FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Armstrong, TA Barish, KN Bennett, SJ Chikanian, A Coe, SD Cormier, TM Davies, R DeCataldo, G Dee, P Diebold, GE Dover, CB Fachini, P Finch, LE George, NK Giglietto, N Greene, SV Haridas, P Hill, JC Hirsch, AS Hoversten, R Huang, HZ Kim, B Kumar, BS Lainis, T Lajoie, JG Lewis, RA Libby, B Majka, RD Munhoz, MG Nagle, JL Pless, IA Pope, JK Porile, NT Pruneau, CA Rabin, MSZ Raino, A Reid, JD Rimai, A Rotondo, FS Sandweiss, J Scharenberg, RP Slaughter, AJ Smith, GA Spinelli, P Tincknell, ML Toothacker, WS VanBuren, G Wohn, FK Xu, Z Zhao, K AF Armstrong, TA Barish, KN Bennett, SJ Chikanian, A Coe, SD Cormier, TM Davies, R DeCataldo, G Dee, P Diebold, GE Dover, CB Fachini, P Finch, LE George, NK Giglietto, N Greene, SV Haridas, P Hill, JC Hirsch, AS Hoversten, R Huang, HZ Kim, B Kumar, BS Lainis, T Lajoie, JG Lewis, RA Libby, B Majka, RD Munhoz, MG Nagle, JL Pless, IA Pope, JK Porile, NT Pruneau, CA Rabin, MSZ Raino, A Reid, JD Rimai, A Rotondo, FS Sandweiss, J Scharenberg, RP Slaughter, AJ Smith, GA Spinelli, P Tincknell, ML Toothacker, WS VanBuren, G Wohn, FK Xu, Z Zhao, K TI Search for exotic strange quark matter in high energy nuclear reactions SO NUCLEAR PHYSICS A LA English DT Article DE strangelet; strange quark matter; relativistic heavy ions; quark-gluon plasma; phase transition ID HEAVY-ION COLLISIONS; HADRONIC MATTER; H DIBARYON; GEV/C SI; PARTICLES; SEPARATION; DROPLETS; PHASES; DECAY AB We report on a search for metastable positively and negatively charged states of strange quark matter in Au + Pb reactions at 11.6 A GeV/c in experiment E864. We have sampled approximately six billion 10% most central Au + Pb interactions and have observed no strangelet states (baryon number A < 100 droplets of strange quark matter). We thus set upper limits on the production of these exotic states at the level of 1-6 x 10(-8) per central collision. These limits are the best and most model independent for this colliding system. We discuss the implications of our results on strangelet production mechanisms, and also on the stability question of strange quark matter. (C) 1997 Elsevier Science B.V. C1 UNIV BARI,IST NAZL FIS NUCL,BARI,ITALY. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. IOWA STATE UNIV,AMES,IA 50011. MIT,AMHERST,MA 02139. PURDUE UNIV,W LAFAYETTE,IN 47907. US MIL ACAD,W POINT,NY 10996. VANDERBILT UNIV,NASHVILLE,TN 37235. WAYNE STATE UNIV,DETROIT,MI 48201. YALE UNIV,NEW HAVEN,CT 06520. UNIV MASSACHUSETTS,AMHERST,MA 01003. RP Armstrong, TA (reprint author), PENN STATE UNIV,UNIVERSITY PK,PA 16802, USA. RI giglietto, nicola/I-8951-2012; OI giglietto, nicola/0000-0002-9021-2888; SPINELLI, Paolo/0000-0001-6688-8864 NR 34 TC 21 Z9 21 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 OCT 27 PY 1997 VL 625 IS 1-2 BP 494 EP 512 DI 10.1016/S0375-9474(97)00399-0 PG 19 WC Physics, Nuclear SC Physics GA YJ902 UT WOS:A1997YJ90200024 ER PT J AU Hori, K Ooguri, H Vafa, C AF Hori, K Ooguri, H Vafa, C TI Non-Abelian conifold transitions and N=4 dualities in three dimensions SO NUCLEAR PHYSICS B LA English DT Article ID STRING THEORY; MIRROR SYMMETRY; MODULI SPACE; BLACK-HOLE; MANIFOLDS; SINGULARITIES; VACUA; QCD AB We show how the Higgs mechanism for non-Abelian N = 2 gauge theories in four dimensions is geometrically realized in the context of type II strings as transitions among compactifications of Calabi-Yau 3-folds. We use this result and T-duality of a further compactification on a circle to derive N = 4, d = 3 dual field theories. This reduces the dualities for N = 4 gauge systems in three dimensions to perturbative symmetries of string theory. Moreover, we find that the dual of a gauge system always exists but may or may not correspond to a Lagrangian system. In particular, we verify a conjecture of Intriligator and Seiberg that an ordinary gauge system is dual to compactification of exceptional tensionless string theory down to three dimensions. (C) 1997 Elsevier Science B.V. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720. HARVARD UNIV,LYMAN LAB PHYS,CAMBRIDGE,MA 02138. RP Hori, K (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,366 LE CONTE HALL,BERKELEY,CA 94720, USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 63 TC 30 Z9 30 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 OCT 27 PY 1997 VL 504 IS 1-2 BP 147 EP 174 DI 10.1016/S0550-3213(97)00529-4 PG 28 WC Physics, Particles & Fields SC Physics GA YE123 UT WOS:A1997YE12300007 ER PT J AU Kim, N Rey, SJ AF Kim, N Rey, SJ TI M(atrix) theory on an orbifold and twisted membrane SO NUCLEAR PHYSICS B LA English DT Article ID INFINITE-DIMENSIONAL ALGEBRAS; AREA-PRESERVING DIFFEOMORPHISMS; BRANES AB M(atrix) theory on an orbifold and classical two-branes therein are studied with particular emphasis on heterotic M(atrix) theory on S-1/Z(2) relevant to strongly coupled heterotic and dual Type IA string theories. By analyzing the orbifold condition on Chan-Paton factors, we show that three choices of gauge group are possible for heterotic M(atrix) theory: SO(2N), SO(2N + 1) or USp(2N). By examining the area-preserving diffeomorphism that underlies the M(atrix) theory, we find that each choice of gauge group restricts the possible topologies of two-branes. The result suggests that only the choice of SO(2N) or SO(2N + 1) allows open two-branes, and hence, is relevant to heterotic M(atrix) theory. We show that the requirement of both local vacuum energy cancellation and of world-sheet anomaly cancellation of the resulting heterotic string identifies supersymmetric twisted sector spectra with sixteen fundamental representation spinors from each of the two fixed points. Twisted open and closed two-brane configurations are obtained in the large N limit. (C) 1997 Published by Elsevier Science B.V. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Kim, N (reprint author), SEOUL NATL UNIV,DEPT PHYS,SEOUL 151742,SOUTH KOREA. OI Rey, Soo-Jong/0000-0002-2589-7331 NR 32 TC 50 Z9 50 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD OCT 27 PY 1997 VL 504 IS 1-2 BP 189 EP 213 DI 10.1016/S0550-3213(97)00513-0 PG 25 WC Physics, Particles & Fields SC Physics GA YE123 UT WOS:A1997YE12300009 ER PT J AU Fu, X Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miao, T Miller, DH Modesitt, M Shibata, EI Shipsey, IPJ Wang, PN Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Dominick, J Fadeyev, V Korolkov, I Lambrecht, M Sanghera, S Shelkov, V Stroynowski, R Volobouev, I Wei, G Artuso, M Efimov, A Gao, M Goldberg, M He, D Horwitz, N Kopp, S Moneti, GC Mountain, R Mukhin, Y Playfer, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Pomianowski, P Schrenk, S Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Palmer, M Selen, M Thaler, JJ Edwards, KW McLean, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB Patel, PM Spaan, B Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Kubota, Y Lattery, M Nelson, JK Patton, S Poling, R Riehle, T Savinov, V Alam, MS Kim, IJ Ling, Z Mahmood, AH ONeill, JJ Severini, H Sun, CR Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM AF Fu, X Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miao, T Miller, DH Modesitt, M Shibata, EI Shipsey, IPJ Wang, PN Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Dominick, J Fadeyev, V Korolkov, I Lambrecht, M Sanghera, S Shelkov, V Stroynowski, R Volobouev, I Wei, G Artuso, M Efimov, A Gao, M Goldberg, M He, D Horwitz, N Kopp, S Moneti, GC Mountain, R Mukhin, Y Playfer, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Pomianowski, P Schrenk, S Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Palmer, M Selen, M Thaler, JJ Edwards, KW McLean, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB Patel, PM Spaan, B Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Kubota, Y Lattery, M Nelson, JK Patton, S Poling, R Riehle, T Savinov, V Alam, MS Kim, IJ Ling, Z Mahmood, AH ONeill, JJ Severini, H Sun, CR Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM TI Observation of exclusive B decays to final states containing a charmed baryon SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANTIBARYON PAIRS; MESON DECAYS AB Using data collected in the region of the Upsilon(4S) resonance with the CLEO-II detector, we report on the first observation of exclusive decays of the B meson to final states with a charmed baryon. We have measured the branching fractions B(B- --> Lambda(c)(+)(p) over bar pi(-)) = (0.62(-0.20)(+0.23) +/- 0.11 +/- 0.10) X 10(-3) and B((B) over bar(0) --> Lambda(c)(+)(p) over bar pi(+)pi(-)) = (1.33(-0.42)(+0.46) +/- 0.31 +/- 0.21) X 10(-3), where the first error is statistical, the second is systematic, and the third is due to uncertainty in the Lambda(c)(+) branching fractions. In addition, we report upper limits for final states of the form (B) over bar --> Lambda(c)(+)(p) over bar(n pi) and Lambda(c)(+)(p) over bar(n pi)pi(0), where (n pi) denotes up to four charged pions. [S0031-9007(97)04176-8]. C1 PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. INST PARTICLE PHYS,MONTREAL,PQ,CANADA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. RP Fu, X (reprint author), UNIV OKLAHOMA,NORMAN,OK 73019, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; OI Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674 NR 11 TC 22 Z9 22 U1 2 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 OCT 27 PY 1997 VL 79 IS 17 BP 3125 EP 3129 DI 10.1103/PhysRevLett.79.3125 PG 5 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200008 ER PT J AU He, YD AF He, YD TI Search for a Dirac magnetic monopole in high energy nucleus-nucleus collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; IONIZING PARTICLES; PAIR PRODUCTION; FIELD-THEORY; COLLIDER; DETECTOR; LIMITS AB A new technique based on barium phosphate glass detectors was used in searching for Dirac pointlike magnetic monopoles with n greater than or equal to 2 in ultrarelativistic heavy ion collisions. No candidates were found in 1.05 x 10(9) and 3.08 x 10(10) interactions of 11A GeV Au nuclei and 1.46 x 10(10) interactions of 160A GeV Pb nuclei with Pb targets. The upper limits, on order of nb, on the production cross sections for Dirac magnetic monopoles and other hypothetical highly ionizing objects are well below those predicted via the Drell-Yan mechanism. [S0031-9007(97)04267-1]. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP He, YD (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 26 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 27 PY 1997 VL 79 IS 17 BP 3134 EP 3137 DI 10.1103/PhysRevLett.79.3134 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200010 ER PT J AU Pai, WW Swan, AK Zhang, ZY Wendelken, JF AF Pai, WW Swan, AK Zhang, ZY Wendelken, JF TI Island diffusion and coarsening on metal (100) surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID CLUSTER DIFFUSION; BROWNIAN-MOTION; VACANCY CLUSTERS; AG(111); FLUCTUATIONS; SIMULATIONS; MECHANISMS; DYNAMICS; DEFECTS; ADATOM AB The diffusion and coarsening of two-dimensional homoepitaxial islands on Cu(100) and Ag(100) surfaces have been studied at room temperature with time-sequenced scanning tunneling microscopy. Quantitative analyses of the dependence of island diffusion coefficient D vs the island side length L, D proportional to L-alpha, yield noninteger scaling exponents which are consistent with island coalescence. Moreover, the near absence of island decay shows that the island diffusion occurs via mass transport along the island periphery. RP Pai, WW (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 187 Z9 189 U1 3 U2 19 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 OCT 27 PY 1997 VL 79 IS 17 BP 3210 EP 3213 DI 10.1103/PhysRevLett.79.3210 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200029 ER PT J AU Ju, HL Sohn, HC Krishnan, KM AF Ju, HL Sohn, HC Krishnan, KM TI Evidence for O-2p hole-driven conductivity in La1-xSrxMnO3 (0<=x<=0.7) and La0.7Sr0.3MnOz thin films SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-ABSORPTION; GIANT MAGNETORESISTANCE; ELECTRONIC-STRUCTURE; SPECTROSCOPY; TRANSITIONS; OXIDES; STATES AB Oxygen K-edge electron-energy-loss spectra have been measured for La1-xSrxMnO3 (0 less than or equal to x less than or equal to 0.7) and La0.7Sr0.3MnOz thin films as a function of x and z. The spectra show a prepeak at the Fermi level, corresponding to transitions to empty states in the O-2p band, at the threshold of the K edge around 529 eV. This prepeak systematically increases with an increase in conductivity through divalent doping (x) or oxygen content (z). This confirms that these materials are charge-transfer-type oxides with carriers having significant oxygen 2p hole character. We argue that, the double exchange mechanism has to include the role of oxygen hole density to satisfactorily describe their transport properties. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Kim, youngjae/I-7780-2012 NR 24 TC 113 Z9 115 U1 2 U2 8 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 OCT 27 PY 1997 VL 79 IS 17 BP 3230 EP 3233 DI 10.1103/PhysRevLett.79.3230 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200034 ER PT J AU Stohlker, T Bosch, F Gallus, A Kozhuharov, C Menzel, G Mokler, PH Prinz, HT Eichler, J Ichihara, A Shirai, T Dunford, RW Ludziejewski, T Rymuza, P Stachura, Z Swiat, P Warczak, A AF Stohlker, T Bosch, F Gallus, A Kozhuharov, C Menzel, G Mokler, PH Prinz, HT Eichler, J Ichihara, A Shirai, T Dunford, RW Ludziejewski, T Rymuza, P Stachura, Z Swiat, P Warczak, A TI Strong alignment observed for the time-reversed photoionization process studied in relativistic collisions with bare uranium ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATIVE ELECTRON-CAPTURE; ATOMIC-COLLISIONS; ANGULAR-DISTRIBUTIONS; X-RAYS; POLARIZATION AB In high-energy atomic collisions between bare high-Z projectiles and low-Z target atoms, an electron may be captured radiatively into an excited projectile state which subsequently decays by x-ray emission. This process is the inverse of two-photon-one-electron ionization, in which the first photon resonantly excites an electron from the hydrogenic 1s(1/2) ground state and a second photon ionizes the excited electron. We present an experimental and theoretical study of the angular distribution of the Ly-alpha(1) (2p(3/2) --> 1s(1/2)) x rays following radiative electron capture. From the observed anisotropic emission pattern a significant alignment of the intermediate 2p(3/2) state is deduced. C1 GESELL SCHWERIONENFORSCH MBH, D-64220 DARMSTADT, GERMANY. HAHN MEITNER INST BERLIN GMBH, BEREICH THEORET PHYS, D-14109 BERLIN, GERMANY. FREE UNIV BERLIN, FACHBEREICH PHYS, D-14195 BERLIN, GERMANY. JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI 31911, JAPAN. ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. INST NUCL STUDIES, PL-05400 OTWOCK, POLAND. INST NUCL PHYS, PL-31342 KRAKOW, POLAND. JAGIELLONIAN UNIV, INST PHYS, PL-30059 KRAKOW, POLAND. RP UNIV FRANKFURT, INST KERNPHYS, D-60486 FRANKFURT, GERMANY. NR 15 TC 55 Z9 55 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 27 PY 1997 VL 79 IS 17 BP 3270 EP 3273 DI 10.1103/PhysRevLett.79.3270 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200044 ER PT J AU Lee, I Lee, JW Greenbaum, E AF Lee, I Lee, JW Greenbaum, E TI Biomolecular electronics: Vectorial arrays of photosynthetic reaction centers SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOSYSTEM-I; MOLECULAR ELECTRONICS; PLATINIZATION; RECTIFICATION; CHLOROPLASTS; MICROSCOPY; P700 AB Two-dimensional vectorial arrays of functional Photosystem I reaction centers have been prepared on atomically flat derivatized gold surfaces. The nature and extent of orientation were controlled by chemical modification of the surface derivative. For mercaptoacetic acid, 83% of the electron transport vectors were parallel to the surface, whereas with 2-mercaptoethanol 70% were oriented perpendicularly in the ''up'' position and only 2% were in the ''down'' position. No preferential orientation was observed with 2-dimethylaminoethanethiol. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. NR 21 TC 123 Z9 124 U1 4 U2 26 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 27 PY 1997 VL 79 IS 17 BP 3294 EP 3297 DI 10.1103/PhysRevLett.79.3294 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200050 ER PT J AU Aranson, I Tsimring, L Vinokur, V AF Aranson, I Tsimring, L Vinokur, V TI Evolution on a rugged landscape: Pinning and aging SO PHYSICAL REVIEW LETTERS LA English DT Article ID FITNESS; DYNAMICS; MODEL AB Population dynamics on a rugged landscape is studied analytically and numerically. The dynamics of the population is described in terms of Langevin diffusion of a single particle in a specific random environment. The randomness in the mutation rate leads to population pinning and to a logarithmic slowdown of the evolution, resembling aging phenomenon in spin glass systems. Individual realizations of evolutionary behavior exhibit so-called punctuated equilibria, or long periods of stasis interrupted by rapid changes of fitness. In contrast, the randomness in the replication rate turns out to be irrelevant for evolution in the long-time limit as it is smoothed out by increasing ''evolution temperature.'' C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CALIF SAN DIEGO,INST NONLINEAR SCI,LA JOLLA,CA 92093. RP Aranson, I (reprint author), BAR ILAN UNIV,IL-52900 RAMAT GAN,ISRAEL. RI Aranson, Igor/I-4060-2013 NR 16 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 OCT 27 PY 1997 VL 79 IS 17 BP 3298 EP 3301 DI 10.1103/PhysRevLett.79.3298 PG 4 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200051 ER PT J AU Zhang, SB Zunger, A AF Zhang, SB Zunger, A TI Structure of the As vacancies on GaAs(110) surfaces - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article RP Zhang, SB (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 7 TC 6 Z9 6 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 27 PY 1997 VL 79 IS 17 BP 3313 EP 3313 DI 10.1103/PhysRevLett.79.3313 PG 1 WC Physics, Multidisciplinary SC Physics GA YC782 UT WOS:A1997YC78200057 ER PT J AU FernandezPerea, R Bermejo, FJ deBernabe, A Loong, CK AF FernandezPerea, R Bermejo, FJ deBernabe, A Loong, CK TI Anomalous temperature dependence of the low-frequency vibrational density of states in vitreous B2O3 SO PHYSICS LETTERS A LA English DT Article ID INELASTIC NEUTRON-SCATTERING; THERMAL-EXPANSION; MOLECULAR-DYNAMICS; STRONG GLASS; SOFT MODES; SOLIDS; OXIDE; POTENTIALS; SPECTRA AB Inelastic neutron-scattering measurements of V-B2O3 reveal an upshift in energy of the first moment of the vibrational density of states for frequencies below approximate to 15 meV as temperature increases from 20 to 300 K. Such a stiffening is at odds with predictions based on some current approaches. Instead, the present result and related anomalies in specific heat and other microscopic and transport properties can be understood in terms of anharmonic motions at low frequencies. The atomic origin of the anharmonicity, and its consequence for the thermodynamical behavior are examined by molecular-dynamics simulations. (C) 1997 Elsevier Science B.V. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP FernandezPerea, R (reprint author), CSIC,INST ESTRUCTURA MAT,SERRANO 123,E-28006 MADRID,SPAIN. RI Fernandez-Perea, Ricardo/E-9118-2016 OI Fernandez-Perea, Ricardo/0000-0002-4011-2344 NR 35 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 27 PY 1997 VL 235 IS 2 BP 169 EP 175 DI 10.1016/S0375-9601(97)00622-1 PG 7 WC Physics, Multidisciplinary SC Physics GA YB645 UT WOS:A1997YB64500013 ER PT J AU Kurmaev, EZ Stadler, S Ederer, DL Hase, I Yarmoshenko, YM Neumann, M Zatsepin, DA Fujimori, A Sato, M Perera, RCC Grush, MM Callcott, TA AF Kurmaev, EZ Stadler, S Ederer, DL Hase, I Yarmoshenko, YM Neumann, M Zatsepin, DA Fujimori, A Sato, M Perera, RCC Grush, MM Callcott, TA TI Excitation energy dependence of S L-2,L-3 X-ray fluorescent emission of BaNiS2 near the S 2p threshold SO PHYSICS LETTERS A LA English DT Article AB The results of measurements of S L-2,L-3 X-ray fluorescent spectra of BaNiS2 near the S 2p threshold using tunable synchrotron radiation are presented. They are computed with FLAPW band structure calculations of BaNiS2. The excitation energy dependence of the SL2,3 spectra is found in the range of 163.5-173.5 eV which is attributed to excitation of inequivalent sulphur atoms (S(1) apical and S(2) in-plane sites). It allowed us to map separately the distribution of the S(2) and S(1)+S(2) 3s3d-partial density of states (DOS) in the valence band. We conclude that S 3d states participate in chemical bonding and hybridize with Ni 3d states. (C) 1997 Elsevier Science B.V. C1 TULANE UNIV,DEPT PHYS,NEW ORLEANS,LA 70118. ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. UNIV OSNABRUCK,FACHBEREICH PHYS,D-49069 OSNABRUCK,GERMANY. UNIV TOKYO,DEPT PHYS,BUNKYO KU,TOKYO 113,JAPAN. NAGOYA UNIV,DEPT PHYS,DIV MAT SCI,CHIKUSA KU,NAGOYA,AICHI 46401,JAPAN. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Kurmaev, EZ (reprint author), RUSSIAN ACAD SCI,INST MET PHYS,URAL DIV,GSP-170,EKATERINBURG 620219,RUSSIA. RI Yarmoshenko, Yuri/E-9531-2011; Kurmaev, Ernst/J-4254-2013; Zatsepin, Dmitry/F-5520-2012 OI Yarmoshenko, Yuri/0000-0001-8971-2052; Kurmaev, Ernst/0000-0003-4625-4930; NR 7 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 27 PY 1997 VL 235 IS 2 BP 191 EP 194 DI 10.1016/S0375-9601(97)00565-3 PG 4 WC Physics, Multidisciplinary SC Physics GA YB645 UT WOS:A1997YB64500017 ER PT J AU Koch, DL Ladd, AJC AF Koch, DL Ladd, AJC TI Moderate Reynolds number flows through periodic and random arrays of aligned cylinders SO JOURNAL OF FLUID MECHANICS LA English DT Article ID DISCRETIZED BOLTZMANN-EQUATION; PARTICULATE SUSPENSIONS; NUMERICAL SIMULATIONS; DYNAMIC SIMULATIONS; NEWTONIAN FLUID; PERMEABILITY; AUTOMATA; MOTION AB The effects of fluid inertia on the pressure drop required to drive fluid flow through periodic and random arrays of aligned cylinders is investigated. Numerical simulations using a lattice-Boltzmann formulation are performed for Reynolds numbers up to about 180. The magnitude of the drag per unit length on cylinders in a square array at moderate Reynolds number is strongly dependent on the orientation of the drag (or pressure gradient) with respect to the axes of the array; this contrasts with Stokes flow through a square array, which is characterized by an isotropic permeability. Transitions to time-oscillatory and chaotically varying flows are observed at critical Reynolds numbers that depend on the orientation of the pressure gradient and the volume fraction. In the limit Re much less than 1, the mean drag per unit length, F, in both periodic and random arrays, is given by F/(mu U) = k(1) + k(2) Re-2, where mu is the fluid viscosity, U is the mean velocity in the bed, and k(1) and k(2) are functions of the solid volume fraction phi. Theoretical analyses based on point-particle and lubrication approximations are used to determine these coefficients in the limits of small and large concentration, respectively. In random arrays, the drag makes a transition from a quadratic to a linear Re-dependence at Reynolds numbers of between 2 and 5. Thus, the empirical Ergun formula, F/(mu U) = c(1) + c(2) Re, is applicable for Re > 5. We determine the constants c(1) and c(2) over a wide range of phi. The relative importance of inertia becomes smaller as the volume fraction approaches close packing, because the largest contribution to the dissipation in this limit comes from the viscous lubrication flow in the small gaps between the cylinders. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Koch, DL (reprint author), CORNELL UNIV, SCH CHEM ENGN, ITHACA, NY 14853 USA. NR 31 TC 156 Z9 156 U1 3 U2 26 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD OCT 25 PY 1997 VL 349 BP 31 EP 66 DI 10.1017/S002211209700671X PG 36 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA YG258 UT WOS:A1997YG25800002 ER PT J AU Camassa, R Holm, DD Levermore, CD AF Camassa, R Holm, DD Levermore, CD TI Long-time shallow-water equations with a varying bottom SO JOURNAL OF FLUID MECHANICS LA English DT Article ID GLOBAL WELL-POSEDNESS; WAVES AB We present and discuss new shallow-water equations that model the long-time effects of slowly varying bottom topography and weak hydrostatic imbalance on the vertically averaged horizontal velocity of an incompressible fluid possessing a free surface and moving under the force of gravity. We consider the regime where the Froude number epsilon is much smaller than the aspect ratio delta of the shallow domain. The new equations are obtained from the epsilon --> 0 limit of the Euler equations (the rigid-lid approximation) at the first order of an asymptotic expansion in delta(2). These equations possess local conservation laws of energy and vorticity which reflect exact layer mean conservation laws of the three-dimensional Euler equations. In addition, they convect potential vorticity and have a Hamilton's principle formulation. We contrast them with the Green-Naghdi equations. C1 LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. UNIV ARIZONA, DEPT MATH, TUCSON, AZ 85721 USA. RP Camassa, R (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 20 TC 22 Z9 23 U1 0 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD OCT 25 PY 1997 VL 349 BP 173 EP 189 DI 10.1017/S0022112097006721 PG 17 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA YG258 UT WOS:A1997YG25800007 ER PT J AU Bell, AT AF Bell, AT TI Experimental and theoretical studies of NO decomposition and reduction over metal-exchanged ZSM-5 SO CATALYSIS TODAY LA English DT Article; Proceedings Paper CT Post-Conference Symposium on Catalysis CY AUG 19-20, 1996 CL KYONGJU, SOUTH KOREA SP Pohang Univ Sci & Technol, Res Ctr Catalyt Technol, Korea Sci & Engn Fdn DE decomposition; nitric oxide; zeolite; metal exchange ID SELECTIVE CATALYTIC REDUCTION; NITROGEN MONOXIDE; NITRIC-OXIDE; CU-ZSM-5; ZEOLITES; OXYGEN; MECHANISM; REMOVAL; METHANE; SITES AB Metal-exchanged zeolites and, in particular, ZSM-5 are candidate catalysts for NO decomposition and reduction. Results of experimental and theoretical studies are presented which focus on understanding the nature of the catalytically active sites and the elementary processes involved in the decomposition of NO over Cu-ZSM-5 and the reduction of NO over Co-ZSM-5. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP Bell, AT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV SCI MAT,BERKELEY,CA 94720, USA. OI Bell, Alexis/0000-0002-5738-4645 NR 38 TC 56 Z9 60 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 OCT 24 PY 1997 VL 38 IS 2 BP 151 EP 156 DI 10.1016/S0920-5861(97)00059-X PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA YE372 UT WOS:A1997YE37200002 ER PT J AU Mills, G Schenter, GK Makarov, DE Jonsson, H AF Mills, G Schenter, GK Makarov, DE Jonsson, H TI Generalized path integral based quantum transition state theory SO CHEMICAL PHYSICS LETTERS LA English DT Article ID VARIATIONAL OPTIMIZATION; HYDROGEN; TEMPERATURE; SIMULATION; CROSSOVER; METALS AB A theory for calculating rates of transitions in quantum systems is presented and applied to desorption of H-2 from a Cu(110) surface. The quantum transition state is defined as a conical dividing surface in the space of closed Feynman paths and a 'reaction coordinate' in this extended space is used to parametrize a reversible work evaluation of the free energy barrier. In a low temperature, harmonic limit the theory reduces to instanton theory. Above the cross-over temperature for tunneling, the theory reduces to the centroid density approximation and in the classical limit, variational classical transition state theory is recovered. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. RP Mills, G (reprint author), UNIV WASHINGTON, DEPT CHEM, BOX 351700, SEATTLE, WA 98195 USA. RI Makarov, Dmitrii/G-8049-2011; Jonsson, Hannes/G-2267-2013; Schenter, Gregory/I-7655-2014 OI Jonsson, Hannes/0000-0001-8285-5421; Schenter, Gregory/0000-0001-5444-5484 NR 22 TC 64 Z9 66 U1 1 U2 10 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 OCT 24 PY 1997 VL 278 IS 1-3 BP 91 EP 96 DI 10.1016/S0009-2614(97)00886-5 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YF643 UT WOS:A1997YF64300015 ER PT J AU Cornil, J Beljonne, D Heller, CM Campbell, IH Laurich, BK Smith, DL Bradley, DDC Mullen, K Bredas, JL AF Cornil, J Beljonne, D Heller, CM Campbell, IH Laurich, BK Smith, DL Bradley, DDC Mullen, K Bredas, JL TI Photoluminescence spectra of oligo-paraphenylenevinylenes: a joint theoretical and experimental characterization SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PHENYLENE VINYLENE OLIGOMERS; CONJUGATED POLYMERS; POLY(P-PHENYLENE VINYLENE); OPTICAL SPECTROSCOPY; ABSORPTION; DEPENDENCE; MODELS; STATES; LENGTH AB We present a joint theoretical and experimental characterization of the absorption and photoluminescence spectra of oligo-paraphenylenevinylenes containing from 2 to 5 phenylene rings, Attention is paid to the emission spectra and their vibronic progressions in order to shed light on the geometry relaxation phenomena in the lowest singlet excited state, The results indicate that the relaxation energy in the excited state increases with inverse chain length. For long conjugated chains, the relaxation energy of the bound electron-hole pair is extrapolated to be of the order of 0.14 eV and the most significant part of the geometry deformations are found to spread over a length of about 20 Angstrom. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV SHEFFIELD,DEPT PHYS,SHEFFIELD S3 7RH,S YORKSHIRE,ENGLAND. UNIV SHEFFIELD,CTR MOL MAT,SHEFFIELD S3 7RH,S YORKSHIRE,ENGLAND. MAX PLANCK INST POLYMER RES,D-55128 MAINZ,GERMANY. RP Cornil, J (reprint author), UNIV MONS,CTR RES MOL ELECT & PHOTON,LAB CHEM NOVEL MAT,PL PARC 20,B-7000 MONS,BELGIUM. RI Bredas, Jean-Luc/A-3431-2008; Bradley, Donal/F-6068-2011 OI Bredas, Jean-Luc/0000-0001-7278-4471; Bradley, Donal/0000-0001-8713-5060 NR 34 TC 142 Z9 142 U1 3 U2 21 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 OCT 24 PY 1997 VL 278 IS 1-3 BP 139 EP 145 DI 10.1016/S0009-2614(97)00986-X PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YF643 UT WOS:A1997YF64300023 ER PT J AU Kele, M Compton, RN Guiochon, G AF Kele, M Compton, RN Guiochon, G TI Optimization of the high-performance liquid chromatographic separation of fullerenes using 1-methylnaphthalene as the mobile phase on a tetraphenylporphyrin-silica stationary phase SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE stationary phases, LC; mobile phase composition; preparative chromatography; fullerenes; methylnaphthalene ID REVERSED-PHASE; BUCKMINSTERFULLERENE; SOLVENTS; HPLC; C-60; PURIFICATION; EXTRACTION; SOLUBILITY; BEHAVIOR; C-70 AB The separation of C-60 and C-70 was studied on four different stationary phases. The performance of three commercial products, Buckyclutchers, PYE and PBB and of a new phase, immobilized tetraphenylporphyrin on silica, were investigated. The influence of the surface chemistry on this separation is discussed. On all four phases, good resolution is obtained with pure toluene as the mobile phase. With some of them, this result is obtained with stronger eluents, mixtures of toluene and 1-methylnaphthalene. This allows the injection of much more concentrated and larger samples than on conventional systems and gives considerably improved production rates of purified compounds. The optimization of the temperature, the flow velocity, and the mobile phase composition for the separation of C-60 and C-70 on the tetraphenylporphyrin bonded phase is discussed. The overloading of this stationary phase was studied empirically in mixtures of toluene and l-methylnaphthalene. The advantage and properties of this latter solvent are illustrated. Fractions of C-60 with 98.5% purity and C-70 with a purity better than 99% were prepared with near total recovery yield from 5 mg samples. (C) 1997 Elsevier Science B.V. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 26 TC 17 Z9 18 U1 1 U2 3 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 OCT 24 PY 1997 VL 786 IS 1 BP 31 EP 45 DI 10.1016/S0021-9673(97)00556-6 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YH195 UT WOS:A1997YH19500004 ER PT J AU Anderson, DH Weiss, MS Eisenberg, D AF Anderson, DH Weiss, MS Eisenberg, D TI Charges, hydrogen bonds, and correlated motions in the 1 angstrom resolution refined structure of the mating pheromone Er-1 from Euplotes raikovi SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE pheromone; hydrogen bonds; atomic resolution; anisotropy; helix caps ID X-RAY CRYSTALLOGRAPHY; CRYSTAL-STRUCTURE; ATOMIC-RESOLUTION; MACROMOLECULAR STRUCTURES; 1.2-ANGSTROM RESOLUTION; 3-DIMENSIONAL STRUCTURE; HYDROPHOBIC PROTEIN; WATER-STRUCTURE; COMPLEX; BINDING AB A detailed description is given of the structure of the small protein mating pheromone Ev-l at atomic resolution. Emphasis is placed on the locations of charges and hydrogen bonds. The model includes all the protein atoms, anisotropic displacement parameters, four disordered side chains, 22 water molecules, a disordered ethanol, and ''riding'' hydrogen atoms. Analysis of the model revealed that this dense crystal is perfused by hydrogen-bonding networks of solvent and protein atoms. The termini of helices are capped by hydrogen bonding to solvent and protein atoms, and to symmetry-related molecules. An examination of the valencies and charges of the hydrogen-bonding groups suggests that three of the ''water'' molecules capping the C termini of two helices, and one other, may instead be NH4 ions. Water molecules mediate all but one of the interhelical hydrogen bonds, and many of the lattice interactions. Regions of the molecule where the atomic vibrations deviate from isotropy are identified. There is almost no overall Libration of the molecule allowed by the packing, but the side-chains vibrate relative to the backbone. Four side-chains display alternate conformations. Indirect evidence is presented that the switches between their conformations are correlated and driven by protonation of acidic side-chains. These structural features are discussed in the context of function and stability. Equipped with the analysis of the model, we review the course and results of the refinement of the model against 1 Angstrom X-ray diffraction data to a crystallographic X-factor of 12.92%. (C) 1997 Academic Press Limited. C1 UNIV CALIF LOS ANGELES,INST MOL BIOL,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,LOS ANGELES,CA 90095. RI Weiss, Manfred/B-6857-2013 NR 47 TC 7 Z9 8 U1 1 U2 8 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 OCT 24 PY 1997 VL 273 IS 2 BP 479 EP 500 DI 10.1006/jmbi.1997.1318 PG 22 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YD510 UT WOS:A1997YD51000010 PM 9344754 ER PT J AU Lambros, MP Sheu, E Lin, JS Pereira, HA AF Lambros, MP Sheu, E Lin, JS Pereira, HA TI Interaction of a synthetic peptide based on the neutrophil-derived antimicrobial protein CAP37 with dipalmitoyl-phosphatidylcholine membranes SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES LA English DT Article DE lipid membrane; small-angle X-ray scattering; CAP37; differential scanning calorimetry ID ANGLE X-RAY; GRANULOCYTES; SCATTERING; DEFENSINS; SEQUENCE AB CAP37, a cationic antimicrobial protein of M-r 37 kDa is constitutively expressed in human neutrophils. A synthetic peptide, CAP37 P20-44, corresponding to amino acid residues 20 through 44 of the native CAP37 molecule has been shown to mimic the antimicrobial activity of the native protein. An analog of peptide CAP37 P20-44 was synthesized in which the cysteine residues at positions 26 and 42 were replaced with serine residues (CAP37 P20-44Ser). This resulted in a peptide that no longer exhibited bactericidal activity. The effect of different concentrations of the active CAP37 peptide, CAP37 P20-44, and its inactive analog, CAP37 P20-44Ser, on artificial lipid membranes composed of dipalmitoyl phosphatidylcholine (DPPC) was studied using small-angle X-ray scattering and differential scanning calorimetry, The results indicated that CAP37 P20-44 perturbs the periodicity of the lamellar structure as shown by small angle X-ray diffraction, while the effect of the inactive peptide is not as strong, Differential scanning calorimetry further confirms that CAP37 P20-44 interacts with lipid membranes as indicated by increased width of the transition and decreased peak height. Moreover, it completely abolishes the pretransition temperature of the DPPC membranes, The effect of the inactive peptide, CAP37 P20-44Ser on the thermotropic properties of DPPC was small. These studies suggest that CAP37 perturbs the lamellar structure of lipid bilayers and further suggests that the antibiotic action of the molecule may be through its interactions with the lipid components of the Gram negative bacterial membrane. (C) 1997 Elsevier Science B.V. C1 VANTON RES LAB INC,HOPEWELL JCT,NY 12533. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37830. UNIV OKLAHOMA,HLTH SCI CTR,COLL MED,DEPT PATHOL,NORMAN,OK 73190. RP Lambros, MP (reprint author), UNIV OKLAHOMA,HLTH SCI CTR,COLL PHARM,POB 26901,NORMAN,OK 73190, USA. NR 14 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2736 J9 BBA-BIOMEMBRANES JI Biochim. Biophys. Acta-Biomembr. PD OCT 23 PY 1997 VL 1329 IS 2 BP 285 EP 290 PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA YD846 UT WOS:A1997YD84600009 ER PT J AU Blum, O Klem, JF Lear, KL Vawter, GA Kurtz, SR AF Blum, O Klem, JF Lear, KL Vawter, GA Kurtz, SR TI Optically pumped, monolithic, all-epitaxial 1.56 mu m vertical cavity surface emitting laser using Sb-based reflectors SO ELECTRONICS LETTERS LA English DT Article DE vertical cavity surface emitting lasers; molecular beam epitaxial growth ID TEMPERATURE PULSED OPERATION; INP; 1.5-MU-M; MIRROR AB The authors demonstrate, for the first time, 77K CW operation of an optically pumped, monolithic, all-epitaxial vertical cavity laser, emitting at 1.56 mu m. The laser incorporates 15 and 20 period Al0.12Ga0.88As0.56Sb0.44/AlAs0.56Sb0.44 distributed Bragg reflectors for the top and bottom mirrors, respectively. The entire structure was grown in a single growth run by molecular beam epitaxy. C1 Sandia Natl Labs, Dept 1312, Albuquerque, NM 87185 USA. Microopt Devices Inc, Albuquerque, NM 87109 USA. RP Blum, O (reprint author), Sandia Natl Labs, Dept 1312, MS0603, Albuquerque, NM 87185 USA. NR 11 TC 26 Z9 26 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD OCT 23 PY 1997 VL 33 IS 22 BP 1878 EP 1880 DI 10.1049/el:19971284 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA YX453 UT WOS:000072041500035 ER PT J AU Mao, Y Bakac, A AF Mao, Y Bakac, A TI Uranyl-sensitized photochemical oxidation of naphthalene by molecular oxygen. Role of electron transfer SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID RADICAL CATIONS; AROMATIC-HYDROCARBONS; PULSE-RADIOLYSIS; AQUEOUS-SOLUTION; METAL-COMPLEXES; EXCITED-STATES; SPIN-RESONANCE; OH RADICALS; ION; PHOTOLYSIS AB Naphthalene quenches the excited state *UO22+ in two parallel pathways: oxidation to naphthalene radical cation, C10H8.+ (Phi = 0.3), and exciplex formation. The overall rate constant in aqueous acetonitrile containing 0.1 M H3PO4 has a value k(q) = 2.20 x 10(9) M-1 s(-1). In the presence of O-2, a portion of C10H8.+ is converted to 2-formylcinnamaldehyde and several other products, the rest reacting with UO2+ by back electron transfer. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 36 TC 12 Z9 12 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 23 PY 1997 VL 101 IS 43 BP 7929 EP 7933 DI 10.1021/jp962961z PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YD603 UT WOS:A1997YD60300003 ER PT J AU Rowland, B Hess, WP AF Rowland, B Hess, WP TI UV photochemistry of thin film and matrix-isolated acetyl chloride by polarized FTIR SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID INFRARED-SPECTRA; HYDROGEN-CHLORIDE; ALPHA-BOND; AB-INITIO; DISSOCIATION; HALIDES; PHOTODISSOCIATION; SPECTROSCOPY; EXCITATION; ADSORPTION AB A concerted HCl elimination reaction is observed following ultraviolet photoexcitation of neat and matrix-isolated samples of acetyl chloride. The photoreaction of condensed-phase acetyl chloride forms HCl . ketene complexes exclusively, in sharp contrast to the gas-phase photoreaction that produces CI atoms, CH3CO, CH3, and CO. The reaction mechanism involves photoexcitation followed by S-1 --> S-0 interconversion and a four-centered elimination on the ground electronic surface. The HCl . ketene complexes are the only primary photoproduct observed and are found to be aligned with the polarization axis of the irradiating laser. The polarization specific FTIR probe indicates that the HCl ketene complexes form a T-shaped structure quite similar to the transition state structure recently calculated for HCl elimination from CH3COCl. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 49 TC 20 Z9 20 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 23 PY 1997 VL 101 IS 43 BP 8049 EP 8056 DI 10.1021/jp971980l PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YD603 UT WOS:A1997YD60300020 ER PT J AU Liu, TB Zhou, ZK Wu, CH Chu, B Schneider, DK Nace, VM AF Liu, TB Zhou, ZK Wu, CH Chu, B Schneider, DK Nace, VM TI Self-assembly of poly(oxybutylene)-poly(oxyethylene)-poly(oxybutylene) (B6E46B6) triblock copolymer in aqueous solution SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MICELLE FORMATION; ETHYLENE-OXIDE; BUTYLENE OXIDE; MICELLIZATION; ASSOCIATION; BEHAVIOR; BLOCK; SCATTERING; SOLVENTS; GELATION AB Laser light scattering and small-angle neutron scattering were used to study poly(oxybutylene)-poly(oxyethylene)-poly(oxybutylene) triblock copolymers (B6E46B6) in aqueous solution from low to high concentrations and over a range of temperatures from 5 to 35 degrees C. B6E46B6 molecules exist as unimers at low concentrations and low temperatures. At higher concentrations and at low temperature (less than or equal to 15 degrees C), they associate in small numbers and scattering evidence shows that molecular associates with open structures might form. At higher temperatures, typical flowerlike micelles form. The critical micelle concentration decreases with increasing temperature while the association number increases. At high polymer concentrations (e.g., at 35% in mass), further entanglements form among the micelles, yielding another slow mode in dynamic light scattering, which can be attributed to the bridging of two hydrophobic end blacks located iu two different hydrophobic clusters by the hydrophilic middle block. However, these cross-linkings were quite weak and free micelles were still the majority in solution. When the temperature is lowered, a very slow process of microphase separation occurs. The self-assembly behavior of B6E46B6 is compared with that of other BEB type triblock copolymers. 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. DOW CHEM CO USA,FREEPORT,TX 77541. RI Liu, Tianbo/D-8915-2017 OI Liu, Tianbo/0000-0002-8181-1790 NR 25 TC 58 Z9 59 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 23 PY 1997 VL 101 IS 43 BP 8808 EP 8815 DI 10.1021/jp963810z PG 8 WC Chemistry, Physical SC Chemistry GA YD604 UT WOS:A1997YD60400026 ER PT J AU Haw, JF Xu, T Nicholas, JB Goguen, PW AF Haw, JF Xu, T Nicholas, JB Goguen, PW TI Solvent-assisted proton transfer in catalysis by zeolite solid acids SO NATURE LA English DT Article ID IN-SITU NMR; WATER; REACTIVITY; CHEMISTRY; METHANOL AB Intermolecular proton transfer in the gas phase is usually strongly disfavoured because the charged products are highly unstable. It is promoted in aqueous solution, however, because the high dielectric constant (epsilon = 78.3) of water allows efficient stabilization of the corresponding cations and anions. Zeolites-microporous catalysts used in petroleum refining and the synthesis of chemical feedstocks-provide another medium for proton-transfer reactions(1-3), because their anionic aluminosilicate frameworks are highly acidic. The low dielectric constant of zeolites (epsilon approximate to 1.6; ref. 3) suggests, however, that such processes in the zeolite channels should involve concerted action rather than strong charge separation, and thus resemble gas-phase reactions. Here we demonstrate that solution-like proton-transfer behaviour can be induced in zeolites. We find that the co-injection of nitromethane into a catalytic flow reactor clearly enhances the conversion of methanol, isopropanol and acetone over the zeolite catalyst HZSM-5. Conservation of nitromethane during-the course of reaction and its effects on the reactant-zeolite interaction complex seen by solid-state NMR indicate that nitromethane behaves in a manner similar to polar solvents: it promotes proton transfer by stabilizing ion-pair structures. These findings suggest that rationally selected solvents might provide a simple means to increase the efficiency of these industrially important catalysts. C1 PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. RP Haw, JF (reprint author), TEXAS A&M UNIV,DEPT CHEM,LAB MAGNET RESONANCE & MOL SCI,COLLEGE STN,TX 77843, USA. NR 23 TC 70 Z9 70 U1 2 U2 37 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD OCT 23 PY 1997 VL 389 IS 6653 BP 832 EP 835 DI 10.1038/39843 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YC148 UT WOS:A1997YC14800052 ER PT J AU Lyth, DH Riotto, A AF Lyth, DH Riotto, A TI Comments on D-term inflation SO PHYSICS LETTERS B LA English DT Article ID ENTROPY CRISIS; COSMIC STRINGS; ANOMALOUS U(1); SUPERSYMMETRY; SUPERGRAVITY; SUPERSTRINGS; COSMOLOGY; BREAKING AB An inflationary stage dominated by a D-term avoids the slow-roll problem of inflation in supergravity and can naturally emerge in theories with a non-anomalous or anomalous U(1) gauge symmetry. In the latter case, however, the scale of inflation as imposed by the COBE normalization is in contrast with the value fixed by the Green-Schwarz mechanism of anomaly cancellation. In this paper we discuss possible solutions to this problem and comment about the fact that the string-loop generated Fayet-Iliopoulos D-term may trigger the presence of global and local cosmic strings at the end of inflation. (C) 1997 Elsevier Science B.V. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Lyth, DH (reprint author), UNIV LANCASTER,SCH PHYS & CHEM,LANCASTER LA1 4YB,ENGLAND. NR 38 TC 48 Z9 48 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 OCT 23 PY 1997 VL 412 IS 1-2 BP 28 EP 34 DI 10.1016/S0370-2693(97)01044-7 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG530 UT WOS:A1997YG53000005 ER PT J AU Antonuccio, F Brodsky, SJ Dalley, S AF Antonuccio, F Brodsky, SJ Dalley, S TI Light-cone wavefunctions at small x SO PHYSICS LETTERS B LA English DT Article ID NUCLEON; QUARK; QCD; SEA AB There exist an infinite number of exact small momentum fraction-x boundary conditions on light-cone wavefunctions of bound states in gauge theory. They are necessary for finite expectation values of the invariant mass operator and relate components of the wavefunction from different Fock sectors. We illustrate their consequences by analyzing the small-x quark Regge behavior of a heavy large-N meson, finding power-law rise of unpolarized distributions. The polarized distribution changes sign and then vanishes with minus the unpolarized Regge intercept. (C) 1997 Elsevier Science B.V. C1 UNIV HEIDELBERG,INST THEORET PHYS,D-69120 HEIDELBERG,GERMANY. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. RP Antonuccio, F (reprint author), MAX PLANCK INST KERNPHYS,D-69029 HEIDELBERG,GERMANY. NR 11 TC 44 Z9 44 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 OCT 23 PY 1997 VL 412 IS 1-2 BP 104 EP 110 DI 10.1016/S0370-2693(97)01067-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG530 UT WOS:A1997YG53000016 ER PT J AU Brodsky, SJ Miller, GA AF Brodsky, SJ Miller, GA TI Is J/Psi-nucleon scattering dominated by the gluonic van der Waals interaction? SO PHYSICS LETTERS B LA English DT Article ID COLOR TRANSPARENCY; BOUND QUARKONIUM; HEAVY QUARKS; PHOTOPRODUCTION; DEPENDENCE; PARTICLES; HADRONS AB The gluon-exchange contribution to J/psi-nucleon scattering is shown to yield a sizeable scattering length of about -0.25 fm, which is consistent with the sparse available data. Hadronic corrections to gluon exchange which are generated by rho pi and D (D) over bar intermediate states of the J/psi are shown to be negligible. We also propose a new method to study J/psi-nucleon elastic scattering in the reaction pi(+)d-->J/psi pp. (C) 1997 Elsevier Science B.V. C1 UNIV WASHINGTON,NATL INST NUCL THEORY,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 26 TC 47 Z9 47 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 OCT 23 PY 1997 VL 412 IS 1-2 BP 125 EP 130 DI 10.1016/S0370-2693(97)01045-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG530 UT WOS:A1997YG53000019 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, E Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, E Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for heavy neutral and charged leptons in e(+)e(-) annihilation at root s=161 and root s=172 GeV SO PHYSICS LETTERS B LA English DT Article ID Z-DECAYS; L3 EXPERIMENT; MONTE-CARLO; RADIATIVE-CORRECTIONS; ELECTRON-POSITRON; MIRROR FERMIONS; PAIR PRODUCTION; NEUTRINOS; COLLISIONS; PARTICLES AB A search for unstable neutral and charged heavy leptons as well as for stable charged heavy leptons has been made at center-of-mass energies root s = 161 GeV and root s = 172 GeV with the L3 detector at LEP. No evidence for their existence was found. We exclude unstable neutral leptons of Dirac (Majorana) type for masses below 78.0 (66.7), 78.0 (66.7) and 72.2 (58.2) GeV, if the heavy neutrino couples to the electron, muon or tau family, respectively. We exclude unstable charged heavy leptons for masses below 81.0 GeV for a wide mass range of the associated neutral heavy lepton. The production of stable charged heavy leptons with a mass less than 84.2 GeV is also excluded. If the unstable charged heavy lepton decays via mixing into a massless neutrino, we exclude masses below 78.7 GeV. (C) 1997 Elsevier Science B.V. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. LOUISIANA STATE UNIV, BATON ROUGE, LA 70803 USA. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02115 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. UNIV FLORENCE, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. WORLD LAB, FBLIA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. UNIV SCI & TECHNOL CHINA, HEFEI 230029, PEOPLES R CHINA. SEFT, RES INST HIGH ENERGY PHYS, 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. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. CIEMAT, CTR INVEST ENERGETICAS MEDIOAMBIENTALES & TECNOL, E-28040 MADRID, SPAIN. IST NAZL FIS NUCL, I-20133 MILAN, ITALY. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC 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. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, 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 PARTICULES 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, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, 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; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; 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; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016 OI Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; 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; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175 NR 67 TC 10 Z9 10 U1 1 U2 4 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 OCT 23 PY 1997 VL 412 IS 1-2 BP 189 EP 200 DI 10.1016/S0370-2693(97)01074-5 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG530 UT WOS:A1997YG53000026 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Detiers, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordenescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W 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, HJ Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, G Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D 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 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Detiers, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordenescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W 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, HJ Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, G Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D 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 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Ziegler, F TI Search for new physics in energetic single photon production in e(+)e(-) annihilation at the Z resonance SO PHYSICS LETTERS B LA English DT Article ID NEUTRINO MAGNETIC-MOMENT; L3 EXPERIMENT; E+E COLLISIONS; BOSON; LEP; COUPLINGS; DECAY AB Using a sample of e(+)e(-) annihilation events collected with the L3 detector at the Z resonance corresponding to an integrated luminosity of 137 pb(-1), we have searched for anomalous production of gamma X final states where X represents stable, weakly interacting particles and the photon energy is greater than 15 GeV. The sample of events found is consistent with Standard Model expectations. Upper limits are set on Z gamma couplings, the tau neutrino magnetic moment, and the branching ratio for Z --> gamma X. (C) 1997 Elsevier Science B.V. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, 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. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. 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 02215 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, 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. WORLD LAB, FBLJA PROJECT, 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, IN2P3, INST PHYS NUCL, F-69622 VILLEURBANNE, FRANCE. CIEMAT, CTR INVEST ENERGETICAS MEDIOAMBIENTALES & TECNOL, E-28040 MADRID, SPAIN. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC 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. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. PRINCETON UNIV, PRINCETON, NJ 08544 USA. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, 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, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP Acciarri, M (reprint author), IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI Duran, Ignacio/H-7254-2015; Sanchez, Eusebio/H-5228-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; D'Alessandro, Raffaello/F-5897-2015; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; 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; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015 OI Read, Kenneth/0000-0002-3358-7667; Sciacca, Crisostomo/0000-0002-8412-4072; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Goldstein, Joel/0000-0003-1591-6014; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Castellini, Guido/0000-0002-0177-0643; D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532 NR 37 TC 39 Z9 40 U1 1 U2 5 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 OCT 23 PY 1997 VL 412 IS 1-2 BP 201 EP 209 DI 10.1016/S0370-2693(97)01003-4 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG530 UT WOS:A1997YG53000027 ER PT J AU Ashkenazy, Y Glikman, E Kelson, I Haustein, PE AF Ashkenazy, Y Glikman, E Kelson, I Haustein, PE TI Interface characterization by dual neutron activation SO SURFACE SCIENCE LA English DT Article DE atom-solid interactions; crystalline-amorphous interfaces; gold; interface states; radioactive trace methods; silicon oxides AB A new method of characterizing sharp interfaces is presented. The method utilizes the structural modification of the interface caused by thermal-neutron-induced recoil. Dual neutron activations, coupled with chemical etching, are used to correlate the initial and the modified material distributions across the interface. The nuclear and the radiochemical aspects of the method are tested for samples of polycrystalline gold sputtered on amorphous silicon dioxide. (C) 1997 Elsevier Science B.V. C1 TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI ashkenazy, yinon/D-1257-2012 NR 9 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 23 PY 1997 VL 388 IS 1-3 BP 248 EP 253 DI 10.1016/S0039-6028(97)00408-1 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA YD096 UT WOS:A1997YD09600032 ER PT J AU Liu, FQ Tilley, TD AF Liu, FQ Tilley, TD TI Coordination networks based on tetrahedral silane building blocks: Influence of the anion on structures adopted by Ag+-Si(p-C6H4CN)(4) arrays SO INORGANIC CHEMISTRY LA English DT Article ID POLYMERIC SILVER(I) COMPLEXES; RAY CRYSTAL-STRUCTURES; SRSI2 TOPOLOGICAL TYPE; 3-DIMENSIONAL RACEMATE; MOLECULAR RODS; FRAMEWORKS; CHEMISTRY; CHANNELS; CATIONS; DESIGN AB The silane tetrakis(4-cyanophenyl)silane (1) was prepared by the reaction of 4-lithiobenzonitrile with silicon tetrachloride at -100 degrees C. This tetrahedral molecular building block crystallizes with AgOTf (OTf = O3SCF3) from benzene and dichloromethane to give [Ag2Si(p-C6H4CN)(4)][OTf](2) .2C6H6 (2). The extended solid structure of 2 is composed of interpenetrating ''double layers'' which are 3-connected via trigonal planar Ag and tetrahedral Si centers. The individual nets contain six-membered rings which are folded in one corner along a Si ... Si vector to give an envelope conformation. Overall, the structure is heavily cross-linked via -CN-Ag(1)-NC-, -Ag(1)-Ag(2)-NC-, and -CN-Ag(2)(mu-O3SCF3)(2)Ag(2)-NC-linkages. Compound 1 also crystallizes with AgPF6, to give {Ag-3[Si(p-C6H4CN)(4)](2)}[PF6](3) . 1.6THF . 0.5C(6)H(6) . CH2Cl2 (3). This coordination network also contains 3-connected nets, with six-membered rings in the chair conformation. These nets are interwoven to form the 3-dimensional structure. Compounds 2 and 3 are air-sensitive, and their structures are readily broken up by dissolution in acetone. The network of 2 appears to lose crystallinity when exposed to heat and vacuum (by PXRD) but nonetheless retains some properties as a molecular sieve. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 51 TC 75 Z9 76 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 22 PY 1997 VL 36 IS 22 BP 5090 EP 5096 DI 10.1021/ic9703484 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YD386 UT WOS:A1997YD38600025 ER PT J AU Scherer, JJ Aniolek, KW Cernansky, NP Rakestraw, DJ AF Scherer, JJ Aniolek, KW Cernansky, NP Rakestraw, DJ TI Determination of methyl radical concentrations in a methane air flame by infrared cavity ringdown laser absorption spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CH3; OXYGEN AB Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) is employed to determine absolute methyl radical concentrations in a 37.5 Torr laminar methane/air flame. IR-CRLAS rovibrational absorption spectra of the v(3) fundamental band system near 3200 cm(-1) are combined with N-2-CARS temperature measurements to obtain methyl radical concentrations as a function of height above the burner surface. These data are compared with flame chemistry simulations under both stoichiometric and rich flame conditions. Issues regarding the applicability of IR-CRLAS for combustion studies are discussed, including the uncertainties present for the specific case of methyl radical. These IR-CRLAS measurements indicate the ability to monitor reactants, intermediates, and products within a narrow spectral window, and, to our knowledge, constitute the first infrared detection of a polyatomic radical in a flame. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 28 TC 65 Z9 65 U1 3 U2 10 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 OCT 22 PY 1997 VL 107 IS 16 BP 6196 EP 6203 DI 10.1063/1.474284 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YB713 UT WOS:A1997YB71300020 ER PT J AU BonacicKoutecky, V Jellinek, J Wiechert, M Fantucci, P AF BonacicKoutecky, V Jellinek, J Wiechert, M Fantucci, P TI Ab initio molecular dynamics study of solid-to liquidlike transitions in Li-9(+), Li-10, and Li-11(+) clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; SELF-CONSISTENT-FIELD; METAL-CLUSTERS; SILICON MICROCLUSTERS; SODIUM CLUSTERS; EQUILIBRIUM; LI; TEMPERATURE; PREDICTIONS; PHOSPHORUS AB An ab initio Hartree-Fock molecular dynamics procedure is applied to study structural and dynamical properties of Li-9(+), Li-10, and Li-11(+) clusters with eight and ten valence electrons, corresponding to ''closed'' and ''open'' shell systems. Gradients of the ground state energy are used to compute the forces acting on atoms at each geometric configuration along trajectories generated by solving classical equations of motion. Dynamics of different isomers for each cluster size have been investigated as a function of excess energy. It is shown that different isomers, even those similar in energy, can exhibit different structural and dynamical behavior. The analysis of the simulations leads to the conclusion that structures with a central atom, in particular the centered antiprism of Li-9(+), exhibit concerted mobility of the peripheral atoms at relatively low excess energy. In contrast, compact tetrahedral type structures show much more rigid behavior at low excess energy. However, the former ones need larger excess of internal energy to undergo isomerizations to geometrically different structures than the latter ones, at least in the case of Li-9(+) and Li-11(+) clusters. At the time scale of our simulations we found that for the intermediate excess energies it is ''easier'' to carry the duster in the basin of the lowest energy isomer than in the reverse direction. Moreover, for different cluster sizes isomerization processes occur at different excess energies (temperatures), which is a consequence of the differences in the structural properties rather than in the number of the valence electrons. It has been found that the liquidlike behavior in small Li clusters becomes apparent at relatively high temperature in spite of large mobility of their atoms. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. CTR CNR,DIPARTIMENTO CLIN INORGAN MET ORGAN & ANALIT,I-20133 MILAN,ITALY. RP BonacicKoutecky, V (reprint author), HUMBOLDT UNIV BERLIN,WALTHER NERNST INST PHYS & THEORET CHEM,BUNSENSTR 1,D-10117 BERLIN,GERMANY. NR 52 TC 36 Z9 38 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 1997 VL 107 IS 16 BP 6321 EP 6334 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YB713 UT WOS:A1997YB71300033 ER PT J AU Linehan, JC Wallen, SL Yonker, CR Bitterwolf, TE Bays, JT AF Linehan, JC Wallen, SL Yonker, CR Bitterwolf, TE Bays, JT TI In situ NMR observations of the photolysis of cymantrene and methylcymantrene in supercritical fluids: A new technique using high-pressure NMR SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; CARBON-DIOXIDE; HOMOGENEOUS CATALYSIS; RAPID EXPANSION; GAS-PHASE; HYDROGENATION; SPECTROSCOPY; LIQUID; COMPLEXES; POWDERS AB The in situ photolytic exchange of ethylene and hydrogen for carbon monoxide on cymantrene (CpMn(CO)(3), Cp = eta(5)-cyclopentadienyl) and methylcymantrene (MeCpMn(CO)(3), MeCp = monomethyl-eta(5)-cyclopentadienyl) dissolved in subcritical and supercritical solvents (CO2 and ethylene) was investigated by high-resolution, high-pressure H-1 NMR over the temperature range from -40 to 150 degrees C and a pressure range from 35 to 2600 bar. Photolytic substitution of ethylene for CO proceeded to completion under all conditions investigated, and only one ethylene was observed to substitute for CO on the manganese complexes even in neat ethylene under extreme conditions of pressure and temperature. Only small amounts of dihydrogen were observed to substitute for CO on cymantrene at 35 degrees C in a binary solvent mixture of CO2/H-2 during photolysis. The H-1 chemical shifts of the manganese complexes and their ethylene substituted products were found to be linearly dependent on density with temperature and solvent dependence also observed, The spin-lattice relaxation times (T-1) of all the solvent and solute species were observed to be inversely proportional to the density of the solvent over the range of conditions investigated, Temperature and concentration dependent phase behavior and solute saturation were also determined for the methylcymantrene and MeCpMn(CO)(2)(eta(2)-C2H4) solutes in SCF ethylene. These results represent the first NMR detected in situ photolysis study of organometallics in SCF and demonstrate the utility of this technique. C1 UNIV IDAHO, DEPT CHEM, MOSCOW, ID 83844 USA. RP Linehan, JC (reprint author), PACIFIC NW LAB, DEPT CHEM SCI, RICHLAND, WA 99352 USA. NR 32 TC 21 Z9 21 U1 0 U2 11 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 OCT 22 PY 1997 VL 119 IS 42 BP 10170 EP 10177 DI 10.1021/ja9711876 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA YD320 UT WOS:A1997YD32000025 ER PT J AU Ng, DS Francone, OL Forte, TM Zhang, JL Haghpassand, M Rubin, EM AF Ng, DS Francone, OL Forte, TM Zhang, JL Haghpassand, M Rubin, EM TI Differential impact of low HDL on lipid delivery to target tissues in lecithin: Cholesterol acyltransferase (LCAT) deficient mice SO CIRCULATION LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. PFIZER INC,PFIZER CENT RES,GROTON,CT 06340. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 18 EP 18 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88000018 ER PT J AU Bielicki, JK Lee, BC Knoff, LJ Forte, TM AF Bielicki, JK Lee, BC Knoff, LJ Forte, TM TI Gas-phase cigarette smoke inhibits plasma platelet activating factor acetylhydrolase activity SO CIRCULATION LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 925 EP 925 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88000927 ER PT J AU Giedd, KN Amols, H Marboe, CC Weinberger, J AF Giedd, KN Amols, H Marboe, CC Weinberger, J TI Effectiveness of a beta-emitting liquid-filled perfusion balloon to prevent restenosis SO CIRCULATION LA English DT Meeting Abstract C1 COLUMBIA UNIV,NEW YORK,NY. OAK RIDGE NATL LAB,OAK RIDGE,TN. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1215 EP 1215 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001213 ER PT J AU Stevens, ME Cooper, PN Holl, LG Verstuyft, JG Rubin, EM AF Stevens, ME Cooper, PN Holl, LG Verstuyft, JG Rubin, EM TI Atherogenesis in Apo(a) YAC transgenics on an ApoE knock-out background SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1249 EP 1249 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001258 ER PT J AU vanAntwerpen, R Labelle, M Gilkey, JC Krauss, RM AF vanAntwerpen, R Labelle, M Gilkey, JC Krauss, RM TI Structural differences between very-low-density, intermediate-density and low-density lipoproteins visualized using cryo-electron microscopy SO CIRCULATION LA English DT Meeting Abstract C1 UNIV ARIZONA,TUCSON,AZ 85721. UNIV CALIF BERKELEY,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1252 EP 1252 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001261 ER PT J AU LaBelle, M Takanami, Y Krauss, RM Blanche, PJ Chu, BM Gong, EL Tribble, DL AF LaBelle, M Takanami, Y Krauss, RM Blanche, PJ Chu, BM Gong, EL Tribble, DL TI Human plasma platelet-activating factor acetylhydrolase is preferentially associated with an Apo C-III-containing LDL subpopulation SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1254 EP 1254 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001263 ER PT J AU Forte, TM Oda, MN Knoff, LJ Rubin, EM Ng, DS AF Forte, TM Oda, MN Knoff, LJ Rubin, EM Ng, DS TI Targeted disruption of the mouse lecithin: Cholesterol acyltransferase gene is associated with reduction of plasma paraoxonase and platelet-activating factor acetylhydrolase activities SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1260 EP 1260 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001269 ER PT J AU Bielicki, JK Cham, GW Forte, TM AF Bielicki, JK Cham, GW Forte, TM TI Evidence that lipid hydroperoxides inhibit lecithin: Cholesterol acyltransferase (LCAT) activity SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 1261 EP 1261 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88001270 ER PT J AU Tribble, DL BarcellosHoff, MH Rubin, EM Leeuwenburgh, C Heinecke, JW Gong, EL AF Tribble, DL BarcellosHoff, MH Rubin, EM Leeuwenburgh, C Heinecke, JW Gong, EL TI Ionizing radiation accelerates aortic lesion formation in fat-fed mice via a mechanism that is inhibited by overexpression of Cu/Zn superoxide dismutase SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. WASHINGTON UNIV,ST LOUIS,MO. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 2325 EP 2325 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002313 ER PT J AU Lanza, GM Trousil, R Hall, CS Rose, JH Wallace, KD Scott, MJ Miller, JG Gaffney, PJ Wickline, SA AF Lanza, GM Trousil, R Hall, CS Rose, JH Wallace, KD Scott, MJ Miller, JG Gaffney, PJ Wickline, SA TI A simple theoretical model for the unexpected acoustic enhancement of thrombi effected by a novel, liquid, fibrin targeted contrast system SO CIRCULATION LA English DT Meeting Abstract C1 WASHINGTON UNIV,BARNES JEWISH HOSP,ST LOUIS,MO. AMES LAB,AMES,IA. NIBSC,POTTERS BAR,HERTS,ENGLAND. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 2558 EP 2558 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002544 ER PT J AU Blanche, PJ Huang, SR Holl, LG Krauss, RM Berkeley, L AF Blanche, PJ Huang, SR Holl, LG Krauss, RM Berkeley, L TI Changes in LDL subclass distribution on a hypercholesterolemic diet in mice with targeted inactivation of the LDL receptor SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 2675 EP 2675 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002661 ER PT J AU Budinger, TF Schepkin, VD Taylor, SE Choy, IO AF Budinger, TF Schepkin, VD Taylor, SE Choy, IO TI Comparison of triple quantum filtered (TQF) Na-NMR with intracellular Na determined by Co-EDTA perfusion and atomic absorption spectroscopy SO CIRCULATION LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RI Schepkin, Victor/A-1245-2007 NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 2885 EP 2885 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002867 ER PT J AU Marshall, RC PowersRisius, P Huesman, RH Taylor, SE Reutter, BW Budinger, TF AF Marshall, RC PowersRisius, P Huesman, RH Taylor, SE Reutter, BW Budinger, TF TI Estimation of glucose metabolism with fluorodeoxyglucose and deoxyglucose in the rabbit heart using Sokoloff and Patlak models SO CIRCULATION LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 3006 EP 3006 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002988 ER PT J AU Superko, HR Krauss, RM Alderman, EL AF Superko, HR Krauss, RM Alderman, EL TI Diabetics have rapid arteriographic coronary disease progression but also arteriographic benefit from risk reduction SO CIRCULATION LA English DT Meeting Abstract C1 BERKELEY HEARTLAB,SAN MATEO,CA. LAWRENCE BERKELEY NATL LAB,BERKELEY,CA. STANFORD UNIV,STANFORD,CA 94305. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0009-7322 J9 CIRCULATION JI Circulation PD OCT 21 PY 1997 VL 96 IS 8 SU S BP 4289 EP 4289 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YC880 UT WOS:A1997YC88002437 ER PT J AU Erber, T Guralnick, SA Desai, RD Kwok, W AF Erber, T Guralnick, SA Desai, RD Kwok, W TI Piezomagnetism and fatigue SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID MN PIPELINE STEEL; NONDESTRUCTIVE EVALUATION; SQUID MAGNETOMETRY; HYSTERESIS LOOPS; MAGNETIC METHODS; STRESS; MODEL; BEHAVIOR; COLLAPSE; FIELD AB Piezomagnetism refers to a change in the intrinsic magnetization of a material subjected to mechanical actions such as tension or compression. In a ferromagnet such as a mild steel these effects are easily measured: typically a stress of 2 x 10(4) lbs in 2 or 140 MPa induces a magnetic moment of the order of 5 x 10(-3) emu or 5 x 10(-6) A m(2), resulting in flux densities in the range 10 mG or 1 mu T in the vicinity of the specimen, Since piezomagnetic effects are due to interactions between the mechanical and magnetic mesostructure of materials microplastic processes that alter the arrangement of the ferromagnetic domain structure affect the intensity of the associated magnetic fields. The progressive degradation of such materials under cyclic loading can therefore he tracked by following the evolution of the piezomagnetic field. Specifically, if the measurements are displayed as loci in a three-dimensional stress (sigma)-strain (epsilon)-field (B) space, the approach to fatigue failure is paralleled by a series of conspicuous geometric transformations of these curves. Complementary information also appears in continuous-time records of B(f): these magnetograms clearly show the abrupt incidence of 'infarcts' (microcracks) and the cumulation of phase shifts as the material degrades. C1 IIT,DEPT COMP SCI & APPL MATH,CHICAGO,IL 60616. IIT,DEPT CIVIL ENGN,CHICAGO,IL 60616. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Erber, T (reprint author), IIT,DEPT PHYS,CHICAGO,IL 60616, USA. RI 张, 军/I-1551-2012 NR 68 TC 30 Z9 32 U1 1 U2 15 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD OCT 21 PY 1997 VL 30 IS 20 BP 2818 EP 2836 DI 10.1088/0022-3727/30/20/008 PG 19 WC Physics, Applied SC Physics GA YC597 UT WOS:A1997YC59700008 ER PT J AU Dulya, C Adams, D Adeva, B Arik, E Arvidson, A Badelek, B Ballintijn, MK Bardin, D Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P Bonner, BE deBotton, N Boutemeur, M Bradamante, F Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T DallaTorre, S vanDantzig, R Derro, B Deshpande, A Dhawan, S Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Frois, B Gallas, A Garzon, JA Gaussiran, T Gehring, R Giorgi, M vonGoeler, E Goertz, S Gomez, F Gracia, G deGroot, N Perdekamp, MG Gulmez, E Harmsen, J vonHarrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Kalinovskaya, L Karev, A Kessler, HJ Ketel, TJ Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U LeGoff, JM Lehar, F deLesquen, A Lichtenstadt, J Lindqvist, T Litmaath, M Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K Meyer, W vanMiddelkoop, G Miller, D Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Parks, DP PerrotKunne, F Peshekhonov, D Piegaia, R Pinsky, L Platchkov, S Plo, M Pose, D Postma, H Pretz, J Pussieux, T Pyrlik, J Reicherz, G Reyhancan, I Rijllart, A Roberts, JB Rock, S Rodriguez, M Rondio, E Rosado, A Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schuler, KP Segel, R Seitz, R Semertzidis, Y Sever, F Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Teichert, KM Tessarotto, F Tlaczala, W Tripet, A Unel, G Velasco, M Vogt, J Voss, R Weinstein, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Yanez, A Ylostalo, J Zanetti, AM Zaremba, K Zhao, J AF Dulya, C Adams, D Adeva, B Arik, E Arvidson, A Badelek, B Ballintijn, MK Bardin, D Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P Bonner, BE deBotton, N Boutemeur, M Bradamante, F Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T DallaTorre, S vanDantzig, R Derro, B Deshpande, A Dhawan, S Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Frois, B Gallas, A Garzon, JA Gaussiran, T Gehring, R Giorgi, M vonGoeler, E Goertz, S Gomez, F Gracia, G deGroot, N Perdekamp, MG Gulmez, E Harmsen, J vonHarrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Kalinovskaya, L Karev, A Kessler, HJ Ketel, TJ Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U LeGoff, JM Lehar, F deLesquen, A Lichtenstadt, J Lindqvist, T Litmaath, M Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K Meyer, W vanMiddelkoop, G Miller, D Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Parks, DP PerrotKunne, F Peshekhonov, D Piegaia, R Pinsky, L Platchkov, S Plo, M Pose, D Postma, H Pretz, J Pussieux, T Pyrlik, J Reicherz, G Reyhancan, I Rijllart, A Roberts, JB Rock, S Rodriguez, M Rondio, E Rosado, A Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schuler, KP Segel, R Seitz, R Semertzidis, Y Sever, F Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Teichert, KM Tessarotto, F Tlaczala, W Tripet, A Unel, G Velasco, M Vogt, J Voss, R Weinstein, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Yanez, A Ylostalo, J Zanetti, AM Zaremba, K Zhao, J TI A line-shape analysis for spin-1 NMR signals SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID POLARIZATION MEASUREMENT; DEUTERON POLARIZATION; Q-METER; TARGET AB An analytic model of the deuteron absorption function has been developed and is compared to experimental NMR signals of deuterated butanol obtained at the SMC experiment in order to determine the deuteron polarization. The absorption function model includes dipolar broadening and a frequency-dependent treatment of the intensity factors. The high-precision TE signal data available are used to adjust the model for Q-meter distortions and dispersion effects. Once the Q-meter adjustment is made, the enhanced polarizations determined by the asymmetry and TE-calibration methods compare well within the accuracy of each method. In analyzing the NMR signals, the quadrupolar coupling constants could be determined for both the C-D and the O-D bonds of deuterated butanol. C1 RICE UNIV,BONNER LAB,HOUSTON,TX 77251. UNIV SANTIAGO,DEPT PARTICLE PHYS,SANTIAGO COMPOSTE 15706,SPAIN. UNIV UPPSALA,DEPT RADIAT SCI,S-75121 UPPSALA,SWEDEN. ISTANBUL UNIV,ISTANBUL TECH UNIV,CEKMECE NUCL RES CTR,ISTANBUL,TURKEY. BOGAZICI UNIV,ISTANBUL,TURKEY. SOLTAN INST NUCL STUDIES,PL-00681 WARSAW,POLAND. UNIV WARSAW,PL-00681 WARSAW,POLAND. CENS,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. UNIV BIELEFELD,DEPT PHYS,D-33501 BIELEFELD,GERMANY. HELSINKI UNIV TECHNOL,LOW TEMP LAB,FIN-02150 ESPOO,FINLAND. INST PARTICLE PHYS,ESPOO 02150,FINLAND. UNIV MUNICH,DEPT PHYS,D-80799 MUNICH,GERMANY. IST NAZL FIS NUCL,I-34127 TRIESTE,ITALY. UNIV TRIESTE,DEPT PHYS,I-34127 TRIESTE,ITALY. YALE UNIV,DEPT PHYS,NEW HAVEN,CT 06511. UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. INST BEAM PARTICLE DYNAM,HOUSTON,TX 77204. CERN,CH-1211 GENEVA 23,SWITZERLAND. NIKHEF,NL-1009 AJ AMSTERDAM,NETHERLANDS. DELFT UNIV TECHNOL,NL-1009 AJ AMSTERDAM,NETHERLANDS. FOM,NL-1009 AJ AMSTERDAM,NETHERLANDS. FREE UNIV AMSTERDAM,NL-1009 AJ AMSTERDAM,NETHERLANDS. INST HOCHENERGIEPHYS,D-15738 ZEUTHEN,GERMANY. MIYAZAKI UNIV,FAC ENGN,MIYAZAKI 88921,JAPAN. PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. RIKEN,INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. UNIV CALIF SANTA CRUZ,INST PARTICLE PHYS,SANTA CRUZ,CA 95064. KEK NAT LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. JINR,BOGOLIUBOV LAB THEORET PHYS,RU-141980 DUBNA,RUSSIA. UNIV BUENOS AIRES,DEPT PHYS,RA-1428 BUENOS AIRES,DF,ARGENTINA. AMERICAN UNIV,WASHINGTON,DC 20016. BROOKHAVEN NATL LAB,UPTON,NY 11973. RUHR UNIV BOCHUM,DEPT PHYS,D-44780 BOCHUM,GERMANY. NORTHEASTERN UNIV,DEPT PHYS,BOSTON,MA 02115. UNIV MAINZ,INST NUCL PHYS,D-55099 MAINZ,GERMANY. NAGOYA UNIV,CIRSE,CHIKUSA KU,NAGOYA,AICHI 464,JAPAN. NAGOYA UNIV,DEPT PHYS,CHIKUSA KU,NAGOYA,AICHI 464,JAPAN. UNIV FREIBURG,DEPT PHYS,D-79104 FREIBURG,GERMANY. TEL AVIV UNIV,SCH PHYS,IL-69978 TEL AVIV,ISRAEL. NAGOYA UNIV,COLL MED TECHNOL,HIGASHI KU,NAGOYA,AICHI 461,JAPAN. GKSS FORSCHUNGSZENTRUM GEESTHACHT GMBH,D-21494 GEESTHACHT,GERMANY. UNIV MONS,FAC SCI,B-7000 MONS,BELGIUM. JINR,LAB PARTICLE PHYS,DUBNA,RUSSIA. RP Dulya, C (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,405 HILGARD AVE,LOS ANGELES,CA 90024, USA. RI de Groot, Nicolo/A-2675-2009; Hautle, Patrick/C-1044-2012; Zanetti, Anna/I-3893-2012; Martin, Anna/I-9381-2012; CAVATA, Christian/P-6496-2015; Zhao, Jinkui/B-7872-2013; Le Goff, Jean-Marc/E-7629-2013; Semertzidis, Yannis K./N-1002-2013; Gallas Torreira, Abraham Antonio/K-6508-2014; Gomez, Faustino/L-7288-2014; Plo Casasus, Maximo/M-1445-2014; Adeva, Bernardo /L-1378-2014; Saborido Silva, Juan Jose/K-1775-2014; Gulmez, Erhan/P-9518-2015; Yanez, Armando/L-2957-2014; OI Hautle, Patrick/0000-0002-0502-8278; Martin, Anna/0000-0002-1333-0143; Zhao, Jinkui/0000-0002-7756-1952; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954; Gomez, Faustino/0000-0002-6147-8425; Plo Casasus, Maximo/0000-0002-2289-918X; Adeva, Bernardo /0000-0001-9756-3712; Saborido Silva, Juan Jose/0000-0002-6270-130X; Gulmez, Erhan/0000-0002-6353-518X; Yanez, Armando/0000-0003-4626-7993; Gaussiran, Thomas/0000-0002-5442-7507 NR 21 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 109 EP 125 DI 10.1016/S0168-9002(97)00317-3 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500001 ER PT J AU Zimmermann, F AF Zimmermann, F TI An estimate of gas desorption in the damping rings of the next linear collider SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID BEAM-ION INSTABILITY; COEFFICIENTS AB We express the gas desorption in a high-energy electron or positron storage ring in terms of the photoemission and the electron-induced gas-desorption yields of the vacuum-chamber material. The derived expression is used to estimate the gas desorption in the two main damping rings of the Next Linear Collider (NLC) and, in particular, its dependence on the height of the slots which connect the beam pipe proper to an antechamber. RP Zimmermann, F (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 131 EP 138 DI 10.1016/S0168-9002(97)00655-4 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500003 ER PT J AU Chen, YJ AF Chen, YJ TI Control of transverse motion caused by chromatic aberration and misalignments in linear accelerators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Corkscrew beam motion is caused by chromatic aberration and misalignment of a focusing system. To minimize chromatic aberration, we have developed a time-independent steering algorithm that minimizes the observed corkscrew-amplitude averaged over the beam pulse. The steering algorithm can he done quickly and is not sensitive to the alignment, calibration and spacing of the beam position monitors. The steering algorithm can also be used even if the corkscrew motion caused by a given misaligned magnet is fully developed, i.e., the relative phase advance is greater than 2 pi. In this paper, we will discuss corkscrew motion, the optimal dynamic alignment procedure, its corkscrew reduction factor, and the effects of beam position monitors' spacing. RP Chen, YJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-440,LIVERMORE,CA 94551, USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 139 EP 146 DI 10.1016/S0168-9002(97)00738-9 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500004 ER PT J AU Burman, RL Plischke, P AF Burman, RL Plischke, P TI Neutrino fluxes from a high-intensity spallation neutron facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CHARGED PIONS; PROTONS; NUCLEI AB The neutrino production rates for a spallation neutron source with proton beams in the energy range 650 < T-p < 2200 MeV calculated to an estimated accuracy of 25%. The target geometries used are based on the tantalum and mercury targets proposed for the European Spallation Source. Results for nu(mu), nu(e), and <(nu)over bar (mu>) rates due to pi(+) and mu(+) decay at rest, and for nu(mu) rates from pi(+) decay in flight, are presented in terms of neutrinos per proton. Production rates for decay at rest from a tantalum target are calculated to be (v p(-1)) = 0.075 at T-p = 1000 MeV, and 0.327 at 2200 MeV. For a neutrino detector located 20 m from a tantalum target, and at 0 degrees to a 1500 MeV proton beam, the integrated flux of nu(mu) above 150 MeV from pi(+) decay in flight is 3.0 x 10(5) cm(-2) s(-1). Backgrounds of <(nu)over bar (e)>, from the pi(-) decay-in-flight and mu(-) decay-at-rest chain, vary from 0.05% to 0.09% of the nu(e) flux. C1 LOS ALAMOS NATL LAB,P DIV P25 MS H846,LOS ALAMOS,NM 87545. RP Burman, RL (reprint author), FORSCHUNGSZENTRUM KARLSRUHE,INST KERNPHYS 1,D-76021 KARLSRUHE,GERMANY. NR 18 TC 4 Z9 4 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 OCT 21 PY 1997 VL 398 IS 2-3 BP 147 EP 156 DI 10.1016/S0168-9002(97)00821-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500005 ER PT J AU Bogorad, P Brash, EJ Cates, GD Cummings, WJ Gorelov, A Hasinoff, MD Hausser, O Hicks, K Holmes, R Huang, JC Krieger, D Kumar, KS Larson, B Lorenzon, W McCracken, J Michaux, P Middleton, H Saettler, E Siegel, D Souder, PA Swenson, DR Thywissen, J Tupa, D Ullom, J Wang, X Young, AR AF Bogorad, P Brash, EJ Cates, GD Cummings, WJ Gorelov, A Hasinoff, MD Hausser, O Hicks, K Holmes, R Huang, JC Krieger, D Kumar, KS Larson, B Lorenzon, W McCracken, J Michaux, P Middleton, H Saettler, E Siegel, D Souder, PA Swenson, DR Thywissen, J Tupa, D Ullom, J Wang, X Young, AR TI A combined polarized target/ionization chamber for measuring the spin dependence of nuclear muon capture in laser polarized muonic He-3 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE muon; pseudoscalar; ionization chamber; polarized target ID HELIUM ATOM; RB; EXCHANGE; GAS AB We describe a device used in experiment 1231 at LAMPF and in e683 at TRIUMF to study the spin dependence of the reaction mu(-) + He-3 --> H-3 + nu(mu). In order to study the spin dependence, we needed to form and polarize muonic He-3 and in the same volume detect the 1.9 MeV tritons created in the reaction. Furthermore, the recoil direction of the tritons had to be determined. The apparatus served both as a polarized target and as a detector. The detector, a gridded ion chamber, was incorporated inside a 51 polarized target that was filled with 8 atm of He-3 and 100 Torr of N-2 and rubidium metal. At the operating temperature of the device (205-230 degrees C), the rubidium number density was approximately 10(15) atoms/cm(3). Muons that stopped in the target formed muonic helium atoms, which were then polarized by collisions with optically pumped Rb vapor. Two high-powered GaAlAs diode laser arrays were used to polarize the Rb in the 100 cm(3) fiducial volume located inside the ion chamber. The ion chamber produced clean signals from the reaction tritons despite having to operate under the extreme conditions required for efficient optical pumping. The direction of the tritons was determined by analyzing the shapes of the ionization pulses. The muon polarization was measured using the decay electron asymmetry. C1 PRINCETON UNIV,PRINCETON,NJ 08544. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. SIMON FRASER UNIV,BURNABY,BC V5A 1S6,CANADA. UNIV BRITISH COLUMBIA,VANCOUVER,BC V6T 1Z,CANADA. OHIO UNIV,ATHENS,OH 45701. SYRACUSE UNIV,SYRACUSE,NY 13244. UNIV PENN,PHILADELPHIA,PA 19104. UNIV CALIF LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RI Thywissen, Joseph/E-8235-2010 OI Thywissen, Joseph/0000-0002-7007-8204 NR 47 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 211 EP 223 DI 10.1016/S0168-9002(97)00873-5 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500014 ER PT J AU Mebel, MV Iljinov, AS Grandi, C Reffo, G Blann, M AF Mebel, MV Iljinov, AS Grandi, C Reffo, G Blann, M TI Analysis of isotope yields and excitation functions for fissile and non-fissile nuclei with CEF and HMS-ALICE codes SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID LEVEL DENSITIES AB The CEF and ALICE nuclear reaction codes are benchmarked;via comparisons with activation yields for proton-induced reactions in the range of 50 MeV to 1.8 GeV with targets of Ni-58,Ni-62, Bi-209, Th-232, and U-238. The CEF code results are presented over the entire energy range, whereas results for the ALICE code are given only up to 480 MeV incident proton energy. Different targets have been irradiated in different energy intervals. The codes are generally succesful in reproducing the experimental yields and yield patterns. For the ALICE code, we find an underestimation of multiple charged particle emission in heavy elements. C1 ENEA,CTR DATI NUCL,I-40129 BOLOGNA,ITALY. RUSSIAN ACAD SCI,INST NUCL RES,RU-117312 MOSCOW,RUSSIA. LAWRENCE LIVERMORE NATL LAB,E DIV,LIVERMORE,CA 94551. RI Grandi, Claudio/B-5654-2015 OI Grandi, Claudio/0000-0001-5998-3070 NR 30 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 324 EP 342 DI 10.1016/S0168-9002(97)00779-1 PG 19 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500026 ER PT J AU Menk, RH Thomlinson, W Gmur, N Zhong, Z Chapman, D Arfelli, F Dix, WR Graeff, W Lohmann, M Illing, G Schildwachter, L Reime, B Kupper, W Hamm, C Giacomini, JC Gordon, HJ Rubenstein, E Dervan, J Besch, HJ Walenta, AH AF Menk, RH Thomlinson, W Gmur, N Zhong, Z Chapman, D Arfelli, F Dix, WR Graeff, W Lohmann, M Illing, G Schildwachter, L Reime, B Kupper, W Hamm, C Giacomini, JC Gordon, HJ Rubenstein, E Dervan, J Besch, HJ Walenta, AH TI The concept of spatial frequency depending DQE and its application to a comparison of two detectors used in transvenous coronary angiography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE transvenous coronary angiography; photon integrating detectors; spatial frequencies depending detective quantum efficiency; modulation transfer function; noise power spectrum ID SYNCHROTRON-RADIATION AB A comparison of two different multi-channel line detectors utilized in transvenous coronary angiography was performed. An Li+ drifted silicon strip detector (SSD) was tested at the SMERF facility X17B2 at the National Synchrotron Light Source (NSLS). An ionization chamber (IC) was tested at the W2 beamline at HASYLAB. Both detectors were operated in the charge-integrating mode. The main purpose was to measure and compare the Modulation Transfer Function (MTF(f)), Noise Power Spectrum (NPS(f)), Detective Quantum Efficiency (DQE(f)) in terms of spatial frequencies and the dynamic range of both detector systems. Tt turned out that the IC is superior to the SSD in time resolution and dynamic range at a single gain setting and has a slight advantage in the transmission of high spatial frequencies. Although for high photon flux the DQE values of the IC exceed those of the SSD, it is the reverse for low photon flux caused by a higher noise floor of the read-out electronics. This makes the SSD superior to the IC since the incident flux is limited by the tolerable entry dose to the patients. For the comparison other criteria like price, reliability, maintenance, etc., are not taken into consideration. C1 IIT,CSRRI,CHICAGO,IL 60616. ELETTRA,I-34012 TRIESTE,ITALY. DESY,HAMBURGER SYNCHROTRONSTRAHLUNGSLAB HASYLAB,DEUTSCH ELEKTR SYNCHROTRON,D-22603 HAMBURG,GERMANY. HERZ KREISLAUF KLIN BEVENSEN,BAD BEVENSON,GERMANY. UNIV HAMBURG,KLIN EPPENDORF,MED KLIN,D-20246 HAMBURG,GERMANY. STANFORD UNIV,DEPT MED,STANFORD,CA 94305. SUNY STONY BROOK,HLTH SCI CTR,DIV CARDIOL,STONY BROOK,NY 11794. UNIV GESAMTHSCH SIEGEN,D-57068 SIEGEN,GERMANY. RP Menk, RH (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973, USA. NR 15 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 21 PY 1997 VL 398 IS 2-3 BP 351 EP 367 DI 10.1016/S0168-9002(97)00788-2 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YD975 UT WOS:A1997YD97500028 ER PT J AU Doshi, P Jellison, GE Rohatgi, A AF Doshi, P Jellison, GE Rohatgi, A TI Characterization and optimization of absorbing plasma-enhanced chemical vapor deposited antireflection coatings for silicon photovoltaics SO APPLIED OPTICS LA English DT Article DE antireflection coatings; plasma-enhanced chemical vapor deposition; silicon; silicon nitride; photovoltaics; solar cells; absorption ID SOLAR-CELLS; HYDROGEN CONTENT; SPECTROSCOPIC ELLIPSOMETRY; SURFACE; PASSIVATION; NITRIDE; FILMS AB We have optimized plasma-enhanced chemical vapor deposition (PECVD) of SM-based antireflection (AR) coatings with special consideration for the short-wavelength (<600 nm) parasitic absorption in SiN. Spectroscopic ellipsometry was used to measure the dispersion relation for both the refractive index n and the extinction coefficient k, allowing a precise analysis of the trade-off between reflection and absorption in SiN-based AR coatings. Although we focus on photovoltaic applications, this study may be useful for photodetectors, IR optics, and any device for which it is essential to maximize the transmission of light into silicon. We designed and optimized various AR coatings for minimal average (spectrally) weighted reflectance ([R-w]) and average weighted absorptance ([A(w)]), using the air mass 1.5 global solar spectrum. In most situations [R-w] decreased with higher n, but [A(w)] increased because k increased with n. For the practical case of a single-layer AR coating for silicon under glass, an optimum refractive index of similar to 2.23 (at 632.8 nm) was determined. Further simulations revealed that a double-layer SiN stack with an n = 2.42 film underneath an n = 2.03 film gives the minimum total photocurrent loss, Similar optimization of double-layer SiN/SiO2 coatings for silicon in air revealed an optimum of n = 2.28 for SiN. To determine the allowable tolerance in index and film thickness, we generated isotransmittance plots, which revealed more leeway for n values below the optimum than above because absorption begins to reduce photocurrent for high n values. (C) 1997 Optical Society of America. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Doshi, P (reprint author), GEORGIA INST TECHNOL,CTR EXCELLENCE PHOTOVOLTA RES & EDUC,DEPT ELECT & COMP ENGN,ATLANTA,GA 30332, USA. NR 26 TC 100 Z9 102 U1 1 U2 36 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1997 VL 36 IS 30 BP 7826 EP 7837 DI 10.1364/AO.36.007826 PG 12 WC Optics SC Optics GA YB133 UT WOS:A1997YB13300051 PM 18264309 ER PT J AU Fritz, IJ Hafich, MJ Casalnuovo, SA AF Fritz, IJ Hafich, MJ Casalnuovo, SA TI Electric-field-independent band gap superpositioning at 1.3 mu m in an InGaAs-InAlAs strained-layer superlattice SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM-WELL STRUCTURES; HEAVY-HOLE; LIGHT-HOLE; ELECTROABSORPTION; ABSORPTION; MODULATORS; ENHANCEMENT; DEPENDENCE AB We report on the electric-field dependent band-gap energy and near-gap absorption coefficient of a specially designed strained-layer superlattice (SLS) employing tensile strained quantum wells and having a band-gap wavelength near 1.3 mu m. The SLS was grown by molecular-beam epitaxy on an InP substrate and consists of In0.43Ga0.57As wells (4.5-nm-thick) and In0.6Al0.4As barriers (6.75-nm-thick). For applied fields from zero up to at least 2.5 X 10(5) V/cm the band-edge absorption exhibits a single peak, which we attribute to a field-independent superpositioning of the heavy-and light-hole ground states, This result agrees with tunneling resonance calculations, which predict these hole states to have the same zero-field energy and to undergo nearly identical Stark shifts. Absorption-coefficient changes of up to 10(4) cm(-1) were readily achieved with applied biases under 15 V, suggesting potential applications to optical modulator devices. (C) 1997 American Institute of Physics. RP Fritz, IJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 13 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 OCT 20 PY 1997 VL 71 IS 16 BP 2352 EP 2354 DI 10.1063/1.120027 PG 3 WC Physics, Applied SC Physics GA YB436 UT WOS:A1997YB43600043 ER PT J AU Washburn, NR Stacy, AM Portis, AM AF Washburn, NR Stacy, AM Portis, AM TI Low-temperature, flux-grown, Na-doped LaMnO3: Magnetic properties (vol 70, pg 1622, 1997) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 1 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 20 PY 1997 VL 71 IS 16 BP 2397 EP 2397 DI 10.1063/1.120564 PG 1 WC Physics, Applied SC Physics GA YB436 UT WOS:A1997YB43600058 ER PT J AU Tang, IN Tridico, AC Fung, KH AF Tang, IN Tridico, AC Fung, KH TI Thermodynamic and optical properties of sea salt aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER ACTIVITIES; ELECTRODYNAMIC BALANCE; ELECTROLYTE-SOLUTIONS; HYGROSCOPIC AEROSOLS; AMMONIUM-SULFATE; REFRACTIVE-INDEX; PARTICLES AB Sea salt particles are constantly produced from ocean surfaces by wave-wind interactions and removed by deposition and precipitation scavenging. These particles constitute the background aerosol for light scattering in the marine boundary layer. In this work, the thermodynamic and optical properties of sea salt aerosol particles generated from seawater samples are measured at 25 degrees C as a function of relative humidity, using a single-particle levitation technique. Water activities, densities, and refractive indices of aqueous solution droplets containing a single salt NaCl, Na2SO4, MgCl2, or MgSO4 are also reported as a function of concentration. The light-scattering properties of the sea salt aerosol are modeled by the external mixture of these four salt systems selected to approximate the sea salt composition. Good agreements are obtained. It follows that in either visibility reduction or radiative forcing calculations, both freshly produced and aged sea salt aerosols may be modeled by external mixtures of the appropriate inorganic salts, whose solution properties are now available in the literature. RP Tang, IN (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, BLDG 815, UPTON, NY 11973 USA. NR 34 TC 205 Z9 207 U1 9 U2 49 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1997 VL 102 IS D19 BP 23269 EP 23275 DI 10.1029/97JD01806 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YC171 UT WOS:A1997YC17100003 ER PT J AU Ansell, S DupuyPhilon, J Jal, JF Neilson, GW AF Ansell, S DupuyPhilon, J Jal, JF Neilson, GW TI Ionic structure in the aqueous electrolyte glass LiCl center dot 4D(2)O SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID NEUTRON-DIFFRACTION; CHLORIDE SOLUTIONS; LITHIUM-CHLORIDE; TRANSITION; HYDRATION; LIQUID AB The difference methods of neutron diffraction and isotopic substitution were applied to Li+ and Cl- in the aqueous lithium chloride glass LiCl . 4D(2)O at 120 K (the glass transition T-g = 150 K). Results for the ionic hydration show that structural changes are more evident for the Cl- coordination than for the Li+ coordination. At the level of the anion-anion structure there is an appreciable increase in the nearest-neighbour coordination number over that in the liquid which suggests a greater degree of correlation between the Cl- anion and the water molecules. A model of the ionic structure is proposed to explain the relative ease of classification of concentrated aqueous lithium chloride solutions. C1 UNIV BRISTOL,HH WILLS PHYS LAB,BRISTOL BS8 1TL,AVON,ENGLAND. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV LYON 1,DEPT PHYS MAT,F-69622 VILLEURBANNE,FRANCE. NR 20 TC 17 Z9 17 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 20 PY 1997 VL 9 IS 42 BP 8835 EP 8847 DI 10.1088/0953-8984/9/42/002 PG 13 WC Physics, Condensed Matter SC Physics GA YC577 UT WOS:A1997YC57700002 ER PT J AU Lue, L Prausnitz, JM AF Lue, L Prausnitz, JM TI Structure and thermodynamics of homogeneous-dendritic-polymer solutions: Computer simulation, integral-equation, and lattice-cluster theory SO MACROMOLECULES LA English DT Article ID MONTE-CARLO SIMULATIONS; MONOMER STRUCTURE; STARBURST DENDRIMERS; BLENDS; COMPRESSIBILITY; CHEMISTRY; MOLECULES; TOPOLOGY; MICELLES; SHAPE AB We present some calculated structural and thermodynamic properties of homogeneous-dendritic-polymer solutions using computer simulation methods, integral-equation theory, and lattice-cluster theory. Monte-Carlo methods are used to sample conformations of polymer molecules. From these conformations, we first compute two properties of the polymer: the distribution of segments within the molecule and the radius of gyration. Simulations for nonattracting polymer pairs give the potential of mean force and the second virial coefficient. Given the potential of mean force between polymer molecules, we use integral-equation theory to calculate the equation of state of an athermal solution at low polymer concentrations. We apply lattice-cluster theory to obtain solvent activities and liquid-liquid equilibria for homogeneous-dendritic polymers in nonathermal concentrated solution. There is little difference between the vapor pressures of solutions of linear polymers and homogeneous-dendritic polymers. However, there is a modest difference between the liquid-liquid coexistence curve for linear-polymer solutions and homogeneous-dendrimer solutions. The critical temperatures of dendrimer solutions are lower than those of solutions containing corresponding linear polymers. This difference rises with increasing generation number and decreasing separator length. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Lue, Leo/E-7846-2011 OI Lue, Leo/0000-0002-4826-5337 NR 30 TC 49 Z9 49 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 20 PY 1997 VL 30 IS 21 BP 6650 EP 6657 DI 10.1021/ma961809s PG 8 WC Polymer Science SC Polymer Science GA YD345 UT WOS:A1997YD34500036 ER PT J AU Huang, S Ming, ZH Soo, YL Kao, YH Chang, T Fu, LP Gilliland, GD Klem, J Hafich, M AF Huang, S Ming, ZH Soo, YL Kao, YH Chang, T Fu, LP Gilliland, GD Klem, J Hafich, M TI Studies of interfacial roughness of GaAs/AlAs superlattices by grazing incidence X-ray scattering SO MODERN PHYSICS LETTERS B LA English DT Article ID MULTILAYERS; REFLECTIVITY; FLUORESCENCE; FILMS; SI AB A series of type-II GaAs/AlAs superlattices epitaxially grown with different interrupts have been investigated using the techniques of grazing incidence X-ray scattering and diffraction. The interrupts are specifically designed to alter the interfacial roughness in the superlattices for the present study. Various structural parameters including the layer thickness, interfacial roughness, and intra-layer correlation lengths of fluctuations in the quantum-well widths have been determined. These results are compared with measurements made on the same set of samples using photoluminescence and optical imaging techniques. C1 SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. Emory Univ, Dept Phys, Atlanta, GA 30322 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Huang, S (reprint author), SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD OCT 20 PY 1997 VL 11 IS 24 BP 1057 EP 1067 DI 10.1142/S0217984997001274 PG 11 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA YP333 UT WOS:000071266400003 ER PT J AU Schwengner, R Winter, G Schauer, W Grinberg, M Becker, F vonBrentano, P Eberth, J Enders, J vonEgidy, T Herzberg, RD Huxel, N Kaubler, L vonNeumannCosel, P Nicolay, N Ott, J Pietralla, N Prade, H Raman, S Reif, J Richter, A Schlegel, C Schnare, H Servene, T Skoda, S Steinhardt, T Stoyanov, C Thomas, HG Wiedenhover, I Zilges, A AF Schwengner, R Winter, G Schauer, W Grinberg, M Becker, F vonBrentano, P Eberth, J Enders, J vonEgidy, T Herzberg, RD Huxel, N Kaubler, L vonNeumannCosel, P Nicolay, N Ott, J Pietralla, N Prade, H Raman, S Reif, J Richter, A Schlegel, C Schnare, H Servene, T Skoda, S Steinhardt, T Stoyanov, C Thomas, HG Wiedenhover, I Zilges, A TI Two-phonon J=1 states in even-mass Te isotopes with A=122-130 (vol A620, pg 277, 1997) SO NUCLEAR PHYSICS A LA English DT Correction, Addition C1 TECH UNIV MUNICH,DEPT PHYS,D-85747 GARCHING,GERMANY. BULGARIAN ACAD SCI,INST NUCL RES & NUCL ENERGY,BU-1784 SOFIA,BULGARIA. UNIV COLOGNE,INST KERNPHYS,D-64289 COLOGNE,GERMANY. TECH UNIV DRESDEN,INST KERN & TEILCHENPHYS,D-01062 DRESDEN,GERMANY. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37830. YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520. TH DARMSTADT,INST KERNPHYS,D-64289 DARMSTADT,GERMANY. RP Schwengner, R (reprint author), FORSCHUNGSZENTRUM ROSSENDORF EV,INST KERN & HADRONENPHYS,D-01314 DRESDEN,GERMANY. RI Enders, Joachim/B-5501-2009; Zilges, Andreas/G-9984-2011; Herzberg, Rolf-Dietmar/E-1558-2011 OI Enders, Joachim/0000-0002-8441-378X; NR 1 TC 13 Z9 13 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 OCT 20 PY 1997 VL 624 IS 4 BP 776 EP 777 PG 2 WC Physics, Nuclear SC Physics GA YH606 UT WOS:A1997YH60600013 ER PT J AU Alder, BJ Runge, KJ Scalettar, RT AF Alder, BJ Runge, KJ Scalettar, RT TI Variational Monte Carlo study of an interacting electron-phonon model SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; STRONG-COUPLING MODELS; 3-BAND HUBBARD-MODEL; 2-DIMENSIONAL HUBBARD; LATTICE INSTABILITIES; BAPB1-XBIXO3 SYSTEM; SUPERCONDUCTIVITY; LA2CUO4; STATES; RENORMALIZATION AB The phase diagram of a Hamiltonian with both on-site repulsion between electrons and with hopping probabilities which depend on dynamically varying separations of neighboring lattice sites has been studied with a new variational ansatz. A rich phase diagram is obtained as a function of density, electron-electron, and electron-phonon interaction strengths. The superconducting regime is characterized by a pattern of short and long bonds correlated with resonating pair hopping, whereas for the charge density wave phase this pattern is nearly static, and in the disordered and antiferromagnetic regimes all bond lengths are practically the same. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Alder, BJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 32 TC 17 Z9 17 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 OCT 20 PY 1997 VL 79 IS 16 BP 3022 EP 3025 DI 10.1103/PhysRevLett.79.3022 PG 4 WC Physics, Multidisciplinary SC Physics GA YB664 UT WOS:A1997YB66400026 ER PT J AU Kouznetsov, KA Sun, AG Chen, B Katz, AS Bahcall, SR Clarke, J Dynes, RC Gajewski, DA Han, SH Maple, MB Giapintzakis, J Kim, JT Ginsberg, DM AF Kouznetsov, KA Sun, AG Chen, B Katz, AS Bahcall, SR Clarke, J Dynes, RC Gajewski, DA Han, SH Maple, MB Giapintzakis, J Kim, JT Ginsberg, DM TI c-axis Josephson tunneling between YBa2Cu3O7-delta and Pb: Direct evidence for mixed order parameter symmetry in a high-T-c superconductor SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-CRYSTALS; PAIRING STATE; HIGH-TEMPERATURE; S-WAVE; JUNCTIONS AB We report a new class of c-axis Josephson tunneling experiments in which a conventional superconductor (Pb) is deposited across a single twin boundary of a YBa2Cu3O7-delta (YBCO) crystal. We measure the critical current as a function of the magnitude and angle of a magnetic field applied in the plane of the junction. In all samples, we observe a clear experimental signature of an order parameter phase shift across the twin boundary. These results provide strong evidence for mixed d- and s-wave pairing in YBCO, with a reversal in the sign of the s-wave component across the twin boundary. