FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Okrasinski, JR Repond, J Stanek, R Talaga, RL Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Bruni, P Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Crittenden, J Deffner, R Eckert, M Feld, L Frey, A Geerts, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Mengel, S Paul, E Pfeiffer, M Rembser, C Schramm, D Stamm, J Wedemeyer, R CampbellRobson, S Cassidy, A Cottingham, WN Dyce, N Foster, B George, S Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Yoshida, R Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sciulli, F Straub, PB Wai, L Yang, S Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Flasinski, M Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Joos, P Kasemann, M Klanner, R Koch, W Kotz, U Kowalski, H Labs, J Ladage, A Lohr, B Lowe, M Luke, D Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Piotrzkowski, K Roco, M Rohde, M Roldan, J Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zeuner, W Grabosch, HJ Mari, SM Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G DePasquale, S Votano, L Bamberger, A Eisenhardt, S Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Dannemann, A Holm, U Horstmann, D Sinkus, R Wick, K Burow, BD Hagge, L Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Brummer, N Butterworth, I Harris, VL Howell, G Hung, BHU Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, MZ Wang, SM Wu, JT Cloth, P Filges, D An, SH Cho, GH Ko, BJ Lee, SB Nam, SW Park, HS Park, SK Kartik, S Kim, HJ McNeil, RR Metcalf, W Nadendla, VK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Matthews, CG Murray, WN Ochs, A Patel, PM Riveline, M Stairs, DG StLaurent, M Ullmann, R Zacek, G Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Gladilin, LK Golubkov, YA Kobrin, VD Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Savin, AA Shcheglova, LM Solomin, AN Zotov, NP Botje, M Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E vanWoudenberg, R Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Li, C Ling, TY Nylander, P Park, IH Romanowski, TA Bailey, DS Cashmore, RJ CooperSarkar, AM Devenish, RCE Harnew, N Lancaster, M Lindemann, L McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Wilson, FF Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F DeGiorgi, M Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Zuin, F Bulmahn, J Feild, RG Oh, BY Whitmore, JJ DAgostini, G Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Biltzinger, J Seifert, RJ Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Levy, A Fleck, JI Inuzuka, M Ishii, T Kuze, M Mine, S Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Chiba, M Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Peroni, C Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Benard, F Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Bogusz, W Ciborowski, J Gajewski, J Grzelak, G Kasprzak, M Krzyzanowski, M Muchorowski, K Nowak, RJ Pawlak, JM Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Breitweg, J Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Silverstein, S Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Cardy, ML Frisken, WR Khakzad, M Schmidke, WB AF Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Okrasinski, JR Repond, J Stanek, R Talaga, RL Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Bruni, P Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Crittenden, J Deffner, R Eckert, M Feld, L Frey, A Geerts, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Mengel, S Paul, E Pfeiffer, M Rembser, C Schramm, D Stamm, J Wedemeyer, R CampbellRobson, S Cassidy, A Cottingham, WN Dyce, N Foster, B George, S Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Yoshida, R Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sciulli, F Straub, PB Wai, L Yang, S Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Flasinski, M Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Joos, P Kasemann, M Klanner, R Koch, W Kotz, U Kowalski, H Labs, J Ladage, A Lohr, B Lowe, M Luke, D Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Piotrzkowski, K Roco, M Rohde, M Roldan, J Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zeuner, W Grabosch, HJ Mari, SM Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G DePasquale, S Votano, L Bamberger, A Eisenhardt, S Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Dannemann, A Holm, U Horstmann, D Sinkus, R Wick, K Burow, BD Hagge, L Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Brummer, N Butterworth, I Harris, VL Howell, G Hung, BHU Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, MZ Wang, SM Wu, JT Cloth, P Filges, D An, SH Cho, GH Ko, BJ Lee, SB Nam, SW Park, HS Park, SK Kartik, S Kim, HJ McNeil, RR Metcalf, W Nadendla, VK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Matthews, CG Murray, WN Ochs, A Patel, PM Riveline, M Stairs, DG StLaurent, M Ullmann, R Zacek, G Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Gladilin, LK Golubkov, YA Kobrin, VD Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Savin, AA Shcheglova, LM Solomin, AN Zotov, NP Botje, M Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E vanWoudenberg, R Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Li, C Ling, TY Nylander, P Park, IH Romanowski, TA Bailey, DS Cashmore, RJ CooperSarkar, AM Devenish, RCE Harnew, N Lancaster, M Lindemann, L McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Wilson, FF Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F DeGiorgi, M Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Zuin, F Bulmahn, J Feild, RG Oh, BY Whitmore, JJ DAgostini, G Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Biltzinger, J Seifert, RJ Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Levy, A Fleck, JI Inuzuka, M Ishii, T Kuze, M Mine, S Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Chiba, M Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Peroni, C Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Benard, F Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Bogusz, W Ciborowski, J Gajewski, J Grzelak, G Kasprzak, M Krzyzanowski, M Muchorowski, K Nowak, RJ Pawlak, JM Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Breitweg, J Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Silverstein, S Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Cardy, ML Frisken, WR Khakzad, M Schmidke, WB TI Measurement of elastic omega photoproduction at HERA SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID HIGH-ENERGY PHOTOPRODUCTION; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; LUND MONTE-CARLO; CONSTRUCTION; DESIGN; HYDROGEN; PHOTON AB Elastic photoproduction of vector mesons, gamma p --> Vp, has been extensively studied in fixed target experiments at centre-of-mass energies up to W approximate to 20 GeV. The production of rho(0), omega and phi is usually described in the framework of the vector meson dominance model (VDM) [1] and Regge theory [2]. The W dependence of the cross section can be parametrised in Regge theory by the sum of two terms, one due to Pomeron exchange and the other to Reggeon exchange, While the latter falls with W, the former is almost flat, Whereas rho(0) and phi production is predominantly due to Pomeron exchange at all energies, the energy behaviour of omega production investigated before HERA suggests a non-negligible contribution from Reggeon exchange. It is therefore of interest to analyse omega photoproduction at HERA, where Pomeron exchange should dominate. More specifically, it is important to establish if the features typical of elastic rho(0) and phi vector meson production are also observed in omega photoproduction at high energy. Among these features are the weak dependence of the elastic cross section on W, the exponential shape of the differential cross section in t, where t is the squared four momentum transferred at the proton vertex, and the observation that the vector meson retains the helicity of the photon (s-channel helicity conservation, SCHC), In addition, a comparison of the photoproduction cross sections of the light vector mesons rho(0) [3, 4], omega and phi [5] at HERA energies allows another check of their diffractive production mechanism. This paper reports a measurement of the photoproduction of omega mesons using the reaction ep --> e omega p with the ZEUS detector at HERA. The omega meson is observed via its decay into pi(+)pi(-)pi(0)(pi(0) --> gamma gamma) in the kinematic range 70 < W < 90 GeV and p(T)(2) < 0.6 GeV2, where p(T) is the transverse momentum of the omega with respect to the beam axis. For these events the scattered positron was not observed in the detector, thereby restricting the photon virtuality Q(2) to values smaller than 4 GeV2, with a median Q(2) of about 10(-4) GeV2. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI 49104 USA. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-53115 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL BS8 1TL, AVON, ENGLAND. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. IST NAZL FIS NUCL, I-87036 COSENZA, ITALY. COLUMBIA UNIV, NEVIS LABS, IRVINGTON, NY 10533 USA. INST NUCL PHYS, PL-30059 KRAKOW 16, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECH, KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, KRAKOW, POLAND. DESY, D-22607 HAMBURG, GERMANY. DESY, IFH ZEUTHEN, D-15738 ZEUTHEN, GERMANY. UNIV FLORENCE, FLORENCE, ITALY. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV FREIBURG, FAK PHYS, D-79014 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 2, D-22761 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. FORSCHUNGSZENTRUM JULICH, INST KERNPHYS, D-52405 JULICH, GERMANY. KOREA UNIV, SEOUL 136701, SOUTH KOREA. LOUISIANA STATE UNIV, DEPT PHYS & ASTRON, BATON ROUGE, LA 70803 USA. UNIV AUTONOMA MADRID, DEPT FIS TEOR, E-28049 MADRID, SPAIN. MCGILL UNIV, DEPT PHYS, MONTREAL, PQ, CANADA. MEIJI GAKUIN UNIV, FAC GEN EDUC, YOKOHAMA, KANAGAWA, JAPAN. MOSCOW ENGN PHYS INST, MOSCOW, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW, RUSSIA. NIKHEF H, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1012 WX AMSTERDAM, NETHERLANDS. OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. UNIV OXFORD, DEPT PHYS, OXFORD, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, I-35131 PADUA, ITALY. IST NAZL FIS NUCL, I-35131 PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-5900 SIEGEN, GERMANY. TEL AVIV UNIV, SACKLER FAC EXACT SCI, SCH PHYS, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, INST NUCL STUDY, TOKYO, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, TURIN, ITALY. IST NAZL FIS NUCL, I-10125 TURIN, ITALY. UNIV TURIN, FAC SCI 2, ALESSANDRIA, ITALY. IST NAZL FIS NUCL, ALESSANDRIA, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON M5S 1A1, CANADA. UCL, DEPT PHYS & ASTRON, LONDON, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPT PHYS, WARSAW, POLAND. INST NUCL STUDIES, PL-00681 WARSAW, POLAND. WEIZMANN INST SCI, DEPT NUCL PHYS, IL-76100 REHOVOT, ISRAEL. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. YORK UNIV, DEPT PHYS, N YORK, ON M3J 1P3, CANADA. CNR, IROE, I-50127 FLORENCE, ITALY. RP Derrick, M (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Morandin, Mauro/A-3308-2016; Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; OI De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Gladilin, Leonid/0000-0001-9422-8636; Morandin, Mauro/0000-0003-4708-4240; Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525; Lancaster, Mark/0000-0002-8872-7292; Martinez Rodriguez, Manel/0000-0002-9763-9155; Chwastowski, Janusz/0000-0002-6190-8376 NR 43 TC 63 Z9 63 U1 0 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD DEC PY 1996 VL 73 IS 1 BP 73 EP 84 DI 10.1007/s002880050297 PG 12 WC Physics, Particles & Fields SC Physics GA WJ473 UT WOS:A1996WJ47300005 ER PT J AU Campbell, G Deng, YF Glimm, J Wang, YA Yu, QQ Eisenberg, M Grollman, A AF Campbell, G Deng, YF Glimm, J Wang, YA Yu, QQ Eisenberg, M Grollman, A TI Analysis and prediction of hydrogen bonding in protein-DNA complexes using parallel processors SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article ID B-DNA; CRYSTAL-STRUCTURE; RECOGNITION; BINDING AB A number of essential biological functions are controlled by proteins that bind to specific sequences in genomic DNA. In this article we present a simplified model for analyzing DNA-protein interactions mediated exclusively by hydrogen bonds. Based on this model, an optimized algorithm for geometric pattern recognition was developed. The large number of local energy minima are efficiently screened by using a geometric approach to pattern matching based on a square-well potential. The second part of the algorithm represents a closed form solution for minimization based on a quadratic potential. A Monte Carlo method applied to a modified Lennard-Jones potential is used as a third step to rank DNA sequences in terms of pattern matching. Using protein structures derived from four DNA-protein complexes with three-dimensional coordinates established by X-ray diffraction analysis, all possible DNA sequences to which these proteins could bind were ranked in terms of binding energies. The algorithm predicts the correct DNA sequence when at least two hydrogen bonds per base pair are involved in binding to the protein, providing a partial solution to the three-dimensional docking problem. This study laps a framework for future refinements of the algorithm in which the number of assumptions made in the present analysis are reduced. (C) 1996 by John Wiley & Sons, Inc. C1 SUNY STONY BROOK,DEPT PHARMACOL SCI,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT APPL MATH & STAT,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,UPTON,NY 11973. OI Deng, Yuefan/0000-0002-5224-3958 NR 25 TC 2 Z9 2 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD NOV 30 PY 1996 VL 17 IS 15 BP 1712 EP 1725 DI 10.1002/(SICI)1096-987X(19961130)17:15<1712::AID-JCC3>3.0.CO;2-S PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA VP856 UT WOS:A1996VP85600003 ER PT J AU Song, SG Ryba, ER Gray, GT AF Song, SG Ryba, ER Gray, GT TI Orientation relationship and partial lattice match between the decagonal Al-Co-Cu phase and a (CsCl) crystalline Al-Co(Cu) phase SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE crystalline phase; high resolution electron microscopy; X-ray diffraction ID QUASI-CRYSTALLINE; ALLOYS; APPROXIMANTS; AL65CU20CO15 AB A new Al-Co(Cu) cubic phase has been observed to coexist with the decagonal Al-Co-Cu phase in Al65Co15Cu20 alloy. A well-defined orientation relationship is present between the two phases. Partial lattice and atomic match between the two phases, which are a result of the orientation relationship, is presented and discussed. C1 PENN STATE UNIV,DEPT MAT SCI & ENGN,UNIVERSITY PK,PA 16802. RP Song, SG (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 16 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 30 PY 1996 VL 219 IS 1-2 BP 66 EP 70 DI 10.1016/S0921-5093(96)10420-2 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VZ229 UT WOS:A1996VZ22900009 ER PT J AU Wereszczak, AA Liu, E Heng, V Kirkland, TP Ferber, MK AF Wereszczak, AA Liu, E Heng, V Kirkland, TP Ferber, MK TI The high temperature compressive strength of non-oxide ceramic foams SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Letter DE ceramic foams; chemical vapor infiltration; pyrolytic carbon ID MECHANICAL-BEHAVIOR; CELLULAR MATERIALS AB The compression strengths of five coated vitreous carbon foams under development were measured at 25, 1000, 1200 and 1400 degrees C. Only qualitative trends in the measured strengths were obtainable due to a numerical lack of specimens. One developmental foam was a pyrolytic carbon (PC)-coated reticulated vitreous carbon (RVC) foam, and it was tested in argon at the three elevated temperatures. Four developmental RVC foams had chemical vapor infiltration (CVI)-SiC coatings on them, each with different coating thicknesses and consequential different bulk densities; these SIC-RVC foams were tested in ambient air at the elevated temperatures. The strength of the PC-RVC foam was independent of temperature up to 1400 degrees C in argon. The compressive strengths of the SiC-RVC foams having the two thinnest coatings (or the two smallest bulk densities) were equivalent in ambient air to those of the PC-RVC foam in argon up to 1400 degrees C, while the SiC-RVC foams having the two thickest coatings (or the two greatest bulk densities) were consistently stronger. These results show thin-SiC layered SiC-RVC foams grant oxidation protection that PC-RVC foams do not possess to 1400 degrees C, and that thicker SiC layers on SiC-RVC: foams are required for added strength. C1 ULTRAMET INC,PACOIMA,CA 91331. 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 6 TC 6 Z9 6 U1 0 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 30 PY 1996 VL 219 IS 1-2 BP 224 EP 228 DI 10.1016/S0921-5093(96)10482-2 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VZ229 UT WOS:A1996VZ22900027 ER PT J AU Lu, HL Sommer, WF Borden, MJ Tesmer, JR Wu, XD AF Lu, HL Sommer, WF Borden, MJ Tesmer, JR Wu, XD TI The microstructure and properties of a buried AlN layer produced by nitrogen implantation into pure aluminum SO THIN SOLID FILMS LA English DT Article DE ion implantation; aluminium nitride; X-ray diffraction; Rutherford backscattering spectroscopy ID ION-IMPLANTATION; NITRIDE FILMS; BEAM AB A buried aluminum nitride (AlN) layer was formed by nitrogen ion implantation into pure aluminum with doses of 10, 18 and 28 x 10(17) N+ cm(-2) at 200 keV, In order to analyze the profile of the implanted nitrogen in aluminum, 3.5 MeV He-4(+) backscattering was used, in preference to 2.0 Mev(4)He(+) backscattering. A rectangular-like profile of the implanted nitrogen was obtained from the Rutherford backscattering spectra after the dose of 10 x 10(17) N+ cm(-2). The nitrogen to aluminum ratio at the rectangular like profile is about 0.9-1.0. The results of X-ray diffraction and transmission electron diffraction indicated that aluminum nitride structure is essentially the hexagonal crystal. Aluminum nitride with f.c.c. structure also appeared on nitrogen implantation into aluminum. This is a transient structure. The resistivity of AlN formed by nitrogen implantation into aluminum is about (1.4-2.0) x 10(12) Ohm cm. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,SUPERCONDUCT TECHNOL CTR,LOS ALAMOS,NM 87545. RP Lu, HL (reprint author), LOS ALAMOS NATL LAB,MEDIUM ENERGY PHYS DIV,POB 1663,LOS ALAMOS,NM 87545, USA. NR 22 TC 10 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV 30 PY 1996 VL 289 IS 1-2 BP 17 EP 21 DI 10.1016/S0040-6090(96)08872-4 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WB265 UT WOS:A1996WB26500004 ER PT J AU Sugama, T DuVall, JE AF Sugama, T DuVall, JE TI Polyorganosiloxane-grafted potato starch coatings for protecting aluminum from corrosion SO THIN SOLID FILMS LA English DT Article DE polyorganosiloxane; potato starch; coating; aluminum ID POLYMETALLOSILOXANE COATINGS; POLYMERIZATION AB Polyorganosiloxane (POS) grafted polysaccharide copolymers were synthesized through a heat-catalyzed dehydrating condensation reaction between the hydrolysates of potato starch (PS) as source of polysaccharide and N-[3-(triethoxysily)propyl]-4,5,-dihydroimidazole (TSPI) as the antimicrobial agent and source of the graft-forming POS at 200 degrees C in air. The grafting of POS onto PS followed by the opening of glycosidic rings significantly improved the thermal and hydrophobic characteristics of PS. The degree of wettability of Al surfaces by PS solution increased as the TSPI hydrolysate was incorporated into PS, thereby fabricating a thin uniform solid film over the Al substrate suitable for the protection of Al against corrosion. Consequently, the POS-grafted PS coatings derived from the precursor solution with a [PS]/[TSPI] ratio of 90/10 conferred an impedance of greater than 10(5) Ohm cm(2) and salt-spray resistance of 288 h. C1 GREEN VALLEY HIGH SCH,HENDERSON,NV 89014. RP Sugama, T (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,ENERGY EFFICIENCY & CONSERVAT DIV,UPTON,NY 11973, USA. NR 23 TC 21 Z9 21 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV 30 PY 1996 VL 289 IS 1-2 BP 39 EP 48 DI 10.1016/S0040-6090(96)08814-1 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WB265 UT WOS:A1996WB26500008 ER PT J AU Lydeard, C Mulvey, M Davis, GM AF Lydeard, C Mulvey, M Davis, GM TI Molecular systematics and evolution of reproductive traits of North American freshwater unionacean mussels (Mollusca: Bivalvia) as inferred from 16S rRNA gene sequences SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article ID MITOCHONDRIAL-DNA; RIBOSOMAL-RNA; PHYLOGENETIC ANALYSIS; UNIONIDAE BIVALVIA; UNITED-STATES; ORGANIZATION; DROSOPHILA; CONFIDENCE AB North American freshwater unionacean bivalves are a diverse group of nearly 300 species. Unionaceans exhibit an array of conchological, anatomical, life history, and reproductive characteristics that have figured prominently in proposed classification schemes. Recently, two very different classifications of North American unionaceans have been proposed. Depending on the classification system utilized, a very different evolutionary trajectory of anatomical and reproductive features is obtained. The lack of a robust, well corroborated phylogeny of North American unionacean bivalves hinders the progress of evolutionary and ecological studies involving these species. Here we present a mitochondrial DNA (mtDNA) based phylogeny for North American unionacean mussels and compare it to previously proposed classifications. In addition, we present a 'total evidence' phylogeny which incorporates both the mtDNA sequence data and available morphological data. The molecular and total evidence phylogenies agree largely with the conclusions of a previous study based largely on immunoelectrophoretic data. North American unionaceans can be divided into two families: the Unionidae, which is comprised of most of the species and the Margaritiferidae. Within the Unionidae are two subfamilies, the Anodontinae and Ambleminae. The resultant phylogeny was used to examine the evolution of several key anatomical features including the number of gills (demibranchs) used by females to brood developing embryos, incubation length (bradytictic vs tachytictic), larval (glochidial) tooth structures? and shell texture. Both molecular and total evidence phylogenies indicate several of the aforementioned characters evolved independently or were subsequently lost or gained in several lineages. C1 SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. ACAD NAT SCI PHILADELPHIA, PHILADELPHIA, PA 19103 USA. RP Lydeard, C (reprint author), UNIV ALABAMA, DEPT SCI BIOL, AQUAT BIOL PROGRAM, TUSCALOOSA, AL 35487 USA. NR 56 TC 83 Z9 90 U1 0 U2 8 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 EI 1471-2970 J9 PHILOS T R SOC B JI Philos. Trans. R. Soc. B-Biol. Sci. PD NOV 29 PY 1996 VL 351 IS 1347 BP 1593 EP 1603 DI 10.1098/rstb.1996.0143 PG 11 WC Biology SC Life Sciences & Biomedicine - Other Topics GA VW579 UT WOS:A1996VW57900005 PM 9053909 ER PT J AU Zook, HA Grun, E Baguhl, M Hamilton, DP Linkert, G Liou, JC Forsyth, R Phillips, JL AF Zook, HA Grun, E Baguhl, M Hamilton, DP Linkert, G Liou, JC Forsyth, R Phillips, JL TI Solar wind magnetic field bending of Jovian dust trajectories SO SCIENCE LA English DT Article ID JUPITER; EJECTION; GALILEO AB From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by solar wind magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach directions, show that stream-associated dust grain masses are of the order of 10(-18) gram and dust grain velocities exceed 200 kilometers per second. These masses and velocities are, respectively, about 10(3) times less massive and 5 to 10 times faster than earlier reported. C1 MAX PLANCK INST KERNPHYS,D-69029 HEIDELBERG,GERMANY. UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Zook, HA (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,HOUSTON,TX 77058, USA. NR 14 TC 64 Z9 64 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 29 PY 1996 VL 274 IS 5292 BP 1501 EP 1503 DI 10.1126/science.274.5292.1501 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV775 UT WOS:A1996VV77500040 PM 8929405 ER PT J AU Kaiser, RI Ochsenfeld, C HeadGordon, M Lee, YT Suits, AG AF Kaiser, RI Ochsenfeld, C HeadGordon, M Lee, YT Suits, AG TI A combined experimental and theoretical study on the formation of interstellar C3H isomers SO SCIENCE LA English DT Article ID NEUTRAL-NEUTRAL REACTIONS; GAUSSIAN-BASIS SETS; ATOMIC CARBON; MOLECULES; CLOUDS; CHEMISTRY; IRC+10216; ENVELOPE; RATES; BEAM AB The reaction of ground-state carbon atoms with acetylene was studied under single-collision conditions in crossed beam experiments to investigate the chemical dynamics of forming cyclic and linear C3H isomers (c-C3H and l-C3H, respectively) in interstellar environments via an atom-neutral reaction. Combined state-of-the-art ab initio calculations and experimental identification of the carbon-hydrogen exchange channel to both isomers classify this reaction as an important alternative to ion-molecule encounters to synthesize C3H radicals in the interstellar medium. These findings strongly correlate with astronomical observations and explain a higher [c-C3H]/[l-C3H] ratio in the dark cloud TMC-1 than in the carbon star IRC+10216. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RI Lee, Yuan-Tseh/F-7914-2012; Ochsenfeld, Christian/E-8021-2015 OI Ochsenfeld, Christian/0000-0002-4189-6558 NR 32 TC 137 Z9 137 U1 2 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD NOV 29 PY 1996 VL 274 IS 5292 BP 1508 EP 1511 DI 10.1126/science.274.5292.1508 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV775 UT WOS:A1996VV77500042 PM 8929407 ER PT J AU Caldeira, K AF Caldeira, K TI Late Permian extinctions SO SCIENCE LA English DT Article RP Caldeira, K (reprint author), LAWRENCE LIVERMORE NATL LAB,CLIMATE SYST MODELING GRP,7000 EAST AVE,L-256,LIVERMORE,CA 94550, USA. RI Caldeira, Ken/E-7914-2011 NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 29 PY 1996 VL 274 IS 5292 BP 1550 EP 1551 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV775 UT WOS:A1996VV77500058 ER PT J AU Caldarelli, S Hong, M Emsley, L Pines, A AF Caldarelli, S Hong, M Emsley, L Pines, A TI Measurement of carbon-proton dipolar couplings in liquid crystals by local dipolar field NMR spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID C-13 NMR; MAGIC-ANGLE; SPECTRA; SOLIDS AB The performance of several different two-dimensional NMR methods for the measurement of carbon-proton dipolar couplings in liquid crystalline phases is analyzed. Proton-detected local field spectroscopy allows the measurements of short range C-H couplings, which correspond to directly bond pairs, by direct inspection of the spectra. Off magic angle (OMAS) spinning techniques can be applied to anisotropic phases that can be oriented mechanically at an angle to the magnetic field, such as nematic phases. The consequent scaling of the chemical shift anisotropy and dipolar couplings can be used to resolve otherwise overlapping resonances, Moreover, an estimate of the accuracy of the technique can be achieved by performing a series of OMAS experiments with different sample orientations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP Caldarelli, S (reprint author), ECOLE NORMALE SUPER LYON,ENS,LAB STEREOCHIM & INTERACT MOL,CNRS,UMR 117,F-69364 LYON,FRANCE. RI Emsley, Lyndon/C-6108-2008; Caldarelli, Stefano/B-2750-2017 OI Emsley, Lyndon/0000-0003-1360-2572; Caldarelli, Stefano/0000-0001-9008-9392 NR 31 TC 66 Z9 66 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 28 PY 1996 VL 100 IS 48 BP 18696 EP 18701 DI 10.1021/jp962023z PG 6 WC Chemistry, Physical SC Chemistry GA VV354 UT WOS:A1996VV35400008 ER PT J AU deBrouckere, G Feller, D AF deBrouckere, G Feller, D TI Configuration-interaction calculations of miscellaneous properties of the CP and CP- molecules .1. CP(X(2)Sigma(+)) ground state SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; SPECTROSCOPIC PROPERTIES; DIATOMIC-MOLECULES; DIPOLE-MOMENT; SPECTRUM; HYDROGEN; SYSTEM; BANDS AB A variety of theoretical methods have been applied to the X(2) Sigma(+) state of CP. In order to ascertain the degree of convergence in the computed properties with respect to the basis set, a series of correlation-consistent basis sets, ranging up to the quintuple zeta level, were used. For some properties the convergence was sufficiently uniform that a simple analytical expression could be fitted to the available theoretical data, seas to permit an estimate of the complete basis set limit. The set of observables that was examined includes spectroscopic constants (r(e), D-e, omega(e), omega(e)x(e), B-e, alpha(e)), rotational transition energies, one-electron properties (mu(e), Q, etc), vibrational transition energies, vibrational dipole moments and others. The vibrational energies were compared to experiment, as well as to numerical results simulating experiments based on the Rydberg-Klein-Rees-Vanderslice method. Transition Einstein A coefficients, transition wavenumbers and integrated absorption intensities for a selected set of rotational lines in the R branch of selected vibrational bands have been computed using a multireference, configuration-interaction potential energy surface which included a correction for higher-order excitations. The theoretical results are analysed in the light of recent stellar and laboratory-frame observations. Finally, the vibrational lifetimes (with and without rotational dependence)have been derived for the first ten vibrational levels using the latter above-mentioned potential surface. These lifetimes could be measured with existing experimental technologies. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP deBrouckere, G (reprint author), UNIV AMSTERDAM, DEPT PHYS & ASTRON, VALCKENIERSTR 65, NL-1018 XE AMSTERDAM, NETHERLANDS. NR 55 TC 13 Z9 13 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 28 PY 1996 VL 29 IS 22 BP 5283 EP 5303 PG 21 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VW566 UT WOS:A1996VW56600009 ER PT J AU Berrah, N Langer, B Bozek, J Gorczyca, TW Hemmers, O Lindle, DW Toader, O AF Berrah, N Langer, B Bozek, J Gorczyca, TW Hemmers, O Lindle, DW Toader, O TI Angular-distribution parameters and R-matrix calculations of Ar3s(-1)->np resonances SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID PARTIAL CROSS-SECTIONS; BRANCHING RATIOS; SYNCHROTRON RADIATION; ARGON; AUTOIONIZATION; REGION; PHOTOIONIZATION; PHOTOELECTRONS; SPECTROSCOPY; EXCITATION AB Angle-resolved photoelectron spectra have been measured with 6 meV photon resolution for the Ar 3s(2)3p(6) --> 3s3p(6)np (n = 4-16) autoionization resonances in the energy range between 26 and 29.3 eV, using synchrotron light from an undulator beamline of the Advanced Light Source. Photoelectron angular distribution parameters beta have been parametrized according to the prescription of Kabachnik and Sazhina and have been compared with R-matrix calculations similar to those of Burke and Taylor. The agreement was found to be very good. We have also analysed the cross section shape for the first six resonances, confirming previous measurements performed for the lower resonances, and compared them with various calculations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720. UNIV NEVADA,DEPT CHEM,LAS VEGAS,NV 89154. RP Berrah, N (reprint author), WESTERN MICHIGAN UNIV,DEPT PHYS,KALAMAZOO,MI 49008, USA. RI Bozek, John/E-4689-2010; Langer, Burkhard/A-6504-2013; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 36 TC 18 Z9 18 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 28 PY 1996 VL 29 IS 22 BP 5351 EP 5365 DI 10.1088/0953-4075/29/22/013 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VW566 UT WOS:A1996VW56600013 ER PT J AU Boesten, L Tachibana, Y Nakano, Y Shinohara, T Tanaka, H Dillon, MA AF Boesten, L Tachibana, Y Nakano, Y Shinohara, T Tanaka, H Dillon, MA TI Vibrationally inelastic and elastic cross sections for e+NF3 collisions SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ELECTRON MOMENTUM SPECTROSCOPY; LOW-ENERGY; IMPACT IONIZATION; WATER-MOLECULES; SCATTERING; NF3; EXCITATION; COLLISIONS; NH3; SF6 AB Absolute elastic cross sections for electron impact on nitrogen trifluoride (NF3) have been recorded for impact energies from 1.5 to 100 eV and scattering angles from 20 degrees to 130 degrees. Because of the small dipole moment, estimates of the integrated and momentum-transfer cross sections were obtained by extrapolation of the angular range with the help of a modified phase-shift program and subsequent numerical integration under the fits. Vibrational excitation function measurements show a 2 eV wide resonance at 3 eV impact energy. Vibrational loss spectra were measured near this resonance and resolved into their vibrational components v(1) and v(3). From the angular behaviour of these fundamental modes, the resonance can be assigned to a temporary trapping of the impinging electron in the antibonding orbital of irreducible species 'e', the LUMO orbit. C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP Boesten, L (reprint author), SOPHIA UNIV, DEPT PHYS, CHIYODA KU, KIOICHO 7-1, TOKYO 102, JAPAN. NR 82 TC 18 Z9 18 U1 1 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 28 PY 1996 VL 29 IS 22 BP 5475 EP 5491 DI 10.1088/0953-4075/29/22/022 PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VW566 UT WOS:A1996VW56600022 ER PT J AU Ali, R Berry, HG Dunford, RW Gemmell, DS Kanter, EP LeBrun, T Reichenbach, HM Young, L AF Ali, R Berry, HG Dunford, RW Gemmell, DS Kanter, EP LeBrun, T Reichenbach, HM Young, L TI The VUV spectrum from fast heavy-ion induced excitation of C-60 SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CHARGE-STATE DISTRIBUTIONS; CARBON FOILS; PHOTOIONIZATION; FRAGMENTATION; DYNAMICS; BUCKMINSTERFULLERENE; IONIZATION; ENERGY AB We have measured the spectrum of vacuum ultraviolet radiation (500-1700 Angstrom) arising from the impact of 625 MeV xenon ions with C-60. The spectral features are due primarily to emission from neutral and ionized carbon atoms. These photons mask sensitivity to either the C-60 giant dipole resonance or to excited C-2 dimers. We compare with data obtained in collisions of xenon ions with methane and isobutane. Decay times of several of the lines were also measured. Some of the lines persist for times long compared to the lifetimes of the corresponding states in neutral and ionized carbon. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RI Ali, Rami/B-8198-2015 OI Ali, Rami/0000-0002-5273-882X NR 27 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 28 PY 1996 VL 29 IS 22 BP 5607 EP 5617 DI 10.1088/0953-4075/29/22/031 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VW566 UT WOS:A1996VW56600031 ER PT J AU Eichten, E Lane, K AF Eichten, E Lane, K TI Low-scale technicolor at the Tevatron SO PHYSICS LETTERS B LA English DT Article ID TOP-QUARK PRODUCTION; TOPCOLOR-ASSISTED TECHNICOLOR; SYMMETRY-BREAKING; STANDARD MODEL; (P)OVER-BAR-P COLLISIONS; CHIRAL HIERARCHIES; CONDENSATE; BOSONS; HYPERCOLOR; PARAMETERS AB In multiscale models of walking technicolor, relatively light color-singlet technipions are produced in q (q) over bar annihilation in association with longitudinal W and Z bosons and with each other. The technipions decay as pi(T)(0) --> b (b) over bar and pi(T)(+) --> c (b) over bar. Their production rates are resonantly enhanced by isovector technirho vector mesons with mass M(W) + M pi(T) less than or similar to M(rho T) less than or similar to 2M(pi T). At the Tevatron, these associated production rates are 1-10 picobams for M(pi T) similar or equal to 100 GeV. Such a low mass technipion requires topcolor-assisted technicolor to suppress the decay t --> M(pi T)(+). Searches for pi(T) pi(T) production will also be rewarding. Sizable rates are expected if M(rho T) greater than or similar to 2M(pi T) + 10 GeV. The isoscalar omega(T) is nearly degenerate with rho(T) and is expected to be produced at roughly the same rate. The omega(T) should have the distinctive decay modes omega(T) --> gamma(pi)T(0) and Z pi(T)(0). C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. RP Eichten, E (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 50 TC 36 Z9 36 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 NOV 28 PY 1996 VL 388 IS 4 BP 803 EP 807 DI 10.1016/S0370-2693(96)01211-7 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV481 UT WOS:A1996VV48100019 ER PT J AU Butts, MD Scott, BL Kubas, GJ AF Butts, MD Scott, BL Kubas, GJ TI Syntheses and structures of alkyl and aryl halide complexes of the type [(PiPr(3))(2)PtH(eta(1)-XR)]BArf and analogues with Et(2)O, THF, and H-2 ligands. Halide-to-metal pi bonding in halocarbon complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY STRUCTURE; MOLECULAR-STRUCTURE; CRYSTAL-STRUCTURE; TRANSITION-METALS; COORDINATION CHEMISTRY; IODIDE COMPLEXES; FORMULA <(ETA-5-C5H5)RE(NO)(PPH3)(IR)>+BF4; DIHYDROGEN COMPLEXES; OXIDATIVE ADDITION; BINDING-ENERGIES AB The reaction of Pt(PiPr(3))(3) with SO2 led to the formation of (PiPr(3))(2)Pt(SO2) (1), isolated in 93% yield. The addition of [H(OEt(2))(2)](BArf)-B-+(BArf = B(3,5-(CF3)(2)C6H3)(4)) to 1 in ether at -78 degrees C afforded the solvent complex trans-[(PiPr(3))(2)Pt(H)(OEt(2))]BArf (2) in 85% isolated yield. Complex 2 served as a precursor to monodentate halocarbon complexes of the type Pt(eta(1)-XR). The dichloromethane complex trans-[(PiPr(3))(2)Pt(H)(eta(1)-ClCH2Cl)]BArf (3) was isolated in 80% yield by the recrystallization of 2 from CH2Cl2/hexane. IR spectroscopy suggested the existence of dichloromethane binding which was confirmed by X-ray crystallography. The reaction of 2 or 3 with iodo- or bromobenzene led to the isolation of the haloarene complexes trans-[(PiPr(3))(2)Pt(H)(eta(1)-XPh)]BArf, where X = I (4, 87% yield) or Br (5, 60% yield). Both compounds were characterized spectroscopically and by X-ray crystallography. An unexpected steric interaction in 4, suggested by molecular mechanics calculations to be significant, was rationalized in terms of halide-to-metal pi bonding. The PhI complex 4 decomposed under harsh conditions to the bridging iodide compound {trans-[(PiPr(3))(2)Pt(H)](2)(mu-I)}BArf (6) which was structurally characterized. The THF adduct [(PiPr(3))(2)Pt(H)(THF)]BArf (7), isolated in 78% yield and also characterized by X-ray crystallography, was formed when any of the compounds 2, 3, 4, or 5 was dissolved in THF. The CH2Cl2 complex 3 reacted with H-2 to form the dihydrogen complex tans-[(PiPr(3))(2)Pt(H)(eta(2)-H-2)]BArf which was characterized by NMR spectroscopy. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 89 TC 113 Z9 113 U1 1 U2 7 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 NOV 27 PY 1996 VL 118 IS 47 BP 11831 EP 11843 DI 10.1021/ja961836y PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA VV337 UT WOS:A1996VV33700017 ER PT J AU Miedaner, A Curtis, CJ Wander, SA Goodson, PA DuBois, DL AF Miedaner, A Curtis, CJ Wander, SA Goodson, PA DuBois, DL TI Dicationic nickel(II) carbonyl complexes containing tetradentate ligands SO ORGANOMETALLICS LA English DT Article ID RAMAN-SPECTROSCOPIC EVIDENCE; MONOXIDE DEHYDROGENASE; CO DEHYDROGENASE; STRUCTURAL CHARACTERIZATION; CLOSTRIDIUM-THERMOACETICUM; "TRIS(2-DIPHENYLPHOSPHINOETHYL)AMINE; OXIDATION; COBALT(I); PHOSPHINE; BINDING AB This article describes the preparation and spectroscopic characterization of three dicationic Ni(II) carbonyl complexes containing tripodal tetradentate ligands. An X-ray diffraction study of [Ni(PP(3)E)(CO)](BF4)(2) (where PP(3)E is tris(2-(diethylphosphino)ethyl)phosphine) has been completed and confirms a trigonal bipyramidal structure with an apical carbonyl ligand. The binding of CO is weak and reversible. The stability of these complexes is enhanced by the small chelate bite imposed by the tetradentate ligands. The electrochemical behavior of these complexes depends on the nature of the donor atom trans to CO. The [Ni(NP(3)E)(CO)](2+) (where NP(3)E is tris(2-(diethylphosphino)ethyl)amine) cation undergoes two reversible one-electron reductions, whereas the corresponding tetraphosphine cations undergo irreversible two-electron reductions. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 39 TC 13 Z9 13 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD NOV 26 PY 1996 VL 15 IS 24 BP 5185 EP 5190 DI 10.1021/om960416e PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA VV374 UT WOS:A1996VV37400017 ER PT J AU Hang, B Chenna, A FraenkelConrat, H Singer, B AF Hang, B Chenna, A FraenkelConrat, H Singer, B TI An unusual mechanism for the major human apurinic apyrimidinic (AP) endonuclease involving 5' cleavage of DNA containing a benzene-derived exocyclic adduct in the absence of an AP site SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE DNA repair; human carcinogen; 3,N-4-benzetheno-2'-deoxycytidine; dangling base ID COLI EXONUCLEASE-III; REPAIR ENZYME; HUMAN-CELLS; CDNA; BINDING; GLYCOSYLASE; EXPRESSION; NUCLEASE; HOMOLOGY; CLONING AB The major human apurinic/apyrimidinic (AP) endonuclease (class II) is known to cleave DNA 5' adjacent to an AP site, which is probably the most common DNA damage produced hydrolytically or by glycosylase-mediated removal of modified bases, p-Benzoquinone (pBQ), one of the major benzene metabolites, reacts with DNA to form bulky exocyclic adducts, Herein we report that the human AP endonuclease directly catalyzes incision in a defined oligonucleotide containing 3,N-4-benzetheno-2'-deoxycytidine (pBQ-dC) without prior generation of an AP site, The enzyme incises the oligonucleotide 5' to the adduct and generates 3'-hydroxyl and 5'-phosphoryl termini but leaves the pBQ-dC on the 5' terminus of the cleavage fragment, The AP function of the enzyme is not involved in this action, as no preexisting AP site is present nor is a DNA glycosylase activity involved. Nicking of the pBQ-dC adduct also leads to the same ''dangling base'' cleavage when two Escherichia coli enzymes, exonuclease III and endonuclease IV, are used, Our finding of this unusual mode of action used by both human and bacterial AP endonucleases raises important questions regarding the requirements for substrate recognition and catalytic active site(s) for this essential cellular repair enzyme, We believe this to be the first instance of the presence of a bulky carcinogen adduct leading to this unusual mode of action. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DONNER LAB,DIV LIFE SCI,BERKELEY,CA 94720. FU NCI NIH HHS [R01 CA047723, CA 47723]; NIEHS NIH HHS [ES 07363] NR 20 TC 45 Z9 46 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 26 PY 1996 VL 93 IS 24 BP 13737 EP 13741 DI 10.1073/pnas.93.24.13737 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV467 UT WOS:A1996VV46700052 PM 8943004 ER PT J AU Fried, LM Koumenis, C Peterson, SR Green, SL vanZijl, P AllalunisTurner, J Chen, DJ Fishel, R Giaccia, AJ Brown, JM Kirchgessner, CU AF Fried, LM Koumenis, C Peterson, SR Green, SL vanZijl, P AllalunisTurner, J Chen, DJ Fishel, R Giaccia, AJ Brown, JM Kirchgessner, CU TI The DNA damage response in DNA-dependent protein kinase-deficient SCID mouse cells: Replication protein A hyperphosphorylation and p53 induction SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE ionizing radiation; ataxia telangiectasia; M059J ID TUMOR-SUPPRESSOR PROTEIN; NUCLEOTIDE EXCISION-REPAIR; ATAXIA-TELANGIECTASIA GENE; STRAND-BREAK-REPAIR; BINDING-PROTEIN; V(D)J RECOMBINATION; IONIZING-RADIATION; PHOSPHORYLATION SITES; CATALYTIC SUBUNIT; A PHOSPHORYLATION AB Severe combined immunodeficient (SCID) mice display an increased sensitivity to ionizing radiation compared with the parental, C.B-17, strain due to a deficiency in DNA double-strand break repair, The catalytic subunit of DNA-dependent protein kinase (DNA-PKCS) has previously been identified as a strong candidate for the SCID gene. DNA-Ps phosphorylates many proteins in vitro, including p53 and replication protein A (RPA), two proteins involved in the response of cells to DNA damage. To determine whether p53 and RPA are also substrates of DNA-PK in vivo following DNA damage, we compared the response of SCID and MO59J (human DNA-PKcs-deficient glioblastoma) cells with their respective wild-type parents following ionizing radiation, Our findings indicate that (i) p53 levels are increased in SCID cells following ionizing radiation, and (ii) RPA p34 is hyperphosphorylated in both SCID cells and MO59J cells following ionizing radiation. The hyperphosphorylation of RPA p34 in vivo is concordant with a decrease in the binding of RPA to single-stranded DNA in crude extracts derived from both C.B-17 and SCID cells, These results suggest that DNA-PK is not the only kinase capable of phosphorylating RPA, We conclude that the DNA damage response involving p53 and RPA is not associated with the defect in DNA repair in SCID cells and that the physiological substrate(s) for DNA-PK essential for DNA repair has not yet been identified. C1 STANFORD UNIV,SCH MED,CANC BIOL RES LAB,DEPT RADIAT ONCOL,STANFORD,CA 94305. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CROSS CANC INST,EDMONTON,AB T6G 1Z2,CANADA. THOMAS JEFFERSON UNIV,DEPT MICROBIOL & IMMUNOL,PHILADELPHIA,PA 19107. RI Koumenis, Constantinos/B-2002-2008 FU NCI NIH HHS [R01 CA056542, CA15201, CA50519, CA64489, R01 CA050519, R37 CA050519, T32 CA009302] NR 44 TC 86 Z9 86 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 26 PY 1996 VL 93 IS 24 BP 13825 EP 13830 DI 10.1073/pnas.93.24.13825 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV467 UT WOS:A1996VV46700068 PM 8943020 ER PT J AU Fowler, JS Volkow, ND Wang, GJ Pappas, N Logan, J Shea, C Alexoff, D MacGregor, RR Schlyer, DJ Zezulkova, I Wolf, AP AF Fowler, JS Volkow, ND Wang, GJ Pappas, N Logan, J Shea, C Alexoff, D MacGregor, RR Schlyer, DJ Zezulkova, I Wolf, AP TI Brain monoamine oxidase A inhibition in cigarette smokers SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; PARKINSONS-DISEASE; SMOKING CESSATION; MAJOR DEPRESSION; MOCLOBEMIDE; DOPAMINE; TOBACCO; BINDING; SYSTEM; HEAVY AB Several studies have documented a strong association between smoking and depression. Because cigarette smoke has been reported to inhibit monoamine oxidase (MAO) A in vitro and in animals and because MAO A inhibitors are effective antidepressants, we tested the hypothesis that MAO A would be reduced in the brain of cigarette smokers. We compared brain MAO A in 15 nonsmokers and 16 current smokers with [C-11]clorgyline and positron emission tomography (PET). Four of the nonsmokers were also treated with the antidepressant MAO inhibitor drug, tranylcypromine (10 mg/day for 3 days) after the baseline PET scan and then rescanned to assess the sensitivity of [C-11]clorgyline binding to MAO inhibition. MAO A levels were quantified by using the model term lambda k(3) which is a function of brain MAO A concentration. Smokers had significantly lower brain MAO A than nonsmokers in all brain regions examined (average reduction, 28%). The mean lambda k(3) values for the whole brain were 0.18 +/- 0.04 and 0.13 +/- 0.03 cc(brain) (ml(plasma))(-1) min(-1) for nonsmokers and smokers, respectively; P < 0.0003). Tranylcypromine treatment reduced lambda k(3) by an average of 58% for the different brain regions. Our results show that tobacco smoke exposure is associated with a marked reduction in brain MAO A, and this reduction is about half of that produced by a brief treatment with tranylcypromine. This suggests that MAO A inhibition needs to be considered as a potential contributing variable in the high rate of smoking in depression and in the development of more effective strategies for smoking cessation. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. RP Fowler, JS (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NIDA NIH HHS [DA 06891, R01 DA006891]; NINDS NIH HHS [NS 15380] NR 41 TC 280 Z9 287 U1 1 U2 12 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 26 PY 1996 VL 93 IS 24 BP 14065 EP 14069 DI 10.1073/pnas.93.24.14065 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VV467 UT WOS:A1996VV46700109 PM 8943061 ER PT J AU Sung, YS Zhang, XF Kostic, PJ Miller, DJ AF Sung, YS Zhang, XF Kostic, PJ Miller, DJ TI The effects of carbon on TlBa2Ca2Cu3Ox phase formation in the TlF-Ba2Ca2Cu3Oz system SO APPLIED PHYSICS LETTERS LA English DT Article ID CU-O SUPERCONDUCTORS; CRYSTAL-STRUCTURE; TL2BA2CA2CU3O10; CO2 AB The effects of carbon on TlBa2Ca2Cu3Ox phase formation in the TlF-Ba2Ca2Cu3Oz system were investigated by varying the carbon contents in Ba2Ca2Cu3Oz precursor powders that were mixed with TlF and reacted to form the superconducting phase. It was found that carbon induced Tl2Ba2Ca2Cu3Oy phase formation resulting in superlattices formed by c-axis intergrowths between TlBa2Ca2Cu3Ox and Tl2Ba2Ca2Cu3Oy. The superlattices were highly regular and uniform throughout the samples. While TlBa2Ca2Cu3Ox was the main phase at low carbon content (0.231 wt %), Tl2Ba2Ca2Cu3Oy became the dominant phase at high carbon content (0.472 wt %) even with a 1:2:2:3 (Tl:Ba:Ca:Cu) starting composition. (C) 1996 American Institute of Physics. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. RP Sung, YS (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 23 TC 9 Z9 9 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 NOV 25 PY 1996 VL 69 IS 22 BP 3420 EP 3422 DI 10.1063/1.117279 PG 3 WC Physics, Applied SC Physics GA VU647 UT WOS:A1996VU64700042 ER PT J AU Kloc, M Larabell, C Etkin, LD AF Kloc, M Larabell, C Etkin, LD TI Elaboration of the messenger transport organizer pathway for localization of RNA to the vegetal cortex of Xenopus oocytes SO DEVELOPMENTAL BIOLOGY LA English DT Article ID DROSOPHILA OOGENESIS; MATERNAL TRANSCRIPT; ANIMAL DEVELOPMENT; LAEVIS; EMBRYOS; CLONING; VG1; TRANSLOCATION; MICROTUBULES; MECHANISMS AB Previous studies demonstrated that there were two pathways, the messenger transport organizer (METRO) or early and the Vg1 or late, which function during stages I to 3 of oogenesis for the localization of RNAs at the vegetal cortex of Xenopus oocytes. In the present study we analyzed the properties of the METRO pathway, which localizes Xlsirt, Xcat2, and Xwnt11 RNAs to a specific region of the vegetal cortex during stage 1 of oogenesis. A combination of methodologies involving both fixed material and living oocytes was used to analyze RNA localization. We show that in early diplotene pre-stage 1 oocytes (25-50 mu m in diameter) both endogenous and injected exogenous METRO RNAs translocated to multiple mitochondrial aggregates (pre-mitochondrial clouds) that surround the germinal vesicle (GV). However, by early stage I (diplotene oocytes, 50-200 mu m), all three of the RNAs discriminated between the different clouds and translocated exclusively within the METRO of a single mitochondrial cloud. Therefore, in stage 1 diplotene oocytes there is a unique mechanism causing a change in the intrinsic property of the mitochondrial clouds which designates one of them as the RNA transport vehicle. During translocation through the cytoplasm Xlsirt and Xcat2 RNAs were detected associated with cytoplasmic particles of different morphologies. Additionally, we also found that the translocation of RNAs through the early or METRO pathway, unlike that of the late pathway, occurred in the absence of intact microtubule and actin microfilament cytoskeletal elements. This supports a cytoskeletal-independent model for localization of RNAs through the METRO pathway. (C) 1996 Academic Press, Inc. C1 UNIV TEXAS,MD ANDERSON CANCER CTR,DEPT MOL GENET,HOUSTON,TX 77030. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. NR 37 TC 72 Z9 72 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 0012-1606 J9 DEV BIOL JI Dev. Biol. PD NOV 25 PY 1996 VL 180 IS 1 BP 119 EP 130 DI 10.1006/dbio.1996.0289 PG 12 WC Developmental Biology SC Developmental Biology GA VW700 UT WOS:A1996VW70000010 PM 8948579 ER PT J AU Aronson, MC Maple, MB Chau, R Georges, A Tsvelik, AM Osborn, R AF Aronson, MC Maple, MB Chau, R Georges, A Tsvelik, AM Osborn, R TI Non-Fermi-liquid scaling in UCu5-xPdx (x=1, 1.5) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Institute-for-Theoretical-Physics Conference on Non-Fermi Liquid Behaviour in Metals CY JUN 17-21, 1996 CL SANTA BARBARA, CA SP Inst Theoret Phys ID FIELD-THEORY; HEAVY AB We review the compiled measurements of the imaginary part of the dynamical magnetic susceptibility chi ''(omega, T), static susceptibility chi(T), electrical resistivity rho(T) and specific heat C(T) in the uranium intermetallics UCu5-xPdx (x = 1, 1.5). We assess the temperature- and energy-dependences predicted by single-ion and disorder-dominated models and compare these results to experiments. For temperatures T and excitation energies omega in the range 12 K < omega, T < 150 K, our analysis suggests that the dynamics of isolated uranium ions are responsible for the observed temperature and frequency scaling, although inter-ion interactions may become important at lower temperatures and frequencies. C1 UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,INST PURE & APPL RES,LA JOLLA,CA 92093. ECOLE NORMALE SUPER,PHYS THEOR LAB,F-75231 PARIS 05,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3NP,ENGLAND. RP Aronson, MC (reprint author), UNIV MICHIGAN,HARRISON M RANDALL LAB PHYS,ANN ARBOR,MI 48109, USA. RI Osborn, Raymond/E-8676-2011; Georges, Antoine/H-4855-2012 OI Osborn, Raymond/0000-0001-9565-3140; Georges, Antoine/0000-0001-9479-9682 NR 15 TC 28 Z9 28 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 25 PY 1996 VL 8 IS 48 BP 9815 EP 9823 DI 10.1088/0953-8984/8/48/011 PG 9 WC Physics, Condensed Matter SC Physics GA VW563 UT WOS:A1996VW56300011 ER PT J AU Gweon, GH Allen, JW Claessen, R Clack, JA Poirier, DM Benning, PJ Olson, CG Ellis, WP Zhang, YX Schneemeyer, LF Marcus, J Schlenker, C AF Gweon, GH Allen, JW Claessen, R Clack, JA Poirier, DM Benning, PJ Olson, CG Ellis, WP Zhang, YX Schneemeyer, LF Marcus, J Schlenker, C TI Fermi surfaces and single-particle spectral functions of low-dimensional inorganic non-cuprate compounds: The molybdenum bronzes SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID BAND ELECTRONIC-STRUCTURE; RESOLVED PHOTOEMISSION SPECTROSCOPY; LUTTINGER-LIQUID BEHAVIOR; DENSITY-WAVE INSTABILITY; SPIN-CHARGE SEPARATION; 2D HUBBARD-MODEL; PEIERLS TRANSITION; TEMPERATURE-DEPENDENCE; ORGANIC CONDUCTORS; COUPLED CHAINS AB The Fermi surfaces and single-particle spectral functions of several low-dimensional materials have been measured as part of an effort to assess the occurrence of non-Fermi-liquid behaviour in non-cuprate materials. C1 UNIV SAARLAND, FACHRICHTUNG EXPT PHYS 2, D-66041 SAARBRUCKEN, GERMANY. IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. AT&T BELL LABS, LUCENT TECHNOL, MURRAY HILL, NJ 07974 USA. CNRS, ETUD PROPRIETES ELECT SOLIDES LAB, F-38042 GRENOBLE 9, FRANCE. RP Gweon, GH (reprint author), UNIV MICHIGAN, RANDALL LAB PHYS, ANN ARBOR, MI 48109 USA. RI Claessen, Ralph/A-2045-2017 OI Claessen, Ralph/0000-0003-3682-6325 NR 56 TC 63 Z9 63 U1 2 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 25 PY 1996 VL 8 IS 48 BP 9923 EP 9938 DI 10.1088/0953-8984/8/48/017 PG 16 WC Physics, Condensed Matter SC Physics GA VW563 UT WOS:A1996VW56300017 ER PT J AU Puchkov, AV Basov, DN Timusk, T AF Puchkov, AV Basov, DN Timusk, T TI The pseudogap state in high-T-c superconductors: An infrared study SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Institute-for-Theoretical-Physics Conference on Non-Fermi Liquid Behaviour in Metals CY JUN 17-21, 1996 CL SANTA BARBARA, CA SP Inst Theoret Phys ID D-WAVE SUPERCONDUCTIVITY; CUPRATE SUPERCONDUCTORS; OPTICAL-PROPERTIES; SINGLE-CRYSTALS; SPIN-GAP; MAGNETIC-PROPERTIES; NEUTRON-SCATTERING; AXIS CONDUCTIVITY; SPECTRAL-FUNCTION; ENERGY-GAP AB We report on a study of the electromagnetic response of three different families of high-T-c superconductors that in combination allowed us to cover the whole doping range from under- to overdoped. The discussion is focused on the nb-plane charge dynamics in the pseudogap stare which is realized in underdoped materials below a characteristic temperature T*, a temperature that can significantly exceed the superconducting transition temperature T-c. We explore the evolution of the pseudogap response by changing the doping level, by varying the temperature from above to below T*, or by introducing impurities in the underdoped compounds. We employ a memory function analysis of the ab-plane optical data that allows us to observe the effect of the pseudogap most clearly. We compare the infrared data with other experimental results, including the c-axis optical response, de transport, and angle-reserved photoemission. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Puchkov, AV (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. NR 111 TC 355 Z9 356 U1 1 U2 19 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 25 PY 1996 VL 8 IS 48 BP 10049 EP 10082 DI 10.1088/0953-8984/8/48/023 PG 34 WC Physics, Condensed Matter SC Physics GA VW563 UT WOS:A1996VW56300023 ER PT J AU Liets, LC Chalupa, LM AF Liets, LC Chalupa, LM TI The metabotropic glutamate agonist 2-amino-4-phosphonobutyric acid (APB) does not activate currents in postnatal retinal ganglion cells SO NEUROREPORT LA English DT Article DE APB; AP-4; glutamate; retinal ganglion cell; stratification ID ROD BIPOLAR CELLS; PHARMACOLOGICAL MODULATION; PATCH-CLAMP; RAT RETINA; CAT RETINA; RECEPTOR; SENSITIVITY; MEMBRANE AB WHEREAS in the mature retina the glutamate agonist 2-amino-4-phosphonobutyric acid (APB) selectively activates currents in rod bipolar and ON-cone bipolar cells, recent molecular studies have suggested the possibility of a transient appearance of the APB-sensitive receptor in developing retinal ganglion cells. In the present study the whole-cell and perforated variations of the patch-clamp method were employed to assess the responsivity of postnatal cat retinal ganglion cells to APB. Recently, APB treatment has been shown in our laboratory to block the normal stratification of retinal ganglion cell dendrites into ON and OFF sublaminae of the inner plexiform layer. Although application of this glutamate agonist elicited inward sustained currents, amino acid analysis revealed that the APB product (RBI) was contaminated by 8% glycine. In subsequent experiments applications of uncontaminated APB (Gal Biochem) never yielded responses in postnatal retinal ganglion cells which displayed normal currents to other glutamate agonists. The findings do not support the notion of transient expression of APB receptors in retinal ganglion cells during the development period studied. C1 LAWRENCE LIVERMORE NATL LAB,CTR NEUROSCI,DAVIS,CA 95616. RP Liets, LC (reprint author), LAWRENCE LIVERMORE NATL LAB,SECT NEUROBIOL PHYSIOL & BEHAV,DAVIS,CA 95616, USA. FU NEI NIH HHS [EY-03991] NR 18 TC 7 Z9 7 U1 0 U2 0 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0959-4965 J9 NEUROREPORT JI Neuroreport PD NOV 25 PY 1996 VL 7 IS 18 BP 2873 EP 2877 DI 10.1097/00001756-199611250-00013 PG 5 WC Neurosciences SC Neurosciences & Neurology GA WB359 UT WOS:A1996WB35900013 PM 9116200 ER PT J AU Abele, A Adomeit, J Armstrong, DS Baker, CA Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, AR Cramer, O Crowe, KM Dietz, HP Djaoshvili, N Dunnweber, W Engelhardt, D Englert, M Faessler, MA Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holtzhaussen, C Illinger, P Jamnik, D Kammle, B Kammel, P Kiel, T Koch, H Kolo, C Lakata, M Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Pinder, CN Pinter, G Regenfus, C Reissmann, J Rothel, W Schmidt, P Scott, I Seibert, R Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Walther, D Zou, B AF Abele, A Adomeit, J Armstrong, DS Baker, CA Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cooper, AR Cramer, O Crowe, KM Dietz, HP Djaoshvili, N Dunnweber, W Engelhardt, D Englert, M Faessler, MA Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holtzhaussen, C Illinger, P Jamnik, D Kammle, B Kammel, P Kiel, T Koch, H Kolo, C Lakata, M Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Pinder, CN Pinter, G Regenfus, C Reissmann, J Rothel, W Schmidt, P Scott, I Seibert, R Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Walther, D Zou, B TI Further analysis of (p)over-bar-p->3 pi(0), eta eta pi(0) and eta pi(0)pi(0) at rest SO NUCLEAR PHYSICS A LA English DT Article ID FINAL-STATE INTERACTIONS; COUPLED-CHANNEL ANALYSIS; AMPLITUDE ANALYSIS; OMEGA-OMEGA; P-STATES; ETA-ETA; RESONANCE; ANNIHILATION; MESON; DECAY AB A fresh analysis is reported of high statistics Crystal Barrel data on <(p)over bar p> --> 3 pi(0), eta eta pi(0), eta pi(0) pi(0) and eta eta'pi(0) at rest. This analysis is made fully consistent with CERN-Munich data on pi(+)pi(-) --> pi(+)pi(-) up to a mass of 1900 MeV, with GAMS data on pi(+)pi(-) --> pi(0) pi(0), and with BNL and ANL data on pi(+)pi(-) --> , which are fitted simultaneously. There is evidence for an I = 0, J(PC) = 2(++) resonance with weak (less than or equal to 7%) coupling to pi pi, strong coupling to both rho rho and omega omega and pole position 1534 - i90 MeV. This resonance agrees qualitatively with GAMS and VES data on pi pi --> omega omega, previously interpreted in terms of a resonance at 1590-1640 MeV. New masses and widths for (A) f(0)(1370) and (B) f(0)(1500), fitted to all eight data sets, are M(A) = 1300 +/- 15 MeV, Gamma(A) = 230 +/- 15 MeV, M(B) = 1500 +/- 8 MeV, Gamma(B) = 132 +/- 15 MeV. Branching ratios to pi pi and eta eta are given, and differ significantly from earlier determinations because of a new procedure. C1 RUHR UNIV BOCHUM, D-44780 BOCHUM, GERMANY. UNIV BONN, D-53115 BONN, GERMANY. HUNGARIAN ACAD SCI, H-1525 BUDAPEST, HUNGARY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. CERN, CH-1211 GENEVA, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. UNIV KARLSRUHE, D-76021 KARLSRUHE, GERMANY. UNIV LONDON QUEEN MARY & WESTFIELD COLL, LONDON E1 4NS, ENGLAND. UNIV CALIF LOS ANGELES, LOS ANGELES, CA 90024 USA. UNIV MUNICH, D-80799 MUNICH, GERMANY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. CTR RECH NUCL, F-67037 STRASBOURG, FRANCE. UNIV PARIS 06, LPNHE, F-75252 PARIS, FRANCE. UNIV PARIS 07, LPNHE, F-75252 PARIS, FRANCE. