systematic investigation of the effects of organic film structure on light emitting diode performance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID POLYMER; TRANSPORT; ELECTRON; MOBILITY; DEVICES AB We present a systematic investigation of the effects of organic film structure on light emitting diode (LED) performance. Metal/organic film/metal LEDs were fabricated using a five ring, poly(phenylene vinylene) related oligomer as the active layer. The structure of the vacuum evaporated oligomer films was varied from amorphous to polycrystalline by changing the substrate temperature during deposition. The intrinsic properties of the oligomer films and the LED performance were measured. The measured intrinsic film properties include: optical absorption, photoluminescence (PL) spectra, PL lifetime, PL efficiency, and effective carrier mobility. The measured device characteristics include current-voltage, capacitance-voltage, electroluminescence (EL) efficiency, and the contact metal/organic film Schottky barrier heights. The optical absorption and PL properties of the films are weakly dependent on film structure but the effective carrier mobility decreases with increasing crystallinity. The EL quantum efficiency decreases by more than one order of magnitude, the drive voltage at a fixed current increases, and the electron Schottky barrier height increases as the crystallinity of the film is increased. The diode current-voltage characteristic is determined by the dominant hole current and the electroluminescence efficiency is controlled by the contact limited electron injection. These results demonstrate significant effects of organic film structure on the performance of organic LEDs. (C) 1996 American Institute of Physics. C1 UNIV TEXAS,RICHARDSON,TX 75080. RP Joswick, MD (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 23 TC 60 Z9 63 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 1996 VL 80 IS 5 BP 2883 EP 2890 DI 10.1063/1.363140 PG 8 WC Physics, Applied SC Physics GA VE246 UT WOS:A1996VE24600045 ER PT J AU Dobson, JE AF Dobson, JE TI A palaeogeographic link between Australia and eastern North America: A New England connection? SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE graptolites; continental drift; plate tectonics; palaeogeography; palaeontology; lithology ID SOUTHERN APPALACHIANS; CONTINENTAL-DRIFT; PALEOGEOGRAPHY; LAURENTIA; TECTONICS; SEQUENCES; HOTSPOTS; GONDWANA; TERRANES AB This research tests the hypothesis that Australia and eastern North America met in rotational collision during the Palaeozoic with the corollary that the New England fold belt of Australia, rather than the Reguibat promontory of Africa, collided with the Alleghanian orogen in the central Appalachians. Identical Lancefieldian-stage, zone 1 (Early Ordovician) graptolites of the Anisograptid family are found in identical environments in Newfoundland, Norway, and the Lachlan fold belt of Australia. Palaeozoic granites are consistent with a tectonic model in which the Lachlan fold belt caused mechanical deformation of the Canadian Appalachians. The Lachlan and New England fold belts of Australia and the Alleghanian orogen of North America are tectonically consistent with the east coast hypothesis. Major deformations and magmatic episodes are coeval from Silurian to Permian. The tectonic, palaeontologic, lithologic, and geometric evidence for this position is more abundant and precise than the stratigraphic evidence for a west coast location of Australia relative to North America. RP Dobson, JE (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 43 TC 2 Z9 2 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0305-0270 J9 J BIOGEOGR JI J. Biogeogr. PD SEP PY 1996 VL 23 IS 5 BP 609 EP 617 DI 10.1111/j.1365-2699.1996.tb00021.x PG 9 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA WC494 UT WOS:A1996WC49400001 ER PT J AU Campbell, AA Fryxell, GE Linehan, JC Graff, GL AF Campbell, AA Fryxell, GE Linehan, JC Graff, GL TI Surface-induced mineralization: A new method for producing calcium phosphate coatings SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article ID INTERFACE; IMPLANTS AB Calcium phosphate coatings were nucleated and grown from aqueous solution onto titanium metal substrates via surface-induced mineralization (SIM) processing techniques. This process is based on the observation that in nature organisms use biopolymers to produce ceramic composites, such as teeth, bones, and shells. The SIM process involves modification of a surface to introduce surface functionalization followed by immersion in aqueous supersaturated calcium phosphate solutions. This low-temperature process (< 100 degrees C) has advantages over conventional methods of calcium phosphate deposition in that uniform coatings are produced onto complex-shaped and/or microporous samples. Additionally, because it is a low-temperature process, control of the phase and crystallinity of the deposited material can be maintained. (C) 1996 John Wiley & Sons, Inc. RP Campbell, AA (reprint author), PACIFIC NW LAB, DEPT CHEM & MAT SCI, POB 999, RICHLAND, WA 99352 USA. NR 23 TC 93 Z9 100 U1 0 U2 18 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD SEP PY 1996 VL 32 IS 1 BP 111 EP 118 DI 10.1002/(SICI)1097-4636(199609)32:1<111::AID-JBM13>3.0.CO;2-P PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA VC839 UT WOS:A1996VC83900014 PM 8864879 ER PT J AU Good, LF Dimri, GP Campisi, J Chen, KY AF Good, LF Dimri, GP Campisi, J Chen, KY TI Regulation of dihydrofolate reductase gene expression and E2F components in human diploid fibroblasts during growth and senescence SO JOURNAL OF CELLULAR PHYSIOLOGY LA English DT Article ID CELLULAR TRANSCRIPTION FACTOR; CYCLE-DEPENDENT GENES; BINDING PROTEIN; IN-VIVO; FAMILY MEMBERS; DNA-SYNTHESIS; G1/S PHASE; CELLS; PROMOTER; PRODUCT AB The induction of dihydrofolate reductase (DHFR), a key enzyme in DNA biosynthesis that is induced just before the onset of S phase, is markedly attenuated in senescent human fibroblasts (Pang and Chen, 1994, J. Cell. Physiol., 160:531-538). Footprinting analysis of the 365 bp promoter region of the human DHFR gene (-381 to -17) indicated that nuclear proteins bind to a cluster of cis-elements, including two overlapping E2F binding sequences, two SP1 sites, and one Yi sequence. Gel mobility shift assays were performed to assess the role of each cis-element in the regulation of DHFR gene expression. We found that 1) Sp1 binding activity was constitutively expressed throughout the cell cycle in early passage and senescent cells; 2) Yi binding activity was undetectable in both early passage and senescent cells; and 3) E2F binding activity was serum-inducible, senescence-dependent, and prominent in presenescent cells but strikingly diminished in senescent cells. Northern blot analysis of the expression of E2F and DP family members showed that the E2F-1, E2F-4, and E2F-5 mRNA was growth- and senescence-dependent, whereas E2F-3, DP-1, and DP-2 expression was constitutive and senescence-independent. In contrast, E2F-2 mRNA was not detectable in IMR-90 or WI-38 human fibroblasts. Western blot analysis showed that among the E2F-associated proteins, the expression of E2F-1, cyclin A, and cyclin B but not p107 was cell cycle- and senescence-dependent. A nuclear extract mixing experiment suggested that an inhibitory factor may further reduce E2F binding activity in senescent cells. (C) 1996 Wiley-Liss, Inc. C1 RUTGERS STATE UNIV,DEPT CHEM,PISCATAWAY,NJ 08855. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DEPT CANC BIOL,BERKELEY,CA 94720. FU NIA NIH HHS [AG03578, AG09909] NR 44 TC 31 Z9 32 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9541 J9 J CELL PHYSIOL JI J. Cell. Physiol. PD SEP PY 1996 VL 168 IS 3 BP 580 EP 588 DI 10.1002/(SICI)1097-4652(199609)168:3<580::AID-JCP10>3.0.CO;2-3 PG 9 WC Cell Biology; Physiology SC Cell Biology; Physiology GA VE704 UT WOS:A1996VE70400010 PM 8816912 ER PT J AU Logan, J Fowler, JS Volkow, ND Wang, GJ Ding, YS Alexoff, DL AF Logan, J Fowler, JS Volkow, ND Wang, GJ Ding, YS Alexoff, DL TI Distribution volume ratios without blood sampling from graphical analysis of PET data SO JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM LA English DT Article DE distribution volume; graphical analysis; methylphenidate; positron emission tomography; raclopride ID POSITRON EMISSION TOMOGRAPHY; HUMAN-BRAIN; C-11 RACLOPRIDE; DOPAMINE; BINDING; LIGAND; FLUMAZENIL; MODEL AB The distribution volume ratio (DVR), which is a linear Function of receptor availability, is widely used as a model parameter in imaging studies. The DVR corresponds to the ratio of the DV of a receptor-containing region to a nonreceptor region and generally requires the measurement of an arterial input function, Here we propose a graphical method for determining the DVR that does not require blood sampling. This method uses data from a nonreceptor region with an average tissue-to-plasma efflux; constant (K) over bar(2) to approximate the plasma integral, Data from positron emission tomography studies with [C-11]raclopride (n = 20) and [C-11]d-threomethylphenidate([C-11]dMP) (n = 8) in which plasma data were taken and used to compare results from two graphical methods, one that uses plasma data and one that does not, (k) over bar 2 was 0.163 and 0.051 min(-1) for [C-11]raclopride and [C-11]dMP, respectively. Results front both methods were very similar, and the average percentage difference between the methods was -0.11% for [C-11]raclopride and 0.46% for [C-11]dMP for DVR of basal ganglia (BG) to cerebellum (CB). Good agreement between the two methods was also achieved for DVR images created by both methods. This technique provides an alternative method of analysis not requiring blood sampling that gives equivalent results for the two ligands studied. It requires initial studies with blood sampling to determine the average kinetic constant and to test applicability. In some cases, it may be possible to neglect the (k) over bar(2) term if the BG/CB ratio becomes reasonably constant for a sufficiently long period of time over the course of the experiment. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. RP Logan, J (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NIDA NIH HHS [5R01-DA06891]; NINDS NIH HHS [NS15380] NR 17 TC 889 Z9 893 U1 3 U2 21 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0271-678X J9 J CEREBR BLOOD F MET JI J. Cereb. Blood Flow Metab. PD SEP PY 1996 VL 16 IS 5 BP 834 EP 840 PG 7 WC Endocrinology & Metabolism; Hematology; Neurosciences SC Endocrinology & Metabolism; Hematology; Neurosciences & Neurology GA VE555 UT WOS:A1996VE55500008 PM 8784228 ER PT J AU Xiao, CB Tremaine, PR Simonson, JM AF Xiao, CB Tremaine, PR Simonson, JM TI Apparent molar volumes of La(CF3SO3)(3)(aq) and Gd(CF3SO3)3(aq) at 278 K, 298 K, and 318 K at pressures to 30.0 MPa SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID THERMODYNAMIC PROPERTIES; WATER AB Densities of La(CF3SO3)(3)(aq) and Gd(CF3SO3)(3)(aq) have been measured at 278 K, 298 K, and 318 K at pressures of 0.1 MPa, 7.0 MPa, and 30.0 MPa using vibrating-tube densimeters. Apparent molar volumes obtained from the density data have been fitted to the Fitter equation. The standard partial molar volumes V-phi(infinity) and the ion-interaction parameters beta((0)V) and beta((1)V) have been determined through least-squares fitting to the experimental results. The standard partial molar volume of the trifluoromethanesulfonate anion V-phi(infinity)(CF3SO3-,aq) was calculated at 298 K and 0.1 MPa from the partial molar volumes of the gadolinium and lanthanum salts and the available values for the standard partial molar volumes of the cations. Excellent agreement is obtained for V-phi(infinity)(CF3SO3-,aq) calculated from the data for the two salts. C1 MEM UNIV NEWFOUNDLAND,DEPT CHEM,ST JOHNS,NF A1B 3X7,CANADA. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Tremaine, Peter/F-9814-2015 NR 11 TC 11 Z9 11 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 1996 VL 41 IS 5 BP 1075 EP 1078 DI 10.1021/je960107v PG 4 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA VJ010 UT WOS:A1996VJ01000031 ER PT J AU Ernst, M Bush, S Kolbert, AC Pines, A AF Ernst, M Bush, S Kolbert, AC Pines, A TI Second-order recoupling of chemical-shielding and dipolar-coupling tensors under spin decoupling in solid-state NMR SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; HIGH-RESOLUTION NMR; MAGIC-ANGLE; ROTATING SOLIDS; C-13 NMR; FIELD; SPECTROSCOPY; ENHANCEMENT; SEQUENCE; WALTZ-16 AB The source of the residual line broadening in continuous-wave (cw) decoupled spectra under magic-angle sample spinning conditions is reexamined. It is shown that an important contribution to the line broadening comes from a second-order recoupling of the heteronuclear dipolar-coupling tensor and the chemical-shielding tensor of the irradiated spin. Such an interference between the two tensors leads to a sum of a zeroth-rank, a second-rank, and a fourth-rank tensor component in the Hamiltonian. The zeroth-rank and the fourth-rank tensor components are not averaged out under magic-angle sample spinning (MAS) conditions, requiring the use of higher-order averaging such as double rotation (DOR) for obtaining narrow lines. This broadening is distinctly different from off-resonance decoupling effects which transform as a second-rank tensor and can be averaged out by MAS. The properties of this second-order recoupling as a source of structural information are explored, and the conditions for removing the broadening in systems with weak homonuclear dipolar-coupling networks are discussed. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Ernst, Matthias/A-6732-2010 OI Ernst, Matthias/0000-0002-9538-6086 NR 53 TC 58 Z9 59 U1 2 U2 5 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 SEP 1 PY 1996 VL 105 IS 9 BP 3387 EP 3397 DI 10.1063/1.472224 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VD768 UT WOS:A1996VD76800005 ER PT J AU Compton, RN Carman, HS Desfrancois, C AbdoulCarmine, H Schermann, JP Hendricks, JH Lyapustina, SA Bowen, KH AF Compton, RN Carman, HS Desfrancois, C AbdoulCarmine, H Schermann, JP Hendricks, JH Lyapustina, SA Bowen, KH TI On the binding of electrons to nitromethane: Dipole and valence bound anions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ACETALDEHYDE ENOLATE ANION; PHOTOELECTRON-SPECTROSCOPY; POLAR-MOLECULES; NEGATIVE-IONS; EXCITED-STATE; RYDBERG ATOMS; GROUND-STATE; CLUSTERS; ATTACHMENT; COLLISIONS AB Conventional (valence) and dipole-bound anions of the nitromethane molecule are studied using negative ion photoelectron spectroscopy, Rydberg charge exchange and field detachment techniques. Reaction rates for charge exchange between Cs(ns,nd) and Xe(nf) Rydberg atoms with CH3NO2 exhibit a pronounced maximum at an effective quantum number of n*approximate to 13+/-1 which is characteristic of the formation of dipole-bound anions [mu(CH3NO2)=3.46 D]. However, the breadth (Delta n approximate to 5, FWHM) of the n-dependence of the reaction rate is also interpreted to be indicative of direct attachment into a valence anion state via a ''doorway'' dipole anion state. Studies of the electric field detachment of CH3NO2- formed through the Xe(nf) reactions at various n values provide further evidence for the formation of both a dipole-bound anion as well as a contribution from the valence bound anion. Analysis of the field ionization data yields a dipole electron affinity of 12+/-3 meV. Photodetachment of CH3NO2- and CD3NO2- formed via a supersonic expansion nozzle ion source produces a photoelectron spectrum with a long vibrational progression indicative of a conventional (valence bound) anion with a substantial difference in the equilibrium structure of the anion and its corresponding neutral. Assignment of the origin (v'=0, v ''=0) transitions in the photoelectron spectra of CH3NO2- and CD3NO2- yields adiabatic electron affinities of 0.26+/-0.08 and 0.24+/-0.08 eV, respectively. (C) 1996 American Institute of Physics. C1 UNIV PARIS 13,INST GALILEE,PHYS LASERS LAB,URA CNRS URA 282,F-93439 VILLETANEUSE,FRANCE. JOHNS HOPKINS UNIV,DEPT CHEM,BALTIMORE,MD 21218. RP Compton, RN (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Desfrancois, Charles/M-6741-2015 OI Desfrancois, Charles/0000-0003-2512-4387 NR 37 TC 128 Z9 128 U1 4 U2 20 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 SEP 1 PY 1996 VL 105 IS 9 BP 3472 EP 3478 DI 10.1063/1.472993 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VD768 UT WOS:A1996VD76800014 ER PT J AU McNeil, JD Lingle, RL Jordan, RE Padowitz, DF Harris, CB AF McNeil, JD Lingle, RL Jordan, RE Padowitz, DF Harris, CB TI Interfacial quantum well states of Xe and Kr adsorbed on Ag(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID IMAGE-POTENTIAL STATES; 2-PHOTON PHOTOEMISSION; ELECTRON-SCATTERING; METAL-SURFACES; BAND-STRUCTURE; FILMS; AG; LOCALIZATION; FEMTOSECOND; ADSORPTION AB The energies and dispersions of the image states and quantum well electronic states in layers of Xe and Kr on a Ag(lll) substrate were determined by angle-resolved two-photon photoemission (ARTPPE). For Xe, we measured binding energies of unoccupied electronic states for 1-9 layers and their parallel dispersion out to 4 layers. We measured the binding energies for a monolayer of Kr and dispersions for one and two layers. The n = 2 and n = 3 image states of the bare metal evolve into quantum well states of the layer (states of the Xe conduction band discretized by the boundary conditions of a 2-D slab) at higher Xe thicknesses, where the n = 2,3 states exhibit both a perpendicular and parallel dispersion similar to that of the bulk Xe conduction band. The n = 1 state appears to evolve with coverage as an image state screened by the Xe layer, with appreciable electron density in the vacuum. A continuum dielectric model (modified image state picture) reproduces the gross trends in the data, while an explicit quantum well analysis is used to extract the bulk Xe conduction band dispersion. A simple model which takes into account the band structures of the substrate and the overlayer, as well as the image potential, gives good agreement with the binding energy data. The combination of high energy and momentum resolution along both the surface parallel and surface normal yields very precise measurements of the bulk Xe conduction band as well as information about the behavior of conduction band electrons at interfaces. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. AMHERST COLL, DEPT CHEM, AMHERST, MA 01002 USA. NR 35 TC 74 Z9 74 U1 0 U2 7 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 SEP 1 PY 1996 VL 105 IS 9 BP 3883 EP 3891 DI 10.1063/1.472209 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VD768 UT WOS:A1996VD76800057 ER PT J AU Lagomarsino, RJ AF Lagomarsino, RJ TI An improved gas chromatographic method for the determination of perfluorocarbon tracers in the atmosphere SO JOURNAL OF CHROMATOGRAPHIC SCIENCE LA English DT Article RP Lagomarsino, RJ (reprint author), US DOE,ENVIRONM MEASUREMENTS LAB,NEW YORK,NY 10014, USA. NR 12 TC 16 Z9 17 U1 0 U2 1 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 SN 0021-9665 J9 J CHROMATOGR SCI JI J. Chromatogr. Sci. PD SEP PY 1996 VL 34 IS 9 BP 405 EP 412 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VF895 UT WOS:A1996VF89500004 ER PT J AU Xu, Y Mural, RJ Uberbacher, EC AF Xu, Y Mural, RJ Uberbacher, EC TI An iterative algorithm for correcting sequencing errors in DNA coding regions SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE DNA sequencing; sequence analysis; frameshifts; exon recognition; dynamic programming AB Insertion and deletion (indel) sequencing errors in DNA coding regions disrupt DNA-to-protein translation frames, and hence make most frame-sensitive coding recognition approaches fail, This paper extends the authors' previous work on indel detection and ''correction'' algorithms, and presents a more effective algorithm for localizing indels that appear in DNA coding regions and ''correcting'' the located indels by inserting or deleting DNA bases. The algorithm localizes indels by discovering changes of the preferred translation frames within presumed coding regions, and then ''corrects'' them to restore a consistent translation frame within each coding region, An iterative strategy is exploited to repeatedly localize and ''correct'' indels until no more indels can be found, Test results have shown that this improved algorithm can detect and ''correct'' more indels while not worsening the rate of introduction of false indels when compared to the authors' previous work. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. RP Xu, Y (reprint author), OAK RIDGE NATL LAB,DIV COMP SCI & MATH,INFORMAT GRP,OAK RIDGE,TN 37831, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 1066-5277 J9 J COMPUT BIOL JI J. Comput. Biol. PD FAL PY 1996 VL 3 IS 3 BP 333 EP 344 DI 10.1089/cmb.1996.3.333 PG 12 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA VR736 UT WOS:A1996VR73600001 PM 8891953 ER PT J AU Knill, E Schliep, A Torney, DC AF Knill, E Schliep, A Torney, DC TI Interpretation of pooling experiments using the Markov chain Monte Carlo method SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE clone library screening; group testing; Bayes statistics Monte Carlo methods; Gibbs sampling; combinatorial designs; experimental error models ID HUMAN GENOME AB This paper describes an effective method for extracting as much information as possible from pooling experiments for library screening, Pools are collections of clones, and screening a pool with a probe determines whether any of these clones are positive for the probe, The results of the pool screenings are interpreted, or decoded, to infer which clones are candidates to be positive, These candidate positives are subjected to confirmatory testing, Decoding the pool screening results is complicated by the presence of errors, which typically lead to ambiguities in the inference of positive clones, However, in many applications there are reasonable models for the prior distributions for positives and for errors, and Bayes inference is the preferred method for ranking candidate positives, Because of the combinatoric complexity of the Bayes formulation, we implemented a decoding algorithm using a Markov chain Monte Carlo method, The algorithm was used in screening a library with 1298 clones using 47 pools, We corroborated the posterior probabilities for positives with results from confirmatory screening, We also simulated the screening of a 10-fold coverage library of 33,000 clones using 253 pools, The use of our algorithm, effective under conditions where combinatorial decoding techniques are imprudent, allows the use of fewer pools and also introduces needed robustness. C1 UNIV COLOGNE,COLOGNE,GERMANY. RP Knill, E (reprint author), LOS ALAMOS NATL LAB,T-10,MS B265,LOS ALAMOS,NM 87545, USA. NR 17 TC 18 Z9 18 U1 0 U2 2 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 1066-5277 J9 J COMPUT BIOL JI J. Comput. Biol. PD FAL PY 1996 VL 3 IS 3 BP 395 EP 406 DI 10.1089/cmb.1996.3.395 PG 12 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA VR736 UT WOS:A1996VR73600005 PM 8891957 ER PT J AU Wang, GJ Volkow, ND Lau, YH Fowler, JS Meek, AG Park, TL Wong, C Roque, CT Adler, AJ Wolf, AP AF Wang, GJ Volkow, ND Lau, YH Fowler, JS Meek, AG Park, TL Wong, C Roque, CT Adler, AJ Wolf, AP TI Glucose metabolic changes in nontumoral brain tissue of patients with brain tumor following radiotherapy: A preliminary study SO JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY LA English DT Article DE brain, metabolism; brain, neoplasms; emission computed tomography; radiation, effects ID POSITRON EMISSION TOMOGRAPHY; DIAZEPAM-BINDING INHIBITOR; BLOOD-FLOW; OXYGEN UTILIZATION; BENZODIAZEPINE RECEPTORS; VOLUME; DEXAMETHASONE; RADIATION; PET AB Purpose: Our goal was to measure the effect of radiotherapy on the brain glucose metabolism of tumoral and nontumoral tissue of patients with brain malignancies. Method: Fifteen patients with primary or metastatic brain tumors were studied with 2-deoxy-2-[F-18]fluoro-D-glucose and PET prior to radiotherapy, and nine of them were rescanned 1 week after completing radiotherapy. Results: Brain metabolism in patients (all brain regions except for tumoral and edematous tissue) was lower than that of matched controls (34.0 +/- 8.3 vs. 46.5 +/- 6.4 mu mol/100 g/min; p less than or equal to 0.0001). Five of the nine patients retested after radiotherapy showed decrements in tumor metabolism (47 +/- 10%; p less than or equal to 0.05) and increases in brain metabolism (10 less than or equal to 4%; p less than or equal to 0.004), and the other four showed no changes in tumor or in brain metabolism Radiotherapy-induced changes in tumor metabolism were negatively correlated with changes in brain metabolism (r = 0.85, p less than or equal to 0.004), but not with changes in tumor volume (assessed with MR images). Conclusion: The study indicates that radiotherapy-induced increases in metabolism of nontumoral tissue are secondary to decreased tumor metabolic activity and not just due to volume reduction. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT RADIAT ONCOL,STONY BROOK,NY 11794. RP Wang, GJ (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 25 TC 16 Z9 16 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0363-8715 J9 J COMPUT ASSIST TOMO JI J. Comput. Assist. Tomogr. PD SEP-OCT PY 1996 VL 20 IS 5 BP 709 EP 714 DI 10.1097/00004728-199609000-00004 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VG359 UT WOS:A1996VG35900004 PM 8797898 ER PT J AU DeYoreo, JJ Rek, ZU Zaitseva, NP Woods, BW AF DeYoreo, JJ Rek, ZU Zaitseva, NP Woods, BW TI Sources of optical distortion in rapidly grown crystals of KH2PO4 SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth ID FACE AB We report the results of X-ray topographic and optical measurements on KH2PO4 crystals grown at rates of 5-30 mm/day. We show that optical distortion in these crystals is caused primarily by three sources: dislocations, differences in composition between adjacent growth sectors of the crystal, and differences in composition between adjacent sectors of vicinal-growth hillocks within a single growth sector of the crystal. We find that the compositional heterogeneities cause spatial variations in the refractive index and induce a distortion of the transmitted-wave front, while large groups of dislocations are responsible for strain-induced birefringence which leads to beam depolarization. C1 STANFORD SYNCHROTRON RES LAB,STANFORD,CA 94309. RP DeYoreo, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 15 TC 46 Z9 46 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 291 EP 297 DI 10.1016/0022-0248(95)00565-X PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900050 ER PT J AU VanScyoc, JM James, RB Schlesinger, TE Gilbert, TS Schieber, M AF VanScyoc, JM James, RB Schlesinger, TE Gilbert, TS Schieber, M TI Characterization of silver impurities in mercuric iodide and their relationship to gamma-ray-detector performance SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth ID SPECTROMETERS; DEFECTS AB Red mercuric iodide (alpha-HgI2) has been studied extensively for use as a room-temperature radiation-detector material. Although it has several properties which make it an extremely attractive material for such applications, it has not seen large-scale deployment, particularly in the commercial market, because of several continuing problems. These problems arise, in part, from some of the intrinsic properties of the material. However, the primary limiting factors at this point are related to the phenomena of incomplete charge collection and device polarization. This paper examines one purported cause for both the carrier trapping and the device instability. In particular, silver is an elemental impurity that is known to exist in typical HgI2. Leakage-current experiments demonstrate how this electrically active impurity is mobile in bulk HgI2. Detector characterization shows how the presence of the silver degrades the performance and affects the spectral properties of the device over time. These results are combined with related work on impurities in HSI2 to develop a picture of the effects of silver on detectors and the processing requirements for detector fabrication. C1 SANDIA NATL LABS,ADV MAT RES DEPT,LIVERMORE,CA 94551. CARNEGIE MELLON UNIV,DEPT ELECT & COMP ENGN,PITTSBURGH,PA 15213. NR 9 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 384 EP 389 DI 10.1016/0022-0248(95)00556-0 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900067 ER PT J AU Land, TA Malkin, AJ Kutznesov, YG McPherson, A DeYoreo, JJ AF Land, TA Malkin, AJ Kutznesov, YG McPherson, A DeYoreo, JJ TI Mechanisms of protein and virus crystal growth: An atomic force microscopy study of canavalin and STMV crystallization SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth AB The evolution of surface morphology and step dynamics during the growth of rhombohedral crystals of the protein canavalin and crystals of the cubic satellite tobacco mosaic virus (STMV) have been investigated for the first time by in situ atomic force microscopy. These two crystals were observed to grow by very different mechanisms. Growth of canavalin occurs on complex vicinal hillocks formed by multiple, independently acting screw dislocations. Small clusters were observed on the terraces. STMV on the other hand, was observed to grow by 2D nucleation of islands. No dislocations were found on the crystal. The results are used to determine the growth mechanisms and estimate the fundamental materials parameters. The images also illustrate the important mechanism of defect incorporation and provide insight to the processes that limit the growth rate and uniformity of these crystals. C1 UNIV CALIF RIVERSIDE,DEPT BIOCHEM,RIVERSIDE,CA 92521. RP Land, TA (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 14 TC 27 Z9 28 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 893 EP 899 DI 10.1016/0022-0248(95)00563-3 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900157 ER PT J AU Boatner, LA Dryburgh, PM AF Boatner, LA Dryburgh, PM TI Proceedings of the eleventh international conference on crystal growth, the Hague, the Netherlands, June 18-23, 1995 - Preface SO JOURNAL OF CRYSTAL GROWTH LA English DT Editorial Material C1 UNIV EDINBURGH,EDINBURGH EH8 9YL,MIDLOTHIAN,SCOTLAND. RP Boatner, LA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP R13 EP R13 DI 10.1016/0022-0248(96)80044-3 PG 1 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900002 ER PT J AU Cai, Y Chen, SS Rote, DM Coffey, HT AF Cai, Y Chen, SS Rote, DM Coffey, HT TI Vehicle/guideway dynamic interaction in maglev systems SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article AB The importance of vehicle/guideway dynamics in maglev systems is discussed. The particular interests associated with modeling vehicle/guideway interactions and explaining response characteristics of maglev systems for a multicar, multiload vehicle traversing on a single- or double-span flexible guideway are considered, with an emphasis on vehicle/guideway coupling effects, comparison of concentrated and distributed loads, and ride comfort. Coupled effects of vehicle/guideway interactions over a wide range of vehicle speeds with various vehicle and guideway parameters are investigated and appropriate criteria for decoupling at critical vehicle speeds or crossing frequencies are identified. RP Cai, Y (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 15 TC 29 Z9 43 U1 2 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 1996 VL 118 IS 3 BP 526 EP 530 DI 10.1115/1.2801176 PG 5 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA VK047 UT WOS:A1996VK04700018 ER PT J AU Thompson, AG Stall, RA Zawadzki, P Evans, GH AF Thompson, AG Stall, RA Zawadzki, P Evans, GH TI The scaling of CVD rotating disk reactors to large sizes and comparison with theory SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE AlGaAs; CVD; InGaAlP; MOCVD; rotating disk reactors ID CHEMICAL-VAPOR-DEPOSITION; HEAT-TRANSFER; PHASE EPITAXY; QUANTUM-WELLS; HIGH-SPEED; FLOW; GROWTH; DESIGN AB An important advantage of the rotating disk reactor (RDR) geometry for chemical vapor deposition is the one-dimensional nature of the transport process over a wide range of operating conditions. Due to geometric complexity, models for most chemical vapor deposition (CVD) reactors have been used to fit existing data and are not very useful as predictors of performance for changed dimensions, particularly larger ones. Previous RDR modeling results have shown good agreement with experiment for smaller sizes (typically single wafer) and have also resulted in a set of scaling ''laws'' for scaling to larger sizes. In this work, we report the use of these scaling laws to design larger RDRs and to determine optimal process conditions. We then compare the experimental results to those predicted by the model. Previously, our largest RDR utilized an 180 mm diameter disk, which holds 6 x 50 mm or 3 x 76 mm wafers. The new systems have disks of 300 and 420 mm diameter, holding 17 and 38, 50 mm wafers, respectively. In general excellent agreement was obtained when the new systems were run at conditions predicted by the scaling laws. As the disk diameter increases, the model calls for a reduced rotational rate, a lower operating pressure and a main carrier gas flow that increases sublinearly with the disk area. Experimental growths were made with the III-V materials AlGaAs and InGaAlP, on GaAs substrates of 50, 76, and 100 mm diameters. Uniformities and electrical and optical properties similar to those obtained in smaller RDR systems were obtained under conditions predicted be the model. We also discuss the trade-offs involved where one parameter is fixed by process needs, necessitating that others must be adjusted accordingly. It should be stressed that these adjustments are all calculated from the model and are designed to maintain the ideal flow and thermal environments obtained with the smaller systems. We find that typical metalorganic chemical vapor deposition process parameters are easily accommodated for these disk sizes. We believe that this is the first report of a truly scalable CVD reactor geometry with both theoretical and experimental justification. Using the RDR technique therefore enables the grower to develop a process on a small system and transfer it to a larger system for manufacturing, without having to reinvent the process. It also enables the CVD system manufacturer to design and-build new systems that will perform in a predictable manner, or to adapt new process conditions to an existing system, without requiring extensive re-engineering efforts. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP Thompson, AG (reprint author), EMCORE CORP,394 ELIZABETH AVE,SOMERSET,NJ 08873, USA. NR 24 TC 18 Z9 18 U1 1 U2 7 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 SEP PY 1996 VL 25 IS 9 BP 1487 EP 1494 DI 10.1007/BF02655388 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VJ504 UT WOS:A1996VJ50400013 ER PT J AU LilientalWeber, Z Kisielowski, C Ruvimov, S Chen, Y Washburn, J Grzegory, I Bockowski, M Jun, J Porowski, S AF LilientalWeber, Z Kisielowski, C Ruvimov, S Chen, Y Washburn, J Grzegory, I Bockowski, M Jun, J Porowski, S TI Structural characterization of bulk GaN crystals grown under high hydrostatic pressure SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE bulk; GaN; crystal polarity; excess Ga; microstructure; planar defects; surface roughness ID LIGHT-EMITTING-DIODES; GAAS AB This paper describes TEM characterization of bulk GaN crystals grown at 1500-1800K in the form of plates from a solution of atomic nitrogen in liquid gallium under high nitrogen pressure (up to 20 kbars). Their x-ray rocking curves for these crystals were in the range of 20-30 arc-sec. The plate thickness along the c axis was about 100 times smaller than the nonpolar growth directions. A substantial difference in material quality was observed on the opposite sides of the plates normal to the c direction. On one side the surface was atomically flat, while on the other side the surface was rough, with pyramidal features up to 100 nm high. The polarity of the crystals was determined using convergent-beam electron diffraction. The results showed that, regarding the long bond between Ga and N along the c-axis, Ga atoms were found to be closer to the flat side of the crystal, while N atoms were found to be closer to the rough side. Near the rough side, within 1/10 to 1/4 of the plate thickness, there was a high density of planar defects (stacking faults and dislocation loops decorated by Ga/void precipitates). A model explaining the defect information is proposed. C1 POLISH ACAD SCI, HIGH PRESSURE RES CTR UNIPRESS, WARSAW, POLAND. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, CTR ADV MAT, DIV MAT SCI, BERKELEY, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 22 TC 64 Z9 64 U1 0 U2 11 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0361-5235 EI 1543-186X J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 1996 VL 25 IS 9 BP 1545 EP 1550 DI 10.1007/BF02655397 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VJ504 UT WOS:A1996VJ50400022 ER PT J AU Wolf, LJ Cheshier, SR Furgason, RR Hager, WR AF Wolf, LJ Cheshier, SR Furgason, RR Hager, WR TI Engineering technology programs: Maturation or mission drift? SO JOURNAL OF ENGINEERING TECHNOLOGY LA English DT Editorial Material C1 TEXAS A&M UNIV,CORPUS CHRISTI,TX. PENN STATE UNIV,SCH TECHNOL,UNIVERSITY PK,PA 16802. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Wolf, LJ (reprint author), OREGON GRAD INST SCI & TECHNOL,BEAVERTON,OR 97006, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC ENG EDUC PI WASHINGTON PA 1818 N STREET,NW SUITE 600, WASHINGTON, DC 20036 J9 J ENG TECHNOL JI J. Eng. Technol. PD FAL PY 1996 VL 13 IS 2 BP 14 EP 18 PG 5 WC Engineering, Multidisciplinary SC Engineering GA WH960 UT WOS:A1996WH96000003 ER PT J AU Clement, TP Hooker, BS Skeen, RS AF Clement, TP Hooker, BS Skeen, RS TI Numerical modeling of biologically reactive transport near nutrient injection well SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article ID POROUS-MEDIUM; PHYSICAL-PROPERTIES; BIOFILM GROWTH; BIODEGRADATION; DISPERSION; SUBSTRATE; PERMEABILITY; GROUNDWATER; SIMULATIONS; AQUIFERS AB A reactive, radial-transport model to simulate biological processes near a nutrient injection well is presented. An improved numerical procedure that incorporates the attractive features of Eulerian-Lagrangian and reaction-operator split methods is used to solve the model. The numerical procedure is efficient, stable, and mass conserving. An in-situ biostimulation model incorporating aerobic kinetics is solved to demonstrate the usefulness of the modeling procedure and to study the sensitivity of biomass distribution to variations in biokinetic parameters. The resulting mathematical model adequately describes near-well biological processes under varying conditions. The sensitivity analysis shows that the microbial detachment and attachment processes are important transport parameters that control biomass distribution in an aquifer. The results strongly suggest that other expressions that describe these processes and their relationship to growth rate should be examined. RP Clement, TP (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 33 TC 24 Z9 24 U1 0 U2 5 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD SEP PY 1996 VL 122 IS 9 BP 833 EP 839 DI 10.1061/(ASCE)0733-9372(1996)122:9(833) PG 7 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VD781 UT WOS:A1996VD78100011 ER PT J AU Kaplan, DI Cantrell, KJ Wietsma, TW Potter, MA AF Kaplan, DI Cantrell, KJ Wietsma, TW Potter, MA TI Retention of zero-valent iron colloids by sand columns: Application to chemical barrier formation SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID POROUS-MEDIA; FILTRATION; PARTICLES; KINETICS AB Chemical barriers are an emerging technology used for the in situ remediation of groundwater. They are placed in the subsurface environment perpendicular to groundwater how where they selectively remove targeted groundwater contaminants while permitting water and other nontargeted constituents to pass through freely. A novel approach to emplacing chemical barriers is by the injection of zero-valent iron (Fe-0) colloids into the subsurface. The objective of this study was to determine the effect of influent Fe-0 colloid concentration and injection rate on colloid retention by columns of sand. Suspensions of Fe-0 colloids (2 +/- 1 mu m) were injected into coarse-grain sand that simulated a simplified aquifer matrix. Influent colloid injection rate (P less than or equal to 0.01) and concentration (P less than or equal to 0.05) had a significant effect on colloid retention by the sand. Efficiency of the column to retain colloids decreased as the concentration of retained colloids increased. Colloids were uniformly distributed throughout 1-m long columns at concentrations >3 g kg(-1). Based on filtration theory, gravitational settling was clearly the primary mechanism controlling colloid retention; diffusion, electrostatic attraction, and interception were less important mechanisms. These results were rationalized as follows: the high density of the colloids (7.6 g cm(-3)) enhanced gravitational settling, the fast experimental how rates minimized diffusion, the weak surface charge of the colloids and sediments minimized electrostatic attraction, and the small size of the colloids relative to the sand particles (6;10 mu m) minimized interception. RP Kaplan, DI (reprint author), PACIFIC NW LAB, POB 999, MAILSTOP K6-81, RICHLAND, WA 99352 USA. NR 33 TC 22 Z9 23 U1 1 U2 5 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 1996 VL 25 IS 5 BP 1086 EP 1094 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA VH793 UT WOS:A1996VH79300021 ER PT J AU Batson, VL Bertsch, PM Herbert, BE AF Batson, VL Bertsch, PM Herbert, BE TI Transport of anthropogenic uranium from sediments to surface waters during episodic storm events SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID SEQUENTIAL EXTRACTION PROCEDURE; TRACE-METALS; SOIL; EROSION; RIVERS; ENRICHMENT; SPECIATION; ADSORPTION; ARTIFACTS; PITFALLS AB Remobilization of sediment-associated uranium (U) from contaminated floodplain sediments to a stream adjacent to a nuclear weapons processing facility during episodic rain events was investigated. In addition, U solid phase associations in suspended sediments were assessed by a sequential chemical extraction procedure to gauge U chemical lability. Mass flux estimates determined from base flow measurements potentially underestimate the amount of U transported from contaminated terrestrial sources to surface water systems. Erosional processes can effectively mobilize sediment-associated contaminants during storms or flooding. During the various storm events measured, approximately 1500 to 2800% more U was exported to Upper Three Runs Creek (UTRC) relative to base Row measurements. Sequential extraction results suggest the suspended sediment load transports the bulk of U in labile forms predominantly as acid soluble (specifically adsorbed), MnO2 occluded and organically bound phases. This implies that U may be available to the ecosystem under a range of environmental conditions likely to be encountered within depositional environments (e.g., Eh and pH) or as a result of industrial processes. This study demonstrates the need to evaluate contaminant transport during storm events from exposed contaminated sediments, or from industrial waste stockpiles subject to erosion. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. TEXAS A&M UNIV,DEPT GEOL & GEOPHYS,COLLEGE STN,TX 77843. TEXAS A&M UNIV,DEPT GEOL & GEOPHYS,COLLEGE STN,TX 77843. RI Herbert, Bruce/K-4744-2013 OI Herbert, Bruce/0000-0002-6736-1148 NR 48 TC 31 Z9 31 U1 1 U2 9 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 1996 VL 25 IS 5 BP 1129 EP 1137 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA VH793 UT WOS:A1996VH79300026 ER PT J AU Rashidi, M Tompson, A Kulp, T Peurrung, L AF Rashidi, M Tompson, A Kulp, T Peurrung, L TI 3-D microscopic measurement and analysis of chemical flow and transport in porous media SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID PRESSURE SATURATION RELATIONSHIPS; IMAGE VELOCIMETRY; FLUID MOTION; PACKED-BEDS; VISUALIZATION AB Chemical flow and transport have been studied at the pore-scale in an experimental porous medium. Measurements have been taken using a novel nonintrusive fluorescence imaging technique. The experimental setup consists of a cylindrical column carved out of a clear plastic block, packed with clear beads of the same material. A refractive index-matched fluid was pumped under laminar, slow-flow conditions through the column. The fluid was seeded with tracer particles or a solute organic dye for flow and chemical transport measurements, respectively. The system is automated to image through the porous medium for collecting microscopic values of velocity, concentration, and pore geometry at high-accuracy and high-resolution. Various geometric, flow, and transport quantities have been obtained in a full three-dimensional volume within the porous medium. These include microscopic (pore-scale) medium geometry, velocity and concentration fields, dispersive solute fluxes, and reasonable estimates of a representative elementary volume (REV) for the porous medium. the results indicate that the range of allowable REV sizes, as measured from averaged velocity, concentration, and pore volume data, varies among the different quantities, however, a common overlapping range, valid for all quantities, can be determined. For our system, this common REV has been estimated to be about two orders of magnitude larger than the medium's particle volume. Furthermore, correlation results show an increase in correlation of mean-removed velocity and concentration values near the concentration front in our experiments. These results have been confirmed via 3-D plots of concentration, velocity, pore geometry, and microscopic flux distributions in these regions. C1 LAWRENCE LIVERMORE NATL LAB,ENVIRONM PROGRAMS DIRECTORATE,LIVERMORE,CA 94550. RP Rashidi, M (reprint author), LAWRENCE LIVERMORE NATL LAB,LABS COOPERAT APPL PHYS,LIVERMORE,CA 94550, USA. NR 44 TC 8 Z9 8 U1 1 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD SEP PY 1996 VL 118 IS 3 BP 470 EP 480 DI 10.1115/1.2817782 PG 11 WC Engineering, Mechanical SC Engineering GA VN191 UT WOS:A1996VN19100007 ER PT J AU Loehle, C AF Loehle, C TI Forest response to climate change: Do simulations predict unrealistic dieback? SO JOURNAL OF FORESTRY LA English DT Article ID MODEL RP Loehle, C (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 19 Z9 20 U1 0 U2 3 PU SOC AMER FORESTERS PI BETHESDA PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 SN 0022-1201 J9 J FOREST JI J. For. PD SEP PY 1996 VL 94 IS 9 BP 13 EP 15 PG 3 WC Forestry SC Forestry GA VF376 UT WOS:A1996VF37600006 ER PT J AU Jacobson, AR Hoogeveen, G Carlos, RC Wu, GH Fejer, BG Kelley, MC AF Jacobson, AR Hoogeveen, G Carlos, RC Wu, GH Fejer, BG Kelley, MC TI Observations of inner plasmasphere irregularities with a satellite-beacon radio-interferometer array SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID IONOSPHERIC ELECTRIC-FIELDS; DIFFUSE AURORAL BOUNDARY; MAGNETOSPHERIC DISTURBANCES; SOLAR-CYCLE; PLASMAPAUSE; FLUCTUATIONS; INSTABILITY; UNDULATIONS; REGION; MIDLATITUDE AB A radio-interferometer array illuminated by 136-MHz beacons of several geosynchronous satellites has been used to study small (greater than or equal to 10(13) m(-2)) transient disturbances in the total electron content along the lines of sight to the satellites. High-frequency (f > 3 mHz) electron content oscillations are persistently observed, particularly during night and particularly during geomagnetically disturbed periods. The oscillations move across the array plane at speeds in the range 200-2000 m/s, with propagation azimuths that are strongly peaked in lobes toward the western half-plane. Detailed analysis of this azimuth behavior, involving comparison between observations on various satellite positions, indicates compellingly that the phase oscillations originate in radio refraction due to geomagnetically aligned plasma density perturbations in the inner plasmasphere. The motion of the phase perturbations across the array plane is caused by EXB drift of the plasma medium in which the irregularities are embedded. We review the statistics of 2.5 years of around-the-clock data on the local time, magnetic disturbance, seasonal, and line-of-sight variations of these observed irregularities. We compare the irregularities' inferred electrodynamic drifts to what is known about midlatitude plasma drift from incoherent scatter. Finally, we show in detail how the observation of these irregularities provides a unique and complementary monitor of inner plasmasphere irregularity incidence and zonal drift. C1 UTAH STATE UNIV,CTR ATMOSPHER & SPACE SCI,LOGAN,UT 84322. CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853. RP Jacobson, AR (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,LOS ALAMOS,NM 87545, USA. NR 50 TC 12 Z9 12 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 SEP 1 PY 1996 VL 101 IS A9 BP 19665 EP 19682 DI 10.1029/96JA01253 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VF257 UT WOS:A1996VF25700004 ER PT J AU Riley, P Sonett, CP Tsurutani, BT Balogh, A Forsyth, RJ Hoogeveen, GW AF Riley, P Sonett, CP Tsurutani, BT Balogh, A Forsyth, RJ Hoogeveen, GW TI Properties of arc-polarized Alfven waves in the ecliptic plane: Ulysses observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; INTERPLANETARY DISCONTINUITIES; TURBULENCE AB Ulysses observations of the interplanetary magnetic field reveal well-ordered rotations on the timescale of several hours. These have been previously identified as ''arc-polarized'' Alfven waves. Rotational discontinuities (RDs) are often an integral part of the wave. This study focuses on a statistical description of these rotations (ARCs) in the ecliptic plane. It is found that (1) most ARCs are limited to 180 degrees or less in rotation; (2) these ARCs account for between 5 and 10% of the total data set; (3) there appears to be no preferred helicity; (4) the minimum-variance direction typically makes a large oblique angle with the average magnetic field (< B >), while the intermediate-variance direction is loosely aligned with < B >; (5) most of the events display a small but significant nonzero magnetic field component in the direction of minimum variance; (6) the cross helicity of the ARCs tends to be higher than during non-ARC intervals; (7) there are 2.4 times more discontinuities during ARC intervals than during non-ARC intervals; (8) essentially all ARCs are propagating outward in the rest frame of the solar wind plasma; and (9) there is no simple relationship between the rate of occurrence of the ARCs and heliocentric distance. Comparing these results with the predicted signatures of a number of models, it is found that arc-polarized Alfven waves with embedded RDs propagating along the minimum-variance direction best fit the majority of events. C1 UNIV ARIZONA, LUNAR & PLANETARY LAB, TUCSON, AZ 85721 USA. JET PROP LAB, PASADENA, CA 91109 USA. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. UNIV ARIZONA, DEPT PLANETARY SCI, TUCSON, AZ 85721 USA. RP Riley, P (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 22 TC 27 Z9 28 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1996 VL 101 IS A9 BP 19987 EP 19993 DI 10.1029/96JA01743 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VF257 UT WOS:A1996VF25700031 ER PT J AU Robinett, RD Sturgis, BR Kerr, SA AF Robinett, RD Sturgis, BR Kerr, SA TI Moving mass trim control for aerospace vehicles SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB A moving mass trim controller is proposed to increase the accuracy of axisymmetric, ballistic vehicles. The moving mass trim controller differs from other moving mass schemes because it generates an angle of attack directly from the mass motion. The nonlinear equations of motion for a ballistic vehicle with one moving point mass are derived and provide the basis for a detailed simulation model. The nonlinear equations are linearized to produce a set of linear, time-varying autopilot equations. These autopilot equations are analyzed and used to develop theoretical design tools for the creation of moving mass trim controllers for both fast and slow spinning vehicles. A fast spinning moving mass trim controller is designed for a generic artillery rocket that uses principal axis misalignment to generate a trim angle of attack. A slow spinning moving mass trim controller is designed for a generic re-entry vehicle that generates a trim angle of attack with a center of mass offset and aerodynamic drag. The performance of both moving mass trim controllers are evaluated with the detailed simulation. C1 SANDIA NATL LABS,ADV CONCEPTS & ENGN SYST ANAL DEPT,TECH STAFF,ALBUQUERQUE,NM 87185. RP Robinett, RD (reprint author), SANDIA NATL LABS,THREAT & COUNTERMEASURES DEV & EVALUAT DEPT,TECH STAFF,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 33 Z9 65 U1 0 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD SEP-OCT PY 1996 VL 19 IS 5 BP 1064 EP 1070 DI 10.2514/3.21746 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA VE513 UT WOS:A1996VE51300011 ER PT J AU Nilsson, SK Hulspas, R Weier, HUG Quesenberry, PJ AF Nilsson, SK Hulspas, R Weier, HUG Quesenberry, PJ TI In situ detection of individual transplanted bone marrow cells using FISH on sections of paraffin-embedded whole murine femurs SO JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY LA English DT Article DE in situ hybridization; paraformaldehyde perfusion; paraffin sections; murine; bone marrow transplantation ID INSITU HYBRIDIZATION; STEM-CELLS; MICE; OPTIMIZATION; MICROSCOPY; PHENOTYPE; RNA; DNA AB Studies of transplantation biology rely on the detection of donor hemopoietic cells in transplant recipients. Traditionally this has been achieved through ex vivo techniques, including now cytometric analysis of cell surface markers to detect cells expressing specific epitopes, histochemical detection of cytoplasmic proteins, and the detection of Y chromosome-specific sequences by DNA hybridization, Studies using congenic models, such as the Ly5.1/5.2 mouse, or the utilization of fluorescent dyes, such as PKH-26, have allowed more in-depth analysis of transplantation, beginning to address key issues such as cell homing through cell tracking and elucidation of the ''stem cell niche''. However, these methods are limited by labeling sensitivity, specificity, crossreactivity and, in the case of PKH-26 labeling, the number of cell divisions the transplanted cells can make before the signal disappears. We have developed a fluorescent in situ hybridization (FISH) technique that utilizes a murine Y chromosome-specific ''painting'' probe to identify in situ individual transplanted male cells in paraffin-embedded sections of female whole bone marrow while maintaining good morphological integrity. This method is highly sensitive and specific, labeling more than 99% of male cells and no female cells, allowing each transplant to be assessed at the individual cell level, The technique provides unique opportunities to follow the path taken by transplanted cells, both during homing into the marrow and through their maturation and differentiation into mature, functional hemopoietic cells. C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. RP Nilsson, SK (reprint author), UNIV MASSACHUSETTS,MED CTR,CTR CANC,373 PLANTAT ST,SUITE 202,WORCESTER,MA 01605, USA. RI Nilsson, Susie/C-5563-2015 OI Nilsson, Susie/0000-0002-7926-7335 FU NIDDK NIH HHS [DK49650] NR 22 TC 29 Z9 30 U1 1 U2 2 PU HISTOCHEMICAL SOC INC PI NEW YORK PA MT SINAI MEDICAL CENTER 19 EAST 98TH ST SUTIE 9G, NEW YORK, NY 10029 SN 0022-1554 J9 J HISTOCHEM CYTOCHEM JI J. Histochem. Cytochem. PD SEP PY 1996 VL 44 IS 9 BP 1069 EP 1074 PG 6 WC Cell Biology SC Cell Biology GA VF429 UT WOS:A1996VF42900015 PM 8773573 ER PT J AU White, DC Stair, JO Ringelberg, DB AF White, DC Stair, JO Ringelberg, DB TI Quantitative comparisons of in situ microbial biodiversity by signature biomarker analysis SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Article DE microbial biodiversity; signature lipid biomarkers (SLB); phospholipid fatty acids (PLFA); in situ microbial biomass; community composition; nutritional/physiological status; non-culturable viable biomass ID HYDROXY FATTY-ACIDS; CHROMATOGRAPHY MASS-SPECTROMETRY; LIPOPOLYSACCHARIDE LIPID-A; SULFATE-REDUCING BACTERIA; POLY-BETA-HYDROXYBUTYRATE; GRAM-NEGATIVE BACTERIA; COMMUNITY STRUCTURE; DEEP SUBSURFACE; DETRITAL MICROBIOTA; RIBOSOMAL-RNA AB Microscopic examinations have convinced microbial ecologists that the culturable microbes recovered from environmental samples represent a tiny proportion of the extant microbiota. Methods for recovery and enzymatic amplification of nucleic acids from environmental samples have shown that a huge diversity exists in situ, far exceeding any expectations which were based on direct microscopy. It is now theoretically possible to extract, amplify and sequence all the nucleic acids from a community and thereby gain a comprehensive measure of the diversity as well as some insights into the phylogeny of the various elements within this community. Unfortunately, this analysis becomes economically prohibitive if applied to the multitude of niches in a single biome let alone to a diverse set of environments. It is also difficult to utilize PCR amplification on nucleic acids from some biomes because of coextracting enzymatic inhibitors, Signature biomarker analysis which potentially combines gene probe and lipid analysis on the same sample, can serve as a complement to massive environmental genome analysis in providing quantitative comparisons between microniches in the biome under study, This analysis can also give indications of the magnitude of differences in biodiversity in the biome as well as provide insight into the phenotypic activities of each community in a rapid and cost-effective manner, Applications of signature lipid biomarker analysis to define quantitatively the microbial viable biomass of portions of an Eastern USA deciduous forest, are presented. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37983. UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37932. RP White, DC (reprint author), UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,10515 RES DR,SUITE 300,KNOXVILLE,TN 37932, USA. NR 98 TC 191 Z9 222 U1 4 U2 45 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP-OCT PY 1996 VL 17 IS 3-4 BP 185 EP 196 DI 10.1007/BF01574692 PG 12 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WA711 UT WOS:A1996WA71100007 ER PT J AU Zlatkin, IV Schneider, M deBruijn, FJ Forney, LJ AF Zlatkin, IV Schneider, M deBruijn, FJ Forney, LJ TI Diversity among bacteria isolated from the deep subsurface SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Article DE heterotrophic bacteria; diversity; deep subsurface; 16S rDNA; FAME; rep-PCR ID COASTAL-PLAIN; HETEROTROPHIC BACTERIA; SEDIMENTS; WATER; FATTY; IDENTIFICATION; MICROORGANISMS; MICROBIOLOGY; COMMUNITIES; ENUMERATION AB Culturable bacteria from the deep subsurface (179 m) at Cerro Negro, New Mexico were isolated and characterized, The average number of viable aerobic bacteria was estimated to be 5 x 10(5) g(-1) of sediment, but only about 0.1% of these could be recovered on agar medium when incubated under aerobic conditions, Of 158 strains isolated from this depth, 92 were characterized by cellular fatty acid profiles (FAME), 36 by analysis of partial 16S rDNA sequences, and 44 by rep-PCR genome fingerprint analysis using three different sets of oligonucleotide primers (REP, BOX, or ERIC). These analyses showed the majority of isolates (67%) were Gram-positive bacteria and primarily members of genera with a high %G + C DNA. The remaining isolates were alpha-subdivision Proteobacteria (19%) and members of the flavobacteria group (14%), The diversity indices based on these different methods of characterization were very high suggesting this subsurface habitat harbors a highly diverse microbial community. C1 MICHIGAN STATE UNIV,CTR MICROBIAL ECOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT MICROBIOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. NR 52 TC 14 Z9 15 U1 0 U2 1 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP-OCT PY 1996 VL 17 IS 3-4 BP 219 EP 227 DI 10.1007/BF01574696 PG 9 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WA711 UT WOS:A1996WA71100011 ER PT J AU Torok, T Mortimer, RK Romano, P Suzzi, G Polsinelli, M AF Torok, T Mortimer, RK Romano, P Suzzi, G Polsinelli, M TI Quest for wine yeasts - An old story revisited SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Article DE grape(s); wine yeast(s); Saccharomyces cerevisiae; genetic analysis; electrophoretic karyotyping; segregation of chromosomal length polymorphism ID SACCHAROMYCES-CEREVISIAE; GENUS SACCHAROMYCES; ELECTROPHORETIC KARYOTYPES; FERMENTATION; STRAINS; IDENTIFICATION; CHROMOSOMES; PARADOXUS; ECOLOGY; BAYANUS AB Numerous studies have described the yeast biota of grapes, and grape must in order to understand better the succession of yeasts during fermentation of wine. The origin of the wine yeasts has been rather controversial, By using more elaborate isolation methods, classical genetic analysis and electrophoretic karyotyping of monosporic clones, with this study, credible proof now exists that the vineyard is the primary source for the wine yeasts and that strains found on the grapes can be followed through the fermentation process. C1 UNIV CALIF BERKELEY,BERKELEY,CA. UNIV POTENZA,POTENZA,ITALY. UNIV FLORENCE,FLORENCE,ITALY. RP Torok, T (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,MS 70A-3317,BERKELEY,CA 94720, USA. NR 43 TC 42 Z9 46 U1 0 U2 7 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP-OCT PY 1996 VL 17 IS 3-4 BP 303 EP 313 DI 10.1007/BF01574705 PG 11 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WA711 UT WOS:A1996WA71100020 ER PT J AU HunterCevera, JC Jeffries, TW Eveleigh, DE AF HunterCevera, JC Jeffries, TW Eveleigh, DE TI The first of two double issues on microbial diversity - Introduction SO JOURNAL OF INDUSTRIAL MICROBIOLOGY LA English DT Editorial Material C1 USDA,FOREST PROD LAB,MADISON,WI 53705. RUTGERS STATE UNIV,NEW BRUNSWICK,NJ 08903. RP HunterCevera, JC (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Jeffries, Thomas/I-8576-2012 OI Jeffries, Thomas/0000-0001-7408-4065 NR 0 TC 0 Z9 0 U1 0 U2 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL JI J. Indust. Microbiol. PD SEP-OCT PY 1996 VL 17 IS 3-4 BP R6 EP R6 DI 10.1007/BF01574686 PG 1 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WA711 UT WOS:A1996WA71100001 ER PT J AU Parker, GG Segalman, DJ Robinett, RD Inman, DJ AF Parker, GG Segalman, DJ Robinett, RD Inman, DJ TI Decentralized sliding mode control for flexible link robots SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE sliding mode control; robot control; flexible links ID SLEWING CONTROL; MANIPULATORS; TRACKING; DESIGN AB A technique using augmented sliding mode control for robust, real-time control of flexible multiple link robots is presented. For the purpose of controller design, the n-link, n-joint robot is subdivided into n single joint, single link subsystems. A sliding surface for each subsystem is specified so as to be globally, asymptotically stable. Each sliding surface contains rigid-body angular velocity, angular displacement and flexible body generalized velocities. The flexible body generalized accelerations are treated as disturbances during the controller design. This has the advantage of not requiring explicit equations for the flexible body motion. The result is n single input, single output controllers acting at the n joints of the robot, controlling rigid body angular displacement and providing damping for flexible body modes. Furthermore, the n controllers can be operated in parallel so that compute speed is independent of the number of links, affording real-time, robust, control. C1 VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. RP Parker, GG (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 4 Z9 4 U1 2 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD SEP PY 1996 VL 17 IS 1 BP 61 EP 79 DI 10.1007/BF00435716 PG 19 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA VN985 UT WOS:A1996VN98500003 ER PT J AU Tachibana, M Hori, H Suzuki, N Uechi, T Kobayashi, D Iwahana, H Kaya, HK AF Tachibana, M Hori, H Suzuki, N Uechi, T Kobayashi, D Iwahana, H Kaya, HK TI Larvicidal activity of the symbiotic bacterium Xenorhabdus japonicus from the entomopathogenic nematode Steinernema kushidai against Anomala cuprea (Coleoptera: Scarabaeidae) SO JOURNAL OF INVERTEBRATE PATHOLOGY LA English DT Article DE Steinernematidae; insect-parasitic nematode; cupreous chafer; Scarabaeidae; white grub; biological control ID INSECT PATHOGENIC NEMATODES; FORM VARIANTS; ENTEROBACTERIACEAE; HETERORHABDITIS; NEOAPLECTANA; NEMATOPHILUS; SCAPTERISCI; LUMINESCENS; METABOLITES; DERIVATIVES AB The entomopathogenicity of the symbiotic bacterium Xenorhabdus japonicus and the nematode steinernema kushidai was determined. Phase I and II X. Japonicus were cultured on an artificial medium and inoculated into the test insect or established into axenic S. kushidai populations. When 100, 1000, or 10,000 bacterial cells of phase I or II were directly injected into the hemocoels of 3rd instar cupreous chafer, Anomala cuprea, both phases in the late log period killed 100% of the larvae by the 2nd day postinoculation. However, both phases in the stationary period were less pathogenic with cupreous chafer mortality <20 and 80% at 100 and 1000 bacterial cells/larva, respectively. In vitro studies showed that axenic S. kushidai provided with phase I and II symbionts grew well and produced equal numbers of progeny on a dog food medium, but nematodes with no symbionts did not grow at all. Pig liver extracts added as a dietary supplement to the dog food medium completely restored growth and progeny production of the nematode growth and progeny production of the nematode with no bacterial cells. Studies were conducted with infective juveniles (IJs) harboring phase I or II or no symbionts that were applied against 3rd instar cupreous chafer larvae in compost or injected directly into their hemocoels. In the compost study, IJs harboring phase I killed 100% within 10 days. IJs with phase II or no symbionts caused low mortality of the cupreous chafer larvae at 10 days (<20%). In the intrahemocoelic injection study, IJs harboring phase I resulted in 60% larval mortality at five nematodes/larva, and as the number of IJs injected increased, significantly higher larval mortality was obtained. (C) 1996 Academic Press, Inc. C1 KUBOTA CORP,ADV TECHNOL INST,BIOPESTICIDE LAB,IBARAKI,OSAKA 301,JAPAN. TOKYO UNIV AGR & TECHNOL,FAC AGR,APPL BIOL LAB,FUCHU,TOKYO 183,JAPAN. LAWRENCE LIVERMORE NATL LAB,DEPT NEMATOL,DAVIS,CA 95616. NR 32 TC 7 Z9 7 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2011 J9 J INVERTEBR PATHOL JI J. Invertebr. Pathol. PD SEP PY 1996 VL 68 IS 2 BP 152 EP 159 DI 10.1006/jipa.1996.0073 PG 8 WC Zoology SC Zoology GA VL347 UT WOS:A1996VL34700009 PM 8858911 ER PT J AU Orji, CC Silks, LA AF Orji, CC Silks, LA TI Synthesis of [9,amino-N-15(2)]adenine and beta-2'-deoxy-[9,amino-N-15(2)]adenosine SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE [9,amino-N-15(2)]adenine; beta-2'-deoxy-[9,amino-N-15(2)]-adenosine; (NH3)-N-15 ID NITROGEN-15-LABELED DEOXYNUCLEOSIDES; N-15 NMR; DEOXYADENOSINE AB beta-2'-Deoxy-[9,amino-N-15(2)]adenosine has been synthesized in 4 steps from commercially available 5-amino-4,6-dichloropyrimidine and (NH3)-N-15. C1 LOS ALAMOS NATL LAB,NIH STABLE ISOTOPES RESOURCE,BIOSCI & BIOTECHNOL SECT,LOS ALAMOS,NM 87545. NR 14 TC 3 Z9 3 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD SEP PY 1996 VL 38 IS 9 BP 851 EP 856 DI 10.1002/(SICI)1099-1344(199609)38:9<851::AID-JLCR894>3.0.CO;2-8 PG 6 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA VD399 UT WOS:A1996VD39900009 ER PT J AU Cynober, T Mohandas, N Tchernia, G AF Cynober, T Mohandas, N Tchernia, G TI Red cell abnormalities in hereditary spherocytosis: Relevance to diagnosis and understanding of the variable expression of clinical severity SO JOURNAL OF LABORATORY AND CLINICAL MEDICINE LA English DT Article ID HEMOGLOBIN-SC DISEASE; OSMOTIC FRAGILITY; LIGHT-SCATTERING; MEMBRANE; DEFORMABILITY; SPLENECTOMY; VOLUME; EKTACYTOMETRY; ERYTHROCYTES; DISORDERS AB Marked variations in the clinical manifestations of hereditary spherocytosis (HS) have long been recognized. However, neither the molecular nor the cellular basis for this variable expression has been fully delineated. To better define the cellular basis for variable expression of the disease, we evaluated the pathobiology of red cells in a large series of 55 non-splenectomized and 31 splenectomized patients with HS. Red cell membrane surface area, surface area-to-volume ratio, cell volume, and state of cell hydration were quantitated. We found that decreased membrane surface area was a distinguishing feature of red cells in all patients studied, whereas decreased surface area-to-volume ratio as reflected by increased osmotic fragility was noted in only 66% of the non-splenectomized patients. In terms of red cell indexes, the percentage of microcytes was not a good discriminator of HS phenotype but was the best indicator of the severity of the disease. In contrast, the presence of increased numbers of hyperdense cells was an effective discriminating feature of the HS phenotype but a poor indicator of disease severity. These findings have enabled us to define the dominant cellular changes that account for the variable clinical severity of this common red cell membrane disorder and have allowed development of improved approaches for ifs diagnosis. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. HOP BICETRE,HEMATOL LAB,LE KREMLIN BICETR,FRANCE. FU NIDDK NIH HHS [DK26263] NR 39 TC 76 Z9 78 U1 0 U2 2 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 SEP PY 1996 VL 128 IS 3 BP 259 EP 269 DI 10.1016/S0022-2143(96)90027-X PG 11 WC Medical Laboratory Technology; Medicine, General & Internal; Medicine, Research & Experimental SC Medical Laboratory Technology; General & Internal Medicine; Research & Experimental Medicine GA VG398 UT WOS:A1996VG39800008 PM 8783633 ER PT J AU Hauser, J Malouf, DB AF Hauser, J Malouf, DB TI A federal perspective on special education technology SO JOURNAL OF LEARNING DISABILITIES LA English DT Article ID LEARNING-DISABILITIES AB This article examines more than a decade of changes in special education research and in the use of technology. It discusses evolving research and projects funded by the Office of Special Education Programs (OSEP) and raises questions about the use of specific methodologies and about whether children with disabilities are being prepared fur the world in which they will live. And, finally, it describes OSEP's Technology, Educational Media, and Materials strategic program agenda that will drive future planning and priorities. RP Hauser, J (reprint author), US DOE,DIV INNOVAT & DEV,OFF SPECIAL EDUC PROGRAMS,OFF SPECIAL EDUC & REHABIL SERV,WASHINGTON,DC 20202, USA. NR 27 TC 2 Z9 2 U1 0 U2 2 PU PRO-ED INC PI AUSTIN PA 8700 SHOAL CREEK BLVD, AUSTIN, TX 78757-6897 SN 0022-2194 J9 J LEARN DISABIL JI J. Learn. Disabil. PD SEP PY 1996 VL 29 IS 5 BP 504 EP 511 PG 8 WC Education, Special; Rehabilitation SC Education & Educational Research; Rehabilitation GA VJ057 UT WOS:A1996VJ05700005 PM 8870520 ER PT J AU Lynam, EB Rogelj, S Edwards, BS Sklar, LA AF Lynam, EB Rogelj, S Edwards, BS Sklar, LA TI Enhanced aggregation of human neutrophils by MnCl2 or DTT differentiates the roles of L-selectin and beta(2)-integrins SO JOURNAL OF LEUKOCYTE BIOLOGY LA English DT Article DE flow cytometry; DREG200; IB4; PMN adhesion ID COMPLEMENT RECEPTOR TYPE-3; LEUKOCYTE ADHESION; CD11B/CD18 MAC-1; CR3-DEPENDENT ADHESION; MONOCLONAL-ANTIBODY; BETA-2 INTEGRINS; REDUCING AGENTS; FLOW-CYTOMETRY; ALPHA-SUBUNIT; PHORBOL ESTER AB MnCl2 and dithiothreitol (DTT) enhance the adhesive functions of beta(2)-integrins. We have used these agents and flow cytometry to distinguish the contributions of beta(2)-integrins and L-selectin to neutrophil aggregation. Although neither compound induced aggregation, they prolonged N-formyl-methionyl-leucyl-phenylalanine -induced aggregation and produced larger aggregates. Because activated polymorphonuclear granulocytes (PMN) shed L-selectin in the presence of MnCl2, but not DTT, we could evaluate the role of L-selectin in the early and late stages of aggregation. Blocking L-selectin sites with DREG200 Fab and/or beta(2)-integrin sites with IB4 Fab indicated that aggregation under all conditions remained beta(2)-integrin- and L-selectin-dependent. Disaggregation was integrin-dependent whether L-selectin was present or shed. The disaggregation kinetics suggested that integrin bonds turned over at a slower rate in MnCl2-treated cells. Enhanced aggregation due to DTT and MnCl2 retired sustained energy output, suggesting intracellular rather than strictly conformational control. These results provide evidence that PMN aggregation, like leukocyte-endothelial cell adhesion, utilizes L-selectin to form intercellular contacts that are maintained through activated integrins. C1 UNIV NEW MEXICO,SCH MED,DEPT PATHOL,CANC RES & TREATMENT CTR,ALBUQUERQUE,NM 87131. LOVELACE INST,INST BASIC & APPL MED RES,ALBUQUERQUE,NM. LOS ALAMOS NATL LAB,NATL FLOW CYTOMETRY RESOURCE,LOS ALAMOS,NM. FU NCRR NIH HHS [RR-01315]; NHLBI NIH HHS [HL-43026]; NIGMS NIH HHS [GM-37696] NR 35 TC 9 Z9 9 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0741-5400 J9 J LEUKOCYTE BIOL JI J. Leukoc. Biol. PD SEP PY 1996 VL 60 IS 3 BP 356 EP 364 PG 9 WC Cell Biology; Hematology; Immunology SC Cell Biology; Hematology; Immunology GA VH464 UT WOS:A1996VH46400009 PM 8830792 ER PT J AU Bayramian, AJ Marshall, CD Wu, JH Speth, JA Payne, SA Quarles, GJ Castillo, VK AF Bayramian, AJ Marshall, CD Wu, JH Speth, JA Payne, SA Quarles, GJ Castillo, VK TI Ce:LiSrAlF6 laser performance with antisolarant pump beam SO JOURNAL OF LUMINESCENCE LA English DT Article DE Ce:LiSrAlF6 crystals; pump beam; laser performance ID EXCITED-STATE-ABSORPTION; ULTRAVIOLET-LASER; PHOTOIONIZATION; CE-3+-YAG; CRYSTAL; LISAF; CE3+; IONS; NM AB We have explored the impact of 266 nm pump-induced solarization on the 290 nm laser performance of Ce:LiSrAlF6 crystals. Among the issues considered are the incorporation of codopants (e.g. Na+, Mg2+,Zn2+), and the use of an additional 532 nm beam to rapidly destroy the interfering color centers. The solarization mechanism has been unraveled and found to involve two-photon creation of color centers (via the 4f --> 5d -->, conduction band pathway of Ce3+), followed by the one-photon bleaching of the color centers. Ce:LiSrAlF6 (Ce:LiSAF) laser slope efficiencies as high as 47% can be achieved with the simultaneous introduction of the 266 nm pump and 532 nm bleaching beams; 33% with the 266 nm beam only. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. LIGHTNING OPT CORP,TARPON SPRINGS,FL 34689. NR 25 TC 28 Z9 28 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD SEP PY 1996 VL 69 IS 2 BP 85 EP 94 DI 10.1016/0022-2313(96)00081-6 PG 10 WC Optics SC Optics GA VJ720 UT WOS:A1996VJ72000003 ER PT J AU Dikanov, SA Davydov, RM Xun, LY Bowman, MK AF Dikanov, SA Davydov, RM Xun, LY Bowman, MK TI CW and pulsed EPR characterization of the reduction of the Rieske-type iron-sulfur cluster in 2,4,5-trichlorophenoxyacetate monooxygenase SO JOURNAL OF MAGNETIC RESONANCE SERIES B LA English DT Article ID ECHO ENVELOPE MODULATION; PSEUDOMONAS-CEPACIA AC1100; Q-BAND ENDOR; ESCHERICHIA-COLI; MITOCHONDRIAL-MEMBRANES; PHTHALATE DIOXYGENASE; QUADRUPOLE-RESONANCE; FUMARATE REDUCTASE; 2FE-2S CLUSTER; 2 HISTIDINES C1 RUSSIAN ACAD SCI, INST CHEM KINET & COMBUST, NOVOSIBIRSK 630090, RUSSIA. RUSSIAN ACAD SCI, INST CHEM PHYS, MOSCOW 117977, RUSSIA. WASHINGTON STATE UNIV, DEPT MICROBIOL & IMMUNOL, RICHLAND, WA 99352 USA. RP Dikanov, SA (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 39 TC 9 Z9 9 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1064-1866 J9 J MAGN RESON SER B JI J. Magn. Reson. Ser. B PD SEP PY 1996 VL 112 IS 3 BP 289 EP 294 DI 10.1006/jmrb.1996.0144 PG 6 WC Physics, Atomic, Molecular & Chemical SC Physics GA VH454 UT WOS:A1996VH45400012 ER PT J AU Xiong, X Zhu, Q Li, ZG Moss, SC Feng, HH Hor, PH Cox, DE Bhavaraju, S Jacobson, AJ AF Xiong, X Zhu, Q Li, ZG Moss, SC Feng, HH Hor, PH Cox, DE Bhavaraju, S Jacobson, AJ TI Synchrotron x-ray study of interstitial oxygen ordering in the superconducting phase of La2CuO4+delta SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID DIFFRACTION; SEPARATION; NEUTRON AB A synchrotron x-ray powder-diffraction study has been carried out on two samples with well-defined excess oxygen concentrations, delta = 0.045 and 0.055. Evidence for one-dimensional interstitial oxygen ordering along the c-axis was observed from the appearance of a pair of superlattice satellite peaks at (0, 1, 2 +/- Delta) in both samples. In La2CuO4.045, a similar to 5% oxygen-poor Bmab phase coexists with a stage-6 phase and with a small amount of the high-temperature-tetragonal (HTT) phase below the phase separation temperature (similar to 280 K), La2CuO4.055 shows a single stage-5 phase below 170 K, but with two unindexed peaks between (0, 1, 2 +/- 0.2) satellites which may well result from a further domain modulation, The critical temperature T-c is increased by 1.5 K by reducing the stage number from 6 to 5. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. RP Xiong, X (reprint author), UNIV HOUSTON,TEXAS CTR SUPERCOND,HOUSTON,TX 77204, USA. NR 12 TC 9 Z9 9 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1996 VL 11 IS 9 BP 2121 EP 2124 DI 10.1557/JMR.1996.0268 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800001 ER PT J AU Lograsso, TA Delaney, DW AF Lograsso, TA Delaney, DW TI Preparation of large single grains of the quasicrystalline icosahedral Al-Cu-Fe psi phase SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID QUASI-CRYSTALS; DIAGRAM; SYSTEM; ALLOYS AB A cyclic heat-treatment process was used to prepare single grains of the quasicrystalline icosahedral phase, psi-Al65Cu23Fe12 Alloys of appropriate composition are melted and chill cast into copper molds. Multiple cyclic heat treatments at successively higher temperatures below 860 degrees C, the peritectic decomposition temperature of the quasicrystal phase, are used to enhance the growth of the psi phase. Single grains up to 10 mm x 5 mm x 5 mm have been prepared. RP Lograsso, TA (reprint author), IOWA STATE UNIV,US DOE,AMES LAB,MET & CERAM PROGRAM,AMES,IA 50011, USA. NR 12 TC 37 Z9 37 U1 0 U2 0 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 SEP PY 1996 VL 11 IS 9 BP 2125 EP 2127 DI 10.1557/JMR.1996.0269 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800002 ER PT J AU Holesinger, TG AF Holesinger, TG TI Al2O3 additions for isothermal melt processing of Bi2Sr2CaCu2Oy SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CA-CU-O; BI-2212 THICK-FILMS; PHASE; GLASSES; OXYGEN; SYSTEM; WIRES; TAPES AB It is shown that additions of Al2O3 (1.0 wt.%) can significantly aid in the isothermal melt processing of Bi2Sr2CaCu2Oy (Bi-2212). Al2O3 additions provide a means for grain refinement of phases present in the partial melt. By limiting grain growth in the partial melt, solidification to form Bi-2212 proceeds more efficiently, resulting in fewer secondary phases and improved transport properties. Aluminum does not substitute into the superconducting phase to any appreciable extent and is present in fully processed material as small, secondary grains of approximate composition Sr2-xCaxAlOy or Bi2Sr4-xCaxAl3Oy. Al2O3 additions were applied to the isothermal melt processing of Bi-2212 thick films and current leads. RP Holesinger, TG (reprint author), LOS ALAMOS NATL LAB,SUPERCOND TECHNOL CTR,LOS ALAMOS,NM 87545, USA. NR 18 TC 19 Z9 19 U1 0 U2 0 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 SEP PY 1996 VL 11 IS 9 BP 2135 EP 2141 DI 10.1557/JMR.1996.0272 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800005 ER PT J AU Weihnacht, V Fan, WD Jagannadham, K Narayan, J Liu, CT AF Weihnacht, V Fan, WD Jagannadham, K Narayan, J Liu, CT TI A new design of tungsten carbide tools with diamond coatings SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ADHESION AB We have designed tungsten carbide tools with a new binder, which makes them suitable for advanced diamond tool coatings. The new tool substrates, made of tungsten carbide and nickel aluminide as binder phase, are produced by sintering and hot isostatic pressing, and also by combustion synthesis. The high temperature strength of nickel aluminide is key to superior tool performance at elevated temperatures. More importantly, nickel aluminides reduce the formation of graphite and promote diamond growth during chemical vapor deposition. Diamond films are deposited on the new tool substrates to investigate the nucleation density, adhesion, and wear resistance, The diamond coatings are characterized by scanning electron microscopy and Raman spectroscopy. The graphitizing tendency due to cobalt in the tungsten carbide tools was found to be a limitation to improve adhesion of diamond films. The new tool substrates with nickel aluminide binder have been found to exhibit good adhesion and wear resistance. The implications of these results in advanced cutting tools are discussed. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Weihnacht, V (reprint author), N CAROLINA STATE UNIV,DEPT MAT SCI & ENGN,RALEIGH,NC 27695, USA. RI Jagannadham, Kasichainula/A-2953-2008; Narayan, Jagdish/D-1874-2009; OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 12 TC 9 Z9 9 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1996 VL 11 IS 9 BP 2220 EP 2230 DI 10.1557/JMR.1996.0282 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800015 ER PT J AU Smith, LL Davis, RF Kim, MJ Carpenter, RW Huang, Y AF Smith, LL Davis, RF Kim, MJ Carpenter, RW Huang, Y TI Microstructure, electrical properties, and thermal stability of Al ohmic contacts to n-GaN SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID V COMPOUND SEMICONDUCTORS; BARRIER; GAAS AB As-deposited Al contacts were ohmic with a room-temperature contact resistivity of 8.6 x 10(-5) Ohm . cm(2) on Ge-doped, highly n-type GaN (n = 5 x 10(19) cm(-3)). They remained thermally stable to at least 500 degrees C, under flowing N-2 at atmospheric pressure. The specific contact resistivities (rho(c)) calculated from TLM measurements on as-deposited Al layers were found to range from 8.6 x 10(-5) Ohm . cm(2) at room temperature and 6.2 x 10(-5) Ohm . cm(2) at 500 degrees C. Annealing treatments at 550 degrees C and 650 degrees C for 60 s each under flowing N-2 resulted in an overall increase of contact resistivity. Cross-sectional, high-resolution electron microscopy (HREM) revealed that interfacial secondary phase formation occurred during high-temperature treatments, and coincided with the degradation of contact performance. Electron diffraction patterns from the particles revealed a cubic structure with lattice constant n = 0.784 nm, and faceting occurring on the {100} faces. Spectroscopic analysis via electron energy loss spectroscopy (EELS) revealed the presence of nitrogen and small amounts of oxygen in the Al layer, but no appreciable amounts of Ga. The results of microstructural and crystallographic characterization indicate that the new interfacial phase is a type of spinel Al nitride or Al oxynitride. C1 ARIZONA STATE UNIV, CTR SOLID STATE SCI, TEMPE, AZ 85287 USA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP N CAROLINA STATE UNIV, MAT RES CTR, RALEIGH, NC 27695 USA. RI Kim, Moon/A-2297-2010; Davis, Robert/A-9376-2011 OI Davis, Robert/0000-0002-4437-0885 NR 24 TC 29 Z9 31 U1 1 U2 7 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1996 VL 11 IS 9 BP 2257 EP 2262 DI 10.1557/JMR.1996.0286 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800019 ER PT J AU Jia, QX Chu, F Adams, CD Wu, XD Hawley, M Cho, JH Findikoglu, AT Foltyn, SR Smith, JL Mitchell, TE AF Jia, QX Chu, F Adams, CD Wu, XD Hawley, M Cho, JH Findikoglu, AT Foltyn, SR Smith, JL Mitchell, TE TI Characteristics of conductive SrRuO3 thin films with different microstructures SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTRICAL-PROPERTIES; ELECTRODES AB Conductive SrRuO3 thin films were epitaxially grown on (100) LaAlO3 substrates by pulsed laser deposition over a temperature range from 650 degrees C to 825 degrees C. Well-textured films exhibiting a strong orientation relationship to the underlying substrate could be obtained at a deposition temperature as low as 450 degrees C. The degree of crystallinity of the films improved with increasing deposition temperature as confirmed by x-ray diffraction, transmission electron microscopy, and scanning tunneling microscopy. Scanning electron microscopy revealed no particulates on the film surface. The resistivity of the SrRuO3 thin films was found to be a strong function of the crystallinity of the film and hence the substrate temperature during film deposition. A residual resistivity ratio (RRR = rho(300 K)/rho(4.2 K)) of more than 8 was obtained for the SrRuO3 thin films deposited under optimized processing conditions. RP Jia, QX (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 13 TC 37 Z9 38 U1 0 U2 8 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 SEP PY 1996 VL 11 IS 9 BP 2263 EP 2268 DI 10.1557/JMR.1996.0287 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800020 ER PT J AU Boyle, TJ Buchheit, CD Rodriguez, MA AlShareef, HN Hernandez, BA Scott, B Ziller, JW AF Boyle, TJ Buchheit, CD Rodriguez, MA AlShareef, HN Hernandez, BA Scott, B Ziller, JW TI Formation of SrBi2Ta2O9 .1. Synthesis and characterization of a novel ''sol-gel'' solution for production of ferroelectric SrBi2Ta2O9 thin films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB We have developed a simple and rapid method for the synthesis of a precursor solution used in the production of SET powders and thin films of the layered-perovskite phase SrBi2Ta2O9 (SET). Precursor solution preparation takes less than 30 min and involves the generation of two solutions: (a) Bi(O(2)CMe)(3) dissolved in pyridine and (b) Ta(OCH(2)Me)(5) added to Sr(O(2)CMe)(2) and then solubilized by HO(2)CMe. After stirring separately for 10 min, these solutions are combined, stirred for an additional 10 min, and used without any further modifications. The individual solutions and ternary mixture were studied using a variety of analytical techniques. Films of the layered-perovskite phase were formed at temperatures as low as 700 degrees C. Ferroelectric testing of SET films, fired at 750 degrees C, reveals standard hysteresis loops with no fatigue for up to 4 x 10(9) cycles. C1 LOS ALAMOS NATL LAB,XRAY DIFFRACT LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. UNIV CALIF IRVINE,DEPT CHEM,XRAY DIFFRACT LAB,IRVINE,CA 92717. RP Boyle, TJ (reprint author), SANDIA NATL LABS,ADV MAT LAB,1001 UNIV BLVD SE,ALBUQUERQUE,NM 87106, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 23 TC 113 Z9 115 U1 0 U2 10 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 SEP PY 1996 VL 11 IS 9 BP 2274 EP 2281 DI 10.1557/JMR.1996.0289 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800022 ER PT J AU Rodriguez, MA Boyle, TJ Hernandez, BA Buchheit, CD Eatough, MO AF Rodriguez, MA Boyle, TJ Hernandez, BA Buchheit, CD Eatough, MO TI Formation of SrBi2Ta2O9 .2. Evidence of a bismuth-deficient pyrochlore phase SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; EVOLUTION AB A bismuth-deficient pyrochlore phase has been observed in both powder and film samples fired at 775 degrees C. The estimated stoichiometry of this pyrochlore (based on calculated diffraction patterns) was Sr-0.2(Sr0.5Bi0.7)Ta2O6.75. This bismuth-deficient pyrochlore phase may be considered deleterious to the formation of the SrBi2Ta2O9 ''SET'' ferroelectric compound since a significant presence of this pyrochlore compound implies a large deviation from the desired cation ratios. Additionally, films prepared on platinized silicon substrates indicate the SBT phase formation may be encouraged by the substrate; there appears to be some 00l preferential orientation for stoichiometric SBT thin films. RP Rodriguez, MA (reprint author), SANDIA NATL LABS,POB 5800,MS 1405,ALBUQUERQUE,NM 87185, USA. NR 17 TC 99 Z9 99 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 SEP PY 1996 VL 11 IS 9 BP 2282 EP 2287 DI 10.1557/JMR.1996.0290 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800023 ER PT J AU Tuttle, BA Headley, TJ AlShareef, HN Voigt, JA Rodriguez, M Michael, J Warren, WL AF Tuttle, BA Headley, TJ AlShareef, HN Voigt, JA Rodriguez, M Michael, J Warren, WL TI Microstructure and 90 degrees domain assemblages of Pb(Zr,Ti)O-3//RuO2 capacitors as a function of Zr-to-Ti stoichiometry SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; ELECTRICAL-PROPERTIES; ELECTRODES; EVOLUTION AB Planar microstructure, 90 degrees domain configurations, and cross-sectional perovskite grain morphology were characterized for a series of Pb(Zr, Ti)O-3//RuO2 thin film capacitors. Perovskite grain size increased substantially with increasing Zr concentration of the Pb(Zr, Ti)O-3 (PZT) films, being on the order of 0.15 mu m for PZT 20/80 films and 2.5 mu m for PZT 50/50 films. While PZT 20/80 and PZT 30/70 films were single phase perovskite, the PZT 40/60 and 50/50 films contained a second phase with fluorite structure. The second phase matrix consisted of two nanophases, one having fluorite structure while the other was amorphous. Both the amorphous nanophase and the fluorite nanophase were Pb deficient compared to the perovskite phase. Differences in cross-sectional perovskite grain morphology were substantial for these materials, with the PZT 40/60 film being almost entirely columnar and the PZT 20/80 film exhibiting almost entirely granular morphology. Differences in 90 degrees domain wall density were essentially negligible among the films, suggesting that if 90 degrees domains were responsible for the differences in electrical properties, it is not due to 90 degrees domain population. RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 22 TC 19 Z9 19 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1996 VL 11 IS 9 BP 2309 EP 2317 DI 10.1557/JMR.1996.0294 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800027 ER PT J AU Maleki, H Holland, LR Jenkins, GM Zimmerman, RL Porter, W AF Maleki, H Holland, LR Jenkins, GM Zimmerman, RL Porter, W TI Maximum heating rates for producing undistorted glassy carbon ware determined by wedge-shaped samples SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Polymeric carbon artifacts are particularly difficult to make in thick section, Heating rate, temperature, and sample thickness determine the outcome of carbonization of resin leading to a glassy polymeric carbon ware. Using wedge-shaped samples, we found the maximum thickness for various heating rates during gelling (300 K-360 K), curing (360 K-400 K), postcuring (400 K-500 K), and precarbonization (500 K-875 K). Excessive heating rate causes failure, In postcuring the critical heating rate varies inversely as the fifth power of thickness; in precarbonization this varies inversely as the third power of thickness. From thermogravimetric evidence we attribute such failure to low rates of diffusion of gaseous products of reactions occurring within the solid during pyrolysis, Mass spectrometry shows the main gaseous product is water vapor; some carboniferous gases are also evolved during precarbonization. We discuss a diffusion model applicable to any heat-treatment process in which volatile products are removed from solid bodies. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Maleki, H (reprint author), ALABAMA A&M UNIV,DEPT PHYS,CTR IRRADIAT MAT,NORMAL,AL 35762, USA. NR 9 TC 14 Z9 14 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 SEP PY 1996 VL 11 IS 9 BP 2368 EP 2375 DI 10.1557/JMR.1996.0300 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800033 ER PT J AU Mahan, GD AF Mahan, GD TI Quantum Boltzmann equation for photons SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID FLUCTUATIONS; PROPAGATION; SCATTERING AB The quantum Boltzmann equation is derived for photons. The form of the scattering and absorption terms for the case of photon diffusion is discussed in detail. We show how the structure factor of the scattering centers enters into the scattering rate of the photons. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Mahan, GD (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 25 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD SEP PY 1996 VL 37 IS 9 BP 4333 EP 4351 DI 10.1063/1.531661 PG 19 WC Physics, Mathematical SC Physics GA VG131 UT WOS:A1996VG13100010 ER PT J AU Steinacker, H AF Steinacker, H TI Integration on quantum Euclidean space and sphere SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article AB Invariant integrals of functions and forms over q-deformed Euclidean space and spheres in N dimensions are defined and shown to be positive definite, compatible with the star structure and to satisfy a cyclic property involving the D matrix of SOq(N). The definition is based on spherical and radial integration. Stokes theorem is proved with and without spherical boundary terms, as well as on the sphere. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP Steinacker, H (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Steinacker, Harold/0000-0002-3440-8827 NR 15 TC 12 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD SEP PY 1996 VL 37 IS 9 BP 4738 EP 4749 DI 10.1063/1.531658 PG 12 WC Physics, Mathematical SC Physics GA VG131 UT WOS:A1996VG13100035 ER PT J AU Huynen, MA AF Huynen, MA TI Exploring phenotype space through neutral evolution SO JOURNAL OF MOLECULAR EVOLUTION LA English DT Article DE RNA secondary structure; neutral evolution; adaptive evolution; genotype-phenotype relation; sequence space; fitness landscape ID RNA SECONDARY STRUCTURES; SEQUENCES AB RNA secondary-structure folding algorithms predict the existence of connected networks of RNA sequences with identical secondary structures. Fitness landscapes that are based on the mapping between RNA sequence and RNA secondary structure hence have many neutral paths. A neutral walk on these fitness landscapes gives access to a virtually unlimited number of secondary structures that are a single point mutation from the neutral path. This shows that neutral evolution explores phenotype space and can play a role in adaptation. C1 SANTA FE INST,SANTA FE,NM 87501. RP Huynen, MA (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS-K710,LOS ALAMOS,NM 87545, USA. RI Huynen, Martijn/A-1530-2014 NR 15 TC 109 Z9 110 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0022-2844 J9 J MOL EVOL JI J. Mol. Evol. PD SEP PY 1996 VL 43 IS 3 BP 165 EP 169 PG 5 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA VF808 UT WOS:A1996VF80800001 PM 8703081 ER PT J AU Maloney, KM Grandbois, M Salesse, C Grainger, DW Reichert, A AF Maloney, KM Grandbois, M Salesse, C Grainger, DW Reichert, A TI Membrane microstructural templates for enzyme domain formation SO JOURNAL OF MOLECULAR RECOGNITION LA English DT Article DE proteins; lipid monolayers; interfacial recognition; membranes; domains; two-dimensional crystallization ID FLUORESCENCE MICROSCOPY; MONOLAYERS; INTERFACE; BINDING; PHOSPHOLIPASE-A2; LECITHIN; LIQUID AB Soluble proteins can spontaneously self-organize into two-dimensional domains at membrane interfaces, given sufficient mobility and specificity to membrane-localized ligands, The authors' recent results studying interfacial domain formation of the membrane-active enzyme, phospholipase A(2), indicate that latertal phase separation of heterogeneous membrane mixtures creates anionic templates of specific morphology onto which the enzyme deposits, forming large protein assemblies, Selective removal of membrane components (lysolipid or fatty acid) produces different enzyme interfacial responses and domain morphologies, This leads to the conclusion that complex chemical acid physical interactions laterally in the lipid membrane interface as well as between bound protein molecules play a role in organizing protein structures. C1 OREGON GRAD INST SCI & TECHNOL,DEPT CHEM BIOCHEM & MOL BIOL,PORTLAND,OR. UNIV QUEBEC,CTR RECH PHOTOBIOPHYS,TROIS RIVIERES,PQ G9A 5H7,CANADA. COLORADO STATE UNIV,DEPT CHEM,FT COLLINS,CO 80523. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. NR 17 TC 9 Z9 9 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0952-3499 J9 J MOL RECOGNIT JI J. Mol. Recognit. PD SEP-DEC PY 1996 VL 9 IS 5-6 BP 368 EP 374 DI 10.1002/(SICI)1099-1352(199634/12)9:5/6<368::AID-JMR267>3.0.CO;2-S PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WZ027 UT WOS:A1996WZ02700010 PM 9174912 ER PT J AU Devanathan, R Yu, N Sickafus, KE Nastasi, M AF Devanathan, R Yu, N Sickafus, KE Nastasi, M TI Structure and mechanical properties of irradiated magnesium aluminate spinel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID SOLID-STATE AMORPHIZATION; MGAL2O4; MICROSTRUCTURE; HARDNESS; MGO AB The relationship between structure and mechanical properties of MgAl2O4 spinel single crystals following 400 keV Xe2+ irradiation at 100 K to doses up to 1 x 10(20) ions/m(2) was examined. The structural changes in the irradiated layer were studied using electron diffraction from cross-sectional samples. The nano-indentation technique was used to determine the mechanical properties. At low doses, the material transformed into a metastable crystalline phase characterized by the rearrangement of cations. At the onset of this transformation, the Young's modulus and hardness rose to values about 10 and 15% higher, respectively, than those of the unirradiated crystal. Upon further irradiation, the metastable crystal became amorphous. The Young's modulus and hardness of the amorphous state were about 30 and 60% less, respectively, than the corresponding values of unirradiated spinel. These results, in conjunction with the findings of a recent computer simulation study, provide important insights into the exceptional radiation resistance of magnesium aluminate spinel. RP Devanathan, R (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Devanathan, Ram/C-7247-2008 OI Devanathan, Ram/0000-0001-8125-4237 NR 19 TC 34 Z9 34 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1996 VL 232 IS 1 BP 59 EP 64 DI 10.1016/0022-3115(96)00388-1 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA VM110 UT WOS:A1996VM11000007 ER PT J AU Watanabe, S Sakaguchi, N Hashimoto, N Nakamura, M Takahashi, H Namba, C Lam, NQ AF Watanabe, S Sakaguchi, N Hashimoto, N Nakamura, M Takahashi, H Namba, C Lam, NQ TI Radiation-induced segregation accompanied by grain boundary migration in austenitic stainless steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID TERNARY ALLOYS; IRRADIATION; BINARY AB A computer simulation and an electron irradiation in a high voltage electron microscope (1000 kV) were used to study radiation-induced solute segregation and point defect flow in typical austenitic Fe-Cr-Ni alloys. The calculation was conducted by solving the coupled rate equations for solute and defect concentrations considering the Kirkendall effect at a moving grain boundary sink. The experimental solute redistribution profiles were explained qualitatively. Redistribution of nickel and chromium solutes near the grain boundaries and simultaneously grain boundary migration occurred during irradiation. The amount of nickel enrichment at a grain boundary was especially remarkable, comparing to the amount of chromium depletion. It is suggested that grain boundary migration may contribute to the flow of under-sized nickel solute toward the boundary. The influence of the probe size on EDS analysis of compositional profiles was investigated, with some experimental data. C1 NATL INST FUS SCI,DATA & PLANNING CTR,NAGOYA,AICHI 46401,JAPAN. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Watanabe, S (reprint author), HOKKAIDO UNIV,CTR ADV RES ENERGY TECHNOL,SAPPORO,HOKKAIDO 060,JAPAN. RI Sakaguchi, Norihito/A-6652-2012; HASHIMOTO, Naoyuki/D-6366-2012; seiichi, watanabe/E-2622-2012 NR 18 TC 11 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1996 VL 232 IS 2-3 BP 113 EP 118 DI 10.1016/S0022-3115(96)00433-3 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA VV600 UT WOS:A1996VV60000003 ER PT J AU Heinisch, HL Singh, BN AF Heinisch, HL Singh, BN TI Stochastic annealing simulation of differential defect production in high energy cascades SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID MOLECULAR-DYNAMICS; DISPLACEMENT CASCADES; COLLISION CASCADES; PRODUCTION BIAS; COPPER; TRANSIENT AB Recent molecular dynamics (MD) studies have confirmed that significant clustering of both vacancies and self-interstitial atoms (SIAs) rakes place by the end of the quenching stage of a cascade, and that small interstitial clusters are glissile, with migration energies on the oi del of 0.1 eV. The spatial segregation and clustering of the vacancies and SIAs give rise to a differential production of mobile vacancies and SIAs that has a strong temperature dependence. At temperatures above recovery Stage V, vacancies can evaporate from clusters, while large SIA clusters produced in the cascade remain stable, leading to a differential increase of mobile vacancies that represents a 'production bias' thai may be responsible for void swelling. The stochastic annealing simulation code ALSOME is used to investigate quantitatively the differential production of mobile vacancy and SIA defects as a function of temperature for isolated 25 keV cascades in copper generated by MD simulations. The ALSOME code and cascade annealing simulations are described, The annealing simulations indicate that above Stage V, where the cascade vacancy clusters are unstable, nearly 80% of the post-quench vacancies escape the cascade volume, while about half of the post-quench SIAs remain in clusters. The results are sensitive to the relative fractions of SIAs that reside in small, highly mobile clusters and in large, sessile clusters, respectively, which may depend on the cascade energy. C1 RISO NATL LAB, DEPT MAT, DK-4000 ROSKILDE, DENMARK. RP Heinisch, HL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 23 TC 25 Z9 26 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1996 VL 232 IS 2-3 BP 206 EP 213 DI 10.1016/S0022-3115(96)00434-5 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA VV600 UT WOS:A1996VV60000014 ER PT J AU Cooke, DW Bennett, BL Farnum, EH AF Cooke, DW Bennett, BL Farnum, EH TI Optical absorption of neutron-irradiated silica fibers SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID FUNDAMENTAL DEFECT CENTERS; HIGH-PURITY; SYNTHETIC SILICA; FUSED-SILICA; SIO2; LUMINESCENCE; OXYGEN; BANDS; GLASS AB Silica-based optical Fibers capable of transmitting light in the ultraviolet, visible and infrared regions of the electromagnetic spectrum are gaining widespread use in fusion reactor diagnostic systems, To assess radiation damage in these optical materials, the optical absorption has been measured al room temperature in the interval 250-2000 nm of neutron-irradiated silica fibers containing low or high hydroxyl concentrations. Fiber irradiations were done in either low (1.4 x 10(21) n/m(2)) or high (1.1 x 10(23) n/m(2)) neutron fluence (E > 0.1 MeV) regions of the Los Alamos Spallation Radiation Effects Facility. Attenuation in high-fluence irradiated fibers exceeds 10(4) dB/km for wavelengths less than about 700 nm, presumably due to radiation-induced absorption of peroxy radical, non-bridging oxygen hole and E'-type centers. Even the low fluence exposures induced considerable fiber absorption in this spectral region. High-OH content fibers exhibit significant radiation-induced absorption above 1500 nm, in addition to the intrinsic absorption due to OH stretching modes. RP Cooke, DW (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 24 TC 16 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 1996 VL 232 IS 2-3 BP 214 EP 218 DI 10.1016/S0022-3115(96)00405-9 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA VV600 UT WOS:A1996VV60000015 ER PT J AU Pentlow, KS Graham, MC Lambrecht, RM Daghighian, F Bacharach, SL Bendriem, B Finn, RD Jordan, K Kalaigian, H Karp, JS Robeson, WR Larson, SM AF Pentlow, KS Graham, MC Lambrecht, RM Daghighian, F Bacharach, SL Bendriem, B Finn, RD Jordan, K Kalaigian, H Karp, JS Robeson, WR Larson, SM TI Quantitative imaging of iodine-124 with PET SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE PET; iodine-124; quantitative imaging ID POSITRON EMISSION TOMOGRAPHY; MONOCLONAL-ANTIBODIES; COMPUTED-TOMOGRAPHY; PERFORMANCE-CHARACTERISTICS; NEURO-BLASTOMA; BREAST-CANCER; HUMAN TUMOR; I-124; RADIOIMMUNOTHERAPY; DOSIMETRY AB PET is potentially very useful for the accurate in vivo quantitation of time-varying biological distributions of radiolabeled antibodies over several days. The short half-lives of most commonly used positron-emitting nuclides make them unsuitable for this purpose. Iodine-124 is a positron emitter with a half-life of 4.2 days and appropriate chemical properties. It has not been widely used because of a complex decay scheme including several high energy gamma rays. However, measurements made under realistic conditions on several different PET scanners have shown that satisfactory imaging and quantitation can be achieved. Methods: Whole-body and head-optimized scanners with different detectors (discrete BGO, block BGO and BaF2 time-of-flight), different septa and different correction schemes were used. Measurements of resolution, quantitative linearity and the ability to quantitatively image spheres of different sizes and activities in different background activities were made using phantoms. Results: Compared with conventional PET nuclides, resolution and quantitation were only slightly degraded. Sphere detectability was also only slightly worse if imaging time was increased to compensate for the lower positron abundance. Conclusion: Quantitative imaging with I-124 appears to be possible under realistic conditions with various PET scanners. C1 MEM SLOAN KETTERING CANC CTR,DEPT RADIOL,NEW YORK,NY 10021. N SHORE UNIV HOSP,MANHASSET,NY. NIH,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,UPTON,NY 11973. HANNOVER MED SCH,HANNOVER,GERMANY. HOSP UNIV PENN,PHILADELPHIA,PA 19104. KING FAISAL SPECIALIST HOSP & RES CTR,RIYADH 11211,SAUDI ARABIA. RP Pentlow, KS (reprint author), MEM SLOAN KETTERING CANC CTR,DEPT MED PHYS,1275 YORK AVE,NEW YORK,NY 10021, USA. NR 34 TC 122 Z9 122 U1 0 U2 6 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 1996 VL 37 IS 9 BP 1557 EP 1562 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VF797 UT WOS:A1996VF79700043 PM 8790218 ER PT J AU Gerschel, C Hufner, J Quack, E AF Gerschel, C Hufner, J Quack, E TI Empirical regularities in the x-dependence of J/Psi suppression in hadron-nucleus collisions SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID HEAVY-QUARK PRODUCTION; TRANSVERSE-MOMENTUM DEPENDENCE; J-PSI PRODUCTION; QCD CORRECTIONS; CROSS-SECTION; 800 GEV/C; TARGETS; PROTON AB The measured ratios R(x, A(1)/A(2)) for J/Psi, Psi' and mu(+)mu(-) production on two different nuclear targets A(1), A(2) as a function of the fractional momentum x of the final state are fitted well with a very simple functional form having three adjustable parameters. An empirical relation is found between the three parameters of the fit. These observations could guide the way to a deeper understanding of the nuclear effects involved. The deduced J/Psi nucleon absorption cross sections sigma(abs) cluster around two values of which only sigma(abs) = 5.8 +/- 0.2 mb seems acceptable. C1 UNIV HEIDELBERG, INST THEORET PHYS, D-69120 HEIDELBERG, GERMANY. STANFORD LINEAR ACCELERATOR CTR, THEORY GRP, STANFORD, CA 94309 USA. RP INST PHYS NUCL, BP 1, F-91406 ORSAY, FRANCE. NR 27 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 1996 VL 22 IS 9 BP 1335 EP 1342 DI 10.1088/0954-3899/22/9/006 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VH738 UT WOS:A1996VH73800006 ER PT J AU Bertness, KA Friedman, DJ Kurtz, SR Kibbler, AE Kramer, C Olson, JM AF Bertness, KA Friedman, DJ Kurtz, SR Kibbler, AE Kramer, C Olson, JM TI High-efficiency GaInP/GaAs tandem solar cells SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID SINGLE-JUNCTION; 2-JUNCTION; GROWTH AB GaInP/GaAs tandem solar cells have achieved efficiencies between 25.7-30.2%, depending on illumination conditions. The efficiencies are the highest confirmed two-terminal values measured for any solar cell within each standard illumination category, The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes, The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell, The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement, In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance. C1 NATL RENEWABLE ENERGY LAB, MAT SCI BRANCH, DIV BASIC SCI, GOLDEN, CO 80401 USA. NR 35 TC 1 Z9 1 U1 4 U2 9 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 1996 VL 12 IS 5 BP 842 EP 846 DI 10.2514/3.24112 PG 5 WC Engineering, Aerospace SC Engineering GA VG130 UT WOS:A1996VG13000006 ER PT J AU Su, BJ Olson, GL AF Su, BJ Olson, GL TI Benchmark results for the non-equilibrium Marshak diffusion problem SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB As an extension of previous work in the literature, this paper considers a particular one-dimensional, halfspace, non-equilibrium Marshak wave problem. The radiative transfer model employed is a one-group diffusion approximation with Marshak boundary condition, where the radiation and material fields are out of equilibrium. An analytic solution for the distribution of radiative energy and material temperature as a function of space and time to this problem is given and tables of numerical results are generated. These benchmark results, together with the previously published results, are useful as a reference for validating time-dependent radiation diffusion computer codes. A comparison with a finite difference solution is presented which shows excellent agreement when a fine spatial mesh and small time steps are used. Copyright (C) 1996 Published by Elsevier Science Ltd RP Su, BJ (reprint author), LOS ALAMOS NATL LAB,XTM,DIV APPL THEORET & COMPUTAT PHYS,MS B283,LOS ALAMOS,NM 87545, USA. NR 7 TC 37 Z9 38 U1 0 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 SEP PY 1996 VL 56 IS 3 BP 337 EP 351 DI 10.1016/0022-4073(96)84524-9 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA VJ715 UT WOS:A1996VJ71500002 ER PT J AU Rodgers, JA Stangel, PW AF Rodgers, JA Stangel, PW TI Genetic variation and population structure of the endangered snail kite in south Florida SO JOURNAL OF RAPTOR RESEARCH LA English DT Article DE snail kite; Rostrhamus sociabilis; Florida; electrophoresis; population genetics AB Ten enzymatic stains were used to resolve the products of 12 loci for 150 snail kite (Rostrhamus sociabilis) nestlings from four major wetlands in south Florida. Nine loci were monomorphic across all sites; two loci were only slightly polymorphic, with overall allele frequencies <0.05. Average expected heterozygosity among all individuals was 4.6% (range = 0-25%). Average heterozygosity across the four sites ranged from 4.1-5.2%. Mean percent polymorphic loci (0.99 level) was 18.2% (range = 8.3-25%). Overall F-ST was 3.4%, which was significantly different from 0; F-IS and F-IT values suggested a slight heterozygote deficiency. The largest genetic distance was consistently between Lake Okeechobee and the other sites; the shortest genetic distances were between Lake Kissimmee and Conservation Area 2B and between Conservation Area 2B and Conservation Area 3A. Gene flow was estimated at 7.1 migrants per generation. Short genetic distances among the four wetlands in south Florida suggest little differentiation among these populations of snail kites. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP Rodgers, JA (reprint author), FLORIDA GAME & FRESH WATER FISH COMMISS,4005 S MAIN ST,GAINESVILLE,FL 32601, USA. NR 31 TC 6 Z9 6 U1 0 U2 4 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD SEP PY 1996 VL 30 IS 3 BP 111 EP 117 PG 7 WC Ornithology SC Zoology GA VL821 UT WOS:A1996VL82100001 ER PT J AU Cook, LP WongNg, W Paranthaman, P AF Cook, LP WongNg, W Paranthaman, P TI Melting and vaporization of the 1223 phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE melting point; phase equilibria; thallia vapor pressure; Tl-Pb-Ba-Sr-Ca-Cu-O system; 1223 superconductor ID BULK SUPERCONDUCTIVITY; PINNING CENTERS; THIN-FILMS; (TL0.5PB0.5)SR2CA2CU3O9; 120-K; TAPE AB The melting and vaporization of the 1223 [(Tl,Pb):(Ba,Sr):Ca:Cu] oxide phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O) have been investigated using a combination of dynamic methods (differential thermal analysis, thermogravimetry, effusion) and post-quenching characterization techniques (powder x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectrometry). Vaporization rates, thermal events, and melt compositions were followed as a function of thallia loss from a 1223 stoichiometry. Melting and vaporization equilibria of the 1223 phase are complex, with as many as seven phases participating simultaneously. At a total pressure of 0.1 MPa the 1223 phase was found to melt completely at (980 +/- 5) degrees C in oxygen, at a thallia partial pressure (p(Tl2o)) of (4.6 +/- 0.5) kPa, where the quoted uncertainties are standard uncertainties, i.e., 1 estimated standard deviation. The melting reaction involves five other solids and a liquid, nominally as follows: 1223 --> 1212 + (Ca,Sr)(2)CuO3 + (Sr,Ca)CuO2 + BaPbO3 +(Ca,Sr) O + Liquid Stoichiometries of the participating phases have been determined from microchemical analysis, and substantial elemental substitution on the 1212 and 1223 crystallographic sites is indicated. The 1223 phase occurs in equilibrium with liquids from its melting point down to at least 935 degrees C. The composition of the lowest melting liquid detected for the bulk compositions of this study has been measured using microchemical analysis. Applications to the processing of superconducting wires and tapes are discussed. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP Cook, LP (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 41 TC 2 Z9 2 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 675 EP 689 DI 10.6028/jres.101.066 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100006 PM 27805086 ER PT J AU Solomon, MJ Muller, SJ AF Solomon, MJ Muller, SJ TI The transient extensional behavior of polystyrene-based Boger fluids of varying solvent quality and molecular weight SO JOURNAL OF RHEOLOGY LA English DT Article ID TAYLOR-COUETTE INSTABILITY; POLYMER-SOLUTIONS; VISCOELASTIC FLOWS; LIQUID BRIDGES; VISCOSITY; SPHERES; M1; EXTENSIBILITY; CONFORMATION; RHEOLOGY AB The behavior under transient uniaxial elongation of a homologous series of variable extensibility polystyrene-based Boger fluids has been investigated in an apparatus similar to that developed by Sridhar and co-workers. The test fluids are dilute solutions of either 2.0X10(7) or 2.0x10(6) g/mol monodisperse polystyrene dissolved in poor, dioctyl phthalate-based or good, tricresyl phosphate-based solvents. This rational manipulation of Boger fluid solvent quality (assessed based on previously reported light scattering and intrinsic viscometry measurements) and chain length yields a unique opportunity to correlate viscoelastic extensional response to finite extensibility and molecular interactions: here we search for such effects in transient filament extension between parallel plates, an approximation of purely extensional flow. The test device, which can impart a maximum Hencky strain, epsilon, of 4.5 at rates, epsilon over dot, between 0.3 and 3.0 s(-1), is similar to that reported by Sridhar et al. (1991). In agreement with results communicated there and in Tirtaatmadja and Sridhar (1993), large strain hardening is observed for these polymer solutions, as well as certain deviations of the experimental flow from ideal uniaxial extension. As opposed to Tirtaatmadja and Sridhar (1993), no steady-state extensional viscosities are obtained for the comparatively small strains of our experiment. The transient experimental results are roughly consistent with simple one-dimensional FENE-P calculations. However, uncertainties due to the nonideal nature of the flow at short times and the sensitivity of the measured extensional stress growth coefficient to the details of the imposed elongation make it difficult to unambiguously assign L based solely on short time filament stretching results. These results are considered in light of the substantial effects solvent quality and molecular weight have on the measured drag in flow past a sphere [Chmielewski et al. (1990); Solomon and Muller (1996b)]. (C) 1996 Society of Rheology. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. OI Solomon, Michael/0000-0001-8312-257X NR 46 TC 49 Z9 49 U1 1 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD SEP-OCT PY 1996 VL 40 IS 5 BP 837 EP 856 DI 10.1122/1.550770 PG 20 WC Mechanics SC Mechanics GA VG109 UT WOS:A1996VG10900007 ER PT J AU Dyakov, VA Ebbers, CA Pchelkin, MV Pryalkin, VI AF Dyakov, VA Ebbers, CA Pchelkin, MV Pryalkin, VI TI Lithium sodium carbonate: A new nonlinear-optics crystal SO JOURNAL OF RUSSIAN LASER RESEARCH LA English DT Article ID LINACO3 AB A new nonlinear crystal, lithium sodium carbonate (LiNaCO3), has been grown. It has been found that there are phase-matching directions in LiNaCO3 crystals for generation of the second, third, and fourth harmonics of YAG:Nd-laser radiation. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Dyakov, VA (reprint author), MOSCOW MV LOMONOSOV STATE UNIV,CTR INT LASER,VOROBIEVY GORY,MOSCOW 119899,RUSSIA. NR 14 TC 4 Z9 5 U1 3 U2 13 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 1071-2836 J9 J RUSS LASER RES JI J. Russ. Laser Res. PD SEP-OCT PY 1996 VL 17 IS 5 BP 489 EP 494 DI 10.1007/BF02090628 PG 6 WC Optics SC Optics GA WA557 UT WOS:A1996WA55700010 ER PT J AU Horita, J Weinberg, A Das, N Holland, HD AF Horita, J Weinberg, A Das, N Holland, HD TI Brine inclusions in halite and the origin of the Middle Devonian Prairie evaporites of western Canada SO JOURNAL OF SEDIMENTARY RESEARCH LA English DT Article ID PALO DURO BASIN; FLUID INCLUSIONS; FORMATION WATERS; PERMIAN EVAPORITES; SEDIMENTARY BASIN; POTASH EVAPORITES; SEAWATER; MARINE; DIAGENESIS; EVOLUTION AB Brines were extracted from fluid inclusions in Lower Salt halite of the Middle Devonian Prairie Formation in Saskatchewan, Canada, The brines were analyzed by ion chromatography and were found to be of the Na-K-Mg-Ca-Cl type, They do not fall along a simple evaporation trend, Brines from clear, diagenetic halite are significantly lower in Na+ and higher in Mg2+, Ca2+, and Cl- than brines-from cloudy, subaqueously formed halite with che c-ron structures, The isotopic composition of strontium and sulfur in anhydrite associated with the halites was found to be the same as that of Middle Devonian sea water, The composition of the inclusion brines can be derived from that of modern seawater by evaporation, extensive dolomitization of limestone, and albitization of clay minerals, Other evolution paths are, however, also feasible, and it is impossible to rule out effects due to the addition of nonmarine waters (hydrothermal solutions, surface runoff, and groundwater), or dissolutional recycling of existing evaporites within the Prairie evaporite basin. Our analyses and published data on brine inclusions in halite from a number of Phanerozoic evaporite deposits show that the Na-K-Mg-Ca-Cl type brine is more common than the Na-K-Mg-Cl-SO4 type, which is expected from evaporation of modern seawater. C1 HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. RP Horita, J (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 61 TC 27 Z9 34 U1 0 U2 9 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 SN 1073-130X J9 J SEDIMENT RES JI J. Sediment. Res. PD SEP PY 1996 VL 66 IS 5 BP 956 EP 964 PN A PG 9 WC Geology SC Geology GA VM107 UT WOS:A1996VM10700011 ER PT J AU Poesen, JW Boardman, J Wilcox, BP Valentin, C AF Poesen, JW Boardman, J Wilcox, BP Valentin, C TI Water erosion monitoring and experimentation for global change studies SO JOURNAL OF SOIL AND WATER CONSERVATION LA English DT Article ID SOIL-EROSION; CENTRAL BELGIUM; ROCK FRAGMENTS; RILL EROSION; ARABLE LAND; RUNOFF; RATES; ENGLAND; TILLAGE; USA C1 UNIV OXFORD, SCH GEOG, OXFORD OX1 3TB, ENGLAND. UNIV OXFORD, ENVIRONM CHANGE UNIT, OXFORD OX1 3TB, ENGLAND. LOS ALAMOS NATL LAB, ENVIRONM SCI GRP, LOS ALAMOS, NM 87545 USA. ORSTOM, NIAMEY, NIGER. RP Poesen, JW (reprint author), KATHOLIEKE UNIV LEUVEN, NATL FUND SCI RES, LAB EXPT GEOMORPHOL, REDINGENSTR 16, B-3000 LOUVAIN, BELGIUM. NR 67 TC 41 Z9 51 U1 0 U2 6 PU SOIL WATER CONSERVATION SOC PI ANKENY PA 945 SW ANKENY RD, ANKENY, IA 50023-9723 USA SN 0022-4561 J9 J SOIL WATER CONSERV JI J. Soil Water Conserv. PD SEP-OCT PY 1996 VL 51 IS 5 BP 386 EP 390 PG 5 WC Ecology; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA WC484 UT WOS:A1996WC48400008 ER PT J AU Thackeray, MM Mansuetto, MF Johnson, CS AF Thackeray, MM Mansuetto, MF Johnson, CS TI Thermal stability of Li4Mn5O12 electrodes for lithium batteries SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID INSERTION; SPINELS; LIMN2O4; CATHODE; SYSTEM; CELLS AB The thermal stability of the spinel, Li4Mn5O12, which is of interest as an insertion electrode for 3 V lithium cells, has been studied by X-ray diffraction, differential thermal analysis, and thermogravimetric analysis at temperatures up to 1020 degrees C. The data show that as the temperature is raised above 400 degrees C, oxygen and lithia (Li2O) are lost from the structure, which drives the composition of the spinel along the stoichiometric spinel tie-line from Li4Mn5O12 toward Mn3O4. By products of the reaction are the rock-salt phases Li2MnO3 at moderate temperature and LiMnO2 at high temperature. The data are consistent with recent reports of the behavior of other lithium-manganese-oxide spinels; the data highlight, in particular, the sensitivity of lithium-rich spinels to temperatures above 400 degrees C. (C) 1996 Academic Press, Inc. RP Thackeray, MM (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,ELECTROCHEM TECHNOL PROGRAM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 20 TC 32 Z9 35 U1 3 U2 23 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 SEP PY 1996 VL 125 IS 2 BP 274 EP 277 DI 10.1006/jssc.1996.0297 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA VG712 UT WOS:A1996VG71200025 ER PT J AU Li, ZW Pitzer, KS AF Li, ZW Pitzer, KS TI Thermodynamics of aqueous KOH over the full range to saturation and to 573 K SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE potassium hydroxide; density; apparent molar volume; activity coefficient; aqueous solutions ID IONIC-SOLUTIONS; MULTICOMPONENT; ELECTROLYTES; EQUATIONS; MIXTURES; SYSTEMS; SALTS; MODEL AB The thermodynamic properties of aqueous KOH are represented by mole-fraction based equations. The apparent molar volume and the solvent activity are obtained from literature values of experimental measurements of density and solvent vapor pressure for the range 273-573 K. Solute activity measurements are also available up to 343 K. At the highest temperature the dissociated mole fraction of KOH extends to 0.75. The equations represent the data satisfactorily over this very wide range and are of a form readily extended to more complex mixed systems. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. TIANJIN UNIV,DEPT CHEM,TIANJIN 300072,PEOPLES R CHINA. RP Li, ZW (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 27 TC 8 Z9 9 U1 1 U2 14 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 SEP PY 1996 VL 25 IS 9 BP 813 EP 823 DI 10.1007/BF00972574 PG 11 WC Chemistry, Physical SC Chemistry GA VM673 UT WOS:A1996VM67300001 ER PT J AU Canright, G Watson, G AF Canright, G Watson, G TI Disordered ground states for classical discrete-state problems in one dimension SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE Ising models; disorder; ground states; directed graphs; polytypes; third law ID ANTIFERROMAGNET; ORDER AB It is known that one-dimensional lattice problems with a discrete, finite set of states per site ''generically'' have periodic ground states (GSs). We consider slightly less generic cases, in which the Hamiltonian is constrained by either spin (S) or spatial (I) inversion symmetry (or both). We show that such constraints give rise to the possibility of disordered GSs over a finite fraction of the coupling-parameter space-that is, without invoking any nongeneric ''fine tuning'' of coupling constants, beyond that arising from symmetry. We find that such disordered GSs can arise for many values of the number of states k at each site and the range r of the interaction. The Ising (k=2) case is the least prone to disorder: I symmetry allows for disordered GSs (without line tuning) only for r greater than or equal to 5, while S symmetry ''never'' gives rise to disordered GSs. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. RP Canright, G (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 26 TC 5 Z9 5 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD SEP PY 1996 VL 84 IS 5-6 BP 1095 EP 1131 DI 10.1007/BF02174130 PG 37 WC Physics, Mathematical SC Physics GA VL460 UT WOS:A1996VL46000008 ER PT J AU Tang, Y AF Tang, Y TI New algorithm for active structural control SO JOURNAL OF STRUCTURAL ENGINEERING-ASCE LA English DT Article AB A simple effective algorithm for active structural control is proposed. It applies the control force at every time step, minimizing the system energy that is carried over from one time step to the next. The control force needed for the next time step is computed by a simple closed form solution at the current time utilizing the available information. Therefore, the proposed control algorithm is free from time delay problems. The control algorithm is derived from the theory of single-degree-of-freedom (SDF) systems and is extended to multiple-degree-of-freedom (MDF) systems by making use of the modal synthesis. Numerical examples are used to demonstrate the effectiveness of the proposed control law. Practical problems in active control, such as the spillover effect, the actuator's capacity limit, and the problems associated with the limited number of sensors are discussed. Various strategies to cope with these problems, in particular, an artificial neural network as the state estimator, are proposed in the paper. The results of the examples show that the proposed control algorithm can reduce the structural response by one order of magnitude and has the ability to reduce the peak that occurs during the first few cycles of the time history, an ability that linear control laws lack. Unlike most control algorithms that deal with the state space of the system that usually involves complex-valued eigenvalues and eigenvectors, the proposed control algorithm deals with the real-valued normal modes of the system. RP Tang, Y (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 19 TC 1 Z9 1 U1 1 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9445 J9 J STRUCT ENG-ASCE JI J. Struct. Eng.-ASCE PD SEP PY 1996 VL 122 IS 9 BP 1081 EP 1088 DI 10.1061/(ASCE)0733-9445(1996)122:9(1081) PG 8 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA VD992 UT WOS:A1996VD99200013 ER PT J AU Tadros, ME Adkins, CLJ Russick, EM Youngman, MP AF Tadros, ME Adkins, CLJ Russick, EM Youngman, MP TI Synthesis of titanium dioxide particles in supercritical CO2 SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article DE supercritical carbon dioxide; titanium dioxide; titanium alkoxides; aqueous dispersions; Zonyl FSI ID CARBON-DIOXIDE; MICROEMULSIONS; MGAL2O4; FLUIDS; PHASE AB Spherical particles of titanium dioxide, anatase, were prepared in a supercritical carbon dioxide medium from titanium alkoxides and water, The dissolution of the alkoxide and stabilization of water dispersions in supercritical CO2 were found to be required for the formation of spherical particles, An anionic fluorinated surfactant was used to stabilize water dispersions in supercritical CO2. This could not be realized with hydrocarbon-based surfactants. The solubility of titanium alkoxides in CO2 appears to parallel their vapor pressure which is dependent on the oligomerization of the unhydrolyzed all;oxides. The polydispersity in particle sizes is due to nucleation occurring simultaneously with particle growth, owing to changes in the degree of supersaturation during the transition from the liquid to I-he supercritical state. RP Tadros, ME (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 12 TC 30 Z9 30 U1 2 U2 6 PU PRA PRESS PI CINCINNATI PA POLYMER RES ASSOC INC 9200 MONTGOMERY RD, SUITE 23B, CINCINNATI, OH 45242 SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD SEP PY 1996 VL 9 IS 3 BP 172 EP 176 DI 10.1016/S0896-8446(96)90029-7 PG 5 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VQ527 UT WOS:A1996VQ52700007 ER PT J AU Mehr, CB Biswal, RN Collins, JL Cochran, HD AF Mehr, CB Biswal, RN Collins, JL Cochran, HD TI Supercritical carbon dioxide extraction of caffeine from Guarana SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article DE supercritical fluid extraction; caffeine; diffusion; guarana ID COFFEE; THEOPHYLLINE; MECHANISM; DIFFUSION; KINETICS; INFUSION AB A single-pass system was designed to study extraction of caffeine from wet guarana seeds using supercritical carbon dioxide. Extraction was studied as a function of pressure and temperature to determine caffeine solubility at equilibrium conditions between 136.1 and 272.2 atm and temperatures of 35, 45, and 55 degrees C. Solubility of caffeine into supercritical CO2 was affected directly by CO2 density. Caffeine solubility was modeled by using thermodynamic relationships and the Peng-Robinson equation of state on a water-free basis. Effective diffusion coefficients of caffeine in ground guarana seeds were determined by conducting long-term extraction experiments. C1 UNIV TENNESSEE,DEPT FOOD SCI & TECHNOL,AGR EXPT STN,KNOXVILLE,TN 37901. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. NR 42 TC 35 Z9 38 U1 1 U2 25 PU PRA PRESS PI CINCINNATI PA POLYMER RES ASSOC INC 9200 MONTGOMERY RD, SUITE 23B, CINCINNATI, OH 45242 SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD SEP PY 1996 VL 9 IS 3 BP 185 EP 191 DI 10.1016/S0896-8446(96)90031-5 PG 7 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VQ527 UT WOS:A1996VQ52700009 ER PT J AU Kadish, A TenCate, JA Johnson, PA AF Kadish, A TenCate, JA Johnson, PA TI Frequency spectra of nonlinear elastic pulse-mode waves SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT 3rd Joint Meeting of the Acoustical-Society-of-America/Acoustical-Society-of-Japan CY DEC 02-06, 1996 CL HONOLULU, HI SP Acoust Soc Amer, Acoust Soc Japan ID PROPAGATION AB The frequency spectrum of simple waves is used to derive a closed form analytical representation for the frequency spectrum of damped nonlinear pulses in elastic materials. The damping modification of simple wave theory provides an efficient numerical method for calculating propagating wave forms. The spectral representation, which is neither pulse length nor amplitude limited, is used to obtain estimates for parameters of the nonlinear state relation for a sandstone sample from published experimental data, and the results are compared with those of other theories. The method should have broad application to many solids. C1 UNIV PARIS 06,BUR MECAN,F-75252 PARIS 05,FRANCE. RP Kadish, A (reprint author), LOS ALAMOS NATL LAB,EES-4,MS D443,LOS ALAMOS,NM 87545, USA. NR 9 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 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 1996 VL 100 IS 3 BP 1375 EP 1382 DI 10.1121/1.415984 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VK273 UT WOS:A1996VK27300022 ER PT J AU TenCate, JA VanDenAbeele, KEA Shankland, TJ Johnson, PA AF TenCate, JA VanDenAbeele, KEA Shankland, TJ Johnson, PA TI Laboratory study of linear and nonlinear elastic pulse propagation in sandstone SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT 3rd Joint Meeting of the Acoustical-Society-of-America/Acoustical-Society-of-Japan CY DEC 02-06, 1996 CL HONOLULU, HI SP Acoust Soc Amer, Acoust Soc Japan ID WAVE PROPAGATION AB Linear and nonlinear elastic wave pulse propagation experiments were performed in sandstone rods, both at ambient conditions and in vacuum. The purpose of these experiments was to obtain a quantitative measure of the extremely large nonlinear response found in microcracked (i.e., micro-inhomogeneous) media like rock. Two rods were used, (1) a 2-m-long, 5-cm-diam rod of Berea sandstone (with embedded detectors) used in previously published experiments and (2) a somewhat smaller 1.8-m-long, 3.8-cm-diam rod. In the earlier experiments, wave scattering from the embedded detectors was a critical problem. In most of the experiments reported here, this problem was avoided by mounting accelerometers directly to the outside surface of the rod. Linear results show out of vacuum attenuations varied from 1.7 Np/m at 15 kHz (Q = 10) for the large rod to 0.4 Np/m at 15 kHz (Q = 55) for the small rod; attenuations for the small rod in vacuum were much less, typically about 0.15 Np/m at 15 kHz (Q = 150). Wave velocities ranged from 1900 to 2600 m/s. The nonlinear results illustrate growth of the second and third harmonics and accompanying decay of the fundamental. These nonlinear results compare well with a numerical model. Although the results here were performed at peak strain amplitudes as low as 5 x 10(-7), they still show the pronounced nonlinearity characteristic of rock, in agreement with static and resonance studies using the same rock type. C1 KATHOLIEKE UNIV LEUVEN,B-3001 LOUVAIN,BELGIUM. UNIV PARIS 06,DEPT RECH PHYS,F-75252 PARIS 05,FRANCE. RP TenCate, JA (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,MAIL STOP D443,LOS ALAMOS,NM 87545, USA. NR 21 TC 32 Z9 37 U1 0 U2 0 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 SEP PY 1996 VL 100 IS 3 BP 1383 EP 1391 DI 10.1121/1.415985 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VK273 UT WOS:A1996VK27300023 ER PT J AU Hogden, J Lofqvist, A Gracco, V Zlokarnik, I Rubin, P Saltzman, E AF Hogden, J Lofqvist, A Gracco, V Zlokarnik, I Rubin, P Saltzman, E TI Accurate recovery of articulator positions from acoustics: New conclusions based on human data SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT 3rd Joint Meeting of the Acoustical-Society-of-America/Acoustical-Society-of-Japan CY DEC 02-06, 1996 CL HONOLULU, HI SP Acoust Soc Amer, Acoust Soc Japan ID VOWEL PRODUCTION; VOCAL-TRACT; SPEECH-PERCEPTION; COMPENSATION; PERTURBATION; INVERSION; ALGORITHM; SHAPES AB Vocal tract models are often used to study the problem of mapping from the acoustic transfer function to the vocal tract area function (inverse mapping). Unfortunately, results based on vocal tract models are strongly affected by the assumptions underlying the models. In this study, the mapping from acoustics (digitized speech samples) to articulation (measurements of the positions of receiver coils placed on the tongue, jaw, and lips) is examined using human data from a single speaker: Simultaneous acoustic and articulator measurements made for vowel-to-vowel transitions, /g/ closures, and transitions into and out of /g/ closures. Articulator positions were measured using an EMMA system to track coils placed on the Lips, jaw, and tongue. Using these data, look-up tables were created that allow articulator positions to be estimated from acoustic signals. On a data set not used for making look-up tables, correlations between estimated and actual coil positions of around 94% and root-mean-squared errors around 2 mm are common for coils on the tongue. An error source evaluation shows that estimating articulator positions from quantized acoustics gives root-mean-squared errors that are typically less than 1 mm greater than the errors that would be obtained from quantizing the articulator positions themselves. This study agrees with and extends previous studies of human data by showing that for the data studied, speech acoustics can be used to accurately recover articulator positions. (C) 1996 Acoustical Society of America. C1 HASKINS LABS INC, NEW HAVEN, CT 06511 USA. RP LOS ALAMOS NATL LAB, MS B265, LOS ALAMOS, NM 87545 USA. FU NIDCD NIH HHS [DC-00865, DC-00121] NR 50 TC 35 Z9 37 U1 1 U2 6 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 1996 VL 100 IS 3 BP 1819 EP 1834 DI 10.1121/1.416001 PG 16 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VK273 UT WOS:A1996VK27300064 PM 8817906 ER PT J AU Schaeffer, VH Bhooshan, B Chen, SB Sonenthal, JS Hodgson, AT AF Schaeffer, VH Bhooshan, B Chen, SB Sonenthal, JS Hodgson, AT TI Characterization of volatile organic chemical emissions from carpet cushions SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article; Proceedings Paper CT International Symposium on Engineering Solutions to Indoor Air Quality Problems CY JUL, 1995 CL RES TRIANGLE PK, NC SP Air & Waste Management Assoc, US EPA, Air Pollut Prevent & Control Div AB The U.S. Consumer Product