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. RP Kouznetsov, KA (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 23 TC 175 Z9 175 U1 1 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 OCT 20 PY 1997 VL 79 IS 16 BP 3050 EP 3053 DI 10.1103/PhysRevLett.79.3050 PG 4 WC Physics, Multidisciplinary SC Physics GA YB664 UT WOS:A1997YB66400033 ER PT J AU Penetrante, BM Hsiao, MC Bardsley, JN Merritt, BT Vogtlin, GE Kuthi, A Burkhart, CP Bayless, JR AF Penetrante, BM Hsiao, MC Bardsley, JN Merritt, BT Vogtlin, GE Kuthi, A Burkhart, CP Bayless, JR TI Decomposition of methylene chloride by electron beam and pulsed corona processing SO PHYSICS LETTERS A LA English DT Article DE electron beam; pulsed corona; non-thermal plasma; methylene chloride ID DILUTE CONCENTRATIONS; CARBON-TETRACHLORIDE; PLASMA; CHCL3; AIR; STREAMS; CCL4 AB Experiments on the plasma-assisted decomposition of dilute concentrations of methylene chloride in atmospheric-pressure NZ and dry air streams by electron beam and pulsed corona processing are presented. This paper presents the first experimental evidence showing that the decomposition of methylene chloride in a non-thermal plasma at ambient gas temperature proceeds via reaction with nitrogen atoms. The decomposition is more efficient with energy deposition in electron beam generated plasmas because of the higher rate for electron-impact dissociation of Nz. In dry air mixtures, the decomposition of methylene chloride is degraded substantially because the nitrogen atoms are consumed in the production of nitrogen oxides. At higher gas temperatures (300 degrees C), the decomposition of methylene chloride in dry air is shown to proceed via reaction with oxygen atoms. The main products of methylene chloride decomposition in dry air mixtures are CO, CO2, HCl, and probably Cl-2. (C) 1997 Elsevier Science B.V. C1 FIRST POINT SCI INC,AGOURA HILLS,CA 91301. RP Penetrante, BM (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 TC 23 Z9 25 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 20 PY 1997 VL 235 IS 1 BP 76 EP 82 DI 10.1016/S0375-9601(97)00611-7 PG 7 WC Physics, Multidisciplinary SC Physics GA YB832 UT WOS:A1997YB83200013 ER PT J AU Eickmeier, C Junga, H Matzger, AJ Scherhag, F Shim, M Vollhardt, KPC AF Eickmeier, C Junga, H Matzger, AJ Scherhag, F Shim, M Vollhardt, KPC TI 5,6,11,12,17,18-hexadehydro-1,4,7,10,13,16-hexaethynyltribenzo[a,e,i]cyc lododecene: Synthesis and CpCo-catalyzed cycloisomerization to the first superdelocalized oligophenylenes SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE aromaticity; carbon allotropes; cyclotrimerizations; phenylenes; superdelocalization ID AROMATIC-COMPOUNDS; CARBON; BIPHENYLENE; PHENYLENES; CYCLOARENES; HYDROCARBON; AGGREGATION; PHENYLENES; MOLECULES; SKELETON C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Shim, Moonsub/A-7875-2009; Matzger, Adam/G-7497-2016 OI Shim, Moonsub/0000-0001-7781-1029; Matzger, Adam/0000-0002-4926-2752 NR 56 TC 57 Z9 57 U1 0 U2 7 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD OCT 17 PY 1997 VL 36 IS 19 BP 2103 EP 2108 DI 10.1002/anie.199721031 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA YC826 UT WOS:A1997YC82600017 ER PT J AU Cerritelli, ME Cheng, NQ Rosenberg, AH McPherson, CE Booy, FP Steven, AC AF Cerritelli, ME Cheng, NQ Rosenberg, AH McPherson, CE Booy, FP Steven, AC TI Encapsidated conformation of bacteriophage T7 DNA SO CELL LA English DT Article ID DOUBLE-STRANDED DNA; CRYO-ELECTRON-MICROSCOPY; HERPES-SIMPLEX VIRUS; X-RAY-DIFFRACTION; 3-DIMENSIONAL STRUCTURE; SECONDARY STRUCTURE; SIMIAN VIRUS-40; WILD-TYPE; HEADS; ORGANIZATION AB The structural organization of encapsidated T7 DNA was investigated by cryo-electron microscopy and image processing. A tail-deletion mutant was found to present two preferred views of phage heads: views along the axis through the capsid vertex where the connector protein resides and via which DNA is packaged; and side views perpendicular to this axis. The resulting images reveal striking patterns of concentric rings in axial views, and punctate arrays in side views. As corroborated by computer modeling, these data establish that the T7 chromosome is spooled around this axis in approximately six coaxial shells in a quasicrystalline packing, possibly guided by the core complex on the inner surface of the connector. C1 NIAMSD,STRUCT BIOL LAB,NIH,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 49 TC 252 Z9 256 U1 0 U2 14 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD OCT 17 PY 1997 VL 91 IS 2 BP 271 EP 280 DI 10.1016/S0092-8674(00)80409-2 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA YC350 UT WOS:A1997YC35000014 PM 9346244 ER PT J AU Ogino, T Kobuchi, H Sen, CK Roy, S Packer, L Maguire, JJ AF Ogino, T Kobuchi, H Sen, CK Roy, S Packer, L Maguire, JJ TI Monochloramine inhibits phorbol ester-inducible neutrophil respiratory burst activation and T cell interleukin-2 receptor expression by inhibiting inducible protein kinase C activity SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NF-KAPPA-B; NADPH-OXIDASE; SIGNAL-TRANSDUCTION; POLYMORPHONUCLEAR LEUKOCYTES; SUPEROXIDE PRODUCTION; INTRACELLULAR CA2+; ARACHIDONIC-ACID; BINDING-PROTEINS; ALPHA GENE; PHOSPHORYLATION AB Monochloramine derivatives are long lived physiological oxidants produced by neutrophils during the respiratory burst, The effects of chemically prepared monochloramine (NH2Cl) on protein kinase C (PKC) and PKC-mediated cellular responses were studied in elicited rat peritoneal neutrophils and human Jurkat T cells, Neutrophils pretreated with NH2Cl (30-50 mu M) showed a marked decrease in the respiratory burst activity induced by phorbol 12-myristate 13-acetate (PMA), which is a potent PKC activator. These cells, however, were viable and showed a complete respiratory burst upon arachidonic acid stimulation, which induces the respiratory burst by a PKC-independent mechanism, The NH2Cl-treated neutrophils showed a decrease in both PRC activity and PMA-induced phosphorylation of a 47-kDa protein, which corresponds to the cytosolic factor of NADPH oxidase, p47(phox). Jurkat T cells pretreated with NH2Cl (20-70 mu M) showed a decrease in the expression of the interleukin-a receptor a chain following PMA stimulation. This was also accompanied by a decrease in both PKC activity and nuclear transcription factor-kappa B activation, also without loss of cell viability, These results show that NH2Cl inhibits PKC-mediated cellular responses through inhibition of the inducible PKC activity. C1 UNIV CALIF BERKELEY,ENVIRONM ENERGY TECHNOL DIV,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Ogino, T (reprint author), UNIV CALIF BERKELEY,DEPT CELLULAR & MOL BIOL,LAWRENCE BERKELEY LAB,251 LSA,BERKELEY,CA 94720, USA. RI OGINO, Tetsuya/B-1999-2011; Sen, Chandan/A-8762-2013; Roy, sashwati/E-3990-2011 FU NIGMS NIH HHS [GM27345] NR 63 TC 25 Z9 25 U1 1 U2 3 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD OCT 17 PY 1997 VL 272 IS 42 BP 26247 EP 26252 DI 10.1074/jbc.272.42.26247 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YB139 UT WOS:A1997YB13900027 PM 9334193 ER PT J AU Nohaile, M Kern, D Wemmer, D Stedman, K Kustu, S AF Nohaile, M Kern, D Wemmer, D Stedman, K Kustu, S TI Structural and functional analyses of activating amino acid substitutions in the receiver domain of NtrC: Evidence for an activating surface SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE two-component systems; constitutive mutant forms of NtrC; phosphorylation; signal transduction; NMR chemical shift analysis ID CHEMOTAXIS PROTEIN CHEY; NITROGEN REGULATOR-I; ESCHERICHIA-COLI; SIGNAL-TRANSDUCTION; TRANSCRIPTIONAL ACTIVATOR; BACTERIAL CHEMOTAXIS; BACILLUS-SUBTILIS; RESPONSE REGULATOR; NMR-SPECTROSCOPY; ENTERIC BACTERIA AB The bacterial enhancer-binding protein NtrC activates transcription when phosphorylated on aspartate 54 in its amino (N)-terminal regulatory domain or when altered by constitutively activating amino acid substitutions. The N-terminal domain of NtrC, which acts positively on the remainder of the protein, is homologous to a large family of signal transduction domains called receiver domains. Phosphorylation of an aspartate residue in a receiver domain modulates the function of downstream target, but the accompanying structural changes are not clear. In the present work we examine structural and functional differences between the wild-type receiver domain of NtrC and mutant forms carrying constitutively activating substitutions. Combinations of such substitutions resulted in both increased structural changes in the N-terminal domain, monitored by NMR chemical shift differences, and increased transcriptional activation by the full-length protein. Structural changes caused by substitutions outside the active site (D86N and A89T) were not only local but extended over a substantial portion of the N-terminal domain including the region from alpha-helix 3 to beta-strand 5 (''3445 face'') and propagating to the active site. Interestingly, the activating substitution of glutamate for aspartate at the site of phosphorylation (D54E) also triggered structural changes in the 3445 face. Thus, the active site and the 3445 face appear to interact. Implications with respect to how phosphorylation may affect the structure of receiver domains and how structural changes may be communicated to the remainder of NtrC are discussed. (C) 1997 Academic Press Limited. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV BIOL STRUCT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CELL & MOL BIOL,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM38361] NR 92 TC 41 Z9 41 U1 3 U2 4 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 OCT 17 PY 1997 VL 273 IS 1 BP 299 EP 316 DI 10.1006/jmbi.1997.1296 PG 18 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YC180 UT WOS:A1997YC18000025 PM 9367763 ER PT J AU Brown, JH Enquist, BJ West, GB AF Brown, JH Enquist, BJ West, GB TI Allometric scaling laws in biology - Response SO SCIENCE LA English DT Letter C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Brown, JH (reprint author), UNIV NEW MEXICO,DEPT BIOL,ALBUQUERQUE,NM 87131, USA. NR 4 TC 8 Z9 8 U1 2 U2 23 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 17 PY 1997 VL 278 IS 5337 BP 372 EP 373 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YB355 UT WOS:A1997YB35500007 ER PT J AU Wang, XB Ding, CF Wang, LS AF Wang, XB Ding, CF Wang, LS TI Vibrationally resolved photoelectron spectra of TiCx- (x=2-5) clusters SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID CARBON CLUSTERS; THERMODYNAMIC PROPERTIES; ELECTRONIC-STRUCTURE; METALLOCARBOHEDRENES; SPECTROSCOPY; IRON; TRANSITION; NIOBIUM; RINGS; FECN AB Vibrationally resolved photoelectron spectra are obtained for the small TiCx- (x = 2-5) clusters. Adiabatic electron affinities (EAs) and low-lying electronic states are measured for the neutral TiCx clusters. While the EAs are similar for the series of clusters, 1.542 eV for TiC2, 1.561 eV for TiC3, 1.494 eV for TiC4, and 1.748 eV for TiC5, the observed ground-state vibrational frequencies decrease for the larger clusters: 560 cm(-1) for TiC2, 650 cm(-1) for TiC3, 440 cm(-1) for TiC4, and 240 cm(-1) for TiC5. The results are interpreted using ring-type structures that are known to be the ground-state structure for similar YCx and LaCx clusters. The current results provide the first and only spectroscopic and electronic information that will be valuable to test future theoretical calculations to understand the detailed structure and bonding of these simple titanium carbon clusters. C1 WASHINGTON STATE UNIV, DEPT PHYS, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 38 TC 48 Z9 49 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 16 PY 1997 VL 101 IS 42 BP 7699 EP 7701 DI 10.1021/jp971838k PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YB795 UT WOS:A1997YB79500003 ER PT J AU Buck, DR Savikhin, S Struve, WS AF Buck, DR Savikhin, S Struve, WS TI Effect of diagonal energy disorder on circular dichroism spectra of Fenna-Matthews-Olson trimers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID GREEN PHOTOSYNTHETIC BACTERIA; BACTERIOCHLOROPHYLL-A-PROTEIN; EXCITED-STATE STRUCTURE; PROSTHECOCHLORIS-AESTUARII; OPTICAL-SPECTRA; ABSORPTION; ANTENNA; CHLOROPHYLLS; MOLECULES; COMPLEX AB Circular dichroism spectra of Fenna-Matthews-Olson trimers (bacteriochlorophyll a-protein antenna complexes from green photosynthetic bacteria) are unusually sensitive to diagonal energy disorder because the resonance interactions between pigments belonging to different protein subunits are weak (less than or equal to 20 cm(-1)). Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Future simulations of FMO optical properties such as CD and pump-probe anisotropies should consider diagonal disorder in order to accurately describe this antenna's electronic structure. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,USDA,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 19 TC 6 Z9 6 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 16 PY 1997 VL 101 IS 42 BP 8395 EP 8397 DI 10.1021/jp971758g PG 3 WC Chemistry, Physical SC Chemistry GA YB794 UT WOS:A1997YB79400001 ER PT J AU Barkigia, KM Renner, MW Fajer, J AF Barkigia, KM Renner, MW Fajer, J TI Configurational multiplicity of porphyrin pi cation radicals: Nickel pi-pi dimers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID PHOTOSYNTHETIC REACTION-CENTER; MOLECULAR-STRUCTURE; CRYSTAL-STRUCTURE; CHLOROPHYLL; RESOLUTION; PEROXIDASE; RESONANCE; ORIGIN AB The molecular structure of the Ni(II)OEP+ClO4- pi cation radical is reported (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrin). The vibrational spectrum of a single crystal, recorded with an FT-IR micrcospectrometer, shows the (2)A(lu), HOMO occupancy marker band predicted for an OEP cation radical. The radical crystallizes as a cofacial pi-pi dimer, (NiOEP+ClO4-)(2) . 24=H2Cl2, in an eclipsed configuration with the following parameters: mean interplanar separation 3.36 Angstrom, Ni-Ni = 3.41 Angstrom, Ct-Ct = 3.46 Angstrom, lateral shift = 0.83 Angstrom, translational slip angle = 13.9 degrees, and zero rotation of equivalent N-Ni-N axes. This dimeric configuration differs significantly from that of a related (NiOEP+ClO4-)(2) . 8CH(2)Cl(2) dimer and from those of several other metallo (M) OEP radical dimers described previously. The present results offer exceptions to generalizations recently proposed regarding the geometry and extent of pi-pi interactions in fully and partially oxidized MOEP+ dimeric pi cation radicals such as (MOEP+)(2) and (MOEP)(2)(+). Indeed, the configuration and geometry of the (NiOEP+ClO4-)(2) dimer reported here are more akin to those of a half-oxidized dimer (NiOEP)(2)+SbCl6- than to those of a fully oxidized (NiOEP+ClO4-)2 dimer reported previously (Scheidt et al. Inorg. Chem. 1996, 35, 7500). The present results do demonstrate that identical porphyrin pi cation radicals can aggregate in and adopt more than one unique cofacial geometry with different conformations, pi-pi overlaps, and intermolecular spacings. Such multiple configurational architectures may help explain why the oxidized bacteriochlophyll dimers (special pairs) of bacterial photosynthetic reaction centers exhibit varying unpaired spin density profiles. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 31 TC 17 Z9 17 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 16 PY 1997 VL 101 IS 42 BP 8398 EP 8401 DI 10.1021/jp972380p PG 4 WC Chemistry, Physical SC Chemistry GA YB794 UT WOS:A1997YB79400002 ER PT J AU Bruinsma, PJ Smith, PA Bunker, BC AF Bruinsma, PJ Smith, PA Bunker, BC TI Dynamic mobility spectra of multicomponent colloidal suspensions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTROPHORETIC MOBILITY; PARTICLES AB Recently, the electrokinetic sonic amplitude (ESA) signal has been measured over a range of frequencies (collectively termed the dynamic mobility spectrum) for the simultaneous determination of particle charge and size in moderately concentrated suspensions. Based on these advances, we develop theory describing the dynamic mobility spectra for multicomponent suspensions, The dynamic mobility spectrum of multicomponent suspensions can be interpreted as the weighted sum of the individual component dynamic mobility spectra. Weighting coefficients are defined and a methodology for determining these weighting coefficients for binary suspensions with a least-squares technique is developed, Results from multicomponent suspension data are in good agreement with theory. Experimental conditions are restricted to constant pH and ionic strength to avoid changes in the shape of the dynamic mobility spectra of the components, possibly due to agglomeration effects. RP Bruinsma, PJ (reprint author), PACIFIC NW NATL LAB,MAIL STOP K8-93,RICHLAND,WA 99352, USA. NR 12 TC 6 Z9 6 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 16 PY 1997 VL 101 IS 42 BP 8410 EP 8417 DI 10.1021/jp970892y PG 8 WC Chemistry, Physical SC Chemistry GA YB794 UT WOS:A1997YB79400004 ER PT J AU Jameson, CJ Jameson, AK Gerald, RE Lim, HM AF Jameson, CJ Jameson, AK Gerald, RE Lim, HM TI Anisotropic Xe chemical shifts in zeolites. The role of intra- and intercrystallite diffusion SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; NA-A ZEOLITE; MOLECULAR-DYNAMICS SIMULATION; MONTE-CARLO SIMULATIONS; XE-129 NMR; MICROPOROUS SOLIDS; Y-ZEOLITES; CATION LOCATION; SELF-DIFFUSION; RARE-GASES AB We provide observations and interpretations of Xe-129 chemical shifts in open zeolite networks in which the Xe is in fast exchange among a large number of cavities and channels, in two zeolite types different from the A types that we have used before, and provide quantitative comparisons of adsorption isotherms and average Xe-129 chemical shifts using grand canonical Monte Carlo (GCMC) simulations employing the same methods and shielding functions used previously, We examine the temperature dependence of the Xe chemical shift at a fixed loading in NaY and silicalite and compare the predicted behavior with that of Xe-n in the alpha cages of NaA. Furthermore, we consider the most general case where the chemical shift reported by a Xe atom includes sampling environments in several crystallites and intercrystalline gas during acquisition of the NMR signal. C1 LOYOLA UNIV,DEPT CHEM,CHICAGO,IL 60626. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Jameson, CJ (reprint author), UNIV ILLINOIS,DEPT CHEM,845 W TAYLOR,CHICAGO,IL 60607, USA. RI Jameson, Cynthia/G-4097-2012 OI Jameson, Cynthia/0000-0001-5909-0643 NR 93 TC 36 Z9 36 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 16 PY 1997 VL 101 IS 42 BP 8418 EP 8437 DI 10.1021/jp971013a PG 20 WC Chemistry, Physical SC Chemistry GA YB794 UT WOS:A1997YB79400005 ER PT J AU Kane, SM Rufael, TS Gland, JL Huntley, DR Fischer, DA AF Kane, SM Rufael, TS Gland, JL Huntley, DR Fischer, DA TI Role of hydrogen in benzene formation from benzenethiol on the Ni(111) surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID VIBRATIONAL EELS; ADSORPTION; HYDRODESULFURIZATION; PT(111); DESULFURIZATION; SPECTROSCOPY; THIOPHENOL; MECHANISM; CATALYSTS; THIOLATE AB The role of surface hydrogen in the desulfurization of benzenethiol to form benzene on the Ni(111) surface has been explored in hydrogen pressures ranging between UHV and up to 7 x 10(-3) Torr. Hydrogen availability plays a significant role in the reaction of adsorbed benzenethiol, as demonstrated over a wide range of reaction conditions. Adsorbed hydrogen and phenylthiolate, formed from sulfur-hydrogen bond scission of the benzenethiol upon adsorption at 100 K, react with increasing temperature to produce the primary desorbing products benzene and hydrogen. The dominant benzene formation channel at high coverage occurs at 260 K, with a smaller benzene peak occurring at 290 K and a final benzene peak near 400 K, Increasing the availability of surface hydrogen does not significantly affect either the benzene yield or the benzene formation temperature for high benzenethiol coverage. The same reaction temperature is observed even for hydrogen pressures up to 7 x 10(-3) Ton, as indicated by in situ temperature programmed fluorescence yield near edge spectroscopy (TP-FYNES) experiments. For low coverages of phenylthiolate on the clean Ni(111) surface, benzene formation decreases substantially and the higher temperature processes become more important. Hydrogen preadsorption in the low benzenethiol coverage case dramatically increases the amount of benzene formed at 260 K and decreases the high-temperature peak. Deuterium incorporation following reaction with coadsorbed deuterium clearly indicates three distinct levels of isotope incorporation for the benzene: peaks at 260, 290, and 400 K. Incorporation of a single deuterium dominates for the peak at 260 K, indicating an adsorbed phenylthiolate intermediate dominates for this low-temperature process. Multiple incorporation dominates for the peak at 240 K, indicating a dehydrogenated intermediate of the ''benzyne'' type, which is also observed by vibrational spectroscopy. Benzene formed above 400 K includes even more extensive deuterium incorporation, suggesting an even more extensively dehydrogenated intermediate. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV MICHIGAN,ANN ARBOR,MI 48109. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NR 23 TC 18 Z9 18 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 16 PY 1997 VL 101 IS 42 BP 8486 EP 8491 DI 10.1021/jp970988s PG 6 WC Chemistry, Physical SC Chemistry GA YB794 UT WOS:A1997YB79400013 ER PT J AU Klein, DL Roth, R Lim, AKL Alivisatos, AP McEuen, PL AF Klein, DL Roth, R Lim, AKL Alivisatos, AP McEuen, PL TI A single-electron transistor made from a cadmium selenide nanocrystal SO NATURE LA English DT Article ID QUANTUM DOTS; SEMICONDUCTOR NANOCRYSTALLITES; PHOTOLUMINESCENCE; SPECTROSCOPY; MONOLAYERS; POLYMER; GOLD AB The techniques of colloidal chemistry permit the routine creation of semiconductor nanocrystal(1,2) whose dimensions are much smaller than those that can be realized using lithographic techniques(3-6). The sizes of such nanocrystals can be varied systematically to study quantum size effects or to make novel electronic or optical materials with tailored properties(7-9). Preliminary studies of both the electrical(10-13) and optical properties(14-16) of individual nanocrystals have been performed recently, These studies show clearly that a single excess charge on a nanocrystal can markedly influence its properties. Here we present measurements of electrical transport in a single-electron transistor made from a colloidal nanocrystal of cadmium selenide. This device structure enables the number of charge carriers on the nanocrystal to be tuned directly, and so permits the measurement of the energy required for adding successive charge carriers, Such measurements are invaluable in understanding the energy-level spectra of small electronic systems, as has been shown by similar studies of lithographically patterned quantum dots(3-6) and small metallic grains(17). C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 23 TC 1011 Z9 1034 U1 22 U2 147 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD OCT 16 PY 1997 VL 389 IS 6652 BP 699 EP 701 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YA959 UT WOS:A1997YA95900045 ER PT J AU Atwood, D Sher, M AF Atwood, D Sher, M TI t->cWW and WW->(t)over-bar-c+t(c)over-bar in extended models SO PHYSICS LETTERS B LA English DT Article AB Jenkins has pointed out that the process t --> cW(+)W(-) is GIM suppressed in the standard model, In this note, we calculate the branching ratio for a wide range of models, in which the decay occurs at tree level through exchange of a scalar, fermion or vector. In the case of scalar exchange, a scalar mass between 2m(W) and 200 GeV leads to a resonant enhancement, giving a branching ratio as high as a few tenths of a percent. We then note that all of these models will also allow W+W- --> <(t)over bar c> + <(tc)over bar>, and we calculate the single-top/sinle-charm production rate at the LHC. The rates are such that the background from single-top/single-bottom production will probably swamp the signal. (C) 1997 Published by Elsevier Science B.V. C1 COLL WILLIAM & MARY,DEPT PHYS,WILLIAMSBURG,VA 23187. RP Atwood, D (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,THEORY GRP,NEWPORT NEWS,VA 23606, USA. NR 9 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 1997 VL 411 IS 3-4 BP 306 EP 312 DI 10.1016/S0370-2693(97)00976-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900011 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for anomalous four-jet events in e(+)e(-) annihilation at root s=130-172 GeV SO PHYSICS LETTERS B LA English DT Article ID W-PAIR PRODUCTION; L3 EXPERIMENT; MONTE-CARLO; LEP2/NLC AB A study of hadronic events with high jet-multiplicity is performed using the data sample collected by the L3 experiment at LEP at root s = 130-172 GeV. The observed event rates agree with the Standard Model predictions and upper limits are set on the production cross section of pairs of heavy particles that decay hadronically. (C) 1997 Elsevier Science B.V. C1 WORLD LAB, FBLJA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, HEFEI 230029, PEOPLES R CHINA. RES INST HIGH ENERGY PHYS, SEFT, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. UNIV LECCE, I-73100 LECCE, ITALY. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST NUCL PHYS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. ITEP, MOSCOW, RUSSIA. UNIV NAPLES, I-80125 NAPLES, ITALY. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC 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. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, 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, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, CNRS, IN2P3, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. LOUISIANA STATE UNIV, BATON ROUGE, LA 70803 USA. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. 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 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV FLORENCE, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. RP Acciarri, M (reprint author), IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI Duran, Ignacio/H-7254-2015; Sanchez, Eusebio/H-5228-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; D'Alessandro, Raffaello/F-5897-2015; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; 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; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015 OI Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532 NR 17 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 1997 VL 411 IS 3-4 BP 330 EP 338 DI 10.1016/S0370-2693(97)01001-0 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900015 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP COlino, N Commichau, V COstantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P 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 Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, LH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D 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 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP COlino, N Commichau, V COstantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P 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 Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, LH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B 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 RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D 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 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Ziegler, F TI Study of hadronic events and measurements of alpha(s) between 30 and 91 GeV SO PHYSICS LETTERS B LA English DT Article ID E+E-ANNIHILATION; L3 EXPERIMENT; JET STRUCTURE; QCD MODELS; ENERGIES; RESONANCE; EMISSION; LEP AB We have studied the structure of hadronic events with a hard, isolated photon in the final state (e(+)e(-) --> Z --> hadrons + gamma) in the 3.6 million hadronic events collected with the L3 detector at centre-of-mass energies around 91 GeV. The centre-of-mass energy of the hadronic system is in the range 30 GeV to 86 GeV. Event shape variables have been measured at these reduced centre-of-mass energies and have been compared with the predictions of different QCD Monte Carlo programs. The event shape variables and the energy dependence of their mean values are well reproduced by QCD models. We fit distributions of several global event shape variables to resummed O/alpha(s)(2)/calculations to determine the strong coupling constant a, over a wide range of energies. We find that the strong coupling constant alpha(s) decreases with increasing energy, as expected from QCD. (C) 1997 Elsevier Science B.V. C1 HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, 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. WORLD LAB, FBLJA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. USTC, HEFEI 230029, ANHUI, PEOPLES R CHINA. RES INST HIGH ENERGY PHYS, SEFT, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. UNIV LECCE, I-73100 LECCE, ITALY. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST NUCL PHYS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. ITEP, MOSCOW, RUSSIA. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC 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. UNIV PERUGIA, I-06100 PERUGIA, ITALY. INFM, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTIUCLAS 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, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. 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. RP Acciarri, M (reprint author), IST NAZL FIS NUCL, I-20133 MILAN, ITALY. RI D'Alessandro, Raffaello/F-5897-2015; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; 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; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; OI D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Longo, Egidio/0000-0001-6238-6787; Castellini, Guido/0000-0002-0177-0643; Diemoz, Marcella/0000-0002-3810-8530; Doria, Alessandra/0000-0002-5381-2649; Faccini, Riccardo/0000-0003-2613-5141 NR 46 TC 27 Z9 27 U1 0 U2 3 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 OCT 16 PY 1997 VL 411 IS 3-4 BP 339 EP 353 DI 10.1016/S0370-2693(97)01000-9 PG 15 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900016 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N VonDombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kurilla, U Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pick, B Pietra, C PInder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Zou, BS AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N VonDombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kurilla, U Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pick, B Pietra, C PInder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Zou, BS TI rho-omega interference in (p)over-bar-p-annihilation at rest into pi(+)pi(-)eta SO PHYSICS LETTERS B LA English DT Article ID ANTIPROTON-PROTON ANNIHILATION; PION FORM-FACTOR; ATOMIC S-STATES; ETA; PHYSICS AB The pi(+)pi(-) invariant mass distribution produced in <(p)over bar p> annihilation at rest and recoiling against eta mesons exhibits large interference between the amplitudes for rho eta and omega eta production. The interference can be quantitatively described within the framework of rho-omega interference. We find full coherence between the rho eta-omega eta production amplitudes and a vanishing relative production phase. The implications of this result for <(p)over bar p> annihilation dynamics are discussed. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LBNL,BERKELEY,CA 94720. RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV BONN,D-53115 BONN,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV HAMBURG,D-22761 HAMBURG,GERMANY. CERN,CH-1211 GENEVA 4,SWITZERLAND. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MUNICH,D-80333 MUNICH,GERMANY. LPNHE,F-75252 PARIS,FRANCE. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. RP Abele, A (reprint author), UNIV KARLSRUHE,D-76021 KARLSRUHE,GERMANY. RI Meyer, Curtis/L-3488-2014 OI Meyer, Curtis/0000-0001-7599-3973 NR 25 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 1997 VL 411 IS 3-4 BP 354 EP 360 DI 10.1016/S0370-2693(97)01032-0 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900017 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N VonDombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kurilla, U Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Zou, BS AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N VonDombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Heinzelmann, M Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kurilla, U Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R OuldSaada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Zou, BS TI Measurement of the omega->eta gamma decay branching ratio SO PHYSICS LETTERS B LA English DT Article ID RADIATIVE DECAYS; ANNIHILATION; MESONS; OMEGA; REST AB We have measured the branching ratio for the radiative decay omega --> eta gamma with omega mesons produced in antiproton-proton annihilation at rest into pi(0) omega and eta omega. Taking into account rho - omega mixing we find a branching ratio B(omega --> eta gamma) = (6.6 +/- 1.7) x 10(-4), in accord with the constructive interference solution in other experiments. The upper-limit for the direct radiative decay omega --> 3 gamma is 1.9 x 10(-4) at 95% confidence level. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LBNL,BERKELEY,CA 94720. RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV BONN,D-53115 BONN,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,CH-1211 GENEVA 4,SWITZERLAND. UNIV HAMBURG,D-22761 HAMBURG,GERMANY. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MUNICH,D-80333 MUNICH,GERMANY. LPNHE,F-75252 PARIS,FRANCE. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. RP Abele, A (reprint author), UNIV KARLSRUHE,D-76021 KARLSRUHE,GERMANY. RI Meyer, Curtis/L-3488-2014; Ratajczak, Mariusz Zdzislaw/N-1599-2014 OI Meyer, Curtis/0000-0001-7599-3973; NR 26 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 1997 VL 411 IS 3-4 BP 361 EP 372 DI 10.1016/S0370-2693(97)01024-1 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900018 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, HJ LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmidt, D Schmidt, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banerjee, S Banicz, K Barczyk, A 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 Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT 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 Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, HJ LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmidt, D Schmidt, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, A 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 Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y 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, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for the standard model Higgs boson in e(+)e(-) interactions at 161<=root s<=172 GeV SO PHYSICS LETTERS B LA English DT Article ID STATE QED CORRECTIONS; W-PAIR PRODUCTION; MONTE-CARLO; L3 EXPERIMENT; DETECTOR; CONSTRUCTION; CALORIMETER; COLLISIONS; LEP2/NLC; ENERGIES AB A search for the Standard Model Higgs boson has been performed with the L3 detector at LEP. The data sample was collected at three centre-of-mass energies, 161.3, 170.3 and 172.3 GeV with integrated luminosities of 10.8, 1.0 and 9.2 pb, respectively. No Higgs signal is observed. In combination with previous data taken at the Z resonance, a lower Higgs mass limit, M-H > 69.5 GeV, is obtained at 95% confidence level. (C) 1997 Elsevier Science B.V. C1 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, IN2P3, CNRS, INST NUCL PHYS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. ITEP, MOSCOW, RUSSIA. 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. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHANTRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. UNIV AMSTERDAM, NL-1009 AB AMSTERDAM, NETHERLANDS. NIKHEF H, NL-1009 AB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. LOUISIANA STATE UNIV, BATON ROUGE, LA 70803 USA. IHEP, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. 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 114, HUNGARY. RP Acciarri, M (reprint author), IST NAZL FIS NUCL, I-20133 MILAN, ITALY. RI Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; 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; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015 OI Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306 NR 48 TC 40 Z9 40 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 1997 VL 411 IS 3-4 BP 373 EP 386 DI 10.1016/S0370-2693(97)01033-2 PG 14 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YG529 UT WOS:A1997YG52900019 ER PT J AU Benner, WH AF Benner, WH TI A gated electrostatic ion trap to repetitiously measure the charge and m/z of large electrospray ions SO ANALYTICAL CHEMISTRY LA English DT Article ID MOLECULAR-WEIGHT DETERMINATION; RESONANCE MASS-SPECTROMETRY; INDIVIDUAL IONS; TIME AB The design and operation of a new type of ion trap provides a way to measure mass, charge, and velocity of large individual electrospray ions (>1 MDa, >250 charges) repeatedly during the time the ion is trapped. The trap consists of an image charge detection tube mounted between two ion mirrors. The mirrors are sets of parallel electrodes drilled with holes aligned with the bore of the detector tube. The device relies on voltages applied to the electrodes to establish symmetrically opposing ion focusing mirrors for the purpose of cycling ions through the charge detection tube many times. This design does mot use magnetic or radio frequency fields to trap ions. Gating one of the mirrors to 0 V while maintaining voltages appropriate for reflecting ions on the opposite mirror allows an ion to pass through the holes il the mirror and enter the detector tube, A low-noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. When a highly charged electrospray ion enters the detector tube, its image charge triggers a circuit that enables the entrance electrodes, thus closing the electrostatic gate to the trap. Ion mass is calculated from simultaneous measurements of ion charge and velocity every time an ion passes through the detector. Individual ions have been trapped for as long as about 10 ms, during which time they cycled 450 times through the detector tube. At this level of trapping time, a theoretical precision for charge measurement as small as about two electrons rms can be achieved for 200 eV/charge ions carrying more than 250 charges. The operation of the system is demonstrated by trapping 2.88 MDa ions of DNA. RP Benner, WH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT ENGN SCI,INSTRUMENTAT GRP,HUMAN GENOME CTR,BERKELEY,CA 94720, USA. NR 13 TC 74 Z9 74 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1997 VL 69 IS 20 BP 4162 EP 4168 DI 10.1021/ac970163e PG 7 WC Chemistry, Analytical SC Chemistry GA YA446 UT WOS:A1997YA44600011 ER PT J AU Tan, WH Yeung, ES AF Tan, WH Yeung, ES TI Monitoring the reactions of single enzyme molecules and single metal ions SO ANALYTICAL CHEMISTRY LA English DT Article ID LACTATE-DEHYDROGENASE ISOENZYMES; FLUORESCENCE DETECTION; INDIVIDUAL MOLECULES; MICROSCOPY AB One approach for studying single molecules is to cycle the molecule through a reaction repeatedly, i.e., to monitor the products from a reaction catalyzed by the molecule of interest. By using a laser-based optical microscope and a CCD detection system, we have determined the chemical activities of individual enzyme molecules. Single molecules are trapped inside femtoliter-size vials (pores in membranes or nanoscopic silica vials manufactured by photolithography) ranging from 5 to 12 Crm in diameter and from 4 to 6 mu m deep, which act as individual nanoscopic reactors, Single lactate dehydrogenase (LDH-1) molecules are isolated by filling these reactors with very low concentrations of LDH-1, excess lactate, and nicotin-amide adenine dinucleotide (NAD(+)). The fluorescent product NADH in more than 100 individual reactors can be followed simultaneously in real time. Different reaction characteristics are observed, both in terms of the instantaneous reaction rates and the average rates over a 30-min interval. We found that even when the microenvironments are identical, individual enzyme molecules reveal heterogeneities in their activities, This indicates that distinct molecular conformations may exist in otherwise identical molecules. We have further used this technique for the study of single metal ion-catalyzed reactions, Uniform catalytic activities are observed for individual Os(VIII) ions. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RI Tan, Weihong/A-5412-2008 OI Tan, Weihong/0000-0002-8066-1524 NR 23 TC 95 Z9 98 U1 5 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1997 VL 69 IS 20 BP 4242 EP 4248 DI 10.1021/ac970631k PG 7 WC Chemistry, Analytical SC Chemistry GA YA446 UT WOS:A1997YA44600022 ER PT J AU Ettinger, JM AF Ettinger, JM TI Finitely presented partially ordered Abelian groups SO DISCRETE MATHEMATICS LA English DT Article AB We study the partially ordered abelian group, F(P,R), generated by a set of generators, P, and inequality relations, R, and its representations in Euclidean space. First F(P,R) is defined by a universal property and then existence is shown proof-theoretically. We then characterize the order structure of F(P,R). The first main result of the paper utilizes the Marriage Theorem to prove that if the set of relations, R, is derived from a finite partially ordered set then F(P,R) is isomorphically embeddable in R-n for n sufficiently large. The second main result utilizes the Compactness Theorem to prove that for finite R, F(P,R) is pseudo-Archimedean. C1 UNIV WISCONSIN,DEPT MATH,MADISON,WI 53706. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-365X J9 DISCRETE MATH JI Discret. Math. PD OCT 15 PY 1997 VL 175 IS 1-3 BP 133 EP 141 DI 10.1016/S0012-365X(96)00146-X PG 9 WC Mathematics SC Mathematics GA YC698 UT WOS:A1997YC69800011 ER PT J AU Rutt, U Diederichs, A Strempfer, J Schneider, JR Shirane, G AF Rutt, U Diederichs, A Strempfer, J Schneider, JR Shirane, G TI Depth dependence of strain, mosaicity and sharp component in the critical scattering of SrTiO3 (vol 39, pg 395, 1997) SO EUROPHYSICS LETTERS LA English DT Correction, Addition C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Rutt, U (reprint author), DESY,HAMBURGER SYNCHROTRONSTRAHLUNGSLAB HASYLAB,NOTKESTR 85,D-22603 HAMBURG,GERMANY. NR 1 TC 1 Z9 1 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 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD OCT 15 PY 1997 VL 40 IS 2 BP 235 EP 235 DI 10.1209/epl/i1997-00452-6 PG 1 WC Physics, Multidisciplinary SC Physics GA YC085 UT WOS:A1997YC08500023 ER PT J AU Ludwig, DL Chen, FQ Peterson, SR Nussenzweig, A Li, GC Chen, DJ AF Ludwig, DL Chen, FQ Peterson, SR Nussenzweig, A Li, GC Chen, DJ TI Ku80 gene expression is Sp1-dependent and sensitive to CpG methylation within a novel cis element SO GENE LA English DT Article DE DNA repair; transcription; V(D)J recombination; DNA-dependent protein kinase ID DEPENDENT PROTEIN-KINASE; STRAND-BREAK-REPAIR; DIFFERENTIATING MOUSE MYOBLASTS; HUMAN AUTOANTIGEN KU; V(D)J RECOMBINATION; DNA-BINDING; CATALYTIC SUBUNIT; TRANSCRIPTION; CELLS; AUTOANTIBODIES AB The Ku70/80 complex, known as Ku, constitutes the DNA end binding component of the DNA-dependent protein kinase (DNA-PK). We have characterized the promoter region of the mouse and human Ku80 genes to delineate transcriptional elements necessary for basal gene expression and proliferation-dependent regulation. Consensus Sp1 recognition elements were identified in both promoters, and were determined to be essential for basal expression. We further identified a near-perfect palindrome of 21 base pairs located immediately 5' to one Sp1 element. This sequence was present once within the mouse Ku80 promoter and seven times, in a head-to-tail tandem array, within the human Ku80 promoter. This sequence possessed homology with a methylation-sensitive promoter element, Enh2, present in the LTR of mouse intractisternal A-particles. Promoter deletion studies and expression analysis of in-vitro methylated reporter gene constructs provided strong evidence that, in vivo, this repeat sequence regulates Ku80 gene expression in cis, through a mechanism involving CpG methylation. Evidence is also presented, suggesting that Ku is directly involved in this regulatory process. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. MEM SLOAN KETTERING CANC CTR,NEW YORK,NY 10021. FU NCI NIH HHS [CA50519, CA31397, CA56909] NR 40 TC 30 Z9 30 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 15 PY 1997 VL 199 IS 1-2 BP 181 EP 194 DI 10.1016/S0378-1119(97)00366-1 PG 14 WC Genetics & Heredity SC Genetics & Heredity GA YB732 UT WOS:A1997YB73200023 PM 9358055 ER PT J AU Vinogradova, T Volik, S Lebedev, Y Shevchenko, Y Lavrentyeva, I Khil, P Grzeschik, KH Ashworth, LK Sverdlov, E AF Vinogradova, T Volik, S Lebedev, Y Shevchenko, Y Lavrentyeva, I Khil, P Grzeschik, KH Ashworth, LK Sverdlov, E TI Positioning of 72 potentially full size LTRs of human endogenous retroviruses HERV-K on the human chromosome 19 map. Occurrences of the LTRs in human gene sites SO GENE LA English DT Article DE physical mapping; gene expression regulation; molecular genetics ID ZINC-FINGER GENE; LONG TERMINAL REPEATS; SEQUENCES; EXPRESSION; HUMAN-CHROMOSOME-19; KRUPPEL; PROTEIN; FAMILY; IDENTIFICATION; TRANSCRIPTION AB Seventy-two near full size long terminal repeats (LTRs) of human endogenous retrovirus of K-family (HERV-K) have been precisely located on the metric map of human chromosome 19. The LTR-related sequences were identified and assigned to cosmids by hybridization with two independent chromosome 19 specific cDNA clones corresponding to different parts of U3 region of LTR of HERV-K. The presence of full-size LTR sequences in a cosmid was further verified by PCR assay with a pair of primers complementary to the termini of the LTR. Coincidences of the LTR and the known genes positions are discussed. (C) 1997 Elsevier Science B.V. C1 PHILIPPS UNIV MARBURG KLINIKUM,MED ZENTRUM HUMANGENET,D-3550 MARBURG,GERMANY. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550. RP Vinogradova, T (reprint author), RUSSIAN ACAD SCI,MM SHEMYAKIN BIOORGAN CHEM INST,MIKLUKHO MAKLAYA 16-10,MOSCOW 117871,RUSSIA. RI Lebedev, Yuri/G-6738-2012; Smolina, Irina/E-5783-2011; OI Lebedev, Yuri/0000-0003-4554-4733; Khil, Pavel/0000-0002-4903-8777 NR 38 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 15 PY 1997 VL 199 IS 1-2 BP 255 EP 264 DI 10.1016/S0378-1119(97)00376-4 PG 10 WC Genetics & Heredity SC Genetics & Heredity GA YB732 UT WOS:A1997YB73200031 PM 9358063 ER PT J AU MacQueen, DB Lange, C Calvin, M Otvos, JW Spreer, LO Allan, CB Ganse, A Frankel, RB AF MacQueen, DB Lange, C Calvin, M Otvos, JW Spreer, LO Allan, CB Ganse, A Frankel, RB TI Reaction of dioxygen with a cross-conjugated carbon-carbon double bond in a bis-macrocycle diiron compound SO INORGANICA CHIMICA ACTA LA English DT Article DE iron complexes; macrocyclic ligand complexes; dioxygen complexes ID OXYGEN AB Dioxygen at atmospheric pressure attacks a cross-conjugated carbon-carbon double bond in a diiron complex to form two, like, keto macrocyclic iron(II) complexes. This reaction occurs with high yield in both solution and in the solid state. A dioxetane intermediate is, therefore, invoked. The rate of the reaction is very dependent on the nature of the axial ligands on the low-spin iron(II) ions in the bimetallic complex. The rate is at least a factor of 10(4) faster with DMF ligands than with CH3CN axial ligands. This rate dependence is explained by stabilization of a peroxo biradical transition state en route to a dioxetane intermediate. The keto-macrocyle product has the carbonyl group conjugated with a beta-diimine in a six-membered chelate ring. The conformation of this keto macrocycle is fixed on the NMR time scale and the spectra of all ten non-equivalent protons in the complex can be unambiguously assigned. The keto beta-diimine ligand is an excellent pi-acceptor as indicated by the high Fe(II) to Fe(III) oxidation potential of the compound and by the Mossbauer spectrum, which shows a low value for the center shift and a high value for the quadrupole splitting parameter. (C) 1997 Elsevier Science S.A. C1 UNIV PACIFIC,DEPT CHEM,STOCKTON,CA 95211. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CALIF POLYTECH STATE UNIV SAN LUIS OBISPO,DEPT PHYS,SAN LUIS OBISPO,CA 93407. NR 9 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD OCT 15 PY 1997 VL 263 IS 1-2 BP 125 EP 131 DI 10.1016/S0020-1693(97)05607-7 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YD821 UT WOS:A1997YD82100017 ER PT J AU Renner, MW Barkigia, KM Fajer, J AF Renner, MW Barkigia, KM Fajer, J TI Conformational landscapes of nonplanar porphyrins: superstructure, ligation, binding pockets and oxidation effects in Cu(II) porphyrins SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; copper complexes; nonplanar porphyrin complexes; porphyrin pi cation radical complexes ID PI-CATION RADICALS; PHOTOSYNTHETIC REACTION-CENTER; CRYSTAL-STRUCTURE; RHODOPSEUDOMONAS-VIRIDIS; ANGSTROM RESOLUTION; MOLECULAR-STRUCTURE; AXIAL LIGAND; COMPOUND-I; PEROXIDASE; HEME AB The crystal structure of the porphyrin pi cation radical Cu(II)OETPP(+)pyl(3)(-). py is reported (OETPP = 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin; py = pyridine). The compound is readily prepared by oxidation of Cu(II)OETPP in CH,CI, with excess I, in the presence of py. The structure exhibits the following features: (1) The porphyrin is oxidized, not the Cu(II). (2) The Cu(II) is pentacoordinated with one py as axial ligand. (3) The sterically crowded macrocycle is saddle shaped. This distortion and the peripheral substituents combine to form superstructural, orthogonal 'trenches' above and below the porphyrin plane. (4) The trenches impose a specific orientation on the ligated axial py along the N-Cu-N axis of the porphyrin and also form a 'distal' binding pocket that traps a second molecule of py. (5) The Cu(II)OETPP+ py radical is diamagnetic because of antiferromagnetic coupling between the unpaired electrons of the Cu d(x2-y2) and the porphyrin pi orbitals which is favored by the nonplanarity of the macrocycle. (6) The radical is more distorted than its nonplanar parent and provides additional support for the thesis that nonplanar porphyrins can easily undergo additional structural excursions. Conformational changes of the type reported here may also influence the reactivities of the rr cation radicals formed in the (photo)catalytic cycles of photosynthetic and hemoproteins also comprised of nonplanar porphyrins. Crystallographic data Cc (No. 9), a=21.706(2) Angstrom, b=16.077(2)Angstrom, c=19.993(2) Angstrom, beta=103.34(1)degrees, V=6789(1) Angstrom(3), Z=4. (C) 1997 Elsevier Science S.A. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 45 TC 33 Z9 33 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD OCT 15 PY 1997 VL 263 IS 1-2 BP 181 EP 187 DI 10.1016/S0020-1693(97)05570-9 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YD821 UT WOS:A1997YD82100024 ER PT J AU Williams, KR Hedman, B Hodgson, KO Solomon, EI AF Williams, KR Hedman, B Hodgson, KO Solomon, EI TI Ligand K-edge X-ray absorption spectroscopic studies: metal-ligand covalency in transition metal tetrathiolates SO INORGANICA CHIMICA ACTA LA English DT Article DE X-ray absorption spectroscopy; metal-ligand covalency; transition metal complexes; tetrathiolate complexes ID IRON MOLYBDENUM COFACTOR; STRUCTURAL INSIGHTS; COPPER; SITE; NITROGENASE; PROTEINS; SERIES; PROBE; FE AB X-ray absorption spectroscopy (XAS) at the sulfur K-edge at similar to 2470 eV has been applied to a series of S-4 M(SR)(4)(2-) complexes (M = Ni(II), Co(II), Fe(II) and Mn(II)) (R = 2-Ph-C6H4) to determine the covalency of the thiolate-metal bond. Previously, a methodology was developed fora TdMCl42- series (M = Cu(II), Ni(II), Co(II) and Fe(II)) which relates the intensity of the pre-edge feature to covalency. This study is now extended to metal tetrathiolates where S-4 site symmetry is applied and there is anisotropic covalency in the thiolate valence orbitals. This research forms the foundation for future sulfur K-edge XAS studies of electronic structure in transition metal centers in proteins and model complexes. (C) 1997 Elsevier Science S.A. C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. NR 24 TC 53 Z9 53 U1 1 U2 16 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD OCT 15 PY 1997 VL 263 IS 1-2 BP 315 EP 321 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YD821 UT WOS:A1997YD82100039 ER PT J AU Restrepo, JM Leaf, GK AF Restrepo, JM Leaf, GK TI Inner product computations using periodized Daubechies wavelets SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE wavelets; Galerkin; differential operators; connection coefficients ID PARTIAL-DIFFERENTIAL EQUATIONS AB Inner products of wavelets and their derivatives are presently known as connection coefficients. The numerical calculation of inner products of periodized Daubechies wavelets and their derivatives is reviewed, with the aim at providing potential users of the publicly-available numerical scheme, details of its operation. The numerical scheme for the calculation of connection coefficients is evaluated in the context of approximating differential operators, information which is useful in the solution of partial differential equations using wavelet-Galerkin techniques. Specific details of the periodization of inner products in the solution differential equations are included in this presentation. (C) 1997 John Wiley & Sons, Ltd. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. RP Restrepo, JM (reprint author), UNIV CALIF LOS ANGELES,DEPT MATH,LOS ANGELES,CA 90095, USA. OI Restrepo, Juan/0000-0003-2609-2882 NR 23 TC 19 Z9 19 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD OCT 15 PY 1997 VL 40 IS 19 BP 3557 EP 3578 DI 10.1002/(SICI)1097-0207(19971015)40:19<3557::AID-NME227>3.0.CO;2-A PG 22 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA XX981 UT WOS:A1997XX98100004 ER PT J AU Anders, A AF Anders, A TI Growth and decay of macroparticles: A feasible approach to clean vacuum arc plasmas? SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CATHODE SPOTS; TRANSPORT; PARTICLES; DUCTS AB Metal and carbon plasmas produced at nonstationary cathode spots are inherently contaminated with micron-size macroparticles, and their removal is typically done by guiding the plasma through curved magnetic macroparticle filters in order to spatially separate plasma and macroparticles. In this article, a possible alternative approach is discussed in which macroparticles are destroyed rather than removed. Mass and energy transfer from the plasma to macroparticles are considered. Both cold and warm ion approximations are discussed. It was found that the desired result-complete evaporation of macroparticles before arrival at the substrate - cannot be easily achieved in any case. Ion bombardment heating is reduced by thermionic electron emission when the macroparticle approaches the temperature region of strong evaporation. The heat loss;mechanisms, thermal radiation and evaporation, increase strongly with temperature, Direct heating of the macroparticle seems to be most promising. Microwave heating was ruled out because of the plasma shielding effect. The use of infrared lasers has been proposed, but this solution is likely to be uneconomical. (C) 1997 American Institute of Physics. RP Anders, A (reprint author), UNIV CALIF BERKELEY, ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 34 TC 26 Z9 30 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1997 VL 82 IS 8 BP 3679 EP 3688 DI 10.1063/1.365731 PG 10 WC Physics, Applied SC Physics GA YA572 UT WOS:A1997YA57200006 ER PT J AU Miller, PA Riley, ME AF Miller, PA Riley, ME TI Dynamics of collisionless rf plasma sheaths SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FREQUENCY-INDUCTION PLASMA; COUPLED PLASMA; BOHM CRITERION; REFERENCE CELL; DISCHARGES; MODEL; REACTOR AB The behavior of rf plasma sheaths has been the subject of much scientific study and also is technologically important for plasma etching and deposition in the manufacture of integrated circuits. This paper presents a semianalytic model of rf sheaths and describes an experiment that tested the model. An approximation to the first integral of the Poisson equation allows solving for the response of plasma sheaths to an imposed rf bias voltage. This approximation enables the plasma sheaths to be included within an electrical model of the plasma and external rf circuit components, and affords a prediction of the ion energy distributions impacting the electrodes, which are in contact with the plasma. The model is a significant advance beyond previous sheath models because it has no restriction on the ratio of the rf period to the ion transit time across the sheath. The model is applicable to those high-density, low-pressure plasmas in which the Debye length is a small fraction of the ion mean-free path, which itself is a small fraction of the plasma dimension. The experimental test of the model was conducted by comparing the predicted and measured rf potential, current, and power at the sheath adjacent to a capacitively coupled, rf-biased electrode in a plasma reactor with argon discharges sustained by an inductively coupled plasma source. The comparisons included both linear and nonlinear components of the rf electrical parameters. Results of the experiment were in substantial agreement with model predictions. (C) 1997 American Institute of Physics. RP Miller, PA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 42 TC 115 Z9 115 U1 4 U2 19 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 OCT 15 PY 1997 VL 82 IS 8 BP 3689 EP 3709 DI 10.1063/1.365732 PG 21 WC Physics, Applied SC Physics GA YA572 UT WOS:A1997YA57200007 ER PT J AU Tarver, CM Kury, JW Breithaupt, RD AF Tarver, CM Kury, JW Breithaupt, RD TI Detonation waves in triaminotrinitrobenzene SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHOCK INITIATION; EXPLOSIVES AB Fabry-Perot laser interferometry is used to obtain nanosecond time resolved particle velocity histories of the free surfaces of copper, tantalum, or magnesium disks driven by detonating triaminotrinitrobenzene (TATB)-based charges and of the interfaces between detonating TATE and transparent salt crystals. Detonation reaction zone profiles are measured for self-sustaining detonation waves propagating through various thicknesses of LX-17 (92.5% TATE and 7.5% KelF binder) and pure ultrafine particle size TATE. The experimental records are compared to particle velocity histories calculated with the DYNA2D hydrodynamic code using the ignition and growth reactive flow model. The calculations yield excellent agreement with the experimental records for LX-17 using an unreacted von Neumann spike pressure of 33.7 GPa, a reaction-rate law which releases 70% of the chemical energy within 100 ns, and the remaining 30% over 300 additional ns, and a reaction product equation of state fit to cylinder test and supracompression data with a Chapman-Jouguet (C-J) pressure of 25 GPa. The late time energy release is attributed to diffusion controlled solid carbon particle formation. Ultrafine TATE, pressed to a lower density (1.80 g/cm(3)) than LX-17 (1.905 g/cm(3)), exhibits lower unreacted spike and C-J pressures than LX-17 but similar reaction rates. (C) 1997 American Institute of Physics. RP Tarver, CM (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 47 TC 53 Z9 57 U1 5 U2 20 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 OCT 15 PY 1997 VL 82 IS 8 BP 3771 EP 3782 DI 10.1063/1.365739 PG 12 WC Physics, Applied SC Physics GA YA572 UT WOS:A1997YA57200016 ER PT J AU Kim, KJ Kang, JH Bahng, JH Lee, MH Lynch, DW AF Kim, KJ Kang, JH Bahng, JH Lee, MH Lynch, DW TI Optical properties of Fe1-xSix alloys (x<=0.1) studied by spectroscopic ellipsometry SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FE; NI AB Optical properties of dilute Fe1-xSix (x less than or equal to 0.1> alloys were studied by spectroscopic ellipsometry in the 1.5-6 eV photon energy region. The absorption strength of the alloys is found to decrease in the entire energy region as the Si composition increases. The interband-transition edges of Fe at about 2.5 eV in the minority-spin bands and at about 5 eV in the majority-spin bands shift to lower energies as the Si composition increases. The decrease in the absorption strength is interpreted as due to a decrease in the density of states of the Fe host and also due to a reduction of conduction-electron concentration in the alloys. The shifts of the 2.5 and 5 eV interband-transition edges can be explained in terms of a perturbative variation in the band structure of Fe induced by its alloying with Si. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP Kim, KJ (reprint author), KONKUK UNIV, DEPT PHYS, SEOUL 143701, SOUTH KOREA. NR 15 TC 1 Z9 1 U1 0 U2 0 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 OCT 15 PY 1997 VL 82 IS 8 BP 4043 EP 4046 DI 10.1063/1.365756 PG 4 WC Physics, Applied SC Physics GA YA572 UT WOS:A1997YA57200059 ER PT J AU Zhou, D Krauss, AR Gruen, DM AF Zhou, D Krauss, AR Gruen, DM TI Low voltage electron emission from calcium carbonate whiskers coated with a thin layer of gold SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERFORMANCE; CATHODES AB Cold cathode electron field emission from aragonite CaCO3 whiskers coated with 10-nm-thick gold has been observed. The microstructure of the whiskers grown on a Ni substrate by electrochemical deposition has been examined by scanning electron microscope, energy dispersive x-ray spectrometer, x-ray diffraction spectrometer, and Raman spectroscopy. For a 220 mu m anode-cathode gap, emission current densities in excess of similar to 2x10(-6) A/cm(2) are observed for applied voltages of 660 V or greater. Although it is believed that the electric field is locally enhanced by the geometry of the whiskers, the voltage required increases roughly Linearly with the anode-cathode spacing, corresponding to a turn-on field of approximately 3 V/mu m, and an emission current density of 0.4 mA/cm(2) has been obtained for an applied held of 5.5 V/mu m. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 14 TC 6 Z9 6 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1997 VL 82 IS 8 BP 4051 EP 4054 DI 10.1063/1.365714 PG 4 WC Physics, Applied SC Physics GA YA572 UT WOS:A1997YA57200061 ER PT J AU Perry, WL Katz, JD Rees, D Paffet, MT Datye, AK AF Perry, WL Katz, JD Rees, D Paffet, MT Datye, AK TI Kinetics of the microwave-heated CO oxidation reaction over alumina-supported Pd and Pt catalysts SO JOURNAL OF CATALYSIS LA English DT Article ID FIELD; DIFFERENCE; METHANE; CARBON; SINGLE AB The kinetics of the CO oxidation reaction on Pt/Al2O3 as well as Pd/Al2O3 have been measured in a packed bed reactor heated by microwave energy. The reaction rate was also measured in an identical reactor that was heated via conventional means, Several methods of temperature measurement were explored for the determination of catalyst temperature in the microwave heated reactor, Insertion of a thermocouple after the microwaves have been switched off provided the best method for temperature measurement in this study, However, large-scale temperature gradients must be eliminated before this method can provide accurate temperature measurements, After suitable modifications in our packed bed reactor to eliminate nonisothermality, we found that the rate of reaction and the reaction kinetics (order of reaction) for the microwave heated CO oxidation reaction were comparable to those for the conventionally heated reactor. The CO oxidation reaction therefore serves as an in situ probe of metal surface temperature, These observations suggest that the Pt and Pd crystallites in a supported catalyst are not significantly hotter than the alumina support in a microwave heated reactor. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,CTR MICROENGINEERED MAT,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87131. OI Datye, Abhaya/0000-0002-7126-8659 NR 27 TC 25 Z9 26 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD OCT 15 PY 1997 VL 171 IS 2 BP 431 EP 438 DI 10.1006/jcat.1997.1824 PG 8 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA YD852 UT WOS:A1997YD85200009 ER PT J AU Loong, CK Thiyagarajan, P Richardson, JW Ozawa, M Suzuki, S AF Loong, CK Thiyagarajan, P Richardson, JW Ozawa, M Suzuki, S TI Microstructural evolution of zirconia nanoparticles caused by rare-earth modification and heat treatment SO JOURNAL OF CATALYSIS LA English DT Article ID ANGLE NEUTRON-SCATTERING; OXYGEN STORAGE CAPACITY; X-RAY-SCATTERING; EXHAUST CATALYSTS; SILICA; AEROGELS; MODEL AB High-surface-area zirconias are widely used as catalytic support of noble metals or oxygen sensor electrolytes in automobile exhaust-emission-control systems. Doping zirconia with small amounts of rare-earth (RE) elements may tailor its properties for better catalytic performance. The microstructure in terms of primary-particle size, surface area, porosity, and fractal aggregates of 10 mol% RE-doped zirconias (RE = Nd and Ce) and pure ZrO2 were characterized by nitrogen adsorption isotherm and small-angle neutron scattering measurements. The crystal phases of these powders were examined by neutron powder diffraction method. Fresh pure zirconia prepared by a hydrolysis method at low temperature consists of small (similar to 4 nm) particles and micropores. Subsequent heat treatments induce a transformation from microporosity to mesoporosity thereby an increase of particle size and a reduction of surface area. In the case of pure ZrO2 a crossover from a mass-fractal aggregate of rough particles to clustering of smooth particles at a heat-treatment temperature of 600 degrees C was observed. The Nd-modified zirconias prepared by a coprecipitation method, on the other hand, show high resistance to sintering and retain a small particle size and the mass-fractal aggregate after heat treatment at 600 degrees C. Because of the different oxidation states and ionic sizes of Nd3+ and Ce4+ ions, Nd0.1Zr0.9O1.95 and Ce0.1Zr0.9O2 powders exhibit different crystal phases, particle size distributions, and pore structure. (C) 1997 Academic Press. C1 NAGOYA INST TECHNOL,TAJIMI,GIFU 507,JAPAN. RP Loong, CK (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 39 TC 18 Z9 18 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD OCT 15 PY 1997 VL 171 IS 2 BP 498 EP 505 DI 10.1006/jcat.1997.1833 PG 8 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA YD852 UT WOS:A1997YD85200017 ER PT J AU Boukari, H Lin, JS Harris, MT AF Boukari, H Lin, JS Harris, MT TI Small-angle X-ray scattering study of the formation of colloidal silica particles from alkoxides: Primary particles or not? SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article ID FRACTAL GEOMETRY; GROWTH-MODEL; PRECIPITATION; CONDENSATION; HYDROLYSIS; KINETICS; POWDERS; SPHERES AB The formation of colloidal silica particles and the dynamics of the nanostructure of the particles are investigated by small-angle X-ray scattering (SAXS) technique. Solute concentrations of 0.5 M tetraethylorthosilicate (TEOS), 1.1 or 2.2 M water (H2O), and 0.04 or 0.1 M ammonia base (NH3) in ethanol were used to obtain reaction conditions as close to those of the Stober method as possible and to have reaction kinetics that were slow enough to probe the changes in the nanostructure of the growing particles and to obtain good statistics from the SAXS measurements. We measured the changes in the radius of gyration and the fractal dimension as a function of time during growth. Remarkably, we find that, after an induction period, the first particles to appear in the solution have a radius of gyration of approximately 10 nm and are mass fractals characterized by their polymeric, open structure. This stage is followed by an intraparticle densification process and smoothing of the interface, leading to the usual compact nonfractal, stable structures. The growth models proposed so far cannot account for the observed continuous changes of stages during the formation and growth of the particles. (C) 1997 Academic Press. C1 UNIV MARYLAND,DEPT CHEM ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 33 TC 67 Z9 67 U1 3 U2 32 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD OCT 15 PY 1997 VL 194 IS 2 BP 311 EP 318 DI 10.1006/jcis.1997.5112 PG 8 WC Chemistry, Physical SC Chemistry GA YG927 UT WOS:A1997YG92700006 ER PT J AU Singhal, A Toth, LM Beaucage, G Lin, JS Peterson, J AF Singhal, A Toth, LM Beaucage, G Lin, JS Peterson, J TI Growth and structure of zirconium hydrous polymers in aqueous solutions SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE small angle X-ray scattering; aggregation; zirconium hydrous polymers ID X-RAY-SCATTERING; CHLORIDE AB Zirconium oxychloride solutions prepared at different pH were heated at elevated temperatures for various aging periods to gain an understanding of the growth mechanism and structure of zirconium hydrous polymers. Small angle X-ray scattering (SAXS) measurements were made on these solutions. It was observed that shape of clusters at the earlier stages of growth is close to a rod rather than a sheet as suggested earlier, The scattering data indicate that a rod-shaped primary particle is formed at pH 1.2, and on an increase in the pH, the primary particles become more branched. On aging more than 1250 min at 92 degrees C, these primary particles form large aggregates while retaining the primary particle structure. These aggregates, which are mass fractal in nature, restructure while growing in size and eventually transform into dense particles. Scattering data in this study were not enough to determine a specific kinetic growth model of the aggregates because the scattering intensity at low q constantly changes with time during the restructuring process. (C) 1997 Academic Press. C1 OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. UNIV CINCINNATI, DEPT MAT SCI & ENGN, CINCINNATI, OH 45220 USA. UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. NR 30 TC 29 Z9 32 U1 3 U2 18 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD OCT 15 PY 1997 VL 194 IS 2 BP 470 EP 481 DI 10.1006/jcis.1997.5117 PG 12 WC Chemistry, Physical SC Chemistry GA YG927 UT WOS:A1997YG92700025 ER PT J AU Terry, KW Lugmair, CG Tilley, TD AF Terry, KW Lugmair, CG Tilley, TD TI Tris(tert-butoxy)siloxy complexes as single-source precursors to homogeneous zirconia- and hafnia-silica materials. An alternative to the sol-gel method SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; M = AL; METAL ALKOXIDES; TETRAGONAL ZIRCONIA; CATALYTIC PROPERTIES; TITANIA-SILICA; MIXED OXIDES; AEROGELS; ZR; TRANSFORMATION AB The tris(tert-butoxy)siloxy complexes M[OSi((OBu)-Bu-t)(3)](4) (1, M = Zr and 2, M = Hf) are efficient single source precursors to homogeneous zirconia-silica and hafnia-silica materials. The ceramic conversions occur pyrolytically at low temperatures, give the theoretical yield for MO2 . 4SiO(2) compositions, and occur without the incorporation of carbon. Compounds 1 and 2 are isomorphous, and crystallize as a mixture of two Isomers. One isomer contains a 4-coordinate metal center, while the other is 5-coordinate and features a chelating eta(2)-OSi((OBu)-Bu-t)(3) ligand. The solid-state transformation of 1 to ZrO2 . 4SiO(2) produces an open, fibrous material that is somewhat ordered with pores which are similar to 20 nm in diameter. The solution-phase thermolysis of 1 produces a xerogel composed of small primary particles (less than or equal to similar to 5 nm). This xerogel possesses a high surface area (700 m(2) g(-1) for samples heated to 200 degrees C). Solutions of the precursors have been used to cast crack-free thin films of MO2 . 4SiO(2). The MO2 . 4SiO(2) materials are amorphous as initially formed, and subsequent crystallizations of tetragonal ZrO2, monoclinic ZrO2, and cristobalite occur at relatively high temperatures. The enhanced stabilization of the amorphous and tetragonal phases of zirconia, relative to those derived from many sol-gel systems, implies that these single-source precursors initially produce homogeneous materials and that subsequent crystallizations are to a large degree diffusion-controlled. Homogeneity in the initially formed ZrO2 . 4SiO(2) material is also suggested by solid-state Si-29 NMR spectra. The molecular route to oxide materials described here represents an alternative to the sol-gel method and may offer certain advantages. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 96 TC 104 Z9 105 U1 3 U2 22 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 OCT 15 PY 1997 VL 119 IS 41 BP 9745 EP 9756 DI 10.1021/ja971405v PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA YB372 UT WOS:A1997YB37200017 ER PT J AU Lucas, CA Markovic, NM Ross, PN AF Lucas, CA Markovic, NM Ross, PN TI Underpotential deposition of lead onto Pt(001): Interface structure and the influence of adsorbed bromide SO LANGMUIR LA English DT Article ID X-RAY-SCATTERING; BY-LAYER GROWTH; AG(111); AG AB Using in-situ X-ray diffraction, we have studied the underpotential deposition of Ph onto a Pt(001) electrode both in pure perchloric acid and in the presence of bromide anions. In pure perchloric acid, the Pb adlayer forms monolayer-high islands which fully cover the Pt surface but have no long range order in the surface plane. The presence of strongly adsorbed Br atoms at step edges on the Pt(001) surface and the competitive nature of the Pb-Br interaction cause a rapid exchange of Pb and Br on the Pt terraces, the Pb then forming a strongly bonded c(2 x 2) adlayer. C1 UNIV LIVERPOOL,OLIVER LODGE LAB,DEPT PHYS,LIVERPOOL L69 7ZE,MERSEYSIDE,ENGLAND. RP Lucas, CA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. OI Lucas, Christopher/0000-0001-5743-3868 NR 18 TC 10 Z9 10 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 15 PY 1997 VL 13 IS 21 BP 5517 EP 5520 DI 10.1021/la9702805 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YB530 UT WOS:A1997YB53000001 ER PT J AU Carter, RJ Baeyens, KJ SantaLucia, J Turner, DH Holbrook, SR AF Carter, RJ Baeyens, KJ SantaLucia, J Turner, DH Holbrook, SR TI The crystal structure of an RNA oligomer incorporating tandem adenosine-inosine mismatches SO NUCLEIC ACIDS RESEARCH LA English DT Article ID CENTER-DOT-A; BASE-PAIRS; B-DNA; HAMMERHEAD RIBOZYME; INTERNAL LOOPS; DOUBLE HELIX; MOLECULAR-DYNAMICS; RIBOSOMAL-RNA; GA MISMATCHES; DUPLEX AB The X-ray crystallographic structure of the RNA duplex [r(CGCAIGCG)](2) has been refined to 2.5 Angstrom. It shows a symmetric internal loop of two non-Watson-Crick base pairs which form in the middle of the duplex. The tandem A-I/I-A pairs are related by a crystallographic two-fold axis. Both A(anti)-I(anti) mismatches are in a head-to-head conformation forming hydrogen bonds using the Watson-Crick positions. The octamer duplexes stack above one another in the cell forming a pseudo-infinite helix throughout the crystal. A hydrated calcium ion bridges between the 3'-terminal of one molecule and the backbone of another. The tandem A-I mismatches are incorporated with only minor distortion to the backbone. This is in contrast to the large helical perturbations often produced by sheared G-A pairs in RNA oligonucleotides. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. KATHOLIEKE UNIV LEUVEN,LAB ANALYT CHEM & MED PHYSICOCHEM,B-3001 LOUVAIN,BELGIUM. WAYNE STATE UNIV,DEPT CHEM,DETROIT,MI 48202. UNIV ROCHESTER,DEPT CHEM,ROCHESTER,NY 14627. RI Schroeder, Susan/D-3946-2011 FU NIGMS NIH HHS [GM 49215] NR 33 TC 24 Z9 24 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD OCT 15 PY 1997 VL 25 IS 20 BP 4117 EP 4122 DI 10.1093/nar/25.20.4117 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YC609 UT WOS:A1997YC60900025 PM 9321667 ER PT J AU Wong, KK Markillie, LM Saffer, JD AF Wong, KK Markillie, LM Saffer, JD TI A novel method for producing partial restriction digestion of DNA fragments by PCR with 5-methyl-CTP SO NUCLEIC ACIDS RESEARCH LA English DT Article AB Partial digestion of DNA fragments is a standard procedure for subcloning analysis and for generating restriction maps. We have developed a novel method to generate a partial digestion for any DNA fragment that can be amplified by PCR. The method involves the incorporation of 5-methyl-dCTP into the PCR product to protect most of the restriction sites. As a result, complete digestion of the modified PCR products with a 5-methyl-dCTP-sensitive enzyme will produce an array of restriction fragments equivalent to a partial restriction enzyme digestion reaction done on unmethylated PCR products. This method reduces the time and material needed to produce partially-digested DNA fragments by traditional methods. Furthermore, using fluorescein-labeled primers in the reaction, we were able to detect the fluorescein-labeled end fragments resulting from the enzyme digestion using a fluorimager or anti-fluorescein-AP antibody and thus determine the restriction maps. RP Wong, KK (reprint author), PACIFIC NW LAB, MOL BIOSCI DEPT P7 56, POB 999, RICHLAND, WA 99352 USA. OI Wong, Kwong-Kwok/0000-0002-0375-6669 NR 7 TC 7 Z9 7 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD OCT 15 PY 1997 VL 25 IS 20 BP 4169 EP 4171 DI 10.1093/nar/25.20.4169 PG 3 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YC609 UT WOS:A1997YC60900035 PM 9321677 ER PT J AU Deng, L Garrett, WR Payne, MG Lee, DZ AF Deng, L Garrett, WR Payne, MG Lee, DZ TI Observation of broadband forward hyper-Raman emission with high intensity focused laser beams SO OPTICS COMMUNICATIONS LA English DT Article ID DEPENDENT QUANTUM INTERFERENCE; 4D 2-PHOTON RESONANCE; MULTIPHOTON IONIZATION; 3-PHOTON RESONANCE; SUPPRESSION; SCATTERING; XE; GENERATION; SHIFTS; VAPOR AB We show that the well known multiphoton destructive interference, which leads to hyper-Raman gain suppression in the weak pumping regime, no longer occurs under strong pumping conditions. In contrast to the weak pumping case, where no forward hyper-Raman can be observed and strong backward hyper-Raman occurs, forward hyper-Raman emission is found to be much stronger under strong pumping conditions. The emission spectrum acquires new characteristics due to the ac Stark effect introduced by the strong laser field. The frequency spectrum of the forward hyper-Raman is no longer determined by the laser bandwidth, instead a continuum of forward hyper-Raman emission is observed with the width being determined by the peak power density. We will present here a comparison between strong and weak pumping regimes. (C) 1997 Elsevier Science B.V. C1 UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER,BC V5K 2T3,CANADA. GEORGIA SO UNIV,DEPT PHYS,STATESBORO,GA 30460. RP Deng, L (reprint author), OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831, USA. RI Deng, Lu/B-3997-2012 NR 23 TC 2 Z9 2 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 1997 VL 142 IS 4-6 BP 253 EP 256 DI 10.1016/S0030-4018(97)00316-7 PG 4 WC Optics SC Optics GA YB814 UT WOS:A1997YB81400020 ER PT J AU Sweetser, JN Krumbugel, MA Trebino, R AF Sweetser, JN Krumbugel, MA Trebino, R TI Amplified ultrafast optical switching by cascading cascaded second-order nonlinearities in a polarization-gate geometry SO OPTICS COMMUNICATIONS LA English DT Article ID GENERATION AB We demonstrate amplified ultrafast all-optical switching of 250-fs pulses using two different types of cascaded second-order nonlinearities (CSNs) simultaneously in a simple polarization-gate geometry using a type II crystal. The first set of CSN processes has the effect of rotating the input-pulse polarization. yielding polarization gating. This signal pulse is then amplified by a second (different) set of CSN processes involving second-harmonic generation of the gate followed by a stimulated parametric down-conversion process. Using these ''cascaded cascaded'' second-order processes, we observe amplified switching with 320% efficiency and an on-off ratio of 6 x 10(5) in a 1-mm-thick crystal of BBO. (C) 1997 Elsevier Science B.V. RP Sweetser, JN (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,MS9057,LIVERMORE,CA 94551, USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 1997 VL 142 IS 4-6 BP 269 EP 272 DI 10.1016/S0030-4018(97)00342-8 PG 4 WC Optics SC Optics GA YB814 UT WOS:A1997YB81400024 ER PT J AU Moodenbaugh, AR Lewis, LH Soman, S AF Moodenbaugh, AR Lewis, LH Soman, S TI Superconductivity of polycrystalline La2-x-yNdySrxCuO4 SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE substitution effects; magnetization ID DOPED LA2-XSRXCUO4; MAGNETIZATION; LA2-XBAXCUO4; TRANSITIONS AB Recent work on the charge stripe phase and its relationship to superconducting behavior observed in single crystals has motivated a reinvestigation of superconductivity in the La2-x-yNdySrxCuO4 system, Literature values of superconducting transition temperature T-c for nominally similar polycrystalline La2-x-yNdySrxCuO4 are at variance [compare Crawford et al., Phys. Rev. B 44 (1991) 7749 and Buchner et al., Phys. Rev. Lett, 73 (1994) 1841]. This paper reports low magnetic field measurements of polycrystalline samples which support a broad range of superconductivity in good agreement with Crawford, and are consistent with the observed superconductivity in single crystals. (C) 1997 Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. RP Moodenbaugh, AR (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 20 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 15 PY 1997 VL 290 IS 1-2 BP 98 EP 104 DI 10.1016/S0921-4534(97)01637-7 PG 7 WC Physics, Applied SC Physics GA YN500 UT WOS:000071174800012 ER PT J AU Biswas, R Li, QM Yoon, Y Branz, HM AF Biswas, R Li, QM Yoon, Y Branz, HM TI Dangling-bond levels and structure relaxation in hydrogenated amorphous silicon SO PHYSICAL REVIEW B LA English DT Article ID SI-H; DEFECT RELAXATION; A-SI; EQUILIBRIUM; LUMINESCENCE; SYSTEMS AB Tight-binding molecular-dynamics calculations are utilized to study the spatial extent and time scales of the structure relaxation, following a change of the charge state of dangling bonds in hydrogenated amorphous silicon. Structural relaxation is found to be local, primarily involving large displacements (>0.1 Angstrom) of the nearest neighbors of the dangling bond and of a few nearby H atoms. Calculated optical transition levels have the D- level below both D-0 levels and the D+ level above the D-0 levels. A smooth energy surface is found for transitions between the neutral and charged dangling-bond configurations. Molecular-dynamics simulations show that electron levels relax in tens of picoseconds following electron capture qr emission by a dangling bond, but large oscillations of the gap levels may be present as a result of the strong coupling between the charge and local structure. The results do not appear to support either the slow relaxation model of Cohen, Leen, and Rasmussen, or the D structural memory model of Branz and Fedders. C1 IOWA STATE UNIV,US DEPT ENERGY,AMES LAB,IOWA CITY,IA 50011. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Biswas, R (reprint author), IOWA STATE UNIV,US DEPT ENERGY,DEPT PHYS & ASTRON,MICROELECT RES CTR,IOWA CITY,IA 50011, USA. NR 19 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1997 VL 56 IS 15 BP 9197 EP 9200 DI 10.1103/PhysRevB.56.9197 PG 4 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100005 ER PT J AU Hehlen, MP Cockroft, NJ Gosnell, TR Bruce, AJ AF Hehlen, MP Cockroft, NJ Gosnell, TR Bruce, AJ TI Spectroscopic properties of Er3+- and Yb3+-doped soda-lime silicate and aluminosilicate glasses SO PHYSICAL REVIEW B LA English DT Article ID EXCITED-STATE ABSORPTION; VISIBLE UP-CONVERSION; WAVE-GUIDE AMPLIFIER; ENERGY-TRANSFER; ERBIUM; IONS; AMPLIFICATION; TRANSITIONS; PARAMETERS; DYNAMICS AB A spectroscopic investigation of an extensive series of Er3+-doped and Er3+, Yb3+-codoped soda-lime-silicate (SL) and aluminosilicate (AS) glasses is presented. Compared to SL glasses, 4f transitions in AS glasses show higher oscillator strengths, larger inhomogeneous broadening, and smaller crystal-field splittings of the respective excited-state multiplets. The Er3+ excited-state relaxation dynamics is adequately described by a combination of the Judd-Ofelt model and the energy-gap law. With the exception of I-4(13/2), multiphonon relaxation is dominant for all excited states, making it possible to efficiently pump the 1.55 mu m I-4(13/2) --> I-4(15/2) emission by excitation of I-4(11/2) at around 980 nm. The absolute I-4(13/2) luminescence quantum yield, for low 980-nm excitation density (similar to 5 W/cm(2)), eta, is similar to 0.9 at 0.4 mol % Er2O3 and drops to about 0.65 upon increasing Er2O3 to 1.2 mol %, indicating the onset of energy-transfer processes. Samples with high OH- impurity concentration suffer from significantly higher quenching of I-4(13/2) luminescence at higher Er3+ concentrations. Energy migration to the minority of Er3+ ions coordinated to OH-, followed by efficient multiphonon relaxation accounts for this effect. At low excitation densities, the strong near-infrared absorption of Yb3+ in combination with efficient Yb --> Er energy transfer increases the I-4(13/2) population density in Yb3+, Er3+-codoped samples by up to 2 orders of magnitude compared to equivalent samples without Yb3+. The dependence of eta on Yb3+ codotation of 0.4 mol % Er2O3-doped samples predicts that a minimum of similar to 0.8 mol % Yb2O3 is required to achieve efficient sensitization of Er3+ by Yb3+. The relative intensities of upconversion luminescence from S-4(3/2) and H-2(11/2) are used to analyze internal sample heating in detail. Due to the high absorption cross section of Yb3+, increasing the Yb3+ concentration in Yb3+, Er3+-codoped samples of given length increases the absorbed power and subsequently the total density of multiphonon emission, leading to internal temperatures of up to 572 K in 0.4 mol % Er2O3 samples codoped with 4 mol % Yb2O3 and excited with 51 kW/cm(2). Multiphonon relaxation from I-4(13/2) is shown to be inefficient even at these high internal sample temperatures. From upconversion luminescence spectra of a series of glasses, the thermal conductivity is estimated to be between 3.5 x 10(-2) and 7.7 x 10(-2) W m(-1) K-1, in good agreement with the known value of 4.8 x 10(-2) W m(-1) K-1 for soda-lime-silicate glass. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LUCENT TECHNOL,MURRAY HILL,NJ 07974. NR 41 TC 200 Z9 207 U1 5 U2 61 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 OCT 15 PY 1997 VL 56 IS 15 BP 9302 EP 9318 DI 10.1103/PhysRevB.56.9302 PG 17 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100032 ER PT J AU Gonis, A Schulthess, TC Turchi, PEA vanEk, J AF Gonis, A Schulthess, TC Turchi, PEA vanEk, J TI Treatment of electron-electron correlations in electronic structure calculations SO PHYSICAL REVIEW B LA English DT Article ID SELF-ENERGY; BAND-GAPS; SEMICONDUCTORS; SYSTEMS; APPROXIMATIONS; INSULATORS; POTENTIALS AB A methodology is introduced for the systematic treatment of electron-electron correlations in solids and other interacting quantum N-particle systems. The method is developed within the framework of electronic structure theory (band theory) but, in contrast to conventional approaches, which are based on the single-particle picture, it is formulated within a many-particle picture in which n particles in d-dimensional phase space are treated as a single particle in a phase space of nd dimensions. In this phase space, interparticle interactions appear as external potentials allowing the treatment of the system of particles through the use of single-particle methods,while at the same time allowing a systematic, direct, and nonperturbative treatment of interparticle interactions. The method makes use of the invariance of the Hamiltonian describing gn interacting-particle system under partitioning into subsystems of n particles. This treatment leads to exact results in the limit n --> N. Based on such partitioning, we propose a generalization of density functional theory and an appropriately defined local density approximation to treat the interactions between the n-particle units in a system of N greater than or equal to n particles. This approach yields n-particle correlated densities and n-particle states which can be used in an analysis of the electronic properties of materials, such as total energy, phase stability, electronic transport, and others. We use the formal construct of multiple-scattering theory to develop the method for the calculation of the two-particle electronic structure of a solid and the corresponding total energy of the ground state. We also illustrate some of the properties of the method in terms of a Hubbard model Hamiltonian on a linear ring. Various features of the method and further possible applications are presented in a discussion section. C1 TULANE UNIV, DEPT PHYS, NEW ORLEANS, LA 70118 USA. RP LAWRENCE LIVERMORE NATL LAB, DEPT CHEM & MAT SCI, L-268, LIVERMORE, CA 94550 USA. NR 30 TC 44 Z9 44 U1 0 U2 3 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 OCT 15 PY 1997 VL 56 IS 15 BP 9335 EP 9351 DI 10.1103/PhysRevB.56.9335 PG 17 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100034 ER PT J AU Yao, HD Johs, B James, RB AF Yao, HD Johs, B James, RB TI Optical anisotropic-dielectric response of mercuric iodide SO PHYSICAL REVIEW B LA English DT Article ID HGI2 AB Anisotropic optical properties of mercuric iodide (HgI2) were studied by variable-angle spectroscopic ellipsometry (VASE). Angular-dependent polarized reflectance and transmittance at three special optical-axis configurations, concerning the uniaxial anisotropic nature of the crystal, were derived to facilitate the VASE analysis. Two surface orientations of this tetragonal crystal were selected, i.e., an a-plane and a c-plane sample. Room-temperature multiple-angle spectroscopic ellipsometry measurements from both samples with three different optical configurations along with polarized transmission measurements were jointly analyzed by the VASE analysis through multiple-sample, multiple-model methods. Anisotropic dielectric functions of single-crystal HgI2, epsilon(perpendicular to)(omega) and epsilon(parallel to)(omega), for optical electric-field vector oriented perpendicular and parallel to the c axis-respectively, were obtained in the range 1.24-5.1 eV. Different absorption energy-band edges, at room temperature, were observed from the ordinary and extraordinary dielectric responses at 2.25 and 2.43 eV, respectively. This is consistent with the results related to the optical transitions between the conduction band and the heavy-and light-hole valence band indicated by theoretical studies. A surface model related to the surface roughness and defects of HgI2 was established and characterized by the VASE analysis. C1 UNIV NEBRASKA,DEPT ELECT ENGN,LINCOLN,NE 68588. JA WOOLLAM CO INC,LINCOLN,NE 68508. SANDIA NATL LABS,LIVERMORE,CA 94551. RP Yao, HD (reprint author), UNIV NEBRASKA,CTR MICROELECT & OPT MAT RES,LINCOLN,NE 68588, USA. NR 20 TC 17 Z9 18 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 OCT 15 PY 1997 VL 56 IS 15 BP 9414 EP 9421 DI 10.1103/PhysRevB.56.9414 PG 8 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100042 ER PT J AU AsenPalmer, M Bartkowski, K Gmelin, E Cardona, M Zhernov, AP Inyushkin, AV Taldenkov, A Ozhogin, VI Itoh, KM Haller, EE AF AsenPalmer, M Bartkowski, K Gmelin, E Cardona, M Zhernov, AP Inyushkin, AV Taldenkov, A Ozhogin, VI Itoh, KM Haller, EE TI Thermal conductivity of germanium crystals with different isotopic compositions SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; SCATTERING; DIAMOND; PHONONS; GE; GE-70 AB We have measured the thermal conductivity of seven germanium crystals with different isotopic compositions in the temperature range between 2 K and 300 K. These samples, including one made of highly enriched Ge-70(99.99%), show intrinsic behavior at room temperature with the exception of a p-type sample with /N-d-N-a/ congruent to 2 x 10(16) cm(-3). The ''undoped'' samples exhibit a T-3 dependence at low temperatures, basically determined by boundary scattering. The maximum value of kappa (which falls in the range between 13 K and 23 K) is found to be a monotonically decreasing function of the isotopic mass variance parameter g. The maximum kappa(m) measured for the most highly enriched Ge-70(99.99%) sample is 10.5 kW/mK, one order of magnitude higher than for natural germanium. The experimental data have been fitted with the full Callaway theory, modified by treating transverse and longitudinal modes separately, using three free adjustable parameters for each set of modes to represent anharmonic effects plus the calculated contributions from isotopic and boundary scattering. For the isotopically purest Ge-70(99.99%) sample, dislocation scattering, or a similar mechanism, must be added in order to fit the data. We have also checked the effect of various surface treatments on the thermal conductivity in the low temperature region. The highest values of kappa are found after polish etching with a SYTON suspension. C1 IV KURCHATOV ATOM ENERGY INST,RUSSIAN RES CTR,MOSCOW 123182,RUSSIA. UNIV CALIF BERKELEY,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP AsenPalmer, M (reprint author), MAX PLANCK INST FESTKORPERFORSCH,D-70569 STUTTGART,GERMANY. RI Itoh, Kohei/C-5738-2014 NR 82 TC 210 Z9 211 U1 2 U2 29 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 OCT 15 PY 1997 VL 56 IS 15 BP 9431 EP 9447 DI 10.1103/PhysRevB.56.9431 PG 17 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100044 ER PT J AU McCluskey, MD Haller, EE AF McCluskey, MD Haller, EE TI Interstitial oxygen in silicon under hydrostatic pressure SO PHYSICAL REVIEW B LA English DT Article ID SPECTROSCOPY; ABSORPTION; GERMANIUM AB Using infrared spectroscopy, we have measured the vibrational spectrum of interstitial oxygen in silicon under hydrostatic pressures as high as 70 kbar at temperatures from 4 to 20 K. The application of pressure transforms the transverse motion of the oxygen from that of a harmonic oscillator to that of a rotor. As the motion becomes more rotational, the splitting between the l=0 and l=+/-1 low-frequency modes decreases. In addition, the splitting between the stretch modes at 1136 and 1128 cm(-1) decreases with increasing pressure and can no longer be resolved for pressures greater than 55 kbar. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP McCluskey, MD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 19 TC 17 Z9 17 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 OCT 15 PY 1997 VL 56 IS 15 BP 9520 EP 9523 DI 10.1103/PhysRevB.56.9520 PG 4 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100054 ER PT J AU Saleh, AA Shutthanandan, V Shivaparan, NR Smith, RJ Tran, TT Chambers, SA AF Saleh, AA Shutthanandan, V Shivaparan, NR Smith, RJ Tran, TT Chambers, SA TI Epitaxial growth of fcc Ti films on Al(001) surfaces SO PHYSICAL REVIEW B LA English DT Article ID CENTERED-CUBIC TITANIUM; ENERGY ION-SCATTERING; PHOTOELECTRON DIFFRACTION; AL(110) SURFACES; AUGER AB High-energy ion scattering (HEIS), x-ray photoelectron spectroscopy, and x-ray photoelectron diffraction (XPD) were used to study the growth of thin Ti films on Al(001) surfaces. The Al surface peak area in the backscattered ion spectrum of MeV He+ ions, incident along the [001] direction, was used to monitor the atomic structure of the Ti films during growth. An initial decrease in the area was observed indicating epitaxial film growth. This decrease continued up to a critical film thickness of about 5.5 ML, after which point the structure of the film changed. Titanium films 3, 5, and 9 ML thick were characterized using XPD in the same chamber. Both the HEIS and XPD results show that the Ti films grow with an fee structure on Al(001). A tetragonal distortion of 2.4% in the fee Ti film was measured using ions incident along the [10 (1) over bar] direction. Although there is a general similarity of fee Ti growth on both Al(001) and Al(110), the submonolayer growth regime does show differences for the two surfaces. C1 MONTANA STATE UNIV, DEPT PHYS, BOZEMAN, MT 59717 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. OI saleh, adli/0000-0001-9813-9374 NR 20 TC 38 Z9 40 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1997 VL 56 IS 15 BP 9841 EP 9847 DI 10.1103/PhysRevB.56.9841 PG 7 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100093 ER PT J AU McCarthy, MI Schenter, GK ChaconTaylor, MR Rehr, JJ Brown, GE AF McCarthy, MI Schenter, GK ChaconTaylor, MR Rehr, JJ Brown, GE TI Prediction of extended x-ray-absorption fine-structure spectra from molecular interaction models: Na+(H2O)(n)-MgO (100) interface SO PHYSICAL REVIEW B LA English DT Article ID MULTIPLE-SCATTERING; AB-INITIO; SURFACE; WATER; ADSORPTION; MGO(100); MGO; SITES; SPECTROSCOPY; COMPLEXES AB A theoretical approach is presented that can be used to model extended x-ray-absorption fine-structure (EXAFS) spectra for complex systems at finite temperatures. This method has the ability to compute, directly, the effects of thermal motion on EXAFS spectra and to deconvolve the EXAFS signal into contributions from individual scattering paths. Classical molecular-dynamics simulations of the interface are used to generate configurations corresponding to a given temperature and are used to compute the Debye-Waller factors for all (single and multiple) scattering paths. Interface geometries and first- (r(eff)), second- (sigma(2)), and third-order cumulants are computed directly from the configurations and input into the multiple-scattering x-ray-absorption fine-structure code, FEFF6, which calculates the EXAFS spectra. This method is applied to predict EXAFS spectra of sodium ions adsorbed at the MgO (100) interface at three types of surface sites-flat terrace, step edge, and step corner (kink). The calculations indicate that the experiments should only be able to detect signals from sodium ions adsorbed onto defect sites-step edges and corners. in situ spectra are computed from models of Na+ at the aqueous-MgO interfaces using sodium ions imbedded in finite water clusters. The strong overlap of features attributable to the water oxygens and the nearest-neighbor surface oxygens may complicate the structural analysis from the experimental spectra; however, the scattering from the magnesium atoms and focusing multiple-scattering paths at longer distances are clear signatures of the interface. C1 UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. STANFORD UNIV, DEPT GEOG & ENVIRONM SCI, STANFORD, CA 94305 USA. RP McCarthy, MI (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, MAILSTOP K1-96, RICHLAND, WA 99352 USA. RI Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 51 TC 27 Z9 27 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 OCT 15 PY 1997 VL 56 IS 15 BP 9925 EP 9936 DI 10.1103/PhysRevB.56.9925 PG 12 WC Physics, Condensed Matter SC Physics GA YC391 UT WOS:A1997YC39100105 ER PT J AU Bellaiche, L Wei, SH Zunger, A AF Bellaiche, L Wei, SH Zunger, A TI Composition dependence of interband transition intensities in GaPN, GaAsN, and GaPAs alloys SO PHYSICAL REVIEW B LA English DT Article ID SPECIAL QUASIRANDOM STRUCTURES; SEMICONDUCTOR ALLOYS; ELECTRONIC-STRUCTURE; SOLID-SOLUTIONS; DENSITY; BAND; GAN; IMPURITIES; GAAS1-XPX; SPECTRA AB Using large (512-atom) pseudopotential supercell calculations, we have investigated the composition dependence of the momentum matrix element M-v,M-c for transitions between the valence-band maximum and the conduction-band minimum of three semiconductor alloys: GaP1-xNx and GaAs1-xNx, exhibiting large chemical and size differences between their alloyed elements, and GaP1-xAsx, which is a weakly perturbed alloy. In the composition ranges where these alloys have a direct band gap, we find that (i) in GaP1-xAsx, M-v,M-c is large (like the virtual-crystal value) and nearly composition independent; (ii) in GaAs1-xNx, M-v,M-c is strongly composition dependent: large for small x and small for large x; and (iii) in GaP1-xNx, M-v,M-c is only slightly composition dependent and is significantly reduced relative to the virtual-crystal value. The different behavior of GaP1-xAsx, GaP1-xNx, and GaAs1-xNx is traced to the existence/absence of impurity levels at the dilute alloy limits: (a) there are no gap-level impurity states at the x-->1 or x-->0 limits of GaP1-xAsx, (b) an isolated As impurity in GaN (Ga (N) under bar:As) has a deep band gap impurity level but no deep impurity state is found for N in GaAs, and (c) Ga (N) under bar:P exhibits a P-localized deep band-gap impurity state and Ga (P) under bar:N has an N-localized resonant state. The existence of deep levels leads to wave-function localization in real space, thus to a spectral spread in momentum space and to a reduction of M-v,M-c. These impurity levels are facilitated by atomic relaxations, as evident by the fact that unrelaxed Ga (N) under bar:As and Ga (N) under bar:P, show no deep levels, have extended wave functions, and have large interband transition elements. [S0163-1829(97)05339-3]. RP Bellaiche, L (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 36 TC 148 Z9 150 U1 1 U2 21 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 OCT 15 PY 1997 VL 56 IS 16 BP 10233 EP 10240 DI 10.1103/PhysRevB.56.10233 PG 8 WC Physics, Condensed Matter SC Physics GA YD475 UT WOS:A1997YD47500042 ER PT J AU Berman, GP Bulgakov, EN Campbell, DK Krive, IV AF Berman, GP Bulgakov, EN Campbell, DK Krive, IV TI Quantum nonlinear resonance and quantum chaos in Aharonov-Bohm oscillations in mesoscopic semiconductor rings SO PHYSICAL REVIEW B LA English DT Article ID EXCITED HYDROGEN-ATOMS; FREQUENCY ELECTROMAGNETIC-FIELD; PERSISTENT CURRENTS; NORMAL-METAL; ENERGY SPACE; LOCALIZATION; TRANSPORT; LOOP; TIME; TRANSMISSION AB We consider Aharonov-Bohm oscillations in a mesoscopic semiconductor ring threaded by both a constant magnetic flux and a time-dependent, resonant magnetic field with one or two frequencies. Working in the ballistic regime, we establish that the theory of ''quantum nonlinear resonance'' applies, and thus that this system represents a possible solid-state realization of ''quantum nonlinear resonance'' and ''quantum chaos.'' In particular, we investigate the behavior of the time-averaged electron energy at zero temperature in the regimes of (i) an isolated quantum nonlinear resonance and (ii) the transition to quantum chaos, when two quantum nonlinear resonances overlap. The time-averaged energy exhibits sharp resonant behavior as a function of the applied constant magnetic flux, and has a staircase dependence on the amplitude of the external time-dependent field. In the chaotic regime, the resonant behavior exhibits complex structure as a function of flux and frequency. We compare and contrast the quantum chaos expected in these mesoscopic ''solid-state atoms'' with that observed in Rydberg atoms in microwave fields, and discuss the prospects for experimental observation of the effects we predict. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LV KIRENSKII INST PHYS,KRASNOYARSK 660036,RUSSIA. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. UKRAINIAN ACAD SCI,INST LOW TEMP PHYS & ENGN,UA-310164 KHARKOV,UKRAINE. RP Berman, GP (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 51 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1997 VL 56 IS 16 BP 10338 EP 10354 DI 10.1103/PhysRevB.56.10338 PG 17 WC Physics, Condensed Matter SC Physics GA YD475 UT WOS:A1997YD47500057 ER PT J AU Aronov, IE Beletskii, NN Berman, GP Bishop, AR AF Aronov, IE Beletskii, NN Berman, GP Bishop, AR TI Collective electromagnetic excitations in a double-layer two-dimensional electron system in a high magnetic field SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM HALL SYSTEMS; FILLED LANDAU-LEVELS; PHASE-TRANSITIONS; CYCLOTRON-RESONANCE; SURFACE-POLARITONS; ENERGY-SPECTRUM; WELL SYSTEMS; GAS; OSCILLATIONS; STATE AB A new type of collective electromagnetic excitations, namely the surface polaritons (SP's), in a double-layer two-dimensional electron system (DL2DES) (of nn-type, pp-type, and np-type) in a high magnetic field is predicted. Using a Wigner distribution function formalism, we investigate the spectrum, damping, and polarization of the SP's in a wide range of the frequencies omega and the wave vectors k. It is shown that near the cyclotron resonance (CR) (omega similar to Omega=eB/mc) the phase velocity of the SP's is drastically slowed down, and the group velocity undergoes the fundamental steps defined by the fine-structure constant alpha=e(2)/(h) over bar c (as well as for the one-layer 2DES). For the nn-type DL2DES, each dispersion curve splits, and strongly correlated collective electromagnetic excitations propagate in the system. The group velocity of these excitations is defined by the interlayer distance d, and is much smaller than that for the one-layer 2DES. In the vicinity of a CR subharmonic (omega similar to 2 Omega) the negative (anomalous) dispersion of the SP occurs. For the np-type DL2DES the branches of the dispersion curves are intercrossed in the long-wave region, near the subharmonic (hole) CR, and in the short-wave region, due to the resonance interaction between the principal (electron) CR mode and the subharmonic (hole) CR made. The relaxation of the electrons (or holes) in the DL2DES leads to the occurrence of a dissipative collective mode of the SP type-the ''additional SP's'' (ASP's). This mode exists under certain threshold condition, which is determined by a fine-structure constant alpha. As a consequence, the dispersion curves for these excitations exhibit spectrum endpoints, and mode's confluence. The threshold condition for the ASP's in the DL2DES has a ''geometrical oscillating'' form due to the coherence effects between the split ASP modes, The potential Importance for various applications in microelectronics is discussed. C1 LOS ALAMOS NATL LAB,CNLS,LOS ALAMOS,NM 87545. NATL ACAD SCI UKRAINE,INST RADIOPHYS & ELECT,UA-310085 KHARKOV,UKRAINE. RP Aronov, IE (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 86 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1997 VL 56 IS 16 BP 10392 EP 10403 DI 10.1103/PhysRevB.56.10392 PG 12 WC Physics, Condensed Matter SC Physics GA YD475 UT WOS:A1997YD47500062 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI d-electron frustration and the large fcc versus hcp binding preference in O adsorption on Pt(111) SO PHYSICAL REVIEW B LA English DT Article ID SURFACES; PSEUDOPOTENTIALS; SITES AB First-principles calculations show that at saturation on Pt(111) terraces, O adatoms favor ''fcc'' over ''hcp'' sites by roughly 0.5 eV. This preference is a consequence of d-electron depletion between first- and second-neighbor Pt atoms in the fee binding geometry which does nor occur in the hcp case. The source of the different d-electron distributions is the electrostatic requirement that the d hole on each Pt atom adjacent to an O lie along the line connecting the two. [S0163-1829(97)03340-7]. RP Feibelman, PJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 31 TC 43 Z9 43 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 OCT 15 PY 1997 VL 56 IS 16 BP 10532 EP 10537 DI 10.1103/PhysRevB.56.10532 PG 6 WC Physics, Condensed Matter SC Physics GA YD475 UT WOS:A1997YD47500079 ER PT J AU Kang, JS Hwang, DW Olson, CG Youn, SJ Kang, KC Min, BI AF Kang, JS Hwang, DW Olson, CG Youn, SJ Kang, KC Min, BI TI Energy dispersions and bandwidth in Pd 4d photoemission spectra SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; PHOTOIONIZATION CROSS-SECTIONS; ELECTRONIC-STRUCTURE; TRANSITION-METALS; BAND DISPERSIONS; COOPER-MINIMUM; NI; SURFACES; SPECTROSCOPY; PALLADIUM AB Atomic and electronic structures of a Pd(111) single crystal and a polycrystalline Pd film have been investigated by using low-energy electron diffraction (LEED) and photoemission spectroscopy (PES). LEED patterns of a clean Pd(111) show a threefold symmetry, suggesting no surface reconstruction. Band structures of Pd(111) for k(1) along the <(Gamma)over bar>-(M) over bar', <(Gamma)over bar>-(M) over bar, and <(Gamma)over bar>-(M) over bar symmetry lines have been determined experimentally from angle-resolved photoemission spectroscopy measurements and compared to those calculated within the local-density-functional approximation (LDA). The valence band PES spectrum of Pd film is also obtained and compared to the calculated 4d angular momentum projected local density of states within LDA. Experimental and LDA band structures of Pd(111) exhibit a reasonably good agreement, whereas experimental bandwidths are narrower than the LDA bulk bandwidths by 0.5-1 eV. Such a discrepancy can be improved theoretically by taking into account more localized Pd surface states. Tn contrast, the calculated Pd 4d quasiparticle spectral density by including the on-site Coulomb correlation cannot resolve the disagreement between PES and LDA, suggesting that the Coulomb correlation effect is not substantial in understanding PES spectra of Pd. [S0163-1829(97)01540-3]. C1 POSCON, CTR RES & DEV, POHANG 790380, SOUTH KOREA. IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. POHANG UNIV SCI & TECHNOL, DEPT PHYS, POHANG 790784, SOUTH KOREA. RP CATHOLIC UNIV KOREA, DEPT PHYS, PUCHON 422743, SOUTH KOREA. NR 56 TC 14 Z9 14 U1 0 U2 6 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 OCT 15 PY 1997 VL 56 IS 16 BP 10605 EP 10613 DI 10.1103/PhysRevB.56.10605 PG 9 WC Physics, Condensed Matter SC Physics GA YD475 UT WOS:A1997YD47500089 ER PT J AU Turner, MS Weinberg, EJ AF Turner, MS Weinberg, EJ TI Pre-big-bang inflation requires fine-tuning SO PHYSICAL REVIEW D LA English DT Article ID HOMOGENEOUS COSMOLOGICAL MODELS; STRING COSMOLOGY; EXPANSION; CONSTANT; FLATNESS AB The pre-big-bang cosmology inspired by superstring theories has been suggested as an alternative to slow-roll inflation. We analyze, in both the Jordan and Einstein frames, the effect of spatial curvature on this scenario and show that too much curvature - of either sign - reduces the duration of the inflationary era to such an extent that the flatness and horizon problems are not solved. Hence, a fine-tuning of initial conditions is required to obtain enough inflation to solve the cosmological problems. [S0556-2821(97)01020-5]. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. RP Turner, MS (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637, USA. NR 18 TC 80 Z9 80 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 OCT 15 PY 1997 VL 56 IS 8 BP 4604 EP 4609 DI 10.1103/PhysRevD.56.4604 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YC321 UT WOS:A1997YC32100017 ER PT J AU Silveira, V Waga, I AF Silveira, V Waga, I TI Cosmological properties of a class of Lambda decaying cosmologies SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL LENS SURVEY; IA SUPERNOVAE; HUBBLE CONSTANT; UNIVERSE; QUASARS; DIAGRAM; MATTER; ENERGY; MODELS AB We investigate some properties of flat cosmological models with a Lambda term that decreases with time as Lambda proportional to a(-m) (a is the scale factor and m is a parameter 0 less than or equal to m < 3). The models are equivalent to standard cosmology with matter and radiation plus an exotic fluid with the equation of state p(x) = (m/3 - 1)rho(x). We study the effect of the decaying Lambda term on the cosmic microwave background anisotropy and by using a seminumeric method we compute the angular power spectrum (up to l = 20) for different values of m and Omega(m0). We also investigate the constraints imposed on the models by the magnitude-redshift test in which high-redshift type Ia supernovae (SNe Ia) are used as standard candles. We obtain the 95.4%, 90%, and 68% confidence levels on the parameters m and Omega(m0) and compare them with those arising from lensing statistics. Our analysis reveals that the SNe Ia constraints are stronger for low values of m and Omega(m0), while those from lensing statistics are more important for m greater than or similar to 1. Models with Omega(m0)greater than or similar to 0.2 and m greater than or similar to 1.6 are in good agreement with the data.[S0556-2821(97)03620-5]. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV FED RIO DE JANEIRO,INST FIS,BR-21945970 RIO JANEIRO,BRAZIL. RP Silveira, V (reprint author), UNIV BRASILIA,INT CTR CONDENSED MATTER PHYS,CP 04513,BR-70919970 BRASILIA,DF,BRAZIL. RI Waga, Ioav/B-6288-2014 NR 45 TC 51 Z9 52 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 1997 VL 56 IS 8 BP 4625 EP 4632 DI 10.1103/PhysRevD.56.4625 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YC321 UT WOS:A1997YC32100020 ER PT J AU Turner, MS White, M AF Turner, MS White, M TI CDM models with a smooth component SO PHYSICAL REVIEW D LA English DT Article ID COLD DARK-MATTER; COSMOLOGICAL CONSTANT; MASS FLUCTUATIONS; BARYON CONTENT; UNIVERSE; INFLATION; CLUSTERS; DENSITY; GALAXIES; FIELDS AB The inflationary prediction of a flat Universe is at odds with current determinations of the matter density (Omega(M) similar or equal to 0.2-0.4). This dilemma can be resolved if a smooth component contributes the remaining energy density (Omega(X) = 1 - Omega(M)). We parametrize the smooth component by its equation of state, p(X) = w rho(X), and show that XCDM with w similar or equal to -0.6, Omega(M) similar or equal to 0.3, and h similar or equal to 0.7 is the best fit to all present cosmological data. Together, the position of the peak in the CMB angular power spectrum and the type Ia supernova magnitude-redshift diagram provide a crucial test of XCDM. [S0556-2821(97)50220-7]. C1 FERMILAB NATL ACCELERATOR LAB,NASA,CTR ASTROPHYS,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Turner, MS (reprint author), UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637, USA. RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 68 TC 469 Z9 469 U1 0 U2 3 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 OCT 15 PY 1997 VL 56 IS 8 BP R4439 EP R4443 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YC321 UT WOS:A1997YC32100001 ER PT J AU Muralidharan, G Wu, XZ You, H Paulikas, AP Veal, BW AF Muralidharan, G Wu, XZ You, H Paulikas, AP Veal, BW TI An x-ray reflectivity study of beta-NiAl oxidation SO SCRIPTA MATERIALIA LA English DT Article ID TRANSIENT OXIDATION; MECHANISM AB Early stages in the cyclic oxidation of beta-NiAl at 500 degrees C were investigated using the technique of x-ray reflectivity. By fitting the reflectivity curves to a model function, oxide layer thickness, roughness of the oxide-gas and the oxide-substrate interfaces were obtained as a function of oxidation time. It was observed that the oxide thickness increased logarithmically with time. Comparison of the roughness of the oxide-substrate interface with that of the oxide-gas interface showed that the oxide-gas interface was rougher than the oxide-substrate interface. This is consistent with the postulated growth mechanism (outward diffusion of cations) for oxide growth during the early stages of oxidation at low temperatures in this material. Thus, x-ray reflectivity offers a convenient way of determining oxide growth rates along with the roughness of the interfaces when the oxide layer is thin; this regime cannot be easily studied with techniques that are currently being used for oxidation studies. Published by Elsevier Science Ltd. C1 NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP Muralidharan, G (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Muralidharan, Govindarajan/J-6155-2015; You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 10 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 15 PY 1997 VL 37 IS 8 BP 1177 EP 1183 DI 10.1016/S1359-6462(97)00232-7 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XY049 UT WOS:A1997XY04900012 ER PT J AU Chen, MW Lin, DL Xia, YM Liu, CT AF Chen, MW Lin, DL Xia, YM Liu, CT TI Strain rate sensitivity of ductility in a Fe-28Al alloy under tensile impact SO SCRIPTA MATERIALIA LA English DT Article ID ROOM-TEMPERATURE DUCTILITY; IRON ALUMINIDES; EMBRITTLEMENT; FRACTURE; FE3AL; FEAL C1 UNIV SCI & TECHNOL CHINA,DEPT MODERN MECH,HEFEI,PEOPLES R CHINA. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Chen, MW (reprint author), SHANGHAI JIAO TONG UNIV,DEPT MAT SCI & ENGN,SHANGHAI 200030,PEOPLES R CHINA. RI Chen, Mingwei/A-4855-2010; OI Chen, Mingwei/0000-0002-2850-8872; Liu, Chain Tsuan/0000-0001-7888-9725 NR 9 TC 1 Z9 1 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 15 PY 1997 VL 37 IS 8 BP 1243 EP 1248 DI 10.1016/S1359-6462(97)00219-4 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XY049 UT WOS:A1997XY04900021 ER PT J AU Windisch, CF Cox, JL Greenwell, EN AF Windisch, CF Cox, JL Greenwell, EN TI A Raman spectroscopic study of the interaction of cesium ions with oxyanions in carbonate melts SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE Raman spectroscopy; molten salts; carbonates; cesium; ionic interactions ID MOLTEN AB The Raman spectra of molten carbonate salts containing salts of other oxyanions including sulfate, molybdate and phosphate, exhibited vibrational bands assigned to carbonate and the other oxyanions. Increments of a cesium salt were added to each mixture to obtain varying values of the cation-dependent parameter log P alpha. The variations of log P alpha with the frequencies of the Raman bands revealed a trend in the sensitivities of the various oxyanions to the cesium content of the melt that appears to be related to the basicity of the oxyanions. If the interactions that contribute to the observed frequency changes also influence the volatility of cesium in molten carbonates, the results suggest that addition of oxyanions like sulfate, that are significantly less basic than carbonate, will decrease the cesium volatility. This conclusion is consistent with recent studies that showed sulfate salts were effective in lowering the volatility of cesium in molten sodium carbonate at 900 degrees C. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW NATL LAB,RICHLAND,WA 99352. NR 20 TC 4 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD OCT 15 PY 1997 VL 53 IS 12 BP 1981 EP 1993 DI 10.1016/S1386-1425(97)00117-0 PG 13 WC Spectroscopy SC Spectroscopy GA YH953 UT WOS:A1997YH95300006 ER PT J AU Radziszewski, JG Abildgaard, J Thulstrup, EW AF Radziszewski, JG Abildgaard, J Thulstrup, EW TI The vibrational spectrum of acenaphthylene: linear dichroism and ab initio model calculations SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE acenaphthylene; linear dichroism; vibrational spectrum ID DENSITY-FUNCTIONAL THEORY; STATES; ENERGY AB Complete infrared linear dichroism spectra were recorded between 50 and 3200 cm(-1) of acenaphthylene aligned in stretched polyethylene and polyethylene-d(4) as well as Raman solution spectra. The information obtained from the infrared spectra made it possible to separate the electric dipole allowed transitions into three groups, corresponding to three different excited state symmetries. The separation is possible for the C-2v symmetric molecule, since the three groups of transitions correspond to three mutually perpendicular transition moment directions, which in the stretched polymer obtain different average alignments. This information makes a safe assignment of all allowed fundamental vibrational transitions, belonging to three of the four C-2v symmetry classes, possible. Similarly, the Raman spectra permitted an assignment of vibrations belonging to the fourth symmetry class. The assignments were supported by ab initio quantum mechanical modelling calculations at various levels. A comparison of the present assignments with those from recent linear dichroism studies of acenaphthylene aligned in a nematic liquid crystal matrix confirmed most assignments, but also led to new assignments and reassignment of several transitions. This was possible because of the additional information that becomes available in the stretched polyethylene method, which provide an excellent separation of the excited state symmetries corresponding to the two in-plane transition moment directions. (C) 1997 Elsevier Science B.V. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80309. ROSKILDE UNIV CTR,DEPT CHEM & LIFE SCI,DK-4000 ROSKILDE,DENMARK. NR 18 TC 4 Z9 4 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD OCT 15 PY 1997 VL 53 IS 12 BP 2095 EP 2107 DI 10.1016/S1386-1425(97)00130-3 PG 13 WC Spectroscopy SC Spectroscopy GA YH953 UT WOS:A1997YH95300018 ER PT J AU Brauning, H Dorner, R Cocke, CL Prior, MH Krassig, B BrauningDemian, A Carnes, K Dreuil, S Mergel, V Richard, P Ullrich, J SchmidtBocking, H AF Brauning, H Dorner, R Cocke, CL Prior, MH Krassig, B BrauningDemian, A Carnes, K Dreuil, S Mergel, V Richard, P Ullrich, J SchmidtBocking, H TI Recoil ion and electronic angular asymmetry parameters for photo double ionization of helium at 99 eV SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID RESOLVED DOUBLE PHOTOIONIZATION; NEAR-THRESHOLD; CROSS-SECTION; ENERGY; DYNAMICS AB Recoil ion momentum spectroscopy has been used to map the entire five-dimensional momentum space of the photo double ionization of helium at 20 eV above threshold. Angular asymmetry parameters for the relative motion of the electrons and the recoil ion have been determined and are found to be close to similar data at 1 eV above threshold. In addition the asymmetry parameter of one photoelectron is found to be in good agreement with recent theory. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV FRANKFURT,INST KERNPHYS,D-60486 FRANKFURT,GERMANY. ARGONNE NATL LAB,ARGONNE,IL 60349. GESELL SCHWERIONENFORSCH MBH,D-64291 DARMSTADT,GERMANY. RP Brauning, H (reprint author), KANSAS STATE UNIV,DEPT PHYS,CARDWELL HALL,MANHATTAN,KS 66506, USA. RI Doerner, Reinhard/A-5340-2008 OI Doerner, Reinhard/0000-0002-3728-4268 NR 22 TC 25 Z9 25 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD OCT 14 PY 1997 VL 30 IS 19 BP L649 EP L655 DI 10.1088/0953-4075/30/19/004 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YB249 UT WOS:A1997YB24900004 ER PT J AU Kung, H Lu, YC Griffin, AJ Nastasi, M Mitchell, TE Embury, JD AF Kung, H Lu, YC Griffin, AJ Nastasi, M Mitchell, TE Embury, JD TI Observation of body centered cubic Cu in Cu/Nb nanolayered composites SO APPLIED PHYSICS LETTERS LA English DT Article ID TETRAGONAL COPPER; EPITAXIAL-GROWTH; MICROSTRUCTURE; MULTILAYERS AB The deposition of thin alternating layers of Cu and Nb on Si(100) substrates has been studied by transmission electron microscopy as a function of layer thickness. For layer thickness above 25 Angstrom, there is a strong texture orientation relationship with the close packed planes of fee Cu parallel to close packed planes of bcc Nb, forming the so-called ''Kurdjumov-Sachs'' orientation relationship. However, at thicknesses of under 12 Angstrom, the Cu is constrained to grow as a slightly distorted bcc structure. It is thought that, when it reaches a critical thickness between 12 and 20 Angstrom, the bcc Cu loses coherency and transforms martensitically to the fee phase, resulting in the observed Kurdjumov-Sachs orientation relationship. Electron energy loss spectroscopy observations indicate a difference of 2 eV in the L-3 edge suggesting that the Fermi energy is lower in the constrained bcc form of Cu than in the equilibrium fee structure. (C) 1997 American Institute of Physics. RP Kung, H (reprint author), LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. NR 15 TC 30 Z9 30 U1 1 U2 14 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 OCT 13 PY 1997 VL 71 IS 15 BP 2103 EP 2105 DI 10.1063/1.119611 PG 3 WC Physics, Applied SC Physics GA YA209 UT WOS:A1997YA20900015 ER PT J AU Toellner, TS Hu, MY Sturhahn, W Quast, K Alp, EE AF Toellner, TS Hu, MY Sturhahn, W Quast, K Alp, EE TI Inelastic nuclear resonant scattering with sub-meV energy resolution SO APPLIED PHYSICS LETTERS LA English DT Article ID SYNCHROTRON-RADIATION AB With an undulator-based synchrotron source and a tunable x-raf monochromator, we produce an x-ray beam with a flux of 4X10(8) photons/s in an energy bandwidth of 920+/-110 mu eV (Delta E/E approximate to 6.2X10(-8)) at a photon energy of 14.4 keV. The tunability of the monochromator allows for a measurement of lattice excitations in alpha-Fe using the technique of inelastic nuclear resonant scattering from Fe-57. The phonon density-of-states are extracted from the measurement and compared to the calculated phonon density-of-states derived from neutron-scattering measurements. (C) 1997 American Institute of Physics. RP Toellner, TS (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 16 TC 65 Z9 66 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 1997 VL 71 IS 15 BP 2112 EP 2114 DI 10.1063/1.120448 PG 3 WC Physics, Applied SC Physics GA YA209 UT WOS:A1997YA20900018 ER PT J AU Klebanov, IR Rajaraman, A Tseytlin, AA AF Klebanov, IR Rajaraman, A Tseytlin, AA TI Intermediate scalars and the effective string model of black holes SO NUCLEAR PHYSICS B LA English DT Article DE black-hole radiation; non-minimally coupled scalars; higher-dimensional supergravity; effective string model ID ENTROPY; DECAY AB We consider five-dimensional black holes modeled by D-strings bound to D5-branes, with momentum along the D-strings, We study the greybody factors for the non-minimally coupled scalars which originate from the gravitons and R-R antisymmetric tensor particles polarized along the 5-brane, with one index along the string and the other transverse to the string. These scalars, which we call intermediate, couple to the black holes differently from the minimal and the fixed scalars which were studied previously, Analysis of their fluctuations around the black hole reveals a surprising mixing between these NS-NS and R-R scalars. We disentangle this mixing and obtain two decoupled scaler equations. These equations have some new features, and we are able to calculate the greybody factors only in certain limits. The results agree with corresponding calculations in the effective string model provided one of the intermediate scalars couples to an operator of dimension (1,2), while the other to an operator of dimension (2,1). Thus, the intermediate scalars are sensitive probes of the chiral operators in the effective string action. (C) 1997 Elsevier Science B.V. PACS: 04.70.Dy; 04.65.+e; 11.25.-w; 11.25.Pm. C1 STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. RP Klebanov, IR (reprint author), PRINCETON UNIV,JOSEPH HENRY LABS,PRINCETON,NJ 08544, USA. RI Tseytlin, Arkady/M-5045-2015 OI Tseytlin, Arkady/0000-0002-5066-8282 NR 26 TC 16 Z9 16 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 OCT 13 PY 1997 VL 503 IS 1-2 BP 157 EP 176 DI 10.1016/S0550-3213(97)00415-X PG 20 WC Physics, Particles & Fields SC Physics GA YD660 UT WOS:A1997YD66000006 ER PT J AU Ellis, RK Ross, DA Veseli, S AF Ellis, RK Ross, DA Veseli, S TI Vector boson production in hadronic collisions SO NUCLEAR PHYSICS B LA English DT Article DE W and Z production; transverse momentum; spectra model; Drell-Yan ID LARGE TRANSVERSE-MOMENTUM; TO-BACK JETS; = 1.8 TEV; DIMUON PRODUCTION; PBARP COLLISIONS; PAIR PRODUCTION; QCD CORRECTIONS; CROSS-SECTIONS; MONTE-CARLO; W-BOSON AB We consider the production of gamma*, W and Z vector bosons in hadron-hadron collisions in perturbative QCD. We present results from a new numerical program which gives a full description of the production of the vector bosons and of their decay products, At small q(T) the calculation includes resummation of large logarithms and non-perturbative effects. The resummation is matched with the full O(alpha(s)) calculation, In addition, the program correctly reproduces the known O(alpha(s)) cross section when integrated over q(T). Besides presenting results for W and Z production at the Tevatron, we also review constraints on the non-perturbative functions using fixed-target data on lepton pair production, and make several observations on this topic. (C) 1997 Elsevier Science B.V, PACS: 13.38.Be; 13.38.Dg; 13.87.Ce; 14.70.Fm; 14.70.Hp. C1 UNIV SOUTHAMPTON,DEPT PHYS,SOUTHAMPTON SO9 5NH,HANTS,ENGLAND. RP Ellis, RK (reprint author), FERMILAB NATL ACCELERATOR LAB,THEORY GRP,POB 500,BATAVIA,IL 60510, USA. NR 45 TC 68 Z9 68 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 OCT 13 PY 1997 VL 503 IS 1-2 BP 309 EP 338 DI 10.1016/S0550-3213(97)00403-3 PG 30 WC Physics, Particles & Fields SC Physics GA YD660 UT WOS:A1997YD66000013 ER PT J AU Carena, M Quiros, M Riotto, A Vilja, I Wagner, CEM AF Carena, M Quiros, M Riotto, A Vilja, I Wagner, CEM TI Electroweak baryogenesis and low energy supersymmetry SO NUCLEAR PHYSICS B LA English DT Article ID MODEL CP-VIOLATION; PHASE-TRANSITION; STANDARD MODEL; FINITE-TEMPERATURE; BARYON ASYMMETRY; FIELD-THEORY; 2-LOOP CORRECTIONS; LEADING ORDER; HIGGS-MODEL; LIGHT STOP AB Electroweak baryogenesis is an interesting theoretical scenario, which demands physics beyond the Standard Model at energy scales of the order of the weak boson masses. It has been recently emphasized that, in the presence of light stops, the electroweak phase transition can be strongly first order, opening the window for electroweak baryogenesis in the MSSM. For the realization of this scenario, the Higgs boson must be light, at the reach of the LEP2 collider. In this article, we compute the baryon asymmetry assuming the presence of non-trivial CP-violating phases in the parameters associated with the left-right stop mixing term and the Higgsino mass mu. We conclude that a phase \sin phi(mu)\ > 0.01 and Higgsino and gaugino mass parameters \mu\ similar or equal to M-2, and of the order of the electroweak scale, are necessary in order to generate the observed baryon asymmetry. (C) 1997 Elsevier Science B.V. PACS: 11.10.Wx; 11.30.Pb; 12.60.Jv. C1 CSIC,INST ESTRUCTURA MAT,E-28006 MADRID,SPAIN. UNIV TURKU,DEPT PHYS,FIN-20014 TURKU,FINLAND. CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. RP Carena, M (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 87 TC 155 Z9 155 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 OCT 13 PY 1997 VL 503 IS 1-2 BP 387 EP 404 DI 10.1016/S0550-3213(97)00412-4 PG 18 WC Physics, Particles & Fields SC Physics GA YD660 UT WOS:A1997YD66000016 ER PT J AU Kob, W Donati, C Plimpton, SJ Poole, PH Glotzer, SC AF Kob, W Donati, C Plimpton, SJ Poole, PH Glotzer, SC TI Dynamical heterogeneities in a supercooled Lennard-Jones liquid SO PHYSICAL REVIEW LETTERS LA English DT Article ID GLASS-FORMING LIQUIDS; MODE-COUPLING THEORY; MULTIDIMENSIONAL NMR; 2-DIMENSIONAL LIQUID; ORTHO-TERPHENYL; RELAXATION; TRANSITION; MIXTURE; BEHAVIOR; MEMORY AB We present the results of a molecular dynamics computer simulation study in which we investigate whether a supercooled Lennard-Jones liquid exhibits dynamical heterogeneities. We evaluate the non-Gaussian parameter for the self part of the van Hove correlation function and use it to identify ''mobile'' particles. We find that these particles form clusters whose sizes grow with decreasing temperature. We also find that the relaxation time of the mobile particles is significantly shorter than that of the average particle, and that this difference increases with decreasing temperature. C1 NATL INST STAND & TECHNOL, CTR THEORET & COMPUTAT MAT SCI, GAITHERSBURG, MD 20899 USA. NATL INST STAND & TECHNOL, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. SANDIA NATL LABS, PARALLEL COMPUTAT SCI DEPT, ALBUQUERQUE, NM 87185 USA. UNIV WESTERN ONTARIO, DEPT APPL MATH, LONDON, ON N6A 5B7, CANADA. RP UNIV MAINZ, INST PHYS, STAUDINGER WEG 7, D-55099 MAINZ, GERMANY. RI Poole, Peter/C-7943-2009; Donati, Claudio/J-5180-2012; Kob, Walter/L-7010-2013; OI Poole, Peter/0000-0001-5985-0585; Kob, Walter/0000-0001-7405-2178; Donati, Claudio/0000-0001-8688-1651 NR 30 TC 628 Z9 630 U1 4 U2 88 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 13 PY 1997 VL 79 IS 15 BP 2827 EP 2830 DI 10.1103/PhysRevLett.79.2827 PG 4 WC Physics, Multidisciplinary SC Physics GA YA302 UT WOS:A1997YA30200019 ER PT J AU LilientalWeber, Z Chen, Y Ruvimov, S Washburn, J AF LilientalWeber, Z Chen, Y Ruvimov, S Washburn, J TI Formation mechanism of nanotubes in GaN SO PHYSICAL REVIEW LETTERS LA English DT Article AB A formation mechanism for so-called nanotube defects in GaN is proposed. It is shown that two related types of defects are formed: nanotubes and pinholes. Both start with V shaped facets on {10 (1) over bar 1} polar planes. Slow growth rate on these polar planes and impurity poisoning of growth steps are suggested as being responsible for initiation of these defects. RP LilientalWeber, Z (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 9 TC 226 Z9 227 U1 3 U2 19 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 OCT 13 PY 1997 VL 79 IS 15 BP 2835 EP 2838 DI 10.1103/PhysRevLett.79.2835 PG 4 WC Physics, Multidisciplinary SC Physics GA YA302 UT WOS:A1997YA30200021 ER PT J AU Carpinelli, JM Weitering, HH Bartkowiak, M Stumpf, R Plummer, EW AF Carpinelli, JM Weitering, HH Bartkowiak, M Stumpf, R Plummer, EW TI Surface charge ordering transition: alpha phase of Sn/Ge(111) SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ELECTRON-GAS; GROUND-STATE; PB; SI(111); SPECTROSCOPY; COVERAGE; GE(111); STM AB We have identified and characterized a charge-density wave transition (T-c similar to -60 degrees C) in the low-coverage ct phase of the Sn/Ge(111) interface both experimentally and theoretically. Charge ordering is accompanied by a structural distortion from (root 3 x root 3)R30 degrees to (3 x 3) symmetry. Density-functional theory calculations are unable to correctly reproduce the observed ground state and, more importantly, indicate that Fermi surface nesting does not play a role in this transition. Both signal the importance of many-body effects in this system. Experiment and theory indicate that the Sn/Ge(111) overlayer is fundamentally different from the Pb/Ge(111) overlayer previously reported. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP Carpinelli, JM (reprint author), UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. NR 33 TC 186 Z9 186 U1 5 U2 27 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 13 PY 1997 VL 79 IS 15 BP 2859 EP 2862 DI 10.1103/PhysRevLett.79.2859 PG 4 WC Physics, Multidisciplinary SC Physics GA YA302 UT WOS:A1997YA30200027 ER PT J AU Lee, LT Kent, MS AF Lee, LT Kent, MS TI Direct measurement of the penetration of free chains into a tethered chain layer SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON REFLECTIVITY; POLYMER BRUSH AB Direct measurements of the penetration of free chains into a layer of tethered chains in good solvent conditions are reported. The segmental profiles of both the tethered chains (N = 1625 monomer units) and the free chains (P = 413 and 3846 monomer units) are obtained by neutron reflection. At 6 vol. %, the free chains penetrate the tethered layer at low surface density (sigma), but are progressively excluded from the layer with increasing sigma. At the highest sigma (sigma pi R-g(2) congruent to 12) there remains significant penetration into the layer for both values of P; however, the form of the profile is strikingly different. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP CENS, LAB LEON BRILLOUIN, F-91191 GIF SUR YVETTE, FRANCE. NR 18 TC 10 Z9 10 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 13 PY 1997 VL 79 IS 15 BP 2899 EP 2902 DI 10.1103/PhysRevLett.79.2899 PG 4 WC Physics, Multidisciplinary SC Physics GA YA302 UT WOS:A1997YA30200037 ER PT J AU Kelly, PJ Dekker, JP Stumpf, R AF Kelly, PJ Dekker, JP Stumpf, R TI Theoretical prediction of the structure of insulating YH3 - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material ID YTTRIUM C1 VRIJE UNIV AMSTERDAM,FAC PHYS & ASTRON,NL-1081 HV AMSTERDAM,NETHERLANDS. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Kelly, PJ (reprint author), PHILIPS RES LABS,PROF HOLSTLAAN 4,NL-5656 AA EINDHOVEN,NETHERLANDS. RI Kelly, Paul/G-4210-2010 OI Kelly, Paul/0000-0001-9040-1868 NR 11 TC 15 Z9 15 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 13 PY 1997 VL 79 IS 15 BP 2921 EP 2921 DI 10.1103/PhysRevLett.79.2921 PG 1 WC Physics, Multidisciplinary SC Physics GA YA302 UT WOS:A1997YA30200044 ER PT J AU Zhang, J MacPhee, AG Lin, J Wolfrum, E Smith, R Danson, C Key, MH Lewis, CLS Neely, D Nilsen, J Pert, GJ Tallents, GJ Wark, JS Warwick, PJ AF Zhang, J MacPhee, AG Lin, J Wolfrum, E Smith, R Danson, C Key, MH Lewis, CLS Neely, D Nilsen, J Pert, GJ Tallents, GJ Wark, JS Warwick, PJ TI Optimisation of drive pulse configuration for a Ni-like Sn X-ray laser at 12 nm SO PHYSICS LETTERS A LA English DT Article DE Ni-like X-ray lasers; saturation ID XUV LASER; ENERGY; GAIN; IONS AB The current saturated operation of X-ray lasers at wavelengths > 15 nm requires at least kilojoule drive energy, which is only available at the largest laser installations in the world, Using a specially designed drive pulse configuration, saturated operation of a Ni-like Sn X-ray laser at 12 nm has been achieved with only 75 J drive energy, An efficiency as high as 9 x 10(6) in converting laser energy from the 1 eV optical spectral range to the 100 eV soft X-ray range has been reached, This paves the way for applications of saturated X-ray lasers at 12 nm at many other smaller laboratories. (C) 1997 Published by Elsevier Science B.V. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. QUEENS UNIV BELFAST,SCH MATH & PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. RP Zhang, J (reprint author), RUTHERFORD APPLETON LAB,CENT LASER FACIL,CHILTON OX11 0QX,OXON,ENGLAND. RI Zhang, Jie/O-8767-2014 NR 22 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD OCT 13 PY 1997 VL 234 IS 6 BP 410 EP 414 DI 10.1016/S0375-9601(97)00553-7 PG 5 WC Physics, Multidisciplinary SC Physics GA YB833 UT WOS:A1997YB83300002 ER PT J AU Hay, BP Yang, LR Zhang, DL Rustad, JR Wasserman, E AF Hay, BP Yang, LR Zhang, DL Rustad, JR Wasserman, E TI An extended molecular mechanics (MM3(96)) force field for benzocrown ethers, calixarenes, and spherands SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE molecular mechanics; MM3; crown ether; calixarene; spherand ID MACROCYCLE INTERACTION; STRUCTURAL CRITERIA; SELECTIVE LIGANDS; RATIONAL DESIGN; CROWN-ETHERS; VINYL ETHERS; KINETIC DATA; CATIONS; MM3; HYDROCARBONS AB The X-ray crystal structures of 60 molecules containing aliphatic and conjugated ether functional groups were calculated with an extended version of the molecular mechanics MM3(96) force field. The structures fit well with overall deviations of 0.014 Angstrom in bond length, 1.1 degrees in bond angle, and 3.2 degrees in torsion angle. (C) 1997 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hay, BP (reprint author), Pacific NW Natl Lab, MSIN K9-77, Richland, WA 99352 USA. NR 25 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD OCT 13 PY 1997 VL 417 IS 1-2 BP 19 EP 34 DI 10.1016/S0166-1280(96)04960-3 PG 16 WC Chemistry, Physical SC Chemistry GA YM265 UT WOS:000071046300003 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Bennett, DP Charles, PA Cook, KH Freeman, KC Griest, K Lehner, MJ Livio, M Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Bennett, DP Charles, PA Cook, KH Freeman, KC Griest, K Lehner, MJ Livio, M Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W TI Optical identification of the LMC supersoft source RX J0527.8-6954 from MACHO project photometry SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE accretion, accretion discs; binaries: close; binaries: spectroscopic; stars: individual: RX J0527.8-6954; X-rays: stars ID LARGE MAGELLANIC CLOUD; X-RAY SOURCES; SPACED DATA; CAL-87; BINARY; MODELS; ROSAT AB We identify the likely optical counterpart to the Large Magellanic Cloud (LMC) supersoft X-ray source RX J0527.8-6954, and hence recover HV 2554. This identification is based on an analysis of similar to 4 yr of optical photometry obtained serendipitously via the MACHO project. We see a steady fading of the star of similar to 0.5 mag over the duration of the observations. Evidence is also presented for an orbital modulation of similar to 0.05-mag semi-amplitude on a period of P = 0.392 62 +/- 0.000 15 d. Our optical observations are consistent with the suggestion that the X-ray decline in this system is caused by cooling after a weak shell hash. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV OXFORD,DEPT ASTROPHYS,NUCL & ASTROPHYS LAB,OXFORD OX1 3RH,ENGLAND. UNIV CALIF SAN DIEGO,DEPT PHYS,SAN DIEGO,CA 92093. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Alcock, C (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013 OI Stubbs, Christopher/0000-0003-0347-1724; NR 23 TC 3 Z9 3 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 11 PY 1997 VL 291 IS 1 BP L13 EP L16 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YD914 UT WOS:A1997YD91400004 ER PT J AU Wang, YM Sheeley, NR Phillips, JL Goldstein, BE AF Wang, YM Sheeley, NR Phillips, JL Goldstein, BE TI Solar wind stream interactions and the wind speed-expansion factor relationship SO ASTROPHYSICAL JOURNAL LA English DT Article DE interplanetary medium; solar wind; Sun, corona; Sun, magnetic fields ID FLUX-TUBE DIVERGENCE; ECLIPTIC-PLANE; CORONAL HOLE; SYSTEM; FIELD; EVOLUTION; FRONTS; FLOWS AB Previous studies have shown that the solar wind speed observed near Earth is inversely correlated with the divergence rate of magnetic flux tubes near the Sun. We test the global validity of this relationship by employing Ulysses wind speed measurements during 1990-1997 as well as inecliptic data for 1976-1997. When the correspondence between wind speeds and expansion factors is adjusted to yield optimal agreement with the high-latitude Ulysses measurements, the model matches the overall patterns of fast and slow wind near the ecliptic but predicts too much very fast wind there. We show how this discrepancy can be resolved by taking account of wind stream interactions, where we apply a crude algorithm based on the propagation times of neighboring wind parcels; the interactions reduce the amount of very fast wind at latitudes where slow wind is present. We also test and reject an alternative model in which the wind speed is assumed to be a function only of angular distance from the heliospheric neutral sheet. C1 NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058. CALTECH,JET PROP LAB,PASADENA,CA 91109. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Wang, YM (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,CODE 7672,WASHINGTON,DC 20375, USA. NR 25 TC 54 Z9 54 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1997 VL 488 IS 1 BP L51 EP & DI 10.1086/310918 PN 2 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YB998 UT WOS:A1997YB99800013 ER PT J AU Jensen, RJ Guettler, RD Lyman, JL AF Jensen, RJ Guettler, RD Lyman, JL TI The ultraviolet absorption spectrum of hot carbon dioxide SO CHEMICAL PHYSICS LETTERS LA English DT Article ID TEMPERATURE-DEPENDENCE; EXCITED-STATES; CROSS-SECTION; CO2; PHOTODISSOCIATION; NM AB The vacuum ultraviolet absorption spectrum of CO2 shifts significantly to longer wavelengths with increasing temperature. We have measured this temperature dependence and present absorption cross sections for 230 to 355 nn at temperatures from 1523 to 2273 K. At 2273 K this red shift extends the absorption above 300 nm and well into the blue end of the solar spectrum. In CO2 the thermal shift is enhanced because of the relative position and shapes of the excited and ground state potential curves. (C) 1997 Elsevier Science B.V. RP Jensen, RJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 11 TC 33 Z9 33 U1 0 U2 0 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 OCT 10 PY 1997 VL 277 IS 4 BP 356 EP 360 DI 10.1016/S0009-2614(97)00919-6 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YD709 UT WOS:A1997YD70900013 ER PT J AU Sailer, BL Valdez, JG Steinkamp, JA Darzynkiewicz, Z Crissman, HA AF Sailer, BL Valdez, JG Steinkamp, JA Darzynkiewicz, Z Crissman, HA TI Monitoring uptake of ellipticine and its fluorescence lifetime in relation to the cell cycle phase by flow cytometry SO EXPERIMENTAL CELL RESEARCH LA English DT Article ID ANTHRACYCLINE RETENTION; MAMMALIAN-CELLS; MODULATION; FLUOROCHROMES; PROGRESSION; PARTICLES; SURVIVAL; SIGNALS; DNA AB Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole) is a green fluorescent plant alkaloid that inhibits DNA topoisomerase II activity and possesses pharmacologic activity toward both murine and human leukemias in vivo. In this flow cytometric study, the uptake of ellipticine was monitored as a function of cell volume and cell cycle phase in viable human promyelocytic (HL-60) cells costained with the DNA fluorochrome Hoechst 33342. Uptake of ellipticine was time and dose dependent; however, drug content was quantitatively similar in all phases of the cell cycle when normalized for DNA content or similar to cell size when correlated with cell volume. The fluorescence lifetime values of ellipticine in HL-60 cells, as analyzed by novel flow cytometric analysis, reached a plateau when the intracellular ellipticine intensity was still rising with increasing drug concentration. Since the free drug and the different subcellular ellipticine complexes, including DNA and RNA, had different lifetime values, the changes in the lifetime values appear to reflect differing proportions of unbound drug to that bound to different cellular constituents in the cells. Further development of phase-sensitive flow cytometry will provide for multiple lifetime determinations so that quantitation of drugs bound to the different cellular components can be performed along with the simultaneous determination of total drug uptake and cell cycle position. Such analyses should provide useful information for the design of drugs with greater affinity for cytotoxic targets. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NEW YORK MED COLL,CANC RES INST,VALHALLA,NY 10595. OI Darzynkiewicz, Zbigniew/0000-0002-2040-7081 FU NCRR NIH HHS [P41-RR01315, R01 RR06758, R01 RR07855] NR 22 TC 10 Z9 10 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0014-4827 J9 EXP CELL RES JI Exp. Cell Res. PD OCT 10 PY 1997 VL 236 IS 1 BP 259 EP 267 DI 10.1006/excr.1997.3717 PG 9 WC Oncology; Cell Biology SC Oncology; Cell Biology GA YC724 UT WOS:A1997YC72400028 PM 9344606 ER PT J AU Pikuz, SA Maksimchuk, A Umstadter, D Nantel, M Skobelev, IY Faenov, AY Osterheld, A AF Pikuz, SA Maksimchuk, A Umstadter, D Nantel, M Skobelev, IY Faenov, AY Osterheld, A TI Observation of laser satellites in a plasma produced by a femtosecond laser pulse SO JETP LETTERS LA English DT Article AB Laser satellites are detected in the emission spectra of magnesium and aluminum plasmas produced by femtosecond laser pulses. This is made possible by the realization of picosecond time resolution in a high luminosity x-ray spectrograph with a spherically curved mica crystal. The temporal characteristics of these newly recorded spectral lines show unequivocally that they are formed as a result of nonlinear processes. (C) 1997 American Institute of Physics. [S0021-3640(97)00219-3]. C1 CTR ULTRAFAST OPT SCI,ANN ARBOR,MI. ALL RUSSIA SCI RES INST PHYSICOTECH & RADIO ELECT,ATOM SPECT DATA CTR,MENDELEYEVSK 141570,MOSCOW REGION,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Pikuz, SA (reprint author), RUSSIAN ACAD SCI,PN LEBEDEV PHYS INST,MOSCOW 118927,RUSSIA. RI Umstadter, Donald/A-1581-2016; Pikuz, Sergey/M-8231-2015 OI Umstadter, Donald/0000-0002-2182-4346; NR 12 TC 18 Z9 18 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-3640 J9 JETP LETT+ JI Jetp Lett. PD OCT 10 PY 1997 VL 66 IS 7 BP 480 EP 486 DI 10.1134/1.567554 PG 7 WC Physics, Multidisciplinary SC Physics GA YG951 UT WOS:A1997YG95100002 ER PT J AU Baer, EM Fisher, RV Fuller, M Valentine, G AF Baer, EM Fisher, RV Fuller, M Valentine, G TI Turbulent transport and deposition of the Ito pyroclastic flow: Determinations using anisotropy of magnetic susceptibility SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID HIGH-GRADE IGNIMBRITE; PROGRESSIVE AGGRADATION; WELDED TUFFS; NEW-MEXICO; EMPLACEMENT; MOUNTAINS; CALDERA; REAPPRAISAL; PARTICULATE; ERUPTION AB The Ito pyroclastic flow erupted about 22,000 years ago from Aira caldera in southern Kyushu, Japan. Flow directions were determined by anisotropy of magnetic susceptibility (AMS), which measured the preferential alignment of magnetite microphenocrysts, usually less than or equal to 0.25 mm in diameter. The microphenocrysts are aligned with the long axis of the clasts during strain and fracture in the vent. The grains are then deposited parallel to the flow direction with an imbrication. There is no evidence of rolling of clasts or nonflow parallel lineations, and thus AMS can be used to determine now directions that occurred immediately before deposition. Beyond 30 km from the center of the caldera, flow directions were predominantly down paleogradient, indicating expanded flow and that the depositional system was gravity driven and largely decoupled from the transport system. Within 30 km, measured flow directions are random, indicating that sedimentation occurred from a depositional system that was closely coupled to the turbulent transport system. Individual flow directions at all sites except one varied more than the analytical error, demonstrating that a variety of flow directions existed even within a small area of the flow. This implies that the depositional system was turbulent. C1 UNIV CALIF SANTA BARBARA, DEPT GEOL SCI, SANTA BARBARA, CA 93106 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Baer, EM (reprint author), HIGHLINE COMMUNITY COLL, DEPT GEOL, POB 98000, 2400 S 240TH ST, DES MOINES, WA 98198 USA. NR 70 TC 52 Z9 52 U1 0 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 OCT 10 PY 1997 VL 102 IS B10 BP 22565 EP 22586 DI 10.1029/96JB01277 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YB715 UT WOS:A1997YB71500013 ER PT J AU Walsh, JB Brown, SR Durham, WB AF Walsh, JB Brown, SR Durham, WB TI Effective media theory with spatial correlation for flow in a fracture SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SURFACE-ROUGHNESS; FAULT SURFACES; ROCK JOINTS; FLUID-FLOW; TRANSPORT; RENORMALIZATION; PERCOLATION; NETWORKS AB Standard effective media theory, real-space renormalization, and first-order perturbation theory all predict that a percolation threshold, where the electrical and hydraulic conductivity become zero, is reached when the area of contact is half of the total area. However, calculations of the flow properties of joints; whether simulated by continuous fields or discretely as a network of resistors, show that how is maintained at appreciably larger contact areas. This behavior has been termed ''channeling'' in the literature. We have modified the standard effective media theory by introducing a rudimentary sort of nonrandomness in an attempt to simulate features like topographic hills and valleys. Using this new model we calculate overestimates and underestimates of electrical and hydraulic conductivity as a function df the separation between the fracture surfaces. The underestimate is found to be very close to the standard effective media theory, real-space renormalization, and first-order perturbation theory results. The mean of the overestimate and underestimate is a good approximation to the published values found from calculations of electrical and hydraulic conductivities for simulations of real joints. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 26 TC 14 Z9 14 U1 0 U2 8 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 OCT 10 PY 1997 VL 102 IS B10 BP 22587 EP 22594 DI 10.1029/97JB01895 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YB715 UT WOS:A1997YB71500014 ER PT J AU Bowie, JU AF Bowie, JU TI Helix packing in membrane proteins SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE bacteriorhodopsin; cytochrome c oxidase; photosynthetic reaction center; protein structure ID PHOTOSYNTHETIC REACTION CENTER; RHODOBACTER-SPHAEROIDES R-26; TRANSMEMBRANE ALPHA-HELICES; CYTOCHROME-C-OXIDASE; CRYSTALLOGRAPHIC REFINEMENT; SECONDARY STRUCTURE; PREDICTION; BACTERIORHODOPSIN; RESOLUTION; PEPTIDES AB A survey of 45 transmembrane (TM) helices and 88 helix packing interactions In three independent transmembrane protein structures reveals the following features, (1) Helix lengths range from 14 to 36 residues with an average length of 26.4 residues. There is a preference for lengths greater than 20 residues. (2) The helices are tilted with respect to the bilayer normal by an average of 21 degrees, but there is a decided preference for smaller tilt angles. (3) The distribution of helix packing angles is very different than for soluble proteins. The most common packing angles for TM helices are centered around +20 degrees while for soluble proteins packing angles of around -35 degrees are the most prevalent. (4) The average distance of closest approach is 9.6 Angstrom, which is the same as soluble proteins. (5) There is no preference for the positioning of the point of closest approach along the length of the helices (6) It is almost a rule that TM helices pack against: neighbors in the sequence. Of the 37 helices that have a sequence neighbor, 36 of them are in significant contact with a neighbor. (7) An antiparallel orientation is more prevalent than a parallel orientation and antiparallel interactions are more intimate on average. The general features of helix bundle membrane protein architecture described in this survey should prove useful in the modeling of helix bundle transmembrane proteins. (C) 1997 Academic Press Limited. RP Bowie, JU (reprint author), UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,DEPT CHEM & BIOCHEM,405 HILGARD AVE,LOS ANGELES,CA 90095, USA. NR 40 TC 259 Z9 261 U1 0 U2 7 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 OCT 10 PY 1997 VL 272 IS 5 BP 780 EP 789 DI 10.1006/jmbi.1997.1279 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YB267 UT WOS:A1997YB26700010 PM 9368657 ER PT J AU Stephenson, GJ Goldman, T McKellar, BHJ AF Stephenson, GJ Goldman, T McKellar, BHJ TI MSW-like enhancements without matter SO MODERN PHYSICS LETTERS A LA English DT Article ID NEUTRINO-MASS HIERARCHY; EARLY UNIVERSE; OSCILLATIONS; NUCLEOSYNTHESIS; BOUNDS AB We study the effects of a scalar field, coupled only to neutrinos, on oscillations among weak interaction current eigenstates. The effect of a real scalar held appears as effective masses for the neutrino mass eigenstates, the same for upsilon as for upsilon. Under some conditions, this can lead to a vanishing of delta m(2),which maximizes mixing independently of the vacuum mixing angles, as in the MSW effect. We discuss some examples and show that it is possible to resolve an apparent discrepancy in spectra required by r-process nucleosynthesis in the mantles of supernovae and by solar neutrino solutions. C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. RP Stephenson, GJ (reprint author), Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. NR 28 TC 22 Z9 22 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD OCT 10 PY 1997 VL 12 IS 31 BP 2391 EP 2398 DI 10.1142/S021773239700248X PG 8 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA ZA099 UT WOS:000072328800010 ER PT J AU Bromberg, SE Yang, H Asplund, MC Lian, T McNamara, BK Kotz, KT Yeston, JS Wilkens, M Frei, H Bergman, RG Harris, CB AF Bromberg, SE Yang, H Asplund, MC Lian, T McNamara, BK Kotz, KT Yeston, JS Wilkens, M Frei, H Bergman, RG Harris, CB TI The mechanism of a C-H bond activation reaction in room-temperature alkane solution SO SCIENCE LA English DT Article ID FEMTOSECOND TRANSIENT ABSORPTION; RESOLVED INFRARED-SPECTROSCOPY; (HBPZ'(3))RH(CO)(2) PZ'=3,5-DIMETHYLPYRAZOLYL; SOLUTION PHOTOCHEMISTRY; OXIDATIVE ADDITION; VIBRATIONAL-ENERGY; METAL-COMPLEXES; ULTRAFAST; MATRIX; DYNAMICS AB Chemical reactions that break alkane carbon-hydrogen (C-H) bonds are normally carried out under conditions of high temperature and pressure because these bonds are extremely strong (similar to 100 kilocalories per mole), but certain metal complexes can activate C-H bonds in alkane solution under the mild conditions of room temperature and pressure. Time-resolved infrared experiments probing the initial femtosecond dynamics through the nano-and microsecond kinetics to the final stable products have been used to generate a detailed picture of the C-H activation reaction. Structures of all of the intermediates involved in the reaction of Tp*Rh(CO)(2) (Tp* = HB-Pz(3)*, Pz* = 3,5-dimethylpyrazolyl) in alkane solution have been identified and assigned, and energy barriers for each reaction step from solvation to formation of the final alkyl hydride product have been estimated from transient lifetimes. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,MS CALVIN LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Lian, Tianquan/L-8992-2013; Wilkens, Matthew/I-3720-2014 OI Lian, Tianquan/0000-0002-8351-3690; Wilkens, Matthew/0000-0001-6749-9318 NR 38 TC 191 Z9 192 U1 6 U2 61 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 10 PY 1997 VL 278 IS 5336 BP 260 EP 263 DI 10.1126/science.278.5336.260 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YA564 UT WOS:A1997YA56400037 ER PT J AU Bushaw, BA Cannon, BD AF Bushaw, BA Cannon, BD TI Diode laser based resonance ionization mass spectrometric measurement of strontium-90 SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE diode lasers; mass spectrometry; radionuclides; strontium; trace analysis ID ENVIRONMENTAL-SAMPLES; ISOTOPE SHIFTS; SPECTROSCOPY; SR-90; SR-89 AB A diode laser based scheme for the isotopically selective excitation and ionization of strontium is presented. The double-resonance excitation 5s(2) S-1(0) --> 5s5p P-3(i) --> 5s6s S-3(1) is followed by photoionization at 488 nm. The isotope shifts and hyperfine structure in the resonance transitions have been accurately measured for the stable isotopes and Sr-90, with the measurement of the Sr-90 shifts using sub-pg samples. Analytical tests, using graphite crucible atomization, demonstrated Sr-90 detection limits of 0.8 fg and overall (optical + mass spectrometer) isotopic selectivity of > 10(10) against stable strontium. (C) 1997 Elsevier Science B.V. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Bushaw, BA (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 31 TC 41 Z9 41 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD OCT 10 PY 1997 VL 52 IS 12 BP 1839 EP 1854 DI 10.1016/S0584-8547(97)00066-9 PG 16 WC Spectroscopy SC Spectroscopy GA YL739 UT WOS:000070988000011 ER PT J AU Gole, JL Dixon, DA AF Gole, JL Dixon, DA TI Suggested correlation between the visible photoluminescence and the Fourier transform infrared spectrum of a porous silicon surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LUMINESCENCE MECHANISM; OPTICAL-PROPERTIES; ANODIC-OXIDATION; BASIS-SETS; SI; IDENTIFICATION; ABSTRACTION; PREDICTION; CHEMISTRY; EXCITONS AB The FTIR spectrum for a heavily oxidized porous silicon (PS) surface is considered. It is suggested that a portion of this spectrum be reassigned to the Si=O stretch frequency of a surface bound-silanone-based silicon oxyhydride consistent also with the O-18(2)/O-16(2) isotopic labeling of the FTIR spectrum and with matrix isolation infrared spectra for silanone, silanoic acid, and silicic acid. Within the framework of this assignment the FTIR spectrum, the photoluminescence excitation spectrum, and the visible photoluminescence spectrum of PS correlate well with a surface-bound silanone-based silicon oxyhydride fluorophor. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP GEORGIA INST TECHNOL, SCH PHYS, ATLANTA, GA 30332 USA. NR 50 TC 41 Z9 41 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 9 PY 1997 VL 101 IS 41 BP 8098 EP 8102 DI 10.1021/jp971177r PG 5 WC Chemistry, Physical SC Chemistry GA YA485 UT WOS:A1997YA48500011 ER PT J AU Schlichthorl, G Huang, SY Sprague, J Frank, AJ AF Schlichthorl, G Huang, SY Sprague, J Frank, AJ TI Band edge movement and recombination kinetics in dye-sensitized nanocrystalline TiO2 solar cells: A study by intensity modulated photovoltage spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON-TRANSFER REACTIONS; PHOTOCURRENT SPECTROSCOPY; SEMICONDUCTOR ELECTRODES; CONVERSION; EFFICIENCIES; ELECTRICITY; OUTPUT; LIGHT AB The charge-recombination kinetics and band edge movement in dye-sensitized nanocrystalline TiO2 solar cells are investigated by intensity modulated photovoltage spectroscopy (IMVS). A theoretical model of IMVS for dye-sensitized nanocrystalline semiconductor electrodes is developed, and analytical expressions for the frequency dependence of the photovoltage response at open circuit are derived. The model considers charge trapping/detrapping and electron transfer from the conduction band and surface states of the semiconductor to redox species at the solid/solution interface. IMVS is shown to be valuable in elucidating the contributions of band edge shift and recombination kinetics to changes of the open-circuit photovoltage (V-oc) resulting from surface modifications of the semiconductor. IMVS measurements indicate that surface treatment of [RuL2(NCS)(2)] (L = 2,2'-bipyridyl-4,4'-dicarboxylic acid)-sensitized TiO2 electrodes with 4-tert-butylpyridine or ammonia leads to a significant band edge shift concomitant with a more negative V,. Surface-modified dye-covered TiO2 electrodes exhibit a much higher photovoltage, for a given concentration of accumulated photogenerated electrons, than the unmodified dye-covered electrode. The accumulated charge in the TiO2 electrode is not sufficient to induce a major potential drop across the Helmholtz layer and cannot thus explain the observed photovoltage. The surface charge density is also not sufficient to support an accumulation layer strong enough to have a major influence on the photovoltage. The movement of the Fermi level of the TiO2 electrode, arising from the accumulation of photogenerated electrons in the conduction band, accounts for the observed Vac. The second-order nature of the recombination reaction with respect to I-3(-) concentration is confirmed. Furthermore, the IMVS study indicates that recombination at the nanocrystallite/redox electrolyte interface occurs predominantly via trapped electrons in surface states. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RI Wei, Zhanhua/D-7544-2013 OI Wei, Zhanhua/0000-0003-2687-0293 NR 35 TC 704 Z9 713 U1 17 U2 170 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 9 PY 1997 VL 101 IS 41 BP 8141 EP 8155 DI 10.1021/jp9714126 PG 15 WC Chemistry, Physical SC Chemistry GA YA485 UT WOS:A1997YA48500017 ER PT J AU Liu, J Wang, LQ Samuels, WD Exarhos, GJ AF Liu, J Wang, LQ Samuels, WD Exarhos, GJ TI Aggregation and dispersion of colloidal suspensions by inorganic surfactants: Effect of chemical speciation and molecular conformation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TAPE-CASTING TECHNOLOGY; MAGNETIC-RESONANCE; SLIP ADDITIVES; STABILITY AB Polyphosphates are widely used as inorganic dispersants, but the mechanism of the dispersing is not well understood. In this study, the colloidal properties of fine alumina suspensions in water were studied at different pH conditions in the presence of linear chain polymetaphosphates. The chemical speciation and molecular conformation were probed using liquid and solid state P-31 and Al-27 nuclear magnetic resonance spectroscopy. Three regimes have been found: (i) Neutral pH-long-chain metaphosphates are partially anchored to the alumina surface. The negatively charged metaphosphate molecules extend from the particle surface to the solution to provide an effective electrosteric repulsion force that acts to disperse the colloidal particles. (ii) Low pH-the alumina particle surfaces hydrolyze and the dissolved species react with the surfactant to form amorphous aluminum phosphate gels. The reaction product causes bridging flocculation of the suspension. (iii) High pH-partial dissolution of alumina produces tetrahedrally bonded hydroxyaluminate anions, which induces the long-chain polymetaphosphates to dissociate into phosphate anions. Under these conditions, the metaphosphate no longer exhibits dispersion properties. A fundamental understanding of the particle-surfactant interactions in terms of adsorption, chemical reaction, and molecular conformation will provide insights for the rational design of more effective inorganic dispersants. RP Liu, J (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 25 TC 9 Z9 9 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 9 PY 1997 VL 101 IS 41 BP 8264 EP 8269 DI 10.1021/jp971609y PG 6 WC Chemistry, Physical SC Chemistry GA YA485 UT WOS:A1997YA48500033 ER PT J AU Isfort, RJ Cody, DB Doersen, CJ Richards, WG Yoder, BK Wilkinson, JE Kier, LD Jirtle, RL Isenberg, JS Klounig, JE Woychik, RP AF Isfort, RJ Cody, DB Doersen, CJ Richards, WG Yoder, BK Wilkinson, JE Kier, LD Jirtle, RL Isenberg, JS Klounig, JE Woychik, RP TI The tetratricopeptide repeat containing Tg737 gene is a liver neoplasia tumor suppressor gene SO ONCOGENE LA English DT Article DE Tg737; tumor suppressor gene; liver neoplasia ID POLYCYSTIC KIDNEY-DISEASE; STEM-CELLS; HUMAN HOMOLOG; SNAP HELIX; GROWTH; PROTEIN; DIFFERENTIATION; MUTATION; MOUSE; CARCINOGENESIS AB The Tg737 gene was investigated for gross alterations in a series of rodent/human liver tumors and human tumorigenic cell lines. The Tg737 gene was found to be altered in approximately 40% of the rodent chemically-induced liver tumors, 40% of the human liver tumors, and in liver, kidney and pancreatic human tumor cell lines. Ectopic re-expression of the Tg737 gene in a Tg737 deleted mouse liver tumor cell line resulted in suppression of tumorigenic growth, without altering in vitro cell culture growth. Treatment of mice which are either homozygous normal or heterozygous deleted at the Tg737 locus with the carcinogen diethylnitrosamine resulted in an increase in preneoplastic foci formation in the Tg737 heterozygous deleted mice. Ectopic expression of the Tg737 gene results in multinucleated cells, loss of Tg737 gene expression results in the proliferation of liver stem cells (oval cells) without concomitant differentiation, and reexpression of the Tg737 gene reestablished responsiveness to external differentiation factors. We believe this is the first report demonstrating tumor suppression activity for a tetratricopeptide repeat gene family member and provides insights into the function of this family of genes in mammalian cells. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,SCH VET MED,KNOXVILLE,TN. MONSANTO AGR CO,ST LOUIS,MO. DUKE UNIV,MED CTR,DURHAM,NC. INDIANA UNIV,SCH MED,DEPT PHARMACOL & TOXICOL,INDIANAPOLIS,IN 46202. RP Isfort, RJ (reprint author), PROCTER & GAMBLE CO,MIAMI VALLEY LABS,POB 398707,CINCINNATI,OH 45247, USA. NR 40 TC 26 Z9 31 U1 0 U2 2 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0950-9232 J9 ONCOGENE JI Oncogene PD OCT 9 PY 1997 VL 15 IS 15 BP 1797 EP 1803 DI 10.1038/sj.onc.1201535 PG 7 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA XZ725 UT WOS:A1997XZ72500006 PM 9362446 ER PT J AU Helgesson, J Randrup, J AF Helgesson, J Randrup, J TI Effects of spin-isospin modes in transport simulations SO PHYSICS LETTERS B LA English DT Article DE spin-isospin modes; transport simulation; in-medium properties; heavy-ion collisions; delta-hole model; pion production ID HEAVY-ION COLLISIONS; PIONIC MODES; DILEPTON PRODUCTION AB In-medium properties derived for nuclear matter in a microscopic pi+NN-1 + Delta N-1 model are incorporated into transport simulations of nuclear collisions by means of a local-density approximation and by utilizing a local medium frame. Certain features of the transport results differ from those based on the corresponding vacuum properties. Comparisons of the pi and Delta production rates, as well as pion energy spectra, are discussed in particular. (C) 1997 Published by Elsevier Science B.V. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. RP EUROP CTR STUD THEOR NUCL PHYS & RELAT AREAS, ECT, TRENT, ITALY. NR 18 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD OCT 9 PY 1997 VL 411 IS 1-2 BP 1 EP 8 DI 10.1016/S0370-2693(97)00965-9 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF991 UT WOS:A1997YF99100001 ER PT J AU Fischler, W Rajaraman, A AF Fischler, W Rajaraman, A TI M(atrix) string theory on K3 SO PHYSICS LETTERS B LA English DT Article AB We conjecture that M-theory compactified on an ALE space (or K3) is described by O-branes moving on the ALE space. We give evidence for this by showing that if we compactify another circle, we recover string theory on the ALE space. This guarantees that in the large N limit, the matrix model correctly describes the force law between gravitons moving in an ALE background, We also show the appearance in M(atrix) theory of the duality of M-theory on K3 with the heterotic string on a three-torus. (C) 1997 Elsevier Science B.V. C1 STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Fischler, W (reprint author), UNIV TEXAS,DEPT PHYS,THEORY GRP,AUSTIN,TX 78712, USA. OI Fischler, Willy/0000-0002-9075-015X NR 30 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 9 PY 1997 VL 411 IS 1-2 BP 53 EP 58 DI 10.1016/S0370-2693(97)00994-5 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF991 UT WOS:A1997YF99100008 ER PT J AU Brodsky, SJ Navarra, FS AF Brodsky, SJ Navarra, FS TI Looking for exotic multiquark states in nonleptonic B decays SO PHYSICS LETTERS B LA English DT Article ID QUARKONIUM; BARYONS; PHYSICS AB Recent data on inclusive B decays into charmonium states taken by the CLEO Collaboration suggest that a sizeable fraction of the nonleptonic decays may consist of the J/psi Lambda (p) over bar three body final state, corresponding to a distinct enhancement in the inclusive J/psi momentum distribution. The kinematical boundary of this structure corresponds to the case where the J/psi recoils nearly monoenergetically in the B rest system against a partner having mass of similar or equal to 2 GeV. This may allow the observation of a Lambda - (p) over bar bound state near or just below threshold; i.e., strange baryonium, even if the production rate is small. Using a phase space approach to the B meson decay, we study the J/psi momentum distribution and the effect of baryonium formation. We also discuss the possible observation of pentaquarks and hadronically-bound J/psi by the observation of monoenergetic baryons in these decays. (C) 1997 Elsevier Science B.V. C1 UNIV SAO PAULO,INST FIS,BR-05315970 SAO PAULO,BRAZIL. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 18 TC 26 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 9 PY 1997 VL 411 IS 1-2 BP 152 EP 158 DI 10.1016/S0370-2693(97)00998-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF991 UT WOS:A1997YF99100021 ER PT J AU Mahlon, G Parke, S AF Mahlon, G Parke, S TI Maximizing spin correlations in top quark pair production at the Tevatron SO PHYSICS LETTERS B LA English DT Article ID HADRON COLLIDERS; FERMILAB; DECAY AB A comparison is made between the off-diagonal and helicity spin bases for top quark pair production at the FNAL Tevatron. In the off-diagonal basis, 92% of the top quark pairs are in the spin configuration up-down plus down-up, whereas in the helicity basis only 70% are left-right plus right-left. The off-diagonal basis maximizes the spin asymmetry and hence the measured angular correlations between the decay products, which are more than twice as big in this basis as compared to the helicity basis. In addition, for the process q (q) over bar --> t (t) over bar, we give a very simple analytic expression for the matrix element squared which includes all spin correlations between the production and subsequent decay of the top quarks. (C) 1997 Elsevier Science B.V. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Mahlon, G (reprint author), UNIV MICHIGAN,DEPT PHYS,500 E UNIV AVE,ANN ARBOR,MI 48109, USA. OI Parke, Stephen/0000-0003-2028-6782 NR 15 TC 135 Z9 135 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 OCT 9 PY 1997 VL 411 IS 1-2 BP 173 EP 179 DI 10.1016/S0370-2693(97)00987-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF991 UT WOS:A1997YF99100024 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 Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P 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 Mihalcea, D 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 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 Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P 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 Mihalcea, D 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 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 Asymmetries between the production of D-s(-) and D-s(+) mesons from 500 GeV/c pi(-) nucleon interaction as functions of x(F) and p(t)(2) SO PHYSICS LETTERS B LA English DT Article ID P-INTERACTIONS; INTRINSIC CHARM; FEYNMAN-X; D+; HADROPRODUCTION; STATES; QCD AB We present measurements of the production of D-2(-) mesons relative to D-s(+) mesons as functions of x(F) and of p(t)(2) for a sample of 2445 D-s decays to phi pi. The D-s mesons were produced in Fermilab experiment E791 with 500 GeV/c pi(-) mesons incident on one platinum and four carbon foil targets. The acceptance-corrected integrated asymmetry in the x(F) range -0.1 to 0.5 for Ds(-/+) mesons is 0.032 +/- 0.022 +/- 0.022, consistent with no net asymmetry. We compare the results as functions of x(F) and p(t)(2) to predictions and to the large production asymmetry observed for D+/- mesons in the same experiment. These comparisons support the hypothesis that production asymmetries come from the fragmentation process and not from the charm quark production itself. (C) 1997 published by Elsevier Science B.V. C1 UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. KANSAS STATE UNIV, MANHATTAN, KS 66506 USA. ILLINOIS INST TECHNOL, CHICAGO, IL 60616 USA. FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. CINVESTAV, MEXICO CITY 14000, DF, MEXICO. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. CTR BRASILEIRO PESQUISAS FIS, RIO DE JANEIRO, BRAZIL. OHIO STATE UNIV, COLUMBUS, OH 43210 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. UNIV AUTONOMA PUEBLA, MEXICO CITY, DF, MEXICO. UNIV S CAROLINA, COLUMBIA, SC 29208 USA. STANFORD UNIV, STANFORD, CA 94305 USA. TEL AVIV UNIV, IL-69978 TEL AVIV, ISRAEL. TUFTS UNIV, MEDFORD, MA 02155 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. RP UNIV MISSISSIPPI, UNIVERSITY, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X NR 25 TC 50 Z9 50 U1 0 U2 1 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 OCT 9 PY 1997 VL 411 IS 1-2 BP 230 EP 236 DI 10.1016/S0370-2693(97)00952-0 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF991 UT WOS:A1997YF99100032 ER PT J AU Xie, XB McCarley, RE AF Xie, XB McCarley, RE TI Synthesis, characterization, and structure of neutral and anionic complexes containing octahedral W6Te8 cluster units SO INORGANIC CHEMISTRY LA English DT Article ID SUPERCONDUCTING CHEVREL PHASES; MOLECULAR-MODEL; HYDRODESULFURIZATION AB The first examples of molecular telluride complexes, W6Te8L6 [L =pyridine (py), piperidine (pip), and PEt3], and the reduced salt [Na(py)(6)](+)[W6Te8(py)(6)](-) were discovered. The amine complexes were prepared by reaction of W6Cl12 With Na2Te or a Na2Te/Na2Te2 mixture in the amine solvents, whereas W6Te8(PEt3)6 was established by displacement of pyridine in W6Te8(py)(6) by PEt3. The cluster unit, W6Te8, showed characteristic T-1n W-Te stretching vibrations around 180-200 cm(-1). From XPS the W4f(7/2) binding energy of 30.8 eV for W6Te8L6 compared favorably with values of 30.5 and 30.8 eV for the sulfide and selenide analogues, respectively. Crystallographic data for the three compounds on which structure analyses were performed are as follows: W6Te8(pip)(6) . 6pip, hexagonal, R (3) over bar, a = 17.738(6) Angstrom, c = 24.318(10) Angstrom, Z = 3; W6Te8(PEt3)(6), monoclinic, C2/c, a = 24.724(6) Angstrom, b = 19.716(4) Angstrom, c = 13.543(9) Angstrom, beta = 108.56(3)degrees, Z = 4; [Na(py)(6)](+)[W6Te8(py)(6)](-). py, triclinic, P (1) over bar, a = 12.433(3) Angstrom, b = 12.760(2) Angstrom, c = 12.882(2) Angstrom, alpha = 96.78(1)degrees, beta = 100.03(1)degrees, gamma = 98.58(1)degrees, Z = 1. The average W-Te bond distance of 2.753 Angstrom is very close to the average W-W bond distance of 2.748 Angstrom in these telluride clusters. For the anionic complex, both the small distortion of the octahedral cluster unit and the shortening of the average W-W bond distance confirmed addition of the extra electron to a bonding orbital in the reduced 21e cluster unit. Extended Huckel MO calculations indicate that the structural distortion of the [W6Te8(py)(6)](-) anion arises from the Jahn-Teller effect on the E-2(g) ground state. The unique cationic unit [Na(py)(6)](+) is the first documented example of a sodium ion octahedrally coordinated with six pyridine molecules. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 37 TC 18 Z9 18 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 8 PY 1997 VL 36 IS 21 BP 4665 EP 4675 DI 10.1021/ic970037t PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YA504 UT WOS:A1997YA50400011 ER PT J AU Allen, PG Bucher, JJ Shuh, DK Edelstein, NM Reich, T AF Allen, PG Bucher, JJ Shuh, DK Edelstein, NM Reich, T TI Investigation of aquo and chloro complexes of UO22+, NpO2+, Np4+, and Pu3+ by X-ray absorption fine structure spectroscopy SO INORGANIC CHEMISTRY LA English DT Article ID NEAR-EDGE STRUCTURE; PERCHLORATE SOLUTIONS; ELECTRONIC-STRUCTURE; AQUEOUS PERCHLORATE; ACTINIDE COMPOUNDS; URANYL-ION; NEPTUNIUM(V); EXAFS; COORDINATION; DIFFRACTION AB U, NP, and PU L-II.III-edge X-ray absorption fine structure (XAFS) spectra were collected for the UO22+, NpO2+, Np4+, and PU3+ ions as a function of chloride concentration in aqueous solution. At low chloride concentration, the hydration numbers and corresponding bond lengths for the different ions are as follows: UO22+, N = 5.3, R = 2.41 Angstrom; NpO2+, N = 5.0, R = 2.50 Angstrom; Np4+, N = 11.2, R = 2.40 Angstrom; Pu3+, N = 10.2, R = 2.51 Angstrom. As the Cl- concentration increases, inner-sphere Cl- complexation occurs, resulting in a decrease in the hydration numbers and an expansion of the actinide-oxygen (water) bond lengths. The Pu3+ ion showing only a decrease in hydration number (40%) and no inner-sphere Cl- complexation for [Cl-] < 14 M. For concentrations up to 10-14 M Cl- the average Cl- coordination numbers and bond lengths are as follows: UO22+, N = 2.6, R = 2.73 Angstrom; NpO2+, N = 1.0, R = 2.84 Angstrom; Np4+, N = 2.O, R = 2.61 Angstrom. Structural changes are observed in the near-edge spectral region as shown by significant changes in the White line intensities upon Cl- complexation. For ions with similar structures, i.e. Pu3+ and Np4+ or the actinyl ions NpO2+ and UO22+, positive energy shifts are observed with increasing oxidation state. The ability to use XAFS speciation results to calculate equilibrium constants and the relationship gf these results to previous Studies are discussed. C1 ROSSENDORF INC,FORSCHUNGSZENTRUM ROSSENDORF EV,INST RADIOCHEM,D-01314 DRESDEN,GERMANY. RP Allen, PG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. RI Reich, Tobias/C-7064-2016 OI Reich, Tobias/0000-0002-5600-3951 NR 64 TC 253 Z9 255 U1 8 U2 81 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 8 PY 1997 VL 36 IS 21 BP 4676 EP 4683 DI 10.1021/ic970502m PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YA504 UT WOS:A1997YA50400012 ER PT J AU Dai, S Shin, YS Toth, LM Barnes, CE AF Dai, S Shin, YS Toth, LM Barnes, CE TI Comparative UV-Vis studies of uranyl chloride complex in two basic ambient-temperature melt systems: The observation of spectral and thermodynamic variations induced via hydrogen bonding SO INORGANIC CHEMISTRY LA English DT Article ID STEREOGNOSTIC COORDINATION CHEMISTRY; IONIC LIQUIDS; MOLTEN-SALTS; CHLOROALUMINATE; URANIUM(IV); ELECTROCHEMISTRY; SPECTROSCOPY; CRYSTALS; DESIGN; UO22+ C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Dai, S (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 33 TC 70 Z9 72 U1 0 U2 30 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD OCT 8 PY 1997 VL 36 IS 21 BP 4900 EP 4902 DI 10.1021/ic970251h PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YA504 UT WOS:A1997YA50400043 ER PT J AU Fukuto, M Penanen, K Heilmann, RK Pershan, PS Vaknin, D AF Fukuto, M Penanen, K Heilmann, RK Pershan, PS Vaknin, D TI C-60-propylamine adduct monolayers at the gas/water interface: A Brewster angle microscopy and x-ray scattering study SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID AIR-WATER-INTERFACE; LIQUID-CRYSTAL FILMS; BOND-ORIENTATIONAL ORDER; FATTY-ACID MONOLAYERS; PHASE-TRANSITIONS; LANGMUIR MONOLAYERS; SURFACTANT MONOLAYERS; VAPOR INTERFACE; DIFFRACTION; C-60 AB Brewster angle microscopy (BAM), x-ray specular reflectivity and grazing-incidence x-ray diffraction (GID) studies of C-60-propylamine adduct monolayers at the gas/water interface as a function of molecular area are reported. At large molecular areas (A>similar to 150 Angstrom(2)/molecule), BAM images reveal macroscopic heterogeneity in the film, consisting of the coexistence between regions covered with uniform solidlike monolayer and bare water surface. After compression to a limiting molecular area of 150 Angstrom(2)/molecule, the film is observed to be homogeneous, with the uniform monolayer covering the entire available surface. Both the x-ray reflectivity results and the GID patterns are consistent with the formation of a uniform monolayer at A similar to 150 Angstrom(2)/molecule, while the little dependence that the GID patterns have on the molecular area for A>similar to 150 Angstrom(2)/molecule is consistent with the heterogeneity in the film. Upon further compression to higher densities (A95% stable photoproduct below 10 K. The Soret peak of the photoproduct is red-shifted by 4 nm relative to deoxy-myoglobin (Mb), similar to previous results for carbonmonoxy-(MbCO) and oxy-myoglobin (MbO(2)) (Miller et al., 1996). Mb(II)NO completely rebinds by 35 K, indicating that the rebinding barrier for NO is lower than MbCO, consistent with room temperature picosecond kinetic measurements. For ferric nitrosyl myoglobin (Mb(III)NO), we find that the photoproduct yield at cryogenic temperatures is less than unity and dependent on the distal pocket residue. Native Mb(III)NO has a lower photoproduct yield than the mutant, Mb(III)(H64L)NO, where the distal histidine is replaced by leucine. The rebinding rates for the native and mutant species are similar to each other and to Mb(II)NO. By using FTIR difference spectroscopy (photolyzed/unphotolyzed) of isotopically labeled ferrous nitrosyl myoglobin (Mb(II)NO), the NO stretching frequencies in both the ligand-bound states and photoproduct states are determined. Two ligand-bound conformational states (1607 and 1613 cm(-1)) and two photoproduct conformational states (1852 and 1857 cm(-1)) are observed for Mb(II)NO. This is the first direct observation of photolyzed NO in the distal pocket of myoglobin. The ligand-bound frequencies are consistent with a bent Mb(II)NO moiety, where the unpaired pi*(NO) electron remains localized on NO, causing v(N-O) to be similar to 300 cm(-1) lower than Mb(III)NO. Similar to MbO(2) we suggest that N-epsilon of the distal histidine is protonated, forming a hydrogen bond to the NO Ligand. For native Mb(III)NO, a single ligand-bound conformational state with respect to v(N-O) is observed at 1927 cm(-1). This frequency decreases to 1904 cm(-1) for the mutant, Mb(III)(H64L)NO, contrary to the increase of the carbon monoxide (CO) stretching frequency in the isoelectronic Mb(II)(H64L)CO mutant versus native MbCO, For linear Mb(III)NO, we suggest that backbonding from the unpaired pi*(NO) electron to iron results in an increased positive charge on the NO ligand, Fe(delta-)-NO(delta+). This can be facilitated by tautomerism of the distal histidine, leaving N-epsilon of the imidazole ring unprotonated and able to accept positive charge from the Fe(delta-)-NO(delta+) moiety, resulting in a higher bond order (and a 23 cm(-1) shift to higher frequency) for native Mb(III)NO versus Mb(III)(H64L)NO, where this interaction is absent. These different interactions between the distal histidine and the ferrous versus ferric species illustrate potential ways the protein can stabilize the bound ligand and demonstrate the versatile nature by which NO can bind to hemeproteins. C1 YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT PHYSIOL & BIOPHYS,BRONX,NY 10461. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. FU NHLBI NIH HHS [HL-45892] NR 54 TC 100 Z9 100 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 7 PY 1997 VL 36 IS 40 BP 12199 EP 12207 DI 10.1021/bi962744o PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YA264 UT WOS:A1997YA26400022 PM 9315857 ER PT J AU Miksovska, J Kalman, L Schiffer, M Maroti, P Sebban, P Hanson, DK AF Miksovska, J Kalman, L Schiffer, M Maroti, P Sebban, P Hanson, DK TI In bacterial reaction centers rapid delivery of the second proton to Q(B) can be achieved in the absence of L212Glu SO BIOCHEMISTRY LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; RHODOBACTER-SPHAEROIDES R-26; HERBICIDE-RESISTANT MUTANTS; RHODOPSEUDOMONAS-VIRIDIS; ELECTRON-TRANSFER; 2ND-SITE MUTATION; PURPLE BACTERIUM; BINDING-SITE; WILD-TYPE; QUINONE AB In the reaction center (RC) of Rhodobacter capsulatus, residue L212Glu is a component of the pathway for proton transfer to the reduced secondary quinone, Q(B). We isolated phenotypic revertants of the photosynthetically incompetent (PS-) L212Glu-->Gln mutant; all of them retain the L212Glu-->Gln substitution and carry a second-site mutation: L227Leu-->Phe, L228Gly-->Asp, L231Arg-->Cys, or M231Arg-->Cys. We also characterized the L212Ala strain, which is a phenotypic revertant of the PS- L212Glu-L213Asp-->Ala-Ala mutant. The activities of the RCs of these strains-all of which lack L212Glu-were studied by flash-induced absorption spectroscopy. At pH 7.5, the rate of second electron transfer in the L212Q mutant is comparable to the wild-type rate. However, this mutant shows a marked decrease in the rate of-cytochrome oxidation under strong continuous illumination and a very slow phase (0.66 s(-1)) of the proton transfer kinetics following the second flash, indicating that transfer of the second proton to Q(B) is slowed more than 1000-fold. The levels of recovery of the functional capabilities in the revertant RCs vary widely; their rates of cytochrome oxidation were intermediate between those of the wild-type and the L212Q mutant. The kinetics of proton transfer following the second flash show a significant recovery in the L212Q + M231C and L212A RCs (330-540 s(-1)), but the L212Q + L227F RCs recover this function only partially. Compensation for the lack of L212Glu in revertant RCs is discussed in terms of (i) conformational changes that could allow water molecules to approach closer to Q(B) and/or (ii) the increase in the negative electrostatic environment and the resultant I ise in the free energy level of Q(B)(-) that is induced by the mutations. The stoichiometries of H+/Q(B)(-) proton uptake below pH 7.5 in the L212Q, mutant, the L212Q + M231C revertant, and the wild-type strains are essentially equivalent, suggesting that L212Glu is protonated at neutral pH in wild-type RCs. This is also supported by the P(+)Q(-) charge recombination data. Comparison of H+/Q(B)(-) proton uptake data with those obtained previously for the stoichiometries of H+/Q(A)(-) proton uptake [Miksovska, J., Maroti, P., Tandori, J., Schiffer, M., Hanson, D. K., Sebban, P. (1996) Biochemistry. 35, 15411-15417] suggests that L212Glu is the key to the electrostatic and perhaps structural interaction between the two quinone sites. C1 CNRS,CTR GENET MOL,F-91198 GIF SUR YVETTE,FRANCE. ATTILA JOZSEF UNIV,INST BIOPHYS,SZEGED,HUNGARY. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. FU NIGMS NIH HHS [GM36598] NR 47 TC 38 Z9 39 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD OCT 7 PY 1997 VL 36 IS 40 BP 12216 EP 12226 DI 10.1021/bi970442w PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YA264 UT WOS:A1997YA26400024 PM 9315859 ER PT J AU Falkenstein, Z Coogan, JJ AF Falkenstein, Z Coogan, JJ TI The development of a silent discharge-driven XeBr* excimer UV light source SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID DIELECTRIC BARRIER DISCHARGES; GENERATION; RADIATION; WATER AB In this paper we present the optimization of a silent discharge-driven XeBr* excimer UV light source. The radiant power and emission efficiency were measured as functions of the gas gap, partial pressure of Br-2 and total Xe plus Br-2 pressure for uncooled lamps driven by a sinusoidal voltage. Approximately 90% of the lamp output was in ihs B-X transition at 282 nm, The optimal lamp performance was measured with a gap spacing of 7.5 mm and a 150 Torr filling of 0.15% Br-2 in Xe. For the optimized system, UV production efficiencies, including losses in the screen electrode, exceeded 7.5% and UV output power densities of 10 mW cm(-2) were measured at a driving frequency of 45 kHz. RP Falkenstein, Z (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST18,MAILSTOP E 525,LOS ALAMOS,NM 87545, USA. NR 17 TC 29 Z9 30 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD OCT 7 PY 1997 VL 30 IS 19 BP 2704 EP 2710 DI 10.1088/0022-3727/30/19/008 PG 7 WC Physics, Applied SC Physics GA YB259 UT WOS:A1997YB25900008 ER PT J AU SrinivasanRao, T Babzien, M Sakai, F Mori, Y Sasaki, T AF SrinivasanRao, T Babzien, M Sakai, F Mori, Y Sasaki, T TI Conversion efficiency and damage threshold measurements of CsLiB6O10 with a train of laser pulses SO APPLIED PHYSICS LETTERS LA English DT Article AB The energy conversion efficiency and the damage threshold of a CsLiB6O10 crystal have been measured for a pulse train with 80 pulses at 532 nm, each with energy up to 200 mu J, 14 ps duration and 25 ns pulse to pulse spacing. Maximum energy conversion efficiency of 38% has been measured when the crystal was used to convert 532 nm to 266 nm. The damage threshold of the crystal for this pulse train was measured to be >130 and <520 GW/cm(2). Both the high intensity of the micropulse and the fluence of the macropulse appear to affect the damage threshold. (C) 1997 American Institute of Physics. C1 SUMITOMO HEAVY IND LTD,KANAGAWA,JAPAN. OSAKA UNIV,DEPT ELECT ENGN,OSAKA,JAPAN. RP SrinivasanRao, T (reprint author), BROOKHAVEN NATL LAB,BLDG 535B,UPTON,NY 11973, USA. RI Mori, Yusuke/C-3302-2014 NR 8 TC 1 Z9 1 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 OCT 6 PY 1997 VL 71 IS 14 BP 1927 EP 1929 DI 10.1063/1.119983 PG 3 WC Physics, Applied SC Physics GA XZ514 UT WOS:A1997XZ51400009 ER PT J AU Sidebottom, DL Hruschka, MA Potter, BG Brow, RK AF Sidebottom, DL Hruschka, MA Potter, BG Brow, RK TI Increased radiative lifetime of rare earth-doped zinc oxyhalide tellurite glasses SO APPLIED PHYSICS LETTERS LA English DT Article ID IONS AB We have investigated the structural and optical properties of rare earth-doped zinc tellurite glasses modified by the substitution of ZnF2. Raman and phonon sideband spectroscopies were employed to characterize changes in the glass structure as well as to probe vibrational behavior in the immediate vicinity of the rare earth ion. These measurements are combined with photoluminescence and optical absorption to monitor the effect of halide substitution upon the optical behavior of the rare earth dopant. A substantial increase in the intrinsic radiative lifetime of Nd3+ is observed with increasing halide concentration. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Sidebottom, DL (reprint author), UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87131, USA. NR 15 TC 29 Z9 30 U1 1 U2 8 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 OCT 6 PY 1997 VL 71 IS 14 BP 1963 EP 1965 DI 10.1063/1.119756 PG 3 WC Physics, Applied SC Physics GA XZ514 UT WOS:A1997XZ51400021 ER PT J AU McHugo, SA AF McHugo, SA TI Release of metal impurities from structural defects in polycrystalline silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID DIFFUSION LENGTH; DISLOCATIONS AB Metal impurity release from structural defects in polycrystalline silicon was studied following thermal treatments, and, in addition, a correlation between impurity distributions and structural defects was established. impurities were mapped with synchrotron-based x-ray fluorescence in the as-grown state, after rapid thermal annealing and following aluminum gettering treatments. The goal of this work was to determine if impurity release from structural defects limits gettering of metal impurities. The results reveal that nickel and copper metal impurities are primarily found at dislocations in as-grown crystals, and the release of these impurities from defects occurs rapidly with no apparent barrier to dissolution. Gettering treatments dissolved metal impurity precipitates to <2-5 nm in radii; however, the material performance was not greatly enhanced. (C) 1997 American Institute of Physics. RP McHugo, SA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720, USA. NR 16 TC 36 Z9 36 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 OCT 6 PY 1997 VL 71 IS 14 BP 1984 EP 1986 DI 10.1063/1.119762 PG 3 WC Physics, Applied SC Physics GA XZ514 UT WOS:A1997XZ51400028 ER PT J AU Takeuchi, I Wei, T Duewer, F Yoo, YK Xiang, XD Talyansky, V Pai, SP Chen, GJ Venkatesan, T AF Takeuchi, I Wei, T Duewer, F Yoo, YK Xiang, XD Talyansky, V Pai, SP Chen, GJ Venkatesan, T TI Low temperature scanning-tip microwave near-field microscopy of YBa2Cu3O7-x films SO APPLIED PHYSICS LETTERS LA English DT Article AB We have explored the low temperature capability of a scanning-tip microwave near-field microscope to study superconductors. The shift in the quality factor of the microscope resonator can be used to obtain the temperature dependence of the surface resistance of a local region under the tip. Patterned YBa2Cu3O7-x films were scanned at various temperatures and surface resistance mapping was performed with high spatial resolution at 1.2 GHz. Superconducting transitions at different positions on a film can be detected. Edge-region defects in wet-etched patterns were observed and were shown to be nonsuperconducting at microwave frequencies at 80 K. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT,COLLEGE PK,MD 20742. RI Xiang, Xiaodong/A-9445-2012; Venkatesan, Thirumalai/E-1667-2013; Xiang, Xiaodong/A-5936-2017 NR 8 TC 44 Z9 45 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 6 PY 1997 VL 71 IS 14 BP 2026 EP 2028 DI 10.1063/1.119776 PG 3 WC Physics, Applied SC Physics GA XZ514 UT WOS:A1997XZ51400042 ER PT J AU Kerchner, HR Norton, DP Goyal, A Budai, JD Christen, DK Kroeger, DM Specht, ED He, Q Paranthaman, M Lee, DF Sales, BC List, FA Feenstra, R AF Kerchner, HR Norton, DP Goyal, A Budai, JD Christen, DK Kroeger, DM Specht, ED He, Q Paranthaman, M Lee, DF Sales, BC List, FA Feenstra, R TI Alternating current losses in biaxially textured YBa2Cu3O7-delta films deposited on Ni tapes SO APPLIED PHYSICS LETTERS LA English DT Article ID GRAIN-BOUNDARIES; CURRENT-DENSITY AB YBa2Cu3O7-delta films grown on rolling-assisted biaxially textured substrates carry critical current densities 10(5)-10(6) A/cm(2) at 77 K and low applied magnetic fields. In the low-field and low-current regime, ac transport current studies show hysteresis energy loss (per cycle and per unit length) roughly the value expected for a superconductor of elliptic cross section. The critical current I-c was deduced from observed de and dynamic current-voltage relations. The power loss rises sharply as I-0 (the maximum current in each cycle) is raised above I-c. In the present configuration, ferromagnetic hysteresis of the Ni substrate contributes little or no loss. (C) 1997 American Institute of Physics. RP Kerchner, HR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI 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 22 TC 24 Z9 24 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 OCT 6 PY 1997 VL 71 IS 14 BP 2029 EP 2031 DI 10.1063/1.119777 PG 3 WC Physics, Applied SC Physics GA XZ514 UT WOS:A1997XZ51400043 ER PT J AU Boudreau, N Andrews, C Srebrow, A Ravanpay, A Cheresh, DA AF Boudreau, N Andrews, C Srebrow, A Ravanpay, A Cheresh, DA TI Induction of the angiogenic phenotype by Hox D3 SO JOURNAL OF CELL BIOLOGY LA English DT Article ID MICROVASCULAR ENDOTHELIAL-CELLS; MIDDLE T-ONCOGENE; HOMEOBOX GENES; INTEGRIN ALPHA-V-BETA-3; ADHESIVE PROPERTIES; EXPRESSION; GROWTH; MICE; ALPHA(V)BETA(3); LOCALIZATION AB Angiogenesis is characterized by distinct phenotypic changes in vascular endothelial cells (EC). Evidence is provided that the Hox D3 homeobox gene mediates conversion of endothelium from the resting to the angiogenic/invasive state. Stimulation of EC with basic fibroblast growth factor (bFGF) resulted in increased expression of Hox D3, integrin alpha v beta 3, and the urokinase plasminogen activator (uPA). Hox D3 anti-sense blocked the ability of bFGF to induce uPA and integrin alpha v beta 3 expression, yet had no effect on EC cell proliferation or bFGF-mediated cyclin D1 expression. Expression of Hox D3, in the absence of bFGF, resulted in enhanced expression of integrin alpha v beta 3 and uPA. In fact, sustained expression of Hox D3 in vivo on the chick chorioallantoic membrane retained EC in this invasive state and prevented vessel maturation leading to vascular malformations and endotheliomas. Therefore, Hox D3 regulates EC gene expression associated with the invasive stage of angiogenesis. C1 Scripps Res Inst, DEPT IMMUNOL & VASC BIOL, LA JOLLA, CA 92037 USA. ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. FU NHLBI NIH HHS [HL54444] NR 42 TC 165 Z9 167 U1 0 U2 0 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD OCT 6 PY 1997 VL 139 IS 1 BP 257 EP 264 DI 10.1083/jcb.139.1.257 PG 8 WC Cell Biology SC Cell Biology GA YB446 UT WOS:A1997YB44600021 PM 9314544 ER PT J AU Zakharov, O Cohen, ML Louie, SG Penn, DR AF Zakharov, O Cohen, ML Louie, SG Penn, DR TI Dynamical screening at the metal-semiconductor interface and excitonic superconductivity SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MECHANISM; MODEL AB We examine the possibility of excitonic superconductivity at a metal-semiconductor interface. An ab initio RPA calculation of the screened Coulomb electron-electron interaction is performed for the silicon-jellium multilayer model. The superconducting kernel for this multilayered system is found to be positive in the whole frequency range considered. We show that the inclusion of local field effects does not change the sign of the kernel and thus does not enhance the excitonic mechanism. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NIST,DIV ELECTRON & OPT PHYS,PHYS LAB,TECHNOL ADM,DEPT COMMERCE,GAITHERSBURG,MD 20899. RP Zakharov, O (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 17 TC 0 Z9 0 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD OCT 6 PY 1997 VL 9 IS 40 BP 8501 EP 8514 DI 10.1088/0953-8984/9/40/016 PG 14 WC Physics, Condensed Matter SC Physics GA YB246 UT WOS:A1997YB24600015 ER PT J AU Nguyen, DM Mayer, TM Hubbard, SF Singer, KD Mann, JA Lando, JB AF Nguyen, DM Mayer, TM Hubbard, SF Singer, KD Mann, JA Lando, JB TI Polar polymeric Langmuir-Blodgett films for optical applications SO MACROMOLECULES LA English DT Article ID AIR-WATER-INTERFACE; X-RAY REFLECTIVITY; MATCHED 2ND-HARMONIC GENERATION; LIQUID-CRYSTALLINE POLYMER; SELF-ASSEMBLED MONOLAYERS; WAVE-GUIDE; THIN-FILMS; BLUE-LIGHT; ELLIPSOMETRY; POLYSILOXANES AB A side-chain liquid crystalline copolymer containing ether-nitrobiphenyl groups was investigated as a nonlinear optical material. Ultrathin films have shown second harmonic generation and therefore have a variety of interesting applications. Waveguides composed of multilayers of the copolymer have been fabricated, and propagation losses as low as 2.3 dB/cm in a lowest order TE mode at 800 nm wavelength have been measured. The second harmonic coefficient is d(33) = 42.0 +/- 1.7 pm/V at the 1064 nm fundamental wavelength and is consistent with an oriented gas model. From spectroscopic ellipsometry measurements the film refractive index is 2.24 +/- 0.15 and the extinction coefficient less than or equal to 0.05 in the visible range of wavelengths. The monolayer and multilayer repeat structures were also studied by X-ray reflectivity and diffraction. The optical thickness and the oscillations in the reflectivity were in reasonable accord with a repeat length of about 3.6 nm. C1 CASE WESTERN RESERVE UNIV,DEPT MACROMOL SCI,CLEVELAND,OH 44106. CASE WESTERN RESERVE UNIV,DEPT PHYS,CLEVELAND,OH 44106. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI Singer, Kenneth/G-6553-2011 NR 45 TC 9 Z9 9 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 6 PY 1997 VL 30 IS 20 BP 6150 EP 6157 DI 10.1021/ma961256l PG 8 WC Polymer Science SC Polymer Science GA YA289 UT WOS:A1997YA28900026 ER PT J AU Festag, R Alexandratos, SD Cook, KD Joy, DC Annis, B Wunderlich, B AF Festag, R Alexandratos, SD Cook, KD Joy, DC Annis, B Wunderlich, B TI Single- and few-chain polystyrene particles by electrospray SO MACROMOLECULES LA English DT Article; Proceedings Paper CT SPIE Meeting Space Processing of Materials CY 1996 CL DENVER, CO SP SPIE ID IONIZATION MASS-SPECTROMETRY; POLY(ETHYLENE GLYCOLS); MICROSCOPY; SEPARATION; DROPLETS; POLYMERS; FISSION AB An electrospray method is used for the conversion of isolated molecules of atactic polystyrene of high molar mass in solution to solid, single-molecule particles. With this process it is possible to produce not only single molecules but also clusters of several molecules. Particle size and shape distributions were characterized using scanning force and scanning electron microscopy. The size of the clusters of more than one molecule can be tailored to ones needs by controlling the spray conditions. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT BIOCHEM & CELLULAR & MOL BIOL,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. OI Cook, Kelsey/0000-0003-2053-3309 NR 40 TC 24 Z9 24 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 6 PY 1997 VL 30 IS 20 BP 6238 EP 6242 DI 10.1021/ma970211x PG 5 WC Polymer Science SC Polymer Science GA YA289 UT WOS:A1997YA28900037 ER PT J AU Lu, SX Cebe, P Capel, M AF Lu, SX Cebe, P Capel, M TI Effects of molecular weight on the structure of poly(phenylene sulfide) crystallized at low temperatures SO MACROMOLECULES LA English DT Article ID STAGE MELT CRYSTALLIZATION; GLASS-TRANSITION; POLY(PARA-PHENYLENE SULFIDE); THERMAL-ANALYSIS; X-RAY; BEHAVIOR; PPS; MORPHOLOGY; KINETICS; POLYMERS AB We report a study of the effects of molecular weight on the structure and properties of poly(phenylene sulfide), PPS, crystallized from the rubbery amorphous state at temperatures just above the glass transition. PPS films were characterized using temperature-modulated differential scanning calorimetry (MDSC), small angle X-ray scattering (SAXS), and dynamic mechanical analysis (DMA). For samples crystallized so as to have the same half-time, we find (1) the degree of crystallinity, chi(e), is not dependent upon molecular weight and (2) as the molecular weight increases, the heat capacity increment at the glass transition increases. These results suggest that lower molecular weight PPS contains a greater fraction of the rigid amorphous phase, probably as a result of formation of taut tie molecules between crystals. It is found from DMA that molecular weight is the determining factor that affects the Young's modulus value at the higher temperature. A lower E' is observed for the higher molecular weight material. MDSC data suggest that higher molecular weight PPS has a slower crystallization rate and reorganization rate. The amount of crystals formed during heating is smaller in higher molecular weight PPS, and this may be the explanation for the reduced Young's modulus above T-g. C1 TUFTS UNIV,CTR SCI & TECHNOL,DEPT PHYS & ASTRON,MEDFORD,MA 02155. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 46 TC 46 Z9 46 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 6 PY 1997 VL 30 IS 20 BP 6243 EP 6250 DI 10.1021/ma961600e PG 8 WC Polymer Science SC Polymer Science GA YA289 UT WOS:A1997YA28900038 ER PT J AU Curro, JG Weinhold, JD Rajasekaran, JJ Habenschuss, A Londono, JD Honeycutt, JD AF Curro, JG Weinhold, JD Rajasekaran, JJ Habenschuss, A Londono, JD Honeycutt, JD TI Intermolecular packing in stereoregular polypropylene liquids: Comparison between theory and X-ray scattering experiments SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; SATURATED-HYDROCARBON POLYMERS; MULTIPLE CHAIN SYSTEMS; POLYETHYLENE MELTS; BLENDS; DIFFRACTION; DIMENSIONS; CONFORMATION; SIMULATION; MOLECULES AB Atomistically realistic polymer reference interaction site model (PRISM) calculations on isotactic and syndiotactic polypropylene liquids were compared with wide-angle X-ray scattering measurements at 180 and 183 degrees C. The intramolecular structure factors, required as input to PRISM theory, were obtained from single-chain, Monte Carlo simulations using three models with progressively more realism: a rotational isomeric state model, a united atom model, and an explicit atom model. Excellent agreement between PRISM theory, employing the united and explicit atom models. was found with the experimentally determined structure factor in the wavevector range 0.3 Angstrom(-1) less than or equal to k less than or equal to 16 Angstrom(-1). Good agreement was also seen between theory and experiment for the average intermolecular radial distribution function in r-space estimated from the Fourier transform of the scattering data. The rotational isomeric state model predicted a structure factor qualitatively inconsistent with the scattering experiments. This suggests that continuously varying rotations are important in the packing of vinyl polymers. The six individual site-site intermolecular pair correlation functions calculated from PRISM theory show universal behavior on long length scales in the correlation hole regime but reveal significant system specific differences in structure on short length scales near contact. At short distances, the pendant methyl groups on the polypropylene backbone tend to shield the backbone groups from approaching each other closely in the melt. Subtle differences were seen in the pair correlation functions between isotactic and syndiotactic polypropylene on local length scales. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. MOL SIMULAT INC,SAN DIEGO,CA 92121. RP Curro, JG (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 40 TC 16 Z9 16 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 6 PY 1997 VL 30 IS 20 BP 6264 EP 6273 DI 10.1021/ma970500l PG 10 WC Polymer Science SC Polymer Science GA YA289 UT WOS:A1997YA28900040 ER PT J AU Espe, MP Mattes, BR Schaefer, J AF Espe, MP Mattes, BR Schaefer, J TI Packing in amorphous regions of hydrofluoric-acid-doped polyaniline powder by N-15-F-19 REDOR NMR SO MACROMOLECULES LA English DT Article ID TO-METAL TRANSITION; ANGLE SPINNING NMR; C-13 NMR; RESONANCE NMR; POLYCARBONATE; SPECTROSCOPY; POLYMER; PAIRS AB Anhydrous N-15-labeled polyaniline powders have been examined by C-13, N-15, and F-19 solid-state NMR as a function of HF doping. Chemical shifts in the F-19 NMR spectra of doped polyaniline reveal three distinct types of charged environments. Carbon, nitrogen, and fluorine spin counts show that only about one-third of all the chains in fully HF-doped polyaniline are detected. This observation is consistent with the assumption that the entire crystalline region, and amorphous regions within 50 Angstrom of the crystalline border, is rendered unobservable by paramagnetic delocalized electrons in the crystalline region. Rotational-echo double-resonance N-15 NMR (with F-19 dephasing) indicates that in the observable amorphous regions the polyaniline chains are tightly packed with an in-plane interchain separation of 10 Angstrom and that fully charged main-chain nitrogens have, on average, one nearest-neighbor fluorine 4 Angstrom away and three next-nearest-neighbor fluorines with an average N-15-F-19 distance of just over 5 Angstrom. C1 WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 38 TC 31 Z9 31 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 6 PY 1997 VL 30 IS 20 BP 6307 EP 6312 DI 10.1021/ma970742l PG 6 WC Polymer Science SC Polymer Science GA YA289 UT WOS:A1997YA28900045 ER PT J AU Kinney, WH Kolb, EW Turner, MS AF Kinney, WH Kolb, EW Turner, MS TI Ribbons on the cosmic background radiation sky: A powerful test of a baryon symmetric universe SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANTIMATTER AB If the Universe consists of domains of matter and antimatter, annihilations at domain interfaces leave a distinctive imprint on the cosmic background radiation (CBR) sky. The signature is anisotropies in the form of long, thin ribbons of width Bw theta(W) similar to 0.1 degrees, separated by angle theta(L) similar or equal to 1 degrees(L/100h(-1) Mpc) (L is the characteristic domain size) and with distortion parameter y approximate to 10(-6). Such a pattern could potentially be detected by the high-resolution CBR anisotropy experiments planned for the next decade, and such experiments may finally settle the question of whether or not our Hubble volume is baryon symmetric. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP Kinney, WH (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. NR 13 TC 17 Z9 17 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 OCT 6 PY 1997 VL 79 IS 14 BP 2620 EP 2623 DI 10.1103/PhysRevLett.79.2620 PG 4 WC Physics, Multidisciplinary SC Physics GA XZ544 UT WOS:A1997XZ54400006 ER PT J AU Allen, B Caldwell, RR Dodelson, S Knox, L Shellard, EPS Stebbins, A AF Allen, B Caldwell, RR Dodelson, S Knox, L Shellard, EPS Stebbins, A TI Cosmic microwave background anisotropy induced by cosmic strings on angular scales 15' SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOPPLER PEAKS; ACTIVE PERTURBATIONS; COBE AB We have computed an estimate of the angular power spectrum of the cosmic microwave background induced by cosmic strings on angular scales greater than or similar to 15', using a numerical simulation of a cosmic string network and have decomposed this pattern into scalar, vector, and tensor parts. The anisotropies from vector modes dominate except on very small angular scales, and we find no evidence for strong acoustic oscillations in the scalar anisotropy. The anisotropies generated after recombination are even more important than in adiabatic models. The total anisotropy on small scales is inconsistent with current measurements. The calculation has a number of uncertainties, the largest of which is due to finite temporal range. C1 UNIV PENN,DEPT PHYS & ASTRON,PHILADELPHIA,PA 19106. NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. CANADIAN INST THEORET ASTROPHYS,TORONTO,ON M5S 3H8,CANADA. UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 9EW,ENGLAND. RP Allen, B (reprint author), UNIV WISCONSIN,DEPT PHYS,POB 413,MILWAUKEE,WI 53201, USA. RI Allen, Bruce/K-2327-2012; OI Allen, Bruce/0000-0003-4285-6256; Caldwell, Robert/0000-0001-7490-7463 NR 24 TC 109 Z9 109 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 OCT 6 PY 1997 VL 79 IS 14 BP 2624 EP 2627 DI 10.1103/PhysRevLett.79.2624 PG 4 WC Physics, Multidisciplinary SC Physics GA XZ544 UT WOS:A1997XZ54400007 ER PT J AU Dine, M Riotto, A AF Dine, M Riotto, A TI An inflaton candidate in gauge mediated supersymmetry breaking SO PHYSICAL REVIEW LETTERS LA English DT Article ID COSMOLOGICAL MODULI PROBLEM; PHYSICS; TECHNICOLOR; UNIVERSE; SCALE AB Inflation requires the presence of fields (inflatons) with very flat potentials. Models of low-energy supersymmetry (SUSY) breaking yield new candidates for the inflaton field. We present a simple model for slow-rollover inflation where the vacuum energy driving inflation is related to the scale of supersymmetry breaking among ordinary particles. This opens the possibility of gaining possible knowledge about SUSY dynamics from measurements of the microwave background. Gravitinos do not pose a cosmological problem, while the moduli problem is ameliorated. C1 NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Dine, M (reprint author), UNIV CALIF SANTA CRUZ,SANTA CRUZ INST PARTICLE PHYS,SANTA CRUZ,CA 95064, USA. NR 32 TC 25 Z9 25 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 6 PY 1997 VL 79 IS 14 BP 2632 EP 2635 DI 10.1103/PhysRevLett.79.2632 PG 4 WC Physics, Multidisciplinary SC Physics GA XZ544 UT WOS:A1997XZ54400009 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J 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 Barone, M 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 Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G 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, YH 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 Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L 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 Feild, G Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fukui, Y Funaki, S Galeotti, S Gallinaro, M Ganel, O GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Happacher, F 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, TW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, TD 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, KI Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT 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 Mesropian, C 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 Ngan, CY 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 Parashar, N 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 Reher, D 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 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 Tannenbaum, B 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 Trischuk, W deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH 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 Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M John, 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 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 Barone, M 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 Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G 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, YH 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 Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L 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 Feild, G Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fukui, Y Funaki, S Galeotti, S Gallinaro, M Ganel, O GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Happacher, F 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, TW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, TD 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, KI Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT 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 Mesropian, C 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 Ngan, CY 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 Parashar, N 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 Reher, D 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 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 Tannenbaum, B 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 Trischuk, W deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH 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 Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M John, 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 diffractive dijet production at the Fermilab Tevatron SO PHYSICAL REVIEW LETTERS LA English DT Article ID POMERON AB We report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron (p) over bar p collider at root s = 1.8 TeV. In events with two jets of E-T > 20 GeV, 1.8 < \eta\ < 3.5, and eta(1) eta(2) > 0, we find that the diffractive to nondiffractive production ratio is R-JJ = [0.75 +/- 0.05(stat) +/- 0.09(syst)]%. By comparing this result, in combination with our measured rate for diffractive W boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be f(g) = 0.7 +/- 0.2. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,INST NAZL FIS NUCL,I-40127 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02264. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60638. DUKE UNIV,DURHAM,NC 28708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV FLORIDA,GAINESVILLE,FL 33611. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. 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 ORLANDO LAWRENCE BERKELEY NATL 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 87132. OHIO STATE UNIV,COLUMBUS,OH 43320. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,SEZ PADOVA,I-36132 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 15270. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14628. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11530,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 315,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53806. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,KEK,TSUKUBA,IBARAKI 315,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; Tartarelli, Giuseppe Francesco/A-5629-2016; OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Wyss, Jeffery/0000-0002-8277-4012; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; Tartarelli, Giuseppe Francesco/0000-0002-4244-502X; Bertolucci, Sergio/0000-0003-1738-4736; Gallinaro, Michele/0000-0003-1261-2277; Turini, Nicola/0000-0002-9395-5230 NR 14 TC 91 Z9 91 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 6 PY 1997 VL 79 IS 14 BP 2636 EP 2641 DI 10.1103/PhysRevLett.79.2636 PG 6 WC Physics, Multidisciplinary SC Physics GA XZ544 UT WOS:A1997XZ54400010 ER PT J AU Esarey, E Hubbard, RF Leemans, WP Ting, A Sprangle, P AF Esarey, E Hubbard, RF Leemans, WP Ting, A Sprangle, P TI Electron injection into plasma wake fields by colliding laser pulses SO PHYSICAL REVIEW LETTERS LA English DT Article ID STIMULATED RAMAN BACKWARD; SELF-MODULATION; ACCELERATION; SCATTERING; WAVES; PROPAGATION; EXCITATION AB An injector and accelerator is analyzed that uses three collinear laser pulses in a plasma: an intense pump pulse, which generates a large wake field (greater than or equal to 20 GV/m), and two counterpropagating injection pulses. When the injection pulses collide, a slow phase velocity beat wave is generated that injects electrons into the fast wake field for acceleration. Particle tracking simulations in 1D with injection pulse intensities near 10(17) W/cm(2) indicate the production of relativistic electrons with bunch durations as short as 3 fs, energy spreads as small as 0.3%, and densities as high as 10(18) cm(-3). C1 UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Esarey, E (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 27 TC 367 Z9 374 U1 4 U2 35 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 OCT 6 PY 1997 VL 79 IS 14 BP 2682 EP 2685 DI 10.1103/PhysRevLett.79.2682 PG 4 WC Physics, Multidisciplinary SC Physics GA XZ544 UT WOS:A1997XZ54400021 ER PT J AU Sachleben, RA Bryan, JC Lavis, JM Starks, CM Burns, JH AF Sachleben, RA Bryan, JC Lavis, JM Starks, CM Burns, JH TI Synthesis and structures of isomerically pure bis-(alkylbenzo) crown ethers SO TETRAHEDRON LA English DT Article ID SOLVENT-EXTRACTION; MACROCYCLE INTERACTION; INCLUSION-COMPOUNDS; CRYSTAL-STRUCTURES; KINETIC DATA; COMPLEXATION; ACETONITRILE; 18-CROWN-6; CATIONS; SIZE AB A convenient method for the synthesis of bis-(4-alkyl-2-hydroxyphenoxy) alkoxy ethers, precursors to highly lipophilic, alkylbenzo-substituted crown ethers, is described. Thirteen isomerically-pure, bis-t-alkylbenzo crown ethers were prepared. The solid-state structures of three representative, bis-t-octylbenzo crown ethers are reported, representing the first structures ever reported for t-octylbenzocrown ethers. Published by Elsevier Science Ltd. RP Sachleben, RA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,MS-6119-4500S,POB 2008,OAK RIDGE,TN 37831, USA. NR 36 TC 10 Z9 10 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0040-4020 J9 TETRAHEDRON JI Tetrahedron PD OCT 6 PY 1997 VL 53 IS 40 BP 13567 EP 13582 DI 10.1016/S0040-4020(97)00932-0 PG 16 WC Chemistry, Organic SC Chemistry GA XZ447 UT WOS:A1997XZ44700003 ER PT J AU Klimov, VI McBranch, DW Barashkov, NN Ferraris, JP AF Klimov, VI McBranch, DW Barashkov, NN Ferraris, JP TI Femtosecond dynamics of excitons in pi-conjugated oligomers: the role of intrachain two-exciton states in the formation of interchain species SO CHEMICAL PHYSICS LETTERS LA English DT Article ID POLYMERS; POLY(P-PHENYLENEVINYLENE); ABSORPTION; PHOTOLUMINESCENCE; RELAXATION; SPECTRA; PHOTOEXCITATIONS; EXCITATION; VINYLENE); DECAY AB We report femtosecond transient absorption results for solutions and thin films of a substituted oligomer of poly(para-phenylene vinylene) performed over wide spectral and pump-intensity ranges. Solutions and films exhibit a photoinduced absorption (PA) band with dynamics matching those of the stimulated emission, demonstrating unambiguously that these features originate from intrachain singlet excitons. Thin films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the formation of non-emissive interchain excitons. Correlations in the dynamics of the two PA features, as well as the intensity-dependence, provide strong evidence that the formation of interchain excitons is mediated by intrachain two-exciton states. (C) 1997 Elsevier Science B.V. C1 UNIV TEXAS,DALLAS,TX 75230. RP Klimov, VI (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST 6,MS J567,POB 1663,LOS ALAMOS,NM 87545, USA. NR 31 TC 47 Z9 47 U1 2 U2 11 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 OCT 3 PY 1997 VL 277 IS 1-3 BP 109 EP 117 DI 10.1016/S0009-2614(97)00923-8 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YC094 UT WOS:A1997YC09400018 ER PT J AU Pinnaduwage, LA Zhu, YF AF Pinnaduwage, LA Zhu, YF TI Long-time stability of superexcited high Rydberg molecular states SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NITRIC-OXIDE; IONIZATION; SPECTROSCOPY; LIFETIMES; ENERGY; ATTACHMENT AB Using a time-resolved, mass analyzed, pulsed field ionization technique it is shown that molecules excited to energies within several electron volts above their lowest ionization thresholds can survive for several microseconds. These observations are consistent with the recent observations of efficient dissociative electron attachment to molecules excited to energies above their ionization thresholds. (C) 1997 Elsevier Science B.V. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Pinnaduwage, LA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 23 TC 17 Z9 17 U1 0 U2 5 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 OCT 3 PY 1997 VL 277 IS 1-3 BP 147 EP 152 DI 10.1016/S0009-2614(97)00913-5 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YC094 UT WOS:A1997YC09400024 ER PT J AU Tong, W Yeung, ES AF Tong, W Yeung, ES TI On-column monitoring of secretion of catecholamines from single bovine adrenal chromaffin cells by capillary electrophoresis SO JOURNAL OF NEUROSCIENCE METHODS LA English DT Article DE epinephrine; norepinephrine; chromaffin; release; capillary electrophoresis; acetylcholine; laser-induced fluorescence ID NATIVE FLUORESCENCE DETECTION; MEDULLARY CELLS; VESICLE FUSION; MAST-CELLS; EXOCYTOSIS; EPINEPHRINE; MECHANISMS; RELEASE; HISTAMINE; RECEPTOR AB The secretion of catecholamines from individual bovine adrenal medullary cells was quantitatively monitored by capillary electrophoresis with laser-induced native fluorescence detection. By using a physiological balanced-salt solution as the running buffer for CE, the amount of norepinephrine (NE) and epinephrine (E) secreted by their physiological secretagogue, acetylcholine, and the amount remaining in a single cell can be simultaneously quantified. Among the six different glands (from separate cows) studied, a predominance of E-rich cells were found. There was no apparent relationship between the ratio of NE/E released and the original NE/E content in the cell. The secretion process was also monitored dynamically with this method by continuously passing acetylcholine over the cell during stimulation. From the peak width and shape of the released material, one can estimate the time scale of the release process. (C) 1997 Elsevier Science B.V. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,DEPT CHEM,AMES LAB,AMES,IA 50011. NR 38 TC 39 Z9 39 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-0270 J9 J NEUROSCI METH JI J. Neurosci. Methods PD OCT 3 PY 1997 VL 76 IS 2 BP 193 EP 201 DI 10.1016/S0165-0270(97)00098-8 PG 9 WC Biochemical Research Methods; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA YA519 UT WOS:A1997YA51900010 PM 9350971 ER PT J AU Collins, PG Zettl, A Bando, H Thess, A Smalley, RE AF Collins, PG Zettl, A Bando, H Thess, A Smalley, RE TI Nanotube nanodevice SO SCIENCE LA English DT Article ID CARBON NANOTUBES; ELECTRONIC-PROPERTIES; MICROTUBULES; CONDUCTANCE; DEFECTS AB A scanning tunneling microscope (STM) was used to explore the local electrical characteristics of single-wall carbon nanotubes. As the STM tip was moved along the length of the nanotubes, well-defined positions were found where the transport current changes abruptly from a graphitic-like response to one that is highly nonlinear and asymmetrical, including near-perfect rectification. The observations are consistent with the existence of localized, on-tube nanodevices of a type proposed theoretically. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. ELECTROTECH LAB, DIV PHYS SCI, TSUKUBA, IBARAKI 305, JAPAN. RICE UNIV, CTR NANOSCALE SCI & TECHNOL, HOUSTON, TX 77005 USA. RICE UNIV, DEPT CHEM, HOUSTON, TX 77005 USA. RICE UNIV, DEPT PHYS, HOUSTON, TX 77005 USA. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 18 TC 844 Z9 878 U1 12 U2 73 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 3 PY 1997 VL 278 IS 5335 BP 100 EP 103 DI 10.1126/science.278.5335.100 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XZ124 UT WOS:A1997XZ12400046 ER PT J AU Nozette, S Shoemaker, EM Spudis, P Lichtenberg, CL AF Nozette, S Shoemaker, EM Spudis, P Lichtenberg, CL TI The possibility of ice on the Moon SO SCIENCE LA English DT Article ID RADAR REFLECTIVITY; SURFACE; VENUS C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. LUNAR & PLANETARY INST,HOUSTON,TX 77058. USN,RES LAB,WASHINGTON,DC 20375. RP Nozette, S (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 11 TC 18 Z9 18 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 3 PY 1997 VL 278 IS 5335 BP 144 EP 145 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XZ124 UT WOS:A1997XZ12400060 ER PT J AU Bradshaw, JP Bushby, RJ Giles, CCD Saunders, MR Saxena, A AF Bradshaw, JP Bushby, RJ Giles, CCD Saunders, MR Saxena, A TI The headgroup orientation of dimyristoylphosphatidylinositol-4-phosphate in mixed lipid bilayers: a neutron diffraction study SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES LA English DT Article DE neutron diffraction; dimyristoylphosphatidylinositol-3-phosphate; biomembrane; synthesis; headgroup orientation ID PHOSPHOLIPID-BILAYERS; MODEL MEMBRANES; 2ND MESSENGERS; X-RAY; CONFORMATION; PHOSPHATIDYLINOSITOL; PHOSPHATIDYLETHANOLAMINE; PHOSPHATIDYLCHOLINE; PHOSPHORAMIDITE; PACKING AB The trisodium salt of dimyristoylphosphatidylinositol-4-phosphate (DMPI-4P) has been synthesised specifically deuterated at particular sites in the headgroup. These materials have been used in neutron diffraction experiments, which successfully located the position (depth) of each of these deuterated sites to within +/- 0.5 Angstrom in a mixed model membrane (a 1:1 molar mixture of DMPl-4P with dimyristoyl-phosphatidylcholine, DMPC, in the L-alpha phase, hydrated to the level of 28 water molecules per lipid molecule). The diffracted intensities were measured at four different D2O/H2O ratios and six orders of diffraction were obtained. These data sets, in conjunction with computer modelling, have been used to determine the orientation of the inositol ring of DMPI-4P, localising each vertical H-H distance to within approximately +/-0.03 Angstrom. The orientation of the inositol ring is found to be one in which the C5 hydroxyl is extended out into the aqueous medium. This is, therefore, the most accessible site for water-borne reagents. This may be significant for the important pathway leading from PI-4P to PI-4,5P(2). On the assumption that the P/ODAG bond is orientated parallel to the bilayer normal, these results are consistent with two possible conformations for the portion of the headgroup connecting the diacylglycerol to the inositol ring. Distinction between these two is difficult, but one may be favoured since the other involves close atom-atom contacts. (C) 1997 Elsevier Science B.V. C1 UNIV LEEDS,SCH CHEM,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND. UNIV EDINBURGH,ROYAL DICK SCH VET STUDIES,DEPT PRECLIN VET SCI,EDINBURGH EH9 1QH,MIDLOTHIAN,SCOTLAND. SMITHKLINE BEECHAM PHARMACEUT,WELWYN GARDEN CIT AL6 9AR,HERTS,ENGLAND. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 32 TC 11 Z9 11 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2736 J9 BBA-BIOMEMBRANES JI Biochim. Biophys. Acta-Biomembr. PD OCT 2 PY 1997 VL 1329 IS 1 BP 124 EP 138 DI 10.1016/S0005-2736(97)00093-X PG 15 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA YB985 UT WOS:A1997YB98500013 PM 9370250 ER PT J AU Fairbrother, DH Sullivan, DJD Johnston, HS AF Fairbrother, DH Sullivan, DJD Johnston, HS TI Global thermodynamic atmospheric modeling: Search for new heterogeneous reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SULFURIC-ACID; OZONE HOLE; GAS-PHASE; CHLORINE; CHEMISTRY; NITROGEN; HYDROGEN; STRATOSPHERE; FORMALDEHYDE; SURFACES AB This article demonstrates quantitatively how far reactions are from chemical equilibrium over the full space of a two-dimensional atmospheric model. This method could be used with data where an instrument-equipped aircraft measures numerous species simultaneously, An atmospheric reaction is displaced from equilibrium by solar radiation and relocation of species by atmospheric motions, One purpose of this study is to seek additional stratospheric or tropospheric gas-phase chemical reactions that might undergo heterogeneous catalysis. Hypothetical cases can be rapidly screened in terms of their thermodynamic potential to react under measured or modeled atmospheric conditions of temperature and local species concentrations. If a reaction is interesting, is slow in the gas phase, and has a high thermodynamic tendency to react, it is a good candidate for a laboratory study to seek a heterogeneous catalyst, if the reaction is thermodynamically unfavorable, there is no catalyst that can cause the reaction to occur. If a reaction is thermodynamically favored to occur but also endothermic, it will tend to be slow at stratospheric temperatures. We find, as expected, that four heterogeneous reactions important in causing the Antarctic ''ozone hole'' have high thermodynamic tendencies to occur under atmospheric conditions, but one of these is only weakly thermodynamically allowed in some regions of the atmosphere. The reaction of SO2 and HNO3 to form HONO has a high thermodynamic potential to occur, is a well-known laboratory reaction at ice temperature, and may occur in nitric acid-rich sulfate aerosols. Throughout the troposphere and stratosphere, we find that formaldehyde has an extremely high thermodynamic potential to reduce. nitric acid. Formaldehyde is known to stick to and remain in sulfuric acid solution, where it adds water to form H2C(OH)(2). Near room-temperature H2C(OH)(2) reacts with nitric acid in a two-step mechanism to form two molecules of HONO, but the rate of this process under conditions of stratospheric sulfuric acid aerosols is unknown. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 25 TC 16 Z9 16 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 2 PY 1997 VL 101 IS 40 BP 7350 EP 7358 DI 10.1021/jp971250d PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XZ201 UT WOS:A1997XZ20100008 ER PT J AU Magid, LJ Han, Z Warr, GG Cassidy, MA Butler, PD Hamilton, WA AF Magid, LJ Han, Z Warr, GG Cassidy, MA Butler, PD Hamilton, WA TI Effect of counterion competition on micellar growth horizons for cetyltrimethylammonium micellar surfaces: Electrostatics and specific binding SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHARGED COLLOIDAL DISPERSIONS; ANGLE NEUTRON-SCATTERING; DYNAMIC LIGHT-SCATTERING; WORMLIKE MICELLES; ORIENTATIONAL BINDING; ORGANIC COUNTERIONS; SODIUM-SALICYLATE; RODLIKE MICELLES; AQUEOUS-MEDIA; SALT CONTENT AB Counterion-mediated micellar growth for cetyltrimethylammonium 2,6-dichlorobenzoate alone and together with cetyltrimethylammonium chloride has been investigated using small-angle scattering techniques. Variations in counterion composition at constant ionic strength cause large changes in micelle size. The selectivity coefficient for adsorption of the aromatic counterion over chloride ions at CTA(+) surfaces has been determined. The effects of the two counterions on micellar surface potentials, together with H-1 NMR chemical shift data, allow inferences to be drawn about the penetration of the aromatic counterion into the head group region of the micelles. The aromatic ion increases the surfactant-packing parameter by both increasing the average volume per surfactant monomer, a cosurfactant-like effect, and decreasing the area per head group by screening electrostatic repulsions. Counterions such as chloride, which show only surface adsorption, affect only area and are much less effective at driving micellar growth. Some comparisons are also made with literature data for CTABr. C1 UNIV SYDNEY, SCH CHEM, SYDNEY, NSW 2006, AUSTRALIA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RP Magid, LJ (reprint author), UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. RI Butler, Paul/D-7368-2011 NR 60 TC 121 Z9 122 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 2 PY 1997 VL 101 IS 40 BP 7919 EP 7927 DI 10.1021/jp970864f PG 9 WC Chemistry, Physical SC Chemistry GA XZ202 UT WOS:A1997XZ20200007 ER PT J AU Zaban, A Meier, A Gregg, BA AF Zaban, A Meier, A Gregg, BA TI Electric potential distribution and short-range screening in nanoporous TiO2 electrodes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NANOCRYSTALLINE SEMICONDUCTOR-FILMS; PHOTOELECTROCHEMICAL CELLS; CHARGE SEPARATION; TRANSPORT; PHOTOSENSITIZATION; SPECTROSCOPY; INJECTION; LIGHT; SNO2 AB Impedance spectroscopy and electrochemical dye desorption experiments were employed to study the electrical characteristics of nanoporous TiO2 electrodes in the dark. The results show an unusual potential distribution across the TiO2 films, caused by the semiconducting nature of the TiO2 and the ion motion through the porous film that neutralizes applied electric fields over a short range. These results may have several implications for the functioning of dye-sensitized solar cells: (1) The potential of much of the TiO2 film will not necessarily correspond to the potential applied to the substrate electrode. (2) Charge carrier motion through the TiO2 is expected to occur primarily via diffusion rather than drift. (3) The transient electric field generated upon illumination will be quickly neutralized under steady state conditions, but may be an important factor in transient measurements. (4) Systems without excess supporting electrolyte, such as some solid state versions of the dye-sensitized cells, may not be able to efficiently neutralize the field generated by photoinduced charge separation, leading to enhanced charge recombination. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 36 TC 214 Z9 215 U1 2 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 2 PY 1997 VL 101 IS 40 BP 7985 EP 7990 DI 10.1021/jp971857u PG 6 WC Chemistry, Physical SC Chemistry GA XZ202 UT WOS:A1997XZ20200015 ER PT J AU Suwa, G Asfaw, B Beyene, Y White, TD Katoh, S Nagaoka, S Nakaya, H Uzawa, K Renne, P WoldeGabriel, G AF Suwa, G Asfaw, B Beyene, Y White, TD Katoh, S Nagaoka, S Nakaya, H Uzawa, K Renne, P WoldeGabriel, G TI The first skull of Australopithecus boisei SO NATURE LA English DT Article ID LAKE TURKANA; EARLY HOMINID; KENYA; HOMO; EVOLUTION; ETHIOPIA; REGION; EAST; WEST AB Australopithecus boisei was first described from a cranium recovered in 1959 from Olduvai Gorge, Tanzania(1,2). This and subsequent finds, mostly from Kenya's Turkana basin(3-5), resulted in its characterization as a specialized Australopithecus species with a hyper-robust masticatory apparatus(2,4,6). A distinct A. boisei facial morphology has been emphasized to differentiate robust Australopithecus lineages from East and South Africa(6). A preference for closed and/or wet habitats has been hypothesizes. Here we report some new A. boisei specimens, including the taxon's first cranium and associated mandible, from Konso, Ethiopia These fossils extend the known geographical range of A. boisei. They provide clear evidence for the coexistence of A. boisei and Homo erectus within a predominantly dry grassland environment. The A. boisei specimens from Konso demonstrate considerable morphological variation within the species. The unexpected combination of cranial and facial features of this skull cautions against the excessive taxonomic splitting of early hominids based on morphological detail documented in small and/or geographically restricted samples. C1 RIFT VALLEY RES SERV,ADDIS ABABA,ETHIOPIA. MINIST INFORMAT & CULTURE,DEPT ARCHAEOL & ANTHROPOL,CRCCH,ADDIS ABABA,ETHIOPIA. UNIV CALIF BERKELEY,HUMAN EVOLUT STUDIES LAB,BERKELEY,CA 94720. HYOGO MUSEUM HIMAN & NAT ACTIV,DIV EARTH SCI,SANDA,HYOGO 66913,JAPAN. NAGASAKI UNIV,DEPT GEOG,NAGASAKI 852,JAPAN. KAGAWA UNIV,DEPT EARTH SCI,TAKAMATSU,KAGAWA 852,JAPAN. BERKELEY GEOCHRONOL CTR,BERKELEY,CA 94709. LOS ALAMOS NATL LAB,EES1 D462,LOS ALAMOS,NM 87545. RP Suwa, G (reprint author), UNIV TOKYO,DEPT SCI BIOL,BUNKYO KU,TOKYO 113,JAPAN. NR 30 TC 68 Z9 69 U1 0 U2 15 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD OCT 2 PY 1997 VL 389 IS 6650 BP 489 EP 492 DI 10.1038/39037 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XY909 UT WOS:A1997XY90900054 PM 9333236 ER PT J AU Varmette, PG Shidot, DT Ma, WC Ramayya, AV Janssens, RVF Davids, CN Hamilton, JH Ahmad, I Amro, H Babu, BRS Back, B Bindra, KS Blumenthal, DJ Brown, LT Carpenter, MP Croft, WL Crowell, B Fischer, SM Garg, U Henry, RG Ishii, T Khoo, TL Kormicki, J Lauritsen, T Lister, CJ Nisius, D Penttila, H Piercey, RB Winger, JA Zhu, SJ Semmes, PB AF Varmette, PG Shidot, DT Ma, WC Ramayya, AV Janssens, RVF Davids, CN Hamilton, JH Ahmad, I Amro, H Babu, BRS Back, B Bindra, KS Blumenthal, DJ Brown, LT Carpenter, MP Croft, WL Crowell, B Fischer, SM Garg, U Henry, RG Ishii, T Khoo, TL Kormicki, J Lauritsen, T Lister, CJ Nisius, D Penttila, H Piercey, RB Winger, JA Zhu, SJ Semmes, PB TI Identification of Hg-181 and shape coexistence in odd-A Hg isotopes SO PHYSICS LETTERS B LA English DT Article DE Hg-181 deduced levels; spin; parity; band structure; configuration ID HIGH-SPIN STATES; CHARGE RADII; ALPHA-DECAY; BANDS; MOMENTS; EVEN AB In-beam gamma-ray transitions in Hg-181, the lightest odd-A Hg isotope known thus far, have been identified from fragment mass-gamma and gamma-gamma coincidence measurements. Five prolate deformed rotational bands were placed in the level scheme. A decoupled band built on the strongly prolate deformed 1/2(-)[521] ground state was observed up to 29/2(-). A 5/2(-)[512] configuration is suggested for a pair of strongly coupled bands displaying no signature splitting. The other two bands are also signature partner bands. They are populated with the largest intensity and exhibit splitting. They have been associated with the mixed neutron i(13/2) orbitals and are proposed to decay to an i(13/2) isomeric state associated with an oblate state. (C) 1997 Published by Elsevier Science B.V. C1 MISSISSIPPI STATE UNIV,DEPT PHYS,MISSISSIPPI STATE,MS 39762. VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37253. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. UNIV NOTRE DAME,DEPT PHYS,S BEND,IN 46556. JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. TSING HUA UNIV,DEPT PHYS,BEIJING 100084,PEOPLES R CHINA. TENNESSEE TECHNOL UNIV,DEPT PHYS,COOKEVILLE,TN 38505. RI Penttila, Heikki/A-4420-2013; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 26 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 2 PY 1997 VL 410 IS 2-4 BP 103 EP 109 DI 10.1016/S0370-2693(97)01035-6 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YF990 UT WOS:A1997YF99000006 ER PT J AU Hanks, CL Lorenz, J Teufel, L Krumhardt, AP AF Hanks, CL Lorenz, J Teufel, L Krumhardt, AP TI Lithologic and structural controls on natural fracture distribution and behavior within the Lisburne Group, northeastern Brooks Range and North Slope subsurface, Alaska SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Article ID FIELD AB The Carboniferous Lisburne Group of northern Alaska has been deformed into a variety of map-scale structures in both compressional and extensional structural settings, thus providing a series of natural experiments for observing the formation, distribution, and behavior of fractures in this thick carbonate unit, Two fracture sets dominate the Lisburne Group carbonates of the North Slope subsurface and the nearby northeastern Brooks Range fold and thrust belt, North-northwest-striking regional extension fractures probably formed in front of the northeastern Brooks Range fold and thrust belt, In the North Slope subsurface, this fracture set overprints east-northeast-striking fractures related to earlier extensional deformation; in contrast, in the fold and thrust belt, the north-northwest-striking fracture set is overprinted by younger east-northeast-striking fractures related to subsequent contractional deformation, Lithology is the primary control on the fracture density of both sets, In mildly deformed Lisburne Group carbonates, grainstones are the least fractured and dolomitic mudstones the most fractured, However, structural position plays a greater role in the overall fracture character and density in folded and thrust-faulted Lisburne carbonates, Explorationists in the Lisburne Group and other potentially fracture-controlled or -enhanced carbonate reservoirs need to consider both carbonate lithology and structural position when developing predictive models for fracture development. Fracture character and density can change abruptly across a given area, and even across an individual structure, Rock types less prone to fracturing in the less deformed sections may experience the greatest relative increase in fracture intensity as deformation increases. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NEW MEXICO INST MIN & TECHNOL,DEPT PETR & NAT GAS ENGN,SOCORRO,NM 87801. RP Hanks, CL (reprint author), UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775, USA. NR 41 TC 65 Z9 73 U1 0 U2 0 PU AMER ASSOC PETROLEUM GEOLOGIST PI TULSA PA 1444 S BOULDER AVE, PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD OCT PY 1997 VL 81 IS 10 BP 1700 EP 1720 PG 21 WC Geosciences, Multidisciplinary SC Geology GA YA593 UT WOS:A1997YA59300006 ER PT J AU Rao, BR Edwards, C Linden, T Moore, R Seager, M AF Rao, BR Edwards, C Linden, T Moore, R Seager, M TI Exploring largeness, complexity and scalability from the OOT perspective SO ACM SIGPLAN NOTICES LA English DT Editorial Material AB This panel will lay the foundation for understanding the needs of Large Systems so that OO practitioners can: appreciate the problems faced; understand the issues involved; and re-orient their approaches to provide a viable solution when participating in similar efforts. Specifically, this panel will establish the foundation for discussions on Large Systems by establishing concepts, exposing terminology, and highlighting the state-of-the art. RP Rao, BR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0362-1340 J9 ACM SIGPLAN NOTICES JI ACM Sigplan Not. PD OCT PY 1997 VL 32 IS 10 BP 106 EP 107 DI 10.1145/263700.263727 PG 2 WC Computer Science, Software Engineering SC Computer Science GA YE492 UT WOS:A1997YE49200011 ER PT J AU Oler, J Lindstrom, G Critchlow, T AF Oler, J Lindstrom, G Critchlow, T TI Migrating relational data to an ODBMS: Strategies and lessons from a molecular biology experience SO ACM SIGPLAN NOTICES LA English DT Article; Proceedings Paper CT 1997 ACM SIGPLAN Conference on Object-Oriented Programming Systems, Languages and Applications (OOPSLA 97) CY OCT 05-09, 1997 CL ATLANTA, GA SP ACM SIGPLAN ID SYSTEM AB The growing maturity of ODBMS technology is causing many enterprises to consider migrating relational databases to ODBMS's. While data remapping is relatively straightforward in most cases, greater challenges lie in economically and non-invasively adapting legacy application software. We report on a genetics laboratory database migration experiment, which was facilitated by both organization of the relational data in object-like form and a C++ framework designed to insulate application code from relational artifacts. Although this experiment was largely successful, we discovered to our surprise that the framework failed to encapsulate three subtle aspects of the relational implementation, thereby ''contaminating'' application code. We analyze the underlying issues, and offer cautionary guidance to future migrators. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP UNIV UTAH, DEPT COMP SCI, 50 S CENT CAMPUS DR, RM 3190, SALT LAKE CITY, UT 84112 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 2 PENN PLAZA, STE 701, NEW YORK, NY 10121-0701 USA SN 0362-1340 EI 1558-1160 J9 ACM SIGPLAN NOTICES JI ACM Sigplan Not. PD OCT PY 1997 VL 32 IS 10 BP 243 EP 252 DI 10.1145/263700.263741 PG 10 WC Computer Science, Software Engineering SC Computer Science GA YE492 UT WOS:A1997YE49200023 ER PT J AU Cohen, AE Craven, BM Klooster, WT AF Cohen, AE Craven, BM Klooster, WT TI Structure and thermal vibrations of spermine phosphate hexahydrate from neutron diffraction data at 125K SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article AB Spermine phosphate hexahydrate crystallizes in space group P2(1)/a with unit-cell dimensions a = 7.931 (I), b = 23.158 (5), c = 6.856 (2) Angstrom, and beta = 113.44(2)(o) at 125 K with unit-cell contents [(C10H30N4)(2)(4+)(HPO4)(4)(2-). 12H(2)O]. The packing of spermines and monohydrogen phosphates in this crystal structure has features which may be relevant to the binding of spermine to DNA. Another important structural feature is the presence of channels containing water that is hydrogen bonded as in ice-Ih with disordered protons. The channels occur between sheets of spermine long chains and are also bordered by hydrogen-bonded monohydrogen phosphate chains. The hydrogen-bonding scheme of these water chains proposed on the basis of an earlier X-ray study is now confirmed. Nuclear positions, anisotropic mean-square (m.s.) displacements, an overall scale factor and two extinction parameters (rho and g) were refined using full-matrix least-squares giving values of R(F-0(2)) = 0.09, Rw(F-0(2)) = 0.11 and S = 1.02. Thermal vibrational analysis revealed that the backbone of the spermine cation can be described as a single rigid segment with a substantial libration of 27 deg(2) around the spermine molecular long axis. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Cohen, AE (reprint author), UNIV PITTSBURGH,DEPT CRYSTALLOG,PITTSBURGH,PA 15260, USA. FU NIGMS NIH HHS [GM-39513] NR 32 TC 5 Z9 5 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Commun. PD OCT 1 PY 1997 VL 53 BP 787 EP 794 DI 10.1107/S0108768197005892 PN 5 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA YD279 UT WOS:A1997YD27900008 PM 9351188 ER PT J AU Liu, YM Mitchell, TE Wadley, HNG AF Liu, YM Mitchell, TE Wadley, HNG TI Anisotropic damage evolution in unidirectional fiber reinforced ceramics SO ACTA MATERIALIA LA English DT Article ID MATRIX COMPOSITES; MECHANICAL-PROPERTIES; ULTRASOUND; BEHAVIOR; CRACKING; FAILURE AB Damage transverse to the loading direction of a unidirectionally reinforced ceramic matrix composite has been observed and characterized by ultrasonic methods and acetate replicas. A laser-ultrasonic technique approach was developed and used to measure the ultrasonic velocity anisotropy, thus the complete elastic stiffness tensor, during uniaxial tensile loading/unloading of calcium aluminosilicate (GAS) composites reinforced by NicalonTM SIC fibers. Acoustic emission and surface replica observations link degradation of the axial stiffness to the accumulation of matrix cracks normal to the loading (and fiber) direction. The substantial loss of transverse stiffness is proposed to originate from the fiber/matrix interface debonding near matrix cracks. These observations may significantly impact the constitutive models used to design multiaxially loaded ceramic matrix composites. (C) 1997 Acta Metallurgica Inc. C1 UNIV VIRGINIA,SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,CHARLOTTESVILLE,VA 22903. RP Liu, YM (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MAIL STOP K765,LOS ALAMOS,NM 87545, USA. NR 33 TC 9 Z9 9 U1 1 U2 3 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 OCT PY 1997 VL 45 IS 10 BP 3981 EP 3992 DI 10.1016/S1359-6454(97)00097-9 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XY517 UT WOS:A1997XY51700004 ER PT J AU Sanders, PG Eastman, JA Weertman, JR AF Sanders, PG Eastman, JA Weertman, JR TI Elastic and tensile behavior of nanocrystalline copper and palladium SO ACTA MATERIALIA LA English DT Article ID MECHANICAL-BEHAVIOR; STRENGTH; MODULUS; CU; FE AB The elastic and tensile behavior of high-density, high-purity nanocrystalline Cu and Pd was determined. Samples with grain sizes of 10-110 nm and densities of greater than 98% of theoretical were produced by inert-gas condensation and warm compaction. Small decrements from coarse-grained values observed in the Young's modulus are caused primarily by the slight amount of porosity in the samples. The yield strength of nanocrystalline Cu and Pd was 10-15 times that of the annealed, coarse-grained metal. Total elongations of 1-4% were observed in samples with grain sizes less than 50 nm, while a sample with a grain size of 110 nm exhibited >8% elongation, perhaps signifying a change in deformation mechanism with grain size. Hardness measurements followed the predictions of the Hall-Fetch relationship for the coarse-grained copper down to approximate to 15 nm, and then plateaued. Hardness values (divided by 3) were 2-3 times greater than the tensile yield strengths. Processing flaws may cause premature tensile failure and lower yield strengths. The size and distribution of processing flaws was determined by small-angle neutron scattering. Tensile strength increased with decreasing porosity, and may be significantly affected by a few large processing flaws. (C) 1997 Acta Metallurgica Inc. C1 NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Weertman, Julia/B-7540-2009; Eastman, Jeffrey/E-4380-2011; OI Eastman, Jeff/0000-0002-0847-4265 NR 32 TC 587 Z9 622 U1 15 U2 138 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 OCT PY 1997 VL 45 IS 10 BP 4019 EP 4025 DI 10.1016/S1359-6454(97)00092-X PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XY517 UT WOS:A1997XY51700007 ER PT J AU Reidys, CH AF Reidys, CH TI Random induced subgraphs of generalized n-cubes SO ADVANCES IN APPLIED MATHEMATICS LA English DT Article AB The subject of this paper is to analyse connectivity and paths in random induced subgraphs of generalized n-cubes over an alphabet A with \A\ = alpha, Q(alpha)(n). The vertices of Q(alpha)(n) are n-tuples (x(1),...,x(n)), where x(i) is an element of A, i = 1,..., n, and two vertices are adjacent if they differ in exactly one coordinate. Random induced subgraphs, Gamma(n) < Q(alpha)(n), are obtained by selecting each vertex of Q(alpha)(n) independently with probability lambda(n). The first theorem shows that for lambda(n) = (c ln(n))/n there exists a unique largest component in Gamma(n) < Q(alpha)(n) which contains almost all vertices and that the size of the second largest component is less than or equal to Cn/ln(n), C > 0. The second theorem describes connectivity and paths of Gamma(n) for constant probability lambda > 0. It is proved that two vertices P, Q contained in the largest component of Gamma(n), that have distance k in Q(alpha), have a distance less than or equal to k + k in Gamma(n) and are typically connected by a large number of independent Gamma(n)-paths. Further, for any two vertices P, Q contained in the largest Gamma(n) component there exists a constant c(P,Q) > 0 such that their distance is less than or equal to c(P,Q)n. (C) 1997 Academic Press. RP Reidys, CH (reprint author), LOS ALAMOS NATL LAB,MAIL STOP TA-0,SM-1237,LOS ALAMOS,NM, USA. NR 14 TC 23 Z9 23 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 0196-8858 J9 ADV APPL MATH JI Adv. Appl. Math. PD OCT PY 1997 VL 19 IS 3 BP 360 EP 377 DI 10.1006/aama.1997.0553 PG 18 WC Mathematics, Applied SC Mathematics GA XX792 UT WOS:A1997XX79200006 ER PT J AU Stover, RL Tobias, CW Denn, MM AF Stover, RL Tobias, CW Denn, MM TI Bubble coalescence dynamics SO AICHE JOURNAL LA English DT Article ID NONLINEAR OSCILLATIONS; GAS-BUBBLES; DROPS AB zCoalescence of electrolytically-generated, 50- to 600-mu m-diameter gas bubbles was observed using an optical technique that employs a linear photodiode away to detect interface movement with a resolution of 10(-6)s. When two bubbles coalesce, the surface energy that is released causes interface velocities of 2 to 4 m/s; these are followed by large-amplitude damped oblate-prolate oscillations. Within the viscosity range studied, the oscillation period is insensitive to the viscosity and damping is insensitive to surface tension, in agreement with a scaling analysis based on a damped harmonic oscillator. Surface waves are superimposed on the motion. Finite-element solutions of the free-surface, nonlinear Navier-Stokes equations are consistent with the experiments. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. NR 20 TC 35 Z9 37 U1 0 U2 9 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD OCT PY 1997 VL 43 IS 10 BP 2385 EP 2392 DI 10.1002/aic.690431002 PG 8 WC Engineering, Chemical SC Engineering GA YA024 UT WOS:A1997YA02400001 ER PT J AU Volkow, ND Wang, GJ Overall, JE Hitzemann, R Fowler, JS Pappas, N Frecska, E Piscani, K AF Volkow, ND Wang, GJ Overall, JE Hitzemann, R Fowler, JS Pappas, N Frecska, E Piscani, K TI Regional brain metabolic response to lorazepam in alcoholics during early and late alcohol detoxification SO ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH LA English DT Article DE PET; FDG; orbitofrontal cortex; addiction; GABA ID OBSESSIVE-COMPULSIVE DISORDER; CEREBRAL GLUCOSE-UTILIZATION; RAT; ETHANOL; INTOXICATION; DEPRESSION; DEPENDENCE; ABUSERS; RISK; PET AB Changes in GABA function have been postulated to be involved in alcohol tolerance, withdrawal and addiction. In this study we measured regional brain metabolic responses to lorazepam, to indirectly assess GABA function (benzodiazepines facilitate GABAergic neurotransmission), in alcoholics during early and late withdrawal, Brain metabolism was measured using PET and 2-deoxy-2[F-18]fluoro-D-glucose after placebo (baseline) and after lorazepam (30 mu g/kg intravenously) in 10 alcoholics and 16 controls, In the alcoholics evaluations were performed 2 to 3 weeks after detoxification and were repeated 6 to 8 weeks later. Controls were also evaluated twice at a 6 to 8 weeks interval, While during the initial evaluation metabolism was significantly lower for most brain regions in the alcoholics than in controls in the repeated evaluation the only significant differences were in cingulate and orbitofrontal cortex, Lorazepam-induced decrements in metabolism did not change with protracted alcohol withdrawal and the magnitude of these changes were similar in controls and alcoholics except for a trend towards a blunted response to lorazepam in orbitofrontal cortex in alcoholics during the second evaluation, Abnormalities in orbitofrontal cortex and cingulate gyrus in alcoholics are unlikely to be due to withdrawal since they persist 8 to 11 weeks after detoxification. The fact that there was only a trend of significance for an abnormal response to lorazepam in orbitofrontal cortex indicates that mechanisms other than GABA are involved in the brain metabolic abnormalities observed in alcoholic subjects. C1 BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. SUNY STONY BROOK, DEPT PSYCHIAT, STONY BROOK, NY 11794 USA. UNIV TEXAS, SCH MED, DEPT PSYCHIAT, HOUSTON, TX USA. VET ADM MED CTR, NORTHPORT, NY USA. RP Volkow, ND (reprint author), BROOKHAVEN NATL LAB, DEPT MED, BLDG 490, UPTON, NY 11973 USA. FU NIAAA NIH HHS [AA 09481] NR 47 TC 56 Z9 57 U1 1 U2 4 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0145-6008 J9 ALCOHOL CLIN EXP RES JI Alcoholism (NY) PD OCT PY 1997 VL 21 IS 7 BP 1278 EP 1284 DI 10.1097/00000374-199710000-00018 PG 7 WC Substance Abuse SC Substance Abuse GA YC413 UT WOS:A1997YC41300018 PM 9347090 ER PT J AU Silveira, P Cynober, T Dhermy, D Mohandas, N Tchernia, G AF Silveira, P Cynober, T Dhermy, D Mohandas, N Tchernia, G TI Red blood cell abnormalities in hereditary elliptocytosis and their relevance to variable clinical expression SO AMERICAN JOURNAL OF CLINICAL PATHOLOGY LA English DT Article DE hereditary elliptocytosis; membrane disorders; red blood cells; hemolytic anemia ID ERYTHROCYTE-MEMBRANE; MUTATIONS; PROTEIN-4.1; DEFORMABILITY; SKELETAL; FORMS AB Marked variations are seen in the clinical manifestations of hereditary elliptocytosis (HE). To define the cellular alteration(s) that best reflect the variable expression of the disease, we evaluated the pathobiologic features of red blood cells in a series of 18 patients with HE, 15 persons from six families with HE as a result of defects in spectrin, and 3 persons from one family with HE caused by partial or total deficiency of protein 4.1. We found that decreased cellular deformability is a distinguishing feature of red blood cells in all patients studied. Comparison of volume and hemoglobin content histograms of red blood cells and reticulocytes revealed that cell fragmentation is a feature of mature red blood cells. The extent of red blood cell fragmentation as reflected by increased percentage of microcytic red blood cells was the best indicator of the severity of hemolytic anemia. Furthermore, we found that the observed variations in cellular properties of HE red blood cells in different persons is the consequence of varying amounts of mutant protein assembled into the membrane. These findings enabled us to define the mechanistic basis for cellular changes in this red blood cell membrane disorder better and also to obtain insight into the cellular basis for variable clinical expression. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. HOP BICETRE,HEMATOL LAB,LE KREMLIN BICETR,FRANCE. FU NIDDK NIH HHS [DK26263] NR 20 TC 15 Z9 16 U1 0 U2 1 PU AMER SOC CLIN PATHOLOGISTS PI CHICAGO PA 2100 W HARRISON ST, CHICAGO, IL 60612 SN 0002-9173 J9 AM J CLIN PATHOL JI Am. J. Clin. Pathol. PD OCT PY 1997 VL 108 IS 4 BP 391 EP 399 PG 9 WC Pathology SC Pathology GA XX434 UT WOS:A1997XX43400005 PM 9322591 ER PT J AU Batzer, MA Arcot, SS Risch, G LaFleur, J Adamson, AW Lamerdin, JE Carrano, AV AF Batzer, MA Arcot, SS Risch, G LaFleur, J Adamson, AW Lamerdin, JE Carrano, AV TI Distribution and insertion polymorphism of recently integrated chromosome 19 specific Alu family members. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Louisiana State Univ, Med Ctr, Stanley S Scott Canc Ctr, Dept Pathol, New Orleans, LA USA. Louisiana State Univ, Med Ctr, Stanley S Scott Canc Ctr, Dept Biometry & Genet, New Orleans, LA USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1120 BP A194 EP A194 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001123 ER PT J AU Burmeister, M Meyer, GE Gordon, L Kapfhamer, D Sufalko, DK Carskagon, S Puttagunda, R Mike, D Kantheti, PR Chung, W Jenne, D Olsen, A AF Burmeister, M Meyer, GE Gordon, L Kapfhamer, D Sufalko, DK Carskagon, S Puttagunda, R Mike, D Kantheti, PR Chung, W Jenne, D Olsen, A TI Comparative genetic and physical maps of human 19p13.3 and mouse chromosome 10. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Michigan, Mental Hlth Res Inst, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Psychiat, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Human Genet, Ann Arbor, MI 48109 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Rockefeller Univ, New York, NY 10021 USA. Max Planck Inst Psychiat, D-8033 Martinsried, Germany. RI Burmeister, Margit/A-3157-2013 OI Burmeister, Margit/0000-0002-1914-2434 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1346 BP A232 EP A232 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001347 ER PT J AU Chen, S Wang, QL Nie, Z Copeland, NG Jenkins, NA Lennon, G Zack, DJ AF Chen, S Wang, QL Nie, Z Copeland, NG Jenkins, NA Lennon, G Zack, DJ TI Cloning and characterization of RHDP3, a novel photoreceptor-specific Otx-like homeodomain protein that binds to and transactivates the rhodopsin promoter. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Johns Hopkins Univ, Sch Med, Baltimore, MD 21287 USA. NCI, Frederick Canc Res & Dev Ctr, Mammalian Genet Lab, ABL, Frederick, MD 21702 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 36 BP A9 EP A9 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000036 ER PT J AU Chuu, YJ Lowe, X Kidd, S Weisiger, K Moore, D Eskenazi, B Wyrobek, AJ AF Chuu, YJ Lowe, X Kidd, S Weisiger, K Moore, D Eskenazi, B Wyrobek, AJ TI Sperm disomies involving chromosomes X, Y and 21 are highly elevated in a father of four consecutive aneuploid pregnancies. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Biol Biotech Res Program, Livermore, CA USA. Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 683 BP A121 EP A121 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000684 ER PT J AU Deng, Z Aksentijevich, I Balow, JE Blake, T Centola, M Chen, X Collins, FS Doggett, N Fischel-Ghodsian, N Gumucio, D Liu, P Pras, E Pras, M Richards, N Richards, RI Ricke, DO Rotter, JI Shohat, M Sood, R Wood, G Yokoyama, Y Zaks, N Kastner, DL AF Deng, Z Aksentijevich, I Balow, JE Blake, T Centola, M Chen, X Collins, FS Doggett, N Fischel-Ghodsian, N Gumucio, D Liu, P Pras, E Pras, M Richards, N Richards, RI Ricke, DO Rotter, JI Shohat, M Sood, R Wood, G Yokoyama, Y Zaks, N Kastner, DL TI Identification of FMF positional candidate genes within a 115-kb interval defined by historical recombinants. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 NIAMS, ARB, NIH, Bethesda, MD USA. NHGRI, LGT, NIH, Bethesda, MD USA. Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Michigan, Ann Arbor, MI 48109 USA. Chaim Sheba Med Ctr, IL-52621 Tel Hashomer, Israel. Womens & Childrens Hosp, Adelaide, SA, Australia. Beilinson Med Ctr, IL-49100 Petah Tiqwa, Israel. RI Liu, Paul/A-7976-2012 OI Liu, Paul/0000-0002-6779-025X NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1356 BP A234 EP A234 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001358 ER PT J AU Eskenazi, B Chuu, YJ Kidd, S Lowe, X Aylstock, M Weisiger, K Moore, D Wyrobek, AJ AF Eskenazi, B Chuu, YJ Kidd, S Lowe, X Aylstock, M Weisiger, K Moore, D Wyrobek, AJ TI Frequencies of aneuploid sperm (X-Y and 21-21) were elevated in fathers of boys with Klinefelter syndrome when the extra X was of paternal origin. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Biol Biotech Res Grp, Livermore, CA USA. Klinefelter Ass, Roseville, NSW, Australia. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 264 BP A50 EP A50 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000266 ER PT J AU Gabriel, JM Gray, TA Ohta, T Stubbs, L Nicholls, RD AF Gabriel, JM Gray, TA Ohta, T Stubbs, L Nicholls, RD TI Structure/function correlations in the imprinted mouse Snrpn gene locus. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Case Western Reserve Univ, Cleveland, OH 44106 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 982 BP A171 EP A171 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000983 ER PT J AU Gustavsson, P Tentler, D Elinder, G Eklof, O Gordon, L Mandel, A Dahl, N AF Gustavsson, P Tentler, D Elinder, G Eklof, O Gordon, L Mandel, A Dahl, N TI Fiber-FISH analysis of a microdeletion in 19q13 associated with Diamond-Blackfan anaemia, mental retardation and skeletal abnormalities. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Uppsala Univ, Childrens Hosp, Dept Clin Genet, Uppsala, Sweden. Sacchska Hosp, Dept Paediat, Stockholm, Sweden. Karolinska Hosp, Dept Paediat Radiol, S-10401 Stockholm, Sweden. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1364 BP A235 EP A235 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001365 ER PT J AU Ji, Y Walkowicz, MJ Buiting, K Rinchik, EM Amos-Landgraf, JM Tarvin, RE Horsthemke, B Johnson, DK Stubbs, L Nicholls, RD AF Ji, Y Walkowicz, MJ Buiting, K Rinchik, EM Amos-Landgraf, JM Tarvin, RE Horsthemke, B Johnson, DK Stubbs, L Nicholls, RD TI Characterization of a large transcript associated with neuromuscular tremor, runting, juvenile lethality, and sperm defects in jdf2 mice. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. Univ Essen Gesamthsch, Essen, Germany. RI Amos-Landgraf, James/K-9288-2013 OI Amos-Landgraf, James/0000-0003-2535-7746 NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 170 BP A33 EP A33 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000169 ER PT J AU Jia, L Wilkin, DJ Bittner, M Robey, P Young, M Yamada, Y Krizman, D Liotta, L Bonner, R Schuler, G Boguski, M Powell, J Lennon, G Roodman, D Hotchkiss, R Meltzer, P Trent, J Francomano, CA AF Jia, L Wilkin, DJ Bittner, M Robey, P Young, M Yamada, Y Krizman, D Liotta, L Bonner, R Schuler, G Boguski, M Powell, J Lennon, G Roodman, D Hotchkiss, R Meltzer, P Trent, J Francomano, CA TI SGAP: The skeletal genome anatomy project. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 NHGRI, NIH, Bethesda, MD USA. NIDR, NIH, Bethesda, MD USA. NCI, NIH, Bethesda, MD USA. NCRR, NIH, Bethesda, MD USA. NCBI, NIH, Bethesda, MD USA. DCRT, NIH, Bethesda, MD USA. Lawrence Livermore Natl Lab, Lawrence, CA USA. Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. Hosp Special Surg, New York, NY 10021 USA. RI Robey, Pamela/H-1429-2011; Bonner, Robert/C-6783-2015 OI Robey, Pamela/0000-0002-5316-5576; NR 0 TC 4 Z9 4 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 2212 BP A378 EP A378 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446002213 ER PT J AU Johnson, DK Dahar, MS Rebert, NA Nicholls, RD AF Johnson, DK Dahar, MS Rebert, NA Nicholls, RD TI A mouse model for Angelman syndrome. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN USA. Case Western Reserve Univ, Dept Genet, Cleveland, OH 44106 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 201 BP A39 EP A39 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000201 ER PT J AU Marchetti, F Lowe, X Bishop, J Wyrobek, AJ AF Marchetti, F Lowe, X Bishop, J Wyrobek, AJ TI Identification and characterization of chromosomal abnormalities in mouse zygotes that are predictive of pregnancy wastage and de novo translocations at birth. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, BBRP, Livermore, CA USA. Natl Inst Environm Hlth Sci, Res Triangle Pk, NC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 755 BP A133 EP A133 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000756 ER PT J AU Mears, AJ Collins, C Mirzayans, F Myambo, K Wernick, M Kuo, WL Pearce, WG Walter, MA AF Mears, AJ Collins, C Mirzayans, F Myambo, K Wernick, M Kuo, WL Pearce, WG Walter, MA TI Physical and genetic mapping of the IGDA locus at 6p25 SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Alberta, Dept Ophthalmol, Edmonton, AB, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif San Francisco, Ctr Canc, San Francisco, CA 94143 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1665 BP A285 EP A285 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001667 ER PT J AU Mohrenweiser, HW Tsujimoto, S Gordon, L Olsen, AS AF Mohrenweiser, HW Tsujimoto, S Gordon, L Olsen, AS TI Regions of sex-specific hypo- and hyper-recombination identified through integration of 180 genetic markers into the metric physical map of human chromosome 19. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1393 BP A240 EP A240 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001397 ER PT J AU Nolan, JP Cai, H Kommander, K White, PS AF Nolan, JP Cai, H Kommander, K White, PS TI Microsphere-based assays for genome analysis using flow cytometry. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1398 BP A241 EP A241 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001400 ER PT J AU Nystuen, A Benke, PJ Mohrenweiser, H Burmeister, M Stone, EM Sheffield, VC AF Nystuen, A Benke, PJ Mohrenweiser, H Burmeister, M Stone, EM Sheffield, VC TI Physical, transcript, and genetic fine map of the Cayman cerebellar ataxia region on chromosome 19p13.3. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Iowa, Howard Hughes Med Inst, Iowa City, IA 52242 USA. Univ Iowa, Dept Pediat, Iowa City, IA 52242 USA. Univ Iowa, Dept Ophthalmol, Iowa City, IA 52242 USA. Univ Miami, Sch Med, Mailman Ctr Child Dev, Miami, FL USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Michigan, Mental Hlth Res Inst, Ann Arbor, MI 48109 USA. RI Burmeister, Margit/A-3157-2013 OI Burmeister, Margit/0000-0002-1914-2434 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1682 BP A288 EP A288 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001682 ER PT J AU Olsen, AS Gordon, LA Ashworth, LK Lamerdin, JE McCready, P Wagner, M Lennon, G Mohrenweiser, H Carrano, AV AF Olsen, AS Gordon, LA Ashworth, LK Lamerdin, JE McCready, P Wagner, M Lennon, G Mohrenweiser, H Carrano, AV TI An integrated genetic and physical map of chromosome 19 as substrate for large scale genomic sequencing. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1399 BP A241 EP A241 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001403 ER PT J AU Pinkel, D Segraves, R Sudar, D Clark, S Poole, I Chen, C Gray, J Albertson, DG AF Pinkel, D Segraves, R Sudar, D Clark, S Poole, I Chen, C Gray, J Albertson, DG TI Analysis of complex patterns of DNA copy number variation on chromosome 20 and deletion and amplification of specific genes in breast cancer cell lines and tumors using comparative genomic hybridization to DNA microarrays. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Berkeley, CA USA. Vysis Inc, Downers Grove, IL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 427 BP A78 EP A78 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000427 ER PT J AU Sago, H Huang, TT Carlson, EJ Smith, DJ Kilbridge, J Chen, XN Korenberg, JR Rubin, EM Mobley, WC Epstein, CJ AF Sago, H Huang, TT Carlson, EJ Smith, DJ Kilbridge, J Chen, XN Korenberg, JR Rubin, EM Mobley, WC Epstein, CJ TI Ts108Cje, a partial trisomy 16 mouse model for Down syndrome, exhibits slow learning. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94143 USA. LBNL, Berkeley, CA USA. Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 156 BP A31 EP A31 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000159 ER PT J AU Symula, DJ Frazer, K Ueda, Y Zhu, Y Cheng, JF Rubin, EM AF Symula, DJ Frazer, K Ueda, Y Zhu, Y Cheng, JF Rubin, EM TI Functional analysis of an asthma-associated QTL using an in vivo library of human genomic DNA in transgenic mice. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Human Genome, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 298 BP A56 EP A56 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446000301 ER PT J AU White, S Tatum, OL Deaven, L Longmire, JL AF White, S Tatum, OL Deaven, L Longmire, JL TI New polymorphic tetranucleotide microsatellites from the human Y chromosome. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Gen Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. Texas Tech Univ, Dept Biol Sci, Lubbock, TX 79409 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1754 BP A300 EP A300 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001754 ER PT J AU Wright, TJ Naranjo, C Ortega, E Altherr, MR AF Wright, TJ Naranjo, C Ortega, E Altherr, MR TI Comparative analysis of a novel gene mapping into the Wolf Hirshhorn Syndrome critical region on chromosome 4p16.3. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Gen Grp, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1068 BP A185 EP A185 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001068 ER PT J AU Yoshiura, K Machida, J Daack-Hirsch, S Ashworth, LK Hecht, JT Murray, JC AF Yoshiura, K Machida, J Daack-Hirsch, S Ashworth, LK Hecht, JT Murray, JC TI Cloning of the gene disrupted by a chromosomal translocation in a three generation family with cleft lip and palate SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Iowa, Dept Pediat, Iowa City, IA 52242 USA. Univ Iowa, Dept Biol Sci, Iowa City, IA 52242 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA USA. Univ Texas, Sch Med, Dept Pediat, Houston, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 2064 BP A352 EP A352 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446002067 ER PT J AU Zevin-Sonkin, D Liberzon, A Ghochikyan, A Mugasimangalam, RC Shwartzburd, J Rozovskaya, TA Sobolev, IA Lvovsky, L Ulanovsky, LE AF Zevin-Sonkin, D Liberzon, A Ghochikyan, A Mugasimangalam, RC Shwartzburd, J Rozovskaya, TA Sobolev, IA Lvovsky, L Ulanovsky, LE TI DNA sequencing using differential extension with nucleotide subsets (DENS): application to the sequencing of Human Genomic DNA. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Weizmann Inst Sci, Dept Struct Biol, IL-76100 Rehovot, Israel. Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1997 VL 61 IS 4 SU S MA 1438 BP A247 EP A247 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA YQ995 UT WOS:000071446001438 ER PT J AU Moore, DH Patterson, HW Hatch, F Discher, D Schneider, JS Bennett, D Mendelsohn, ML AF Moore, DH Patterson, HW Hatch, F Discher, D Schneider, JS Bennett, D Mendelsohn, ML TI Case-control study of malignant melanoma among employees of the Lawrence Livermore National Laboratory SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article DE melanoma; occupation; ionizing radiation; chemicals; case-control study ID CANCER INCIDENCE; MORTALITY; RISK AB During 1972 to 1977, the Lawrence Livermore National Laboratory (LLNL) experienced increased diagnosis of malignant melanoma among employees. In 1984, a report on the results of a case-control study of 39 cases concluded that occupational factors, including exposures to ionizing radiation and to chemicals, caused the excess incidence. The study reported here, based on results from 69 case-control pairs, re-examines the role of the occupational factors implicated by the earlier study in melanoma causation. Results from this study suggest that constitutional factors, including skin reactivity to sunlight, sunbathing frequency, and number of moles, explain most of the excess melanoma. Exposures to occupational factors, including ionizing radiation and chemicals, were found to be no different in cases than in controls. (C) 1997 Wiley-Liss, Inc. C1 UNIV CALIF SAN FRANCISCO,DEPT EPIDEMIOL & BIOSTAT,SAN FRANCISCO,CA 94143. CALIF PACIFIC MED CTR,RES INST,SAN FRANCISCO,CA. SO CALIF PERMANENTE MED GRP,SAN RAFAEL,CA. UNIV CALIF SAN FRANCISCO,DEPT DERMATOL,SAN FRANCISCO,CA 94143. RP Moore, DH (reprint author), LAWRENCE LIVERMORE NATL LAB,L-452,LIVERMORE,CA 94550, USA. NR 27 TC 24 Z9 24 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD OCT PY 1997 VL 32 IS 4 BP 377 EP 391 DI 10.1002/(SICI)1097-0274(199710)32:4<377::AID-AJIM9>3.0.CO;2-R PG 15 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA XP455 UT WOS:A1997XP45500009 PM 9258392 ER PT J AU Castro, A Williams, JGK AF Castro, A Williams, JGK TI Single-molecule detection of specific nucleic acid sequences in unamplified genomic DNA SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYMERASE CHAIN-REACTION; CAPILLARY ELECTROPHORESIS; CONTAMINATION; PCR; HYBRIDIZATION; FRAGMENTS AB A new technique is described for the rapid detection of specific nucleic acid sequences in unamplified DNA samples. The method consists of using two nucleic acid probes complementary to different sites on a target DNA sequence. The two probes are each labeled with different fluorescent dyes. When mixed with a sample containing the target DNA, the two probes hybridize to their respective binding sites on the same target DNA molecule. The sample is then analyzed by a laser-based ultrasensitive fluorescence system capable of detecting single fluorescent molecules at two different wavelength channels simultaneously. Since the probes are bound to the same target DNA molecule, their signals appear simultaneously. Thus, coincident detection of both dyes provides the necessary specificity to detect an unamplified, single-copy target DNA molecule in a homogeneous assay. If the target is not present, only uncorrelated events originating from free probes will be observed at either channel. Phage lambda DNA in a background of salmon genomic DNA was detected as a two-dye coincident signal at a relative concentration of one lambda molecule per salmon genome. In a control sample, cleavage of the lambda DNA between the two probe binding sites eliminated the coincident signals. In a second experiment, a single-copy transgene was detected in maize. Detection parameters and possible future applications to genetic analysis are discussed. RP Castro, A (reprint author), LOS ALAMOS NATL LAB,MS D454,POB 1663,LOS ALAMOS,NM 87545, USA. NR 26 TC 136 Z9 139 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 1997 VL 69 IS 19 BP 3915 EP 3920 DI 10.1021/ac970389h PG 6 WC Chemistry, Analytical SC Chemistry GA XX933 UT WOS:A1997XX93300015 PM 9322430 ER PT J AU Hagaman, EW Kee, SK Britt, PF AF Hagaman, EW Kee, SK Britt, PF TI Synthesis and solid state C-13 and F-19 NMR characterization of aliphatic and aromatic carboxylic acid fluoride polymers SO ANALYTICAL CHEMISTRY LA English DT Article ID CROSS-POLARIZATION; MAS NMR; SUBSTANCES AB A new chemical/spectroscopic couple that differentiates aromatic from aliphatic carboxylic acid polymers was developed. The method is complementary to more traditional methods of identification (IR) and its applicable to the analysis of complex mixtures were IR determinations are complicated by extensive vibrational band overlap. The method entails (1) conversion of carboxylic acids into acid fluorides and (2) specific detection of the resonances of the acid fluoride carbon and the carbon directly attached to the carbonyl carbon by solid state F-19-C-13 cross polarization (CP)/MAS C-13 NMR. The assignment of the chemical shift of the latter resonance to either the sp(2) or sp(3) carbon resonance manifold specifies the nature of the acid functionality. The preparation of the acid fluoride derivatives of several polymers containing aliphatic and aromatic carboxylic acid functionality was evaluated using sulfur tetrafluoride (SF4), diethylaminosulfur trifluoride (DAST), cyanuric fluoride, and thionyl fluoride. Room temperature reactions using DAST in methylene chloride or neat SF4 gave the acid fluorides in yields greater than or equal to 90% for the acids studies. Aromatic acid fluoride yields were essentially quantitative. Aliphatic acid fluorides were contaminated with the anhydride of the acid. The acid fluoride polymers were characterized by solid state C-13 and F-19 MAS/NMR. RP Hagaman, EW (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 16 TC 2 Z9 2 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 OCT 1 PY 1997 VL 69 IS 19 BP 3950 EP 3958 DI 10.1021/ac9703663 PG 9 WC Chemistry, Analytical SC Chemistry GA XX933 UT WOS:A1997XX93300019 PM 21639211 ER PT J AU Willinger, W Paxson, V AF Willinger, W Paxson, V TI Heavy tail modeling and teletraffic data - Discussion SO ANNALS OF STATISTICS LA English DT Editorial Material ID AREA TCP CONNECTIONS; WIDE C1 AT&T Bell Labs, Res, Florham Park, NJ 07932 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Willinger, W (reprint author), AT&T Bell Labs, Res, Florham Park, NJ 07932 USA. NR 18 TC 10 Z9 10 U1 0 U2 0 PU INST MATHEMATICAL STATISTICS PI HAYWARD PA IMS BUSINESS OFFICE-SUITE 7, 3401 INVESTMENT BLVD, HAYWARD, CA 94545 USA SN 0090-5364 J9 ANN STAT JI Ann. Stat. PD OCT PY 1997 VL 25 IS 5 BP 1856 EP 1866 PG 11 WC Statistics & Probability SC Mathematics GA 176DE UT WOS:000079135000004 ER PT J AU Vallet, CE AF Vallet, CE TI Comparison of scanning probe microscopies with RBS and SEM/EDX for the analysis of RuO2,TiO2 composites SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID TUNNELING MICROSCOPY; ION-IMPLANTATION; SURFACE; ELECTRODES; ELECTROCATALYSIS; SPECTROSCOPY; EVOLUTION; FILMS AB Scanning tunneling microscopy (STM) was used in the constant height mode for analyzing the local composition of (RuO2, TiO2) mixed oxide thin films. A digital processing of the images leads to a bipolar distribution of values of current that reflects the difference in conductivity of metallic RuO? and semiconducting TiO2. The analytical results are compared with those from Rutherford backscattering spectrometry and energy dispersive X-ray imaging on these samples. STM, with digital processing of the current mapping image, shows promises for developing into a chemically sensitive probe of composite materials with nanometer spatial resolution. RP Vallet, CE (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 34 TC 4 Z9 4 U1 0 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD OCT PY 1997 VL 65 IS 4-5 BP 387 EP 394 DI 10.1007/s003390050597 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA YA615 UT WOS:A1997YA61500009 ER PT J AU Frankle, SC Conaway, JG AF Frankle, SC Conaway, JG TI MCNP (TM) simulations for identifying environmental contaminants using prompt gamma rays from thermal neutron capture reactions SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB The primary purpose of the Multispectral Neutron Logging (MSN) project was to assess the effectiveness of existing neutron-induced spectral gamma-ray logging techniques for identifying environmental contaminants along boreholes, to further improve the technology, and to transfer that technology to industry (Conaway and Frankle, 1993). The logging instrument incorporated a pulsed 14 MeV neutron source and HPGe detector. Gamma-ray spectra from thermal neutron capture reactions were used to identify contaminants in the borehole environment. This type of technique complements physical sampling and is useful in environmental restoration projects where characterization of contaminated sites is required and long-term monitoring may be needed. We used an enhanced version of the Monte Carlo N-Particle computer code (MCNP(TM)) to investigate many more potential contaminants than could be accomplished experimentally. MCNP was tested and benchmarked with experimental data for Cl provided by our collaborators (Myers, 1988; Frankle, 1994) and experimental data for Cl, Cd, Sm, Gd and Hg obtained as part of this project (Conaway and Duray, 1994). A number of enhancements were developed for MCNP as a result of this project, some of which will be part of the next major code release. The results from the benchmarking effort, estimates of minimum detection thresholds for our instrument based on MCNP simulations, and some of the MCNP code enhancements will be discussed. Published by Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Frankle, SC (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS B226, Los Alamos, NM 87545 USA. NR 12 TC 5 Z9 5 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1337 EP 1341 DI 10.1016/S0969-8043(97)00128-0 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT758 UT WOS:000071642100010 ER PT J AU Sprinkle, JK Christiansen, A Cole, R Collins, ML Hsue, ST Knepper, PL McKown, TO Siebelist, R AF Sprinkle, JK Christiansen, A Cole, R Collins, ML Hsue, ST Knepper, PL McKown, TO Siebelist, R TI Low-resolution gamma-ray measurements of uranium enrichment SO APPLIED RADIATION AND ISOTOPES LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Siebelist, R (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1525 EP 1528 DI 10.1016/S0969-8043(97)00151-6 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 YT758 UT WOS:000071642100035 PM 9463875 ER PT J AU Sprinkle, JK Cole, R Collins, ML Hsue, ST Russo, PA Siebelist, R Smith, HA Ceo, RN Smith, SE AF Sprinkle, JK Cole, R Collins, ML Hsue, ST Russo, PA Siebelist, R Smith, HA Ceo, RN Smith, SE TI Low-resolution gamma-ray measurements of process hold-up SO APPLIED RADIATION AND ISOTOPES LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lockheed Martin Energy Syst, Plant Y12, Oak Ridge, TN 37831 USA. RP Sprinkle, JK (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1529 EP 1534 DI 10.1016/S0969-8043(97)00152-8 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT758 UT WOS:000071642100036 PM 9463876 ER PT J AU Sampson, TE Kelley, TA AF Sampson, TE Kelley, TA TI PC/FRAM: a code for the nondestructive measurement of the isotopic composition of actinides for safeguards applications SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB The Nuclear Safeguards Program at the Los Alamos National Laboratory has developed and fielded techniques for the gamma-ray spectrometry measurement of the isotopic composition of plutonium and other actinides for over 20 years, ever since Parker and Reilly first proposed a practical method for the measurement of the arbitrary sample. Their procedures, incorporating internal (to the measured gamma-ray spectrum) or 'intrinsic' self-determination of the relative efficiency function of the sample-detector measurement system, are widely applied today. The PC/FRAM code is the most recent and most highly developed Los Alamos code developed specifically for the nuclear safeguards applications of this technique. We will describe the measurement principles that allow accurate measurements to be taken on samples of arbitrary size, shape, and measurement geometry-and of arbitrary physical and chemical composition-through the use of known nuclear decay data (half-lives and branching intensities). Subsequently, we will describe the analysis methodology, which is driven by an easily edited parameter file that frees the user from dependence on a dedicated programmer for analyses of special cases. This methodology relies on internal gamma-ray peaks from the spectrum under analysis to self-calibrate the unknown spectrum for energy and peak shape (energy dependence of full width at half maximum (FWHM) and tailing parameters). The program uses these parameters to calculate response functions that are fit to the analysis peaks requested in the parameter file. The structure of the code and its Windows 3.1 user interface allows use with equal ease by the experienced spectroscopist or operator-level personnel in a working facility. The code has been applied primarily to the analysis of gamma-ray spectra from plutonium with the isotopic results used to calculate the parameters Pu-240(eff) for interpretation of neutron coincidence counting assays and P-eff (W/g Pu) for the interpretation of calorimetry measurements. These measurement combinations form the backbone of nondestructive assay measurements for materials control and accountability both domestically and internationally. We will present examples of the results of measurements of these parameters with PC/FRAM and discuss the wide range of materials measured, including uranium samples and samples with lead shielding. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kelley, TA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 12 TC 11 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1543 EP 1548 DI 10.1016/S0969-8043(97)00154-1 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT758 UT WOS:000071642100038 ER PT J AU Miller, MC Byrd, RC Ensslin, N Feldman, WC Krick, MS Prettyman, TH Russo, PA AF Miller, MC Byrd, RC Ensslin, N Feldman, WC Krick, MS Prettyman, TH Russo, PA TI Design of a fast neutron coincidence counter SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID ASSAY AB Monte Carlo simulations were carried out to simulate the response of a boron-loaded plastic scintillator array. These detectors offer potential advantages compared to moderated He-3 systems because of their fast response and high efficiency. Tallies were made of neutron capture probability as a function of time and the results were coupled to assay variance estimates to evaluate detector performance. Orders-of-magnitude reductions in count time relative to a 50% efficient thermal counter are possible,in principle, for high (alpha,n) samples. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Miller, MC (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Prettyman, Thomas/0000-0003-0072-2831 NR 7 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1549 EP 1555 DI 10.1016/S0969-8043(97)00155-3 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT758 UT WOS:000071642100039 ER PT J AU Martin, RC Laxson, RR Miller, JH Wierzbicki, JG Rivard, MJ Marsh, DL AF Martin, RC Laxson, RR Miller, JH Wierzbicki, JG Rivard, MJ Marsh, DL TI Development of high-activity Cf-252 sources for neutron brachytherapy SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using Cf-252 medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing less than or equal to 30 mu g Cf-252 in the form of a cermet wire of Cf2O3 in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop very compact, high-activity Cf-252 neutron Sources for use with remote afterloading equipment in order to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors, To date, the REDC has demonstrated that Cf-252 loadings can be greatly increased in cermet wires and with much smaller diameters. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC. Published by Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Wayne State Univ, Harper Hosp, Dept Radiat Oncol, Detroit, MI 48201 USA. Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. RP Martin, RC (reprint author), Oak Ridge Natl Lab, Div Chem Technol, POB 2008, Oak Ridge, TN 37831 USA. NR 6 TC 17 Z9 17 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1567 EP 1570 DI 10.1016/S0969-8043(97)00157-7 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 YT758 UT WOS:000071642100042 PM 9463877 ER PT J AU Martin, RC Laxson, RR Knauer, JB AF Martin, RC Laxson, RR Knauer, JB TI Proposed Californium-252 user facility for neutron science at Oak Ridge National Laboratory SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory has petitioned to establish a Californium-252 User Facility for Neutron Science for academic, industrial, and governmental researchers. The REDC Californium Facility (CF) stores the national inventory of sealed Cf-252 neutron sources for university and research loans. Within the CF, the Cf-252 storage pool and two uncontaminated hot cells currently in service for the Californium Program will form the physical basis for the User Facility. Relevant applications include dosimetry and experiments for neutron tumor therapy; fast and thermal neutron activation analysis of materials; experimental configurations for prompt gamma neutron activation analysis; neutron shielding and material damage studies; and hardness testing of radiation detectors, cameras, and electronics. A formal User Facility simplifies working arrangements and agreements between U.S. Department of Energy facilities, academia, and commercial interests. (C) 1997 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Martin, RC (reprint author), Oak Ridge Natl Lab, Div Chem Technol, POB 2008, Oak Ridge, TN 37831 USA. NR 5 TC 0 Z9 0 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT-DEC PY 1997 VL 48 IS 10-12 BP 1691 EP 1695 DI 10.1016/S0969-8043(97)00170-X PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT758 UT WOS:000071642100060 ER PT J AU Drake, LR Hensman, CE Lin, S Rayson, GD Jackson, PJ AF Drake, LR Hensman, CE Lin, S Rayson, GD Jackson, PJ TI Characterization of metal ion binding sites on Datura innoxia by using lanthanide ion probe spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE laser-induced luminescence; Eu(III) luminescence; spectral deconvolution; biomass material ID LUMINESCENCE EXCITATION SPECTROSCOPY; CARBON PASTE ELECTRODE; CHEMICAL MODIFICATION; EU(III) LUMINESCENCE; HUMATE INTERACTIONS; ENERGY-TRANSFER; ALGAE CELLS; PRECONCENTRATION; BIOSORPTION; EXCHANGE AB The excitation spectra associated with the F-7(0)-->D-5(0) transition of Eu+3 has been used to examine the binding sites on cell wall fragments of Datura innoxia. Both native and esterified cell wall fragments were each examined at pH 5 and pH 2 to determine the contributions to metal ion sorption from both the carboxylate and sulfonate functional groups, The excitation spectra have been deconvoluted into the individual groups responsible for metal ion uptake, At least four unique binding sites can be described as being responsible for metal ion uptake, The higher affinity sites involve carboxylates in the binding of Eu+3 in a tridentate (3:1 ligand-to-metal ratio) configuration. C1 NEW MEXICO STATE UNIV,DEPT CHEM & BIOCHEM,LAS CRUCES,NM 88003. LOS ALAMOS NATL LAB,DIV LIFE SCI,ENVIRONM MOL BIOL GRP,LS 7,LOS ALAMOS,NM 87545. NR 46 TC 13 Z9 13 U1 0 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD OCT PY 1997 VL 51 IS 10 BP 1476 EP 1483 DI 10.1366/0003702971939253 PG 8 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA YB386 UT WOS:A1997YB38600008 ER PT J AU Templeton, MR McNamara, BJ Guzik, JA Bradley, PA Cox, AN Middleditch, J AF Templeton, MR McNamara, BJ Guzik, JA Bradley, PA Cox, AN Middleditch, J TI A new pulsation spectrum and asteroseismology of delta Scuti SO ASTRONOMICAL JOURNAL LA English DT Article ID WHOLE-EARTH-TELESCOPE; STARS; VARIABLES AB We present the results of a five-year Stromgren y photometric campaign on delta Scuti. Our data set consists of 6515 discrete differential magnitudes, and spans the period of 1983 June to 1988 September. We found the primary pulsation mode at 59.731129+/-0.000002 mu Hz, in close agreement with the frequency determination of Fitch (1976, IAU Colloquium, 29, 167), but we find our best-fit observed frequencies for other pulsation modes differ by 0.5-2 cycles per year from Fitch's results. In the case of the second strongest pulsation mode, we found a frequency of 61.936104+/-0.000009 mu Hz-one cycle per year off of the commonly quoted frequency. All of the other modes not classified as harmonics or beating modes were identified in our data, as well as a new pulsation frequency at 96.21443+/-0.00005 mu HZ discovered in both Stromgren y and b observations. We measured the phase differences between our Stromgren y data and a short string of Stromgren b data taken during the 1987 multisite campaign, and find phase differences ranging from 0 to 0.33 radians, suggesting that there are modes of different spherical harmonic order present in delta Scuti. Finally, we evolved a set of M=1.8-2.4 M. models with solar abundances (X=0.7, Z=0.02) and two (M=2.2 and M=2.4 M.) models with solar abundances scaled to (X=0.66,Z =0.06), using recent opacity and reaction rate data, and applied Linear, nonadiabatic pulsation analysis to models in the shell hydrogen burning phase. The Z=0.02 model which best fit the observed spectral type of F2 III, the Hipparcos absolute magnitude of M-v=1.0, and the radius estimate of Cugier and Monier of R=4.1 R., and which has a pure radial mode at 59.731 mu Hz has a mass of 2.1 M., with T-eff=6894 K, R=4.14 R., and M-v=1.0. The best-fit Z=0.06 model has M=2.4 M., T-eff=6827 K, R=4.28 R., and M-v=1.0. For the best-fit models, the highest amplitude observed mode is the radial fundamental mode, with several nonradial modes being simultaneously excited, This contradicts the results of Balona et al. that the strongest mode of delta Scuti is first overtone. In addition, the second radial overtone falls at nu=97.4 mu Hz for both models, thus eliminating the two observed frequencies at 96.2 and 99.4 mu Hz as candidates for the second radial overtone, unless second-order rotation effects are considered. We are unable to perform a more comprehensive asteroseismological analysis because the theoretical nonradial modes overlap in frequency when rotational splitting is taken into account, thus making it impossible to uniquely determine the mode type without more observational identifications of the pulsation mode types. However, the mode spacing of the Z=0.06 model is less degenerate than the Z=0.02 model, so with more observational identifications, it may be possible to actually make definitive model fits. We discuss the implications of our results on delta Scuti star modeling in some detail. (C) 1997 American Astronomical Society. C1 LOS ALAMOS NATL LAB,LAS CRUCES,NM 88003. RP Templeton, MR (reprint author), NEW MEXICO STATE UNIV,DEPT ASTRON,LAS CRUCES,NM 88003, USA. NR 29 TC 21 Z9 21 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 1997 VL 114 IS 4 BP 1592 EP 1601 DI 10.1086/118590 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XX797 UT WOS:A1997XX79700029 ER PT J AU Rottgering, HJA vanOjik, R Miley, GK Chambers, KC vanBreugel, WJM deKoff, S AF Rottgering, HJA vanOjik, R Miley, GK Chambers, KC vanBreugel, WJM deKoff, S TI Spectroscopy of ultra-steep spectrum radio sources: a sample of z>2 radio galaxies SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies: active; galaxies: redshifts; galaxies: ISM; radio continuum: galaxies ID LINE EMITTING GAS; HIGH-REDSHIFT; ALPHA EMISSION; LUMINOSITY FUNCTION; SKY SURVEY; QUASARS; ABSORPTION; EVOLUTION; ALIGNMENT; DISCOVERY AB We present spectroscopic observations for 64 radio galaxies having ultra steep radio spectra. Twenty-nine objects have redshifts z > 2, the largest redshifts being almost 4. Our ultra steep spectrum (USS) criterion (alpha < -1) has proven to be the most efficient way of finding distant radio galaxies. We find that even among the USS sources, there is a strong statistical correlation between the spectral index and redshift. The most distant radio galaxies within the USS sample have the steepest radio spectra. In our sample there are 3 radio galaxies at z > 3 compared with 26 at 2 < z < 3. However, the present data do not allow us to decide whether there is a decrease in co-moving source density at the highest redshifts. We have analyzed the spectra of the 30 objects with the highest redshifts (z > 1.9). For these high redshift radio galaxies, Ly alpha is almost always the dominant emission line, with a rest frame equivalent width ranging from similar to 100 Angstrom to more than 1000 Angstrom. The equivalent widths of the most important emission lines (Ly alpha, C IV, He II, C III]) are found to correlate strongly with each other. The large rest frame equivalent widths and the correlation between the equivalent widths of the emission lines, confirm that photoionization by a central continuum source is most likely the dominant ionization mechanism. There are significant velocity differences between the various emission lines of our high redshift radio galaxies; in particular the Ly alpha line is shifted with respect to the higher ionization lines. Velocity shifts range from 100 to almost 1000 km s(-1) in some cases. Simulations show that the effects of associated H I absorption on the Ly alpha emission line may be responsible for most of these velocity shifts. However, other mechanisms such as organized kinematics of the Ly alpha emission line gas (e.g. inflow or outflow) and obscuration of the line emission from the far side of the radio galaxy may also play a role. C1 UNIV CAMBRIDGE, CAVENDISH LAB, MULLARD RADIO ASTRON OBSERV, CAMBRIDGE CB3 0HE, ENGLAND. UNIV CAMBRIDGE, INST ASTRON, CAMBRIDGE CB3 0HA, ENGLAND. UNIV HAWAII, INST ASTRON, HONOLULU, HI 96822 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. RP Rottgering, HJA (reprint author), LEIDEN OBSERV, POB 9513, NL-2300 RA LEIDEN, NETHERLANDS. NR 70 TC 78 Z9 78 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 OCT PY 1997 VL 326 IS 2 BP 505 EP 527 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YB994 UT WOS:A1997YB99400009 ER PT J AU Bedding, TR Minniti, D Courbin, F Sams, B AF Bedding, TR Minniti, D Courbin, F Sams, B TI Stellar populations from adaptive optics observations: four test cases SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques: miscellaneous galaxies: stellar content; galaxies: individual: NGC 5128, IC 5152, NGC 300; galaxy: stellar content ID COLOR-MAGNITUDE DIAGRAMS; LATE-TYPE STARS; GLOBULAR-CLUSTERS; CCD PHOTOMETRY; LOCAL GROUP; NGC-300; BULGE; GALAXIES; M31; PERFORMANCE AB We describe a first attempt to apply adaptive optics to the study of resolved stellar populations in galaxies. Advantages over traditional approaches are (i) improved spatial resolution and point-source sensitivity through adaptive optics, and (ii) use of the near-infrared region, where the peak of the spectral energy distribution for old populations is found. Disadvantages are the small area covered and the need for excellent seeing. We made observations with the ADONIS system at the European Southern Observatory of the peculiar elliptical galaxy NGC 5128; the irregular galaxy IC 5152 (a possible outer member of the Local Group); the Sc galaxy NGC 300 (a member of the Sculptor group); and the Sgr window in the bulge of the Milky Way. These different fields give excellent test cases for the potential of adaptive optics. In the first two cases, we failed to obtain photometry of individual stars, which would have required excellent seeing. For NGC 300 we measured magnitudes for nine individual supergiants (H = 18.3-20.2), but did not go deep enough to detect the tip of the RGB of an old population. For the Sgr field we produced a infrared luminosity function and colour-magnitude diagram for 70 stars down to K similar or equal to 19.5. These are the deepest yet measured for the Galactic bulge, reaching beyond the turn-off. C1 EUROPEAN SO OBSERV, D-85748 GARCHING, GERMANY. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. UNIV LIEGE, INST ASTROPHYS, B-4000 LIEGE, BELGIUM. MAX PLANCK INST ASTROPHYS, D-85748 GARCHING, GERMANY. RP Bedding, TR (reprint author), UNIV SYDNEY, SCH PHYS, CHATTERTON ASTROPHYS DEPT, SYDNEY, NSW 2006, AUSTRALIA. NR 33 TC 5 Z9 5 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 1997 VL 326 IS 3 BP 936 EP 940 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YC421 UT WOS:A1997YC42100015 ER PT J AU Walsh, JR Dudziak, G Minniti, D Zijlstra, AA AF Walsh, JR Dudziak, G Minniti, D Zijlstra, AA TI Chemical abundances of planetary nebulae in the Sagittarius dwarf elliptical galaxy SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, abundances; galaxies, individual (Sagittarius, Fornax); planetary nebulae, individual (He 2-436, Wray 16-423) ID INTERMEDIATE-MASS STARS; ASYMPTOTIC GIANT BRANCH; STELLAR EVOLUTION; MAGELLANIC CLOUDS; EMISSION; NUCLEI; DISTRIBUTIONS AB Spectrophotometry and imaging of the two planetary nebulae He 2-436 and Wray 16-423, recently discovered to be in the Sagittarius dwarf elliptical galaxy, are presented. Wray 16-423 is a high-excitation planetary nebula (PN) with a hot central star. In contrast, He 2-436 is a high-density nebula with a cooler central star and evidence of local dust, the extinction of which exceeds that for Wray 16-423 by EB-V = 0.28. The extinction to Wray 16-423 (EB-V = 0.14) is consistent with the line-of-sight extinction to the Sagittarius Dwarf. Both PNs show Wolf-Rayet features in their spectra, although the lines are weak in Wray 16-423. Images in [O III] and H alpha + [N II], although affected by poor seeing, yield a diameter of 1.'' 2 for Wray 16-423 after deconvolution, while He 2-436 was unresolved. He 2-436 has a luminosity about twice that of Wray 16-423, and its size and high density suggest a younger nebula. In order to reconcile the differing luminosity and nebular properties of the two nebulae with similar-age progenitor stars, it is suggested that they are on He-burning tracks An abundance analysis is presented for both PNs using empirical abundance determinations. The abundance pattern is very similar in both nebulae, and both show an oxygen depletion of -0.4 dex with respect to the mean oxygen abundance of Galactic planetary nebulae and [O/H] = -0.6. The Sagittarius PN progenitor stars are representative of the higher metallicity tail of the Sagittarius population. The pattern of abundance depletion is similar to that in the only other planetary nebula in a dwarf galaxy companion of the Milky Way, that in Fornax, for which new spectra are presented. However, the abundances are larger than for Galactic halo PNs, suggesting a later formation age. The oxygen abundance of the Sagittarius galaxy deduced from its PN shows similarities with that of dwarf ellipticals around M31, advancing the notion that this galaxy was a dwarf elliptical before its interaction with the Milky Way. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Walsh, JR (reprint author), EUROPEAN SO OBSERV,SPACE TELESCOPE EUROPEAN COORDINATING FACIL,KARL SCHWARZSCHILD STR 2,D-85748 GARCHING,GERMANY. NR 60 TC 29 Z9 29 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 OCT 1 PY 1997 VL 487 IS 2 BP 651 EP 662 DI 10.1086/304653 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YA040 UT WOS:A1997YA04000017 ER PT J AU Copi, CJ AF Copi, CJ TI A stochastic approach to chemical evolution SO ASTROPHYSICAL JOURNAL LA English DT Review DE Galaxy, abundances; Galaxy, evolution; Galaxy, stellar content; nuclear reactions, nucleosynthesis, abundances ID BIG-BANG NUCLEOSYNTHESIS; RED GIANT STARS; GALACTIC EVOLUTION; HALO-STARS; DEUTERIUM ABUNDANCE; NITROGEN ABUNDANCES; SOLAR NEIGHBORHOOD; LITHIUM ABUNDANCES; OXYGEN ABUNDANCES; BARYON DENSITY AB Observations of elemental abundances in the Galaxy have repeatedly shown an intrinsic scatter as a function of time and metallicity. The standard approach to chemical evolution does not attempt to address this scatter in abundances since only the mean evolution is followed. In this work, the scatter is addressed via a stochastic approach to solving chemical evolution models. Three simple chemical evolution scenarios are studied using this stochastic approach: a closed box model, an infall model, and an outflow model. These models are solved for the solar neighborhood in a Monte Carlo fashion. The evolutionary history of one particular region is determined randomly based on the star formation rate and the initial mass function. Following the evolution in an ensemble of such regions leads to the predicted spread in abundances expected, based solely on different evolutionary histories of otherwise identical regions. In this work, 13 isotopes are followed, including the light elements, the CNO elements, a few alpha-elements, and iron. It is found that the predicted spread in abundances for a 10(5) M. region is in good agreement with observations for the alpha-elements. For CN, the agreement is not as good, perhaps indicating the need for more physics input for low-mass stellar evolution. Similarly for the light elements, the predicted scatter is quite small, which is in contradiction to the observations of He-3 in H II regions. The models are tuned for the solar neighborhood so that good agreement with H II regions is not expected. This has important implications for low-mass stellar evolution and on using chemical evolution to determine the primordial light-element abundances in order to test big bang nucleosynthesis. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Copi, CJ (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 112 TC 26 Z9 26 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 OCT 1 PY 1997 VL 487 IS 2 BP 704 EP 718 DI 10.1086/304627 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YA040 UT WOS:A1997YA04000022 ER PT J AU Brotherton, MS Tran, HD VanBreugel, W Dey, A Antonucci, R AF Brotherton, MS Tran, HD VanBreugel, W Dey, A Antonucci, R TI Spectropolarimetry of first broad absorption line quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE polarization; quasars, absorption lines; quasars, emission lines; quasars, general; quasars, individual (FIRST J084044.5+363328, FIRST J155633.8+351758) ID ACTIVE GALACTIC NUCLEI; FE-II; ULTRAVIOLET-SPECTRUM; POLARIZATION; EMISSION; HAWAII-167; MODELS; QSOS AB We present Keck spectropolarimetry of two rare low-ionization broad absorption line (BAL) quasars (QSOs), FIRST J084044.5+363328 and FIRST J155633.8+351758, that also exhibit narrow absorption lines from metastable excited levels of Fe II (''iron Lo-BALs''). These QSOs were discovered in optical follow-ups to a deep radio survey; FIRST J155633.8+351758 is radio-loud, the first BAL QSO so identified. FIRST J084044.5+363328 is highly polarized and exhibits many features found in other BAL QSOs. The continuum is approximate to 4% polarized near the 2000 Angstrom rest frame, falling to approximate to 2% at longer wavelengths, at a position angle of approximate to 50 degrees. The emission lines are unpolarized. The polarization rises to approximate to 8% in the low-ionization troughs of Mg II lambda 2800 and Al III lambda 1860. The polarization and its position angle vary in a complicated manner across the metastable Fe II absorption lines, which suggests that more than one mechanism is at work or that the system geometry is complex. FIRST J155633.8+351758 may be the most highly polarized BAL QSO known, and it exhibits other unusual polarization properties compared with those of other highly polarized BAL QSOs. The continuum is approximate to 13% polarized near the 2000 Angstrom rest frame, falling to approximate to 7% at longer wavelengths, at a position angle of 153 degrees. The emission lines are polarized like the continuum, but in the absorption troughs the polarization drops to zero. Currently available data cannot yet discriminate among the possible lines of sight to BAL QSOs (edge-on, pole-on, or random). C1 ASSOC UNIV RES ASTRON INC, NATL OPT ASTRON OBSERV, KITT PEAK NATL OBSERV, TUCSON, AZ 85726 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. RP Brotherton, MS (reprint author), LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, 7000 EAST AVE, POB 808, L413, LIVERMORE, CA 94550 USA. OI tran, hien/0000-0001-7548-6664 NR 32 TC 49 Z9 49 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 1997 VL 487 IS 2 BP L113 EP L116 DI 10.1086/310898 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YA042 UT WOS:A1997YA04200003 ER PT J AU Grainger, DJ Reckless, J Metcalfe, JC Rubin, EM Lawn, R AF Grainger, DJ Reckless, J Metcalfe, JC Rubin, EM Lawn, R TI Lp(a) and endothelium: A feedback loop in atherosclerosis SO ATHEROSCLEROSIS LA English DT Meeting Abstract C1 UNIV CAMBRIDGE,DEPT MED,CAMBRIDGE CB2 2QQ,ENGLAND. UNIV CAMBRIDGE,DEPT BIOCHEM,CAMBRIDGE CB2 2QQ,ENGLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD UNIV,DEPT CARDIOVASC MED,STANFORD,CA 94305. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0021-9150 J9 ATHEROSCLEROSIS JI Atherosclerosis PD OCT PY 1997 VL 134 IS 1-2 SI SI BP 15 EP 15 DI 10.1016/S0021-9150(97)88175-0 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA XY106 UT WOS:A1997XY10600052 ER PT J AU Chiesa, G Parolini, C Canavesi, M Colombo, N Rubin, EM Franceschini, G Bernini, F AF Chiesa, G Parolini, C Canavesi, M Colombo, N Rubin, EM Franceschini, G Bernini, F TI Role of human apolipoproteins in cell cholesterol efflux: Studies with transgenic mice SO ATHEROSCLEROSIS LA English DT Meeting Abstract C1 UNIV MILAN,INST PHARMACOL SCI,MILAN,ITALY. UNIV MILAN,E GROSSI PAOLETTI CTR,MILAN,ITALY. UNIV PARMA,INST PHARMACOL & PHARMACOGNOSY,I-43100 PARMA,ITALY. UNIV CALIF BERKELEY,DIV LIFE SCI,LAWRENCE BERKELEY LAB,BERKELEY,CA. RI Parolini, Cinzia/G-8984-2012; Chiesa, Giulia/G-8987-2012; Bernini, Franco/B-6740-2011 OI Parolini, Cinzia/0000-0002-5699-0918; Chiesa, Giulia/0000-0001-5553-1210; NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0021-9150 J9 ATHEROSCLEROSIS JI Atherosclerosis PD OCT PY 1997 VL 134 IS 1-2 SI SI BP 33 EP 33 DI 10.1016/S0021-9150(97)88260-3 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA XY106 UT WOS:A1997XY10600135 ER PT J AU Bielicki, JK McCall, MR Knoff, L Ravanadi, A Kuksis, A Forte, TM AF Bielicki, JK McCall, MR Knoff, L Ravanadi, A Kuksis, A Forte, TM TI Conversion of nascent pre-alpha high density lipoproteins (HDL) to alpha migrating HDL SO ATHEROSCLEROSIS LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0021-9150 J9 ATHEROSCLEROSIS JI Atherosclerosis PD OCT PY 1997 VL 134 IS 1-2 SI SI BP 364 EP 364 DI 10.1016/S0021-9150(97)89851-6 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA XY106 UT WOS:A1997XY10601681 ER PT J AU Nolte, J Wagner, HG Temps, F Sears, TJ AF Nolte, J Wagner, HG Temps, F Sears, TJ TI Far infrared laser magnetic resonance detection of CF3, CHF2, and CH2F SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article DE chemical kinetics; molecular structure; radicals; spectroscopy, infrared ID MICROWAVE-SPECTRUM; DIODE-LASER; BAND; SPECTROSCOPY; TRANSITIONS; ARGON; LINE; HCO AB Far infrared laser magnetic resonance (FIR-LMR) spectra of CF3, CHF2, and CH2F radicals were observed in the 300-800 mu m wavelength region in the reactions of F atoms with a series of different hydrocarbon and partially fluorinated hydrocarbon molecules. To identify the carriers of the observed resonance patterns and to exclude or identify contamination of the spectra by additional resonances from other paramagnetic species, numerous chemical tests were developed and performed. With optimized sources and the chemical tests in hand, many spectra could be unambiguously attributed to CF3, CHF2, and CH2F, respectively. The present study reports the first gas phase detection of CHF2 radicals in their ground electronic state. C1 CHRISTIAN ALBRECHTS UNIV KIEL,INST PHYS CHEM,D-24098 KIEL,GERMANY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Nolte, J (reprint author), MAX PLANCK INST STROMUNGSFORSCH,BUNSENSTR 10,D-37073 GOTTINGEN,GERMANY. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 32 TC 3 Z9 3 U1 0 U2 2 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD OCT PY 1997 VL 101 IS 10 BP 1421 EP 1428 PG 8 WC Chemistry, Physical SC Chemistry GA YD490 UT WOS:A1997YD49000002 ER PT J AU Cherbonnel-Lasserre, C Dosanjh, MK AF Cherbonnel-Lasserre, C Dosanjh, MK TI Suppression of apoptosis by overexpression of Bcl-2 or Bcl-x(L) promotes survival and mutagenesis after oxidative damage SO BIOCHIMIE LA English DT Article DE Bcl-2; Bcl-x(L); apoptosis; oxidative damage; mutagenesis; H2O2 ID PROGRAMMED CELL-DEATH; DIPLOID HUMAN-LYMPHOBLASTS; TRANSGENIC MICE; LYMPHOID-CELLS; B-CELLS; PROTEIN; GENE; P53; MUTATION; ASSAY AB Apoptosis is the physiological process by which unwanted cells in an organism are killed. Bcl-2, a membrane-bound cytoplasmic protein, and its close relative Bcl-X-L, are both effective inhibitors of apoptosis induced by a wide variety of stimuli in many different cell types. In a previous study, we reported that suppression of apoptosis by BCl-2 or Bcl-X-L, markedly elevates the levels of radiation-induced mutations at the specific locus thymidine kinase. We investigated the effect of the Bcl-2 or Bcl-X-L overproduction on hydrogen peroxide-induced mutagenesis. Oxidative DNA damage has been implicated in biological processes such as mutagenesis, carcinogenesis and aging. Overexpression of either Bcl-2 or Bcl-X-L enhances oxidative stress mutagenesis in cells with wild type p53 as well as with mutated p53 protein. These results support the hypothesis that apoptosis plays a crucial role in maintaining genomic integrity by selectively eliminating highly mutated cells from the population. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Dosanjh, MK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, M5934-54A,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Cherbonnel, Corinne/0000-0002-3419-1357 NR 35 TC 40 Z9 42 U1 0 U2 0 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 0300-9084 J9 BIOCHIMIE JI Biochimie PD OCT PY 1997 VL 79 IS 9-10 BP 613 EP 617 DI 10.1016/S0300-9084(97)82011-1 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZD116 UT WOS:000072653000012 PM 9466700 ER PT J AU Conry, MJ AF Conry, MJ TI The influence of different nitrogenous fertilisers and foliar-applied sulphur on the yield, grain nitrogen and screenings of spring malting barley SO BIOLOGY AND ENVIRONMENT-PROCEEDINGS OF THE ROYAL IRISH ACADEMY LA English DT Article ID WINTER BARLEY; IRELAND; SULFUR; QUALITY; CEREALS; SOILS; RATES AB Nine experiments were conducted on three different soil types in the south-east of Ireland over a three-year period to examine the effect of six commercially-available nitrogenous fertilisers (some containing sulphur) and foliar-applied sulphur on the grain yield and quality, ex-farm, of spring-sown Blenheim malting barley. Five of the N fertilisers (calcium ammonium nitrate, Super Net, Chilian nitrate of soda, ammonium sulphate nitrate and 18.6.12 NPK compound) applied at the same rate of N (100kg/ha) gave similar yields and grain N levels. Urea, even when worked into the soil at sowing time, gave significant yield reductions in six of the experiments when compared with the other five N sources. The urea-treated plots gave significantly lower grain N levels in only one of the experiments. The type of N fertiliser had little or no effect on the amount of grain screenings. The sulphur-containing nitrogenous fertilisers, Super Net and ammonium sulphate nitrate, gave significantly greater yields than the non-sulphur-containing calcium ammonium sulphate (CAN) in two of die three experiments on the light-textured sandy soil only, but had no effect on grain N or grain size. Foliar-applied sulphur had little effect on grain yield or quality. C1 Oak Pk Res Ctr, Carlow, Ireland. RP Conry, MJ (reprint author), Oak Pk Res Ctr, Carlow, Ireland. NR 19 TC 2 Z9 2 U1 1 U2 3 PU ROYAL IRISH ACADEMY PI DUBLIN PA 19 DAWSON STREET, DUBLIN 2, IRELAND SN 0791-7945 J9 BIOL ENVIRON JI Biol. Environ.-Proc. R. Irish Acad. PD OCT PY 1997 VL 97B IS 2 BP 133 EP 138 PG 6 WC Biology; Environmental Sciences SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology GA ZE495 UT WOS:000072798600003 ER PT J AU Jones, LN Simon, M Watts, NR Booy, FP Steven, AC Parry, DAD AF Jones, LN Simon, M Watts, NR Booy, FP Steven, AC Parry, DAD TI Intermediate filament structure: hard alpha-keratin SO BIOPHYSICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 12th International Biophysics Congress CY AUG 12-16, 1996 CL AMSTERDAM, NETHERLANDS DE intermediate filament; wool; alpha-keratin; disulfide bonds; mass measurements; X-ray diffraction ID TRANSMISSION ELECTRON-MICROSCOPY; EPIDERMAL KERATIN; ASSEMBLED INVITRO; MASS ANALYSIS; COILED-COILS; MOLECULES; VIMENTIN; STEM; MICROFIBRIL; MECHANISM AB Structurally there are four classes of intermediate filaments (IF) with distinct but closely related axial organisations. One of these, hard alpha-keratin IF, has been studied to clarify several apparently exceptional features which include the number of molecules in the IF cross-section and the mode by which the axial organisation of its constituent molecules is stabilised. Using the dark-field mode of the STEM at the Brookhaven National Laboratory (USA) mass measurements were obtained from unstained IF isolated from hair keratin. The data thus obtained show that the number of chains in cross-section is about 30 (+/-3: standard deviation) and is very similar to the numbers determined in previous STEM experiments for the dominant filament type in other classes of IF (about 32). Furthermore, re-analysis of the low-angle equatorial X-ray diffraction pattern reveals, in contrast to earlier work, solutions that are compatible with the number of chains in cross-section indicated by the STEM data. The absence of the head-to-tail overlap between parallel molecules characteristic of most IF may be compensated in hard alpha-keratin by a network of intermolecular disulfide bonds. It is concluded that native IF of hard alpha-keratin and desmin/vimentin - and probably many other kinds of IF as well - contain about 32 chains in cross-section, and that the axial structures of these various kinds of IF differ in small but significant ways, while generally observing the same basic modes of aggregation. (C) 1997 Elsevier Science B.V. C1 CSIRO, Div Wool Technol, Belmont, Vic 3216, Australia. Brookhaven Natl Lab, Upton, NY 11973 USA. NIAMSD, Struct Biol Res Lab, NIH, Bethesda, MD 20892 USA. Massey Univ, Dept Phys, Palmerston North, New Zealand. RP Jones, LN (reprint author), CSIRO, Div Wool Technol, POB 21, Belmont, Vic 3216, Australia. NR 39 TC 36 Z9 36 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD OCT PY 1997 VL 68 IS 1-3 BP 83 EP 93 DI 10.1016/S0301-4622(97)00013-6 PG 11 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA YU299 UT WOS:000071702700009 PM 9468612 ER PT J AU Savikhin, S Buck, DR Struve, WS AF Savikhin, S Buck, DR Struve, WS TI Pump-probe anisotropies of Fenna-Matthews-Olson protein trimers from Chlorobium tepidum: A diagnostic for exciton localization? SO BIOPHYSICAL JOURNAL LA English DT Article ID BACTERIOCHLOROPHYLL-A-PROTEIN; GREEN PHOTOSYNTHETIC BACTERIA; AMINO-ACID SEQUENCE; PROSTHECOCHLORIS-AESTUARII; ENERGY-TRANSFER; ANTENNA COMPLEX; OPTICAL-SPECTRA; STATE STRUCTURE; FMO TRIMERS; ABSORPTION AB Exciton calculations on symmetric and asymmetric Fenna-Matthews-Olson (FMO) trimers, combined with absorption difference anisotropy measurements on FMO trimers from the green bacterium Chlorobium tepidum, suggest that real samples exhibit sufficient diagonal energy disorder so that their laser-excited exciton states are noticeably localized. Our observed anisotropies are clearly inconsistent with 21-pigment exciton simulations based on a threefold-symmetric FMO protein. They are more consistent with a 7-pigment model that assumes that the laser-prepared slates are localized within a subunit of the trimer. Differential diagonal energy shifts of 50 cm(-1) between symmetry-related pigments in different subunits are large enough to cause sharp localization in the stationary states; these shifts are commensurate with the similar to 95 cm(-1) inhomogeneous linewidth of the lowest exciton levels. Experimental anisotropies (and by implication steady-state linear and circular dichroism) likely arise from statistical averaging over states with widely contrasting values of these observables, in consequence of their sensitivity to diagonal energy disorder. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. US DOE,AMES LAB,AMES,IA 50011. NR 27 TC 14 Z9 14 U1 0 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 1997 VL 73 IS 4 BP 2090 EP 2096 PG 7 WC Biophysics SC Biophysics GA XY955 UT WOS:A1997XY95500038 PM 9336204 ER PT J AU HeadGordon, T Sorenson, JM Pertsemlidis, A Glaeser, RM AF HeadGordon, T Sorenson, JM Pertsemlidis, A Glaeser, RM TI Differences in hydration structure near hydrophobic and hydrophilic amino acids SO BIOPHYSICAL JOURNAL LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; SUPERCOOLED LIQUID WATER; SOLVENT STRUCTURE; CLATHRATE-LIKE; MODEL; STATE AB We use molecular dynamics to simulate recent neutron scattering experiments on aqueous solutions of N-acetyl-leucine-amide and N-acelyl-glutamine-amide, and break down the total scattering function into contributions from solute-solute, solute-water, water-water, and intramolecular correlations. We show that the shift of the main diffraction peak to smaller angle that is observed for leucine, but not for glutamine, is attributable primarily to alterations in water-water correlations relative to bulk. The perturbation of the water hydrogen-bonded network extends roughly two solvation layers from the hydrophobic side chain surface, and is characterized by a distribution of hydrogen bonded ring sizes that are more planar and are dominated by pentagons in particular than those near the hydrophilic side chain. The different structural organization of water near the hydrophobic solute that gives rise to the inward shift in the main neutron diffraction peak under ambient conditions may also provide insight into the same directional shift for pure liquid water as it is cooled and supercooled. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MOL & CELLULAR BIOL,BERKELEY,CA 94720. RP HeadGordon, T (reprint author), LAWRENCE BERKELEY LAB,DIV LIFE SCI,314 DONNER,BERKELEY,CA 94720, USA. RI Head-Gordon, Teresa/E-5818-2011; OI Pertsemlidis, Alexander/0000-0003-1624-9372 NR 37 TC 32 Z9 32 U1 1 U2 11 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 1997 VL 73 IS 4 BP 2106 EP 2115 PG 10 WC Biophysics SC Biophysics GA XY955 UT WOS:A1997XY95500040 PM 9336206 ER PT J AU Lazrak, A Griffin, GD Gailey, PC AF Lazrak, A Griffin, GD Gailey, PC TI Studying electric field effects on embryonic myocytes SO BIOTECHNIQUES LA English DT Article ID DYNAMICS AB Several problems arise when electrophysiological measurements are attempted on cells exposed to an electric field. In addition to field distortion produced by the reference electrode, membrane potential measurements by conventional microelectrode or patch-clamp techniques suffer serious interference from the applied field. We describe here a novel method for measurement of cardiac myocyte response to an alternating electric field that avoids these problems by sensing the mechanical activity of the cells rather than their electrical activity. A miniature electromechanical force transducer is used for this purpose. A glass pipet is attached to the force transducer, and only this pipet makes actual contact with the cell preparation. The resistive elements of the transducer are arranged as two legs of a Wheatstone bridge. Contractile activity of the cells produces small displacements of the cells produces small displacements of the micropipet and a resulting change in the transducer resistances. The Wheatstone bridge output is a current signal by a picoammeter before amplification and recording for later analysis. The technique may find applications in a variety of experimental studies of contractile tissues. C1 OAK RIDGE NATL LAB, DIV ENERGY, OAK RIDGE, TN 37831 USA. NR 15 TC 2 Z9 2 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD OCT PY 1997 VL 23 IS 4 BP 736 EP 741 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YA070 UT WOS:A1997YA07000042 PM 9343701 ER PT J AU Barton, JW Reed, EK Davison, BH AF Barton, JW Reed, EK Davison, BH TI Gas-phase enzyme catalysis using immobilized lipase for ester production SO BIOTECHNOLOGY TECHNIQUES LA English DT Article ID ETHANOL; VAPOR AB Bench-scale reactors were operated in continuous recycle and single-pass modes using immobilized porcine lipase to catalyze gas-phase esterification of ethyl alcohol with two carboxylic acids (acetic acid and propionic acid). Approximately one order of magnitude increases (over uncatalyzed reactions) in conversion were achieved; production concentrations ranged from 0.1 to 0.5 mM in air, and were affected strongly by substrate concentration and acid-induced enzyme inactivation. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 12 TC 9 Z9 10 U1 0 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0951-208X J9 BIOTECHNOL TECH JI Biotechnol. Tech. PD OCT PY 1997 VL 11 IS 10 BP 747 EP 750 DI 10.1023/A:1018448502602 PG 4 WC Biochemical Research Methods; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA YB244 UT WOS:A1997YB24400011 ER PT J AU Priestley, KF Patton, HJ AF Priestley, KF Patton, HJ TI Calibration of m(b)(P-n), m(b)(L-g) scales and transportability of the M-0:m(b) discriminant to new tectonic regions SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID UNDERGROUND NUCLEAR-EXPLOSIONS; WESTERN UNITED-STATES; FREQUENCY-DEPENDENT ATTENUATION; JOINT VERIFICATION EXPERIMENT; MOMENT TENSOR INVERSION; SPECTRAL CHARACTERISTICS; MAGNITUDE RELATIONS; WAVE ATTENUATION; YIELD ESTIMATION; EAST KAZAKHSTAN AB We have developed M-0:m(b) relationships for earthquakes and explosions in central Asia using regional waveform data from the Chinese broadband, digital station, WMQ, Regional magnitude scales, m(b)(P-n) and m(b)(L-g), were established by (1) determining the attenuation rates of P-n and L-g waves, (2) calibrating the m(b)(P-n) against the teleseismic m(b), and (3) applying Nuttli's method to determine m(b) from the L-g waves. Seismic moments for earthquakes and explosions were obtained by applying the Bolt and Herraiz (1983) method calibrated using CMT moments for earthquakes and regional moment estimates of the Soviet Joint Verification Experiment (JVE) explosion. The results show that M-0:m(b)(P-n) relationships for central Asian earthquakes and explosions are in excellent agreement with the relationships for the western United States. This demonstrates that the M-0:m(b) discriminant is transportable to other regions and supports theoretical claims (Patton and Waiter, 1993) that M-0:m(b) are directly comparable for explosions detonated in different emplacement media. Successful application depends upon correcting the m(b)(P-n) for the magnitude bias known to exist between the Shagan River test site and the Nevada Test Site (NTS). In general, region-specific m(b) bias must be accounted for whenever regional magnitude scales are calibrated against teleseismic m(b), as pointed out by Douglas and Marshall (1996), Transporting M-0:m(b)(L-g) can be problematic because attenuation rates based on coda waves or L-g waves from earthquakes may not necessarily apply to L-g waves from explosions, and vice versa. This is demonstrated for the western United States where the coda Q measured from explosion data is much lower than the coda Q from earthquake data. We show that m(b)(L-g) for earthquakes located dose to NTS is greatly overestimated using the Q values determined from the coda of NTS explosions. This is apparently not a problem for L-g calibration in central Asia, perhaps because of differences in velocity and/or Q structures for the two regions. Other important considerations are the character of L-g propagation on short paths (<400 km) for NTS explosions versus long paths (1000 km) for East Kazakh explosions and the properties of coda-wave spreading as a function of distance and velocity structures for different tectonic regions. C1 LAWRENCE LIVERMORE NATL LAB,ENVIRONM PROGRAMS DIRECTORATE,LIVERMORE,CA 94551. RP Priestley, KF (reprint author), UNIV CAMBRIDGE,DEPT EARTH SCI,BULLARD LABS,CAMBRIDGE C83 DEZ,ENGLAND. NR 51 TC 23 Z9 23 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD OCT PY 1997 VL 87 IS 5 BP 1083 EP 1099 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YC392 UT WOS:A1997YC39200001 ER PT J AU Miller, RM Hetrick, BAD Wilson, GWT AF Miller, RM Hetrick, BAD Wilson, GWT TI Mycorrhizal fungi affect root stele tissue in grasses SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE LA English DT Article DE stele; root anatomy; mycorrhizal dependency; functional growth strategy; mycorrhiza; C3 and C4 grasses ID ALLIUM-PORRUM L; ARBUSCULAR MYCORRHIZAS; CASPARIAN BANDS; WARM-SEASON; DEPENDENCE; INFECTION; GROWTH; ARCHITECTURE; PHOSPHORUS; PHENOLOGY AB Although arbuscular mycorrhizal symbiosis was initially believed to have little or no impact on root morphology, we now recognize that subtle changes do occur and that these changes may be of considerable consequence to host growth and nutrition, as well as functional growth strategy. In examining the stele and root diameters of C3 and C4 grasses, C4 grasses were demonstrated to have a significantly larger proportion of their fibrous roots occupied by stele tissue than do C3 grasses. In fact, functional growth strategy (C3 versus C4) was observed to be a relatively good predictor of stele area. Mycorrhizal fungi also influenced the amount of stele tissue, but the effect was not the same for both C3 and C4 grasses. The stele area of all C4 grasses except for Sorghastrum nutans was greater in the presence of mycorrhizal colonization. Among the C3 grasses, only Bromus inermis showed a significant increase, although Elymus cinereus and Lolium perenne displayed significant decreases in response to arbuscular mycorrhizal colonization. Changes in the stele area of the plant species were closely related to their responsiveness to mycorrhizal symbiosis and might in part explain both beneficial and detrimental responses of plants to mycorrhizae. An increase in stele circumference induced by mycorrhizae would allow for greater uptake and passage of water and nutrients to the vascular cylinder, and growth depressions could be a direct outcome of reduced stele circumference. Thus, differences in stele circumference represent a possible mechanism for mycorrhizal impacts on host plants. These findings indicate that structural differences among grasses are related to different functional capabilities and further emphasize the need for better integration of comparative anatomy and morphology procedures in the study of mycorrhizal symbiosis. C1 UNIV NO IOWA,DEPT BIOL,CEDAR FALLS,IA 50614. KANSAS STATE UNIV,DEPT PLANT PATHOL,MANHATTAN,KS 66506. RP Miller, RM (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Wilson, Gail/G-4255-2012 NR 29 TC 20 Z9 20 U1 4 U2 19 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4026 J9 CAN J BOT JI Can. J. Bot.-Rev. Can. Bot. PD OCT PY 1997 VL 75 IS 10 BP 1778 EP 1784 PG 7 WC Plant Sciences SC Plant Sciences GA YJ561 UT WOS:A1997YJ56100019 ER PT J AU PereaReeves, SJ Stockman, HW AF PereaReeves, SJ Stockman, HW TI A lattice-gas study of dispersion in alveolated channels SO CHEMICAL ENGINEERING SCIENCE LA English DT Article ID AXIAL-DISPERSION; SOLUTE TRANSPORT; AUTOMATA; SIMULATION; DIFFUSION; EQUATION; FLOW AB Axial dispersion in alveolated channels was studied via lattice-gas automata(LGA), for both slug and step-change inlet conditions. There was good agreement between the effective diffusion coefficient (D*) calculated by the LGA method, and the D* predicted by the 'stagnant pocket' formalism developed by Aris, Turner, and Tsuda et al. The enhancement of D* was dependent on the ratio of alveolar volume to central channel volume and the Peclet number. For Pe greater than or equal to 5, D* was substantially greater than the Taylor-Aris prediction for flow between parallel flat plates. For Pe < 3, D* was less than the molecular diffusion coefficient, D-m. In the absence of buoyancy, inlet conditions (pulse vs step-change) had little effect on the calculated D* (less than or equal to 3%). The effect of buoyancy, however, depends on the inlet condition; for an LGA corresponding to 1 mol% SF6 tracer gas in air, D* was increased up to 20% for the step-change, and decreased up to 6% for the slug. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,DEPT 6118,ALBUQUERQUE,NM 87185. UNIV NEW MEXICO,DEPT CIVIL ENGN,ALBUQUERQUE,NM 87131. NR 28 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD OCT PY 1997 VL 52 IS 19 BP 3277 EP 3286 DI 10.1016/S0009-2509(97)00155-3 PG 10 WC Engineering, Chemical SC Engineering GA XY589 UT WOS:A1997XY58900006 ER PT J AU Wham, RM Basaran, OA Byers, CH AF Wham, RM Basaran, OA Byers, CH TI Wall effects on flow past fluid spheres at finite Reynolds number: wake structure and drag correlations SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE flow past drops; fluidized drops; falling drops; vorticity transport; separation; wake structure; finite elements ID BUOYANCY-DRIVEN MOTION; QUIESCENT LIQUID; BUBBLE AB Following the pioneering works of Leal and coworkers, a detailed report is made on the dynamics of recirculating wakes that form at finite Reynolds number Re due to vorticity accumulation at the rear of a fluid sphere that is either suspended in a tube by an upflowing fluid (the fluidized drop problem) or falling in a tube (the falling drop problem). The axisymmetric, steady flow of a Newtonian fluid past the fluid sphere is determined by finite element analysis using a consistent penalty formulation. By way of example, the flow past a fluid sphere that is falling in a tube for which the ratio of the tube radius to the drop radius 1/lambda = 5 undergoes remarkable transitions when the ratio of the viscosity of the drop to that of the ambient fluid, kappa, varies over a narrow range. When kappa less than or equal to 2.75, no wake forms behind the sphere as Re increases. When 3 less than or equal to kappa < 10, an eddy that is detached from the drop forms at a critical value of Re = Re-c((1)), grows, and eventually disappears as Re rises above a certain amount Re-c((2)). Remarkably, when kappa = 3, these critical Reynolds numbers are as low as Re-c((1)) = 51 +/- 1 and Re-c((2)) = 77 +/- 1. When kappa greater than or equal to 10, it is shown by using as many as 46,000 velocity degrees of freedom that the detached eddy attaches to the drop when Re exceeds a critical value, Re greater than or equal to Re-c*, which was heretofore unknown. Whereas only a single, large - primary - eddy is present inside the drop when Re < Re-c*, a second but much smaller - secondary - eddy also forms inside the drop upon attachment. Two new correlations are developed that account for the effects of a tube wall and finite fluid inertia on drag for fluidized and falling droplets. Moreover, in contrast to related correlations of others for fluid spheres that are placed in an infinite expanse of ambient fluid, the new correlations are valid over the entire range of Reynolds numbers considered. (C) 1997 Elsevier Science Ltd. RP Wham, RM (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. NR 24 TC 10 Z9 10 U1 0 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 OCT PY 1997 VL 52 IS 19 BP 3345 EP 3367 DI 10.1016/S0009-2509(97)00145-0 PG 23 WC Engineering, Chemical SC Engineering GA XY589 UT WOS:A1997XY58900013 ER PT J AU Grad, R Shapiro, R Hingerty, BE Broyde, S AF Grad, R Shapiro, R Hingerty, BE Broyde, S TI A molecular mechanics and dynamics study of the minor adduct between DNA and the carcinogen 2-(Acetylamino)fluorene (dG-N-2-AAF) SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID NUCLEIC-ACIDS; DOUBLE HELIX; FORCE-FIELD; RAT-LIVER; MODIFIED DEOXYGUANOSINE; SOLUTION CONFORMATION; CRYSTAL-STRUCTURE; AROMATIC-AMINES; BASE-PAIR; DUPLEX AB Experimental studies involving the carcinogenic aromatic amine 2-(acetylamino)fluorene (AAF) have afforded two acetylated DNA adducts, the major one bound to C8 of guanine and a minor adduct bound to N-2 Of guanine. The minor adduct may be important in carcinogenesis because it persists, while the major adduct is rapidly repaired. Primer extension studies of the minor adduct have indicated that it blocks DNA synthesis, with some bypass and misincorporation of adenine opposite the lesion [Shibutani, S., and Grollman, A. P. (1993) Chem. Res. Toxicol. 6, 819-824]. No experimental structural information is available for this adduct. Extensive minimized potential energy searches involving thousands of trials and molecular dynamics simulations were used to study the conformation of this adduct in three sequences: I, d(C1-G2-C3-[AAF]G4-C5-G6-C7). d(G8-C9-G10-C11-G12-C13-G14); II, the sequence of Shibutani and Grollman, d(C1-T2-A3-[AAF]G4-T5-C6-A7). d(T8-G9-A10-C11-T12-A13-G14); and III, which is the same as II but with a mismatched adenine in position 11, opposite the lesion. AAF was located in the minor groove in the low-energy structures of all sequences. In the lowest energy form of the C3-[AAF]G4-C5 sequence I, the fluorenyl rings point in the 3' direction along the modified strand and the acetyl in the 5' direction. These orientations are reversed in the second lowest energy structure of this sequence, and the energy of this structure is 1.4 kcal/mol higher. Watson-Crick hydrogen bonding is intact in both structures. In the two lowest energy structures of the A3-[AAF]G4-T5 sequence II, the AAF is also located in the minor groove with Watson-Crick hydrogen bonding intact. However, in the lowest energy form, the fluorenyl rings point in the 5' direction and the acetyl in the 3' direction. The energy of the structure with opposite orientation is 5.1 kcal/mol higher. In sequence III with adenine mismatched to the modified guanine, the lowest energy form also had the fluorenyl rings oriented 5' in the minor groove with intact Watson-Crick base pairing. However, the mispaired adenine adopts a syn orientation with Hoogsteen pairing to the modified guanine. These results suggest that the orientation of the AAF in the minor groove may be DNA sequence dependent. Mobile aspects of favored structures derived from molecular dynamics simulations with explicit solvent and salt support the essentially undistorting nature of this lesion, which is in harmony with its persistence in mammalian systems. C1 NYU,DEPT BIOL,NEW YORK,NY 10003. NYU,DEPT CHEM,NEW YORK,NY 10003. OAK RIDGE NATL LAB,DIV LIFE SCI,OAK RIDGE,TN 37831. FU NCI NIH HHS [CA 75449, CA 28038]; NCRR NIH HHS [RR-06458] NR 43 TC 14 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD OCT PY 1997 VL 10 IS 10 BP 1123 EP 1132 DI 10.1021/tx970092e PG 10 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA YB089 UT WOS:A1997YB08900010 PM 9348435 ER PT J AU Ford, RG Bertsch, PM Seaman, JC AF Ford, RG Bertsch, PM Seaman, JC TI Goethite morphologies investigated via X-ray diffraction of oriented samples SO CLAYS AND CLAY MINERALS LA English DT Article DE goethite; oriented film; particle morphology; powder X-ray diffraction; XRD C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,AIKEN,SC 29802. NR 16 TC 13 Z9 13 U1 0 U2 3 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD OCT PY 1997 VL 45 IS 5 BP 769 EP 772 DI 10.1346/CCMN.1997.0450515 PG 4 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA YJ808 UT WOS:A1997YJ80800015 ER PT J AU Covey, C Hoffert, MI AF Covey, C Hoffert, MI TI The sun-climate connection: A challenge to conventional wisdom? SO CLIMATIC CHANGE LA English DT Editorial Material C1 NYU,EARTH SYST GRP,NEW YORK,NY 10003. RP Covey, C (reprint author), LAWRENCE LIVERMORE NATL LAB,PROGRAM CLIMATE MODEL DIAG & INTERCOMPARISON,LIVERMORE,CA 94551, USA. NR 8 TC 2 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD OCT PY 1997 VL 37 IS 2 BP 387 EP 390 DI 10.1023/A:1005366531556 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA XZ628 UT WOS:A1997XZ62800005 ER PT J AU Zharnitsky, V AF Zharnitsky, V TI Breakdown of stability of motion in superquadratic potentials SO COMMUNICATIONS IN MATHEMATICAL PHYSICS LA English DT Article AB Based on the KAM theory, investigation of the equation of motion of a classical particle in a one-dimensional superquadratic potential well, under the influence of an external time-periodic forcing, raised a hope that all the solutions are bounded. Indeed, due to the superquadraticity of the potential the frequency of oscillations of the solutions in the system tends to infinity as the amplitude increases. Therefore, because of this relationship between the frequency and the amplitude, intuitively one might expect that all resonances that could cause the accumulation of energy would be destroyed, and thus all solutions would stay bounded for all time. More formally, according to Moser's twist theorem, this could mean the existence of invariant tubes in the extended phase space and therefore would result in the boundedness of the solutions. Actually, the boundedness results have been established for a large class of superquadratic potentials, but in general, the above intuition turns out to be wrong. Littlewood showed it by creating a superquadratic potential in which an unbounded motion occurs in the presence of some particular piecewise constant forcing. Moreover, Littlewood's result holds for a larger class of forcings. Here it is proven for the continuous time-periodic forcing. For this purpose a new averaging technique for the forced motions in superquadratic potentials with rather weak assumptions on the differentiability of the potentials has been developed. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Zharnitsky, V (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-3616 J9 COMMUN MATH PHYS JI Commun. Math. Phys. PD OCT PY 1997 VL 189 IS 1 BP 165 EP 204 DI 10.1007/s002200050195 PG 40 WC Physics, Mathematical SC Physics GA YF738 UT WOS:A1997YF73800009 ER PT J AU Anderson, LE Li, D Muslin, EH Stevens, FJ Schiffer, M AF Anderson, LE Li, D Muslin, EH Stevens, FJ Schiffer, M TI Predicting redox-sensitive cysteines in plant enzymes by homology modeling SO COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES LA English DT Article DE light activation; reductive activation; redox-sensitive cysteines; light inactivation; oxidative inactivation; domain-locking disulfides ID NADP-MALATE DEHYDROGENASE; SITE-DIRECTED MUTAGENESIS; FERREDOXIN-THIOREDOXIN REDUCTASE; PROTEIN-STRUCTURE PREDICTION; DEPENDENT REGULATORY SITE; AMINO-ACID-SEQUENCE; CHLAMYDOMONAS-REINHARDTII; CRYSTAL-STRUCTURE; CHLOROPLAST SEDOHEPTULOSE-1,7-BISPHOSPHATASE; GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE AB One of the unsolved problems in plant biochemistry has been the identification of the regulatory cysteines in the reductively light-activated and -inactivated chloroplast enzymes. Homology modeling based on the sequences of these enzymes and the three-dimensional structures of homologous enzymes has now allowed tentative identification of the redox-sensitive Cys residues in four light-activated chloroplast enzymes. In each case the regulatory disulfides are not positioned in the active site but instead appeal to be positioned so as to affect the flexibility or the conformation of the enzyme, and thereby to affect catalysis. In glyceraldehyde-3-P dehydrogenase and malate dehydrogenase inter-domain movement would be restricted. In fructose bisphosphatase and sedoheptulose bisphosphatase the regulatory Cys residues are located on the nucleotide binding domain iri a region Known to be sensitive to nit allosteric effector of other fructose bisphosphatases. Results of site-directed mutagenesis experiments to date are in general agreement with the domain-locking hypothesis. The redox sensitivity of a number of cytosolic enzymes suggests that reductive modulation might occur outside of the chloroplast in leaves, and in the roots, stems and germinating seeds of green plants. Our better understanding of the mechanism of redox regulation may lead to new approaches for the regulation of enzyme activity with biotechnological applications. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. RP Anderson, LE (reprint author), UNIV ILLINOIS,DEPT BIOL SCI,845 W TAYLOR ST,CHICAGO,IL 60607, USA. NR 82 TC 2 Z9 2 U1 0 U2 0 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 141 RUE JAVEL, 75747 PARIS, FRANCE SN 0764-4469 J9 CR ACAD SCI III-VIE JI Comptes Rendus Acad. Sci. Ser. III-Sci. Vie-Life Sci. PD OCT PY 1997 VL 320 IS 10 BP 767 EP 781 DI 10.1016/S0764-4469(97)85012-3 PG 15 WC Biology; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Science & Technology - Other Topics GA YF059 UT WOS:A1997YF05900001 ER PT J AU Signer, A AF Signer, A TI MENLO_PARC, a program for e(+)e(-)->4 jets at next-to-leading order SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE electron-positron annihilation; next-to-leading order corrections; four jet; subtraction method ID E+E ANNIHILATION; CROSS-SECTIONS; 4-JET EVENTS; 3-GLUON VERTEX; COLLIDERS; QCD; AMPLITUDES; 3-JET AB MENLO-PARC is a general purpose Monte Carlo program for calculating the next-to-leading order O(alpha(s)(3)) corrections to four-jet quantities in electron-positron annihilation. Any quantity which can be constructed out of the four jet momenta and which is insensitive to the quark helicities and the beam orientation can be computed. Both virtual photon and Z intermediate states (and gamma-Z interference) are included, hence the quantities can be computed for arbitrary center of mass energies. The cancellation of real and virtual singularities has been achieved using a general version of the subtraction method. The only approximation which has been made is the neglect of the light quark masses and terms which are suppressed by 1/m(top)(4) or higher powers of the top quark mass. (C) 1997 Elsevier Science B.V. RP Signer, A (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 30 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD OCT PY 1997 VL 106 IS 1-2 BP 125 EP 138 DI 10.1016/S0010-4655(97)00093-3 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA YG159 UT WOS:A1997YG15900011 ER PT J AU McNab, WW AF McNab, WW TI Simulation of reactive geochemical transport in groundwater using a semi-analytical screening model SO COMPUTERS & GEOSCIENCES LA English DT Article DE reactive chemical transport; geochemical modeling; groundwater geochemistry ID HETEROGENEOUS CHEMICAL-REACTIONS; MULTICOMPONENT MASS-TRANSPORT; ACID-MINE DRAINAGE; NUMERICAL ALGORITHM; AQUIFER; CONTAMINATION; DEGRADATION; OXIDATION; CHEMISTRY; TOLUENE AB A reactive geochemical transport model, based on a semi-analytical solution to the advective-dispersive transport equation in two dimensions, is developed as a screening tool for evaluating the impact of reactive contaminants on aquifer hydrogeochemistry. Because the model utilizes an analytical solution to the transport equation, it is less computationally intensive than models based on numerical transport schemes, is faster, and it is not subject to numerical dispersion effects. Although the assumptions used to construct the model preclude consideration of reactions between the aqueous and solid phases, thermodynamic mineral saturation indices are calculated to provide qualitative insight into such reactions. Test problems involving acid mine drainage and hydrocarbon biodegradation signatures illustrate the utility of the model in simulating essential hydrogeochemical phenomena. (C) 1997 Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Environm Restorat Div, Livermore, CA 94550 USA. RP McNab, WW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Environm Restorat Div, POB 808 L-530, Livermore, CA 94550 USA. NR 34 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-3004 J9 COMPUT GEOSCI JI Comput. Geosci. PD OCT PY 1997 VL 23 IS 8 BP 869 EP 882 DI 10.1016/S0098-3004(97)00056-3 PG 14 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA YN463 UT WOS:000071171100005 ER PT J AU Dongarra, JJ Dunigan, T AF Dongarra, JJ Dunigan, T TI Message-passing performance of various computers SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB This report compares the performance of different computer systems for basic message passing, Latency and bandwidth are measured on Convex, Gray, IBM, Intel, KSR, Meiko, nCUBE, NEC, SGI and TMC multiprocessors. Communication performance is contrasted with the computational power of each system, The comparison includes both shared and distributed memory computers as well as networked workstation clusters, (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV TENNESSEE, DEPT COMP SCI, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN USA. RI Dongarra, Jack/E-3987-2014 NR 9 TC 14 Z9 14 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD OCT PY 1997 VL 9 IS 10 BP 915 EP 926 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA YF889 UT WOS:A1997YF88900001 ER PT J AU Lee, TY Raghavendra, CS Nicholas, JB AF Lee, TY Raghavendra, CS Nicholas, JB TI Parallel implementation of a ray tracing algorithm for distributed memory parallel computers SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB Ray tracing is a well known technique to generate life-like images, Unfortunately, ray tracing complex scenes can require large amounts of CPU time and memory storage, Distributed memory parallel computers with large memory capacities and high processing speeds are ideal candidates to perform ray tracing, However, the computational cost of rendering pixels and patterns of data access cannot be predicted until runtime, To parallelize such an application efficiently on distributed memory parallel computers, the issues of database distribution, dynamic data management and dynamic load balancing must be addressed, In this paper, we present a parallel implementation of a ray tracing algorithm on the Intel Delta parallel computer, In our database distribution, a small fraction of database is duplicated on each processor, while the remaining part is evenly distributed among groups of processors, In the system, there are multiple copies of the entire database in the memory of groups of processors, Dynamic data management is acheived by an ALRU cache scheme which can exploit image coherence to reduce data movements in ray tracing consecutive pixels, We balance load among processors by distributing subimages to processors in a global fashion based on previous workload requests, The success of our implementation depends crucially on a number of parameters which are experimentally evaluated, (C) 1997 by John Wiley & Sons, Ltd. C1 NANTAI INST TECHNOL, DEPT INFORMAT MANAGEMENT, TAINAN, TAIWAN. WASHINGTON STATE UNIV, SCH ELECT ENGN & COMP SCI, PULLMAN, WA 99164 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 23 TC 1 Z9 1 U1 1 U2 1 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 OCT PY 1997 VL 9 IS 10 BP 947 EP 965 PG 19 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA YF889 UT WOS:A1997YF88900003 ER PT J AU Schoonover, JR Bignozzi, CA Meyer, TJ AF Schoonover, JR Bignozzi, CA Meyer, TJ TI Application of transient vibrational spectroscopies to the excited states of metal polypyridyl complexes SO COORDINATION CHEMISTRY REVIEWS LA English DT Review ID RESOLVED RESONANCE RAMAN; INTRAMOLECULAR ELECTRON-TRANSFER; CHARGE-TRANSFER EMISSION; RUTHENIUM(II) COMPLEXES; ENERGY-TRANSFER; PHOTOINDUCED ELECTRON; INFRARED-SPECTROSCOPY; PHOTOPHYSICAL PROPERTIES; POLYNUCLEAR COMPLEXES; MULTIPLE EMISSIONS AB Time-resolved resonance Raman and infrared spectroscopies have been applied to a variety of problems arising in excited states and molecular assemblies based on polypyridyl complexes of Re(I), Ru(II) and Os(II). Application of transient resonance Raman spectroscopy has been used to assign the acceptor ligand in heteroleptic Ru(II) complexes and to characterize molecular structure in acceptor ligands. It has been applied to intramolecular electron transfer in chromophore-quencher complexes and molecular assemblies and to intramolecular energy transfer in polynuclear complexes. Time-resolved infrared spectroscopy has opened new avenues for the study of excited-state electronic structure and dynamics by the observation of v(CO) and v(CN) bands in transient absorption difference spectra. This technique has been applied to distinguishing between metal-to-ligand charge transfer and ligand-based pi pi* states in Re (I) complexes and to intramolecular energy transfer in cyano-bridged oligomers. (C) 1997 Elsevier Science S.A. C1 UNIV FERRARA, DIPARTIMENTO CHIM, I-44100 FERRARA, ITALY. UNIV N CAROLINA, DEPT CHEM, VENABLE & KENAN LABS, CHAPEL HILL, NC 27599 USA. RP Schoonover, JR (reprint author), LOS ALAMOS NATL LAB, BIOSCI & BIOTECHNOL GRP CST4, MAIL STOP J586, LOS ALAMOS, NM 87545 USA. OI Bignozzi, Carlo Alberto/0000-0002-7882-3694 NR 93 TC 61 Z9 61 U1 3 U2 18 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 EI 1873-3840 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD OCT PY 1997 VL 165 BP 239 EP 266 PG 28 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YJ675 UT WOS:A1997YJ67500004 ER PT J AU Danielson, M AF Danielson, M TI Modeling of certain electrode parameters on the electrochemical noise response SO CORROSION LA English DT Article DE conductivity; current; electrical circuits; electrochemical noise; electrodes; general corrosion; modeling; pitting; potential; stress corrosion cracking; zero-resistance ammeter AB Electrical circuit analogs of electrochemical corrosion processes were used to investigate the electrochemical noise (EN) behavior of electrodes. The Simulation Program with Integrated-Circuit Emphasis (SPICE) was used to solve the equations that describe the current-vs-potential transient response of the electrical circuits. Results provided insight into the effects of electrode area, solution conductivity, coatings, and instrumentation on the measurement and interpretation of EN events in one-and two-electrode configurations. A technique was suggested to permit measurement of the current and potential noise for polarized electrodes. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Danielson, M (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 9 TC 6 Z9 7 U1 1 U2 1 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD OCT PY 1997 VL 53 IS 10 BP 770 EP 777 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YT224 UT WOS:000071578300003 ER PT J AU Falkowski, PG AF Falkowski, PG TI Photosynthesis: The paradox carbon dioxide efflux SO CURRENT BIOLOGY LA English DT Article ID MARINE-PHYTOPLANKTON; LIMITATION AB The discovery that photosynthetic marine cyanobacteria can actually leak CO2 has been predicted from theory but, until now, never experimentally demonstrated. The apparent paradox can be explained by known chemistry and biochemistry, but the phenomenon may have important implications for paleoclimatology. (C) Current Biology Ltd ISSN 0960-9822. RP Falkowski, PG (reprint author), BROOKHAVEN NATL LAB,ENVIRONM BIOPHYS & MOL BIOL PROGRAM,UPTON,NY 11973, USA. NR 13 TC 14 Z9 15 U1 1 U2 10 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0960-9822 J9 CURR BIOL JI Curr. Biol. PD OCT 1 PY 1997 VL 7 IS 10 BP R637 EP R639 DI 10.1016/S0960-9822(06)00322-8 PG 3 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA YB583 UT WOS:A1997YB58300019 PM 9368746 ER PT J AU Larese, JZ AF Larese, JZ TI Structure and dynamics of physisorbed phases SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID AB-INITIO; ADSORPTION; MOLECULES; MGO(100); SURFACES; GRAPHITE; AMMONIA; FILMS; MGO; NH3 AB Neutron, X-ray and helium atom scattering techniques are ideally suited for the study of the structure and dynamics of atoms and molecules physisorbed on surfaces. High flux beam reactors, high intensity spallation sources, the growing number of third generation synchrotron X-ray sources and the increased number of compact helium beam sources have led to a steady increase in our knowledge of the adsorption process. RP Larese, JZ (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 49 TC 3 Z9 3 U1 0 U2 0 PU CURRENT SCIENCE LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD OCT PY 1997 VL 2 IS 5 BP 539 EP 545 DI 10.1016/S1359-0286(97)80042-3 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA YD944 UT WOS:A1997YD94400006 ER PT J AU Trewhella, J AF Trewhella, J TI Insights into biomolecular function from small-angle scattering SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Article ID X-RAY-SCATTERING; MALTODEXTRIN-BINDING-PROTEIN; LIGHT-CHAIN KINASE; MALTOSE-BINDING; CONFORMATIONAL-CHANGES; FOLDING INTERMEDIATE; NEUTRON-SCATTERING; ACTIVE-TRANSPORT; CHEMOTAXIS; COMPLEXES AB Recent advances in neutron and X-ray sources and instrumentation, new and improved scattering techniques, and molecular biology techniques, which have permitted facile preparation of samples, have each led to new opportunities in using small-angle scattering to study the conformations and interactions of biological macromolecules in solution as a function of their properties. For example, new instrumentation on synchrotron sources has facilitated time-resolved studies that yield insights into protein folding. More powerful neutron sources, combined with molecular biology tools that isotopically label samples, have facilitated studies of biomolecular interactions, including those involving active enzymes. (C) Current Biology Ltd ISSN 0959-440X RP Trewhella, J (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MAIL STOP G758,LOS ALAMOS,NM 87545, USA. OI Trewhella, Jill/0000-0002-8555-6766 NR 37 TC 41 Z9 42 U1 0 U2 3 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD OCT PY 1997 VL 7 IS 5 BP 702 EP 708 DI 10.1016/S0959-440X(97)80081-4 PG 7 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA YB579 UT WOS:A1997YB57900015 PM 9345630 ER PT J AU Holmgren, M Scheffer, M Huston, MA AF Holmgren, M Scheffer, M Huston, MA TI The interplay of facilitation and competition in plant communities SO ECOLOGY LA English DT Article DE competition; facilitation; light; model; nurse plants; physiological trade-offs; plant communities; water ID CACTUS NEOBUXBAUMIA-TETETZO; INTERSPECIFIC COMPETITION; FIELD EXPERIMENTS; MIMOSA-LUISANA; SONORAN DESERT; SEEDLING ESTABLISHMENT; POSITIVE INTERACTIONS; NATURAL COMMUNITIES; ISOLATED TREES; GROWTH AB If plants cannot simultaneously acclimate to shade and drought because of physiological trade-offs, then plants are expected to be less tolerant to shading under drier conditions. One observation that, at first sight, seems incompatible with this idea is the fact that the establishment of new plants in dry areas is often restricted to shady sites under the canopy of other plants, called ''nurse plants.'' We use a graphical model to resolve this paradox. The model visualizes how facilitative patterns can be understood from the simultaneous effects of plant canopies on microsite light and moisture, and the growth response of establishing seedlings to those factors. The approach emphasizes the fact that positive and negative effects of plant canopies always occur simultaneously. In the presented light-water model, facilitation only occurs when the improvement of plant water relations under the canopy exceeds the costs caused by lower light levels. This may be true under dry conditions, whereas in less dry situations, competition rather than facilitation is observed. The model shows how changes in water availability may shift interactions from competitive to facilitative and vice versa, as observed in some field patterns. It is argued that other environmental factors explaining facilitative patterns can be understood in the same context. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. INST INLAND WATER MGMT & WASTE WATER TREATMENT,RIZA,NL-8200 AA LELYSTAD,NETHERLANDS. RI Huston, Michael/B-1434-2009; Scheffer, Marten/C-1852-2012 OI Huston, Michael/0000-0001-9513-1166; NR 80 TC 574 Z9 603 U1 28 U2 205 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD OCT PY 1997 VL 78 IS 7 BP 1966 EP 1975 DI 10.1890/0012-9658(1997)078[1966:TIOFAC]2.0.CO;2 PG 10 WC Ecology SC Environmental Sciences & Ecology GA XZ789 UT WOS:A1997XZ78900004 ER PT J AU Jagoe, RH Newman, MC AF Jagoe, RH Newman, MC TI Bootstrap estimation of community NOEC values SO ECOTOXICOLOGY LA English DT Article DE toxicity; NOEC; prediction; extrapolation; bootstrapping AB Recent estimations of NOEC (no observed effect concentration) values for communities use single species effect data to predict the concentration at which not more than some particular acceptable percentage of the species in a community will be affected. This method has a number of difficulties, not the least of which is obtaining effects data for enough of the right species to accurately represent the whole community. Typically one has to make do with existing data sets in which the choice of species tested has been made for convenience rather than representativeness. Usually the raw data alone are not sufficient to make reasonable estimates. Statistical methods have been proposed which deal with this problem by assigning a specific distribution to the data. But assumption of a specific distribution may not be valid. We present an alternative method and an associated computer program which use resampling (bootstrap) methods to estimate the NOEC without assuming a specific distribution. This method has the advantage that no underlying distribution is assumed. Simulated and published data sets were used to compare this approach with published methods. The use of this technique to assess representativeness was also demonstrated. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NR 18 TC 27 Z9 30 U1 0 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD OCT PY 1997 VL 6 IS 5 BP 293 EP 306 DI 10.1023/A:1018639113818 PG 14 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA YA134 UT WOS:A1997YA13400004 ER PT J AU Braun, B Blanch, HW Prausnitz, JM AF Braun, B Blanch, HW Prausnitz, JM TI Capillary electrophoresis of DNA restriction fragments: Effect of polymer properties SO ELECTROPHORESIS LA English DT Article DE capillary electrophoresis; DNA restriction fragments; hydroxyethylcellulose; polyvinylpyrrolidone; star polyethylene oxide ID ZONE ELECTROPHORESIS; DIASTEREOMERIC DERIVATIVES; SEPARATION; POLYVINYLPYRROLIDONE; ENANTIOMERS; NETWORK AB The mechanism of DNA separation by dilute polymer solutions in capillary electrophoresis is not well understood. To provide information on the effect of polymer properties on DNA separations, four polymers that differ in size, shape and stiffness were examined. Hydroxyethylcellulose of high molecular weight provides excellent separation of large DNA fragments (2027 bp - 23 130 bp). Polyvinylpyrrolidone separates DNA from 72 bp to 23 kbp; star-(polyethylene oxide) and linear poly(ethylene oxide) provide separation of fragments to 1353 bp. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. FU NHGRI NIH HHS [HGO1432A] NR 14 TC 17 Z9 17 U1 1 U2 3 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD OCT PY 1997 VL 18 IS 11 BP 1994 EP 1997 DI 10.1002/elps.1150181119 PG 4 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YJ957 UT WOS:A1997YJ95700018 PM 9420158 ER PT J AU Poyer, DA Henderson, L Teotia, APS AF Poyer, DA Henderson, L Teotia, APS TI Residential energy consumption across different population groups: comparative analysis for Latino and non-Latino households in USA SO ENERGY ECONOMICS LA English DT Article DE energy consumption; Latino vs. non-Latino households ID ECONOMETRIC-ANALYSIS; DEMAND; ELECTRICITY; MODEL AB Residential energy cost is an important part of the household budget and could vary significantly across different population groups in many countries. In the United States, many studies have analyzed household fuel consumption by fuel type, including electricity, natural gas, fuel oil, and liquefied petroleum gas (LPG), and by geographic areas. Past research has also demonstrated significant variation in residential energy use across various population groups, including white, black, and Latino. However, our research shows that residential energy demand by fuel type for Latinos, the fastest growing population group, has not been explained by economic and non-economic factors in any statistical model in public domain. The purpose of this paper was to discuss energy demand and expenditure patterns for Latino and non-Latino households in the United States as a case example of analyzing residential energy consumption across different population groups in a country. The linear expenditure system model developed by Stone and Geary is the basis of the statistical model developed to explain fuel consumption and expenditures for Latino households. For comparison, the models are also developed for non-Latino, black, and non-black households. These models estimate energy consumption of and expenditures for electricity, natural gas, fuel oil, and LPG by various households at the national level. Significant variations in the patterns of these fuels consumption for Latinos and non-Latinos are highlighted. The model methodology and results of this research should be useful to energy policymakers in government and industry, researchers, and academicians who are concerned with economic and energy issues related to various population groups in their country. (C) 1997 Elsevier Science B.V. C1 Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. Univ Maryland, Baltimore, MD 21202 USA. RP Teotia, APS (reprint author), Argonne Natl Lab, Div Energy Syst, Bldg 362, Argonne, IL 60439 USA. NR 34 TC 18 Z9 18 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-9883 J9 ENERG ECON JI Energy Econ. PD OCT PY 1997 VL 19 IS 4 BP 445 EP 463 DI 10.1016/S0140-9883(97)01024-4 PG 19 WC Economics SC Business & Economics GA YM994 UT WOS:000071122500004 ER PT J AU Bunde, RL Rosentreter, JJ Liszewski, MJ Hemming, CH Welhan, J AF Bunde, RL Rosentreter, JJ Liszewski, MJ Hemming, CH Welhan, J TI Effects of calcium and magnesium on strontium distribution coefficients SO ENVIRONMENTAL GEOLOGY LA English DT Article DE strontium; calcium; magnesium; distribution; distribution coefficient; K-d; competing cations ID AQUIFER; SR-90 AB The effects of calcium and magnesium on the distribution of strontium between a surficial sediment and simulated wastewater solutions were measured as part of an investigation to determine strontium transport properties of surficial sediment at the Idaho National Engineering Laboratory (INEL), Idaho. The investigation was conducted by the U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy. Batch experimental techniques were used to determine strontium linear sorption isotherms and distribution coefficients (K-d's) using simulated wastewater solutions prepared at pH 8.0 +/- 0.1 with variable concentrations of calcium and magnesium. Strontium linear sorption isotherm K-d's ranged from 12 +/- 1 to 85 +/- 3 ml/g, increasing as the concentration of calcium and magnesium decreased. The concentration of sorbed strontium and the percentage of strontium retained by the sediment were correlated to aqueous concentrations of strontium, calcium, and magnesium. The effect of these cation concentrations on strontium sorption was quantified using multivariate least-squares regression techniques. Analysis of data from these experiments indicates that increased concentrations of calcium and magnesium in wastewater discharged to waste disposal ponds at the INEL increases the availability of strontium for transport beneath the ponds by decreasing strontium sorption to the surficial sediment. C1 US GEOL SURVEY,IDAHO FALLS,ID 83403. IDAHO STATE UNIV,DEPT CHEM,POCATELLO,ID 83209. IDAHO STATE UNIV,IDAHO GEOL SURVEY,POCATELLO,ID 83209. NR 24 TC 17 Z9 18 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD OCT PY 1997 VL 32 IS 3 BP 219 EP 229 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA YF784 UT WOS:A1997YF78400007 ER PT J AU Steenland, K Cedillo, L Tucker, J Hines, C Sorensen, K Deddens, J Cruz, V AF Steenland, K Cedillo, L Tucker, J Hines, C Sorensen, K Deddens, J Cruz, V TI Thyroid hormones and cytogenetic outcomes in backpack sprayers using ethylenebis(dithiocarbamate) (EBDC) fungicides in Mexico SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE cytogenetics; ethylenebis(dithiocarbamates); EBDCs; ethylene thiourea; ETU; pesticides; thyroid ID ETHYLENEBISDITHIOCARBAMATE FUNGICIDES; CHROMOSOME-ABERRATIONS; SISTER CHROMATIDS; ETHYLENETHIOUREA; EXPOSURE; LYMPHOCYTES; THYROTROPIN; WORKERS; DAMAGE; HUMANS AB Ethylenebis(dithiocarbamate) (EBDC) fungicides are used heavily in the United States. EBDCs (e.g., mancozeb, maneb) are metabolized to ethylene thiourea (ETU). The EPA classifies ETU as a carcinogen, based on thyroid and other cancers in rodents, and has restricted the use of EBDCs, while requiring workers to use protective equipment. There are no data on the potential carcinogenicity of EBDCs in humans, and there is only one study on human genotoxicity. ETU is known to cause decreases of thyroxine (T-4) and increases in thyroid-stimulating hormone (TSH) in rodents. We have studied cytogenetic outcomes and serum thyroid hormone levels among 49 heavily exposed workers without protective equipment spraying EBDC on tomatoes in Mexico. We also studied 14 lightly exposed landowners and 31 nonexposed controls. Urinary ETU was used to compare exposure between groups. We found an increase in TSH (p = 0.05) among applicators compared to controls, but no decrease in thyroid hormone (T-4). We found increases in sister chromatid exchange (p = 0.03) and in chromosome translocations (chromosome aberrations that persist through cell division) for applicators compared to controls (p 0.05). However, the subset of reciprocal translocations showed a lesser increase (p = 0.24). Our data suggest that EBDCs affect the thyroid gland and the lymphocyte genome among heavily exposed workers. However, our data are limited to subclinical outcomes, are of borderline statistical significance, and should he interpreted with caution. C1 NIOSH, Cincinnati, OH 45226 USA. Inst Nacl Salud Publ, Cuernavaca, Morelos, Mexico. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Steenland, K (reprint author), NIOSH, Mailstop R13,4676 Columbia Pkwy, Cincinnati, OH 45226 USA. NR 28 TC 55 Z9 56 U1 1 U2 8 PU US DEPT HEALTH HUMAN SERVICES PUBLIC HEALTH SERVICE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SERVICES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 1997 VL 105 IS 10 BP 1126 EP 1130 DI 10.1289/ehp.971051126 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA ZB726 UT WOS:000072501400022 PM 9349837 ER PT J AU Mason, CFV Turney, WRJR Thomson, BM Lu, N Longmire, PA ChisholmBrause, CJ AF Mason, CFV Turney, WRJR Thomson, BM Lu, N Longmire, PA ChisholmBrause, CJ TI Carbonate leaching of uranium from contaminated soils SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID FERNALD; SPECIATION; PHASES AB Uranium(U)was successfully removed from contaminated soils from the Fernald Environmental Management Project (FEMP) site near Fernald, Ohio. The laboratory column leach process, referred to as the simulated heap leach process, using 0.5 M sodium bicarbonate as the dominant reagent, was able to achieve uranium removals of 75-90%, corresponding approximately to the percentage of uranium in the oxidized state. Parametric optimization studies are reported. The dissolution of uranium took place in two stages: a rapid desorption associated with soil surfaces and a slow step associated with diffusion of uranium toward solid surfaces. In addition, use of the oxidizing agent, sodium peroxide, improved uranium removal due to oxidation of U(IV), enhancing the solubility of the uranium. The results suggest that the process will be effective for field scale remediation of uranium-contaminated soils because of the efficiency, mild complexing agent employed, lack of prescreening of the sail and the simple equipment necessary. Two relevant companion studies have recently been completed. The first, a scale-up demonstration [Turney, W. R. J. R.; Mason, C. F. V.; Lu, N.; Duff, M. C.; Dry, D. Pilot Treatment Project for the Remediation of Uranium-Contaminated Soil at a Former Nuclear Weapons Development Site at the LANL; Waste Management '97, Tucson, 1997], using a Los Alamos site, confirms the approach to be effective up to 1 ton of soil and the second, a cost study, suggests this method is economically competitive for large soil volumes (> 1000 cu yd) when combined with a radionuclide presort [Cummings, M.; Booth, S. R. Remediation of Uranium-Contaminated Soil using the Segmented Gate System and Containerized Vat Leaching Techniques: A Cost Effectiveness Study. C1 UNIV NEW MEXICO,DEPT CIVIL ENGN,ALBUQUERQUE,NM 87305. VIRGINIA INST MARINE SCI,COLL WILLIAM & MARY,GLOUCESTER POINT,VA 23062. RP Mason, CFV (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST-7,LOS ALAMOS,NM 87545, USA. NR 18 TC 91 Z9 99 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1997 VL 31 IS 10 BP 2707 EP 2711 DI 10.1021/es960843j PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XZ787 UT WOS:A1997XZ78700024 ER PT J AU Seaman, JC Bertsch, PM Strom, RN AF Seaman, JC Bertsch, PM Strom, RN TI Characterization of colloids mobilized from southeastern coastal plain sediments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID TRACE-ELEMENT CONCENTRATIONS; GRADIENT FLOW CONDITIONS; POROUS-MEDIA; IRON-OXIDE; FACILITATED TRANSPORT; GROUNDWATER COLLOIDS; SUSPENDED PARTICLES; AQUATIC COLLOIDS; SANDY AQUIFER; CONTAMINANTS AB Two subsurface samples representing highly weathered sediments of the Up per Coa sta I Plain (Aiken, SC) that differed in Fe-oxide content (7.3 vs 35.9 g Fe kg(-1)) were evaluated in terms of mobile colloid generation in response to changes in solution composition. In repacked columns, the two sediments were leached (similar to 0.72 m d(-1) Darcy velocity) with either 0.001 N NaCl or CaCl2 solutions for 10 pore Volumes followed by 10 pore Volumes of deionized water. Bulk clay mineralogy from the two samples and suspensions generated in the column studies was characterized by energy dispersive X-ray analysis (EDXA) using a field-emission scanning electron microscope (SEM). SEM results were confirmed by selected-area electron diffraction (SAED) and EDXA in a transmission electron microscope. In column experiments, the sample lower in Fe oxide displayed increased effluent turbidity that coincided with a decrease in effluent pH during injection of the CaCl2 solutions. in contrast, no effluent turbidity was observed during the leaching of NaCl solutions. The sample higher in iron oxide displayed greater effluent turbidity from the onset of leaching that decreased over the duration of injection for both the CaCl2 and NaCl solutions. Colloids generated from both materials displayed positive electrophoretic mobilities, confirming the importance of iron oxides in controlling dispersion and surface charge properties of the mobile colloids. Minor differences in the clay mineralogy (i.e., iron oxide/kaolinite content) between the samples were reflected in both their sensitivity to pore-solution composition and the relative degree of dispersion observed for each sample. Electron microscopy, EDXA, and thermal gravimetric analysis (TGA) confirmed that the mobile colloids consisted mainly of submicron sized Al-rich goethite, with lesser amounts of kaolinite, the predominate layer silicate of the bulk sediments, and varying amounts of crandallite. C1 WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29802. RP Seaman, JC (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,DRAWER E,AIKEN,SC 29802, USA. NR 56 TC 40 Z9 40 U1 1 U2 7 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 OCT PY 1997 VL 31 IS 10 BP 2782 EP 2790 DI 10.1021/es961075z PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XZ787 UT WOS:A1997XZ78700036 ER PT J AU Bergin, MH Ogren, JA Schwartz, SE McInnes, LM AF Bergin, MH Ogren, JA Schwartz, SE McInnes, LM TI Evaporation of ammonium nitrate aerosol in a heated nephelometer: Implications for field measurements SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID RELATIVE-HUMIDITY; SIZE; TEMPERATURE; DEPENDENCE AB Ammonium nitrate is a semivolatile aerosol component under typical ambient conditions and thus difficult to measure. In the field, the aersosol scattering coefficient is usually measured with a nephelometer by heating the ambient aerosol to a low reference relative humidity (similar to 40%) in order to measure a light scattering coefficient that is intrinsic to an aerosol rather than dependent on atmospheric relative humidity. In this paper, we examine the decrease in the light scattering coefficient of ammonium nitrate aerosol due to evaporation in a heated nephelometer. Changes in the scattering coefficient of a laboratory-generated ammonium nitrate aerosol are measured as a function of mean residence time and temperature within the nephelometer sample volume. At the same time, the change in the aerosol size distribution due to ammonium nitrate evaporation is directly measured with a laser particle counter. The change in the aerosol size distribution and scattering coefficient is modeled as a function of mean residence time and temperature. Model results for the change in the aerosol scattering coefficient due to evaporation agree with measurements to within 10%. Application of the theory to conditions typical of NOAA field sites suggests that the decrease in the aerosol scattering coefficient due to the evaporation of ammonium nitrate is generally less than 20%. C1 BROOKHAVEN NATL LAB,ENVIRONM CHEM DIV,UPTON,NY 11973. RP Bergin, MH (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,R-E-CG1,BOULDER,CO 80303, USA. RI Schwartz, Stephen/C-2729-2008; Ogren, John/M-8255-2015 OI Schwartz, Stephen/0000-0001-6288-310X; Ogren, John/0000-0002-7895-9583 NR 22 TC 56 Z9 59 U1 1 U2 8 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 OCT PY 1997 VL 31 IS 10 BP 2878 EP 2883 DI 10.1021/es970089h PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XZ787 UT WOS:A1997XZ78700049 ER PT J AU Lingenfelser, SF Dallas, CE Jagoe, CH Smith, MH Brisbin, IL Chesser, RK AF Lingenfelser, SF Dallas, CE Jagoe, CH Smith, MH Brisbin, IL Chesser, RK TI Variation in DNA content of blood cells of largemouth bass from contaminated and uncontaminated waters SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE flow cytometry; coefficient of variation; largemouth bass; aneuploidy ID FLOW CYTOMETRIC ANALYSIS; MERCURY; RESERVOIR; DAMAGE; ERYTHROCYTES; EXPOSURE; SCRIPTA; ERROR; FISH AB Largemouth bass (Micropterus salmoides) were collected from locations with and without documented histories of pollution in Georgia and South Carolina. Whole blood samples were collected from over 3,000 bass and analyzed by flow cytometry to measure changes in cellular DNA content and cell cycle distribution. The coefficient of variation (CV) of the cell cycle phase G(0)/G(1) peak was used as a measure of variation in DNA content within an individual. The mean CV varied significantly among locations, and some locations with known chemical or radioactive contaminants had higher CVs. Plotting the frequency distribution of CV values for each site revealed greater skewness and kurtosis in most locations with known contaminants. In each case, a right skewness indicated higher proportions of bass with unusually high CV in these locations. Aneuploid-like patterns were detected in the DNA histograms of five fish, all from locations with histories of contamination. The percentage of cells distributed among phases of the cell cycle (G(0)/G(1), S, and G(2)/M) varied significantly among locations, but there was no apparent relationship to contaminant distribution. Differences in CV and frequency of aneuploids among sites with and without histories of pollution were generally small, but increased variation in DNA content may be associated with contaminant exposure at some locations. C1 UNIV GEORGIA,COLL PHARM,DEPT PHARMACOL & TOXICOL,ATHENS,GA 30602. US FISH & WILDLIFE SERV,MID CTY CTR,WHITE MARSH,VA 23183. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NR 40 TC 9 Z9 9 U1 1 U2 2 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD OCT PY 1997 VL 16 IS 10 BP 2136 EP 2143 DI 10.1897/1551-5028(1997)016<2136:VIDCOB>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA XZ451 UT WOS:A1997XZ45100021 ER PT J AU Ehrhart, EJ Segarini, P Tsang, MLS Carroll, AG BarcellosHoff, MH AF Ehrhart, EJ Segarini, P Tsang, MLS Carroll, AG BarcellosHoff, MH TI Latent transforming growth factor beta 1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation SO FASEB JOURNAL LA English DT Article DE ionizing radiation; reactive oxygen species; mammary gland; extracellular matrix; collagen; gene expression ID MOLECULAR-WEIGHT COMPLEX; MATRIX GENE-EXPRESSION; MOUSE MAMMARY-GLAND; TGF-BETA; EXTRACELLULAR-MATRIX; IONIZING-RADIATION; PLASMINOGEN-ACTIVATOR; PULMONARY FIBROSIS; COLLAGEN-SYNTHESIS; BINDING-PROTEIN AB The biological activity of transforming growth factor beta 1 (TCF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control, We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland, Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation, In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling, After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation, Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy, However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy, Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment, We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation, Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation, RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment, These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the reciprocal shift in immunoreactivity as evidence of activation, and implicate TGF-beta as a mediator of tissue response to ionizing radiation, The sensitivity of activation to low radiation doses points to a potential role for TGF-beta in orchestrating tissue response to oxidative stress, As such, radiation may be useful as a probe to delineate the consequences of latent TGF-beta 1 activation in situ. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. COLORADO STATE UNIV,FT COLLINS,CO 80523. CELTRIX PHARMACEUT INC,SANTA CLARA,CA 95050. R&D SYST INC,MINNEAPOLIS,MN 55413. NR 64 TC 165 Z9 170 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD OCT PY 1997 VL 11 IS 12 BP 991 EP 1002 PG 12 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA YA724 UT WOS:A1997YA72400009 PM 9337152 ER PT J AU Malekani, K Rice, JA Lin, JS AF Malekani, K Rice, JA Lin, JS TI Fractal character of humin and its components SO FRACTALS-AN INTERDISCIPLINARY JOURNAL ON THE COMPLEX GEOMETRY OF NATURE LA English DT Article; Proceedings Paper CT Fractal 97 Meeting CY APR 08-11, 1997 CL ESTES PK, COLORADO SP Univ Denver ID SOIL ORGANIC-MATTER; SURFACE-AREA; SUBSTANCES; SCATTERING; POLLUTANTS; SEDIMENTS; PARTITION; RESIDUES; POROSITY; WATER AB Natural organic matter in soils is usually found in intimate association with inorganic materials, primarily aluminosilicates, during the early stages of diagenesis to form an organo-mineral composite known as humin. Such composites typically represent more than 50 % of the organic carbon present. Because of humin's insolubility and the surface reactivity of its organic components it is recognized as an important adsorbent of many anthropogenic organic compounds introduced into natural soil systems. Fractal analysis of small-angle X-ray scattering data was used to characterize the surface roughness of four humin samples following sequential removal of organic matter. The surface fractal dimensions were observed to decrease with removal of organic matter which also resulted in a decrease in surface pore size. These results suggest that the mineral components of humin have smooth surfaces over length scales of similar to 1 to similar to 15 nm, and that it is the organic matter coatings that are responsible for their surface roughness. Models clay-organic compounds exhibited results that are consistent with the observation made for natural samples. The surfaces of all the components of humin were found to be dominated by micro-and mesopores that could explain humin's high sorptive uptake of organic chemicals in the environment. C1 S Dakota State Univ, Dept Chem & Biochem, Brookings, SD 57007 USA. Oak Ridge Natl Lab, Ctr Small Angle Scattering, Div Solid State, Oak Ridge, TN 37831 USA. RP Malekani, K (reprint author), S Dakota State Univ, Dept Chem & Biochem, Brookings, SD 57007 USA. NR 47 TC 2 Z9 2 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-348X J9 FRACTALS JI Fractals-Interdiscip. J. Complex Geom. Nat. PD OCT PY 1997 VL 5 SU S BP 83 EP 100 DI 10.1142/S0218348X9700084X PG 18 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA YY488 UT WOS:000072151600006 ER PT J AU Wendt, K Blaum, K Bushaw, BA Juston, F Nortershauser, W Trautmann, N Wiche, B AF Wendt, K Blaum, K Bushaw, BA Juston, F Nortershauser, W Trautmann, N Wiche, B TI Ultratrace analysis of calcium with high isotopic selectivity by diodelaser resonance ionisation mass spectrometry SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 3rd Symposium on Mass Spectrometric Method of Elemental Trace Analysis and 12th ICP-MS Users Meeting CY SEP 23-26, 1996 CL RES CTR, JULICH, GERMANY HO RES CTR ID IONIZATION SPECTROSCOPY AB A resonance ionisation mass spectrometer for the ultratrace determination of calcium isotopes is presented. It achieves high overall efficiency, ultra-high isotopic abundance sensitivity of more than 10(10) and complete suppression of isobars. The system can be used for isotope ratio studies on stable and long-lived trace isotopes with the final goal of radiodating via Ca-41-determination. For the different applications optical one-, two-or three-step resonance excitation and subsequent ionisation is applied using simple and inexpensive diodelasers. Additional mass analysis is accomplished in a commercial quadrupole mass spectrometer. The experimental set-up and first results on synthetical and meteorite samples are described. C1 UNIV MAINZ, INST KERNCHEM, D-55099 MAINZ, GERMANY. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Wendt, K (reprint author), UNIV MAINZ, INST PHYS, D-55099 MAINZ, GERMANY. RI Wendt, Klaus/D-7306-2011; Nortershauser, Wilfried/A-6671-2013 OI Wendt, Klaus/0000-0002-9033-9336; Nortershauser, Wilfried/0000-0001-7432-3687 NR 4 TC 17 Z9 19 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD OCT-NOV PY 1997 VL 359 IS 4-5 BP 361 EP 363 DI 10.1007/s002160050587 PG 3 WC Chemistry, Analytical SC Chemistry GA YC028 UT WOS:A1997YC02800010 ER PT J AU Corley, RA Markham, DA Banks, C Delorme, P Masterman, A Houle, JM AF Corley, RA Markham, DA Banks, C Delorme, P Masterman, A Houle, JM TI Physiologically based pharmacokinetics and the dermal absorption of 2-butoxyethanol vapor by humans SO FUNDAMENTAL AND APPLIED TOXICOLOGY LA English DT Article ID GLYCOL MONOBUTYL ETHER; PERCUTANEOUS-ABSORPTION; BUTOXYACETIC ACID; HEMOLYTIC-ACTIVITY; MAJOR METABOLITE; HUMAN BLOOD; RATS AB It has generally been assumed that the skin contributes only minor amounts to the total uptake of solvent vapors, relative to the respiratory tract. Contrary to this assumption, the widely used glycol ether solvent, 2-butoxyethanol (BE), has been reported to be more effectively absorbed through the skin (75% of the total uptake) than through the lungs of humans (Johanson and Boman, 1991, Br. J. Ind. Med. 48, 788). The possibility that the finger prick blood sampling technique used in the Johanson and Boman study was confounded by locally high concentrations of BE at the site of absorption was suggested using a previously developed PBPK model (Corley et al., 1994, Toxicol. Appl. Pharmacol. 129, 61). The current study was conducted to verify the PBPK analysis and to determine whether or not the skin was the major site for absorption of BE vapor by exposing one arm from each of six human volunteers to 50 ppm C-13(2)-BE vapor for 2 hr. To evaluate the potential consequences of blood sampling techniques, samples were taken from both the unexposed arm (catheter; during and after exposure) and the exposed arm (finger prick; end of the exposure only) for analysis of both BE and its major metabolite, butoxyacetic acid (BAA). Butoxyacetic acid is responsible for the hemolysis observed in toxicity studies with laboratory animals. Humans, however, are significantly less sensitive to this effect. The concentration of BE in the finger prick blood samples averaged 1500 times higher than the corresponding concentration in venous blood sampled from a catheter installed in the unexposed arm at the end of the exposure. Blood BAA levels were generally within a factor of 4 of each other for the two techniques and, therefore, was considered a better indicator of systemic absorption. Urine was collected for 24 hr and analyzed for the following metabolites found in rat metabolism studies: free and conjugated BE, BAA, ethylene glycol (EG), and glycolic acid (GA), with only BAA detected in the human urine. More importantly, urinary BAA was found to be extensively conjugated (similar to 67%) with glutamine, confirming recent reports. These results, coupled with PBPK modeling of worst-case exposure scenarios (no clothing, 100% of the body was exposed), demonstrated that no more than 15-27% (low-to-high relative temperatures and humidities), not 75%, of the total uptake of BE could be attributed to the skin of humans during simulated 8-hr exposures to the ACGIH TLV concentration of 25 ppm. Even less of the total uptake was attributed to the skin during simulations of exercise with whole-body exposures (5-9%) or by more realistic exposures of only the arms and head (1-8%). As a result, humans are unlikely to reach hemolytic concentrations of the metabolite BAA in blood following vapor exposures to BE. (C) 1997 Society of Toxicology. C1 DOW CHEM CO USA,HLTH & ENVIRONM RES LAB,TOXICOL RES LAB,MIDLAND,MI 48674. BIORES LABS LTD,SENNEVILLE,PQ H9X 3R3,CANADA. LAB PHARMACOL RES INT INC,VAUDREUIL,PQ J7V 8P5,CANADA. RP Corley, RA (reprint author), BATTELLE MEM INST,PACIFIC NW DIV,MOL BIOSCI DEPT,POB 999,MS P7-59,RICHLAND,WA 99352, USA. NR 24 TC 51 Z9 55 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 0272-0590 J9 FUND APPL TOXICOL JI Fundam. Appl. Toxicol. PD OCT PY 1997 VL 39 IS 2 BP 120 EP 130 DI 10.1006/faat.1997.2363 PG 11 WC Toxicology SC Toxicology GA YH051 UT WOS:A1997YH05100005 PM 9344624 ER PT J AU Belge, G Garcia, E Rippe, V Fusco, A Bartnitzke, S Bullerdiek, J AF Belge, G Garcia, E Rippe, V Fusco, A Bartnitzke, S Bullerdiek, J TI Breakpoints of 19q13 translocations of benign thyroid tumors map within a 400 kilobase region SO GENES CHROMOSOMES & CANCER LA English DT Article ID CYTOGENETIC FINDINGS; INSITU HYBRIDIZATION; ADENOMAS; ABERRATIONS; CHROMOSOME-19; CHARACTERIZE; RECURRENT; ARM AB Structural rearrangements involving the long arm of chromosome 19 characterize a cytogenetic subgroup of benign thyroid tumors. To localize the breakpoint of the 19q13 aberrations, we have established three cell lines derived from benign thyroid tumors showing translocations in this region. We have used these cell lines and four additional primary tumors with 19q13 abnormalities for fluorescence in situ hybridization (FISH) mapping studies with ten cosmid clones located between the molecular markers POLD1 and TNNT1. The breakpoints of all chromosome 19 abnormalities mapped within a 400 kb region. (C) 1997 Wiley-Liss, Inc. C1 UNIV BREMEN,CTR HUMAN GENET & GENET COUNSELLING,D-2800 BREMEN 33,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. FAC MED & CHIRURG NAPOLI,DIPARTIMENTO BIOL & PATOL CELLULARE & MOL,NAPLES,ITALY. RI Rippe, Volkhard/I-1927-2013; OI Rippe, Volkhard/0000-0001-8758-6013; Fusco, Alfredo/0000-0003-3332-5197 NR 23 TC 5 Z9 5 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1045-2257 J9 GENE CHROMOSOME CANC JI Gene Chromosomes Cancer PD OCT PY 1997 VL 20 IS 2 BP 201 EP 203 DI 10.1002/(SICI)1098-2264(199710)20:2<201::AID-GCC11>3.0.CO;2-T PG 3 WC Oncology; Genetics & Heredity SC Oncology; Genetics & Heredity GA XZ209 UT WOS:A1997XZ20900011 PM 9331571 ER PT J AU Rikke, BA Johnson, DK Johnson, TE AF Rikke, BA Johnson, DK Johnson, TE TI Murine albino-deletion complex: High-resolution microsatellite map and genetically anchored YAC framework map SO GENETICS LA English DT Article ID FES-HBB REGION; MOUSE CHROMOSOME-7; EXTRAEMBRYONIC ECTODERM; CHIASMA FREQUENCY; LOCUS REGION; GENE; GENOME; RECOMBINATION; MARKERS; MICE AB The murine albino-deletion complex developed as part of the Oak Ridge specific-locus test covers 6-11 cM of chromosome 7. This complex has proven to be a valuable resource for localizing traits to a small target region suitable for positional cloning. In this study, we mapped the endpoints of deletions in this complex using all of the available Mit simple-sequence length polymorphism (SSLP) markers. Concurrently, this mapping has determined the map order of nearly all of the SSLP markers, most of which were previously unresolved. The SSLP-based deletion map was confirmed and genetic distances were determined using the European Collaborative Interspecific Backcross panel of nearly a thousand mice. The average SSLP marker resolution is 0.3-0.4 cM, comparable to the cloning capacity of yeast artificial chromosomes (YACs). The SSLP markers were then used to construct a genetically anchored YAC framework map that further confirms the deletion map. We find that the largest deleted region distal to Tyr is about two to three times larger than the largest proximal deleted region, and the original C3H/101 regions flanking the deletions (moved to an St2A c(ch)/c(ch) background) are smaller than anticipated, which we suggest may result from increased recombination rates immediately flanking the deleted regions. C1 UNIV COLORADO,INST BEHAV GENET,BOULDER,CO 80309. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. FU NIAAA NIH HHS [AA-03527, AA-08940, AA-00195] NR 50 TC 15 Z9 15 U1 0 U2 0 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 SN 0016-6731 J9 GENETICS JI Genetics PD OCT PY 1997 VL 147 IS 2 BP 787 EP 799 PG 13 WC Genetics & Heredity SC Genetics & Heredity GA XY919 UT WOS:A1997XY91900037 PM 9335613 ER PT J AU Shi, YP Mohapatra, G Miller, J Hanahan, D Lander, E Gold, P Pinkel, D Gray, J AF Shi, YP Mohapatra, G Miller, J Hanahan, D Lander, E Gold, P Pinkel, D Gray, J TI FISH probes for mouse chromosome identification SO GENOMICS LA English DT Article ID FLUORESCENCE INSITU HYBRIDIZATION; IN-SITU HYBRIDIZATION; LIBRARIES; DNA; GENERATION; SYSTEM AB P1 clones near the telomeres and centromeres of each mouse chromosome except Y have been selected from a mouse genomic library and mapped using fluorescence in situ hybridization (FISH). Each clone was selected to contain a genetically mapped polymorphic DNA sequence as close as possible to the centromere or telomere of a chromosome. The genetic distance from the various P1 clones to the most distal genetically mapped polymorphic sequence ranged from 0 for about half of the clones to 6.7 cM for the probe at the telomere of chromosome 14. The average distance to the most distal or proximal chromosome marker was 1.5 cM. The use of FISH with these probes for mouse chromosome identification during comparative genomic hybridization is illustrated. (C) 1997 Academic Press. C1 UNIV CALIF SAN FRANCISCO,CTR CANC,N415,SAN FRANCISCO,CA 94143. UNIV CALIF SAN FRANCISCO,HORMONE RES INST,SAN FRANCISCO,CA 94143. GENOME SYST INC,ST LOUIS,MO 63114. WHITEHEAD INST BIOMED RES,CAMBRIDGE,MA 02142. EO LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. FU NCI NIH HHS [CA45919] NR 17 TC 50 Z9 50 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 0888-7543 J9 GENOMICS JI Genomics PD OCT 1 PY 1997 VL 45 IS 1 BP 42 EP 47 DI 10.1006/geno.1997.4904 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA YA721 UT WOS:A1997YA72100006 PM 9339359 ER PT J AU Greenwood, JP Riciputi, LR McSween, HY AF Greenwood, JP Riciputi, LR McSween, HY TI Sulfide isotopic compositions in shergottites and ALH84001, and possible implications for life on Mars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MARTIAN METEORITE ALH84001; SNC METEORITES; SULFUR ISOTOPE; ION MICROPROBE; BASALTS; RATIOS; PETROGRAPHY; CHEMISTRY; ORIGIN AB The shergottite and ALH84001 meteorites hold keys for understanding geologic and possibly biologic processes on Mars. Recently, it has been proposed that carbonates in ALH84001, and the Fe-sulfides they contain, are products of extraterrestrial biogenic activity (McKay et al., 1996). Here we report ion microprobe analyses of sulfides in shergottites and ALH84001. The sulfur isotope ratios of igneous pyrrhotites in shergottites (mean delta(34)S(CDT):Shergotty = -0.4 parts per thousand, Zagami = +2.7 parts per thousand, EETA79001A = -1.9 parts per thousand, EETA79001B = -1.7 parts per thousand, LEW88516 = -1.9 parts per thousand, QUE94201 = +0.8 parts per thousand) are similar to those of terrestrial ocean-floor basalts, suggesting that the sulfur isotopic composition of the Martian mantle may be similar to that of the mantle of the Earth. The sulfur isotopic systematics of ALH84001 sulfides are distinct from the shergottites. Measured sulfur isotope ratios of eight pyrite grains (delta(34)S(CDT) = +2.0 to +7.3 parts per thousand) in crushed zones confirm previously reported analyses of isotopically heavy sulfides (Shearer et al., 1996) and are indistinguishable from an Fe-sulfide zone within a carbonate globule (delta(34)S(CDT) = +6.0 parts per thousand). Analyses of synthesized, fine-grained mixtures of sulfide, carbonate, and magnetite indicate that the measured sulfur isotope ratio is independent of the presence of carbonate and magnetite in the sputtered volume, confirming the accuracy of the analysis of the fine-grained sulfide in the carbonate globule. Terrestrial biogenic sulfate reduction typically results in light isotopic enrichments. The similarity of delta(34)S values of the sulfides in ALH84001 imply that the Fe-sulfide zones within ALH84001 carbonates are probably not the result of bacterial reduction of sulfate. Copyright (C) 1997 Elsevier Science Ltd. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Greenwood, JP (reprint author), UNIV TENNESSEE,DEPT GEOL SCI,KNOXVILLE,TN 37996, USA. NR 38 TC 32 Z9 32 U1 2 U2 11 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 OCT PY 1997 VL 61 IS 20 BP 4449 EP 4453 DI 10.1016/S0016-7037(97)00246-9 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YH279 UT WOS:A1997YH27900019 ER PT J AU Berner, RA Caldeira, K AF Berner, RA Caldeira, K TI The need for mass balance and feedback in the geochemical carbon cycle SO GEOLOGY LA English DT Editorial Material ID ATMOSPHERIC CO2; MODEL C1 LAWRENCE LIVERMORE NATL LAB,CLIMATE SYST MODELING GRP,LIVERMORE,CA 94550. RP Berner, RA (reprint author), YALE UNIV,DEPT GEOL & GEOPHYS,POB 6666,NEW HAVEN,CT 06520, USA. RI Caldeira, Ken/E-7914-2011 NR 15 TC 83 Z9 88 U1 1 U2 62 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD OCT PY 1997 VL 25 IS 10 BP 955 EP 956 DI 10.1130/0091-7613(1997)025<0955:TNFMBA>2.3.CO;2 PG 2 WC Geology SC Geology GA YB062 UT WOS:A1997YB06200023 ER PT J AU Vasco, DW AF Vasco, DW TI Groups, algebras, and the non-linearity of geophysical inverse problems SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE gravity; inverse problem; inversion; numerical techniques ID PARTIAL-DIFFERENTIAL EQUATIONS; ELECTROMAGNETIC INDUCTION; TRAVEL TIMES; TAU METHOD; SYMMETRIES; GRAVITY; NEVADA; EXISTENCE; LIE AB Mathematical methods from the theory of continuous groups are used to determine whether a non-linear inverse problem, in the form of a functional, can be transformed into a linear inverse problem. If such transformations exist they can be constructed from the solutions of a linear system of differential equations. An illustration of the methodology is given by the linearization of the functional relating basement topography to observed surface gravity. The linearized inversion of gravity data for basement topography is applied to observations from Yucca Mountain, Nevada. A 2.0 km step in the basement to the west of Yucca Mountain, corresponding to the Bare Mountain fault, matches the Bouguer gravity anomaly. The resolution and uncertainty associated with the estimates of basement topography indicate that the structure directly beneath the gravity line is well constrained. C1 UNIV CALIF BERKELEY, SEISMOG STN, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CTR COMPUTAT SEISMOL, BERKELEY, CA 94720 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 59 TC 5 Z9 5 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD OCT PY 1997 VL 131 IS 1 BP 9 EP 23 DI 10.1111/j.1365-246X.1997.tb00592.x PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YA085 UT WOS:A1997YA08500004 ER PT J AU Anandakrishnan, S Taylor, SR Stump, BW AF Anandakrishnan, S Taylor, SR Stump, BW TI Quantification and characterization of regional seismic signals from cast blasting in mines: a linear elastic model SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article ID QUARRY BLASTS; CHEMICAL EXPLOSIONS; SURFACE-WAVES; MINING BLASTS; SPALL; DISCRIMINATION AB Cast blasts in coal mines, designed to move large volumes of overburden, are a source of large (1-5 kt), frequent explosions in parts of the world with near-surface coal resources. Mining events of this source type are triggering the prototype International Monitoring System for the Comprehensive Test Ban Treaty being tested under the Group of Scientific Experts Technical Test 3 (GSETT-3). We wish to develop techniques to distinguish between the seismic signals produced by these explosions and equivalent size single (or point) sources. To that end, we have developed a linear elastic model to simulate regional-distance seismograms from mining cast blasts. Cast blasting involves a shot-array with delayed detonations casting rock horizontally into a pit. We model the effects of the millisecond-delay-firing pattern, the depth of the pit and the cast of material into the pit. We attempt to separate the effects due to the explosion, the vertical movement of mass and the horizontal movement of mass in order to produce a physical understanding of the resulting waveforms, which can be used to assess potential discriminants for these types of explosions. These physical models of source processes are constrained by near-surface measurements of cast blasts in NE Wyoming that are triggering GSETT-3. Two observational results at regional distances that are replicated by these models are the excitation of 8-12 s surface waves by the cast blasts and the insensitivity of peak amplitude to total explosive size for normal blasting practices. The insensitivity of peak amplitudes from the cast blast to total source size is a consequence of the delay-firing practice under normal procedures. This practice was initiated to reduce ground motions in the near-source region around the mine and it appears that it is also successful in controlling peak amplitudes at regional distances. The mass transfer into the pit has both a vertical and a horizontal force component, each of which contribute to the final seismogram, the latter being azimuthally dependent. Assuming maximum coupling, the contribution to the seismogram due to the vertical force component is approximately equal to the explosion contribution for pit depths of about 10 m, but dominates for pit depths of 20 m or greater. The contribution due to the horizontal force component is mainly in the enhanced Rayleigh waves. Comparison of high-frequency seismic radiation from the single shot and cast blast shows little qualitative difference in the regional waveforms. C1 LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. NR 26 TC 13 Z9 13 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD OCT PY 1997 VL 131 IS 1 BP 45 EP 60 DI 10.1111/j.1365-246X.1997.tb00594.x PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YA085 UT WOS:A1997YA08500006 ER PT J AU Laroche, J Nuzzi, R Waters, R Wyman, K Falkowski, PG Wallace, DWR AF Laroche, J Nuzzi, R Waters, R Wyman, K Falkowski, PG Wallace, DWR TI Brown Tide blooms in Long Island's coastal waters linked to interannual variability in groundwater flow SO GLOBAL CHANGE BIOLOGY LA English DT Article DE algal blooms; Aureococcus anophagefferens; brown tide; groundwater; nitrogen ID SUBTIDAL VOLUME FLUXES; AUREOCOCCUS-ANOPHAGEFFERENS; NARRAGANSETT-BAY; ALGAL BLOOMS; RHODE-ISLAND; NITRATE; CHRYSOPHYCEAE; SEDIMENTS; INPUTS AB There has been a widespread increase in the reporting of harmful and 'nuisance' algal blooms in the coastal ocean over the past few decades. On the global scale this is suspected to be a consequence of coastal eutrophication, however, on a case-by-case basis there is usually insufficient evidence to discriminate between the effects of human and natural causal factors. Intense blooms of the 'Brown Tide' unicellular algae (Aureococcus anophagefferens) have occurred sporadically since 1985 in coastal waters of Eastern Long Island and have devastated the local commercial scallop fishery. Analysis of an Ii-year time-series dataset from this region indicates that bloom intensity is correlated with higher salinities and inversely correlated with the discharge of ground-water. Laboratory and field studies suggest that whereas salinity is unlikely to represent a direct physiological control on Brown Tide blooms, the addition of inorganic nitrogen tends to inhibit Brown Tide blooms. Budget calculations indicate that the inorganic nitrogen supply from groundwater is 1-2 orders of magnitude higher than any other external source of nitrogen for this ecosystem. Biweekly time series data collected in 1995 demonstrate that Brown Tide blooms utilize dissolved organic nitrogen (DON) for growth, as evidenced by a large decrease in DON parallel with an increase in cell abundance. On an interannual basis, bloom intensity was also positively correlated with mean DON concentrations. We hypothesize that bloom initiation is regulated by the relative supply of inorganic and organic nitrogen, determined to a large extent by temporal variability in groundwater flow. The 1980s and 1990s were characterized by exceptionally high and interannually variable groundwater discharge, associated with a large-scale climate shift over the North Atlantic. This, coupled with the time-lagged discharge of groundwater with high nitrate concentrations resulting from increased fertilizer use and population increase during the 1960s and 1970s, may have been a key factor in the initiation of Brown Tide blooms in 1985. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. SUFFOLK CTY DEPT HLTH SERV,OFF ECOL,CTY CTR,RIVERHEAD,NY 11901. RI LaRoche, Julie/A-1109-2010 NR 47 TC 133 Z9 144 U1 2 U2 23 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD OCT PY 1997 VL 3 IS 5 BP 397 EP 410 DI 10.1046/j.1365-2486.1997.00117.x PG 14 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA YA089 UT WOS:A1997YA08900002 ER PT J AU Hein, EW Whitaker, SJ AF Hein, EW Whitaker, SJ TI Homing in eastern fence lizards (Sceloporus undulatus) following short-distance translocation SO GREAT BASIN NATURALIST LA English DT Article DE barrier; disturbance; eastern fence lizard; Sceloporus undulatus; homing; New Mexico; translocation ID AMPHIBIANS; REPTILES; SIZE AB We conducted an experiment on eastern fence lizards (Sceloporus undulatus) during August-September 1995 near Los Alamos, New Mexico, (1) to ascertain if lizards that were relocated short distances exhibited homing, (2) to investigate a possible barrier to movement, and (3) to determine the effect of translocating individuals from a transplant area on lizards in a recipient area. We relocated 15 of an estimated population of 39 (95% CI 36-45) lizards an average distance of 46 m. Fourteen of 15 translocated lizards returned to within 6.81 (s(chi) = 1.43) mof the original capture location. Movement distances did not vary (F = 0.76; 1,53 df; P = 0.381) between resident and translocated lizards during the pretreatment period and did not vary for resident (F = 2.86; 1,12 df; P = 0.1166), but varied between pretreatment and posttreatment periods for translocated (F = 14.65, 1,7 elf, P = 0.0065) lizards. Translocated lizards did not affect the resighting probability of resident lizards (F = 0.96; 1,14 df; P = 0.34), low this may be related to low power (1 - beta = 0.15) and translocated lizards moving out of the area quickly. C1 LOS ALAMOS NATL LAB,EES 15,ENVIRONM SCI GRP,MS J495,LOS ALAMOS,NM 87545. NR 20 TC 10 Z9 11 U1 1 U2 3 PU BRIGHAM YOUNG UNIV PI PROVO PA 290 LIFE SCIENCE MUSEUM, PROVO, UT 84602 SN 0017-3614 J9 GREAT BASIN NAT JI Gt. Basin Nat. PD OCT PY 1997 VL 57 IS 4 BP 348 EP 351 PG 4 WC Ecology SC Environmental Sciences & Ecology GA YG501 UT WOS:A1997YG50100006 ER PT J AU Leggett, RW AF Leggett, RW TI Basis and implications of the ICRP's new biokinetic model for thorium SO HEALTH PHYSICS LA English DT Article DE thorium; bioassay; dosimetry; safety standards ID STATES TRANS-URANIUM; EXCRETION MODEL; HUMAN-TISSUES; PLUTONIUM; AGE; METABOLISM; RETENTION; AMERICIUM; BIOASSAY AB The International Commission on Radiological Protection (ICRP) has adopted a new, age-specific biokinetic model for thorium, along with new assumptions concerning the fate of radioactive progeny produced in the body after intake of thorium. This paper explains the basis for the model and assumptions and examines some of their implications with regard to radiation dosimetry and bioassay. The new model differs substantially from the ICRP's previous biokinetic model for thorium (introduced in 1979 in ICRP Publication 30) with regard to model structure, sources of data used to derive parameter values, predictions of integrated activities of long-lived thorium isotopes in some radiosensitive organs, and predictions of the rates of urinary and fecal excretion of thorium at times remote from exposure. For the case of injection of Th-232 info blood of an adult, the new model and assumptions yield 4- to 8-fold decreases in predictions of 50-y committed equivalent doses to radiosensitive skeletal tissues but 7- to 55-fold increases in predictions of committed equivalent doses to extra-skeletal tissues, compared with the model and treatment of decay chain members recommended in ICRP Publication 30. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 46 TC 8 Z9 8 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 OCT PY 1997 VL 73 IS 4 BP 587 EP 600 DI 10.1097/00004032-199710000-00002 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA XX080 UT WOS:A1997XX08000002 PM 9314218 ER PT J AU Voelz, GL Lawrence, JNP Johnson, ER AF Voelz, GL Lawrence, JNP Johnson, ER TI Years of plutonium exposure to the Manhattan Project plutonium workers: An update SO HEALTH PHYSICS LA English DT Article DE plutonium; epidemiology; Manhattan Project; mortality ID MEDICAL FOLLOW-UP; URINARY-EXCRETION; SYSTEMIC PU; MORTALITY; RADIATION; REGISTRY; BODY AB Twenty-six white mate workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions, Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv, As of the end of 1994, 7 individuals have died compared with an expected 16 deaths based on mortality rates of U.S. white males in the general population. The standardized mortality ratio (SMR) is 0.43, When compared with 876 unexposed Los Alamos workers of the same period, the plutonium worker's mortality rate was also not elevated (SMR = 0.77). The 19 living persons have diseases and physical changes characteristic of a male population with a median age of 72 y (range = 69 to 86 y). Eight of the twenty-six workers have been diagnosed as having one or more cancers, which is within the expected range. The underlying cause of death in three of the seven deceased persons was from cancer, namely cancer of prostate, lung, and bone. Mortality from all cancers was not statistically elevated. The effective doses from plutonium to these individuals are compared with current radiation protection guidelines. C1 LOS ALAMOS NATL LAB, OCCUPAT MED GRP, LOS ALAMOS, NM 87545 USA. NR 28 TC 34 Z9 34 U1 1 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD OCT PY 1997 VL 73 IS 4 BP 611 EP 619 DI 10.1097/00004032-199710000-00004 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA XX080 UT WOS:A1997XX08000004 PM 9314220 ER PT J AU Kraig, DH AF Kraig, DH TI Dose reconstruction for weapons experiments involving La-140 at Los Alamos National Laboratory 1943-1962 SO HEALTH PHYSICS LA English DT Article DE dose; dose assessment; environmental impact; radioactivity, environmental AB A series of 254 weapons design experiments was conducted by Los Alamos National Laboratory from 1944 through 1962 and resulted in the dispersal of approximately II PBq (300 kCi) of radioactive La-140. All shots occurred at Point Able in Bayo Canyon, east of the Los Alamos townsite, Public interest and the Government Accounting Office probe precipitated a dose reconstruction to assess potential exposures to members of the public, The information available for each shot included explosive charge size, date and time of explosion, and shot activity, Detailed meteorological data were not available for the majority of the shots, requiring the development of statistically representative meteorological data, A wind rose was developed specific to the afternoon-evening time of the shots, and the wind frequency in each sector was used to determine the fraction of activity dispersed towards each hypothetical receptor, HOTSPOT 7, a Gaussian plume-based dispersion model, was used to determine the average dose per sector per unit of shot activity, The dose from penetrating radiation from ground-deposited La-190 was greater by several orders of magnitude than the dose from inhalation and immersion, The highest doses to a permanent resident probably occurred in the easternmost part of the Los Alamos townsite. The highest annual dose occurred in 1955 and was approximately 0.23 mSv, Assuming an individual had been at the location of maximum potential exposure in the Los Alamos townsite continuously throughout the experiments, the total dose from the 18-y series mould have been approximately 1.4 mSv with an average dose of approximately 0.09 mSv y(-1). Doses at nearby Totavi trailer park, San Ildefonso Pueblo, and Santa Clara Pueblo were approximately 75%, 40%, and 15%. respectively, of those at Los Alamos. Visitors to nearby public areas received negligible doses. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD OCT PY 1997 VL 73 IS 4 BP 620 EP 628 DI 10.1097/00004032-199710000-00005 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA XX080 UT WOS:A1997XX08000005 PM 9314221 ER PT J AU Cheng, YS Dahl, AR Jow, HN AF Cheng, YS Dahl, AR Jow, HN TI Dissolution of metal tritides in a simulated lung fluid SO HEALTH PHYSICS LA English DT Article DE tritium; lungs, human; radionuclides; dose AB Metal tritides including titanium tritide (Ti H-3(x)) and erbium tritide (Er H-3(x)) have been used as components of neutron generators. The current understanding of metal tritides and their radiation dosimetry for internal exposure is very limited, and the ICRP Publication 30 does not provide for tritium dosimetry in metal tritide form. However, a few papers in the literature suggest that the solubility of metal tritides could be low. The current radiation protection guidelines for metal tritide particles are based on the assumption that their biological behavior is similar to tritiated water, which could be easily absorbed into body fluid, Therefore, these particles could have relatively short biological half-lives (10 d). If the solubility is low, the biological half-life of metal tritide particles and the dosimetry of an inhalation exposure to these particles could be quite different from tritiated water. This paper describes experiments on the dissolution rate of titanium tritide particles in a simulated lung fluid. Titanium tritide particles with mean sizes of 103 mu m (coarse) and 0.95 mu m (fine) were used. The results showed that the coarse particles dissolved much more slowly than the fine particles. The long-term dissolution half times were 361 and 33 d for the coarse and fine particles, respectively. Dissolution data of the fine particles were consistent with the diffusion theory. The dissolution half times mere longer than the 10-d biological half time for tritiated water in the body. This finding has significant implications for the current health protection guidelines, including annual limits of intakes and derived air concentrations. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. LOVELACE RESP RES INST, ALBUQUERQUE, NM USA. NR 18 TC 21 Z9 22 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 OCT PY 1997 VL 73 IS 4 BP 633 EP 638 DI 10.1097/00004032-199710000-00007 PG 6 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 XX080 UT WOS:A1997XX08000007 PM 9314223 ER PT J AU Musolino, SV Greenhouse, NA Hull, AP AF Musolino, SV Greenhouse, NA Hull, AP TI An estimate by two methods of thyroid absorbed doses due to bravo fallout in several Northern Marshall Islands SO HEALTH PHYSICS LA English DT Article DE fallout; weapons; Marshall Islands; thyroid ID NEOPLASIA; EXPOSURE AB Estimates of the thyroid absorbed doses due to fallout originating from the 1 March 1954 BRAVO thermonuclear test on Bikini Atoll have been made for several inhabited locations in the Northern Marshall Islands, Rongelap, Utirik, Rongerik and Ailinginae Atolls mere also inhabited on 1 March 1954, where retrospective thyroid absorbed doses have previously been reconstructed, The current estimates are based primarily on external exposure data, which were recorded shortly after each nuclear test in the Castle Series, and secondarily on soil concentrations of Cs-137 in samples collected in 1978 and 1988, along with aerial monitoring done in 1978. The external exposures and Cs-137 soil concentrations were representative of the atmospheric transport and deposition patterns of the entire Castle Series tests and show that the BRAVO test was the major contributor to fallout exposure during the Castle series and other test series which were carried out in the Marshall Islands, These data have been used as surrogates for fission product radioiodines and telluriums in order to estimate the range of thyroid absorbed doses that may have occurred throughout the Marshall Islands, Dosimetry based on these two sets of estimates agreed within a factor of 4 at the locations where BRAVO was the dominant contributor to the total exposure and deposition. Both methods indicate that thyroid absorbed doses in the range of 1 Gy (100 rad) may have been incurred in some of the northern locations, whereas the doses at southern locations did not significantly exceed levels comparable to those from worldwide fallout, The results of these estimates indicate that a systematic medical survey for thyroid disease should he conducted, and that a more definitive dose reconstruction should be made for all the populated atolls and islands in the Northern Marshall Islands beyond Rongelap, Utirik, Rongerik and Ailinginae, which were significantly contaminated by BRAVO fallout. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. NR 31 TC 6 Z9 6 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 OCT PY 1997 VL 73 IS 4 BP 651 EP 662 DI 10.1097/00004032-199710000-00011 PG 12 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 XX080 UT WOS:A1997XX08000011 PM 9314227 ER PT J AU Hanf, RW Schreckhise, RG Patton, GW Poston, TM Jaquish, RE AF Hanf, RW Schreckhise, RG Patton, GW Poston, TM Jaquish, RE TI Public participation in radiological surveillance SO HEALTH PHYSICS LA English DT Article DE environmental impact; monitoring, environmental; public information; operational topics AB In 1989, Pacific Northwest National Laboratory developed a program, for the U.S. Department of Energy, to involve local citizens in environmental surveillance at the Hanford Site. The Community-Operated Environmental Surveillance Program was patterned after similar community-involvement efforts at the Nevada Test Site and the Three wile Island nuclear facility, Its purpose is to increase the flow of information to the public, thereby enhancing the public's awareness and understanding of surveillance activities. The program consists of two components: radiological air monitoring at nine offsite locations and agricultural product sampling at selected locations near the site. At each air-monitoring station, two local school teachers collect air particulate samples and operate equipment to monitor ambient radiation levels, Atmospheric tritium samples (as water vapor) are also collected at some locations, Four of the air-monitoring stations include large, colorful informational displays for public viewing. These displays provide details on station equipment, sample types, and sampling pul poses. Instruments in the displays also monitor, record, and show real-time ambient radiation readings (measured with a pressurized ionization chamber) and meteorological conditions, Agricultural products, grown primarily by middle-school-aged students, are obtained from areas downwind of the site, Following analysis of these samples, environmental surveillance staff visit the schools to discuss the results with the students and their teachers, The data collected by these air and agricultural sampling efforts are summarized with other routinely collected sitewide surveillance data and reported annually in the Hanford Site environmental report. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. WASHINGTON STATE UNIV, RICHLAND, WA 99352 USA. WASHINGTON STATE DEPT HLTH, DIV RADIAT PROTECT, RICHLAND, WA 99352 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD OCT PY 1997 VL 73 IS 4 BP 700 EP 705 DI 10.1097/00004032-199710000-00019 PG 6 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 XX080 UT WOS:A1997XX08000019 PM 9314235 ER PT J AU Hando, JC Tucker, JD Davenport, M Tepperberg, J Nath, J AF Hando, JC Tucker, JD Davenport, M Tepperberg, J Nath, J TI X chromosome inactivation and micronuclei in normal and Turner individuals SO HUMAN GENETICS LA English DT Article ID Y-CHROMOSOME; ANEUPLOIDY; LYMPHOCYTES; SEX; FREQUENCY; AGE AB Studies on aneuploidy have shown that the X is the most frequently lost chromosome in females, and that the number of X chromosome-positive micronuclei increases with age in women. Recently, we showed that the inactive X chromosome is incorporated preferentially in micronuclei. The objectives of the current study were, firstly, to determine the incidence of X chromosome incorporation into micronuclei in males and, secondly, to determine the incidence of X chromosome incorporation into micronuclei of females with Turner syndrome, Blood samples were obtained from 18 male newborns and 35 normal adult males ranging in age from 22 to 79 years and from seven women with non-mosaic Turner syndrome aged 11-39 years. Isolated lymphocytes were cultured in the presence of cytochalasin B and 2000 binucleated cells per subject were scored for micronuclei, Cells were then hybridized with the biotinylated X centromere-specific probe, pBamX7, and visualized with fluorescein-conjugated avidin. All micronucleated cells were relocated and evaluated for the presence or absence of the X chromosome, Of the 335 micronuclei observed, 6.6% (22/335) contained an X chromosome. Analysis of variance shows a statistically significant increase, for both males and Turner females, in the number of X chromosome-positive micronuclei with age (P < 0.001). These data also show that the X chromosome is included in micronuclei from males more often than would be expected by chance (P <0.005; chi(2) analysis, 15 df). Here we show that there is a tenfold difference in the frequency of X chromosome-positive micronuclei in 46,XX females compared to 46,XY males and 45,X females, providing further support to our previous finding that the X chromosome in micronuclei is the inactive chromosome. C1 W VIRGINIA UNIV,COLL AGR & FORESTRY,GENET & DEV BIOL PROGRAM,MORGANTOWN,WV 26506. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. UNIV N CAROLINA,DEPT PEDIAT,CHAPEL HILL,NC 27599. LAB CORP AMER,RES TRIANGLE PK,NC. NR 20 TC 36 Z9 36 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6717 J9 HUM GENET JI Hum. Genet. PD OCT PY 1997 VL 100 IS 5-6 BP 624 EP 628 DI 10.1007/s004390050564 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA XY681 UT WOS:A1997XY68100025 PM 9341883 ER PT J AU Banowetz, GM Hess, JR Carman, JG AF Banowetz, GM Hess, JR Carman, JG TI Monoclonal antibodies against the plant cytokinin, dihydrozeatin riboside SO HYBRIDOMA LA English DT Article ID ZEATIN RIBOSIDE; ISOPENTENYL ADENOSINE; GROWTH-REGULATOR; ABSCISIC-ACID; QUANTIFICATION; IMMUNOASSAY; WHEAT AB Three monoclonal antibodies (all IgG(1)) were prepared against the plant cytokinin dihydrozeatin riboside (diH[9R]Z) and characterized for suitability in the isolation and quantification of dihydrozeatin-type phytohormones. These antibodies detected as little as 5-10 pg of the homologous cytokinin when used in both competitive and noncompetitive immunoassays and each had characteristic crossreactivity with structurally-related cytokinins. One antibody was used to quantify HPLC-purified diH[9R]Z recovered from wheat tissue. The same antibody also was linked to an insoluble support for use in affinity purification of a mixture of cytokinins. These antibodies will be useful for purification and quantification of dihydrozeatin and its 9-riboside and 9-glucoside in plant tissue. C1 INEL,IDAHO FALLS,ID. UTAH STATE UNIV,DEPT PLANTS SOILS & BIOMETEOROL,LOGAN,UT 84311. RP Banowetz, GM (reprint author), USDA ARS,3450 SW CAMPUS WAY,CORVALLIS,OR 97331, USA. NR 21 TC 6 Z9 6 U1 1 U2 1 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 0272-457X J9 HYBRIDOMA JI Hybridoma PD OCT PY 1997 VL 16 IS 5 BP 479 EP 483 DI 10.1089/hyb.1997.16.479 PG 5 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Immunology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology GA YE707 UT WOS:A1997YE70700010 PM 9388032 ER PT J AU Biefeld, RM Kurtz, SR Allerman, AA AF Biefeld, RM Kurtz, SR Allerman, AA TI Novel materials and device design by metal-organic chemical vapour deposition for use in IR emitters SO IEE PROCEEDINGS-OPTOELECTRONICS LA English DT Article; Proceedings Paper CT 1st International Conference on Mid-IR Optoelectronics - Materials and Devices CY SEP, 1996 CL UNIV LANCASTER, LANCASTER, ENGLAND HO UNIV LANCASTER DE infrared emitters; chemical vapour deposition; antimonides; light emitting diodes ID STRAINED-LAYER SUPERLATTICES; PHASE EPITAXIAL-GROWTH; MU-M; LASERS; ALLOYS; ALGASB AB The authors have grown AlSb and AlAsxSb1-x epitaxial layers by metal-organic chemical vapour deposition (MOCVD) using trimethylamine or ethyldimethylamine alane, triethylantimony and arsine. These layers were successfully doped p- or n-type using diethylzinc or tetraethyltin, respectively. The authors have examined the growth of AlAsxSb1-x using temperatures of 500 to 600 degrees C, pressures of 65 to 630 torr, V/III ratios of 1-17, and growth rates of 0.3 to 2.7 mu m/hour in a horizontal quartz reactor. The authors have also grown gain-guided, injection lasers using AlAsSb for optical confinement and a strained InAsSb/InAs multiquantum well active region using MOCVD. The semi-metal properties of a p-GaAsSb/n-InAs heterojunction were utilised as a source for injection of electrons into the active region of the laser. In pulsed mode, the laser operated up to 210K with an emission wavelength of 3.8-3.9 mu m. The dependence of active region composition on wavelength was determined. The authors also report on the 2-colour emission of a light-emitting diode with two different active regions to demonstrate multistage operation of these devices. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Biefeld, RM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 6 Z9 6 U1 0 U2 3 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1350-2433 J9 IEE P-OPTOELECTRON JI IEE Proc.-Optoelectron. PD OCT PY 1997 VL 144 IS 5 BP 271 EP 276 DI 10.1049/ip-opt:19971301 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA ZQ542 UT WOS:000073872500004 ER PT J AU Paxson, V AF Paxson, V TI End-to-end routing behavior in the Internet SO IEEE-ACM TRANSACTIONS ON NETWORKING LA English DT Article DE communication system routing; computer networks; computer network performance; computer network reliability; failure analysis; internetworking; stability ID NETWORKS AB The large-scale behavior of routing in the Internet has gone virtually without any formal study, the exceptions being Chinoy's analysis of the dynamics of Internet routing information, and recent work, similar in spirit, by Labovitz, Malan, and Jahanian. We report on an analysis of 40 000 end-to-end route measurements conducted using repeated ''traceroutes'' between 37 Internet sites. We analyze the routing behavior for pathological conditions, routing stability, and routing symmetry, For pathologies, we characterize the prevalence of routing loops, erroneous routing, infrastructure failures, and temporary outages. We find that the likelihood of encountering a major routing pathology more than doubled between the end of 1994 and the end of 1995, rising from 1.5% to 3.3%. For routing stability, we define two separate types of stability, ''prevalence,'' meaning the overall likelihood that a particular route is encountered, and ''persistence,'' the likelihood that a route remains unchanged over a long period of time. We find that Internet paths are heavily dominated by a single prevalent route, but that the time periods over which routes persist show wide variation, ranging from seconds up to days. About two-thirds of the Internet paths had routes persisting for either days or weeks. For routing symmetry, we look at the likelihood that a path through the Internet visits at least one different city in the two directions. At the end of 1995, this was the case half the time, and at least one different autonomous system was visited 30% of the time. RP Paxson, V (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NETWORK RES GRP,BERKELEY,CA 94720, USA. NR 46 TC 226 Z9 253 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 1063-6692 J9 IEEE ACM T NETWORK JI IEEE-ACM Trans. Netw. PD OCT PY 1997 VL 5 IS 5 BP 601 EP 615 DI 10.1109/90.649563 PG 15 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA YF521 UT WOS:A1997YF52100001 ER PT J AU Hauer, J Trudnowski, D Rogers, G Mittelstadt, B Litzenberger, W Johnson, J AF Hauer, J Trudnowski, D Rogers, G Mittelstadt, B Litzenberger, W Johnson, J TI Keeping an eye on power system dynamics SO IEEE COMPUTER APPLICATIONS IN POWER LA English DT Article C1 MONTANA TECH UNIV, DEPT ENGN SCI, BUTTE, MT USA. RP Hauer, J (reprint author), US DOE, PACIFIC NW LAB, POWER SYST GRP, RICHLAND, WA 99352 USA. NR 6 TC 40 Z9 42 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 0895-0156 J9 IEEE COMPUT APPL POW JI IEEE Comput. Appl. Power PD OCT PY 1997 VL 10 IS 4 BP 50 EP 54 DI 10.1109/67.625375 PG 5 WC Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA XY928 UT WOS:A1997XY92800011 ER PT J AU Chow, WW Choquette, KD Crawford, MH Lear, KL Hadley, GR AF Chow, WW Choquette, KD Crawford, MH Lear, KL Hadley, GR TI Design, fabrication, and performance of infrared and visible vertical-cavity surface-emitting lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Review DE optoelectronic devices; semiconductor device fabrication; semiconductor lasers ID DISTRIBUTED BRAGG REFLECTORS; WELL HETEROSTRUCTURE LASERS; MOLECULAR-BEAM EPITAXY; VAPOR-PHASE EPITAXY; 0.85 MU-M; LOW-THRESHOLD; BURIED HETEROSTRUCTURE; LASING CHARACTERISTICS; SELECTIVE OXIDATION; SERIES RESISTANCE AB This paper discusses the issues involving the design and fabrication of vertical-cavity surface-emitting lasers (VCSEL's). A review of the basic experimental structures is given, with emphasis on recent developments in distributed Bragg reflectors, gain media, as well as current and optical confinement techniques. The paper describes present VCSEL performance, in particular, those involving selective oxidation and visible wavelength operation. RP Chow, WW (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 102 TC 157 Z9 171 U1 2 U2 27 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD OCT PY 1997 VL 33 IS 10 BP 1810 EP 1824 DI 10.1109/3.631287 PG 15 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XX249 UT WOS:A1997XX24900026 ER PT J AU Skidmore, JA Freitas, BL Reinhardt, CE Utterback, EJ Page, RH Emanuel, MA AF Skidmore, JA Freitas, BL Reinhardt, CE Utterback, EJ Page, RH Emanuel, MA TI High-power operation of InGaAsP-InP laser diode array at 1.73 mu m SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE semiconductor device fabrication; semiconductor laser arrays; semiconductor lasers; solid-state lasers AB InGaAsP-InP laser bars with an emission wavelength of 1.73 mu m have been fabricated using compressively strained multiple-quantum-well (MQW) separate-confinement heterostructures (SCH). One-cm-wide, 0.7-fill-factor, diode bars are bonded onto Si microchannel heatsinks and stacked into a two-dimensional (2-D) laser array. 16 W of continuous-wave (CW) power was produced from a l-cm bar and 200 W of peak power was generated from a id-bar array with an emitting aperture of 1 cm(2). RP Skidmore, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 13 TC 6 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD OCT PY 1997 VL 9 IS 10 BP 1334 EP 1336 DI 10.1109/68.623254 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XV977 UT WOS:A1997XV97700012 ER PT J AU Vallett, DP Soden, JM AF Vallett, DP Soden, JM TI Finding fault with deep-submicron ICs SO IEEE SPECTRUM LA English DT Article C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Vallett, DP (reprint author), IBM CORP,MICROELECT DIV,ESSEX JCT,VT 05452, USA. NR 6 TC 10 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD OCT PY 1997 VL 34 IS 10 BP 39 EP 50 DI 10.1109/6.625244 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA YA490 UT WOS:A1997YA49000012 ER PT J AU Rao, NSV AF Rao, NSV TI Distributed decision fusion using empirical estimation SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article ID COMPLEXITY AB The problem of optimal data fusion in multiple detection systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors committed by the individual detectors. Earlier solutions to this problem require some knowledge of the error distributions of the detectors, for example, either in a parametric form or in a closed analytical form. Here we show that, given a sufficiently large training sample, an optimal fusion rule can be implemented with an arbitrary level of confidence. We first consider the classical cases of Bayesian rule and Neyman-Pearson test for a system of independent detectors. Then we show a general result that any test function with a suitable Lipschitz property can be implemented with arbitrary precision, based on a training sample whose size is a function of the Lipschitz constant, number of parameters, and empirical measures. The general case subsumes the cases of nonindependent and correlated detectors. RP Rao, NSV (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,POB 20008,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 21 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD OCT PY 1997 VL 33 IS 4 BP 1106 EP 1114 DI 10.1109/7.624346 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA XZ476 UT WOS:A1997XZ47600002 ER PT J AU Leung, WY Biswas, R Cheng, SD Sigalas, MM McCalmont, JS Tuttle, G Ho, KM AF Leung, WY Biswas, R Cheng, SD Sigalas, MM McCalmont, JS Tuttle, G Ho, KM TI Slot antennas on photonic band gap crystals SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Letter DE slot antennas AB The radiation patterns of a slot antenna placed on a photonic band gap crystal have been measured. We used a layer-by-layer photonic band gap crystal having a three-dimensional stop band between 12 and 15 GHz. The slot antenna radiation depends sensitively on the relative position and orientation of the slot in the surface unit cell of the photonic crystal. We have found configurations of the slot antenna with an increase of radiated power by 2-3 dB. The photonic band gap crystal can considerably improve the performance of a simple slot antenna. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. ELECT TECHNOL CORP,AMES,IA 50010. RP Leung, WY (reprint author), IOWA STATE UNIV,MICROELECT RES CTR,AMES,IA 50011, USA. NR 8 TC 21 Z9 23 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD OCT PY 1997 VL 45 IS 10 BP 1569 EP 1570 DI 10.1109/8.633871 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA XY929 UT WOS:A1997XY92900023 ER PT J AU Reich, RK Mountain, RW Robinson, M McGonagle, WH Loomis, AH Kosicki, BB Savoye, ED AF Reich, RK Mountain, RW Robinson, M McGonagle, WH Loomis, AH Kosicki, BB Savoye, ED TI An epitaxially-grown charge modulation device SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article ID HIGH-RESOLUTION; OVERLAID; CHANNEL; NOISE AB A charge modulation device (CMD) has been fabricated in a p-type epitaxial layer grown from the buried-channel silicon region of a charge-coupled device (CCD). Construction of the CMD directly above the CCD buried-channel and over the oxidized CCD transfer gates lowers the effective sense capacitance while providing isolation of the CMD source/drain regions. Responsivity values of 28 and 66 mu V/e for feedback and no feedback conditions, respectively, were measured dynamically on test devices. Input-referred noise values of approximately four electrons rms were calculated from noise spectral density measurements assuming a low-pass filter 3 dB cutoff frequency of 5 MHz and correlated double sampling. C1 LAWRENCE SEMICOND RES LAB INC,TEMPE,AZ 85282. RP Reich, RK (reprint author), MIT,LINCOLN LAB,244 WOOD ST,LEXINGTON,MA 02173, USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD OCT PY 1997 VL 44 IS 10 BP 1672 EP 1678 DI 10.1109/16.628822 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA XX729 UT WOS:A1997XX72900018 ER PT J AU Huesman, RH Coxson, PG AF Huesman, RH Coxson, PG TI Consolidation of common parameters from multiple fits in dynamic PET data analysis SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Letter DE approximation methods; maximum-likelihood estimation; parameter estimation; positron emission tomography; uncertainty ID TOMOGRAPHY AB In dynamic positron emission tomographs (PET) data analysis, regions of interest (ROI's) are analyzed hg fitting a parametric model to the time-activity curve acquired after a radio-labeled tracer has been introduced into the patient's bloodstream, This procedure can be carried out for multiple ROI's and/or multiple injections of the same or a different radiopharmaceutical. The approach presented here takes advantage of prior knowledge that some of the parameters of those multiple fits are the same. Reduction of the total number of parameters to be estimated results in smaller statistical uncertainty for all parameter estimates, especially those common to multiple fits. C1 UNIV CALIF SAN FRANCISCO,SCH MED,DEPT MED,SAN FRANCISCO,CA 94143. RP Huesman, RH (reprint author), UNIV CALIF BERKELEY,CTR FUNCT IMAGING,EO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL25840, HL47675] NR 12 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD OCT PY 1997 VL 16 IS 5 BP 675 EP 683 DI 10.1109/42.640758 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA YE919 UT WOS:A1997YE91900021 PM 9368123 ER PT J AU Castoldi, A Guazzoni, C Longoni, A Gatti, E Rehak, P Struder, L AF Castoldi, A Guazzoni, C Longoni, A Gatti, E Rehak, P Struder, L TI Conception and design criteria of a novel silicon device for the measurement of position and energy of X rays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE fast read-out; high-energy resolution; silicon detector; X-ray imaging ID DRIFT DETECTORS; TIME; CCDS AB In this paper we present the working principle and the design criteria of the Controlled-Drift Detector, a novel device suitable for the simultaneous measurement of energy and two-dimensional position of X rays. In the Controlled-Drift Detector the pixel structure typical of a charge-coupled de,ice and the fast readout typical of a silicon drift detector are joined. When the radiation is to be detected, suitable potential barriers are generated to prevent the drift of the signal electrons that are confined within a matrix of integration webs. The potential barrier which prevents the drift is selectively removable to allow the fast transport of the confined signal electrons to the readout electrodes by means of a static drift field. In principle such a device can achieve excellent energy resolution and readout times of some tens of microseconds. Three different confining mechanisms that allow control of the drift of the stored electrons are studied, and their advantages and drawbacks are discussed. First prototypes of the Controlled-Drift Detector are currently in production. C1 POLITECN MILAN,DIPARTIMENTO ELETTR,I-20133 MILAN,ITALY. BROOKHAVEN NATL LAB,UPTON,NY 11973. MAX PLANCK INST HALBLEITERLABOR,D-81245 MUNICH,GERMANY. RP Castoldi, A (reprint author), UNIV MILAN,DIPARTIMENTO FIS,VIA CELORIA 16,I-20133 MILAN,ITALY. RI Guazzoni, Chiara/A-5070-2008 OI Guazzoni, Chiara/0000-0001-6399-8670 NR 17 TC 34 Z9 34 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 1997 VL 44 IS 5 BP 1724 EP 1732 DI 10.1109/23.633425 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA YA225 UT WOS:A1997YA22500004 ER PT J AU Yuasa, T Akiba, M Takeda, T Kazama, M Hoshino, A Watanabe, Y Hyodo, K Dilmanian, FA Akatsuka, T Itai, Y AF Yuasa, T Akiba, M Takeda, T Kazama, M Hoshino, A Watanabe, Y Hyodo, K Dilmanian, FA Akatsuka, T Itai, Y TI Incoherent-scatter computed tomography with monochromatic synchrotron X ray: Feasibility of multi-CT imaging system for simultaneous measurement of fluorescent and incoherent scatter X rays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE computed tomography; incoherent scatter; least squares method; Monte Carlo simulation; singular value decomposition; synchrotron radiation ID MONTE-CARLO SIMULATION; RADIATION AB We describe a new system of incoherent scatter computed tomography (ISCT) using monochromatic synchrotron X rays, and we discuss its potential to be used in in vivo imaging for medical use. The system operates on the basis of computed tomography (CT) of the first generation. The reconstruction method for ISCT uses the least squares method with singular value decomposition. The research was carried out at the BLNE-5A bending magnet beam line of the Tristan Accumulation Ring in KEK, Japan. An acrylic cylindrical phantom of 20-mm diameter containing a cross-shaped channel was imaged. The channel was filled with a diluted iodine solution with a concentration of 200 mu gI/ml. Spectra obtained with the system's high purity germanium (HPGe) detector separated the incoherent X-ray line from the other notable peaks? i.e., the K-alpha and K-beta 1 X-ray fluorescent lines and the coherent scattering peak. CT images were reconstructed from projections generated by integrating the counts in the energy window centering around the incoherent scattering peak and whose width was approximately 2 keV. The reconstruction routine employed an X-ray attenuation correction algorithm. The resulting image showed more homogeneity than one without the attenuation correction. C1 UNIV TSUKUBA,INST CLIN MED,TSUKUBA,IBARAKI 305,JAPAN. NATL LAB HIGH ENERGY PHYS,PHOTON FACTORY,TSUKUBA,IBARAKI 305,JAPAN. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP Yuasa, T (reprint author), YAMAGATA UNIV,FAC ENGN,YONEZAWA,YAMAGATA 992,JAPAN. RI Yuasa, Tetsuya/F-5006-2013 NR 23 TC 16 Z9 18 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 1997 VL 44 IS 5 BP 1760 EP 1769 DI 10.1109/23.633430 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA YA225 UT WOS:A1997YA22500009 ER PT J AU Snyder, SC LeRoux, AM AF Snyder, SC LeRoux, AM TI Time-resolved laser-induced fluorescence of atomic nitrogen in a free-burning arc discharge SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE arc discharge; atomic measurements; laser measurement applications; plasma measurements; time-resolved fluorescence spectroscopy; two-photon laser ID HYDROGEN; PLASMA; LIFETIME; FLAMES AB An experiment to detect ground-state atomic nitrogen in an atmospheric-pressure argon-nitrogen free-burning 200 A are by time-resolved two-photon laser-induced fluorescence is described, The time decay of the fluorescence pulses showed that quenching of the laser-excited state is rapid, Upper bound estimates of the pulse-decay time were determined as a function of radius, and were found to be on the order of 1 ns, and to decrease with increasing radii, The implications of rapid quenching of the laser-excited state to the application of laser-induced fluorescence as a plasma diagnostic tool are discussed. C1 MONTANA STATE UNIV,DEPT PHYS,BOZEMAN,MT 59717. RP Snyder, SC (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 13 TC 3 Z9 3 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 1997 VL 25 IS 5 BP 824 EP 827 DI 10.1109/27.649576 PG 4 WC Physics, Fluids & Plasmas SC Physics GA YJ847 UT WOS:A1997YJ84700004 ER PT J AU SariSarraf, H Brzakovic, D AF SariSarraf, H Brzakovic, D TI A shift-invariant discrete wavelet transform SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Letter AB This correspondence presents a unifying approach to the derivation and implementation of a shift-invariant wavelet transform of one-and two-dimensional (1-D and 2-D) discrete signals, Starting with Mallat's multiresolution wavelet representation (MRWAR), the correspondence presents an analytical process through which a shift-invariant, orthogonal, discrete wavelet transform called the multiscale wavelet representation (MSWAR) is obtained, The coefficients in MSWAR are shown to be inclusive of those in MRWAR with the implication that the derived representation is invertible. The computational complexity of MSWAR is quantified in terms of the required convolutions, and its implementation is shown to be equivalent to the filter upsampling technique. C1 UNIV TENNESSEE,DEPT ELECT ENGN,KNOXVILLE,TN 37996. LEHIGH UNIV,DEPT ELECT ENGN & COMP SCI,BETHLEHEM,PA 18015. RP SariSarraf, H (reprint author), OAK RIDGE NATL LAB,DIV INSTRUMENTAT & CONTROLS,POB 2008,OAK RIDGE,TN 37830, USA. NR 7 TC 24 Z9 26 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD OCT PY 1997 VL 45 IS 10 BP 2621 EP 2626 DI 10.1109/78.640735 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA YA483 UT WOS:A1997YA48300029 ER PT J AU Brooks, MW Lynn, S AF Brooks, MW Lynn, S TI Recovery of calcium carbonate and hydrogen sulfide from waste calcium sulfide SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID TEMPERATURE H2S REMOVAL; COAL-GAS; LIMESTONE; SORBENTS; KINETICS; SORPTION AB The removal of H2S from hot coal gas using a limestone-based sorbent generates a large quantity of calcium sulfide waste (e.g., 67 tons/day from the gasification of 1000 tons/day of 3% S coal) that cannot be landfilled because of potential H2S evolution and sulfide leaching. In the process proposed here, the CaS is dissolved by reaction with H2S complexed with aqueous methyldiethanolamine (MDEA) or other alkanolamines. In the second step, the highly soluble Ca(HS)(2) reacts readily with CO2, also complexed with aqueous MDEA, to precipitate pure CaCO3 of uniform crystal size and to form MDEA-complexed H2S in solution. The solution from step 2 is split-half is recycled to step 1 and half is sent to a stripper to recover H2S and from there to a column where the needed CO2 is absorbed from a combustion gas. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 13 TC 17 Z9 17 U1 1 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 OCT PY 1997 VL 36 IS 10 BP 4236 EP 4242 DI 10.1021/ie970151j PG 7 WC Engineering, Chemical SC Engineering GA XZ188 UT WOS:A1997XZ18800026 ER PT J AU Sekulic, DP Edeskuty, FJ Uzelac, Z AF Sekulic, DP Edeskuty, FJ Uzelac, Z TI Heat transfer through a high temperature superconducting current lead at cryogenic temperatures SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID DEVICES; DESIGN; MAGNET AB A study of heat transfer through a high temperature superconducting (HTSC) current lead in both, resistive and superconducting mode, has been performed. The set of dimensionless governing parameters was defined, and the physical meaning of different parameters elaborated. An optimal selection of thermal design parameters was suggested. The selection of parameters has been based on : (i) the numerical solution of a set of nonlinear governing differential equations; and (ii) an estimation of the irreversibility induced by heat transfer and Joule heating phenomena. The results were discussed for a YBa2Cu3O7-delta (YBCO) compound system. The case study has been based on a cryogenic current lead model that includes the nonlinearities as follows: (i) variable thermal conductivity; (ii) variable electrical resistivity (in resistive mode); and (iii) Variable heat transfer coefficient. The results obtained correspond to the temperature range between 4.2 and 77 K. It was shown that a local variation in heat transfer coefficient does not influence the selection of optimal design parameters. (C) 1997 Elsevier Science Ltd. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV NOVI SAD,FAC TECH SCI,YU-21000 NOVI SAD,YUGOSLAVIA. RP Sekulic, DP (reprint author), UNIV KENTUCKY,DEPT MECH ENGN,LEXINGTON,KY 40506, USA. NR 15 TC 1 Z9 1 U1 0 U2 1 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 OCT PY 1997 VL 40 IS 16 BP 3917 EP 3926 DI 10.1016/S0017-9310(97)00013-6 PG 10 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA XK389 UT WOS:A1997XK38900012 ER PT J AU Dong, YJ Steinberg, M AF Dong, YJ Steinberg, M TI Hynol - An economical process for methanol production from biomass and natural gas with reduced CO2 emission SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (a) hydrogasification of biomass, (b) steam reforming of the produced gas with additional natural gas feedstock, and (c) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps. The H-2-rich gas remaining after methanol synthesis is recycled to gasify the biomass in an energy neutral reactor so that there is no need for an expensive oxygen plant as required by commercial steam gasifiers. Recycling gas allows the methanol synthesis reactor to perform at a relatively lower pressure than conventional while the plant still maintains high methanol yield. Energy recovery designed into the process minimizes heat loss and increases the process thermal efficiency. If the Hynol methanol is used as an alternative and more efficient automotive fuel, an overall 41% reduction in CO2 emission can be achieved compared to the use of conventional gasoline fuel. A preliminary economic estimate shows that the total capital investment for a Hynol plant is 40% lower than that for a conventional biomass gasification plant. The methanol production cost is $0.43/gal for a 1085 million gal/yr Hynol plant which is competitive with current U.S. methanol and equivalent gasoline prices. Process flowsheet and simulation data using biomass and natural gas as cofeedstocks are presented. The Hynol process can convert any condensed carbonaceous material, especially municipal solid waste (MSW). to produce methanol. (C) 1997 International Association for Hydrogen Energy. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 11 TC 38 Z9 43 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD OCT-NOV PY 1997 VL 22 IS 10-11 BP 971 EP 977 DI 10.1016/S0360-3199(96)00198-X PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA YG144 UT WOS:A1997YG14400003 ER PT J AU Gordon, RL Sieglaff, DR Rutherford, GH Stricklett, KL AF Gordon, RL Sieglaff, DR Rutherford, GH Stricklett, KL TI Optically enhanced electron attachment by p-benzoquinone SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE electron attachment; excited states; trochoidal monochromator; mass spectrometry ID NEGATIVE-ION; METHYLATED DERIVATIVES; MOLECULES; CAPTURE; STATES AB The relative rate of formation of long-lived parent anions in p-benzoquinone (BQ) by attachment of electrons with energies between 0 and 3 eV has been measured at an energy resolution of roughly 50 meV using a trochoidal electron monochromatorbased electron impact negative ion mass spectrometer. A comparison of measurements taken near 0 eV shows an increase of the order of 10(5) in the attachment cross-section for BQ molecules excited by UV/visible light from a xenon are lamp over that of ground state molecules. Resonances in attachment by ground state molecules are observed at impact energies of approximately 0.8, 1.0, and 1.3 eV. Negative ion resonances exhibited in the transmitted electron current corroborate these observations. Comparison is made with the results of previous work. (C) 1997 Elsevier Science B.V. C1 GROVE CITY COLL,DEPT PHYS,GROVE CITY,PA 16127. ILLINOIS STATE UNIV,DEPT PHYS,NORMAL,IL 61790. NIST,GAITHERSBURG,MD 20899. RP Gordon, RL (reprint author), US DOE,DIV CHEM SCI ER 142,19901 GERMANTOWN RD,GERMANTOWN,MD 20874, USA. NR 15 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD OCT PY 1997 VL 164 IS 3 BP 177 EP 191 DI 10.1016/S0168-1176(97)00094-3 PG 15 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA YE478 UT WOS:A1997YE47800002 ER PT J AU Riley, GN Malozemoff, AP Li, Q Fleshler, S Holesinger, TG AF Riley, GN Malozemoff, AP Li, Q Fleshler, S Holesinger, TG TI The freeway model: New concepts in understanding supercurrent transport in Bi-2223 tapes SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID CRITICAL-CURRENT DENSITY; SILVER-SHEATHED TAPES; T-C SUPERCONDUCTORS; GRAIN-BOUNDARIES; TWIST BOUNDARIES; CURRENT FLOW; AG; TEMPERATURE; BICRYSTALS; DEPENDENCE AB A variety of mechanisms for supercurrent transport in (Bi,Pb)(2)Sr2Ca2Cu3Ox(Bi-2223) tapes have been proposed, including the brick-wall and railway-switch models and the more recent freeway model. In this article, these models' are compared to a growing library of data, including structural and transport studies on specific grain boundary types as well as the systematics of microstructure and transport in the polycrystalline tapes, including new transmission electron microscopy data on some of the highest-performing samples yet fabricated. Additionally, the freeway model is developed, with the concepts of rotary junction bottlenecks corresponding to edge colony boundaries, of lane changes corresponding to c-axis redistribution within colonies, and on-ramps corresponding to tilted and bent grains. C1 Amer Supercond Corp, Westborough, MA 01581 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Riley, GN (reprint author), Amer Supercond Corp, 2 Technol Dr, Westborough, MA 01581 USA. NR 45 TC 12 Z9 12 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD OCT PY 1997 VL 49 IS 10 BP 24 EP + DI 10.1007/BF02914734 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 114QN UT WOS:000075620500005 ER PT J AU Ilcisin, KJ Buzak, TS Parker, GJ AF Ilcisin, KJ Buzak, TS Parker, GJ TI The switching dynamics of the plasma addressed liquid crystal display SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT XXIIIrd International Conference on Phenomena in Ionized Gases CY JUL 17-22, 1997 CL TOULOUSE, FRANCE AB The plasma addressed liquid crystal display (PLAC) is a flat, large area, full-colour television and monitor technology made possible through the unique application of the properties of an ionized gas. Liquid crystal displays require an active switching element at the location of each pixel. The PALC display uses a plasma switch to address each of the display pixels, replacing typically used semiconductor devices. The use of the plasma switch permits the manufacture, in very large sizes, of a display possessing excellent image quality. The performance of the PALC display is intrinsically related to the behaviour of the plasma used as the switching element. This paper reviews the trends that led to the development of the PALC display, describes the operating principals, and examines, in detail, one of the many areas of ongoing plasma physics The successful development of a model, which agrees with the measured decay behaviour of the plasma, contributed to a significant improvement in the performance of the PALC display. C1 Tech Vis Inc, Beaverton, OR 97077 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ilcisin, KJ (reprint author), Tech Vis Inc, M-S 46-944,14000 SW Karl Braun Dr, Beaverton, OR 97077 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 1997 VL 7 IS C4 BP 225 EP 233 DI 10.1051/jp4:1997418 PG 9 WC Physics, Multidisciplinary SC Physics GA YU920 UT WOS:000071769900019 ER PT J AU Hering, S Gundel, L Daisey, JM AF Hering, S Gundel, L Daisey, JM TI A microslot impactor for organic aerosol sampling SO JOURNAL OF AEROSOL SCIENCE LA English DT Article ID DISTRIBUTIONS AB A microslot impactor has been designed with the objective of collecting large, concentrated samples suitable for chemical analysis of trace organic constituents. It employs a single slotted orifice per stage, with orifice widths as small as 0.1 mm. Using a relatively small pump (13 kg), five cutpoints from 0.1 to 3.5 mu m are obtained at st flow rate of 36 l min(-1) (6 x 10(-4) m(3) s(-1)). The microslot impactor operates with incompressible how and minimal pressure drops for the upper four stages, and sonic flow through the last (fifth) stage. Measured cutpoints for the incompressible flow stages are somewhat higher than predicted, with critical Stokes numbers corresponding to 10 to 30% greater than theory. (C) 1997 Elsevier Science Ltd. C1 Aerosol Dynam Inc, Berkeley, CA 94710 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Indoor Environm Program, Berkeley, CA 94720 USA. RP Hering, S (reprint author), Aerosol Dynam Inc, Berkeley, CA 94710 USA. RI Hering, Susanne/B-1906-2012 NR 13 TC 9 Z9 9 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0021-8502 J9 J AEROSOL SCI JI J. Aerosol. Sci. PD OCT PY 1997 VL 28 IS 7 BP 1283 EP 1290 DI 10.1016/S0021-8502(96)00484-3 PG 8 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA YM833 UT WOS:000071106000011 ER PT J AU Houk, RS Winge, RK Chen, XS AF Houk, RS Winge, RK Chen, XS TI High speed photographic study of wet droplets and solid particles in the inductively coupled plasma SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE inductively coupled plasma; inductively coupled plasma mass spectrometry; nebulization; sample introduction; slurry; noise; particles; droplets ID DRIED MICROPARTICULATE INJECTOR; MASS-SPECTROMETRY; THERMAL-DECOMPOSITION; METAL NITRATES; VAPORIZING PARTICLES; SIGNAL FLUCTUATIONS; SLURRY NEBULIZATION; SPECTROSCOPY; DESOLVATION; MECHANISMS AB Motion pictures of the ICP were taken at 4000 frames s(-1), An intact wet droplet containing yttrium causes the formation of a pale red cloud juxtaposed on the usual ambient emission structure of the plasma, Most of these droplet clouds are shaped like an oval or a comet, A few droplets produce small, bright spheres followed by faint, wispy streaks that point downstream, Such a spherical cloud is caused by some rapid event such as explosion of a droplet in the final stages of solvent evaporation, The faint sneaks are some residue, perhaps small solid particles, In a particular frame, a number of these faint streaks protrude from the tip of the initial radiation zone (IRZ) into tbe normal analytical zone (NAZ). When wet droplets are introduced, that portion of the analyte that navels through the center of the plasma passes through three distinct regions (i.e., the IRZ, the streaks, then the NAZ), rather than directly from the IRZ to the NAZ, Groups of two or three droplets tend to appear together in the same time interval (approximate to 0.12 ms) in the plasma, These droplet clouds are not seen, and the particle streaks are much less evident, when the solvent is removed before the aerosol is injected into the plasma, Aqueous slurries of Y2O3 in various particle sizes (0.1 or 3 mu m mean diameter) produce white streaks along the center line of the plasma, which are attributed to individual solid particles, These observations also support the general precept that calibration of the response for slurries using aqueous solution standards is best accomplished by keeping the particle loading such that each wet droplet contains no more than one solid slurry particle. RP Houk, RS (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES LAB,US DEPT ENERGY,AMES,IA 50011, USA. NR 45 TC 51 Z9 52 U1 1 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 OCT PY 1997 VL 12 IS 10 BP 1139 EP 1148 DI 10.1039/a607579g PG 10 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA YB975 UT WOS:A1997YB97500008 ER PT J AU Wayne, DM AF Wayne, DM TI Direct determination of trace noble metals (palladium, platinum and rhodium) in automobile catalysts by glow discharge mass spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE glow discharge mass spectrometry; automobile catalyst; noble metal; palladium; rhodium; platinum; spectral interference ID LA-ICP-MS; SOLIDS; IMPURITIES AB Most automobile catalysis consist of a CeO2- and Al2O3-rich washcoat deposited on a porous, honeycombed cordierite support block. The active ingredients in the automobile catalyst are several noble metals (usually Pd, Rh and Pt) contained in the washcoat. Rapid, precise and accurate quantification of noble metals in automobile catalysis is desirable for noble metal tracking and accountability. Determination of Pd, Rh and Pt in the catalysts by ID-ICP-MS is possible only after extensive treatment with highly corrosive acids in sealed quartz tubes at high temperatures. By contrast, GDMS permits the direct determination of noble metals in the catalysts without prior dissolution. Although the auto catalyst powders are non-conducting, they may be combined with a metallic binder and analysed. Aluminium powder was chosen as the binder material for its superior gettering abilities, and because the Al mass spectrum in the vicinity of the Pd, Rh and Pt peaks was clear of interferences. Results from the GDMS analysis of noble metals in NIST Standard Reference Material 2557 Used Auto Catalyst (monolith) are precise and accurate to <10% RSD for Pd, Rh and Pt. The current generation of auto catalyst materials also contain significant amounts (approximate to 0.3% by mass) of ZrO2, which causes isobaric (ZrO)(+) interference on m/z 106, 107, 108, 110 and 112. A simple mathematical peak-stripping routine was devised to eliminate the (ZrO)(+) interference. RP Wayne, DM (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST-8,MAIL STOP G740,LOS ALAMOS,NM 87545, USA. NR 20 TC 37 Z9 37 U1 1 U2 9 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 OCT PY 1997 VL 12 IS 10 BP 1195 EP 1202 DI 10.1039/a701959i PG 8 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA YB975 UT WOS:A1997YB97500016 ER PT J AU Ravelli, RBG Sweet, RM Skinner, JM Duisenberg, AJM Kroon, J AF Ravelli, RBG Sweet, RM Skinner, JM Duisenberg, AJM Kroon, J TI STRATEGY: a program to optimize the starting spindle angle and scan range for X-ray data collection SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB STRATEGY is a program for determination of the optimal starting spindle angle and scan range for X-ray diffracton data collection. It is optimized for crystals of macromolecular compounds using a one-circle diffractometer with a two-dimensional detector. In its current implementation, the program reads the starting crystal orientation and cell parameters from a DENZO intensities '.x' file and simulates all the reflections that can occur during a 360 degrees rotation of the crystal. It determines whether the reflections can be recorded on the detector and sorts them on spindle angle. Then it gives diagrams representing the needed sweep as a function of the starting spindle angle for different degrees of completeness of the data set wanted, and produces redundancy tables for the shortest data collection possible for each desired completeness. Use of the program assists in careful planning of data collection: it will assure a complete data set, and certainly will allow data collection in the shortest possible time, sometimes reducing the data-collection time by a factor of two or more, depending on the lattice symmetry and the data-collection mode. C1 BROOKHAVEN NATL LAB,DEPT BIOL STRUCT,UPTON,NY 11973. RP Ravelli, RBG (reprint author), UNIV UTRECHT,BIJVOET CTR BIOMOL RES,DEPT CRYSTAL & STRUCT CHEM,PADUALAAN 8,NL-3584 CH UTRECHT,NETHERLANDS. NR 9 TC 58 Z9 58 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 1997 VL 30 IS 1 BP 551 EP 554 DI 10.1107/S0021889897003543 PN 5 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA YE856 UT WOS:A1997YE85600006 ER PT J AU Nguyen, B Clarke, CJ Eisenberg, A Rafailovich, MH Sokolov, J Smith, GS AF Nguyen, B Clarke, CJ Eisenberg, A Rafailovich, MH Sokolov, J Smith, GS TI Investigation of polymer brushes and adsorbed layers under shear SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on Small-Angle Scattering CY JUL 21-26, 1996 CL CAMPINAS, BRAZIL ID NEUTRON REFLECTIVITY; FLOW; ADSORPTION; CHAIN AB Neutron reflectometry was used to investigate the density profiles of polymer brushes and an adsorbed polymer layer under shear. The brushes consisted of end-functionalized deuterated polystyrene. The adsorbed polymer was a random copolymer of deuterated styrene and 4-vinylpyridine. The brush and the adsorbed layer were sheared by the flowing of solvents over the polymer, with a maximum shear rate of 10(4) s(-1). Density profiles of the brush and the layer were determined before, during and after shear. The shear had no observable effect on the polymer profiles in any of the experiments. We discuss these results in the context of other experiments and a recent theory. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. McGill Univ, Dept Chem, Montreal, PQ H3A 2K6, Canada. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Nguyen, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Eisenberg, Adi/B-8676-2008 NR 23 TC 12 Z9 12 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 1997 VL 30 IS 2 BP 680 EP 683 DI 10.1107/S0021889897001532 PN 5 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA YT746 UT WOS:000071640900024 ER PT J AU Londono, JD Dharmapurikar, R Cochran, HD Wignall, GD McClain, JB Betts, DE Canelas, DA DeSimone, JM Samulski, ET Chillura-Martino, D Triolo, R AF Londono, JD Dharmapurikar, R Cochran, HD Wignall, GD McClain, JB Betts, DE Canelas, DA DeSimone, JM Samulski, ET Chillura-Martino, D Triolo, R TI The morphology of block copolymer micelles in supercritical carbon dioxide by small-angle neutron and X-ray scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on Small-Angle Scattering CY JUL 21-26, 1996 CL CAMPINAS, BRAZIL ID SURFACTANTS; AGGREGATION AB Above its critical point, carbon dioxide forms a supercritical fluid which promises to be an environmentally responsible replacement for the organic solvents traditionally used in polymerizations. Many lipophilic polymers such as polystyrene (PS) are insol- uble in CO(2), though polymerizations may be accomplished via the use of PS-fluoropolymer stabilizers, which act as emulsifying agents. Small-angle neutron and X-ray scattering have been used to show that these molecules form micelles with a CO(2)-phobic PS core and a CO(2)-philic fluoropolymer corona. When the PS block was fixed in length and the fluorinated corona block was varied, the number of block copolymer molecules per micelle (six to seven) remained constant. Thus, the coronal block molecular weight exerts negligible influence on the aggregation number, in accordance with the theoretical predictions of Halperin, Tirrell & Lodge [Adv. Polym. Sci. (1992), 100, 31-46]. These observations are relevant to understanding the mechanisms of micellization and solubilization in supercritical fluids. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Univ Palermo, Dipartimento Chim Fis, I-90123 Palermo, Italy. RP Londono, JD (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM ll@ornl.gov RI Chillura Martino, Delia/E-5730-2012 OI Chillura Martino, Delia/0000-0001-5141-7285 NR 24 TC 34 Z9 34 U1 0 U2 6 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 1997 VL 30 IS 2 BP 690 EP 695 DI 10.1107/S0021889897002446 PN 5 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA YT746 UT WOS:000071640900026 ER PT J AU Stuhrmann, HB Van den Brandt, B Hautle, P Konter, JA Niinikoski, TO Schmitt, M Willumeit, R Zhao, J Mango, S AF Stuhrmann, HB Van den Brandt, B Hautle, P Konter, JA Niinikoski, TO Schmitt, M Willumeit, R Zhao, J Mango, S TI Polarized neutron scattering from polarized nuclei near paramagnetic centers SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT 10th International Conference on Small-Angle Scattering CY JUL 21-26, 1996 CL CAMPINAS, BRAZIL ID TARGET AB Polarized neutron scattering from dynamically polarized targets has been used for the study of hydrogenous materials in several laboratories. A new variant, which is less dependent on specific deuteration, is proposed. This is based on the observation that a radio frequency (RF) held swept over a selected part of an NMR line depolarizes the spins depending on their spatial distribution in and around paramagnetic molecules. An RF field swept over a narrow frequency interval has little effect on polarized nuclear spins in the paramagnetic centers, whereas remote nuclear spins can be depolarized. When applying the sweep over a much larger frequency range, all spins are depolarized. This was observed both by NMR and by polarized neutron scattering after selective depolarization of the proton spins in a solid solution of protonated EHBA-Cr-V, Na(C12H20O7CrV). D2O, in a mixture of deuterated glycerol and water. The decay time of proton spin polarization in domains associated with the paramagnetic centers varies between 5 h in a deuterated solvent and less than 1 min in a protonated solvent. The size of such a domain is barely larger than 1 nm. The same observation is also made when the nuclear polarization is reversed by adiabatic fast passage. If the RF sweep is limited to frequencies close to the central peak of the proton NMR line, the proton spins far away from the paramagnetic centers are reversed, whereas those of EHBA-Cr-V and close to the centers maintain their original polarization. This method may become a useful tool in neutron scattering once the paramagnetic centers can be fixed as spin labels to well defined sites in a macromolecule, preferably in a crystal lattice. C1 GKSS Forschungszentrum Geesthacht GmbH, D-21502 Geesthacht, Germany. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CERN, CH-1211 Geneva 23, Switzerland. RP Stuhrmann, HB (reprint author), Inst Biol Struct, 41 Ave Martyrs, F-38027 Grenoble, France. RI Hautle, Patrick/C-1044-2012; Zhao, Jinkui/B-7872-2013 OI Hautle, Patrick/0000-0002-0502-8278; Zhao, Jinkui/0000-0002-7756-1952 NR 19 TC 5 Z9 5 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT 1 PY 1997 VL 30 IS 2 BP 839 EP 843 DI 10.1107/S0021889897001611 PN 5 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA YT746 UT WOS:000071640900054 ER PT J AU Whiteman, CD Bian, XD Zhong, SY AF Whiteman, CD Bian, XD Zhong, SY TI Low-level jet climatology from enhanced rawinsonde observations at a site in the southern Great Plains SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SLOPING TERRAIN; UNITED-STATES; MODEL AB A climatology of the Great Plains low-level jet (LLJ) is developed from 2 yr of research rawinsonde data obtained up to eight times per day at a site in north-central Oklahoma. These data have better height and time resolution than earlier studies, and show that jets are stronger than previously reported and that the heights of maximum wind speed are closer to the ground. LLJs are present in 47% of the warm season soundings and 45% of the cold season soundings. More than 50% of the LLJs have wind maxima below 500 m above ground level (AGL). Because the 404-MHz radar profiler network in the central United States has its first data points at 500 m AGL, it is likely to miss some LLJ events and will have inadequate Vertical resolution of LLJ wind structure. Previous studies have identified LLJs on the basis of a wind speed profile criterion. This criterion fails to separate the classical southerly LLJs from the less frequent northerly jets, which differ in both structure and evolution. Classical southerly jets are more frequent; they occur year round, with the highest frequency in the summer and at night. Southerly LLJ wind speed maxima are most frequently found at 300-600 m AGL, and peak speeds, typically between 15 and 21 m s(-1), are attained at 0200 CST. The height of the wind speed maximum varies little during nightime--a period when surface-based inversions grow in depth but generally remain below the jet. Winds at the nose of the southerly jets exhibit a distinct diurnal clockwise turning in wind direction and an oscillation in speed. Northerly jets occur year round. They are generally associated with cold air outbreaks and are found in the cold air behind southward-moving cold fronts. In winter, their frequency of occurrence rivals that of the southerly jets. Their occurrence, however, is less dependent on time of day, with a weak daytime maximum. They are more variable in the heights of their wind speed maxima, are associated more frequently with elevated frontal inversions, and do not exhibit a clockwise turning with time. The heights of the jet speed maxima are found to increase with distance behind the surface cold front. RP Whiteman, CD (reprint author), PACIFIC NW LAB, K9 30, POB 999, RICHLAND, WA 99352 USA. NR 25 TC 112 Z9 117 U1 1 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 1997 VL 36 IS 10 BP 1363 EP 1376 DI 10.1175/1520-0450(1997)036<1363:LLJCFE>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XY744 UT WOS:A1997XY74400005 ER PT J AU Lee, HN AF Lee, HN TI Improvement of surface flux calculations in the atmospheric surface layer SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PROFILE RELATIONSHIPS; MODEL; LAND AB Simple and efficient formulas for calculating surface fluxes are presented for the nondimensional profile functional forms of wind and temperature in the atmospheric surface layer. Four formulations representing nondimensional profile functional forms are examined. New approximate solutions for the relationship between A/L and the bulk Richardson number are proposed. These new solutions are an improvement over the existing approximate solutions and give much better agreement with the numerical solutions obtained by iteration. The approach can be extended to other similar nondimensional profile functional forms. RP US DOE, ENVIRONM MEASUREMENTS LAB, 201 VARICK ST, 5TH FLOOR, NEW YORK, NY 10014 USA. NR 12 TC 22 Z9 25 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 1997 VL 36 IS 10 BP 1416 EP 1423 DI 10.1175/1520-0450(1997)036<1416:IOSFCI>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XY744 UT WOS:A1997XY74400009 ER PT J AU Zasadzinski, R DeWilde, Y Crabtree, GW AF Zasadzinski, R DeWilde, Y Crabtree, GW TI Observation of the development of hysteretic behavior using a scanning tunneling microscope SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CALIBRATION AB A scanning tunneling microscope was used to record tip-sample displacements inferred from the tunnel current versus applied piezoelectric voltage. This provides a means to determine the range in which the mechanical system, especially the piezoelectric element, exhibits hysteretic behavior. Graphite and gold were used as the substrate samples. With graphite, reversible behavior of the displacements is observed until 2.1 Angstrom; beyond this point, the system exhibits persistent irreversible behavior. In the gold system, irreversible behavior appears initially at 0.8 Angstrom but repeated cycling extends the range of reversibility to a displacement of 3-4.8 Angstrom. Irreversible behavior dominates beyond this tip displacement range, although the system exhibits sporadic reversible behavior even for tip excursions as large as 46 Angstrom. (C) 1997 American Institute of Physics. RP Zasadzinski, R (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI De Wilde, Yannick/0000-0002-5973-1460 NR 16 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1997 VL 82 IS 7 BP 3175 EP 3181 DI 10.1063/1.365646 PG 7 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700001 ER PT J AU Davis, HA Bartsch, RR Olson, JC Rej, DJ Waganaar, WJ AF Davis, HA Bartsch, RR Olson, JC Rej, DJ Waganaar, WJ TI Intense ion beam optimization and characterization with infrared imaging SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NEUTRAL BEAM; DIODES AB We have developed two-dimensional calorimetry with infrared imaging of beam targets to optimize and measure the energy-density distribution of intense ion beams. The technique, which measures a complete energy-density distribution on each machine firing, has been used to rapidly develop and characterize two very different beams - a 400 keV beam used to study materials processing and an 80 keV beam used for magnetic fusion diagnostics. Results of measurements, using this technique, varying the diode applied magnetic field strength and geometry, anode material type and configuration, and anode-cathode gap spacing are presented and correlated with other observations. An assessment of calorimeter errors due to target ablation is made by comparison with Faraday cup measurements and computer modeling of beam-target interactions. (C) 1997 American Institute of Physics. RP Davis, HA (reprint author), LOS ALAMOS NATL LAB,MS E526,LOS ALAMOS,NM 87545, USA. NR 22 TC 27 Z9 32 U1 1 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 OCT 1 PY 1997 VL 82 IS 7 BP 3223 EP 3231 DI 10.1063/1.365629 PG 9 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700009 ER PT J AU Schiferl, D Nicol, M Zaug, JM Sharma, SK Cooney, TF Wang, SY Anthony, TR Fleischer, JF AF Schiferl, D Nicol, M Zaug, JM Sharma, SK Cooney, TF Wang, SY Anthony, TR Fleischer, JF TI The diamond C-13/C-12 isotope Raman pressure sensor system for high-temperature/pressure diamond-anvil cells with reactive samples SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SM-YAG; RUBY; CALIBRATION; DEPENDENCE; LINE; FLUORESCENCE; SCATTERING; STATE; SPECTROSCOPY; NITROGEN AB By using a thin C-13 diamond chip together with a C-12 diamond chip as sensors, the diamond Raman spectra provide the means to measure pressure precisely (+/- 0.3 GPa) at any temperature (10-1200 K) and simultaneous hydrostatic (or quasihydrostatic) pressure (0-25 GPa) for any, sample compatible with an externally heated diamond-anvil cell. Minimum interference between the Raman spectrum from the diamond anvils and those of the pressure sensors is obtained by measuring pressures with the Raman signal from the C-13 diamond chip up to 13 GPa, and that from the C-12 chip above 10 GPa. The best crystallographic orientation of the diamond anvils is with the [100] direction along the direction of applied force, in order to further minimize the interference. At 298 K, the pressure dependence of the C-13 diamond first-order Raman line is given by v(P) v(RT) +aP for 91 at.% C-13 diamond, where v(RT)(C-13) = 1287.79 +/- 0.28 cm(-1) and a(C-13) = 2.83 +/- 0.05 cm(-1)/GPa. Analysis of values from the literature shows that the pressure dependence of the Raman line of C-12 diamond is best described by the parameters v(RT)(C-12) = 1332.5 cm(-1) and a(C-12) = 2.90 +/- 0.05 cm(-1)/GPa. The temperature dependence of the diamond Raman line is best described by v(T) - v(RT) = b(0) for T less than or equal to 200K, and v(T) - v(RT) = b(0) + b(1.5)T(k)(1.5) for 200K less than or equal to T less than or equal to 1500K, where T-k = T - 200K. For 91 at.% C-13 diamond, the parameters are b(0) = 0.450 +/- 0.025 cm(-1) b(1.5) = -(7.36 +/- 0.09) X 10(-4) cm(-1) K-1.5; and for C-12 diamond, the parameters are b(0) = 0.467 +/- 0.033 cm(-1), b(1.)5 = -(7.56 +/- 0.10) X 10(-4) cm(-1) K-1.5. Although no quantitative theoretical models are available for calculating the Raman shift as a function of temperature, the excellent fits to the data suggest that the T-k(1.5) dependence above has a physical basis. (C) 1997 American Institute of Physics. C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. UNIV HAWAII,HAWAII INST GEOPHYS & PLANETOL,SCH OCEAN & EARTH SCI & TECHNOL,HONOLULU,HI 96822. GE CO,CTR RES & DEV,SCHENECTADY,NY 12309. RP Schiferl, D (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 69 TC 68 Z9 68 U1 1 U2 17 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 OCT 1 PY 1997 VL 82 IS 7 BP 3256 EP 3265 DI 10.1063/1.366268 PG 10 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700013 ER PT J AU Lewis, LH Thurston, TR Panchanathan, V Wildgruber, U Welch, DO AF Lewis, LH Thurston, TR Panchanathan, V Wildgruber, U Welch, DO TI Spatial texture distribution in thermomechanically deformed 2-14-1-based magnets SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ND-FE-B; ND2FE14B SINGLE-CRYSTALS; EARTH PERMANENT-MAGNETS; DIE-UPSET MAGNETS; X-RAY-SCATTERING; ELECTRON-MICROSCOPY; ANGULAR-DEPENDENCE; SINTERED MAGNETS; BONDED MAGNETS; QUENCHED NDFEB AB Quantifying the relationship between crystallographic texture and magnetic properties is highly desirable for engineering high-energy-product magnets. Such an undertaking is a challenge for melt-quenched magnets formed from Nd2Fe14B-based alloys because they possess a nanoscale microstructure complicated by the presence of multiple phases, both ferromagnetic and paramagnetic. Procedures for the evaluation of texture in permanent magnets often rely upon magnetic remanence measurements; however, such determinations are based on the use of the Stoner-Wohlfarth model, and are applicable only to assemblies of noninteracting particles, which nullifies their use in texture determinations of ''exchange-spring'' magnets. To overcome these inherent experimental difficulties, alternative techniques for the measurement of the bulk texture of permanent magnets are explored in this work. Crystallographic alignment was investigated in both neutron and hard x-ray diffraction experiments. Transmission synchrotron x-ray diffraction measurements of the rocking curve width as a function of both the vertical and horizontal positions were performed on a series of thermomechanically processed, melt-quenched magnets based on the Nd2Fe14B composition. The results of the hard x-ray diffraction experiments were verified by neutron diffraction work. A simple model based on a squared-lorentzian distribution is used to obtain a quantitative estimation of the population of misoriented grains for a given rocking curve half-width. It is deduced that even the most deformed magnets still possess a significant degree of particle misalignment; over 50% of the constituent grains have a misorientation of at least 15 degrees from the overall axial direction at the center of the magnet. The spatial distribution of the rocking curve widths indicates that the development of the c-axis texture is initiated in the center region of the magnet and progresses to the perimeter with increasing deformation. Samples with lower deformation levels possess more uneven texture distributions than do those with higher deformation levels, and the degree of orientation seems to develop rapidly near a deformation level of 50%. The results of this work are utilized to produce a phenomenological model, consistent with the findings of past researchers, of deformation based on mass transport under applied stress via a liquid grain-boundary phase. It is proposed that the micromagnetic structure consists primarily of relatively large clusters of exchange-coupled grains that result in lower-coercivity areas within the magnet. Recommendations are included for improving the production and processing of thermomechanically deformed melt-quenched magnets. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. MAGNEQUENCH INT INC,ANDERSON,IN 46013. RP Lewis, LH (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV MAT SCI,UPTON,NY 11973, USA. NR 56 TC 38 Z9 38 U1 2 U2 28 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 OCT 1 PY 1997 VL 82 IS 7 BP 3430 EP 3441 DI 10.1063/1.365659 PG 12 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700040 ER PT J AU Hanson, DE Voter, AF Kress, JD AF Hanson, DE Voter, AF Kress, JD TI Molecular dynamics simulation of reactive ion etching of Si by energetic Cl ions SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INDUCED THERMAL-DESORPTION; DIMERIZED SI(100) SURFACE; COMPUTER-SIMULATION; FLUORINE-ATOMS; SILICON; CHLORINE; MECHANISMS; CHEMISTRY; EVOLUTION; MODEL AB We report results from molecular dynamics simulations of the etching of a Si surface by energetic Cl atoms (15 eV less than or equal to E less than or equal to 200 eV). We find that the energy dependence of the Si yield (number of Si atoms desorbed per incident Cl ion) is in reasonable agreement with recent experiments and with previous simulations performed up to 50 eV. We also investigate the variation of the Si yield with the impact angle of incidence, the stoichiometry of the desorbed material, and the effect of a thermal background Cl flux to the surface in the presence of an ion flux at 50 eV. Surface roughening due to etching was observed and the calculated rms roughness is in reasonable agreement with experiments. (C) 1997 American Institute of Physics. RP Hanson, DE (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,POB 1663,LOS ALAMOS,NM 87545, USA. NR 41 TC 67 Z9 67 U1 1 U2 8 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 OCT 1 PY 1997 VL 82 IS 7 BP 3552 EP 3559 DI 10.1063/1.365674 PG 8 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700058 ER PT J AU Sutherland, DGJ Terminello, LJ Carlisle, JA Jimenez, I Himpsel, FJ Baines, KM Shuh, DK Tong, WM AF Sutherland, DGJ Terminello, LJ Carlisle, JA Jimenez, I Himpsel, FJ Baines, KM Shuh, DK Tong, WM TI The chemisorption of H2C[Si(CH3)(3)](2) and Si-6(CH3)(12) on Si(100) surfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; SILICON-CARBIDE FIBER; ATOMIC LAYER EPITAXY; CUBIC SIC FILMS; THIN-FILMS; ALKYL MONOLAYERS; LOW-TEMPERATURES; GROWTH; POLYCARBOSILANE; CRYSTALLINE AB The chemisorption of bis(trimethylsilyl)methane (BTM, CH2[Si(CH3)(3)](2)) and dodecamethylcyclohexasilane (DCS, Si-6(CH3)(12)) on clean Si(100) surfaces has been studied by C 1s core-level and valence-band photoemission spectroscopy. Our model for the deposition of carbon by BTM involves decomposition into a -CH2Si(CH3)(3) surface moiety for room-temperature adsorption, which further decomposes upon annealing to 550 degrees C to form a surface terminated primarily by CHx units. DCS deposits almost three times as much C on the surface as BTM. The data are consistent with DCS undergoing a ring opening and bonding to the surface as polydimethylsilane chains. Annealing both adsorbates to 950 degrees C causes a large decrease in the C is signal due to the fact that Si segregates to the surface at temperatures above 900 degrees C. The valence-band photoemission of Si(100) dosed with DCS at 950 degrees C is in good agreement with that of beta-SIC, whereas the analogous BTM spectrum deviates significantly. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53701. UNIV WESTERN ONTARIO,DEPT CHEM,LONDON,ON N6A 5B7,CANADA. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Sutherland, DGJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Jimenez, Ignacio/F-7422-2010; Tong, William/D-2564-2010 OI Jimenez, Ignacio/0000-0001-5605-3185; NR 34 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1997 VL 82 IS 7 BP 3567 EP 3571 DI 10.1063/1.365759 PG 5 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700060 ER PT J AU Kwok, SH Yu, PY Uchida, K Arai, T AF Kwok, SH Yu, PY Uchida, K Arai, T TI Addendum - Deep emission band at GaInP/GaAs interface SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HETEROSTRUCTURES; SUPERLATTICES; GAAS AB We have performed high pressure photoluminescence studies of the deep emission band in GaInP/ GaAs quantum well. Our results suggest that this peak is related to donor-acceptor pair transitions in the GaAs well. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV SCI MAT,BERKELEY,CA 94720. NIPPON SANSO CO,TSUKUBA LABS,TSUKUBA,IBARAKI 30033,JAPAN. RP Kwok, SH (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1997 VL 82 IS 7 BP 3630 EP 3632 DI 10.1063/1.365686 PG 3 WC Physics, Applied SC Physics GA XY057 UT WOS:A1997XY05700073 ER PT J AU Duval, H Bulach, V Fischer, J Renner, MW Fajer, J Weiss, R AF Duval, H Bulach, V Fischer, J Renner, MW Fajer, J Weiss, R TI Correlation of macrocycle distortion with oxidation potentials of iron(III) porphyrins: molecular structure of the sterically crowded chloro-iron(III) 7,8,17,18-tetrabromo-5,10,15,20-tetraphenylporphyrin SO JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY LA English DT Article DE porphyrin conformation; oxidation potentials; molecular orbital calculations; heme proteins ID PHOTOSYNTHETIC REACTION-CENTER; SELECTIVE AIR-OXIDATION; BETA-PYRROLE POSITIONS; CRYSTAL-STRUCTURE; REDOX POTENTIALS; COMPOUND-I; CRYSTALLOGRAPHIC REFINEMENT; HORSERADISH-PEROXIDASE; NONPLANAR PORPHYRINS; EFFICIENT CATALYSTS AB The chloro-iron(III) complex of the tetraphenylporphyrin tetrabrominated at the antipodal beta-pyrrole positions [(7,8,17,18-tetrabromo-5,10,15,20-tetraphenyl)porphyrin] has been synthesized and characterized by spectroscopy and X-ray crystallography. The iron atom is bonded to the chloride ion and the four pyrrole nitrogens. The Fe-Cl bond distance is 2.209(4) Angstrom, and the mean value of the two opposite Fe-N-p lengths at the brominated pyrrole rings is 2.079(8) Angstrom, whereas the mean value of the two opposite Fe-N-p' bond distances at the non-brominated pyrrole rings is 2.031(8) Angstrom. The X-ray structure determination and the analysis of the UV-Vis spectra obtained in solution and on thin films indicate that \FeCl(tpp-Br-4)\ (1) is principally saddle-shaped in the solid state and in solution. Variable-temperature (195-325 K) H-1 NMR spectroscopy confirms the high-spin state (S=5/2) of the iron(III) center and indicates that the saddle-shaped conformation of 1 is maintained in solution. EPR spectra obtained in frozen CH2Cl2 solution and in the solid state show a rhombic symmetry with g values of 6.25, 5.70 and 1.99, Kadish et al. have shown that the one-electron oxidation potential of 1 increases only by 0.06 V relative to that of the non-brominated complex \FeCl(tpp)\. The present study, indicates that the in crease of the first oxidation potential of 1 is related to the non-planar distortion of the porphyrin. Relative to the unbrominated derivative \FeCl(tpp)\, this distortion destabilizes the rr system of the macrocycle and thus compensates for the effects of the four electron-withdrawing bromine substituents. C1 UNIV STRASBOURG 1,INST LE BEL,LAB CRISTALLOCHIM & CHIM STRUCT,URA 424,F-67070 STRASBOURG,FRANCE. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 56 TC 17 Z9 17 U1 1 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0949-8257 J9 J BIOL INORG CHEM JI J. Biol. Inorg. Chem. PD OCT PY 1997 VL 2 IS 5 BP 662 EP 666 DI 10.1007/s007750050181 PG 5 WC Biochemistry & Molecular Biology; Chemistry, Inorganic & Nuclear SC Biochemistry & Molecular Biology; Chemistry GA YF712 UT WOS:A1997YF71200012 ER PT J AU Goldman, M Lee, M Gronsky, R Pruitt, L AF Goldman, M Lee, M Gronsky, R Pruitt, L TI Oxidation of ultrahigh molecular weight polyethylene characterized by Fourier Transform Infrared Spectrometry SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE UHMWPE; FTIR; oxidation; joint replacements; orthopedics ID STERILIZATION; IRRADIATION; RADIATION AB The effects of processing conditions, sterilization treatment, aging time, and poststerilization aging environment on the oxidation behavior of ultrahigh molecular weight polyethylene (UHMWPE) are examined. Oxidation is monitored by observing changes in the carbonyl peak appearing in Fourier Transform Infrared Spectrometry (FTIR) and is found to be relatively insensitive to processing conditions but strongly influenced by sterilization treatments and aging parameters. Oxygen uptake by UHMWPE increases as a result of gamma or electron beam irradiation and continues to rise during subsequent aging at a rate influenced by the aging environment. A hydrogen peroxide ambient causes more severe oxidation than either air or hyaluronic acid. Control (unsterilized) samples and those sterilized in ethylene oxide are resistant to oxidation under all conditions except hydrogen peroxide aging. (C) 1997 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. NR 29 TC 59 Z9 59 U1 1 U2 12 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 OCT PY 1997 VL 37 IS 1 BP 43 EP 50 DI 10.1002/(SICI)1097-4636(199710)37:1<43::AID-JBM6>3.0.CO;2-J PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA XZ371 UT WOS:A1997XZ37100006 PM 9335348 ER PT J AU Culf, AS Gerig, JT Williams, PG AF Culf, AS Gerig, JT Williams, PG TI Tritium NMR studies of the human carbonic anhydrase I-benzenesulfonamide complex SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE tritium; enzyme; carbonic anhydrase; enzyme inhibitor; aromatic ring rotation ID NUCLEAR MAGNETIC-RESONANCE; MOLECULAR MECHANICS; BINDING; ENZYME; SPECTROSCOPY; INHIBITORS; SULFONAMIDES; GRAPHICS; PROTEIN; RELAXATION AB Tritium NMR spectroscopy has been used to examine the complex formed by [4-H-3]benzenesulfon-amide and human carbonic anhydrase I. The results show that in solution the inhibitor forms a 1:1 complex with the enzyme. A 100-spin computational model of the system, constructed with reference to crystallographic results, was used to interpret tritium relaxation behavior and H-3{H-1} NOEs. The analysis shows that the rate of dissociation of the enzyme-sulfonamide complex is 0.35 s(-1) and that the aromatic ring of the inhibitor undergoes rapid rotation while complexed. C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. FU NCRR NIH HHS [P41 RR01237]; NIGMS NIH HHS [GM 25975] NR 43 TC 14 Z9 14 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD OCT PY 1997 VL 10 IS 3 BP 293 EP 299 DI 10.1023/A:1018358101811 PG 7 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA YG934 UT WOS:A1997YG93400011 PM 9390408 ER PT J AU Buchko, GW Ni, SS Thrall, BD Kennedy, MA AF Buchko, GW Ni, SS Thrall, BD Kennedy, MA TI Human nucleotide excision repair protein XPA: Expression and NMR backbone assignments of the 14.7 kDa minimal damaged DNA binding domain (Met(98)-Phe(219)) SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE zinc-binding domain; DNA repair; XPA; backbone assignments ID XERODERMA-PIGMENTOSUM C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. PACIFIC NW LAB, MOL BIOSCI DEPT, RICHLAND, WA 99352 USA. RI Buchko, Garry/G-6173-2015 OI Buchko, Garry/0000-0002-3639-1061 NR 9 TC 6 Z9 6 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD OCT PY 1997 VL 10 IS 3 BP 313 EP 314 DI 10.1023/A:1018321319578 PG 2 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA YG934 UT WOS:A1997YG93400016 PM 9390412 ER PT J AU Ojha, RP Dhingra, MM Sarma, MH Myer, YP Setlik, RF Shibata, M Kazim, AL Ornstein, RL Rein, R Turner, CJ Sarma, RH AF Ojha, RP Dhingra, MM Sarma, MH Myer, YP Setlik, RF Shibata, M Kazim, AL Ornstein, RL Rein, R Turner, CJ Sarma, RH TI Structure of an anti-HIV-1 hammerhead ribozyme complex with a 17-mer DNA substrate analog of HIV-1 gag RNA and a mechanism for the cleavage reaction: 750 MHz NMR and computer experiments SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; METAL-ION MECHANISM; SELF-CLEAVAGE; SEQUENCE REQUIREMENTS; SECONDARY STRUCTURE; CATALYTIC RNA; DOMAIN; TRANSITION; ACIDS; SPECTROSCOPY AB The structure of an anti-HIV-1 ribozyme-DNA abortive substrate complex was investigated by 750 MHz NMR and computer modeling experiments. The ribozyme was a chimeric molecule with 30 residues-18 DNA nucleotides, and 12 RNA residues in the conserved core. The DNA substrate analog had 17 residues. The chimeric ribozyme and the DNA substrate formed a shortened ribozyme-abortive substrate complex of 47 nucleotides with two DNA stems (stems I and III) and a loop consisting of the conserved core residues. Circular dichroism spectra showed that the DNA stems assume A-family conformation at the NMR concentration and a temperature of 15 degrees C, contrary to the conventional wisdom that DNA duplexes in aqueous solution populate entirely in the B-form. It is proposed that the A-family RNA residues at the core expand the A-family initiated at the core into the DNA stems because of the large free energy requirement for the formation of A/B junctions. Assignments of the base H8/H6 protons and H1' of the 47 residues were made by a NOESY walk. In addition to the methyl groups of all T's, the imino resonances of stems I and III and AH2's were assigned from appropriate NOESY walks. The extracted NMR data along with available crystallographic data, were used to derive a structural model of the complex. Stems I and III of the final model displayed a remarkable similarity to the A form of DNA; in stem III, a GC base pair was found to be moving into the floor of the minor groove defined by flanking AT pairs data suggest the formation of a buckled rhombic structure with the adjacent pair; in addition, the base pair at the interface of stem III and the loop region displayed deformed geometry. The loop with the catalytic core, and the immediate region of the stems displayed conformational multiplicity within the NMR time scale. A catalytic mechanism for ribozyme action based on the derived structure, and consistent with biochemical data in the literature, is proposed. The complex between the anti HIV-1 gag ribozyme and its abortive DNA substrate manifests in the detection of a continuous track of Ave A.T base pairs; this suggests that the interaction between the ribozyme and its DNA substrate is stronger than the one observed in the case of the free ribozyme where the bases in stem I and stem III regions interact strongly with the ribozyme core region (Sarma, R. H., et al. FEBS Letters 375, 317-23, 1995). The complex formation provides certain guidelines in the design of suitable therapeutic ribozymes. if the residues in the ribozyme stem regions interact with the conserved core, it may either prevent or interfere with the formation of a catalytically active tertiary structure. C1 SUNY ALBANY, INST BIOMOL STEREODYNAM, ALBANY, NY 12222 USA. MIT, FRANCIS BITTER NATL MAGNET LAB, CAMBRIDGE, MA 02139 USA. ROSWELL PK CANC INST, DEPT BIOPHYS, CCC 218, BUFFALO, NY 14263 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. GORAKHPUR UNIV, BIOPHYS UNIT, GORAKHPUR 273009, UTTAR PRADESH, INDIA. FU NCI NIH HHS [CA16056-21]; NCRR NIH HHS [RR00995] NR 59 TC 8 Z9 8 U1 0 U2 0 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD OCT PY 1997 VL 15 IS 2 BP 185 EP 215 PG 31 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA YH369 UT WOS:A1997YH36900005 PM 9399149 ER PT J AU Blaudeau, JP McGrath, MP Curtiss, LA Radom, L AF Blaudeau, JP McGrath, MP Curtiss, LA Radom, L TI Extension of Gaussian-2 (G2) theory to molecules containing third-row atoms K and Ca SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUADRATIC CONFIGURATION-INTERACTION; RELATIVISTIC EFFECTIVE POTENTIALS; SPIN-ORBIT OPERATORS; BASIS-SETS; 2ND-ROW COMPOUNDS; ENERGIES; LI; 1ST-ROW AB Gaussian-2 (G2) theory has been extended to molecules containing the third-row nontransition elements K and Ca. Basis sets compatible with those used in G2 theory for molecules containing first-and second-row atoms, as well as the third-row elements Ga-Kr, have been derived. As for Ga-Kr, first-order spin-orbit corrections are included explicitly in the G2 energies of K-and Ca-containing atoms and molecules. In contrast to the procedure for Ga-Kr, the 3s and 3p orbitals need to be included in the cell-elation space for K-and Ca-containing molecules. The geometries obtained with the new basis sets are in satisfactory agreement with experiment. Assessment of the thermochemical predictions is limited because of the sparsity of accurate experimental data for molecules containing K and Ca, Ionization energies are generally in good agreement with experimental values, as are the atomization energies for K-containing molecules. However. there are larger differences between theoretical and experimental atomization energies for Ca-containing molecules. (C) 1997 American Institute of Physics. C1 UNIV CALIF IRVINE, DEPT CHEM, IRVINE, CA 92717 USA. AUSTRALIAN NATL UNIV, RES SCH CHEM, CANBERRA, ACT 0200, AUSTRALIA. RP Blaudeau, JP (reprint author), ARGONNE NATL LAB, CHEM TECHNOL MAT SCI DIV, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 25 TC 512 Z9 513 U1 3 U2 33 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 OCT 1 PY 1997 VL 107 IS 13 BP 5016 EP 5021 DI 10.1063/1.474865 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XX840 UT WOS:A1997XX84000029 ER PT J AU deLeon, MJ McRae, T Rusinek, H Convit, A DeSanti, S Tarshish, C Golomb, J Volkow, N Daisley, K Orentreich, N McEwen, B AF deLeon, MJ McRae, T Rusinek, H Convit, A DeSanti, S Tarshish, C Golomb, J Volkow, N Daisley, K Orentreich, N McEwen, B TI Cortisol reduces hippocampal glucose metabolism in normal elderly, but not in Alzheimer's disease SO JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM LA English DT Article ID PITUITARY-ADRENAL AXIS; POSITRON EMISSION TOMOGRAPHY; RAT SKELETAL-MUSCLE; CORTICOSTEROID RECEPTORS; GLUCOCORTICOID TOXICITY; CEREBROSPINAL-FLUID; INSULIN-RECEPTOR; PLASMA-CORTISOL; MEMORY; ATROPHY AB Glucocorticoids are known to play a role in the regulation of peripheral glucose mobilization and metabolism. Although several animal studies have shown that hippocampal glucose metabolism is reduced acutely and chronically by the action of corticosterone and that excess glucocorticoids are harmful to hippocampal neurons, little is known about the central effects of glucocorticoids in the human. In this study we examined the brain glucose utilization (CMRglu) response to hydrocortisone (cortisol) in seven normal elderly and eight Alzheimer's disease (AD) patients. On 2 separate days, immediately after the administration of a bolus of either 35 mg hydrocortisone or placebo, we administered 2-deoxy-2-[F-18]fluoro-D-glucose. After a 35-min radiotracer uptake period, positron emission tomography (PET) images were collected. PET CMRglu images were analyzed using two methods: an image transformation that allowed analyses across cases on a voxel by voxel basis, and an anatomically based region of interest method that used coregistered magnetic resonance imaging scans. Both image analysis methods yielded similar results, identifying relative to placebo, a specific hippocampal CMRglu reduction in response to the hydrocortisone challenge that was restricted to the normal group. The region of interest technique showed CMRglu reductions of 16% and 12% in the right and left hippocampi, respectively. Blood collected during the PET scans showed, for the normal group, a rise in plasma glucose levels, starting approximately 25 min after hydrocortisone administration. The AD group did not show this effect. Baseline cortisol was elevated in the AD group, but the clearance of hydrocortisone was not different between the groups. In conclusion, these data show that among normal individuals in the presence of a pharmacological dose of cortisol, the glucose utilization of the hippocampus is specifically reduced, and serum glucose levels increase. Based in hart on other studies, we offer the interpretation that glucocorticoid-mediated regulation of glucose transport is altered in AD, and this may underlie both the hippocampal insensitivity to cortisol and the failure in these patients to mount a peripheral glucose response. As our findings could reflect an altered state of the AD patients, we interpret our results as preliminary with respect to evidence for metabolic abnormalities in AD. The results suggest the continued study of the hydrocortisone challenge as a test of hippocampal responsivity. C1 NYU MED CTR, SCH MED, DEPT MED, NEW YORK, NY 10016 USA. NYU MED CTR, SCH MED, DEPT RADIOL, NEW YORK, NY 10016 USA. NYU MED CTR, SCH MED, DEPT DERMATOL, NEW YORK, NY 10016 USA. NYU MED CTR, SCH MED, DEPT NEUROL, NEW YORK, NY 10016 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. ORENTREICH FDN ADVANCEMENT SCI, COLD SPRING, NY USA. ROCKEFELLER UNIV, NEUROENDOCRINOL LAB, NEW YORK, NY 10021 USA. NATHAN S KLINE INST PSYCHIAT RES, ORANGEBURG, NY 10962 USA. RP deLeon, MJ (reprint author), NYU MED CTR, SCH MED, DEPT PSYCHIAT, NEUROIMAGING LAB, 550 1ST AVE, NEW YORK, NY 10016 USA. OI de Leon, Mony/0000-0003-2245-4380 FU NIA NIH HHS [AG-12101, AG-13616, P30-AG-08051] NR 93 TC 133 Z9 134 U1 4 U2 11 PU ENDOCRINE SOC PI CHEVY CHASE PA 8401 CONNECTICUT AVE, SUITE 900, CHEVY CHASE, MD 20815-5817 USA SN 0021-972X J9 J CLIN ENDOCR METAB JI J. Clin. Endocrinol. Metab. PD OCT PY 1997 VL 82 IS 10 BP 3251 EP 3259 DI 10.1210/jc.82.10.3251 PG 9 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA YA002 UT WOS:A1997YA00200014 PM 9329348 ER PT J AU Lee, K Look, JL Harris, MT McCormick, AV AF Lee, K Look, JL Harris, MT McCormick, AV TI Assessing extreme models of the Stober synthesis using transients under a range of initial composition SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE SiO2 colloids; Si-29-NMR; kinetic model; precipitation; nucleation; aggregation ID AMMONIA-CATALYZED HYDROLYSIS; MONODISPERSED SILICA POWDERS; TETRAETHYL ORTHOSILICATE; REACTION-KINETICS; MONOMER-ADDITION; GROWTH-MODEL; PARTICLES; ALKOXIDES; PRECIPITATION; CONDENSATION AB Si-29-NMR, conductimetry, and photon correlation spectroscopy are used to monitor the temporal profile of intermediate concentrations in Stober synthesis (i.e., ammonia-catalyzed hydrolysis of tetraethoxysilane in a batch reactor). Extreme models of the process are assessed by examining the effect of initial composition on these transients (over a wider range of composition than attempted previously). The trends with initial composition suggest that the nucleation is rate-limited by the hydrolysis of the singly hydrolyzed monomer, the product of which probably phase separates. Moreover, the trends are consistent with the aggregation model discussed by G. H. Bogush and C. F. Zukoski (J. Colloid Interface Sci. 142, 1, 19 (1991) and by M. T. Harris (Ph.D. dissertation, Univ. of Tennessee, 1992). The trends are not consistent with a growth model without aggregation. (C) 1997 Academic Press. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,CTR INTERFACIAL ENGN,MINNEAPOLIS,MN 55455. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV MARYLAND,DEPT CHEM ENGN,COLLEGE PK,MD 20742. RI Lee, Kangtaek/G-8026-2012 NR 37 TC 63 Z9 66 U1 1 U2 22 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD OCT 1 PY 1997 VL 194 IS 1 BP 78 EP 88 DI 10.1006/jcis.1997.5089 PG 11 WC Chemistry, Physical SC Chemistry GA YG926 UT WOS:A1997YG92600010 ER PT J AU Shadid, JN Tuminaro, RS Walker, HF AF Shadid, JN Tuminaro, RS Walker, HF TI An inexact Newton method for fully coupled solution of the Navier-Stokes equations with heat and mass transport SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Navier-Stokes equations; inexact Newton methods; Newton iterative (truncated Newton) methods; Newton-Krylov methods; forcing terms; GMRES ID LINEAR-SYSTEMS; FLOW AB The solution of the governing steady transport equations for momentum, heat and mass transfer in flowing fluids can be very difficult. These difficulties arise from the nonlinear, coupled, nonsymmetric nature of the system of algebraic equations that results from spatial discretization of the PDEs. In this manuscript we focus on evaluating a proposed nonlinear solution method based on an inexact Newton method with backtracking. In this context we use a particular spatial discretization based on a pressure stabilized Petrov-Galerkin finite element formulation of the low Mach number Navier-Stokes equations with heat and mass transport. Our discussion considers computational efficiency, robustness and some implementation issues related to the proposed nonlinear solution scheme. Computational results are presented for several challenging CFD benchmark problems as well as two large scale 3D flow simulations. (C) 1997 Academic Press. C1 WORCESTER POLYTECH INST,DEPT MATH SCI,WORCESTER,MA 01609. RP Shadid, JN (reprint author), SANDIA NATL LABS,MS 1111,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 21 TC 37 Z9 38 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 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT PY 1997 VL 137 IS 1 BP 155 EP 185 DI 10.1006/jcph.1997.5798 PG 31 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA YF667 UT WOS:A1997YF66700006 ER PT J AU Liska, R Wendroff, B AF Liska, R Wendroff, B TI Analysis and computation with stratified fluid models SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID FLOW; WAVES AB Vertical averaging of the three-dimensional incompressible Euler equations leads to several reduced dimension models of flaw over topography. including the one-layer and two-layer classic shallow water equations, and the one-layer and two-layer nonhydrostatic Green-Naghdi equations. These equations are derived and their well-posedness is discussed. Several implicit and explicit finite difference approximations of both the shallow water and Green-Naghdi models are presented. but for Green-Naghdi these are obtained using automatic code generation software. Numerical results are given in both well-posed and ill-posed regimes and compared with computations obtained by others. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Liska, R (reprint author), CZECH TECH UNIV,FAC NUCL SCI & PHYS ENGN,BREHOVA 7,CR-11519 PRAGUE 1,CZECH REPUBLIC. RI Liska, Richard/C-3142-2009 OI Liska, Richard/0000-0002-6149-0440 NR 26 TC 16 Z9 16 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD OCT PY 1997 VL 137 IS 1 BP 212 EP 244 DI 10.1006/jcph.1997.5806 PG 33 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA YF667 UT WOS:A1997YF66700008 ER PT J AU Hou, HQ Crawford, MH Hammons, BE Hickman, RJ AF Hou, HQ Crawford, MH Hammons, BE Hickman, RJ TI Metalorganic vapor phase epitaxial growth of All-AlGaAs visible (similar to 700 nm) vertical-cavity surface-emitting lasers on misoriented substrates SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 8th Biennial Workshop on Organometallic Vapor Phase Epitaxy CY APR 13-17, 1997 CL DANA POINT, CA DE metalorganic vapor phase epitaxy (MOVPE); substrate misorientation; vertical-cavity surface-emitting laser (VCSEL); (311)A ID CONTINUOUS-WAVE OPERATION; GAAS; ORIENTATION; DEPENDENCE; OXYGEN AB We present a study on the growth of visible (similar to 700nm) vertical-cavity surface-emitting lasers (VCSELs) by metalorganic vapor phase epitaxy. The structure was based on AlGaAs for both the quantum well active region and the distributed Bragg reflectors, Photoluminescence intensity from AlGaAs quantum wells was optimized vs the substrate misorientations from the (100) surface. The doping efficiency for n-type by Si and p-type by C was studied as a function of the substrate misorientation and the growth temperature. High-quality VCSEL materials were grown on (311)A substrates. The structure was processed by selective oxidation, and high-performance VCSELs emitting at similar to 700nm were achieved in a continuous-wave mode at room temperature. RP Hou, HQ (reprint author), SANDIA NATL LABS, CTR COMPOUND SEMICOND TECHNOL, MS 0603, ALBUQUERQUE, NM 87185 USA. RI Schaff, William/B-5839-2009 NR 15 TC 1 Z9 1 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD OCT PY 1997 VL 26 IS 10 BP 1140 EP 1144 DI 10.1007/s11664-997-0010-2 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA XZ503 UT WOS:A1997XZ50300011 ER PT J AU Hou, HQ Breiland, WG Hammons, BE Biefeld, RM Baucom, KC Stall, RA AF Hou, HQ Breiland, WG Hammons, BE Biefeld, RM Baucom, KC Stall, RA TI Growth study of AlGaAs using dimethylethylamine alane as the aluminum precursor SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 8th Biennial Workshop on Organometallic Vapor Phase Epitaxy CY APR 13-17, 1997 CL DANA POINT, CA DE dimethylethylamine alane (DMEAA); high-purity AlGaAs; metalorganic vapor phase epitaxy (MOVPE) ID VAPOR-PHASE-EPITAXY; GAAS/ALGAAS QUANTUM-WELL; TRIMETHYLAMINE ALANE; ALXGA1-XAS AB We present a comprehensive study an the growth of AlGaAs by using an alternative Al precursor, dimethylethylamine alane (DMEAA), and a Ga coprecursor, either triethylgallium (TEG) or trimethylgallium. The growth rate of AlAs determined by using in situ reflectometry was studied as a function of the growth temperature, V/III ratio, growth pressure, and rotation speed of the substrate. The presence of gas phase reactions of DMEAA with arsine and TEG was indicated, and their reduction was achieved at a lower growth pressure, lower V/III ratio, or a lower growth temperature, Negligible pre-reaction of DMEAA with TMG was observed. Excellent material uniformity of AlGaAs was achieved on a 2'' diameter wafer. Secondary ion mass spectroscopy measurements revealed extremely low C and O contents in the AlAs layer grown by DMEAA. Photoluminescence measurements suggested the presence of some non-radiative defects in the as-grown DMEAA AlGaAs layers. C1 EMCORE CORP,SOMERSET,NJ 08873. RP Hou, HQ (reprint author), SANDIA NATL LABS,MS 0603,ALBUQUERQUE,NM 87185, USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD OCT PY 1997 VL 26 IS 10 BP 1178 EP 1183 DI 10.1007/s11664-997-0016-9 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA XZ503 UT WOS:A1997XZ50300018 ER PT J AU Biefeld, RM Allerman, AA Kurtz, SR Burkhart, JH AF Biefeld, RM Allerman, AA Kurtz, SR Burkhart, JH TI The growth of InAsSb/InAsP strained-layer superlattices for use in infrared emitters SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 8th Biennial Workshop on Organometallic Vapor Phase Epitaxy CY APR 13-17, 1997 CL DANA POINT, CA DE InAsSb; metalorganic chemical vapor deposition (MOCVD); mid-infrared lasers; strained-layer superlattices ID CHEMICAL-VAPOR-DEPOSITION; CONTINUOUS-WAVE OPERATION; 3.5 MU-M; LASERS; INAS1-XSBX; DIODES AB We describe the metalorganic chemical vapor deposition of InAsSb/InAsP strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. These SLSs were grown at 500 degrees C, and 200 Torr in a horizontal quartz reactor using TMIn, TESb, AsH3 and PH3. By changing the layer thickness and composition, we have prepared structures with low temperature (less than or equal to 20K) photoluminescence wavelengths ranging from 3.2 to 4.4 mu m. Excellent performance was observed for a SLS light emitting diode (LED) and both optically pumped and electrically injected SLS lasers. An optically pumped, double heterostructure laser emitted at 3.86 mu m with a maximum operating temperature of 240K and a characteristic temperature of 33K. We have also made electrically injected lasers and LEDs utilizing a GaAsSb/InAs semi-metal injection scheme. The semi-metal injected, broadband LED emitted at 4 mu m with 80 mu W of power at 300K and 200 mA average current. The InAsSb/InAsP SLS injection laser emitted at 3.6 mu m at 120K. C1 IDAHO STATE UNIV,POCATELLO,ID 83201. RP Biefeld, RM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 6 Z9 6 U1 1 U2 3 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 OCT PY 1997 VL 26 IS 10 BP 1225 EP 1230 DI 10.1007/s11664-997-0024-9 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA XZ503 UT WOS:A1997XZ50300026 ER PT J AU Richards, GA Gemmen, RS Yip, MJ AF Richards, GA Gemmen, RS Yip, MJ TI A test device for premixed gas turbine combustion oscillations SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID PRESSURE-GAIN; PULSE AB We report the design and operation of a rest device suitable for studying combustion oscillations produced by commercial-scale gas turbine fuel nozzles. Unlike conventional test stands, this test combustor uses a Helmholtz acoustic geometry to replicate the acoustic response that would otherwise be observed only during complete engine testing. We suggest that successful simulation of engine oscillations requires that the flame geometry and resonant frequency of the test device should match the complete engine environment. Instrumentation for measuring both pressure and heat release variation is described. Preliminary tests suggest the importance of characterizing the oscillating behavior in terms of a nozzle reference velocity and inlet air temperature. Initial tests also demonstrate that the stabilizing effect of a pilot flame depends on the operating conditions. RP Richards, GA (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,MORGANTOWN,WV 26505, USA. NR 21 TC 8 Z9 8 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1997 VL 119 IS 4 BP 776 EP 782 DI 10.1115/1.2817054 PG 7 WC Engineering, Mechanical SC Engineering GA YD474 UT WOS:A1997YD47400002 ER PT J AU Wereszczak, AA Kirkland, TP AF Wereszczak, AA Kirkland, TP TI Creep performance of candidate SiC and Si3N4 materials for land-based, gas turbine engine components SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND ID ADVANCED SILICON-NITRIDE; BEHAVIOR; RUPTURE AB The tensile creep-rupture performance of a commercially available gas pressure sintered silicon nitride (Si3N4) and a sintered silicon carbide (SiC) is examined at 1038, 1150, and 1350 degrees C. These two ceramic materials are candidates for nozzles and combustor tiles that are to be retrofitted in land-based gas turbine engines, and interest exists to investigate their high-temperature mechanical performance over service times up to, and in excess of 10,000 hours (approximate to 14 months). To achieve lifetimes approaching 10,000 hours for the candidate Si3N4 ceramic, it was found (or it was estimated based on ongoing test data) that a static tensile stress of 300 MPa at 1038 and 1150 degrees C, and a stress of 125 MPa at 1350 degrees C cannot be exceeded. For the SiC ceramic, it was estimated from ongoing test data that a static tensile stress of 300 MPa at 1038 degrees C, 250 MPa at 1150 degrees C, and 180 MPa at 1350 degrees C cannot be exceeded. The creep-stress exponents for this Si3N4 were determined to be 33, 17, and 8 for 1038, 1150, and 1350 degrees C, respectively. The fatigue-stress exponents for the Si3N4 were found to be equivalent to the creep exponents, suggesting that the fatigue mechanism that ultimately causes fracture is controlled and related to the creep mechanisms. Little success was experienced at generating failures in the SiC after several decades of time through exposure to appropriate tensile stress; it was typically observed that if failure did not occur on loading, then the SiC specimens most often did not creep rupture. However, creep-stress exponents for the SiC were determined to be 57, 27, and 11 for 1038, 1150, and 1350 degrees C, respectively. For SiC, the fatigue-stress exponents did not correlate as well with creep-stress exponents. Failures that occurred in the SiC were a result of slow crack growth that was initiated from the specimen's surface. RP Wereszczak, AA (reprint author), OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831, USA. RI Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 13 TC 3 Z9 3 U1 0 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 1997 VL 119 IS 4 BP 799 EP 806 DI 10.1115/1.2817057 PG 8 WC Engineering, Mechanical SC Engineering GA YD474 UT WOS:A1997YD47400005 ER PT J AU Fossum, AF AF Fossum, AF TI Parameter estimation for an internal variable model using nonlinear optimization and analytical/numerical response sensitivities SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CONSTITUTIVE-EQUATIONS AB This paper demonstrates through examples that erroneous material constants for complex visco-plastic material models can be obtained from simultaneous parameter estimation by nonlinear optimization methods unless the laboratory load paths used in the fitting process give significant model response sensitivities to changes in all of the material parameters. A general procedure is proposed in which a nonlinear optimization algorithm is coupled with analytically/numerically derived response sensitivities to evaluate an unambiguous set of material parameters. Response sensitivities enter into the parameter estimation procedure in two ways. Relative response sensitivities are first used to identify an efficient test matrix that when simulated with the model, give model responses that are sensitive to changes in each of the material parameters. Then the corresponding nonzero response sensitivities are used to construct the gradient and Hessian matrices in a gradient-driven optimization algorithm to evaluate the material parameters. A model for braze alloys is used to demonstrate that erroneous parameter values may result if not all of the relative response sensitivities are ''nonzero'' and district. RP Fossum, AF (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 23 Z9 23 U1 2 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD OCT PY 1997 VL 119 IS 4 BP 337 EP 345 DI 10.1115/1.2812267 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YE461 UT WOS:A1997YE46100003 ER PT J AU Chan, KS Brodsky, NS Fossum, AF Munson, DE Bodner, SR AF Chan, KS Brodsky, NS Fossum, AF Munson, DE Bodner, SR TI Creep-induced cleavage fracture in WIPP salt under indirect tension SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID INELASTIC FLOW; TRIAXIAL COMPRESSION; CONSTITUTIVE MODEL; DAMAGE EVOLUTION; BRITTLE SOLIDS; ROCK-SALT; FAILURE AB The phenomenon of cleavage fracture initiation in rock salt undergoing concurrent creep was studied experimentally using the Brazilian indirect tension test technique. The tensile creep and cleavage fracture behaviors were characterized for rack salt from the Waste Isolation Pilot Plant (WIPP) site. The Brazilian test consists of a compressive line load applied diametrically on a disk specimen to produce a region of tensile stress in the center of the disk. The damage processes were documented using video photography. The experimental results were analyzed in terms of a wing-crack feature model and an independently developed, coupled time-dependent, mechanism-based constitutive model whose parameters were obtained from triaxial compression creep tests. Analytical results indicate that coupling between creep and cleavage fracture in WIPP salt results in a fracture behavior that exhibits time-dependent characteristics and obeys a failure criterion involving a combination of stress difference and tensile stress. Implications of creep-induced cleavage fracture to the integrity of WIPP structures are discussed. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. TECHNION ISRAEL INST TECHNOL,DEPT MECH ENGN,IL-32000 HAIFA,ISRAEL. RE SPEC,RAPID CITY,SD. RP Chan, KS (reprint author), SW RES INST,6220 CULEBRA RD,SAN ANTONIO,TX 78238, USA. NR 23 TC 7 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 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD OCT PY 1997 VL 119 IS 4 BP 393 EP 400 DI 10.1115/1.2812275 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YE461 UT WOS:A1997YE46100010 ER PT J AU Gu, BH Siegrist, RL AF Gu, BH Siegrist, RL TI Dehalogenation of chlorinated organic compounds by strong alkalis SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article ID CONTAMINATED SOIL; TRICHLOROETHYLENE; MEDIA; VAPOR; BIODEGRADATION; SORPTION; BEHAVIOR; PCB AB Chlorinated organic compounds such as trichloroethylene (TCE) are the most prevalent contaminants found in soil and ground water, and pose serious health risks even at trace concentrations. This research reports a new chemical treatment technique for rapid degradation of TCE in strong alkaline solutions. Batch kinetic reactions between TCE and NaOH indicate that TCE can be rapidly and completely dechlorinated in NaOH at elevated temperatures. The reaction can be described by a pseudo-first-order rate kinetics with an estimated activation energy of similar to 85 kJ/mol. The half-lives for TCE degradation in 2M NaOH at 40, 60, 80, and 100 degrees C were approximately 347, 48.8, 4.0, and 2.4 min, respectively. The reaction end-products are primarily Cl- anions and Na-glycollate, both of which are nonhazardous. This treatment technique is applicable for degrading other halogenated organic compounds wherein a nucleophilic substitution or elimination is the major reaction mechanism or pathway. Potential applications of this technology includes the removal and destruction of vapor-phase chlorinated volatile organic compounds (VOCs) in off-gases when soil vapor extraction or air-stripping techniques are used for remediating VOC-contaminated soils and ground water. A bench-scale alkaline destruction module was tested, and results indicated that similar to 90% of TCE was destroyed when TCE vapor (10 mg/L) was passed through a destruction column with a retention time of similar to 1 min at 95 degrees C. C1 OAK RIDGE NATL LAB COLORADO SCH MINES,ENVIRONM SCI ENGN DIV,GOLDEN,CO 80401. RP Gu, BH (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS-6036,OAK RIDGE,TN 37831, USA. RI Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 24 TC 4 Z9 4 U1 0 U2 3 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD OCT PY 1997 VL 123 IS 10 BP 982 EP 987 DI 10.1061/(ASCE)0733-9372(1997)123:10(982) PG 6 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XX176 UT WOS:A1997XX17600006 ER PT J AU Borovsky, JE Thomsen, MF McComas, DJ AF Borovsky, JE Thomsen, MF McComas, DJ TI The superdense plasma sheet: Plasmaspheric origin, solar wind origin, or ionospheric origin? SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC ION COMPOSITION; BOUNDARY-LAYER; MARCH 22; MAGNETOPAUSE CROSSINGS; GEOSYNCHRONOUS ORBIT; GEOMAGNETIC-ACTIVITY; SUPRATHERMAL O+; 1979 CDAW-6; SUBSTORM; ELECTRON AB A few times per month, the density of the plasma sheet is several times higher than its usual density. Such superdense plasma sheet intervals are observed both in the midtail region and at geosynchronous orbit. Typically at geosynchronous orbit, a superdense plasma sheet occurs on the first day of a geomagnetic storm and lasts about 12-18 hours. The occurrences of superdense plasma sheets are found to be related to a distinct pattern of Kp: Kp rising after it has been low for an extended period. The occurrences are also associated with high-density solar wind. Three sources for the material of the superdense plasma sheet are explored: (1) the outer plasmasphere, which is stripped away and drawn into the dayside neutral line when Kp increases, wherein it joins the lobe and eventually joins the plasma sheet; (2) high-density solar-wind, which may have its entry into the plasma sheet controlled by the solar-wind magnetic field; and (3) ionospheric outflow, which is known to be Kp dependent. The occurrence of a superdense plasma sheet has several consequences: it adds to the intensity of the ring current, it may alter the dynamics of the magnetotail and the nature of substorms, and it may provide an enhanced source population for storm-time energetic particles. RP Borovsky, JE (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MAIL STOP D466,LOS ALAMOS,NM 87545, USA. NR 63 TC 127 Z9 127 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 1997 VL 102 IS A10 BP 22089 EP 22097 DI 10.1029/96JA02469 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XZ208 UT WOS:A1997XZ20800005 ER PT J AU Takahashi, K Anderson, BJ Ohtani, S Reeves, GD Takahashi, S Sarris, TE Mursula, K AF Takahashi, K Anderson, BJ Ohtani, S Reeves, GD Takahashi, S Sarris, TE Mursula, K TI Drift-shell splitting of energetic ions injected at pseudo-substorm onsets SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; PARTICLE; MAGNETOSPHERE; PROTON; MODEL; MULTISATELLITE; ECHOES; PSEUDOBREAKUP; PULSATIONS; EXPANSION AB One feature of a magnetospheric substorm is the injection of energetic particles into closed drift orbits. Injections are routinely observed by geosynchronous satellites and have been used to identify the occurrence of substorms and the local time of particle energization. In this study we examine pitch angle distributions of ion injections in the 50- to 300-keV energy range observed by the Active Magnetospheric particle Tracer Explorers Charge Composition Explorer (AMPTE/CCE) satellite, hereinafter CCE. In a dipole field, all pitch angles follow the same drift shell, but the day-night asymmetry of the magnetospheric magnetic field introduces a pitch angle dependence in particle drift orbits, so that particles with different pitch angles disperse radially as they drift. The effect is known as drift-shell splitting. For satellite observations near noon at a fixed geocentric distance, the guiding center orbits of ions detected at small pitch angles intersect the midnight meridian at larger geocentric distances than do ions with near-90 degrees pitch angles. The ion pitch angle distributions detected on the dayside therefore provide information about the radial distance of the nightside acceleration region. We apply this principle to study ion injection events observed on September 17-18, 1984, in association with pseudo-substorm onsets. CCE was at 13 hours local time near its apogee (8.8 R-E) and observed a series of ion flux enhancements. Energy dispersion of the timing of the Bur increases assures that they are due to injections on the nightside. The flux increases were observed only at pitch angles from 0 degrees to 60 degrees. We calculate drift orbits of protons using the Tsyganenko 89c magnetic field model and find that the drift orbits for 60 degrees pitch angle protons observed at the satellite pass through midnight at 9 R-E, well outside of geostationary orbit, indicating that the ion injections occurred tailward of 9 R-E. Energetic ion data from geostationary satellites for the same time interval show no evidence of injections at 6.6 R-E, consistent with the calculated inner boundary of the injections. Model calculations are presented demonstrating that dispersive injections observed near noon outside geosynchronous orbit provide the greatest sensitivity to drift-shell splitting effects and are therefore most suitable for remote sensing the radial boundaries of substorm injections. C1 JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723. UNIV OULU,DEPT PHYS SCI,FIN-90571 OULU,FINLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV ATHENS,DEPT PHYS,ZOGRAFOS 16232,GREECE. HITACHI LTD,POWER & IND R&D DIV,HITACHI,IBARAKI 31912,JAPAN. RP Takahashi, K (reprint author), NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA,AICHI 442,JAPAN. RI Anderson, Brian/I-8615-2012; Mursula, Kalevi/L-8952-2014; Reeves, Geoffrey/E-8101-2011; Ohtani, Shinichi/E-3914-2016 OI Mursula, Kalevi/0000-0003-4892-5056; Reeves, Geoffrey/0000-0002-7985-8098; Ohtani, Shinichi/0000-0002-9565-6840 NR 39 TC 16 Z9 16 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 1997 VL 102 IS A10 BP 22117 EP 22130 DI 10.1029/97JA01870 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XZ208 UT WOS:A1997XZ20800008 ER PT J AU Garrett, AJ Hayes, DW AF Garrett, AJ Hayes, DW TI Cooling lake simulations compared to thermal imagery and dye tracers SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID TURBULENCE CLOSURE-MODEL; CIRCULATION AB We compare three-dimensional simulations of two cooling lakes at the Savannah River site to calibrated temperature data derived from high resolution thermal imagery and to data from two dye tracer experiments. The observed temperatures include detailed surface temperature maps created from calibrated thermal imagery and vertical temperature profiles measured at five locations across one of the cooling lakes. The dye tracer data consist of time series of concentrations recorded near the cooling water outlet of one of the cooling lakes. There is generally good agreement between observed and measured quantities, but the agreement is best for the smaller cooling lake that had a relatively higher heat load. We suggest that wind stress variability may have been at least partially responsible for the poorer agreement between observation and simulation for the larger cooling lake. The primary conclusion from this study is that thermal imagery is an excellent additional data source to dye tracer data for cooling lake model verification because imagery provides detailed information about the surface temperatures over the entire cooling lake allowing for a more complete verification of model simulations. RP Garrett, AJ (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,BUILD 773-A,AIKEN,SC 29802, USA. NR 29 TC 22 Z9 22 U1 0 U2 4 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD OCT PY 1997 VL 123 IS 10 BP 885 EP 894 DI 10.1061/(ASCE)0733-9429(1997)123:10(885) PG 10 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA XX494 UT WOS:A1997XX49400006 ER PT J AU Ding, YS Liang, F Fowler, JS Kuhar, MJ Carroll, FI AF Ding, YS Liang, F Fowler, JS Kuhar, MJ Carroll, FI TI Synthesis of [F-18]norchlorofluoroepibatidine and its N-methyl derivative: New PET ligands for mapping nicotinic acetylcholine receptors SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE nicotinic acetylcholine receptors; epibatidine; fluorine-18; positron emission tomography ID NUCLEOPHILIC AROMATIC-SUBSTITUTION; POISON FROG; EPIBATIDINE; (+/-)-EPIBATIDINE AB Fluorine-18 labeled norchlorofluoroepibatidine (NFEP), a high-affinity nicotinic acetylcholine receptor ligand, was prepared by a one-pot, two-step synthesis: nucleophilic heteroaromatic substitution of a tert-Boc protected precursor (7-tert-butyloxycarbonyl-exo-2-(2'-N,N,N-trimethylammonium-5'-pyridinyl)-7-[2.2.1]heptane iodide) using no-carrier-added [F-18]fluoride followed by deprotection with trifluoroacetic acid. Subsequent reductive N-methylation with formaldehyde and sodium cyanoborohydride afforded fluorine-lb labeled N-methyl-norchlorofluoroepibatidine (N-methyl-NFEP). The unusually high radiochemical yield for the first step (70%) and the quantitative conversions in the deprotection and N-methylation steps afforded overall radiochemical yields of 55-65% (decay corrected based on starting [F-18]fluoride) for [F-18]NFEP (synthesis time 65 min) and 45-55% for [F-18]N-methyl-NFEP (synthesis time 75 min), with a specific activity of 2-9 Ci/mu mole (EOB). C1 RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. NIDA,ADDICT RES CTR,BALTIMORE,MD 21224. RP Ding, YS (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 21 TC 24 Z9 25 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD OCT PY 1997 VL 39 IS 10 BP 827 EP 832 DI 10.1002/(SICI)1099-1344(199710)39:10<827::AID-JLCR29>3.3.CO;2-Z PG 6 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA XZ102 UT WOS:A1997XZ10200005 ER PT J AU Leong, KH Geyer, HK Sabo, KR Sanders, PG AF Leong, KH Geyer, HK Sabo, KR Sanders, PG TI Threshold laser beam irradiances for melting and welding SO JOURNAL OF LASER APPLICATIONS LA English DT Article DE lasers; threshold irradiance; laser beam welding ID ALUMINUM AB A model based on the conservation of energy for a moving heat source incident on a flat plate is used to predict the threshold laser beam irradiance required to initiate melting on a metal surface, With the use of a non-dimensional variable and its solution, the threshold irradiance can be predicted with the use of a simple equation. This equation is a function of the absorptivity of the surface, thermal conductivity of the metal, temperature increase for melting, diameter of the laser beam at the surface and the non-dimensional variable value for the ratio of the thermal diffusivity of the metal to the product of the beam diameter and velocity used, Laser beam irradiances exceeding these predicted values are required for welding. The model predictions are validated with experimental results of beam irradiances required for welding different metals. RP Leong, KH (reprint author), ARGONNE NATL LAB,DIV TECHNOL DEV,ARGONNE,IL 60439, USA. NR 20 TC 8 Z9 8 U1 2 U2 2 PU LASER INST AMER PI ORLANDO PA 12424 RESEARCH PARKWAY SUITE 125, ORLANDO, FL 32826 SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD OCT PY 1997 VL 9 IS 5 BP 227 EP 231 PG 5 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA YB393 UT WOS:A1997YB39300002 ER PT J AU Guenther, AH AF Guenther, AH TI Laser-Induced Damage in Optical Materials at the October 7-9, 1996 Symposium on Optical Materials for High-Power Lasers (the Boulder Damage Symposium) Boulder, Colorado SO JOURNAL OF LASER APPLICATIONS LA English DT Editorial Material DE laser damage; laser interaction; optical components; optical fabrication; optical materials and properties; thin film coating; laser diodes ID ASTM SYMPOSIUM AB The 28th annual symposium on optical materials for high-power lasers (Boulder damage symposium) was held at the National Institute of Standards and Technology in Boulder, CO, 7-9 October 1996. The symposium was held under the joint sponsorship of Bennett Optical Research, the Center for Research and Education in Optics and Lasers (CREOL) at the Center for Research and Education in Optics and Lasers (CREOL) at the University of Central Florida, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratories, and SPIE-The International Society for Optical Engineering. Over 130 scientists attended the symposium, including representatives from France, Germany, Japan, Russia, South Africa, Hungary, Armenia, Israel, the UK, and the US. The symposium was divided into sessions concerning materials and measurements, surfaces and mirrors, thin films, fundamental mechanisms, and a mini-symposium on 'Laser-Induced Damage in Optical Fibers: organized by R.E. Setchell and Sandia National Laboratories. As in previous years, the emphasis of the papers presented at the symposium was directed toward new frontiers and new developments. Particular emphasis was given to materials for high-power laser systems. The wavelength range of prime interest was from 10.6 mu m in the infrared to the UV region. Highlights included surface characterization, thin film/substrate boundaries, and advances in fundamental laser-matter interactions and mechanisms. Harold E. Bennett of Bennett Optical Research, Inc., Arthur H. Guenther of Sandia National Laboratories, Mark R. Kozlowski of the Lawrence Livermore National Laboratory, Brian E. Newnam of the Los Alamos National Laboratory, and M. J. Soileau of the University of Central Florida were co-chairs of the symposium. The 29th annual symposium is scheduled for 6-8 October 1997 at the National Institute of Standards and Technology, Boulder, CO. An added feature will be a wholly self-contained mini-symposium on 'Damage in Laser Diodes' organized by David Welch of Spectra Diode Laboratories. RP Guenther, AH (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87106, USA. NR 45 TC 5 Z9 5 U1 0 U2 2 PU LASER INST AMER PI ORLANDO PA 12424 RESEARCH PARKWAY SUITE 125, ORLANDO, FL 32826 SN 1042-346X J9 J LASER APPL JI J. Laser Appl. PD OCT PY 1997 VL 9 IS 5 BP 261 EP 266 PG 6 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA YB393 UT WOS:A1997YB39300006 ER PT J AU Hall, AL Wilson, BS Pfeiffer, JR Oliver, JM Sklar, LA AF Hall, AL Wilson, BS Pfeiffer, JR Oliver, JM Sklar, LA TI Relationship of ligand-receptor dynamics to actin polymerization in RBL-2H3 cells transfected with the human formyl peptide receptor SO JOURNAL OF LEUKOCYTE BIOLOGY LA English DT Article DE cell surface molecules; signaling molecules; cell signaling; mast cells/basophils; motility; chemotaxis ID C5A CHEMOATTRACTANT RECEPTORS; DIFFERENTIATED HL-60 CELLS; BASOPHILIC LEUKEMIA-CELLS; A(3) ADENOSINE RECEPTOR; CHEMOTACTIC PEPTIDE; G-PROTEIN; SIGNAL TRANSDUCTION; HUMAN-NEUTROPHILS; MAST-CELLS; POLYMORPHONUCLEAR LEUKOCYTES AB The human formylpeptide receptor (FPR) expressed in RBL-2H3 transfectants (RBLFPR) behaves qualitatively like the FPR expressed by neutrophils except that it causes sustained F-actin accumulation and cell shape change responses on formyl peptide stimulation, These sustained responses were not accounted for by changes in the transfected receptor's ability to interact with ligand or by receptor density, Signal transduction pathways of transfected and neutrophil FPRs are apparently similar, In transfected cells, dissociation of ligand is sensitive to guanine nucleotide, the G protein is pertussis toxin-sensitive, FPR and G protein appear to be precoupled, the F-actin response is stimulated with the same dose-response profile as in neutrophils, and the F-actin accumulation response is directly regulated by the FPR, even long after initial stimulation, Potentially significant differences between neutrophil and transfected FPR were found when receptor processing was measured, In neutrophils, practically 100% of the FPR is converted to forms that dissociate slowly from ligand and are inactive in signal transduction within 2 min of ligand stimulation, By contrast, 20% or more of transfected FPR remains rapidly dissociating even 5 min after stimulation, Although 80% of neutrophil FPR is internalized by 5 min after stimulation, transfected FPR appears to plateau at 50-60% internalized, Because actin responses in neutrophils are regulated by a small number of active receptors, the inefficiency of receptor inactivation in RBLFPR transfectants may account for the prolonged F-actin accumulation response. C1 UNIV NEW MEXICO, HLTH SCI CTR, CANC RES & TREATMENT CTR 325, SCH MED, ALBUQUERQUE, NM 87131 USA. UNIV NEW MEXICO, SCH MED, DEPT PATHOL, ALBUQUERQUE, NM 87131 USA. LOS ALAMOS NATL LAB, NATL FLOW CYTOMETRY RESOURCE, LOS ALAMOS, NM 87545 USA. FU NCRR NIH HHS [RR01315]; NIAID NIH HHS [AI19032] NR 52 TC 7 Z9 7 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0741-5400 EI 1938-3673 J9 J LEUKOCYTE BIOL JI J. Leukoc. Biol. PD OCT PY 1997 VL 62 IS 4 BP 535 EP 546 PG 12 WC Cell Biology; Hematology; Immunology SC Cell Biology; Hematology; Immunology GA YA004 UT WOS:A1997YA00400016 PM 9335325 ER PT J AU Birmingham, JT Richards, PL AF Birmingham, JT Richards, PL TI The heat capacity of He-4 monolayers adsorbed on evaporated gold SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID BOSE STATISTICS; METAL-SURFACES; 2 DIMENSIONS; AG FILMS; HELIUM; GRAPHITE; CESIUM; ADSORPTION; TRANSITIONS; HYDROGEN AB The specific heat of He-4 condensed on an evaporated gold surface has been measured for coverages between 0.007 and 0.096 Angstrom(-2) and temperatures between 0.4 and 3.0 K. There are at least two types of physisorption site on the gold surface with binding energies -83+/-7 and -94+/-7 K. For coverages below 0.06 Angstrom(-2) (similar to 0.5 monolayers), the He-4 is a two-dimensional classical gas at sufficiently high temperatures. At lower temperatures and higher coverages, the 4He forms condensed phases, including liquids, solids commensurate with the gold lattice, and incommensurate solids. The phase diagram of He-4/evaporated gold is similar to that for He-4/graphite, but the phase boundaries are shifted and not well defined, nor is the diagram as rich in structure. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 41 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 EI 1573-7357 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD OCT PY 1997 VL 109 IS 1-2 BP 267 EP 286 DI 10.1007/BF02396735 PG 20 WC Physics, Applied; Physics, Condensed Matter SC Physics GA YG808 UT WOS:A1997YG80800010 ER PT J AU Liao, TW Li, K Breder, K AF Liao, TW Li, K Breder, K TI Flexural strength of ceramics ground under widely different conditions SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article DE flexural strength; ceramics ID ELASTIC-PLASTIC INDENTATION; CRACK SYSTEM; DAMAGE AB This study evaluates the degree of strength degradation for three different ceramic materials ground under widely different conditions. Based on the results of this study, 13 observations are made. In particular, it is found that two different groups of average flexural strength, sigma(f), surface roughness, R-a and effective point of application of the resultant force on the are of wheel-workpiece contact, K, are formed: one for conditions having h(m), a(m) and f(n) smaller than the critical values; and the other for the remaining conditions; where h(m), a(m) and f(n) are the grit depth of cut, the average cross-sectional area of active cutting edges, and the mean normal force per grit, respectively. The results are discussed and compared with those reported by other researchers. (C) 1997 Elsevier Science S.A. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Liao, TW (reprint author), LOUISIANA STATE UNIV,DEPT IND & MFG SYST ENGN,BATON ROUGE,LA 70803, USA. RI Liao, Thunshun/B-2724-2009 NR 20 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECH JI J. Mater. Process. Technol. PD OCT PY 1997 VL 70 IS 1-3 BP 198 EP 206 DI 10.1016/S0924-0136(97)80801-1 PG 9 WC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA XZ497 UT WOS:A1997XZ49700027 ER PT J AU Plucknett, KP Becher, PF Subramanian, R AF Plucknett, KP Becher, PF Subramanian, R TI Melt-infiltration processing of TiC/Ni3Al composites SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MECHANICAL-PROPERTIES; NI3AL; PREFORMS; STRENGTH; ELEMENTS AB A simple melt-infiltration processing route has been developed for the fabrication of TiC/Ni3Al ceramic/intermetallic composites, which involves a combination of infiltration and subsequent liquid phase sintering. For Ni3Al contents from 8 to 25 vol. %, densities in excess of 98% of theoretical are readily obtained when processing at 1450 degrees C. TiC and Ni3Al are the only phases detected in the densified materials. Ni3Al ductility is retained after processing, leading to the possibility of ductile phase toughened TiC composites for elevated temperature applications (up to similar to 1100 degrees C). RP Plucknett, KP (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 22 TC 29 Z9 32 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 1997 VL 12 IS 10 BP 2515 EP 2517 DI 10.1557/JMR.1997.0332 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA YD170 UT WOS:A1997YD17000003 ER PT J AU Zhang, J Smith, PA Golcar, GR Wang, LQ Darab, JG AF Zhang, J Smith, PA Golcar, GR Wang, LQ Darab, JG TI Hydrated K2SO4 center dot 2MgSO(4) structure revealed by TGA/DTA and magic-angle spinning H-1-NMR spectroscopy SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID MAS-NMR; PROTON NMR; MGSO4.7H2O; EPSOMITE; SURFACE; SI-29 AB The hydration of K2SO4 . 2MgSO(4) as a function of water addition was examined by pore-size distribution, thermo-gravimetric analysis/differential thermal analysis and nuclear magnetic resonance (NMR) spectroscopy. Thermal studies indicated that the dehydration reactions occur within three distinct temperature regimes which correspond to different degree of hydrogen bonded water or water in different pore-size environments. Solid NMR studies resolved three different proton peaks at each water loading, that represent different chemical environments around water, and also the different range of hydrogen bonding strengths. Therefore, the different chemical environments associated with pore size around water are key factors influencing the NMR spectra. Both thermal and NMR studies suggested that pore size affects the molecular interactions between water and water, and water and the substrate. Also X-ray diffraction studies identified the presence of three phases existing in the hydrated products after the hydration reaction. RP Zhang, J (reprint author), PACIFIC NW LAB, CHEM SEPERAT & SLURRY PROC GRP, POB 999, RICHLAND, WA 99352 USA. NR 19 TC 0 Z9 0 U1 0 U2 2 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 OCT 1 PY 1997 VL 32 IS 19 BP 5113 EP 5122 DI 10.1023/A:1018617417066 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA YA579 UT WOS:A1997YA57900010 ER PT J AU Khang, YH Yang, ZK Burlage, RS AF Khang, YH Yang, ZK Burlage, RS TI Measurement of iron-dependence of pupA promoter activity by a pup-lux bioreporter SO JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article DE siderophores; Fe(III); pup-lux; pupA bioreporter ID PSEUDOMONAS-PUTIDA WCS358; FERRIC-PSEUDOBACTIN RECEPTOR; SIDEROPHORE-MEDIATED UPTAKE; BIOSYNTHESIS; PROTEIN AB The promoter region of the pupA gene of Pseudomonas putida WCS358 was fused with the structural genes for bioluminescence (luxCDABE) from Vibrio fischeri, and the resulting fusion plasmid harbored by the WCS358 host. The pup-lux fusion gene was then used for quantitative analysis of the iron-dependence of pupA promoter activity. Factors affecting bioluminescence produced by the pup-lux bioreporter were found to be cell activity, iron-chelator concentrations, Fe(III) concentrations, and nutrient components. Light production rates of the pup-lux bioreporter were inversely dependent upon iron molecules when FeCl3 concentrations were between 10(-2) and 1 mu M in nutrient-poor minimal media, and between 0.1 and 10 mM in nutrient-rich complex media. C1 YEUNGNAM UNIV,DEPT APPL MICROBIOL,KYONGSAN 712749,SOUTH KOREA. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 12 TC 4 Z9 4 U1 0 U2 5 PU KOREAN SOC APPLIED MICROBIOLOGY PI SEOUL PA 635-4 YEOGSAM-DONG, KANGNAM-KU, SEOUL, 135-703, KOREA SN 1017-7825 J9 J MICROBIOL BIOTECHN JI J. Microbiol. Biotechnol. PD OCT PY 1997 VL 7 IS 5 BP 352 EP 355 PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YD954 UT WOS:A1997YD95400012 ER PT J AU Felder, CE Botti, SA Lifson, S Silman, I Sussman, JL AF Felder, CE Botti, SA Lifson, S Silman, I Sussman, JL TI External and internal electrostatic potentials of cholinesterase models SO JOURNAL OF MOLECULAR GRAPHICS & MODELLING LA English DT Article DE cholinesterase; electrostatics; electric potential; electrostatic motif ID RATE CONSTANTS; TORPEDO-CALIFORNICA; IONIC-STRENGTH; ACETYLCHOLINESTERASE; PROTEIN; SEQUENCE; CHARGE; SITE; ASSOCIATION; SIMULATION AB The electrostatic potentials for the three-dimensional structures of cholinesterinases from various species were calculated, using the Delphi algorithm, on the basis of the Poisson-Boltzmann equation. We used structures for Torpedo californica and mouse acetylcholinesterase, and built homology models of the human, Bungarus fasciatus, and Drosophila melanogaster acetylcholinesterases and human butyrylcholinesterase. All these structures reveal a negative external surface potential, in the area around the entrance to the active-site gorge, that becomes more negative as the rim of the gorge is approached. Moreover in all cases, the potential becomes increasingly more negative along the central axis running down the gorge, and is largest at the base of` the gorge, near the active site. Ten key acidic residues conserved in the sequence alignments of AChE from various species, both in the surface area near the entrance of the active-site gorge and at its base, appear to be primarily responsible for these potentials. The potentials are highly correlated among the structures examined, down to sequence identities as low as 35%. This indicates that they are a conserved property of the cholinesterase family could serve to attract the positively charged substrate into and down the gorge to the active site, and may play other roles important for cholinesterase function. (C) 1998 by Elsevier Science Inc. C1 Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. Weizmann Inst Sci, Dept Neurobiol, IL-76100 Rehovot, Israel. Weizmann Inst Sci, Dept Chem Phys, IL-76100 Rehovot, Israel. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Sussman, JL (reprint author), Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. OI Sussman, Joel/0000-0003-0306-3878 NR 36 TC 56 Z9 57 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1093-3263 J9 J MOL GRAPH MODEL JI J. Mol. Graph. PD OCT PY 1997 VL 15 IS 5 BP 318 EP + DI 10.1016/S1093-3263(98)00005-9 PG 13 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Computer Science, Interdisciplinary Applications; Crystallography; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Computer Science; Crystallography; Mathematical & Computational Biology GA ZU476 UT WOS:000074201600005 PM 9640563 ER PT J AU Rao, Q Piepel, GF Hrma, P Crum, JV AF Rao, Q Piepel, GF Hrma, P Crum, JV TI Liquidus temperatures of HLW glasses with zirconium-containing primary crystalline phases SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article AB Three empirical models are investigated for predicting liquidus temperatures (T-L) as a function of glass composition for high-level waste (HLW) glasses with zirconium-containing primary crystalline phases. The three models are: (1) first-order multiple regression, (2) first-order single regression, and (3) second order multiple regression. For each of two HLW data sets and their union, the models were developed using least squares regression on data from glasses with any zirconium-containing primary phase, and for the subset of glasses with zircon (ZrSiO4) as the primary phase. The fitted models, evaluations of their performances, and interpretations of results are presented. The first-and second-order models fit very well for four of the six combinations of data set (A, B, A + B) and primary phase (zircon, zirconium-containing), and reasonably well for the other two combinations. For the composition regions and primary phases studied, T-L is: (i) increased by ZrO2, Al2O3, and MgO, (ii) decreased by Na2O and Li2O, and (iii) moderately to negligibly affected by SiO2, B2O3, and CaO. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 10 TC 14 Z9 14 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD OCT PY 1997 VL 220 IS 1 BP 17 EP 29 DI 10.1016/S0022-3093(97)00227-5 PG 13 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA YH539 UT WOS:A1997YH53900003 ER PT J AU DiStefano, JR DeVan, JH AF DiStefano, JR DeVan, JH TI Reactions of oxygen with V-Cr-Ti alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Fusion reactors have been proposed with a vanadium alloy as the structural/containment material. However, vanadium has a significant affinity for interstitial contamination that could deleteriously affect its mechanical properties. The effects of oxygen pick-up in air and low pressure oxygen environments were investigated at 400-500 degrees C for two V-Cr-Ti alloys. As expected the studies showed that the room temperature tensile ductility is reduced by exposure to air or low pressure oxygen environments. However, the magnitude depends upon processing history and subsequent heat treatment. Possible embrittling mechanisms such as gain boundary weakening or weakening of near-boundary regions are discussed. (C) 1997 Elsevier Science B.V. RP DiStefano, JR (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 13 TC 22 Z9 22 U1 1 U2 5 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 OCT PY 1997 VL 249 IS 2-3 BP 150 EP 158 DI 10.1016/S0022-3115(97)00217-1 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YC697 UT WOS:A1997YC69700008 ER PT J AU Pareige, P Stoller, RE Russell, KF Miller, MK AF Pareige, P Stoller, RE Russell, KF Miller, MK TI Atom probe characterization of the microstructure of nuclear pressure vessel surveillance materials after neutron irradiation and after annealing treatments SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID STEELS; PRECIPITATION; COPPER; ALLOYS; APFIM AB Microstructural changes due to neutron irradiation of weld and forging materials were characterized using the atom probe field ion microscope (APFIM). Neutron-induced clusters containing Cu, P, Ni, Mn and Si were detected in the high copper weld (0.24 at.% Cu) after irradiation to fluences of 6.6 X 10(22) and 3.47 X 10(23) nm(-2); only phosphorus atmospheres were observed in the low copper forging material (0.02 at.% Cu) irradiated to an intermediate fluence of 1.5 X 10(23) nm(-2). These results are in agreement with previous studies and with their respective measured transition temperature shifts. In addition, APFIM experiments were carried out on the high fluence weld material after two post-irradiation annealing treatments. The first annealing treatment of 168 h at 454 degrees C is similar to the proposed condition for in situ pressure vessel annealing and the second, 29 h at 610 degrees C, is similar to the final stress relief heat treatment employed in vessel fabrication. Annealing at 454 degrees C led to coarsening of the copper-enriched precipitates and a 92% recovery of the radiation-induced transition temperature shift. Essentially complete rehomogenization of the solutes was obtained in the simulated stress relief treatment at 610 degrees C. (C) 1997 Elsevier Science B.V. C1 FAC SCI & TECH,LABS MICROSCOPIE ION,F-76134 MONT ST AIGNAN,FRANCE. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RI Stoller, Roger/H-4454-2011; PAREIGE, Philippe/A-2588-2013 NR 25 TC 53 Z9 58 U1 1 U2 15 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 OCT PY 1997 VL 249 IS 2-3 BP 165 EP 174 DI 10.1016/S0022-3115(97)00215-8 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YC697 UT WOS:A1997YC69700010 ER PT J AU McGrail, BP Ebert, WL Bakel, AJ Peeler, DK AF McGrail, BP Ebert, WL Bakel, AJ Peeler, DK TI Measurement of kinetic rate law parameters on a Na-Ca-Al borosilicate glass for low-activity waste SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID DISSOLUTION; CONSTRAINTS AB The dissolution kinetics of a Na-Ca-Al borosilicate glass, being studied for immobilization of low-activity waste, were measured between 20 and 90 degrees C and solution pH between 6 and 12 using the single-pass flow-through method. Dissolution kinetics measurements are needed to parameterize a mechanistic model that is being used to compute the corrosion rate of the glass waste form as a function of temperature, pH, and the concentrations of the other glass components in water percolating through a proposed shallow-land disposal facility. The key factors that were found to influence the test results include test duration and background subtraction of the raw data. Background subtraction is shown to be important to prevent a non-physical increase in the computed rate with increasing flow rate, particularly in tests run at higher flow rates, Experimental factors that were found to have no detectable influence on the test results included the glass particle size and buffer type. We also illustrate how flow rate variations can be used to obtain information about the reaction order and equilibrium constant parameters in a conventional transition-state theory rate law. (C) 1997 Elsevier Science B.V. C1 ARGONNE NATL LAB, DEPT CHEM TECHNOL, ARGONNE, IL 60439 USA. WESTINGHOUSE SAVANNAH RIVER CO, AIKEN, SC 29808 USA. RP McGrail, BP (reprint author), PACIFIC NW NATL LAB, APPL GEOL & GEOCHEM DEPT, POB 999, RICHLAND, WA 99352 USA. NR 18 TC 82 Z9 82 U1 4 U2 15 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 OCT PY 1997 VL 249 IS 2-3 BP 175 EP 189 DI 10.1016/S0022-3115(97)00213-4 PG 15 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YC697 UT WOS:A1997YC69700011 ER PT J AU Burns, PC Finch, RJ Hawthorne, FC Miller, ML Ewing, RC AF Burns, PC Finch, RJ Hawthorne, FC Miller, ML Ewing, RC TI The crystal structure of ianthinite, [U-2(4+)(UO2)(4)O-6(OH)(4)(H2O)(4)](H2O)(5): a possible phase for Pu4+ incorporation during the oxidation of spent nuclear fuel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID DISSOLUTION; URANINITE; CORROSION; MINERALS; UO2 AB Ianthinite, [U-2(4+)(UO2)(4)O-6(OH)(4)(H2O)(4)](H2O)(5), is the only known uranyl oxide hydrate mineral that contains U4+, and it has been proposed that ianthinite may be an important Pu4+-bearing phase during the oxidative dissolution of spent nuclear fuel. The crystal structure of ianthinite, orthorhombic, a = 0.7178(2), b = 1.1473(2), c = 3.039(1) nm, V = 2.5027 nm(3), Z = 4, space group P2(1)cn, has been solved by direct methods and refined by least-squares methods to an R index of 9.7% and a wR index of 12.6% using 888 unique observed [\F\greater than or equal to 5 sigma\F\] reflections. The structure contains both U6+ and U4+. The U6+ cations are present as roughly linear (U6+O2)(2+) uranyl ions (Ur) that are in turn coordinated by five O2- and OH- located at the equatorial positions of pentagonal bipyramids. The U4+ cations are coordinated by O2-, OH- and H2O in a distorted octahedral arrangement. The Ur phi(5) and U4+ phi(6) (phi: O2-, OH-, H2O) polyhedra link by sharing edges to form two symmetrically distinct sheets at z approximate to 0.0 and z approximate to 0.25 that are parallel to (001). The sheets have the beta-U3O8 sheet anion-topology. There are five symmetrically distinct H2O groups located at z approximate to 0.125 between the sheets of U phi(n) polyhedra, and the sheets of U phi(n) polyhedra are linked together only by hydrogen bonding to the intersheet H2O groups. The crystal-chemical requirements of U4+ and Pu4+ are very similar, suggesting that extensive Pu4+ <-> U4+ substitution may occur within the sheets of U phi(n) polyhedra in the structure of ianthinite. (C) 1997 Published by Elsevier Science B.V. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. UNIV MANITOBA,DEPT GEOL SCI,WINNIPEG,MB R3T 2N2,CANADA. UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,ALBUQUERQUE,NM 87131. RP Burns, PC (reprint author), UNIV ILLINOIS,DEPT GEOL,245 NAT HIST BLDG,1301 W GREET ST,URBANA,IL 61801, USA. RI Hawthorne, Frank/F-6864-2011; Finch, Robert/D-9553-2013; Burns, Peter/J-3359-2013; OI Hawthorne, Frank/0000-0001-6405-9931; Finch, Robert/0000-0001-9342-5574; Burns, Peter/0000-0002-2319-9628 NR 42 TC 63 Z9 64 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD OCT PY 1997 VL 249 IS 2-3 BP 199 EP 206 DI 10.1016/S0022-3115(97)00212-2 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YC697 UT WOS:A1997YC69700013 ER PT J AU Ackermann, D Back, BB Betts, RR Carpenter, M Corradi, L Fischer, SM Ganz, R Gil, S Hackman, G Hofman, DJ Janssens, RVF Khoo, TL Montagnoli, G Nanal, V Scarlassara, F Schlapp, M Seweryniak, D Stefanini, AM Wuosmaa, AH AF Ackermann, D Back, BB Betts, RR Carpenter, M Corradi, L Fischer, SM Ganz, R Gil, S Hackman, G Hofman, DJ Janssens, RVF Khoo, TL Montagnoli, G Nanal, V Scarlassara, F Schlapp, M Seweryniak, D Stefanini, AM Wuosmaa, AH TI Spin distributions - another approach for experimentally probing the fusion barrier distribution SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Heavy-Ion Collisions at Near-Barrier Energies (FUSION97) CY MAR 17-21, 1997 CL SOUTH DURRAS, AUSTRALIA SP ANU, Dept Nucl Phys, ANU, Dept Theoret Phys, Res Sch Phys Sci & engn, IOP Publ, Bicron Corp, Alphatech Int, Goodfellow Cambridge Ltd ID SUBBARRIER FUSION; COULOMB BARRIER; CROSS-SECTIONS; EXCITATION; HEAVY AB The investigation of subbarrier fusion is undergoing a revival following the suggestion of a way to extract an experimental representation of the barrier distribution from the second derivative, d(2)(E sigma(fus))/dE(2). By performing precise measurements of fusion excitation functions one is able to extract the strength and height of the barriers, providing important information on the coupling mechanism. As an alternative approach, it has recently been proposed that the first derivative of the compound nucleus (CN) spin distribution is equivalent to d(2)(E sigma(fus))/(dE(2)). Multiplicity distributions for the reactions Ni-64+Mo-100 and S-32 + Pd-110 have been measured making use of the Argonne/Notre Dame-BGO-array and GASP, respectively. In particular, the influence of fission on the high spin tail of the spin distribution and the consequences for the experimental representation of the distribution of barriers is discussed for Ni-64 + Mo-100. C1 LAB NAZL LEGNARO, I-35020 LEGNARO, ITALY. UNIV BUENOS AIRES, DEPT PHYS, BUENOS AIRES, DF, ARGENTINA. UNIV PADUA, DEPT PHYS, PADUA, ITALY. RP Ackermann, D (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Carpenter, Michael/E-4287-2015; OI Carpenter, Michael/0000-0002-3237-5734; Scarlassara, Fernando/0000-0002-4663-8216; Ackermann, Dieter/0000-0001-6284-1516 NR 11 TC 5 Z9 5 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 OCT PY 1997 VL 23 IS 10 BP 1167 EP 1174 DI 10.1088/0954-3899/23/10/003 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YB251 UT WOS:A1997YB25100003 ER PT J AU Moretto, LG Jing, KX Phair, L Wozniak, GJ AF Moretto, LG Jing, KX Phair, L Wozniak, GJ TI Particle structure function and sub-barrier fusion in hot nuclei SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Heavy-Ion Collisions at Near-Barrier Energies (FUSION97) CY MAR 17-21, 1997 CL SOUTH DURRAS, AUSTRALIA SP ANU, Dept Nucl Phys, ANU, Dept Theoret Phys, Res Sch Phys Sci & engn, IOP Publ, Bicron Corp, Alphatech Int, Goodfellow Cambridge Ltd AB The study of particle evaporation spectra can provide information about shape polarization phenomena induced by the nascent particle on the residual nucleus, and about optical modulations felt by the particle as it is preformed inside the nucleus. These aspects can be studied as a function temperature. Preliminary experimental evidence about these features has been obtained. RP Moretto, LG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 0 TC 11 Z9 11 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD OCT PY 1997 VL 23 IS 10 BP 1323 EP 1330 DI 10.1088/0954-3899/23/10/021 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YB251 UT WOS:A1997YB25100021 ER PT J AU Morton, CR Buda, A Paul, P Shaw, NP Beene, JR Gan, N Halbert, ML Stracener, DW Varner, RL Thoennessen, M Thirolf, P Dioszegi, I AF Morton, CR Buda, A Paul, P Shaw, NP Beene, JR Gan, N Halbert, ML Stracener, DW Varner, RL Thoennessen, M Thirolf, P Dioszegi, I TI Fission dynamics using the decay of the giant dipole resonance SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Heavy-Ion Collisions at Near-Barrier Energies (FUSION97) CY MAR 17-21, 1997 CL SOUTH DURRAS, AUSTRALIA SP ANU, Dept Nucl Phys, ANU, Dept Theoret Phys, Res Sch Phys Sci & engn, IOP Publ, Bicron Corp, Alphatech Int, Goodfellow Cambridge Ltd ID CHARGED-PARTICLE MULTIPLICITIES; FUSION-FISSION; QUASI-FISSION; NUCLEAR-DEFORMATION; TIME SCALES; EMISSION; STRENGTH; THORIUM AB High-energy gamma-rays from the decay of the giant dipole resonance built on excited states were measured in coincidence with fission for the S-32 + W-nat, Pb-208 reactions. Both the gamma-ray multiplicity and the gamma-fission angular correlation were determined; the latter quantity is sensitive to the deformation of the fissioning nucleus. This sensitivity has been used in order to estimate the breakdown of dynamical fission time tau(f) into its pre- tau(pre) and post-saddle tau(post) components. A statistical model analysis, using a version of CASCADE modified to include pre- and post-saddle delay times in order to simulate the effects of dynamics, can reproduce the data with tau(pre)approximate to 10x10(-21) s and t(post)approximate to 20x10(-21) s for a dynamical fission time tau(f) approximate to 30x10(-21). C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. MICHIGAN STATE UNIV,NSCL,E LANSING,MI 48824. HUNGARIAN ACAD SCI,INST ISOTOPES,H-1525 BUDAPEST,HUNGARY. RP Morton, CR (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. NR 22 TC 8 Z9 8 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD OCT PY 1997 VL 23 IS 10 BP 1383 EP 1392 DI 10.1088/0954-3899/23/10/028 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YB251 UT WOS:A1997YB25100028 ER PT J AU Betts, RR AF Betts, RR TI Concluding remarks SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Editorial Material C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. RP Betts, RR (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD OCT PY 1997 VL 23 IS 10 BP 1497 EP 1501 DI 10.1088/0954-3899/23/10/042 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YB251 UT WOS:A1997YB25100042 ER PT J AU Johnson, CS Dees, DW Mansuetto, MF Thackeray, MM Vissers, DR Argyriou, D Loong, CK Christensen, L AF Johnson, CS Dees, DW Mansuetto, MF Thackeray, MM Vissers, DR Argyriou, D Loong, CK Christensen, L TI Structural and electrochemical studies of alpha-manganese dioxide (alpha-MnO2) SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 8th International Meeting on Lithium Batteries CY JUN 16-21, 1996 CL NAGOYA, JAPAN DE manganese dioxide; lithium batteries; structure; electrochemical properties ID INELASTIC NEUTRON-SCATTERING AB The structural and electrochemical properties of alpha-MnO2, prepared by acid digestion of Mn2O3, and its lithiated derivatives xLi(2)O . MnO2 (0 less than or equal to x less than or equal to 0.25) have been investigated as insertion compounds in the search for new and viable cathode materials for rechargeable 3 V batteries. The alpha-MnO2 product fabricated by this technique contains water within the large (2 x 2) channels of the structure; the water can be removed from the alpha-MnO2 framework without degradation of the structure, and then at least partially replaced by Li2O (lithium oxide). The Li2O-doped alpha-MnO2 electrodes, described generically as xLi(2)O . MnO2, stabilize the structure and provide higher capacities on cycling than the parent material, The structures of these alpha-MnO2-type electrode materials are described, and electrochemical data are presented for both liquid electrolyte and polymer electrolyte Li/alpha-MnO2 and Li/xLi(2)O . MnO2 cells. (C) 1997 Published by Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Electrochem Technol Program, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source Div, Electrochem Technol Program, Argonne, IL 60439 USA. 3M Co, 3M Ctr, St Paul, MN 55144 USA. RP Johnson, CS (reprint author), Argonne Natl Lab, Div Chem Technol, Electrochem Technol Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 17 TC 111 Z9 118 U1 7 U2 66 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT PY 1997 VL 68 IS 2 BP 570 EP 577 DI 10.1016/S0378-7753(96)02633-X PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA YP187 UT WOS:000071251300088 ER PT J AU Takada, T Hayakawa, H Akiba, E Izumi, F Chakoumakos, BC AF Takada, T Hayakawa, H Akiba, E Izumi, F Chakoumakos, BC TI Novel synthesis process and structure refinements of Li4Mn5O12 for rechargeable lithium batteries SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 8th International Meeting on Lithium Batteries CY JUN 16-21, 1996 CL NAGOYA, JAPAN DE spinel; structure refinement; lithium manganese oxides; Rietveld method; lithium batteries ID THERMAL-STABILITY; SPINEL; LIMN2O4; OXYGEN AB Well-crystallized Li4Mn5O12 powder with grain size of 0.1-0.4 mu m was prepared by heating a eutectic mixture of lithium acetate (LiOAc), and manganese nitrate (Mn(NO3)(2)), in an oxygen atmosphere. The structure of Li4Mn5O12 crystallites was found to be a cubic spinel using Rietveld refinement of both neutron and X-ray powder diffraction data. We confirmed that lithium ions occupy both the tetrahedral 8a sites, and part of the octahedral 16d sites, but not the 16c sites in the space group Fd (3) over bar m, while all the manganese ions occupy the 16d sites. The lattice parameter was found to be sensitive to the synthesis temperature as a result of the variation in manganese valence. Samples prepared at 500 degrees C showed better electrode performance. A rechargeable capacity of about 135 mAh/g for the cell Li/Li4Mn5O12 was obtained in the 2.5-3.6 V range of cell voltages. (C) 1997 Elsevier Science S.A. C1 Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 305, Japan. Natl Inst Res Inorgan Mat, Tsukuba, Ibaraki 305, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Takada, T (reprint author), Natl Inst Mat & Chem Res, Higashi 1-1, Tsukuba, Ibaraki 305, Japan. RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 10 TC 37 Z9 40 U1 2 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT PY 1997 VL 68 IS 2 BP 613 EP 617 DI 10.1016/S0378-7753(96)02570-0 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA YP187 UT WOS:000071251300097 ER PT J AU Johnson, BJ Doughty, DH Voigt, JA Boyle, TJ AF Johnson, BJ Doughty, DH Voigt, JA Boyle, TJ TI Electrochemical impedance spectroscopy studies of lithium diffusion in doped manganese oxide SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 8th International Meeting on Lithium Batteries CY JUN 16-21, 1996 CL NAGOYA, JAPAN DE manganese oxide; lithium-ion batteries; diffusion ID ELECTRODE; CATHODE; CELLS AB The electrochemical properties of LiMn2O4 and LiAlxMn2-xO4 (where x = 0.125, 0.25, 0.375) were studied for variations in lithium-ion diffusion, The largest diffusion coefficient was shown for the undoped material, DLi+ = 2.7 X 10(-11) cm(2)/s. As the level of dopant was increased a concurrent decrease in diffusion coefficient is shown. This effect was attributed to a decrease in the lattice parameter caused by dopant addition. (C) 1997 Published by Elsevier Science S.A. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Johnson, BJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 21 Z9 23 U1 2 U2 14 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT PY 1997 VL 68 IS 2 BP 634 EP 636 DI 10.1016/S0378-7753(96)02636-5 PG 3 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA YP187 UT WOS:000071251300101 ER PT J AU Lee, RW AF Lee, RW TI Radiative properties of hot dense matter III - Preface SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Editorial Material C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lee, RW (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP IX EP IX DI 10.1016/S0022-4073(97)87939-3 PG 1 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400001 ER PT J AU Alexiou, S Calisti, A Gauthier, P Klein, L Leboucher-Dalimier, E Lee, RW Stamm, R Talin, B AF Alexiou, S Calisti, A Gauthier, P Klein, L Leboucher-Dalimier, E Lee, RW Stamm, R Talin, B TI Aspects of plasma spectroscopy: Recent advances SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LINE-BROADENING THEORY; SPECTRAL-LINES; ISOELECTRONIC SEQUENCE; TRANSITIONS; ALPHA; HE+ AB Two important recent developments in Stark broadening are presented in this work: The first describes the Frequency Separation Technique (FST), which is motivated by the standard electron-ion separation and has important applications in that, coupled to any of a variety of methods capable of treating the intermediate ion-dynamical regime: (but not capable of treating ion impact), presents a unified and practical solution to the ion-dynamical problem. That is, this technique allows the relaxation of the quasistatic approximation. The second describes recent improvements that allow the accurate calculation of electron impact widths. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Paris 06, F-75272 Paris 05, France. Ecole Polytech, LULI, F-91128 Palaiseau, France. Univ Aix Marseille 1, PIIM, Ctr St Jerome, F-13397 Marseille 20, France. Howard Univ, Dept Phys, Washington, DC 20059 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Alexiou, S (reprint author), Univ Paris 06, 4 Pl Jussieu,T22-23,Case 136, F-75272 Paris 05, France. OI Calisti, Annette/0000-0001-6727-9286 NR 35 TC 23 Z9 23 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 399 EP 413 DI 10.1016/S0022-4073(97)00048-4 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400002 ER PT J AU Back, CA Perry, TS Bach, DR Wilson, BG Iglesias, CA Landen, OL Davidson, SJ Crowley, BJB AF Back, CA Perry, TS Bach, DR Wilson, BG Iglesias, CA Landen, OL Davidson, SJ Crowley, BJB TI Opacity measurements: Extending the range and filling in the gaps SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LOCAL THERMODYNAMIC-EQUILIBRIUM; ABSORPTION-MEASUREMENTS; HOT; PLASMA; MODEL; IRON AB A series of experiments to explore Ge opacity at temperatures where the M-shell is almost filled will be discussed. Data are obtained at lower temperatures than previously explored and allow us to investigate the role of atomic structure calculations and their impact on opacity scalings. The experiment uses the Nova. laser to irradiate a gold hohlraum within which a CH-tamped Ge sample is radiatively heated. A Nd backlight probes the sample 2 nsec later to produce Ge spectral absorption features in the 1.2-1.5 keV energy range. Temperature is monitored by the use of an Al dopant and density is monitored by measuring the edge-on expansion of the sample. Temporal resolution of similar to 200 psec is obtained by using a short pulse backlight. Calculations in this photon energy region show significant changes in the spectral features. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Atom Weapons Estab, Reading RG7 4PR, Berks, England. RP Back, CA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-473, Livermore, CA 94551 USA. RI Perry, Theodore/K-3333-2014; OI Perry, Theodore/0000-0002-8832-2033; Crowley, Basil/0000-0001-9226-6006 NR 19 TC 39 Z9 39 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 415 EP 425 DI 10.1016/S0022-4073(97)00049-6 PG 11 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400003 ER PT J AU Csanak, G Kilcrease, DP AF Csanak, G Kilcrease, DP TI Photoabsorption in hot, dense plasmas - The average atom, the spherical cell model, and the random phase approximation SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID FUNCTIONAL THEORY; ELECTRON-GAS; STATES; MATTER; FIELD AB In this report we show that the orbitals calculated in the average atom (AA) or in the spherical cell (SC) models cannot represent an "average excited orbital" of an atom or ion in a plasma and therefore they give poor approximations for photoabsorption cross sections. We propose here the use of the random phase approximation (RPA) for inhomogeneous systems at finite temperature for the calculation of cross sections for photoabsorption from the initial equilibrium state. The essential feature of the RPA that is most important for the present purpose is that it produces the appropriate potential for the excited electron and incorporates channel-coupling effects. We also suggest the use of the Matsubara Green's function technique which we show can be used for the derivation of the RPA and which also easily lends itself to the definition of higher approximation schemes for systems in equilibrium at finite temperature with attendant physical interpretation. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret T4, Los Alamos, NM 87545 USA. RP Csanak, G (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret T4, Los Alamos, NM 87545 USA. OI Kilcrease, David/0000-0002-2319-5934 NR 39 TC 9 Z9 9 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 537 EP 551 DI 10.1016/S0022-4073(97)00060-5 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400014 ER PT J AU Elton, RC Griem, HR Welch, BL Osterheld, AL Mancini, RC Knauer, J Pien, G Watt, RG Cobble, JA Jaanimagi, PA Bradley, DK Delettrez, JA Epstein, R AF Elton, RC Griem, HR Welch, BL Osterheld, AL Mancini, RC Knauer, J Pien, G Watt, RG Cobble, JA Jaanimagi, PA Bradley, DK Delettrez, JA Epstein, R TI Satellite spectral lines in high density laser-produced plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID HIGH-RESOLUTION MEASUREMENT; IDENTIFICATION; RECOMBINATION; TRANSITIONS; TRANSPORT; ENERGY; TIME AB Two types of satellite lines are studied in laser-produced plasmas as potential diagnostic tools. One consists of a pair of lines straddling the wavelength of a dipole-forbidden line and displaced from it by the laser frequency. The relative intensities are a measure of the local laser electric field in the plasma. Possible satellites of this sort associated with He-like and Li-like magnesium n = 2 to n = 3 transitions are indicated in the data. The second type of satellite arises from an innershell transition in Li-like aluminum (and magnesium) and the lines occur adjacent to the He-like 1s(2 1)S-1s3p P-1 x-ray resonance line. The upper level configuration for one satellite does not readily autoionize, and hence is populated mainly by electron collisions in a high density plasma. It is an electron density indicator, and in the present case the relative intensity is consistent with electron densities similar to 10(20) cm(-3), according to atomic physics modeling. The wavelengths of these Li-like innershell satellites appear to be shifted shorter by similar to 13 m Angstrom when compared to those of nearby He-like resonance lines. The sequence of such ionic x-ray lines from streak data are in agreement with a numerical code. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Nevada, Reno, NV 89557 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Elton, RC (reprint author), Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. NR 43 TC 20 Z9 20 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 559 EP 570 DI 10.1016/S0022-4073(97)00062-9 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400016 ER PT J AU Heading, DJ Machacek, A Whitford, LC Varney, AJ Wark, JS Lee, RW Stamm, R Talin, B AF Heading, DJ Machacek, A Whitford, LC Varney, AJ Wark, JS Lee, RW Stamm, R Talin, B TI Rapid generation of approximate optical spectra of dense cool plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID STARK WIDTHS; ATOM LINES; SHIFTS AB In recent experiments uniform plasmas have been generated at high densities and low temperatures, (typically electron densities of 10(19) cm(-3) and T similar to 2 - 5 eV). Additionally, such plasmas are also produced during free laser ablation - a topic of relevance to the deposition of thin solid films. Standard methods used to diagnose plasmas are difficult to apply at these conditions, as there is significant overlap of the broad spectral lines from different elements and ion stages. It is therefore of interest to attempt to calculate the entire spectrum in the appropriate wavelength regime. For most elements, the number of individual spectral line profiles that have been calculated as a, function of density and temperature using the semi-classical method is very small, hindering such a synthesis of the full spectra. However, a technique for approximating line shapes simply and rapidly (the modified semi-empirical method) has previously been developed for individual lines. We utilise this method, coupled with an accurate database, to generate a large number of density dependent line profiles, and hence an approximation to the full spectrum. We evaluate the accuracy and utility of such an approach by comparison with the few extant semi-classical calculations. The method described facilitates the rapid generation of approximate spectra. It can also be used as a post processor to a hydrodynamic code to obtain both time dependent and time integrated spectra in the approximation that the laser-ablated plasma is both optically thin and in LTE. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Oxford, Clarendon Lab, Dept Phys, Oxford OX1 3PU, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Aix Marseille 1, PIIM, Ctr St Jerome, URA 773, F-13397 Marseille, France. RP Heading, DJ (reprint author), Univ Oxford, Clarendon Lab, Dept Phys, Parks Rd, Oxford OX1 3PU, England. NR 12 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 619 EP 626 DI 10.1016/S0022-4073(97)00068-X PG 8 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400022 ER PT J AU Iglesias, CA Lee, RW AF Iglesias, CA Lee, RW TI Density effects on collisional rates and population kinetics SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID NONIDEAL HYDROGEN PLASMA; TRANSPARENCY WINDOW; SPECTRAL-LINES; RECOMBINATION; IONIZATION; COEFFICIENTS; SHIFTS; SERIES AB Although detailed quantum kinetic theory calculations obtained large plasma effects on electron collisional rates, population kinetics calculations indicate that the main impact of the density on non-equilibrium plasma models is continuum lowering. Density effects beyond continuum lowering lead to significantly smaller corrections on level populations and are uncertain since usual approximations may introduce anomalous behavior. These kinetics calculations take advantage of simple approximations to the electron collisional rates that compare reasonably well with the quantum kinetic theory results. Finally, the analysis indicates that since continuum lowering is already included in standard kinetics models, the expected impact on level populations from the quantum kinetic theory results may not be realized. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Iglesias, CA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 29 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 637 EP 643 DI 10.1016/S0022-4073(97)00070-8 PG 7 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400024 ER PT J AU Jacobs, VL Decaux, V Beiersdorfer, P AF Jacobs, VL Decaux, V Beiersdorfer, P TI K alpha emission in equilibrium and non-equilibrium plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID DIELECTRONIC SATELLITE SPECTRA; HIGH-TEMPERATURE PLASMAS; RAY-LINE EMISSION; FE-XXV; RADIATIVE TRANSITIONS; UNIFIED DESCRIPTION; ELECTRON-BEAM; CHARGED IONS; RECOMBINATION; POLARIZATION AB A detailed spectral model has been under development for the computer simulation of 2p --> 1s K alpha x-ray emissions from highly-charged Fe ions in plasmas. Particular interest has been directed at the K alpha emissions produced by the ions from Fe XVIII to Fe XXIV, which occur in the spectral range from 1.84 to 1.94 Angstrom. Account has been taken of the fundamental radiative emission processes associated with radiationless electron capture or dielectronic recombination, inner-shell-electron collisional excitation, and inner-shell-electron collisional ionization. In high-temperature plasmas, small or moderate departures from steady-state corona-model charge-state distributions may occur due to the effects of ion transport processes. However, the assumption of equilibrium (Maxwellian) electron energy distributions is usually accepted to be valid. Particular emphasis has now been directed at the identification of spectral features that can serve as diagnostics of extreme non-equilibrium or transient-ionization conditions, which can occur in both low-density and high-density plasmas as well as in electron-ion beam interactions. In the development of the general theoretical description of the emission spectra, it has been necessary to allow for an arbitrary (non-Maxwellian) electron energy distribution. In order to provide a microscopic investigation of the fundamental K alpha line-formation processes that can play a dominant role under extreme non-equilibrium conditions, the observed x-ray emission spectra from Fe ions in the Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory have been simulated. For the precise interpretation of the high-resolution x-ray observations, which may involve the analysis of blended spectral features composed of many lines, it has been necessary to take into account the multitude of fine-structure components of the K alpha radiative transitions in the ions from Fe XVIII to Fe XXIV. A complex situation can be encountered for densities that are higher than the validity range of the simple corona-model approximation. With increasing density, collisionally-induced transitions among the low-lying fine-structure states can play an important role. We have developed a hierarchy of simplified statistical-population models for the distribution of the initial ions among the different low-lying fine-structure states. The inadequacies of this simple approximation can be fundamentally remedied only by tie application of a detailed (and possibly time-dependent) collisional-radiative-model description of the fine-structure excitation, de-excitation, and ionization processes. It has been found that inner-shell-electron collisional excitation and ionization processes involving the complex intermediate ions from Fe XVIII to Fe XXI produce spectral features, in the wavelength range from 1.89 to 1.94 Angstrom, which are particularly sensitive to density variations and transient-ionization conditions. For a precise analysis of the x-ray observations produced by anisotropic (directed) electron collisional excitations, it will be necessary in a future extension of this investigation to take into account the angular distribution and polarization of the emitted radiation. Published by Elsevier Science Ltd. C1 USN, Res Lab, Div Condensed Matter & Radiat Sci, Complex Syst Theory Branch, Washington, DC 20375 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Jacobs, VL (reprint author), USN, Res Lab, Div Condensed Matter & Radiat Sci, Complex Syst Theory Branch, Code 6693, Washington, DC 20375 USA. NR 41 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 645 EP 659 DI 10.1016/S0022-4073(97)00071-X PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400025 ER PT J AU Kato, T Kato, M Shepherd, R Young, B More, R Osterheld, A AF Kato, T Kato, M Shepherd, R Young, B More, R Osterheld, A TI Time-dependent H-like and He-like Al lines produced by ultra-short pulse laser SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB AB We perform numerical modeling of time-resolved x-ray spectra from thin foil targets heated by the LLNL Ultra-short pulse (USP) laser. The targets were aluminum foils of thickness ranging from 250 to 1250 A, heated with 120 fsec pulses of 400 nm light from the USP laser. The laser energy was approximately 0.2 J focused to a 3 mu m spot size for a peak intensity near 2 x 10(19) W/cm(2). Ly alpha and He alpha lines were recorded using a 900 fsec x-ray streak camera. We calculate the effective ionization, recombination and emission rate coefficients including density effects for H-like and He-like aluminum ions using a collisional-radiative model. We calculate time-dependent ion abundances using these effective ionization and recombination rate coefficients. The time-dependent electron temperature and density used in the calculation are based on an analytical model for the hydrodynamic expansion of the target foils. During the laser pulse the target is ionized. After the laser heating stops, the plasma begins to recombine. Using the calculated time-dependent ion abundances and the effective emission rate coefficients, we calculate the time-dependent Ly alpha and He alpha lines. The calculations reproduce the main qualitative features of the experimental spectra. We also calculate the He-like spectra including satellite lines. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Natl Inst Fus Sci, Nagoya, Aichi 46401, Japan. Univ Calif Lawrence Livermore Natl Lab, Div 5, Livermore, CA 94550 USA. RP Kato, T (reprint author), Natl Inst Fus Sci, Nagoya, Aichi 46401, Japan. NR 8 TC 5 Z9 5 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 661 EP 675 DI 10.1016/S0022-4073(97)00072-1 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400026 ER PT J AU Kilcrease, DP Murillo, MS Collins, LA AF Kilcrease, DP Murillo, MS Collins, LA TI Theoretical and molecular dynamics studies of dense plasma microfield nonuniformity SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA HO LAWRENCE LIVERMORE NATL LAB ID ION-QUADRUPOLE INTERACTION; HYDROGEN LINES; ASYMMETRY; DISTRIBUTIONS; TEMPERATURE AB We critically examine several theories of the electric microfield constrained average of the plasma microfield gradient [partial derivative epsilon(i)/partial derivative x(j)](epsilon), where partial derivative epsilon(i) partial derivative x(j) is a component of the plasma microfield spatial derivative and epsilon is the magnitude of the microfield. This quantity is important in the treatment of ion quadrupole effects on Stark broadened line shapes. The constrained average itself is also of more general interest as a means of calculating other plasma quantities such as time derivatives elf plasma microfields. We compare several theoretical models, both many-body and nearest-neighbor, with accurate molecular dynamics simulations. We show that one previously published many-body theory diverges for physical conditions of interest in plasmas. We also discuss some basic problems in formulating a theoretical description of the ion-radiator interaction in plasmas due to the finite size of the quantum mechanical radiator and the use of simple model screened potentials. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Kilcrease, DP (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. OI Kilcrease, David/0000-0002-2319-5934 NR 20 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 677 EP 686 DI 10.1016/S0022-4073(97)00073-3 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400027 ER PT J AU Lagattuta, K Winske, D AF Lagattuta, K Winske, D TI X-ray emission calculations for plasma over a wide range of Z SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB C1 LANL, X Div, Los Alamos, NM 87545 USA. RP Lagattuta, K (reprint author), LANL, X Div, Los Alamos, NM 87545 USA. NR 6 TC 2 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 703 EP 708 DI 10.1016/S0022-4073(97)00076-9 PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400030 ER PT J AU Langer, SH Scott, HA Keane, CJ Landen, OL Marinak, MM AF Langer, SH Scott, HA Keane, CJ Landen, OL Marinak, MM TI Yield and emission line ratios from ICF target implosions with multi-mode Rayleigh-Taylor perturbations SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID INDIRECTLY DRIVEN; K-SHELL; NOVA; SPECTROSCOPY; SPECTRA; FUSION; MIX AB Mix due to hydrodynamic instabilities reduces the yield in inertial confinement fusion implosions. Line emission from dopants placed in the capsule can be used to diagnose the extent of the instabilities. This paper compares line emission measured in experiments performed on the Nova laser to 1D mix models and 2D models in which many different instability wavelengths interact. The 2D models properly handle the distorted interface between the fuel and the capsule shell, instead of assuming a region where fuel and shell material are atomically mixed as in the 1D models. Both models agree reasonably well with the dependence of thermonuclear yield on capsule roughness. The 2D models do a better job of matching the line emission for capsules with rough surfaces. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Langer, SH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 21 TC 5 Z9 5 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 709 EP 720 DI 10.1016/S0022-4073(97)00077-0 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400031 ER PT J AU Leboucher-Dalimier, E Angelo, P Gauthier, P Sauvan, P Poquerusse, A Derfoul, H Ceccotti, T Back, CA Shepard, TD Forster, E Uschmann, I Vollbrecht, M AF Leboucher-Dalimier, E Angelo, P Gauthier, P Sauvan, P Poquerusse, A Derfoul, H Ceccotti, T Back, CA Shepard, TD Forster, E Uschmann, I Vollbrecht, M TI X-ray spectroscopy and imaging of hot dense plasma created by colliding foils. Simulation of spectra. SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LASER; CRYSTAL AB A simple strategy is presented to create moderately coupled plasmas: it consists in a colliding foil system irradiated by two laser beams. In these correlated plasmas, signatures of transient molecular behaviour are shown. Two studies are intensively developed here: the simulation of the experiment and the X-ray spectroscopic and imaging diagnostics. A reciprocal action between the two studies allows an optimization of both the compression and the associated dense plasma effects. We present accurate fluorine Ly beta spectra as an appropriate example for the exhibition of the non-spherical symmetry of the bound electronic structure. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Paris 06, CNRS, LULI, F-75252 Paris 05, France. Ecole Polytech, F-91128 Palaiseau, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Jena, MPG Res Unit Xray Opt, D-6900 Jena, Germany. RP Leboucher-Dalimier, E (reprint author), Univ Paris 06, CNRS, LULI, 4 Pl Jussieu, F-75252 Paris 05, France. RI Sauvan, Patrick/M-3778-2014 OI Sauvan, Patrick/0000-0002-9128-8817 NR 19 TC 15 Z9 15 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 721 EP 735 DI 10.1016/S0022-4073(97)00078-2 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400032 ER PT J AU Lee, RW Nash, JK Ralchenko, Y AF Lee, RW Nash, JK Ralchenko, Y TI Review of the NLTE kinetics code workshop SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB AB The first workshop to compare the output from Non-LTE kinetics codes using a standardized set of problems is reviewed. The background for the workshop is discussed and the planning is briefly outlined. The participation and general constraints for the workshop are given. Next the defined cases and a motivation for each case is presented. Some results from the workshop are shown which indicate both the utility of the workshop and some of the difficulties faced by those involved in NLTE kinetics modeling. Plans for the next workshop are discussed in the conclusion, (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Weizmann Inst Sci, IL-76100 Rehovot, Israel. RP Lee, RW (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-399,Box 808, Livermore, CA 94550 USA. RI Ralchenko, Yuri/E-9297-2016 OI Ralchenko, Yuri/0000-0003-0083-9554 NR 1 TC 71 Z9 74 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 737 EP 742 DI 10.1016/S0022-4073(97)00079-4 PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400033 ER PT J AU Lenosky, TJ Kress, JD Collins, LA Kwon, I AF Lenosky, TJ Kress, JD Collins, LA Kwon, I TI Molecular dynamics simulations of compressed liquid hydrogen SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID DENSE HYDROGEN; SOLID HYDROGEN; METALLIC HYDROGEN; GROUND-STATE; HOT; TRANSITIONS; PSEUDOPOTENTIALS; DISSOCIATION; EQUATION; JUPITER AB Molecular dynamics simulations have been performed for highly compressed fluid hydrogen in the density and temperature regime of recent shock-compression experiments. Both density functional and tight-binding electronic structure techniques have been used to describe interatomic forces. A new tight-binding model of hydrogen has been developed with a single s orbital on each atom that reproduces properties of the dimer, of various crystalline structures, and of the fluid. The simulations give pressures and electrical conductivities in general agreement with the measured values. The pressures are also compared with recent quantum Monte Carlo results. This analysis provides a firm foundation for exploring the origins of the rapid change in electrical conductivity with temperature and density observed in the experiments. The simulations indicate that the conductivity in fluid hydrogen in this regime arises both from: (1) closing of the band gap due to thermal effects and compression; (2) electron hopping facilitated by the dissociated atoms (monomers) with the latter process the most important. Finally, we find that the internal structure of cool, dense hydrogen has a pronounced time-dependent nature with molecules (dimers) constantly dissociating and atoms (monomers) constantly associating all of:he time. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Lenosky, TJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 38 TC 16 Z9 16 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 743 EP 755 DI 10.1016/S0022-4073(97)00080-0 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400034 ER PT J AU Merdji, H Eidmann, K Chenais-Popovics, C Winhart, G Gauthier, JC Mirone, A Iglesias, CA AF Merdji, H Eidmann, K Chenais-Popovics, C Winhart, G Gauthier, JC Mirone, A Iglesias, CA TI K-shell spectroscopy of radiatively heated aluminium SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID ABSORPTION-MEASUREMENTS; OPACITY MEASUREMENTS; HOT; PLASMA; IRON; GERMANIUM; SPECTRUM AB Thin solid tamped foils were heated by the x-rays generated in spherical gold hohlraums which were irradiated by the high power laser ASTERIX IV with an energy of up to 500 J and a pulse duration of 0.4 ns. The sample foils were probed by the radiation of a back-lighter with a variable delay to the main beam. Previous opacity studies in the extreme uv range (G. Winhart er al., PRE, 53, R1332, 1996) have now been completed by measurements in the keV range by using a crystal spectrometer. We present K-shell absorption spectra of aluminium at temperatures between 20 and 30 eV. For the analysis we used local thermodynamic equilibrium opacity codes. The resulting mean ionization of the sample is compared with hydro-code simulations which were post-processed by solving the rate equations using a collisional radiative model. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Ecole Polytech, CNRS, LULI, F-91128 Palaiseau, France. Max Planck Inst Quantenopt, D-85740 Garching, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Merdji, H (reprint author), Ecole Polytech, CNRS, LULI, F-91128 Palaiseau, France. NR 20 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 773 EP 781 DI 10.1016/S0022-4073(97)00082-4 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400036 ER PT J AU Mosse, C Calisti, A Stamm, R Talin, B Lee, RW Koch, J Asfaw, A Seely, J Wark, J Klein, L AF Mosse, C Calisti, A Stamm, R Talin, B Lee, RW Koch, J Asfaw, A Seely, J Wark, J Klein, L TI X-ray laser photopumped resonance fluorescence SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID FREQUENCY-FLUCTUATION MODEL; PLASMA SPECTROSCOPY; DENSE AB A calculation of the resonance fluorescence spectrum of the 146.526 Angstrom 3d-2p transition of fluorine-like magnesium photopumped by the 146.515 Angstrom zirconium X-ray laser line is discussed in connection with an experimental measurement in a hot, dense laser produced plasma. The calculation of the fluorescence spectral profile is based on a recent extension of the Frequency Fluctuation Model (FFM) that enables the computation of radiative redistribution and other higher order radiative processes. The discussion of the photopumping experiment includes an analysis of the optimal plasma conditions and the associated characteristics of the redistributed radiation with specific reference to the experimental feasibility. The potential information to je acquired in the comparison of the computational and experimental results also will be considered. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Aix Marseille 1, UMR 6633, Ctr St Jerome, F-13397 Marseille 20, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Addis Ababa, Dept Phys, Addis Ababa, Ethiopia. USN, Res Lab, Washington, DC 20357 USA. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Howard Univ, Dept Phys, Washington, DC 20059 USA. RP Mosse, C (reprint author), Univ Aix Marseille 1, UMR 6633, Ctr St Jerome, F-13397 Marseille 20, France. OI Calisti, Annette/0000-0001-6727-9286 NR 15 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 803 EP 810 DI 10.1016/S0022-4073(97)00085-X PG 8 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400039 ER PT J AU Murillo, MS Cox, ME Carr, SM AF Murillo, MS Cox, ME Carr, SM TI Magnetized plasma microfield studies by molecular dynamics simulation SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LASER-PRODUCED PLASMAS; HYDROGEN-ATOM; FIELDS AB Ionized radiators and charged perturbers in a hot, dense plasma undergo cyclotron motion and experience the motional Stark effect in the presence of an external magnetic field. In this paper, we consider a magnetized two-body radiating system and indicate how the lineshape can be modified by an intense magnetic field (e.g. non-uniform magnetic fields, Doppler-Stark coupling, etc.) We then focus specifically on quasistatic properties and present results based on simulations, using one-component ion-quasiparticle molecular dynamics, of a hot dense plasma in an external magnetic field. Results are presented for the three generalized microfields P(epsilon), P-B(epsilon), and P(epsilon) which are the B = 0 microfield, the microfield including ion cyclotron motion, and the total microfield, including the motional Stark field, respectively. We have considered short-pulse laser experiments, white dwarf atmospheres, and gas bag experiments. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Nebraska Wesleyan Univ, Lincoln, NE 68504 USA. RP Murillo, MS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 3 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 811 EP 820 DI 10.1016/S0022-4073(97)00086-1 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400040 ER PT J AU Osterheld, AL Young, BKF Dunn, J Stewart, RE Skobelev, IY Faenov, AY Magunov, AI AF Osterheld, AL Young, BKF Dunn, J Stewart, RE Skobelev, IY Faenov, AY Magunov, AI TI Influence of laser satellite transitions on spectroscopy of high-intensity laser-produced plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID SPECTRA AB The oscillating electromagnetic field of an intense laser pulse can significantly affect the emission properties of ions in a plasma. For sufficiently intense laser fields, induced second order processes produce discrete radiative transitions. In addition, these induced radiative processes alter the level population kinetics, and the spectrum of spontaneous transitions. We discuss the effects of these processes on the n = 2-1 spectrum of He-like ions, as well as implications for some x-ray laser schemes pumped by intense, short-pulse lasers. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. VNIIFTRI, Multi Charged Ions Spectral Data Ctr, Mendeleevo 141570, Moscow Region, Russia. RP Osterheld, AL (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 12 TC 14 Z9 14 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 827 EP 833 DI 10.1016/S0022-4073(97)00088-5 PG 7 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400042 ER PT J AU Patel, PK Wark, JS Renner, O Djaoui, A Rose, SJ Heading, DJ Hauer, A AF Patel, PK Wark, JS Renner, O Djaoui, A Rose, SJ Heading, DJ Hauer, A TI Experimental and simulated profiles of the Al XIII Ly-alpha resonance line from a cylindrically expanding plasma SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LASER-PRODUCED PLASMAS; ESCAPE PROBABILITIES; VELOCITY-GRADIENTS; SPECTROSCOPY; MEDIA AB Spectral profiles of optically thick line radiation emitted by an expanding cylindrical laser-produced plasma have been recorded in high resolution using a vertical dispersion variant of the double-crystal spectrometer. By uniformly irradiating a narrow wire with a 1 ns pulse a quasi-steady plasma expansion is generated with a velocity gradient in excess of 10(9) s(-1). Such velocity fields strongly influence the transfer of radiation through a plasma, resulting in a complex distortion of the lineshapes of optically thick lines. We have computed theoretical profiles of the Al XIII Ly-alpha resonance line. Simulation of the laser-plasma interaction is performed using the 1D Lagrangian hydrocode MED103 which incorporates a non-LTE time-dependent excitation and ionisation package based on the average-atom model. Line emission profiles are calculated by the method of multi-frequency line transfer in the co-moving frame. We investigate the sensitivity of the lineshape on plasma parameters such as the velocity profile, comparing our theoretical predictions with experiment. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Acad Sci Czech Republ, Inst Phys, CZ-18040 Prague, Czech Republic. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Patel, PK (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI Patel, Pravesh/E-1400-2011; Renner, Oldrich/C-1591-2010 OI Renner, Oldrich/0000-0003-4942-2637 NR 16 TC 11 Z9 11 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 835 EP 844 DI 10.1016/S0022-4073(97)00089-7 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400043 ER PT J AU Rosmej, FB Faenov, AY Pikuz, TA Flora, F Di Lazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Batani, D Bossi, S Bornardinello, A Scafati, A Reale, L Zigler, A Fraenkel, M Cowan, RD AF Rosmej, FB Faenov, AY Pikuz, TA Flora, F Di Lazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Batani, D Bossi, S Bornardinello, A Scafati, A Reale, L Zigler, A Fraenkel, M Cowan, RD TI Inner-shell satellite transitions in dense short pulse plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID LI-LIKE SATELLITES; HE-LIKE IONS; BE-LIKE; ENERGETIC ELECTRONS; SPECTRA; LINES; RESONANCE; ENERGIES; PHYSICS AB Soft x-ray spectra originating from dense plasmas, generated by a laser irradiating a solid target with ns-and fs-laser pulses, have been obtained with simultaneous high spectral (lambda/delta lambda approximate to 10 000) and spatial resolution (delta x approximate to 10 mu m). Interesting structure of the He-like resonance line together with strong emission of the Li-like n = 2 satellites have been observed very close to the target surface. We show here that the resonance line structure is strongly influenced by higher order satellites of the type 1s(2)nl'-1s2lnl' which overlap for n > 2. For plasmas created with short pulse duration lasers there are high density and low temperature regions near the target that give rise to three body recombination into Rydberg satellite levels leading to substantial intensity at the position of the resonance transition. Atomic data necessary for spectra simulations have been calculated with inclusion of configuration interaction and relativistic effects and these results;Ire cross-checked with other calculational methods. Time-dependent simulations of the spectra including the effects of optical thickness, energetic electrons and numerous high order Rydberg satellites (up to n = 7) are found to be in good agreement with experimental data. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Ruhr Univ Bochum, Inst Exp Phys 5, D-44780 Bochum, Germany. VNIFFTRI, MCISDC, Moscow 141570, Russia. ENEA, INN, I-00044 Frascati, RM, Italy. Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Ist Nazl Fis Nucl, GC LNGS, Laquila, Italy. Univ Milan, Dipartimento Fis, Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Ist Super Sanita, Fis Lab, I-00161 Rome, Italy. Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rosmej, FB (reprint author), Ruhr Univ Bochum, Inst Exp Phys 5, D-44780 Bochum, Germany. NR 41 TC 50 Z9 50 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 859 EP 878 DI 10.1016/S0022-4073(97)00092-7 PG 20 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400046 ER PT J AU Shepherd, R More, R Young, B Price, D Walling, R Osterheld, A Stewart, R Kato, T AF Shepherd, R More, R Young, B Price, D Walling, R Osterheld, A Stewart, R Kato, T TI Reduced conduction cooling in high energy-density plasmas using ultrashort pulse laser heated thin foil targets SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB AB We have conducted experiments to determine the effects of target thickness on the time history and spectra from short pulse laser produced plasmas. A reduced contribution to conduction cooling was achieved by using thin targets. The experiment was done using aluminum foils of thickness ranging from 250 Angstrom to 1250 Angstrom. The foils were heated with a 400 nm, 150 fs (FWHM), 250 mJ laser focused to a spot size of 2 mu m, resulting in a peak intensity of 5.3 x 10(19) W/cm(2). The 1s(2)-1s2p transition in He-like aluminum was temporally resolved using a 900 fs x-ray streak camera. An analytic model is derived to describe the time rate of change of the 1s(2)-1s2p transition in He-like aluminum. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Div 5, Livermore, CA 94550 USA. Natl Inst Fus Sci, Nagoya, Aichi 46401, Japan. RP Shepherd, R (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div 5, POB 808, Livermore, CA 94550 USA. NR 20 TC 14 Z9 14 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 911 EP 916 DI 10.1016/S0022-4073(97)00097-6 PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400050 ER PT J AU Springer, PT Wong, KL Iglesias, CA Hammer, JH Porter, JL Toor, A Goldstein, WH Wilson, BG Rogers, FJ Deeney, C Dearborn, DS Bruns, C Emig, J Stewart, RE AF Springer, PT Wong, KL Iglesias, CA Hammer, JH Porter, JL Toor, A Goldstein, WH Wilson, BG Rogers, FJ Deeney, C Dearborn, DS Bruns, C Emig, J Stewart, RE TI Laboratory measurement of opacity for stellar envelopes SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID HOT; PLASMA AB We have measured the frequency dependent opacity of a low density iron plasma in Local Thermodynamic Equilibrium (LTE). The measured iron plasma conditions of 20 eV temperature and 10(-4) g/cc density, match those of stellar envelopes where iron dominates the radiative transport. Properties of the M-shell Delta n = 0 transition arrays in iron are measured in this experiment, providing the first direct test of opacity models used in stellar pulsation and evolution calculations. We describe new methods to obtain LTE opacity data for plasmas at 100 times lower density than previous measurements. Experimental requirements include: high spectral resolution, large homogenous plasma sources, and Planckian radiation fields lasting tens of nanoseconds. These conditions were achieved using the 500 kJ SATURN facility at Sandia National Laboratory. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Springer, PT (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 17 TC 72 Z9 74 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 927 EP 935 DI 10.1016/S0022-4073(97)00099-X PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400052 ER PT J AU Stepanov, AE Starostin, AN Roerich, VC Makhrov, VA Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Flora, F Bollanti, S Di Lazzaro, P Lisi, N Letardi, T Palladino, L Reale, A Batani, D Bossi, S Bornadinelo, A Scafati, A Reale, L Osterheld, A Goldstein, WH AF Stepanov, AE Starostin, AN Roerich, VC Makhrov, VA Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Flora, F Bollanti, S Di Lazzaro, P Lisi, N Letardi, T Palladino, L Reale, A Batani, D Bossi, S Bornadinelo, A Scafati, A Reale, L Osterheld, A Goldstein, WH TI Modeling of the He-like magnesium spectral lines radiation from the plasma created by XeCl and Nd-glass lasers SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID RAY AB Resonant and intercombination spectral line formation of He-like magnesium is analyzed both experimentally and numerically. Simulations of the laser-produced plasma evolution in 1D approximation made using the code GIDRA show fairly good agreement with experimental data both close and far from the target. It is shown that in plasma created by XeCl laser at flux density 8 x 10(12) W/cm(2) the peak of electron temperature is placed downstream from the critical surface at density significantly smaller than critical, and radiation in both resonant and recombination lines is also produced by the plasma region with density below critical. Simulations also show significant line radiation at large distances (1-2 mm) from the target as it was observed in experiments. This secondary peak is produced by a compression wave forming near the plasma front. In contrast, radiation in these lines in plasma created by Nd-glass laser at flux density 5 x 10(13) W/cm(2) comes from the plasma region placed, deeper than the critical surface and has no tail at large distances. Spectral line radiation reabsorbtion in the plasma was found to be responsible for the observed relative intensity of the resonant and intercombination lines. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Troitsk Inst Innovat & Fus Res, Ctr Theoret Phys & Computat Math, Troitsk 142092, Moscow Region, Russia. VNIIFTRI, MISDC, Mendeleevo 141570, Moscow Region, Russia. Ctr Ric Frascati, Settore Fis Appl, ENEA, Dipartimento Innovaz, I-00044 Frascati, Rome, Italy. Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Univ Aquila, Ist Nazl Fis Nucl, GC LNGS, I-67100 Laquila, Italy. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Super Sanita, I-00161 Rome, Italy. Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Stepanov, AE (reprint author), Troitsk Inst Innovat & Fus Res, Ctr Theoret Phys & Computat Math, Troitsk 142092, Moscow Region, Russia. EM stepanov@fly.triniti.troitsk.ru NR 21 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 937 EP 952 DI 10.1016/S0022-4073(97)00100-3 PG 16 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400053 ER PT J AU Talin, B Calisti, A Ferri, S Koubiti, M Meftah, T Mosse, C Mouret, L Stamm, R Alexiou, S Lee, RW Klein, L AF Talin, B Calisti, A Ferri, S Koubiti, M Meftah, T Mosse, C Mouret, L Stamm, R Alexiou, S Lee, RW Klein, L TI Ground work supporting the codes based upon the frequency fluctuation model SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID II-P-ALPHA; LINES; DYNAMICS; SHAPE AB The development of the frequency fluctuation model (FFM) had two strong motivations. First, there was interest to model line shapes accounting fbr ion dynamics and second the inclusion of higher order radiative processes in plasmas was considered important for future development. The FFM relies on the hypothesis that the emitter-plasma system behaves approximately like a pseudo-molecule embedded into a thermal bath. As a result, the pseudo-system can be considered to have internal states connected to each others by collisions with the bath. This simple starting point has been translated into a powerful renormalization process, called FFM, resulting, a few years ago, in a fast line shape code called Pim Pam Poum (PPP) and more recently into a code for the computation of radiative redistribution. We present a few of the milestones in this evolution, starting with the motivations for choosing the FFM technique. In this part of the discussion a simple three level model will be used to provide a comprehensive explanation of the links between FFM, ion dynamics and molecular dynamics simulation. Next we present new results motivated by highly accurate line shape measurements. The first example illustrates the low density domain found in tokamaks where high-n hydrogen lines are useful for density diagnostic. The second example is the hydrogen-like helium Paschen alpha (P-alpha) line observed in high intensity discharges which illustrates the high density case. The P-alpha line embodies the activity of last ten years concerning charged emitter spectroscopy and we believe this transition to be a real benchmark for line shape codes. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Aix Marseille 1, URA 773, Ctr St Jerome, F-13397 Marseille 20, France. Ecole Polytech, LULI, F-91128 Palaiseau, France. Univ Paris 06, F-75252 Paris 05, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Howard Univ, Dept Phys, Washington, DC 20059 USA. RP Talin, B (reprint author), Univ Aix Marseille 1, URA 773, Ctr St Jerome, F-13397 Marseille 20, France. OI Calisti, Annette/0000-0001-6727-9286 NR 11 TC 19 Z9 18 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 953 EP 964 DI 10.1016/S0022-4073(97)00101-5 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400054 ER PT J AU Woolsey, NC Hammel, BA Keane, CJ Back, CA Moreno, JC Nash, JK Calisti, A Mosse, C Godbert, L Stamm, R Talin, B Hooper, CF Asfaw, A Klein, LS Lee, RW AF Woolsey, NC Hammel, BA Keane, CJ Back, CA Moreno, JC Nash, JK Calisti, A Mosse, C Godbert, L Stamm, R Talin, B Hooper, CF Asfaw, A Klein, LS Lee, RW TI Spectroscopic line shape measurements at high densities SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID INERTIAL CONFINEMENT FUSION; X-RAY SPECTROSCOPY; NEUTRON SPECTROSCOPY; DETECTOR ARRAY; DENSE-PLASMAS; K-SHELL; IMPLOSIONS; SPECTRA; TEMPERATURES; COMPRESSION AB A comprehensive spectroscopic investigation of plasmas at extreme conditions produced by indirectly driven inertially confined implosions is described. In these experiments argon is doped into the gas filled core of implosion targets and the Ar K-shell emission is used to make time resolved measurements of electron density and electron temperature. The electron density is derived from the Stark broadened Ar XVII 1s(2)-1s3p line shape, the electron temperature is derived from the line intensity ratio of the Ar XVII ls(2)-ls(3)p transition and the lithium-like dielectronic satellites 2l2l', 2l3l' lying on the low energy side of the resonance line. We give examples of the experimental data and compare the extracted time histories of electron density and electron temperature with simple radiation hydrodynamic simulations, where broad agreement is found. Detailed line shape measurements of the Ar XVII ls(2)-ls3p transition are presented and the absence of an intensity dip at line center in the experiment results is discussed. The validity of the quasi-static non approximation for these plasma conditions is tested by varying the mass of the fill gas in the core. Results from deuterium, deuterated methane, and nitrogen filled implosions are presented and indicate ion dynamic effects are not responsible for the line center discrepancy. We discuss other possibilities including spatial gradients in the core affecting measurements of the intrinsic lineshape. (C) 1997 Published by Elsevier Science Ltd. All nights reserved. C1 Queens Univ Belfast, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Aix Marseille 1, St Jerome Ctr, PIIM, F-13397 Marseille, France. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Howard Univ, Dept Phys, Washington, DC 20059 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Woolsey, NC (reprint author), Queens Univ Belfast, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. OI Calisti, Annette/0000-0001-6727-9286 NR 31 TC 25 Z9 25 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 975 EP 989 DI 10.1016/S0022-4073(97)00103-9 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400056 ER PT J AU Young, BKF Wilson, BG Zimmerman, GB Price, DF Stewart, RE AF Young, BKF Wilson, BG Zimmerman, GB Price, DF Stewart, RE TI Generation and modeling of near-LTE plasmas using ultrashort pulse laser heated, tamped mid-Z targets SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article; Proceedings Paper CT Meeting on Radiative Properties of Hot Dense Matter III CY 1996 CL LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CALIFORNIA HO LAWRENCE LIVERMORE NATL LAB ID PUMPED TI-SAPPHIRE; X-RAY; IONIZATION BALANCE; TEMPERATURE; HOT; SPECTROSCOPY; INTENSITY; ALUMINUM; SPECTRA; CAMERA AB High-intensity, high-contrast (approximate to 10(-7)), ultrashort laser pulses generated at the Ultrashort Pulse Laser (USP) at Lawrence Livermore National Laboratory have been used to study near solid density plasmas and to investigate whether these plasmas approach local thermodynamic equilibrium (LTE) conditions. Typical targets consisted of a 200 A thick germanium layer tamped by 100-1000 Angstrom of CH and heated by a 400 nm, 130 fs laser pulse of intensity 3 x 10(17) W cm(-2). The measured L-shell x-ray spectra was compared to various LTE and non-LTE LASNEX hydrodynamic simulations using a simple average atom model, and using a non-LTE/STA package similar to the RADIOM non-LTE methodology of Busquet (M. Busquet, Phys. Fluids B, 1993, 5, 4191). Very good qualitative agreement was found with the non-LTE/STA simulations. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Young, BKF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 38 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD OCT-DEC PY 1997 VL 58 IS 4-6 BP 991 EP 1000 DI 10.1016/S0022-4073(97)00105-2 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA YR509 UT WOS:000071502400057 ER PT J AU Garcia, AL Alexander, FJ Alder, BJ AF Garcia, AL Alexander, FJ Alder, BJ TI A particle method with adjustable transport properties - The generalized consistent Boltzmann algorithm SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE direct simulation Monte Carlo; van der Waals equation of state; Enskog theory; hard-sphere gas; kinetic theory; molecular dynamics ID HARD-SPHERE FLUID; MOLECULAR-DYNAMICS; EQUATION AB The consistent Boltzmann algorithm (CBA) for dense, hard-sphere gases is generalized to obtain the van der Waals equation of state and the corresponding exact viscosity at all densities except at the highest temperatures. A general scheme for adjusting any transport coefficients to higher values is presented. C1 SAN JOSE STATE UNIV,DEPT PHYS,SAN JOSE,CA 95192. BOSTON UNIV,CTR COMPUTAT SCI,BOSTON,MA 02215. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Garcia, AL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,BERKELEY,CA 94720, USA. NR 16 TC 10 Z9 12 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 OCT PY 1997 VL 89 IS 1-2 BP 403 EP 409 DI 10.1007/BF02770772 PG 7 WC Physics, Mathematical SC Physics GA YJ022 UT WOS:A1997YJ02200024 ER PT J AU Hein, MA Bauer, C Diete, W Hensen, S Kaiser, T Kresin, VZ Muller, G AF Hein, MA Bauer, C Diete, W Hensen, S Kaiser, T Kresin, VZ Muller, G TI Magnetic field-induced recovery of superconductivity in epitaxial YBa2Cu3O7-x films at microwave frequencies SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE surface impedance; penetration depth; high-temperature superconductors; pair breaking; two-fluid model ID SURFACE IMPEDANCE; THIN-FILMS; YBCO FILMS; SYMMETRY; STATE; FLUX AB An anomalous magnetic field-effect has been observed in the microwave surface impedance of epitaxial YBa2CU3O7-x films on LaAlO3 substrates. The application of de and microwave magnetic fields up to 20 mT caused a significant decrease of microwave surface reactance X-s (less than or equal to 3%) and resistance R-s (less than or equal to 20%) at 8.5 GHz, 77 K and at 87 GHz, 4.2 K. The field effects on X, and R, were found to correlate within the framework of the two-fluid model. The observed effect is attributed to the presence of magnetic impurities in the superconducting films, giving rise to pair breaking. Alignment of the impurity spins suppresses the spin-flip scattering rate and, as a result, leads to a recovery of microwave superconductivity. C1 Berg Univ Gesamthsch Wuppertal, FB Phys, D-42097 Wuppertal, Germany. Accel Instruments GMBH, D-51429 Bergisch Gladbach, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hein, MA (reprint author), Berg Univ Gesamthsch Wuppertal, FB Phys, Gauss Str 20, D-42097 Wuppertal, Germany. NR 30 TC 26 Z9 26 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD OCT PY 1997 VL 10 IS 5 BP 485 EP 493 DI 10.1007/BF02767683 PG 9 WC Physics, Applied; Physics, Condensed Matter SC Physics GA YT500 UT WOS:000071612700003 ER PT J AU Koushafar, H Pham, L Lee, C Rubinsky, B AF Koushafar, H Pham, L Lee, C Rubinsky, B TI Chemical adjuvant cryosurgery with antifreeze proteins SO JOURNAL OF SURGICAL ONCOLOGY LA English DT Article DE cryosurgery; liver surgery; antifreeze proteins; freezing damage; chemical adjuvant cryosurgery ID DIRECTIONAL SOLIDIFICATION; ULTRASOUND; PROSTATE; CELLS AB Background and Objectives: Imaging monitored cryosurgery is emerging as an important minimally invasive surgical technique for treatment of cancer. Although imaging allows excellent control over the process of freezing itself, recent studies show that at high subzero temperatures cells survive freezing. Antifreeze proteins (AFP) are chemical compounds that modify ice crystals to needle-like shapes that can destroy cells in cellular suspensions. The goal of this study was to determine whether these antifreeze proteins can also destroy cells in frozen tissue and serve as chemical adjuvants to cryosurgery. Methods: Livers from six rats were excised, perfused with solutions of either phosphate-buffered saline (PBS) or PBS with 10 mg/ml AFP-I, and frozen with a special cryosurgery apparatus. Lobes were frozen with one or two freeze-thaw cycles and the cell viability was examined with a two stain fluorescent dye test and histological assessment. Results: A significant percentage of hepatocytes survive freezing on the margin of a frozen cryolesion. AFP significantly increase cellular destruction in that region apparently through formation of intracellular ice. Conclusions: This preliminary study demonstrates that antifreeze proteins may be effective chemical adjuvants to cryosurgery. (C) 1997 Wiley-Liss, Inc. C1 UNIV CALIF BERKELEY,DEPT MECH ENGN,BIOMED ENGN LAB,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. RI Rubinsky, Boris/B-4439-2010 OI Rubinsky, Boris/0000-0002-2794-1543 NR 23 TC 55 Z9 55 U1 0 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0022-4790 J9 J SURG ONCOL JI J. Surg. Oncol. PD OCT PY 1997 VL 66 IS 2 BP 114 EP 121 DI 10.1002/(SICI)1096-9098(199710)66:2<114::AID-JSO8>3.0.CO;2-G PG 8 WC Oncology; Surgery SC Oncology; Surgery GA YB977 UT WOS:A1997YB97700008 PM 9354167 ER PT J AU Cancelo, GIE Hansen, S AF Cancelo, GIE Hansen, S TI NETMAP: An integrated system for building analog neural networks SO JOURNAL OF SYSTEMS ARCHITECTURE LA English DT Article DE neural networks; multi-layer perceptrons; parallel implementation; analog signal processing AB NETMAP hardware is described in detail along with our solutions to optimize inter-processor data throughput. Four processors of very different nature interact in the system: The PC central processor, a digital signal processor, a bit-slice microsequencer and a neural network processor called ETANN. A description of the software modules for the processors is given. The weight setting and network training algorithms are also described. Finally, performance considerations and test results are analyzed. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Cancelo, GIE (reprint author), NATL UNIV LA PLATA,FAC INGN,CC 91,RA-1900 LA PLATA,ARGENTINA. NR 17 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-7621 J9 J SYST ARCHITECT JI J. Syst. Architect. PD OCT PY 1997 VL 44 IS 1 BP 63 EP 73 PG 11 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA YD605 UT WOS:A1997YD60500005 ER PT J AU Bender, BR Kubas, GJ Jones, LH Swanson, BI Eckert, J Capps, KB Hoff, CD AF Bender, BR Kubas, GJ Jones, LH Swanson, BI Eckert, J Capps, KB Hoff, CD TI Why does D-2 bind better than H-2? A theoretical and experimental study of the equilibrium isotope effect on H-2 binding in a M(eta(2)-H-2) complex. Normal coordinate analysis of W(CO)(3)(PCy3)(2)(eta(2)-H-2) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-HYDROGEN COMPLEXES; INELASTIC-NEUTRON-SCATTERING; ROTATIONAL RAMAN-SPECTRUM; H-H BOND; DIHYDROGEN COMPLEXES; OXIDATIVE ADDITION; TRANSITION-METALS; XENON SOLUTION; LIQUID XENON; DIHYDRIDE AB Vibrational data (IR, Raman and inelastic neutron scattering) and a supporting normal coordinate analysis for the complex trans-W(CO)(3)(PCy3)(2)(eta(2)-H-2) (1) and its HD and D-2 isotopomers are reported. The vibrational data and force constants support the well-established eta(2)-bonding mode for the H-2 ligand and provide unambiguous assignments for all metal-hydrogen stretching and bending frequencies. The force constant for the HH stretch, 1.3 mdyn/Angstrom, is less than one-fourth the value in free H-2 and is similar to that for the WH stretch, indicating that weakening of the H-H bond and formation of W-H bonds are well along the reaction coordinate to oxidative addition. The equilibrium isotope effect (EIE) for the reversible binding of dihydrogen (H-2) and dideuterium (D-2) to 1 and 1-d(2) has been calculated from measured vibrational frequencies for 1 and 1-d(2). The-calculated EIE is ''inverse'' (1-d(2) binds D-2 better than 1 binds H-2), With K-H/K-D = 0.78 at 300 K. The EIE calculated from vibrational frequencies may be resolved into a large normal mass and moment of inertia factor (MMI = 5.77), an inverse vibrational excitation factor (EXC=0.67), and an inverse zero-point energy factor (ZPE=0.20), where EIE = MMI x EXC x ZPE. An analysis of the zero-point energy components of the EIE shows that the large decrease in the HH stretching frequency (force constant) predicts a large normal EIE but that zero-point energies from five new vibrational modes (which originate from translational and rotational degrees of freedom from hydrogen) offset the change in zero-point energy from the H-2(D-2) stretch. The calculated EIE is compared to experimental data obtained for the binding of H-2 or D-2 to Cr(CO)(3)(PCy3)(2) over the temperature range 12-36 degrees C in THF solution. For the binding of H-2 Delta H=-6.8+/-0.5 kcal mol(-1) and Delta S=-24.7+/-2.0 cal mol(-1) deg(-1); for D-2 Delta H=-8.6+/-0.5 kcal/mol and Delta S=-30.0+/-2.0 cal/(mol deg). The EIE at 22 degrees C has a value of K-H/K-D=0.65+/-0.15. Comparison of the equilibrium constants for displacement of N-2 by H-2 or D-2 in the complex W(CO)(3)(PCy3)(2)(N-2) in THF yielded a value of K-H/K-D=0.70+/-0.15 at 22 degrees C. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV MIAMI,DEPT CHEM,CORAL GABLES,FL 33124. RP Bender, BR (reprint author), CATALYT INC,430 FERGUSON DR,MT VIEW,CA 94043, USA. NR 71 TC 75 Z9 75 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 1 PY 1997 VL 119 IS 39 BP 9179 EP 9190 DI 10.1021/ja971009c PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA XY938 UT WOS:A1997XY93800013 ER PT J AU Benner, WH Horn, DM Jaklevic, JM Frank, M Mears, C Labov, S Barfknecht, AT AF Benner, WH Horn, DM Jaklevic, JM Frank, M Mears, C Labov, S Barfknecht, AT TI Simultaneous measurement of flight time and energy of large matrix-assisted laser desorption ionization ions with a superconducting tunnel junction detector SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID CRYOGENIC PARTICLE DETECTORS; BIOPOLYMER MASS-SPECTROMETER; SECONDARY-ION AB We evaluated a cryogenically cooled superconducting Nb-Al2O3-Nb tunnel junction (STJ) for use as a molecular ion detector in a matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometer. The STJ responds to ion energy and theoretically should detect large molecular ions with a velocity-independent efficiency approaching 100%. The STJ detector produces pulses whose heights are approximately proportional to ion energy, thus the height of a pulse generated by the impact of a doubly charged ion is about twice the height of a singly charged ion pulse. Measurements were performed by bombarding the STJ with human serum albumin (HSA) (66,000 Da) and immunoglobulin (150,000 Da) ions. We demonstrate that pulse height analysis of STJ signals provides a way to distinguish with good discrimination HSA(+) from 2HSA(2+), whose night times ape coincident. The rise time of STJ detector pulses allows ion flight times to be determined with a precision better than 200 ns, which is a value smaller than the night time variation typically observed for large isobaric MALDI ions detected with conventional microchannel plate (MCP) detectors. Deflection plates in the flight tube of the mass spectrometer provided a way to aim ions alternatively at a MCP ion detector. (C) 1997 American Society for Mass Spectrometry. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. CONDUCTUS INC, SUNNYVALE, CA 94086 USA. RP Benner, WH (reprint author), LAWRENCE BERKELEY LAB, DEPT ENGN SCI,HUMAN GENOME CTR,INSTRUMENTAT GRP, 1 CYCLOTRON RD, MS 70A-3363, BERKELEY, CA 94720 USA. RI Frank, Matthias/O-9055-2014 NR 17 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD OCT PY 1997 VL 8 IS 10 BP 1094 EP 1102 PG 9 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA XY214 UT WOS:A1997XY21400008 ER PT J AU Robinett, RD Parker, GG AF Robinett, RD Parker, GG TI Least squares sliding mode control tracking of spacecraft large angle maneuvers SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article ID VARIABLE-STRUCTURE CONTROL; FLEXIBLE SPACECRAFT; SYSTEMS AB A method for sliding mode control tracking of Euler parameter commands for large body angle maneuvers is presented. The closed-loop responses of the four attitude Euler parameters are specified as stable sliding surfaces in the error-error rate Euler parameter phase planes. The matrix coefficient of the typical discontinuous disturbance accommodation portion of the sliding mode control law is chosen as the configuration dependent transformation between body-fixed coordinate angular velocities and the quaternion rates. This choice of control law parameterization results in a globally asymptotically stable closed-loop response when the tracking performance matches the desired in a least squares sense. In addition, all inherent kinematic singularities are removed since the Euler parameters are directly tracked. Simulation results for a typical satellite system are presented exemplifying theoretical development of robustness to mass property and initial condition uncertainty. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Michigan Technol Univ, Houghton, MI 49931 USA. RP Robinett, RD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 5 Z9 6 U1 0 U2 1 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD OCT-DEC PY 1997 VL 45 IS 4 BP 433 EP 450 PG 18 WC Engineering, Aerospace SC Engineering GA 102DE UT WOS:000074907300004 ER PT J AU Suematsu, H Petrovic, JJ Mitchell, TE AF Suematsu, H Petrovic, JJ Mitchell, TE TI Anisotropy of the Knoop hardness in silicon nitride single crystals and their slip system at room temperature SO JOURNAL OF THE CERAMIC SOCIETY OF JAPAN LA Japanese DT Article DE Si3N4; single crystal; slip system; dislocation; Knoop hardness ID SI3N4 AB Knoop hardness in alpha-Si3N4 on the surfaces of (<1(1)over bar 00>), (<1(1)over bar 20>) and (0001) was investigated. Hardness values had isotropic character on all surfaces. Effective resolved shear stress (ERSS) was calculated assuming the slip systems of (0001)[<11(2)over bar 0>], {<1(1)over bar 00}[<11(2)over bar 0>], {<1(1)over bar 00>}[0001], {<1(1)over bar 01>}[<11(2)over bar 0>] and {<2(2)over bar 01>}[<11(2)over bar 0>] to be activated. The ERSS curve of the {<1(1)over bar 01>}[<11(2)over bar 0>] slip system explains Knoop hardness better than those of other slip systems. This fact supports {<1(1)over bar 01>}[<11(2)over bar 0>] to be the primary slip system in alpha-Si3N4 at room temperature. C1 NATL INST RES INORGAN MAT, TSUKUBA, IBARAKI 305, JAPAN. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 15 TC 2 Z9 2 U1 0 U2 1 PU CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI PI TOKYO PA 22-17, HYAKUNIN-CHO 2-CHOME, SHINJUKU-KU, TOKYO, 169-0073, JAPAN SN 1882-0743 EI 1348-6535 J9 J CERAM SOC JPN JI J. Ceram. Soc. Jpn. PD OCT PY 1997 VL 105 IS 10 BP 842 EP 846 DI 10.2109/jcersj.105.842 PG 5 WC Materials Science, Ceramics SC Materials Science GA YB375 UT WOS:A1997YB37500004 ER PT J AU Stevenson, JW Armstrong, TR McCready, DE Pederson, IR Weber, WJ AF Stevenson, JW Armstrong, TR McCready, DE Pederson, IR Weber, WJ TI Processing and electrical properties of alkaline earth-doped lanthanum gallate SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PEROVSKITE-TYPE OXIDE; OXYGEN-ION CONDUCTIVITY; ZRO2-Y2O3 AB Alkaline earth-doped lanthanum gallate powders were prepared by glycine/nitrate combustion synthesis. Compacts of powders synthesized under fuel-rich conditions were sintered to densities greater than 97% of theoretical. Appropriate doping with Sr or Ba on the A-site of the perovskite structure, and Mg on the B-site, resulted in oxygen ion conductivity higher than that of yttria-stabilized zirconia (YSZ), and high ionic transference numbers. Doping with Ca and Mg resulted in lower conductivity than YSZ. Thermal expansion coefficients of the doped gallates were higher than that of YSZ. RP Stevenson, JW (reprint author), PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 21 TC 155 Z9 161 U1 0 U2 8 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 OCT PY 1997 VL 144 IS 10 BP 3613 EP 3620 DI 10.1149/1.1838057 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YB720 UT WOS:A1997YB72000053 ER PT J AU Sun, J Bartholomew, RF Bellur, K Srivastava, A Osburn, CM Masnari, NA Westhoff, R AF Sun, J Bartholomew, RF Bellur, K Srivastava, A Osburn, CM Masnari, NA Westhoff, R TI A comparative study of n(+)/p junction formation for deep submicron elevated source/drain metal oxide semiconductor field effect transistors SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID EPITAXIAL COSI2 FILMS; SOURCE DRAIN MOSFET; 001 SILICON; RESISTANCE AB Ultrashallow elevated n(+)/p junctions (similar to 75 nm) incorporating selectively deposited epitaxial silicon layers were fabricated. The undoped epi layers (similar to 100 nm) were deposited on exposed diffusion areas in an Advanced Semiconductor Material Epsilon I system specifically designed for low thermal budget single-wafer processing. Shallow junctions (similar to 75 nm) were formed by ion implantation (As, 4 x 10(15)/cm(2), 80 keV) into undoped epi layers and out-diffusion into the underlying substrate. Alternatively, an ion implanted (As, 4 x 10(15)/cm(2), 60 keV) elevated layer was utilized to contact a shallow junction, which was formed (As, 1.5 x 10(15)/cm(3), 15 keV) before the epi deposition All junctions were annealed at 950 degrees C for 10 s. Nonsilicided elevated junctions and conventional nonelevated (As, 1.5 x 10(15)/cm(2), 15 keV) ones displayed very similar junction characteristics. Silicided nonelevated ultrashallow junctions, however, showed large reverse leakage current due to the substrate consumption. Both silicided elevated (post-epi and pre-epi) junctions exhibited excellent forward characteristics and low reverse leakage current. The difference in the reverse leakage characteristics of these two elevated junctions was attributed to the epi faceting formed at the sidewall edge of localized oxidation of silicon isolation. Deep submicron n = channel metal oxide semiconductor field effect transistors incorporating these junctions were also fabricated and electrically tested. Both elevated source/drain (S/D) devices show superior current driving capability compared to nonelevated ones as a result of much reduced parasitic resistance from contact source/drain junctions. C1 N CAROLINA STATE UNIV, DEPT ELECT & COMP ENGN, RALEIGH, NC 27695 USA. LAWRENCE SEMICOND RES LAB, TEMPE, AZ 85282 USA. NR 19 TC 5 Z9 5 U1 0 U2 0 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 OCT PY 1997 VL 144 IS 10 BP 3659 EP 3664 DI 10.1149/1.1838066 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YB720 UT WOS:A1997YB72000062 ER PT J AU Kim, B Shinn, ND Erskine, JL AF Kim, B Shinn, ND Erskine, JL TI Photoemission study of W(4f) core-level shifts on (1x1)Fe/W(110) SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article ID W(110) SURFACE; W(100); FILMS AB High-resolution photoemission spectra of W(4f(7/2)) on (1 x 1) Fe/W(110) have been obtained from submonolayer to 2.5 overlayers of Fe. It is observed that the second layer of tungsten is modified by Fe overlayer, as well as by the first tungsten layer, during bi-metallic epitaxy. The first-layer tungsten atoms exhibit incremental W(4f(7/2)) shifts to lower binding energies with increasing Fe-W coordination whereas the W(4f(7/2)) level for the second-layer tungsten atoms shifts in the opposite direction. A coordination number and lattice relaxation shifts are proposed to account for these opposing core-level shifts of the first and second layer W atoms, respectively. C1 SANDIA NATL LABS,DEPT 1114,ALBUQUERQUE,NM 87185. UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712. RP Kim, B (reprint author), POHANG UNIV SCI & TECHNOL,POHANG LIGHT SOURCE,POHANG 790784,SOUTH KOREA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD OCT PY 1997 VL 31 IS 4 BP 625 EP 628 PG 4 WC Physics, Multidisciplinary SC Physics GA YA965 UT WOS:A1997YA96500016 ER PT J AU Flynn, TJ AF Flynn, TJ TI Two-dimensional phase unwrapping with minimum weighted discontinuity SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID RADAR INTERFEROMETRY; ALGORITHM; MAPS AB Given an interferometric phase image of a surface profile, the task of two-dimensional phase unwrapping is to reconstruct the profile by adding multiples of 2 pi to the image. Discontinuities in the unwrapped phase must be restricted to areas of noise and true discontinuity in the profile. Such areas can often be identified by their low quality. This suggests that the unwrapped phase should be chosen to minimize a weighted sum of discontinuity magnitudes. An algorithm is presented that computes such an unwrapped phase from any initial guess. The elementary operation of the algorithm is to partition the image into two connected regions, then raise the unwrapped phase by 2 pi in one of the regions, reducing the weighted sum; this is done repeatedly until no suitable partitions exist. The operations are found by creating paths that follow discontinuity curves and extending them to form complete partitions. The algorithm terminates when no path can be extended. The behavior of the algorithm and the benefits of weighting are illustrated with an example. (C) 1997 Optical Society of America. RP Flynn, TJ (reprint author), SANDIA NATL LABS,POB 5800,MAIL STOP 0576,ALBUQUERQUE,NM 87185, USA. NR 10 TC 215 Z9 243 U1 5 U2 16 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 OCT PY 1997 VL 14 IS 10 BP 2692 EP 2701 DI 10.1364/JOSAA.14.002692 PG 10 WC Optics SC Optics GA XY742 UT WOS:A1997XY74200013 ER PT J AU Kim, D Mullin, CS Shen, YR AF Kim, D Mullin, CS Shen, YR TI Second-harmonic generation in atomic vapor with picosecond laser pulses SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OPTICAL 2ND-HARMONIC GENERATION; MULTIPOLAR CONTRIBUTIONS; VACUUM ULTRAVIOLET; ISOTROPIC FLUIDS; FORBIDDEN NATURE; HYDROGEN; FIELD; RADIATION; STATES AB Picosecond laser pulses were used to study the highly forbidden resonant second-harmonic generation (SHG) in potassium vapor. The input intensity dependence, vapor density dependence, buffer-gas pressure dependence, and spatial prove of the SHG were measured. A pump-probe experiment was conducted to probe the time dependence of the SHG signal. The experimental results can be understood from an ionization-initiated de-field-induced SHG model. A theory of a de-field-induced SHG model is developed that takes into account the time development of the de electric field in detail. This temporal buildup of the de field along with transient coherent excitation between two-photon-allowed transitions can explain the experimental results quantitatively, including the previous vapor SHG results with nanosecond laser pulses. (C) 1997 Optical Society of America. C1 LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Kim, D (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RI Kim, Doseok/J-8776-2013 NR 44 TC 5 Z9 5 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD OCT PY 1997 VL 14 IS 10 BP 2530 EP 2542 DI 10.1364/JOSAB.14.002530 PG 13 WC Optics SC Optics GA YA003 UT WOS:A1997YA00300015 ER PT J AU Collins, BS Wein, GR AF Collins, BS Wein, GR TI Mass allocation and self-burial of Aristida tuberculosa florets SO JOURNAL OF THE TORREY BOTANICAL SOCIETY LA English DT Article DE Aristida tuberculosa; allometry; hygroscopic awns ID SEED SIZE VARIATION; DESMODIUM-PANICULATUM; DISPERSAL; GERMINATION; GROWTH; ESTABLISHMENT; MICROSITE; GRASSES; ERODIUM; UNITS AB Aristida tuberculosa is an annual grass of impoverished old fields on the southeastern coastal plain. Mature florets have hygroscopic awns and self-bury; florets that do not implant usually do not germinate, or seedlings fail to establish. We examined the influence of soil fertility on mass allocation in Aristida plants and florets, and the consequences of relative investment in caryopsis and awn for self-burial on litter and bare substrate. In the greenhouse, soil fertility did not influence mean per-floret mass or awn length, but fertilized plant florets had lighter caryopses and greater relative investment in awn than unfertilized plant florets. In field-collected propagules, caryopsis mass and awn length were inversely related to soil fertility; mean per-floret mass and relative investment in awn and caryopsis did not differ among fields. Relative investment in awn and caryopsis did not influence floret burial in field or greenhouse trials. Litter cover did enhance burial in both the field and the greenhouse; florets buried deeper in the heavier litter of the most fertile field site. We conclude that, although soil fertility influences floret biomass allocation in Aristida, relative allocation to awn and caryopsis does not influence floret performance. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Collins, BS (reprint author), Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. NR 26 TC 4 Z9 5 U1 2 U2 8 PU TORREY BOTANICAL SOCIETY PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0040-9618 J9 J TORREY BOT SOC JI J. Torrey Bot. Soc. PD OCT-DEC PY 1997 VL 124 IS 4 BP 306 EP 311 DI 10.2307/2997265 PG 6 WC Plant Sciences SC Plant Sciences GA YN198 UT WOS:000071142900005 ER PT J AU Ishikiriyama, K Boller, A Wunderlich, B AF Ishikiriyama, K Boller, A Wunderlich, B TI Melting of indium by temperature-modulated differential scanning calorimetry SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE indium; melting; temperature calibration; TMDSC ID CALIBRATION; TRANSITIONS; DSC AB The melting and crystallization of a sharply melting standard has been explored for the calibration of temperature-modulated differential scanning calorimetry, TMDSC. Modulated temperature and heat flow have been followed during melting and crystallization of indium. It is observed that indium does not supercool as long as crystal nuclei remain in the sample when analyzing quasi-isothermally with a small modulation amplitude. For standard differential scanning calorimetry, DSC, the melting and crystallization temperatures of indium are sufficiently different not to permit its use for calibration on cooling, unless special analysis modes are applied. For TMDSC with an underlying heating rate of 0.2 K min(-1) and a modulation amplitude of 0.5-1.5 K at periods of 30-90 s, the extrapolated onsets of melting and freezing were within 0.1 K of the known melting temperature of indium. Further work is needed to separate the effects originating from loss of steady state between sample and sensor on the one hand and from supercooling on the other. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 14 TC 32 Z9 32 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PD OCT PY 1997 VL 50 IS 4 BP 547 EP 558 DI 10.1007/BF01979027 PG 12 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA YE875 UT WOS:A1997YE87500003 ER PT J AU Howell, LH Beckner, VE AF Howell, LH Beckner, VE TI Discrete ordinates algorithm for domains with embedded boundaries SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID HEAT-TRANSFER; GEOMETRIES AB Embedded boundary methods model fluid flows in complex geometries by treating boundaries as tracked interfaces in a regular mesh. Though often referred to as Cartesian grid methods, they are equally well-suited to axisymmetric problems. This paper describes a formulation of the discrete ordinates method for radiative transfer calculations with embedded boundaries. The method uses diamond-difference stencils in the interior with a conservative extension to boundary cells based on a volume-of-fluid approach. Numerical examples are presented in both two-dimensional Cartesian and axisymmetric geometries, including a model of the BERL 300-kW natural gas burner. RP Howell, LH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,BERKELEY,CA 94720, USA. NR 16 TC 9 Z9 9 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD OCT-DEC PY 1997 VL 11 IS 4 BP 549 EP 555 DI 10.2514/2.6297 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA YA622 UT WOS:A1997YA62200009 ER PT J AU Delwart, EL Pan, H Sheppard, HW Wolpert, D Neumann, AU Korber, B Mullins, JI AF Delwart, EL Pan, H Sheppard, HW Wolpert, D Neumann, AU Korber, B Mullins, JI TI Slower evolution of human immunodeficiency virus type I quasispecies during progression to AIDS SO JOURNAL OF VIROLOGY LA English DT Article ID LONG-TERM NONPROGRESSORS; PRIMARY HIV-1 INFECTION; DISEASE PROGRESSION; GENETIC-VARIATION; ENVELOPE PROTEIN; V3 LOOP; TYPE-1-INFECTED PATIENTS; 1-INFECTED INDIVIDUALS; REVERSE-TRANSCRIPTASE; ANTIBODY-RESPONSES AB The evolution of human immunodeficiency virus type 1 (HIV-1) quasispecies at the envelope gene was studied from the time of infection in II men who experienced different rates of CD4(+) cell count decline and 6 men with unknown dates of infection by using DNA heteroduplex mobility assays. Quasispecies were genetically homogeneous near the time of seroconversion. Subsequently slower proviral genetic diversification and higher plasma viremia correlated with rapid CD4(+) cell count decline, Except for the fastest progressors to AIDS, highly diverse quasispecies del eloped in all subjects within 3 to 4 years. High quasispecies diversity was then maintained for years until again becoming more homogeneous in a subset of late-stage AIDS patients, Individuals who maintained high CD4(+) cell counts showed continuous genetic turnover of their complex proviral quasispecies, while more closely related sets of variants were found in longitudinal samples of severely immunocompromised patients, The limited number of variants that grew out in short-tel nl PBMC cocultures were rare in the uncultured proviral quasispecies of healthy. long-term infected individuals but more common in vivo in patients with low CD4(+) cell counts. The slower evolution of HIV-1 observed during rapid progression to AIDS and in advanced patients may reflect ineffective host-mediated selection pressures on replicating quasispecies. C1 CALIF DEPT HLTH SERV,VIRAL & RICKETTSIAL DIS LAB,BERKELEY,CA 90704. SANTA FE INST,SANTA FE,NM 87501. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87454. UNIV WASHINGTON,DEPT MICROBIOL & MED,SEATTLE,WA 98195. RP Delwart, EL (reprint author), ROCKEFELLER UNIV,AARON DIAMOND AIDS RES CTR,455 1ST AVE,NEW YORK,NY 10016, USA. OI Delwart, Eric/0000-0002-6296-4484; Korber, Bette/0000-0002-2026-5757 FU NIAID NIH HHS [AI32885, AI27742, AI34783] NR 93 TC 152 Z9 154 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0022-538X J9 J VIROL JI J. Virol. PD OCT PY 1997 VL 71 IS 10 BP 7498 EP 7508 PG 11 WC Virology SC Virology GA XW142 UT WOS:A1997XW14200043 PM 9311829 ER PT J AU Cullinan, VI Simmons, MA Thomas, JM AF Cullinan, VI Simmons, MA Thomas, JM TI A Bayesian test of hierarchy theory: scaling up variability in plant cover from field to remotely sensed data SO LANDSCAPE ECOLOGY LA English DT Article DE hierarchy theory; Bayesian analysis; scales of pattern ID PATTERN AB Hierarchy theory predicts that a hierarchy of process rates should be reflected in a hierarchy of spatial and temporal scales observable on the landscape. We will show that multiple scales of pattern for total plant cover measured in the field at 1-m resolution are correlated with scales of vegetative pattern obtained from remotely sensed data with resolutions of 25 m(2) and 30 m(2). Second, using four models based on postulates of hierarchy theory, we will combine the scales of pattern of each individual species within a community to estimate the remotely sensed community scales of pattern. Finally, we will compare the four models using a Bayesian analysis to determine which model best portrays how vegetative patterns of individual species combine to produce remotely observed community patterns. The results of the model comparisons provide an example of how postulates of hierarchy theory can be tested and how individual species patterns can be scaled-up to estimate remotely observed scales of pattern. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Cullinan, VI (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 17 TC 13 Z9 16 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-2973 J9 LANDSCAPE ECOL JI Landsc. Ecol. PD OCT PY 1997 VL 12 IS 5 BP 273 EP 285 DI 10.1023/A:1007962415318 PG 13 WC Ecology; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 150UN UT WOS:000077684100002 ER PT J AU Brigmon, RL Lusk, DE Aldrich, HC Yang, JC Zam, SG AF Brigmon, RL Lusk, DE Aldrich, HC Yang, JC Zam, SG TI Production of a cell wall-specific monoclonal antibody to Fibrobacter succinogenes SO LETTERS IN APPLIED MICROBIOLOGY LA English DT Article ID CLOSTRIDIUM-ALDRICHII; BACTERIA; S85 AB A monoclonal antibody (mAb) was raised against Fibrobacter succinogenes and produced after fusion as ascites in BALB/c mice. An ELISA was used to test for specificity and sensitivity of the mAb to detect F. succinogenes. The mAb BD1 was tested for sensitivity and crossreactivity in detecting F. succinogenes with ELISA. The lower limits for F. succinogenes detection in pure and mixed culture using mAb BD1 with ELISA was 10(5) cells ml(-1). Twenty-six other species of bacteria, including 12 cellulolytic species, were tested for cross-reactivity with the ELISA but none was detected. Electron micrographs off. succinogenes cells with immunogold labelling showed that the mAb BD1 reacted exclusively with cell wall epitopes but not intracellular material, as confirmed by ELISA. C1 UNIV FLORIDA,DEPT MICROBIOL & CELL SCI,GAINESVILLE,FL 32611. UNIV FLORIDA,DEPT AGR ENGN,GAINESVILLE,FL 32611. RP Brigmon, RL (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECH CTR,DEPT ENVIRONM SCI & TECHNOL,AIKEN,SC 29808, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0266-8254 J9 LETT APPL MICROBIOL JI Lett. Appl. Microbiol. PD OCT PY 1997 VL 25 IS 4 BP 261 EP 264 DI 10.1046/j.1472-765X.1997.00221.x PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YF373 UT WOS:A1997YF37300008 PM 9351275 ER PT J AU Burton, H AF Burton, H TI Zeros plus ones: The matrix of women plus machines - Plant,S SO LIBRARY JOURNAL LA English DT Book Review RP Burton, H (reprint author), 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 OCT 1 PY 1997 VL 122 IS 16 BP 110 EP 110 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA XZ054 UT WOS:A1997XZ05400200 ER PT J AU Harris, RV AF Harris, RV TI Acoustic birefringence: Methods and difficulties in material characterization SO MATERIALS EVALUATION LA English DT Article DE acoustic birefringence; aging; anisotropy; microstructure; nondestructive testing; sensitization; shear wave; steel; transverse wave; ultrasonics AB Acoustic birefringence measurements in five aged coupons of 304 stainless steel shaw marked spatial variations in magnitude and direction of birefringence and a weak correlation with aging. Polar presentations facilitate data interpretation. RP Harris, RV (reprint author), PACIFIC NW LAB, BATTELLE BLVD, POB 999, RICHLAND, WA 99352 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD OCT PY 1997 VL 55 IS 10 BP 1159 EP 1161 PG 3 WC Materials Science, Characterization & Testing SC Materials Science GA YA062 UT WOS:A1997YA06200010 ER PT J AU Raine, DA Brenizer, JS AF Raine, DA Brenizer, JS TI The analysis and correction of neutron scattering effects in neutron imaging SO MATERIALS EVALUATION LA English DT Article DE computed tomography; imaging; neutron radiography; nondestructive testing; radiography; scattering effect AB A method of correcting for the scattering effects present in neutron radiographic and computed tomographic imaging has been developed. Prior work has shown that beam, object, and imaging system geometry factors, such as the LID ratio and angular divergence, Rue the primary sources contributing to the degradation of neutron images. With objects smaller than 20-40 mm (0.75-1.5 in.) in width, a parallel beam approximation can be made where the effects from geometry are negligible. Factors which remain important in the image formation process Rue the pixel size of the imaging system, neutron scattering, the size of the object, the conversion material, and the beam energy spectrum. The Monte Carlo N-Particle transport code, version 4A (MCNP4A), was used to separate and evaluate the effect that each of these parameters has on neutron image data. The simulations were used to develop a correction algorithm which is easy to implement and requires no a priori knowledge of the object. The correction algorithm is based on the determination of the object scatter function (OSF) using available data outside the object to estimate the shape and magnitude of the OSF based on a Gaussian functional form. For objects smaller than 1 mm (0.04 in.) in width, the correction function can be well approximated by a constant function. Errors in the determination and correction of the MCNP simulated neutron scattering component were under five percent and larger errors were only noted in objects which were at the extreme high end of the range of object sizes simulated. The Monte Carlo data also indicated that scattering does not play a significant role in the blurring of neutron radiographic and tomographic images. The effect of neutron scattering on computed tomography is shown to be minimal at best, with the most serious effect resulting when the basic backprojection method is used. C1 UNIV VIRGINIA,DEPT MECH AEROSP & NUCL ENGN,CHARLOTTESVILLE,VA 22903. RP Raine, DA (reprint author), OAK RIDGE NATL LAB,POB 2008 MS-6064,OAK RIDGE,TN 37831, USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD OCT PY 1997 VL 55 IS 10 BP 1174 EP 1178 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA YA062 UT WOS:A1997YA06200013 ER PT J AU Stilianakis, NI Dietz, K Schenzle, D AF Stilianakis, NI Dietz, K Schenzle, D TI Analysis of a model for the pathogenesis of AIDS SO MATHEMATICAL BIOSCIENCES LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; REPLICATIVE CAPACITY; HIV-1 INFECTION; PROGRESSION; LYMPHOCYTES; PHENOTYPE; DECLINE AB According to a previously proposed mathematical model, the pathogenesis of acquired immunodeficiency syndrome (AIDS) could be explained by two phenomena: direct human immunodeficiency virus (HIV) infection of CD4(+) T-cell populations and ongoing generation and selection of HIV mutants with increasing replicative capacity. In the present paper, the results obtained with this model are described in more detail. For different values of biologically interpretable parameters, the model predicts very different patterns of CD4(+) T-cell decline after primary infection. With the assumption of a variability of 10% to 25% of three parameters between infected individuals, the model yields a realistic distribution curve of the incubation period to AIDS. (C) 1997 Elsevier Science Inc. C1 UNIV TUBINGEN,DEPT MED BIOMETRY,D-72070 TUBINGEN,GERMANY. RP Stilianakis, NI (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,GRP T10,MS K710,LOS ALAMOS,NM 87545, USA. RI Dietz, Klaus/R-9268-2016 OI Dietz, Klaus/0000-0001-8503-9737 FU NIDA NIH HHS [DA-04722] NR 30 TC 30 Z9 31 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0025-5564 J9 MATH BIOSCI JI Math. Biosci. PD OCT 1 PY 1997 VL 145 IS 1 BP 27 EP 46 DI 10.1016/S0025-5564(97)00018-7 PG 20 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA XR014 UT WOS:A1997XR01400002 PM 9271894 ER PT J AU Gubbi, AN George, EP Ohriner, EK Zee, RH AF Gubbi, AN George, EP Ohriner, EK Zee, RH TI Influence of cerium additions on high-temperature-impact ductility and fracture behavior of iridium alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID GRAIN-BOUNDARY EMBRITTLEMENT; SEGREGATION; BORON; NI3AL; SURFACE; SULFUR; NICKEL AB High-temperature tensile impact testing was carried out on Ir + 0.3 wt pct W alloys doped with cerium and thorium individually, and with cerium and thorium together, Impact ductility was evaluated as a function of grain size and test temperature. Cerium by itself was not as effective as thorium in improving the grain boundary cohesion, even though it segregated more strongly than thorium to the grain boundaries. This lower grain boundary cohesion was responsible for lower impact ductility and higher brittle-to-ductile transition temperature of cerium-doped alloys compared to those of the thorium- or thorium plus cerium-doped alloys. Reduction in thorium content by a factor of 5 (from 50 to 10 appm) in the bulk did not result in any significant reduction in high-temperature impact ductility or an increase in the brittle-to-ductile transition temperature as long as sufficient cerium was added to provide grain refinement, Grain boundary strengths of thorium- and thorium plus cerium-doped alloys were almost identical. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. AUBURN UNIV,MAT ENGN PROGRAM,AUBURN,AL 36849. RI George, Easo/L-5434-2014 NR 25 TC 13 Z9 13 U1 0 U2 2 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 OCT PY 1997 VL 28 IS 10 BP 2049 EP 2057 DI 10.1007/s11661-997-0161-z PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YA656 UT WOS:A1997YA65600009 ER PT J AU OBrien, J Logan, R Hosford, W AF OBrien, J Logan, R Hosford, W TI R values of fiber-textured tantalum plates SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID GLIDE AB Computations have been made of the effect of crystallographic texture on the R values in sheets of bcc metals with an upper-bound model based on [111] pencil glide. Sheets having [111] and [100] textural components with rotational symmetry about the sheet normal were considered. The predicted R values increase with the fraction [111] component up to a maximum of about 3 for pure [111]. Experiments were made on disks of tantalum produced by upsetting of rods, which produced textures having rotational symmetry about the disk normal. X-ray diffraction showed mixed [111] and [100] textures, with the fraction of [111] varying from about 34 to 96 pet. R values were measured in tension and compression tests on these sheets, and their dependence on fraction [111] agrees very well with the theoretical predictions. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP OBrien, J (reprint author), UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109, USA. NR 6 TC 2 Z9 2 U1 1 U2 2 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 OCT PY 1997 VL 28 IS 10 BP 2085 EP 2088 DI 10.1007/s11661-997-0165-8 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YA656 UT WOS:A1997YA65600013 ER PT J AU Williamson, RL Zanner, FJ Grose, SM AF Williamson, RL Zanner, FJ Grose, SM TI Arc voltage distribution properties as a function of melting current, electrode gap, and CO pressure during vacuum arc remelting SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article AB An industrial vacuum are remelting experiment was carried out at Cytemp Specialty Steel Corp, (Titusville, PA) during which a 0.432-m-diameter Alloy 718 electrode was remelted into a 0.508-m-diameter ingot. The purpose of the experiment was to investigate the response of the are voltage distribution properties (mean, standard deviation, and skewness) and the drip-short frequency to melting current, electrode gap, and CO pressure. The responses were characterized by recording and analyzing changes in the temporally averaged properties. Each independent variable was systematically varied in accordance with a modified Yates order factor space experimental design within the following ranges: melting current, 5000 to 11,200 A; electrode gap, 0.004 to 0.056 m; and CO pressure, 0.40 to 14.7 Pa. Statistical models were developed describing the correlation between the averaged arc voltage distribution properties and the independent variables, The models demonstrate that all of the voltage distribution properties, as well as the drip-short frequency, are directly related to electrode gap. An are column model is presented to account for the mean are voltage properties and the model is used to estimate the are column pressure. The potential usefulness of the distribution properties as process diagnostics and control responses is evaluated. C1 INCO ALLOYS INT INC, HUNTINGTON, WV 25705 USA. RP Williamson, RL (reprint author), SANDIA NATL LABS, DEPT MAT PROC, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 18 TC 10 Z9 10 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD OCT PY 1997 VL 28 IS 5 BP 841 EP 853 DI 10.1007/s11663-997-0012-8 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YB112 UT WOS:A1997YB11200012 ER PT J AU Frueh, C Poirier, DR Maguire, MC AF Frueh, C Poirier, DR Maguire, MC TI The effect of silica-containing binders on the titanium/face coat reaction SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article AB The interactions of CP-Ti and Ti-6Al-4V with investment molds containing alumina/silica and yttria/silica face coat systems were studied. ''Containerless'' melting in argon was employed and small test samples were made by drop casting into the molds. The effects of the face coat material and mold preheat temperatures on the thickness of the alpha case in the drop castings were evaluated with microhardness and microprobe measurements. It was found that the thickness of the alpha case was the same, whether a yttria/silica or alumina/silica face coat was used, indicating that the silica binder can reduce the apparent inertness of a more stable refractory, such as yttria. It was also found that the alloyed titanium castings had a thinner alpha case than those produced from CP-Ti, which suggests that the thickness of the alpha case depends on the crystal structure of the alloy during cooling from high temperatures. Furthermore, the small drop castings made in small yttria crucibles used as molds exhibited little or no alpha case. C1 SANDIA NATL LABS, LIQUID MET PROC DEPT, ALBUQUERQUE, NM 87185 USA. RP Frueh, C (reprint author), UNIV ARIZONA, DEPT MAT SCI & ENGN, TUCSON, AZ 85721 USA. NR 23 TC 18 Z9 19 U1 2 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD OCT PY 1997 VL 28 IS 5 BP 919 EP 926 DI 10.1007/s11663-997-0019-1 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YB112 UT WOS:A1997YB11200019 ER PT J AU Mi, J Figliola, RS Anderson, IE AF Mi, J Figliola, RS Anderson, IE TI A numerical investigation of gas flow effects on high-pressure gas atomization due to melt tip geometry variation SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article AB A parametric numerical study is presented on how melt feed tube geometry influences the gas flow field of a high-pressure gas atomizer (HPGA). The axisymmetric, turbulent, compressible Navier-Stokes equations are solved for the gas-only flow in the vicinity of the melt tip for a confined-feed, annular-slit atomizer. The numerical results indicate that a fully retracted melt tip can develop a high overambient base pressure over a wide range of operating pressures, while an extended melt tip can develop a subambient pressure, called an aspirating effect, which encourages melt to flow. Adding a taper angle to an extended melt tip decreases the aspirating effect. However, a melt tip can develop a radial pressure gradient along its base that forces the melt to move radially outward into a high-shear region of the flow, thus encouraging droplet formation. A fully retracted melt tip develops the highest such radial force, but this tends to decrease in magnitude with tip extension, Hence, a compromise must be established whereby the good aspiration character of a longer tip is balanced against the good pressure-driving force along the base of a shorter tip. The results provide details of the flow field and the effects due to variation of melt tip taper and extension. C1 CLEMSON UNIV, DEPT MECH ENGN, CLEMSON, SC 29631 USA. RP Mi, J (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, DIV MET & CERAM, AMES, IA 50011 USA. NR 16 TC 15 Z9 18 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD OCT PY 1997 VL 28 IS 5 BP 935 EP 941 DI 10.1007/s11663-997-0021-7 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YB112 UT WOS:A1997YB11200021 ER PT J AU Henderson, C AF Henderson, C TI Computer-based training for failure analysis SO MICROELECTRONICS AND RELIABILITY LA English DT Article; Proceedings Paper CT 8th European Symposium on Reliability of Electron Devices Failure Physics and Analysis (ESREF 97) CY OCT 07-10, 1997 CL ARCACHON, FRANCE AB The amount of information necessary to perform failure analysis (FA) is beginning to overwhelm the analyst. Methods for managing and locating FA information must be developed if we are to continue to be effective in solving problems that occur during design, fab, packaging, and field use. To this end, Sandia National Laboratories has developed a computer-based training tool for FA known as FASTAdvice. FASTAdvice is a hypertext-based, multimedia tool that simulates the thinking process of a number of failure analysis experts and contains a substantial portion of the knowledge necessary to successfully perform FA. (C) 1997 Elsevier Science Ltd. RP Henderson, C (reprint author), SANDIA NATL LABS,ELECT QUAL RELIABIL CTR,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 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 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD OCT-NOV PY 1997 VL 37 IS 10-11 BP 1445 EP 1448 DI 10.1016/S0026-2714(97)00083-8 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA YB683 UT WOS:A1997YB68300008 ER PT J AU Romig, AD Dressendorfer, PV Palmer, DW AF Romig, AD Dressendorfer, PV Palmer, DW TI High performance microsystem packaging: A perspective SO MICROELECTRONICS AND RELIABILITY LA English DT Article; Proceedings Paper CT 8th European Symposium on Reliability of Electron Devices Failure Physics and Analysis (ESREF 97) CY OCT 07-10, 1997 CL ARCACHON, FRANCE AB The second silicon revolution will be based on intelligent, integrated microsystems where multiple technologies (such as analog, digital, memory, sensor, micro-electro-mechanical, and communication devices) are integrated onto a single chip or within a multichip module. A necessary element for such systems is cost-effective, high-performance packaging. This paper examines many of the issues associated with the packaging of integrated microsystems, with an emphasis on the areas of packaging design, manufacturability, and reliability. (C) 1997 Published by Elsevier Science Ltd. C1 SANDIA NATL LABS,ADV PACKAGING,ALBUQUERQUE,NM 87185. SANDIA NATL LABS,HIGH FREQUENCY & PROTON APPLICAT,ALBUQUERQUE,NM 87185. RP Romig, AD (reprint author), SANDIA NATL LABS,MICROELECT & PHOTON,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 14 Z9 14 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD OCT-NOV PY 1997 VL 37 IS 10-11 BP 1771 EP 1781 DI 10.1016/S0026-2714(97)00158-3 PG 11 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA YB683 UT WOS:A1997YB68300082 ER PT J AU Smith, DL AF Smith, DL TI Piezoelectric effects in strained layer heterostructures grown on novel index substrates SO MICROELECTRONICS JOURNAL LA English DT Article; Proceedings Paper CT 2nd International Workshop on Growth, Characterization and Exploitation of Epitaxial Compound Semiconductor on Novel Index Surfaces (NIS 96) CY OCT 07-09, 1996 CL LYON, FRANCE SP Inst Natl Sci Appliquees Lyon ID QUANTUM-WELLS; SUPERLATTICES; FIELDS; GAAS AB III-V and II-VI semiconductors are piezoelectric and therefore electric fields can be generated in strained layer heterostructures formed from these materials. The strain induced electric fields depend on the symmetry of the strain, which in turn depends on the orientation of the substrate on which the heterostructure is grown. For strain generated electric fields to occur in a zincblende structure semiconductor, the strain must distort the angles of the cubic unit cell away from 90 degrees. Strains in (100) oriented heterostructures do not distort the 90 degrees angles of the cubic unit cell and no electric fields are generated. However, for other substrate orientations, electric fields can be generated in the strained layers. These electric fields can lead to large changes in the optical properties of the heterostructure which can be externally. modulated to make, for trample, electro-optic devices. They can also cause charge accumulation which can be used in field effect transistor and resonant tunneling structures. (C) 1997 Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smith, DL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Schaff, William/B-5839-2009 NR 23 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0026-2692 J9 MICROELECTR J JI Microelectron. J. PD OCT-DEC PY 1997 VL 28 IS 8-10 BP 707 EP 715 DI 10.1016/S0026-2692(96)00108-5 PG 9 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA YM949 UT WOS:000071118000002 ER PT J AU Browning, ND Wallis, DJ Nellist, PD Pennycook, SJ AF Browning, ND Wallis, DJ Nellist, PD Pennycook, SJ TI EELS in the STEM: Determination of materials properties on the atomic scale SO MICRON LA English DT Review DE STEM; EELS; Z-contrast imaging; interfaces; defects; nanoscale particles ID TRANSMISSION ELECTRON-MICROSCOPY; ENERGY-LOSS-SPECTROSCOPY; RESOLUTION; SCATTERING; CRYSTALS; SPECTROMETRY; CONTRAST AB By performing EELS in conjunction with the Z-contrast imaging technique in the scanning transmission electron microscope (STEM), detailed information on the composition, chemistry and structure of materials can be obtained with atomic resolution and sensitivity. This unprecedented resolution can be achieved by using an atomic resolution Z-contrast image to first identify structural features of interest and then to position the electron probe over the feature for spectral acquisition. This method greatly limits the number of spectra that need to be acquired from a given specimen, thus reducing total acquisition time and specimen stability problems. In addition, a key advantage of this methodology is that the collection conditions for the spectrum can be tailored to produce an incoherent, atomic resolution spectrum that can be correlated directly with the image. This means the image can be used as a reference atomic structure for theoretical modeling of the spectral fine-structure. Using multiple scattering analysis, the reference structure can be modified to reproduce the experimental spectrum, thus giving a 3-dimensional structural determination that is sensitive to single atom vacancies and impurities. In this paper, the application of this combined EELS and Z-contrast technique to various materials problems is described. In the case of the MBE growth of CdTe on Si, the combined atomic resolution techniques allow the diffusion of Te into the silicon substrate to be identified and a novel graphoepitaxial grow-th mechanism to be identified. For nanoscale iron particles used as a fuel additive to reduce/enhance soot formation during combustion, measurement of the distribution of iron oxidation states within the particles permits a mechanism for soot formation to be proposed. The application of the multiple scattering analysis techniques to the study of grain boundaries is described for tilt boundaries in TiO(2) and SrTiO(3). In both cases, the multiple scattering analysis gives information not present in the image and allows the 3-dimensional structure of each boundary to be determined. C1 Univ Illinois, Dept Phys MC 273, Chicago, IL 60607 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Browning, ND (reprint author), Univ Illinois, Dept Phys MC 273, 845 W Taylor St, Chicago, IL 60607 USA. OI Browning, Nigel/0000-0003-0491-251X NR 41 TC 63 Z9 63 U1 2 U2 44 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0968-4328 J9 MICRON JI Micron PD OCT PY 1997 VL 28 IS 5 BP 333 EP 348 DI 10.1016/S0968-4328(97)00033-4 PG 16 WC Microscopy SC Microscopy GA YZ338 UT WOS:000072244400002 ER PT J AU Chen, G Goodson, KE Grigoropoulos, C Hipwell, MC Liepmann, D Majumdar, A Maruyama, S Thundat, T Tien, CL Tien, NC AF Chen, G Goodson, KE Grigoropoulos, C Hipwell, MC Liepmann, D Majumdar, A Maruyama, S Thundat, T Tien, CL Tien, NC TI Report of workshop: Thermophysical phenomena in microscale sensors, devices, and structures SO MICROSCALE THERMOPHYSICAL ENGINEERING LA English DT Editorial Material C1 STANFORD UNIV,STANFORD,CA 94305. UNIV CALIF BERKELEY,BERKELEY,CA 94720. SEAGATE TECHNOL,BLOOMINGTON,MN. UNIV TOKYO,TOKYO,JAPAN. OAK RIDGE NATL LAB,OAK RIDGE,TN. CORNELL UNIV,ITHACA,NY. RP Chen, G (reprint author), UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024, USA. RI Maruyama, Shigeo/B-1848-2008; Goodson, Kenneth/C-3545-2011 NR 0 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1089-3954 J9 MICROSCALE THERM ENG JI Microscale Thermophys. Eng. PD OCT-DEC PY 1997 VL 1 IS 4 BP 267 EP 274 DI 10.1080/108939597200133 PG 8 WC Thermodynamics; Engineering, Mechanical; Nanoscience & Nanotechnology; Materials Science, Characterization & Testing; Physics, Applied SC Thermodynamics; Engineering; Science & Technology - Other Topics; Materials Science; Physics GA YJ869 UT WOS:A1997YJ86900001 ER PT J AU Drost, MK Call, C Cuta, J Wegeng, R AF Drost, MK Call, C Cuta, J Wegeng, R TI Microchannel combustor/evaporator thermal processes SO MICROSCALE THERMOPHYSICAL ENGINEERING LA English DT Article ID FLOW AB This article presents the results of an experimental investigation of the performance of an integrated microchannel combustor/evaporator. Separate experimental investigations were conducted on combustion in small channels and evaporation in microchannels. These results, along with the results of a simulation of heat transfer from the flue gas in microchannels, were used to design, and subsequently fabricate and test, microchannel combustor/evaporators. Performance results showed that the combustor/evaporator was capable of achieving high heat flares (up to 30 W/cm(2)) while maintaining a high combustor efficiency. RP Drost, MK (reprint author), PACIFIC NW NATL LAB, DIV ENERGY, 902 BATTELLE BLVD, POB 999, RICHLAND, WA 99352 USA. NR 11 TC 28 Z9 28 U1 0 U2 1 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1089-3954 J9 MICROSCALE THERM ENG JI Microscale Thermophys. Eng. PD OCT-DEC PY 1997 VL 1 IS 4 BP 321 EP 332 PG 12 WC Thermodynamics; Engineering, Mechanical; Nanoscience & Nanotechnology; Materials Science, Characterization & Testing; Physics, Applied SC Thermodynamics; Engineering; Science & Technology - Other Topics; Materials Science; Physics GA YJ869 UT WOS:A1997YJ86900005 ER PT J AU Zhang, Y Sperber, KR Boyle, JS AF Zhang, Y Sperber, KR Boyle, JS TI Climatology and interannual variation of the East Asian winter monsoon: Results from the 1979-95 NCEP/NCAR reanalysis SO MONTHLY WEATHER REVIEW LA English DT Article ID DECEMBER 1974; COLD SURGES AB This paper presents the climatology and interannual variation of the East Asian winter monsoon based on the 1979-95 National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis. In addition to documenting the frequency, intensity, and preferred propagation tracks of cold surges and the evolution patterns of related fields, the authors discuss the temporal distribution of the Siberian high and cold surges. Further, the interannual variation of the cold surges and winter monsoon circulation and its relationship with ENSO were examined. There are on average 13 cold surges in each winter season (October-April), of which two are strong cases. The average intensity of cold surges, measured by maximum sea level pressure, is 1053 hPa. The cold surges originate from two source regions: 1) northwest of Lake Baikal, and 2) north of Lake Balkhash. The typical evolution of a cold surge occurs over a period of 5-14 days. Trajectory and correlation analyses indicate that, during this time, high pressure centers propagate southeastward around the edge of the Tibetan Plateau from the mentioned source regions. Some of these high pressure centers then move eastward and diminish over the oceans, while others proceed southward. The signatures of the associated temperature, wind, and pressure fields propagate farther southward and eastward. The affected area encompasses the bulk of the maritime continent. Although the intensity of the Siberian high peaks during December and January, the frequency of cold surges reaches a maximum in November and in March. This result suggests that November through March should be considered as the East Asian winter monsoon season. Two stratifications of cold surges are used to examine the relationship between ENSO and the interannual variation of the winter monsoon. The first one, described as conventional cold surges, indicates that the surge frequency reaches a minimum a year after El Nino events. The second one, defined as a maximum wind event near the South China Sea, shares the same origin as the first. The surge frequency is in good agreement with the Southern Oscillation index (SOI). A low (high) SOI event coincides with a low (high) frequency of cold surges. The interannual variation of winter northerlies near the South China Sea is dominated by the South China Sea cold surges and is well correlated (R = 0.82) with the SOI. Strong wind seasons are associated with La Nina and high SOI years; on the other hand, weak wind seasons are associated with El Nino and low SOI years. This pattern is restricted to an area north of the equator within the region of (0 degrees-20 degrees N,100 degrees-130 degrees E) and is confined to the near-surface layer. The SST variation in the same region is similar to the wind pattern but lags the wind for approximately 1-5 months, which suggests that the SST variation is forced by the wind. The surface Siberian high, 500-hPa trough, and 200-hPa jet stream, all representing the large-scale monsoon flow, are weaker than normal during El Nino years. In particular, the interannual variation of the Siberian high is in general agreement with the SOI. RP Zhang, Y (reprint author), LAWRENCE LIVERMORE NATL LAB,PROGRAM CLIMATE MODEL DIAG & INTERCOMPARIS,LIVERMORE,CA 94550, USA. RI Sperber, Kenneth/H-2333-2012 NR 27 TC 216 Z9 249 U1 7 U2 29 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1997 VL 125 IS 10 BP 2605 EP 2619 DI 10.1175/1520-0493(1997)125<2605:CAIVOT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XZ561 UT WOS:A1997XZ56100013 ER PT J AU Kadkhodayan, S Salazar, EP Ramsey, MJ Takayama, K Zdzienicka, MZ Tucker, JD Weber, CA AF Kadkhodayan, S Salazar, EP Ramsey, MJ Takayama, K Zdzienicka, MZ Tucker, JD Weber, CA TI Molecular analysis of ERCC2 mutations in the repair deficient hamster mutants UVL-1 and V-H1 SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE DNA repair; ERCC2; mutation analysis; hamster; xeroderma pigmentosum ID PIGMENTOSUM GROUP-D; GROUP-D GENE; DNA-REPAIR; XERODERMA-PIGMENTOSUM; CELL-LINES; SACCHAROMYCES-CEREVISIAE; COMPLEMENTATION GROUP; YEAST RAD3; CHO CELLS; EXCISION AB The cDNA sequence of the Chinese hamster ERCC2 nucleotide excision repair and transcription gene from the UVL-1 Chinese hamster ovary (CHO) mutant cell line and the V-HI Chinese hamster V79 mutant line was analyzed. ERCC2 encodes:a presumed ATP-dependent DNA helicase, and is single copy in CHO lines due to the structural hemizygosity of chromosome 9. Both UVL-1 and V-H1 have intermediate levels of (6-4) photoproduct repair but are as highly UV sensitive as the group 2 mutants that have no detectable repair. Deficiency in cyclobutane dimer removal has also been shown for V-H1. In UVL-1, a single base substitution resulting in an Arg75 --> Trp substitution in helicase domain la was identified. The equivalent amino acid position Is also Arg in the human, mouse, Xiphophorus maculatus, Saccharomyces cerevisiae, and Schizosaccharomyces pombe homologs. In V-H1, a single base substitution resulting in a Thr46 --> Ile substitution in helicase domain I (the ATP-binding domain) was identified in both alleles. The equivalent amino acid position is also Td; in the five homologs. Analysis of three V-H 1 partial revertants revealed that they still have the original V-H 1 mutation in both alleles, indicating that these are second site reversion events. Site-specific mutagenesis was used to introduce the Thr46 --> Ile, Arg75 --> Trp. and Lys48 --> Arg (helicase domain I) mutations into a hamster ERCC2 expression plasmid. These plasmids each failed to confer UV resistance to group 2 mutant cells, further demonstrating that the changes identified are the causative mutations in V-H1 add UVL-1. Correlations between specific mutations; biochemical activities, and repair phenotype are discussed. (C) 1997 Elsevier Science B.V. C1 LEIDEN STATE UNIV,MGC,DEPT RADIAT GENET & CHEM MUTAGENESIS,LEIDEN,NETHERLANDS. RP Kadkhodayan, S (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,POB 808,L-452,LIVERMORE,CA 94551, USA. FU NCI NIH HHS [CA52679] NR 39 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD OCT PY 1997 VL 385 IS 1 BP 47 EP 57 DI 10.1016/S0921-8777(97)00030-X PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA YE075 UT WOS:A1997YE07500006 PM 9372848 ER PT J AU Munitz, A Kimmel, G Rawers, JC Fields, RJ AF Munitz, A Kimmel, G Rawers, JC Fields, RJ TI Ball milling induced bct phase formation in iron and iron alloys SO NANOSTRUCTURED MATERIALS LA English DT Article ID FE POWDER AB A variety of attritor ball milled Fe and Fe alloy powders, processed in an argon or a nitrogen environment, were studied using X-ray diffraction techniques. Broadened XRD spectra were obtained due to severe plastic deformation during ball milling. The broadening was non-uniform, displaying a systematic deviation from the average, with the (310) reflection peak being the broadest, and the (222) reflection peak being the sharpest. The systematic variation in broadening is interpreted as a tetragonal distortion. The tendency towards a tetragonal distortion occurred in all ball-milled samples. (C) 1998 Acta Metallurgica Inc. C1 Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. US DOE, Albany, OR 97321 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Munitz, A (reprint author), Nucl Res Ctr Negev, POB 9001, IL-84190 Beer Sheva, Israel. NR 14 TC 13 Z9 13 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD OCT-NOV PY 1997 VL 8 IS 7 BP 867 EP 877 DI 10.1016/S0965-9773(98)00017-8 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA YZ598 UT WOS:000072270100010 ER PT J AU Chitanvis, SM Dewey, M Hademenos, G Powers, WJ Massoud, TF AF Chitanvis, SM Dewey, M Hademenos, G Powers, WJ Massoud, TF TI A nonlinear quasi-static model of intracranial aneurysms SO NEUROLOGICAL RESEARCH LA English DT Article DE intracranial saccular aneurysm; aneurysm rupture; theoretical model ID SACCULAR ANEURYSMS; MATHEMATICAL-MODEL; CEREBRAL ANEURYSMS; FLOW-ANALYSIS; RUPTURE; MECHANICS; BIFURCATION; ORIGIN AB Biomathematical models of intracranial aneurysms can provide qualitative and quantitative information on stages of aneurysm development through elucidation of biophysical interactions and phenomena. However, most current aneurysm models, based on Laplace's law, are renditions of static, linearly elastic spheres. The primary goal of this study is to: 1. develop a nonlinear constitutive quasi-static model and 2. derive an expression for the critical size/pressure of an aneurysm, with subsequent applications to clinical data. A constitutive model of an aneurysm, based on experimental data of tissue specimens available in the literature, was incorporated into a time-dependent set of equations describing the dynamic behavior of a saccular aneurysm in response to pulsatile blood flow. The set of differential equations was solved numerically, yielding mathematical expressions for aneurysm radius and pressure. This model was applied to clinical data obtained from 24 patients presenting with ruptured aneurysms. Aneurysm development and eventual rupture exhibited an inverse relationship between aneurysm size and blood pressure. In general, the model revealed that rupture becomes highly probable for an aneurysm diameter greater than 2.0mm and a systemic blood pressure greater than 125mmHg. However, an interesting observation was that the critical pressure demonstrated a minimal sensitivity to the critical radius, substantiating similar clinical and experimental observations that blood pressure was not correlated, to any degree, with aneurysm rupture. Undulations in the aneurysm wall, presented by irregular multilobulated morphologies, could play an important role in aneurysm rupture. However, due to the large variation in results, more extensive studies will be necessary for further evaluation and validation of this model. C1 LOS ALAMOS NATL LAB,APPL THEORY DIV,LOS ALAMOS,NM 87545. UNIV CALIF LOS ANGELES,SCH MED,DEPT RADIOL SCI,ENDOVASC THERAPY SERV,LOS ANGELES,CA 90024. RP Chitanvis, SM (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MAIL STOP B268,LOS ALAMOS,NM 87545, USA. NR 23 TC 11 Z9 11 U1 0 U2 0 PU FOREFRONT PUBL GROUP PI WILTON PA C/O MARY J RAWLINS, 5 RIVER RD, STE 113, WILTON, CT 06897 SN 0161-6412 J9 NEUROL RES JI Neurol. Res. PD OCT PY 1997 VL 19 IS 5 BP 489 EP 496 PG 8 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA YF249 UT WOS:A1997YF24900004 PM 9329025 ER PT J AU Kulak, RF Pfeiffer, PA Plaskacz, EJ AF Kulak, RF Pfeiffer, PA Plaskacz, EJ TI Modeling of containment structures on high performance computers SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 13th International Conference on Structural Mechanics in Reactor Technology (SMiRT 13) CY AUG 21-22, 1995 CL BRASILIA, BRAZIL AB With recent advances in parallel supercomputers and network-connected workstations, the solution of large scale structural engineering problems, such as containment structures, has now become tractable. High-performance computer architectures, which are usually available at large universities and national laboratories, now can solve large nonlinear problems. At the other end of the spectrum, network connected workstations can be configured to become a distributed-parallel computer. A description of the development of a parallelized finite element computer program for the solution of static nonlinear structural mechanics problems is presented here. Also, a finite element methodology is presented for use in finding the structural capacity of reinforced concrete structures. The method is applicable to both cylindrical and rectilinear geometries. Containment structures for nuclear reactors are the final barrier between released radionuclides and the public. Containment structures are constructed from steel, reinforced concrete. or prestressed concrete. US nuclear reactor containment geometries tend to be cylindrical with elliptical or hemispherical heads. The older Soviet designed reactors do not use a containment building to mitigate the effects of accidents. Instead, they employed a sealed set of rectilinear, interconnected compartments, collectively called the accident localization system (ALS), to reduce the release of radionuclides to the atmosphere during accidents. As an illustrative example, the methodology developed herein is applied to a generic VVER-440/V213 design subjected to internal overpressure. (C) 1997 Argonne National Laboratory. Published by Elsevier Science S.A. RP Kulak, RF (reprint author), ARGONNE NATL LAB,REACTOR ENGN DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD OCT PY 1997 VL 174 IS 2 BP 143 EP 156 DI 10.1016/S0029-5493(97)00079-4 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA YK387 UT WOS:A1997YK38700004 ER PT J AU Wright, JC Phillips, CK Bonoli, PT AF Wright, JC Phillips, CK Bonoli, PT TI A direct calculation of current drive by fast magnetosonic waves in toroidal geometry SO NUCLEAR FUSION LA English DT Letter ID TOKAMAK PLASMAS; EFFICIENCY AB The magnitude and radial profiles of non-inductive currents driven by fast magnetosonic waves in tokamaks have been calculated directly from the wave induced quasi-linear Bwr in a toroidal geometry and a Green's function for the current. An expression for the quasi-linear flux has been derived that accounts for coupling between modes in the spectrum of waves launched from the antenna. A Fokker-Planck code for the Green's function and a full wave code for the electric field in the quasi-ii-near flux are used to evaluate the current in a specified toroidal geometry. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. MIT, Plasma Sci Fus Ctr, Cambridge, MA 02139 USA. RP Wright, JC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 13 TC 6 Z9 6 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 1997 VL 37 IS 10 BP 1349 EP 1353 DI 10.1088/0029-5515/37/10/I02 PG 5 WC Physics, Fluids & Plasmas SC Physics GA YN329 UT WOS:000071156300002 ER PT J AU Maddi, JA Stoyer, MA Archambault, LF Ayers, JJ Nitschke, JM AF Maddi, JA Stoyer, MA Archambault, LF Ayers, JJ Nitschke, JM TI High power target measurements and finite element calculations for ISL targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Methods for cooling thick spallation targets (emphasis is on targets for an ISL facility) to uniform temperatures are discussed along with methods for testing targets in a manner that does not require an accelerator facility or result in induced radioactivity. Empirical data is supplemented by computer models using a custom finite element analysis package which allows modeling of combined heat and fluid flow. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 9 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 1 PY 1997 VL 397 IS 2-3 BP 209 EP 220 DI 10.1016/S0168-9002(97)00805-X PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YA687 UT WOS:A1997YA68700001 ER PT J AU Aleksan, R Amerman, L Aston, D Benkebil, M Besson, P Bonneaud, G Bourgeois, P Brown, D Chauveau, J Ciocio, A Cizeron, R deLesquen, A delBuono, L Emery, S Gaidot, A Gosset, L Hale, D deMonchenault, GH Hamon, O Hearty, C Jouenne, A Kadyk, J Kawahara, H Krueger, H London, G Long, M Lu, A Lutz, AM Lynch, G McShurley, D Meadows, B Noppe, JM Pasquetto, E Plaszczynski, S Pope, W Pripstein, M Przybylski, G Rasson, J Ratcliff, BN Reif, R Sarazin, X Schune, MH Schwiening, J Sen, S Shapiro, S Sokoloff, M Staengle, H Stiles, P Taylor, JD Therville, D Torassa, E Vasileiadis, G Vasseur, G Vavra, J Verderi, M Warner, D Weber, TF Wenzel, W Wilson, R Wormser, G Yeche, C Zito, M AF Aleksan, R Amerman, L Aston, D Benkebil, M Besson, P Bonneaud, G Bourgeois, P Brown, D Chauveau, J Ciocio, A Cizeron, R deLesquen, A delBuono, L Emery, S Gaidot, A Gosset, L Hale, D deMonchenault, GH Hamon, O Hearty, C Jouenne, A Kadyk, J Kawahara, H Krueger, H London, G Long, M Lu, A Lutz, AM Lynch, G McShurley, D Meadows, B Noppe, JM Pasquetto, E Plaszczynski, S Pope, W Pripstein, M Przybylski, G Rasson, J Ratcliff, BN Reif, R Sarazin, X Schune, MH Schwiening, J Sen, S Shapiro, S Sokoloff, M Staengle, H Stiles, P Taylor, JD Therville, D Torassa, E Vasileiadis, G Vasseur, G Vavra, J Verderi, M Warner, D Weber, TF Wenzel, W Wilson, R Wormser, G Yeche, C Zito, M TI Test of a large scale prototype of the DIRC, a Cherenkov imaging detector based on total internal reflection for BABAR at PEP-II SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID COUNTERS AB The principles of the DIRC ring imaging Cherenkov technique are briefly explained and its choice for the BABAR detector particle identification system is motivated. A large scale prototype of the DIRC for the BABAR experiment is then described. Details of the design of this prototype and its test in a hadronic particle beam at the CERN-PS are presented, and results from various prototype and test configurations are given. For example, after correcting for geometrical acceptance and estimated collection effects, the number of photoelectrons was measured to be 146 +/- 1.8 +/- 9 cm(-1), for a track angle of 20 degrees at zero photon transmission distance. The effective attenuation loss was measured to be 4.1 +/- 0.7% per meter of bar length, and the observed single photon resolution was 10.0 +/- 0.2 mrad. This performance is consistent with what was expected from earlier tests and Monte Carlo simulations, and will be fully adequate for the physics demands of the BABAR experiment. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. COLORADO STATE UNIV,FT COLLINS,CO 80523. CEA,DAPNIA,CE SACLAY,GIF SUR YVETTE,FRANCE. LAL,ORSAY,FRANCE. UNIV PARIS 06,LPNHE,F-75252 PARIS 05,FRANCE. UNIV PARIS 07,LPNHE,F-75221 PARIS 05,FRANCE. ECOLE POLYTECH,LPNHE,PALAISEAU,FRANCE. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV BRITISH COLUMBIA,VANCOUVER,BC V5Z 1M9,CANADA. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV CINCINNATI,CINCINNATI,OH 45221. RI Torassa, Ezio/I-1788-2012; OI Hamel de Monchenault, Gautier/0000-0002-3872-3592; Wilson, Robert/0000-0002-8184-4103; Torassa, Ezio/0000-0003-2321-0599 NR 22 TC 45 Z9 45 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 OCT 1 PY 1997 VL 397 IS 2-3 BP 261 EP 282 DI 10.1016/S0168-9002(97)00744-4 PG 22 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YA687 UT WOS:A1997YA68700005 ER PT J AU Rowe, MW Moltz, DM Batchelder, JC Ognibene, TJ Tighe, RJ Cerny, J AF Rowe, MW Moltz, DM Batchelder, JC Ognibene, TJ Tighe, RJ Cerny, J TI Development and characterization of a low-energy particle-identification telescope array for proton and alpha spectroscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID DECAY; STATE; EMISSION; RADIOACTIVITY; NUCLEI; MG-23; AS-65 AB Six improved low-energy gas-Delta E/gas-Delta E/Si-E particle-identification telescopes have been incorporated into an array. Calibration experiments have shown that these telescopes are capable of detecting and identifying protons with energies as low as similar to 180keV and alpha particles with energies as low as similar to 450keV, even when operating in a high-radiation environment. Methods of calibration at very low energies have been developed and tested. A survey of the beta-delayed proton emitters Mg-21, S-29, (SC)-S-40 and Ti-41 revealed no new intense proton groups at low energies. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720. NR 41 TC 3 Z9 4 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 OCT 1 PY 1997 VL 397 IS 2-3 BP 292 EP 303 DI 10.1016/S0168-9002(97)00682-7 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YA687 UT WOS:A1997YA68700007 ER PT J AU Isaac, MCP Hurley, D McDonald, RJ Norman, EB Smith, AR AF Isaac, MCP Hurley, D McDonald, RJ Norman, EB Smith, AR TI A natural calibration source for determining germanium detector efficiencies SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB In many applications of gamma-ray spectroscopy one is faced with the task of efficiency determinations for large and/or unusually shaped samples. We propose an efficiency calibration technique that takes advantage of the well-understood decays of the long-lived naturally occurring radioisotopes, Lu-176, La-138 and K-40. Mixtures of known amounts of chemical compounds like Lu2O3, LuCl3, La2O3, La(NO3)(3), K2SO4 and KCl provide efficiency values for six gamma lines ranging from 88 to 1461keV. We present results of this procedure in different samples. RP Isaac, MCP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,MS 50-208,BERKELEY,CA 94720, USA. NR 11 TC 11 Z9 11 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 OCT 1 PY 1997 VL 397 IS 2-3 BP 310 EP 316 DI 10.1016/S0168-9002(97)00754-7 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YA687 UT WOS:A1997YA68700009 ER PT J AU Yen, YF Bowman, JD Lowie, LY Masuda, Y Mitchell, GE Penttila, SI AF Yen, YF Bowman, JD Lowie, LY Masuda, Y Mitchell, GE Penttila, SI TI Determination of the gamma-ray background in a pulsed epithermal neutron beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PARITY NONCONSERVATION; COMPOUND-NUCLEUS; SYSTEM; LA-139 AB The gamma-ray background in the pulsed neutron beam at the Los Alamos Neutron Scattering Center was measured with an array of B-10-loaded liquid scintillators. With the method employed the gamma-ray contribution in the neutron beam can be determined without knowledge of the energy spectrum of the gamma-rays. The ratio of gamma-ray to neutron intensities in the beam was determined during the time interval following the beam burst that corresponds to neutron energies from E-n = 1 to 340 eV. The gamma-ray content in the beam ranges from 2% at 1 eV to 10% at 340 eV. C1 N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. NR 13 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 1 PY 1997 VL 397 IS 2-3 BP 365 EP 370 DI 10.1016/S0168-9002(97)00709-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YA687 UT WOS:A1997YA68700015 ER PT J AU He, YD Hancox, CI Solarz, M AF He, YD Hancox, CI Solarz, M TI Measurement of general etch rate for CR-39 plastic at short distance scale SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE track-etch technique; CR-3g; etch rate; interferometry ID INDUCTION TIME; SENSITIVITY; DEPENDENCE; PRODUCTS; TRACKS AB Submicron changes in the thickness of solid state nuclear track: detectors during chemical etching can be measured by using a laser interferometer. Such a real-time monitoring allows us to determine with good accuracy the general etch rate of the detectors al very short distance scale. Combined with track measurements from an atomic force microscope, it is possible to study the detector response in this previously unexplored regime. We report a set of measurements for CR-39 plastic detectors obtained with this technique. No short-term variation of general etch rates was found within an accuracy of 5 nm h(-1) beyond the shortest measurable distance of similar to 50 nm. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP He, YD (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 12 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 1997 VL 132 IS 1 BP 109 EP 113 DI 10.1016/S0168-583X(97)00396-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YF322 UT WOS:A1997YF32200015 ER PT J AU Womble, PC Vourvopoulos, G Ball, JC Persons, KA AF Womble, PC Vourvopoulos, G Ball, JC Persons, KA TI Calculations of neutron transport through a simulated waste matrix SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE radioactive waste; transuranic assay; MCNP; differential die-away AB The assay of nuclear waste characterized as Remote Handled Transuranic (RH-TRU) waste presents a formidable problem due to the waste's high neutron and gamma-ray backgrounds, The differential die-away technique (DDT) that is currently employed as a method for the assay requires the incidence of a large fluence of thermal neutrons within the volume element that contains fissile material. To study the neutron moderation and transport through nuclear waste matrices of different densities, the simulation of neutron transport was initiated using the Monte Carlo N-Particle (MCNP) code. A series of calculations using the MCNP 4A computer code have taken place. The calculations were performed to examine neutron transport across a wide range of waste matrix densities and interrogating neutron source energies. A composite matrix based on elemental analysis of RH-TRU legacy waste at ORNL was simulated and the density of this composite was varied between 200 and 2000 kg/m(3). An isotropic interrogating neutron source was varied from 0.01 to 15 MeV to examine the transport of neutrons across these various densities. Fast (0.01-15 MeV), epithermal (10(-7)-0.01 MeV), and thermal (10(-8)-10(-7) MeV) neutron transport was examined. The moderation of fast neutrons into thermal neutrons and their subsequent transport to the center of the drum was studied. A table with predictions of lower limits of detection of fissile material in a RH-TRU waste drum under certain conditions has been prepared. (C) 1997 Elsevier Science B.V. C1 OAK RIDGE NATL LAB,APPL RADIAT MEASUREMENTS DEPT,OAK RIDGE,TN 37831. RP Womble, PC (reprint author), WESTERN KENTUCKY UNIV,DEPT PHYS & ASTRON,1 BIG RED WAY,BOWLING GREEN,KY 42101, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 1997 VL 132 IS 1 BP 123 EP 134 DI 10.1016/S0168-583X(97)00417-5 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YF322 UT WOS:A1997YF32200018 ER PT J AU Liu, F Monteiro, OR Yu, KM Brown, IG AF Liu, F Monteiro, OR Yu, KM Brown, IG TI Self-neutralized ion implantation into insulators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID CHARGE NEUTRALIZATION AB We have carried out some ion implantation experiments into conducting and insulating substrates with a metal ion beam produced by a vacuum are ion source. We show that the broad ion beam produced by this implanter configuration is space-charge neutralized to a high degree, allowing ion implantation of insulating materials without complication due to charge build-up. The implantation is in effect self-neutralized, with the ion beam carrying along its own cold electron flood. Published by Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 14 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 1997 VL 132 IS 1 BP 188 EP 192 DI 10.1016/S0168-583X(97)00385-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YF322 UT WOS:A1997YF32200024 ER PT J AU Reinhold, CO Burgdorfer, J Frey, MT Dunning, FB AF Reinhold, CO Burgdorfer, J Frey, MT Dunning, FB TI Creating and probing coherent atomic states SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Joint US/Latin-American Seminar on Atomic Collisions CY MAR 16-19, 1997 CL ROSARIO, ARGENTINA SP US Natl Sci Fdn, CONICET ID HALF-CYCLE PULSES; RYDBERG WAVE-PACKETS; ELECTROMAGNETIC PULSES; STARK STATES; IONIZATION; SUBPICOSECOND; DYNAMICS; COLLISIONS; HYDROGEN; FIELD AB We present a brief review of recent experimental and theoretical time-resolved studies of the evolution of atomic wavepackets, in particular, wavepackets comprising a superposition of very-high-lying Rydberg states that are created either using a short half-cycle pulse (HCP) or by rapid application of a DC field. The properties of the wavepackets are probed using a second HCP that is applied following a variable time delay and which ionizes a fraction of the atoms, much like a passing-by ion in atomic collisions. (C) 1997 Elsevier Science B.V. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RICE UNIV,DEPT PHYS,HOUSTON,TX 77005. RICE UNIV,RICE QUANTUM INST,HOUSTON,TX 77005. RP Reinhold, CO (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 42 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 1997 VL 132 IS 2 BP 316 EP 325 DI 10.1016/S0168-583X(97)00433-3 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YH043 UT WOS:A1997YH04300015 ER PT J AU Church, DA Steiger, J Beck, B Gruber, L Weinberg, G McDonald, J Schneider, D AF Church, DA Steiger, J Beck, B Gruber, L Weinberg, G McDonald, J Schneider, D TI Collisions and spectroscopy of cold, highly charged high-Z ions in RETRAP SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Joint US/Latin-American Seminar on Atomic Collisions CY MAR 16-19, 1997 CL ROSARIO, ARGENTINA SP US Natl Sci Fdn, CONICET ID PENNING TRAP; ELECTRON; ENERGY; ATOMS AB Recent experimental results from the RETRAP apparatus, including electron capture measurements on highly charged high-Z ions and laser cooling of a mixed cloud of Be+ and Be2+ ions, are briefly described. These results are used as a basis for discussion of planned spectroscopy measurements on hydrogen-like and beryllium-like high-Z highly charged ions. Experimental parameters for potential measurements of the ground state hyperfine structure of a hydrogen-like high-Z ion, and the g-factor of the electron bound in that ion, are emphasized. (C) 1997 Elsevier Science B.V. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94530 USA. RP Church, DA (reprint author), TEXAS A&M UNIV, DEPT PHYS, COLLEGE STN, TX 77843 USA. NR 23 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD OCT PY 1997 VL 132 IS 2 BP 335 EP 343 DI 10.1016/S0168-583X(97)00435-7 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YH043 UT WOS:A1997YH04300018 ER PT J AU Bouland, O Derrien, H Larson, NM Leal, LC AF Bouland, O Derrien, H Larson, NM Leal, LC TI R-matrix analysis of the Pu-240 neutron cross sections in the thermal to 5700-eV energy range SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID PARAMETERS; RESONANCE; U-235 AB A Bayesian R-matrix-fitting code called SAMMY is used in a new analysis of the Pu-240 neutron cross sections in the 0.02- to 5700-eV energy range. This work aims to resolve the discrepancies revealed by the JEF2 validation studies. A set of experimental data, suitable for the analysis, is determined from preliminary SAMMY analyses of the available experimental data treated individually Finally, the sequential analysis of the selected transmission, total, and fission cross-section measurements gives an accurate set of resonance parameters. For the 1.056-eV resonance, the analysis of a recent transmission measurement gives parameters very close to those adopted in ENDF/B-VI. In the energy range above 200 eV, the average capture cross section calculated from the present evaluation is in agreement with ENDF/B-VI but is 25% lower than the values of JEF-2 and JENDL-3. A rigorous study of the statistical properties of the resonance parameters is done during this work. Although 158 new resonances are identified by the careful examination of the experimental fission cross-section and transmission data, the value of the average spacing above 2750 eV(D-0 = 16.10 eV) shows a 25% loss of resonances compared with the lower energy region (D-0 = 12.06 eV). Finally, for the s-wave resonance parameters, this work recommends the following average values: resonance spacing, D-0 = 12.06 +/- 0.60 eV, strength function, S-0 = (1.032 +/- 0.072) x 10(-4) eV; and capture width, <(Gamma)over bar> = 31.92 +/- 1.6 meV. C1 NUCL ENERGY AGCY DATA BANK,ORG ECON COOPERAT & DEV,F-92130 ISSY MOULINEAUX,FRANCE. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Bouland, O (reprint author), CEN CADARACHE,CEA,LAB ETUD PHYS,F-13108 ST PAUL DURANCE,FRANCE. NR 26 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 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 1997 VL 127 IS 2 BP 105 EP 129 PG 25 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XZ721 UT WOS:A1997XZ72100001 ER PT J AU Fanning, TH Palmiotti, G AF Fanning, TH Palmiotti, G TI Variational nodal transport methods with heterogeneous nodes SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID EQUATIONS AB The variational nodal transport method is generalized for the treatment of heterogeneous nodes while maintaining nodal balances. Adapting variational methods to heterogeneous nodes requires the ability to integrate over a node with discontinuous cross sections. Integrals are evaluated using composite Gaussian quadrature rules, which permit accurate integration while yielding acceptable computing times. Allowing structure within a nodal solution scheme avoids some of the necessity of cross-section homogenization and more accurately defines the intranodal flux shape. Ideally, any desired heterogeneity can be constructed within the node, bur in reality, the finite set of basis functions limits the intranodal complexity that can be modeled. Comparison tests show that the heterogeneous variational nodal method provides accurate results for moderate heterogeneities, even if some improvements are needed for very difficult configurations. C1 UNIV WISCONSIN,DEPT NUCL ENGN & ENGN PHYS,MADISON,WI 53706. RP Fanning, TH (reprint author), ARGONNE NATL LAB,REACTOR ANAL DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 18 TC 4 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 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 1997 VL 127 IS 2 BP 154 EP 168 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XZ721 UT WOS:A1997XZ72100004 ER PT J AU Beard, CA Buksa, JJ Davidson, JW Eaton, SL Park, JJ Toevs, JW Werley, KA AF Beard, CA Buksa, JJ Davidson, JW Eaton, SL Park, JJ Toevs, JW Werley, KA TI A radiation barrier alloy for long-term storage of special nuclear materials: Definition and preliminary assessment SO NUCLEAR TECHNOLOGY LA English DT Article AB The radiation barrier alloy (RBA) concept is a method for introducing radioactive, chemical, and physical barriers for storing weapons-grade plutonium, and yet still allowing for accurate material control and accountability, as well as for retrieving the material by the host nation if desired. The radioactive and chemical barriers are achieved by fabricating the plutonium in the form of a plutonium-beryllium compound (PuBe13), which results in neutron emission resulting from (alpha,n) reactions within the compound and multiplication from (n,fission) processes in the plutonium. Preliminary physics analyses have been completed, as well as a general review of fabrication techniques and availability of the required materials. These studies revealed that dose levels in excess of 500 rem/h at a 1-m distance from the surface of the RBA assembly can be obtained. However, essential for achieving these nose levels is operation at a high level of neutron multiplication (k(eff) similar to 0.9). Criticality concerns, even under flooded conditions, can be eliminated through the use of a thermal-neutron-absorbing material (e.g., cadmium) either as a cladding material or a container material surrounding the RBA assembly. Fabrication techniques for the Pu-Be compound are well demonstrated and fully compatible with the RBA assembly fabrication. Data from disassembly of Pu-Be sources indicate that the compound is stable and no significant physical degradation occurs over a 40-yr time frame. There is no reason to believe that any additional problems exist for longer time frames, given that the components are designed for the appropriate lifetimes (i.e., adequately account for gas production). The materials required for RBA implementation are available in the required quantities, and cost of these materials is not prohibitive. The possible exception is tantalum, although its use is nonessential for RBA performance and hence it will probably be eliminated from future RBA designs. Additional physical barriers can be added by welding the assembly together and encasing the assembly in an outer container. If desired, the assembly (inside the outer container) can also be immersed in a neutronically inert matrix such as lead. The lead serves a dual role in that in makes it difficult to move because of the additional weight, and it increases safety by reducing the possibility of a criticality accident resulting from flooding or assembly crushing. To further the RBA preconceptual analyses, a baseline design based on physics performance was developed. For the baseline RBA configuration, approximately six RBA assemblies, each 31 m(3) in volume, would be required to store 50 Mt of weapons-grade plutonium. RP Beard, CA (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD OCT PY 1997 VL 120 IS 1 BP 19 EP 40 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XY560 UT WOS:A1997XY56000002 ER PT J AU Caselles, V Kimmel, R Sapiro, G Sbert, C AF Caselles, V Kimmel, R Sapiro, G Sbert, C TI Minimal surfaces: a geometric three dimensional segmentation approach SO NUMERISCHE MATHEMATIK LA English DT Article ID VISCOSITY SOLUTIONS; LEVEL SETS; CURVE EVOLUTION; MEAN-CURVATURE; PLANE-CURVES; SHAPE; PROPAGATION; EQUATIONS; DIFFUSION; CONTOURS AB A novel geometric approach for three dimensional object segmentation is presented. The scheme is based on geometric deformable surfaces moving towards the objects to be detected, We show that this model is related to the computation of surfaces of minimal area (local minimal surfaces). The space where these surfaces are computed is induced from the three dimensional image in which the objects are to be detected. The general approach also shows the relation between classical deformable surfaces obtained via energy minimization and geometric ones derived from curvature flows in the surface evolution framework. The scheme is stable, robust, and automatically handles changes in the surface topology during the deformation. Results related to existence, uniqueness, stability, and correctness of the solution to this geometric deformable model are presented as well. Based on an efficient numerical algorithm for surface evolution, we present a number of examples of object detection in real and synthetic images. C1 HEWLETT PACKARD LABS, PALO ALTO, CA 94304 USA. UNIV ILLES BALEARS, DEPT MATH & INFORMAT, E-07071 PALMA DE MALLORCA, SPAIN. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Sbert, Catalina/K-8768-2014 NR 68 TC 44 Z9 45 U1 0 U2 3 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 0029-599X EI 0945-3245 J9 NUMER MATH JI Numer. Math. PD OCT PY 1997 VL 77 IS 4 BP 423 EP 451 DI 10.1007/s002110050294 PG 29 WC Mathematics, Applied SC Mathematics GA YB005 UT WOS:A1997YB00500001 ER PT J AU Beck, CW AF Beck, CW TI Effect of changes in resource level on age and size at metamorphosis in Hyla squirella SO OECOLOGIA LA English DT Article DE age at metamorphosis; size at metamorphosis; Hyla; developmental plasticity; phenotypic plasticity ID LARVAL GROWTH HISTORY; PITCHER-PLANT MOSQUITO; AMPHIBIAN METAMORPHOSIS; PHENOTYPIC PLASTICITY; SCAPHIOPUS-COUCHII; GENETIC-VARIATION; LIFE-HISTORY; TIME; POPULATION; RESPONSES AB Recent experiments suggest that timing of metamorphosis is fixed during development in some anurans, insects, and freshwater invertebrates. Yet, these experiments do not exclude a growth rate optimization model for the timing of metamorphosis. I manipulated food resources available to larvae of squirrel treefrogs (Hyla squirella) to determine if there is a loss of plasticity in duration of larval period during development and to critically test growth rate models for the timing of metamorphosis. Size-specific resource levels for individual tadpoles were switched from low to high or high to low at three developmental stages spaced throughout larval development. The effects of changes in resource availability on larval period and mass at metamorphosis were measured. Switching food levels after late limb bud development did not significantly affect larval period in comparison to constant food level treatments. Therefore, developmental rate in H. squirella is better described by a fixed developmental rate model, rather than a growth rate optimization model. The timing of fixation of developmental rate in H. squirella is similar to that found in other anuran species, suggesting a taxonomically widespread developmental constraint on the plasticity of larval period duration. Mass at metamorphosis was not significantly affected by the timing of changes in food levels; the amount of food available later in development determined the size at metamorphosis. Larval period and mass at metamorphosis were negatively correlated in only one of two experiments, which contrasts with the common assumption of a phenotypic trade-off between decreased larval period and increased mass at metamorphosis. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29801. RP Beck, CW (reprint author), UNIV GEORGIA,INST ECOL,ATHENS,GA 30602, USA. NR 35 TC 31 Z9 32 U1 0 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0029-8549 J9 OECOLOGIA JI Oecologia PD OCT PY 1997 VL 112 IS 2 BP 187 EP 192 DI 10.1007/s004420050299 PG 6 WC Ecology SC Environmental Sciences & Ecology GA YA693 UT WOS:A1997YA69300007 PM 28307569 ER PT J AU Pint, BA AF Pint, BA TI On the formation of interfacial and internal voids in alpha-Al2O3 scales SO OXIDATION OF METALS LA English DT Article DE alpha-Al2O3; voids; growth mechanism; metal-oxide interface, scale adhesion ID HIGH-TEMPERATURE OXIDATION; CR-AL ALLOYS; OXIDE-SCALE; REACTIVE-ELEMENT; ELECTRON-MICROSCOPY; ION-IMPLANTATION; CYCLIC OXIDATION; ALUMINA SCALES; SULFUR REMOVAL; NICRAL ALLOYS AB Microstructural observations were used as the basis for a discussion of the formation and growth of voids in alumina scales. Reactive-element additions to alloys and alloy desulfurization appear to inhibit the growth of interfacial voids, thus improving scale adhesion. This phenomenon is analyzed in terms of surface energies. In addition, a model is proposed for the formation of large internal voids in alpha-Al2O3 scales, These voids appear to be too large to form as a result of vacancy coalescence and are more frequently observed in scales not doped with a reactive element. The model is based on a growth mechanism where inward and outward growing ridges at scale grain boundaries eventually seal off and form internal voids. RP Pint, BA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 86 TC 117 Z9 122 U1 2 U2 30 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0030-770X J9 OXID MET JI Oxid. Met. PD OCT PY 1997 VL 48 IS 3-4 BP 303 EP 328 DI 10.1007/BF01670505 PG 26 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA YD179 UT WOS:A1997YD17900008 ER PT J AU Han, K Weatherly, GC AF Han, K Weatherly, GC TI Transmission electron microscopy investigation of twinning in titanium carbonitride SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID FILMS; DEPOSITION; COATINGS; LAYERS; WEAR; TIN AB The microstructure of titanium carbonitride fabricated by hot pressing titanium nitride and titanium carbide powders has been studied by transmission electron microscopy. The titanium carbonitride had a fee structure but there was no evidence of ordering of the interstitial atoms. (111)-type twinning, with a twin plane of Ti atoms, was observed in the titanium carbonitride. Incoherent twin boundaries or steps were found to connect coherent twin boundaries lying on (111). (a/6)<[11(2)over bar ]>-type dislocations were found to be associated with atomic steps at the twin boundary. The factor responsible for twinning is discussed. C1 MCMASTER UNIV,DEPT MAT SCI & ENGN,HAMILTON,ON L8S 4L7,CANADA. RP Han, K (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MAIL STOP 765,LOS ALAMOS,NM 87545, USA. NR 30 TC 6 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD OCT PY 1997 VL 76 IS 4 BP 247 EP 258 DI 10.1080/095008397178995 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA XY662 UT WOS:A1997XY66200002 ER PT J AU Yoo, MH AF Yoo, MH TI On the dislocation pole mechanism for twinning in TiAl crystals SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID INTERMETALLIC ALLOYS AB A dislocation model is proposed for twin formation in the L1(0) structure, under a compressive applied stress along the c axis, on the basis of the original pole mechanism for twinning in the fee structure. Dissociation of a jog on an ordinary [110]/2 dislocation into a Shockley and a Frank partial in TiAl is energetically favourable according to anisotropic elasticity theory. While a pileup of <[10(1)over bar ]> superdislocations assists a Shockley loop to spiral around two sessile nodes, the Frank partial expands under mechanical and chemical stresses and mitigates the high repulsive interaction between two Shockley partials. Available data on the apparent critical resolved shear stress for twinning in Ti-56 at.% Al single crystals are explained in terms of reasonable values of a local stress concentration factor and a vacancy supersaturation at elevated temperatures. RP Yoo, MH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 20 Z9 20 U1 2 U2 13 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD OCT PY 1997 VL 76 IS 4 BP 259 EP 268 DI 10.1080/095008397179002 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA XY662 UT WOS:A1997XY66200003 ER PT J AU Campbell, EP AF Campbell, EP TI Balanced editorial SO PHOTONICS SPECTRA LA English DT Letter RP Campbell, EP (reprint author), LAWRENCE LIVERMORE NATL LAB,LASER PROGRAMS,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 OCT PY 1997 VL 31 IS 10 BP 12 EP 12 PG 1 WC Optics SC Optics GA YA618 UT WOS:A1997YA61800002 ER PT J AU Batinic, M Svarc, A Lee, TSH AF Batinic, M Svarc, A Lee, TSH TI Near threshold eta production in proton-proton collisions SO PHYSICA SCRIPTA LA English DT Article ID NUCLEON NUCLEON COLLISIONS; PP->PP-ETA REACTION; MESON PRODUCTION; NEAR-THRESHOLD; SCATTERING; MODEL AB The total cross sections for the near threshold eta production in proton-proton collisions has been investigated with the assumption that the production mechanism is due to the emission of a meson chi(pi eta sigma from one of the nucleons followed by a chi N --> eta N transition on the second nucleon. The chi N --> eta N amplitudes are generated from the unitary multi-channel multiresonance model which has recently been constructed by fitting the data of pi N elastic scattering and pi N --> eta N reaction. The initial and final pp distortions are calculated from a coupled-channel pi NN model which describes the NN scattering data up to about 2 GeV. With the chi NN vertex functions taken from the Bonn potential, the predicted total cross sections of threshold pp --> eta pp reaction are in good agreement with the data. In contrast to previous works, we find that the eta-exchange plays an important role. C1 ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. RP RUDJER BOSKOVIC INST, POB 1016, ZAGREB, CROATIA. NR 19 TC 67 Z9 67 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0031-8949 EI 1402-4896 J9 PHYS SCRIPTA JI Phys. Scr. PD OCT PY 1997 VL 56 IS 4 BP 321 EP 324 DI 10.1088/0031-8949/56/4/001 PG 4 WC Physics, Multidisciplinary SC Physics GA YA117 UT WOS:A1997YA11700001 ER PT J AU Bartos, I Barbieri, A VanHove, MA Chung, WF Cai, Q Altman, MS AF Bartos, I Barbieri, A VanHove, MA Chung, WF Cai, Q Altman, MS TI Cu(111) electron band structure and channeling by VLEED SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article ID ENERGY AB Very-low-energy electron diffraction (VLEED) intensities from clean Cu(111) surface have been measured in detail in the energy range 15 to 35 eV by low-energy electron microscope. Corresponding theoretical I-V curves are obtained in good agreement with experimental data when the anisotropy of the electron attenuation is taken into account. The coincidence of the peaks in the I-V curves at normal incidence with two kinds oi energy gaps of the electron band structure of the copper crystal (E-k parallel to=0) is interpreted. The small width of the resonance peak in the I-V curve at normal incidence is explained in terms of electron surface channeling. VLEED thus provides information about the unoccupied part of the electron band structure of copper which complements that obtained from angular resolved photoemission. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. HONG KONG UNIV SCI & TECHNOL, DEPT PHYS, KOWLOON, HONG KONG. RP Bartos, I (reprint author), ACAD SCI CZECH REPUBL, INST PHYS, PRAGUE, CZECH REPUBLIC. RI Van Hove, Michel/A-9862-2008; Bartos, Igor/G-5780-2014 OI Van Hove, Michel/0000-0002-8898-6921; NR 22 TC 0 Z9 0 U1 3 U2 6 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD OCT PY 1997 VL 163 IS 2 BP 455 EP 464 DI 10.1002/1521-396X(199710)163:2<455::AID-PSSA455>3.0.CO;2-M PG 10 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA YE413 UT WOS:A1997YE41300021 ER PT J AU Shi, L Zhou, GE Feng, Y Huang, YS Fang, Y Xu, M Zhang, YH AF Shi, L Zhou, GE Feng, Y Huang, YS Fang, Y Xu, M Zhang, YH TI Temperature dependent structural change of YBa2Cu3O7-y single crystals studied by X-ray diffraction SO PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS LA English DT Article ID CERAMIC SUPERCONDUCTOR; TRANSITION; ANOMALIES; TC; BEHAVIOR AB Superconducting single crystals of YBa2Cu3O7-y were studied by X-rai diffraction over a temperature range from 297 to 77 K. Changes of profiles along a, b and c directions of the crystal were observed, respectively. It is found that the profile of the (001) diffraction has undergone dramatic changes in the temperature region from 242 to 142 Ei. Meanwhile, there is no observable change along the a and b directions of the single crystal. After the temperature of 98 K. the (007) diffraction peak obviously begins to broaden. The results indicate several minor structural changes of the YBCO lattice between room temperature and the superconducting transition. C1 NW INST NONFERROUS METAL RES, BAOJI SHANXI 721014, PEOPLES R CHINA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. CCAST, WORLD LAB, BEIJING 100080, PEOPLES R CHINA. RP Shi, L (reprint author), UNIV SCI & TECHNOL CHINA, ACAD SINICA, STRUCT RES LAB, HEFEI 230026, ANHUI, PEOPLES R CHINA. RI 张, 裕恒/H-4377-2011 NR 24 TC 0 Z9 0 U1 2 U2 7 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0370-1972 EI 1521-3951 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Solid State Phys. PD OCT PY 1997 VL 203 IS 2 BP 305 EP 311 DI 10.1002/1521-3951(199710)203:2<305::AID-PSSB305>3.0.CO;2-B PG 7 WC Physics, Condensed Matter SC Physics GA YD056 UT WOS:A1997YD05600005 ER PT J AU Leung, DW Nielsen, MA Chuang, IL Yamamoto, Y AF Leung, DW Nielsen, MA Chuang, IL Yamamoto, Y TI Approximate quantum error correction can lead to better codes SO PHYSICAL REVIEW A LA English DT Article AB We present relaxed criteria for quantum error correction that are useful when the specific dominant quantum noise process is known. As an example, we provide a four-bit code that corrects for a single amplitude damping error. This code violates the usual Hamming bound calculated for a Pauli description of the error process and has no simple explanation in terms of the usual Pauli basis GF(4) codes. C1 UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106. UNIV NEW MEXICO,CTR ADV STUDIES,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Leung, DW (reprint author), STANFORD UNIV,EDWARD L GINZTON LAB,ERATO,QUANTUM FLUCTUAT PROJECT,STANFORD,CA 94305, USA. RI Yamamoto, Yoshihisa/A-2811-2012 NR 16 TC 60 Z9 60 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2567 EP 2573 DI 10.1103/PhysRevA.56.2567 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000020 ER PT J AU Graber, T Kanter, EP Levin, J Zajfman, D Vager, Z Naaman, R AF Graber, T Kanter, EP Levin, J Zajfman, D Vager, Z Naaman, R TI Direct measurement of bending conformations in triatomic dihydride ions SO PHYSICAL REVIEW A LA English DT Article ID MOLECULAR-IONS; INFRARED-SPECTROSCOPY; PHOTOELECTRON-SPECTROSCOPY; LASER SPECTROSCOPY; ELECTRONIC STATES; IMAGING DETECTOR; COMET-KOHOUTEK; H2O+; SPECTRUM; ABINITIO AB The distributions of bond angles in the triatomic dihydride ion series CH2+, NH2+, and H2O+ have been studied using the Coulomb explosion imaging method. These distributions were measured as a function of the cooling of the internal degrees of freedom of these ions. The distribution for the coldest sample of CH2+ molecules shows the most probable structure to be bent with substantial tunneling through the linear conformation. The most probable geometry for NH2+ was found to be linear, though the angular distribution is significantly different from a shape of a 'harmonic-oscillator ground-state prediction. In the case of H2O+, we find a bent structure as expected from theory. Evidence. for a linear excited state in H2O+ is seen in the hotter distributions. Comparison to the adiabatic theoretical predictions shows good agreement with the most probable geometries. However, the measured distributions are systematically wider than the squared vibronic wave functions derived from the corresponding potential-energy surfaces. C1 ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. WEIZMANN INST SCI, DEPT PARTICLE PHYS, IL-76100 REHOVOT, ISRAEL. WEIZMANN INST SCI, DEPT CHEM PHYS, IL-76100 REHOVOT, ISRAEL. NR 55 TC 8 Z9 8 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2600 EP 2613 DI 10.1103/PhysRevA.56.2600 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000024 ER PT J AU Lidberg, J AlKhalili, A Cowan, RD Norlin, LO Royen, P Mannervik, S AF Lidberg, J AlKhalili, A Cowan, RD Norlin, LO Royen, P Mannervik, S TI Determinations of metastable lifetimes in singly charged xenon by laser probing of a stored ion beam SO PHYSICAL REVIEW A LA English DT Article ID STORAGE-RING; PRECISION-MEASUREMENT; STATE; SPECTROSCOPY AB By utilizing the long observation time provided by an ion storage ring and a laser probing technique, time-resolved studies of the 5d F-4(7/2), 5d (2)G(9/2), 5d (2)G(7/2) and 5d D-4(7/2), metastable levels about 12 eV above the round state in the Xe+ ion have been performed. Extensive studies of possible systematic effects have been carried out in order to establish accurate values for the metastable lifetimes. Values for the 5d F-4(7/2), 5d (2)G(9/2), and 5d (2)G(7/2) lifetimes (57.2 +/- 0.7, 44.7 +/- 1.1, and 3.4 +/- 1.0 ms, respectively) are presented and compared with the results of theoretical calculations. C1 UNIV STOCKHOLM,DEPT PHYS,S-11385 STOCKHOLM,SWEDEN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. ROYAL INST TECHNOL,PHYS DEPT FRESCATI,S-10405 STOCKHOLM,SWEDEN. RP Lidberg, J (reprint author), UNIV STOCKHOLM,S-10405 STOCKHOLM,SWEDEN. NR 20 TC 19 Z9 19 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2692 EP 2698 DI 10.1103/PhysRevA.56.2692 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000033 ER PT J AU Belkacem, A Gould, H Feinberg, B Bossingham, R Meyerhof, WE AF Belkacem, A Gould, H Feinberg, B Bossingham, R Meyerhof, WE TI Capture, ionization, and pair-production processes in relativistic heavy-ion collisions in the 1-GeV/nucleon energy range SO PHYSICAL REVIEW A LA English DT Article ID RADIATIVE ELECTRON-CAPTURE; K-SHELL IONIZATION; COUPLED-CHANNEL CALCULATIONS; ATOMIC-COLLISIONS; CROSS-SECTIONS; CHARGE-TRANSFER; POSITRON PAIRS; MOMENTUM-SPACE; SULFUR IONS; MULTIPLE IONIZATION AB The cross sections for capture, ionization, capture from pair production, and free pair production were measured for 0.96-GeV/nucleon U92+ and 0.405-, 0.96-, and 1.3-GeV/nucleon La57+ ions incident on Au, Ag, and Cu targets. The cross sections for capture from pair production, free pair production, ionization, and total capture (the sum of capture from pair production, radiative electron capture, and nonradiative capture) are analyzed as a function of collision energy, projectile, and target atomic numbers. We find that, when the collision energy is increased from 0.405 GeV/nucleon to 1.3 GeV/nucleon, the capture from pair production and the free pair production cross sections increase by almost a factor of 6, while the capture cross section decreases by two orders of magnitude. The ionization cross section is found to vary very weakly with the collision energy in the 1-GeV/nucleon energy range. We found a dependence of free pair production cross sections on the target and projectile atomic number to be close to Z(2), characteristic of an ionizationlike process. We also found a dependence of the capture from pair production cross sections on the target atomic number to be usually sleeper than Z(t)(2), and on the projectile atomic number, somewhat steeper than the Z(p)(5), characteristic of a capturelike process, Theory and experiment are in some disagreement for capture from pair production, and free pair production, cross sections, but are in general agreement for the other capture processes and for ionization. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. RP Belkacem, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BLDG 71-259,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 75 TC 38 Z9 38 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2806 EP 2818 DI 10.1103/PhysRevA.56.2806 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000047 ER PT J AU Stohlker, T Kramer, A Elliott, SR Marrs, RE Scofield, JH AF Stohlker, T Kramer, A Elliott, SR Marrs, RE Scofield, JH TI Measurement of L-shell electron-impact ionization cross sections for highly charged uranium ions SO PHYSICAL REVIEW A LA English DT Article ID RELATIVISTIC CALCULATIONS; HYDROGENLIKE; TRAP AB L-shell electron-impact ionization cross sections for highly charged uranium ions from fluorinelike U83+ through lithiumlike U89+ have been measured at 45-, 60-, and 75-keV electron energy. The cross sections were obtained from x-ray measurements of the equilibrium ionization balance in an electron beam ion trap. The measured cross sections agree with recent relativistic distorted wave calculations. C1 GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Stohlker, T (reprint author), UNIV FRANKFURT,D-60486 FRANKFURT,GERMANY. NR 15 TC 11 Z9 12 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2819 EP 2824 DI 10.1103/PhysRevA.56.2819 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000048 ER PT J AU Rescigno, TN Orel, AE McCurdy, CW AF Rescigno, TN Orel, AE McCurdy, CW TI Low-energy electron scattering from CH3Cl SO PHYSICAL REVIEW A LA English DT Article ID EFFECTIVE POTENTIAL METHODS; VARIATIONAL TREATMENTS; MOLECULAR CALCULATIONS; COLLISION PROCESSES; ABINITIO; ATTACHMENT; SCHWINGER; CHLORINE; METHANE AB The complex Kohn variational method is used to study low-energy electron collision processes involving CH3Cl. The elastic differential and momentum transfer cross sections are studied from low electron energy (0.5 eV) through the resonance region (3.5 eV) to 10 eV. The effects of target correlation and polarization are studied. A comparison is made between the results of this study and experimental results available for this system. C1 UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94550. LAWRENCE BERKELEY LAB,NATL ENERGY RES SCI COMP CTR,BERKELEY,CA 94720. RP Rescigno, TN (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA 94550, USA. NR 26 TC 18 Z9 18 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2855 EP 2859 DI 10.1103/PhysRevA.56.2855 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000052 ER PT J AU Ovchinnikov, SY Macek, JH Khrebtukov, DB AF Ovchinnikov, SY Macek, JH Khrebtukov, DB TI Theory of ionization in ion-atom collisions: Spectra of ejected electrons SO PHYSICAL REVIEW A LA English DT Article ID SADDLE-POINT ELECTRONS; ANGULAR-DISTRIBUTION; STURMIAN EXPANSION; GREEN-FUNCTION; TRANSITIONS; HYDROGEN AB A Galilean invariant theory of atomic collisions is constructed for straight-line trajectories of nuclei with arbitrary impact parameters, The theory is based on Sturmian expansions in Fourier space, and provides an exact description of excitation and ionization processes for a wide range of collision velocities. Advantages of Sturmian sets over conventional eigenstates are emphasized. Detailed spectra of electrons ejected in head-on ion-atom collisions are calculated. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. AF IOFFE PHYS TECH INST,ST PETERSBURG 194021,RUSSIA. RP Ovchinnikov, SY (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Ovchinnikov, Serguei/C-4994-2014 NR 31 TC 17 Z9 17 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 2872 EP 2886 DI 10.1103/PhysRevA.56.2872 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000055 ER PT J AU Nilsen, J Zhang, J MacPhee, AG Lin, J Barbee, TW Danson, C DaSilva, LB Key, MH Lewis, CLS Neely, D ORourke, RMN Pert, GJ Smith, R Tallents, GJ Wark, JS Wolfrum, E AF Nilsen, J Zhang, J MacPhee, AG Lin, J Barbee, TW Danson, C DaSilva, LB Key, MH Lewis, CLS Neely, D ORourke, RMN Pert, GJ Smith, R Tallents, GJ Wark, JS Wolfrum, E TI Near-field spatial imaging of a Ni-like Ag 140-angstrom x-ray laser SO PHYSICAL REVIEW A LA English DT Article ID 7.9 NM AB We measure the two-dimensional, near-field spatial distribution of a 140-Angstrom nickel-like silver x-ray laser at the output aperture with high magnification using a curved multilayer x-ray mirror to image the output onto an x-ray charge-coupled device camera. Lasing is created by illuminating silver slab targets with a pair of 75 ps laser pulses separated by 2.2 nsec from the Vulcan laser. The two-dimensional, high-resolution, spatial image shows the x-ray laser source size and its position relative to the target surface. A dramatic change in both the position and source size are observed for the refraction compensating curved target as compared with the flat targets. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. QUEENS UNIV BELFAST,SCH MATH & PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. UNIV YORK,DEPT COMPUTAT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. RUTHERFORD APPLETON LAB,CENT LASER FACIL,CHILTON OX11 0QX,OXON,ENGLAND. RP Nilsen, J (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Zhang, Jie/O-8767-2014 NR 12 TC 21 Z9 23 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 3161 EP 3165 DI 10.1103/PhysRevA.56.3161 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000089 ER PT J AU Fan, XD Wang, HL Hou, HQ Hammons, BE AF Fan, XD Wang, HL Hou, HQ Hammons, BE TI Laser emission from semiconductor microcavities: The role of cavity polaritons SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM-WELL STRUCTURES; EXCITON; PHOTOLUMINESCENCE; OSCILLATIONS; DYNAMICS; REGIME AB We present an experimental study on the role of cavity polaritons in laser emissions from a GaAs quantum-well microcavity. We show that cavity polaritons play no role in the laser emission process when the cavity is nearly resonant with the excitons. The laser emissions emerge from the bare cavity mode instead of from a cavity-polariton branch and the threshold density is much higher than the saturation density at which cavity polaritons vanish. We also show that the presence of emission doublers near the lasing threshold, which was previously taken as an evidence for laser emission from cavity polaritons, is primarily the result of spatial and/or temporal variations of exciton densities within the excitation volume. C1 UNIV OREGON,OREGON CTR OPT,EUGENE,OR 97403. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Fan, XD (reprint author), UNIV OREGON,DEPT PHYS,EUGENE,OR 97403, USA. RI Wang, Hailin/A-2362-2011 NR 16 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 1997 VL 56 IS 4 BP 3233 EP 3236 DI 10.1103/PhysRevA.56.3233 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YA780 UT WOS:A1997YA78000098 ER PT J AU Quong, AA Liu, AY AF Quong, AA Liu, AY TI First-principles calculations of the thermal expansion of metals SO PHYSICAL REVIEW B LA English DT Article ID THERMODYNAMIC PROPERTIES; TRANSITION-METALS; FREE-ENERGY; SEMICONDUCTORS; DIAMOND; PSEUDOPOTENTIALS; CONSTANTS; DYNAMICS; ALUMINUM; SOLIDS AB We present first-principles calculations of the thermal expansion of several simple metals (Al, Li, and Na) within the quasiharmonic approximation. Linear-response theory is used to determine the volume-dependent phonon frequencies within the density-functional framework. Our results indicate that the treatment of anharmonic effects at the quasiharmonic level provides a remarkably good description of the structural and elastic properties of these materials up to their melting points. C1 GEORGETOWN UNIV,DEPT PHYS,WASHINGTON,DC 20057. RP Quong, AA (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. RI Liu, Amy/E-2266-2015 OI Liu, Amy/0000-0002-2011-1854 NR 28 TC 80 Z9 83 U1 3 U2 23 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 OCT 1 PY 1997 VL 56 IS 13 BP 7767 EP 7770 DI 10.1103/PhysRevB.56.7767 PG 4 WC Physics, Condensed Matter SC Physics GA YD866 UT WOS:A1997YD86600005 ER PT J AU Pettit, K Gider, S Parkin, SSP Salamon, MB AF Pettit, K Gider, S Parkin, SSP Salamon, MB TI Strong biquadratic coupling and antiferromagnetic-ferromagnetic crossover in NiFe/Cu multilayers SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC MULTILAYERS; FE/CR(001) SUPERLATTICES; EXCHANGE; LAYERS; MECHANISM; TRILAYERS; MODEL AB We report clear manifestations of biquadratic exchange in the magnetoresistance (MR) of (110) single-crystal NiFe/Cu multilayers. Magnetoresistance curves show a low-field MR minimum which results from an asymmetric canting of the moments away from the applied magnetic field. The stability of these magnetic configurations indicates that the biquadratic coupling can be significantly stronger than the bilinear coupling. In samples with ferromagnetic (F) bilinear coupling the strength of both the bilinear and biquadratic coupling decays in the temperature range from 200 to 400 K. In samples that are coupled antiferromagnetically (AF) at room temperature, we observe a crossover from AF to F bilinear coupling as the temperature is lowered below 200 K. We attribute the strong biquadratic coupling and temperature dependence of the bilinear coupling to pinholes in the Cu spacer layers. C1 IBM CORP,ALMADEN RES CTR,DIV RES,SAN JOSE,CA 95120. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. RP Pettit, K (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. RI Parkin, Stuart/D-2521-2012 NR 24 TC 20 Z9 20 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 1997 VL 56 IS 13 BP 7819 EP 7822 DI 10.1103/PhysRevB.56.7819 PG 4 WC Physics, Condensed Matter SC Physics GA YD866 UT WOS:A1997YD86600019 ER PT J AU Detlefs, C Islam, AHMZ Gu, T Goldman, AI Stassis, C Canfield, PC Hill, JP Vogt, T AF Detlefs, C Islam, AHMZ Gu, T Goldman, AI Stassis, C Canfield, PC Hill, JP Vogt, T TI Magnetoelastic tetragonal-to-orthorhombic distortion in ErNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID OSCILLATORY MAGNETIC ORDER; NEUTRON POWDER DIFFRACTION; SUPERCONDUCTOR HONI2B2C; BORIDE CARBIDE; CRYSTAL; LUNI2B2C; COEXISTENCE; LNNI2B2C; STATE AB We have performed synchrotron x-ray scattering experiments on single crystals of ErNi2B2C. Below 6.3 K, the (2,0,0) Bragg peak splits, indicating a tetragonal-to-orthorhombic distortion. The mismatch between the a and b lattice parameters appears coincident with the onset of long-range antiferromagnetic order and increases continuously with decreasing temperature, reaching a value of a/b-1 approximate to 0.2% at 3.7 K. C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Detlefs, C (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. RI Detlefs, Carsten/B-6244-2008; Vogt, Thomas /A-1562-2011; Canfield, Paul/H-2698-2014 OI Detlefs, Carsten/0000-0003-2573-2286; Vogt, Thomas /0000-0002-4731-2787; NR 35 TC 46 Z9 46 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 OCT 1 PY 1997 VL 56 IS 13 BP 7843 EP 7846 DI 10.1103/PhysRevB.56.7843 PG 4 WC Physics, Condensed Matter SC Physics GA YD866 UT WOS:A1997YD86600025 ER PT J AU Adrian, SD Wolf, SA Dolgov, O Shulga, S Kresin, VZ AF Adrian, SD Wolf, SA Dolgov, O Shulga, S Kresin, VZ TI Density of states and the energy gap in superconducting cuprates SO PHYSICAL REVIEW B LA English DT Article ID PENETRATION DEPTH; SINGLE-CRYSTALS; CONVENTIONAL MULTILAYERS; LAYERED SUPERCONDUCTORS; TUNNELING SPECTROSCOPY; 2-GAP STRUCTURE; POINT-CONTACT; TL2BA2CUO6+DELTA; HGBA2CUO4+DELTA; YBA2CU3O7-DELTA AB The superconducting density of states for the cuprates, particularly for the Y-Ba-Cu-O compound, has been evaluated, add its dependence on temperature and the oxygen content has been analyzed. The analysis is based on the two-gap model. Moreover, the magnetic scattering and corresponding pair-breaking effect, correlated with the oxygen depletion, is taken into account as a key factor. The temperature dependencies of the energy gaps are calculated. Intensive magnetic scattering leads to gaplessness. The calculation allows us to describe various experimental data. C1 PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. RUSSIAN ACAD SCI,INST SPECT,TROITSK 142092,RUSSIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Adrian, SD (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Wolf, Stuart/A-7513-2009 NR 29 TC 18 Z9 18 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 1997 VL 56 IS 13 BP 7878 EP 7881 DI 10.1103/PhysRevB.56.7878 PG 4 WC Physics, Condensed Matter SC Physics GA YD866 UT WOS:A1997YD86600034 ER EF