Safety Commission is investigating chemical emissions from carpet systems in order to determine whether the emissions may be responsible for the numerous health complaints associated with carpet installation. As part of this effort, a study was conducted to identify and quantify volatile organic compounds (VOCs) released into the air by five major product types of new carpet cushions. Cushion samples were tested in small-volume dynamic chambers over a six-hour exposure period. Airborne VOCs collected on multisorbent samplers were identified using sensitive gas chromatography/mass spectrometry. The emissions of selected VOCs were quantitated with the small-scale chamber method and further characterized in larger environmental chambers conducted over a 96-hour period under conditions more representative of indoor environments. A separate chamber method was developed to screen polyurethane cushions for emissions of toluene diisocyanates (TDI). Over 100 VOCs, spanning a broad range of chemical classes, were emitted from 17 carpet cushions. The pattern of emitted VOCs varied between and among product types, which reflects probable differences in manufacturing processes and ingredients. No significant quantities of TDI or formaldehyde were released by any cushions. Emission profiles were characterized for total VOCs and for the predominant individual VOCs. As a group, the synthetic fiber cushion samples emitted the lowest quantities of VOCs. Cushion samples purchased from carpet retailers released lesser amounts of VOCs than samples of the same cushion types obtained directly from the manufacturing mills, suggesting that chemical losses from the bulk material may ensue as a result of transport, handling, and storage prior to installation. The data suggest that placement of carpet on top of a carpet cushion, as would occur in a residential installation, reduced the rate of some VOC emissions when compared to the cushion alone. C1 US CONSUMER PROD SAFETY COMMISS,HLTH SCI LAB,ROCKVILLE,MD 20850. EO LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP Schaeffer, VH (reprint author), US CONSUMER PROD SAFETY COMMISS,DIRECTORATE EPIDEMIOL & HLTH SCI,WASHINGTON,DC 20207, USA. NR 11 TC 8 Z9 9 U1 2 U2 4 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 1996 VL 46 IS 9 BP 813 EP 820 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VG129 UT WOS:A1996VG12900004 PM 28081404 ER PT J AU Jacoby, WA Blake, DM Fennell, JA Boulter, JE Vargo, LM George, MC Dolberg, SK AF Jacoby, WA Blake, DM Fennell, JA Boulter, JE Vargo, LM George, MC Dolberg, SK TI Heterogeneous photocatalysis for control of volatile organic compounds in indoor air SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article; Proceedings Paper CT International Symposium on Engineering Solutions to Indoor Air Quality Problems CY JUL, 1995 CL RES TRIANGLE PK, NC SP Air & Waste Management Assoc, US EPA, Air Pollut Prevent & Control Div ID OXIDATION; TRICHLOROETHYLENE AB Research results concerning the photocatalytic activity and selectivity of benzene are discussed. This compound, which represents one of an important class of volatile organic compounds found in indoor air, was oxidized in an annular photocatalytic reactor featuring a thin film of titanium dioxide and illuminated by a fluorescent black light. The gas phase products, carbon dioxide and carbon monoxide, were quantified with a Fourier transform infrared spectrometer (FTIR). Adsorbed intermediates were extracted from the surface with water. The extract was analyzed via high performance liquid chromatography and some of the adsorbed species were provisionally identified by retention time matching. The adsorption of reactants on the catalyst surface was studied explicitly, particularly with respect to the effect of near-UV radiation on adsorption processes. Maximum and steady-state rates of the surface reactions are reported here as functions of the operating conditions. Deactivation of the catalyst surface is characterized and methods of regeneration of catalyst activity are explored. This established research methodology provides the framework for a broader outline of research into enhancement of indoor air quality via photocatalytic oxidation. The results of investigations are discussed that pertain to a variety of classes of compounds representative of indoor air pollutants. RP Jacoby, WA (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 10 TC 114 Z9 119 U1 0 U2 23 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 1996 VL 46 IS 9 BP 891 EP 898 PG 8 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VG129 UT WOS:A1996VG12900013 PM 28081402 ER PT J AU Pan, XQ Gu, H vanWeeren, R Danforth, SC Cannon, RM Ruhle, M AF Pan, XQ Gu, H vanWeeren, R Danforth, SC Cannon, RM Ruhle, M TI Grain-boundary microstructure and chemistry of a hot isostatically pressed high-purity silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID INTERGRANULAR FILM THICKNESS; EQUILIBRIUM THICKNESS; CERAMICS AB Two high-purity Si3N4 materials were fabricated by hot isostatic pressing without the presence of sintering additives, using an amorphous laser-derived Si3N4 powder with different oxygen contents. High-resolution transmission electron microscopy and electron energy-loss spectroscopy (EELS) analysis of the Si3N4 materials showed the presence of an amorphous SiO2 grain-boundary phase in the three-grain junctions. Spatially resolved EELS analysis indicated the presence of a chemistry similar to silicon oxynitride at the two-grain junctions, which may be due to partial dissolution of nitrogen in the grain-boundary film. The chemical composition of the grain-boundary film was SiNxOy (x approximate to 0.53 and y approximate to 1.23), and the triple pocket corresponded to the amorphous SiO2 containing similar to 2 wt% nitrogen. The equilibrium grain-boundary-film thickness was measured and found to be smaller for the material with the lower oxygen content. This difference in thickness has been explained by the presence of the relatively larger calcium concentration in the material with the lower amount of SiO2 grain-boundary phase, because the concentration of foreign ions has been shown to affect the grain-boundary thickness. C1 RUTGERS STATE UNIV, CTR CERAM RES, PISCATAWAY, NJ 08855 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Pan, XQ (reprint author), MAX PLANCK INST MET RES, INST WERKSTOFFWISSENSCH, SEESTR 92, D-70174 STUTTGART, GERMANY. NR 18 TC 41 Z9 41 U1 1 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1996 VL 79 IS 9 BP 2313 EP 2320 DI 10.1111/j.1151-2916.1996.tb08978.x PG 8 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700012 ER PT J AU Ruiz, L Readey, MJ AF Ruiz, L Readey, MJ TI Effect of heat-treatment on grain size, phase assemblage, and mechanical properties of 3 mol% Y-TZP SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MEASURING FRACTURE-TOUGHNESS; INDENTATION-INDUCED CRACKS; ZIRCONIA SINGLE-CRYSTALS; TETRAGONAL ZIRCONIA; Y2O3-STABILIZED ZRO2; FLAW TOLERANCE; TRANSFORMATION; BEHAVIOR; PSZ; MICROSTRUCTURE AB The effect of heat treatment on the grain size, phase assemblage, and mechanical properties of a 3 mol% Y-TZP ceramic was investigated, Specimens were initially sintered for 2 h at 1450 degrees C to near theoretical density; some specimens were then heat-treated at 1550 degrees, 1650 degrees, 1750 degrees, or 1850 degrees C to coarsen the microstructure. The average grain size increased with heat treatment from <0.5 to similar to 10 mu m. Phase analyses revealed predominantly tetragonal and cubic phases below 1750 degrees C, with a significant decrease in tetragonal content and increase in monoclinic content for temperatures >1750 degrees C, The maximum fraction of tetragonal phase that transformed during fracture corresponded with the largest tetragonal grain size of similar to 5-6 mu m. Strength was on the order of 1 GPa, and was surprisingly insensitive to heat-treatment temperature and grain size, contrary to previous studies, The fracture toughness increased from 4 to 10 MPa . m(1/2) with increasing grain size, owing to an increasing transformation zone size, Grain sizes larger than 5-6 mu m spontaneously transformed to monoclinic phase during cooling, Such critical grain sizes are much larger than those found in past investigations, and may be due to the greater fraction of cubic phase present which decreases the strain energy arising from crystallographic thermal expansion anisotropy of the tetragonal phase. C1 CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 41 TC 89 Z9 90 U1 3 U2 22 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 SEP PY 1996 VL 79 IS 9 BP 2331 EP 2340 DI 10.1111/j.1151-2916.1996.tb08980.x PG 10 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700014 ER PT J AU Brow, RK Tallant, DR Turner, GL AF Brow, RK Tallant, DR Turner, GL TI Raman and B-11 nuclear magnetic resonance spectroscopic studies of alkaline-earth lanthanoborate glasses SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID BORATE GLASSES; CRYSTAL-STRUCTURE; SCATTERING; CHEMISTRY AB Glasses from the RO . La2O3 . B2O3 (R = Mg, Ca, and Ba) systems have been examined, Glass formation is centered along the metaborate tie line, from La(BO2)(3) to R(BO2)(2). Glasses generally have transition temperatures >600 degrees C and expansion coefficients between 60 x 10(-7)/degrees C and 100 x 10(-7)/degrees C. Raman and solid-state nuclear magnetic resonance spectroscopies reveal changes in the metaborate network that depend on both the [R]:[La] ratio and the type of alkaline-earth ion, The fraction of tetrahedral sites is generally reduced in alkaline earth-rich glasses, with magnesium glasses possessing the lowest concentration of B[4]. Raman spectra indicate that, with increasing [R]:[La] ratio, the preferred metaborate anion changes from a double-chain structure associated with crystalline La(BO2)(3) to the single-chain and ring metaborate anions found in crystalline R(BO2)(2) phases, In addition, disproportionation of the metaborate anions leads to the formation of a variety of other species, including pyroborates with terminal oxygens and more-polymerized species, such as diborates, with tetrahedral borons, Such structural changes are related to the ease of glass formation and some of the glass properties. C1 SPECTRAL DATA SERV,CHAMPAIGN,IL 61820. RP Brow, RK (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 32 TC 45 Z9 45 U1 1 U2 8 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 SEP PY 1996 VL 79 IS 9 BP 2410 EP 2416 DI 10.1111/j.1151-2916.1996.tb08990.x PG 7 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700024 ER PT J AU Searcy, AW Bullard, JW Carter, WC AF Searcy, AW Bullard, JW Carter, WC TI Possible explanations of transient neck formation between pairs of{100} faceted particles SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GROWTH AB Rankin and Boatner have observed that {100} faceted MgO particles in contact along either corners or edges developed, on heating, necks that initially grew, but then shrank and broke, General thermodynamic models are provided that predict this transient neck formation for any cubic particles that share only a small fraction of an edge and for particles that share an edge that is less than 0.6 times as long as the orthogonal edges, A third model, which assumes that reaction of MgO particles with their carbon substrate removes MgO from the MgO-carbon interface at a constant rate, explains the observation that the neck shrinkage rate greatly exceeds the neck growth rate, Application of the theory to explaining the seeming prevalence of rounded surfaces in sintering powders is described. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. NIST,BLDG MAT DIV,GAITHERSBURG,MD 20899. NIST,DIV CERAM,GAITHERSBURG,MD 20899. RP Searcy, AW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Carter, W/K-2406-2012 NR 28 TC 5 Z9 5 U1 0 U2 2 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 SEP PY 1996 VL 79 IS 9 BP 2443 EP 2451 DI 10.1111/j.1151-2916.1996.tb08995.x PG 9 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700029 ER PT J AU Lee, WY More, KL Stinton, DP Bae, YW AF Lee, WY More, KL Stinton, DP Bae, YW TI Characterization of Si3N4 coated with chemically-vapor-deposited mullite after Na2SO4-induced corrosion SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Si3N4 substrates coated with chemically-vapor-deposited, crystalline mullite (3Al(2)O(3) . 2SiO(2)) were subjected to a corrosive environment containing Na2SO4 and O-2 at 1000 degrees C for 100 h. The composition and microstructure of the as-deposited and corroded specimens were examined and compared. The coating appeared to be effective in preserving and therefore protecting the surface microstructure of the underlying Si3N3 substrates. However, a small degree of Na penetration through mullite grain boundaries was observed to a coating depth of similar to 1 mu m. RP Lee, WY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 10 TC 22 Z9 22 U1 1 U2 4 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 SEP PY 1996 VL 79 IS 9 BP 2489 EP 2492 DI 10.1111/j.1151-2916.1996.tb09003.x PG 4 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700037 ER PT J AU Fahrenholtz, WG Ewsuk, KG Ellerby, DT Loehman, RE AF Fahrenholtz, WG Ewsuk, KG Ellerby, DT Loehman, RE TI Near-net-shape processing of metal-ceramic composites by reactive metal penetration SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID INFILTRATION AB Metal-ceramic composites were made to near-net shape by reacting phase-pure mullite and mullite-glass preforms with molten Al using a reactive metal penetration process. Conversion of the two ceramic preforms to Al2O3/Al composites was accompanied by a 0.32% volume expansion and a 1.42% volume shrinkage, respectively. Molar volume and density calculations made assuming a net-shape reaction estimate similar to 17 and similar to 27 vol% Al to be present in the two composites after reaction. Results from quantitative stereology measurements used to quantify the concentration of metal in the reactively formed composites validate the calculations. C1 UNIV NEW MEXICO, ALBUQUERQUE, NM 87106 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP Fahrenholtz, WG (reprint author), ADV MAT LAB, ALBUQUERQUE, NM 87106 USA. OI Fahrenholtz, William/0000-0002-8497-0092 NR 17 TC 33 Z9 34 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1996 VL 79 IS 9 BP 2497 EP 2499 DI 10.1111/j.1151-2916.1996.tb09005.x PG 3 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700039 ER PT J AU Wu, QY Anderson, GA Udseth, HR Sherman, MG VanOrden, S Chen, R Hofstadler, SA Gorshkov, MV Mitchell, DW Rockwood, AL Smith, RD AF Wu, QY Anderson, GA Udseth, HR Sherman, MG VanOrden, S Chen, R Hofstadler, SA Gorshkov, MV Mitchell, DW Rockwood, AL Smith, RD TI A high performance low magnetic field internal electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID QUADRUPOLAR EXCITATION; LARGE MOLECULES; REMEASUREMENT; BIOMOLECULES; ACCUMULATION; AXIALIZATION; SPECTRA; TRAP AB A new in-magnetic field electrospray ionization (ESI) and Fourier transform ion cyclotron resonance mass spectrometer has been constructed and evaluated. This system is characterized by the use of multiple concentric cryopanels to achieve ultrahigh vacuum in the ion cyclotron resonance cell region, a probe-mounted internal ESI source, and a novel in-field shutter. Initial experiments demonstrate high resolution mass measurement capability at a field strength of 1 T. Mass resolution of 700,000 has been obtained for the 3+ charge state of Met-Lys-bradykinin (at m/z 440) generated by electrospray ionization. When electron impact ionization was employed, resolution in excess of 9,200,000 was achieved for nitrogen molecular ions (N-2(+)). Isotopic resolution for molecular ions of bovine ubiquitin (MW = 8565 mu) also was achieved by using small ion populations. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Gorshkov, Mikhail/E-8522-2010; Smith, Richard/J-3664-2012; Gorshkov, Mikhail/N-4984-2013 OI Smith, Richard/0000-0002-2381-2349; Gorshkov, Mikhail/0000-0001-9572-3452 NR 39 TC 6 Z9 6 U1 0 U2 2 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 SEP PY 1996 VL 7 IS 9 BP 915 EP 922 DI 10.1016/1044-0305(96)00022-0 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA VE058 UT WOS:A1996VE05800001 PM 24203605 ER PT J AU Goodner, KL Milgram, KE Watson, CH Eyler, JR Dejsupa, C Barshick, CM AF Goodner, KL Milgram, KE Watson, CH Eyler, JR Dejsupa, C Barshick, CM TI Internal glow discharge Fourier transform ion cyclotron resonance mass spectrometry SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ELECTROSPRAY-IONIZATION; MAGNETIC-FIELD; DESORPTION-IONIZATION; PLASMA; BIOMOLECULES; INJECTION; GUIDE AB A glow discharge (GD) ion source has been developed to work within the high magnetic field of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Characterization of this source revealed that the optimum operating voltage, pressure, and current are significantly lower than those for normal glow discharges. The sputter rate was lowered to 1/30th of that found with a normal glow discharge source operated external to the high magnetic field region. Operation of the GD source closer to the FTICR analyzer cell than with previous experimental designs resulted in improved ion transport efficiency. Preliminary results from this internal GD source have established detection limits in the low parts per million range for selected elemental species. C1 UNIV FLORIDA,DEPT CHEM,GAINESVILLE,FL 32611. BRIGHAM YOUNG UNIV,DEPT CHEM & BIOCHEM,PROVO,UT 84602. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 35 TC 5 Z9 5 U1 0 U2 1 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 SEP PY 1996 VL 7 IS 9 BP 923 EP 929 DI 10.1016/1044-0305(96)00025-6 PG 7 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA VE058 UT WOS:A1996VE05800002 PM 24203606 ER PT J AU Song, XB Budde, WL AF Song, XB Budde, WL TI Capillary electrophoresis-electrospray mass spectra of the herbicides paraquat and diquat SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ZONE ELECTROPHORESIS; IONIZATION; SPECTROMETRY AB The positive ion electrospray mass spectra of the quaternary ammonium salt herbicides paraquat and diquat are examined by on-line separation with capillary electrophoresis (CE) and by direct infusion of the analytes. The analytes are separated by CE in 7-10 min at pH 3.9 in 50% methanol-water by using several different separation buffer electrolytes. The capillary electrophoresis-electrospray ionization (CE-ES) mass spectra of paraquat and diquat consist primarily of doubly charged molecular ions, singly charged molecular ions, and singly charged deprotonated ions. The direct infusion spectra consist primarily of doubly charged molecular ions and singly charged deprotonated ions. The relative abundances of the doubly charged and deprotonated ions depend strongly on the presence or absence of ammonium ion in the CE separation buffer or the direct infusion solution. A deprotonation mechanism is proposed in which the free base ammonia is the deprotonating agent in the desolvating charged droplets or in the gas phase. The analytical potential of the CE-ES electrospray approach for environmental analyses is evaluated in terms of the precision of replicate injections, linear concentration range, and estimated detection Limit. C1 US EPA, OFF RES & DEV, NATL EXPOSURE RES LAB, CINCINNATI, OH 45268 USA. OAK RIDGE INST SCI & EDUC, CINCINNATI, OH USA. NR 10 TC 42 Z9 43 U1 2 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1044-0305 EI 1879-1123 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD SEP PY 1996 VL 7 IS 9 BP 981 EP 986 DI 10.1016/1044-0305(96)00070-0 PG 6 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA VE058 UT WOS:A1996VE05800010 PM 24203613 ER PT J AU Hildebrandt, F Nothwang, HG Strahm, B Kuber, M Denich, D Schwabe, J Gingrich, JC Brandis, M AF Hildebrandt, F Nothwang, HG Strahm, B Kuber, M Denich, D Schwabe, J Gingrich, JC Brandis, M TI Cloning the nephronophthisis (NPH) genetic region: Generation of an integrated YAC, PAC and transcriptional map on chromosome 2q13. SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 UNIV FREIBURG,CHILDRENS HOSP,FREIBURG,GERMANY. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENET,LIVERMORE,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1996 VL 7 IS 9 BP A1742 EP A1742 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA VK074 UT WOS:A1996VK07401738 ER PT J AU Richards, WG Yoder, BK Sweeney, WE Wilkinson, JE Avner, ED Woychik, RP AF Richards, WG Yoder, BK Sweeney, WE Wilkinson, JE Avner, ED Woychik, RP TI A hypomorphic allele of the EGF-R (waved-2) abrogates collecting duct cyst formation in a mouse polycystic kidney disease model. SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. CASE WESTERN RESERVE UNIV,DEPT PEDIAT,CLEVELAND,OH 44106. UNIV TENNESSEE,COLL VET MED,KNOXVILLE,TN 37996. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1996 VL 7 IS 9 BP A1773 EP A1773 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA VK074 UT WOS:A1996VK07401769 ER PT J AU Sommardahl, CS Wilkinson, JE Sweeney, WE Avner, ED Woychik, RP AF Sommardahl, CS Wilkinson, JE Sweeney, WE Avner, ED Woychik, RP TI The effect of taxol on cystic kidney and liver lesions in the TgN737Rpw mouse model or polycystic kidney disease. SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 UNIV TENNESSEE,DEPT PATHOBIOL,KNOXVILLE,TN 37901. CASE WESTERN RESERVE UNIV,DEPT PEDIAT,CLEVELAND,OH 44106. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1996 VL 7 IS 9 BP A1781 EP A1781 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA VK074 UT WOS:A1996VK07401777 ER PT J AU Thomas, CP Doggett, N Zhong, C Stokes, J AF Thomas, CP Doggett, N Zhong, C Stokes, J TI Structure of the human gamma ENaC gene and identification of regulatory elements in the 5' flanking region SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 UNIV IOWA,IOWA CITY,IA. LANL,LOS ALAMOS,NM. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1996 VL 7 IS 9 BP A0227 EP A0227 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA VK074 UT WOS:A1996VK07400226 ER PT J AU Yoder, BK Richards, WG Sommardahl, C Sweeney, WE Michaud, EJ Wilkinson, JE Avner, ED Woychik, RP AF Yoder, BK Richards, WG Sommardahl, C Sweeney, WE Michaud, EJ Wilkinson, JE Avner, ED Woychik, RP TI Differential genetic rescue of the phenotype in an ARPKD mouse mutant: A new model to study the liver lesion and proximal tubule defects SO JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. CASE WESTERN RESERVE UNIV,DEPT PEDIAT,CLEVELAND,OH 44106. UNIV TENNESSEE,DEPT PATHOBIOL,KNOXVILLE,TN 37901. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1046-6673 J9 J AM SOC NEPHROL JI J. Am. Soc. Nephrol. PD SEP PY 1996 VL 7 IS 9 BP A1804 EP A1804 PG 1 WC Urology & Nephrology SC Urology & Nephrology GA VK074 UT WOS:A1996VK07401800 ER PT J AU Chen, YF Evans, JW AF Chen, YF Evans, JW TI Thermal analysis of lithium-ion batteries SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LITHIUM/POLYMER BATTERY; TEMPERATURE; CELL; OPTIMIZATION; DISCHARGE; MODULE AB A thermal analysis of lithium-ion batteries during charge/discharge and thermal runaway has been carried out with a mathematical model. The main concern with the thermal behavior of the room temperature batteries is the possible significant temperature increase which may cause thermal runaway, The emphases of this work include the examination of the effects of battery design parameters and operating conditions on temperature rise/profile during normal battery operation and the evaluation of the possibility of the occurrence of thermal runaway due to battery abuse. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP Chen, YF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. NR 27 TC 89 Z9 93 U1 5 U2 33 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 SEP PY 1996 VL 143 IS 9 BP 2708 EP 2712 DI 10.1149/1.1837095 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VH209 UT WOS:A1996VH20900018 ER PT J AU Stevenson, JW Armstrong, TR Carneim, RD Pederson, LR Weber, WJ AF Stevenson, JW Armstrong, TR Carneim, RD Pederson, LR Weber, WJ TI Electrochemical properties of mixed conducting perovskites La(1-x)M(x)Co(1-y)Fe(y)O(3-delta) (M=Sr,Ba,Ca) SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTRICAL-PROPERTIES; OXYGEN PERMEATION; DEFECT STRUCTURE; SEEBECK COEFFICIENT; OXIDES; LA1-XSRXCO1-YFEYO3 AB Perovskite compositions in the system La(1-x)M(x)Co(1-y)Fe(y)O(3-delta) (M = Sr, Ba, Ca) exhibited high electronic and ionic conductivity. Substantial reversible weight loss was observed at elevated temperatures as the materials became increasingly oxygen deficient. This loss of lattice oxygen at high temperatures, which tended to increase with increasing acceptor content, resulted in a decrease in the electronic conductivity. In an oxygen partial pressure gradient, oxygen flux through dense sintered membranes of these materials was highly dependent on composition and increased with increasing temperature. The increase in oxygen flux with increasing temperature was attributed to increases in the mobility and concentration of lattice oxygen vacancies. The calculated ionic conductivities of some compositions exceeded that of yttria-stabilized zirconia. RP Stevenson, JW (reprint author), PACIFIC NW NATL LAB,DEPT MAT SCI,RICHLAND,WA 99352, USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 30 TC 430 Z9 449 U1 12 U2 83 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 SEP PY 1996 VL 143 IS 9 BP 2722 EP 2729 DI 10.1149/1.1837098 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VH209 UT WOS:A1996VH20900021 ER PT J AU Armstrong, TR Stevenson, JW Pederson, LR Raney, PE AF Armstrong, TR Stevenson, JW Pederson, LR Raney, PE TI Dimensional instability of doped lanthanum chromite SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID DEFECT STRUCTURE; CONDUCTIVITY AB Lattice expansion, phase stability, and dimensional stability of doped lanthanum chromites have been examined over a wide range of temperatures and oxygen partial pressures. Reduction of doped lanthanum chromite resulted in a linear expansion of the sample that was dependent on the acceptor (Sr, Ca) concentration, temperature, oxygen partial pressure, and oxygen content within the sample. Additional doping with aliovalent B-site additives significantly reduced lattice expansion in reducing environments. The lattice expansion in reducing environments was directly related to the loss of lattice oxygen and the simultaneous reduction of Cr2+ to Cr3+ to maintain electroneutrality. RP Armstrong, TR (reprint author), PACIFIC NW NATL LAB, DEPT MAT SCI, RICHLAND, WA 99352 USA. NR 23 TC 100 Z9 101 U1 1 U2 10 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1996 VL 143 IS 9 BP 2919 EP 2925 DI 10.1149/1.1837127 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VH209 UT WOS:A1996VH20900050 ER PT J AU Frye, GC Blair, DS Schneider, TW Mowry, CD Colburn, CW Donovan, RP AF Frye, GC Blair, DS Schneider, TW Mowry, CD Colburn, CW Donovan, RP TI Development and evaluation of on-line detection techniques for polar organics in ultrapure water SO JOURNAL OF THE INSTITUTE OF ENVIRONMENTAL SCIENCES LA English DT Article DE on-line monitor; water analysis; gas chromatograph; surface acoustic wave; SAW; purge and trap; adsorbent; acetone isopropanol ID GAS-CHROMATOGRAPHY; SENSOR RESPONSES; COATINGS; VAPORS AB An on-line monitor that can perform rapid trace detection of polar organics such as acetone and isopropanol in ultrapure water (UPW) is necessary to efficiently recycle water in semiconductor manufacturing facilities. The detection of these analytes is problematic due to their high solubility in water, resulting in low partitioning into sensor coatings for direct water analysis or into the vapor phase for detection by vapor phase analyzers. After considering various options, two conventional laboratory techniques have been evaluated: gas chromatography and ion mobility spectroscopy. In addition, optimizations of sensor coating materials and sample preconditioning systems were performed with the goal of a low-cost, chemical sensor system for this application. Results from these evaluations, including recommendations for meeting the needs of this application, are reported. RP Frye, GC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU INST ENVIRONMENTAL SCI PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 SN 1052-2883 J9 J INST ENVIRON SCI JI J. Inst. Environ. Sci. PD SEP-OCT PY 1996 VL 39 IS 5 BP 30 EP 37 PG 8 WC Engineering, Environmental; Environmental Sciences; Instruments & Instrumentation SC Engineering; Environmental Sciences & Ecology; Instruments & Instrumentation GA VQ197 UT WOS:A1996VQ19700007 ER PT J AU Beran, MJ Mason, TA Adams, BL Olson, T AF Beran, MJ Mason, TA Adams, BL Olson, T TI Bounding elastic constants of an orthotropic polycrystal using measurements of the microstructure SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE microstructures; constituitive behavior; polycrystalline material; electron microscopy AB We show how information about the elastic stiffness and compliance of an orthotropic polycrystal may be obtained from measurements of the statistical properties of the microstructure. We begin by discussing the statistical properties of the governing equations and the hierarchy that results when the equations are averaged. Perturbation solutions are obtained in terms of low-order statistical information. Using methods previously developed, we derive bounds for the elastic stiffnesses and compliances. A hierarchy of bounds is derived using the statistical information obtained from measurement of the microstructure. We discuss the methods used to obtain the correlation functions of the microstructure and provide a specific example, using data obtained from a copper sample. Copyright (C) 1996 Elsevier Science Ltd C1 LOCKHEED IDAHO TECHNOL CO, IDAHO FALLS, ID 83415 USA. CARNEGIE MELLON UNIV, DEPT MAT SCI & ENGN, PITTSBURGH, PA 15213 USA. MICHIGAN TECHNOL UNIV, DEPT MATH, HOUGHTON, MI 49931 USA. RP Beran, MJ (reprint author), TEL AVIV UNIV, FAC ENGN, RAMAT AVIV, ISRAEL. NR 21 TC 59 Z9 60 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD SEP PY 1996 VL 44 IS 9 BP 1543 EP 1563 DI 10.1016/0022-5096(96)00052-X PG 21 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VF629 UT WOS:A1996VF62900006 ER PT J AU Lindaas, S Howells, H Jacobsen, C Kalinovsky, A AF Lindaas, S Howells, H Jacobsen, C Kalinovsky, A TI X-ray holographic microscopy by means of photoresist recording and atomic-force microscope readout SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID BIOLOGICAL SPECIMENS; RADIATION; RESOLUTION; IMAGE; LASER AB We have reconstructed in-line (or Gabor) x-ray holograms at 40-50-nm resolution from a complex biological specimen. The holograms were recorded as a relief pattern on photoresist with use of 1.89-nm, soft, x rays from the X1A undulator beam line at the National Synchrotron Light Source at Brookhaven National Laboratory. We have improved the resolution and the fidelity and simplified the experiment compared with earlier work by employing a special atomic-force microscope to examine and digitize the holograms. Following digitization the holograms were reconstructed numerically, allowing both the absorptive and phase-shifting properties of the reconstructed objected to be mapped. A comparison of the reconstructed images with images obtained from holographic technique. The method offers promise as a technique for soft-x-ray microscopy and diffraction tomography of dry and frozen hydrated specimens and for microscopy with pulsed x-ray sources. (C) 1996 Optical Society of America. C1 SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. RP Lindaas, S (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Jacobsen, Chris/E-2827-2015 OI Jacobsen, Chris/0000-0001-8562-0353 NR 59 TC 51 Z9 52 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 1996 VL 13 IS 9 BP 1788 EP 1800 DI 10.1364/JOSAA.13.001788 PG 13 WC Optics SC Optics GA VE113 UT WOS:A1996VE11300002 ER PT J AU Sullivan, A White, WE Chu, KC Heritage, JP Delong, KW Trebino, R AF Sullivan, A White, WE Chu, KC Heritage, JP Delong, KW Trebino, R TI Quantitative investigation of optical phase-measuring techniques for ultrashort pulse lasers SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID SINGLE-SHOT MEASUREMENT; TI-SAPPHIRE LASER; FEMTOSECOND PULSES; SPECTRAL PHASE; BEAM ANALYSIS; LIGHT-PULSES; AMPLIFICATION; INTENSITY; RETRIEVAL; GENERATION AB We have performed a quantitative investigation into the capabilities and the limitations of two phase-measuring techniques: second-harmonic-generation frequency-resolved optical gating and direct optical-spectral phase measurement. In particular, we have studied the reproducibility and the accuracy of these techniques in measuring the frequency-dependent phase of ultrashort pulses with varying amounts of cubic and quadratic phase. We find that both of these techniques are accurate to within 5% in measuring phase distortions in optical pulses. (C) 1996 Optical Society of America. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 40 TC 8 Z9 8 U1 1 U2 4 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 SEP PY 1996 VL 13 IS 9 BP 1965 EP 1978 DI 10.1364/JOSAB.13.001965 PG 14 WC Optics SC Optics GA VF898 UT WOS:A1996VF89800018 ER PT J AU Kramer, CF Thode, HC Barancik, JI Kahn, CJ AF Kramer, CF Thode, HC Barancik, JI Kahn, CJ TI Untitled - Reply SO JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE LA English DT Letter RP Kramer, CF (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 1079-6061 J9 J TRAUMA JI J. Trauma-Injury Infect. Crit. Care PD SEP PY 1996 VL 41 IS 3 BP 576 EP 578 DI 10.1097/00005373-199609000-00048 PG 3 WC Critical Care Medicine; Surgery SC General & Internal Medicine; Surgery GA VH571 UT WOS:A1996VH57100052 ER PT J AU Collins, GW Bittner, DN Monsler, E Letts, S Mapoles, ER Bernat, TP AF Collins, GW Bittner, DN Monsler, E Letts, S Mapoles, ER Bernat, TP TI Infrared redistribution of D-2 and HD layers for inertial confinement fusion SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID TRITIUM AB We describe a technique to form uniform solid D-2 or HD layers for inertial confinement fusion targets. Pumping the infrared (IR) collision induced vibration-rotation band in solid D-2 or HD redistributes the solid into a relatively uniform layer depending on the IR intensity profile. Measured redistribution time constants are near the calculated values. We have observed redistribution time constants in HD up to ten times smaller than the DT value. (C) 1996 American Vacuum Society. C1 WJ SCHAFER ASSOCIATES INC,LIVERMORE,CA 94550. RP Collins, GW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 9 TC 32 Z9 36 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1996 VL 14 IS 5 BP 2897 EP 2900 DI 10.1116/1.580241 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VJ242 UT WOS:A1996VJ24200029 ER PT J AU Britten, JA Nguyen, HT Falabella, SF Shore, BW Perry, MD Raguin, DH AF Britten, JA Nguyen, HT Falabella, SF Shore, BW Perry, MD Raguin, DH TI Etch-stop characteristics of Sc2O3 and HfO2 films for multilayer dielectric grating applications SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB High-efficiency, high laser-damage threshold reflection gratings can be made by etching a grating structure into the top layer of a multilayer high-reflectivity stack. Spatial efficiency and wave-front uniformity can be maximized by taking advantage of the etch-stop properties of the layer underneath the top layer to be etched. The etch-stop layer must have a high optical damage resistance, which places severe restrictions on available materials. The etch characteristics of HfO2 and Sc2O3, two materials commonly used in high laser-damage optical coatings, have been evaluated. The etch rate selectivities of e-beam evaporated SiO2/HfO2/Sc2O3 thin films in a reactive ion etching system optimized for SiO2 etching are approximately 100/10/1. Gratings etched to a HfO2 etch-stop layer suffered from deposition of fluorinated Kf compounds on the SiO2 grating sidewalls, but sidewalls were clean when Sc2O3 was used as the etch-stop layer. (C) 1996 American Vacuum Society. C1 ROCHESTER PHOTON CORP,ROCHESTER,NY 14623. RP Britten, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 11 TC 28 Z9 30 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1996 VL 14 IS 5 BP 2973 EP 2975 DI 10.1116/1.580256 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VJ242 UT WOS:A1996VJ24200044 ER PT J AU Tsai, W Mueller, G Lindquist, R Frazier, B Vahedi, V AF Tsai, W Mueller, G Lindquist, R Frazier, B Vahedi, V TI High selectivity plasma etching of silicon dioxide with a dual frequency 27/2 MHz capacitive radio frequency discharge SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID HIGH-DENSITY PLASMA; RADIOFREQUENCY AB A 27 MHz/2 MHz Ar/CO/CFx rf capacitive discharge was used to selectively etch submicron SiO2/Si, SiO2/TiSi2 and SiO2/TiN structures. The borophosphosilicate glass etch rate (similar to 1.0 mu m/min) was observed to decrease with bottom electrode temperature, whereas etch selectivity to TiSi2 (>50:1) was found to increase with temperature, with a photoresist selectivity >50:1. Plasma emission of the dual frequency discharge indicated the presence of an abundant concentration of the CF2 radical (249 nm) as compared to a lower frequency (400 kHz) rf discharge with low etch selectivity (<20:1). Langmuir probe measurement indicated an enhancement of ion density of an order of magnitude (similar to 5x10(10) cm(-3)) as compared to the low frequency (400 kHz) rf discharge. Particle-in-cell simulation was used to calculate plasma density as a function of excitation frequency. Plasma density scales with the square of the source frequency while it remains relatively independent of the substrate frequency. (C) 1995 American Vacuum Society. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Tsai, W (reprint author), LAM RES CORP,4650 CUSHING PKWY,FREMONT,CA 94538, USA. NR 21 TC 62 Z9 62 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 1996 VL 14 IS 5 BP 3276 EP 3282 DI 10.1116/1.588820 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VM922 UT WOS:A1996VM92200011 ER PT J AU Cardwell, H Jager, HI Sale, MJ AF Cardwell, H Jager, HI Sale, MJ TI Designing instream flows to satisfy fish and human water needs SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID ALTERNATIVES AB The relicensing of nonfederal hydropower projects and the mandated reevaluation of federal water projects require policy makers to balance the human use of water with instream releases for environmental values, To meet the need for planning level tools for instream flow determination, we develop a flexible multiobjective optimization model, The model considers both the size and frequency of water supply shortages and the habitat available for fish species as the fish progress through life stages. We use a habitat capacity metric to combine expected mortality, the fraction of a life stage in a particular month, and the areal habitat needs per individual fish. The model incorporates human water supply concerns such as monthly variations in human water demand, water-year types, and flood control restrictions. We apply this monthly optimization model to a west-slope Sierra Nevada stream used for municipal and agricultural supply and for supporting an anadromous fish population. Results identified a range of alternative solutions that involve trade-offs between water shortage levels and fish population capacity. RP Cardwell, H (reprint author), OAK RIDGE NATL LAB,ECORISK GRP,DIV ENVIRONM SCI,POB 2008,MS 6036,OAK RIDGE,TN 37831, USA. NR 28 TC 40 Z9 44 U1 1 U2 7 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD SEP-OCT PY 1996 VL 122 IS 5 BP 356 EP 363 DI 10.1061/(ASCE)0733-9496(1996)122:5(356) PG 8 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA VD983 UT WOS:A1996VD98300005 ER PT J AU Smith, A AF Smith, A TI Software facilitates nonlinear-crystal selection SO LASER FOCUS WORLD LA English DT Article RP Smith, A (reprint author), SANDIA NATL LABS,LASERS OPT & REMOTE SENSING DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD SEP PY 1996 VL 32 IS 9 BP 171 EP 172 PG 2 WC Optics SC Optics GA VX397 UT WOS:A1996VX39700035 ER PT J AU Nelson, JS Milner, TE Tanenbaum, BS Goodman, DM VanGemert, MJC AF Nelson, JS Milner, TE Tanenbaum, BS Goodman, DM VanGemert, MJC TI Infra-red tomography of port-wine-stain blood vessels in human skin SO LASERS IN MEDICAL SCIENCE LA English DT Article DE port-wine stain; infra-red tomography; laser treatment; blood vessel; photothermolysis ID PULSED DYE-LASER; PHOTOTHERMOLYSIS; CHILDREN AB Specifying the distribution of laser energy within a tissue is the first step towards understanding and capitalizing on a variety of laser-tissue interactions, Whether photothermal, photochemical or photomechanical in nature, laser-tissue interactions begin with the absorption of photon energy. The spatial distribution of photon absorption specifies the required laser exposure to be delivered and the extent of subsequent therapeutic action. Using infra-red tomography (IRT), the broad, long-term objective of this research is the development of a tomographic reconstruction algorithm as a means to determine: (1) the depths and physical dimensions of discrete subsurface port-wine-stain (PWS) blood vessels in human skin; and (2) the initial space-dependent temperature increase in PWS blood vessels immediately following pulsed laser exposure. In this report, preliminary studies are described which demonstrate the potential application of IRT in the clinical management of PWS patients. C1 HARVEY MUDD COLL,DEPT ENGN,CLAREMONT,CA 91711. LAWRENCE LIVERMORE NATL LAB,DIV IMAGING SCI,LIVERMORE,CA 94550. UNIV AMSTERDAM,ACAD MED CTR,CTR LASER,NL-1105 AZ AMSTERDAM,NETHERLANDS. RP Nelson, JS (reprint author), UNIV CALIF IRVINE,BECKMAN LASER INST & MED CLIN,1002 HLTH SCI RD E,IRVINE,CA 92612, USA. NR 18 TC 13 Z9 14 U1 0 U2 2 PU W B SAUNDERS CO LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0268-8921 J9 LASER MED SCI JI Lasers Med. Sci. PD FAL PY 1996 VL 11 IS 3 BP 199 EP 204 DI 10.1007/BF02156765 PG 6 WC Engineering, Biomedical; Surgery SC Engineering; Surgery GA VX245 UT WOS:A1996VX24500010 ER PT J AU Guo, LD Santschi, PH Cifuentes, LA Trumbore, SE Southon, J AF Guo, LD Santschi, PH Cifuentes, LA Trumbore, SE Southon, J TI Cycling of high-molecular-weight dissolved organic matter in the middle Atlantic bight as revealed by carbon isotopic (C-13 and C-14) signatures SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID U-238 TH-234 DISEQUILIBRIA; GULF-OF-MEXICO; STABLE CARBON; COLLOIDAL MATERIAL; NORTHEAST PACIFIC; OCEAN; GEOCHEMISTRY; WATER; BIOGEOCHEMISTRY; RADIOCARBON AB Carbon isotopes (C-13 and C-14) and elemental composition (C and N) in two fractions of colloidal organic matter (COM) were measured to study the origin and cycling of dissolved organic matter (DOM) in the Middle Atlantic Eight (MAE). COM(1) (1 kDa-0.2 mu m) was 59% of the bulk DOM in surface Chesapeake Bay waters and decreased to 30-35% in waters of the MAB. COM(10) (10 kDa-0.2 mu m), which was the high-molecular-weight (HMW) component of COM(1), comprised 3-12% of the bulk DOM, with highest concentrations in Chesapeake Bay waters and the lowest in deep waters in the MAB. Delta(14)C values of COM(1) decreased from nearshore (-21 to +12 parts per thousand) to offshore and from surface (-166 to -85 parts per thousand) to bottom waters (-400 to -304 parts per thousand). Although Delta(14)C values of surface-water HMW COM(10) were generally high (-2 to -7 parts per thousand), values for bottom-water COM(10) were much lower (-129 to -709 parts per thousand). The high Delta(14)C values in the surface water suggest a particulate origin of pelagic COM, consistent with the contemporary Delta(14)C values of particulate organic matter (POM). The very low Delta(14)C values of bottom-water COM(10) imply that in addition to the pelagic origin, sedimentary organic C may serve as an important source for the benthic colloids in the bottom nepheloid layer. The general flow direction of organic carbon is from POM to HMW and to LMW DOM. Three colloidal end-members were identified in the MAB as well as in the Gulf of Mexico: estuarine colloids with high Delta(14)C values, high C:N ratios, and lower delta(13)C values; offshore surface water colloids with intermediate Delta(14)C values, lower C:N ratios, and higher delta(13)C values; and offshore deep-water colloids with low Delta(14)C values, intermediate C:N ratios, and variable delta(13)C values. C1 TEXAS A&M UNIV, DEPT OCEANOG, COLLEGE STN, TX 77843 USA. UNIV CALIF IRVINE, DEPT EARTH SYST SCI, IRVINE, CA 92717 USA. LAWRENCE LIVERMORE NATL LAB, CAMS, LIVERMORE, CA 94551 USA. RP Guo, LD (reprint author), TEXAS A&M UNIV, DEPT OCEANOG, 5007 AVE U, GALVESTON, TX 77551 USA. RI Guo, Laodong/F-6045-2010; Santschi, Peter/D-5712-2012; Trumbore, Susan/B-1948-2013 OI Guo, Laodong/0000-0002-5010-1630; NR 40 TC 86 Z9 92 U1 0 U2 14 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 1996 VL 41 IS 6 BP 1242 EP 1252 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VZ476 UT WOS:A1996VZ47600009 ER PT J AU Ludwig, DL Mudgett, JS Park, MS PerezCastro, AV MacInnes, MA AF Ludwig, DL Mudgett, JS Park, MS PerezCastro, AV MacInnes, MA TI Molecular cloning and structural analysis of the functional mouse genomic XPG gene SO MAMMALIAN GENOME LA English DT Article ID EXCISION-REPAIR GENE; XERODERMA-PIGMENTOSUM; MAMMALIAN-CELLS; SCHIZOSACCHAROMYCES-POMBE; SACCHAROMYCES-CEREVISIAE; LEUKEMIA-L1210 CELLS; COCKAYNE-SYNDROME; SPLICE SITES; DNA-SEQUENCE; COMPLEMENTATION AB The mouse XPG gene is a homolog of the human DNA excision repair gene known to be defective in the hereditary sun-sensitive disorder xeroderma pigmentosum (group-G). Defects in mouse XPG have been shown to directly affect the sensitivity of cultured cells to chemotherapy agents and may play a role in tumor cell drug resistance bl vivo. A full-length cosmid clone of mouse XPG was isolated by complementation of the UV sensitivity and repair defect in CHO-UV135 cells. Exon mapping determined that the gene consisted of 15 exons within 32 kb of genomic DNA. Sequencing of intron-exon boundaries revealed that mouse XPG possesses a rare class of intron previously identified in only four other eukaryotic genes; it utilizes AT and AC dinucleotides instead of the expected GT and AG within the splice junctions. Promoter analysis determined that mouse XPG is expressed constitutively and probably initiates transcription from multiple start sites, yet, unlike the yeast homolog RAD2, we found no evidence that it is WC inducible in cultured cells. Amino acid comparison with human XPG identified a highly conserved acidic region of homology not previously described. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 35 TC 9 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD SEP PY 1996 VL 7 IS 9 BP 644 EP 649 DI 10.1007/s003359900198 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VF859 UT WOS:A1996VF85900002 PM 8703115 ER PT J AU Famula, TR Oberbauer, AM Sousa, CA AF Famula, TR Oberbauer, AM Sousa, CA TI A threshold model analysis of deafness in Dalmatians SO MAMMALIAN GENOME LA English DT Article ID AUDITORY-EVOKED RESPONSE; ORDERED CATEGORICAL-DATA; INNER-EAR; HEREDITARY DEAFNESS; MOUSE; ABNORMALITIES; DOGS AB To elucidate the inheritance of deafness in Dalmatian dogs, 825 dogs in 111 litters were evaluated for abnormalities in hearing through the brainstem auditory evoked response (BAER). Recorded along with their quality of hearing (normal, unilaterally deaf, or bilaterally deaf) were the sex, coat color, eye color and the presence or absence of a color patch. The analysis considered deafness an ordered categorical trait in a threshold model. The underlying, unobservable continuous variate of the threshold model was assumed to be a Linear function of sex of dog, coat color (black or liver and white), color patch (presence or absence), eye color, the deafness phenotype of the parents and a random family effect. Twenty-six percent of dogs were deaf in at least one ear. Eye color, color patch, sex and the hearing status of the parents were all significant contributions to deafness. The heritability of deafness, on the continuous unobservable scale, was 0.21. This value was computed after correction for eye color, color patch, parental hearing status and sex, implying that significant genetic variation exists beyond the contribution of several single loci. C1 ANIM DERMATOL CLIN,SACRAMENTO,CA 95819. RP Famula, TR (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ANIM SCI,DAVIS,CA 95616, USA. NR 24 TC 31 Z9 31 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD SEP PY 1996 VL 7 IS 9 BP 650 EP 653 DI 10.1007/s003359900199 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VF859 UT WOS:A1996VF85900003 PM 8703116 ER PT J AU Davies, KTR Glasser, ML Protopopescu, V Tabakin, F AF Davies, KTR Glasser, ML Protopopescu, V Tabakin, F TI The mathematics of principal value integrals and applications to nuclear physics, transport theory, and condensed matter physics SO MATHEMATICAL MODELS & METHODS IN APPLIED SCIENCES LA English DT Article ID DISPERSION-RELATIONS; EQUATIONS; MODEL AB A review of developments in the mathematics and methods for principal value (PV) integrals is presented. These topics include single-pole formulas for simple and higher-order PVs, simple and higher-order poles in double integrals, and products of simple poles in general multiple integrals. Two generalizations of the famous Poincare-Bertrand (PB) theorem are studied. We then review the following topics: dispersion relations for the advanced, retarded, and causal Green's functions; Titchmarsh's theorem; applications of the PB theorem to two- and three-particle loop integrals; and the R and T matrix formalism. Also, various applications of the PV methods to nuclear physics, transport theory, and condensed matter physics are studied. In the appendices several methods for evaluating PV integrals, including the Haftel-Tabakin procedure for calculating the R and T matrices, are reviewed. C1 OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. CLARKSON UNIV,CORA & BAYARD CLARKSON SCI CTR,DEPT PHYS,POTSDAM,NY 13676. OAK RIDGE NATL LAB,DIV MATH & COMP SCI,OAK RIDGE,TN 37831. UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260. RP Davies, KTR (reprint author), DUQUESNE UNIV,DEPT PHYS,PITTSBURGH,PA 15282, USA. NR 61 TC 13 Z9 13 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-2025 J9 MATH MOD METH APPL S JI Math. Models Meth. Appl. Sci. PD SEP PY 1996 VL 6 IS 6 BP 833 EP 885 DI 10.1142/S0218202596000353 PG 53 WC Mathematics, Applied SC Mathematics GA VF475 UT WOS:A1996VF47500006 ER PT J AU Glimm, JG Plohr, BJ Sharp, DH AF Glimm, JG Plohr, BJ Sharp, DH TI Tracking of shear bands .1. The one-dimensional case SO MECHANICS OF MATERIALS LA English DT Article DE elastoplasticity; shear bands; front tracking AB We develop a model for the dynamics of a fully developed shear band that allows effective computation across several length scales, From a macroscopic point of view, a shear band is a discontinuity in tangential velocity that supports a shear stress, Numerical simulation of the full system of governing equations reveals that the internal structure of the band consists of a quasistatic core surrounded by a thermal layer, We show that the shear band can be modeled as a composite structure whose evolution is governed by an integral equation, coupled to the external flow through jump conditions, We establish the accuracy of the model equations by numerical experiments. C1 SUNY STONY BROOK,DEPT APPL MATH & STAT,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT MATH,STONY BROOK,NY 11794. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD SEP PY 1996 VL 24 IS 1 BP 31 EP 41 DI 10.1016/0167-6636(96)00029-4 PG 11 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA VP330 UT WOS:A1996VP33000004 ER PT J AU Gandin, CA Eshelman, M Trivedi, R AF Gandin, CA Eshelman, M Trivedi, R TI Orientation dependence of primary dendrite spacing SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID TIP GROWTH; SOLIDIFICATION; FUNDAMENTALS; STABILITY AB The orientation dependence of the primary dendrite spacing is examined through the solidification of a succinonitrile-3.61 wt pet acetone alloy with a Bridgman-type device. Primary dendrite spacing has been studied as a function of the primary dendrite trunk orientation with respect to the thermal gradient direction under different growth rate conditions. The observations show that the orientation dependence of the primary dendrite spacing can be related to the formation of new primary dendrites at divergent grain boundaries via the branching mechanism. A branching-based model is developed to study the interaction between secondary and tertiary dendrite arms. Based on this model, a simple analytical relationship is proposed to account for the orientation dependence of the primary dendrite spacing. C1 IOWA STATE UNIV,US DOE,AMES LAB,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Gandin, CA (reprint author), ECOLE POLYTECH FED LAUSANNE,MET PHYS LAB,CH-1015 LAUSANNE,SWITZERLAND. OI GANDIN, Charles-Andre/0000-0002-6270-5407 NR 27 TC 34 Z9 35 U1 0 U2 10 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 SEP PY 1996 VL 27 IS 9 BP 2727 EP 2739 DI 10.1007/BF02652367 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VH386 UT WOS:A1996VH38600034 ER PT J AU Park, JS Verhoeven, JD AF Park, JS Verhoeven, JD TI Transitions between type A flake, type D flake, and coral graphite eutectic structures in cast irons SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID C-SI ALLOYS; FE-C; MORPHOLOGICAL TRANSITIONS; GROWTH; TE AB Directional solidification experiments were used to measure the transition velocities between the type A and coral eutectic structures in high-purity cast irons and between the type A and type D eutectic structures in S and Te doped cast irons. Introduction of O into the gas atmosphere was found to have little effect on the A double right arrow D transition velocities in S doped alloys, but it produced a strong reduction in the A double right arrow coral transition velocities in high-purity irons. Transmission electron microscopy revealed interesting variations in the defect structures of the graphite in the flake irons vs the type of flake (A or D) and the type of doping element. Scanning Auger microscopy demonstrated that both S and Te segregate to the iron/graphite interface. In the S doped alloys, type A flakes are generally covered with a monolayer of S with patches of O in the form of iron oxide having a thickness on the order of 2 nm. A series of experiments, including examination of fracture surfaces at the quenched solid/liquid growth front, have shown that S segregates to the iron/graphite interfaces from the liquid at the growth front, but O forms at these interfaces during the cooldown. These results are discussed in relation to current models of eutectic growth in cast irons. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 39 TC 7 Z9 7 U1 1 U2 6 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 SEP PY 1996 VL 27 IS 9 BP 2740 EP 2753 DI 10.1007/BF02652368 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VH386 UT WOS:A1996VH38600035 ER PT J AU Dunand, DC Mari, D Bourke, MAM Roberts, JA AF Dunand, DC Mari, D Bourke, MAM Roberts, JA TI NiTi and NiTi-TiC composites .4. Neutron diffraction study of twinning and shape-memory recovery SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID METAL MATRIX COMPOSITES; MARTENSITIC-TRANSFORMATION; CRYSTAL-STRUCTURE; ALLOY; CRYSTALLOGRAPHY; DEFORMATION; BEHAVIOR AB Neutron diffraction measurements of internal elastic strains and crystallographic orientation were performed during compressive deformation of martensitic NiTi containing 0 vol pct and 20 vol pet TiC particles. For bulk NiTi, some twinning takes place upon initial loading below the apparent yield stress, resulting in a low apparent Young's modulus; for reinforced NiTi, the elastic mismatch from the stiff particles enhances this effect. However, elastic load transfer between matrix and reinforcement takes place above and below the composite apparent yield stress, in good agreement with continuum mechanics predictions. Macroscopic plastic deformation occurs by matrix twinning, whereby (1 0 0) planes tend to align perpendicular to the stress axis. The elastic TiC particles do not alter the overall twinning behavior, indicating that the mismatch stresses associated with NiTi plastic deformation are fully relaxed by localized twinning at the interface between the matrix and the reinforcement. For both bulk and reinforced NiTi, partial reverse twinning takes place upon unloading, as indicated by a Bauschinger effect followed by rubberlike behavior, resulting in very low residual stresses in the unloaded condition. Shape-memory heat treatment leads to further recovery of the preferred orientation and very low residual stresses, as a result of self-accommodation during the phase transformations. It is concluded that, except for elastic load transfer, the thermal, transformation, and plastic mismatches resulting from the TiC particles are efficiently canceled by matrix twinning, in contrast to metal matrix composites deforming by slip. C1 ADV COMPOSITE & MICROWAVE ENGN, CH-1015 LAUSANNE, SWITZERLAND. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Dunand, DC (reprint author), MIT, DEPT MAT SCI & ENGN, CAMBRIDGE, MA 02139 USA. RI Dunand, David/B-7515-2009 NR 53 TC 66 Z9 66 U1 1 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 1996 VL 27 IS 9 BP 2820 EP 2836 DI 10.1007/BF02652374 PG 17 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VH386 UT WOS:A1996VH38600041 ER PT J AU Fliermans, CB AF Fliermans, CB TI Ecology of Legionella: From data to knowledge with a little wisdom SO MICROBIAL ECOLOGY LA English DT Review ID FREE-LIVING AMEBAS; NOSOCOMIAL LEGIONNAIRES-DISEASE; GREEN-ALGAE CYANOBACTERIA; COOLING-TOWERS; POTABLE WATER; PONTIAC FEVER; LONGBEACHAE SEROGROUP-1; AQUATIC HABITATS; GUINEA-PIG; PNEUMOPHILA AB The respiratory diseases produced by the Legionella genus of bacteria are collectively called Legionellosis. Presently more than 34 species of Legionella have been identified, 20 of which have been isolated from both environmental and clinical sources. The diseases produced by Legionella include the pneumonic form, Legionnaires' disease, and the flu-like form, Pontiac fever. Because the vast majority of Legionellosis is caused by the L. pneumophila species, this bacterium is the thrust of the discussion. Legionella is a global bacterium. The relationship of the bacterium to its environment has told us many things about infectious diseases. Not until Legionellosis and the discovery of its etiologic agent, Legionella, has such a successful modem-day marriage been consummated between the agent and its environment. Nearly two decades have passed since the term Legionellosis found its way into the vocabulary of the scientific journals, the popular press, and courtroom proceedings. Too often the scientific development, engineering implementation, and societal acceptance are disconnected. The focus of scientific research sometimes does not reflect engineering or societal needs and thus contributes little to the solution of immediate and important problems. At other times, scientific knowledge that could contribute to solutions is overlooked because of poor communication between the problem holders, the scientific community, regulatory agencies, the problem makers, and the public. The scope of this paper provides insights on the ecological niche of Legionella, describes the organism's ecological relationships in the natural world, and provides wisdom for effective control of the bacterium for the industrial and user communities. RP Fliermans, CB (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29808, USA. NR 162 TC 53 Z9 57 U1 1 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD SEP-OCT PY 1996 VL 32 IS 2 BP 203 EP 228 PG 26 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA UZ021 UT WOS:A1996UZ02100006 ER PT J AU Fong, CY Klein, BM Nelson, JS AF Fong, CY Klein, BM Nelson, JS TI Energy spacing in charging a quantum dot: The effect of the electron-electron interactions SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID CAPACITANCE; SPECTROSCOPY AB Recent experiments on quantum dots have shown that by adding one electron at a time to a quantum dot the energy spacings 'are rather uniform and decrease slightly' as the number of electrons increases (Ashoori et nl 1993 Phys. Rev. Lett. 71 613). By applying the scaled Kohn-Sham equations to a cylindrical quantum dot system we show that this is due to the effect of the electron-electron interactions. The interactions, especially the Coulomb interaction, cause a significant redistribution of the electronic charge density which is determined by the effect of the boundary condition of the quantum dot in minimizing the total energy of the system. To ensure that the effect of the electron-electron interactions is independent of the specific potential used in defining the quantum dot, two model potentials (a constant potential and a potential that is harmonic in the radial part) are considered. C1 SANDIA NATL LABS,SEMICOND MAT & DEVICE SCI,ALBUQUERQUE,NM 87123. RP Fong, CY (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD SEP PY 1996 VL 4 IS 5 BP 433 EP 441 DI 10.1088/0965-0393/4/5/001 PG 9 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VX343 UT WOS:A1996VX34300001 ER PT J AU Blackwell, LJ Borowiec, JA Mastrangelo, IA AF Blackwell, LJ Borowiec, JA Mastrangelo, IA TI Single-stranded-DNA binding alters human replication protein a structure and facilitates interaction with DNA-dependent protein kinase SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID SIMIAN VIRUS-40 DNA; POLYMERASE-ALPHA PRIMASE; SV40 T-ANTIGEN; V(D)J RECOMBINATION; INVITRO REPLICATION; LIMITED PROTEOLYSIS; A PHOSPHORYLATION; EXCISION-REPAIR; MULTIPLE STAGES; HUMAN-CELLS AB Human replication protein A (hRPA) is an essential single-stranded-DNA-binding protein that stimulates the activities of multiple DNA replication and repair proteins through physical interaction. To understand DNA binding and its role in hRPA heterologous interaction, we examined the physical structure of hRPA complexes with single-stranded DNA (ssDNA) by scanning transmission electron microscopy. Recent biochemical studies have shown that hRPA combines with ssDNA in at least two binding modes: by interacting with 8 to 10 nucleotides (hRPA(8nt)) and with 30 nucleotides (hRPA(30nt)). We find the relatively unstable hRPA(8nt) complex to be notably compact with many contacts between hRPA molecules. In contrast, on similar lengths of ssDNA, hRPA(30nt) complexes align along the DNA and make few intermolecular contacts. Surprisingly, the elongated hRPA(30nt), complex exists in either a contracted or an extended form that depends on ssDNA length. Therefore, homologous-protein interaction and available ssDNA length both contribute to the physical changes that occur in hRPA when it binds ssDNA. We used activated DNA-dependent protein kinase as a biochemical probe to detect alterations in conformation and demonstrated that formation of the extended hRP(30nt) complex correlates with increased phosphorylation of the hRPA 29-kDa subunit. Our results indicate that hRPA binds ssDNA in a multistep pathway, inducing new hRPA alignments and conformations that can modulate the functional interaction of other factors with hRPA. C1 NYU,MED CTR,DEPT BIOCHEM,NEW YORK,NY 10016. NYU,MED CTR,KAPLAN COMPREHENS CANC CTR,NEW YORK,NY 10016. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NCI NIH HHS [P30CA16087]; NCRR NIH HHS [RR0177]; NIAID NIH HHS [AI29963] NR 60 TC 107 Z9 108 U1 0 U2 4 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD SEP PY 1996 VL 16 IS 9 BP 4798 EP 4807 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VC897 UT WOS:A1996VC89700024 PM 8756638 ER PT J AU Livshits, MA Mirzabekov, AD AF Livshits, MA Mirzabekov, AD TI Kinetics of DNA hybridization with oligonucleotides immobilized in gel layer SO MOLECULAR BIOLOGY LA English DT Article DE DNA sequencing; hybridization; kinetics; oligonucleotides; gel AB Theoretical analysis of the kinetics of DNA hybridization with oligonucleotides immobilized in apolyacrylamide gel layer showed that establishment of the equilibrium uniform DNA distribution is governed by the mechanism of retarded diffusion; the equilibration time is longer for more stable duplexes than for less stable ones. Conditions for optimal discrimination of perfect duplexes from those with mismatches are analyzed. The hybridization process should be brought to equilibrium under low-temperature nonsaturating conditions. The kinetic differences between perfect and imperfect duplexes allow further contrasting of the hybridization pattern through additional washing at low temperature of appropriate duration after hybridization. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Livshits, MA (reprint author), RUSSIAN ACAD SCI,ENGELHARDT INST MOL BIOL,MOSCOW 117984,RUSSIA. RI Livshits, Mikhail/P-6744-2015 OI Livshits, Mikhail/0000-0001-8027-2273 NR 10 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 0026-8933 J9 MOL BIOL+ JI Mol. Biol. PD SEP-OCT PY 1996 VL 30 IS 5 BP 694 EP 698 PN 2 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WG844 UT WOS:A1996WG84400006 ER PT J AU BarcellosHoff, MH Dix, TA AF BarcellosHoff, MH Dix, TA TI Redox-mediated activation of latent transforming growth factor-beta 1 SO MOLECULAR ENDOCRINOLOGY LA English DT Article ID ARTERY ENDOTHELIAL-CELLS; FACTOR TYPE-BETA; EXTRACELLULAR-MATRIX; OXIDATIVE STRESS; MAMMARY-GLAND; FREE-RADICALS; EXPRESSION; PROTEINS; TGF-BETA-1; GROWTH-FACTOR-BETA-1 AB Transforming growth factor beta 1 (TGF beta) is a multifunctional cytokine that orchestrates response to injury via ubiquitous cell surface receptors. The biological activity of TGF beta is restrained by its secretion as a latent complex (LTGF beta) such that activation determines the extent of TGF beta activity during physiological and pathological events, TGF beta action has been implicated in a variety of reactive oxygen-mediated tissue processes, particularly inflammation, and in pathologies such as reperfusion injury, rheumatoid arthritis, and atherosclerosis. It was recently shown to be rapidly activated after in vivo radiation exposure, which also generates reactive oxygen species (ROS). In the present studies, the potential for redox-mediated LTGF beta activation was investigated using a cell-free system in which ROS were generated in solution by ionizing radiation or metal ion-catalyzed ascorbate reaction, Irradiation (100 Gray) of recombinant human LTGF beta in solution induced 26% activation compared with that elicited by standard thermal activation, Metal-catalyzed ascorbate oxidation elicited extremely efficient recombinant LTGF beta activation that matched or exceeded thermal activation. The efficiency of ascorbate activation depended on ascorbate concentration and the presence of transition metal ions. We postulate that oxidation of specific amino acids in the latency-conferring peptide leads to a conformation change in the latent complex that allows release of TGF beta. Oxidative activation offers a novel route for the involvement of TGF beta in tissue processes in which ROS are implicated and endows LTGF beta with the ability to act as a sensor of oxidative stress and, by releasing TGF beta, to function as a signal for orchestrating the response of multiple cell types. LTGF beta redox sensitivity is presumably directed toward recovery of homeostasis; however, oxidation may also be a mechanism of LTGF beta activation that can be deleterious during disease mechanisms involving chronic ROS production. C1 MED UNIV S CAROLINA, DEPT PHARMACEUT SCI, CHARLESTON, SC 29425 USA. RP BarcellosHoff, MH (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV LIFE SCI, BLDG 74-166, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. FU NCI NIH HHS [CA-51841] NR 54 TC 332 Z9 343 U1 1 U2 12 PU ENDOCRINE SOC PI CHEVY CHASE PA 8401 CONNECTICUT AVE, SUITE 900, CHEVY CHASE, MD 20815-5817 USA SN 0888-8809 J9 MOL ENDOCRINOL JI Mol. Endocrinol. PD SEP PY 1996 VL 10 IS 9 BP 1077 EP 1083 DI 10.1210/me.10.9.1077 PG 7 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VF482 UT WOS:A1996VF48200003 PM 8885242 ER PT J AU Allen, MJ Lee, JD Lee, C Balhorn, R AF Allen, MJ Lee, JD Lee, C Balhorn, R TI Extent of sperm chromatin hydration determined by atomic force microscopy SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE AFM; nuclear volume; mouse sperm; bull sperm ID MOUSE SPERM; DNA; PROTEINS; DECONDENSATION; PROTAMINE; NUCLEI; HEAD AB Volume measurements were performed on intact bull and mouse sperm heads and amembranous sperm nuclei, both in the fully hydrated (fluid cell) and dehydrated (air-dried on glass coverslips) states by atomic force microscopy (AFM). Data were obtained by analyzing a small population of cells/nuclei, as well as by performing repeated measurements on single cells imaged following the addition of increasing concentrations of propanol. Results show that the volume of fully hydrated, intact sperm heads and amembranous sperm chromatin particles are at least twice the volume of their air-dried counterparts. Dehydration occurs rapidly in air, and the reduction in volume of chromatin induced by water loss appears to be completely reversible. These studies demonstrate that both mouse and bull sperm chromatin are extensively hydrated in the native state, and are not as compact as previous studies have suggested. (C) 1996 Wiley-Liss, Inc. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. DIGITAL INSTRUMENTS,SANTA BARBARA,CA. UNIV CALIF SAN FRANCISCO,SCH MED,SAN FRANCISCO,CA 94143. NR 16 TC 22 Z9 22 U1 1 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD SEP PY 1996 VL 45 IS 1 BP 87 EP 92 DI 10.1002/(SICI)1098-2795(199609)45:1<87::AID-MRD12>3.0.CO;2-U PG 6 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA VF008 UT WOS:A1996VF00800012 PM 8873074 ER PT J AU Tucker, JD Preston, RJ AF Tucker, JD Preston, RJ TI Chromosome aberrations, micronuclei, aneuploidy, sister chromatid exchanges, and cancer risk assessment SO MUTATION RESEARCH-REVIEWS IN GENETIC TOXICOLOGY LA English DT Article DE chromosome aberration; micronucleus; aneuploidy; sister chromatid exchanger cancer; risk assessment ID IN-SITU HYBRIDIZATION; GENE-TOX PROGRAM; HUMAN-LYMPHOCYTES; IONIZING-RADIATION; CELLS; EXPOSURE; FREQUENCY; INDUCTION; VITRO AB This paper describes the four cytogenetic endpoints most frequently used in hazard identification assays as the first step in the risk assessment process. These are structural chromosome aberrations, micronuclei, aneuploidy, and sister chromatid exchanges. The biological mechanisms involved in the formation of the alterations observed in each assay are briefly discussed. Variations in and recent improvements to each assay are described, with an emphasis on the use of molecular techniques to improve the sensitivity of the assay, and to allow for detection of specific alterations that are, or could be, associated with cancer induction. This, in turn, will make the data obtained in the cytogenetic assays more useful in cancer and genetic risk assessment. Thus, the aim of this paper is to encourage cytogeneticists to design their experiments in such a way that the data obtained will be of maximum possible benefit for characterizing and quantifying adverse human health effects, particularly cancer. C1 CHEM IND INST TOXICOL,RES TRIANGLE PK,NC 27709. RP Tucker, JD (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,POB 808,L-452,LIVERMORE,CA 94551, USA. FU NCI NIH HHS [CA55861] NR 47 TC 241 Z9 249 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-1110 J9 MUTAT RES-REV GENET JI Mutat. Res.-Rev. Genet. Toxicol. PD SEP PY 1996 VL 365 IS 1-3 SI SI BP 147 EP 159 DI 10.1016/S0165-1110(96)90018-4 PG 13 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA VP854 UT WOS:A1996VP85400011 PM 8898995 ER PT J AU Tuzun, RE Noid, DW Sumpter, BG Merkle, RC AF Tuzun, RE Noid, DW Sumpter, BG Merkle, RC TI Dynamics of fluid flow inside carbon nanotubes SO NANOTECHNOLOGY LA English DT Article ID MOLECULAR-DYNAMICS; SIMULATIONS AB The dynamics of fluid flow through nanomachines is different from in other systems in that the flow is granular (no continuum assumption) and that the 'walls' move. We have performed molecular dynamics simulations of the flow of helium and argon inside carbon (graphite) nanotubes of several sizes. The fluid was started at some initial velocity; fluid particles were allowed to recycle axially through the tube via minimum image boundary conditions. Argon slowed down more quickly than helium. In addition, the behaviour of the fluid strongly depended on the rigidity of the tube; a dynamic tube slowed down the fluid far more quickly than one in which the tube was held frozen. It also depended on the fluid density and tube diameter. It did not, however, depend on the tube length, because fluid flow tended to prevent the development of strong longitudinal modes, whose behaviour is length dependent. C1 XEROX PARC,PALO ALTO,CA 94303. RP Tuzun, RE (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 14 TC 161 Z9 166 U1 2 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD SEP PY 1996 VL 7 IS 3 BP 241 EP 246 DI 10.1088/0957-4484/7/3/012 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA VL331 UT WOS:A1996VL33100013 ER PT J AU Mackle, TR Parr, CR Stakelum, GK Bryant, AM MacMillan, KL AF Mackle, TR Parr, CR Stakelum, GK Bryant, AM MacMillan, KL TI Feed conversion efficiency, daily pasture intake, and milk production of primiparous Friesian and Jersey cows calved at two different liveweights SO NEW ZEALAND JOURNAL OF AGRICULTURAL RESEARCH LA English DT Article DE Friesian; Jersey; cows; alkanes; dry matter intake; milk; protein; milk fat; feed conversion efficiency ID VOLUNTARY FOOD-INTAKE; DAIRY-COWS; BODY CONDITION; COMPLETE DIETS; PERFORMANCE; CATTLE; NUTRITION; LACTATION; ALKANES; BREEDS AB Pasture dry matter intake (DMI), milk yield and composition, and calculated feed conversion efficiencies (FCE), were monitored throughout lactation for primiparous Friesian (n = 16; F) and Jersey (n = 16; J) cows calved at either high (H) or low (L) calving liveweights (CLW). Half of the cows within each breed were differentially fed (H versus L) during the 8 weeks before expected calving date to produce CLWs of 404 (FH), 354 (FL), 334 (JH), and 277 (JL) +/- 14 (SED) kg. Animals were fully fed on pasture as one group after calving throughout lactation. J cows were more efficient than F cows in converting DM into solids-corrected milk (SCM) (1.63 versus 1.49 +/- 0.07 kg/kg DMI), milksolids (MS) (129 versus 115 +/- 5 g/kg DMI), milk fat (79 versus 67 +/- 3.8 g/kg DMI), and metabolisable energy intake (MEI) into milk energy (43 versus 37 +/- 1.8%). Average DMI measured during six periods across lactation and once after the completion of lactation, were higher for F than J cows (10.5 versus 8.6 +/- 0.2 kg/cow per day) but CLW had no effect on average DMI. CLW did however, affect DMI at 215 days since calving (DSC) when LCLW cows consumed more DM (FH, 11.3; FL, 12.0; JH, 9.4; JL, 10.2 (0.4 kg DM/cow per day). Liveweight-corrected DMI were slightly greater for J cows (2.66 versus 2.55 +/- 0.05 kg/cow per day per 100 kg LW). The HCLW cows lost LW while LCLW cows gained LW until 56 DSC (FH, -8.9; FL, 33.4; JH, -25.9; JL, 10.4 (8.5 kg LW/cow), with JH cows losing more than FH (P < 0.01). The LCLW cows produced less (P < 0.01) milk, SCM, protein, milk fat, and lactose over the first 30-56 DSC. Thereafter, differences between CLW groups were not significant. Average daily milk yield across the whole lactation was affected by CLW (12.2 versus 11.0 (0.6 kg/cow per day; HCLW versus LCLW). LCLW cows had higher concentrations of milk protein (38.5 versus 36.1 +/- 0.8 g/1000 g) and milk fat (57.1 versus 54.1 +/- 1.5 g/1000 g). It was concluded that J cows were more efficient converters of pasture DM into MS, primarily because of a greater efficiency in milk fat production. CLW reduced milk production during the early part of lactation but did not affect DMI until mid lactation. C1 TEAGASC,AGR & FOOD DEV AUTHOR,MOOREPK RES CTR,FERMOY,CORK,IRELAND. RP Mackle, TR (reprint author), DAIRYING RES CORP,PRIVATE BAG 3123,HAMILTON,NEW ZEALAND. NR 42 TC 22 Z9 24 U1 0 U2 9 PU SIR PUBLISHING PI WELLINGTON PA PO BOX 399, WELLINGTON, NEW ZEALAND SN 0028-8233 J9 NEW ZEAL J AGR RES JI N. Z. J. Agric. Res. PD SEP PY 1996 VL 39 IS 3 BP 357 EP 370 PG 14 WC Agriculture, Multidisciplinary SC Agriculture GA VK942 UT WOS:A1996VK94200005 ER PT J AU Batha, SH Levinton, FM Hirshman, SP Bell, MG Wieland, RM AF Batha, SH Levinton, FM Hirshman, SP Bell, MG Wieland, RM TI Sensitivity of equilibrium profile reconstruction to motional stark effect measurements SO NUCLEAR FUSION LA English DT Article ID MAGNETIC MEASUREMENTS; TOKAMAK EQUILIBRIA; PLASMA; TFTR AB The magnetic-field pitch-angle profile, gamma(p)(R) = tan(-1)(B-pol/B-tor), is measured on TFTR using a motional Stark effect (MSE) polarimeter. Measured pitch angle profiles, along with kinetic profiles and external magnetic measurements, are used to compute a self-consistent equilibrium using the free-boundary variational moments equilibrium code VMEC. Uncertainties in the q profile due to uncertainties in gamma(p)(R), magnetic measurements and kinetic measurements are Found to be small. Subsequent uncertainties in the VMEC-calculated current density and shear profiles are also small. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Batha, SH (reprint author), FUS PHYS & TECHNOL,TORRANCE,CA, USA. NR 24 TC 10 Z9 10 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1996 VL 36 IS 9 BP 1133 EP 1143 DI 10.1088/0029-5515/36/9/I03 PG 11 WC Physics, Fluids & Plasmas SC Physics GA XY895 UT WOS:A1996XY89500003 ER PT J AU Okabayashi, M Pomphrey, N Manickam, J Ward, DJ Bell, RE Hatcher, RE Kaita, R Kaye, SM Kugel, HW LeBlanc, B Levinton, FM Roberts, DW Sesnic, S Sun, Y Takahashi, H AF Okabayashi, M Pomphrey, N Manickam, J Ward, DJ Bell, RE Hatcher, RE Kaita, R Kaye, SM Kugel, HW LeBlanc, B Levinton, FM Roberts, DW Sesnic, S Sun, Y Takahashi, H TI Role of the stabilizing shell in high-beta, low-q disruptions in PBX-M SO NUCLEAR FUSION LA English DT Article ID WALL STABILIZATION; PLASMA ROTATION; DIII-D; MODES; TOKAMAKS; PERFORMANCE; REACTOR; SHEAR; LIMIT AB The characteristics of high-beta, low-q disruptions have been studied in PBX-M, a device with a nearby conducting shell. The coupling between the wall and the plasma was varied by choosing different plasma shapes, including nearly circular plasmas, D-shaped plasmas and bean-shaped plasmas (indented on the midplane), and by increasing the effective coverage of the plasma by the shell. Disruption precursors were observed to have a strong dependence on the coupling between the plasma and the shell. Measured mode growth times vary from between several times the Aifven time-scale (similar to 100 mu s) to the L/R time-scale of the wail (similar to 20 ms). The behaviour of observed disruption precursors is interpreted in terms of the resistive wall mode theory of ideal plasmas, and a detailed calculation of the stability of a strongly coupled bean configuration using the NOVA-W linear stability code is presented. The experimental observations are in good agreement with the theoretical predictions. RP Okabayashi, M (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI pomphrey, neil/G-4405-2010 NR 32 TC 42 Z9 42 U1 1 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 SEP PY 1996 VL 36 IS 9 BP 1167 EP 1188 DI 10.1088/0029-5515/36/9/I06 PG 22 WC Physics, Fluids & Plasmas SC Physics GA XY895 UT WOS:A1996XY89500006 ER PT J AU Strachan, JD McCauley, JS Munsat, T Barnes, CW Budny, RV Jassby, DL Johnson, LC McCune, DC Roquemore, AL AF Strachan, JD McCauley, JS Munsat, T Barnes, CW Budny, RV Jassby, DL Johnson, LC McCune, DC Roquemore, AL TI Triton burnup profile measurements SO NUCLEAR FUSION LA English DT Article ID FUSION TEST REACTOR; ABSOLUTE CALIBRATION; CROSS CALIBRATION; NEUTRON DETECTORS; FAST IONS; TFTR; TOKAMAK; TRITIUM; PLASMAS; DEUTERIUM AB The TFTR helium proportional counters measured the 14 MeV neutron emission profiles from the 1 MeV tritons produced by d(d, p)t fusion reactions in deuterium plasmas. The magnitude and profile of the 1 MeV triton burnup indicate that there is no energetic triton transport(D less than or similar to 0.1 m(2)/s) as the tritons slow down from 1 MeV to similar to 0.09 MeV. RP Strachan, JD (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 24 TC 6 Z9 6 U1 2 U2 5 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1996 VL 36 IS 9 BP 1189 EP 1200 DI 10.1088/0029-5515/36/9/I07 PG 12 WC Physics, Fluids & Plasmas SC Physics GA XY895 UT WOS:A1996XY89500007 ER PT J AU Yamada, M Pomphrey, N Ono, Y Katsurai, M AF Yamada, M Pomphrey, N Ono, Y Katsurai, M TI Global stability study of the ultralow aspect ratio tokamak, ULART SO NUCLEAR FUSION LA English DT Letter AB By introducing a slender current carrying conductor through the geometric centre axis of the TS-3 device at Tokyo Univesity, ultralow aspect ratio tokamak (ULART) configurations have been generated with aspect ratios as low as 1.1. In this extreme limit the transition of the spheromak (q(edge) = 0, I-1f = 0) to an ULART plasma (q(edge) = 2-20) is studied. The global MHD characteristics of ULART are investigated by comparing the theoretical results viith the experimental data obtained. A small current (compared with the plasma current) in the centre conductor is found to improve significantly the global MHD stability characteristics of the plasmas formed by effectively stabilizing the global tilt/shift mode. Theoretical calculations of the threshold toroidal field current required for stability and the growth rates of the tilt/shift modes agree well with the TS-3 data. C1 UNIV TOKYO,DEPT ELECT ENGN,TOKYO 113,JAPAN. RP Yamada, M (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI pomphrey, neil/G-4405-2010; Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 17 TC 13 Z9 13 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD SEP PY 1996 VL 36 IS 9 BP 1210 EP 1216 DI 10.1088/0029-5515/36/9/I10 PG 7 WC Physics, Fluids & Plasmas SC Physics GA XY895 UT WOS:A1996XY89500010 ER PT J AU Lapostolle, P Lombardi, AM Tanke, E Valero, S Garnett, RW Wangler, TP AF Lapostolle, P Lombardi, AM Tanke, E Valero, S Garnett, RW Wangler, TP TI A modified space charge routine for high intensity bunched beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB In 1991 a space charge calculation for bunched beam with a three-dimensional ellipsoid was proposed, replacing the usual SCHEFF routines. It removes the cylindrical symmetry required in SCHEFF and avoids the point to point interaction computation, whose number of simulation points is limited. This routine has now been improved with the introduction of two or three ellipsoids giving a good representation of the complex non-symmetrical form of the bunch (unlike the 3-d ellipsoidal assumption). The ellipsoidal density distributions are computed with a new method, avoiding the difficulty encountered near the centre (the axis in 2-d problems) by the previous method. It also provides a check of the ellipsoidal symmetry for each part of the distribution. Finally, the Fourier analysis reported in 1991 has been replaced by a very convenient Hermite expansion, which gives a simple but accurate representation of practical distributions. Comparisons with other space charge routines have been made, particularly with the ones applying other techniques such as SCHEFF. Introduced in the versatile beam dynamics code DYNAC, it should provide a good tool for the study of the various parameters responsible for the halo formation in high intensity linacs. Improvements of the method are under development by the authors. These improvements, which might lead to a new step in space charge computations, are however beyond the scope of this article. C1 CERN,DIV PS,CH-1211 GENEVA 23,SWITZERLAND. CEA SACLAY,GECA,DSM,F-91191 GIF SUR YVETTE,FRANCE. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 8 TC 10 Z9 11 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 SEP 1 PY 1996 VL 379 IS 1 BP 21 EP 40 DI 10.1016/0168-9002(96)00427-5 PG 20 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VH097 UT WOS:A1996VH09700003 ER PT J AU Williams, EK Ila, D Sarkisov, S Venkateswarlu, P Poker, DB AF Williams, EK Ila, D Sarkisov, S Venkateswarlu, P Poker, DB TI Application of NRA/channeling to study He+ implanted waveguides SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID WAVE-GUIDES; LINBO3; PROFILES AB Four different techniques (RBS/channeling, NRA/channeling, prism coupling, and TRIM) for estimating the depth and width of a damaged layer created by ion implantation in LiNbO3 are compared. Waveguides can be created in LiNbO3 by lattice disruption damage with light ions (protons, alphas) or by implantation with Ti. End of range damage results in a decrease in refractive index that acts as a low index barrier to create a waveguide. In the electronic stopping region the ordinary index of LiNbO3 is decreased while the extraordinary index is increased. The damage in the electronic stopping regime is removed by annealing to a temperature lower than that needed to remove the nuclear damage. RBS/channeling is used to examine displacement of Nb atoms and NRA/channeling is used to study displacement of Li atoms using Li(p,alpha) and Li(p,gamma) reactions. We have analyzed waveguides produced by implantation of 1.7 MeV He+. Comparison of the NRA/channeling results of as implanted acid 175 degrees C and 400 degrees C annealed crystals suggest that lithium movement towards the nuclear damage region is responsible for the increase in the extraordinary index in the electronic stopping region. C1 ALABAMA A&M UNIV, CTR NONLINEAR OPT, NORMAL, AL 35762 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RP Williams, EK (reprint author), ALABAMA A&M UNIV, CTR IRRADIAT MAT, NORMAL, AL 35762 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 57 EP 61 DI 10.1016/0168-583X(95)01194-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100013 ER PT J AU Andersen, JU Ball, GC Davies, JA Forster, JS Geiger, JS Haakenaasen, R Hecker, NE Rehn, LE Sharma, RP Uguzzoni, A AF Andersen, JU Ball, GC Davies, JA Forster, JS Geiger, JS Haakenaasen, R Hecker, NE Rehn, LE Sharma, RP Uguzzoni, A TI Use of the 7.6 MeV O-16(alpha,alpha) resonance in studying the anomalous channeling behaviour of YBa2Cu3O7-x near T-c SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID SUPERCONDUCTING TRANSITION; ION AB By using the intense O-16 (He-4, He-4) elastic scattering resonance at 7.3-7.6 MeV, we have been able to extend the earlier investigations [1-4] of the channeling behaviour in YBa2Cu3O7-x around T-c to include the backscattering signal from the oxygen sublattice. We have also developed a computer code enabling us to simulate c-axis angular scans for each atomic sublattice as a function of depth. These simulations reproduce very well the observed oxygen angular scans at 70 K (below T-c) and at 100 K (above T-c), with magnitudes of the thermal vibrational amplitudes which are in reasonable agreement with neutron-scattering data. Concerning small changes at T-c, as observed in earlier channeling investigations, we have concentrated on the analysis of oxygen scans. A direct fit of the simulations to our measurements indicates an increase above T-c of about 0.5 pm in the amplitude of oxygen vibrations perpendicular to the c-axis, or a smaller increase combined with a static displacement. Within the estimated uncertainties, this result is consistent with the neutron data. The oxygen (O4) atoms on the CuO rows along the c-axis contribute a wider channeling dip than the other oxygen atoms (O1, O2 acid O3), which form pure oxygen rows along the c-axis. Hence, the magnitude of the O4 vibrational amplitude is important only for the yield in the shoulders of the combined oxygen dip and it can be determined independently from the fit to measurements. Our results do not confirm the large change of this amplitude at T-c suggested by Remmel et al. [8]. C1 AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. UNIV BOLOGNA,IST NAZL FIS NUCL,BOLOGNA,ITALY. RP Andersen, JU (reprint author), UNIV AARHUS,INST PHYS & ASTRON,DK-8000 AARHUS,DENMARK. 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 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 190 EP 195 DI 10.1016/0168-583X(96)00243-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100037 ER PT J AU Bair, AE Atzmon, Z Russell, SW Barbour, JC Alford, TL Mayer, JW AF Bair, AE Atzmon, Z Russell, SW Barbour, JC Alford, TL Mayer, JW TI Comparison of elastic resonance and elastic recoil detection in the quantification of carbon in SiGeC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID BACKSCATTERING; OXYGEN; FILMS AB The carbon concentrations of chemical vapor deposition grown Si1-x-yGexCy (0.25 < x < 0.37 and 0.01 < y0.12) layers on (100) Si with uniform composition profiles were quantified by two ion analysis techniques. Measurements made with backscattering spectrometry using a 4.295 MeV He2+ incident ion were compared to compositions predicted by elastic recoil detection (ERD) using a 24 MeV Si5+ incident ion. To enhance the carbon scattering cross section for the backscattering measurements, the 4.265 MeV C-12(alpha, alpha)C-12 elastic resonance reaction was used. The carbon concentrations of the films were calculated by integrating the resonant scattering cross section using the energy width of the layer as the limits of integration. The results of this backscattering analysis technique were compared to the predicted carbon concentrations obtained by ERD. It was found that the predictions of these techniques correlated within the uncertainty of each method. C1 ARIZONA STATE UNIV,CTR SOLID STATE SCI,TEMPE,AZ 85287. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Bair, AE (reprint author), ARIZONA STATE UNIV,DEPT CHEM BIO & MAT ENGN,TEMPE,AZ 85287, 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 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 274 EP 277 DI 10.1016/0168-583X(95)01468-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100053 ER PT J AU Howe, LM Phillips, D Zou, H Forster, J Siegele, R Davies, JA Motta, AT Faldowski, JA Okamoto, PR AF Howe, LM Phillips, D Zou, H Forster, J Siegele, R Davies, JA Motta, AT Faldowski, JA Okamoto, PR TI Application of ion-beam-analysis techniques to the study of irradiation damage in zirconium alloys SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID ZR3FE; AMORPHIZATION; ZR; BACKSCATTERING; ZIRCALOY-2; DIFFUSION; ZR-2.5NB AB Ion-beam-analysis techniques are being used to provide an understanding of the nature of collision cascades, irradiation-induced phase changes, lattice location of solute atoms and defect-solute atom interactions in various zirconium alloys. In zirconium intermetallic compounds, such as Zr3Fe, Zr2Fe, ZrFe2, and Zr-3(Fe-x,Ni-1-x), electron and ion irradiations have been used to obtain detailed information on the crystalline-Eo-amorphous transformation occurring during the irradiation. Transmission-electron-microscopy (TEM) observations have provided information on the nature of the damage produced in individual cascades, the critical dose required for amorphization, and the critical temperature for amorphization. In a study on the electron-energy dependence of amorphization in Zr3Fe, Zr2Fe and ZrCr2 in situ high-voltage-electron-microscope investigations were combined with high-energy forward-elastic-recoil measurements to yield information on the threshold displacement energies for Zr and Fe or Cr in these lattices, as well as the role of secondary displacements of lattice atoms by recoil impurities (C,O) at low electron energies. In Zr implanted with Fe-56 ions and subsequently bombarded with Ar-40 ions at 723 K, subsequent secondary-ion-mass-spectrometry (SIMS) analyses were used to monitor che effect of irradiation on the migration of Fe in the Zr lattice. In addition, ion-channeling investigations have been used to determine the lattice sites of solute atoms in Zr as well as the details of the interaction between the solute atoms and the irradiation-produced defects. C1 MCMASTER UNIV,ACCELERATOR LAB,HAMILTON,ON L8S 4M1,CANADA. PENN STATE UNIV,DEPT NUCL ENGN,UNIVERSITY PK,PA 16802. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Howe, LM (reprint author), AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. NR 27 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 663 EP 669 DI 10.1016/0168-583X(96)80117-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100128 ER PT J AU Uslu, C Lee, DH Berta, Y Park, B Poker, DB Riester, L AF Uslu, C Lee, DH Berta, Y Park, B Poker, DB Riester, L TI Enhanced surface hardness in nitrogen-implanted silicon carbide SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID CARBON NITRIDE; THIN-FILMS; ION-IMPLANTATION; SPECTROSCOPY; DIAMOND; SOLIDS; MODULI AB Preliminary studies have been performed on the feasibility of carbon-silicon nitride formation (beta-Si1.5C1.5N4, the homologue of equilibrium beta-Si3N4 or hypothetical beta-C3N4) by high dose N+-implantation into polycrystalline beta-SiC (cubic). Thin films were formed using 100 keV implantations with varying ion doses in the range from 1.1x10(17) to 27.1x10(17) N/cm(2), and target temperatures between -196 degrees C and 980 degrees C. X-ray diffraction with a position-sensitive detector and cross-sectional transmission electron microscopy revealed that the as-implanted surfaces (up to 860 degrees C) contained similar to 0.1 mu m thick buried amorphous layers. Rutherford backscattering spectroscopy showed that the peak concentration of nitrogen saturated up to approximately 54 at.% with increasing doses, suggesting formation of a new phase. Implantation to doses of 1.1 x 10(17) and 2.3 x 10(17) N/cm(2) at 980 degrees C caused enhanced surface hardness compared to SiC. C1 GEORGIA INST TECHNOL, SCH MAT SCI & ENGN, ATLANTA, GA 30332 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RI Park, Byungwoo/F-5431-2013 NR 38 TC 8 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 693 EP 697 DI 10.1016/0168-583X(95)01482-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100134 ER PT J AU Burkhart, JH Denison, D Barbour, JC Apblett, CA AF Burkhart, JH Denison, D Barbour, JC Apblett, CA TI Composition analysis of ECR-grown SiO2 and SiOxFy films SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS AB Low dielectric constant insulating films, such as SiO2 and fluorine doped SiOx, are an important class of materials in semiconductor manufacturing. Evaluation of a new process to grow low temperature SiOxFy films using an electron cyclotron resonance plasma (ECR) was done, Ion beam analysis techniques were used to characterize the compositions of the insulating films and correlate this with their physical and electrical properties. Since Si, O, F and H are of primary interest in these films, three different techniques were utilized in order to get a more thorough analysis. 2.8 MeV He Rutherford Backscattering Spectrometery (RBS) revealed the Si and O content, but because of the low fluorine concentrations [2-10 at.%) RBS proved difficult for analysis of the F content. Instead. Nuclear Reaction Analysis (NRA), which used 872 keV protons in the F-19(p, alpha gamma)O-16 reaction, was employed. Finally, 30 MeV Si Elastic Recoil Detection (ERD) was used to obtain the H concentration and supplement the O analysis. The dielectric constant decreased from epsilon = 4 to epsilon = 3.55 as the F concentration increased from 0 to 10%. C1 IDAHO STATE UNIV,POCATELLO,ID 83201. LAM RES CORP,FREMONT,CA 94538. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 7 TC 1 Z9 1 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 698 EP 703 DI 10.1016/0168-583X(96)00255-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100135 ER PT J AU Yu, N Levine, TE Sickafus, KE Nastasi, M Mitchell, JN Maggiore, CJ Evans, CR Hollander, MG Tesmer, JR Weber, WJ Mayer, JW AF Yu, N Levine, TE Sickafus, KE Nastasi, M Mitchell, JN Maggiore, CJ Evans, CR Hollander, MG Tesmer, JR Weber, WJ Mayer, JW TI In situ MeV ion beam analysis of ceramic surfaces modified by 100-400 keV ion irradiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS AB This paper describes the use of an in situ ion beam analysis facility developed at Los Alamos National Laboratory for the study of irradiation effects in ceramic materials. In this facility, an analytical beamline of 3 MV tandem accelerator and an irradiation beamline of 200 kV ion implanter are connected at 60 degrees to a common target chamber, This facility provides a fast, efficient, and quantitative measurement tool to monitor changes of composition and crystallinity of materials irradiated by 100-400 keV ions through sequential measurement of backscattering events of MeV ions combined with ion channeling techniques. We will describe the details of the in situ ion beam analysis and ion irradiation and discuss some of the important issues and their solutions associated with the in situ experiment, These issues include (1) the selection of an axial ion channeling direction for the measurement of radiation damage; (2) sample surface charging and charge collection for data acquisition; (3) surface sputtering during ion irradiation; (4) the effects of MeV analytical beam on the materials; and (5) the sample heating effect on ion beam analysis. C1 CORNELL UNIV, DEPT MAT SCI & ENGN, ITHACA, NY 14853 USA. PACIFIC NW LAB, DEPT MAT SCI, RICHLAND, WA 99352 USA. ARIZONA STATE UNIV, DEPT CHEM BIO & MAT ENGN, TEMPE, AZ 85287 USA. RP Yu, N (reprint author), LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, POB 1663, LOS ALAMOS, NM 87545 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 7 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 766 EP 771 DI 10.1016/0168-583X(95)01204-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100148 ER PT J AU Im, J Krauss, AR Lin, YP Schultz, JA Auciello, OH Gruen, DM Chang, RPH AF Im, J Krauss, AR Lin, YP Schultz, JA Auciello, OH Gruen, DM Chang, RPH TI In situ analysis of thin film deposition process using time of flight (TOF) ion beam analysis methods SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 12th International Conference on Ion Beam Analysis (IBA-12) CY MAY 22-26, 1995 CL ARIZONA STATE UNIV CAMPUS, TEMPE, AZ HO ARIZONA STATE UNIV CAMPUS ID SURFACE-STRUCTURE; SCATTERING SPECTROSCOPY; REAL-TIME; IN-SITU; NEUTRALS; GROWTH; ICISS AB The use of non-destructive, in situ methods for the characterization of thin film growth phenomena is the key both to obtaining a better understanding of thin film growth processes and to the development of more reliable deposition procedures, especially for complex layered structures involving multi-phase materials. However, surface characterization methods that utilize tither electrons (e.g. AES or XPS) or low energy ions (SIMS) for the signal require an ultra-high vacuum (UHV) environment and utilize instrumentation which obstructs line of sight access to the substrate. These methods are therefore incompatible with line of sight deposition methods and thin film deposition processes which introduce gas, either as an intrinsic part of the deposition procedure or in order to produce the desired composition. We have developed a means of differentially pumping both the ion beam source and detectors of a TOF ion beam surface analysis spectrometer that does not interfere with the deposition process and permits compositional and structural analysis of the growing film in the present system, at pressures up to several mTorr. Higher pressures are feasible with modified source-detector geometry. In order to quantify the sensitivity of Ion Scattering Spectroscopy (ISS) and Direct Recoil Spectroscopy (DRS), we have measured the signal intensity for stabilized clean metals in a variety of gas environments as a function of the ambient gas species and pressure, and ion beam species and kinetic energy. The results are: interpreted in terms of collision cross sections which are compared with known gas phase scattering data and provide an apriori basis for the evaluation of time-of-flight ion scattering and recoil spectroscopies (ToF-ISARS) for various industrial processing environments which involve both inert and reactive gases. The cross section data for primary ion-gas molecule and recoiled atom-gas molecule interactions are also provided, from which the maximum operating pressure in any experimental configuration can be obtained. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. QQC CORP, DEARBORN, MI 48126 USA. IONWERKS, HOUSTON, TX 77005 USA. MCNC, ELECT TECHNOL DIV, RES TRIANGLE PK, NC 27709 USA. RI Chang, R.P.H/B-7505-2009 NR 17 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD SEP PY 1996 VL 118 IS 1-4 BP 772 EP 781 DI 10.1016/0168-583X(95)01205-2 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VN261 UT WOS:A1996VN26100149 ER PT J AU Noh, T Miller, WF AF Noh, T Miller, WF TI The effectiveness of P-2 and simplified P-2 synthetic accelerations in the solutions of discrete ordinates transport equations SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID SLAB GEOMETRY AB Using the operator form of a synthetic acceleration, the P-1 acceleration [diffusion synthetic acceleration (DSA)] and P-2 acceleration schemes for one-dimensional slab and the P-1 and simplified P-2 acceleration schemes for two-dimensional x-y geometry are derived. The convergence rate of each scheme for a simple model problem is compared, and the result is generalized by performing a Fourier analysis. In the one-dimensional case, the new second-moment P-2 acceleration outperforms an earlier third-moment P-2 acceleration developed by Miller and Larsen. However, it is still less efficient than P-1 acceleration. Similar results show that the P-1 acceleration converges faster than the simplified P-2 acceleration in two-dimensional x-y geometry. These results confirm that one cannot simply assume that replacement of the DSA method with a higher order operator will lead to a smaller spectral radius. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP HONGIK UNIV, 72-1 SANGSU DONG, MAPO GU, SEOUL, SOUTH KOREA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0029-5639 EI 1943-748X J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD SEP PY 1996 VL 124 IS 1 BP 18 EP 30 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VG772 UT WOS:A1996VG77200002 ER PT J AU Wareing, TA Walters, WF Morel, JE AF Wareing, TA Walters, WF Morel, JE TI A diffusion-accelerated solution method for the nonlinear characteristic scheme in slab geometry SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID DISCRETE-ORDINATES EQUATIONS AB Recently, the nonlinear characteristic (NC) scheme for spatially discretizing the discrete ordinates equations was introduced. This scheme is accurate for both optically thin and optically thick spatial meshes and produces strictly positive angular fluxes. The NC discrete ordinates equations can be solved wing the source iteration method; however, it is well known that this method converges prohibitively slowly for optically thick problems with scattering ratios at or near unity. A general nonlinear diffusion synthetic acceleration method for solving the NC equations in slab geometry is described. Numerical results to show the effectiveness and efficiency of the new solution method are provided. RP Wareing, TA (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 13 TC 2 Z9 4 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 SEP PY 1996 VL 124 IS 1 BP 72 EP 81 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VG772 UT WOS:A1996VG77200005 ER PT J AU Ashby, SF Falgout, RD AF Ashby, SF Falgout, RD TI A parallel multigrid preconditioned conjugate gradient algorithm for groundwater flow simulations SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID HETEROGENEOUS POROUS-MEDIA; GRID METHOD AB The numerical simulation of groundwater flow through heterogeneous porous media is discussed. The focus is on the performance of a parallel multigrid preconditioner for accelerating convergence of conjugate gradients, which is used to compute the pressure head. The numerical investigation considers the effects of boundary conditions, coarse grid solver strategy, increasing the grid resolution, enlarging the domain, and varying the geostatistical parameters used to define the subsurface realization. Scalability is also examined. The results were obtained using the PARFLOW groundwater flow simulator on the CRAY T3D massively parallel computer. RP Ashby, SF (reprint author), LAWRENCE LIVERMORE NATL LAB, CTR APPL SCI COMP, POB 808, L-561, LIVERMORE, CA 94551 USA. NR 26 TC 146 Z9 147 U1 0 U2 17 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD SEP PY 1996 VL 124 IS 1 BP 145 EP 159 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VG772 UT WOS:A1996VG77200011 ER PT J AU Bari, RA Ludewig, H Weeks, JR AF Bari, RA Ludewig, H Weeks, JR TI Advanced Neutron Source enrichment study SO NUCLEAR TECHNOLOGY LA English DT Article AB A study has been performed of the impact on performance of using low-enriched uranium (20% U-235) or medium-enriched uranium (35% U-235) as an alternative fuel for the Advanced Neutron Source, which wa initially designed to use uranium enriched to 93% U-235. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fuel at increasing material density was specifically addressed by a panel of international experts on research reactor fuels. The most viable alternative designs for the reactor at lower enrichments were identified and discussed. Several sensitivity analysis were performed to gain an understanding of the performance of the reactor at parametric values of power, fuel density, core volume, and enrichment that were interpolations between the boundary values imposed on the study or extrapolations from known technology. RP Bari, RA (reprint author), BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,UPTON,NY 11973, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 1996 VL 115 IS 3 BP 243 EP 265 PG 23 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VD634 UT WOS:A1996VD63400001 ER PT J AU Liu, HYB AF Liu, HYB TI Design of a small-animal thermal neutron irradiation facility at the Brookhaven Medical Research Reactor SO NUCLEAR TECHNOLOGY LA English DT Article ID CAPTURE THERAPY AB The broad beam facility (BBF) at the Brookhaven Medical Research Reactor (BMRR) can provide a thermal neutron beam with flux intensity and quality comparable to the beam currently used for research on neutron capture therapy using cell-culture and small-animal irradiations. Monte Carlo computations were made, first, to compare with the dosimetric measurements at the existing BBF and, second, to calculate the neutron and gamma fluxes and doses expected at the proposed BBF. Multiple cell cultures or small animals could be irradiated simultaneously at the so-modified BBF under conditions similar to or better than those individual animals irradiated at the existing thermal neutron irradiation facility (TNIF) of the BMRR. The flux intensity of the collimated thermal neutron beam at the proposed BBF would be 1.7 x 10(10) n/cm(2) . s at 3-MW reactor power, the same as at the TNIF. However, the proposed collimated beam would have much lower gamma (0.89 x 10(-11) cGy . cm(2)/n(th)) and fast neutron (0.58 x 10(-11) cGy . cm(2)/n(th)) contaminations, 64 and 18% of those at the TNIF, respectively. The feasibility of remodeling the facility is discussed. RP Liu, HYB (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD SEP PY 1996 VL 115 IS 3 BP 311 EP 319 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VD634 UT WOS:A1996VD63400006 ER PT J AU Schieber, M James, RB Lund, JC McGregor, DS Gilbert, TS VanScyoc, JM Olsen, RW Pontau, AE Schlesinger, TS Toney, J AF Schieber, M James, RB Lund, JC McGregor, DS Gilbert, TS VanScyoc, JM Olsen, RW Pontau, AE Schlesinger, TS Toney, J TI State of the art of wide-bandgap semiconductor nuclear radiation detectors SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA A-NUCLEI PARTICLES AND FIELDS LA English DT Article ID MERCURIC IODIDE AB The leading materials which operate as room temperature nuclear radiation detectors are HgI2, CdTe, and Cd1-xZnxTe (0.05 > x > 0.25). However, additional materials have also been developed, such as semi-insulating GaAs and PbI2. A comparison of the charge transport properties of all these materials will be made, followed by a discussion of each of the materials separately. Crystal growth methods of spectrometer-grade materials will be mentioned, and defects which Limit their performance will be discussed. Nuclear spectra measurements with detectors fabricated from these materials, for low X-ray energies as well as for high-energy gamma-rays, will be shown. Polarization effects which occur in some detectors such as HgI2 will also be discussed. Correlation between crystalline perfection and detector performance will be shown. Results of quantitative chemical analysis of various detector materials and problems encountered in determining accurate values of x in Cd1-xZnxTe and its homogeneity in the bulk will be presented. Finally, the present state of the art and developments for the near future will be discussed. C1 CARNEGIE MELLON UNIV, DEPT ELECT & COMP ENGN, PITTSBURGH, PA 15213 USA. HEBREW UNIV JERUSALEM, GRAD SCH APPL SCI, IL-91904 JERUSALEM, ISRAEL. RP Schieber, M (reprint author), SANDIA NATL LABS, ADV ELECT MFG TECHNOL DEPT, LIVERMORE, CA 94550 USA. NR 12 TC 3 Z9 4 U1 1 U2 3 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 1124-1861 J9 NUOVO CIMENTO A JI Nuovo Cimento Soc. Ital. Fis. A-Nucl. Part. Fields PD SEP PY 1996 VL 109 IS 9 BP 1253 EP 1260 DI 10.1007/BF02773511 PG 8 WC Physics, Particles & Fields SC Physics GA VR772 UT WOS:A1996VR77200002 ER PT J AU Kaspari, M AF Kaspari, M TI Testing resource-based models of patchiness in four Neotropical litter ant assemblages SO OIKOS LA English DT Article ID BARRO-COLORADO ISLAND; SPECIES-DIVERSITY; TROPICAL FOREST; LEPTOTHORAX-LONGISPINOSUS; COMMUNITY STRUCTURE; ALLOCATION RATIOS; LEAF LITTER; COMPETITION; FOOD; PATTERNS AB In four Neotropical forests I studied how resource availability affected patchiness in litter ants, colonies of about 100 workers living in hollow twigs. At the regional scale, and contrary to Species Energy Theory, Costa Rica and Panama forests had similar species richness, despite the former being more productive. At the m(2) scale, nest densities varied 10-fold, often exceeding 10 nests/plot. I tested four predictions linking this patchiness to resource limitation and depletion. First, nest densities increased weakly with estimates of litter quantity and quality. Second, nest addition experiments doubled colony densities after four months in the two Panama assemblages. Third, colonies of most common species appeared to grow as fast when they were small as when they were large. Fourth, there was no suggestion of self-thinning among colonies: plots with large colonies did not have fewer colonies after removing the effects of litter. Combined, these results suggest that resources in the litter, most notably nest sites, may limit local patchiness, but that there is little evidence for food depletion. The unstable litter environment may preclude tropical litter ant colonies from growing large or populous enough to saturate their environment. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. OI Kaspari, Michael/0000-0002-9717-5768 NR 85 TC 81 Z9 85 U1 1 U2 10 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0030-1299 EI 1600-0706 J9 OIKOS JI Oikos PD SEP PY 1996 VL 76 IS 3 BP 443 EP 454 DI 10.2307/3546338 PG 12 WC Ecology SC Environmental Sciences & Ecology GA VH374 UT WOS:A1996VH37400004 ER PT J AU Ellis, D Engelman, B Fruchter, J Shipp, B Jensen, R Lewis, R Scott, H Trent, S AF Ellis, D Engelman, B Fruchter, J Shipp, B Jensen, R Lewis, R Scott, H Trent, S TI Environmental applications of oilfield technology SO OILFIELD REVIEW LA English DT Article AB Investigation of subsurface sites before and after disposal of hazardous waste is a new and growing field for oilfield technology. Whether the problem is identifying and monitoring contaminated layers in the subsurface or characterising a potential waste repository, techniques designed for hydrocarbon exploration and production are finding applications in a new environment. C1 SCHLUMBERGER DOLL RES CTR, RIDGEFIELD, CT 06877 USA. PACIFIC NW LAB, ENVIRONM TECHNOL DIV, RICHLAND, WA 99352 USA. SCHLUMBERGER WIRELINE & TESTING HOUSTON PROD CTR, ELECT & NUCL DEPT, SUGAR LAND, TX USA. BECHTEL HANFORD INC, RICHLAND, WA USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0923-1730 J9 OILFIELD REV JI Oilfield Rev. PD FAL PY 1996 VL 8 IS 3 BP 44 EP 57 PG 14 WC Engineering, Petroleum SC Engineering GA WC822 UT WOS:A1996WC82200005 ER PT J AU Tsang, T Krumbugel, MA DeLong, KW Fittinghoff, DN Trebino, R AF Tsang, T Krumbugel, MA DeLong, KW Fittinghoff, DN Trebino, R TI Frequency-resolved optical-gating measurements of ultrashort pulses using surface third-harmonic generation SO OPTICS LETTERS LA English DT Article ID PHASE AB We demonstrate what is to our knowledge the first frequency-resolved optical gating (FROG) technique to measure ultrashort pulses from an unamplified Ti:sapphire laser oscillator without direction-of-time ambiguity. This technique utilizes surface third-harmonic generation as the nonlinear-optical effect and, surprisingly, is the most sensitive third-order FROG geometry yet. (C) 1996 Optical Society of America C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Tsang, T (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 9 TC 47 Z9 49 U1 3 U2 18 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 1 PY 1996 VL 21 IS 17 BP 1381 EP 1383 DI 10.1364/OL.21.001381 PG 3 WC Optics SC Optics GA VE310 UT WOS:A1996VE31000023 PM 19876359 ER PT J AU Gropp, W Lusk, E Doss, N Skjellum, A AF Gropp, W Lusk, E Doss, N Skjellum, A TI A high-performance, portable implementation of the MPI message passing interface standard SO PARALLEL COMPUTING LA English DT Article DE message passing interface; parallel programming environment; benchmark; performance; portability; MPI-2 ID PARALLEL AB MPI (Message Passing Interface) is a specification for a standard library for message passing that was defined by the MPI Forum, a broadly based group of parallel computer vendors, library writers, and applications specialists. Multiple implementations of MPI have been developed. In this paper, we describe MPICH, unique among existing implementations in its design goal of combining portability with high performance. We document its portability and performance and describe the architecture by which these features are simultaneously achieved. We also discuss the set of tools that accompany the free distribution of MPICH, which constitute the beginnings of a portable parallel programming environment. A project of this scope inevitably imparts lessons about parallel computing, the specification being followed, the current hardware and software environment for parallel computing, and project management; we describe those we have learned. Finally, we discuss future developments for MPICH, including those necessary to accommodate extensions to the MPI Standard now being contemplated by the MPI Forum. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. MISSISSIPPI STATE UNIV,DEPT COMP SCI,MISSISSIPPI STATE,MS 39762. MISSISSIPPI STATE UNIV,NSF,ENGN RES CTR,MISSISSIPPI STATE,MS 39762. OI Gropp, William/0000-0003-2905-3029 NR 46 TC 779 Z9 799 U1 6 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD SEP PY 1996 VL 22 IS 6 BP 789 EP 828 DI 10.1016/0167-8191(96)00024-5 PG 40 WC Computer Science, Theory & Methods SC Computer Science GA VK084 UT WOS:A1996VK08400001 ER PT J AU Storey, BG Kirk, MA Osborne, JA Marks, LD Kostic, P Veal, BW AF Storey, BG Kirk, MA Osborne, JA Marks, LD Kostic, P Veal, BW TI Structural features of defect cascades in YBa(2)CusO(x) as a function of oxygen stoichiometry SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; NEUTRON-IRRADIATION; COLUMNAR DEFECTS; ION IRRADIATION; SINGLE-CRYSTALS; YBA2CU3O7-X; ARTIFACTS; ENERGY; BA AB Single crystals of YBa2Cu3Ox, of various oxygen stoichiometries, were irradiated with 50keV Kr+ to create defect cascades similar to those resulting from fast neutron irradiation. Two-beam dark-field transmission electron microscopy in weak dynamic conditions was used to measure the defect cascade size distribution in the principal axes for four different oxygen stoichiometries, and high-resolution electron microscopy verified the mean size of these cascades. The mean size of the defect cascades generated was independent of oxygen stoichiometry from x = 6.35 to x = 6.9, which indicates that magnetic flux pinning does not vary because of any association between the oxygen concentration and the cascade size. For Kr+ incident near the c axis the defect cascades have on average a circular cross-section of 3.5 nm diameter perpendicular to the ion beam, while an elliptical cross-section was found for ions incident near the x axis. The minor axis (3.5 nm) was in the [001] direction and the major axis (5.5 nm) was in the [010] direction. This aspect ratio of 1.6 matches that found for high-energy heavy-ion track damage in YBa2Cu3Ox, which implies that the shape is determined not by the recoil damage mechanism but in the cooling or relaxation stage where the anisotropy in thermal conductivity determines the defect shape. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Storey, BG (reprint author), NORTHWESTERN UNIV,DEPT STAT,EVANSTON,IL 60208, USA. RI Marks, Laurence/B-7527-2009 NR 33 TC 1 Z9 1 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD SEP PY 1996 VL 74 IS 3 BP 617 EP 628 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA VG173 UT WOS:A1996VG17300003 ER PT J AU Ponce, FA OKeefe, MA Nelson, EC AF Ponce, FA OKeefe, MA Nelson, EC TI Transmission electron microscopy of the AlN-SiC interface SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID LIGHT-EMITTING-DIODES; BUFFER LAYER; GAN; EPITAXY; GROWTH AB The AlN-SiC interface has been studied using high-resolution transmission electron microscopy. Cross-section lattice images of the AlN-SiC interface have been analysed to establish the connection between image contrast and the atomic positions in the lattice. Assuming atomically abrupt and planar AlN-SiC interfaces, four possible atomic bonding configurations are taken into account for SIC substrates with the (0001)(Si) orientation. Image simulations of these four interface models are compared with the experimental images. Considering variations at the interface of the image contrast, the basal-plane distance and the projected charge density, it is shown that the C-Al and Si-N bonds are in agreement with the experimental images and are not distinguishable under our experimental conditions. The other two possibilities, involving C-N and Si-Al bonds, are not consistent with our observations. C1 LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. RP Ponce, FA (reprint author), XEROX CORP,PALO ALTO RES CTR,3333 COYOTE HILL RD,PALO ALTO,CA 94304, USA. RI Ponce, Fernando/M-8649-2013 OI Ponce, Fernando/0000-0002-1275-9386 NR 16 TC 4 Z9 4 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD SEP PY 1996 VL 74 IS 3 BP 777 EP 789 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA VG173 UT WOS:A1996VG17300013 ER PT J AU Cooke, DW Bennett, BL Lawson, AC Huber, JG Oostens, J Boekema, C Flint, JA Lichti, RL AF Cooke, DW Bennett, BL Lawson, AC Huber, JG Oostens, J Boekema, C Flint, JA Lichti, RL TI Spontaneous magnetic ordering in CeRh3B2 observed by zero-field muon-spin relaxation SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID RAY LINEAR-DICHROISM; ANOMALOUS FERROMAGNETISM; CRYSTAL-FIELD; STATE; BORIDES; SYSTEM; CE AB Muon-spin relaxation measurements have been made on polycrystalline CeRh3B2 in zero magnetic field. Well above the Curie temperature (T-C congruent to 120 K) muon relaxation is described by a Gaussian rate (similar to 0.1 mu s(-1)) indicative of static and random nuclear B-11 dipole moments. Near Te the relaxation rate increases dramatically due to slowing down of fluctuating Ce magnetic moments. Oscillations are observed in the muon spin polarization below T-C, which is unambiguous evidence for the onset of local magnetic ordering. The magnitude of the ordered field initially increases with decreasing temperature and attains a maximum value of 13 mT near 50 K. The general shape of the field versus temperature curve resembles the magnetization curve, as expected for an ordinary ferromagnet. However, further decrease in temperature reduces the field to 11 mT at 12 K, which we attribute to magnetic ordering of Rh moments. Below 50 K these moments appear to order antiferromagnetically with Ce moments thus producing an effective field at the muon site that is reduced in magnitude. The muon-spin relaxation data unambiguously demonstrate the onset of magnetic ordering in CeRh3B2 in zero magnetic field and contradicts previous neutron scattering results which suggested the ordering was field induced. C1 SAN JOSE STATE UNIV,SAN JOSE,CA 95192. TEXAS TECH UNIV,LUBBOCK,TX 79409. RP Cooke, DW (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD SEP PY 1996 VL 74 IS 3 BP 259 EP 267 DI 10.1080/01418639608243522 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VG172 UT WOS:A1996VG17200004 ER PT J AU Kresin, VV Kresin, VZ AF Kresin, VV Kresin, VZ TI Low-frequency 'demon'-like excitations in small metal particles and their interaction with light SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID COLLECTIVE RESONANCES; LITHIUM CLUSTERS; EVOLUTION; ELECTRONS; PLASMONS; BULK AB We consider collective excitations in microscopic metal particles containing two overlapping sets of electrons of different effective masses (e.g. transition-metal compounds). We show that a new type of low-frequency electron collective mode appears in such systems. In the bulk limit, this mode develops into an acoustic plasmon (demon). It is predicted that, in small particles, such excitations acquire dipole oscillator strength and give rise to a photoabsorption band. This effect is unique to finite systems. Consequently, the demon-like collective states can be detected by optical spectroscopy of microclusters. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Kresin, VV (reprint author), UNIV SO CALIF,DEPT PHYS & ASTRON,LOS ANGELES,CA 90089, USA. RI Kresin, Vitaly/N-8095-2014 OI Kresin, Vitaly/0000-0002-6226-4576 NR 20 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD SEP PY 1996 VL 74 IS 3 BP 301 EP 307 DI 10.1080/01418639608243526 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VG172 UT WOS:A1996VG17200008 ER PT J AU Nairn, RS Morizot, DC Kazianis, S Woodhead, AD Setlow, RB AF Nairn, RS Morizot, DC Kazianis, S Woodhead, AD Setlow, RB TI Nonmammalian models for sunlight carcinogenesis: Genetic analysis of melanoma formation in Xiphophorus hybrid fish SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID RECEPTOR TYROSINE KINASE; MALIGNANT-MELANOMA; CELL-DIFFERENTIATION; TUMOR SUPPRESSION; PLATYFISH; INDUCTION; LINKAGE; SUSCEPTIBILITY; POECILIIDAE; SWORDTAILS AB Genetic hybrids of Xiphophorus fishes have been used for decades to study heritable melanoma formation. In these models, overexpression of pigmentation patterns from melanin-producing pigment cells can lead to genetically regulated melanoma formation in backcross hybrids, In the best studied of these models, the Gordon-Kosswig hybrid melanoma, tumors form spontaneously in all individuals of a subset of backcross hybrids between the platyfish Xiphophorus maculatus Jp 163 A and the swordtail species Xiphophorus helleri. Backcross hybrids susceptible to melanoma formation inherit a sea-linked oncogene, Xmrk, associated with the spotted dorsal (Sd) pigment pattern and have lost both copies of an autosomal gene, DIFF, from the X. maculatus parent, Spontaneous melanoma formation conforms to simple, two-gene Mendelian inheritance in which DIFF behaves as a recessive tumor suppressor gene, Recently, Xiphophorus hybrids in which melanomas can be induced by UV and near-UV visible light exposure have been described, We report here results of genetic linkage analysis of one of these Xiphophorus light-inducible hybrid melanoma models, in backcross hybrids between the two platyfish species X, maculatus Jp 163 B and Xiphophorus; couchianus. Our linkage results provide the first estimate of recombination between the tumor suppressor locus, DIFF, and glycerate-2-dehydrogenase (GLYDH) in Xiphophorus linkage group V. Also, they demonstrate that DIFF regulates hyperplasia of spotted side (Sp) pigment cells in this hybrid model, analogous to its regulation of hyperplasia of Sd pigment cells in the ''classical'' Gordon-Kosswig hybrid. Joint segregation analyses of melanoma-bearing fish indicate that segregation of DIFF is genetically linked to melanoma induction by 405 nm light in this model but that induction of melanomas by UV wavelengths apparently does not depend on segregation of the DIFF locus. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP Nairn, RS (reprint author), UNIV TEXAS,MD ANDERSON CANC CTR,SCI PK RES DIV,POB 389,SMITHVILLE,TX 78957, USA. FU NCI NIH HHS [CA55245, CA09480] NR 53 TC 40 Z9 41 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD SEP PY 1996 VL 64 IS 3 BP 440 EP 448 DI 10.1111/j.1751-1097.1996.tb03089.x PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VG533 UT WOS:A1996VG53300008 PM 8806224 ER PT J AU Sutherland, BM Takayanagi, S Sullivan, JH Sutherland, JC AF Sutherland, BM Takayanagi, S Sullivan, JH Sutherland, JC TI Plant responses to changing environmental stress: Cyclobutyl pyrimidine dimer repair in soybean leaves SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID ULTRAVIOLET-B RADIATION; DNA-DAMAGE; NONRADIOACTIVE DNA; ALFALFA SEEDLINGS; STRAND BREAKS; DARK-REPAIR; QUANTITATION; GROWTH; PHOTOREACTIVATION; ELECTROPHORESIS AB We have determined the capacity of soybean seedlings to repair DNA damage by UV doses that do not produce apparent injury in the plants, They remove cyclobutane pyrimidine dimers by both excision and photoreactivation, The rates and relative contributions of these repair processes were determined as a function of initial level of cyclobutyl pyrimidine dimers, Photoreactivation was detected in seedlings at all initial dimer levels. Although excision was not observed at the lowest dimer frequencies, at higher initial dimer levels it was quite effective in dimer removal. The rates of repair in soybean were substantially higher than in alfalfa seedlings at the same DNA damage levels. C1 TOHO UNIV,SCH MED,DEPT BIOL,TOKYO,JAPAN. UNIV MARYLAND,DEPT HORT & LANDSCAPE ARCHITECTURE,COLLEGE PK,MD. RP Sutherland, BM (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,BLDG 463,UPTON,NY 11973, USA. NR 26 TC 22 Z9 23 U1 1 U2 3 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD SEP PY 1996 VL 64 IS 3 BP 464 EP 468 DI 10.1111/j.1751-1097.1996.tb03092.x PG 5 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VG533 UT WOS:A1996VG53300011 ER PT J AU Sauer, K Cogdell, RJ Prince, SM Freer, A Isaacs, NW Scheer, H AF Sauer, K Cogdell, RJ Prince, SM Freer, A Isaacs, NW Scheer, H TI Structure-based calculations of the optical spectra of the LH2 bacteriochlorophyll-protein complex from Rhodopseudomonas acidophila SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID LIGHT-HARVESTING COMPLEX; CIRCULAR-DICHROISM SPECTRA; EXCITATION-ENERGY TRANSFER; RESOLVED RATE CONSTANTS; UV-VISIBLE ABSORPTION; C-PHYCOCYANIN; PHOTOSYNTHETIC BACTERIA; RHODOBACTER-SPHAEROIDES; CHROMOPHORE-PROTEIN; CRYSTAL-STRUCTURE AB The molecular structure of the light-harvesting complex 2 (LH2) bacteriochlorophyll-protein antenna complex from the purple non-sulfur photosynthetic bacterium Rhodopseudomonas acidophila, strain 10050 provides the positions and orientations of the 27 bacteriochlorophyll (BChl) molecules in the complex, Our structure-based model calculations of the distinctive optical properties (absorption, CD, polarization) of LH2 in the near-infrared region use a point-monopole approximation to represent the BChl Q(y) transition moment, The results of the calculations support the assignment of the ring of 18 closely coupled BChl to B850 (BChl absorbing at 850 mm) and the larger diameter, parallel ring of 9 weakly coupled BChl to B800, All of the significantly allowed transitions in the near infrared are calculated to be perpendicular to the C9 symmetry axis, in agreement with polarization studies of this membrane-associated complex, To match the absorption maxima of the B800 and B850 components using a relative permittivity (dielectric constant) of 2.1, we assign different site energies (12 500 and 12 260 cm(-1), respectively) for the Q(y) transitions of the respective BChl in their protein binding sites, Excitonic coupling is particularly strong among the set of B850 chromophores, with pairwise interaction energies nearly 300 cm(-1) between nearest neighbors, comparable with the experimental absorption bandwidths at room temperature, These strong interactions, for the full set of 18 B850 chromophores, result in an excitonic manifold that is 1200 cm(-1) wide. Some of the upper excitonic states should result in weak absorption and perhaps stronger CD features, These predictions from the calculations await experimental verification. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV GLASGOW,DIV BIOCHEM & MOL BIOL,GLASGOW,LANARK,SCOTLAND. UNIV GLASGOW,DEPT CHEM,GLASGOW,LANARK,SCOTLAND. UNIV MUNICH,INST BOT,D-8000 MUNICH,GERMANY. RP Sauer, K (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720, USA. NR 41 TC 231 Z9 240 U1 3 U2 32 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD SEP PY 1996 VL 64 IS 3 BP 564 EP 576 DI 10.1111/j.1751-1097.1996.tb03106.x PG 13 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VG533 UT WOS:A1996VG53300025 ER PT J AU Yocky, DA AF Yocky, DA TI Multiresolution wavelet decomposition image merger of landsat thematic mapper and SPOT panchromatic data SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID ENHANCEMENT; TRANSFORM AB Spatially registered Landsat Thematic Mapper (TM) and SPOT (Systeme Pour l'Observation de la Terre) panchromatic images were merged by combining multiresolution wavelet decomposition components from each, and then reconstructing a merged image using the inverse wavelet transform. Three wavelet merging techniques were compared to the intensity-hue-saturation merging technique. The comparison results show the wavelet merger providing greater flexibility and the potential for higher accuracy for combining and preserving spectral-spatial information for remotely sensed data and their applications. RP Yocky, DA (reprint author), SANDIA NATL LABS,SYST ANAL DEPT 3,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 23 TC 132 Z9 144 U1 0 U2 2 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD SEP PY 1996 VL 62 IS 9 BP 1067 EP 1074 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA VJ217 UT WOS:A1996VJ21700007 ER PT J AU Ault, SK Lowry, ME AF Ault, SK Lowry, ME TI Automated packaging: A cure for market growing pains ..... SO PHOTONICS SPECTRA LA English DT Article RP Ault, SK (reprint author), LAWRENCE LIVERMORE NATL LAB,PHOTON GRP,H DIV,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAURIN PUBL CO INC PI PITTSFIELD PA BERKSHIRE COMMON PO BOX 1146, PITTSFIELD, MA 01202 SN 0731-1230 J9 PHOTON SPECTRA JI Photon. Spect. PD SEP PY 1996 VL 30 IS 9 BP 120 EP & PG 4 WC Optics SC Optics GA VF716 UT WOS:A1996VF71600040 ER PT J AU Moodenbaugh, AR Fischer, DA Wang, YL Fukumoto, Y AF Moodenbaugh, AR Fischer, DA Wang, YL Fukumoto, Y TI Superconductivity, oxygen content, and hole state density in Bi2Sr1.75Ca1.25Cu2O8.18+y (-0.09 1000 in the region of the n = 2-4 Ne-like resonance Lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions. C1 VNIIFTRI,MISDC,MENDELEYEVSK,RUSSIA. RUSSIAN ACAD SCI,PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. RP Osterheld, AL (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. RI Pikuz, Sergey/M-8231-2015 NR 29 TC 4 Z9 4 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 SEP PY 1996 VL 54 IS 3 BP 240 EP 249 DI 10.1088/0031-8949/54/3/003 PG 10 WC Physics, Multidisciplinary SC Physics GA VF168 UT WOS:A1996VF16800003 ER PT J AU Qui, YH Muller, J Burgdorfer, J AF Qui, YH Muller, J Burgdorfer, J TI Periodic-orbit spectra of hydrogen and helium SO PHYSICAL REVIEW A LA English DT Article ID DOUBLY-EXCITED HELIUM; PLANETARY ATOM STATES; SEMICLASSICAL QUANTIZATION; MAGNETIC-FIELDS; HAMILTONIAN-SYSTEMS; CLASSICAL ORBITS; 2-ELECTRON ATOMS; CLOSED ORBITS; ENERGY-LEVELS; STRANGE SETS AB The semiclassical expression for the spectral density (Gutzwiller's trace formula) can be viewed as a Fourier expansion in terms of classical (quasi)periodic orbits. The inverse Fourier transform of the full quantum spectral density therefore not only gives the periodic orbit spectrum in the semiclassical limit, but may also provide a tool to characterize the quantum spectrum. We investigate the scaled energy Fourier transform spectrum of the hydrogen atom and doubly excited states of helium. For exactly solvable hydrogenic Rydberg spectra we study the ''window'' effect due to the finite length of the spectrum, the influence of resonance width, and of quantum defects. In helium a large number of periodic orbits including previously unknown orbits can be identified. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. NR 67 TC 1 Z9 1 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 1922 EP 1935 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000028 ER PT J AU Menzel, A Frigo, SP Whitfield, SB Caldwell, CD Krause, MO AF Menzel, A Frigo, SP Whitfield, SB Caldwell, CD Krause, MO TI Partial photoionization cross sections and photoelectron angular distributions for double excitations up to the N=5 threshold in helium SO PHYSICAL REVIEW A LA English DT Article ID FINAL-STATE SYMMETRY; EXCITED-STATES; 2-ELECTRON ATOMS; HE; RESONANCE; SERIES; SATELLITES; AUTOIONIZATION; SPECTROMETRY; HE+(N=2) AB Partial photoionization cross sections sigma(n) and photoelectron angular distributions beta(n) were measured for all possible final ionic states He+(n) in the region of the double excitations N(K,T)(A) up to the N=5 threshold. At a photon energy bandpass of 12 meV below the thresholds N=3,4, and 5, this level of differentiation offers the most critical assessment of the dynamics of the two-electron excitations to date. The experimental data are very well described by the most advanced theoretical calculations. Weaker double-excitation series with K=N-4 are clearly visible in the beta(n) data, and even previously unobserved extremely weak series members with A=-1 can be discerned, showing the high sensitivity of the angular resolved measurements. The shapes of the resonance-induced variations of sigma(n) or beta(n) in the double excitations below a given threshold N change radically depending on the final ionic state n but display striking similarities when comparing the satellite states with n=N-1 and n=N-2 below each threshold N. These systematic patterns may indicate a general rule for the underlying two-electron dynamics. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Menzel, A (reprint author), UNIV CENT FLORIDA,DEPT PHYS,ORLANDO,FL 32816, USA. NR 48 TC 35 Z9 35 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 2080 EP 2090 DI 10.1103/PhysRevA.54.2080 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000045 ER PT J AU Jung, M Krassig, B Gemmell, DS Kanter, EP LeBrun, T Southworth, SH Young, L AF Jung, M Krassig, B Gemmell, DS Kanter, EP LeBrun, T Southworth, SH Young, L TI Experimental determination of nondipolar angular distribution parameters for photoionization in the Ar K and Kr L shells SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; MULTIPOLE CORRECTIONS; IMPACT IONIZATION; AUGER ELECTRONS; X-RAYS; PHOTOELECTRONS; RETARDATION; POLARIZATION; SUBSHELLS AB We report the measurement of nondipolar asymmetry parameters for the angular distributions of argon 1s, krypton 2s, and krypton 2p photoemission within 2-3 keV above their respective thresholds. Pronounced asymmetries with respect to the direction of photon propagation are present even at low electron kinetic energies. The energy dependence of the asymmetry is Z and subshell specific and causes the direction of preferred electron emission to change sign at least once in each of the cases studied. Towards higher energies the asymmetry increases and the photoelectron emission pattern is forward skewed for all three cases. The measured asymmetry parameters are in good agreement with recent predictions from nonrelativistic calculations which include the interference between electric-dipole and electric-quadrupole transition amplitudes in the photoabsorption process. RP Jung, M (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 35 TC 86 Z9 86 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 2127 EP 2136 DI 10.1103/PhysRevA.54.2127 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000051 ER PT J AU Raghavan, S Kenkre, VM Dunlap, DH Bishop, AR Salkola, MI AF Raghavan, S Kenkre, VM Dunlap, DH Bishop, AR Salkola, MI TI Relation between dynamic localization in crystals and trapping in two-level atoms SO PHYSICAL REVIEW A LA English DT Article ID ELECTRIC-FIELD; BLOCH OSCILLATIONS; PARTICLE; SOLITON; LATTICE AB It is shown that a recently reported realization of trapping in a two-level system with frequency-modulated fields in quantum optics is intimately related to an earlier demonstration of dynamic localization of charges moving in a crystal under the action of a time-periodic electric field. Size effects on the phenomenon are explored. C1 UNIV NEW MEXICO, DEPT PHYS & ASTRON, ALBUQUERQUE, NM 87131 USA. LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. MCMASTER UNIV, DEPT PHYS & ASTRON, HAMILTON, ON L8S 4M1, CANADA. RP UNIV NEW MEXICO, CTR ADV STUDIES, ALBUQUERQUE, NM 87131 USA. NR 18 TC 48 Z9 48 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP R1781 EP R1784 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000010 ER PT J AU Lawrence, JM Kwei, GH Sarrao, JL Fisk, Z Mandrus, D Thompson, JD AF Lawrence, JM Kwei, GH Sarrao, JL Fisk, Z Mandrus, D Thompson, JD TI Structure and disorder in YbInCu4 SO PHYSICAL REVIEW B LA English DT Article ID VALENCE PHASE-TRANSITION; YBXIN1-XCU2 AB We present neutron diffraction results for YbInCu4, and Rietveld refinements of the structure. The ground state has the same structure (C15B) as the high temperature state, so that the first-order phase transition at T-s=40 K is indeed isomorphic, i.e., the lattice constant changes without a change of crystal symmetry. The site disorder and the diffraction linewidths decrease systematically on going from polycrystal samples with two transitions (at 40 and 70 K) to polycrystals with a single (40 K) transition to flux-grown single crystals with a sharp transition at 40 K. We argue that in site-disordered samples, the effect of doping Yb onto the In site is to increase T-s and cause the transition to become continuous. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Lawrence, JM (reprint author), UNIV CALIF IRVINE,IRVINE,CA 92697, USA. RI Mandrus, David/H-3090-2014 NR 7 TC 66 Z9 66 U1 0 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 SEP 1 PY 1996 VL 54 IS 9 BP 6011 EP 6014 DI 10.1103/PhysRevB.54.6011 PG 4 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900002 ER PT J AU Strauss, B Frey, F Petry, W Trampenau, J Nicolaus, K Shapiro, SM Bossy, J AF Strauss, B Frey, F Petry, W Trampenau, J Nicolaus, K Shapiro, SM Bossy, J TI Martensitic phase transformation and lattice dynamics of fcc cobalt SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; HCP; TRANSITION; ALLOYS; CO; CO0.92FE0.08 AB The phonon dispersion of the high-temperature fee phase of pure cobalt has been measured by inelastic neutron scattering at 833 K. Transverse phonon branches were measured above and below the Martensitic hcp-fcc transformation in order to learn about an influence of lattice dynamics, if any. No new anomalies could be observed, except those confirming an anomalous decrease of the c(44) (hcp) shear constant when approaching the transformation from below and those confirming a transverse T[00 xi](hcp) and T[xi xi xi](fcc) branch of relative low energy. The small shear constant and results from an analysis of elastic diffuse and Bragg data can be understood in the framework of a dislocation-driven transformation mechanism proposed by Seeger. C1 TECH UNIV MUNICH,PHYS DEPT E13,D-85747 GARCHING,GERMANY. BROOKHAVEN NATL LAB,UPTON,NY 11973. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. RP Strauss, B (reprint author), UNIV MUNICH,INST KRISTALLOG,D-80333 MUNICH,GERMANY. NR 25 TC 33 Z9 33 U1 3 U2 12 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 SEP 1 PY 1996 VL 54 IS 9 BP 6035 EP 6038 DI 10.1103/PhysRevB.54.6035 PG 4 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900008 ER PT J AU Zuo, F Schlueter, JA Geiser, U Williams, JM AF Zuo, F Schlueter, JA Geiser, U Williams, JM TI Anomalous magnetic properties in the single-crystal kappa-(BEDT-TTF)(2)Cu(NCS)(2) superconductor SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; PRESSURE ORGANIC SUPERCONDUCTOR; IRREVERSIBILITY LINE; BEDT-TTF; LAYERED SUPERCONDUCTOR; PENETRATION DEPTH; KAPPA-(BEDT-TTF)2CUBR; STATE; CREEP; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE AB Magnetization measurements have been performed on single crystals of the organic superconductor kappa-(BEDT-TTF)(2)Cu(SCN)(2) with the held parallel to the a axis (perpendicular to the conducting plane). At high temperatures, the magnetization M displays a power-law dependence on H with M proportional to H-alpha and alpha=-0.45+/-0.05. At low temperatures (T less than or equal to 7.5 K), an anomalous field dependence in M(H) is observed. The irreversibility field determined from magnetic hysteresis loops displays a universal temperature dependence, i.e., from a high-temperature power-law dependence to a low-temperature exponential dependence. The results are qualitatively similar to the fishtail magnetization reported for the highly anisotropic oxide superconductors. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Zuo, F (reprint author), UNIV MIAMI,DEPT PHYS,CORAL GABLES,FL 33124, USA. NR 25 TC 3 Z9 3 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 SEP 1 PY 1996 VL 54 IS 9 BP 6107 EP 6110 DI 10.1103/PhysRevB.54.6107 PG 4 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900027 ER PT J AU Mitchell, JF Argyriou, DN Potter, CD Hinks, DG Jorgensen, JD Bader, SD AF Mitchell, JF Argyriou, DN Potter, CD Hinks, DG Jorgensen, JD Bader, SD TI Structural phase diagram of La1-xSrxMnO3+delta: Relationship to magnetic and transport properties SO PHYSICAL REVIEW B LA English DT Article ID DEFECT CHEMISTRY; GIANT MAGNETORESISTANCE; THIN-FILMS; LAMNO3+/-DELTA; LAMNO3+DELTA; LA1-XCAXMNO3; TRANSITION; SYSTEM; SM AB The structural properties of La1-xSrxMnO3+delta have been studied using neutron powder diffraction as a function of both Sr doping (0 less than or equal to x less than or equal to 0.225) and oxygen partial pressure during synthesis [2.1x10(-4) atm less than or equal to P(O-2)less than or equal to 1 atm]. A structural phase diagram constructed as a function of these parameters has a rhombohedral phase (R3c), an orthorhombic phase (Pbnm), and a monoclinic phase (P2(1)/c). For a given x, decreasing P(O-2) yields smaller cation vacancy concentrations. At low temperature, the R phase is ferromagnetic, while the M phase is antiferromagnetic. The O phase is ferromagnetic for x greater than or equal to 0.125, and the ferromagnetism is independent of the O-R phase transition that coincides with the transition from nonmetal to metal. Transport measurements made between 20 and 350 K show that O and M samples are nonmetallic (d rho/dT<0), while the R samples exhibit a temperature-dependent nonmetal-to-metal transition at temperatures close to the Curie temperature. Magnetoresistance (MR) is observed in all three phases. The largest value at 9 T, found in the orthorhombic and monoclinic samples, is of similar order (Delta rho=rho(0)-rho(9T)similar to 10(4) Omega cm) to that reported for 10(6)% colossal MR powder samples. However, our lower sintering temperatures result in large rho(9T) values that yield Delta rho/rho(9T)similar to 230%. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. RP Mitchell, JF (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 30 TC 357 Z9 358 U1 7 U2 64 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 SEP 1 PY 1996 VL 54 IS 9 BP 6172 EP 6183 DI 10.1103/PhysRevB.54.6172 PG 12 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900040 ER PT J AU Jenks, CJ Chang, SL Anderegg, JW Thiel, PA Lynch, DW AF Jenks, CJ Chang, SL Anderegg, JW Thiel, PA Lynch, DW TI Photoelectron spectra of an Al70Pd21Mn9 quasicrystal and the cubic alloy Al60Pd25Mn15 SO PHYSICAL REVIEW B LA English DT Article ID QUASI-CRYSTALLINE COATINGS; CORE-LEVEL SHIFTS; BINDING-ENERGY SHIFTS; PD-MN ALLOYS; ELECTRONIC-STRUCTURE; ELECTRICAL-RESISTIVITY; SURFACE; PHOTOEMISSION; METALS; AL70PD20MN10 AB Photoelectron spectra of a fivefold quasicrystalline alloy Al70Pd21Mn9 and a related cubic alloy Al60Pd25Mn15 reveal two noteworthy features. The first is that the Pd 3d lines fall at binding energies which are 2.2 eV higher than in pure Pd. A similar shift is observed for Pd in other alloys. The second noteworthy feature is that the Mn 2p(3/2) line is very sharp in the quasicrystal. Fitting the experimental peaks with a Doniach-Sunjic line shape suggests that the position and density of Mn states near EF is very sensitive to the structural and/or chemical environment of Mn in the alloys, and that this accounts for the shape of the 2p(3/2) Mn line. The sharpness of the Mn line may be a fingerprint of the quasicrystalline phase within the AlPdMn family. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Jenks, CJ (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011, USA. NR 50 TC 48 Z9 48 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 SEP 1 PY 1996 VL 54 IS 9 BP 6301 EP 6306 DI 10.1103/PhysRevB.54.6301 PG 6 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900054 ER PT J AU Liu, SH AF Liu, SH TI Spin excitations in the low-temperature phase of Tm SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC EXCITATIONS; THULIUM METAL; WAVES AB The rare-earth metal thulium has the ferrimagnetic-antiphase-domain spin arrangement at low temperatures. We show that the spin excitations in this magnetic structure are nearly localized and largely dispersionless modes. There are seven such modes between 8 and 10 meV, and they have not been resolved by neutron scattering experiments. On the other hand, these modes have different neutron scattering cross sections in different magnetic superzones, and this gives rise to what appears as a dispersion in the spin excitation peak in the extended Brillouin zone of the crystal. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Liu, SH (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6401 EP 6406 DI 10.1103/PhysRevB.54.6401 PG 6 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900066 ER PT J AU Zheludev, A Tranquada, JM Vogt, T Buttrey, DJ AF Zheludev, A Tranquada, JM Vogt, T Buttrey, DJ TI Magnetic excitations and soft-mode transition in the quasi-one-dimensional mixed-spin antiferromagnet Pr2BaNiO5 SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM ENERGY-GAP; HALDANE-GAP; HEISENBERG-ANTIFERROMAGNET; NEUTRON-SCATTERING; MONTE-CARLO; STRUCTURAL CHARACTERIZATION; METAL OXIDE; DYNAMICS; CSNICL3; CHAIN AB Neutron diffraction and inelastic neutron scattering were used to investigate three-dimensional (3D) antiferromagnetic ordering and magnetic excitations in Pr2BaNiO5, a quasi-ID mixed-spin antiferromagnet. Three distinct features of the magnetic excitation spectrum were observed above the Neel temperature T-N: a strongly 1D gap excitation propagating on the Ni chains, a single-ion crystal-field transition associated with Pr3+, and a strongly temperature-dependent mixed Pr-Ni magnetic-exciton band. Ni-chain modes persist in the 3D ordered phase, and the energy gap increases with decreasing T below T-N. The magnetic-exciton band undergoes a complete softening at the antiferromagnetic zone center as T-N is approached from above, driving the magnetic phase transition. C1 UNIV DELAWARE,NEWARK,DE 19716. RP Zheludev, A (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; Vogt, Thomas /A-1562-2011 OI Tranquada, John/0000-0003-4984-8857; Vogt, Thomas /0000-0002-4731-2787 NR 46 TC 46 Z9 48 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 SEP 1 PY 1996 VL 54 IS 9 BP 6437 EP 6447 DI 10.1103/PhysRevB.54.6437 PG 11 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900070 ER PT J AU Saslow, WM Agnolet, G Campbell, CE Clements, BE Krotscheck, E AF Saslow, WM Agnolet, G Campbell, CE Clements, BE Krotscheck, E TI Theory of first-order layering transitions in thin helium films SO PHYSICAL REVIEW B LA English DT Article ID HE-4 FILMS; MIXTURE FILMS; QUANTUM-SYSTEMS; BINDING-ENERGY; HEAT-CAPACITY; GROUND-STATE; MONTE-CARLO; SURFACE; LIQUID-HE-4; GRAPHITE AB Thin liquid He-4 films on graphite show evidence of layered growth with increasing number density via a succession of first-order phase transitions. These so-called ''layering transitions'' separate uniformly covering phases, such as monolayers and bilayers. The present work is a detailed theoretical study of such layering transitions using a Maxwell construction. We model the graphite surface by a strong substrate potential, and using a microscopic variational theory we obtain the uniform coverage solutions for liquid helium. For each layer, the theory yields the chemical potential mu and surface tension alpha as functions of coverage n, and from this we deduce mu(a). For each set of adjacent layers, we then obtain the crossing point in the curves of mu(alpha). In this way we obtain the values of mu, alpha, and surface coverages for the transition. Particular attention is paid to the monolayer-bilayer transition. C1 TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Saslow, WM (reprint author), TEXAS A&M UNIV,CTR THEORET PHYS,COLLEGE STN,TX 77843, USA. NR 41 TC 9 Z9 9 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 SEP 1 PY 1996 VL 54 IS 9 BP 6532 EP 6538 DI 10.1103/PhysRevB.54.6532 PG 7 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900078 ER PT J AU Fong, HF Keimer, B Reznik, D Milius, DL Aksay, IA AF Fong, HF Keimer, B Reznik, D Milius, DL Aksay, IA TI Polarized and unpolarized neutron-scattering study of the dynamical spin susceptibility of YBa2Cu3O7 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTING ORDER-PARAMETER; MAGNETIC EXCITATIONS; HEISENBERG-ANTIFERROMAGNET; TEMPERATURE; LATTICE; PHONON; DEPENDENCE; VIBRATIONS; MODEL; GAP AB We report an extensive study of magnetic excitations in fully oxygenated YBa2Cu3O7, using neutron scattering with and without spin polarization analysis. By calibrating the measured magnetic intensity against calculated structure factors of optical phonons and against antiferromagnetic spin waves measured in the same crystal after deoxygenation to YBa2Cu3O6.2, we establish an absolute intensity scale for the dynamical spin susceptibility, chi ''(q,omega). The integrated spectral weight of the sharp magnetic resonance at h omega=40 meV and q(parallel to)=(pi/a,pi/a) in the superconducting state is integral d(h omega)chi(res)''(q,w)=(0.52+/-0.1) at low temperatures. The energy and spectral weight of the resonance are measured up to T=0.8T(c). The resonance disappears in the normal state, and a conservative upper limit of 30 states/eV is established for the normal state dynamical susceptibility at q(parallel to)=(pi/a,pi/a) and 10 meV less than or equal to h omega less than or equal to 40 meV. Our results are compared to previous neutron-scattering data on YBa2Cu3O7, theoretical interpretations of NMR data and current models of the 40 meV resonance. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NIST,GAITHERSBURG,MD 20899. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. RP Fong, HF (reprint author), PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544, USA. RI Aksay, Ilhan/B-9281-2008 NR 47 TC 120 Z9 120 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6708 EP 6720 DI 10.1103/PhysRevB.54.6708 PG 13 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900099 ER PT J AU Aminov, BA Hein, MA Muller, G Piel, H Wehler, D Kresin, VZ Ponomarev, YG Buschmann, L Winkeler, L Guntherodt, G AF Aminov, BA Hein, MA Muller, G Piel, H Wehler, D Kresin, VZ Ponomarev, YG Buschmann, L Winkeler, L Guntherodt, G TI Observation of a geometrical resonance effect in Bi2Sr2CaCu2O8+x break junctions SO PHYSICAL REVIEW B LA English DT Article ID PROXIMITY-EFFECT SANDWICHES; TC OXIDE SUPERCONDUCTORS; TUNNELING SPECTROSCOPY; STATE; CRYSTALS AB A periodic structure has been observed in the tunneling characteristics of Bi2Sr2CaCu2O8+x break junctions. The observed structure is explained by the electron-hole interference effect in the surface layer, which produces a periodic structure in the tunneling characteristics. Good qualitative agreement has been obtained between measured data and calculated with Arnold's proximity model characteristics. The observed effect indicates an important role of the proximity effect on surface sensitive properties of high-T-c superconductors, and explains the reported discrepancy of energy-gap values for Bi2Sr2CaCu2O8+x. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MOSCOW MV LOMONOSOV STATE UNIV,FAC PHYS,MOSCOW 119899,RUSSIA. RHEIN WESTFAL TH AACHEN,INST PHYS 2,D-5100 AACHEN,GERMANY. RP Aminov, BA (reprint author), UNIV GESAMTHSCH WUPPERTAL,FACHBEREICH PHYS,D-42097 WUPPERTAL,GERMANY. RI Ponomarev, Yaroslav/G-5530-2010 OI Ponomarev, Yaroslav/0000-0002-4857-0315 NR 37 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6728 EP 6733 DI 10.1103/PhysRevB.54.6728 PG 6 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900101 ER PT J AU Sun, AG Truscott, A Katz, AS Dynes, RC Veal, BW Gu, C AF Sun, AG Truscott, A Katz, AS Dynes, RC Veal, BW Gu, C TI Direction of tunneling in Pb/I/YBa2Cu3O7-x tunnel junctions SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTALS; INPLANE ANISOTROPY; PENETRATION DEPTH; ORDER-PARAMETER; PAIRING STATE; YBA2CU3O7-DELTA; YBA2CU4O8; SYMMETRY; GOLD AB Pb/I/YBCO tunnel junctions have been fabricated on ''ab edge'' surfaces of YBCO single crystals (the ''ab edge'' surface is parallel to c axis and normal to a or b axis). The characteristics of these ab junctions were compared to those of c-axis junctions. In addition, STM studies were carried out on c-axis YBCO surfaces (studying exposed ab planes). We conclude from the combined results that the tunneling current in our previously studied c-axis junctions is along the c direction and is the result of c-axis coupling. c-axis Josephson coupling between a conventional superconductor and YBCO provides strong evidence for the existence of an s-wave component in the YBCO order parameter. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Sun, AG (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. NR 25 TC 55 Z9 55 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6734 EP 6741 DI 10.1103/PhysRevB.54.6734 PG 8 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900102 ER PT J AU Burlachkov, L Koshelev, AE Vinokur, VM AF Burlachkov, L Koshelev, AE Vinokur, VM TI Transport properties of high-temperature superconductors: Surface vs bulk effect SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; BOSON LOCALIZATION; FLUX-CREEP; BARRIERS; CRYSTALS; IRREVERSIBILITY; HGBA2CUO4+DELTA; MAGNETIZATION; PENETRATION; RELAXATION AB We investigate surface-related transport properties of high-temperature superconductors. We find the mean vortex velocity under applied transport current determined by the activation energies for vortex penetration and exit through the Bean-Livingston barrier. We determine the current distribution between the surfaces of superconductor and the field and current dependencies of the transport activation energies. For a three-dimensional superconductor the transport activation energy, U-s(3D), is found to decrease with the external field, H, and transport current, J, as U(s)(3D)proportional to H--1/2 and U(s)(3D)proportional to J(-1/2), respectively. In the quasi-two-dimensional compounds, U-s(2D) decays logarithmically with field and current. The interplay between the surface and the bulk contributions to the transport properties, such as current-voltage characteristics, is discussed. C1 BAR ILAN UNIV,DEPT PHYS,INST SUPERCONDUCT,IL-52900 RAMAT GAN,ISRAEL. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Burlachkov, L (reprint author), BAR ILAN UNIV,DEPT PHYS,JACK & PEARL RESNICK INST ADV TECHNOL,IL-52900 RAMAT GAN,ISRAEL. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 31 TC 63 Z9 64 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 SEP 1 PY 1996 VL 54 IS 9 BP 6750 EP 6757 DI 10.1103/PhysRevB.54.6750 PG 8 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900104 ER PT J AU Xu, W Moriarty, JA AF Xu, W Moriarty, JA TI Atomistic simulation of ideal shear strength, point defects, and screw dislocations in bcc transition metals: Mo as a prototype SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-MECHANICAL CALCULATION; CENTERED-CUBIC METALS; EMBEDDED-ATOM-METHOD; INTERATOMIC POTENTIALS; VACANCY FORMATION; CORE STRUCTURES; ANGULAR FORCES; TIGHT-BINDING; PHASE-DIAGRAM; BOND ORDER AB Using multi-ion interatomic potentials derived from first-principles generalized pseudopotential theory, we have studied ideal shear strength, point defects, and screw dislocations in the prototype bcc transition metal molybdenum (Mo). Many-body angular forces, which are important to the structural and mechanical properties of such central transition metals with partially filled d bands, are accounted for in the present theory through explicit three- and four-ion potentials. For the ideal shear strength of Mo, our computed results agree well with those predicted by full electronic-structure calculations. For point defects in Mo, our calculated vacancy-formation and activation energies are in excellent agreement with experimental results. The energetics of six self-interstitial configurations have also been investigated. The [110] split dumbbell interstitial is found to have the lowest formation energy, in agreement with the configuration found by x-ray diffuse scattering measurements. In ascending order, the sequence of energetically stable interstitials is predicted to be [110] split dumbbell, crowdion, [111] split dumbbell, tetrahedral site, [001] split dumbbell, and octahedral site. In addition, the migration paths for the [110] dumbbell self-interstitial have been studied. The migration energies are found to be 3-15 times higher than previous theoretical estimates obtained using simple radial-force Finnis-Sinclair potentials. Finally, the atomic structure and energetics of [lll] screw dislocations in Mo have been investigated. We have found that the so-called ''easy'' core configuration has a lower formation energy than the ''hard'' one, consistent with previous theoretical studies. The former has a distinctive threefold symmetry with a spread out of the dislocation core along the [112] directions, an effect which is driven by the strong angular forces present in these metals. RP Xu, W (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 42 TC 126 Z9 131 U1 5 U2 31 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 SEP 1 PY 1996 VL 54 IS 10 BP 6941 EP 6951 DI 10.1103/PhysRevB.54.6941 PG 11 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200032 ER PT J AU Nakotte, H Purwanto, A Robinson, RA Tun, Z Prokes, K Larson, AC Havela, L Sechovsky, V Maletta, H AF Nakotte, H Purwanto, A Robinson, RA Tun, Z Prokes, K Larson, AC Havela, L Sechovsky, V Maletta, H TI Commensurate and incommensurate magnetic structures of UNiGe SO PHYSICAL REVIEW B LA English DT Article ID TRANSITIONS AB A single crystal of the orthorhombic intermetallic compound UNiGe has been studied at both steady-state and pulsed neutron sources in its commensurate (T<41.5 K) and incommensurate (41.5T-N. However, in the ordered phase the spin gap increases. The observed behavior is totally different from that found in other Haldane gap systems undergoing 3D antiferromagnetic ordering, such as CsNiCl3. C1 UNIV DELAWARE,NEWARK,DE 19716. RP Zheludev, A (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; Vogt, Thomas /A-1562-2011 OI Tranquada, John/0000-0003-4984-8857; Vogt, Thomas /0000-0002-4731-2787 NR 30 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 SEP 1 PY 1996 VL 54 IS 10 BP 7210 EP 7215 DI 10.1103/PhysRevB.54.7210 PG 6 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200062 ER PT J AU Zheludev, A Hill, JP Buttrey, DJ AF Zheludev, A Hill, JP Buttrey, DJ TI X-ray magnetic scattering study of three-dimensional magnetic order in the quasi-one-dimensional antiferromagnet Nd2BaNiO5 SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL CHARACTERIZATION; NEUTRON-DIFFRACTION; SINGLE-CRYSTAL; HALDANE-GAP; POLARIZATION; RESONANCE; Y2BANIO5; POLYMORPHISM; TRANSITIONS; HOLMIUM AB We report a resonant x-ray-scattering determination of order parameter of the Nd sublattice in the quasi-one-dimensional antiferromagnet, Nd2BaNiO5. We find that long-range order develops below T-N=48 K, and that the staggered magnetization continues to grow down to T=10 K. This is in contrast with the behavior of the Ni sublattice, which quickly saturates, as determined previously by neutron-scattering. We find this behavior is modeled well by a self-consistent mean-field theory. Large resonant enhancements were obtained at both the Nd L(II) and L(III) absorption edges, with the largest count rates being achieved at the L(II) edge, where structure consistent with magnetic diffraction anomalous fine structure was observed. A double peak observed at the L(III) resonance is also discussed. C1 UNIV DELAWARE,NEWARK,DE 19716. RP Zheludev, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Hill, John/F-6549-2011 NR 29 TC 29 Z9 29 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 SEP 1 PY 1996 VL 54 IS 10 BP 7216 EP 7221 DI 10.1103/PhysRevB.54.7216 PG 6 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200063 ER PT J AU Paolasini, L Lander, GH Shapiro, SM Caciuffo, R Lebech, B Regnault, LP Roessli, B Fournier, JM AF Paolasini, L Lander, GH Shapiro, SM Caciuffo, R Lebech, B Regnault, LP Roessli, B Fournier, JM TI Magnetic excitations in the itinerant ferromagnet UFe2 SO PHYSICAL REVIEW B LA English DT Article ID SPIN MAGNETISM; INTERMETALLICS; NEUTRON; CEFE2 AB UFe2 (Laves phase, fee crystal structure) is a ferromagnet with T-C=165 K, Previous neutron elastic measurements have established that the Fe moment is 0.6 mu(B) and that the moment on the U atom is almost zero because of the cancellation of the spin and orbital moments, which are both about 0.23 mu(B), but are oppositely directed. We have now examined the spin dynamics from a large single crystal with both thermal and cold-source triple-axis spectrometers. Comparisons with the extensive work performed on RFe(2)(R=Tb, Ho, Er) suggests that two dispersive modes should be seen at low energy (i.e., less than similar to 20 meV). However, only one mode has been found in UFe2 and this involves the precession of the Fe spins. We propose that the acoustic mode involving the uranium spin is sufficiently broadened in (q,omega) space that we cannot readily detect the excitation. Nevertheless, the influence of the U-Fe exchange may be seen in (a) the presence of a gap in the Fe spin-wave spectrum at q=0, and (b) in an increase in the Fe spin-wave stiffness constant (D) as compared to that found in pure Fe. This last property is a direct consequence of the hybridization between the U5f and Fe3d electrons. We find also that D is strongly temperature dependent, presumably due to two-magnon interactions. Thus, this effect, together with the low moment on the Fe atoms, results in the comparatively low, as compared to the RFe(2) compounds, T-C of 165 K in UFe2. C1 CEA,MDN,SPSMS,DEPT RECH FONDAMENTALE MAT CONDENSEE,F-38054 GRENOBLE 09,FRANCE. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV ANCONA,DIPARTIMENTO SCI MAT & TERRA,I-60131 ANCONA,ITALY. IST NAZL FIS MAT,I-60131 ANCONA,ITALY. RISO NATL LAB,DEPT PHYS,DK-4000 ROSKILDE,DENMARK. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. UNIV GRENOBLE 1,F-38000 GRENOBLE,FRANCE. RP Paolasini, L (reprint author), COMMISS EUROPEAN COMMUNITIES,JOINT RES CTR,INST TRANSURANIUM ELEMENTS,POSTFACH 2340,D-76125 KARLSRUHE,GERMANY. RI Lebech, Bente/A-9629-2016; OI Lebech, Bente/0000-0002-6403-4141; Caciuffo, Roberto G. M./0000-0002-8708-6219 NR 38 TC 21 Z9 22 U1 1 U2 7 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 SEP 1 PY 1996 VL 54 IS 10 BP 7222 EP 7232 DI 10.1103/PhysRevB.54.7222 PG 11 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200064 ER PT J AU Kiryukhin, V Keimer, B Hill, JP Coad, SM Paul, DM AF Kiryukhin, V Keimer, B Hill, JP Coad, SM Paul, DM TI Synchrotron x-ray-scattering study of magnetic-field-induced transitions in Cu-1-x(Zn,Ni)(x)GeO3 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-PEIERLS TRANSITION; SYSTEM CUGEO3; DOPED CUGEO3; STATE; POLYACETYLENE; DIMERIZATION; SOLITONS; ORDER AB We have studied the high-field phase behavior of the spin-chain compound Cu-1-x(Zn, Ni)(x)GeO3 by synchrotron x-ray scattering in magnetic fields up to 13 T. The rich magnetic phase diagram of this system includes uniform, low-field commensurate spin-Peierls (C), high-field incommensurate spin-Peierls (IC), and Neel phases. For the pure system (x=0), we have determined the shape of the phase boundaries as well as the incommensurability and harmonic content of the incommensurate lattice distortion in the IC phase as a function of field and temperature. The results are in good qualitative agreement with predictions based on the soliton lattice model of the IC phase, but significant quantitative discrepancies are found. Dilution of the copper oxide spin-1/2 chains with very small amounts (x similar to 0.01) of spin-0 (Zn) or spin-1 (Ni) impurities results in a short-range-ordered IC phase with an anisotropic correlation length comparable to the average impurity separation. This presumably reflects strong pinning of the magnetic solitons to the impurities. For larger x the long-range order is disrupted also in the C phase, and the system undergoes a Neel transition at low temperatures. Aided by supplementary neutron-diffraction measurements, we construct magnetic phase diagrams for the diluted systems. For these systems we also present detailed measurements of the incommensurabilities and correlation lengths as a function of both field and temperature. The data are interpreted in terms of a simple phenomenological model based on lifetime broadening of the spin excitations in finite-sized chain segments. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. RP Kiryukhin, V (reprint author), PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544, USA. NR 33 TC 42 Z9 42 U1 1 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 SEP 1 PY 1996 VL 54 IS 10 BP 7269 EP 7278 DI 10.1103/PhysRevB.54.7269 PG 10 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200067 ER PT J AU Schmiedeshoff, GM Lacerda, A Fisk, Z Smith, JL AF Schmiedeshoff, GM Lacerda, A Fisk, Z Smith, JL TI Electrical resistivity of UBe13 in high magnetic fields SO PHYSICAL REVIEW B LA English DT Article ID FERMION SUPERCONDUCTOR UBE13; CRYSTAL-FIELD; HEAVY; MAGNETORESISTANCE; SYSTEMS AB We have measured the temperature dependent electrical resistivity of single and polycrystal samples of UBe13 in high magnetic fields. Two maxima in the resistivity are observed at T-M1 and T-M2. T-M1 the temperature of the colder maximum, increases quadratically with magnetic field H, a field dependence previously observed under hydrostatic pressure. The high temperature maximum at T-M2 emerges in fields above about 4 T and increases linearly with H, a behavior which may be due to a sharpening of the crystal field levels associated with a depression of the Kondo effect by high magnetic fields. C1 LOS ALAMOS NATL LAB,PULSE FACIL,NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Schmiedeshoff, GM (reprint author), OCCIDENTAL COLL,DEPT PHYS,LOS ANGELES,CA 90041, USA. NR 33 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP 7401 EP 7405 DI 10.1103/PhysRevB.54.7401 PG 5 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200083 ER PT J AU Tranquada, JM Axe, JD Ichikawa, N Nakamura, Y Uchida, S Nachumi, B AF Tranquada, JM Axe, JD Ichikawa, N Nakamura, Y Uchida, S Nachumi, B TI Neutron-scattering study of stripe-phase order of holes and spins in La1.48Nd0.4Sr0.12CuO4 SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL HUBBARD-MODEL; INCOMMENSURATE MAGNETIC CORRELATIONS; HIGH-TEMPERATURE SUPERCONDUCTORS; T-J MODEL; DOPED ANTIFERROMAGNET; CHARGE-TRANSPORT; SINGLE-CRYSTAL; COPPER OXIDES; HARTREE-FOCK; FERMI-LIQUID AB We present a neutron diffraction study of charge and spin order within the CuO2 planes of La1.48Nd0.4Sr0.12CuO4, a crystal in which superconductivity is anomalously suppressed. At low temperatures we observe elastic magnetic superlattice peaks of the type (1/2+/-epsilon 1/2,0) and charge-order peaks at (2+/-2 epsilon,0,0), where epsilon=0.118. After cooling the crystal through the low-temperature-orthorhombic (LTO) to low-temperature-tetragonal (LTT) phase transition near 70 K, the charge-order peaks appear first at similar to 60 K, with the magnetic peaks appearing below 50 K. The magnetic peaks increase in intensity by an order of magnitude below 3 K due to ordering of the Nd ions. We show that the observed diffraction features are consistent with stripe-phase order, in which the dopant-induced holes collect in domain walls that separate antiferromagnetic antiphase domains. The Q dependence of the magnetic scattering indicates that the low-temperature correlation length within the planes is substantial (similar to 170 Angstrom), but only very weak correlations exist between next-nearest-neighbor planes. Correlations between nearest-neighbor layers are frustrated by pinning of the charge stripes to the lattice distortions of the LTT phase. The spin-density-wave amplitude corresponds to a Cu moment of 0.10+/-0.03 mu(B). The behavior of the electrical resistivity within the LTT phase is examined, and the significance of stripe-phase correlations for understanding the unusual transport properties of layered cuprates is discussed. C1 UNIV TOKYO, BUNKYO KU, TOKYO 113, JAPAN. COLUMBIA UNIV, DEPT PHYS, NEW YORK, NY 10027 USA. RP Tranquada, JM (reprint author), BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RI Tranquada, John/A-9832-2009; Nakamura, Yasunobu/H-1300-2012 OI Tranquada, John/0000-0003-4984-8857; NR 77 TC 489 Z9 490 U1 3 U2 27 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP 7489 EP 7499 DI 10.1103/PhysRevB.54.7489 PG 11 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200095 ER PT J AU Thompson, JR Ossandon, JG Christen, DK Paranthaman, M Specht, ED Kim, YC AF Thompson, JR Ossandon, JG Christen, DK Paranthaman, M Specht, ED Kim, YC TI Comparative study of the characteristic length scales and fields of Hg-based high-T-c superconductors SO PHYSICAL REVIEW B LA English DT Article ID GRAIN-ALIGNED HGBA2CA2CU3O8+DELTA; REVERSIBLE MAGNETIZATION; VORTEX FLUCTUATIONS; HGBA2CACU2O6+DELTA; HGBA2CUO4+DELTA; PARAMETERS; YBA2CU3O7-DELTA; VORTICES AB The equilibrium magnetization was studied in magnetically aligned Hg-based cuprate superconductors with a crystal structure containing one, two, and three adjacent Cu-O layers. The mixed state magnetization was measured with the magnetic field applied perpendicular to the layers, along with low field Meissner effect and normal state susceptibility studies for volume correction factors. The internally consistent analysis is used to identify systematics as the number ''n'' of Cu-O layers increases. The study reveals a linear increase in the slope of upper critical field -dH(c2)/dT with ''n''. Most importantly, we find a nearly constant carrier doping per Cu-O layer. This result is compared with other studies, e.g., Rietveld analysis of neutron diffractometry, and its implications are discussed. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. UNIV TALCA,FAC INGN,CURICO,CHILE. RP Thompson, JR (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531 NR 38 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP 7505 EP 7511 DI 10.1103/PhysRevB.54.7505 PG 7 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200097 ER PT J AU Bulaevskii, LN Dominguez, D Maley, MP Bishop, AR Tsui, OKC Ong, NP AF Bulaevskii, LN Dominguez, D Maley, MP Bishop, AR Tsui, OKC Ong, NP TI Linewidth of c-axis plasma resonance in Josephson-coupled superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BI2SR2CACU2O8 SINGLE-CRYSTALS; PERPENDICULAR MAGNETIC-FIELDS; HIGH-TC SUPERCONDUCTORS; LAYERED SUPERCONDUCTORS; VORTEX STATE; VORTICES; PHASE; FLUCTUATIONS; JUNCTIONS AB We derive equations which describe the interaction of the phase collective mode with vortex oscillations in multilayer superconductors with Josephson interlayer coupling. Using these dynamic equations for the phase difference between neighboring layers and pancake coordinates we calculate the linewidth of the c-axis plasma resonance in the vortex glass phase when a magnetic field is applied along the c axis. Three mechanisms contribute to the linewidth: interlayer tunneling of quasiparticles, inhomogeneous Josephson interaction in the presence of randomly positioned vortices (inhomogeneous broadening), and dissipation of the plasma mode into vortex oscillations. The phase collective mode is mixed with vortex oscillations in the linear approximation via the Josephson interaction when pancakes are positioned randomly along the c axis due to pinning and thermal fluctuations. Analyzing experimental data for the plasma resonance linewidth in a Bi-2:2:1:2 superconductor we conclude that in magnetic fields below 7 T the linewidth is determined mainly by inhomogeneous broadening. This leads to a nearly temperature-independent linewidth which is inversly proportional to the magnetic field. At higher fields or lower pinning the dissipation of the plasmon into vortex oscillations may become the dominant mechanism of line broadening. In this case the linewidth weakly depends on the magnetic field. C1 PRINCETON UNIV, JOSEPH HENRY LABS PHYS, PRINCETON, NJ 08544 USA. RP Bulaevskii, LN (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Dominguez, Daniel/E-9304-2016; OI Dominguez, Daniel/0000-0002-6204-0150; Tsui, Ophelia K. C./0000-0001-5987-2733 NR 46 TC 28 Z9 28 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP 7521 EP 7535 DI 10.1103/PhysRevB.54.7521 PG 15 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200099 ER PT J AU Hayden, SM Aeppli, G Perring, TG Mook, HA Dogan, F AF Hayden, SM Aeppli, G Perring, TG Mook, HA Dogan, F TI High-frequency spin waves in YBa2Cu3O6.15 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; HEISENBERG-ANTIFERROMAGNET; MAGNETIC EXCITATIONS; LA2CUO4; DYNAMICS AB Pulsed neutron spectroscopy is used to absolute measurements of the dynamic magnetic susceptibility of insulating YBa2Cu3O6.15. Acoustic and optical modes, derived from in- and out-of-phase oscillation of spins in adjacent CuO2 planes, dominate the spectra and are observed up to 250 meV. The optical modes appear first at 74+/-5 meV. Linear-spin-wave theory gives an excellent description of the data and yields intralayer and interlayer exchange constants of J(parallel to) = 125+/-5 meV and J(perpendicular to) = 11+/-2 meV, respectively, and a spin-wave intensity renormalization Z(chi) = 0.4+/-0.1. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. RUTHERFORD APPLETON LAB,ISIS FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV WASHINGTON,DEPT MAT SCI & ENGN,SEATTLE,WA 98195. RP Hayden, SM (reprint author), UNIV BRISTOL,HH WILLS PHYS LAB,TYNDALL AVE,BRISTOL BS8 1TL,AVON,ENGLAND. RI Hayden, Stephen/F-4162-2011 OI Hayden, Stephen/0000-0002-3209-027X NR 23 TC 80 Z9 81 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 SEP 1 PY 1996 VL 54 IS 10 BP R6905 EP R6908 PG 4 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200027 ER PT J AU Maksimov, AA Pronin, DA Zaitsev, SV Tartakovskii, II Blumberg, G Klein, MV Karlow, M Cooper, SL Paulikas, AP Veal, BW AF Maksimov, AA Pronin, DA Zaitsev, SV Tartakovskii, II Blumberg, G Klein, MV Karlow, M Cooper, SL Paulikas, AP Veal, BW TI Influence of oxygen-ordering kinetics on Raman and optical response in YBa2Cu3O6.4 SO PHYSICAL REVIEW B LA English DT Article ID OFF-STOICHIOMETRIC YBA2CU3OZ; ROOM-TEMPERATURE; CHARGE-TRANSFER; SUPERCONDUCTIVITY; FLUCTUATIONS; SCATTERING; TRANSITION; CRYSTALS AB Kinetics of the optical and Raman response in YBa2Cu3O6.4 were studied during room-temperature annealing following heat treatment. The superconducting T-c, dc resistivity, and low-energy optical conductivity recover slowly, implying a long relaxation time for the carrier density. Short relaxation times are observed for the B-1g Raman scattering-magnetic, continuum, and phonon-and the charge transfer band. Monte Carlo simulations suggest that these two relaxation rates are related to two length scales corresponding to local oxygen ordering (fast) and long chain and twin formation (slow). C1 UNIV ILLINOIS,NSF,SCI & TECHNOL CTR SUPERCONDUCT,URBANA,IL 61801. UNIV ILLINOIS,NSF,DEPT PHYS,URBANA,IL 61801. INST CHEM PHYS & BIOPHYS,EE-0001 TALLINN,ESTONIA. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Maksimov, AA (reprint author), RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. RI Maksimov, Andrei/C-5828-2017 NR 20 TC 6 Z9 6 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP R6901 EP R6904 PG 4 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200026 ER PT J AU Sasago, Y Koide, N Uchinokura, K Martin, MC Hase, M Hirota, K Shirane, G AF Sasago, Y Koide, N Uchinokura, K Martin, MC Hase, M Hirota, K Shirane, G TI New phase diagram of Zn-doped CuGeO3 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-PEIERLS TRANSITION; CUGE1-XSIXO3; ORDER AB A series of high-quality single crystals of Cu1-xZnxGeO3 have been examined by neutron-scattering techniques. An antiferromagnetic (AF) ordering is confirmed for four samples in the range 0.009 less than or equal to x less than or equal to 0.047, in complete agreement with previous reports. We show that the spin-Peierls (SP) phase transition persists to 4.7% Zn, whereas previous magnetic-susceptibility measurements reported a deterioration of the SP transition above 2% Zn. We present some details of the successive transitions upon lowering temperature into the spin-Peierls phase which is followed by a transition into an antiferromagnetically ordered phase. Below the Neel temperature we observe the coexistence of the SP lattice dimerization and AF states. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Sasago, Y (reprint author), UNIV TOKYO,DEPT APPL PHYS,BUNKYO KU,7-3-1 HONGO,TOKYO 113,JAPAN. RI Hirota, Kazuma/C-6797-2008; Hase, Masashi/B-8900-2008 OI Hase, Masashi/0000-0003-2717-461X NR 11 TC 76 Z9 76 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 SEP 1 PY 1996 VL 54 IS 10 BP R6835 EP R6837 PG 3 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200009 ER PT J AU Ognibene, TJ Powell, J Moltz, DM Rowe, MW Cerny, J AF Ognibene, TJ Powell, J Moltz, DM Rowe, MW Cerny, J TI Additional results from the beta-delayed proton decays of P-27 and Cl-31 SO PHYSICAL REVIEW C LA English DT Article ID SD-SHELL NUCLEI; ENERGY-LEVELS; EMISSION; VALUES AB beta-delayed proton decays of the nuclides P-27 and Cl-31 were measured using the helium-jet recoil collection technique and low-energy particle identification detector telescopes. In P-27, two new proton groups at 466+/-3 keV and 612+/-2 keV, with intensities of 9+/-2% and 97+/-3% relative to the main (100%) group at 731+/-2 keV, were discovered. Additionally, during the P-27 experiments, a new proton transition was identified following the beta decay of P-28. This group, at a proton energy of 1452+/-4 keV, had a 2+/-1% intensity relative to the 100% group at 679+/-1 keV. A total P-27 beta-delayed proton branch of 0.07% was estimated. The experimental Gamow-Teller beta-decay strengths of the observed transitions from P-27 were compared to results from shell model calculations. A search for new proton transitions in Cl-31, the next member of this A = 4n + 3, T-z = -3/2 series, was unsuccessful. However. several proton peaks that had been previously assigned to Cl-31 decay were shown to be from the decay of Si-25. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Ognibene, TJ (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 29 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1098 EP 1105 DI 10.1103/PhysRevC.54.1098 PG 8 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900014 ER PT J AU Baldsiefen, G Stoyer, MA Cizewski, JA Mcnabb, DP Younes, W Becker, JA Bernstein, LA Brinkman, MJ Farris, LP Henry, EA Hughes, JR Kuhnert, A Wang, TF Cederwall, B Clark, RM Deleplanque, MA Diamond, RM Fallon, P Lee, IY Macchiavelli, AO Oliveira, J Stephens, FS Burde, J Vo, DT Frauendorf, S AF Baldsiefen, G Stoyer, MA Cizewski, JA Mcnabb, DP Younes, W Becker, JA Bernstein, LA Brinkman, MJ Farris, LP Henry, EA Hughes, JR Kuhnert, A Wang, TF Cederwall, B Clark, RM Deleplanque, MA Diamond, RM Fallon, P Lee, IY Macchiavelli, AO Oliveira, J Stephens, FS Burde, J Vo, DT Frauendorf, S TI Shears bands in Pb-193 SO PHYSICAL REVIEW C LA English DT Article ID DIPOLE ROTATIONAL BANDS; COLLECTIVE OBLATE; 1ST OBSERVATION; LIFETIME MEASUREMENTS; BISMUTH NUCLEI; STATES; ISOTOPES; REGION; PB-200 AB Four bands of enhanced dipole transitions, with weak crossovers, have been observed in Pb-195. Three of these bands are connected to the spherical levels. in addition, the spherical level scheme has been extended. The nuclear spectroscopy was done with the early implementation of GAMMASPHERE and HERA arrays of Get detectors. The nucleus Pb-193 was populated in the Yb-174(Mg-24,5n) reaction at beam energies of 129, 131, and 134 MeV. The experimental results are compared to tilted-axis cranking calculations. The systematical behavior of the dipole bands in the heavier odd-A Pb isotopes, Pb-195,Pb-197,Pb-199,Pb-201, is also discussed. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. IOWA STATE UNIV, AMES, IA 50011 USA. FORSCHUNGSZENTRUM ROSSENDORF EV, D-01314 DRESDEN, GERMANY. RP RUTGERS STATE UNIV, NEW BRUNSWICK, NJ 08903 USA. RI Oliveira, Jose Roberto/J-3124-2012; Cederwall, Bo/M-3337-2014 OI Oliveira, Jose Roberto/0000-0003-1362-7382; Cederwall, Bo/0000-0003-1771-2656 NR 43 TC 30 Z9 30 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1106 EP 1116 DI 10.1103/PhysRevC.54.1106 PG 11 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900015 ER PT J AU Wu, HC Ginocchio, JN Dieperink, AEL Scholten, O AF Wu, HC Ginocchio, JN Dieperink, AEL Scholten, O TI Double charge exchange on Te isotopes in the generalized seniority scheme SO PHYSICAL REVIEW C LA English DT Article ID DOUBLE-BETA-DECAY; INTERACTING-BOSON-APPROXIMATION; NUCLEAR SHELL-MODEL AB The pion double-charge-exchange reactions on the Te isotopes are discussed in the generalized seniority scheme, The elementary process of charge exchange is described in a double scattering process within the plane wave Limit. The transition rates are calculated for double-isobaric-analog state as well as for ground-state reactions. C1 UNIV ANTIOQUIA,DEPT FIS,MEDELLIN,COLOMBIA. LOS ALAMOS NATL LAB,DIV THEORET,MS B283,LOS ALAMOS,NM 87545. KERNFYS VERSNELLER INST,NL-9747 AA GRONINGEN,NETHERLANDS. RP Wu, HC (reprint author), OREGON STATE UNIV,DEPT PHYS,CORVALLIS,OR 97331, USA. NR 20 TC 5 Z9 5 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1208 EP 1216 DI 10.1103/PhysRevC.54.1208 PG 9 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900027 ER PT J AU Farrar, KA Sanders, SJ Dummer, AK Hasan, AT Prosser, FW Back, BB Bearden, IG Betts, RR Carpenter, MP Crowell, B Freer, M Henderson, DJ Janssens, RVF Beck, C Freeman, RM Cavallaro, S deToledo, AS AF Farrar, KA Sanders, SJ Dummer, AK Hasan, AT Prosser, FW Back, BB Bearden, IG Betts, RR Carpenter, MP Crowell, B Freer, M Henderson, DJ Janssens, RVF Beck, C Freeman, RM Cavallaro, S deToledo, AS TI Fission decay of Cr-48 at E*(CN)approximate to 60 MeV SO PHYSICAL REVIEW C LA English DT Article ID HIGH-SPIN STATES; INELASTIC-SCATTERING; S-32+MG-24 REACTION; MG-24+MG-24 SYSTEM; FUSION-FISSION; MG-24; COMPETITION; RESONANCES AB The fully energy-damped yields for the Ar-36 + C-12 and Ne-20 + Si-28 reactions at E(c.m.)=47.0 MeV and 45.5 MeV, respectively, are explored using particle-particle-gamma coincidence data. These reactions reach a similar excitation energy of E(CN)*=59.5 MeV in the Cr-48 compound nucleus as was obtained in an earlier particle-particle coincidence study of the Mg-24 + Mg-24 reaction. The overall mass and total kinetic energy distributions of the fission fragments are found to be well reproduced by statistical-model calculations. These calculations are also found to reproduce structure seen in the excitation-energy spectra for the Ne-20 + Si-28 and Mg-24 + Mg-24 exit channels for all three reactions. In previous excitation-function measurements, strong heavy-ion resonance behavior has been observed in elastic and inelastic cross sections for the Mg-24 + Mg-24 system. There has been speculation that peaks observed in the corresponding excitation-energy spectra at more negative Q values may also be a consequence of this resonance phenomenon. The observation of very similar behavior with the asymmetric-mass entrance channels makes it less likely, though, that the peaks arise from any special configuration of the compound system. Instead, an analysis of the gamma-ray data and the results of statistical-model calculations support the conclusion that most of the observed high-lying structure can be accounted for in terms of statistical fission from a fully energy- and shape-equilibrated compound nucleus. For the Mg-24 + Mg-24 entrance channel, however, comparisons with the statistical model indicate a reduction of high-angular-momentum partial cross sections, leading to the Mg-24 + Mg-24 fission channel. For the first time, we are able to deduce the nature of the competition between the resonance and statistical-fission mechanisms in this mass region. C1 UNIV KANSAS,DEPT PHYS & ASTRON,LAWRENCE,KS 66045. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV STRASBOURG 1,CTR RECH NUCL,IN2P3,CNRS,F-67037 STRASBOURG 2,FRANCE. UNIV CATANIA,DIPARTMENTO FIS,I-95129 CATANIA,ITALY. UNIV SAO PAULO,INST FIS,DEPT FIS NUCL,BR-01498970 SAO PAULO,BRAZIL. RI Freer, Martin/F-9379-2013; Bearden, Ian/M-4504-2014; Carpenter, Michael/E-4287-2015 OI Bearden, Ian/0000-0003-2784-3094; Carpenter, Michael/0000-0002-3237-5734 NR 31 TC 22 Z9 22 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 SEP PY 1996 VL 54 IS 3 BP 1249 EP 1261 DI 10.1103/PhysRevC.54.1249 PG 13 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900032 ER PT J AU Zahar, M Belbot, M Kolata, JJ Lamkin, K Morrissey, DJ Sherrill, BM Lewitowicz, M Wuosmaa, AH AlKhalili, JS Tostevin, JA Thompson, IJ AF Zahar, M Belbot, M Kolata, JJ Lamkin, K Morrissey, DJ Sherrill, BM Lewitowicz, M Wuosmaa, AH AlKhalili, JS Tostevin, JA Thompson, IJ TI Quasielastic scattering of Li-9 on C-12 SO PHYSICAL REVIEW C LA English DT Article ID QUASI-ELASTIC SCATTERING AB The quasielastic scattering of Li-9 on a C-12 target has been measured at an incident energy of 540 MeV. The new experimental data are used to extract an effective interaction for Li-9 + C-12 scattering. The uncertainty in this interaction was previously a major obstacle to extracting information on the structure of Li-11 from existing Li-11 + C-12 quasielastic-scattering data. C1 MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. GANIL,F-14021 CAEN,FRANCE. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. UNIV SURREY,DEPT PHYS,GUILDFORD GU2 5XH,SURREY,ENGLAND. RP Zahar, M (reprint author), UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556, USA. RI Sherrill, Bradley/B-4098-2009; Sherrill, Bradley/B-3378-2011 NR 9 TC 16 Z9 16 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1262 EP 1266 DI 10.1103/PhysRevC.54.1262 PG 5 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900033 ER PT J AU Madani, H Mignerey, AC Marchetti, AA WestonDawkes, AP Kehoe, WL Obenshain, F AF Madani, H Mignerey, AC Marchetti, AA WestonDawkes, AP Kehoe, WL Obenshain, F TI Excitation energy division in heavy-ion reactions SO PHYSICAL REVIEW C LA English DT Article ID 8.5 MEV GE-74; DAMPED REACTIONS; NUCLEAR COLLISIONS; NEUTRON EMISSION; ANGULAR-MOMENTUM; MASS; TRANSPORT; DISTRIBUTIONS; PARTITION; CHARGE AB The excitation energy of the primary products from the reaction Fe-56 on Ho-165 at 672 MeV was determined by the kinematic coincidence technique. The Fraction of the rural excitation energy of the system stored in the projectilelike fragment was found to decrease with increasing energy loss. However, thermal equilibrium is not reached, even at the highest energy damping. A small correlation between excitation energy partition and reaction exit channel was observed. Monte Carlo simulations of the present experiment confirmed that some of this correlation is due to the finite resolution of the measured parameters. C1 UNIV MARYLAND,COLLEGE PK,MD 20742. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Mignerey, Alice/D-6623-2011 NR 26 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 SEP PY 1996 VL 54 IS 3 BP 1291 EP 1301 DI 10.1103/PhysRevC.54.1291 PG 11 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900036 ER PT J AU Blann, M AF Blann, M TI New precompound decay model SO PHYSICAL REVIEW C LA English DT Article ID PRE-EQUILIBRIUM DECAY; PREEQUILIBRIUM AB A new precompound Monte Carlo simulation model is presented. It permits unlimited multiple precompound emission for each interaction, may be used to give exclusive spectra and yields, and does not rely upon those exciton state densities shown to be inconsistent with the assumed two body transitions in the hybrid and exciton model formulations. Results of the new model are compared with Zr-90 (p,xn) single differential spectra for incident energies from 25 to 160 MeV, and for Co-59 (p,x) and V-51 (p,x) excitation functions for incident proton energies up to 200 MeV. The new model gives significant improvement over the hybrid model for calculation of excitation functions. Multiple precompound decay predictions are compared for the two models. It is shown that the restriction to two precompound nucleons per decay in the hybrid model becomes a poor approximation for incident proton energies above approximate to 80 MeV. RP Blann, M (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-59,LIVERMORE,CA 94551, USA. NR 23 TC 89 Z9 90 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1341 EP 1349 DI 10.1103/PhysRevC.54.1341 PG 9 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900042 ER PT J AU Lee, TSH AF Lee, TSH TI Medium effects on binary collisions with the Delta resonance SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; MESON-EXCHANGE CALCULATION; NUCLEAR-MATTER; DILEPTON PRODUCTION; TRANSPORT MODEL; SCATTERING; PI; SYSTEM; PIONS; NN AB To facilitate the relativistic heavy-ion calculations based on transport equations, the binary collisions involving a Delta resonance in either the entrance channel or the exit channel are investigated within a Hamiltonian formulation of pi NN interactions. An averaging procedure is developed to define a quasiparticle Delta* and to express the experimentally measured NN-->pi NN cross section in terms of an effective NN-->N Delta* cross section. In contrast to previous works, the main feature of the present approach is that the mass and the momentum of the produced Delta*'s are calculated dynamically from the bare Delta<->pi N Vertex interaction of the model Hamiltonian and are constrained by the unitarity condition. The procedure is then extended to define the effective cross sections for the experimentally inaccessible N Delta*-->NN and N Delta*-->N Delta* reactions. The predicted cross sections are significantly different from what are commonly assumed in relativistic heavy-ion calculations. The Delta potential in nuclear matter has been calculated by using a Bruckner-Hartree-Fock approximation. By including the mean-field effects on the Delta propagation, the effective cross sections of the NN-->N Delta*, N Delta*-->NN and N Delta*-->N Delta* reactions in nuclear matter are predicted. It is demonstrated that the density dependence is most dramatic in the energy region close to the pion production threshold. RP Lee, TSH (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 30 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1350 EP 1359 DI 10.1103/PhysRevC.54.1350 PG 10 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900043 ER PT J AU Ornik, U Plumer, M Schlei, BR Strottman, D Weiner, RM AF Ornik, U Plumer, M Schlei, BR Strottman, D Weiner, RM TI Hydrodynamical analysis of symmetric nucleus-nucleus collisions near 200A GeV SO PHYSICAL REVIEW C LA English DT Article ID BOSE-EINSTEIN CORRELATIONS; HEAVY-ION COLLISIONS; HIGH-ENERGY COLLISIONS; RELATIVISTIC HYDRODYNAMICS; PHASE-TRANSITION; FLUID-DYNAMICS; MODEL; INTERMITTENCY; COLLECTIVITY; EXPANSION AB We present a coherent theoretical study of ultrarelativistic heavy-ion data obtained at the CERN/SPS by the NA35/NA49 Collaborations using (3+1)-dimensional relativistic hydrodynamics. We find excellent agreement with the rapidity spectra of negative hadrons and protons and with the correlation measurements in two experiments: S+S at 200A GeV and Pb+Pb at 160A GeV (preliminary results). Within our model this implies that for Pb+Pb (S+S) a quark-gluon plasma of initial volume 174 fm(3) (24 fm(3)) with a lifetime 3.4 fm/c (1.5 fm/c) was formed. It is found that the Bose-Einstein correlation measurements do not determine the maximal effective radii of the hadron sources because of the large contributions from resonance decay at small momenta. Also within this study we present an NA49 acceptance-corrected two-pion Bose-Einstein correlation function in the invariant variable Q(inv). C1 UNIV MARBURG,DEPT PHYS,D-3550 MARBURG,GERMANY. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Ornik, U (reprint author), SOULTEK INTERNET SERV,SOFTWARE CTR 5,MARBURG,GERMANY. NR 46 TC 35 Z9 36 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 SEP PY 1996 VL 54 IS 3 BP 1381 EP 1389 DI 10.1103/PhysRevC.54.1381 PG 9 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900047 ER PT J AU Benesh, CJ Hayes, AC Friar, JL AF Benesh, CJ Hayes, AC Friar, JL TI Quantum-mechanical equivalent-photon spectrum for heavy-ion physics SO PHYSICAL REVIEW C LA English DT Article ID ELECTRIC QUADRUPOLE EXCITATIONS; ELECTROMAGNETIC DISSOCIATION; AU-197 TARGETS; COULOMB DISSOCIATION; RELATIVISTIC NUCLEI; COLLISIONS; ENERGIES; PROJECTILES; CO-59; Y-89 AB In a previous paper, we calculated the fully quantum-mechanical cross section for electromagnetic excitation during peripheral heavy-ion collisions. Here, we examine the sensitivity of that cross section to the detailed structure of the projectile and target nuclei. At the transition energies relevant to nuclear physics, we find the cross section to be weakly dependent on the projectile charge radius and to be sensitive to only the leading momentum-transfer dependence of the target transition form. factors. We exploit these facts to derive a quantum-mechanical ''equivalent-photon spectrum'' valid in the long-wavelength limit. This improved spectrum includes the effects of projectile size, the finite longitudinal momentum transfer required by kinematics, and the response of the target nucleus to the off-shell photon. C1 UNIV NO IOWA, DEPT PHYS, CEDAR FALLS, IA 50614 USA. INT INST THEORET & APPL PHYS, AMES, IA 50011 USA. AECL RES, CHALK RIVER LABS, CHALK RIVER, ON K0J 1J0, CANADA. RP Benesh, CJ (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 40 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 SEP PY 1996 VL 54 IS 3 BP 1404 EP 1413 DI 10.1103/PhysRevC.54.1404 PG 10 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900049 ER PT J AU Wisshak, K Voss, F Theis, C Kappeler, F Guber, K Kazakov, L Kornilov, N Reffo, G AF Wisshak, K Voss, F Theis, C Kappeler, F Guber, K Kazakov, L Kornilov, N Reffo, G TI Stellar neutron capture cross sections of the tin isotopes SO PHYSICAL REVIEW C LA English DT Article ID BARIUM FLUORIDE DETECTOR; S-PROCESS; P-PROCESS; NUCLEOSYNTHESIS; ABUNDANCES; DENSITY; TA-181; SOLAR; NB-93 AB The neutron capture cross sections of Sn-114, Sn-115, Sn-116, Sn-117, Sn-118, and Sn-120 were measured in the energy range from 3 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the Li-7(p,n)Be-7 reaction using a pulsed proton beam. Capture events were registered with the Karlsruhe 4 pi barium fluoride detector. The experiment was complicated by the small (n,gamma) cross sections of the proton magic tin isotopes and by the comparably low enrichment of the rare isotopes Sn-114 and Sn-115. Despite significant corrections for capture of scattered neutrons and for isotopic impurities, the high efficiency and the spectroscopic quality of the BaF2 detector allowed the determination of the cross-section ratios with overall uncertainties of 1-2%, five times smaller compared to existing data. Based on these results, Maxwellian averaged (n,gamma) cross sections were calculated for thermal energies between kT-10 and 100 keV. These data are used for a discussion of the solar tin abundance and for an improved determination of the isotopic s- and r-process components. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. INST PHYS & POWER ENGN,OBNINSK,KALUGA REGION,RUSSIA. COMITATO NAZL RICERCA,I-40138 BOLOGNA,ITALY. SVILUPPO ENERGIA NUCL,I-40138 BOLOGNA,ITALY. CTR DATI NUCL,ENERGIA ALTERNAT,I-40138 BOLOGNA,ITALY. RP Wisshak, K (reprint author), FORSCHUNGSZENTRUM KARLSRUHE,INST KERNPHYS,POSTFACH 3640,D-76021 KARLSRUHE,GERMANY. NR 37 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1451 EP 1462 DI 10.1103/PhysRevC.54.1451 PG 12 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900055 ER PT J AU Koehler, PE Spencer, RR Winters, RR Guber, KH Harvey, JA Hill, NW Smith, MS AF Koehler, PE Spencer, RR Winters, RR Guber, KH Harvey, JA Hill, NW Smith, MS TI Resonance neutron capture and transmission measurements and the stellar neutron capture cross sections of Ba-134 and Ba-136 SO PHYSICAL REVIEW C LA English DT Article ID S-PROCESS NUCLEOSYNTHESIS; ISOTOPES; MODELS; STARS AB We have made high-resolution neutron capture and transmission measurements on isotopically enriched samples of Ba-134 and Ba-136 at the Oak Ridge Electron Linear Accelerator (ORELA) in the energy range from 20 eV to 500 keV. Previous measurements had a lower energy limit of 3-5 keV, which is too high to determine accurately the Maxwellian-averaged capture cross section at the low temperatures (kT approximate to 8-12 keV) favored by the most recent stellar models of the s process. By fitting the data with a multilevel R-matrix code, we determined parameters for 86 resonances in Ba-134 below 11 keV and 92 resonances in Ba-136 below 35 keV. Astrophysical reaction rates were calculated using these parameters together with our cross section data for the unresolved resonance region. Our results for the astrophysical reaction rates are in good agreement with the most recent previous measurement at the classical s-process temperature kT=30 keV, but show significant differences at lower temperatures. We determined that these differences were due to the effect of resonances below the energy range of previous experiments and to the use of incorrect neutron widths in a previous resonance analysis. Our data show that the ratio of reaction rates for these two isotopes depends more strongly on temperature than previous measurements indicated. One result of this temperature dependence is that the mean s-process temperature we derived from a classical analysis of the branching at Cs-134 is too low to be consistent with the temperature derived from other branching points. This inconsistency is evidence for the need for more sophisticated models of the s process beyond the classical model. We used a reaction network code to explore the changes in the calculated isotopic abundances resulting from our new reaction rates for an s-process scenario based on a stellar model. These calculations indicate that the previously observed 20% discrepancy with respect to the solar barium abundance is reduced but not resolved by our new reaction rates. C1 DENISON UNIV,DEPT PHYS,GRANVILLE,OH 43023. RP Koehler, PE (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Koehler, Paul/0000-0002-6717-0771 NR 37 TC 45 Z9 45 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1463 EP 1477 DI 10.1103/PhysRevC.54.1463 PG 15 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900056 ER PT J AU Robinson, SJ Altgilbers, AS Hindi, MM Norman, EB Larimer, RM AF Robinson, SJ Altgilbers, AS Hindi, MM Norman, EB Larimer, RM TI Weak gamma-transition intensities in the electron capture decay of Pm-144 SO PHYSICAL REVIEW C LA English DT Article AB We have determined the absolute intensity of weak gamma transitions in the level scheme of Nd-144, observed following the electron capture decay of Pm-144. The absolute intensity of the 1397-keV E3 branch from the 2093-keV (5(1)(-)) level was determined to he (4.9 +/- 0.7) X 10(-4)%. This leads to a revised absolute transition rate of B(E3;5(1)(-)-->2(1)(+))=26(-12)(+15) Weisskopf units, which is still consistent with an interpretation of the 5(1)(-) level based on quadrupole-octupole coupling. C1 TENNESSEE TECHNOL UNIV,DEPT PHYS,COOKEVILLE,TN 38505. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. NR 6 TC 3 Z9 3 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 SEP PY 1996 VL 54 IS 3 BP 1478 EP 1480 DI 10.1103/PhysRevC.54.1478 PG 3 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900057 ER PT J AU Gyulassy, M Pop, VT Wang, XN AF Gyulassy, M Pop, VT Wang, XN TI Strangeness enhancement in p+A and S+A interactions at energies near 200A GeV - Reply SO PHYSICAL REVIEW C LA English DT Letter ID PARTICLE-PRODUCTION; NUCLEAR COLLISIONS; MODEL; PP AB In this Reply we argue that the factor of 4 enhancement of the local midrapidity densities of Lambda and the strong suppression of Lambda in the projectile fragmentation region in p+S relative to p+p reactions provide strong evidence of nonequilibrium dynamics in strangeness production. Second, we show that the dramatic changes in the Lambda rapidity distributions in pA cannot be attributed to nuclear baryon stopping power. C1 INST SPACE RES,BUCHAREST,ROMANIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Gyulassy, M (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. NR 17 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD SEP PY 1996 VL 54 IS 3 BP 1498 EP 1499 DI 10.1103/PhysRevC.54.1498 PG 2 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900063 ER PT J AU Joss, DT Paul, ES Archer, DE Devlin, M Fallon, P Hibbert, IM LaFosse, DR Nolan, PJ OBrien, NJ Pfohl, J Riley, MA Sarantites, DG Sheline, R Simpson, J Wadsworth, R AF Joss, DT Paul, ES Archer, DE Devlin, M Fallon, P Hibbert, IM LaFosse, DR Nolan, PJ OBrien, NJ Pfohl, J Riley, MA Sarantites, DG Sheline, R Simpson, J Wadsworth, R TI Multiple superdeformed bands in Nd-132 SO PHYSICAL REVIEW C LA English DT Article ID MASS REGION; NUCLEI AB High-spin states have been studied in neutron-deficient Nd-132, produced in the Pd-105(Cl-35,alpha p3n gamma) reaction, using the Gammasphere gamma-ray spectrometer in conjunction with the Microball charged-particle detector array. Three new, weakly populated rotational bands have been found, which are believed to be associated with a superdeformed (second minimum) prolate shape. Comparison of the properties of these bands with Woods-Saxon cranking calculations suggests that they are built upon negative-parity neutron configurations that involve only one intruder orbital (nu i(13/2)) from the N=6 shell. One of the bands has been linked into the normally deformed states allowing an estimation of the spin, parity, and excitation energy of the band. C1 FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. LAWRENCE BERKELEY NATL LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. CCLRC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Joss, DT (reprint author), UNIV LIVERPOOL,OLIVER LODGE LAB,POB 147,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 14 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 SEP PY 1996 VL 54 IS 3 BP R969 EP R972 DI 10.1103/PhysRevC.54.R969 PG 4 WC Physics, Nuclear SC Physics GA VJ469 UT WOS:A1996VJ46900001 ER PT J AU Adams, MR Aid, S Anthony, PL Averill, DA Baker, MD Baller, BR Banerjee, A Bhatti, AA Bratzler, U Braun, HM Carroll, TJ Clark, HL Conrad, JM Davisson, R Derado, I Dietrich, FS Dougherty, W Dreyer, T Eckardt, V Ecker, U Erdmann, M Fang, GY Figiel, J Finlay, RW Gebauer, HJ Geesaman, DF Griffioen, KA Guo, RS Haas, J Halliwell, C Hantke, D Hicks, KH Jackson, HE Jaffe, DE Jancso, G Jansen, DM Jin, Z Kaufman, S Kennedy, RD Kinney, ER Kobrak, HGE Kotwal, AV Kunori, S Lord, JJ Lubatti, HJ McLeod, D Madden, P Magill, S Manz, A Melanson, H Michael, DG Montgomery, HE Morfin, JG Nickerson, RB Novak, J ODay, S Olkiewicz, K Osborne, L Otten, R Papavassiliou, V Pawlik, B Pipkin, FM Potterveld, DH Ramberg, EJ Roser, A Ryan, JJ Salgado, CW Salvarani, A Schellman, H Schmitt, M Schmitz, N Siegert, C Skuja, A Snow, GA Stier, HE Stopa, P Swanson, RA Venkataramania, H Wilhelm, M Wilson, R Wittek, W Wolbers, SA Zghiche, A Zhao, T AF Adams, MR Aid, S Anthony, PL Averill, DA Baker, MD Baller, BR Banerjee, A Bhatti, AA Bratzler, U Braun, HM Carroll, TJ Clark, HL Conrad, JM Davisson, R Derado, I Dietrich, FS Dougherty, W Dreyer, T Eckardt, V Ecker, U Erdmann, M Fang, GY Figiel, J Finlay, RW Gebauer, HJ Geesaman, DF Griffioen, KA Guo, RS Haas, J Halliwell, C Hantke, D Hicks, KH Jackson, HE Jaffe, DE Jancso, G Jansen, DM Jin, Z Kaufman, S Kennedy, RD Kinney, ER Kobrak, HGE Kotwal, AV Kunori, S Lord, JJ Lubatti, HJ McLeod, D Madden, P Magill, S Manz, A Melanson, H Michael, DG Montgomery, HE Morfin, JG Nickerson, RB Novak, J ODay, S Olkiewicz, K Osborne, L Otten, R Papavassiliou, V Pawlik, B Pipkin, FM Potterveld, DH Ramberg, EJ Roser, A Ryan, JJ Salgado, CW Salvarani, A Schellman, H Schmitt, M Schmitz, N Siegert, C Skuja, A Snow, GA Stier, HE Stopa, P Swanson, RA Venkataramania, H Wilhelm, M Wilson, R Wittek, W Wolbers, SA Zghiche, A Zhao, T TI Proton and deuteron structure functions in muon scattering at 470 GeV SO PHYSICAL REVIEW D LA English DT Article ID NUCLEON STRUCTURE FUNCTIONS; STRUCTURE-FUNCTION F2; PARTON DISTRIBUTIONS; CROSS-SECTIONS; LOW Q2; REGION; PARAMETRIZATION; EXTRACTION; HYDROGEN; HERA AB The proton and deuteron structure functions F-2(p) and F-2(d) are measured in inelastic muon scattering with an average beam energy of 470 GeV. The data were taken at Fermilab experiment E665 during 1991 and 1992 using liquid hydrogen and deuterium targets. The F-2 measurements are reported in the range 0.0008Ze SO PHYSICAL REVIEW D LA English DT Article ID W-BOSON MASS; TOP-QUARK; COLLISIONS; MOMENTS AB We extend our previous analysis of the sensitivity of the energy dependence of the polarization asymmetry in gamma e-->W nu to the possible existence of anomalous trilinear gauge couplings to the gamma e-->Ze case. We find that by combining the constraints imposed by both the energy dependence of the total cross section and polarization asymmetry, strong limits on the anomalous gamma ZZ couplings are obtainable at the Next Linear Collider. Further constraints obtained from a consideration of the angular distribution are briefly discussed. RP Rizzo, TG (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 41 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3057 EP 3064 DI 10.1103/PhysRevD.54.3057 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800004 ER PT J AU Berger, EL Contopanagos, H AF Berger, EL Contopanagos, H TI Perturbative resummed series for top quark production in hadron reactions SO PHYSICAL REVIEW D LA English DT Article ID PRINCIPAL-VALUE RESUMMATION; PRODUCTION CROSS-SECTION; POWER CORRECTIONS; QCD CORRECTIONS; EVENT SHAPES; COLLISIONS; EXPANSIONS AB Our calculation of the total cross section for inclusive production of pairs in hadron collisions is presented. The principal ingredient of the calculation is resummation of the universal leading-logarithm effects of gluon radiation to all orders in the quantum chromodynamics coupling strength, restricted to the region of phase space that is demonstrably perturbative. We derive the perturbative regime of the resummed series, starting from the principal-value resummation approach, and we isolate the perturbative domain in both moment space and, upon inversion of the corresponding Mellin transform, in momentum space. We show that our perturbative result does not depend on the manner nonperturbative or infrared effects are handled in principal-value resummation. We treat both the quark-antiquark and gluon-gluon production channels consistently in the <(MS)over bar> factorization scheme. We compare our method and results with other resummation methods that rely on the choice of infrared cutoffs. We derive the renormalization or factorization scale dependence of our resummed cross section, and we discuss factorization scheme dependence and remaining theoretical uncertainties, including estimates of possible nonperturbative contributions. We include the full content of the exact next-to-leading order calculation in obtaining our final results. We present predictions of the physical cross section as a function of top quark mass in proton-antiproton reactions at center-of-mass energies of 1.8 and 2.0 TeV. We also provide the differential cross section as a function of the parton-parton subenergy. RP Berger, EL (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 36 TC 118 Z9 118 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3085 EP 3113 DI 10.1103/PhysRevD.54.3085 PG 29 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800007 ER PT J AU Quack, E Henning, PA AF Quack, E Henning, PA TI Photon production from a quark-gluon plasma SO PHYSICAL REVIEW D LA English DT Article ID SUPER PROTON SYNCHROTRON; HEAVY-ION COLLISIONS; JONA-LASINIO MODEL; HOT GAUGE-THEORIES; FIELD-THEORY; FINITE TEMPERATURE; PHASE-TRANSITION; QCD PREDICTIONS; TRANSVERSE FLOW; GREEN-FUNCTIONS AB In-medium interactions of a particle in a hot plasma are considered in the framework of thermal held theory. The formalism to calculate gauge-invariant rates for photon and dilepton production from the medium is given. In the application to a QED plasma, astrophysical consequences are pointed out. The photon production rate from strongly interacting quarks in the quark-gluon plasma, which might be formed in ultrarelativistic heavy ion collisions, is calculated in the previously unaccessible regime of photon energies of the order of the plasma temperature. For temperatures below the chiral phase transition, an effective field theory incorporating dynamical chiral symmetry breaking is employed, and perturbative QCD at higher temperatures. A smooth transition between both regions is obtained. The relevance to the soft photon problem and to high energy heavy ion experiments is discussed. C1 GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. RP Quack, E (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,THEORY GRP,POB 4349,STANFORD,CA 94309, USA. NR 63 TC 10 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3125 EP 3136 DI 10.1103/PhysRevD.54.3125 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800009 ER PT J AU Dimopoulos, S Thomas, S Wells, JD AF Dimopoulos, S Thomas, S Wells, JD TI Implications of low energy supersymmetry breaking at the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID TECHNICOLOR AB The signatures for low energy supersymmetry breaking at the Fermilab Tevatron are investigated. It is natural that the lightest standard model superpartner is an electroweak neutralino, which decays to an essentially massless Goldstino and photon, possibly within the detector. In the simplest model of gauge-mediated supersymmetry breaking, the production of right-handed sleptons, neutralinos, and charginos leads to a pair of hard photons accompanied by leptons and/or jets with missing transverse energy. The relatively hard leptons and softer photons of the single e(+)e(-)gamma gamma+E(T) event observed by CDF implies this event is best interpreted as e arising from left-handed slepton pair production. In this case the rates for l(+/-)gamma gamma+E(T) and gamma gamma+E(T) are comparable to that for l(+)l(-)gamma gamma+E(T). C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Dimopoulos, S (reprint author), CERN,DIV THEORET PHYS,CH-1211 GENEVA 23,SWITZERLAND. NR 28 TC 105 Z9 105 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3283 EP 3288 DI 10.1103/PhysRevD.54.3283 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800023 ER PT J AU Atwood, D Reina, L Soni, A AF Atwood, D Reina, L Soni, A TI R(b) and R(c) in the two-Higgs-doublet model with flavor-changing neutral currents SO PHYSICAL REVIEW D LA English DT Article ID BBAR-MESON DECAY; TOP-QUARK; QCD-CORRECTIONS; RADIATIVE-CORRECTIONS; B->SG DECAYS; WEAK-SCALE; B->S-GAMMA; MASS; REGULARIZATION; COLLIDERS AB A study of R(b) and R(c) is presented in the context of a two-Higgs-doublet model with flavor-changing scalar currents (FCSC's). Implications of the model for the rho parameter and for b-->s gamma are also considered. The experimental data on R(b) places stringent constraints on the model parameters that are difficult to reconcile with the constraints from b-->s gamma and rho. If we treat the couplings of the model as purely phenomenological, then the model can still survive albeit in a rather narrow region of the parameter space. Noting that aspects of the experimental analysis for R(b) and R(c) may be of some concern, we also disregard R(b)(expt) and R(c)(expt) and give predictions for these using constraints from b-->s gamma and the rho parameter only. We emphasize the theoretical and experimental advantages of the observable R(b+c)=Gamma(Z-->b (b) over bar or c (c) over bar/Gamma(Z--> hadrons). We also stress the role of R(l)=Gamma(Z--> hadrons)/Gamma(Z-->l(+)l(-)) in testing the standard model despite its dependence on QCD corrections. Noting that in models with FCNC's the amplitude for Z-->c (c) over bar receives a contribution which grows with m(t)(2) the importance and uniqueness of precision Z-->c (c) over bar measurements for constraining flavor-changing t (c) over bar currents is underscored. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Atwood, D (reprint author), SE UNIV RES ASSOC,CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL,THEORY GRP,NEWPORT NEWS,VA 23606, USA. NR 56 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3296 EP 3308 DI 10.1103/PhysRevD.54.3296 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800025 ER PT J AU Greub, C Hurth, T Wyler, D AF Greub, C Hurth, T Wyler, D TI Virtual O(alpha(s)) corrections to the inclusive decay b->s gamma SO PHYSICAL REVIEW D LA English DT Article ID RARE B-DECAYS; RENORMALIZED GREENS FUNCTIONS; PHOTON ENERGY-SPECTRUM; MASSLESS PARTICLES; MESON DECAY; QCD; B->X(S)+GAMMA; B->SG AB We present in detail the calculation of the O(alpha(s)) virtual corrections to the matrix element for b-->s gamma. In addition to the one-loop virtual corrections of the electromagnetic and color dipole operators O-7 and O-8, we include the important two-loop contribution of the four-Fermi operator O-2. By applying the Mellin-Barnes representation to certain internal propagators, the result of the two-loop diagrams is obtained analytically as an expansion in m(c)/m(b). These results are then combined with existing O(alpha(s)) bremsstrahlung corrections in order to obtain the inclusive rate for B-->X(s) gamma. The new contributions drastically reduce the large renormalization scale dependence of the leading logarithmic result. Thus, a very precise standard model prediction for this inclusive process will become possible once the corrections to the Wilson coefficients are also available. C1 UNIV ZURICH,INST THEORET PHYS,CH-8057 ZURICH,SWITZERLAND. RP Greub, C (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 48 TC 226 Z9 226 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3350 EP 3364 DI 10.1103/PhysRevD.54.3350 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800030 ER PT J AU Suzuki, M AF Suzuki, M TI Analytic study of disoriented chiral condensates SO PHYSICAL REVIEW D LA English DT Article ID HIGH-ENERGY; COLLISIONS; DOMAINS; FIELD AB By introducing a quark source in the nonlinear a model, we obtain an analytic boost-invariant solution as a candidate for the disoriented chiral condensate (DCC) in 3+1 dimensions. In order to trigger formation of the DCC, a strong transfer of axial isospin charge must occur between the expanding source and the interior in the baked Alaska scenario. An explicit chiral symmetry breaking is incorporated in the solution by connecting the decay period to the formation period. Quantitative estimates are presented with our simple solution. At least in this class of solutions, the explicit symmetry breaking masks almost completely the disorientation which would be reached asymptotically in the symmetric limit. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Suzuki, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 22 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP 3556 EP 3562 DI 10.1103/PhysRevD.54.3556 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800051 ER PT J AU Pisarski, RD Tytgat, M AF Pisarski, RD Tytgat, M TI Propagation of cool pions SO PHYSICAL REVIEW D LA English DT Article ID FINITE-TEMPERATURE; NUCLEAR-MATTER; EFFECTIVE LAGRANGIANS; CORRELATORS; DISPERSION; DILEPTONS; DYNAMICS; VECTOR; MESONS; FIELD AB For an exact chiral symmetry that is spontaneously broken at zero temperature, we show that, at nonzero temperature, generally pions travel at less than the speed of light. This effect first appears at next-to-leading order in an expansion around low temperature. When the chiral symmetry is approximate we obtain two formulas, like that of Gell-Mann, Oakes, and Renner, for the static and dynamic pion masses. RP Pisarski, RD (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 39 TC 81 Z9 81 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 1 PY 1996 VL 54 IS 5 BP R2989 EP R2993 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VF928 UT WOS:A1996VF92800001 ER PT J AU Luscombe, JH Luban, M AF Luscombe, JH Luban, M TI Nonequilibrium structure factor for conserved spin dynamics: Abrupt temperature increase SO PHYSICAL REVIEW E LA English DT Article ID KINETIC ISING-MODEL; RENORMALIZATION-GROUP; DISORDERING KINETICS; PHASE-SEPARATION; GROWTH-KINETICS; ONE DIMENSION; SYSTEMS; DECOMPOSITION; DIFFUSION AB We consider the nonequilibrium, elastic-scattering structure factor S(q,t) (q denotes the wave vector, t the time), for the Kawasaki spin-conserving kinetic Ising model of a one-dimensional system with nearest neighbor interactions, initially in equilibrium at temperature T-I, that is suddenly placed in contact with a heat hath at temperature T-F, with T-F much greater than T-I. We present detailed results for the case of T-F = infinity, for which we have succeeded in calculating the exact form of S(q,t). For finite T-F, we present an approximation scheme far the higher-order nonequilibrium correlation functions that leads to closure of the hierarchy of equations of motion. The merits of this approximation are that (i) S(q,t) is guaranteed to satisfy an exact sum rule over the Brillouin zone (BZ) of wave vectors q, and (ii) S(q,t) evolves to the correct value in the long-time limit. For antiferromagnetic coupling, the structure factor, initially dominated by the Bragg peak associated with T-I at the edge of the BZ, decays exponentially with time, e(-t/tau q) while approximately preserving its shape in q space, since the lifetime tau(q) is nearly independent of q. Except near the center of the BZ, after the Bragg peak has decayed sufficiently, the dependence of S(q,t) on q can be characterized as though the spins rapidly quasiequilibrate to the equilibrium structure factor associated with T-F, chi(q,T-F), in that S(q,t)/chi(q,T-F) is independent of q, but is time dependent, slowly approaching unity as t(-1/2) for large t. For q approximate to 0 the initial form. of S remains in effect until the value of t is of order q(-2). For ferromagnetic coupling, the initial Bragg peak for q approximate to 0 does not preserve its shape while decaying exponentially since the lifetime tau(q) strongly depends on the wave-vector q, diverging as q(-2) for q --> 0, and, in particular, It is as though the spins for q approximate to 0 remain ''frozen'' at T-I. Analogous to the behavior for antiferromagnetic interactions, away from the center of the BZ, we find that S(q,t)/chi/(q,T-F) is independent of q and is a function of t/t(w), very slowly approaching unity. The characteristic ''waiting time'' t(w) is anomalously long, proportional to xi(2), where xi is the equilibrium correlation length at temperature T-t. This behavior of t(w) can be related to the random walk of domain boundaries. C1 IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP USN, POSTGRAD SCH, DEPT PHYS, MONTEREY, CA 93943 USA. NR 59 TC 2 Z9 2 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 2266 EP 2290 DI 10.1103/PhysRevE.54.2266 PG 25 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500021 ER PT J AU Rintoul, MD Torquato, S Yeong, C Keane, DT Erramilli, S Jun, YN Dabbs, DM Aksay, IA AF Rintoul, MD Torquato, S Yeong, C Keane, DT Erramilli, S Jun, YN Dabbs, DM Aksay, IA TI Structure and transport properties of a porous magnetic gel via x-ray microtomography SO PHYSICAL REVIEW E LA English DT Article ID DIFFUSION-CONTROLLED REACTIONS; RANDOM HETEROGENEOUS MATERIALS; 2-PHASE RANDOM-MEDIA; LINEAL-PATH FUNCTION; FLUID PERMEABILITY; MATHEMATICAL FORMULATION; VARIATIONAL-PRINCIPLES; RELAXATION-TIMES; RIGOROUS BOUNDS; COMPOSITES AB A three-dimensional digitized image of a porous magnetic gel is determined by x-ray microtomographic techniques. The complex connected pore-space topology is quantitatively characterized by measuring a variety of statistical correlation functions, including the chord-length distribution function, the pore-size distribution function, and the Lineal-path function. This structural information is then employed to estimate transport properties, such as the fluid permeability and trapping rate, of the gel. C1 PRINCETON UNIV,PRINCETON MAT INST,PRINCETON,NJ 08540. ARGONNE NATL LAB,DUPONT NW DOW COLLABORAT ACCESS TEAM SYNCHROTORN,ARGONNE,IL 60439. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. RP Rintoul, MD (reprint author), PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544, USA. RI Dabbs, Daniel/B-9276-2008; Aksay, Ilhan/B-9281-2008 NR 43 TC 68 Z9 72 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 2663 EP 2669 DI 10.1103/PhysRevE.54.2663 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500068 ER PT J AU Kwon, I Collins, L Kress, J Troullier, N AF Kwon, I Collins, L Kress, J Troullier, N TI Electrical conductivities for hot, dense hydrogen SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; SOLID HYDROGEN; TRANSPORT-PROPERTIES; METALLIC HYDROGEN; GROUND-STATE; PLASMA; EQUATION; PSEUDOPOTENTIALS; TRANSITIONS; MODELS AB We report electrical conductivities for a hydrogen plasma at temperatures between a few tenths to a few tens of electron volts and densities ranging from 0.3 to 3 g/cm(3). The ac conductivities were determined within the Kubo-Greenwood formulation based on eigenstates from 3 finite-temperature density functional calculation at selected time steps along a lengthy molecular-dynamics (MD) simulation trajectory. Density functional, tight-binding, and effective pair potentials were employed in the MD simulations for samples of 50 to 250 atoms within a periodically replicated reference cell. We compare with other techniques and discuss trends with density and temperature. Good agreement results at the higher temperatures and densities with generalized Ziman forms. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. IBM CORP,ALMADEN RES CTR,STSS,SAN JOSE,CA 95120. NR 59 TC 34 Z9 34 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 2844 EP 2851 DI 10.1103/PhysRevE.54.2844 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500090 ER PT J AU Heifets, SA AF Heifets, SA TI Microwave instability beyond threshold SO PHYSICAL REVIEW E LA English DT Article AB Stability of the steady-state bunch distribution described by the Haissinski solution [J. Haissinski, Nuovo Cimento 18B, 72 (1973)] is studied above the threshold of microwave instability. It is shown that instability may lead to a new self-consistent state corresponding to particles trapped in a separatrix of an unstable mode. The free energies of the two solutions are compared. The relaxation oscillations between the new and Haissinski solutions are possible and may be related to the sawtooth instability observed recently in the experiments [P. Krejcik et al., (unpublished)]. RP Heifets, SA (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 12 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 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 2889 EP 2898 DI 10.1103/PhysRevE.54.2889 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500095 ER PT J AU Feng, X Holzscheiter, MH Charlton, M Cverna, F Ichioka, T King, NSP Lewis, RA Morgan, GL Rochet, J Yamazaki, Y AF Feng, X Holzscheiter, MH Charlton, M Cverna, F Ichioka, T King, NSP Lewis, RA Morgan, GL Rochet, J Yamazaki, Y TI Ultralow-energy antiprotons for antihydrogen spectroscopy and antimatter gravity SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 3rd International Conference on Nucleon-Antinucleon Physics CY SEP 11-16, 1995 CL INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA SP Russian Acad Sci, Dept Nucl Phys, Russian Fdn Basic Res, Inst Theoret & Exptl Phys, Int Sci Fdn, INFN, Lab Nazl Frascati, Italy HO INST THEORET & EXPTL PHYS AB Approximately one million antiprotons have been captured in a large-scale Penning trap at the Low Energy Antiproton Ring (LEAR) at CERN. Up to 65% of the captured antiprotons have subsequently been electron cooled to energies below 1 eV and have been stored up to one hour This has opened new discussions of the possible use of ultralow-energy antiprotons for gravitational physics, as well as for precision spectroscopy of antihydrogen for CPT tests. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. UNIV LONDON UNIV COLL,DEPT PHYS & ASTRON,LONDON WC1E 6BT,ENGLAND. UNIV TOKYO,INST PHYS,TOKYO 153,JAPAN. PENN STATE UNIV,OSMOND LAB,UNIVERSITY PK,PA 16802. RP Feng, X (reprint author), AARHUS UNIV,DEPT PHYS & ASTRON,DK-8000 AARHUS C,DENMARK. RI Yamazaki, Yasunori/N-8018-2015 OI Yamazaki, Yasunori/0000-0001-5712-0853 NR 12 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD SEP PY 1996 VL 59 IS 9 BP 1492 EP 1496 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VJ078 UT WOS:A1996VJ07800002 ER PT J AU Kamyshkov, YA Bugg, WM Cohn, HO Condo, GT Efremenko, YV Lamoreaux, SK Lillie, RA Plasil, F Raman, S Rennich, MJ Shmakov, KD Wilson, R Young, GR AF Kamyshkov, YA Bugg, WM Cohn, HO Condo, GT Efremenko, YV Lamoreaux, SK Lillie, RA Plasil, F Raman, S Rennich, MJ Shmakov, KD Wilson, R Young, GR TI Future prospects for neutron->antineutron transition searches SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 3rd International Conference on Nucleon-Antinucleon Physics CY SEP 11-16, 1995 CL INST THEORET & EXPTL PHYS, MOSCOW, RUSSIA SP Russian Acad Sci, Dept Nucl Phys, Russian Fdn Basic Res, Inst Theoret & Exptl Phys, Int Sci Fdn, INFN, Lab Nazl Frascati, Italy HO INST THEORET & EXPTL PHYS ID NEUTRON-ANTINEUTRON OSCILLATIONS; NUCLEI; STABILITY; LIMITS; TIME AB An ORNL-UTK-UW-Harvard group is exploring the possibility of performing a new experiment to search for neutron-antineutron transitions either at the ORNL HFIR reactor or at a new proposed neutron spallation source. The advanced layout, based on a large mirror focusing reflector proposed for this experiment, should allow improving the discovery potential of searches for an n --> (n) over bar transition by 3 to 4 orders of magnitude in relation to the most recent similar experiment at ILL-Grenoble, It should be possible to establish a limit on the characteristic transition time of tau() > 10(10) s. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. WASHINGTON UNIV,SEATTLE,WA 98195. HARVARD UNIV,CAMBRIDGE,MA 02138. RP Kamyshkov, YA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Kamyshkov, Yuri/J-7999-2016; OI Kamyshkov, Yuri/0000-0002-3789-7152; Rennich, Mark/0000-0001-6945-0075 NR 26 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 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD SEP PY 1996 VL 59 IS 9 BP 1554 EP 1557 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VJ078 UT WOS:A1996VJ07800011 ER EF