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 29 TC 46 Z9 47 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD NOV 25 PY 1996 VL 609 IS 4 BP 562 EP 584 DI 10.1016/S0375-9474(96)00306-5 PG 23 WC Physics, Nuclear SC Physics GA VV365 UT WOS:A1996VV36500008 ER PT J AU Burakovsky, L Horwitz, LP AF Burakovsky, L Horwitz, LP TI Hadronic resonance spectrum may help in resolution of meson nonet enigmas SO NUCLEAR PHYSICS A LA English DT Article DE hadronic resonance spectrum; quark model; hadron classification ID 2 ETA-MESONS; ANTIPROTON ANNIHILATIONS; REST; PI; G(1590); STATES; GEV/C; SYSTEM; DECAYS; PROTON AB The identification of problematic meson states as the members of the quark model nonets by using a hadronic resonance spectrum is discussed. The results favor the currently adopted assignments for the tensor and 1 F-3(4) J(PC) = 4(++) meson nonets, and suggest a new assignments for the scalar and axial-vector nonets which favor the interpretation of the f(0)(980), f(0)(1710) and f(1)(1510) mesons as non- objects. We also suggest that the 2 S-3(1) 1/2 (1(-)) State should be identified with the K*(1680) rather than K*(1410) meson. C1 INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T8,LOS ALAMOS,NM 87545, USA. NR 63 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 NOV 25 PY 1996 VL 609 IS 4 BP 585 EP 599 DI 10.1016/S0375-9474(96)00310-7 PG 15 WC Physics, Nuclear SC Physics GA VV365 UT WOS:A1996VV36500009 ER PT J AU Poppitz, E Shadmi, Y Trivedi, SP AF Poppitz, E Shadmi, Y Trivedi, SP TI Duality and exact results in product group theories SO NUCLEAR PHYSICS B LA English DT Article DE supersymmetry; duality; gauge theory; nonperturbative; supersymmetry breaking ID DYNAMICAL SUPERSYMMETRY BREAKING; ELECTRIC-MAGNETIC DUALITY; GAUGE-THEORIES; EXACT SUPERPOTENTIALS; SYMMETRY BREAKING; 4 DIMENSIONS AB We study the non-perturbative behavior of some N = 1 supersymmetric product-group gauge theories with the help of duality, As a test case we investigate an SU(2) x SU(2) theory in detail, Various dual theories are constructed using known simple-group duality for one group or both groups in succession. Several stringent tests show that the low-energy behavior of the dual theories agrees with that of the electric theory. When the theory is in the confining phase we calculate the exact superpotential. Our results strongly suggest that, in general, dual theories for product groups can be constructed in this manner, by using simple-group duality for both groups, Turning to a class of theories with SU(N) x SU(M) gauge symmetry we study the renormalization group flows in the space of the two gauge couplings and show that they are consistent with the absence of phase transitions. Finally, we show that a subset of these theories, with SU(N) x SU(N - 1) symmetry break supersymmetry dynamically. C1 FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. RP UNIV CHICAGO, ENRICO FERMI INST, 5640 S ELLIS AVE, CHICAGO, IL 60637 USA. NR 29 TC 49 Z9 49 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV 25 PY 1996 VL 480 IS 1-2 BP 125 EP 169 DI 10.1016/S0550-3213(96)00464-6 PG 45 WC Physics, Particles & Fields SC Physics GA VU710 UT WOS:A1996VU71000006 ER PT J AU Becker, K Bekcer, M Morrison, DR Ooguri, H Oz, Y Yin, Z AF Becker, K Bekcer, M Morrison, DR Ooguri, H Oz, Y Yin, Z TI Supersymmetric cycles in exceptional holonomy manifolds and Calabi-Yau four-folds SO NUCLEAR PHYSICS B LA English DT Article DE Calabi-Yau four-folds; Cayley cycles; exceptional holonomy manifolds; supersymmetric cycles; mirror symmetry; 3-brane; special Lagrangian submanifolds ID STRING THEORY AB We derive in the SCFT and low energy effective action frameworks the necessary and sufficient conditions for supersymmetric cycles in exceptional holonomy manifolds and Calabi-Yau four-folds. We show that the Cayley cycles in Spirt(7) holonomy eight-manifolds and the associative and coassociative cycles in G(2) holonomy seven-manifolds preserve half of the space-time supersymmetry. We find that while the holomorphic and special Lagrangian cycles in Calabi-Yau four-folds preserve half of the space-time supersymmetry, the Cayley submanifolds are novel as they preserve only one quarter of it. We present some simple examples. Finally, we discuss the implications of these supersymmetric cycles on mirror symmetry in higher dimensions. C1 UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. DUKE UNIV, DEPT MATH, DURHAM, NC 27708 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, THEORET PHYS GRP, BERKELEY, CA 94720 USA. WEIZMANN INST SCI, DEPT PARTICLE PHYS, IL-76100 REHOVOT, ISRAEL. RP UNIV CALIF SANTA BARBARA, INST THEORET PHYS, SANTA BARBARA, CA 93106 USA. RI Ooguri, Hirosi/A-4407-2011 NR 21 TC 71 Z9 71 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD NOV 25 PY 1996 VL 480 IS 1-2 BP 225 EP 238 DI 10.1016/S0550-3213(96)00491-9 PG 14 WC Physics, Particles & Fields SC Physics GA VU710 UT WOS:A1996VU71000010 ER PT J AU Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Johnson, E Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fulton, R Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R Frasconi, F He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Perera, L Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ 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 Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ehrlich, R Elia, R Foland, AD Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI 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 Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Athanas, M Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Kim, DYJ Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL AF Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Johnson, E Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fulton, R Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R Frasconi, F He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Perera, L Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ 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 Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ehrlich, R Elia, R Foland, AD Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI 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 Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Athanas, M Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Kim, DYJ Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL TI A search for nonresonant B+->h(+)h(-)h(+) decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP AB We use data collected by the CLEO II detector at the Cornell Electron Storage Ring (CESR) to search for B+ --> h(+)h(-)h(+) (nonresonant) decays, where h(+/-) can be either pi(+/-), K-+/-, or p((p) over bar). We see no evidence for signals and set upper limits on the branching fractions in the range (2.8-8.9) x 10(-5). If observed, these decays may display CP violating asymmetries. C1 CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. 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,HONOLULU,HI 96822. RP Bergfeld, T (reprint author), UNIV ILLINOIS,CHAMPAIGN,IL 61801, USA. RI Schaffner, Stephen/D-1189-2011; Britton, David/F-2602-2010; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016; OI Britton, David/0000-0001-9998-4342; Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587; Bean, Alice/0000-0001-5967-8674; Poling, Ronald/0000-0001-7305-4702; Bloom, Kenneth/0000-0002-4272-8900 NR 12 TC 14 Z9 14 U1 1 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 NOV 25 PY 1996 VL 77 IS 22 BP 4503 EP 4507 DI 10.1103/PhysRevLett.77.4503 PG 5 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200006 ER PT J AU Dorner, R Khemliche, H Prior, MH Cocke, CL Gary, JA Olson, RE Mergel, V Ullrich, J SchmidtBocking, H AF Dorner, R Khemliche, H Prior, MH Cocke, CL Gary, JA Olson, RE Mergel, V Ullrich, J SchmidtBocking, H TI Imaging of saddle point electron emission in slow p-He collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION-ATOM COLLISIONS; TRIPLE-CENTER TREATMENT; IONIZING COLLISIONS; CROSS-SECTIONS; MOMENTUM SPECTROSCOPY; ANGULAR-DISTRIBUTION; PROTON-IMPACT; CHARGED IONS; IONIZATION; VELOCITY AB The two-dimensional velocity distribution of electrons emitted in 5-15 keV p-He collisions has been measured for completely determined motion of the nuclei, that is, as a function of the impact parameter and in a well defined scattering plane. The electrons are emitted preferentially in the scattering plane and in the forward direction. The velocity distributions show sharp structures that vary strongly with impact parameter and projectile velocity. The results are compared to classical trajectory calculations. C1 KANSAS STATE UNIV,DEPT PHYS,MANHATTAN,KS 66506. LBNL,BERKELEY,CA 94720. UNIV MISSOURI,ROLLA,MO 65401. GESELL SCHWERIONENFORSCH MBH,D-64291 DARMSTADT,GERMANY. RP Dorner, R (reprint author), UNIV FRANKFURT,INST KERNPHYS,AUGUST EULER STR 6,D-60486 FRANKFURT,GERMANY. RI Doerner, Reinhard/A-5340-2008 OI Doerner, Reinhard/0000-0002-3728-4268 NR 28 TC 84 Z9 84 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 25 PY 1996 VL 77 IS 22 BP 4520 EP 4523 DI 10.1103/PhysRevLett.77.4520 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200010 ER PT J AU Higgins, J Ernst, WE Callegari, C Reho, J Lehmann, KK Scoles, G Gutowski, M AF Higgins, J Ernst, WE Callegari, C Reho, J Lehmann, KK Scoles, G Gutowski, M TI Spin polarized alkali clusters: Observation of quartet states of the sodium trimer SO PHYSICAL REVIEW LETTERS LA English DT Article ID HELIUM CLUSTERS; SPECTROSCOPY; SF6 AB Using helium cluster-isolation spectroscopy we have prepared and characterized the lowest quartet state (1(4)A'(2)) of the sodium trimer. Upon excitation to the 2(4)E' electronic state, laser induced fluorescence excitation and emission spectra have been obtained. With the aid of ab initio calculations, the spectra have been vibronically assigned and new insights on the nonadditivity of van der Waals interactions have been obtained. It is found that approximately 80% of the interaction energy in the 1(4)A'(2) state of Na-3 is due to nonadditive effects. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV GDANSK, DEPT CHEM, PL-80952 GDANSK, POLAND. RP Higgins, J (reprint author), PRINCETON UNIV, DEPT CHEM, PRINCETON, NJ 08544 USA. RI Ernst, Wolfgang E/B-3257-2016; OI Ernst, Wolfgang E/0000-0001-8849-5658; Callegari, Carlo/0000-0001-5491-7752 NR 22 TC 80 Z9 80 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 25 PY 1996 VL 77 IS 22 BP 4532 EP 4535 DI 10.1103/PhysRevLett.77.4532 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200013 ER PT J AU Young, PE Bolton, PR AF Young, PE Bolton, PR TI Propagation of subpicosecond laser pulses through a fully ionized plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNDERDENSE PLASMAS; ELECTROMAGNETIC-WAVES; ULTRASHORT-PULSE; SELF-MODULATION; BEAMS; IONIZATION; INTENSITY; PHASE AB Propagation of subpicosecond laser pulses through a fully ionized plasma has been studied experimentally. Measurements of the light transmitted through the plasma and of the light scattered at 90 deg to the beam show the onset and growth of relativistic filamentation. Frequency-resolved optical gating of the transmitted pulse shows motion of electrons into acid out of the beam. RP Young, PE (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,LIVERMORE,CA 94550, USA. NR 32 TC 47 Z9 47 U1 3 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 NOV 25 PY 1996 VL 77 IS 22 BP 4556 EP 4559 DI 10.1103/PhysRevLett.77.4556 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200019 ER PT J AU Freericks, JK Jarrell, M Mahan, GD AF Freericks, JK Jarrell, M Mahan, GD TI The anharmonic electron-phonon problem SO PHYSICAL REVIEW LETTERS LA English DT Article ID INFINITE DIMENSIONS; SUPERCONDUCTIVITY; HOLSTEIN; MODEL AB The anharmonic electron-phonon problem is solved in the infinite-dimensional limit using quantum Monte Carlo simulation. Charge-density-wave order is seen to remain at half filling even though the anharmonicity removes the particle-hole symmetry of the model. Superconductivity is strongly favored away from half filling but the anharmonicity does not enhance transition temperatures over the maximal values found in the harmonic limit. C1 UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Freericks, JK (reprint author), GEORGETOWN UNIV,DEPT PHYS,WASHINGTON,DC 20057, USA. RI Freericks, James/D-7502-2011; OI Freericks, James/0000-0002-6232-9165 NR 17 TC 37 Z9 37 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 25 PY 1996 VL 77 IS 22 BP 4588 EP 4591 DI 10.1103/PhysRevLett.77.4588 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200027 ER PT J AU Zurek, WH Laflamme, R AF Zurek, WH Laflamme, R TI Quantum logical operations on encoded qubits SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECOHERENCE; COMPUTERS AB We show how to carry out quantum logical operations (controlled-not and Toffoli gates) on encoded qubits for several encodings which protect against various 1-bit errors. This improves the reliability of these operations by allowing one to correct for 1-bit errors which either preexisted or occurred in the course of operation. The logical operations we consider allow one to carry out the vast majority of the steps in the quantum factoring algorithm. RP Zurek, WH (reprint author), LOS ALAMOS NATL LAB,T-6,MS B288,LOS ALAMOS,NM 87545, USA. NR 22 TC 25 Z9 26 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 25 PY 1996 VL 77 IS 22 BP 4683 EP 4686 DI 10.1103/PhysRevLett.77.4683 PG 4 WC Physics, Multidisciplinary SC Physics GA VU502 UT WOS:A1996VU50200051 ER PT J AU Kouri, DJ Hoffman, DK Peng, T Zhang, JHZ AF Kouri, DJ Hoffman, DK Peng, T Zhang, JHZ TI Reactant-product decoupling for state-to-state reactive scattering: Further partitioning in the product arrangements SO CHEMICAL PHYSICS LETTERS LA English DT Article ID COLLISIONS AB Recently, Peng and Zhang have derived a new time-dependent wavepacket ''divide and conquer'' formalism for decoupling the reactant and product pieces of the wavepacket. The approach makes it possible to treat the initial and product arrangement dynamics separately while still permitting the determination of quantitatively accurate S-matrix elements. In this paper we show how this procedure can be employed (using suitably defined partitioning potentials) to separate various types of inelastic scattering within any (or all) of the arrangements, both in reactions and photodissociation. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NYU,DEPT CHEM,NEW YORK,NY 10003. RP Kouri, DJ (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. NR 20 TC 29 Z9 29 U1 1 U2 3 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 NOV 22 PY 1996 VL 262 IS 5 BP 519 EP 525 DI 10.1016/S0009-2614(96)01114-1 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VU368 UT WOS:A1996VU36800003 ER PT J AU Zhang, XJ Jonah, CD AF Zhang, XJ Jonah, CD TI Electron solvation in 1-propanol and 2-propanol as a function of temperature SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OPTICAL-ABSORPTION SPECTRUM; TERT-BUTYL ALCOHOL; HYDRATED ELECTRON; PULSE-RADIOLYSIS; BENZOPHENONE ANION; POLAR LIQUIDS; DYNAMICS; SPECTROSCOPY; CLUSTERS; SOLVENTS AB The kinetics and activation energy for electron solvation in 1-propanol and 2-propanol were measured from -20 to -50 degrees C. The activation energy for electron solvation in 1-propanol (14.4 +/- 1.4 kJ/mol) is less than that for hydrogen-bond breakage while the activation energy for electron solvation in 2-propanol (21 +/- 2 kJ/mol) is greater than that for hydrogen-bond breakage. These results suggest that (1) the electron is solvated in preexisting clusters, (2) in 1-propanol, these clusters are cyclic and rotational motion that breaks hydrogen bonds is not rate-limiting, and (3) in 2-propanol, linear structures dominate and the solvation process requires hydrogen-bond breakage. RP Zhang, XJ (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 35 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 22 PY 1996 VL 262 IS 5 BP 649 EP 655 DI 10.1016/S0009-2614(96)01118-9 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VU368 UT WOS:A1996VU36800022 ER PT J AU Barnes, CJ Wahl, AF Shen, BH Park, MS Bambara, RA AF Barnes, CJ Wahl, AF Shen, BH Park, MS Bambara, RA TI Mechanism of tracking and cleavage of adduct-damaged DNA substrates by the mammalian 5'- to 3'-exonuclease endonuclease RAD2 homologue 1 or flap endonuclease 1 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NUCLEOTIDE EXCISION-REPAIR; POLYMERASE-EPSILON; 3' EXONUCLEASE; CALF THYMUS; DRUG CIS-DIAMMINEDICHLOROPLATINUM(II); REPLICATION; YEAST; CISPLATIN; RESISTANCE; ENCODES AB The mammalian 5'- to 3'-exonuclease/endonuclease, called RAD2 homologue 1 or flap endonuclease 1, has a unique cleavage activity, dependent on specific substrate structure. On a primer-template, in which the primer has an unannealed 5'-tail, endonucleolytic cleavage near the annealing point releases the tail intact. Entering at the 5'-end, the nuclease tracks along the entire tail to the point of cleavage, Genetic analyses suggest that this nuclease removes DNA adducts in vivo (Sommers, C. H., Miller, E. J., Dujon, B., Prakash, S., and Prakash, L. (1995) J. Biol. Chem. 270, 4193-4196). Micrococcal nuclease footprinting shows that after tracking the nuclease protects a region of the tail 25 nucleotides long, adjacent to the cleavage site. Substrates with adducts at specific locations were used to assess the mechanism of RAD2 homologue 1 nuclease tracking and its ability to cleave modified DNA. Either a conventional cis-diamminedichloroplatinum (II) (CDDP) or a bulky CDDP derivative was placed within or beyond the region protected by the nuclease. The nuclease cleaved the tail of both substrates. In contrast, a CDDP adduct just adjacent to the expected cleavage point was inhibitory. A CDDP adduct at the very 5'-end of the tail was also cleaved. The nuclease could remove tails containing adducts on the sugar-phosphate backbone. Apparently, the nuclease is designed to slide over various types of damage on single stranded DNA and then cut past the damaged site. C1 UNIV ROCHESTER, MED CTR, DEPT BIOCHEM, SCH MED & DENT, ROCHESTER, NY 14642 USA. UNIV ROCHESTER, SCH MED & DENT, CTR CANC, ROCHESTER, NY 14642 USA. BRISTOL MYERS SQUIBB PHARMACEUT RES INST, GROWTH REGULAT DEPT, SEATTLE, WA 98121 USA. LOS ALAMOS NATL LAB, DIV LIFE SCI, LOS ALAMOS, NM 87545 USA. FU NIGMS NIH HHS [GM24441] NR 51 TC 45 Z9 46 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD NOV 22 PY 1996 VL 271 IS 47 BP 29624 EP 29631 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VU525 UT WOS:A1996VU52500021 PM 8939893 ER PT J AU DeMott, MS Shen, BH Park, MS Bambara, RA Zigman, S AF DeMott, MS Shen, BH Park, MS Bambara, RA Zigman, S TI Human RAD2 homolog 1 5'- to 3'-exo/endonuclease can efficiently excise a displaced DNA fragment containing a 5'-terminal abasic lesion by endonuclease activity SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID DEOXYRIBOSE-PHOSPHATE RESIDUES; APURINIC APYRIMIDINIC SITES; ESCHERICHIA-COLI; ELIMINATION REACTIONS; BETA-ELIMINATION; EXONUCLEASE-I; DAMAGED DNA; REPAIR; DEOXYRIBOPHOSPHODIESTERASE; POLYMERASE AB Repair of abasic lesions, one of the most common types of damage found in DNA, is crucial to an organism's well-being, Studies in vitro indicate that after apurinic-apyrimidinic endonuclease cleaves immediately upstream of a baseless site, removal of the 8'-terminal sugar-phosphate residue is achieved by deoxyribophosphodiesterase activity, an enzyme-mediated beta-elimination reaction, or by endonucleolytic cleavage downstream of the baseless sugar, Synthesis and ligation complete repair. Eukaryotic RADS homolog 1 (RTH1) nuclease, by genetic and biochemical evidence, is involved in repair of modified DNA. Efficient endonucleolytic cleavage by RTH1 nuclease has been demonstrated for annealed primers that have unannealed 5'-tails, In vivo, such substrate structures could result from repair-related strand displacement synthesis, Using 5'-tailed substrates, we examined the ability of human RTH1 nuclease to efficiently remove 5'-terminal abasic residues, A series of upstream primers were used to increasingly displace an otherwise annealed downstream primer containing a 5'-terminal deoxyribose-5-phosphate. Until displacement of the first annealed nucleotide, substrates resisted cleavage, With further displacement, efficient cleavage occurred at the 3'-end of the tail, Therefore, in combination with strand displacement activity, RTH1 nucleases may serve as an important alternative to other pathways in repair of abasic sites in DNA. C1 UNIV ROCHESTER,MED CTR,DEPT OPHTHALMOL,SCH MED & DENT,ROCHESTER,NY 14642. UNIV ROCHESTER,MED CTR,DEPT BIOCHEM,SCH MED & DENT,ROCHESTER,NY 14642. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NEI NIH HHS [EY00459]; NIGMS NIH HHS [GM24441] NR 36 TC 64 Z9 64 U1 0 U2 0 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 NOV 22 PY 1996 VL 271 IS 47 BP 30068 EP 30076 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VU525 UT WOS:A1996VU52500082 PM 8939954 ER PT J AU Hirao, K Nakano, H Nakayama, K Dupuis, M AF Hirao, K Nakano, H Nakayama, K Dupuis, M TI A complete active space valence bond (CASVB) method SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR ELECTRONIC WAVEFUNCTIONS; 2ND-ORDER PERTURBATION-THEORY; METAL ALKYLIDENE COMPLEXES; BENZENE MOLECULE; FORS MODEL; SCF METHOD; ORBITALS; STATES; CONFIGURATIONS; ABSORPTION AB A complete active space valence bond (CASVB) method is proposed which is particularly adapted to chemical interpretation. A CASVB wave function can be obtained simply by transforming a canonical CASSCF function and readily interpreted in terms of the well known classical VB resonance structures. The method is applied to the ground and excited states of benzene, butadiene, and the ground state of methane. The CASVB affords a clear view of the wave functions for the various states. The electronic excitation is represented in a VB picture as rearrangements of the spin couplings or as charge transfers which involve breaking covalent bonds and forming new ionic bonds. The former gives rise to covalent excited states and the latter to ionic excited states. The physical reasons why it is so difficult to describe the ionic excited states at the CASSCF level with a single active space and why the lowest 1 B-1(2)+ state in cis-butadiene is so stabilized compared to the corresponding 1 B-1(u)+ state in the trans isomer are easily identified in view of a VB picture. The CASVB forms a useful bridge from molecular orbital theory to the familiar concepts of chemists. (C) 1996 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Hirao, K (reprint author), UNIV TOKYO, GRAD SCH ENGN, DEPT APPL CHEM, TOKYO 113, JAPAN. RI Hirao, Kimihiko/N-5483-2015; Nakano, Haruyuki/B-9925-2017 OI Nakano, Haruyuki/0000-0002-7008-0312 NR 49 TC 64 Z9 64 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 1996 VL 105 IS 20 BP 9227 EP 9239 DI 10.1063/1.472754 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VV049 UT WOS:A1996VV04900026 ER PT J AU Chialvo, AA Cummings, PT Simonson, JM Mesmer, RE AF Chialvo, AA Cummings, PT Simonson, JM Mesmer, RE TI Temperature and density effects on the high temperature ionic speciation in dilute Na+/Cl- aqueous solutions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR COEXISTENCE CURVE; SUPERCRITICAL WATER; MOLECULAR SIMULATION; PAIR; NACL; ASSOCIATION; MIXTURES; MPA AB Molecular simulation of dilute NaCl aqueous solutions is performed to study the Na+/Cl- ion-pair association and the constant of equilibrium between the solvent separated (shared) and contact ion pairs at high temperature. Using the simple point charge, the Pettitt-Rossky, and the Fumi-Tosi models for the water-water, the ion-water, and the ion-ion interactions, we determine the density dependence of the constants along the T-r = T/T-c = 1.05 isotherm, and the temperature dependence along the rho(r) = rho/rho(c) = 1.5 isochore. The simulation results for the association constant are then compared with the predictions of two recent correlations based on conductance measurements at high temperature. The outcome of the comparison is interpreted in terms of the microstructural behavior of the solvent around the ions and the realism of its dielectric behavior. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Chialvo, AA (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,419 DOUGHERTY ENGN BLDG,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 30 TC 39 Z9 39 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 1996 VL 105 IS 20 BP 9248 EP 9257 DI 10.1063/1.472756 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VV049 UT WOS:A1996VV04900028 ER PT J AU Jorgensen, JD Carpenter, JM Aeppli, G AF Jorgensen, JD Carpenter, JM Aeppli, G TI Cold neutron production SO SCIENCE LA English DT Letter C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,PRINCETON,NJ 08540. NEC RES INST,PRINCETON,NJ 08540. RP Jorgensen, JD (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 22 PY 1996 VL 274 IS 5291 BP 1288 EP 1289 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU954 UT WOS:A1996VU95400009 ER PT J AU Maitra, S Dombrowski, SM Waters, LC Ganguly, R AF Maitra, S Dombrowski, SM Waters, LC Ganguly, R TI Three second chromosome-linked clustered Cyp6 genes show differential constitutive and barbital-induced expression in DDT-resistant and susceptible strains of Drosophila melanogaster SO GENE LA English DT Article DE DNA sequencing; in situ hybridization; cytochrome P450 monooxygenase; RNA blot analysis; P element transformation; gene regulation; multigene family ID HOUSE-FLY; CYTOCHROME-P450 GENES; BACILLUS-MEGATERIUM; MOLECULAR-CLONING; MUSCA-DOMESTICA; X-CHROMOSOME; LOCALIZATION; P450(BM-1); ELEMENTS; DIPTERA AB The level of expression of the Cyp6a2 gene is much higher in the DDT-resistant 91-R strain than in the susceptible 91-C strain of Drosophila melanogaster (Waters et al. (1992b) Proc. Natl. Acad. Sci. USA, 89, 4855-4859). To understand the role of Cyp6a2 and related genes in insecticide resistance, we have isolated and characterized two new Cyp6 genes from the 91-R strain. The polypeptides encoded by these two genes, Cyp6a8 and Cyp6a9, show 77 and 75% amino acid sequence similarity, and 60 and 55% identity with Cyp6a2 of D. melanogaster, respectively. In the genome, Cyp6a8 and Cyp6a9 genes are closely clustered within 4 kb and map at region 51C of the second chromosome. In between them another Cyp gene is present which is more related to Cyp6a9 than to Cyp6a8. The Cyp6a8 gene which is transcriptionally highly active in 91-R, moderately active in ry(506) and silent in the 91-C strain hybridizes with 2.0- and 1.8-kb RNAs. Two different-sized RNAs, 2.1 and 1.8 kb, also hybridize with the Cyp6a9 and/or Cyp6a9-related genes. While the level of 2.1-kb RNA is similar in all three strains, the level of 1.8-kb RNA is highest in the 91-R strain and barely detectable in 91-C strain. Transgenic experiments showed that a 8.3-kb BamHI fragment contains the cis-regulatory elements for the expression of both Cyp6a8 and Cyp6a9-related genes. Barbital induces all these genes in all three strains and increases the levels of the two Cyp6a8 transcripts and the 1.8-kb RNA produced by the Cyp6a9 and/or Cyp6a9-related genes. Expression of the Cyp6a8 gene is down-regulated in the hybrids of 91-R and 91-C strains despite the fact that the hybrids carry one copy of the highly active allele of the Cyp6a8 gene of the 91-R strain. Based on these results we propose that the Cyp6a8 gene in 91-C strain may be turned off by an active repressor which might be inhibited by barbital treatment. In the 91-R strain, the putative repressor may be defective, allowing high level of constitutive expression of the Cyp6a8 gene. C1 UNIV TENNESSEE, DEPT BIOCHEM MOL & CELL BIOL, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. NR 21 TC 75 Z9 86 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD NOV 21 PY 1996 VL 180 IS 1-2 BP 165 EP 171 DI 10.1016/S0378-1119(96)00446-5 PG 7 WC Genetics & Heredity SC Genetics & Heredity GA VY054 UT WOS:A1996VY05400024 PM 8973362 ER PT J AU Anchell, JL Hess, AC AF Anchell, JL Hess, AC TI H2O dissociation at low-coordinated sites on (MgO)(n) clusters, n=4,8 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MAGNESIUM-OXIDE; MGO(001) SURFACE; HARTREE-FOCK; ABINITIO MO; MGO; HYDROGEN; METHANE; ADSORPTION; WATER; H-2 AB We investigate the interactions of one and two H2O molecules at three-coordinated sites of (MgO)(4) and (MgO)(8) clusters. Energies of adsorption are calculated and compared to similar work involving periodic and embedded cluster systems. The cluster model results predict that H2O chemidissociates without a barrier directly onto adjacent three-coordinated sites. The chemidissociation energy per water molecule is observed to be greater upon the dissociation of two neighboring water molecules compared to the dissociation of a single water molecule: a positive cooperativity effect. Correlation energy treated at the MP2 level of theory reduces the predicted chemidissociation energy by approximately 10 kcal/mol, and it is found that the MP2 single-point energies evaluated at the RHF-optimized geometries, MP2/RHF, differ from the energy of the MP2-optimized structures by approximately 1 kcal/mol. RP Anchell, JL (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI RES LAB, POB 999, RICHLAND, WA 99352 USA. NR 26 TC 40 Z9 40 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 21 PY 1996 VL 100 IS 47 BP 18317 EP 18321 DI 10.1021/jp961108x PG 5 WC Chemistry, Physical SC Chemistry GA VU825 UT WOS:A1996VU82500004 ER PT J AU Bowman, LE Palmer, BJ Garrett, BC Fulton, JL Yonker, CR Pfund, DM Wallen, SL AF Bowman, LE Palmer, BJ Garrett, BC Fulton, JL Yonker, CR Pfund, DM Wallen, SL TI Infrared and molecular dynamics study of D2O rotational relaxation in supercritical CO2 and Xe SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CARBON-DIOXIDE; VIBRATIONAL-RELAXATION; HYDROPHOBIC HYDRATION; RAMAN-SPECTRA; LIQUIDS; FLUIDS; SPECTROSCOPY; SIMULATIONS; PRESSURE; EQUATION AB Supercritical fluid solvents allow continuous tuning of solvent density and therefore continuous control of the number and distance of solvent-solute interactions. Such interactions exert torque on molecules in solution and thereby influence the way in which the rotational orientation of a solute molecule varies with time. In this work, we examine the rotational relaxation of D2O in two supercritical fluid solvents: Xe and CO2. In the former case, there are no electrostatic interactions between the solute and solvent. Since the nonelectrostatic interactions of D2O are very nearly centrosymmetric about the center of mass, Xe is expected to exert tittle torque on the rotating solute until liquid densities are reached. For D2O dissolved in CO2, the dipole-quadrupole interaction can exert torque on the rotating D2O, thereby hindering its rotation. Molecular dynamics simulations of these systems were used to calculate dipole autocorrelation functions containing only contributions from the solute rotational motion. These were then used to predict the rotation wings of the asymmetric stretching band, v(3), of D2O. Infrared spectra for this band were obtained in both solvents at 110.0 degrees C as a function of density. In Xe, the experimental and simulated correlation functions indicated that the solute was free to rotate, even at the highest densities examined. In CO2, however, the rotation of D2O was increasingly hindered as the solvent density was increased from gaslike to liquidlike densities. At low densities the correlation functions had negative minima, indicating a partial reversal in the direction of the average transition dipole moment vector as the molecules freely rotated. In CO2, at high densities the functions exhibited simple, monotonic decay, indicating a persistence in the direction of the vector with time and substantially hindered rotation. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Garrett, Bruce/F-8516-2011 NR 40 TC 29 Z9 30 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 21 PY 1996 VL 100 IS 47 BP 18327 EP 18334 DI 10.1021/jp9611176 PG 8 WC Chemistry, Physical SC Chemistry GA VU825 UT WOS:A1996VU82500006 ER PT J AU Clinton, DE Tryk, DA Bae, IT Urbach, FL Antonio, MR Scherson, DA AF Clinton, DE Tryk, DA Bae, IT Urbach, FL Antonio, MR Scherson, DA TI In situ vanadium K-edge and tungsten L(III)-edge X-ray absorption fine structure of vanadium-substituted heteropolytungstates immobilized in a high-area carbon electrode in acid aqueous electrolytes SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID POLYNUCLEAR MOLYBDENUM; COORDINATION-COMPOUNDS; BLOOD-CELLS; EXAFS XANES; SPECTROSCOPY; CATALYSTS; SPECTRA; REDUCTION; COMPLEXES; TITANIUM AB Electronic and structural aspects of vanadium-substituted heteropolytungstates immobilized in a high-area carbon (XC-72) as a function of oxidation state have been examined by in situ X-ray absorption near-edge structure (XANES) in an acidic electrolyte. The results obtained for K4PVW11O40 revealed a sizable shift in the V K-edge XANES region, which is characterized by a prominent pre-edge peak, following a one-electron reduction. Such behavior has been attributed to the transfer of an electron to an orbital localized mainly on vanadium. Injection of a second electron gives rise to the near disappearance of the pre-edge peak without major shifts in the position of edge jump, a phenomenon ascribed to an increase in the symmetry of the vanadium site upon reduction to yield a nearly octahedral environment. Similar behavior is observed for Cs6PV3W9O40 when the electrode is polarized in the potential regions where the vanadium ions are reduced to V-IV and V-III, respectively. No changes in the in situ W L(III)-edge XANES could be discerned for these vanadium-substituted heteropolytungstates in their various oxidation states, for which the spectral features were the same as those of H3PW12O40 adsorbed on XC-72 under otherwise identical conditions. C1 CASE WESTERN RESERVE UNIV,ERNEST B YEAGER CTR ELECTROCHEM SCI,CLEVELAND,OH 44106. CASE WESTERN RESERVE UNIV,DEPT CHEM,CLEVELAND,OH 44106. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RI Tryk, Donald/D-5931-2012 OI Tryk, Donald/0000-0003-4660-9674 NR 36 TC 15 Z9 15 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 21 PY 1996 VL 100 IS 47 BP 18511 EP 18514 DI 10.1021/jp961781m PG 4 WC Chemistry, Physical SC Chemistry GA VU825 UT WOS:A1996VU82500031 ER PT J AU Baker, GA Kawashima, N AF Baker, GA Kawashima, N TI Renormalized coupling constant in the Ising model SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID CALLAN-SYMANZIK EQUATION; LATTICE FIELD-THEORY; MONTE-CARLO; CRITICAL EXPONENTS; CRITICAL-DYNAMICS; CRITICAL INDEXES; 3 DIMENSIONS; PERCOLATION; ALGORITHMS; BEHAVIOR AB The three-dimensional Ising model is studied by means of the Swendsen-Wang, cluster, Monte Carlo method. The simulations are performed on finite sized systems up to the 96-cube, and the renormalized coupling constant is estimated to be g* = 25.0(5). We make further arguments and computations and say that g* greater than or equal to (g) over cap and 4.5 less than or similar to (g) over cap less than or similar to 5.4 so that g* > 0 which implies the validity of hyperscaling. The Josephson hyperscaling relation also appears to hold. We give estimates for some of the critical indices. C1 TOHO UNIV, DEPT PHYS, FUNABASHI, CHIBA 274, JAPAN. RP LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87544 USA. NR 49 TC 15 Z9 15 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD NOV 21 PY 1996 VL 29 IS 22 BP 7183 EP 7197 DI 10.1088/0305-4470/29/22/018 PG 15 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA VW564 UT WOS:A1996VW56400018 ER PT J AU Magnussen, OM Ocko, BM Deutsch, M Regan, MJ Pershan, PS Abernathy, D Grubel, G Legrand, JF AF Magnussen, OM Ocko, BM Deutsch, M Regan, MJ Pershan, PS Abernathy, D Grubel, G Legrand, JF TI Self-assembly of organic films on a liquid metal SO NATURE LA English DT Article ID X-RAY REFLECTIVITY; WATER-INTERFACE; SURFACE; MONOLAYERS; MERCURY; DIFFRACTION; ALKANES AB THE structure and phase behaviour of organic thin films result from the subtle interplay of intermolecular Van der Waals interactions, which promote self-assembly and long-ranged order, and the more complex interactions between the end groups bf the organic chains and the substrate. The structure of molecular films of amphiphiles has been extensively studied on subphases of dielectric liquids, notably water (Langmuir monolayers) and on solid surfaces (self-assembled monolayers, SAMs)(1-4). Here we report structural studies, by synchrotron X-ray re scattering, of an Intermediate case: densely packed alkanethiol films on the surface of liquid mercury, White, like SAMs, these films form strong chemical bonds to the subphase, this subphase is smooth and unstructured, as in the case of Langmuir monolayers, But unlike either of these(1,2,5-7), our films have no inplane long-range order, We suggest that the strong interaction of the thiol group with the underlying disordered liquid dominates here over the order-promoting interactions of the alkyl chains. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BAR ILAN UNIV,DEPT PHYS,IL-52100 RAMAT GAN,ISRAEL. HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38041 GRENOBLE,FRANCE. UNIV GRENOBLE 1,SPECTROMETRIE PHYS LAB,F-38403 GRENOBLE,FRANCE. RI Abernathy, Douglas/A-3038-2012 OI Abernathy, Douglas/0000-0002-3533-003X NR 19 TC 98 Z9 98 U1 1 U2 25 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 21 PY 1996 VL 384 IS 6606 BP 250 EP 252 DI 10.1038/384250a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VU381 UT WOS:A1996VU38100046 ER PT J AU Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Buchholz, R Bruncko, D Chechelnitski, S Claxton, B Cozzika, G Cvach, J DagoretCampagne, S Dau, WD Deckers, H Deckers, T Deschamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Ferencei, J Fominykh, B Goerlach, U Gorbov, LA Gorelov, I Hajduk, L Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Lamarche, F Landon, MPJ Laforge, B Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rybicki, K Rostovtsev, A Royon, C Schleif, S Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stiewe, J Tchernyshov, V Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K AF Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Buchholz, R Bruncko, D Chechelnitski, S Claxton, B Cozzika, G Cvach, J DagoretCampagne, S Dau, WD Deckers, H Deckers, T Deschamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Ferencei, J Fominykh, B Goerlach, U Gorbov, LA Gorelov, I Hajduk, L Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Lamarche, F Landon, MPJ Laforge, B Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rybicki, K Rostovtsev, A Royon, C Schleif, S Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stiewe, J Tchernyshov, V Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K TI Hadronic response and e/pi separation with the H1 lead/fibre calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SHOWER AB Hadronic response and electron identification performance of the new H1 lead-scintillating fibro calorimeter are investigated in the 1 to 7 GeV energy range using data taken at the CERN Proton Synchrotron. The energy response to minimum ionizing particles and interacting pions are studied and compared to Monte Carlo simulations. The measured energy of pions interacting either in the electromagnetic or in the hadronic section is found to scale linearly with the incident energy, providing an energy resolution sigma/E similar to 38% within a depth of one interaction length and sigma/E similar to 29% for a total depth of two interaction lengths. Several electron identification estimators are studied and combined as a function of energy and impact point. The probability for pions to be misidentified as electrons of any measured energy above 1 GeV ranges from 5% (for 2 GeV incident pions) to 0.49% (at 7 GeV) for an electron detection efficiency of 90%. The probability for pions of a given energy to be misidentified as electrons of the same energy falls to 0.25% at 7 GeV. C1 DESY,D-2000 HAMBURG,GERMANY. UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. UNIV DORTMUND,INST PHYS,D-4600 DORTMUND,GERMANY. UNIV HEIDELBERG,INST HOCHENERGIEPHYS,HEIDELBERG,GERMANY. SLOVAK ACAD SCI,INST EXPT PHYS,KOSICE 04353,SLOVAKIA. UNIV LONDON QUEEN MARY COLL,LONDON E1 4NS,ENGLAND. INST THEORET & EXPT PHYS,MOSCOW 117259,RUSSIA. ECOLE POLYTECH,LPNHE,IN2P3,CNRS,PALAISEAU,FRANCE. UNIV PARIS 06,LPNHE,PARIS,FRANCE. UNIV PARIS 07,CNRS,IN2P3,PARIS,FRANCE. ACAD SCI CZECH REPUBL,INST PHYS,PRAGUE,CZECH REPUBLIC. CHARLES UNIV,NUCL CTR,PRAGUE,CZECH REPUBLIC. INST NUCL PHYS,KRAKOW,POLAND. RUTHERFORD APPLETON LAB,DIV ELECT,CHILTON,ENGLAND. CHRISTIAN ALBRECHTS UNIV KIEL,INST REINE & ANGEW KERNPHYS,D-2300 KIEL,GERMANY. LUND UNIV,DEPT PHYS,LUND,SWEDEN. PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CTR ETUD SACLAY,CEA,DSM,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. RI Eliseev, Alexandr/N-2090-2015; Gorelov, Igor/J-9010-2015; Ozerov, Dmitry/E-9139-2016; Cvach, Jaroslav/G-6269-2014 OI Gorelov, Igor/0000-0001-5570-0133; NR 23 TC 19 Z9 19 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 NOV 21 PY 1996 VL 382 IS 3 BP 395 EP 412 DI 10.1016/S0168-9002(96)00769-3 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VZ886 UT WOS:A1996VZ88600004 ER PT J AU Kamae, T Arai, K Ohtsuka, T Tsuchida, N Aihara, H AF Kamae, T Arai, K Ohtsuka, T Tsuchida, N Aihara, H TI Focussing DIRC - A new compact Cherenkov ring imaging device SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We present a new device for particle identification, the Focussing DIRC that fits into a tight detector configuration and fully exploits the potentiality of Cherenkov ring imaging technique in the momentum range of high-energy fixed-target and collider experiments. In the device, internally reflected Cherenkov rings in a thin quartz radiator plate are focussed by a toroidal mirror surface to arc-fike loci at the circumference of the plate. The image is taken on the focal surface by segmented photon detectors or by tightly packed optical fibers of diameter around 1 mm. The focussing optics is implemented as extension of the radiator plate and occupies no more than about 10 sm by 12 cm in cross section. The image width of the Cherenkov ring is mostly determined by the chromatic dependence of the Cherenkov angle and the multiple Coulomb scattering in the radiator plate. We expect to separate pions and kaons by similar to 3.5-4 sigma up to 3.5 GeV/e and by similar to 3 sigma up al 4 GeV/e with presently available photon sensors. With higher quantum efficiency sensors such as VLPCs, we will be able to separate kaons from pions up to similar to 10 GeV/c with a 2 cm thick quartz radiator. C1 UNIV TOKYO,RES CTR EARLY UNIV,TOKYO,JAPAN. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Kamae, T (reprint author), UNIV TOKYO,DEPT PHYS,BUNKYO KU,7-3-1 HONGO,TOKYO 113,JAPAN. RI Aihara, Hiroaki/F-3854-2010 OI Aihara, Hiroaki/0000-0002-1907-5964 NR 17 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 1996 VL 382 IS 3 BP 430 EP 440 DI 10.1016/S0168-9002(96)00817-0 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VZ886 UT WOS:A1996VZ88600007 ER PT J AU Ratzmann, P AF Ratzmann, P TI Thermal analysis of the CDF SVX II silicon vertex detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A simple finite difference technique is used to model conduction and convection in silicon detector components. The solution is found using a simultaneous equation solver which solves in minutes and enables parametric studies to be performed quickly and easily. The modelling technique is compared to output from a finer mesh, solved using ANSYS [11]. The method lends itself to the problem of thermal runaway in silicon detectors, which occurs when internal (temperature dependent) heat generation within the silicon exceeds the heat removal rate by conduction and convection, the effect of which increases with radiation dose. Comparisons between the computer simulation and some physical models are provided, as well as a comparison with analytical techniques. This modelling technique is then applied to the CDF SVX II silicon detector to determine the temperature profile of the silicon during operating conditions. RP Ratzmann, P (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 1996 VL 382 IS 3 BP 447 EP 460 DI 10.1016/S0168-9002(96)00784-X PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VZ886 UT WOS:A1996VZ88600009 ER PT J AU Poppitz, E Shadmi, Y Trivedi, SP AF Poppitz, E Shadmi, Y Trivedi, SP TI Supersymmetry breaking and duality in SU(N)xSU(N-M) theories SO PHYSICS LETTERS B LA English DT Article ID GAUGE-THEORIES AB We consider a class of N=1 supersymmetric Yang-Mills theories, with gauge group SU(N)xSU(N-M) and fundamental matter content. Duality plays an essential role in analyzing the nonperturbative infrared dynamics of these models. We find that Yukawa couplings drive these theories into the confining phase, and show how the nonperturbative superpotentials arise in the dual picture. We show that the odd-N, M=2 models with an appropriate tree-level superpotential break supersymmetry. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Poppitz, E (reprint author), UNIV CHICAGO,ENRICO FERMI INST,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. NR 20 TC 43 Z9 43 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 NOV 21 PY 1996 VL 388 IS 3 BP 561 EP 568 DI 10.1016/S0370-2693(96)01192-6 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU657 UT WOS:A1996VU65700016 ER PT J AU Riotto, A Tornkvist, O Mohapatra, RN AF Riotto, A Tornkvist, O Mohapatra, RN TI Higgs boson mass in models with gauge-mediated supersymmetry breaking SO PHYSICS LETTERS B LA English DT Article ID STANDARD MODEL; PHYSICS AB We present the predictions for the mass M(h) of the lightest Higgs boson in models with gauge-mediated supersymmetry breaking as a function of the SUSY-breaking scale. We include all radiative corrections up to two loops and point out that if the CDF e(+)e(-)gamma gamma event is interpreted in terms of these models, then the lightest Higgs boson should be lighter than 110 GeV. C1 UNIV MARYLAND,DEPT PHYS & ASTRON,COLLEGE PK,MD 20742. RP Riotto, A (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 32 TC 19 Z9 19 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 NOV 21 PY 1996 VL 388 IS 3 BP 599 EP 604 DI 10.1016/S0370-2693(96)01186-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU657 UT WOS:A1996VU65700021 ER PT J AU Viecelli, JA AF Viecelli, JA TI Levy statistics of light scattering in turbulent mixing layers SO APPLIED OPTICS LA English DT Article ID RADIATIVE-TRANSFER; TRANSPORT; SURFACES; MIXTURES; MEDIA; EARTH; JETS AB Experimental evidence and computational evidence suggest that the distribution of random segment lengths defined by the intersections of ray paths with the contorted and folded interface between two fluids mixed by turbulence follows a probability distribution with a Levy law tail. Assuming that the two fluids have different optical properties, one finds that the statistics of light scattered by the mixing interface reflect the probability distribution for the random distances between the intersection points of straight ray paths with the interface. Examples of light-scattering calculations for limiting cases, including the planetary albedo problem and imaging through a transparent mixing layer, are discussed. (C) 1996 Optical Society of America RP Viecelli, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 33 TC 0 Z9 0 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1996 VL 35 IS 33 BP 6504 EP 6513 DI 10.1364/AO.35.006504 PG 10 WC Optics SC Optics GA VT736 UT WOS:A1996VT73600008 PM 21127674 ER PT J AU Felcher, GP Kleb, R AF Felcher, GP Kleb, R TI Antiferromagnetic domains and the spin-flop transition of MnF2 SO EUROPHYSICS LETTERS LA English DT Article ID NEUTRON AB In antiferromagnetic MnF2 the magnetic moments of manganese are aligned along the tetragonal axis of the rutile structure. In a magnetic field H-SF along that axis (9.27 T at 4.2 K) the antiferromagnetic moments flop in the basal plane. Polarized neutron diffraction measurements showed that at about H-SF the entire crystal becomes aligned in a single antiferromagnetic domain, which persists even after the field is suppressed. The effect is due to a minute misalignment (a fraction of degree) of the applied held with the tetragonal axis of the crystal. The ensuing breakdown of symmetry at the spin-flop transition provides a way to control domains in this type of antiferromagnet. RP Felcher, GP (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 13 TC 20 Z9 20 U1 1 U2 9 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 NOV 20 PY 1996 VL 36 IS 6 BP 455 EP 460 DI 10.1209/epl/i1996-00251-7 PG 6 WC Physics, Multidisciplinary SC Physics GA VW165 UT WOS:A1996VW16500010 ER PT J AU Darovsky, A Kezerashvili, V Coppens, P Weyhermuller, T Hummel, H Wieghardt, K AF Darovsky, A Kezerashvili, V Coppens, P Weyhermuller, T Hummel, H Wieghardt, K TI Temperature dependence of the electron transfer in a (MnMnIII)-Mn-II(mu-OH) mixed-valence manganese SO INORGANIC CHEMISTRY LA English DT Article ID LACTOBACILLUS-PLANTARUM; PSEUDOCATALASE; CATALASE; DYNAMICS AB The observed metal-ligand bond lengths in the mixed-valence complex [ttacnMn(II)(mu-OH)(mu-pivalonato)(2)-Mn(III)ttacn](ClO4)(2) show a significant temperature dependence in the 20-298 K range. Spectroscopic and crystallographic evidence indicates the temperature dependence to be due to a superposition of two orientations with different energies in the crystal, which are interconverted by electron transfer between the metal centers. C1 SUNY BUFFALO,DEPT CHEM,BUFFALO,NY 14260. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RI Weyhermuller, Thomas/G-6730-2012; Wieghardt, Karl/B-4179-2014 OI Weyhermuller, Thomas/0000-0002-0399-7999; NR 17 TC 19 Z9 19 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 20 PY 1996 VL 35 IS 24 BP 6916 EP & DI 10.1021/ic9610391 PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VV040 UT WOS:A1996VV04000005 ER PT J AU Lipton, AS Mason, SS Myers, SM Reger, DL Ellis, PD AF Lipton, AS Mason, SS Myers, SM Reger, DL Ellis, PD TI Cd-113 shielding tensors of monomeric cadmium compounds containing nitrogen donor atoms .3. CP/MAS studies on five-coordinate cadmium complexes having N(3)X(2) (X=H,N,O, and S) donor atoms SO INORGANIC CHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; SOLID-STATE; SINGLE-CRYSTAL; NMR-SPECTROSCOPY; CARBONIC-ANHYDRASE; DILUTE SPINS; DIHYDRATE; PROTEINS; PYRIDINE; CENTERS AB The principal elements of the Cd-113 shielding tensor for a set of five- coordinate compounds having mixed donor atoms coordinating to the cadmium were determined via CP/MAS NMR experiments. The first complex, [HB(3,5-Me(2)pz)(3)]CdBH4 (where pz = pyrazolyl), has a CdN3H2 inner coordination sphere. The isotropic chemical shift in the solid state is 355.1 ppm, and its chemical shift anisotropy (CSA, Delta sigma) is -596,ppm with an asymmetry parameter (eta) of 0.64. The second complex, [HB(3,5-Me(2)pz)(3)]Cd[H2B(pz)(2)], has five nitrogen donor atoms bonded to the cadmium. This N-5 or N3N2 compound was the only material of this study to manifest dipolar splitting of the cadmium resonance from the quadrupolar(14)N. Th, isotropic chemical shift, CSA, and the value of eta for this material were therefore determined at higher field where the dipolar splitting was less than the linewidth, yielding values of 226.6 ppm, -247 ppm, and 0.32, respectively. A second N-5 material, [HB(3-Phpz)(3)]Cd[H2B(3,5-Me(2)-pz)(2)], was also investigated and has an isotropic shift of 190.2 ppm, a CSA of 254 ppm, and an eta of 0.86. Also studied was [HB(3-Phpz)(3)]Cd[(Bu(t)CO)(2)CH], which has an CdN3O2 inner core. The isotropic chemical shift of this complex is 173.6 ppm, and the values of Delta sigma and eta were determined to be -258 ppm and 0.38, respectively. The final compound, [HB(3,5-Me(2)pz)(3)]Cd[S(2)CNEt(2)], with N3S2 donor atoms, has an isotropic shift of 275.8 ppm, an eta of 0.51, and a CSA of +375 ppm. Utilizing previous assignments, the most shielded tensor element was determined to be oriented normal to the plane of the tridentate ligand. The shielding tensor information is used to speculate on the Coordination geometry of the CdN3O2 inner core complex. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV S CAROLINA, DEPT CHEM & BIOCHEM, COLUMBIA, SC 29208 USA. NR 46 TC 17 Z9 17 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 20 PY 1996 VL 35 IS 24 BP 7111 EP 7117 DI 10.1021/ic951528l PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA VV040 UT WOS:A1996VV04000033 ER PT J AU Bian, XD Berkowitz, CM Zhong, SY AF Bian, XD Berkowitz, CM Zhong, SY TI Aircraft observations of the effects of internal gravity waves on ozone over the western North Atlantic SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DISTURBANCES AB A series of wave-like patterns in ozone mixing ratio, potential temperature, and dew point were observed during aircraft horizontal sampling at a constant elevation of approximately 1700 m over the Gulf of Maine and the western North Atlantic. Several hypotheses about the cause for such phenomena are examined. Both the observational evidence and a simple theoretical analysis suggest that the most likely explanation is the atmospheric perturbation associated with internal gravity waves trapped in a stable boundary layer. RP Bian, XD (reprint author), PACIFIC NW LAB, ENVIRONM & ENERGY SCI DIV, POB 999, RICHLAND, WA 99352 USA. NR 11 TC 4 Z9 4 U1 0 U2 0 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 NOV 20 PY 1996 VL 101 IS D20 BP 26017 EP 26021 DI 10.1029/96JD02746 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VU988 UT WOS:A1996VU98800013 ER PT J AU Singhal, A Toth, LM Lin, JS Affholter, K AF Singhal, A Toth, LM Lin, JS Affholter, K TI Zirconium(IV) tetramer/octamer hydrolysis equilibrium in aqueous hydrochloric acid solution SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ANGLE X-RAY; SCATTERING; CHLORIDE AB Small-angle X-ray scattering measurements were performed on zirconium acidic aqueous solutions to investigate the structure and the size of polynuclear species larger than the previously identified tetrameric species. Solutions with [H+](added) and [OH-](added) ranging from 0.0 to 1.0 M and 0.0 to 0.02 M, respectively, were analyzed. This study demonstrates that an octameric species, Zr-8(OH)(20)(H2O)(24)Cl-12, exists in equilibrium with the tetrameric species, Zr-4(OH)(8)(H2O)(16)Cl-6(2+), such that, for 0.05 M Zr(IV) in highly acidic solutions ([H+](added) greater than or equal to 0.6 M), the tetramer is the dominant species; and at conditions with [H+](added) less than or equal to 0.05 M, the octameric species becomes predominant. The estimated value of the equilibrium quotient obtained for the tetramer/octamer equilibrium is 0.20 +/- 0.05 M(3). The tetramer and octamer have radii of gyration of 3.8 and 5.1 +/- 0.2 Angstrom and a hydrolysis ratio of 2.0 and 2.5, respectively. The octamer forms by stacking two tetramers on top of each other. At conditions where small amounts of NaOH are added, unidentified polymeric Zr(IV) species larger in size than the octameric species appear. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 22 TC 120 Z9 121 U1 2 U2 42 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 NOV 20 PY 1996 VL 118 IS 46 BP 11529 EP 11534 DI 10.1021/ja9602399 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA VU995 UT WOS:A1996VU99500021 ER PT J AU Gordon, MS Gano, DR Curtiss, E AF Gordon, MS Gano, DR Curtiss, E TI Potential energy surfaces for proton abstractions from acetic acid SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-ORBITAL METHODS; GAS-PHASE; BASIS-SETS; GAUSSIAN-2 THEORY; ANION; ELEMENTS; 1ST-ROW AB The abstractions of hydrogen from both carbon and oxygen in acetic acid by hydride, fluoride, and hydroxide anions have been studied using nb initio electronic structure calculations. Molecular structures were optimized at the Hartree-Fock level of theory using the 6-31++G(d,p) basis set. For energetics, the 6-311++G(d,p) basis set was used, with second- and fourth-order perturbation theory corrections, for both minima and transition states. For the hydride and fluoride ion abstractions of hydrogen from carbon, a small activation energy exists at the Hartree-Fock level, but vanishes when correlation energy corrections are introduced. No other barriers are found for the abstraction reactions, but intermediate minima are found on the F- + CH3COOH --> FH + (CH2COOH)-C-- surface and on the analogous OH- + CH3COOH surface. The calculated heats of formation for both acetic acid anions are in good agreement with the experimental values. The fourth-order perturbation theory calculation of the activation energy for the isomerization of acetate to enolate ion is 50.4 kcal/mol. The G2 values for the gas phase acidities of acetic acid at the OH and CH ends of the molecule are 339.3 and 365.8 kcal/mol, respectively. The former result is in good agreement with experiment. C1 MINOT STATE UNIV, DEPT CHEM, MINOT, ND 58707 USA. RP Gordon, MS (reprint author), IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. NR 33 TC 4 Z9 4 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD NOV 20 PY 1996 VL 118 IS 46 BP 11592 EP 11598 DI 10.1021/ja9538546 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA VU995 UT WOS:A1996VU99500028 ER PT J AU Wenk, HR Chateigner, D Pernet, M Bingert, J Hellstrom, E Ouladdiaf, B AF Wenk, HR Chateigner, D Pernet, M Bingert, J Hellstrom, E Ouladdiaf, B TI Texture analysis of Bi-2212 and 2223 tapes and wires by neutron diffraction SO PHYSICA C LA English DT Article ID CRITICAL-CURRENT-DENSITY; SHEATHED BI(2223) TAPES; BSCCO SUPERCONDUCTORS; PREFERRED ORIENTATION; DEPENDENCE; (BI AB The crystallographic texture of silver sheathed monocore tapes and wires, and multifilamentary tapes containing Bi2Sr2CaCu2Ox (Bi-2212) and Bi2Sr2Ca2Cu3Ox (Bi-2223) superconducting oxides was determined by neutron diffraction, using a position sensitive detector. The orientation distribution (OD) was obtained from measurements of 4-6 pole figures. The oxide textures of these tapes and wires displayed axial symmetry, indicative of a grain-shape-controlled orientation mechanism. In monocore and multifilamentary tapes the c-axes of Bi-2212 and Bi-2223 are oriented perpendicular to the rolling plane, in wires they are perpendicular to the wire direction, The multifilamentary tape has the strongest texture with an OD maximum of 46 times that of a random sample, Monocore tapes are 26 and 35 mrd, and wires are 2.1 and 1.5 mrd. For comparison, a sinter-forged Bi-2223 barpowder was analyzed and exhibited c-axes parallel to the compression direction with a maximum of only 3.4 mrd, The texture of the silver sheaths depends on the processing conditions. C1 CNRS,CRISTALLOG LAB,F-38042 GRENOBLE 9,FRANCE. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,MSTG,LOS ALAMOS,NM 87545. UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. ILL GRENOBLE,F-38042 GRENOBLE 09,FRANCE. RP Wenk, HR (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI Chateigner, Daniel/A-7654-2008 OI Chateigner, Daniel/0000-0001-7792-8702 NR 35 TC 17 Z9 17 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD NOV 20 PY 1996 VL 272 IS 1-2 BP 1 EP 12 DI 10.1016/S0921-4534(96)00561-8 PG 12 WC Physics, Applied SC Physics GA VZ259 UT WOS:A1996VZ25900001 ER PT J AU Graden, JA Posewitz, MC Simon, JR George, GN Pickering, IJ Winge, DR AF Graden, JA Posewitz, MC Simon, JR George, GN Pickering, IJ Winge, DR TI Presence of a copper(I)-thiolate regulatory domain in the copper-activated transcription factor Amt1 SO BIOCHEMISTRY LA English DT Article ID X-RAY-ABSORPTION; DNA-BINDING PROTEIN; CUP2 GENE-PRODUCT; METALLOTHIONEIN GENE; SACCHAROMYCES-CEREVISIAE; YEAST METALLOTHIONEIN; CANDIDA-GLABRATA; FINE-STRUCTURE; EXPRESSION; CLUSTER AB The Amt1 transcription factor from Candida glabrata is activated by the formation of a tetracopper-thiolate cluster. Recombinant Amt1 (residues 1-110) is isolated as a Cu,ZnAmt1 complex. Previous mapping studies [Farrell et al, (1996) Biochemistry 35, 1571-1580] revealed that the Zn(II) site is enfolded by an independent, N-terminal domain consisting of residues 1-40. One prediction from the mapping study is that the tetracopper cluster is enfolded by residues 41-110. A truncated Amt1 peptide consisting of residues 37-110 was expressed and isolated asa CuAmt1 complex with 4 mol equiv of Cu(I) bound. The bound Cu(I) ions in the truncated Amt1 complex were spectroscopically similar to Cu(I) ions bound in the 110-mer Amt1 molecule in the energies and intensities of the ultraviolet S --> Cu charge transfer transitions and luminescence. Copper K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) of the truncated CuAmt1 complex revealed the same 2.26 Angstrom mean Cu-S bond distance as in the Cu,ZnAmt1 complex. A diagnostic feature of the polycopper-thiolate cluster in Cu,ZnAmt1 is the short 2.7 Angstrom Cu-Cu distance determined by Cu K-edge EXAFS. The truncated CuAmt1 complex had the same short 2.7 Angstrom Cu-Cu distance. The truncated CuAmt1 complex bound DNA specifically and with high affinity consistent with residues 41-110 being an independent domain stabilized by the tetracopper cluster. Thus, Amt1 consists of three independent and contiguous domains, an N-terminal Zn module (residues 1-40), an adjacent Cu regulatory domain (residues 41-110), and a C-terminal transcriptional activation domain. Cu(I) activation of Amt1 appears to consist of conversion of the 70-residue Cu regulatory domain from an inactive conformer to a structure containing the tetracopper cluster. C1 UNIV UTAH,HLTH SCI CTR,SALT LAKE CITY,UT 84132. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RI George, Graham/E-3290-2013; Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 FU CSAP SAMHSA HHS [SP30-CA 42014]; NIEHS NIH HHS [ES 03817] NR 31 TC 39 Z9 40 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 19 PY 1996 VL 35 IS 46 BP 14583 EP 14589 DI 10.1021/bi961642v PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VU224 UT WOS:A1996VU22400017 PM 8931556 ER PT J AU Goodwin, TJ Leppert, VJ Smith, CA Risbud, SH Niemeyer, M Power, PP Lee, HWH Hrubesh, LW AF Goodwin, TJ Leppert, VJ Smith, CA Risbud, SH Niemeyer, M Power, PP Lee, HWH Hrubesh, LW TI Synthesis of nanocrystalline gallium nitride in silica aerogels SO APPLIED PHYSICS LETTERS LA English DT Article ID LIGHT-EMITTING-DIODES; GREEN; BLUE AB Nanocrystals of gallium nitride were synthesized in silica aerogel host matrices by pyrolysis of dimeric dimethylgallium-diphenylamide precursor sequestered in the nanometer scale aerogel pores. Powder x-ray diffraction (XRD) and selected area electron-diffraction results verify the formation of hexagonal gallium nitride material in the aerogels, and Scherrer-broadening analysis of the XRD data indicate the gallium nitride particle size is similar to 20 nm. Transmission electron microscopy results show that the gallium nitride nanoparticles have diameters between 10 and 40 nm with an average diameter of 23 nm. The synthesis parameters for the gallium nitride nanocrystals in the aerogel hosts are discussed. (C) 1996 American Institute of Physics. C1 UNIV CALIF DAVIS, DEPT CHEM, DAVIS, CA 95616 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP UNIV CALIF DAVIS, DEPT CHEM ENGN & MAT SCI, DAVIS, CA 95616 USA. NR 13 TC 32 Z9 34 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 18 PY 1996 VL 69 IS 21 BP 3230 EP 3232 DI 10.1063/1.118019 PG 3 WC Physics, Applied SC Physics GA VT731 UT WOS:A1996VT73100039 ER PT J AU Oden, PI Datskos, PG Thundat, T Warmack, RJ AF Oden, PI Datskos, PG Thundat, T Warmack, RJ TI Uncooled thermal imaging using a piezoresistive microcantilever SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOMIC-FORCE MICROSCOPE; MICROMECHANICAL SENSORS; CANTILEVER PROBES; ULTRAHIGH-VACUUM AB The operation of an uncooled, microcantilever-based infrared (IR) imaging device is demonstrated. Bending of the microcantilever is a function of the IR radiation intensity incident on the cantilever surface. The infrared image of the source is obtained by rastering a microfabricated cantilever over the image formed at the focal plane of a concave mirror. The bending variation of the microcantilever, as it scanned the focal plane of the mirror, is used to construct an infrared image of the source in front of the mirror. The thermal image obtained by scanning a single element cantilever is presented. (C) 1996 American Institute by Physics. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RP Oden, PI (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,CHEM BIOL PHYS SECT,OAK RIDGE,TN 37831, USA. NR 38 TC 78 Z9 81 U1 2 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 18 PY 1996 VL 69 IS 21 BP 3277 EP 3279 DI 10.1063/1.117309 PG 3 WC Physics, Applied SC Physics GA VT731 UT WOS:A1996VT73100055 ER PT J AU Cummings, PT Chialvo, AA AF Cummings, PT Chialvo, AA TI Molecular simulation of supercritical water and aqueous solutions SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 3rd Liquid Matter Conference CY JUL 06-10, 1996 CL UNIV E ANGLIA, NORWICH, ENGLAND SP European Phys Soc, Liquid Sect, Univ E Anglia, Inst Phys HO UNIV E ANGLIA ID SOLVENT ELECTROLYTE-SOLUTIONS; VAPOR-LIQUID-EQUILIBRIUM; MONTE-CARLO SIMULATION; ION-PAIR; SODIUM-CHLORIDE; COMPUTER-SIMULATION; MEAN FORCE; TEMPERATURES; DYNAMICS; ASSOCIATION AB We describe molecular dynamics simulations of supercritical water and supercritical aqueous solutions using simple non-polarizable models of water and a new polarizable model for water developed by our research group. We compare the simulation results to neutron diffraction studies where available and to experimental measurements of ion pairing in the case of supercritical aqueous electrolyte solutions. Simulation results obtained on massively parallel supercomputers are used to evaluate size effects in the simulations and to speed up the CPU-time-consuming polarizability component of the simulation. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Cummings, PT (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 45 TC 11 Z9 12 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 18 PY 1996 VL 8 IS 47 BP 9281 EP 9287 DI 10.1088/0953-8984/8/47/016 PG 7 WC Physics, Condensed Matter SC Physics GA VW562 UT WOS:A1996VW56200016 ER PT J AU DiCicco, A AF DiCicco, A TI Local structure in binary liquids probed by EXAFS SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 3rd Liquid Matter Conference CY JUL 06-10, 1996 CL UNIV E ANGLIA, NORWICH, ENGLAND SP European Phys Soc, Liquid Sect, Univ E Anglia, Inst Phys HO UNIV E ANGLIA ID RAY-ABSORPTION SPECTROSCOPY; NEUTRON-DIFFRACTION; MOLTEN-SALTS; CHLORIDE AB An overview of recent EXAFS measurements on binary liquids, including molten ionic and superionic salts, is given. Multiple-edge EXAFS data analysis using multiple-scattering theory is shown to be able to give accurate and reliable information on short-range structure, complementary to that obtained using diffraction techniques. Structural results on alkali bromides (KBr, RbBr) are illustrated and shown to be in agreement with computer simulations based on well established interatomic potentials. EXAFS results of liquid CuBr, for which a neutron diffraction study using the isotopic substitution method is available, are presented. Evidence for a narrower Cu-Br bond-length distribution is found. The usefulness of the performance of EXAFS measurements on binary liquid systems is addressed. C1 UNIV CAMERINO,DIPARTIMENTO MATEMAT & FIS,UDR INFM,I-62032 CAMERINO,MC,ITALY. RP DiCicco, A (reprint author), STANFORD SYNCHROTRON RADIAT LAB,POB 4349,BIN 69,STANFORD,CA 94305, USA. NR 22 TC 10 Z9 10 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 18 PY 1996 VL 8 IS 47 BP 9341 EP 9345 PG 5 WC Physics, Condensed Matter SC Physics GA VW562 UT WOS:A1996VW56200026 ER PT J AU Bodmer, AR Murali, S Usmani, QN AF Bodmer, AR Murali, S Usmani, QN TI Nuclear core dynamics and rearrangement energy for hypernuclei SO NUCLEAR PHYSICS A LA English DT Article ID VARIATIONAL CALCULATIONS; BINDING-ENERGIES AB The effect of the nuclear core dynamics on the binding energies of Lambda hypernuclei is studied in the framework of variational correlated wave functions. In addition to the core energy and to a Lambda single-particle contribution epsilon(A). We exhibit a rearrangement energy E(R) which in particular depends on the Lambda N correlations F and on the difference delta Phi(N) between the core wave function and its exact ground-state value. E(R) is nonzero only if there are both Lambda N correlations (F not equal 1) and if delta Phi(N) not equal 0. The latter can result from core polarization by the Lambda or from errors in the ground-state variational wave function of the core. E(R) varies linearly with delta Phi(N) for small delta Phi(N). Detailed numerical results for central Lambda N and NN potentials with repulsive cores confirm these general features. For a given core wave function Lambda N correlations reduce the radius of the core nucleons relative to their c.m.; however E(R) leads to an expansion of the core rather than to a contraction with only epsilon(A). The core polarization energy is quite small similar or equal to 0.4 MeV. We study the effects of errors in the variational core wave function by detuning this as a function of one of the variational parameters. C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60680. JAMIA MILLIA ISLAMIA,DEPT PHYS,NEW DELHI 110025,INDIA. RP Bodmer, AR (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 17 TC 10 Z9 10 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 NOV 18 PY 1996 VL 609 IS 3 BP 326 EP 338 DI 10.1016/S0375-9474(96)00251-5 PG 13 WC Physics, Nuclear SC Physics GA VU941 UT WOS:A1996VU94100003 ER PT J AU Veil, JA AF Veil, JA TI Salt caverns show promise for nonhazardous oil field waste disposal SO OIL & GAS JOURNAL LA English DT Article RP Veil, JA (reprint author), ARGONNE NATL LAB,WASHINGTON,DC 20024, USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD NOV 18 PY 1996 VL 94 IS 47 BP 42 EP 45 PG 4 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA VU274 UT WOS:A1996VU27400024 ER PT J AU Kolb, EW Linde, A Riotto, A AF Kolb, EW Linde, A Riotto, A TI Grand-unified-theory baryogenesis after preheating SO PHYSICAL REVIEW LETTERS LA English DT Article ID INFLATIONARY UNIVERSE; BARYON ASYMMETRY; COSMOLOGY AB At the end of inflation the Universe is frozen in a near zero-entropy state with energy density in a coherent scalar field and must be ''defrosted'' to produce the observed entropy and baryon number. We propose that the baryon asymmetry is generated by the decay of supermassive grand-unified-theory (GUT) bosons produced nonthermally in a preheating phase after inflation. We show that baryogenesis is possible for an inflaton mass of order 10(13) GeV and a GUT Higgs boson mass of order 10(14) GeV, thus solving many drawbacks facing GUT baryogenesis in the old reheating scenario. C1 UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. STANFORD UNIV, DEPT PHYS, STANFORD, CA 94305 USA. RP FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. NR 27 TC 115 Z9 115 U1 2 U2 3 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 NOV 18 PY 1996 VL 77 IS 21 BP 4290 EP 4293 DI 10.1103/PhysRevLett.77.4290 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200003 ER PT J AU Koreshev, V Jesik, R Mendez, H Abramov, V Antipov, Y Baldin, B Crittenden, R Davis, C Dauwe, L Denisov, S Dyshkant, A Dzierba, A Glebov, V Goldberg, H Gribushin, A Krider, J Krinitsyn, A Li, R Margulies, S Marshall, T Martin, J Petrukhin, A Solomon, J Sirotenko, V Smith, P Sulanke, T Sulyaev, R Vaca, F Zieminski, A Apanasevich, L Bacigalupi, J Begel, M Blusk, S Bromberg, C Chang, P Choudhary, B Chung, WH deBarbaro, L Dlugosz, W Dunlea, J Engels, E Fanourakis, G Ginther, G Hartman, K Huston, J Kapoor, V Lirakis, C Mani, S Mansour, J Maul, A Miller, R Osborne, G Pellett, D Pothier, E Roser, R Shepard, P Skow, D Slattery, P Sorrell, L Striley, D Varelas, N Weerasundara, D Yosef, C Zielinski, M Zutshi, V AF Koreshev, V Jesik, R Mendez, H Abramov, V Antipov, Y Baldin, B Crittenden, R Davis, C Dauwe, L Denisov, S Dyshkant, A Dzierba, A Glebov, V Goldberg, H Gribushin, A Krider, J Krinitsyn, A Li, R Margulies, S Marshall, T Martin, J Petrukhin, A Solomon, J Sirotenko, V Smith, P Sulanke, T Sulyaev, R Vaca, F Zieminski, A Apanasevich, L Bacigalupi, J Begel, M Blusk, S Bromberg, C Chang, P Choudhary, B Chung, WH deBarbaro, L Dlugosz, W Dunlea, J Engels, E Fanourakis, G Ginther, G Hartman, K Huston, J Kapoor, V Lirakis, C Mani, S Mansour, J Maul, A Miller, R Osborne, G Pellett, D Pothier, E Roser, R Shepard, P Skow, D Slattery, P Sorrell, L Striley, D Varelas, N Weerasundara, D Yosef, C Zielinski, M Zutshi, V TI Production of charmonium states in pi Be-- collisions at 515 GeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID HADRONIC COLLISIONS; J/PSI; TEVATRON; DECAY AB We report on chi(c1) and chi(c2) production in the Feynman:x range 0.1 < x(F) < 0.8 in 515 GeV/c pi(-)Be collisions. The chi(c) states are observed via their radiative decays into J/psi's. The resulting photons are detected tither as showers in the electromagnetic calorimeter or after conversion in the target as e(+)e(-) pairs in the tracking system. The fraction of J/psi production due to chi(c1) and chi(c2) decays is 0.443 +/- 0.041 +/- 0.035. The ratio of the chi(c1) to chi(c2) cross section is 0.57 +/- 0.18 +/- 0.06. Our results on J/psi, psi(2S), and chi(c) production indicate that 0.454 +/- 0.034 +/- 0.042 of J/psi's are produced directly. C1 INST HIGH ENERGY PHYS,SERPUKHOV,RUSSIA. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. UNIV LOUISVILLE,LOUISVILLE,KY 40292. UNIV MICHIGAN,FLINT,MI 48502. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV DELHI,DELHI 110007,INDIA. MICHIGAN STATE UNIV,E LANSING,MI 48824. NORTHEASTERN UNIV,BOSTON,MA 02115. PENN STATE UNIV,UNIVERSITY PK,PA 16802. UNIV PITTSBURGH,PITTSBURGH,PA 15260. UNIV ROCHESTER,ROCHESTER,NY 14627. RP Koreshev, V (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Gribushin, Andrei/J-4225-2012 NR 31 TC 29 Z9 29 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 NOV 18 PY 1996 VL 77 IS 21 BP 4294 EP 4297 DI 10.1103/PhysRevLett.77.4294 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200004 ER PT J AU Hino, KI Macek, JH AF Hino, KI Macek, JH TI Strong induced-dipole-field oscillations of the dt mu system above the t mu(n=2) threshold SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULES AB Elastic, inelastic, and muon transfer processes of the dt mu system above the t mu(n = 2) threshold are studied theoretically using the hyperspherical coordinate method. Strong oscillation structures in the cross sections for these processes due to strong, attractive dipole potentials in this system are found. In addition to the expected Gailitis-Damburg Stark mixing oscillations, unexpected oscillations due to diabatic couplings of channels lacking attractive dipole potentials with those that have them are evident. The two types of oscillations interfere to produce the structure that appears in the computed cross sections. C1 INST PHYS & CHEM RES,ATOM PHYS LAB,WAKO,SAITAMA 35101,JAPAN. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Hino, KI (reprint author), UNIV ELECTROCOMMUN,DEPT APPL PHYS & CHEM,CHOU KU,TOKYO 182,JAPAN. NR 15 TC 10 Z9 10 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 NOV 18 PY 1996 VL 77 IS 21 BP 4310 EP 4313 DI 10.1103/PhysRevLett.77.4310 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200008 ER PT J AU Back, CA Kalantar, DH Kauffman, RL Lee, RW MacGowan, BJ Montgomery, DS Powers, LV Shepard, TD Stone, GF Suter, LJ AF Back, CA Kalantar, DH Kauffman, RL Lee, RW MacGowan, BJ Montgomery, DS Powers, LV Shepard, TD Stone, GF Suter, LJ TI Measurements of electron temperature by spectroscopy in Hohlraum targets SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY CONFINEMENT; LASER-LIGHT; PLASMAS; NOVA; SYMMETRY; FUSION AB We report on the use of x-ray spectroscopy of mid-Z dopants to measure the electron temperature of hohlraum targets. The hohlraums are gas-filled Au cylinders and, when irradiated with 20 kJ of 0.35 mu m laser light, they become mm-sized plasmas bathed in a radiation field. The peak temperatures achieved by the target are 3.7 keV. In addition to being the first electron temperature measurements of the hohlraum itself, these measurements enable an investigation of the thermal energy and electron conduction of the target. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP LAWRENCE LIVERMORE NATL LAB, POB 808, LIVERMORE, CA 94551 USA. OI Montgomery, David/0000-0002-2355-6242 NR 28 TC 27 Z9 29 U1 1 U2 3 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 NOV 18 PY 1996 VL 77 IS 21 BP 4350 EP 4353 DI 10.1103/PhysRevLett.77.4350 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200018 ER PT J AU Birtcher, RC Donnelly, SE AF Birtcher, RC Donnelly, SE TI Plastic flow induced by single ion impacts on gold SO PHYSICAL REVIEW LETTERS LA English DT Article ID IRRADIATION; SURFACES; DAMAGE AB The formation of holes in thin gold foils as a result of single ion impacts by 200 keV Xe ions has been followed using transmission electron microscopy. Video recording provided details of microstructure evolution with a time resolution of 1/30th sec. Hole formation involves the movement by plastic flow of massive amounts of material, on the order of tms of thousands of Au atoms per ion impact. Plastic Row, as a consequence of individual ion impacts, results in a filling of both holes and craters as well as a thickening of the gold foil. Change in morphology during irradiation is attributed to a localized, thermal-spike induced melting, coupled with plastic flow under the influence of surface forces. RP Birtcher, RC (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Donnelly, Stephen/0000-0002-9749-5550 NR 12 TC 49 Z9 50 U1 2 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 18 PY 1996 VL 77 IS 21 BP 4374 EP 4377 DI 10.1103/PhysRevLett.77.4374 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200024 ER PT J AU Han, DX Wang, K VonRoedern, B AF Han, DX Wang, K VonRoedern, B TI Dispersive-transport-controlled luminescence in hydrogenated amorphous silicon SO PHYSICAL REVIEW LETTERS LA English DT Article ID A-SI-H; ELECTROLUMINESCENCE; RECOMBINATION; DIODES AB Significant differences in the features of thr electroluminescence (EL) and photoluminescence (PL) in amorphous silicon p-i-n structures have been observed. At low temperatures the Eb, peak energy is similar to 0.2 eV lower than that of the FL, shifts to lower energies with temperature only weakly relative to FL, and also shifts to higher energy with increasing electric field. The EL efficiency shows a maximum at the temperature at which the carrier transport mechanism changes. The long-standing puzzling differences between EL and PL are described not as an experimental artifact but as a direct result of the physics governing trapping and transport in amorphous materials. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Han, DX (reprint author), UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599, USA. NR 15 TC 7 Z9 8 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 NOV 18 PY 1996 VL 77 IS 21 BP 4410 EP 4413 DI 10.1103/PhysRevLett.77.4410 PG 4 WC Physics, Multidisciplinary SC Physics GA VT692 UT WOS:A1996VT69200033 ER PT J AU Timofeev, EN Smirnov, IP Haff, LA Tishchenko, EI Mirzabekov, AD Florentiev, VL AF Timofeev, EN Smirnov, IP Haff, LA Tishchenko, EI Mirzabekov, AD Florentiev, VL TI Methidium intercalator inserted into synthetic oligonucleotides SO TETRAHEDRON LETTERS LA English DT Article ID TRIPLE-HELIX FORMATION; SEQUENCE; BINDING AB A new methidium intercalator phosphoramidite has been synthesized Methidium incorporation into an oligonucleotide during the synthesis was confirmed by UV and MALDI TOF MS data. UV melting experiments showed enhanced stability of a duplex, containing internal methidium. Copyright (C) 1996 Elsevier Science Ltd C1 VA ENGELHARDT MOL BIOL INST,MOSCOW 117984,RUSSIA. PERSEPT BIOSYST INC,FRAMINGHAM,MA 01701. RP Timofeev, EN (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 9 TC 4 Z9 4 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD NOV 18 PY 1996 VL 37 IS 47 BP 8467 EP 8470 DI 10.1016/0040-4039(96)01968-5 PG 4 WC Chemistry, Organic SC Chemistry GA VU405 UT WOS:A1996VU40500003 ER PT J AU Basilevsky, MV Chudinov, GE Rostov, IV Liu, YP Newton, MD AF Basilevsky, MV Chudinov, GE Rostov, IV Liu, YP Newton, MD TI Quantum-chemical evaluation of energy quantities governing electron transfer kinetics: Applications to intramolecular processes SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE electron transfer; reorganization energy ID NONEQUILIBRIUM SOLVATION; CONTINUUM; SOLVENT; SOLUTE; REORGANIZATION; DISTANCE; DYNAMICS; APPROXIMATION; EQUILIBRIUM; FORMULATION AB Important energy quantities governing electron transfer (ET) kinetics in polar solutions (reorganization energy, E(r), and net free energy change, Delta U) are evaluated on the basis of quantum-chemical self-consistent reaction-field (SCRF) models. Either self-consistent field (SCF) or configuration interaction (CI) wavefunctions are used for the solute, which occupies a molecular cavity of realistic shape in a dielectric continuum. A classical SCRF model together with unrestricted Hartree-Fock SCF wavefunctions based on the semiempirical PM3 Hamiltonian is applied to the calculation of the solvent portion of E(r) (denoted E(s)) for two different series of radical ion ET systems: radical cations and anions of biphenylyl/naphthyl donor/acceptor (D/A) pairs Linked by cyclohexane-based spacer groups and trans-staggered radical anions of the type (CH2)(2m), m = 2-5. Results for E(s) based on two-configurational CI wavefunctions and an alternative reaction field (the so-called Born-Oppenheimer model, which recognizes the fast timescales of solvent electrons relative to those involved in ET) are also noted. Results for inner-sphere (i.e. intra-solute) reorganization, E(i), and for Delta U are also reported. The semiempirical E(s) results are quite similar to corresponding ab initio results and display the form of the two-sphere Marcus model for E(s) as a function of D/A separation. Nevertheless, in the one case where direct comparison is possible, the calculated E(s) result is more than twice the magnitude of the estimate based on experimental ET kinetic data. To reconcile this situation, a generalized SCRF model is proposed, which assigns different effective solute cavity sizes to the optical and inertial components of the solvent response, using ideas based on non-local solvation models. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Basilevsky, MV (reprint author), LY KARPOV PHYS CHEM RES INST,VORONTSOVO POLE 10,MOSCOW 103064,RUSSIA. NR 50 TC 5 Z9 5 U1 1 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 NOV 18 PY 1996 VL 371 BP 191 EP 203 PG 13 WC Chemistry, Physical SC Chemistry GA WD890 UT WOS:A1996WD89000024 ER PT J AU Stephenson, JL McLuckey, SA AF Stephenson, JL McLuckey, SA TI Ion/ion proton transfer reactions for protein mixture analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID MULTIPLY-CHARGED IONS; IONIZATION MASS-SPECTROMETRY; ASSISTED LASER DESORPTION; CYTOCHROME-C IONS; ELECTROSPRAY-IONIZATION; LARGE BIOMOLECULES; GAS-PHASE; DIELECTRIC POLARIZABILITY; MOLECULE REACTIONS; COULOMB ENERGY AB Ion/ion proton transfer reactions are shown to tie an effective means to facilitate the resolution of ions in electrospray mass spectrometry that differ in mass and charge but are similar in mass-to-charge ratio, Examples are shown in which a minor contaminant protein in a ribonuclease B solution is clearly apparent after ion/ion proton transfer but not in the conventional electrospray mass spectrum, A further example involving a mixture of bovine serum albumin and bovine transferrin also showed the identification of a previously unnoticed ''contaminant'' polymer, The latter mixture also illustrated important issues in the use of the quadrupole ion trap as a reaction vessel and mass analyzer for high mass-to-charge ratio ions, The results suggest that the use of ion trap operating parameters specifically tailored for storage, ejection, detection, and mass-to-charge analysis of high mass-to-charge ratio ions can have attractive analytical figures of merit for determining mixtures of relatively high-mass proteins and, by extension, other types of high-mass biopolymers. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 FU NIGMS NIH HHS [R01GM45372] NR 49 TC 91 Z9 92 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 15 PY 1996 VL 68 IS 22 BP 4026 EP 4032 DI 10.1021/ac9605657 PG 7 WC Chemistry, Analytical SC Chemistry GA VT087 UT WOS:A1996VT08700023 PM 8916454 ER PT J AU Paszty, C Narla, M Rubin, EM Kuypers, F Yuan, J Ma, L Schrier, SL AF Paszty, C Narla, M Rubin, EM Kuypers, F Yuan, J Ma, L Schrier, SL TI A viable murine model of severe beta-thalassemia: Exploration of the role of programmed cell death (PCD) in ineffective erythropoiesis (IE). SO BLOOD LA English DT Meeting Abstract C1 CHILDRENS HOSP OAKLAND,OAKLAND,CA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720. STANFORD UNIV,DIV HEMATOL,SCH MED,STANFORD,CA 94305. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 598 EP 598 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98300598 ER PT J AU Takakuwa, Y XiuLi, A Nunomura, W Manno, S Mohandas, N AF Takakuwa, Y XiuLi, A Nunomura, W Manno, S Mohandas, N TI Modulation of band 3-ankyrin interaction by protein 4.1: Functional implications in regulation of erythrocyte membrane mechanical properties. SO BLOOD LA English DT Meeting Abstract C1 TOKYO WOMENS MED COLL,TOKYO 162,JAPAN. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 1095 EP 1095 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98301095 ER PT J AU Knowles, D Tilley, L Mohandas, N Chasis, IA AF Knowles, D Tilley, L Mohandas, N Chasis, IA TI Erythrocyte membrane vesiculation: Model for the molecular mechanism of protein sorting. SO BLOOD LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 1096 EP 1096 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98301096 ER PT J AU Sorette, M Mohandas, N AF Sorette, M Mohandas, N TI Measurement of surface area and sphericity of red cells and reticulocytes: Application to diagnosis of red cell membrane disorders. SO BLOOD LA English DT Meeting Abstract C1 BAYER CORP,TARRYTOWN,NY. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 1834 EP 1834 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98301834 ER PT J AU Rivers, A Aguinaga, MP Kopsombut, P Koury, MJ Roa, PD Turner, EA Popp, RA AF Rivers, A Aguinaga, MP Kopsombut, P Koury, MJ Roa, PD Turner, EA Popp, RA TI Effects of folate deficiency on globin chain synthesis in sickle cell transgenic mice. SO BLOOD LA English DT Meeting Abstract C1 VANDERBILT UNIV,MEHARRY MED COLL,CTR COMPREHENS SICKLE CELL,NASHVILLE,TN. VET ADM MED CTR,NASHVILLE,TN 37203. OAK RIDGE NATL LAB,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 1964 EP 1964 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98301964 ER PT J AU Paszty, C Brion, CM Witkowska, E Mohandas, N Rubin, EM AF Paszty, C Brion, CM Witkowska, E Mohandas, N Rubin, EM TI Creation of viable transgenic/gene-knock-out sickle mice that produce exclusively human sickle hemoglobin (HbS). SO BLOOD LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720. CHILDRENS HOSP,OAKLAND RES INST,OAKLAND,CA 94609. CTR COMPREHENS SICKLE CELL,SAN FRANCISCO,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 2470 EP 2470 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98302470 ER PT J AU Fabry, ME Paszty, C Costantini, F Rubin, EM Nagel, RL AF Fabry, ME Paszty, C Costantini, F Rubin, EM Nagel, RL TI A homozygous alpha-knockout of a transgenic mouse model for sickle cell disease. SO BLOOD LA English DT Meeting Abstract C1 ALBERT EINSTEIN COLL MED,DIV HEMATOL,BRONX,NY 10467. COLUMBIA UNIV,DEPT GENET & DEV,NEW YORK,NY. LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1996 VL 88 IS 10 SU 1 BP 2471 EP 2471 PN 1 PG 1 WC Hematology SC Hematology GA VT983 UT WOS:A1996VT98302471 ER PT J AU Dai, S Xu, W Metcalf, DH Toth, LM AF Dai, S Xu, W Metcalf, DH Toth, LM TI Energy transfer between UO22+ and Eu3+ in sol-gel glasses: A spectroscopic investigation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LASER-INDUCED FLUORESCENCE; UP-CONVERSION; ZEOLITES; SPECIATION AB Silica glasses doped with uranyl ions (UO22+) and europium ions (Eu3+) via sol-gel processes have been prepared so that the quenching of the UO22+ emission by Eu3+ in the sol-gel glass could be investigated. The quenching efficiency is found to be much less than that in aqueous solutions. This difference between the quenching efficiencies in the solid sol-gel glass and the liquid solutions can be attributed to that of the mobility of Eu3+ and UO22+ in two systems. A static energy-transfer process is proposed as the dominant mechanism for the quenching of UO22+ emission by Eu3+ in the sol-gel glass. RP Dai, S (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37813, USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 28 TC 13 Z9 13 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 NOV 15 PY 1996 VL 262 IS 3-4 BP 315 EP 320 DI 10.1016/0009-2614(96)01088-3 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT117 UT WOS:A1996VT11700024 ER PT J AU Cerullo, G Bardeen, CJ Wang, Q Shank, CV AF Cerullo, G Bardeen, CJ Wang, Q Shank, CV TI High-power femtosecond chirped pulse excitation of molecules in solution SO CHEMICAL PHYSICS LETTERS LA English DT Article ID COHERENT VIBRATIONAL MOTION; WAVE-PACKET EVOLUTION; IMPULSIVE EXCITATION; LASER-PULSES; DYNAMICS; SELECTIVITY; COMPRESSION AB The effects of varying the chirp and intensity of an ultrashort pulse exciting the molecules LD690 and LDS750 in room temperature liquid solutions are investigated experimentally and theoretically. For low-power excitation, we find that the absorption and amount of excited state population are independent of chirp, while for high-power excitation we observe a strong chirp dependence. The high-power data results from an intra-pulse pump-dump process which is enhanced by negatively chirped pulses and prevented by positively chirped pulses. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Cerullo, G (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Cerullo, Giulio/F-6534-2011; OI Cerullo, Giulio/0000-0002-9534-2702 NR 21 TC 144 Z9 144 U1 1 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 NOV 15 PY 1996 VL 262 IS 3-4 BP 362 EP 368 DI 10.1016/0009-2614(96)01092-5 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT117 UT WOS:A1996VT11700031 ER PT J AU Hoffman, DK Frishman, A Kouri, DJ AF Hoffman, DK Frishman, A Kouri, DJ TI Distributed approximating functional approach to fitting multi-dimensional surfaces SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; AVERAGE-CASE COMPLEXITY; PROPAGATOR; SCHRODINGER; DYNAMICS AB A method for fitting multi-dimensional surfaces using known values of the function on a finite set of grid points is presented. The points in the set need not be regularly distributed in the domain of the variables and in fact can be random. The method is based on the theory of distributed approximating functionals. The method is illustrated by fitting model potential functions of one, two, and three variables. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. UNIV HOUSTON, DEPT CHEM, HOUSTON, TX 77204 USA. UNIV HOUSTON, DEPT PHYS, HOUSTON, TX 77204 USA. RP Hoffman, DK (reprint author), IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. NR 14 TC 28 Z9 28 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 NOV 15 PY 1996 VL 262 IS 3-4 BP 393 EP 399 DI 10.1016/0009-2614(96)01085-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT117 UT WOS:A1996VT11700036 ER PT J AU Pearlstein, RM AF Pearlstein, RM TI Antenna exciton trapping kinetics as a probe of primary electron transfer heterogeneity in the photosynthetic reaction center SO CHEMICAL PHYSICS LETTERS LA English DT Article ID BACTERIAL REACTION CENTERS; PRIMARY CHARGE SEPARATION; LIGHT-HARVESTING ANTENNA; RHODOBACTER-SPHAEROIDES; FLUORESCENCE KINETICS; RHODOSPIRILLUM-RUBRUM; EXCITATION-ENERGY; ABSORPTION; MIGRATION AB The multipicosecond nonexponential decay of the electronically excited primary electron donor, P*, observed in isolated photosynthetic reaction centers, is just as readily explained by multistep homogeneous electron transfer as by single-step heterogeneous transfer. With the aid of a one-antenna-site hopping model, it is shown here that the exciton trapping kinetics in the associated core antenna theoretically can be used to distinguish homogeneous from heterogeneous mechanisms of primary electron transfer in the reaction center. C1 INDIANA UNIV PURDUE UNIV,DEPT PHYS,INDIANAPOLIS,IN 46202. RP Pearlstein, RM (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 22 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 15 PY 1996 VL 262 IS 3-4 BP 442 EP 448 DI 10.1016/0009-2614(96)01093-7 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT117 UT WOS:A1996VT11700043 ER PT J AU Spath, BW Miller, WH AF Spath, BW Miller, WH TI Semiclassical calculation of Franck-Condon intensities for reactive systems SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FROZEN GAUSSIAN APPROXIMATION; PATH INTEGRATION; REAL-TIME; PHOTODETACHMENT; PROPAGATION; DYNAMICS; SCATTERING; MECHANICS; FORMALISM AB A Filinov transformation of the initial value representation of the semiclassical propagator has been used to obtain Franck-Condon intensities for a model of the photodetachment of H-3(-) --> H + H-2 + e(-). Resonance peak widths and heights are obtained which are in good agreement with quantum results. C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Spath, BW (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 36 TC 36 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 15 PY 1996 VL 262 IS 3-4 BP 486 EP 494 DI 10.1016/0009-2614(96)01112-8 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT117 UT WOS:A1996VT11700050 ER PT J AU Superko, HR AF Superko, HR TI Beyond LDL cholesterol reduction SO CIRCULATION LA English DT Editorial Material DE editorials; cholesterol; lipoproteins ID CORONARY-ARTERY DISEASE; LOW-DENSITY-LIPOPROTEIN; SUBCLASS PATTERNS; HEART-DISEASE; RISK-FACTORS; ATHEROSCLEROSIS; MEN; PROGRESSION; HETEROGENEITY; TRIGLYCERIDE C1 BERKELEY HEARTLAB,SAN MATEO,CA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Superko, HR (reprint author), CHOLESTEROL GENET & HEART DIS INST,1875 S GRANT ST,SUITE 700,SAN MATEO,CA 94402, USA. OI Superko, H. Robert/0000-0002-3542-0393 NR 28 TC 87 Z9 89 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 NOV 15 PY 1996 VL 94 IS 10 BP 2351 EP 2354 PG 4 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VT114 UT WOS:A1996VT11400001 PM 8921770 ER PT J AU Chen, WYC AF Chen, WYC TI The skew, relative, and classical derangements SO DISCRETE MATHEMATICS LA English DT Article DE derangements; bijection AB In his popular combinatorics text, Brualdi elucidates the principle of inclusion and exclusion with the classical and the relative derangements. Eventually, the two kinds of derangements are linked up via an algebraic relationship from the parallel use of the principle of inclusion and exclusion. We introduce the notion of skew derangements and relate them to relative derangements and the classical derangements by a purely combinatorial correspondence. Moreover, with the aid of our bijection we easily generalize the relative derangements, obtaining a binomial-type formula for the number of such generalized relative derangements on n elements in terms of the classical derangement number. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NANKAI UNIV,NANKAI INST MATH,TIANJIN 300071,PEOPLES R CHINA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-365X J9 DISCRETE MATH JI Discret. Math. PD NOV 15 PY 1996 VL 160 IS 1-3 BP 235 EP 239 DI 10.1016/0012-365X(95)00116-E PG 5 WC Mathematics SC Mathematics GA VU622 UT WOS:A1996VU62200018 ER PT J AU Steingrimsson, E Nii, A Fisher, DE FerreDAmare, AR McCormick, RJ Russell, LB Burley, SK Ward, JM Jenkins, NA Copeland, NG AF Steingrimsson, E Nii, A Fisher, DE FerreDAmare, AR McCormick, RJ Russell, LB Burley, SK Ward, JM Jenkins, NA Copeland, NG TI The semidominant Mi(b) mutation identifies a role for the HLH domain in DNA binding in addition to its role in protein dimerization SO EMBO JOURNAL LA English DT Article DE bHLH-Zip transcription factors; DNA binding; melanocytes; microphthalmia; retinal degeneration ID RECESSIVE RETINITIS-PIGMENTOSA; INHERITED RETINAL DYSTROPHY; MICROPHTHALMIA GENE; TRANSCRIPTION FACTOR; B/HLH/Z DOMAIN; ALPHA-SUBUNIT; HUMAN HOMOLOG; BROWN LOCUS; MOUSE MODEL; ONE FORM AB The mouse microphthalmia (mi) locus encodes a basic helix-loop-helix-leucine zipper (bHLH-Zip) transcription factor called MITF (microphthalmia transcription factor). Mutations at mi affect the development of several different cell types, including melanocytes, mast cells, osteoclasts and pigmented epithelial cells of the eye. Here we describe the phenotypic and molecular characterization of the semidominant Microphthalmia(brownish) (Mi(b)) mutation. We show that this mutation primarily affects melanocytes and produces retinal degeneration. The mutation is a G to A transition leading to a Gly244Glu substitution in helix 2 of the HLH dimerization domain. This location is surprising since other semidominant mi mutations characterized to date have been shown to affect DNA binding or transcriptional activation domains of MITF and act as dominant negatives, while mutations that affect MITF dimerization are inherited recessively. Gel retardation assays showed that while the mutant MITF(Mi-b) protein retains its dimerization potential, it is defective in its ability to bind DNA. Computer modeling suggested that the Gly244Glu mutation might disrupt DNA binding by interfering with productive docking of the protein dimer onto DNA. The Mi(b) mutation therefore appears to dissociate a DNA recognition function of the HLH domain from its role in protein dimerization. C1 NCI,MAMMALIAN GENET LAB,ABL BASIC RES PROGRAM,FREDERICK CANC RES & DEV CTR,FREDERICK,MD 21702. NCI,OFF LAB ANIM SCI,VET & TUMOR PATHOL SECT,FREDERICK,MD 21702. HARVARD UNIV,CHILDRENS HOSP,SCH MED,BOSTON,MA 02115. HARVARD UNIV,SCH MED,DANA FARBER CANC INST,DIV PEDIAT HEMATOL ONCOL,BOSTON,MA 02115. ROCKEFELLER UNIV,HOWARD HUGHES MED INST,MOL BIOPHYS LAB,NEW YORK,NY 10021. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 43 TC 38 Z9 38 U1 0 U2 2 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD NOV 15 PY 1996 VL 15 IS 22 BP 6280 EP 6289 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VW418 UT WOS:A1996VW41800029 PM 8947051 ER PT J AU Riddle, R Lesuer, D Syn, C Gogolewski, R Cunningham, B AF Riddle, R Lesuer, D Syn, C Gogolewski, R Cunningham, B TI Application of metal laminates to aircraft structures: Prediction of penetration performance SO FINITE ELEMENTS IN ANALYSIS AND DESIGN LA English DT Article; Proceedings Paper CT Symposium on Computational Modeling of Aircraft Structures CY OCT 23-25, 1995 CL NEW BRUNSWICK, NJ ID STRAIN RATES AB A major thrust of the transportation industries in the US is the incorporation of advanced structural materials in airplanes and automobiles. These advanced materials include metal matrix composites, where particulate or whisker reinforcements stiffen and strengthen a ductile phase matrix. In aerospace structures, specific stiffness, improved strength, and weight reduction are key factors. Both in the certain parts of the airframe structure and in the engine fan containment area, increased emphasis is being given to the ability of the material to resist penetration from engine debris and other projectiles which might impact the aircraft structures. Experimental measurements of the ballistic limit velocity of a material versus material thickness gives a method to rank the relative penetration performance of aircraft structural materials. Dynamic finite element analysis aids in understanding the experimental results and in predicting the aircraft debris containment response. For certain aluminum alloys and metal laminates, the relationship between the ballistic limit velocity and plate thickness is linear, while for an aerospace titanium alloy, the ballistic penetration response is more complex. RP Riddle, R (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 15 TC 9 Z9 9 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-874X J9 FINITE ELEM ANAL DES JI Finite Elem. Anal. Des. PD NOV 15 PY 1996 VL 23 IS 2-4 BP 173 EP 192 DI 10.1016/S0168-874X(96)80006-0 PG 20 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA VU930 UT WOS:A1996VU93000007 ER PT J AU Wagner, J Gordon, LA Heng, HHQ Tremblay, ML Olsen, AS AF Wagner, J Gordon, LA Heng, HHQ Tremblay, ML Olsen, AS TI Physical mapping of receptor type protein tyrosine phosphatase sigma (PTPRS) to human chromosome 19p13.3 SO GENOMICS LA English DT Article ID LEUKOCYTE-COMMON-ANTIGEN; GENOMIC ORGANIZATION; MOLECULAR-CLONING; NERVOUS-SYSTEM; HUMAN LAR; GENE; EXPRESSION; REGION; MAP; HUMAN-CHROMOSOME-19 AB Receptor type protein tyrosine phosphatase sigma (PTPRS), a member of a subfamily of receptor type protein tyrosine phosphatases, has been mapped to human chromosome 19p13.3 using fluorescence in situ hybridization (FISH) analysis, Hybridization analysis of chromosome 19 library cosmids has revealed several positive clones that are part of a contig located in the same region, The location of this contig was verified since one of the cosmid clones is anchored to a high-resolution FISH map of human chromosome 19p, In addition, the location of this gene relative to previously mapped proximal markers reveals a new point in the human-mouse synteny map by extending the mouse chromosome 17 synteny region in the telomeric direction. (C) 1996 Academic Press, Inc. C1 MCGILL UNIV,DEPT BIOCHEM,MONTREAL,PQ H3G 1Y6,CANADA. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. UNIV TORONTO,DEPT MED & MOL GENET,TORONTO,ON M5G 1X8,CANADA. NR 23 TC 9 Z9 9 U1 1 U2 2 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 NOV 15 PY 1996 VL 38 IS 1 BP 76 EP 78 DI 10.1006/geno.1996.0594 PG 3 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA VV024 UT WOS:A1996VV02400011 PM 8954782 ER PT J AU Delmore, JE Huett, T Olson, JE Appelhans, AD AF Delmore, JE Huett, T Olson, JE Appelhans, AD TI Ion/neutral mass spectrometry of thermal ionizers: Application to ionization mechanisms from zeolites SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE ion/neutral mass spectrometry; thermal ionization; alkali metal ions; zeolites; silver ions ID ION AB Ion emission mechanisms from high temperature inorganic matrices are poorly understood, and pathways for sample loss are largely unknown. In an effort to gain better understanding of these processes, an instrument was designed, built and tested which measured in sequence the ions, and then the neutrals coming from the surface of high temperature matrices. Switching between modes was rapid enough to follow changes. This instrument was applied to the study of ion formation from potassium and silver zeolites. It was shown that the only form in which potassium sublimes from potassium zeolite is as monatomic cations. This helps to explain the high alkali metal ion formation efficiency observed from zeolite matrices and supports the concept that alkali metal ions are subliming directly from the solid state into the gas phase. In contrast, silver sublimes from silver zeolite as a combination of monatomic cations and neutrals, with the ion emission intensity about 3 orders of magnitude less than the emission of ions from alkali metal impurities. RP Delmore, JE (reprint author), IDAHO NATL ENGN LAB,BOX 1626,IDAHO FALLS,ID 83415, USA. RI Garcia-Sanchez, Almudena/B-3303-2009 NR 10 TC 5 Z9 5 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 NOV 15 PY 1996 VL 155 IS 3 BP 149 EP 162 DI 10.1016/S0168-1176(96)04413-8 PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VW495 UT WOS:A1996VW49500004 ER PT J AU Nada, R Nicholas, JB McCarthy, MI Hess, AC AF Nada, R Nicholas, JB McCarthy, MI Hess, AC TI Basis sets for ab initio periodic Hartree-Fock studies of zeolite/adsorbate interactions: He, Ne, and Ar in silica sodalite SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID ABINITIO; ZEOLITES; ELECTRON AB Silica sodalite is an ideal model system to establish base-line computer requirements of ab initio periodic Hartree-Fock (FHF) calculations of zeolites. In this article, we investigate the effect of various basis sets on the structural and electronic properties of bulk silica sodalite. We also study the interaction of He, Ne, and Ar with the sodalite cage. Our work shows that basis-set superposition errors (BSSE) in calculations using STO-3G and 6-21G(*) basis sets are as large as the interaction energies, leading to poor confidence in the results. To cure this problem, we present high-quality basis sets for Si, O, He, Ne, and Ar, optimized for use with PHF methods, and demonstrate that the new basis set greatly reduces BSSE. The theoretical barriers for transfer of the rare gases between sodalite cages are 5.6, 13.2, and 62.1 kcal/mol for He, Ne, and Ar. (C) 1996 John Wiley & Sons, Inc. C1 PACIFIC NW LAB, SOLID STATE CHEM GRP, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 27 TC 40 Z9 41 U1 0 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV 15 PY 1996 VL 60 IS 4 BP 809 EP 820 DI 10.1002/(SICI)1097-461X(1996)60:4<809::AID-QUA3>3.0.CO;2-0 PG 12 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA VM442 UT WOS:A1996VM44200003 ER PT J AU Branagan, DJ McCallum, RW AF Branagan, DJ McCallum, RW TI The effects of Ti, C, and TiC on the crystallization of amorphous Nd2Fe14B SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE amorphous Nd2Fe24B; crystallization; energy product; titanium; carbon; titanium carbide ID ND-FE-B; MAGNETIC-PROPERTIES; ALLOYS AB The effects of Ti, C, and TiC on the crystallization of amorphous Nd2Fe14B have been investigated. Through the selection of appropriate alloying additions the as-crystallized energy product can be significantly increased. Two factors are attributed to this increase. First, by dissolution of the additions into the glass the intrinsic properties of the glass are altered, resulting in an increase in the crystallization temperature of some alloys. Since the nucleation rate has an Arrehnius temperature dependence more nuclei per unit time should result in a finer and more uniform grain size. Secondly, stable carbide and boride phases may serve as inoculation sites promoting uniform nucleation. In order to obtain high as-crystallized energy products, the alloying additions should have very low equilibrium solubilities in the 2-14-1 phase and must not cause an overall reduction in the amount of hard magnetic phase or cause the formation of other soft magnetic phases. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 12 TC 5 Z9 7 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 15 PY 1996 VL 245 BP 15 EP 19 DI 10.1016/S0925-8388(96)02415-2 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WB358 UT WOS:A1996WB35800013 ER PT J AU Kim, JS Haanappel, E Mayr, F Stewart, GR AF Kim, JS Haanappel, E Mayr, F Stewart, GR TI High field magnetization of the spin fluctuation compounds UPt3, U0.1Pr0.9In3 and U1-xYxAl2 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Letter DE field magnetization; spin fluctuation compounds ID METAMAGNETIC TRANSITION; HEAT; TIBE2 AB Measurements on M vs H up to 50 T in pulsed fields are reported for the spin fluctuation compounds UPt3 (where measurements up to 35 T already exist), U1-xYxAl2 and Pr0.9U0.1In3. The known metamagnetic transition at 20 T in UPt3 is observed; no further transition is observed in Upt(3) up to 50 T. Although the compounds U0.9Y0.1Al2, U0.7Y0.3Al2 and Pr0.9U0.1In3 also show T-3 ln T spin fluctuation terms in their specific heat with specific heat gamma values spanning the range 190-670 mJ per mole U-K-2, (where Upt(3) has gamma=450 mJ per mole-K-2), no metamagnetic transitions up to 50 T are observed in these systems. Possible scaling relations between B-metamag and various parameters are discussed. C1 UNIV FLORIDA,GAINESVILLE,FL 32611. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV AUGSBURG,D-86159 AUGSBURG,GERMANY. NR 20 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 15 PY 1996 VL 245 BP L33 EP L35 DI 10.1016/S0925-8388(96)02704-1 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WB358 UT WOS:A1996WB35800010 ER PT J AU Nichols, DG Dantsker, E Kleiner, R Muck, M Clarke, J AF Nichols, DG Dantsker, E Kleiner, R Muck, M Clarke, J TI Linearity of high-T-c dc superconducting quantum interference device operated in a flux-locked loop SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SQUID MAGNETOMETER; NOISE; FEEDBACK AB Measurements have been made of the linearity of a high transition temperature dc superconducting quantum interference device (SQUID) operated at 77 K with 130 kHz flux modulation in a flux-locked loop. The degree of nonlinearity was determined from harmonic generation. A sinusoidal magnetic flux with harmonic content less than -130 dB was applied to the SQUID, which was cooled in a magnetic field below 10(-7) T, and the harmonics at the output of the flux-locked loop were measured with a spectrum analyzer, For input signals at frequencies up to 248 Hz and amplitudes up to 20 Phi(0) rms (Phi(0) is the flux quantum), the second, third, and fourth harmonics were each at least 115 dB below the fundamental, At higher frequencies the harmonic content began to increase because of the reduction in the open-loop gain of the flux-locked loop. The magnitude of the harmonics was not measurably changed when the SQUID was cooled in a field of 100 mu T. The amplitudes of the even harmonics depended critically on the amplitude of the 130 kHz flux modulation, and became zero when its peak-to-peak value was precisely Phi(0)/2. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 15 TC 11 Z9 11 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1996 VL 80 IS 10 BP 6032 EP 6038 DI 10.1063/1.363603 PG 7 WC Physics, Applied SC Physics GA VU987 UT WOS:A1996VU98700074 ER PT J AU Grimsditch, M Popova, S Polian, A AF Grimsditch, M Popova, S Polian, A TI Test of the equation of state of water up to freezing at 100 and 200 degrees C SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FUNDAMENTAL EQUATION; ELASTIC PROPERTIES; HIGH-PRESSURE; LIQUID WATER; ICE-VII; 20 GPA; RANGE; KBAR; COMPRESSION; DENSITY AB The sound velocity in water at 100 and 200 degrees C has been determined up to the freezing pressure using Brillouin scattering. In this temperature and pressure range there is little experimental data on any physical property of water. Our results, therefore, provide a convenient test of existing equations of state. We find our results to be in good agreement with those calculated from the most reliable equation of state. (C) 1996 American Institute of Physics. C1 UNIV PARIS 06,F-75252 PARIS 05,FRANCE. RUSSIAN ACAD SCI,INST HIGH PRESSURE PHYS,TROITSK 142092,MOSCOW,RUSSIA. RP Grimsditch, M (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Polian, Alain/E-1555-2017 OI Polian, Alain/0000-0003-2261-9114 NR 21 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 15 PY 1996 VL 105 IS 19 BP 8801 EP 8803 DI 10.1063/1.472659 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT102 UT WOS:A1996VT10200033 ER PT J AU Gai, HD Schenter, GK Dang, LX Garrett, BC AF Gai, HD Schenter, GK Dang, LX Garrett, BC TI Quantum statistical mechanical simulation of the ion-water cluster I-(H2O)(n): The importance of nuclear quantum effects and anharmonicity SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; PHOTOELECTRON-SPECTROSCOPY; IODINE ANION; SOLVATION AB Monte Carlo simulations of quantum statistical mechanical properties using the Feynman path integral method were carried out at temperatures of 70, 100, 200, and 300 K to study the structure and energetics of the ion-water cluster I- (H2O)(n), with n = 1-6. Simulation results at low temperatures (i.e., 70 K) can be directly compared with data from photoelectron spectroscopy (PES). The temperature dependence of binding enthalpies and stabilization energies indicate that at low temperatures the classical description of nuclear motion is qualitatively incorrect. The binding enthalpies are also computed within the harmonic approximation using the energy and frequencies at the minimum energy geometry, a method widely used in conjunction with electronic structure calculations to extend zero temperature information to finite temperatures. It is found that the harmonic approximation works well for the cluster with a single water molecule, but not for clusters with more than one water molecule, where the temperature dependence of binding enthalpies is in qualitative disagreement with the exact enthalpy obtained from simulation. (C) 1996 American Institute of Physics. RP Gai, HD (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 19 TC 47 Z9 47 U1 0 U2 13 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 NOV 15 PY 1996 VL 105 IS 19 BP 8835 EP 8841 DI 10.1063/1.472612 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VT102 UT WOS:A1996VT10200037 ER PT J AU Monteiro, OR Wang, Z Brown, IG AF Monteiro, OR Wang, Z Brown, IG TI Chemical vapour deposition of silicon nitride in a microwave plasma assisted reactor SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID GAS-PHASE; SI3N4 AB Microwave plasma assisted chemical vapour deposition was used to produce silicon nitride films on silicon substrates from mixtures of methane and nitrogen. Deposition temperatures varied from 800 to 1000 degrees C and pressure varied from 53.2 to 79.8 x 10(2) Pa. Gas mixtures with low methane content resulted in no reaction. Gas mixtures with high methane content produced an amorphous carbon film on the silicon wafer surface. At intermediate methane contents, the process produces a mixture of alpha and beta silicon nitride. A mechanism is proposed according to which the silicon surface is chemically etched by the activated methyl radicals forming Si(CH3)(4), which then reacts with nitrogen atoms (or ions) to form the silicon nitride. The morphology of the individual crystals evolves from platelets to needle-like depending on the deposition conditions, and on the surface coverage of the silicon surface. RP Monteiro, OR (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 14 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD NOV 15 PY 1996 VL 31 IS 22 BP 6029 EP 6033 DI 10.1007/BF01152155 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA VU993 UT WOS:A1996VU99300025 ER PT J AU McPherson, DW Knapp, FF AF McPherson, DW Knapp, FF TI Structure elucidation via stereoselective synthesis of the acetate center of 1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (IQNP). A high affinity muscarinic imaging agent for SPECT SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID LIGAND; RECEPTOR; ISOMERS; ACIDS RP McPherson, DW (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,NUCL MED GRP,POB 2008,BLDG 4501,MAIL STOP 6229,OAK RIDGE,TN 37831, USA. NR 9 TC 14 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD NOV 15 PY 1996 VL 61 IS 23 BP 8335 EP 8337 DI 10.1021/jo961033t PG 3 WC Chemistry, Organic SC Chemistry GA VT711 UT WOS:A1996VT71100066 ER PT J AU Camassa, R Tin, SK AF Camassa, R Tin, SK TI The global geometry of the slow manifold in the Lorenz-Krishnamurthy model SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INITIALIZATION; EXISTENCE; SYSTEM AB The five-equation model introduced by Lorenz and Krishnamurthy is studied. It is shown that the question of existence of a slow manifold for this model can be addressed by a combination of local and global analysis. Existence of a locally slow manifold and nonexistence of its global counterpart are proven. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV MICHIGAN,DEPT MATH,ANN ARBOR,MI 48109. RP Camassa, R (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 25 TC 12 Z9 12 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD NOV 15 PY 1996 VL 53 IS 22 BP 3251 EP 3264 DI 10.1175/1520-0469(1996)053<3251:TGGOTS>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV304 UT WOS:A1996VV30400005 ER PT J AU Mendez, RA Minniti, D DeMarchi, G Baker, A Couch, WJ AF Mendez, RA Minniti, D DeMarchi, G Baker, A Couch, WJ TI Star counts in the Hubble Deep Field: Constraining galactic structure models SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars, luminosity function, mass function; stars, Population II; white dwarfs; Galaxy, structure; quasars, general ID LOW-MASS STARS; GLOBULAR-CLUSTERS; GALAXY AB Stellar sources are identified in the Hubble Deep Field, and accurate colours and magnitudes are presented. The predictions of a Galactic star counts model are compared with the faint stellar counts in this field. The model reproduces the observations very well in the magnitude range 21.0 < V less than or equal to 26.4, while it overpredicts the counts by a factor of 4 in the range 26.4 < V less than or equal to 30.0. The luminosity function for halo objects must be a factor of 2 smaller than that predicted by an extrapolation of the solar neighbourhood luminosity function for disc stars (with 95 per cent confidence level). This result, seen before in deep Hubble Space Telescope images of globular clusters, is therefore confirmed for the halo field population, The possible nature of a group of faint blue objects is also investigated, concluding that they are most likely non-stellar. The possibility that they are QSOs is ruled out, If we insist upon their stellar nature, they would be halo white dwarfs, with either a very steep halo white dwarf luminosity function fur M(v) > + 11.0, or a stellar density 0.4 times that of the disc white dwarfs in the solar neighbourhood. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV CAMBRIDGE, INST ASTRON, CAMBRIDGE CB3 0HA, ENGLAND. UNIV NEW S WALES, SCH PHYS, SYDNEY, NSW 2052, AUSTRALIA. RP Mendez, RA (reprint author), EUROPEAN SO OBSERV, KARL SCHWARZSCHILD STR 2, D-85748 GARCHING, GERMANY. RI Mendez, Rene/H-9496-2015 NR 22 TC 46 Z9 46 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 15 PY 1996 VL 283 IS 2 BP 666 EP 672 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VT962 UT WOS:A1996VT96200027 ER PT J AU Proudnikov, D Mirzabekov, A AF Proudnikov, D Mirzabekov, A TI Chemical methods of DNA and RNA fluorescent labeling SO NUCLEIC ACIDS RESEARCH LA English DT Article ID ESCHERICHIA-COLI; DEOXYRIBONUCLEIC ACID; CHAIN BREAKAGE; ABASIC SITES; HYBRIDIZATION; OLIGODEOXYRIBONUCLEOTIDES; DEPURINATION; ENDS AB Several procedures have been described for fluorescent labeling of DNA and RNA, They are based on the introduction of aldehyde groups by partial depurination of DNA or oxidation of the 3'-terminal ribonucleoside in RNA by sodium periodate, Fluorescent labels with an attached hydrazine group are efficiently coupled with the aldehyde groups and the hydrazone bonds are stabilized by reduction with sodium cyanoborohydride, Alternatively, DNA can be quantitatively split at the depurinated sites with ethylenediamine, The aldimine bond between the aldehyde group in depurinated DNA or oxidized RNA and ethylenediamine is stabilized by reduction with sodium cyanoborohydride and the primary amine group introduced at these sites is used for attachment of isothiocyanate or succinimide derivatives of fluorescent dyes, The fluorescent DNA labeling can be carried out either in solution or on a reverse phase column, These procedures provide simple, inexpensive methods of multiple DNA labeling and of introducing one fluorescent dye molecule per RNA, as well as quantitative DNA fragmentation and incorporation of one label per fragment, These methods of fluorophore attachment were shown to be efficient for use in the hybridization of labeled RNA, DNA and DNA fragments with oligonucleotide microchips. C1 ARGONNE NATL LAB,CTR MECH BIOL & BIOTECHNOL,JOINT HUMAN GENOME PROGRAM,ARGONNE,IL 60439. VA ENGELHARDT MOL BIOL INST,MOSCOW 117984,RUSSIA. NR 42 TC 86 Z9 89 U1 3 U2 24 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD NOV 15 PY 1996 VL 24 IS 22 BP 4535 EP 4542 DI 10.1093/nar/24.22.4535 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VW528 UT WOS:A1996VW52800021 PM 8948646 ER PT J AU Taylor, AJ Rodriguez, G Clement, TS AF Taylor, AJ Rodriguez, G Clement, TS TI Determination of n(2) by direct measurement of the optical phase SO OPTICS LETTERS LA English DT Article ID NONLINEAR REFRACTIVE-INDEX; SINGLE-SHOT MEASUREMENT; PULSES; DISPERSION; INTENSITY; AMPLITUDE; CRYSTALS AB We determine the nonlinear refractive index, n(2), in an optical material through the direct measurement of the phase of an ultrashort optical pulse, using the technique of frequency-resolved optical gating. This method results in the accurate measurement of n(2), with the error dominated by the uncertainty in the fluence measurement. We measure n(2) in fused silica and in potassium dihydrogen phosphate at 804 and 402 nm. These results are consistent with those from previous measurements of n(2) in these materials, and the measured dispersion of n(2) in fused silica agrees with theoretical predictions. (C) 1996 Optical Society of America. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. RP Taylor, AJ (reprint author), LOS ALAMOS NATL LAB,MS D429,LOS ALAMOS,NM 87545, USA. RI Clement, Tracy/A-8885-2008; Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 12 TC 72 Z9 72 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 15 PY 1996 VL 21 IS 22 BP 1812 EP 1814 DI 10.1364/OL.21.001812 PG 3 WC Optics SC Optics GA VR424 UT WOS:A1996VR42400006 PM 19881810 ER PT J AU Chu, KC Heritage, JP Grant, RS White, WE AF Chu, KC Heritage, JP Grant, RS White, WE TI Temporal interferometric measurement of femtosecond spectral phase SO OPTICS LETTERS LA English DT Article ID ULTRASHORT PULSES; INTENSITY AB Fourier spectral analysis of temporal interference resulting from beats between a reference optical frequency and a number of spectral components of a femtosecond optical pulse yields the spectral phase directly without the need for iterative calculations. A periodic multiple-slit mask placed in the Fourier plane of a femtosecond pulse shaper selects an ensemble of frequency components for measurement by cross correlation. An additional, out-of-period slit selects the reference frequency so that none of the desired beat tones overlaps redundant tones. We measure positive and negative cubic phase distortion introduced when the pulse shaper lens is tilted and the phase discontinuity of a 0-pi pulse (odd pulse) with a 13-slit mask. Finally, we demonstrate measurement of the spectral phase associated with true time delays with 17 slits. (C) 1996 Optical Society of America C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Chu, KC (reprint author), UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. NR 9 TC 15 Z9 15 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 15 PY 1996 VL 21 IS 22 BP 1842 EP 1844 DI 10.1364/OL.21.001842 PG 3 WC Optics SC Optics GA VR424 UT WOS:A1996VR42400016 PM 19881820 ER PT J AU Pennycook, SJ Browning, ND McGibbon, MM McGibbon, AJ Jesson, DE Chisholm, MF AF Pennycook, SJ Browning, ND McGibbon, MM McGibbon, AJ Jesson, DE Chisholm, MF TI Direct determination of interface structure and bonding with the scanning transmission electron microscope SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID TILT GRAIN-BOUNDARIES; ATOMIC-STRUCTURE; SCATTERED ELECTRONS; RESOLUTION; CRYSTALS; SPECTROSCOPY AB The scanning transmission electron microscope is capable of forming an electron probe of atomic dimensions, allowing incoherent imaging and microanalysis to be achieved at atomic resolution. Images formed using elastically scattered electrons show strong atomic number (Z) contrast and reveal atomic column locations without the need for preconceived structure models. Column positions and scattering power can be directly retrieved by a maximum entropy analysis. The Z-contrast image also allows the probe to be positioned with atomic precision over selected atomic columns or planes, making possible atomic-resolution electron energy loss spectroscopy. Interfacial structure and bonding can both be determined directly from experimental data, often leading to unexpected insights. In SrTiO3, grain boundary structural units were identified, and found to be reconstructed, an efficient way to overcome the problem of like-ion repulsion in ionic materials. At a CdTe-GaAs [001] interface, 60 degrees dislocations were directly identified to be of glide type, while in the case of Lomer dislocations, an unexpected core structure was found comprising a fourfold ring structure. With these techniques, dislocation core structure and impurity segregation may be studied experimentally at the atomic scale. C1 UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV ILLINOIS, DEPT PHYS MC 273, CHICAGO, IL 60607 USA. RP Pennycook, SJ (reprint author), OAK RIDGE NATL LAB, DIV SOLID STATE, POB 2008, OAK RIDGE, TN 37831 USA. OI Browning, Nigel/0000-0003-0491-251X; Jesson, David/0000-0003-0897-1445 NR 32 TC 15 Z9 15 U1 1 U2 9 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD NOV 15 PY 1996 VL 354 IS 1719 BP 2619 EP 2634 DI 10.1098/rsta.1996.0119 PG 16 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT270 UT WOS:A1996VT27000003 ER PT J AU Allen, JS Holm, DD AF Allen, JS Holm, DD TI Extended-geostrophic Hamiltonian models for rotating shallow water motion SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE balance; geostrophic flow; ocean; atmosphere; dynamics ID BAROTROPIC CONTINENTAL-SHELF; SLOPE FLOW-FIELDS; INTERMEDIATE MODELS; POISSON BRACKETS; EQUATIONS; ELASTICITY; MECHANICS AB By using a small Rossby number expansion in Hamilton's principle for shallow water dynamics in a rapidly rotating reference frame, we derive new approximate extended-geostrophic equations with pressure, or surface height, as the dynamical variable. By introducing modeling parameters into the relation between the ageostrophic velocity and surface height, we obtain a family of models for which the functional form of the potential vorticity, conserved on fluid particles, and of the kinetic energy contribution to the globally conserved energy can be prescribed. The particular approximate equations which result when the ageostrophic velocity is chosen to be in full agreement with an asymptotic small Rossby number expansion of the rotating shallow water equations give a new model with apparently higher-order dynamical consistency than either quasigeostrophy or geostrophic momentum. The geostrophic momentum model is recovered as a special case among these new models. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Allen, JS (reprint author), OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331, USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 24 TC 27 Z9 27 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 229 EP 248 DI 10.1016/0167-2789(96)00120-0 PG 20 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900002 ER PT J AU CAmassa, R Holm, DD Levermore, CD AF CAmassa, R Holm, DD Levermore, CD TI Long-time effects of bottom topography in shallow water SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE shallow water models; nonhydrostatic topographic effects; Hamiltonian formulation ID EQUATIONS; WAVES AB We present and discuss new shallow water equations that provide an estimate of the long-time asymptotic effects of slowly varying bottom topography and weak hydrostatic imbalance on the vertically averaged horizontal velocity of an incompressible fluid with a free surface which is moving under the force of gravity. We consider the regime where the Froude number is much smaller than the aspect ratio delta of the shallow domain. The new equations are obtained at first order in an asymptotic expansion of the solutions of the Euler equations for a shallow fluid by using the small parameter delta(2). The leading order equations in this expansion enforce hydrostatic balance while those obtained at first order retain certain nonhydrostatic effects, Both sets of equations conserve energy and circulation, convect potential vorticity and have a Hamiltonian formulation. The corresponding energy and enstrophy are quadratic integrals with which we can bound the cumulative influence of the nonhydrostatic effects. C1 UNIV ARIZONA,DEPT MATH,TUCSON,AZ 85721. 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 19 TC 37 Z9 37 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 258 EP 286 DI 10.1016/0167-2789(96)00117-0 PG 29 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900004 ER PT J AU Gjaja, I Holm, DD AF Gjaja, I Holm, DD TI Self-consistent Hamiltonian dynamics of wave mean-flow interaction for a rotating stratified incompressible fluid SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE internal waves; phase averaging; Hamilton's principle; WKB approximation ID INTERNAL GRAVITY-WAVES; POISSON BRACKETS; SHEAR FLOWS; MECHANICS; DISTURBANCES; ELASTICITY; THEOREM; OCEAN; WIND AB We derive a hierarchy of approximate models of wave mean-flow interaction (WMFI) by using asymptotic expansions and phase averages either in Euler's equations for a stratified rotating inviscid incompressible fluid, or in Hamilton's principle for these equations. Two small dimensionless parameters are used in these expansions. The first parameter is the ratio of time scales between internal waves at most wave numbers and the mesoscale mean flow of the fluid. This ''adiabatic ratio'' is small and is comparable to the corresponding ratio of space scales for the class of initial conditions that support internal waves. The other small parameter used in these expansions is the ratio of the amplitude of the internal wave to its wavelength. An application of Noether's theorem to the phase-averaged Hamilton's principle shows that the resulting equations conserve the wave action, convect a potentional vorticity and can, depending on the order of approximation, convect wave angular momentum. Passage from the phase- averaged Hamilton's principle to the Hamiltonian formulation brings the WMFI theory into the Lie-Poisson framework in which formal and nonlinear stability analysis may be applied. This framework also suggests a two-fluid model of the interaction of waves and mean flow similar to that for the superfluid and normal fluid components of liquid He-4 without vortices. We also discuss the relations of these results to the Charney-Drazin nonacceleration theorem, Whitham averaging, WKB stability theory, and Lagrangian-mean fluid equations for prescribed wave displacements. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. OI Holm, Darryl D/0000-0001-6362-9912 NR 48 TC 27 Z9 27 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 343 EP 378 DI 10.1016/0167-2789(96)00104-2 PG 36 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900009 ER PT J AU Holm, DD AF Holm, DD TI The ideal Craik-Leibovich equations SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE wave mean-flow interaction; Hamilton's principle; geophysical fluid dynamics ID LANGMUIR CIRCULATIONS; STABILITY; INSTABILITY; PLASMA; FLOWS; WAVES AB We show that the Craik-Leibovich (CL) theory of Langmuir circulation in an ideal incompressible fluid driven by rapidly fluctuating surface waves due to the wind may be formulated in terms of Eulerian mean fluid variables as a Hamiltonian system. This formulation is facilitated by first determining Hamilton's principle for the CL equations. The CL Hamilton's principle is similar to that for a fluid plasma, driven by a rapidly varying external electromagnetic field via ''J . A'' minimal coupling, after averaging the plasma action over the fast phase of the (single frequency) driving field. This similarity leads to a precise analogy between the CL vortex force and the Lorentz force on an electrically charged fluid due to an exernally imposed electromagnetic field. We determine the effect of this force on the inflection point criterion and the Richardson number criterion for stability of planar CL flows. The Noether symmetries of Hamilton's principle for the CL equations (under fluid particle relabeling) lead to conservation laws for Eulerian mean potential vorticity and helicity, and generate the steady Eulerian mean flows as canonical transformations. The generalized Lagrangian mean theory is discussed from the same viewpoint. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Holm, DD (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 26 TC 32 Z9 33 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 415 EP 441 DI 10.1016/0167-2789(96)00105-4 PG 27 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900011 ER PT J AU Leith, CE AF Leith, CE TI Stochastic models of chaotic systems SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE stochastic models; nonlinear oscillator; turbulence; large-eddy simulation; global atmosphere ID TURBULENCE; SIMULATION AB Nonlinear dynamical systems, although strictly deterministic, often exhibit chaotic behavior which appears to be random. The determination of the probabilistic properties of such systems is, in general, an open problem. Closure approximations for moment expansion methods have been unsatisfactory. More successful has been approximation on the dynamics level by the use of linear stochastic models that attempt to generate the probabilistic properties of the original nonlinear chaotic system as closely as possible. Examples are reviewed of this approach to simple nonlinear systems, to turbulence, and to large-eddy simulation. A stochastic model that simulates the transient energy spectrum of the global atmosphere is developed. RP Leith, CE (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 17 TC 42 Z9 43 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 481 EP 491 DI 10.1016/0167-2789(96)00107-8 PG 11 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900014 ER PT J AU Poje, AC Jones, DA Margolin, LG AF Poje, AC Jones, DA Margolin, LG TI Enslaved finite difference approximations for quasigeostrophic shallow flows SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE finite difference methods; numerical simulation; fluid dynamics; shallow water equations; nonlinearity ID MODEL; OCEAN AB We describe a procedure to improve both the accuracy and computational efficiency of finite difference schemes used to simulate the nonlinear PDEs that govern barotropic two-dimensional geophysical fluid dynamics. Our underlying strategy is to reduce the truncation error of a given difference scheme in such a way that the time step restrictions are not changed. To accomplish this reduction, we use information from the governing equations in the case of vanishing time derivatives, Our method is based on a change of variables from fine to coarse grids, which allows us to order the various terms that appear and justify further approximations. These approximations lead to algebraic closures for the new higher-order variables, and finally to a new, enslaved scheme. We demonstrate the utility of the procedure for the shallow water equations in both periodic and closed basins. In the latter case we present results that demonstrate the ability of the enslaved scheme to capture dynamics on scales smaller than those resolved by the original scheme. C1 LOS ALAMOS NATL LAB,IGPP,LOS ALAMOS,NM 87543. NR 14 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 559 EP 573 DI 10.1016/0167-2789(96)00112-1 PG 15 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900020 ER PT J AU Skyllingstad, ED Paluszkiewicz, T Denbo, DW Smyth, WD AF Skyllingstad, ED Paluszkiewicz, T Denbo, DW Smyth, WD TI Nonlinear vertical mixing processes in the ocean: Modeling and parameterization SO PHYSICA D LA English DT Article; Proceedings Paper CT 15th Annual International Conference of the Center-for-Nonlinear-Studies on Nonlinear Phenomena in Ocean Dynamics CY MAY 15-19, 1995 CL LOS ALAMOS, NM SP Los Alamos Natl Lab, Ctr Nonlinear Studies DE mixed layer; deep convection; turbulence; shear instability; ocean large-eddy simulation ID GENERAL-CIRCULATION MODELS; LANGMUIR CIRCULATION; BOUNDARY-LAYER; THERMOHALINE CIRCULATION; CONVECTIVE ADJUSTMENT; SENSITIVITY; SIMULATION; GREENLAND; DRIVEN AB Nonlinear vertical mixing processes are critical in the transport of heat and momentum throughout the ocean and are especially important in the surface mixed layer and in deep convection. This paper reviews recent numerical modeling studies that are being used to help develop more effective parameterizations of nonlinear vertical mixing processes. In particular, we describe two oceanic process studies using a large-eddy simulation (LES) turbulence model and review the performance of an improved vertical mixing parameterization in an ocean general circulation model. The first process study examines the role of wind and heat-flux forcing of turbulence in the tropical western Pacific ocean surface mixed layer. Results from the LES show that mixing is dominated by three key processes: Langmuir circulation near the surface, organized circulations that extend through the mixed-layer depth, and shear instability at the mixed-layer base. The second LES study centers on the onset and strength of deep oceanic convection. Results from this study show that the growth of convective plumes is dependent on the integral properties of heat and salinity forcing. The paper concludes with a test of an improved parameterization of deep convection for ocean general circulation models. C1 OREGON STATE UNIV, COLL OCEANOG & ATMOSPHER SCI, CORVALLIS, OR 97331 USA. RP Skyllingstad, ED (reprint author), PACIFIC NW LAB, MARINE SCI LAB, 1529 W SEQUIM BAY RD, SEQUIM, WA 98382 USA. NR 34 TC 6 Z9 7 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 574 EP 593 DI 10.1016/0167-2789(96)00113-3 PG 20 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900021 ER PT J AU Holm, DD AF Holm, DD TI Hamiltonian balance equations SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE balance; geostrophic flow; ocean; atmosphere; dynamics; asymptotics ID BAROTROPIC CONTINENTAL-SHELF; SLOPE FLOW-FIELDS; NONLINEAR STABILITY ANALYSIS; NUMERICAL-MODEL SOLUTIONS; INTERMEDIATE MODELS; PERIODIC DOMAINS; POISSON BRACKETS; FORMULATION; ELASTICITY; MECHANICS AB We find Hamiltonian balance equations (HBE) in Eulerian variables in the momentum formulation. This is done by expanding Hamilton's principle (HP) for the primitive equations (PE) in powers of the Rossby number, epsilon << 1, truncating at order O(epsilon), then retaining all the terms that result from taking variations. An alternative set of Hamiltonian balance equations is derived in isopycnal variables (IHBE). The two sets of approximate equations HBE and IHBE differ from PE and isopycnal PE (IPE) at order O(epsilon(2)). Each of these four systems conserves energy and possesses an exact Kelvin theorem, which implies exact potential-vorticity advection. However, HBE and IHBE are balanced, while PE and IPE are not. C1 LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. RP Holm, DD (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 32 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 EI 1872-8022 J9 PHYSICA D JI Physica D PD NOV 15 PY 1996 VL 98 IS 2-4 BP 379 EP 414 DI 10.1016/0167-2789(96)00121-2 PG 36 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VT609 UT WOS:A1996VT60900010 ER PT J AU Yi, KS Quinn, JJ AF Yi, KS Quinn, JJ TI Charge and spin response of the spin-polarized electron gas SO PHYSICAL REVIEW B LA English DT Article AB The charge and spin response of a spin-polarized electron gas is investigated including terms beyond the random-phase approximation. We evaluate the charge response, the longitudinal and transverse spin response, and the mixed spin-charge response self-consistently in terms of the susceptibility functions of a noninteracting system. Exchange-correlation effects between electrons of spin sigma and sigma' are included following Kukkonen and Overhauser, by using spin-polarization-dependent generalized Hubbard local-field factors G(sigma)(+/-) and G(<(sigma)over bar>)(+/-) The general condition for charge-density and spin-density-wave excitations of the system is discussed. C1 PUSAN NATL UNIV,DEPT PHYS,PUSAN 609735,SOUTH KOREA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Yi, KS (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 10 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 19 BP 13398 EP 13401 DI 10.1103/PhysRevB.54.13398 PG 4 WC Physics, Condensed Matter SC Physics GA VV264 UT WOS:A1996VV26400002 ER PT J AU Yamamoto, M Chan, CT Ho, KM Naito, S AF Yamamoto, M Chan, CT Ho, KM Naito, S TI First-principles calculation of oxygen adsorption on Zr(0001) surface: Possible site occupation between the second and the third layer SO PHYSICAL REVIEW B LA English DT Article ID LEED CRYSTALLOGRAPHIC INVESTIGATIONS; ELECTRONIC-STRUCTURE; UNDERLAYER FORMATION; METALS; CHEMISORPTION; 4D-TRANSITION; OXIDATION; NITROGEN; TI(0001); HYDROGEN AB The oxygen adsorption on the Zr(0001) surface is studied using first-principles total-energy and force calculations. We calculated the atomic structure, heat of adsorption, work function, and electronic structure for oxygen occupying various surface and subsurface sites for both the Zr(0001)-(1x1)-O and Zr(0001)-(2x1)-O system. We found that the energetically most favorable occupation sites for oxygen are the octahedral sites between the second and the third layer. The change in the work function induced by oxygen adsorption depends strongly on the position of the adsorbed oxygen atoms end the calculated change of work function at the energetically most favorable site is consistent with previous experiments. A large difference in the electronic structure between the overlayer and subsurface adsorption is also found. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,US DOE,AMES LAB,AMES,IA 50011. HONG KONG UNIV SCI & TECHNOL,DEPT PHYS,CLEARWATER BAY,HONG KONG. RP Yamamoto, M (reprint author), KYOTO UNIV,INST ADV ENERGY,UJI,KYOTO 611,JAPAN. NR 36 TC 34 Z9 34 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 19 BP 14111 EP 14120 DI 10.1103/PhysRevB.54.14111 PG 10 WC Physics, Condensed Matter SC Physics GA VV264 UT WOS:A1996VV26400105 ER PT J AU Reynolds, JP Luban, M AF Reynolds, JP Luban, M TI Dephasing of bloch oscillations in epitaxial superlattices SO PHYSICAL REVIEW B LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; SEMICONDUCTOR SUPERLATTICES; ROUGHNESS AB We show that the essential features of the decay of Bloch oscillations observed in epitaxially grown semiconductor superlattices subject to a de electric field can be reproduced using a one-dimensional model of interface roughness (LR). As a result of IR, the electron dynamics can be characterized in terms of many discrete, incommensurate frequencies near the Bloch frequency. The interference effects associated with these frequencies cause a substantial decrease in amplitude of the signal after several Bloch periods. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP Reynolds, JP (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 15 TC 16 Z9 16 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14301 EP 14304 PG 4 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700021 ER PT J AU Campbell, IH Rubin, S Zawodzinski, TA Kress, JD Martin, RL Smith, DL Barashkov, NN Ferraris, JP AF Campbell, IH Rubin, S Zawodzinski, TA Kress, JD Martin, RL Smith, DL Barashkov, NN Ferraris, JP TI Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers SO PHYSICAL REVIEW B LA English DT Article ID LIGHT-EMITTING-DIODES; ALKANETHIOLATE MONOLAYERS; WETTING PROPERTIES; GOLD; POLYMERS; SURFACES; SILVER AB We demonstrate tuning of Schottky energy barriers in organic electronic devices by utilizing chemically tailored electrodes. The Schottky energy barrier of Ag on poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-1,4-phenylene was tuned over a range of more than 1 eV by using self-assembled monolayers (SAM's) to attach oriented dipole layers to the Ag prior to device fabrication. Kelvin probe measurements were used to determine the effect of the SAM's on the Ag surface potential. Ab initio Hartree-Fock calculations of the molecular dipole moments successfully describe the surface potential changes. The chemically tailored electrodes were then incorporated in organic diode structures and changes in the metal/organic Schottky energy barriers were measured using an electroabsorption technique. These results demonstrate the use of self-assembled monolayers to control metal/organic interfacial electronic properties. They establish a physical principle for manipulating the relative energy levels between two materials and demonstrate an approach to improve metal/organic contacts in organic electronic devices. C1 UNIV TEXAS,RICHARDSON,TX 75083. RP Campbell, IH (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 TC 403 Z9 404 U1 10 U2 91 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 NOV 15 PY 1996 VL 54 IS 20 BP 14321 EP 14324 PG 4 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700026 ER PT J AU Ahuja, R Bruhwiler, PA Wills, JM Johansson, B Martensson, N Eriksson, O AF Ahuja, R Bruhwiler, PA Wills, JM Johansson, B Martensson, N Eriksson, O TI Theoretical and experimental study of the graphite 1s x-ray absorption edges SO PHYSICAL REVIEW B LA English DT Article ID AUGER LINE-SHAPE; ELECTRONIC-PROPERTIES; FINE-STRUCTURE; INTERCALATED GRAPHITE; MULTIPLE-SCATTERING; BRILLOUIN-ZONE; BAND-STRUCTURE; SPECIAL POINTS; SIMPLE METALS; CORE EXCITON AB Theoretical calculations in combination with experiments for the pi* and sigma* x-ray absorption edges are reported for graphite. Theory and experiment agree well for the leading pi* and sigma* resonances. By comparing theoretical calculations for a single graphene layer that include the effect of the core hole to similar calculations that do not, we find that 1s x-ray absorption in graphite is to be associated with an excitonic effect. Both the pi* and sigma* excitons are localized primarily on the core-excited atom, but have significant weight on the nearest-neighbor atoms. The results are closely related to the electronic structure of a N impurity. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP Ahuja, R (reprint author), UNIV UPPSALA,DEPT PHYS,BOX 530,S-75121 UPPSALA,SWEDEN. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 72 TC 77 Z9 77 U1 0 U2 14 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 NOV 15 PY 1996 VL 54 IS 20 BP 14396 EP 14404 DI 10.1103/PhysRevB.54.14396 PG 9 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700037 ER PT J AU Albers, RC Boring, AM Wills, JM Cox, LE Eriksson, OE Christensen, NE AF Albers, RC Boring, AM Wills, JM Cox, LE Eriksson, OE Christensen, NE TI Electronic structure and x-ray photoelectron spectroscopy of the alpha, beta, and gamma phases of Np SO PHYSICAL REVIEW B LA English DT Article ID PHOTOEMISSION-SPECTROSCOPY; 5F ELECTRONS; LOCALIZATION; METALS; STATES AB The electronic structure, density of states, and x-ray photoelectron spectroscopy (XPS) intensities of the alpha, beta, and gamma phases of Np have been theoretically determined from self-consistent, fully relativistic, linear muffin-tin-orbital band-structure calculations. The calculated XPS intensities show a large f peak that narrows (due to the larger volumes per atom) and moves closer to the Fermi energy as one progresses through the alpha, beta, and gamma phases. Experimental XPS intensities of the alpha and beta phases are also presented and compared to the theoretical calculations. Experimentally, the alpha and beta intensities are found to be almost identical, and do not show any evidence for the theoretically predicted f-band narrowing. In addition, there is a large additional experimental intensity at higher binding energy that is not present in the calculations. This extra intensity may be evidence for quasilocalized behavior of the 5f electronic states that is induced by the XPS process. For example, the low-energy tail may be related to either multiplet or satellite structure due to final-state localized atomiclike correlation effects. C1 UNIV UPPSALA, DEPT PHYS, UPPSALA, SWEDEN. LOS ALAMOS NATL LAB, CTR MAT SCI, LOS ALAMOS, NM 87545 USA. AARHUS UNIV, INST PHYS, DK-8000 AARHUS C, DENMARK. RP Albers, RC (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 31 TC 6 Z9 6 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14405 EP 14412 DI 10.1103/PhysRevB.54.14405 PG 8 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700038 ER PT J AU McCoy, JM LaFemina, JP AF McCoy, JM LaFemina, JP TI Structure and stability of steps on the GaAs(110) surface SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-BEAM EPITAXY; GROWTH; MICROSCOPY; GAAS(001); RECONSTRUCTIONS; SI(001); FILMS AB The equilibrium structures and step energies of monolayer steps along [1(1) over bar0$], [1(1) over bar1$], and [1(1) over bar2$] on the GaAs(110) surface are examined theoretically using the autocompensation (electron-counting) principle. It is inferred that steps along [1(1) over bar2$] and [1(1) over bar1$] have significantly lower step energies than steps along [1(1) over bar0$]. The reason for this is that, unlike [1(1) over bar0$]-type steps, [1(1) over bar2$]- and [1(1) over bar1$]-type steps have topologies (connectivities) which permit a rehybridization of the step-edge atom dangling bond charge density by the creation of vacancies along the step line, perhaps accompanied by step-edge rebonding via the formation of dimers. This rehybridization results in stable, autocompensated steps. Step-edge atomic geometries are proposed for the step structures along [1(1) over bar2$] and [1(1) over bar1$]. Our results are then used to interpret reported scanning tunneling microscopy data for GaAs(110) surface steps, to discuss the behavior of steps resulting from cleavage, and to explain reported atomistic details of homoepitaxial growth on this surface. These results for steps on the GaAs(110) surface are also expected to be applicable to steps on other III-V (110) surfaces. RP McCoy, JM (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 21 TC 17 Z9 17 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14511 EP 14517 DI 10.1103/PhysRevB.54.14511 PG 7 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700048 ER PT J AU Diez, E Sanchez, A DominguezAdame, F Berman, GP AF Diez, E Sanchez, A DominguezAdame, F Berman, GP TI Electron dynamics in intentionally disordered semiconductor superlattices SO PHYSICAL REVIEW B LA English DT Article ID BLOCH OSCILLATIONS; TIMES AB We study the dynamical behavior of disordered quantum well-based semiconductor superlattices where the disorder is intentional and short-range correlated. We show that, whereas the transmission time of a particle grows exponentially with the number of wells in an usual disordered superlattice for any value of the incident particle energy, for specific values of the incident energy this time increases linearly when correlated disorder is included. As expected, those values of the energy coincide with a narrow subband of extended states predicted by the static calculations of Dominguez-Adame et al. [Phys. Rev. B 51, 14 359 (1994)]; such states are seen in our dynamical results to exhibit a ballistic regime, very close to the WKB approximation of a perfect superlattice. Fourier transform of the output signal for an incident Gaussian wave packet reveals a dramatic filtering of the original signal, which makes us confident that devices based on this property may be designed and used for nanotechnological applications. This is more so in view of the possibility of controlling the output band using a de-electric field, which we also discuss. In the conclusion we summarize our results and present an outlook for future developments arising from this work. C1 UNIV COMPLUTENSE MADRID,FAC FIS,DEPT FIS MAT,E-28040 MADRID,SPAIN. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CNLS,LOS ALAMOS,NM 87545. RP Diez, E (reprint author), UNIV CARLOS III,ESCUELA POLITECN SUPER,DEPT MATEMAT,E-28911 LEGANES,MADRID,SPAIN. RI Sanchez, Angel/A-9229-2008; Dominguez-Adame, Francisco/E-4277-2010; ENRIQUE, DIEZ/M-3691-2014 OI Sanchez, Angel/0000-0003-1874-2881; Dominguez-Adame, Francisco/0000-0002-5256-4196; ENRIQUE, DIEZ/0000-0001-7964-4148 NR 16 TC 15 Z9 15 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1996 VL 54 IS 20 BP 14550 EP 14559 DI 10.1103/PhysRevB.54.14550 PG 10 WC Physics, Condensed Matter SC Physics GA VX717 UT WOS:A1996VX71700053 ER PT J AU Kallosh, R Shmakova, M Wong, WK AF Kallosh, R Shmakova, M Wong, WK TI Freezing of moduli by N=2 dyons SO PHYSICAL REVIEW D LA English DT Article ID SUPERGRAVITY AB In N=2 ungauged supergravity we have found the most general double-extreme dyonic black holes with arbitrary number n(u)psilon of constant vector multiplets and n(h) of constant hypermultiplets. They are double extreme: (1) supersymmetric with coinciding horizons; (2) the mass for a given set of quantized charges is extremal. The spacetime is of the Reissner-Nordstrom form and the vector multiplet moduli depend on dyon charges. As an example we display n(u)psilon complex moduli as functions of 2(n(u)psilon + 1) electric and magnetic charges in a model related to a classical Calabi-Yau moduli space. A specific case includes the complex S, T, U moduli depending on four electric and four magnetic charges of 4 U(1) gauge groups. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Kallosh, R (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 13 TC 47 Z9 47 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 NOV 15 PY 1996 VL 54 IS 10 BP 6284 EP 6292 DI 10.1103/PhysRevD.54.6284 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV263 UT WOS:A1996VV26300035 ER PT J AU Behrndt, K Kallosh, R Rahmfeld, J Shmakova, M Wong, WK AF Behrndt, K Kallosh, R Rahmfeld, J Shmakova, M Wong, WK TI STU black holes and string triality SO PHYSICAL REVIEW D LA English DT Article ID MAXWELL-EINSTEIN SUPERGRAVITY; SPECIAL GEOMETRY; JORDAN ALGEBRAS; N=2 AB We find double-extreme black holes associated with the special geometry of the Calabi-Yau moduli space with the prepotential F = STU. The area formula is STU-moduli independent and has [SL(2,Z)](3) symmetry in space of charges. The dual version of this theory without a prepotential treats the dilaton S asymmetric vs T,U moduli. We display the dual relation between new (STU) black holes and stringy (S\TU) black holes using a particular Sp(8,Z) transformation,The area formula of one theory equals that of the dual theory when expressed in terms of dual charges. We analyze the relation between (STU) black holes to string triality of black holes: (S\TU), (T\US), (U\ST) solutions. In the democratic STU-symmetric version we find that all three S, T, and U duality symmetries are nonperturbative and mix electric and magnetic charges. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. UNIV TENNESSEE,KNOXVILLE,TN 37996. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Behrndt, K (reprint author), HUMBOLDT UNIV BERLIN,INST PHYS,INVALIDENSTR 110,D-10115 BERLIN,GERMANY. NR 20 TC 142 Z9 142 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 NOV 15 PY 1996 VL 54 IS 10 BP 6293 EP 6301 DI 10.1103/PhysRevD.54.6293 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV263 UT WOS:A1996VV26300036 ER PT J AU Kallosh, R Rajaraman, A AF Kallosh, R Rajaraman, A TI Brane-antibrane democracy SO PHYSICAL REVIEW D LA English DT Article ID DILATON BLACK-HOLES; SUPERSYMMETRY; SUPERGRAVITY AB We suggest a duality-invariant formula for the entropy and temperature of nonextreme black holes in supersymmetric string theory. The entropy is given in terms of the duality-invariant parameter of the deviation from extremality and 56 SU(8) covariant-central charges. It interpolates between the entropies of Schwarzschild solution and extremal solutions with various amount of unbroken supersymmetries, and therefore, serves for classification of black holes in supersymmetric string theories. We introduce the second auxiliary 56 via an E(7) symmetric constraint. The symmetric and antisymmetric combinations of these two multiplets are related via moduli to the corresponding two fundamental representations of E(7): brane and antibrane ''numbers.'' Using the CPT as well as C symmetry of the entropy formula and duality one can explain the mysterious simplicity of the nonextreme black hole area formula in terms of branes and antibranes. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Kallosh, R (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1996 VL 54 IS 10 BP 6381 EP 6386 DI 10.1103/PhysRevD.54.6381 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV263 UT WOS:A1996VV26300044 ER PT J AU Bodwin, GT AF Bodwin, GT TI Lattice formulation of chiral gauge theories SO PHYSICAL REVIEW D LA English DT Article ID DOMAIN-WALL FERMIONS; SCHWINGER MODEL; PERTURBATIVE ANALYSIS; STAGGERED FERMIONS; WAVE-GUIDE; REGULARIZATION; NEUTRINOS; OVERLAP; ANOMALIES; ABSENCE AB We present a method for formulating gauge theories of chiral fermions in lattice field theory. The method makes use of a Wilson mass to remove doublers. Gauge invariance is then restored by modifying the theory in two ways:The magnitude of the fermion determinant is replaced with the square root of the determinant for a fermion with vectorlike couplings to the gauge held; a double limit is taken, in which the lattice spacing associated with the fermion field is sent to zero before the lattice spacing associated with the gauge field. The method applies only to theories whose fermions are in an anomaly-free representation of the gauge group. We also present a related technique for computing matrix elements of operators involving fermion fields. Although the analyses of these methods are couched in weak-coupling perturbation theory, it is argued that the computational prescriptions are gauge invariant in the presence of a nonperturbative gauge-field configuration. RP ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 87 TC 22 Z9 22 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1996 VL 54 IS 10 BP 6497 EP 6520 DI 10.1103/PhysRevD.54.6497 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV263 UT WOS:A1996VV26300057 ER PT J AU Suzuki, M AF Suzuki, M TI Topologically nontrivial time-dependent chiral condensates SO PHYSICAL REVIEW D LA English DT Article ID CLASSICAL PION FIELD; HIGH-ENERGY; COLLISIONS; DOMAINS; STATES; FORM AB Topologically nontrivial time-dependent solutions of the classical nonlinear sigma model are studied as candidates of the disoriented chiral condensate (DCC) in 3+1 dimensions. Unlike the analytic solutions so far discussed, these solutions cannot be transformed into isospin-uniform ones by chiral rotations. If they are produced as DCC's, they can be detected by a distinct pattern in the angle-rapidity distribution of the neutral-to-charged pion ratio. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Suzuki, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 37 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 1996 VL 54 IS 10 BP R5922 EP R5926 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VV263 UT WOS:A1996VV26300002 ER PT J AU Cooper, RF Fanselow, JB Weber, JKR Merkley, DR Poker, DB AF Cooper, RF Fanselow, JB Weber, JKR Merkley, DR Poker, DB TI Dynamics of oxidation of a Fe2+-bearing aluminosilicate (Basaltic) melt SO SCIENCE LA English DT Article ID OXYGEN DIFFUSION; CHEMICAL DIFFUSION; SOLID-SOLUTIONS; TEMPERATURES; OLIVINE AB Rutherford backscattering spectroscopy (RBS) and microscopy demonstrate that the similar to 1400 degrees C oxidation of levitated droplets of a natural Fe2+-bearing aluminosilicate (basalt) melt occurs by chemical diffusion of Fe2+ and Ca2+ to the free surface of the droplet; internal oxidation of the melt results from the required counterflux of electron holes. Diffusion of an oxygen species is not required. Oxidation causes the droplets to go subsolidus; magnetite (Fe3O4) forms at the oxidation-solidification front with a morphology suggestive of a Liesegang-band nucleation process. C1 INTERSON INC,NORTHBROOK,IL 60062. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV WISCONSIN,DEPT GEOL & GEOPHYS,MADISON,WI 53706. RP Cooper, RF (reprint author), UNIV WISCONSIN,DEPT MAT SCI & ENGN,1500 ENGN DR,MADISON,WI 53706, USA. NR 26 TC 38 Z9 38 U1 1 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 15 PY 1996 VL 274 IS 5290 BP 1173 EP 1176 DI 10.1126/science.274.5290.1173 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT335 UT WOS:A1996VT33500048 ER PT J AU Imai, T Kojima, S LEsperance, G Hong, BD Jiang, D Nieh, TG AF Imai, T Kojima, S LEsperance, G Hong, BD Jiang, D Nieh, TG TI Effects of temperature on the superplastic characteristics of a powder metallurgy pure aluminum SO SCRIPTA MATERIALIA LA English DT Article ID HIGH-STRAIN RATES; COMPOSITE C1 NAGOYA MUNICIPAL IND RES INST,ATSUTA KU,NAGOYA,AICHI 456,JAPAN. ECOLE POLYTECH,MONTREAL,PQ H3C 3A7,CANADA. HARBIN INST TECHNOL,HARBIN 150001,PEOPLES R CHINA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Imai, T (reprint author), NATL IND RES INST NAGOYA,KITA KU,1 HIRATE CHO,NAGOYA,AICHI 462,JAPAN. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 10 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD NOV 15 PY 1996 VL 35 IS 10 BP 1189 EP 1193 DI 10.1016/1359-6462(96)00288-6 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VL928 UT WOS:A1996VL92800011 ER PT J AU Thompson, AW Chu, WY Williams, JC AF Thompson, AW Chu, WY Williams, JC TI Hydrogen solubility in a titanium aluminide alloy - Comment SO SCRIPTA MATERIALIA LA English DT Article ID BEHAVIOR C1 BEIJING UNIV SCI & TECHNOL,DEPT MAT PHYS,BEIJING 100083,PEOPLES R CHINA. GE CO,AIRCRAFT ENGINES,CINCINNATI,OH 45215. RP Thompson, AW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,MS 62-203,BERKELEY,CA 94720, USA. NR 19 TC 1 Z9 1 U1 0 U2 3 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 NOV 15 PY 1996 VL 35 IS 10 BP 1195 EP 1198 DI 10.1016/1359-6462(96)00282-5 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VL928 UT WOS:A1996VL92800012 ER PT J AU Conroy, JFT Caldwell, K BrucknerLea, CJ Janata, J AF Conroy, JFT Caldwell, K BrucknerLea, CJ Janata, J TI Effects of interfacial tension in tunneling microscopy .1. Theory SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MERCURY SESSILE DROP; ELECTRIC-FIELD; MANIPULATION; ATOMS AB It is shown that variations in interfacial tension induced by the charged tunneling tip may influence the lateral stability of imaged objects during scanning tunneling microscopy experiments on both solid and liquid substrates. The induced interfacial tension gradient may also play a dominating role in the mechanical stability of liquid substrates used for tunneling microscopy. The electrostatic model developed in this work parallels the model of a polarized electrochemical interface. The interfacial tension effect is compared with another electrostatic effect: the interaction between the electric field and dipolar or charged adsorbates. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV UTAH, DEPT BIOENGN, SALT LAKE CITY, UT 84112 USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 14 PY 1996 VL 100 IS 46 BP 18222 EP 18228 DI 10.1021/jp962085p PG 7 WC Chemistry, Physical SC Chemistry GA VT708 UT WOS:A1996VT70800032 ER PT J AU Conroy, JFT Hlady, V BrucknerLea, CJ Janata, J AF Conroy, JFT Hlady, V BrucknerLea, CJ Janata, J TI Effects of interfacial tension in tunneling microscopy .2. Experimental observation of surface instability SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MERCURY SESSILE DROP; MANIPULATION; ELECTRODES; ATOMS AB It has been found that low-frequency waving observed during tunneling microscopy with a stationary tip on liquid mercury is voltage dependent. This phenomenon can be explained by the Gibbs-Lippmann equation, which describes electrostatically induced changes in surface tension of mercury/electrolyte interfaces. The presence of adsorbing compounds overshadows the electrostatic effects, in complete agreement with the Gibbs-Lippmann model. These observations indicate that low bias voltages are required for maximum image resolution when performing tunneling microscopy at liquid surfaces. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV UTAH, DEPT BIOENGN, SALT LAKE CITY, UT 84112 USA. NR 19 TC 4 Z9 4 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 14 PY 1996 VL 100 IS 46 BP 18229 EP 18233 DI 10.1021/jp962086h PG 5 WC Chemistry, Physical SC Chemistry GA VT708 UT WOS:A1996VT70800033 ER PT J AU Rodriguez, JA Kuhn, M Hrbek, J AF Rodriguez, JA Kuhn, M Hrbek, J TI Interaction of silver, cesium, and zinc with alumina surfaces: Thermal desorption and photoemission studies SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID REFLECTION-ABSORPTION SPECTROSCOPY; RAY PHOTOELECTRON-SPECTROSCOPY; ENERGY-LOSS SPECTROSCOPY; CHEMICAL-PROPERTIES; ELECTRONIC-PROPERTIES; PROMOTED SULFIDATION; TRANSITION-METALS; MODEL CATALYSTS; ALPHA-ALUMINA; AU FILMS AB Cs, Ag, and Zn behave in a different way when deposited on surfaces of ultrathin (15-20 Angstrom) films of alumina. In the case of Cs/Al2O3, the alkali atoms wet the oxide, forming strong chemisorption bonds. At small coverages of Cs, desorption of the alkali occurred between 600 and 1000 K. As the amount of Cs deposited increased, there was a reduction in the Cs desorption temperature to similar to 350 K. This broad range of desorption temperatures reflects a continuous decrease in the Cs adsorption energy from 63 to 18 kcal/mol with increasing Cs coverage. The deposition of small amounts of Cs induced large (0.9-1.1 eV) positive shifts in the binding energies of the O KVV, O 1s, and Al 2p features of the alumina films. This is consistent with a transfer of electrons from Cs into surface states of alumina that produces a transformation similar to a change from p-type to n-type semiconductors, AE and Zn do not wet the surface of alumina well and form three-dimensional clusters or particles. In these systems, the activation energies for desorption of the admetal increase with cluster size (20 kcal/mol for Ag, 10 kcal/mol for Zn). The deposition of Ag and Zn induces only minor perturbations in the electronic properties of alumina. Small silver clusters supported on alumina exhibit an incompletely developed metallic band structure. The differences in the behavior of the Cs/Al2O3 and Ag/Al2O3 or Zn/Al2O3 systems are explained in terms of variations in the surface free energy of the admetals and in the nature of the admetal-oxide bonds. RP Rodriguez, JA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Hrbek, Jan/I-1020-2013 NR 91 TC 55 Z9 55 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 14 PY 1996 VL 100 IS 46 BP 18240 EP 18248 DI 10.1021/jp962195w PG 9 WC Chemistry, Physical SC Chemistry GA VT708 UT WOS:A1996VT70800035 ER PT J AU Dunlap, BI Boettger, JC AF Dunlap, BI Boettger, JC TI Local-density-functional study of the fullerenes, graphene and graphite SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID BUCKMINSTERFULLERENE; C-60; APPROXIMATIONS; POTENTIALS; SEPARATION; SURFACES; DILAYER; SYSTEMS AB Large basis set local-density-functional calculations on fullerenes, graphene and graphite suggest that fullerene stability increases monotonically with the number of carbon atoms (N), and is nearly linear in 1/N. C-60 is less stable energetically than C-70 and higher fullerenes, despite the apparent preference for C-60 in nature. The heat of formation found here for C-60 relative to graphite is in good agreement with experiment, while the heat of formation for graphene relative to graphite is overestimated by a factor of two. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Dunlap, BI (reprint author), USN,RES LAB,THEORET CHEM SECT,CODE 6179,WASHINGTON,DC 20375, USA. OI Dunlap, Brett/0000-0003-1356-6559 NR 34 TC 25 Z9 26 U1 2 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 14 PY 1996 VL 29 IS 21 BP 4907 EP 4913 DI 10.1088/0953-4075/29/21/004 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VU407 UT WOS:A1996VU40700004 ER PT J AU Ying, ZC Hettich, RL Compton, RN Haufler, RE AF Ying, ZC Hettich, RL Compton, RN Haufler, RE TI Synthesis of nitrogen-doped fullerenes by laser ablation SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID RESONANCE MASS-SPECTROMETRY; RESOLUTION; C-60 AB Fullerene molecules doped with nitrogen atoms were synthesized using laser ablation of graphite in a heated nitrogen gas. Laser desorption/ionization time-of-flight and Fourier transform mass spectroscopic studies revealed the presence of C-m-N-1(+) ions (m = 60, 70, etc) as well as pure carbon fullerene ions C-m(+). The presence of nitrogen in the product was confirmed by isotope labelled experiments using N-15(2). X-ray photoemission spectroscopy measurements showed the nitrogen 1s level at 400.7 eV. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. COMSTOCK INC,OAK RIDGE,TN 37830. RI Hettich, Robert/N-1458-2016 OI Hettich, Robert/0000-0001-7708-786X NR 16 TC 28 Z9 28 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD NOV 14 PY 1996 VL 29 IS 21 BP 4935 EP 4942 DI 10.1088/0953-4075/29/21/007 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VU407 UT WOS:A1996VU40700007 ER PT J AU Maoz, R Matlis, S DiMasi, E Ocko, BM Sagiv, J AF Maoz, R Matlis, S DiMasi, E Ocko, BM Sagiv, J TI Self-replicating amphiphilic monolayers SO NATURE LA English DT Article ID ASSEMBLING MONOLAYERS; LANGMUIR-BLODGETT; MULTILAYERS; LAYER; NANOSTRUCTURES; NANOCHEMISTRY; CONSTRUCTION; RECOGNITION; SURFACES; TEMPLATE AB MOLECULAR films with predetermined layered structures can be engineered by using techniques such as the Langmuir-Blodgett method(1,2) and self-assembly(1,3-9) to deposit discrete monolayers sequentially on a substrate. Such films might have a variety of uses-as smart surface coatings, nonlinear optical materials and in tribology, for example. Were we report the replicative grow th of a molecular film of self-assembling silane bilayers with hydrogen-interlayer polar regions into which further identical bilayers can be intercalated. The intercalation step is triggered by a chemical treatment and so can be carried out controllably, allowing duplication in one step of an entire multilayer structure. In this way, we can achieve the stepwise exponential growth of a multilayer film with a predictable number of stacked bilayers. C1 WEIZMANN INST SCI,DEPT MAT & INTERFACES,IL-76100 REHOVOT,ISRAEL. WEIZMANN INST SCI,CHEM SERV UNIT,IL-76100 REHOVOT,ISRAEL. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NR 29 TC 80 Z9 80 U1 1 U2 34 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 14 PY 1996 VL 384 IS 6605 BP 150 EP 153 DI 10.1038/384150a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT336 UT WOS:A1996VT33600060 ER PT J AU Dvali, G Riotto, A AF Dvali, G Riotto, A TI Gauge-mediated curvature of the flat directions during preheating SO PHYSICS LETTERS B LA English DT Article ID PARTICLE-PRODUCTION; SUPERSYMMETRIC TECHNICOLOR; COSMOLOGICAL PROBLEMS; ENTROPY CRISIS; INFLATION; BREAKING; UNIVERSE; BARYOGENESIS; SUPERGRAVITY; MODELS AB Usually one expects the inflaton field to be coupled to some gauge-charged particles allowing for its decay during reheating. Such particles then play the role of messengers for the gauge-mediated supersymmetry breaking during and (shortly) after the inflation and radiatively induce soft masses to all other D-flat directions. We show that during the preheating stage this gauge-mediated soft masses are typically much greater than the Hubble parameter during inflation. The dramatic role is played by the supersymmetry (SUSY) breaking due to the parametric resonance effect, which ensures that the inflaton predominantly decays into the bosons and not the fermions. The difference in the Fermi-Bose occupation numbers results in the large gauge-mediated soft masses, which determine the post-inflationary evolution of the flat directions, suggesting that non-thermal phase transitions mediated by gauge messengers may play a crucial role in the Affleck-Dine mechanism for the generation of the baryon asymmetry. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Dvali, G (reprint author), CERN,DIV THEORY,CH-1211 GENEVA,SWITZERLAND. NR 45 TC 7 Z9 7 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 NOV 14 PY 1996 VL 388 IS 2 BP 247 EP 252 DI 10.1016/S0370-2693(96)01139-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400006 ER PT J AU Dorey, N Khoze, VV Mattis, MP AF Dorey, N Khoze, VV Mattis, MP TI A two-instanton test of the exact solution of N=2 supersymmetric QCD SO PHYSICS LETTERS B LA English DT Article ID BREAKING; DUALITY AB The exact solution of N = 2 supersymmetric QCD found by Seiberg and Witten includes a prediction for all multiinstanton contributions to the low-energy dynamics. In the case where the matter hypermultiplets are massless, the leading non-perturbative contribution at weak coupling comes from the two-instanton sector. We calculate this contribution from first principles using the exact two-instanton solution of the self-dual Yang-Mills equation found by Atiyah, Drinfeld, Hitchin and Manin. We find exact agreement with the predictions of Seiberg and Witten for all numbers of flavours, We also confirm their predictions for the case of massive hypermultiplets. C1 UNIV DURHAM,DEPT PHYS,CTR PARTICLE THEORY,DURHAM DH1 3LE,ENGLAND. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Dorey, N (reprint author), UNIV COLL SWANSEA,DEPT PHYS,SWANSEA SA2 8PP,W GLAM,WALES. OI Khoze, Valentin V/0000-0003-3006-4147 NR 19 TC 35 Z9 35 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 NOV 14 PY 1996 VL 388 IS 2 BP 324 EP 330 DI 10.1016/S0370-2693(96)01085-4 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400017 ER PT J AU Hampel, W Heusser, G Kiko, J Kirsten, T Laubenstein, M Pernicka, E Rau, W Ronn, U Schlosser, C Wojcik, M Zakharov, Y vonAmmon, R Ebert, KH Fritsch, T Heidt, D Henrich, E Stieglitz, L Weirich, F Balata, M Sann, M Hartmann, FX Bellotti, E Cattadori, C Cremonesi, O Ferrari, N Fiorini, E Zanotti, L Altmann, M vonFeilitzsch, F Mossbauer, R Berthomieu, G Schatzman, E Carmi, I Dostrovsky, I Bacci, C Belli, P Bernabei, R dAngelo, S Paoluzi, L Bevilacqua, A Cribier, M Gosset, L Rich, J Spiro, M Tao, C Vignaud, D Boger, J Hahn, RL Rowley, JK Stoenner, RW Weneser, J AF Hampel, W Heusser, G Kiko, J Kirsten, T Laubenstein, M Pernicka, E Rau, W Ronn, U Schlosser, C Wojcik, M Zakharov, Y vonAmmon, R Ebert, KH Fritsch, T Heidt, D Henrich, E Stieglitz, L Weirich, F Balata, M Sann, M Hartmann, FX Bellotti, E Cattadori, C Cremonesi, O Ferrari, N Fiorini, E Zanotti, L Altmann, M vonFeilitzsch, F Mossbauer, R Berthomieu, G Schatzman, E Carmi, I Dostrovsky, I Bacci, C Belli, P Bernabei, R dAngelo, S Paoluzi, L Bevilacqua, A Cribier, M Gosset, L Rich, J Spiro, M Tao, C Vignaud, D Boger, J Hahn, RL Rowley, JK Stoenner, RW Weneser, J TI GALLEX solar neutrino observations: Results for GALLEX III SO PHYSICS LETTERS B LA English DT Article ID DETECTOR AB We report the GALLEX solar neutrino results for the measuring period GALLEX III, the period from 12 October 1994-4 October 1995. Counting for these runs was completed on 29 March 1996. The GALLEX III result (14 runs) is [53.9 +/- 10.6(stat.) +/- 3.1 (syst.)] SNU (1 sigma). This is 15.8 SNU below but statistically compatible with the new combined result for GALLEX (I+II+III) (53 runs), which is [69.7 +/- 6.7 (stat.)(-4.5)(+3.9) (syst.)] SNU (1 sigma) or (69.7(-8.1)(+7.8)) SNU With errors quadratically added. We also give the preliminary result from our second Cr-51-source experiment: the measured detector response is 83 +/- 10% of expectation. The combined result from both GALLEX Cr-51-source experiments is 92 +/- 8% of expectation. C1 FORSCHUNGSZENTRUM KARLSRUHE,INST CHEM TECH,D-76021 KARLSRUHE,GERMANY. LAB NAZL GRAN SASSO,I-67010 LAQUILA,ITALY. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. TECH UNIV MUNICH,PHYS DEPT E15,D-85748 GARCHING,GERMANY. OBSERV COTE AZUR,DEPT CASSINI,F-06004 NICE 4,FRANCE. WEIZMANN INST SCI,DEPT ENVIRONM SCI & ENERGY RES,IL-76100 REHOVOT,ISRAEL. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,I-00133 ROME,ITALY. IST NAZL FIS NUCL,SEZ ROMA 2,I-00133 ROME,ITALY. CENS,SERV PHYS PARTICULES,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. BROOKHAVEN NATL LAB,UPTON,NY 11973. JAGIELLONIAN UNIV,INST PHYS,PL-30059 KRAKOW,POLAND. RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. UNIV ROMA 3,DIPARTIMENTO FIS,I-00100 ROME,ITALY. CEN,SAPR,SRS,F-38041 GRENOBLE,FRANCE. COLL FRANCE,LPC,F-75005 PARIS,FRANCE. RP Hampel, W (reprint author), MAX PLANCK INST KERNPHYS,POSTFACH 103980,D-69029 HEIDELBERG,GERMANY. RI Belli, Pierluigi/H-1942-2012; Laubenstein, Matthias/C-4851-2013; Bernabei, Rita/C-1212-2016; OI Belli, Pierluigi/0000-0003-4517-4891; Laubenstein, Matthias/0000-0001-5390-4343; Bernabei, Rita/0000-0003-1786-5396; cattadori, carla maria/0000-0001-7885-6253 NR 17 TC 272 Z9 273 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 NOV 14 PY 1996 VL 388 IS 2 BP 384 EP 396 DI 10.1016/S0370-2693(96)01121-5 PG 13 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400026 ER PT J AU Balest, R Behrens, BH Cho, K Daoudi, M 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 Galik, RS 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 Karliner, I 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 Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Kim, IJ Ling, Z Mahmood, AH 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 Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G 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 Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS AF Balest, R Behrens, BH Cho, K Daoudi, M 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 Galik, RS 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 Karliner, I 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 Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Kim, IJ Ling, Z Mahmood, AH 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 Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G 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 Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS TI Measurement of the tau lepton lifetime SO PHYSICS LETTERS B LA English DT Article ID DECAY; LIBRARY AB We measure the tau lepton lifetime with tau(+)tau(-) pairs in which one or both of the tau's decays to three charged particles. The data were collected with the CLEO II detector operating at the electron-positron collider CESR at energies on and near the Y(4S). We use displacements of the three-track vertices to determine the tau lifetime. The result is tau(tau) = 289.0 +/- 2.8 +/- 4.0 fs. C1 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. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. 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. MCGILL UNIV,MONTREAL,PQ H3A 2T5,CANADA. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. RP Balest, R (reprint author), UNIV COLORADO,BOULDER,CO 80309, USA. RI Schaffner, Stephen/D-1189-2011; Britton, David/F-2602-2010; Briere, Roy/N-7819-2014; OI Britton, David/0000-0001-9998-4342; Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674; Poling, Ronald/0000-0001-7305-4702; Bloom, Kenneth/0000-0002-4272-8900 NR 16 TC 20 Z9 20 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD NOV 14 PY 1996 VL 388 IS 2 BP 402 EP 408 DI 10.1016/S0370-2693(96)01163-X PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400028 ER PT J AU Acciarri, M Adam, A Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Brambilla, E Branson, JG Brigljevic, V Brocka, IC Buijs, A Bujak, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Castello, R Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H 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 Felcini, M Furetta, C Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Galaktionov, Y Ganguli, SN Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hangarter, K Hartmann, B Hasan, A Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Ilyas, MM Innocente, V Janssen, H Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamyshkov, Y Kapinos, P Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koustenko, V Koulbardis, A Kraemer, RW Kramer, T Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Lenti, M Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Ludovici, L Luminari, L Lustermann, W Ma, WG Macchiolo, A Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG Mazumdar, K McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Monteleoni, B Moore, R Morganti, S Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Nippe, A Nowak, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Patrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Raghavan, R RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Rohner, S Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Schoeneich, B Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Sticozzi, F Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonisch, F Tonutti, M Tonwar, SC Toth, J Tsaregorodtsev, A Tully, C Tuchscherer, H Tung, KL Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, YF Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zaccardelli, C Zalite, A Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A AF Acciarri, M Adam, A Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Brambilla, E Branson, JG Brigljevic, V Brocka, IC Buijs, A Bujak, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Castello, R Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H 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 Felcini, M Furetta, C Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Galaktionov, Y Ganguli, SN Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hangarter, K Hartmann, B Hasan, A Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Ilyas, MM Innocente, V Janssen, H Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamyshkov, Y Kapinos, P Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koustenko, V Koulbardis, A Kraemer, RW Kramer, T Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Lenti, M Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Ludovici, L Luminari, L Lustermann, W Ma, WG Macchiolo, A Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG Mazumdar, K McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Monteleoni, B Moore, R Morganti, S Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Nippe, A Nowak, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Patrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Raghavan, R RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Rohner, S Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Schoeneich, B Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Sticozzi, F Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonisch, F Tonutti, M Tonwar, SC Toth, J Tsaregorodtsev, A Tully, C Tuchscherer, H Tung, KL Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, YF Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zaccardelli, C Zalite, A Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A TI Search for new particles in hadronic events with isolated photons SO PHYSICS LETTERS B LA English DT Article ID LUND MONTE-CARLO; HIGGS-BOSON PRODUCTION; JET FRAGMENTATION; COMPOSITE MODELS; L3 EXPERIMENT; E+E-PHYSICS; Z-DECAYS; LEP; EMISSION; PAIRS AB A search for the neutral Higgs boson in the processes e(+)e(-) --> Z --> H-0 gamma --> and e(+)e(-) --> Z --> Z*H-0 --> has been performed using 2.8 million hadronic Z decays collected with the L3 detector at LEP from 1991 through 1994. No evidence for these processes has been observed. Upper limits at 95% confidence level for the corresponding cross sections have been set and the results have been compared with theoretical predictions beyond the Standard Model. C1 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. 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. WORLD LAB, FBLIA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. UNIV SCI & TECHNOL CHINA, 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, INST PHYS NUCL LYON, IN2P3, CNRS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. IST NAZL FIS NUCL, I-20133 MILAN, ITALY. INST THEORET & EXPT PHYS, MOSCOW 117259, 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. 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. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATR & 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. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RI Fiandrini, Emanuele/C-4549-2008; 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; Lista, Luca/C-5719-2008; Ludovici, Lucio/F-5917-2011; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; alpat, ali behcet/G-6290-2013; bertucci, bruna/J-5237-2012; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Tsaregorodtsev, Andrei/E-3873-2016; OI Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Ludovici, Lucio/0000-0003-1970-9960; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; alpat, ali behcet/0000-0002-0116-1506; Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Longo, Egidio/0000-0001-6238-6787; Ambrosi, Giovanni/0000-0001-6977-9559; Tsaregorodtsev, Andrei/0000-0003-4618-520X; Castellini, Guido/0000-0002-0177-0643; Diemoz, Marcella/0000-0002-3810-8530; Doria, Alessandra/0000-0002-5381-2649; Faccini, Riccardo/0000-0003-2613-5141; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Goldstein, Joel/0000-0003-1591-6014 NR 31 TC 14 Z9 14 U1 0 U2 6 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 NOV 14 PY 1996 VL 388 IS 2 BP 409 EP 418 DI 10.1016/S0370-2693(96)00519-9 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400029 ER PT J AU Bearden, IG Boggild, H Boissevain, J Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, JJ Hansen, O Hardtke, D vanHecke, H Holzer, EB Humanic, T Hummel, P Jacak, BV Jayanti, R Kaneta, M Kopytine, M Leltchouk, M Ljubicic, T Lorstad, B Maeda, N Medvedev, A Murray, M Nishimura, S Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Sakaguchi, A SimonGillo, J SchmidtSorensen, J Sondheim, W Spegel, M Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS AF Bearden, IG Boggild, H Boissevain, J Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, JJ Hansen, O Hardtke, D vanHecke, H Holzer, EB Humanic, T Hummel, P Jacak, BV Jayanti, R Kaneta, M Kopytine, M Leltchouk, M Ljubicic, T Lorstad, B Maeda, N Medvedev, A Murray, M Nishimura, S Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Sakaguchi, A SimonGillo, J SchmidtSorensen, J Sondheim, W Spegel, M Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS TI Mid-rapidity protons in 158A center dot GeV Pb+Pb collisions SO PHYSICS LETTERS B LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; CHARGED HADRON DISTRIBUTIONS; S+S COLLISIONS; STOPPING POWER; GEV/C AB Proton distributions at mid-rapidity (2 less than or equal to y less than or equal to 3) have been measured for 158A . GeV Pb+Pb collisions in the focusing spectrometer experiment NA44 at CERN. From baryon number conservation and by comparing the experimentally measured dN/dy distribution with the transport model RQMD, we conclude that a rather high degree of nuclear stopping has been reached for the truly heavy-ion collisions at these energies. Transverse mass distributions exhibit characteristically thermal shapes and the slope parameters increase with the mass of the colliding system. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. PHYS NUCL LAB,F-44072 NANTES,FRANCE. HIROSHIMA UNIV,HIGASHIHIROSHIMA 739,JAPAN. CERN,CH-1211 GENEVA 23,SWITZERLAND. RUDJER BOSKOVIC INST,ZAGREB,CROATIA. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. VIENNA TECH UNIV,A-1040 VIENNA,AUSTRIA. LUND UNIV,DEPT PHYS,S-22362 LUND,SWEDEN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Bearden, IG (reprint author), NIELS BOHR INST,BLEGDAMSVEJ 17,DK-2100 COPENHAGEN,DENMARK. RI Bearden, Ian/M-4504-2014 OI Bearden, Ian/0000-0003-2784-3094 NR 27 TC 46 Z9 46 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 NOV 14 PY 1996 VL 388 IS 2 BP 431 EP 436 DI 10.1016/S0370-2693(96)01249-X PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VU294 UT WOS:A1996VU29400031 ER PT J AU Braun, J Schwesinger, R Williams, PG Morimoto, H Wemmer, DE Limbach, HH AF Braun, J Schwesinger, R Williams, PG Morimoto, H Wemmer, DE Limbach, HH TI Kinetic H/D/T isotope and solid state effects on the tautomerism of the conjugate porphyrin monoanion SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID DOUBLE PROTON-TRANSFER; FREE-BASE PORPHYRINS; N-15 CPMAS NMR; HH/HD/DD ISOTOPE; MESO-TETRAPHENYLPORPHINE; 2-SUBSTITUTED 5,10,15,20-TETRAPHENYLPORPHYRINS; HYDROGEN MIGRATION; CHEMICAL-EXCHANGE; LIQUID-STATE; PORPHINE AB Using dynamic NMR spectroscopy, the kinetic isotope effects of the degenerate single hydron transfer in the conjugate N-15-labeled porphyrin anion Por-H- dissolved in organic solvents have been measured as a function of temperature. Por-H- was generated by dissolving the labeled parent compound porphyrin together with the phosphazene base 1,1,1,5,5,5-hexakis(dimethylamino)-3-[(1,1,2,2,-tetramethylpropyl)imino]-3-[[tris(dimethylamino)-phosphoranyliden]amino]-1 lambda(5),3 lambda(5),5 lambda,1,4-triphosphazadiene (tHept-P-4) in organic solvents. In addition, by reaction of porphyrin with the base 1,1,1,5,5,5-tetrakis[tris(dimethylamino)phosphoranylidene]amino]phosphonium fluoride (P5+F-) Por-H- could be embedded into the solid state and its tautomerism followed by N-15 CPMAS NMR. Surprisingly, within the margin of error, the degeneracy of the tautomerism was not lifted in the solid state and the rate constants of the proton transfer were identical in the liquid and the solid. The kinetic isotope effects at 240 K (extrapolated) are given by k(H)/k(D) = 34 and k(H)/k(T) approximate to 152. The size and the temperature dependence of the isotope effects indicates a proton tunneling mechanism as in the parent porphyrin where this process is nondegenerate. However, the proton tunneling contribution is much larger in the anion as there the process is degenerate. These findings are reproduced in terms of a modified Bell tunnel model for both systems. C1 FREE UNIV BERLIN,INST ORGAN CHEM,D-14195 BERLIN,GERMANY. UNIV FREIBURG,INST ORGAN CHEM,D-79104 FREIBURG,GERMANY. LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. RI Limbach, Hans-Heinrich/G-8858-2011 OI Limbach, Hans-Heinrich/0000-0002-2084-6359 NR 111 TC 53 Z9 54 U1 0 U2 7 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 NOV 13 PY 1996 VL 118 IS 45 BP 11101 EP 11110 DI 10.1021/ja961313q PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA VT466 UT WOS:A1996VT46600018 ER PT J AU Smith, ME Andersen, RA AF Smith, ME Andersen, RA TI Me(5)C(5)Ni(acac): A monomeric, paramagnetic, 18-electron, spin-equilibrium molecule SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID STABLE 16-VALENCE-ELECTRON COMPLEX; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; DERIVATIVES; REACTIVITY; MECHANISM; IRON(II); KINETICS; HYDRIDE; LIGANDS AB New synthetic procedures have been developed for Me(5)C(5)M(acac), M = Co or Ni. The crystal structures of these 17- or 18-electron monomers show that the compounds are isomorphous and in space group P (1) over bar, with the planes defined by the Me(5)C(5) ring and the M(acac) fragment perpendicular to within 5 degrees. The Me(5)C(5) ring in both molecules has an ene-allyl distortion which is rationalized by the low molecular symmetry (C-s), which removes the degeneracy in the e(+) and e(-) ring orbitals. The electronic structure of the cobalt compound is (2)A, as deduced from magnetic susceptibility and EPR spectroscopy. The electronic structure of the nickel compound depends upon the temperature. In the solid state, the compound is diamagnetic below 150 K, but it becomes paramagnetic with increasing temperature. The H-1 NMR chemical shifts of the compound in solution are nonlinear in temperature, and a plot of delta vs T-1 yields an equilibrium constant of 0.47 at 303 K for the low spin <----> high spin equilibrium. The 20-electron phosphine complexes of nickel can be isolated; Me(5)C(5)Ni(acac)(PMe(3)) is a simple paramagnet with two unpaired spins, but the PEt(3) complex exists in equilibrium with its base-free compound in solution. The cobalt compound does not give an isolable phosphine complex. A simple symmetry orbital model is proposed that accounts for the electronic and molecular structures of these organometallic compounds. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DIV CHEM SCI,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 47 TC 63 Z9 63 U1 1 U2 12 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 NOV 13 PY 1996 VL 118 IS 45 BP 11119 EP 11128 DI 10.1021/ja953873f PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA VT466 UT WOS:A1996VT46600020 ER PT J AU Song, JS Szalda, DJ Bullock, RM AF Song, JS Szalda, DJ Bullock, RM TI Ether complexes of tungsten with two different binding modes: An O-bound ether and an eta(2)-(C=C) vinyl ether. Evidence for C-H center dot center dot center dot O hydrogen bonding of vinylic C-H groups SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID REDUCTIVE CLEAVAGE; ORGANOMETALLIC CRYSTALS; IONIC HYDROGENATION; CATION EQUIVALENTS; HYDRIDE TRANSFER; IRON COMPLEXES; LEWIS-ACIDS; ACETALS; OLEFINS; KETALS AB The reaction of PhCH(OCH3)(2) with Cp(CO)(3)WH and HOTf gives [Cp(CO)(3)W(PhCH(2)OCH(3))](+)OTf(-). The structure of this benzyl methyl ether complex was determined by single crystal X-ray diffraction and was shown to have the ether bonded to tungsten through the oxygen. This compound was isolated as a kinetic product of the reaction; it decomposes in solution by releasing free PhCH(2)OCH(3) and forming Cp(CO)(3)WOTf. An analog with the BAr4'(-) counterion [Ar'=3,5-bis(trifluoromethyl)phenyl] is more stable. The reaction of the vinyl acetal CH2=CHCH(OEt)(2) with Cp(CO)(3)WH and HOTf produces [Cp(CO)(3)W(eta(2)-EtOCH=CHCH3)](+)OTf(-), in which the ether is bonded to tungsten through the C=C bond of the vinyl ether. The crystal structure of this compound shows that the W-C(OEt) distance (2.69(3) Angstrom) is significantly longer than the W-C(CH3) distance (2.37(3) Angstrom). There are weak C-H ... O hydrogen bonds between both vinyl CH's and oxygens of triflate counterions. Evidence is presented that some of these weak hydrogen bonds are maintained in CD2Cl2 solution but not in CD3CN. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 68 TC 26 Z9 26 U1 1 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 NOV 13 PY 1996 VL 118 IS 45 BP 11134 EP 11141 DI 10.1021/ja962193p PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA VT466 UT WOS:A1996VT46600022 ER PT J AU Hsiao, JS Krueger, BP Wagner, RW Johnson, TE Delaney, JK Mauzerall, DC Fleming, GR Lindsey, JS Bocian, DF Donohoe, RJ AF Hsiao, JS Krueger, BP Wagner, RW Johnson, TE Delaney, JK Mauzerall, DC Fleming, GR Lindsey, JS Bocian, DF Donohoe, RJ TI Soluble synthetic multiporphyrin arrays .2. Photodynamics of energy-transfer processes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; PHOTOSYNTHETIC MODEL SYSTEMS; COVALENTLY-LINKED PORPHYRIN; LIGHT-HARVESTING COMPLEX; CHARGE SEPARATION; INTRAMOLECULAR ELECTRON; OPTICAL-PROPERTIES; ARTIFICIAL PHOTOSYNTHESIS; EXCITATION-ENERGY; CRYSTAL-STRUCTURE AB Soluble ethyne-linked tetraarylporphyrin arrays that mimic natural light-harvesting complexes by absorbing light and directing excited-state energy have been investigated by static and time-resolved absorption and fluorescence spectroscopies. Of particular interest is the role of the diarylethyne linkers in mediating energy transfer. The major conclusions from this study, which is Limited to the examination of arrays containing Zn and free-base (Fb) porphyrins, include the following: (1) Singlet excited-state energy transfer from the Zn porphyrin to the FD porphyrin is extremely efficient (95-99%). Competitive electron-transfer reactions are not observed. (2) The rate of energy transfer is slowed up to 4-fold by the addition of groups to the linker that limit the ability of the linker and porphyrin to adopt geometries tending toward coplanarity. Thus, the mechanism of energy transfer predominantly involves through-bond communication via the linker. Consistent with this notion, the measured lifetimes of the Zn porphyrin in the dimers at room temperature yield energy-transfer rates ((88 ps)(-1) ; (ii) when the guanine base (G) is replaced by A, C, or T, a lower-affinity family (K-d greater than or equal to 50 nM) can be detected that shows an overall tendency to bind G-rich DNA; (iii) the residues at position 2 on the finger 2 recognition helix do not appear to interact strongly with the complementary 5' base in the finger 1 binding site; and (iv) unexpected substitutions at the amino terminus of finger 1 can occasionally result in specificity for the 3' base in the finger I binding site, A DNA recognition directory was constructed for high-affinity zinc fingers that recognize all three bases in a DNA triplet for seven sequences of the type GNN. Similar approaches may be applied to other zinc fingers to broaden the scope of the directory. C1 UNIV CALIF BERKELEY, EO LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 34 TC 85 Z9 86 U1 0 U2 10 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 12 PY 1996 VL 93 IS 23 BP 12834 EP 12839 DI 10.1073/pnas.93.23.12834 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT054 UT WOS:A1996VT05400031 PM 8917505 ER PT J AU Baeyens, KJ DeBondt, HL Pardi, A Holbrook, SR AF Baeyens, KJ DeBondt, HL Pardi, A Holbrook, SR TI A curved RNA helix incorporating an internal loop with G center dot A and A center dot A non-Watson-Crick base pairing SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HAMMERHEAD RIBOZYME; CRYSTAL-STRUCTURE; NUCLEIC-ACIDS; MISMATCHES; STABILITY; SEQUENCE AB The crystal structure of the RNA dodecamer 5'-GGCC(GAAA)GGCC-3' has been determined from x-ray diffraction data to 2.3-Angstrom resolution. In the crystal, these oligomers form double helices around twofold symmetry axes. Four consecutive non-Watson-Crick base pairs make up an internal loop in the middle of the duplex, including sheared G . A pairs and novel asymmetric A . A pairs. This internal loop sequence produces a significant curvature and narrowing of the double helix. The helix is curved by 34 degrees from end to end and the diameter is narrowed by 24% in the internal loop. A Mn2+ ion is bound directly to the N7 of the first guanine in the Watson-Crick region following the internal loop and the phosphate of the preceding residue. This Mn2+ location corresponds to a metal binding site observed in the hammerhead catalytic RNA. RP Baeyens, KJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,MELVIN CALVIN BLDG,BERKELEY,CA 94720, USA. FU NIAID NIH HHS [R01 AI033098, AI01051, AI33098, R56 AI033098]; NIGMS NIH HHS [GM 4921501] NR 24 TC 91 Z9 92 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 12 PY 1996 VL 93 IS 23 BP 12851 EP 12855 DI 10.1073/pnas.93.23.12851 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT054 UT WOS:A1996VT05400034 PM 8917508 ER PT J AU Bifone, A Song, YQ Seydoux, R Taylor, RE Goodson, BM Pietrass, T Budinger, TF Navon, G Pines, A AF Bifone, A Song, YQ Seydoux, R Taylor, RE Goodson, BM Pietrass, T Budinger, TF Navon, G Pines, A TI NMR of laser-polarized xenon in human blood SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE optical pumping; laser-polarized xenon ID MAGNETIC-RESONANCE; XE-129; GAS AB By means of optical pumping with laser light it is possible to enhance the nuclear spin polarization of gaseous xenon by four to five orders of magnitude, The enhanced polarization has allowed advances in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI), including polarization transfer to molecules and imaging of lungs and other void spaces, A critical issue for such applications is the delivery of xenon to the sample while maintaining the polarization, Described herein is an efficient method for the introduction of laser-polarized xenon into systems of biological and medical interest for the purpose of obtaining highly enhanced NMR/MRI signals. Using this method, we have made the first observation of the time-resolved process of xenon penetrating the red blood cells in fresh human blood-the xenon residence time constant in the red blood cells was measured to be 20.4+/-2 ms. The potential of certain biologically compatible solvents for delivery of laser-polarized xenon to tissues for NMR/MRI is discussed in light of their respective relaxation and partitioning properties. C1 LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DEPT RADIOL,SAN FRANCISCO,CA 94143. NR 27 TC 116 Z9 118 U1 5 U2 20 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 12 PY 1996 VL 93 IS 23 BP 12932 EP 12936 DI 10.1073/pnas.93.23.12932 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT054 UT WOS:A1996VT05400048 PM 8917521 ER PT J AU Russell, LB Russell, WL AF Russell, LB Russell, WL TI Spontaneous mutations recovered as mosaics in the mouse specific-locus test SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE mosaic mutants; cluster mutants; mutation frequencies; mutation spectral ID DOMINANT LETHAL MUTATIONS; MALE-MICE; INDUCTION; FREQUENCIES; RADIATIONS; EXPOSURE; MUTANTS; REGION; RATES; CELLS AB The specific-locus test (SLT) detects new mutants among mice heterozygous for seven recessive visible markers. Spontaneous mutations can be manifested not only as singleton whole-body mutants in controls (for which we report new data), but as mosaics-either visible (manifesting mottled coat color) in the scored generation (G(2)) or masked, among the wild-type parental generation (G(1)), Masked G(1) mosaics reveal themselves by producing clusters of whole-body mutants in G(2). We provide evidence that most, if not all, mosaics detected in the SLT (both radiation and control progenies) result from a single-strand spontaneous mutation subsequent to the last premeiotic mitosis and before the first postmeiotic one of a parental genome-the ''perigametic interval.'' Such events in the genomes of the G(1) and G(0) result, respectively, in visible and masked 50:50 mosaics. Per cell cycle, the spontaneous mutation rate in the perigametic interval is much higher than that in pregamete mitotic divisions. A clearly different locus spectrum further supports the hypothesis of different origin, and casts further doubt on the validity of the doubling-dose risk-estimation method, Because mosaics cannot have arisen in mitotic germ cells, and are not induced by radiation exposure in the perigametic interval, they should not be included in calculations of radiation-induced germ-line mutation rates, For per-generation calculations, inclusion of mosaics yields a spontaneous frequency 1.7 times that calculated from singletons alone for mutations contributed by males; including both sexes, the multiple is 2.2. RP Russell, LB (reprint author), OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831, USA. FU NIEHS NIH HHS [1-Y01-ES-50318-00] NR 30 TC 68 Z9 68 U1 2 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 12 PY 1996 VL 93 IS 23 BP 13072 EP 13077 DI 10.1073/pnas.93.23.13072 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VT054 UT WOS:A1996VT05400073 PM 8917546 ER PT J AU Datskos, PG Oden, PI Thundat, T Wachter, EA Warmack, RJ Hunter, SR AF Datskos, PG Oden, PI Thundat, T Wachter, EA Warmack, RJ Hunter, SR TI Remote infrared radiation detection using piezoresistive microcantilevers SO APPLIED PHYSICS LETTERS LA English DT Article ID FORCE MICROSCOPE CANTILEVERS AB A novel micromechanical infrared (IR) radiation sensor has been developed using commercially available piezoresistive microcantilevers. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress between the top layer (coating and the substrate, The bending causes a change in the piezoresistance and is proportional to the amount of heat absorbed. The microcantilever IR sensor exhibits two distinct thermal responses: a fast one (96%) was ClO((2) Pi)+O(P-3). We also observed production of Cl+O-2 with a quantum yield of up to 3.9+/-0.8% near 404 nm, decreasing at longer and shorter wavelengths. The branching ratios between the two channels were dependent on the OClO(A (2)A(2)) excited state vibrational mode. The Cl+O-2 yield was enhanced slightly by exciting A (2)A(2) levels having symmetric stretching + bending, but diminished by as much as a factor of 10 for neighboring peaks associated with symmetric stretching+asymmetric stretching. Mode specificity was also observed in the vibrationally state resolved translational energy distributions for the dominant ClO((2) Pi)+O(P-3) channel. The photochemical dynamics of OClO possesses two energy regimes with distinctly different dynamics observed for excitation energies above and below similar to 3.1 eV (lambda similar to 400 nn). At excitation energies below 3.1 eV (lambda>400 nm), nearly all energetically accessible ClO vibrational energy levels were populated, and the minor Cl+O-2 channel was observed. Although at least 20% of the O-2 product is formed in the ground (X (3) Sigma(g)(-)) state, most O-2 is electronically excited (a (1) Delta(g)). At E<3.1 eV, both dissociation channels occur by an indirect mechanism involving two nearby excited states, (2)A(1) and B-2(2). Long dissociation time scales and significant parent bending before dissociation led to nearly isotropic polarization angular distributions (beta similar to 0). At excitation energies above 3.1 eV (lambda<400 nm), the Cl+O-2 yield began to decrease sharply, with this channel becoming negligible at lambda<370 nm. At these higher excitation energies, the ClO product was formed with relatively Little vibrational energy and a large fraction of the excess energy was channeled into ClO+O translational energy. The photofragment anisotropy parameter (beta) also increased, implying shorter dissociation time scales. The sharp change in the disposal of excess energy into the ClO products, the decrease of Cl+O-2 production, and more anisotropic product angular distributions at E>3.1 eV signify the opening of a new ClO+O channel. From our experimental results and recent ab initio calculations, dissociation at wavelengths shorter than 380 nm to ClO+O proceeds via a direct mechanism on the optically prepared A (2)A(2) surface over a large potential energy barrier. From the ClO((2) Pi)+O(P-3) translational energy distributions, D-0(O-ClO) was found to be less than or equal to 59.0+/-0.2 kcal/mol. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RI Lee, Yuan-Tseh/F-7914-2012 NR 110 TC 100 Z9 100 U1 1 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 NOV 8 PY 1996 VL 105 IS 18 BP 8142 EP 8163 DI 10.1063/1.472700 PG 22 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VQ841 UT WOS:A1996VQ84100025 ER PT J AU Baras, F Mansour, MM Pearson, JE AF Baras, F Mansour, MM Pearson, JE TI Microscopic simulation of chemical bistability in homogeneous systems SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STRONG SHOCK-WAVES; MOLECULAR-DYNAMICS; MASTER-EQUATIONS; DILUTE GAS; FLUCTUATIONS; INSTABILITY AB Microscopic simulation is used to clarify the status of stochastic theories of homogeneous chemical systems operating in the multiple steady state region. The results demonstrate the failure of the Langevin approach, but show excellent agreement with the master equation formulation. (C) 1996 American Institute of Physics. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Baras, F (reprint author), FREE UNIV BRUSSELS,CTR NONLINEAR PHENOMENA & COMPLEX SYST,CAMPUS PLAINE,CP 231,B-1050 BRUSSELS,BELGIUM. RI Baras, Florence/A-5679-2009 NR 53 TC 30 Z9 30 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 1996 VL 105 IS 18 BP 8257 EP 8261 DI 10.1063/1.472679 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VQ841 UT WOS:A1996VQ84100038 ER PT J AU Chialvo, AA Cummings, PT AF Chialvo, AA Cummings, PT TI Engineering a simple polarizable model for the molecular simulation of water applicable over wide ranges of state conditions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EFFECTIVE PAIR POTENTIALS; LIQUID WATER; SUPERCRITICAL TEMPERATURES; DYNAMICS SIMULATIONS; COMPUTER-SIMULATION AB We perform a systematic analysis of the relationship between the molecular geometry, the force-field parameters, the magnitude of the induced dipoles, and the resulting site-site microstructure of a model for water consisting of simple point charges plus a self-consistent point dipole polarizability. We constrain the model to represent the experimental values of the pressure and the configurational internal energy of water at ambient conditions, while keeping a permanent dipole moment of 1.85 D. The resulting force fields are then used to perform additional simulations at high temperature to determine the effect of polarizabilities on the site-site structure, and to make contact with neutron scattering experiments as well as ab initio simulation results. We show that the parameterization of the model is possible for 0 less than or equal to R(OM)less than or equal to 0.25 Angstrom, where R(OM) is the oxygen-to-negative charge distance along the bisectrix of the H-O-H angle, resulting in total dipole moments from 2.88 to 3.03 D, with polarization energies accounting for 40%-57% of the total configuration internal energy of water. These results, in conjunction with the behavior of the short range site-site correlation functions, highlight the shortcomings of the simple point charge approximation for the polarization behavior at short intermolecular distances, and give a meaningful reference from which we can attempt to overcome these defects. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Chialvo, AA (reprint author), UNIV TENNESSEE,DEPT CHEM ENGN,419 DOUGHERTY ENGN BLDG,KNOXVILLE,TN 37996, USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 46 TC 143 Z9 144 U1 0 U2 18 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 NOV 8 PY 1996 VL 105 IS 18 BP 8274 EP 8281 DI 10.1063/1.472718 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VQ841 UT WOS:A1996VQ84100041 ER PT J AU Harvey, SD Clauss, TRW AF Harvey, SD Clauss, TRW TI Rapid on-line chromatographic determination of trace-level munitions in aqueous samples SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE water analysis; environmental analysis; explosives; trinitrotoluene; hexahydrotrinitrotriazine ID PERFORMANCE LIQUID-CHROMATOGRAPHY; WATER; 2,4,6-TRINITROTOLUENE; TRANSFORMATION AB An on-line trace enrichment system is described that combines a divinylbenzene-vinylpyrrolidone co-polymer precolumn with a reversed-phase C-18 HPLC analytical column. This arrangement allows quantitative preconcentration of munitions on the resin sorbent, followed by complete transfer of analyte to the analytical column for separation, followed by UV absorbance detection at 254 nm. Detection limits were approximately 0.10 ng/ml for TNT and RDX when 10 ml of sample was analyzed. The feasibility of increasing sample volume (up to 50 ml) to obtain detection limits down to 20 pg/ml was also demonstrated for TNT. Analyses of aquifer samples collected in the vicinity of a military installation are presented to show system utility. RP Harvey, SD (reprint author), PACIFIC NW NATL LAB,POB 999,RICHLAND,WA 99352, USA. NR 16 TC 31 Z9 32 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD NOV 8 PY 1996 VL 753 IS 1 BP 81 EP 89 DI 10.1016/S0021-9673(96)00524-9 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VW225 UT WOS:A1996VW22500007 ER PT J AU SchulzeGahmen, U DeBondt, HL Kim, SH AF SchulzeGahmen, U DeBondt, HL Kim, SH TI High-resolution crystal structures of human cyclin-dependent kinase 2 with and without ATP: Bound waters and natural ligand as guides for inhibitor design SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID PROTEIN-KINASE; CATALYTIC SUBUNIT; CDC2 KINASE AB Inhibition of the cell cycle is widely considered as a new approach toward treatment for diseases caused by unregulated cell proliferation, including cancer. Since cyclin-dependent kinases (CDKs) are key enzymes of cell cycle control, they are promissing targets for the design and discovery of drugs with antiproliferative activity. The detailed structural analysis of CDK2 can provide valuable information for the design of new ligands that can bind in the ATP binding pocket and inhibit CDK2 activity. For this objective, the crystal structures of human CDK2 apoenzyme and its ATP complex were refined to 1.8 and 1.9 Angstrom, respectively. The high-resolution refinement reveals 12 ordered water molecules in the ATP binding pocket of the apoenzyme and five ordered waters in that of the ATP complex. Despite a large number of hydrogen bonds between ATP-phosphates and CDK2, binding studies of cyclic AMP-dependent protein kinase with ATP analogues show that the triphosphate moiety contributes little and the adenine ring is most important for binding affinity. Our analysis of CDK2 structural data, hydration of residues in the binding pocket of the apoenzyme, flexibility of the ligand, and structural differences between the apoenzyme and CDK2-ATP complex provide an explanation for the results of earlier binding studies with ATP analogues and a basis for future inhibitor design. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV CATHOLIQUE LOUVAIN, LAB ANALYT CHEM & MED FYSICOCHEM, FAC FARMACEUT WETENSCHAPPEN, B-3000 LOUVAIN LA NEUVE, BELGIUM. RP SchulzeGahmen, U (reprint author), UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 32 TC 137 Z9 143 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-2623 EI 1520-4804 J9 J MED CHEM JI J. Med. Chem. PD NOV 8 PY 1996 VL 39 IS 23 BP 4540 EP 4546 DI 10.1021/jm960402a PG 7 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA VR624 UT WOS:A1996VR62400004 PM 8917641 ER PT J AU Haase, AT Henry, K Zupancic, M Sedgewick, G Faust, RA Melroe, H Cavert, W Gebhard, K Staskus, K Zhang, ZQ Dailey, PJ Balfour, HH Erice, A Perelson, AS AF Haase, AT Henry, K Zupancic, M Sedgewick, G Faust, RA Melroe, H Cavert, W Gebhard, K Staskus, K Zhang, ZQ Dailey, PJ Balfour, HH Erice, A Perelson, AS TI Quantitative image analysis of HIV-1 infection in lymphoid tissue SO SCIENCE LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; FOLLICULAR DENDRITIC CELLS; INSITU HYBRIDIZATION; T-CELLS; REPLICATION; LATENCY; TYPE-1; RNA; LYMPHOCYTES; EXPRESSION AB Tracking human immunodeficiency virus-type 1 (HIV-1) infection at the cellular level in tissue reservoirs provides opportunities to better understand the pathogenesis of infection and to rationally design and monitor therapy. A quantitative technique was developed to determine viral burden in two important cellular compartments in lymphoid tissues. Image analysis and in situ hybridization were combined to show that in the presymptomatic stages of infection there is a large, relatively stable pool of virions on the surfaces of follicular dendritic cells and a smaller pool of productively infected cells. Despite evidence of constraints on HIV-1 replication in the infected cell population in lymphoid tissues, estimates of the numbers of these cells and the virus they could produce are consistent with the quantities of virus that have been detected in the bloodstream. The cellular Sources of virus production and storage in lymphoid tissues can now be studied with this approach over the course of infection and treatment. C1 UNIV MINNESOTA,SCH MED,DEPT MED,MINNEAPOLIS,MN 55455. ST PAUL RAMSEY MED CTR,HIV PROGRAM,ST PAUL,MN 55101. UNIV MINNESOTA,SCH MED,DEPT CELL BIOL & NEUROANAT,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,SCH MED,DEPT OTOLARYNGOL,MINNEAPOLIS,MN 55455. CHIRON CORP,EMERYVILLE,CA 94608. UNIV MINNESOTA,SCH MED,DEPT LAB MED & PATHOL,MINNEAPOLIS,MN 55455. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Haase, AT (reprint author), UNIV MINNESOTA,SCH MED,DEPT MICROBIOL,MINNEAPOLIS,MN 55455, USA. FU NCRR NIH HHS [RR 06555]; NIAID NIH HHS [AI 27661, AI 28246] NR 39 TC 421 Z9 425 U1 2 U2 15 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 8 PY 1996 VL 274 IS 5289 BP 985 EP 989 DI 10.1126/science.274.5289.985 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VR792 UT WOS:A1996VR79200050 PM 8875941 ER PT J AU Wolinsky, SM Kunstman, KJ Safrit, JT Koup, RA Neumann, AU Korber, BTM AF Wolinsky, SM Kunstman, KJ Safrit, JT Koup, RA Neumann, AU Korber, BTM TI HIV-1 evolution and disease progression - Response SO SCIENCE LA English DT Article ID GENETIC-VARIATION; IN-VIVO; DIVERSITY; AIDS; THRESHOLDS; DYNAMICS C1 BRISTOL MYERS SQUIBB,PHARMACEUT RES INST,SEATTLE,WA 98103. AARON DIAMOND AIDS RES CTR,NEW YORK,NY 10016. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. SANTA FE INST,SANTA FE,NM 87505. RP Wolinsky, SM (reprint author), NORTHWESTERN UNIV,SCH MED,303 E CHICAGO,TARRY BLDG,CHICAGO,IL 60611, USA. RI Wolinsky, Steven/B-2893-2012 NR 15 TC 7 Z9 7 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD NOV 8 PY 1996 VL 274 IS 5289 BP 1010 EP 1011 DI 10.1126/science.274.5289.1010 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VR792 UT WOS:A1996VR79200058 PM 17798610 ER PT J AU Crowell, RA Bartels, DM AF Crowell, RA Bartels, DM TI H2O/D2O isotope effect in geminate recombination of the hydrated electron SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LIQUID WATER; FEMTOSECOND; PHOTOIONIZATION; DEPENDENCE; DYNAMICS; KINETICS; H2O; D2O AB Picosecond transient absorption measurements and simulations of the hydrated electron geminate recombination dynamics are presented for 4 eV multiphoton ionization of liquid H2O and D2O. To within the accuracy of the data and simulation, the isotope effect can be accounted for in terms of the decrease in the diffusion coefficients for e(aq)(-), D3O+, and OD. and the e(aq)(-) + D3O+ --> D reaction rate in D2O. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 18 TC 28 Z9 29 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 7 PY 1996 VL 100 IS 45 BP 17713 EP 17715 DI 10.1021/jp962034s PG 3 WC Chemistry, Physical SC Chemistry GA VR570 UT WOS:A1996VR57000002 ER PT J AU Chang, J Brown, NJ AF Chang, J Brown, NJ TI Quantum functional sensitivity analysis of the D+H-2 reaction rate coefficient via the separable rotation approximation SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID POTENTIAL-ENERGY SURFACE; INTEGRAL CROSS-SECTIONS; THERMAL RATE CONSTANTS; KOHN VARIATIONAL PRINCIPLE; GEOMETRIC PHASE; CHEMICAL-REACTIONS; BARRIER HEIGHT; H+H-2 REACTION; SCATTERING; H-3 AB Sensitivities of the D + H-2 cumulative reaction probability (CRP) are calculated for total angular momentum J = 0 and 6 to test the applicability of the separable rotation approximation The CRPs and their sensitivities are then thermally averaged to obtain sensitivities of the log-normalized rate coefficient using a single J. This approach has great promise of being a simple, yet accurate, method of providing reliable feedback information to quantum chemists without resorting to full-dimensionality quantal calculations. On the basis of our sensitivity analysis, we propose three potential energy surface (PES) modifications which should remove the remaining discrepancies between the experimental and theoretical rate coefficients, especially at the high temperatures, Interestingly, none of these potential modifications lie at a particularly ''high''-energy region of the PES as was previously thought. RP UNIV CALIF BERKELEY, ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, DIV ENERGY & ENVIRONM, BERKELEY, CA 94720 USA. NR 52 TC 5 Z9 5 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 7 PY 1996 VL 100 IS 45 BP 17740 EP 17755 DI 10.1021/jp9618690 PG 16 WC Chemistry, Physical SC Chemistry GA VR570 UT WOS:A1996VR57000009 ER PT J AU Taatjes, CA AF Taatjes, CA TI Kinetic isotope effect in the CH[(2)Pi]+O-2 reaction SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TRANSITION-STATE THEORY; ASSOCIATION REACTIONS; RATE CONSTANTS; CH; ABSORPTION; RADICALS; C2H2; DOCO; SPECTROSCOPY; TEMPERATURE AB The reaction rates for CH and CD with O-2 have been measured for temperatures between 293 and 720 K. The rate constant has a slight negative temperature dependence which can be well fit over the temperature range by (4.7 +/- 0.2) x 10(-11)(T/293)(-0.22+/-0.1) cm(3) molecule(-1) s(-1). The deuterium isotope effect has been measured to be k(H)/k(D) = 1.16 +/- 0.06 at 293 K and is approximately constant to within experimental error between 293 and 720 K. The isotope effect and the temperature dependences can be described by a barrierless addition with no collisional stabilization of the adduct before dissociation to products. The effects of the known species HCO2 and HOCO are not evident in the CH + O-2 reaction rate constant at these temperatures and pressures. Simple transition state theory can model the kinetic isotope effect if the transition state for addition involves a weakening of the C-H bond from the free CH molecule. RP Taatjes, CA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,MAIL STOP 9055,LIVERMORE,CA 94551, USA. NR 42 TC 20 Z9 22 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 7 PY 1996 VL 100 IS 45 BP 17840 EP 17845 DI 10.1021/jp961685l PG 6 WC Chemistry, Physical SC Chemistry GA VR570 UT WOS:A1996VR57000023 ER PT J AU Crowell, RA Bartels, DM AF Crowell, RA Bartels, DM TI Multiphoton ionization of liquid water with 3.0-5.0 eV photons SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GEMINATE PAIR RECOMBINATION; HYDRATED ELECTRON; AR MATRICES; FEMTOSECOND; DYNAMICS; PHOTOIONIZATION; H2O; PHOTODISSOCIATION; DISSOCIATION; ICE AB We report a picosecond laser study of the transient absorption of hydrated electrons generated by the 3-5 eV multiphoton ionization of liquid water, The geminate kinetics indicate that e(aq)(-) is produced by at least three different mechanisms over this energy range. Power dependence of the signal amplitude shows a two-photon threshold for 4.0 eV excitation and a three-photon threshold absorption at 3.37 eV, consistent with two- or three-photon excitation of the (A) over tilde(B-1(1)) lowest excited state, For (three-photon) excitation in the range 3.02-3.47 eV very little (less than or equal to 15%) geminate recombination is observed while for the (two-photon) excitation at shorter wavelengths significant recombination (greater than or equal to 55%) is observed. In the region of 3.85-4.54 eV, photon-energy-independent kinetics indicate that e(aq)(-) is produced via two-photon excitation of the (A) over tilde state followed by an ionization process in which the electrons do not obtain any excess kinetic energy, For photon energies in the range of 4.75 - 5.05 eV, the escape fraction increases slightly, consistent with two-photon excitation of higher energy states. Simulation with a diffusion model shows that the electron is ejected at least 25 Angstrom farther into the bulk for the 3.02-3.47 eV photon energies relative to two-photon ionization in the 3.67-5.0 eV range. We conclude that the larger distances result from a (3 + 1)-photon resonance-enhanced multiphoton ionization (REMPT) process, made possible by visible/near-UV absorption of the water excited states. Possible mechanisms of the water ionization are discussed. A new mechanism is proposed to explain the production of solvated electrons from excitation of the (A) over tilde(B-1(1)) state of liquid water, well below the Born-Oppenheimer ionization threshold. On the basis of the gas phase properties of this state, we assume a direct dissociation to give OH radical and H atoms, with the excess energy almost entirely transferred to kinetic energy of the H atoms: H2O* --> OH + H(hot). It is proposed that the hot H atoms immediately react with an adjacent water molecule to form hydronium ion and a solvated electron, in a process analogous to the thermal reaction of H atoms with water at elevated temperatures: H(hot) + H2O --> H3O+ + e(aq)(-). C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60517. NR 57 TC 146 Z9 146 U1 9 U2 49 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 7 PY 1996 VL 100 IS 45 BP 17940 EP 17949 DI 10.1021/jp9610978 PG 10 WC Chemistry, Physical SC Chemistry GA VR570 UT WOS:A1996VR57000037 ER PT J AU Savikhin, S Zhu, YW Blankenship, RE Struve, WS AF Savikhin, S Zhu, YW Blankenship, RE Struve, WS TI Intraband energy transfers in the BChl c antenna of chlorosomes from the green photosynthetic bacterium Chloroflexus aurantiacus SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BACTERIOCHLOROPHYLL-C; SULFUR BACTERIA; ORGANIZATION AB Two-color absorption difference profiles for the bacteriochlorophyll (BChl) c antenna of chlorosomes from Chloroflexus aurantiacus at 19 K show photobleaching/stimulated emission rise features with similar to 300 fs kinetics when the probe wavelength is similar to 30 nm to the red of the excitation wavelength. Similar rise features do not appear at 300 K, or in uphill two-color experiments at 19 K, or when the pump and probe wavelengths are separated by much less than 30 nm. This appears to be the first direct observation of downhill electronic energy transfers within light-harvesting BChl c oligomers in intact chlorosomes. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. ARIZONA STATE UNIV,CTR STUDY EARLY EVENTS PHOTOSYNTHESIS,TEMPE,AZ 85287. ARIZONA STATE UNIV,DEPT CHEM & BIOCHEM,TEMPE,AZ 85287. NR 17 TC 17 Z9 17 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD NOV 7 PY 1996 VL 100 IS 45 BP 17978 EP 17980 DI 10.1021/jp961752b PG 3 WC Chemistry, Physical SC Chemistry GA VR570 UT WOS:A1996VR57000041 ER PT J AU Rard, JA Albright, JG Miller, DG Zeidler, ME AF Rard, JA Albright, JG Miller, DG Zeidler, ME TI Ternary mutual diffusion coefficients and densities of the system {z(1)NaCl+(1-z(1))Na2SO4}(aq) at 298.15 K and a total molarity of 0.5000 mol dm(-3) SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID SOLUTE CONCENTRATION RATIO; VELOCITY CORRELATION-COEFFICIENTS; RAYLEIGH INTERFEROMETRY; ELECTROLYTE-SOLUTIONS; MGCL2 CONCENTRATIONS; WIDE-RANGE; 25-DEGREES-C; NACL-MGCL2-H2O; INSTABILITIES; BINARY AB Isothermal ternary mutual diffusion coefficients (interdiffusion coefficients) have been measured for the system {z(1)NaCl + (1 - z(1))Na2SO4}(aq) at a constant total molarity of 0.5000 mol dm(-3) and 298.15 K using either Rayleigh or Gouy interferometry. Measurements were performed at NaCl molarity fractions of z(1) = 1, 0.90, 0.75, 0.50, 0.25 and 0. Densities of all solutions used in the diffusion experiments were measured using pycnometers and/or a vibrating densimeter. Trace diffusion coefficients have been evaluated from these results for the Cl-(aq) ion in 0.5 mol dm(-3) Na2SO4(aq) and for the SO42-(aq) ion in 0.5 mol dm(-3) NaCl(aq). The resulting values are D*(Cl-) = (1.681 +/- 0.002) x 10(-9) m(2) s(-1) and D*(SO42-) = (0.900 +/- 0.006) x 10(-9) m(2) s(-1), respectively. At all compositions, (D-21)(v), the cross-term diffusion coefficient of Na2SO4 due to a concentration gradient of NaCl, was found to be negative, whereas (D-12)(v), the cross-term diffusion coefficient of NaCl due to a concentration gradient of Na2SO4, was found to be positive. C1 TEXAS CHRISTIAN UNIV,DEPT CHEM,FT WORTH,TX 76129. UNIV TEXAS,JOINT PROGRAM BIOMED ENGN,ARLINGTON,TX 76019. RP Rard, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,GEOSCI & ENVIRONM TECHNOL ENVIRONM PROGRAMS DIREC,LIVERMORE,CA 94550, USA. NR 63 TC 26 Z9 26 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD NOV 7 PY 1996 VL 92 IS 21 BP 4187 EP 4197 DI 10.1039/ft9969204187 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VW573 UT WOS:A1996VW57300008 ER PT J AU Hastings, J AF Hastings, J TI Optics - X-ray lenses near reality SO NATURE LA English DT Editorial Material RP Hastings, J (reprint author), BROOKHAVEN NATL LAB,75 BROOKHAVEN AVE,BLDG 725,UPTON,NY 11973, USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD NOV 7 PY 1996 VL 384 IS 6604 BP 22 EP 22 DI 10.1038/384022a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VR219 UT WOS:A1996VR21900029 ER PT J AU Kao, CW Yang, SN AF Kao, CW Yang, SN TI QED-QCD mixing effect and isospin violation in S-1(0) NN scattering SO PHYSICS LETTERS B LA English DT Article DE charge symmetry breaking; charge independence breaking; up-down quark mass difference; QED-QCD interference effects ID CHARGE-SYMMETRY-BREAKING; MOMENTUM DEPENDENCE; MODEL DEPENDENCE; NUCLEAR-FORCES; QUARK; LENGTH; ENERGY; PARAMETERS; MASS; ANN AB The charge dependence of the nucleon-nucleon scattering length due to the quark effects are examined in a quark cluster model. In addition to the effects induced by the up-down quark mass difference and quark-exchange Coulomb interaction, we consider the interference effects of QCD and QED suggested by Maltman, Stephenson, and Goldman. We find that the total contribution of the quark effects to a(pp) - a(nn) is large and in the direction indicated by the experiments. The effect is, however, small for a(pp) - a(np). C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Kao, CW (reprint author), NATL TAIWAN UNIV,DEPT PHYS,TAIPEI 10617,TAIWAN. NR 37 TC 2 Z9 2 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 NOV 7 PY 1996 VL 388 IS 1 BP 1 EP 4 DI 10.1016/0370-2693(96)01165-3 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VP168 UT WOS:A1996VP16800001 ER PT J AU Song, CS AF Song, CS TI Effective mass of phi mesons at finite temperature SO PHYSICS LETTERS B LA English DT Article ID MATTER; HOT AB The effective mass of phi meson at non-zero temperature is re-examined with an effective chiral Lagrangian. We find that the phi mass decreases with temperature but the effect is small compared to the result obtained from calculations using QCD sum rules. The leading contributions come from kaon loop corrections but vector meson contributions are also important as temperature increases. We discuss consequences of these changes to the phenomena of chiral phase transition in hot hadronic matter. RP Song, CS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,MS70A-3307,BERKELEY,CA 94720, USA. NR 14 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD NOV 7 PY 1996 VL 388 IS 1 BP 141 EP 146 DI 10.1016/0370-2693(96)01153-7 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VP168 UT WOS:A1996VP16800021 ER PT J AU Ayala, AL Ducati, MBG Levin, EM AF Ayala, AL Ducati, MBG Levin, EM TI Unitarity boundary for deep inelastic structure functions SO PHYSICS LETTERS B LA English DT Article ID PARTON DISTRIBUTIONS; DIFFRACTIVE DISSOCIATION; BFKL POMERON; SMALL-X; QCD; PROTON; PHOTOPRODUCTION; SCATTERING; COLLISIONS; MESONS AB In this letter we derive the unitarity boundaries in QCD for the deep inelastic structure function in low x kinematic region: the Froissart boundary and a more restricted one, linked with experiment and based on additional assumptions, justified in the leading log approximation of perturbative QCD. The comparison of the unitarity boundaries with the new HERA experimental data gives rise to a challenge for QCD to explain the matching between the deep inelastic scattering and real photoproduction process. C1 UNIV FED PELOTAS,INST FIS & MATEMAT,BR-96010900 PELOTAS,RS,BRAZIL. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. PETERSBURG NUCL PHYS INST,THEORY DEPT,GATCHINA 188350,ST PETERSBURG,RUSSIA. RP Ayala, AL (reprint author), UNIV FED RIO GRANDE SUL,INST FIS,CAIXA POSTAL 15051,BR-91501970 PORTO ALEGRE,RS,BRAZIL. RI Gay Ducati, Maria Beatriz/C-4930-2013 NR 34 TC 37 Z9 37 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 NOV 7 PY 1996 VL 388 IS 1 BP 188 EP 196 DI 10.1016/0370-2693(96)01149-5 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA VP168 UT WOS:A1996VP16800028 ER PT J AU Nurco, DJ Medforth, CJ Forsyth, TP Olmstead, MM Smith, KM AF Nurco, DJ Medforth, CJ Forsyth, TP Olmstead, MM Smith, KM TI Conformational flexibility in dodecasubstituted porphyrins SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NONPLANAR C1 LAWRENCE LIVERMORE NATL LAB,DEPT CHEM,DAVIS,CA 95616. RI Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 7 TC 125 Z9 125 U1 1 U2 5 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 NOV 6 PY 1996 VL 118 IS 44 BP 10918 EP 10919 DI 10.1021/ja962164e PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VR419 UT WOS:A1996VR41900041 ER PT J AU Harpel, MR Hartman, FC AF Harpel, MR Hartman, FC TI Facilitation of the terminal proton transfer reaction of ribulose 1,5-bisphosphate carboxylase oxygenase by active-site Lys166 SO BIOCHEMISTRY LA English DT Article ID RUBRUM RIBULOSEBISPHOSPHATE CARBOXYLASE; RHODOSPIRILLUM-RUBRUM; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; DIRECTED MUTAGENESIS; BETA-ELIMINATION; CHEMICAL RESCUE; CARBON-DIOXIDE; SIDE REACTIONS; CATALYSIS; INTERMEDIATE AB The terminal step in the carboxylation pathway catalyzed by ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) is stereospecific protonation of the C-2 aci-acid of 3-phosphoglycerate (PGA), X-ray crystallographic results favor the E-amino group of Lys166 as the proton donor in this step [Knight et al. (1990) J. Mol. Biol. 215, 113]. Nonetheless, position-166 mutants are able to catalyze forward processing of isolated 2-carboxy-3-ketoarabinitol 1,5-bisphosphate (CKABP), the carboxylated reaction intermediate [Lorimer, G. H., & Hartman, F. C. (1988) J. Biol. Chem. 263, 6468]. Prior assays for intermediate processing relied solely on formation of acid-stable radioactivity from acid-labile [2'-C-14]CKABP. Therefore, PGA, the normal reaction product, may not have been distinguished from pyruvate, the product from p-elimination of phosphate from the terminal aci-acid intermediate [Andrews, T. J., & Kane, H. J. (1991) J. Biol, Chem. 266, 9447]. If Lys166 indeed serves as the terminal proton donor, mutants lacking an ionizable side chain at position 166 might process the carboxylated intermediate predominantly to pyruvate. We have thus used anion exchange chromatography and enzyme coupling to separate and identify the products from turnover of [2'-C-14]CKABP by wild-type, K166G, and K166S enzymes. Although PGA is the only labeled product of significance formed by wild-type enzyme, pyruvate is a major labeled product formed by the mutants. These results provide the first direct functionally-based evidence that Lys166 is crucial to the last step in Rubisco-catalyzed conversion of RuBP to PGA. C1 OAK RIDGE NATL LAB, DIV BIOL, PROT ENGN PROGRAM, OAK RIDGE, TN 37831 USA. NR 44 TC 17 Z9 17 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 5 PY 1996 VL 35 IS 44 BP 13865 EP 13870 DI 10.1021/bi962184t PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VR098 UT WOS:A1996VR09800001 PM 8909282 ER PT J AU Woodward, CA Kaufman, EN AF Woodward, CA Kaufman, EN TI Enzymatic catalysis in organic solvents: Polyethylene glycol modified hydrogenase retains sulfhydrogenase activity in toluene SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE hydrogenase; organic biocatalysis; polyethylene glycol; modified enzymes; sulfur ID PYROCOCCUS-FURIOSUS; ELEMENTAL SULFUR; HYPERTHERMOPHILIC ARCHAEBACTERIUM; DIMETHYLFORMAMIDE; SOLUBILIZATION; DEHYDROGENASE; REDUCTION; LIPASE; SUGARS; COAL AB Naturally occurring enzymes may be modified by covalently attaching hydrophobic groups that render the enzyme soluble and active in organic solvents, and have the potential to greatly expand applications of enzymatic catalysis. The reduction of elemental sulfur to hydrogen sulfide by a hydrogenase isolated from Pyrococcus furiosus has been investigated as a model system for organic biocatalysis. While the native hydrogenase catalyzed the reduction of sulfur to H2S in aqueous solution, no activity was observed when the aqueous solvent was replaced with anhydrous toluene. Hydrogenase modified with PEG p-nitrophenyl carbonate demonstrated its native biocatalytic ability in toluene when the reducing dye, benzyl viologen, was also present. Neither benzyl viologen nor PEG p-nitrophenyl carbonate alone demonstrated reducing capability. PEG modified cellulase and benzyl viologen were also incapable of reducing sulfur to H2S, indicating that the enzyme itself, and not the modification procedure, is responsible for the conversion in the nonpolar organic solvent. Sulfide production in toluene was tenfold higher than that produced in an aqueous system with equal enzyme activity, demonstrating the advantages of organic biocatalysis. Applications of bioprocessing in nonaqueous media are expected to provide significant advances in the areas of fossil fuels, renewable feedstocks, organic synthesis, and environmental control technology. (C) 1996 John Wiley & Sons, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,BIOPROC RES & DEV CTR,OAK RIDGE,TN 37831. NR 27 TC 10 Z9 10 U1 0 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD NOV 5 PY 1996 VL 52 IS 3 BP 423 EP 428 DI 10.1002/(SICI)1097-0290(19961105)52:3<423::AID-BIT8>3.0.CO;2-M PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA VM105 UT WOS:A1996VM10500008 PM 18629912 ER PT J AU Barrett, R Berry, M Dongarra, J Eijkhout, V Romine, C AF Barrett, R Berry, M Dongarra, J Eijkhout, V Romine, C TI Algorithmic bombardment for the iterative solution of linear systems: A poly-iterative approach SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE algorithmic bombardment; iterative methods; linear systems of equations; poly-iterative approach ID QMR AB Many algorithms employing short recurrences have been developed for iteratively solving linear systems. Yet when the matrix is nonsymmetric or indefinite, or both, it is difficult to predict which method will perform best, or indeed, converge at all. Attempts have been made to classify the matrix properties for which a particular method will yield a satisfactory solution, but ''luck'' still plays large role. This report describes the implementation of a poly-iterative solver. Here we apply three algorithms simultaneously to the system, in the hope that at least one will converge to the solution. While this approach has merit in a sequential computing environment, it is even more valuable in a parallel environment. By combining global communications, the cost of three methods can be reduced to that of a single method. C1 LOS ALAMOS NATL LAB,DISTRIBUTED COMP GRP,LOS ALAMOS,NM 87544. UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RI Dongarra, Jack/E-3987-2014; OI Berry, Michael/0000-0002-9191-9148 NR 21 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD NOV 5 PY 1996 VL 74 IS 1-2 BP 91 EP 109 DI 10.1016/0377-0427(96)00019-2 PG 19 WC Mathematics, Applied SC Mathematics GA VT309 UT WOS:A1996VT30900007 ER PT J AU Bramble, JH Pasciak, JE AF Bramble, JH Pasciak, JE TI Least-squares methods for Stokes equations based on a discrete minus one inner product SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE least-squares; Stokes equations; elasticity equations; preconditioners ID FINITE-ELEMENT METHOD; FLUID-DYNAMICS; ALGORITHMS; SPACES AB The purpose of this paper is to develop and analyze least-squares approximations for Stokes and elasticity problems. The major advantage of the least-squares formulation is that it does not require that the classical Ladyzhenskaya-Babiiska-Brezzi (LBB) condition be satisfied. We provide two methods. The first is posed in terms of the velocity-pressure pair without the introduction of additional variables. The second adds a vorticity variable. Ln both cases, we employ least-squares functionals which involve a discrete inner product which is related to the inner product in H-1(Omega) (the Sobolev space of order minus one on Omega). The use of such inner products (applied to second order problems) was proposed in an earlier paper by Bramble, Lazarov and Pasciak (1994). C1 TEXAS A&M UNIV, DEPT MATH, COLLEGE STN, TX 77843 USA. BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. NR 35 TC 47 Z9 47 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 EI 1879-1778 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD NOV 5 PY 1996 VL 74 IS 1-2 BP 155 EP 173 DI 10.1016/0377-0427(96)00022-2 PG 19 WC Mathematics, Applied SC Mathematics GA VT309 UT WOS:A1996VT30900010 ER PT J AU Yu, ZG Wu, MW Rao, XS Sun, X Bishop, AR AF Yu, ZG Wu, MW Rao, XS Sun, X Bishop, AR TI Excitons in two coupled conjugated polymer chains SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID LIGHT-EMITTING-DIODES; POLY(P-PHENYLENE VINYLENE); TRANS-POLYACETYLENE; CHARGE-TRANSFER; BAND-GAP; SINGLET; TRIPLET; STATES; BIEXCITONS AB We have studied the exciton states in two coupled conjugated polymer chains which are modelled individually by the Su-Schrieffer-Heeger Hamiltonian and coupled by an interchain electron-transfer term. Both the intra- and interchain long-range Coulomb interactions are taken into account. The properties of the lowest symmetric and anti-symmetric exciton states are extensively discussed for both the parallel and anti-parallel ordering between these two chains. It is found that, for these two kinds of ordering, the features of excitons are quite different. Possible implications for the experiment of luminescent polymers are also addressed. C1 FUDAN UNIV,T D LEE LAB,DEPT PHYS,SHANGHAI 200433,PEOPLES R CHINA. NATL LAB INFRARED PHYS,SHANGHAI 200083,PEOPLES R CHINA. STEVENS INST TECHNOL,DEPT PHYS & ENGN PHYS,HOBOKEN,NJ 07030. RP Yu, ZG (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Yu, Z/B-5547-2009; OI , Zhi-Gang/0000-0002-1376-9025 NR 35 TC 15 Z9 15 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD NOV 4 PY 1996 VL 8 IS 45 BP 8847 EP 8857 DI 10.1088/0953-8984/8/45/018 PG 11 WC Physics, Condensed Matter SC Physics GA VR230 UT WOS:A1996VR23000018 ER PT J AU MedellinRodriguez, FJ Phillips, PJ Lin, JS AF MedellinRodriguez, FJ Phillips, PJ Lin, JS TI Melting behavior of high-temperature polymers SO MACROMOLECULES LA English DT Article ID ANGLE X-RAY; POLY(ETHER ETHER KETONE); CRYSTALLIZED POLYMERS; 2-PHASE SYSTEMS; SCATTERING; POLY(ETHYLENE-TEREPHTHALATE); MORPHOLOGY; KINETICS AB The melting behavior of three representative semirigid polymers, poly(aryl ether ether ketone), poly(ethylene terephthalate), and poly(ethylene naphthalenate), has been studied. Analysis of experimental results indicates that the melting process is morphologically the reverse of the isothermal crystallization process with respect to primary and secondary structural elements. On this basis, it is hypothesized that melting of all three polymers occurs in three distinct steps, assuming that spherulites are composed of dominant lamellae and subsidiary branches. The latter might have originated either from material rejected from the dominant lamellae or from noncrystalline molecular sections in the vicinity of the dominant lamellae. Experimental results emerging from differential scanning calorimetry, polarized optical microscopy, and small-angle X-ray scattering can be explained in terms of such a morphology, for which two possible models are suggested. C1 UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 36 TC 77 Z9 77 U1 3 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 4 PY 1996 VL 29 IS 23 BP 7491 EP 7501 DI 10.1021/ma9511659 PG 11 WC Polymer Science SC Polymer Science GA VQ879 UT WOS:A1996VQ87900025 ER PT J AU Talibuddin, S Wu, L Runt, J Lin, JS AF Talibuddin, S Wu, L Runt, J Lin, JS TI Microstructure of melt-miscible, semicrystalline polymer blends SO MACROMOLECULES LA English DT Article ID X-RAY-SCATTERING; POLY(METHYL METHACRYLATE) BLENDS; SMALL-ANGLE SCATTERING; TEREPHTHALATE) POLYARYLATE BLENDS; POLYVINYL ACETATE) BLENDS; POLY(ETHYLENE OXIDE); POLY(VINYLIDENE FLUORIDE); POINT DEPRESSION; ETHER KETONE); MORPHOLOGY AB A combination of small-angle X-ray scattering and optical microscopy was used to investigate the influence of diluent mobility and polymer-polymer interactions on diluent segregation in a series of ''model'' melt-miscible poly(ethylene oxide) (PEO) blends. The amorphous polymeric diluents were selected with regard to their glass transition temperatures relative to the crystallization temperature and the strength of their interactions with PEG. Segregation of the weakly interacting amorphous polymers was found to be largely dependent on their glass transition temperatures: the high-T-g diluent was found to reside exclusively in interlamellar regions whereas the low-T-g diluent was excluded at least partially into interfibrillar regions. The introduction of strong intermolecular interactions between the crystallizable and amorphous components resulted in significantly reduced crystal growth rates and promoted diluent segregation over greater length scales, regardless of diluent mobility at the crystallization temperature. Thus, for the systems under consideration here, the study shows that although diluent mobility contributes to diluent segregation, the growth of the PEO crystals, and the factors that influence the growth rate, dominate the length scale of diluent segregation. C1 PENN STATE UNIV,DEPT MAT SCI & ENGN,UNIVERSITY PK,PA 16802. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI He, Yong/F-8752-2012 NR 48 TC 121 Z9 122 U1 4 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 4 PY 1996 VL 29 IS 23 BP 7527 EP 7535 DI 10.1021/ma960508f PG 9 WC Polymer Science SC Polymer Science GA VQ879 UT WOS:A1996VQ87900030 ER PT J AU Feinendegen, LE Bond, VP Sondhaus, CA Muehlensiepen, H AF Feinendegen, LE Bond, VP Sondhaus, CA Muehlensiepen, H TI Radiation effects induced by low doses in complex tissue and their relation to cellular adaptive responses SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article ID HUMAN-LYMPHOCYTES; X-RAYS; IONIZING-RADIATIONS; MECHANISMS; IRRADIATION; PROTECTION; THYMIDINE; EXPOSURE; INVITRO; REPAIR C1 US DOE, OFF HLTH & ENVIRONM RES, WASHINGTON, DC USA. UNIV ARIZONA, COLL MED, RADIAT CONTROL OFF, TUCSON, AZ USA. RES CTR JULICH, INST MED, JULICH, GERMANY. RP Feinendegen, LE (reprint author), BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. NR 24 TC 33 Z9 34 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD NOV 4 PY 1996 VL 358 IS 2 BP 199 EP 205 DI 10.1016/S0027-5107(96)00121-2 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA VU530 UT WOS:A1996VU53000010 PM 8946025 ER PT J AU Obuti, MM Kobayashi, T Hirata, D Ogawa, Y Ozawa, A Sugimoto, K Tanihata, I Olson, D Christie, W Wieman, H AF Obuti, MM Kobayashi, T Hirata, D Ogawa, Y Ozawa, A Sugimoto, K Tanihata, I Olson, D Christie, W Wieman, H TI Interaction cross section and interaction radius of the B-8 nucleus SO NUCLEAR PHYSICS A LA English DT Article DE radioactive beam; heavy-ion reaction; proton halo; structure of drip line nucleus ID PROTON HALO; MOMENTUM DISTRIBUTIONS; NEUTRON CORRELATIONS; LI-9 FRAGMENT; MEV/NUCLEON; BEAMS AB The interaction cross section (sigma(I)) was re-measured by a transmission-type measurement for B-8(5)3 at 790A . MeV on a C target confirming the previously reported value. B-8, although it has a very small proton separation energy 0.137 MeV, shows no remarkable enhancement of the sigma(I) expected from a possible proton halo, as suggested from studies of the quadrupole moment and other recent data such as the reaction cross section at low energies. The root-mean-square (RMS) radius of the nucleon distribution has been deduced using the Glauber model. The relation between the halo tail and the separation energy is discussed on the mirror nuclei B-8 and Li-8. It was also found that the previously reported narrow momentum distribution of Be-7 from the fragmentation of B-8 is well reproduced by the presently determined density distribution. C1 RIKEN,WAKO,SAITAMA 35101,JAPAN. UNIV SAO PAULO,IFUSP,DEPT NUCL PHYS,SAO PAULO,BRAZIL. OSAKA UNIV,FAC SCI,TOYONAKA,OSAKA 560,JAPAN. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RI Hirata, Daisy/F-3199-2013 NR 26 TC 69 Z9 71 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 NOV 4 PY 1996 VL 609 IS 1 BP 74 EP 90 DI 10.1016/0375-9474(96)00267-9 PG 17 WC Physics, Nuclear SC Physics GA VQ784 UT WOS:A1996VQ78400005 ER PT J AU Ha, T Enderle, T Chemla, DS Selvin, PR Weiss, S AF Ha, T Enderle, T Chemla, DS Selvin, PR Weiss, S TI Single molecule dynamics studied by polarization modulation SO PHYSICAL REVIEW LETTERS LA English DT Article ID OPTICAL MICROSCOPY; SPECTROSCOPY AB We observed and made unambiguous distinctions between abrupt photophysical events of single molecules: a rotational jump of a single dipole, a transition to a dark state (reversible and irreversible photobleaching), and a spectral jump. The study was performed in the far field by modulating the excitation polarization and monitoring the fluorescence in time. This technique also allowed us to measure the in-plane dipole orientation of stationary single molecular dipoles with subdegree accuracy and to resolve desorption and readsorption of fluorophores from and onto a glass surface. In one case, clear evidence was obtained for rapid rotation of the dipole after a desorption process. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,INST MOL DESIGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. RP Ha, T (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Ha, Taekjip/B-9506-2009; weiss, shimon/B-4164-2009 OI Ha, Taekjip/0000-0003-2195-6258; weiss, shimon/0000-0002-0720-5426 NR 19 TC 252 Z9 255 U1 5 U2 39 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 NOV 4 PY 1996 VL 77 IS 19 BP 3979 EP 3982 DI 10.1103/PhysRevLett.77.3979 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700010 ER PT J AU Kimmel, GA Orlando, TM AF Kimmel, GA Orlando, TM TI Observation of negative ion resonances in amorphous ice via low-energy (5-40 eV) electron-stimulated production of molecular hydrogen SO PHYSICAL REVIEW LETTERS LA English DT Article ID CORE-EXCITED RESONANCES; TRANSMISSION SPECTROSCOPY; DISSOCIATIVE ATTACHMENT; H2O; DISTRIBUTIONS; D2O; SCATTERING; IONIZATION; SPECTRA; IMPACT AB The D-2((1) Sigma(g)(+), v = 0-2, J = 0-2) desorbates produced low-energy (5-40 eV) electron-beam irradiation of amorphous (DO)-O-2 ice were monitored using resonance-enhanced laser ionization spectroscopy. We attribute the structure in the D-2 yield as a function of the incident electron energy to core-excited negative ion resonances. These resonances, or the excited states produced after electron autodetachment, decay via molecular elimination to yield D-2((1) Sigma(g)(+)) directly. D-2 is observed with v = 0 or 2 but not v = 1, suggesting a symmetry propensity in the excitation or decay of the resonances. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. OI Kimmel, Greg/0000-0003-4447-2440 NR 24 TC 75 Z9 76 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 NOV 4 PY 1996 VL 77 IS 19 BP 3983 EP 3986 DI 10.1103/PhysRevLett.77.3983 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700011 ER PT J AU Chen, Y Washburn, J AF Chen, Y Washburn, J TI Structural transition in large-lattice-mismatch heteroepitaxy SO PHYSICAL REVIEW LETTERS LA English DT Article ID EPITAXIAL-GROWTH; ISLANDS; GAAS AB The mechanisms of island nucleation, growth, and dislocation formation in large lattice-mismatch heteroepitaxy are analyzed theoretically. It is shown that 2D platelets tend to transform to 3D islands as they exceed a certain critical size. During island growth, the increase of the strain concentration at the island edge makes it increasingly difficult for adatoms to reach the island, which leads to the formation of homogeneously sized islands. The high strain concentration at the island edge is eventually relieved by growing-in of misfit dislocations. RP Chen, Y (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 17 TC 277 Z9 279 U1 4 U2 41 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 NOV 4 PY 1996 VL 77 IS 19 BP 4046 EP 4049 DI 10.1103/PhysRevLett.77.4046 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700027 ER PT J AU Kim, C Matsuura, AY Shen, ZX Motoyama, N Eisaki, H Uchida, S Tohyama, T Maekawa, S AF Kim, C Matsuura, AY Shen, ZX Motoyama, N Eisaki, H Uchida, S Tohyama, T Maekawa, S TI Observation of spin-charge separation in one-dimensional SrCuO2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID LUTTINGER-LIQUID BEHAVIOR; MOMENTUM DISTRIBUTION; HUBBARD-MODEL; PHOTOEMISSION; TRANSITION; SR2CUO2CL2; CHAIN AB Angle-resolved photoemission data from one-dimensional SrCuO2 compounds are found to be qualitatively different from that of two-dimensional Sr2CuO2Cl2. The data can be quantitatively accounted for by the exact diagonalization calculation based on the t-J model. We identify the two underlying bands having approximately 1.2 and 0.3 eV energy dispersion as that of holon and spinon, with their energy scaled by t and J, respectively. C1 STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV TOKYO,DEPT SUPERCONDUCT,BUNKYO KU,TOKYO 133,JAPAN. MIE UNIV,FAC EDUC,DEPT PHYS,TSU,MIE 514,JAPAN. NAGOYA UNIV,DEPT APPL PHYS,NAGOYA,AICHI 46401,JAPAN. TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. RP Kim, C (reprint author), STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305, USA. NR 22 TC 282 Z9 283 U1 4 U2 43 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 NOV 4 PY 1996 VL 77 IS 19 BP 4054 EP 4057 DI 10.1103/PhysRevLett.77.4054 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700029 ER PT J AU Itoh, KM Haller, EE Beeman, JW Hansen, WL Emes, J Reichertz, LA Kreysa, E Shutt, T Cummings, A Stockwell, W Sadoulet, B Muto, J Farmer, JW Ozhogin, VI AF Itoh, KM Haller, EE Beeman, JW Hansen, WL Emes, J Reichertz, LA Kreysa, E Shutt, T Cummings, A Stockwell, W Sadoulet, B Muto, J Farmer, JW Ozhogin, VI TI Hopping conduction and metal-insulator transition in isotopically enriched neutron-transmutation-doped Ge-70:Ga SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRITICAL-BEHAVIOR; DISORDERED-SYSTEMS; CRITICAL EXPONENTS; MAGNETIC-FIELD; SI-AS; LOCALIZATION; SEMICONDUCTORS; GERMANIUM; SILICON AB We report on the electrical conductivity sigma of a series of nominally uncompensated neutron-transmutation-doped isotopically enriched Ge-70:Ga samples with the Ga concentration [Ga] near N-c for the metal-insulator transition. sigma of all insulating samples obeys ln sigma proportional to -(T-0/T)(1/2) with T-0 proportional to (N-c-[Ga])/N-c while the zero temperature conductivity sigma(0) of the metallic samples is sigma(0) sigma {([Ga]-N-c)/N-c}(nu) with the critical exponent nu approximate to 0.5. The values of N-c obtained from the two independent scalings of T-0 and sigma(0) are identical, i.e., nu approximate to 0.5 is established unambiguously for uncompensated Ge:Ga. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MAX PLANCK INST RADIOASTRON,D-53010 BONN,GERMANY. UNIV MISSOURI,COLUMBIA,MO 65211. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. RP Itoh, KM (reprint author), KEIO UNIV,DEPT APPL PHYS & PHYSIOINFORMAT,KOHOKU KU,3-14-1 HIYOSHI,YOKOHAMA,KANAGAWA 223,JAPAN. RI Itoh, Kohei/C-5738-2014 NR 38 TC 93 Z9 95 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 4 PY 1996 VL 77 IS 19 BP 4058 EP 4061 DI 10.1103/PhysRevLett.77.4058 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700030 ER PT J AU Basov, DN Liang, R Dabrowski, B Bonn, DA Hardy, WN Timusk, T AF Basov, DN Liang, R Dabrowski, B Bonn, DA Hardy, WN Timusk, T TI Pseudogap and charge dynamics in CuO2 planes in YBCO SO PHYSICAL REVIEW LETTERS LA English DT Article ID MARGINAL FERMI-LIQUID; VALENCE-BOND STATE; C-AXIS RESPONSE; SPIN-GAP; INFRARED PROPERTIES; OPTICAL-PROPERTIES; YBA2CU3O6+X; YBA2CU4O8; SUPERCONDUCTORS; PHENOMENOLOGY AB We report on the infrared conductivity of YBa2Cu3Ox and YBa2Cu4O8 crystals with different oxygen content and Zn doping. We find a correlation between the structure of the scattering rate spectra 1/tau(a)*(omega,T) in the CuO2 planes and the pseudogap that develops in the c-axis conductivity of underdoped samples for T < T* = 140-250 K. In the pseudogap state, the scattering rate is depressed at low frequencies and follows an omega(2 +/- 0.3) law for omega < 400 cm(-1). When the c-axis pseudogap is suppressed, either by an increase of temperature above T* or by a substitution of Cu with Zn, the spectra of 1/tau(a)*(omega, T) revert to the nearly linear omega dependence of the optimally doped compounds. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV BRITISH COLUMBIA,VANCOUVER,BC V6T 4M1,CANADA. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP Basov, DN (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. NR 30 TC 160 Z9 160 U1 3 U2 24 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 NOV 4 PY 1996 VL 77 IS 19 BP 4090 EP 4093 DI 10.1103/PhysRevLett.77.4090 PG 4 WC Physics, Multidisciplinary SC Physics GA VQ147 UT WOS:A1996VQ14700038 ER PT J AU Pigarov, AY Krasheninnikov, SI AF Pigarov, AY Krasheninnikov, SI TI Application of the collisional-radiative, atomic-molecular model to the recombining divertor plasma SO PHYSICS LETTERS A LA English DT Article ID ALCATOR-C-MOD; HYDROGEN; IONOSPHERES AB On the basis of a generalized collisional-radiative, atomic-molecular model we have calculated the effective rate coefficient for plasma recombination taking into account the plasma chemical reactions with vibrationally excited molecules. The large size of this rate coefficient and its specific dependence on plasma parameters may explain the anomalously fast plasma recombination experimentally observed on many divertor tokamaks. C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. RP Pigarov, AY (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08544, USA. NR 27 TC 83 Z9 83 U1 0 U2 6 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 NOV 4 PY 1996 VL 222 IS 4 BP 251 EP 257 DI 10.1016/0375-9601(96)00629-9 PG 7 WC Physics, Multidisciplinary SC Physics GA VP800 UT WOS:A1996VP80000008 ER PT J AU Parakka, JP Kini, AM Williams, JM AF Parakka, JP Kini, AM Williams, JM TI A facile route to aromatic ring-annelated bis(ethylenedithio)tetrathiafulvalene derivatives SO TETRAHEDRON LETTERS LA English DT Article ID PRESSURE ORGANIC SUPERCONDUCTOR; 1,3-DITHIOLE-2-THIONE-4,5-DITHIOLATE; METAL; TTF AB The synthesis of bis(benzo)- and bis(naphtho)-fused derivatives of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) is easily achieved by employing the (4+2) cycloaddition reaction of oligo(1,3-dithiole 2,4,5-trithione) with appropriate olefins as the key step. Copyright (C) 1996 Elsevier Science Ltd C1 ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. RI Kini, Aravinda/F-4467-2012 NR 16 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD NOV 4 PY 1996 VL 37 IS 45 BP 8085 EP 8088 DI 10.1016/0040-4039(96)01846-1 PG 4 WC Chemistry, Organic SC Chemistry GA VR553 UT WOS:A1996VR55300007 ER PT J AU Allan, ML Kukacka, LE AF Allan, ML Kukacka, LE TI Comparison between slag- and silica fume-modified grouts SO ACI MATERIALS JOURNAL LA English DT Article DE blast furnace slag; grout; microcracking; permeability; rheological properties; silica fume; strength; superplasticizers ID CHROMIUM AB The effects of silica fume and ground granulated blast furnace slag on rheology and hardened properties of superplasticized grouts were studied. Silica fume and slag improved impermeability, strength, and wet-dry durability of grouts. The physical and mechanical properties of slag- and silica fume-modified grouts compared favorably with those of grouts prepared with Type II and V cements. Silica fume was found to have a more pronounced impact on shear stress-shear rate relationships than slag. Gel strength was decreased by slag and increased by silica fume. The rheological properties of the grouts were sensitive to the sequence of superplasticizer addition. Slag- and silica fume-modified grouts are suitable for use in structural and environmental applications. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,PROC MAT GRP,UPTON,NY 11973. RP Allan, ML (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. RI Berndt, Marita/D-1901-2014 OI Berndt, Marita/0000-0002-6622-0597 NR 19 TC 15 Z9 16 U1 0 U2 2 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD NOV-DEC PY 1996 VL 93 IS 6 BP 559 EP 568 PG 10 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA WA771 UT WOS:A1996WA77100007 ER PT J AU Huang, DB Ainsworth, C Solomon, A Schiffer, M AF Huang, DB Ainsworth, C Solomon, A Schiffer, M TI Pitfalls of molecular replacement: The structure determination of an immunoglobulin light-chain dimer SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID BENCE-JONES PROTEIN; 2 CRYSTAL FORMS; CRYSTALLOGRAPHIC ANALYSIS; 3-DIMENSIONAL STRUCTURE; ANTIBODY; REFINEMENT; ARRANGEMENT; RESOLUTION; LOC AB The structure of protein Cle, a human light-chain dimer from the lambda III subgroup, was determined using 2.6 Angstrom data; the R value is 18.4%. The structure was solved, after a false start, by molecular replacement with the lambda II/V Meg protein as a search structure. When the refinement did not proceed beyond an R value of 27%, it was discovered that while the constant domains were in their correct positions in the unit cell, the incorrect variable domains were used for defining the molecule. The correct solution required a rotation of 180 degrees around the local twofold axis that relates the two constant domains of the dimer. The correct variable domain positions overlap about 70% of the same volume as the incorrect ones of a symmetry-related molecule. The refinement distorted the geometries of the domains. Though the constant domains were in their correct positions, the r.m.s. (root-mean-square) deviation of the C alpha atom position was 1.2 Angstrom when the two constant domains were compared. For the correct structure, this value is 0.5 Angstrom. The phi and psi angles, the r.m.s. chiral value and the free R value, even when calculated a posteriori, were good indicators of the correctness of the structure. The quaternary structure of the Cle molecule is similar to that in Meg (crystallized from ammonium sulfate); the elbow bend is 115:. However, the arrangement of the variable domains differs from that observed in other variable domain dimers. The variable domains of Cle are 0.7 Angstrom closer than in Meg or variable dimer Rei. The hydrogen bonding at the interface of the two domains is novel. Residues Tyr36 from both monomers form a hydrogen bond that is part of a network with the Gln89 residues from both monomers. For the first time hydrogen bonds were observed between the main-chain peptide N and O atoms of the complementarity-determining region CDR2 and CDR3 segments of both monomers. C1 UNIV TENNESSEE,MED CTR,SCH MED,HUMAN IMMUNOL & CANC PROGRAM,DEPT MED,KNOXVILLE,TN 37920. RP Huang, DB (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 31 TC 7 Z9 7 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD NOV 1 PY 1996 VL 52 BP 1058 EP 1066 DI 10.1107/S090744499600813X PN 6 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA VW616 UT WOS:A1996VW61600002 PM 15299564 ER PT J AU Parkin, S Rupp, B Hope, H AF Parkin, S Rupp, B Hope, H TI Atomic resolution structure of concanavalin A at 120 K SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID LEAST-SQUARES REFINEMENT; AMINO-ACID SEQUENCE; FREE R-VALUE; 3-DIMENSIONAL STRUCTURE; MACROMOLECULAR STRUCTURES; ANGSTROM RESOLUTION; COVALENT; PROTEIN; ACCURACY; PLASTOCYANIN AB The structure of native concanavalin A has been refined to a resolution of 1.2 Angstrom, against data collected at 120 K. The space group is I222, with a=61.954(8), b=86.053 (11), c=89.079(11) Angstrom. The structure was refined by restrained weighted least-squares minimization of Sigma w(F-o(2)-F-c(2))(2) with SHELXL92/3/6. The final model contains all of the atoms from 237 amino acids, two metal ions and 271 water molecules spread over 287 sites. Disorder is modelled over two conformations for 30 amino-acid side chains. The final weighted R index on F-2 (wR(2)) On all data was 30.4%. Conventional R indices based on F were 14.2 and 11.8% for all data and for data with F > 4 sigma(F), respectively. C1 UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. RP Parkin, S (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,L-452,LIVERMORE,CA 94550, USA. RI Parkin, Sean/E-7044-2011 NR 35 TC 38 Z9 40 U1 1 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD NOV 1 PY 1996 VL 52 BP 1161 EP 1168 DI 10.1107/S0907444996009237 PN 6 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA VW616 UT WOS:A1996VW61600015 PM 15299577 ER PT J AU Carter, DH McGeorge, AC Jacobson, LA Stanek, PW AF Carter, DH McGeorge, AC Jacobson, LA Stanek, PW TI Age hardening in beryllium-aluminum-silver alloys SO ACTA MATERIALIA LA English DT Article AB Three different alloys of beryllium-aluminum-silver were processed to powder by centrifugal atomization in a helium atmosphere. Alloy compositions were, by weight percent, Be-47.5Al-2.5Ag, Be-47Al-3Ag, and Be46Al-4Ag. Due to the low solubility of both aluminum and silver in beryllium, the silver was concentrated in the aluminum phase, which separates from the beryllium in the liquid phase. A fine, continuous composite beryllium-aluminum microstructure was formed, which did not significantly change after hot isostatic pressing. Samples of hot isostatically pressed material were solution treated at 550 degrees C for 1 h, followed by a water quench. Aging temperatures were 150, 175, 200, and 225 degrees C for times ranging from half an hour to 65 h. Results indicate that peak hardness was reached in 36-40 h at 175 degrees C and 12-16 h at 200 degrees C aging temperature. relatively independent of alloy composition. Copyright (C) 1996 Acta Metallurgica Inc. RP Carter, DH (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 10 TC 6 Z9 7 U1 1 U2 1 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 NOV PY 1996 VL 44 IS 11 BP 4311 EP 4315 DI 10.1016/1359-6454(96)00113-9 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VP499 UT WOS:A1996VP49900005 ER PT J AU Yan, M Vitek, V Chen, SP AF Yan, M Vitek, V Chen, SP TI Many-body central force potentials and properties of grain boundaries in NiAl SO ACTA MATERIALIA LA English DT Article ID ATOMIC-STRUCTURE; COMPUTER-SIMULATION; TILT BOUNDARIES; NI3AL; METALS; ALLOYS; TRANSITION; VACANCIES; BRITTLE; PHASES AB Empirical many-body central force potentials of the Finnis-Sinclair type have been constructed for B2 NiAl by fitting a number of equilibrium properties of this alloy and reproducing the asymmetric behaviour of constitutional point defects in off-stoichiometric NiAl. Al the same time these potentials ensure the structural and mechanical stability of the B2 lattice and reproduce quite adequately the equilibrium properties of Ni3Al. Using these potentials, grain boundaries in NiAl have been studied by computer simulation. It was found that in stoichiometric NiAl alloy boundaries with a surplus of aluminium have appreciably lower cohesive strength than the stoichiometric boundaries or boundaries with a surplus of nickel. From the structural point of view, boundaries with a surplus of aluminium possess the largest expansions and large 'holes' usually occur in the boundary regions. On the other hand, boundaries with the stoichiometric configuration or with a surplus of nickel have more compact structures. The interaction of the antisite defects and vacancies with grain boundaries was also studied and segregation of nickel and aluminium in off-stoichiometric alloys discussed with the help of these results. C1 UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. RP Yan, M (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 50 TC 41 Z9 42 U1 2 U2 10 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 NOV PY 1996 VL 44 IS 11 BP 4351 EP 4365 DI 10.1016/1359-6454(96)00117-6 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VP499 UT WOS:A1996VP49900009 ER PT J AU Kamada, H Locher, MP Lee, TSH Glockle, W Witala, H Golak, J AF Kamada, H Locher, MP Lee, TSH Glockle, W Witala, H Golak, J TI Pion absorption on He-3 SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT International Conference MESON 96 CY MAY 10-14, 1996 CL KRAKOW, POLAND SP Jagellonian Univ, Phys Inst, KFA Julich, Inst Kernphys ID FINAL-STATE INTERACTIONS; ELECTRON-SCATTERING; FULL INCLUSION; H-3 AB Pion absorption in the pi(+) He-3 --> ppp reaction is investigated using the Faddeev formalism. As preliminary results, the differential cross sections for the two- and three-body absorption mechanics are shown. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RUHR UNIV BOCHUM,INST THEORET PHYS 2,D-44780 BOCHUM,GERMANY. JAGIELLONIAN UNIV,INST PHYS,PL-30059 KRAKOW,POLAND. RP Kamada, H (reprint author), PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1996 VL 27 IS 11 BP 3381 EP 3384 PG 4 WC Physics, Multidisciplinary SC Physics GA WC596 UT WOS:A1996WC59600066 ER PT J AU Tallarek, U Albert, K Bayer, E Guiochon, G AF Tallarek, U Albert, K Bayer, E Guiochon, G TI Measurement of transverse and axial apparent dispersion coefficients in packed beds SO AICHE JOURNAL LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; LIQUID-CHROMATOGRAPHY; COLUMNS; DIFFUSION; CONSOLIDATION; EFFICIENCY; SILICA; MEDIA; RANGE; ECHO AB The axial and transverse apparent dispersion coefficients of three solvents in two packed chromatographic columns were determined by pulsed-field-gradient nuclear-magnetic resonance in a range of mobile phase velocity. The column beds were packed with 5-mu m particles of porous C18 silica or 30-mu m particles of silica. The solvents used were methanol and acetonitrile (in an 80:20 ACN/water solution) in the former case and acetone in the latter. The coefficients were determined over a range of particle Peclet numbers from less than 0.1 to approximately 10 in the former case and 40 in the latter. The data obtained with short dispersion times were fitted to the correlations suggested by Giddings, Horvath and Lin, Huber, and Knox. These data agreed well only with the Giddings equation. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Tallarek, U (reprint author), UNIV TUBINGEN,INST ORGAN CHEM,MORGENSTELLE 18,D-72076 TUBINGEN,GERMANY. NR 65 TC 79 Z9 80 U1 2 U2 11 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 NOV PY 1996 VL 42 IS 11 BP 3041 EP 3054 DI 10.1002/aic.690421106 PG 14 WC Engineering, Chemical SC Engineering GA VR595 UT WOS:A1996VR59500005 ER PT J AU Becker, U Hochella, MF Apra, E AF Becker, U Hochella, MF Apra, E TI The electronic structure of hematite{001} surfaces: Applications to the interpretation of STM images and heterogeneous surface reactions SO AMERICAN MINERALOGIST LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; MINERAL SURFACES; 001 SURFACES; ALPHA-FE2O3; PHOTOEMISSION; SPECTRA; SPECTROSCOPY; OXIDES; FE2O3; ALPHA-AL2O3 AB Scanning tunneling microscope (STM) images and scanning tunneling spectroscopy (STS) spectra of hematite (alpha-Fe2O3) surfaces were calculated using ab-initio methods, not only to interpret experimentally collected STM data, but also to gain insight into atomic level changes in electronic structure that are associated with heterogeneous surface reactions. The electronic structure and wave functions inside the studied crystal were obtained as a periodic solution of the Schrodinger equation by using the program Crystal92. STM images and STS spectra were calculated by applying a technique similar to the Tersoff and Hamann (1985) method. Experimental STM images of the upper valence band of hematite (001) surfaces, cleaved in air, show a periodic array of bright spots that differs slightly from the O-O separation in the bulk. However, our calculations show that these spots are located at the Fe positions of the surface Fe atoms and above the Fe atoms between the first and second hexagonally close-packed O layers. The calculated STS spectra for tip positions above the three nonequivalent Fe positions show significant differences, in particular because the contribution of O 2p-like and Fe 3d-like states changes with the distance between the tip and the respective Fe atom underneath. Hematite crystals that were used to obtain STM images experimentally in previous studies were cleaved in air, and the presence of adsorbed H2O and O-2 was considered in this study. Calculations that optimize the surface atomic arrangement with respect to total energy of the slab indicate that H2O and O-2 adsorbed to the surface have binding energies too low to withstand the dragging force and the electric potential applied during the scanning process. In addition, only calculations of STM images of fresh hematite surfaces exactly mimic the periodicity of high electronic density spots, as observed in experiments. STS spectra calculated for equivalent Fe positions on terraces and near steps show the increased electron density of the top of the valence band for step sites, which is experimentally observed as higher intensities of bright spots at steps. These calculations show that the local electronic structure of surfaces can be very different from bulk electronic properties and that conclusions drawn from cluster calculations representing the bulk can be misleading. In addition, this theoretical approach helps to explain the increased reactivity at specific sites on hematite, such as steps and kinks, in terms of the electronic surface structure of this mineral. C1 VIRGINIA POLYTECH INST & STATE UNIV, DEPT GEOL SCI, BLACKSBURG, VA 24061 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Apra, Edoardo/F-2135-2010; Becker, Udo/F-7339-2011 OI Apra, Edoardo/0000-0001-5955-0734; Becker, Udo/0000-0002-1550-0484 NR 52 TC 62 Z9 62 U1 1 U2 11 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1996 VL 81 IS 11-12 BP 1301 EP 1314 PG 14 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA WE455 UT WOS:A1996WE45500001 ER PT J AU Cady, SL Wenk, HR Downing, KH AF Cady, SL Wenk, HR Downing, KH TI HRTEM of microcrystalline opal in chert and porcelanite from the Monterey Formation, California SO AMERICAN MINERALOGIST LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; LOW-TRIDYMITE; SILICA DIAGENESIS; CRYSTAL-STRUCTURE; TEMBLOR RANGE; PHASE; SHALE; TRANSFORMATION; CRISTOBALITE; CT AB Microcrystalline opal was investigated using low-dose transmission electron microscopy (TEM) methods to identify microstructural characteristics and possible phase-transformation mechanisms that accommodate silica diagenesis. High-resolution TEM (HRTEM) revealed that microcrystalline opal in opal-CT chert (>90 wt% silica) and opal-CT porce-lanite (50-90 wt% silica) from the Miocene Monterey Formation of California displays various amounts of structural disorder and coherent and incoherent lamellar intergrowths. Species of microfibrous opal identified by HRTEM in early-formed opal-CT chert include length-slow opal-C and unidimensionally disordered length-slow opal-CT (''lussatite''). These fibers often display a microstructure characterized by an aperiodic distribution of highly strained domains that separate ordered domains located at discrete positions along the direction of the fiber axes. Microfibrous opal occurs as several types of fiber-aggregation forms. TEM revealed that the siliceous matrix in later-formed opal-CT porcelanite consists of equidimensional, nanometer-size opal-CT crystallites and lussatite fibers. Pseudo-orthorhombic tridymite (PO-2) was identified by HRTEM in one sample of opal-CT porcelanite. Burial diagenesis of chert and porcelanite results in the precipitation of opal-C and the epitaxial growth of opal-C domains on opal-CT substrates. Diagenetic maturation of lussatite was identified by TEM in banded opal-CT-quartz chert to occur as a result of solid-state ordering. The primary diagenetic silica phase transformations between noncrystalline opal, microcrystalline opal, and quartz occur predominantly by a series of dissolution-precipitation reactions. However, TEM showed that in banded opal-CT-quartz chert, the epitaxial growth of quartz on microfibrous opal enhances the rate of silica diagenesis. C1 UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. RP Cady, SL (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 82 TC 15 Z9 18 U1 1 U2 6 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1996 VL 81 IS 11-12 BP 1380 EP 1395 PG 16 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA WE455 UT WOS:A1996WE45500011 ER PT J AU Muddiman, DC Wunschel, DS Liu, CL PasaTolic, L Fox, KF Fox, A Anderson, GA Smith, RD AF Muddiman, DC Wunschel, DS Liu, CL PasaTolic, L Fox, KF Fox, A Anderson, GA Smith, RD TI Characterization of PCR products from bacilli using electrospray ionization FTICR mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID ASSISTED LASER-DESORPTION; ION ACCUMULATION; DNA; OLIGONUCLEOTIDES; POLYMERASE; DIAGNOSIS; SEQUENCES; AMPLIFICATION; PRINCIPLES; 50-MER AB A procedure for rapid purification of polymerase chain reaction (PCR) products allowing precise molecular weight determination using electrospray ionization-Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry is described, PCR amplification utilized the DNA polymerase from Pyrococcus furiosus (Pfu) which, unlike Tag, does not incorporate a nontemplated terminal deoxyadenosine phosphate, An 89-base pair nucleotide portion of the spacer region between the 16S and 23S ribosomal rRNA genes was amplified from the genome of three members of Bacillus cereus group and a 114 nucleotide region from the Bacillus subtilis, PCR involves polymerization of nucleotide precursors using two oligonucleotide primers and an amplification enzyme, as well as the presence of metal ions, Mass spectrometric analysis greatly benefits from removal of the oligonucleotide primers (15- and 17-mers in this instance) and nucleotide precursors since they adversely affect sensitivity and metal ion adduction results in an inaccurate molecular weight determination, In the presence of guanidinium hydrochloride, the PCR products bind preferentially to a silica resin, allowing removal of other components (i,e,, dNTP's, primers, and salts), Further removal of metal ions was accomplished using a microdialysis device, allowing samples to be pumped through a hollow cellulose fiber with an external countercurrent now of 2.5 mM ammonium acetate, Prior to injection into the mass spectrometer, the sample buffer was adjusted to 50 vol % acetonitrile, 25 mM piperidine, and 25 mM imidazole, which enhanced signal intensity, The molecular weights of the PCR products determined by nucleotide sequence and MS analysis were in excellent agreement, and several PCR products were analyzed where mass differences corresponding to single base substitutions could be accurately assigned, These assignments were possible due to the high mass precision, accuracy, and resolution FTICR inherently affords, This constitutes the first report demonstrating the ionization and detection of PCR products by mass spectrometry with mass precision and accuracy for assigment of such modifications or substitutions. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV S CAROLINA, SCH MED, DEPT MICROBIOL & IMMUNOL, COLUMBIA, SC 29209 USA. RI Wunschel, David/F-3820-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 45 TC 92 Z9 93 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1996 VL 68 IS 21 BP 3705 EP 3712 DI 10.1021/ac960689j PG 8 WC Chemistry, Analytical SC Chemistry GA VQ157 UT WOS:A1996VQ15700008 PM 8914480 ER PT J AU Valentine, TE Mihalczo, JT AF Valentine, TE Mihalczo, JT TI MCNP-DSP: A neutron and gamma ray Monte Carlo calculation of source-driven noise-measured parameters SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID FISSION; CF-252 AB The Cf-252-source-driven noise analysis measurement method was developed to determine the subcriticality and other properties of configurations of fissile material. The method provides measured parameters that can also be used for nuclear weapons identification, nuclear materials control and accountability, quality assurance, process monitoring, and verification of calculation models and cross section data used for criticality safety analyses. MCNP-DSP was developed to calculate the measured frequency analysis parameters, time analysis quantities such as autocorrelation and cross-correlation functions, and the time distribution of counts after Cf-252 fission for both neutrons and/or gamma rays using continuous energy cross sections. MCNP-DSP can be used to validate calculational methods and cross section data sets with measured data from subcritical experiments. In most cases the frequency analysis parameters are more sensitive to cross section changes by as much as 1 or 2 orders of magnitude and thus may be more useful than comparisons of neutron multiplication factors for calculational validation. The use of MCNP-DSP model in place of point kinetics model to interpret subcritical experiments extends the usefulness of this measurement method to systems with much lower neutron multiplication factors. MCNP-DSP can also be used to determine the calculational bias in the neutron multiplication factor (a quantity which is essential to the criticality safety specialist) from in-plant subcritical experiments. This paper describes how MCNP-DSP calculates the measured parameters from the Cf-252-source-driven time and frequency analysis measurement. RP Valentine, TE (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. OI Valentine, Timothy/0000-0001-7495-7348 NR 34 TC 17 Z9 18 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD NOV PY 1996 VL 23 IS 16 BP 1271 EP 1287 DI 10.1016/0306-4549(96)00004-7 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA UU968 UT WOS:A1996UU96800001 ER PT J AU Boreman, GD Dogariu, A Christodoulou, C Kotter, D AF Boreman, GD Dogariu, A Christodoulou, C Kotter, D TI Modulation transfer function of antenna-coupled infrared detector arrays SO APPLIED OPTICS LA English DT Article DE infrared detector; bolometer; antenna; focal-plane array; image quality; modulation transfer function ID IMAGE AB Individual antenna-coupled IR bolometers have recently been demonstrated at wavelengths near 10 mu m. If focal-plane arrays (FPA's) of antenna-coupled detectors can be fabricated, enhancement of IR-imager performance is possible. A first step in the design process is to analyze the image-quality potential of antenna-coupled, FPA-based imagers in terms of the modulation transfer function (MTF). The key step in our analysis is development of a cross-talk MTF that accounts for the electromagnetic coupling between adjacent antennas in the FPA. We find that electromagnetic cross talk will not be a significant image-quality factor in antenna-coupled IR FPA's. (C) 1996 Optical Society of America C1 LOCKHEED MARTIN CORP,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP Boreman, GD (reprint author), UNIV CENT FLORIDA,DEPT ELECT ENGN,CTR RES & EDUC OPT & LASERS,ORLANDO,FL 32816, USA. NR 18 TC 6 Z9 6 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1996 VL 35 IS 31 BP 6110 EP 6114 DI 10.1364/AO.35.006110 PG 5 WC Optics SC Optics GA VP971 UT WOS:A1996VP97100002 PM 21127627 ER PT J AU Moller, KD Warren, JB Heaney, JB Kotecki, C AF Moller, KD Warren, JB Heaney, JB Kotecki, C TI Cross-shaped bandpass filters for the near- and mid-infrared wavelength regions SO APPLIED OPTICS LA English DT Article DE infrared filters; bandpass filters produced by photolithography AB A photolithographic process has been used to form cross-shaped patterns in 3-mu m-thick nickel foils. Patterns with cross arm dimensions in the 10-20-mu m range, and with periodicities in the 16-26-mu m range, yield self-resonant bandpass filters for wavelengths in the 20-25-mu m region. Transmittances as high as 80% were achieved with center wavelength-to-bandwidth ratios (lambda(R)/Delta lambda) of similar to 5. We present a simple empirical formula that relates the wavelength of peak transmittance, or resonant frequency, with cross dimensions and periodicity. (C) 1996 Optical Society of America C1 BROOKHAVEN NATL LAB,DIV INSTRUMENTAT,UPTON,NY 11973. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Moller, KD (reprint author), NEW JERSEY INST TECHNOL,DEPT PHYS,NEWARK,NJ 07102, USA. NR 6 TC 16 Z9 16 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1996 VL 35 IS 31 BP 6210 EP 6215 DI 10.1364/AO.35.006210 PG 6 WC Optics SC Optics GA VP971 UT WOS:A1996VP97100017 PM 21127642 ER PT J AU Hill, SC Saleheen, HI Barnes, MD Whitten, WB Ramsey, JM AF Hill, SC Saleheen, HI Barnes, MD Whitten, WB Ramsey, JM TI Modeling fluorescence collection from single molecules in microspheres: Effects of position, orientation, and frequency SO APPLIED OPTICS LA English DT Article DE fluorescence; single-molecule detection; spheres ID SPONTANEOUS-EMISSION RATES; DIELECTRIC MICROSPHERES; OPTICAL CAVITIES; SMALL PARTICLES; MICRODROPLETS; SCATTERING; MICROPARTICLE; RHODAMINE-6G; RADIATION; RESONANCE AB We present calculations of fluorescence from single molecules (modeled as damped oscillating dipoles) inside a dielectric sphere. For an excited molecule at an arbitrary position within the sphere we calculate the fluorescence intensity collected by an objective in some well-defined detection geometry. We find that, for the cases we model, integration over the emission linewidth of the molecule is essential for obtaining representative results. Effects such as dipole position and orientation, numerical aperture of the collection objective, sphere size, emission wavelength, and linewidth are examined. These results are applicable to single-molecule detection techniques employing microdroplets. (C) 1996 Optical Society of America C1 NEW MEXICO STATE UNIV,DEPT ELECT & COMP ENGN,LAS CRUCES,NM 88003. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Hill, SC (reprint author), USA,RES LAB,2800 POWDER MILL RD,ADELPHI,MD 20783, USA. NR 31 TC 31 Z9 31 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD NOV 1 PY 1996 VL 35 IS 31 BP 6278 EP 6288 DI 10.1364/AO.35.006278 PG 11 WC Optics SC Optics GA VP971 UT WOS:A1996VP97100029 PM 21127654 ER PT J AU Conrad, S Mullins, DR Xin, QS Zhu, XY AF Conrad, S Mullins, DR Xin, QS Zhu, XY TI Thermal and photochemical deposition of sulfur on GaAs(100) SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Symposium on Atomically Controlled Surfaces and Interfaces CY OCT 12-14, 1995 CL RALEIGH, NC ID GAAS(001) SURFACE; GAAS 100; PASSIVATION; ADSORPTION; PHOTOEMISSION; DIFFRACTION; GAAS(111)A; SULFIDE; AES AB The interaction of sulfur with GaAs(100) is of great interest due to its importance in surface passivation. We have investigated the thermal and photochemical deposition of sulfur on GaAs(100) from H2S using synchrotron radiation soft X-ray photoelectron spectroscopy (SXPS). The deposition of S can be achieved by exposing GaAs(100) to H2S at substrate temperatures greater than or equal to 550 K, a result of the irreversible dissociation of H2S on the surface. Both the rate and extent of sulfur deposition can be greatly enhanced by UV laser or white light synchrotron radiation. Heating of sulfur covered GaAs(100) to greater than or equal to 700 K results in a well ordered (2 x 1) surface reconstruction, as indicated by low energy electron diffraction (LEED). This high temperature stabilized surface is characterized by two well defined states of sulfur, both bonded to Ga atoms. One state can be attributed to surface gallium sulfide while the other to sub-surface sulfur which evidently replaces As atoms. This interpretation is supported by the observation that the As/Ga ratio, as determined by the 3p SXPS peak intensities, decreases linearly with increasing sulfur coverage. The implication of this study for improved GaAs surface passivation is addressed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. SO ILLINOIS UNIV,DEPT CHEM,CARBONDALE,IL 62901. NR 30 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD NOV PY 1996 VL 107 BP 145 EP 152 DI 10.1016/S0169-4332(96)00499-0 PG 8 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA VV197 UT WOS:A1996VV19700025 ER PT J AU Deupree, RG AF Deupree, RG TI A reexamination of the core helium flash SO ASTROPHYSICAL JOURNAL LA English DT Article DE convection; hydrodynamics; stars, interiors ID 3-DIMENSIONAL NUMERICAL SIMULATIONS; FLOW; CONVECTION; STARS; MODEL AB The possibility of a dynamical core helium flash has been studied with two-dimensional hydrodynamic simulations using three separate turbulence models for the treatment of time-dependent convection. Two of these are simple algebraic eddy viscosity models. The third model involves a separate equation for the turbulent kinetic energy density, which then feeds into an expression for the eddy viscosity. One of the simple eddy viscosity models is that used by Cole & Deupree in studies of the core helium flash about fifteen years ago. I find that this model can be made to produce a more quiescent flash than Cole & Deupree found by substantially reducing the eddy viscosity from their value. When this is done, all three turbulence models produce the same primary result-the hash does not produce a hydrodynamic event. However, the traditional assumption of adiabatic convection through the flash evolution is found in all cases to be inadequate, primarily through the extensive heating of the region interior to the convective region. RP Deupree, RG (reprint author), LOS ALAMOS NATL LAB,DX-7,MS-P947,LOS ALAMOS,NM 87545, USA. NR 30 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 NOV 1 PY 1996 VL 471 IS 1 BP 377 EP 384 DI 10.1086/177976 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VP223 UT WOS:A1996VP22300029 ER PT J AU McCarthy, PJ Kapahi, VK vanBreugel, W Persson, SE Athreya, RM Subrahmanya, CR AF McCarthy, PJ Kapahi, VK vanBreugel, W Persson, SE Athreya, RM Subrahmanya, CR TI The Molonglo Reference Catalog/1 Jansky radio source survey .1. Radio galaxy identifications SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies, photometry; quasars, general; radio continuum, galaxies; surveys ID PARKES SELECTED REGIONS; HIGH-REDSHIFT; OPTICAL IDENTIFICATIONS; COMPLETE SAMPLE; SOURCE COUNTS; COSMOLOGICAL EVOLUTION; CLUSTER ENVIRONMENTS; PHOTOMETRIC SYSTEM; COSMIC EPOCH; POWERFUL AB This is the first in a series of papers discussing the properties of a complete set of radio sources selected near S-408 - 1 Jy. We present optical or infrared identifications for a sample of 452 radio galaxies. The sources were selected from the 408 MHz Molonglo Reference Catalog, restricted only by flux density and position on the sky, as follows: S-408 greater than or equal to 0.95 Jy and -30 degrees < decl. (1950) < -20 degrees, and 9(h)20(m) < R.A.(1950) < 14(h)4(m) or 20(h)20(m) < R.A.(1950) < 6(h)14(m). This complete sample, the MRC/1 Jy survey, contains 558 radio galaxies or quasars, of which six are occulted by bright stars or galaxies and two are multiple confused sources. Of the remaining 550 sources, 527, or 96%, are identified to an r magnitude of 25, and eight additional sources are identified to K = 19. Of the 17 unocculted objects that remain unidentified, 15 are sources for which we have either poor radio maps or inadequate optical/IR images. This paper presents finding charts and astrometric positions for the 452 sources that are not identified as either quasars or BL Lacertae objects. Magnitudes in the r passband accurate to typically 0.1 mag are given for 353 of the radio galaxy identifications. Redshifts for 268 of the galaxies are also listed; these have been derived from 450 spectroscopic observations. The radio observations, quasar and BL Lac identifications, spectroscopy, and near-IR images will be presented in subsequent papers in this series. C1 TIFR,NATL CTR RADIO ASTROPHYS,PUNE 411007,MAHARASHTRA,INDIA. INST GEOPHYS & PLANETARY PHYS,LLNL,LIVERMORE,CA 94551. RP McCarthy, PJ (reprint author), CARNEGIE INST WASHINGTON OBSERV,813 SANTA BARBARA ST,PASADENA,CA 91101, USA. RI Subramanya, C/D-4898-2012; Astronomy & Astrophysics Group, Raman Res Institute/D-4046-2012 NR 55 TC 71 Z9 71 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD NOV PY 1996 VL 107 IS 1 BP 19 EP & DI 10.1086/192353 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF467 UT WOS:A1996WF46700002 ER PT J AU Loveday, J Peterson, BA Maddox, SJ Efstathiou, G AF Loveday, J Peterson, BA Maddox, SJ Efstathiou, G TI The Stromlo-APM Redshift Survey .4. The Redshift Catalog SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; galaxies, distances and redshifts; surveys; techniques, radial velocities ID LARGE-SCALE STRUCTURE; COLD DARK MATTER; GALAXY REDSHIFTS; EXTRAGALACTIC OBJECTS; STATISTICAL-ANALYSIS; LUMINOSITY FUNCTION; UNIVERSE; DENSITY; 2-POINT; REDUCTION AB The Stromlo-APM Redshift Survey consists of 1797 galaxies with b(J) less than or equal to 17.15 selected randomly at a rate of 1 in 20 from automated plate measurement (APM) scans. The survey covers a solid angle of 1.3 sr (4300 deg(2)) in the south Galactic cap. Redshifts have been measured for 1790 (99.6%) of the galaxies. The median galaxy recession velocity is 15,300 km s(-1), and so the volume probed is V approximate to 1.38 x 10(6) h(-3) Mpc(3). In this paper we describe the construction of the redshift catalog and present the survey data. C1 AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. ROYAL GREENWICH OBSERV,CAMBRIDGE CB3 0EZ,ENGLAND. UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. RP Loveday, J (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. OI Maddox, Stephen/0000-0001-5549-195X NR 33 TC 57 Z9 57 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD NOV PY 1996 VL 107 IS 1 BP 201 EP 214 DI 10.1086/192360 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF467 UT WOS:A1996WF46700009 ER PT J AU LiScholz, A Raman, S Scholz, W AF LiScholz, A Raman, S Scholz, W TI Katharine Way - In memoriam SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Item About an Individual C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP LiScholz, A (reprint author), SUNY ALBANY,DEPT PHYS,1400 WASHINGTON AVE,ALBANY,NY 12222, USA. NR 1 TC 0 Z9 0 U1 2 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD NOV PY 1996 VL 64 IS 2 BP R5 EP R5 DI 10.1006/adnd.1996.0020 PG 1 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA VZ367 UT WOS:A1996VZ36700001 ER PT J AU Mori, K Hatamochi, A Ueki, H Olsen, A Jimenez, SA AF Mori, K Hatamochi, A Ueki, H Olsen, A Jimenez, SA TI The transcription of human alpha 1(1) procollagen gene (COL1A1) is suppressed by tumour necrosis factor-alpha through proximal short promoter elements: Evidence for suppression mechanisms mediated by two nuclear-factor-binding sites SO BIOCHEMICAL JOURNAL LA English DT Article ID GROWTH-FACTOR-BETA; CIS-ACTING ELEMENT; COLLAGEN GENE; DNA-BINDING; MESSENGER-RNAS; I PROCOLLAGEN; FIBROBLASTS; EXPRESSION; PURIFICATION; INVITRO AB Recent studies have demonstrated that tumour necrosis factor-alpha (TNF-alpha) decreases alpha 1(I) procollagen gene (COL1A1) expression in cultured human dermal fibroblasts. The purpose of this study was to analyse the transcriptional control of COL1A1 by TNF-alpha. Cultured human dermal fibroblasts were transiently transfected with plasmids containing 5' flanking sequences of COL1A1 fused to the chloramphenicol acetyltransferase (CAT) gene, and were incubated for 48 h in medium with or without TNF-alpha. TNF-alpha inhibited the CAT activity of fibroblasts transfected with plasmids containing 2,3 kb of 5' flanking sequences of COL1A1, whereas the activity of control plasmids containing the herpes simplex thymidine kinase promoter gene (pBLCAT) was unaltered. A series of deletion constructs or various small substitution mutations of the COL1A1 5' flanking region fused to the CAT gene were also transfected, and CAT activity was measured after incubation with TNF-alpha. TNF-alpha suppressed COL1A1 promoter activity through proximal short promoter elements containing only 107 bp. Short substitution mutations between -101 and -97bp or between -46 and -38bp abolished TNF-alpha suppression of COL1A1 promoter activity. DNA-protein complex formation was observed involving both sites in gel retardation assays. These results suggest that TNF-alpha suppressed COL1A1 promoter activity through elements located between -101 and -97 bp and between -46 and -38 bp of the COL1A1 promoter, and that the suppression involved DNA-protein interactions. C1 KAWASAKI MED UNIV,DEPT DERMATOL,KURASHIKI,OKAYAMA,JAPAN. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550. THOMAS JEFFERSON UNIV,JEFFERSON MED COLL,DEPT MED,DIV RHEUMATOL,PHILADELPHIA,PA 19107. FU NIADDK NIH HHS [AM 19616] NR 34 TC 22 Z9 23 U1 0 U2 0 PU PORTLAND PRESS PI LONDON PA 59 PORTLAND PLACE, LONDON, ENGLAND W1N 3AJ SN 0264-6021 J9 BIOCHEM J JI Biochem. J. PD NOV 1 PY 1996 VL 319 BP 811 EP 816 PN 3 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VT077 UT WOS:A1996VT07700021 PM 8920984 ER PT J AU Livshits, MA Mirzabekov, AD AF Livshits, MA Mirzabekov, AD TI Theoretical analysis of the kinetics of DNA hybridization with gel-immobilized oligonucleotides SO BIOPHYSICAL JOURNAL LA English DT Article ID DUPLEXES; ARRAYS; STABILITY AB A new method of DNA sequencing by hybridization using a microchip containing a set of immobilized oligonucleotides is being developed. A theoretical analysis is presented of the kinetics of DNA hybridization with deoxynucleotide molecules chemically tethered in a polyacrylamide gel layer. The analysis has shown that long-term evolution of the spatial distribution and of the amount of DNA bound in a hybridization cell is governed by ''retarded diffusion,'' i.e., diffusion of the DNA interrupted by repeated association and dissociation with immobile oligonucleotide molecules. Retarded diffusion determines the characteristic time of establishing a final equilibrium state in a cell, i.e., the state with the maximum quantity and a uniform distribution of bound DNA. In the case of cells with the most stable, perfect duplexes, the characteristic lime of retarded diffusion (which is proportional to the equilibrium binding constant and to the concentration of binding sites) can be longer than the duration of the real hybridization procedure. This conclusion is indirectly confirmed by the observation of nonuniform fluorescence of labeled DNA in perfect-match hybridization cells (brighter at the edges), For optimal discrimination of perfect duplexes from duplexes with mismatches the hybridization process should be brought to equilibrium under low-temperature nonsaturation conditions for all cells, The kinetic differences between perfect and nonperfect duplexes in the gel allow further improvement in the discrimination through additional washing at low temperature after hybridization. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Livshits, MA (reprint author), RUSSIAN ACAD SCI,VA ENGELHARDT MOL BIOL INST,32 VAVILOV ST,MOSCOW 117984,RUSSIA. RI Livshits, Mikhail/P-6744-2015 OI Livshits, Mikhail/0000-0001-8027-2273 NR 25 TC 88 Z9 94 U1 0 U2 9 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1996 VL 71 IS 5 BP 2795 EP 2801 PG 7 WC Biophysics SC Biophysics GA VQ520 UT WOS:A1996VQ52000050 PM 8913616 ER PT J AU Lee, I Evans, BR Lane, LM Woodward, J AF Lee, I Evans, BR Lane, LM Woodward, J TI Substrate-enzyme interactions in cellulase systems SO BIORESOURCE TECHNOLOGY LA English DT Article; Proceedings Paper CT IEA Symposium on Biotechnology for the Conversion of Lignocellulosics at the Pacifichem Meeting of the Pacific Rim Chemistry Societies CY 1995 CL HI SP Int Energy Agcy DE cellulase; cellobiohydrolase I; palladium inactivation; cotton fiber disruption; atomic force microscopy ID TRICHODERMA-REESEI; CELLOBIOHYDROLASE-I; BINDING DOMAIN; SYNERGISM; PALLADIUM; PROTEIN AB The interaction between catalytically active and inactive Trichoderma reesei cellulase components and cotton fibers has been examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cellobiohydrolase I (CBH I), the major component, was rendered catalytically inactive by its treatment with ammonium hexachloropalladate; however the inactive enzyme still had the ability to bind to the cotton fiber SEM and AFM provided evidence suggesting that the catalytic activity of CBH I was required for fiber disruption, AFM allowing resolution of cotton fibers to the microfibril level. However, at high magnification slightly elongated holes were observed throughout the surface of the microfibrillar surface of cotton fibers treated with inactivated CBH I. No disruption of cotton fibers was observed by a palladium-inactivated CBH II/EG II mixture. RP Lee, I (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. NR 22 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD NOV PY 1996 VL 58 IS 2 BP 163 EP 169 DI 10.1016/S0960-8524(96)00095-8 PG 7 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA WG398 UT WOS:A1996WG39800008 ER PT J AU Nguyen, QA Dickow, JH Duff, BW Farmer, JD Glassner, DA Ibsen, KN Ruth, MF Schell, DJ Thompson, IB Tucker, MP AF Nguyen, QA Dickow, JH Duff, BW Farmer, JD Glassner, DA Ibsen, KN Ruth, MF Schell, DJ Thompson, IB Tucker, MP TI NREL/DOE ethanol pilot-plant: Current status and capabilities SO BIORESOURCE TECHNOLOGY LA English DT Article; Proceedings Paper CT IEA Symposium on Biotechnology for the Conversion of Lignocellulosics at the Pacifichem Meeting of the Pacific Rim Chemistry Societies CY 1995 CL HI SP Int Energy Agcy DE biomass; bioconversion; enzyme; ethanol; fermentation; lignocellulose; pilot-plant; pretreatment; SSF AB The National Renewable Energy Laboratory (NREL) has built and operated a pilot-plant to convert lignocellulosic feedstocks to ethanol for the U.S. Department of Energy (DOE). The process development unit (PDU) has a designed throughput of I ton (dry basis)/day of biomass and is equipped to handle a variety of feedstocks. Major processing systems include feedstock milling, pretreatment, simultaneous saccharification and fermentation (SSF), and ethanol distillation. Several experimental runs have been successfully completed since the startup of the plant in March 1995. The plant capabilities are continually being improved to meet the needs of our industrial partners and to facilitate NREL's process development work. This paper reports on various aspects of commissioning and operations, the present capabilities, and plans for use of the facility. Copyright (C) 1997 Elsevier Science Ltd. RP Nguyen, QA (reprint author), NATL RENEWABLE ENERGY LAB,ALTERNAT FUELS DIV,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 23 TC 30 Z9 31 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD NOV PY 1996 VL 58 IS 2 BP 189 EP 196 DI 10.1016/S0960-8524(96)00098-3 PG 8 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA WG398 UT WOS:A1996WG39800011 ER PT J AU Fu, LL Smith, RD AF Fu, LL Smith, RD TI Global ocean circulation from satellite altimetry and high-resolution computer simulation SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GENERAL-CIRCULATION; DATA ASSIMILATION; GULF-STREAM; GEOSAT; SEA; TOPEX/POSEIDON; MODEL; ATLANTIC; MONSOON; PACIFIC AB The sea surface elevation relative to the geoid, a dynamic boundary condition for the three-dimensional oceanic pressure field, is being determined over the global ocean every 10 days by a precision radar altimeter aboard the TOPEX/POSEIDON satellite. This is the most accurate altimeter data stream to date for the study of the ocean general circulation and its variability. The authors compare results from 2 years (October 1992-0ctober 1994) of the satellite observations to computer simulations for the same period using a state-of-the-art ocean general circulation model driven by realistic winds from an atmospheric weather-prediction model. The average horizontal resolution of the model is 1/5 degrees (varying from 30 km at the equator to 6 km at the polar latitudes), the highest for a global simulation performed to date. Comparisons of the mean circulation, the mesoscale variability, the amplitude, and phase of the annual cycle, as well as intraseasonal and interannual changes show that the simulations and observations agree fairly well over a broad range of temporal and spatial scares. However, the sea level variance produced by the model is generally less than the observation by a factor of 2, primarily in the eddy-rich regions. Comparison of wavenumber spectra indicates that even higher spatial resolution is needed to fully resolve the mesoscale eddies. The absolute dynamic topography determined from either the data or the model has an error on the order of 10 cm at wavelengths larger than 2000 km. Geoid errors are the limiting factor for the utility of the altimeter data at smaller scales. Heat flux forcing is a key factor in determining the simulated annual cycle of the ocean Improved agreement with the observation is achieved when the model is driven by heat flux forcing instead of being nudged to sea surface temperature climatology The temporal evolution of the intraseasonal fluctuations at mid- and high latitudes as well as the interannual variability of the tropical oceans, both are primarily wind driven, is simulated fairly well by the model. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Fu, LL (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 46 TC 92 Z9 94 U1 3 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1996 VL 77 IS 11 BP 2625 EP 2636 DI 10.1175/1520-0477(1996)077<2625:GOCFSA>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VW729 UT WOS:A1996VW72900001 ER PT J AU Bruce, FR AF Bruce, FR TI No Chernobyls here SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Letter RP Bruce, FR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD NOV-DEC PY 1996 VL 52 IS 6 BP 63 EP 63 PG 1 WC International Relations; Social Issues SC International Relations; Social Issues GA VQ169 UT WOS:A1996VQ16900023 ER PT J AU Bisoffi, M Stephens, ND Chakerian, AE Fore, ML Bryant, JE Moyzis, RK Griffith, JK AF Bisoffi, M Stephens, ND Chakerian, AE Fore, ML Bryant, JE Moyzis, RK Griffith, JK TI Effect of telomerase inhibition on telomerase activity, telomere length and growth properties of human tumor cell lines. SO CANCER GENE THERAPY LA English DT Meeting Abstract C1 UNIV NEW MEXICO,DEPT BIOCHEM,HLTH SCI CTR,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,CANC RES & TREATMENT CTR,HLTH SCI CTR,ALBUQUERQUE,NM 87131. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU APPLETON & LANGE PI E NORWALK PA 25 VAN ZANT ST, E NORWALK, CT 06855 SN 0929-1903 J9 CANCER GENE THER JI Cancer Gene Ther. PD NOV-DEC PY 1996 VL 3 IS 6 SU S BP P99 EP P99 PG 1 WC Biotechnology & Applied Microbiology; Oncology; Genetics & Heredity; Medicine, Research & Experimental SC Biotechnology & Applied Microbiology; Oncology; Genetics & Heredity; Research & Experimental Medicine GA WC571 UT WOS:A1996WC57100099 ER PT J AU Woloschak, GE Paunesku, T Libertin, CR ChangLiu, CM Churchill, M Panozzo, J Grdina, D Gemmell, MA Giometti, C AF Woloschak, GE Paunesku, T Libertin, CR ChangLiu, CM Churchill, M Panozzo, J Grdina, D Gemmell, MA Giometti, C TI Regulation of thymus PCNA expression is altered in radiation-sensitive wasted mice SO CARCINOGENESIS LA English DT Article ID CELL NUCLEAR ANTIGEN; ATAXIA-TELANGIECTASIA; 2-DIMENSIONAL ELECTROPHORESIS; IMMUNOLOGICAL ABNORMALITIES; IONIZING-RADIATION; MOLECULAR-CLONING; REPAIR-DEFICIENT; TISSUE PROTEINS; DNA-REPLICATION; ANIMAL-MODEL AB Mice bearing the autosomal recessive mutation 'wasted' (wst/wst) express a disease syndrome characterized by neurologic dysfunction, immunodeficiency, and increased sensitivity to the killing effects of ionizing radiation relative to normal littermates (wst/*) and to parental control mice (BCF1, BALB/c, and C57BL/6). Many of these abnormalities, evident as early as 21 days of age, have been localized to thymic tissues and T-lymphocyte populations. Comparison of two-dimensional gel electrophoresis patterns of proteins from wst/wst and control mouse thymus revealed that an acidic protein with a molecular mass of approximately 30 kda was consistently expressed at lower levels in wasted mice than in controls, Microsequencing of this protein revealed a sequence of 19 N-terminal amino acids identical to the sequence of murine proliferating cell nuclear antigen (PCNA). Northern blot analyses of PCNA expression in thymus and spleen demonstrated lower accumulation of PCNA-specific transcripts in wasted mice compared with that in controls, Because PCNA expression is associated with cell cycle progression, the percentages of thymic and splenic cells in each stage of the cell cycle were examined; there were no differences in the cell stage distribution of lymphocytes freshly isolated from wasted mice compared with littermate or parental controls, After activation with concanavalin A, however, splenocytes from wst/wst mice showed a lower percentage of cells in S phase compared with that in controls, Southern blots with PCNA probes showed that the PCNA loci from the wasted mice and their normal littermates have the same restriction maps, While differences in polymerase chain reaction (PCR) priming were obtained, these could be attributed to strain-specific differences in mouse PCNA pseudogenes. These results suggest the presence of an alteration in the pathway leading to PCNA expression in radiation-sensitive tissues of wasted mice. C1 LOYOLA UNIV,DEPT PATHOL,MAYWOOD,IL 60153. LOYOLA UNIV,DEPT MED,MAYWOOD,IL 60153. RP Woloschak, GE (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Paunesku, Tatjana/A-3488-2017; Woloschak, Gayle/A-3799-2017 OI Paunesku, Tatjana/0000-0001-8698-2938; Woloschak, Gayle/0000-0001-9209-8954 FU NCI NIH HHS [CA37435] NR 51 TC 5 Z9 5 U1 0 U2 1 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD NOV PY 1996 VL 17 IS 11 BP 2357 EP 2365 DI 10.1093/carcin/17.11.2357 PG 9 WC Oncology SC Oncology GA VW458 UT WOS:A1996VW45800012 PM 8968049 ER PT J AU Ophoff, RA Terwindt, GM Vergouwe, MN vanEijk, R Oefner, PJ Hoffman, SMG Lamerdin, JE Mohrenweiser, HW Bulman, DE Ferrari, M Haan, J Lindhout, D vanOmmen, GJB Hofker, MH Ferrari, MD Frants, RR AF Ophoff, RA Terwindt, GM Vergouwe, MN vanEijk, R Oefner, PJ Hoffman, SMG Lamerdin, JE Mohrenweiser, HW Bulman, DE Ferrari, M Haan, J Lindhout, D vanOmmen, GJB Hofker, MH Ferrari, MD Frants, RR TI Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+ channel gene CACNL1A4 SO CELL LA English DT Article ID HYPOKALEMIC PERIODIC PARALYSIS; CALCIUM-CHANNEL; POINT MUTATIONS; SKELETAL-MUSCLE; SEROTONIN; BRAIN; MAPS; DNA; HETEROGENEITY; MAGNESIUM AB Genes for familial hemiplegic migraine (FHM) and episodic ataxia type-2 (EA-2) have been mapped to chromosome 19p13. We characterized a brain-specific P/Q-type Ca2+ channel alpha 1-subunit gene, CACNL1A4, covering 300 kb with 47 exons. Sequencing of all exons and their surroundings revealed polymorphic variations, including a (CA)(n)-repeat (D19S1150), a (CAG)(n)-repeat in the 3'-UTR, and different types of deleterious mutations in FHM and EA-2. In FHM, we found four different missense mutations in conserved functional domains. One mutation has occurred on two different haplotypes in unrelated FHM families. In EA-2, we found two mutations disrupting the reading frame. Thus, FHM and EA-2 can be considered as allelic channelopathies. A similar etiology may be involved in common types of migraine. C1 LEIDEN UNIV HOSP,DEPT NEUROL,NL-2333 AL LEIDEN,NETHERLANDS. STANFORD UNIV,DEPT GENET,STANFORD,CA 94305. LAWRENCE LIVERMORE NATL LAB,BBRP,LIVERMORE,CA 94550. LONDON HLTH SCI CTR,DEPT CLIN NEUROL SCI,LONDON,ON N6A 5A5,CANADA. IRCCS S RAFFAELE,CLIN MOL BIOL LAB,I-20132 MILAN,ITALY. ERASMUS UNIV ROTTERDAM,MGC,DEPT CLIN GENET,NL-3000 DR ROTTERDAM,NETHERLANDS. RP Ophoff, RA (reprint author), LEIDEN UNIV,MGC,DEPT HUMAN GENET,SYLVIUS LAB,WASSENAARSEWEG 72,NL-2333 AL LEIDEN,NETHERLANDS. RI Ferrari, Maurizio/D-9107-2013; Oefner, Peter/K-1116-2016; OI Oefner, Peter/0000-0002-1499-3977; Lindhout, Dick/0000-0001-9580-624X NR 49 TC 1538 Z9 1580 U1 47 U2 90 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD NOV 1 PY 1996 VL 87 IS 3 BP 543 EP 552 DI 10.1016/S0092-8674(00)81373-2 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VQ466 UT WOS:A1996VQ46600019 PM 8898206 ER PT J AU Sugama, T AF Sugama, T TI Hot alkali carbonation of sodium metaphosphate modified fly ash calcium aluminate blend hydrothermal cements SO CEMENT AND CONCRETE RESEARCH LA English DT Article ID PHOSPHATE CEMENTS; NA2CO3-LADEN WATER AB Sodium metaphosphate-modified fly ash/calcium aluminate blend (SFCB) cements were prepared by autoclaving for 1 day at 300 degrees C and their resistance was evaluated in a highly concentrated Na2CO3 solution at 300 degrees C. The hydroxyapatite and analcime phases formed in the autoclaved SFCB cements prayed an essential role in conferring resistance to the degradation of cements caused by alkali carbonation. Although the carbonating reaction of the analcime phase led to the formation of cancrinite, this analcime cancrinite transformation did not show any influence on the changes in the mechanical and physical properties of the cements. Additionally, there was no formation of the water-soluble calcium bicarbonate in the cements exposed for 28 days. Contrarily, the conventional class G cement systems were very vulnerable to a hot alkali carbonation. The major reason for the damage caused by carbonation of the cements was the fact that the xonotlite phase formed in the 300 degrees autoclaved cements was converted into two carbonation products, calcite and pectolite. Furthermore, the reaction between calcite and carbonic acid derived from Na2CO3 led to the formation of water-soluble calcium bicarbonate, thereby causing the alteration of dense structures into porous ones and the loss of strength of cements. Copyright (C) 1996 Elsevier Science Ltd RP Sugama, T (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,ENERGY EFFICIENCY & CONSERVAT DIV,UPTON,NY 11973, USA. NR 10 TC 8 Z9 8 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD NOV PY 1996 VL 26 IS 11 BP 1661 EP 1672 DI 10.1016/S0008-8846(96)00160-3 PG 12 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA VT316 UT WOS:A1996VT31600006 ER PT J AU Nguyen, HD Paik, S Douglass, RW Pop, I AF Nguyen, HD Paik, S Douglass, RW Pop, I TI Unsteady non-Darcy reaction-driven flow from an anisotropic cylinder in porous media SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE reaction-driven flow; porous media; Forschheimer drag; Brinkman corrections; spectral methods ID FREE-CONVECTION; NATURAL-CONVECTION; HORIZONTAL CYLINDER; CIRCULAR-CYLINDER; CHEMICAL-REACTION; BOUNDARY-LAYERS; SURFACE; STABILITY AB This paper reports a theoretical study of thermal convection in a fluid-saturated porous medium generated by a surface reaction. The convective phenomena driven by temperature gradients, via heat release from an nth-order irreversible reaction, are modeled by the Brinkman-Forschheimer equation including the Boussinesq-Oberbeck approximations together with the energy and species equations. Solutions are obtained by a Fourier spectral element method in conjunction with a semi-implicit method combining the second-order Adams-Bashforth and first-order backward Euler schemes for advancing the solution in time. Numerical results indicate a strong influence of natural convection on the physicochemical process. Effects due to non-Darcy flow are significant for Rayleigh number on the order of 10(6) and that symmetry about theta = pi persists even for anisotropic materials unless the off-diagonal entry of the thermal conductivity tensor is nonzero. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV CLUJ,FAC MATH,R-3400 CLUJ NAPOCA,ROMANIA. RP Nguyen, HD (reprint author), IDAHO NATL ENGN LAB,POB 1625,MS 3808,IDAHO FALLS,ID 83415, USA. NR 20 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD NOV PY 1996 VL 51 IS 22 BP 4963 EP 4977 DI 10.1016/0009-2509(96)00355-7 PG 15 WC Engineering, Chemical SC Engineering GA VP348 UT WOS:A1996VP34800002 ER PT J AU Markovic, N Sewell, TD Nordholm, S Miklavc, A AF Markovic, N Sewell, TD Nordholm, S Miklavc, A TI An improved classical approach quantum encounter treatment of collision-induced vibrational energy transfer. Application to He+CO (n(i)=1,2) SO CHEMICAL PHYSICS LA English DT Article ID LOG-DERIVATIVE METHOD; INELASTIC-COLLISIONS; CROSS-SECTIONS; AR-HCL; POLYATOMIC-MOLECULES; RATE CONSTANTS; ATOM-DIATOM; HE ATOMS; RELAXATION; SCATTERING AB The vibrational energy transfer in a three-dimensional molecular collision is assumed, in the recently published Classical Approach Quantum Encounter (CAQE) theory [J. Chem. Phys. 99 (1993) 2567], to occur in a brief and sharply defined encounter which can be formulated in terms of an effectively one-dimensional atom-diatomic collision, with the parameters for the encounter reflecting the local features of the potential in the neighborhood of the collision geometry. Here we describe improvements to the original CAQE theory. A mathematical recasting renders the theory more conducive to use with accurate quantum encounter methods. The first-order distorted wave Born approximation that was used in the original CAQE theory is here replaced by a numerically exact one-dimensional encounter method. We illustrate the need for the new method using collinear calculations for Ar + HCl and He + CO, and then apply it using a log-derivative method in a three-dimensional calculation of single and multiple quantum vibrational cross sections for He + CO The results are judged by comparison to the results of coupled states and semiclassical calculations, with good agreement being obtained for all conditions over a wide range of energies. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NATL INST CHEM,LJUBLJANA 61115,SLOVENIA. RP Markovic, N (reprint author), CHALMERS UNIV TECHNOL,DEPT PHYS CHEM,S-41296 GOTHENBURG,SWEDEN. RI Nordholm, Sture/A-8506-2010 NR 50 TC 4 Z9 4 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD NOV 1 PY 1996 VL 211 IS 1-3 BP 277 EP 290 DI 10.1016/0301-0104(96)00230-3 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VR360 UT WOS:A1996VR36000023 ER PT J AU North, SW Sears, TJ Hall, GE Suzuki, T AF North, SW Sears, TJ Hall, GE Suzuki, T TI Energy partitioning in photodissociation of methyl, ethyl, and n-propyl iodides at 304 nm - Comment SO CHEMICAL PHYSICS LA English DT Editorial Material ID 248 NM; DIODE-LASER; CH3I; PHOTOFRAGMENTATION; SPECTROSCOPY; DYNAMICS; CD3I C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. INST MOL SCI,OKAZAKI,AICHI 444,JAPAN. RI Sears, Trevor/B-5990-2013; North, Simon/G-5054-2012; Hall, Gregory/D-4883-2013 OI Sears, Trevor/0000-0002-5559-0154; North, Simon/0000-0002-0795-796X; Hall, Gregory/0000-0002-8534-9783 NR 15 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD NOV 1 PY 1996 VL 211 IS 1-3 BP 515 EP 516 DI 10.1016/0301-0104(96)00211-X PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VR360 UT WOS:A1996VR36000046 ER PT J AU Yachandra, VK Sauer, K Klein, MP AF Yachandra, VK Sauer, K Klein, MP TI Manganese cluster in photosynthesis: Where plants oxidize water to dioxygen SO CHEMICAL REVIEWS LA English DT Review ID OXYGEN-EVOLVING COMPLEX; RAY-ABSORPTION-SPECTROSCOPY; ELECTRON-PARAMAGNETIC-RESONANCE; PHOTOSYSTEM-II PREPARATION; SYNECHOCYSTIS SP PCC-6803; DOUBLE-PIVOT MECHANISM; AMINO-ACID-RESIDUES; O-2-EVOLVING COMPLEX; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURE C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 200 TC 840 Z9 850 U1 15 U2 93 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD NOV PY 1996 VL 96 IS 7 BP 2927 EP 2950 DI 10.1021/cr950052k PG 24 WC Chemistry, Multidisciplinary SC Chemistry GA VT053 UT WOS:A1996VT05300020 ER PT J AU Antonio, MR Staub, U Xue, JS Soderholm, L AF Antonio, MR Staub, U Xue, JS Soderholm, L TI Comparison of the cation valence and coordination in Ce2UO6 and Ce2MoO6 SO CHEMISTRY OF MATERIALS LA English DT Article ID X-RAY-ABSORPTION; BISMUTH MOLYBDATE CATALYSTS; TRANSITION-METAL COMPOUNDS; NEUTRON POWDER DIFFRACTION; NEAR-EDGE STRUCTURE; MAGNETIC-SUSCEPTIBILITIES; MOLYBDENUM COMPOUNDS; OCTAHEDRAL SYMMETRY; CRYSTAL-STRUCTURE; PARTIAL OXIDATION AB Ce2UO6 and Ce2MoO6 have both been suggested to have significant charge transfer between the metal ions. To quantify this proposed charge transfer, the valence and coordination of cerium and uranium in Ce2UO6 as well as cerium and molybdenum in Ce2MoO6 were studied through a combination of K-, L-, and M-edge XAFS (X-ray absorption fine structure). The results clearly show that these two compounds are not isostructural. Whereas Ce and U in Ce2UO6 are found to disorder on a single site, consistent with the formation of the solid solution Ce0.67U0.33O2, the Ce and Mo coordination is very different. The Mo sits on a site with tetrahedral coordination. The XANES (X-ray absorption near edge structure) data show that for Ce2UO6, Ce and U are both tetravalent, whereas for Ce2MoO6, Ce is trivalent and Mo is hexavalent. There is no evidence in either compound for any significant charge transfer or intermediate valence. The unusual physical properties exhibited by these materials are discussed in light of these findings. RP Antonio, MR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Staub, Urs/C-4914-2015; OI Antonio, Mark/0000-0002-1208-4534 NR 78 TC 17 Z9 17 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD NOV PY 1996 VL 8 IS 11 BP 2673 EP 2680 DI 10.1021/cm960208c PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VT993 UT WOS:A1996VT99300021 ER PT J AU Narula, CK Allison, JE Bauer, DR Gandhi, HS AF Narula, CK Allison, JE Bauer, DR Gandhi, HS TI Advanced materials for automobiles SO CHEMTECH LA English DT Article C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. FORD MOTOR CO,DEPT MAT SCI,RES LAB,DEARBORN,MI 48121. RP Narula, CK (reprint author), FORD MOTOR CO,DEPT CHEM,SCI RES LAB,POB 2053,DEARBORN,MI 48121, USA. NR 0 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2703 J9 CHEMTECH JI Chemtech PD NOV PY 1996 VL 26 IS 11 BP 48 EP 60 PG 13 WC Chemistry, Applied SC Chemistry GA VQ899 UT WOS:A1996VQ89900010 ER PT J AU Miller, BD Alderman, EL Haskell, WL Fair, JM Krauss, RM AF Miller, BD Alderman, EL Haskell, WL Fair, JM Krauss, RM TI Predominance of dense low-density lipoprotein particles predicts angiographic benefit of therapy in the stanford coronary risk intervention project SO CIRCULATION LA English DT Article DE angiography; atherosclerosis; coronary disease; drugs; lipoproteins ID LIPID-LOWERING THERAPY; ARTERY DISEASE; MYOCARDIAL-INFARCTION; APOLIPOPROTEIN-B; ATHEROSCLEROSIS-REGRESSION; TRIGLYCERIDE-RICH; LDL SUBFRACTIONS; BYPASS GRAFTS; HEART-DISEASE; MEN AB Background LDL particles differ in size and density. Individuals with LDL profiles that peak in relatively small, dense particles have been reported to be at increased risk of coronary artery disease. We hypothesized that response to coronary disease therapy in such individuals might differ from response in individuals whose profiles peak in larger, more buoyant LDL. We examined this hypothesis in the Stanford Coronary Risk Intervention Project, an angiographic trial that compared multifactorial risk-reduction intervention with the usual care of physicians. Methods and Results For 213 men, a bimodal frequency distribution of peak LDL density (g/mL) determined by analytical ultracentrifugation was used to classify baseline LDL profiles as ''buoyant mode'' (density less than or equal to 1.0378) or ''dense mode'' (density >1.0378). Coronary disease progression after 4 years was assessed by rates of change (mm/y, negative tn hen arteries narrow) of minimum artery diameter. Rates for buoyant-mode subjects were -0.038+/-0.007 (mean+/-SEM) in usual care (n=65) and -0.039+/-0.010 in intervention (n=56; P=.5). Rates for dense-mode subjects were -0.054+/-0.012 in usual care (n=51) and -0.008+/-0.009 in intervention (n=41, P=.007). Lipid changes did not account for this difference in angiographic response. Conclusions Different types of LDL profile may predict different responses to specific therapies, perhaps because metabolic processes determine both LDL profiles and responses to therapies. C1 UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY NATL LAB,DONNER LAB,DIV LIFE SCI,BERKELEY,CA 94720. STANFORD UNIV,SCH MED,PALO ALTO,CA 94304. FU NHLBI NIH HHS [HL-18574, R01-HL-33577] NR 31 TC 119 Z9 120 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 NOV 1 PY 1996 VL 94 IS 9 BP 2146 EP 2153 PG 8 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN754 UT WOS:A1996VN75400020 PM 8901665 ER PT J AU SeguretMace, S LattaMahieu, M Castro, G Luc, G Fruchart, JC Rubin, E Denefle, P Duverger, N AF SeguretMace, S LattaMahieu, M Castro, G Luc, G Fruchart, JC Rubin, E Denefle, P Duverger, N TI Potential gene therapy for lecithin-cholesterol acyltransferase (LCAT)-deficient and hypoalphalipoproteinemic patients with adenovirus-mediated transfer of human LCAT gene SO CIRCULATION LA English DT Article DE genes; lipoproteins; cholesterol; lecithin cholesterol acyltransferase; fatty acids ID APOLIPOPROTEIN-A-I; HIGH-DENSITY-LIPOPROTEIN; FRACTIONAL CATABOLIC RATE; GRADIENT GEL-ELECTROPHORESIS; TRANSGENIC MICE; PARTICLE-SIZE; PRE-BETA; TRANSFER PROTEIN; PLASMA; EXPRESSION AB Background Overexpression of human lecithin-cholesterol acyltransferase (LCAT) in transgenic mice results in an increase of the antiatherogenic HDLs. Methods and Results To investigate the potential use of LCAT for gene therapy, a recombinant adenovirus was constructed in which the human LCAT cDNA Was expressed under the control of the human cytomegalovirus immediate/early promoter followed by a chimeric intron (AdCMV human LCAT). Human apolipoprotein (ape) A-I transgenic mice infected with AdCMV human LCAT by intravenous injection accumulated reactive LCAT in the plasma. LCAT activity was increased 201-fold in the plasma of mice infected with 1X10(9) pfu AdCMV human LCAT, from 45+/-2 to 9068+/-812 nmol . mL(-1). h(-1), in comparison with basal LCAT activity measured in control mice, 5 days after injection. Plasma HDL cholesterol levels rose from 117+/-12 to 797+/-48 mg/dL, and plasma human apo A-I concentrations increased from 247+/-14 to 616+/-17 mg/dL, in AdCMV human LCAT-infected mice compared with control mice. HDL particles were larger and had a different electrophoretic mobility. Studies of cholesterol efflux by incubation of serum with cholesterol-loaded Fu5AH cells showed that serum from AdCMV human LCAT-infected mice promoted a significantly higher efflux than did that of the controls. Conclusions These data establish the potential of this approach for treatment of subjects with LCAT gene defects as well as patients with low plasma levels of apo A-I and HDL cholesterol. C1 RHONE POULENC RORER,GENCELL DIV,ATHEROSCLEROSIS DEPT,CTR RECH VITRY ALFORTVILLE,F-94403 VITRY SUR SEINE,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. INST PASTEUR,INSERM 325,F-59019 LILLE,FRANCE. NR 41 TC 35 Z9 35 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 NOV 1 PY 1996 VL 94 IS 9 BP 2177 EP 2184 PG 8 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA VN754 UT WOS:A1996VN75400024 PM 8901669 ER PT J AU Trnovsky, J Weier, HU Ferrante, A McGrath, P AF Trnovsky, J Weier, HU Ferrante, A McGrath, P TI Flow cytometric sorting of chromosomes encapsulated in agarose gel microdrops after in situ hybridization. SO CLINICAL CHEMISTRY LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD NOV PY 1996 VL 42 IS 11 BP 46 EP 46 PG 1 WC Medical Laboratory Technology SC Medical Laboratory Technology GA VQ332 UT WOS:A1996VQ33200083 ER PT J AU Burtis, CA AF Burtis, CA TI Converging technologies and their impact on the clinical laboratory SO CLINICAL CHEMISTRY LA English DT Article DE clinical chemistry; technological change; laboratory management; computers; miniaturization; system; integration; molecular diagnostics; distributed computing; telecommunications ID POLYMERASE CHAIN-REACTION; IN-SITU HYBRIDIZATION; HUMAN GENOME PROJECT; NEURAL NETWORKS; MICROCHIP ELECTROPHORESIS; ARTIFICIAL-INTELLIGENCE; MOLECULAR-BIOLOGY; WHOLE-BLOOD; HEALTH-CARE; SILICON AB Rapid technological change is transforming the world in which we live. Because laboratory services are defined by available products and tools of technology, this ''technological revolution'' is having a significant and profound effect on how clinical laboratories are organized, staffed, equipped, and operated. In this review, I discuss individually and collectively the advances and developments being made in the general areas of measurement, digital, communication, and transportation technology and demonstrate how the convergence of the products evolving from these technologies is affecting the clinical laboratory. C1 OAK RIDGE NATL LAB,DIV HLTH,OAK RIDGE,TN 37831. RP Burtis, CA (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,POB 2008,OAK RIDGE,TN 37831, USA. NR 241 TC 9 Z9 10 U1 0 U2 0 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD NOV PY 1996 VL 42 IS 11 BP 1735 EP 1749 PG 15 WC Medical Laboratory Technology SC Medical Laboratory Technology GA VQ332 UT WOS:A1996VQ33200003 PM 8906071 ER PT J AU Abramson, D Foster, I Michalakes, J Sosic, R AF Abramson, D Foster, I Michalakes, J Sosic, R TI Relative debugging: A new methodology for debugging scientific applications SO COMMUNICATIONS OF THE ACM LA English DT Article C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RP GRIFFITH UNIV, NATHAN, QLD 4111, AUSTRALIA. NR 10 TC 15 Z9 15 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 2 PENN PLAZA, STE 701, NEW YORK, NY 10121-0701 USA SN 0001-0782 EI 1557-7317 J9 COMMUN ACM JI Commun. ACM PD NOV PY 1996 VL 39 IS 11 BP 69 EP 77 DI 10.1145/240455.240475 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VR306 UT WOS:A1996VR30600016 ER PT J AU Tsang, RP Keattithananant, P Chang, TS Hsieh, JW Du, DHC AF Tsang, RP Keattithananant, P Chang, TS Hsieh, JW Du, DHC TI Dynamic resource control for continuous media traffic over ATM networks SO COMPUTER COMMUNICATIONS LA English DT Article DE Asynchronous Transfer Mode (ATM); dynamic traffic control; resource management; rate control; Real-time Variable Bit Rate traffic; continuous media traffic AB Real-time continuous media traffic, such as digital video and audio, is expected to comprise a large percentage of the network load on future high speed packet switch networks such as ATM. A major feature which distinguishes high speed networks from traditional slower speed networks is the large amount of data the network must process very quickly. For efficient network usage, traffic control mechanisms are essential. Currently, most mechanisms for traffic control (such as flow control) have centered on the support of Available Bit Rate (ABR), i.e, non real-time traffic. Traffic control for continuous media traffic is an inherently difficult problem due to the time-sensitive nature of the traffic and its unpredictable bit rate variability. In this study, we present a scheme which controls traffic by dynamically allocating/de-allocating resources among competing VCs based upon their real-time requirements. This scheme incorporates a form of rate-control, real-time burst-level scheduling and link-link flow control. We show analytically potential performance improvements of our rate-control scheme, and present a scheme for buffer dimensioning. We also present simulation results of our schemes and discuss the trade-offs inherent in maintaining high network utilization and statistically guaranteeing many users' Quality of Service. C1 MINIST SCI TECHNOL & ENVIRONM,NATL ELECT & COMP TECHNOL CTR,INFORMAT SUPERHIGHWAY TESTBED,BANGKOK,THAILAND. UNIV MINNESOTA,DEPT COMP SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DISTRIBUTED MULTIMEDIA RES CTR,MINNEAPOLIS,MN 55455. RP Tsang, RP (reprint author), SANDIA NATL LABS,DISTRIBUTED INFORMAT TECHNOL CTR,LIVERMORE,CA 94551, USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD NOV PY 1996 VL 19 IS 13 BP 1092 EP 1111 DI 10.1016/S0140-3664(96)01136-X PG 20 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA WB098 UT WOS:A1996WB09800007 ER PT J AU Kaeding, TA Williams, HT AF Kaeding, TA Williams, HT TI Program for generating tables of SU(3)superset of SU(2)circle times U(1) coupling coefficients SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE SU(3); Clebsch-Gordan coefficients; Wigner coefficients; vector coupling coefficients; isoscalar factors ID CLEBSCH-GORDAN-COEFFICIENTS; SYMMETRY PROPERTIES; SU(3) AB A C-Language program which tabulates the isoscalar factors and Clebsch-Gordan coefficients for products of representations in SU(3) superset of SU(2) x U(1) is presented. These are efficiently computed using recursion relations, and the results are presented in exact precision as square roots of rational numbers. Output is in LaTeX format. C1 WASHINGTON & LEE UNIV,DEPT PHYS,LEXINGTON,VA 24450. RP Kaeding, TA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 29 TC 14 Z9 14 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 NOV PY 1996 VL 98 IS 3 BP 398 EP 414 DI 10.1016/0010-4655(96)00085-9 PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA VQ329 UT WOS:A1996VQ32900009 ER PT J AU Walker, DW Otto, SW AF Walker, DW Otto, SW TI Redistribution of block-cyclic data distributions using MPI SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB Arrays that are distributed in a block-cyclic fashion are important for many applications in the computational sciences since they often lead to parallel algorithms with good load balancing properties, We consider the problem of redistributing such an array to a new black size. This operation is directly expressible in High Performance Fortran (HPF) and will arise in applications written in this language, Efficient message passing algorithms are given for the redistribution operation, expressed in the standardized message passing interface, MPI, The algorithms are analyzed and performance results from the IBM SP-1 and Intel Paragon are given and discussed. The results show that redistribution can be done in time comparable to other collective communication operations, such as broadcast and MPI_ALLTOALL. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. OREGON GRAD INST,DEPT COMP SCI & ENGN,BEAVERTON,OR 97291. RI Walker, David/B-7978-2010; OI Walker, David/0000-0002-1360-6330 NR 11 TC 36 Z9 36 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD NOV PY 1996 VL 8 IS 9 BP 707 EP 728 DI 10.1002/(SICI)1096-9128(199611)8:9<707::AID-CPE269>3.0.CO;2-V PG 22 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VM803 UT WOS:A1996VM80300004 ER PT J AU Fang, Y Danyluk, S Lanagan, MT AF Fang, Y Danyluk, S Lanagan, MT TI Effects of cracks on critical current density in Ag-sheathed superconductor tape SO CRYOGENICS LA English DT Article DE high-T-c superconductors; crack effect; critical current density ID STRAIN TOLERANCE; SILVER AB The effect of partial cracking on critical current density (J(c)) has been modelled for Ag-sheathed superconductor tapes. Effects of crack length and density on current-voltage characteristics and J(c) were evaluated for monofilament and multifilament tapes. The results show that a single long crack is more harmful than numerous small cracks. Multiple small partial cracks (less than 20% of core dimension) can be present in the Bi2Sr2Can-1CunO2n+4 (BSCCO) before J(c) degradation is observed. In general, a multifilament tape can withstand cracks better than a monofilament tape. (C) 1996 Elsevier Science Limited C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Fang, Y (reprint author), GEORGIA INST TECHNOL,GEORGE W WOODRUFF SCH MECH ENGN,ATLANTA,GA 30332, USA. NR 16 TC 26 Z9 26 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD NOV PY 1996 VL 36 IS 11 BP 957 EP 962 DI 10.1016/S0011-2275(96)00069-0 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA VM812 UT WOS:A1996VM81200009 ER PT J AU Tinoco, I AF Tinoco, I TI RNA enzymes: Putting together a large ribozyme SO CURRENT BIOLOGY LA English DT Article ID HAMMERHEAD RIBOZYME; SEQUENCE AB The crystal structure of a 160-nucleotide domain of a ribozyme provides the first detailed view of an RNA large enough to show side-by-aids packing of helices. Several new structural motifs are found: ribose zippers, adenosine platforms and a tetraloop receptor. C1 LAWRENCE BERKELEY NATL LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. RP Tinoco, I (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 12 TC 6 Z9 7 U1 0 U2 3 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 NOV 1 PY 1996 VL 6 IS 11 BP 1374 EP 1376 DI 10.1016/S0960-9822(96)00734-8 PG 3 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VT119 UT WOS:A1996VT11900011 PM 8939599 ER PT J AU Superko, HR AF Superko, HR TI Lipid disorders contributing to coronary heart disease: An update SO CURRENT PROBLEMS IN CARDIOLOGY LA English DT Review ID LOW-DENSITY-LIPOPROTEIN; APOLIPOPROTEIN-E POLYMORPHISM; MONITORED ATHEROSCLEROSIS REGRESSION; FAMILIAL DYSLIPIDEMIC HYPERTENSION; PRIMARY-PREVENTION TRIAL; SUBCLASS PATTERN-A; LDL PARTICLE-SIZE; ARTERY DISEASE; MYOCARDIAL-INFARCTION; RISK FACTOR C1 CHOLESTEROL GENETICS & HEART DIS INST,REDWOOD CITY,CA. RP Superko, HR (reprint author), UNIV CALIF BERKELEY,CHOLESTEROL RES CTR,LAWRENCE ORLANDO BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 202 TC 0 Z9 0 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0146-2806 J9 CURR PROB CARDIOLOGY JI Curr. Probl. Cardiol. PD NOV PY 1996 VL 21 IS 11 BP 738 EP 780 PG 47 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA VW237 UT WOS:A1996VW23700002 ER PT J AU Deka, C Lehnert, BE Lehnert, NM Jones, GM Sklar, LA Steinkamp, JA AF Deka, C Lehnert, BE Lehnert, NM Jones, GM Sklar, LA Steinkamp, JA TI Analysis of fluorescence lifetime and quenching of FITC-conjugated antibodies on cells by phase-sensitive flow cytometry SO CYTOMETRY LA English DT Article DE quenching; fluorescence lifetime; phase-shift; phase-sensitive; fluorescence intensity ID COMPLEMENT PROTEIN-C9; ENERGY-TRANSFER; POLYMERIZATION; SPECTROSCOPY; ACQUISITION AB Fluorescent antibodies are often used to measure the number of receptor sites on cells, The quantitative estimate of the number of receptor sites using this procedure assumes that the fluorescence intensity on a cell is proportional to the number of bound antibodies, Quenching may invalidate this assumption, For many fluorophores, intermolecular interactions and energy transfer between molecules in close proximity to one another result in self-quenching, This effect can occur in antibody probes with a high fluorochrome to protein (F/P) ratio. It can also occur due to close proximity of antibodies relative to one another on a highly labelled cell surface, Since self-quenching is accompanied by a change in the fluorescence decay and a decrease in the fluorescence lifetime, it may be conveniently identified using fluorescence lifetime spectroscopy, In this paper we apply the phase-sensitive detection method to investigate the impact of self-quenching on fluorescence lifetimes by flow cytometry, using a model system consisting of FITC conjugated anti-mouse Thy1.2 antibodies bound to murine thymus cells, We show that in addition to the expected variation of lifetimes as a function of F/P ratio of the probes, the fluorescence lifetime diminishes also as a function of antibody labelling concentration on the cell surface, This is consistent with self-quenching effects expected at high densities of FITC molecules. (C) 1996 Wiley-Liss, Inc. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM. UNIV NEW MEXICO,SCH MED,ALBUQUERQUE,NM 87131. FU NCRR NIH HHS [R01-RR07855RR01315]; NIGMS NIH HHS [GM37696] NR 18 TC 52 Z9 53 U1 3 U2 16 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD NOV 1 PY 1996 VL 25 IS 3 BP 271 EP 279 DI 10.1002/(SICI)1097-0320(19961101)25:3<271::AID-CYTO8>3.0.CO;2-I PG 9 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VR314 UT WOS:A1996VR31400008 PM 8914824 ER PT J AU Burde, S Joss, G Gonzalez, JA Coulon, CH Park, MS Deaven, LL Marrone, BL AF Burde, S Joss, G Gonzalez, JA Coulon, CH Park, MS Deaven, LL Marrone, BL TI Interactive computer-aided assignment of multiple probes to cytogenetic bands by simultaneous dual color fluorescence in situ hybridization and DAPI banding SO CYTOMETRY LA English DT Article DE fluorescence in situ hybridization; human chromosome 11; image cytometry; physical mapping; cytogenetics ID INSITU HYBRIDIZATION; HUMAN CHROMOSOME-11; MICROSCOPY AB A macro function was developed to run in conjunction with the popular image analysis package NM Image, to allow simultaneous determination of mapping positions of one or two separate probes with respect to cytogenetic bands by dual color fluorescence in situ hybridization (FISH) and DAPI banding, and by determination of their fractional distance from pter (FLpter). In order to allow maximal flexibility, a user-defined line along the chromosome is used for measurements, Algorithms were developed to detect the ends of the chromosome and the cytogenetic bands, Results of the analysis are presented ia graphical form, comprising a display of the DAPI intensity along the chromesome, the positions of the probe(s), the locations of bands as determined by analysis of the second derivative of the DAPI intensity profile, and a standard ideogram of the chromosome for comparison, The approach was validated and compared to visual assignment of probes to DAPI bands using the cosmid clone PYGM, which has been previously mapped to chromosome 11q13, and has been used as a landmark for mapping of other probes (3). (C) 1996 Wiley-Liss, Inc. C1 MACQUARIE UNIV,SCH BIOL SCI,N RYDE,NSW,AUSTRALIA. RP Burde, S (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,CYTOMETRY GRP LS5,M888,LOS ALAMOS,NM 87545, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-4763 J9 CYTOMETRY JI Cytometry PD NOV 1 PY 1996 VL 25 IS 3 BP 295 EP 300 DI 10.1002/(SICI)1097-0320(19961101)25:3<295::AID-CYTO11>3.0.CO;2-R PG 6 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VR314 UT WOS:A1996VR31400011 PM 8914827 ER PT J AU Cardinale, GF Howitt, DG McCarty, KF Medlin, DL Mirkarimi, PB Moody, NR AF Cardinale, GF Howitt, DG McCarty, KF Medlin, DL Mirkarimi, PB Moody, NR TI Analysis of residual stress in cubic boron nitride thin films using micromachined cantilever beams SO DIAMOND AND RELATED MATERIALS LA English DT Article DE cubic boron nitride (cBN); residual stress; mechanical properties; micromachined cantilever beams ID PULSED-LASER DEPOSITION; ION PLATING METHOD; BN; MODULUS AB We have investigated the residual stress of cubic boron nitride (cBN) thin films using a cantilever-beam deflection method. The residual stresses were determined by measuring the deflection of cantilever beams micromachined from (100)-oriented silicon, and the hardness and elastic modulus of sp(2)-bonded BN (sp(2)-BN) were determined from nanoindentation experiments. Residual stresses were compressive, and varied from approximately 0.15 GPa to 1.2 GPa for sp(2)-BN films and from 0.5 to 5.5 GPa for cBN-containing films; the lower stresses are below a threshold stress level for cBN formation previously suggested by McKenzie et al. A correlation between the relative cBN content and the compressive film stress was also established: larger residual stresses occurred in the films containing a greater percentage of the cubic phase. We find that both sp(2)-BN and predominantly cBN films have approximately the same elastic strain. Thus, assuming that the strain is independent of composition, we develop a quantitative model that well describes the observed correlation of compressive firm stress with cBN content. Within the model, the film stress increases with increasing cBN content simply because the elastic modulus of cBN is substantially larger than that of sp(2)-BN. The relevance of this analysis to the mechanism of cBN formation is discussed. C1 SANDIA NATL LABS, LIVERMORE, CA 95550 USA. RP UNIV CALIF DAVIS, DEPT CHEM ENGN & MAT SCI, DAVIS, CA 95616 USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 37 TC 62 Z9 62 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 EI 1879-0062 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD NOV PY 1996 VL 5 IS 11 BP 1295 EP 1302 DI 10.1016/0925-9635(96)00541-9 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA VH528 UT WOS:A1996VH52800011 ER PT J AU Costanza, R ONeill, RV AF Costanza, R ONeill, RV TI Introduction: Ecological economics and sustainability SO ECOLOGICAL APPLICATIONS LA English DT Editorial Material DE ecological economics; ecological vs economic models; economic growth; Homo sapiens; interdependence and interrelatedness; sustainability C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Costanza, R (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. RI Costanza, Robert/A-4912-2008 OI Costanza, Robert/0000-0001-6348-8734 NR 4 TC 1 Z9 2 U1 0 U2 7 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1996 VL 6 IS 4 BP 975 EP 977 DI 10.2307/2269580 PG 3 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA VR856 UT WOS:A1996VR85600001 ER PT J AU ONeill, RV AF ONeill, RV TI Perspectives on economics and ecology SO ECOLOGICAL APPLICATIONS LA English DT Article DE ecology and economics, merger of; economic ecology; economics as part of global ecosystem; human impacts; input-output systems; pollution central and economic incentives; population control, human; scales of impact; sustainability AB This paper was prepared as concluding remarks presented at a symposium, ''Ecological economics: building a new paradigm for sustainability,'' organized by R. Costanza and R. V. O'Neill and held at the 7-11 August 1994 annual meeting of the Ecological Society of America. RP ONeill, RV (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 7 Z9 8 U1 2 U2 2 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1996 VL 6 IS 4 BP 1031 EP 1033 DI 10.2307/2269586 PG 3 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA VR856 UT WOS:A1996VR85600007 ER PT J AU Dixon, P Ellison, AM AF Dixon, P Ellison, AM TI Introduction: Ecological applications of Bayesian inference SO ECOLOGICAL APPLICATIONS LA English DT Article DE Bayesian inference; data analysis; decision-making; statistics; uncertainty C1 MT HOLYOKE COLL,DEPT BIOL,S HADLEY,MA 01075. RP Dixon, P (reprint author), SAVANNAH RIVER ECOL LAB,AIKEN,SC, USA. OI Ellison, Aaron/0000-0003-4151-6081 NR 13 TC 19 Z9 19 U1 1 U2 13 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1996 VL 6 IS 4 BP 1034 EP 1035 DI 10.2307/2269587 PG 2 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA VR856 UT WOS:A1996VR85600008 ER PT J AU Turner, MG Wear, DN Flamm, RO AF Turner, MG Wear, DN Flamm, RO TI Land ownership and land-cover change in the southern Appalachian highlands and the Olympic peninsula SO ECOLOGICAL APPLICATIONS LA English DT Article DE land use; land-cover change; landscape ecology; Olympic Peninsula; remote sensing; southern Appalachians; spatial analysis ID LANDSCAPE PATTERNS; FOREST LANDSCAPE; DYNAMICS; MANAGEMENT; GEORGIA AB Social and economic considerations are among the most important drivers of landscape change, yet few studies have addressed economic and environmental influences on landscape structure, and how land ownership may affect landscape dynamics. Watersheds in the Olympic Peninsula, Washington, and the southern Appalachian highlands of western North Carolina were studied to address two questions: (1) Does landscape pattern vary among federal, state, and private lands? (2) Do land-cover changes differ among owners, and if so, what variables explain the propensity of land to undergo change on federal, state, and private lands? Landscape changes were studied between 1975 and 1991 by using spatial databases and a time series of remotely sensed imagery. Differences in landscape pattern were observed between the two study regions and between different categories of land ownership. The proportion of the landscape in forest cover was greatest in the southern Appalachians for both U.S. National Forest and private lands, compared to any landownership category on the Olympic Peninsula. Greater variability in landscape structure through time and between ownership categories was observed on the Olympic Peninsula. On the Olympic Peninsula, landscape patterns did not differ substantially between commercial forest and state Department of Natural Resources lands, both of which are managed for timber, but differed between U.S. National Forest and noncommercial private land ownerships. In both regions, private lands contained less forest cover but a greater number of small forest patches than did public lands. Analyses of land-cover change based on multinomial legit models revealed differences in land-cover transitions through time, between ownerships and between the two study regions. Differences in land-cover transitions between time intervals suggested that additional factors (e.g., changes in wood products or agricultural prices, or changes in laws or policies) cause individuals or institutions to change land management. The importance of independent variables (slope, elevation, distance to roads and markets, and population density) in explaining land-cover change varied between ownerships. This methodology for analyzing land-cover dynamics across land units that encompass multiple owner types should be widely applicable to other landscapes. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. FOREST SERV,USDA,FORESTRY SCI LAB,RES TRIANGLE PK,NC 27709. RI Turner, Monica/B-2099-2010 NR 51 TC 194 Z9 202 U1 4 U2 41 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1996 VL 6 IS 4 BP 1150 EP 1172 DI 10.2307/2269599 PG 23 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA VR856 UT WOS:A1996VR85600020 ER PT J AU Yang, SY Stock, LM AF Yang, SY Stock, LM TI Base-catalyzed hydrogenation: Reduction of polycyclic aromatic compounds SO ENERGY & FUELS LA English DT Article ID HYDRODESULFURIZATION CATALYSTS; GAS-PHASE; HYDRODENITROGENATION; HYDROCARBONS AB Dihydrogen can be activated by lithium and potassium organoamides, particularly the diisopropyl and bis(trimethylsilyl) derivatives, to reduce aromatic compounds at 1000 psig and 200 degrees C. Naphthalene was hydrogenated to tetralin in 100% yield by both reagents; anthracene was reduced with the bis(trimethylsilyl)amide catalyst to a mixture of the corresponding monocyclic aromatic derivatives, 1,2,3,4,4a,9,10,10a-octahydroanthracene (15%) and 1,2,3,4,5,6,7,8-octahydroanthracene (84%); phenanthrene was reduced with this base to a mixture of 1,2,3,4,5,6,7,8-octahydrophenanthrene (63%), 1,2,3,4,4a,9,10,10a-octahydrophenanthrene (33%), and 1,2,3,4-tetrahydrophenanthrene (4%); chrysene was converted by the same reagent to 1,2,2a,3,4,5,6,6a,9,10,11,12-dodecahydrochrysene (70%) and 1,2,2a,3,4,5,6,6a-octahydrochrysene (25%); and 1,2-benzanthracene was hydrogenated to a mixture of dihydro- and dodecahydro-1,2-benzanthracenes. The reaction products show a striking selectivity for the preservation of an interior benzene ring. The catalytic properties of the strong bases depend on the nature of the organic ligands in the dialkylamide and the corresponding metal cations. The reactions proceed at modest pressures, about 500 psig, but require high temperatures, about 200 degrees C. The products of the reaction with dideuterium were investigated by magnetic resonance spectroscopy to define the reaction pathway. The results of these experiments and other available information suggest that hydrogen is transferred from an anionic dihydrogen-dialkylamide complex to the aromatic compound in the slow step of the reaction. C1 UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 34 TC 6 Z9 6 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1996 VL 10 IS 6 BP 1181 EP 1186 DI 10.1021/ef960095j PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA VV056 UT WOS:A1996VV05600006 ER PT J AU White, CM Rohar, PC Shaw, LJ Collins, LW AF White, CM Rohar, PC Shaw, LJ Collins, LW TI Formation of dimethyl polysulfides via reaction of methanol and elemental sulfur SO ENERGY & FUELS LA English DT Article AB Dimethyl polysulfides have been reported in the supercritical methanol extracts of coal and in the pyrolysis products of a high-sulfur Spanish coal that was first extracted with a mixture of dichloromethane and methanol. Dimethyl polysulfides and other products are shown to be formed by the reaction of methanol with elemental sulfur at elevated temperature and pressure. This reaction is a possible source of some of the dimethyl polysulfides observed by others in high-temperature methanol extracts. RP White, CM (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,PITTSBURGH,PA 15236, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1996 VL 10 IS 6 BP 1187 EP 1188 DI 10.1021/ef9600671 PG 2 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA VV056 UT WOS:A1996VV05600007 ER PT J AU Smith, DH Close, MR Grimm, U AF Smith, DH Close, MR Grimm, U TI Mg2Ca(SO4)(3): Correct stoichiometry of the compound previously reported as Mg3Ca(SO4)(4) SO ENERGY & FUELS LA English DT Article AB By elemental analyses of extracts from industrially produced material, X-ray diffraction studies on single crystals and powders, and critical evaluations of the previous literature, it is shown that the compound variously reported or assumed to be Mg3Ca(SO4)(4) in previous studies is actually Mg2Ca(SO4)(3) and that this finding is not only reasonable, but was to be expected. C1 W VIRGINIA UNIV,DEPT CHEM,MORGANTOWN,WV 26506. W VIRGINIA UNIV,DEPT PHYS,MORGANTOWN,WV 26506. RP Smith, DH (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. NR 10 TC 9 Z9 9 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1996 VL 10 IS 6 BP 1241 EP 1244 DI 10.1021/ef9600523 PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA VV056 UT WOS:A1996VV05600016 ER PT J AU Eskay, TP Britt, PF Buchanan, AC AF Eskay, TP Britt, PF Buchanan, AC TI Does decarboxylation lead to cross-linking in low-rank coals? SO ENERGY & FUELS LA English DT Article ID PYROLYSIS; THERMOLYSIS; DEPENDENCE; CONVERSION; RADICALS; BIBENZYL; MODEL AB The pyrolysis of 1,2-(3,3'-dicarboxyphenyl)ethane (1) and 1,2-(4,4'-dicarboxyphenyl)ethane (2) has been investigated between 325 and 425 degrees C as models of free carboxylic acids in low-rank coal to determine if decarboxylation contributes to cross-linking during the thermal processing of low-rank coals. The major reaction pathway from the pyrolysis of 1 and 2 was decarboxylation to pro duce 1-(3-carboxyphenyl)-2-phenylethane and 1-(4-carboxyphenyl)-2-phenylethane. No evidence for aryl-aryl coupling (cross-linking) or high molecular weight products was found, and mass balances were excellent (>97%) even at high conversions (up to 67%). The apparent first-order rate constant for the decarboxylation of 1 to 1-(3-carboxyphenyl)-2-phenylethane was found to be log k (s(-1)) = (9.4 +/- 0.4)-(43 +/- 1)/2.303RT (kcal/mol). It is proposed that the thermal decarboxylation of 1 and 2 proceeds by an acid-promoted, ionic mechanism. The involvement of a free radical decarboxylation pathway was eliminated by the pyrolysis of 1,1,2,2-tetradeuterio-1,2-(3,3'-dicarboxyphenyl)ethane. These results raise into question whether decarboxylation and CO2 evolution are directly related to cross-linking reactions in low-rank coals. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 31 TC 23 Z9 24 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1996 VL 10 IS 6 BP 1257 EP 1261 DI 10.1021/ef960080l PG 5 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA VV056 UT WOS:A1996VV05600019 ER PT J AU Wieringa, MJ Morton, AG AF Wieringa, MJ Morton, AG TI Hydropower, adaptive management, and biodiversity SO ENVIRONMENTAL MANAGEMENT LA English DT Article; Proceedings Paper CT Conference on Managing for Biodiversity - Emerging Ideas for the Electric Utility Industry CY MAR 19-20, 1996 CL WILLIAMSBURG, VA SP Elect Power Res Inst DE adaptive management; biodiversity; hydropower; Glen Canyon Dam; ecology AB Adaptive management is a policy framework within which an iterative process of decision making is followed based on the observed responses to and effectiveness of previous decisions. The use oi adaptive management allows science-based research and monitoring of natural resource and ecological community responses, in conjunction with societal values and goals, to guide decisions concerning man's activities. The adaptive management process has been proposed for application to hydropower operations at Glen Canyon Dam on the Colorado River, a situation that requires complex balancing oi natural resources requirements and competing human uses. This example is representative of the general increase in public interest in the operation of hydropower facilities and possible effects on downstream natural resources and of the growing conflicts between uses and users of river-based resources. This paper describes the adaptive management process, using the Glen Canyon Dam example, and discusses ways to make the process work effectively in managing downstream natural resources and biodiversity. C1 WESTERN AREA POWER ADM,US DEPT ENERGY,CUSTOMER SERV CTR,CRSP,SALT LAKE CITY,UT 84147. RP Wieringa, MJ (reprint author), WESTERN AREA POWER ADM,US DEPT ENERGY,CORP SERV OFF,POB 3402,A3400,GOLDEN,CO 80401, USA. NR 10 TC 12 Z9 12 U1 2 U2 9 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD NOV-DEC PY 1996 VL 20 IS 6 BP 831 EP 840 DI 10.1007/BF01205963 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA VQ941 UT WOS:A1996VQ94100010 ER PT J AU Eiden, GC Hemberger, PH Johnston, RG Nogar, NS AF Eiden, GC Hemberger, PH Johnston, RG Nogar, NS TI Sensing and characterization technologies at Los Alamos National Laboratory SO ENVIRONMENTAL MONITORING AND ASSESSMENT LA English DT Article ID RESONANT LASER-ABLATION; REFRACTIVE-INDEX DETECTOR; ION-TRAP; MASS-SPECTROMETRY; MICROEXTRACTION; DESORPTION AB We describe four sensing and characterization technologies recently developed at Los Alamos National Laboratory; a select set of mass spectral and optical techniques is emphasized. This work describes new, or newly developed, technologies which can be used for on-site, at-line and laboratory analyses. These include two each of optical- and mass spectrometric-based systems. We describe first a field deployable mass spectrometer, based on an ion trap analyzer, and variants of that system. We then describe a hand-held, battery-operated optical spectrometer, usable in either absorption, or fluorescence excitation mode. A laser-based mass spectrometer is also described, which used a minimal tunable laser system, and a time-of-flight mass spectrometer. Finally, a Zeeman effect optical diffractomer is described. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 14 TC 2 Z9 2 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-6369 J9 ENVIRON MONIT ASSESS JI Environ. Monit. Assess. PD NOV PY 1996 VL 43 IS 2 BP 189 EP 200 DI 10.1007/BF00398607 PG 12 WC Environmental Sciences SC Environmental Sciences & Ecology GA VQ210 UT WOS:A1996VQ21000007 PM 24193825 ER PT J AU Chlopecka, A Adriano, DC AF Chlopecka, A Adriano, DC TI Mimicked in-situ stabilization of metals in a cropped soil: Bioavailability and chemical form of zinc SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID EXTRACTION PROCEDURE; CONTAMINATED SOILS; HEAVY-METALS; TRACE-METALS; LEAD; CADMIUM; INACTIVATION; ADSORPTION; CHABAZITE; ZEOLITES AB Agricultural lime, natural zeolite (clinoptilolite), hydroxyapatite, and an iron oxide waste byproduct (Ferich, a trademark name of E. I. du Pont de Nemours) were added to an artificially contaminated Appling silt loam soil to stabilize and limit the uptake of Zn by crops. A greenhouse pot study involved spiking the soil with flue dust (FD) at 0, 150, 300, 600, 1200, and 2400 mg of Zn kg(-1). As much as 40% of the total Zn occurred in an exchangeable form, the form considered most bioavailable to plants, when the pH of the FD-spiked soil was below 6.0, The ameliorants (lime, zeolite, apatite, and Fe-rich) decreased the concentration of the exchangeable form of Zn at each level of FD in soil; however, the largest decrease occurred with the lowest dose. Maize (Zea mays), barley (Hordeum vulgare), and radish (Raphanus sativus) were grown to determine the effects of Zn on the plant growth and Its uptake. The addition of ameliorants to soil enhanced the growth and yield of maize and barley, but only Fe-rich enhanced the growth of radish at all FL) rates. Lime, zeolite, and apatite significantly reduced the Zn concentration in tissues of the 3-week-old maize, in mature maize tissues (roots, young leaves, old leaves, stems, grain), and in barley. The largest reduction (over 80%) in Zn uptake by all crops was effected by Fe-rich, which is consistent with the greatest: reduction in soil-exchangeable Zn by this ameliorant. RP UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, DIV BIOGEOCHEM ECOL, AIKEN, SC 29802 USA. NR 44 TC 114 Z9 129 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD NOV PY 1996 VL 30 IS 11 BP 3294 EP 3303 DI 10.1021/es960072j PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VR631 UT WOS:A1996VR63100046 ER PT J AU Shi, Y Littlejohn, D Chang, SG AF Shi, Y Littlejohn, D Chang, SG TI Integrated tests for removal of nitric: Oxide with iron thiochelate in wet flue gas desulfurization systems SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID NO AB Wet flue gas desulfurization scrubbers can be retrofitted for combined removal of SO2 and NOx from flue gas by adding a newly developed iron(II) thiochelate to limestone slurries. This additive enhances the solubility of NO in limestone slurries by binding NO to form iron nitrosyl thiochelates. The bound NO is then converted to an ammonium ion by iron metal, regenerating the active iron(II) catalyst for continued NO capture. The conditions of the chemical regeneration of iron(II) thiochelate have been studied. This chemical reduction method is efficient, simple, and cost-effective. Integrated tests of this new iron additive on a bench-scale system have been conducted. A turbulent contact absorber was employed to test simultaneous removal of NO and SO2 with iron(II) thiochelate in a limestone slurry. The steady-state NO removal efficiency depends on the operating conditions of an absorber, the iron chelate concentration, the fraction of the flow diverted for regeneration, and the conditions used in the regeneration reactor. The bench-scale test results were used to develop a prediction of the performance of a full-scale spray absorber. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. NR 11 TC 33 Z9 44 U1 3 U2 17 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 NOV PY 1996 VL 30 IS 11 BP 3371 EP 3376 DI 10.1021/es960268j PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VR631 UT WOS:A1996VR63100055 ER PT J AU Ophoff, RA Terwindt, GM Vergouwe, MN vanEijk, R Mohrenweiser, H Litt, M Hofker, MH Haan, J Ferrari, MD Frants, RR AF Ophoff, RA Terwindt, GM Vergouwe, MN vanEijk, R Mohrenweiser, H Litt, M Hofker, MH Haan, J Ferrari, MD Frants, RR TI A 3-Mb region for the familial hemiplegic migraine locus on 19p13.1-p13.2: Exclusion of PRKCSH as a candidate gene SO EUROPEAN JOURNAL OF HUMAN GENETICS LA English DT Article DE familial hemiplegic migraine; chromosome 19p13; genomic structure; protein kinase C substrate 80K-H gene ID PROTEIN KINASE-C; PERIODIC PARALYSIS; POINT MUTATIONS; ATAXIA; MAPS; HETEROGENEITY; NETHERLANDS; 19P13; AURA; DNA AB Familial hemiplegic migraine (FHM) is an autosomal dominant subtype of migraine with attacks, associated with transient episodes of hemiparesis. One of the genes for FHM has been assigned to chromosome 19p13. Detailed analysis of critical recombinants from two different chromosome 19-linked FHM families, using new markers indicated a 6-cM candidate region on 19p13.1-p13.2 flanked by loci D19S394 and D19S226. Another paroxysmal neurological disorder, episodic ataxia type 2 (EA-2), has also been linked to the same chromosomal region. Most of the interval was completely covered by YAC and cosmid contigs; the physical map yielded approximately 3 Mb encompassing several genes including the protein kinase substrate 80K-H (PRKCSH) gene. Since PRKCSH is involved in neuronal signal transduction, it was considered to be an FHM candidate gene. The genomic structure of this gene was established and mutation analysis for all exon and flanking intron sequences was performed in FHM- and EA-2-affected individuals. Five polymorphisms were identified, including a trinucleotide repeat length variation in the coding sequence. However, no potential disease causing mutation was found and therefore the PRKCSH gene can be excluded for both FHM and EA-2. C1 LEIDEN UNIV,MGC DEPT HUMAN GENET,SYLVIUS LAB,NL-2333 AL LEIDEN,NETHERLANDS. LEIDEN UNIV,DEPT NEUROL,NL-2333 AL LEIDEN,NETHERLANDS. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. DEPT BIOCHEM & MED GENET,PORTLAND,OR. RIJNLAND HOSP,DEPT NEUROL,LEIDERDORP,NETHERLANDS. NR 28 TC 10 Z9 11 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1018-4813 J9 EUR J HUM GENET JI Eur. J. Hum. Genet. PD NOV-DEC PY 1996 VL 4 IS 6 BP 321 EP 328 PG 8 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA WG972 UT WOS:A1996WG97200005 PM 9043864 ER PT J AU Sigalas, MM Economou, EN AF Sigalas, MM Economou, EN TI Attenuation of multiple-scattered sound SO EUROPHYSICS LETTERS LA English DT Article ID PERIODIC ELASTIC COMPOSITES; ACOUSTIC BAND-STRUCTURE; SPECTRAL GAPS; WAVES AB We study acoustic waves propagating in two-dimensional (2D) systems consisting of steel cylinders surrounded by air. We use the plane-wave method in order to get the band structure of waves propagating in an infinite periodic system. In addition, we employed, for the first time for acoustic waves, the transfer matrix method in order to find the transmission coefficient of waves propagating along a system with a finite thickness. Both methods are in good agreement with each other and their results agree with recent measurements in a similar system (R. Martinez-Sala et al., Nature, 378 (1995) 241). We also find the optimum conditions for the appearance of spectral gaps. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RES CTR CRETE,IRAKLION 71110,GREECE. UNIV CRETE,DEPT PHYS,IRAKLION,GREECE. RP Sigalas, MM (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Economou, Eleftherios /E-6374-2010 NR 17 TC 104 Z9 111 U1 0 U2 11 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 NOV 1 PY 1996 VL 36 IS 4 BP 241 EP 246 DI 10.1209/epl/i1996-00216-4 PG 6 WC Physics, Multidisciplinary SC Physics GA VR849 UT WOS:A1996VR84900001 ER PT J AU Vikram, CS Pechersky, MJ Feng, C Engelhaupt, D AF Vikram, CS Pechersky, MJ Feng, C Engelhaupt, D TI Residual-stress analysis by local laser heating and speckle-correlation interferometry SO EXPERIMENTAL TECHNIQUES LA English DT Article ID SYSTEM C1 WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC. RP Vikram, CS (reprint author), UNIV ALABAMA,CTR APPL OPT,HUNTSVILLE,AL 35899, USA. NR 20 TC 31 Z9 32 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD NOV-DEC PY 1996 VL 20 IS 6 BP 27 EP 30 DI 10.1111/j.1747-1567.1996.tb00476.x PG 4 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA VW473 UT WOS:A1996VW47300007 ER PT J AU Foley, J Hirsh, DC Pedersen, NC AF Foley, J Hirsh, DC Pedersen, NC TI An outbreak of Clostridium perfringens enteritis in a cattery of Bengal cats and experimental transmission to specific pathogen free cats SO FELINE PRACTICE LA English DT Article ID ENTEROTOXIN; STRAINS; FECES; DOGS AB An outbreak of enteritis with diarrhea, fever, and lethargy was observed in a purebred Bengal cattery. Three kittens developed diarrhea shortly after being introduced to this cattery. All cats were found to be shedding feline coronavirus (FCoV) in their feces (as determined by polymerase chain reaction), but cats with signs of enteritis also shed Clostridium perfringens enterotoxin. As part of an ongoing experiment involving feline coronaviral pathogenesis, four specific pathogen free cats were inoculated with crude fecal extract from this cattery. All tour cats developed fever, malaise, and diarrhea. The donor cat was subsequently shown to be positive for both the FCoV and C. perfringens enterotoxin. Clinical signs in all cats were not responsive to metronidazole, despite favorable in vitro indications, but symptoms did resolve with either clindamycin or amoxycillin/clavulanate therapy. Two cats remained chronic shedders of C. perfringens spores and enterotoxin even after antibiotic therapy. C1 LAWRENCE LIVERMORE NATL LAB,SCH VET MED,DEPT PATHOL MICROBIOL & IMMUNOL,DAVIS,CA 95616. RP Foley, J (reprint author), LAWRENCE LIVERMORE NATL LAB,SCH VET MED,CTR COMPAN ANIM HLTH,DAVIS,CA 95616, USA. NR 15 TC 5 Z9 5 U1 0 U2 3 PU VETERINARY PRACTICE PUBL CO PI IRVINE PA 3 BURROUGHSDR, IRVINE, CA 92618-2804 SN 1057-6614 J9 FELINE PRACT JI Feline Pr. PD NOV-DEC PY 1996 VL 24 IS 6 BP 31 EP 35 PG 5 WC Veterinary Sciences SC Veterinary Sciences GA WA488 UT WOS:A1996WA48800009 ER PT J AU Kardashev, BK Nikanorov, SP Smirnov, BI Lanagan, MT Chen, N Goretta, KK AF Kardashev, BK Nikanorov, SP Smirnov, BI Lanagan, MT Chen, N Goretta, KK TI Internal friction in (BiPb)(2)Sr2Ca2Cu3Oy superconducting ceramics at 6-290 K temperature range SO FIZIKA TVERDOGO TELA LA Russian DT Article ID HIGH-TC SUPERCONDUCTORS; CA-CU-O; SINGLE-CRYSTALS; MAGNETOSTRICTION; DISLOCATIONS; AMPLITUDE C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Kardashev, BK (reprint author), AF IOFFE PHYS TECH INST,POLITEKHNICHESKAYA 26,ST PETERSBURG 194021,RUSSIA. RI Kardashev, Boris/D-2118-2014 NR 28 TC 1 Z9 1 U1 0 U2 0 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0367-3294 J9 FIZ TVERD TELA+ JI Fiz. Tverd. Tela PD NOV PY 1996 VL 38 IS 11 BP 3252 EP 3262 PG 11 WC Physics, Condensed Matter SC Physics GA VZ571 UT WOS:A1996VZ57100007 ER PT J AU Logan, G AF Logan, G TI Session summary and comments for overviews and systems SO FUSION ENGINEERING AND DESIGN LA English DT Editorial Material RP Logan, G (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, L-481, LIVERMORE, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 1 EP 3 DI 10.1016/S0920-3796(96)00443-7 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500002 ER PT J AU Herrmannsfeldt, WB Lee, EP AF Herrmannsfeldt, WB Lee, EP TI Accelerators and beam dynamics SO FUSION ENGINEERING AND DESIGN LA English DT Editorial Material AB In this paper, we review presentations in the areas of heavy ion systems, experiments, and innovative designs. We also cover presentations of basic beam dynamics models and simulations. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Herrmannsfeldt, WB (reprint author), STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 5 EP 9 DI 10.1016/S0920-3796(96)00444-9 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500003 ER PT J AU Tabak, M AF Tabak, M TI Target physics summary SO FUSION ENGINEERING AND DESIGN LA English DT Editorial Material ID ENERGY GAIN; FUSION AB The target physics portion of the Symposium on Heavy ion Fusion is summarized. Target calculations are moving beyond decoupled models to completely integrated calculations. A variety of target topologies were discussed. There is a good theoretical understanding of ignition scaling. Recent experiments have verified our theoretical understanding of atomic opacities and hydrodynamic instability growth. RP Tabak, M (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 15 EP 19 DI 10.1016/S0920-3796(96)00446-2 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500005 ER PT J AU Bangerter, RO AF Bangerter, RO TI The US heavy ion fusion program SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB This paper describes the US Heavy Ion Fusion Program in targets, target chambers and accelerators. It discusses the importance of economics in fusion research in the United States. RP Bangerter, RO (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 23 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 27 EP 32 DI 10.1016/S0920-3796(96)00449-8 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500008 ER PT J AU Moir, RW AF Moir, RW TI Liquid wall inertial fusion energy power plants SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID HYLIFE-II; DESIGN AB Liquid walls interposed between the microexplosions and the chamber structural wall give an inertial fusion energy (IFE) power plant designer flexibility and result in profound advantages. For example, the fusion chamber walls behind the liquid can be made using existing materials (e.g. steel) and last as long as the plant itself without replacement while still meeting non-nuclear-grade construction standards and low level waste requirements. Development can be foreshortened and costs can be reduced by obviating the need for expensive neutron sources to develop first-wall materials. Over the last two decades the idea of using liquid wall protection has been employed in a number of laser, light-ion, and heavy-ion designs, for example, BLASCON, HYLIFE-I, HIBALL, Libra-SP, Cascade, Osiris, HYLIFE-II and others. The liquids found suitable are Li, Flibe (Li2BeF4), and Li17Pb83. The cost of electricity is lowered (depending on how many interior structures need periodic replacement, if any) by as much as 35%, and gives in one case 3.2$ (kW h)(-1) at 2 GW (electric) (4.4$ (kW h)(-1) at 1 GW (electric)). The evolution of ideas illustrated in the designs listed above is reviewed with an emphasis on heavy ion designs. New target designs permit one-sided illumination giving the power plant designer yet more flexibility. It is important to remember that a practical IFE power plant requires, in addition to liquid walls, development of ignition and sufficient gain in targets, low cost, efficient, rep-ratable drivers, and low cost targets. RP Moir, RW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. NR 20 TC 25 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 93 EP 104 DI 10.1016/S0920-3796(96)00456-5 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500015 ER PT J AU Petzoldt, RW Moir, RW AF Petzoldt, RW Moir, RW TI Target injection and tracking for inertial fusion energy SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB In an inertial fusion power plant, several cryogenic targets must be injected each second into a reaction chamber with speeds of about 100 m s(-1). This speed can be achieved with an acceleration in the range from 1000 to 10 000 m s(-2). The total accuracy of driver beam pointing and target position prediction must be less than +/-0.6 mm for a 3 mm beam spot radius. A 0.1 mu m thick dual membrane supporting the capsule in the hohlraum will allow nearly 2000 m s(-2) acceleration. The strength of frozen DT in the capsule is calculated to allow acceleration in excess of 10 000 m s(-2) if the DT temperature is less than 17 K. A gas gun is the preferred device for injecting indirect drive targets owing to its simplicity and proven reliability. The amount of gas required for each target (about 10-100 mg) is acceptable. A revolver loading mechanism is recommendced with a cam-operated poppet valve to control the gas flow. Slots near the muzzle of the gun barrel are recommended to vent gas and thereby to improve accuracy and to aid gas pumping. Optical target tracking and electronic timing devices can predict target arrival time with sufficient accuracy. Target steering by electrostatic deflection of the in-flight target is shown to be feasible and would avoid the need to point the beams actively. Calculations show that induced tumble from electrostatically steering the target is not excessive. An experiment has been designed to develop target injection and to verify the predicted accuracy of sequential injection and tracking of multiple targets. RP Petzoldt, RW (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 113 EP 121 DI 10.1016/S0920-3796(96)00458-9 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500017 ER PT J AU Jameson, RA AF Jameson, RA TI Beam losses and beam halos in accelerators for new energy sources SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Large particle accelerators are proposed as drivers for new ways to produce electricity from nuclear fusion and fission reactions. The accelerators must be designed to deliver high particle beam currents to a target facility with very little beam spill along the accelerator itself, in order that accelerator maintenance can be accomplished without remote manipulators. Typically, particle loss is preceded by the formation of a tenuous halo of particles around the central beam core, caused by beam dynamics effects, often coupled with the slight imperfections inevitable in a practical design. If the halo becomes large enough, particles may be scraped off along the accelerator. The tolerance for beam spill in different applications is discussed, halo mechanisms and recent work to explore and understand their dynamics are reviewed, and possible directions for future investigation are outlined. RP Jameson, RA (reprint author), LOS ALAMOS NATL LAB, POB 1663, AOT-1 MSH817, LOS ALAMOS, NM 87545 USA. NR 16 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 149 EP 157 DI 10.1016/S0920-3796(96)00463-2 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500022 ER PT J AU Chen, CP Qian, Q Davidson, RC AF Chen, CP Qian, Q Davidson, RC TI Chaotic behavior and halo development in the transverse dynamics of heavy-ion beams SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID QUADRUPOLE FOCUSING FIELD; PARTICLE AB This paper reviews results obtained from recent analytical and numerical investigations of chaotic behavior and halo development induced by charge density inhomogeneities in the transverse dynamics of heavy-ion beams. In particular, a test-particle model is used to investigate the charged-particle dynamics in an intense matched heavy-ion beam with non-uniform density profile propagating through an alternating-gradient quadrupole magnetic field in the space-charge-dominated regime. It is shown that self-field non-linearities due to transvere non-uniformities in the beam density not only can result in chaotic ion motion but also can cause halo formation. For heavy-ion fusion applications, these results indicate that accurate density profile control is critical in preventing heavy-ion beams from developing halos. C1 PRINCETON UNIV, PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Chen, CP (reprint author), MIT, CTR PLASMA FUS, 77 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 159 EP 167 DI 10.1016/S0920-3796(96)00464-4 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500023 ER PT J AU Haber, I Callahan, DA Friedman, A Grote, DP Langdon, AB AF Haber, I Callahan, DA Friedman, A Grote, DP Langdon, AB TI Transverse-longitudinal temperature equilibration in a long uniform beam SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Computer simulations are employed to examine the transfer of transverse thermal energy to the longitudinal direction via a collective electrostatic instability which is driven by an initial temperature anisotropy. The nature of the instability is illustrated using electrostatic particle-in-cell simulations in an axisymmetric geometry, but with three components of the velocity. Results are presented for a long coasting space-charge-dominated beam, propagating in a uniform focused channel to illustrate the development of a coherent mode structure with an axial wavelength comparable with the beam diameter, and growth times comparable with the betatron period. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Haber, I (reprint author), USN, RES LAB, DIV PLASMA PHYS, WASHINGTON, DC 20375 USA. NR 12 TC 14 Z9 14 U1 2 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 169 EP 174 DI 10.1016/S0920-3796(96)00465-6 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500024 ER PT J AU Grote, DP Friedman, A Haber, I Yu, S AF Grote, DP Friedman, A Haber, I Yu, S TI Three-dimensional simulations of high current beams in induction accelerators with WARP3d SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB For many issues relevant to acceleration and propagation of heavy ion beams for inertial confinement fusion, understanding the behavior of the beam requires the self-consistent inclusion of the self-fields of the beams in multiple dimensions. For these reasons, the three-dimensional simulation code WARP3d was developed. The code combines the In this paper the general structure of the code is reviewed and details of two ongoing applications are presented along with a discussion of simulation techniques used. The most important results of this work are presented. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. LAWRENCE BERKELEY LAB, BERKELEY, CA USA. RP Grote, DP (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 11 TC 62 Z9 62 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 193 EP 200 DI 10.1016/S0920-3796(96)00469-3 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500028 ER PT J AU Sharp, WM Friedman, A Grote, DP AF Sharp, WM Friedman, A Grote, DP TI Effects of longitudinal space charge in beams for heavy-ion fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB A new analytic model is presented that accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy ion beam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well with exact solutions of Poisson's equation. Field values are shown for several simple beam profiles and are compared with values obtained From simpler models. The model has been implemented in the fluid-envelope code CIRCE and used to study longitudinal confinement in beams with a variety of axial profiles. The effects of errors in the longitudinal control fields are presented. RP Sharp, WM (reprint author), LAWRENCE LIVERMORE NATL LAB, L-440, LIVERMORE, CA 94550 USA. NR 7 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 201 EP 208 DI 10.1016/S0920-3796(96)00470-X PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500029 ER PT J AU Anderson, OA AF Anderson, OA TI Emittance growth from merging arrays of round beamlets SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB The cost of an induction linac for heavy ion fusion (HIF) may be reduced if the number of channels in the main accelerator is reduced. There have been proposals to do this by merging beamlets (perhaps in groups of four) after a suitable degree of preacceleration. This process, which results in r.m.s. emittance growth, occurs in two stages. The first stage occurs instantly when the beamlets, no longer separated by electrodes, enter the merging region. At this point one has a collection of beamlets whose centers are displaced from the central axis by distances delta(xi) delta(yi). The mean square emittance, now calculated for the whole collection, is epsilon(xi)(2) = epsilon(x1)(3) + [delta(x)(2)] V-x(2) and similarly for the y direction. Here epsilon(x1) is the emittance of one undisplaced beamlet, V-x is the r.m.s. thermal velocity and epsilon(xi) is the initial emittance of the composite beam. This first stage of emittance growth is easy to calculate and has obvious scaling properties. The second stage of merged beam emittance growth mostly occurs in about one-quarter of a plasma period, although the full development may take much longer. In this stage, space charge forces cause transverse accelerations. The maximum increase in mean square emittance is proportional to the excess electrostatic energy (free energy) in the array when the merging begins. It tends to dominate the first stage for strongly depressed initial tunes. The relatively complex calculations involving the second stage are the main concern of this paper. In some designs it may be desirable to reduce the emittance growth below that produced by a basic 2 x 2 array. For this a general understanding of the free energy is helpful. Therefore we investigate three factors affecting the normalized free energy U-n of an array of charged interacting beamlets: (1) the number of beamlets N in the array; (2) the ratio eta of beamlet diameter to beamlet center spacing; (3) the shape of the array. For circular arrays we obtain an analytic expression for U-n as a function of N and eta. If eta is held constant, it shows that U-n similar to N-1 in the large-N limit, i.e. U-n would become arbitrarily small in this idealized case. We show that this is not true for square or rectangular arrays, which have larger free energy with a lower limit determined by the non-circular format. Free energy in square arrays can be reduced by omitting corner beamlets; in the case of a 5 x 5 array the reduction factor is as large as 3.3. C1 PARTICLE BEAM CONSULTANTS, BERKELEY, CA 94705 USA. RP Anderson, OA (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 209 EP 217 DI 10.1016/S0920-3796(96)00471-1 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500030 ER PT J AU Celata, CM Chupp, W Faltens, A Fawley, WM Ghiorso, W Hahn, KD Henestroza, E Judd, D Peters, C Seidl, PA AF Celata, CM Chupp, W Faltens, A Fawley, WM Ghiorso, W Hahn, KD Henestroza, E Judd, D Peters, C Seidl, PA TI Transverse combining of four beams in MBE-4 SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Transverse beam combining is a cost-saving option employed in many designs for induction linac heavy ion fusion drivers. The resultant transverse emittance increase, due predominantly to anharmonic space charge forces, must be kept minimal so that the beam remains focusable at the target. A prototype combining experiment has been built using the MBE-4 experimental apparatus. Four new sources produce up to 6.7 mA Cs+ beams at 200 keV. The ion sources are angled toward each other so that the beams converse. Focusing upstream of the merge consists of four quadrupoles and a final combined-function element (quadrupole and dipole). All lattice elements are electrostatic. Owing to the small distance between beams at the last element (about 3-4 mm), the electrodes here are a cage of small rods, each at different voltage. The beams emerge into the 30-period transport lattice of MBE-4 where emittance growth due to merging, as well as the subsequent evolution of the distribution function, can be diagnosed. The combiner design, simulation predictions and preliminary results from the experiment are presented. RP Celata, CM (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 3 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 219 EP 224 DI 10.1016/S0920-3796(96)00472-3 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500031 ER PT J AU Friedman, A Barnard, JJ Cable, MD Callahan, DA Deadrick, FJ Eylon, S Fessenden, TJ Grote, DP Hopkins, HA Karpenko, VP Judd, DL Kirbie, HC Longinotti, DB Lund, SM Nattrass, LA Nelson, MB Newton, MA Sangster, TC Sharp, WM AF Friedman, A Barnard, JJ Cable, MD Callahan, DA Deadrick, FJ Eylon, S Fessenden, TJ Grote, DP Hopkins, HA Karpenko, VP Judd, DL Kirbie, HC Longinotti, DB Lund, SM Nattrass, LA Nelson, MB Newton, MA Sangster, TC Sharp, WM TI Recirculating induction accelerators for inertial fusion: Prospects and status SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID HEAVY-ION FUSION AB The USA is developing the physics and technology of induction accelerators for heavy ion beam-driven inertial fusion. The recirculating induction accelerator repeatedly passes beams through the same set of accelerating and focusing elements, thereby reducing both the length and gradient of the accelerator structure. This promises an attractive driver cost if the technical challenges associated with recirculation can be met. Point designs for recirculator drivers were developed in multiyear study by LLNL, LBNL and FM Technologies and that work is briefly reviewed here. To validate major elements of the recirculator concept, we are developing a small (4.5 m diameter) prototype recirculator which will accelerate a space-charge-dominated beam of K+ ions through 15 laps from 80 to 320 keV and from 2 to 8 mA. Transverse beam confinement is effected via permanent magnet quadrupoles; bending is via electric dipoles. This 'small recirculator' is being developed through a sequence of experiments. An injector, matching section and linear magnetic channel using seven half-lattice periods of permanent magnet quadrupole lenses are operational. A prototype recirculator half-lattice period is being fabricated. This paper outlines the research program and presents initial experimental results. C1 LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Friedman, A (reprint author), LAWRENCE LIVERMORE NATL LAB, L-440, LIVERMORE, CA 94550 USA. NR 27 TC 7 Z9 7 U1 2 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 235 EP 246 DI 10.1016/S0920-3796(96)00475-9 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500034 ER PT J AU Barnard, JJ Cable, MD Callahan, DA Fessenden, TJ Friedman, A Grote, DP Judd, DL Lund, SM Newton, MA Sharp, WM Yu, SS AF Barnard, JJ Cable, MD Callahan, DA Fessenden, TJ Friedman, A Grote, DP Judd, DL Lund, SM Newton, MA Sharp, WM Yu, SS TI Physics design and scaling of recirculating induction accelerators: From benchtop prototypes to drivers SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained by Barnard et al. (UCRL-LR-108095, 1991; Phys. Fluids B Plasma Phys. 5 (1993), 2698) and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration (Friedman et al., 32-33 (1996) 235) involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all the critical beam dynamics issues that have been raised by Barnard et al. and subsequently. We review the design equations for recirculators (which have been incorporated into a MATHEMATICA-based design code) and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion-extraction, vacuum requirements and emittance growth scale from small prototype to driver-size accelerator. C1 LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Barnard, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 20 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 247 EP 258 DI 10.1016/S0920-3796(96)00476-0 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500035 ER PT J AU Newton, MA Deadrick, FJ Hanks, RL Hawkins, SA Holm, KA Kirbie, HC Karpenko, VP Longinotti, DB Nattrass, LA AF Newton, MA Deadrick, FJ Hanks, RL Hawkins, SA Holm, KA Kirbie, HC Karpenko, VP Longinotti, DB Nattrass, LA TI Engineering development for a small-scale recirculator experiment SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Lawrence Livermore National Laboratory (LLNL) is evaluating the physics and technology of recirculating induction accelerators for heavy ion inertial fusion drivers. As part of this evaluation we are building a small-scale recirculator to demonstrate the concept and to use as a test bed for the development of recirculator technologies. System designs have been completed and components are presently being designed and developed for the small-scale recirculator. The hardware being developed includes both mechanical and electrical components of the beam line. Our present development efforts are focused on two areas: (1) the design of the modular beam line component called a ''half-lattice module'' which must satisfy challenging space and vacuum requirements and (2) the development of an advanced solid state modulator which will generate precisely tailored electrical pulses at repetition rates exceeding 100 kHz for acceleration. This paper will discuss results of the design and development activities that are presently being conducted to implement the small-scale recirculator experiments. An overview of the system design will be presented along with a discussion of the implications of this design on the mechanical and electrical hardware. The paper will focus primarily on discussions of the development and design of the half-lattice period hardware and the advanced solid state modulator. C1 EG&G MEASUREMENTS, PLEASANTON, CA USA. RP Newton, MA (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 4 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 259 EP 266 DI 10.1016/S0920-3796(96)00477-2 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500036 ER PT J AU Fessenden, TJ Barnard, JJ Cable, MD Deadrick, FJ Nelson, MB Sangster, TC Eylon, S Hopkins, HS AF Fessenden, TJ Barnard, JJ Cable, MD Deadrick, FJ Nelson, MB Sangster, TC Eylon, S Hopkins, HS TI Intense heavy ion beam transport with electric and magnetic quadrupoles SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB As part of the small induction recirculator development at LLNL we are testing an injector and transport line that delivers 4 mu s beams of potassium with repetition rates up to 10 Hz at a nominal current of 2 mA. The normalized edge equivalent emittance of the beams is near 0.02 mm mrad and is mostly determined by the temperature of the source (0.1 eV). K+ ions generated at 80 keV in a Pierce diode are matched to an alternating gradient transport line by seven electric quadrupoles. Two additional quads have been modified to serve as two-axis steerers. The matching section is followed by a transport section comprised of seven permanent magnet quadrupoles. Matching to this section is achieved by adjusting the voltages on the electric quadrupoles to voltages calculated by an envelope matching code. Measurements of beam envelope parameters are made at the matching section entrance and exit as well as at the end of the permanent magnet transport section. Beam current waveforms along the experiment are compared with results from a one-dimensional longitudinal dynamics code. Initial experiments show particle loss occurring at the beam head as a result of overtaking. Except for this, the beam is transported with essentially no loss of current through the 4.8 m of electric and magnetic focused transport. During transport the emittance increases by approximately 50% from the intrinsic emittance of the source. Some electron effects that have little apparent influence on transport have also been seen. The apparatus is also being used for the development of non- or minimally intercepting diagnostics for future recirculator experiments. These include capacitive monitors for determining beam line change density and position in the recirculator, flying wire scanners for beam position, and gated TV scanners for measuring beam profiles and emittance. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. RP Fessenden, TJ (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 6 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 267 EP 275 DI 10.1016/S0920-3796(96)00478-4 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500037 ER PT J AU Kwan, JW Bangerter, RO Faltens, A Lee, EP Peters, C Reginato, LL Barnard, JJ Sharp, WM AF Kwan, JW Bangerter, RO Faltens, A Lee, EP Peters, C Reginato, LL Barnard, JJ Sharp, WM TI Elise plans and progress SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Elise is a heavy-ion induction linear accelerator that will demonstrate beam manipulations required in a driver for inertial fusion energy. With a line charge density similar to that of heavy-ions drivers, Elise will accelerate a beam pulse (duration of 1 mu s or more) of K+ ions from an initial energy of 2 MeV to a final energy 5 MeV or more. In the present design, the Elise electrostatic quadrupoles (ESQs) will have an aperture of radius 2.33 cm operating at +/- 59 kV. The half-lattice periods range from 21 to 31 cm. The entire machine will be approximately 30 m long, half of which is the induction accelerator with the remaining half being the injector (including the Marx generator) and the matching section. Elise will be built in a way that allows future expansion into the full Induction Linear Accelerator Systems Experiments (ILSE) configuration, so it will have an array of four ESQ focusing channels capable of transporting up to a total of 3.2 A of beam current. Elise will also have an active alignment system with an alignment tolerance of less than 0.1 mm. Initially, only one beam channel will be used during nominal Elise operation. At the currently expected funding rate, the construction time will be 4.75 years, with FY95 being an extra year for research and development before construction. Total project cost is estimated to be US$25.9m, including contingency costs. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Kwan, JW (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 11 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 299 EP 308 DI 10.1016/S0920-3796(96)00482-6 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500041 ER PT J AU Yu, SS Eylon, S Henestroza, E Peters, C Reginato, L Tauschwitz, A Grote, D Deadrick, F AF Yu, SS Eylon, S Henestroza, E Peters, C Reginato, L Tauschwitz, A Grote, D Deadrick, F TI 2 MV injector as the Elise front-end and as an experimental facility SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB We report on progress in the preparation of the 2 MV injector at LBNL as the front end of Elise and as a multipurpose experimental facility for heavy ion fusion beam dynamics studies. Recent advances in the performance and understanding of the injector are described, and some of the ongoing experimental activities are summarized. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Yu, SS (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 9 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 309 EP 315 DI 10.1016/S0920-3796(96)00483-8 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500042 ER PT J AU Henestroza, E Grote, DP AF Henestroza, E Grote, DP TI Transient beam dynamics in the Lawrence Berkeley laboratory 2 MV injector SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB A driver-scale injector for the heavy ion fusion accelerator project has been built at LBL. This machine has exceeded the design goals of high voltage (above 2 MV), high current (more than 0.8 A of K+) and low normalized emittance (less than 1 pi mm mrad). The injector consists of a 750 keV gun pre-injector followed by an electrostatic quadrupole accelerator which provides strong (alternating gradient) focusing for the space-charge-dominated beam, and simultaneously accelerates the ions to 2 MeV. A matching section is being built to match the beam to the electrostatic accelerator ELISE. The gun pre-injector, designed to hold up to 1 MV with minimal breakdown risks, consists of a hot alumino-silicate source with a large curved emitting surface surrounded by a thick ''extraction electrode''. During beam turn-on the voltage at the source is biased from a negative potential, enough to reverse the electric field on the emitting surface and to avoid emission, to a positive potential to start extracting the beam; it stays constant for about 1 mu s, and is reversed to turn off the emission. Since the Marx voltage applied on the accelerating quadrupoles and the main pre-injector gap is a long, constant pulse (several microseconds), the transient behavior is dominated by the extraction pulser voltage time profile. The transient longitudinal dynamics of the beam in the injector was simulated by running the particle-in-cell codes GYMNOS and WARP3D in a time-dependent mode. The generalization and its implementation is WARP3D of a method proposed by Lampel and Tiefenback to eliminate transient oscillations in a one-dimensional planar diode will be presented. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Henestroza, E (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 317 EP 321 DI 10.1016/S0920-3796(96)00484-X PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500043 ER PT J AU Lee, EP Bangerter, RO Chan, CF Faltens, A Kwan, J Henestroza, E Hahn, K Seidl, P Barnard, JJ Friedman, A Grote, DP Sharp, WM AF Lee, EP Bangerter, RO Chan, CF Faltens, A Kwan, J Henestroza, E Hahn, K Seidl, P Barnard, JJ Friedman, A Grote, DP Sharp, WM TI Physics design and scaling of Elise SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB Elise is an electrostatically focused heavy-ion accelerator being designed and constructed at Lawrence Berkeley Laboratory. The machine is intended to be the first half of the four-beam Induction Linear Accelerator (LINAC) Systems Experiment (ILSE), which will ultimately test the principal beam dynamics issues and manipulations of induction heavy-ion drivers for inertial fusion. Elise will use an existing 2 MeV injector and will accelerate space-charge-dominated pulses to greater than 5 MeV. The design objective of Elise is to maximize the output beam energy within the fixed project budget, while allowing for adequate beam diagnostics, flexibility in the acceleration schedule, and beam parameters suitable for ILSE and the experimental program. We review the design equations and 'rules of thumb' used for choosing the beam and lattice parameters for heavy-ion induction accelerators, and we discuss incorporating these relations in a spreadsheet program that generates internally consistent lattice layouts and acceleration schedules. These designs have been tested using a one-dimensional particle simulation code (SLIDE), a three-dimensional fluid/envelope code (CIRCE) and a three-dimensional particle-in-cell code (WARP3d). Sample results from these calculations are presented. Results from these dynamics codes are also shown, illustrating sensitivities to beam and lattice errors, and testing various strategies for longitudinal confinement of the beam ends. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Lee, EP (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 13 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 323 EP 335 DI 10.1016/S0920-3796(96)00485-1 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500044 ER PT J AU Reginato, L Peters, C AF Reginato, L Peters, C TI Engineering research and development for the Elise heavy ion induction accelerator SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB The Fusion Energy Research engineering team has been conducting research and development associated with the construction of the Elise accelerator since the approval of key decision 1 (this is the start of construction). The engineering design effort has worked in close cooperation with the physics design staff to achieve all parameters of the Elise accelerator. The design included the 2 MV injector, matching section, combiner, induction cells, electric-magnetic quadrupoles, alignment system and controls. All major designs and some hardware testing will be discussed. RP Reginato, L (reprint author), LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 337 EP 345 DI 10.1016/S0920-3796(96)00486-3 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500045 ER PT J AU Slutz, SA Lockner, TL Humphries, S AF Slutz, SA Lockner, TL Humphries, S TI Space-charge-neutralized ion induction linacs with cusp insulation SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID DIODE AB The space charge of ions limits the current that can be accelerated in a conventional ion linear accelerator (linac). Furthermore, the accelerating electric field must be kept low enough to avoid the generation and acceleration of counterstreaming electrons. These limitations have resulted in heavy ion fusion accelerator designs that employ long beam lines and would be expensive to build. Space charge neutralization and magnetic insulation of the acceleration gaps could substantially reduce these two limitations, but at the expense of increasing the complexity of the beam physics. We consider it necessary to keep all structures out of the beam path to maintain beam symmetry and to avoid beam-induced outgassing. Using only field coils outside of the beam results in a cusp field to insulate the accelerating gaps and a solenoidal field between acceleration gaps, which provides a containment force. Electrons can enter the beam region along the magnetic field lines and provide fairly good space charge neutralization. We have performed three-dimensional particle-in-cell simulations, which indicate that electrons remain tied to magnetic field lines, despite the development of electromagnetic fluctuations. Thus, the center of the beam is not neutralized, resulting in a non-linear net focusing force. We have developed a simple model to determine the beam emittance induced by the non-linearity of the focussing force. We discuss the constraints this model puts on the choice of ion and the number of stages required for the accelerator. C1 UNIV NEW MEXICO, ALBUQUERQUE, NM 87131 USA. RP Slutz, SA (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 347 EP 353 DI 10.1016/S0920-3796(96)00487-5 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500046 ER PT J AU Fawley, WM Vella, MC Peters, C Stuart, M Faltens, A AF Fawley, WM Vella, MC Peters, C Stuart, M Faltens, A TI Design and construction of a large aperture quadrupole electromagnet SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB We are currently constructing a prototype quadrupole electromagnet for the proposed Induction Linac Systems Experiments (ILSE) at LBNL. ILSE (PUB-5219, 1989 (Lawrence Berkeley Laboratory)) will address many physics and engineering issues relevant to the design of a heavy ion fusion driver accelerator. The pulsed electromagnet has two layers of current windings and will produce a field gradient of 28 T m(-1), with a usable aperture radius of 6 cm. It operates at a repetition rate of 1 Hz, steady state. In this paper, we discuss how the interaction of various concerns such as maximum dynamic aperture, short lattice period, field quality, iron yoke weight, heat transfer, and voltage stand-off have led to our particular design choices. We also present two- and three-dimensional numerical calculations concerning field topography and the results of transport simulations of space-charge-dominated ion beams with ILSE parameters. RP Fawley, WM (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 395 EP 400 DI 10.1016/S0920-3796(96)00495-4 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500054 ER PT J AU Lund, SM Halbach, K AF Lund, SM Halbach, K TI Iron-free permanent magnet systems for charged particle beam optics SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID COBALT AB The strength and astounding simplicity of certain permanent magnet materials allow a wide variety of simple, compact configurations of high field strength and quality multipole magnets. Here we analyze the important class of iron-free permanent magnet systems for charged particle beam optics. The theory of conventional segmented multipole magnets formed from uniformly magnetized block magnets placed in regular arrays about a circular magnet aperture is reviewed. Practical multipole configurations resulting are presented that are capable of high and intermediate aperture field strengths. A new class of elliptical aperture magnets is presented within a model with continuously varying magnetization angle. Segmented versions of these magnets promise practical high field dipole and quadrupole magnets with an increased range of applicability. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Lund, SM (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 8 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 401 EP 415 DI 10.1016/S0920-3796(96)00496-6 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500055 ER PT J AU Hahn, K Lee, E AF Hahn, K Lee, E TI A study of stripped pinched-beam transport for heavy ion fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB AB One of the alternative scenarios for a heavy ion driver for inertial confinement fusion is final transport as a self-magnetic pinch. A beam is stripped by passing it through a thin foil (or gas) which also supplies neutralizing electrons. The beam is then centered in a long conducting pipe which may be surrounded by a solenoid to help the confinement of neutralizing electrons. Additional electrons are supplied by ionization of a low pressure gas in the pipe. Immediately before the stripping foil a mini final focusing system would be applied, which makes the envelope waist of a few millimetre radius at the foil. In this scheme, the usual chromatic aberration constraint on the heavy ion fusion driver can be relaxed by at least an order of magnitude, which gives substantial relief on the longitudinal beam dynamics issues. A simulation study has been performed using an (r,z) particle-in-cell code for all six electromagnetic field components and the three components of particle velocity. RP Hahn, K (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 7 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 417 EP 424 DI 10.1016/S0920-3796(96)00497-8 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500056 ER PT J AU Eylon, S Henestroza, E AF Eylon, S Henestroza, E TI A high charge state heavy ion beam source for heavy ion fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID INDUCTION AB A high current, low emittance, high charge state heavy ion beam source is being developed. This is designed to deliver a heavy ion fusion (HIF) driver accelerator scale beam. Using a high charge state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system, which consists of a gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using. 3D beam simulations and experimental feasibility study results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Eylon, S (reprint author), DULY RES INC, 1912 MACARTHUR ST, RANCHO PALOS VERDES, CA 90275 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 435 EP 440 DI 10.1016/S0920-3796(96)00499-1 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500058 ER PT J AU Callahan, DA AF Callahan, DA TI Chamber propagation physics for heavy ion fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID INERTIAL FUSION AB Chamber transport is a key area of study for heavy ion fusion. Final focus and chamber transport are high leverage areas providing opportunities to decrease significantly the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime (below about 0.003 Torr), ballistic or nearly ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime (above about 0.1 Torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber and then transporting it at small radius (about 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity. RP Callahan, DA (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808 L-440, LIVERMORE, CA 94551 USA. NR 33 TC 60 Z9 60 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 441 EP 452 DI 10.1016/S0920-3796(96)00500-5 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500059 ER PT J AU Barboza, N AF Barboza, N TI Heavy ion beam transport in an inertial confinement fusion reactor SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID PARTICLE AB A new code, BTRAC, is under development to determine whether a beam of heavy ions can be focused to the necessary spot size radius of about 2 mm within an inertial confinement reactor chamber where the background gas densities are on the order of 10(14)-10(15) cm(-3) of lithium (or equivalent). Beam transport is expected to be strongly affected by stripping and collective plasma phenomena; if propagation is possible in this regime, it could lead to simplified reactor designs. The beam is modeled using a 2 1/2-dimensional particle-in-cell (PIC) simulation code coupled with a Monte Carlo (MC) method for analyzing collisions. The MC code follows collisions between the beam ions and neutral background gas atoms that account for the generation of electrons and background gas ions (ionization), and an increase in the charge state of the beam ions (stripping). The PIC code models the complete dynamics of the interaction of the various charged particle species with the self-generated electromagnetic fields. Details of the code model and preliminary results are presented. RP Barboza, N (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 453 EP 466 DI 10.1016/S0920-3796(96)00501-7 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500060 ER PT J AU Welch, DR Olson, CL AF Welch, DR Olson, CL TI Self-pinched transport for ion-driven inertial confinement fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID BEAMS; GAS AB Efficient transport of intense ion beams is necessary for ion-driven inertial confinement fusion (ICF). The self-pinched transport scheme involves the focusing of an ion beam to a radius of about 1 cm or less. At this radius, using the beam's self-magnetic field for confinement, the ion beam propagates through the reactor chamber to an ICF target. A promising regime for self-pinched transport involves the injection of a high current beam into an initally neutral gas at about 200 mTorr less. A simple equilibrium theory of a beam with a temporally pinching radial envelope predicts that large confining magnetic fields are possible with net currents of more than 50% of the beam current. The magnitude of these fields is strongly dependent on the rate of ionization of the given ion species. We have simulated ion-beam propagation, using the hybrid code IPROP, which self-consistently calculates the gas breakdown and electromagnetic fields. In agreement with the theory, a propagation window of 20-200 mTorr of argon is calculated for a 50 kA, 5 MeV proton beam similar to the parameters of the SABRE accelerator at Sandia National Laboratories. We present simulations of the focusing and propagation of the SABRE beam, with the purpose of designing a self-pinch experiment. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP Welch, DR (reprint author), MISSION RES CORP, ALBUQUERQUE, NM 87106 USA. NR 6 TC 21 Z9 21 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 477 EP 483 DI 10.1016/S0920-3796(96)00503-0 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500062 ER PT J AU Olson, CL Hanson, DL Poukey, JW Welch, DR AF Olson, CL Hanson, DL Poukey, JW Welch, DR TI Microcharge neutralization transport experiments and simulations for ion-driven inertial confinement fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID BEAM TRANSPORT; GAS AB Space charge neutralization for intense beams for inertial confinement fusion is usually assumed to be perfect. However. small charge clumps in the beam will not be totally charge neutralized, and the residual net minimum potential set by electron trapping (e phi approximate to 1/2 m(e)v(i)(2) where m(e) is the electron mass and v(i) is the ion velocity) may lead to a substantial microdivergence. Experiments on the SABRE accelerator and simulations with the IPROP computer code are being performed to assess this mechanism. We have successfully created a 5 mrad beam on the SABRE accelerator, by expanding the beam (a process consistent with Liouville's theorem) and, by passing the beam through a plate with pinholes, we have created low divergence beamlets to study this mechanism. Results clearly show: (1) at low pressures, trapping does neutralize the beamlets, but only down to e phi approximate to 1/2 m(e)v(i)(2); and (2) at higher pressures (approximate to 0.1-1 Torr), plasma shielding does remove the effect. C1 MISSION RES CORP, ALBUQUERQUE, NM 87106 USA. RP Olson, CL (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 6 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 485 EP 491 DI 10.1016/S0920-3796(96)00504-2 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500063 ER PT J AU Tauschwitz, A Yu, SS Eylon, S Bangerter, RO Leemans, W Peters, C Rasmussen, JO Reginato, L Barnard, JJ Sharp, WM AF Tauschwitz, A Yu, SS Eylon, S Bangerter, RO Leemans, W Peters, C Rasmussen, JO Reginato, L Barnard, JJ Sharp, WM TI Plasma lens focusing and plasma channel transport for heavy ion fusion SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Symposium on Heavy Ion Inertial Fusion CY SEP 06-09, 1995 CL PRINCETON PLASMA PHYS LAB, PRINCETON, NJ HO PRINCETON PLASMA PHYS LAB ID ULTRAVIOLET-LASERS; IONIZATION; BEAMS AB The capabilities of adiabatic, current-carrying plasma lenses for the final focus problem in heavy-ion-beam-driven inertial confinement fusion are explored and compared with the performance of non-adiabatic plasma lenses, and with that of conventional quadrupole lenses. A final focus system for a fusion reactor is proposed, consisting of a conventional quadrupole lens to prefocus the driver beams to the entrance aperture of the adiabatic lens, the plasma lens itself, and a high current discharge channel inside the chamber to transport the focused beam to the fusion pellet. Two experiments are described that address the issues of adiabatic focusing, and of transport channel generation and stability for ion beam transport. The test of the adiabatic focusing principle shows a 26-fold current density increase of a 1.5 MeV potassium ion beam during operation of the lens. The lens consist of a discharge of length 300 mm, filled with helium gas at a pressure of 1 Torr and is pulsed with a current between 5 and 15 kA. The investigations of discharge channels for ion beam transport show that preionization of the discharge channels with a UV laser can be an efficient way to direct and stabilize the discharge. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Tauschwitz, A (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 19 TC 24 Z9 24 U1 2 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP 493 EP 502 DI 10.1016/S0920-3796(96)00505-4 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500064 ER PT J AU Davidson, RC Fessenden, TJ AF Davidson, RC Fessenden, TJ TI Seventh international symposium on heavy ion inertial fusion - Princeton Plasma Physics Laboratory, Princeton, NJ, USA, 6-9 September 1995 SO FUSION ENGINEERING AND DESIGN LA English DT Editorial Material RP Davidson, RC (reprint author), PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD NOV PY 1996 VL 32-33 BP R9 EP R10 DI 10.1016/S0920-3796(97)85061-2 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WC005 UT WOS:A1996WC00500001 ER PT J AU Bell, RE Hatcher, RE Lagin, LJ Okabayashi, M Sichta, P AF Bell, RE Hatcher, RE Lagin, LJ Okabayashi, M Sichta, P TI Advancing plasma control on the Princeton Beta Experiment Modification SO FUSION TECHNOLOGY LA English DT Article ID PBX-M TOKAMAK; PROFILE AB A digital plasma control system for the Princeton Beta Experiment Modification (PBX-M) is being prepared. The functions of the existing analog shape and position control subsystems will be assumed by the upgraded control system. Plasma profile control will be pursued by making use of the lower hybrid current drive and the ion Bernstein wave heating systems to modify the plasma current and pressure profiles. A framework for integrating these plasma control functions is presented. Existing profile diagnostics can, with some modification, provide the information necessary to feed back on the plasma profiles. The digital control hardware is commercially available. Four real-time processors, which can be programmed independently, reside on a single Versa Module Euro-card board with dedicated shared memory. The parallel programming capability allows the separation by function of the vertical position control, shaping control, and profile control, which have different characteristic timescales. RP Bell, RE (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1996 VL 30 IS 2 BP 151 EP 158 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ754 UT WOS:A1996VQ75400004 ER PT J AU Kessel, CE Jardin, SC Bulmer, RH Pillsbury, RD Wang, PW Neilson, GH Strickler, DJ AF Kessel, CE Jardin, SC Bulmer, RH Pillsbury, RD Wang, PW Neilson, GH Strickler, DJ TI Poloidal field control for the Tokamak Physics Experiment SO FUSION TECHNOLOGY LA English DT Article AB Control of the poloidal field (PF) in the Tokamak Physics Experiment (TPX) is critical to achieving its mission of advanced tokamak research. Extensive examination of the plasma equilibrium; plasma start-up; plasma position, shape, and current control; and plasma shape reconstruction have been performed as part of the design process. This paper reports the progress in this area. The PF coils have been designed to produce a wide range of plasmas. plasma start-up can be achieved for multiple conditions. Fast plasma position control coils inside the vacuum vessel are used for short timescale control of the plasma vertical and radial position. Shape and total plasma-current control are provided by the PF coils over a slower timescale. A new algorithm for shape control of a few critical plasma boundary points is described and used in simulations using the Tokamak Simulation Code. Fast magnetostatic reconstruction of the plasma shape is examined to determine the impact of measurement locations and their quality. RP Kessel, CE (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Jardin, Stephen/E-9392-2010 NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1996 VL 30 IS 2 BP 184 EP 200 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ754 UT WOS:A1996VQ75400007 ER PT J AU Mueller, D Bell, MG Fredrickson, E Janos, AC Jobes, FC AF Mueller, D Bell, MG Fredrickson, E Janos, AC Jobes, FC TI Disruption avoidance on TFTR SO FUSION TECHNOLOGY LA English DT Article ID TOKAMAKS AB Disruptions on the Tokamak Fusion Test Reactor (TFTR), especially those occurring at high stored energy, result in lost experimental run time because many discharges are required to regain wall conditions necessary for good plasma performance. A variety of disruption types have been observed on TFTR. These include density-limit disruptions, those caused by a high influx of impurities, those occurring during the current ramp-down, those resulting from locked modes, and those occurring at high normalized beta (beta(N) = beta(T)aB(T)/I-p). A combination of operational experience and limiter development has helped to avoid many potential disruptions. However the experimental goal of high fusion power production engenders the risk of high-beta(N) disruptions. A system to limit beta(N) by reducing the neutral beam power as a preprogmmmed beta(N) limit is reached is now in use to help avoid high-beta(N) disruptions. Operational issues of disruption avoidance, the beta(N) feedback system, the limitations and possible improvements of the system are discussed. C1 ITER SAN DIEGO JOINT WORK SITE,LA JOLLA,CA 92037. RP Mueller, D (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD NOV PY 1996 VL 30 IS 2 BP 251 EP 257 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ754 UT WOS:A1996VQ75400011 ER PT J AU Houck, LD Mendonca, MT Lynch, TK Scott, DE AF Houck, LD Mendonca, MT Lynch, TK Scott, DE TI Courtship behavior and plasma levels of androgens and corticosterone in male marbled salamanders, Ambystoma opacum (Ambystomatidae) SO GENERAL AND COMPARATIVE ENDOCRINOLOGY LA English DT Article ID SEXUAL-BEHAVIOR; TESTOSTERONE SECRETION; FROG ELEUTHERODACTYLUS; REPRODUCTIVE-BEHAVIOR; RANA-CATESBEIANA; LARVAL DENSITY; HORMONE LEVELS; CRESTED NEWT; MALE MICE; STRESS AB We measured plasma levels of testosterone, dihydrotestosterone (DHT), and corticosterone for male marbled salamanders (Ambystoma opacum) collected during the breeding season. Our goal was to ascertain whether steroid levels changed in response to particular reproductive behaviors or laboratory confinement. Six groups of salamanders were examined: (a) MIGRATING, males migrating toward the pond basin during the breeding season; (b) LABORATORY, males kept under confined conditions in the laboratory for 10 days; (c) LAB-FIELD, laboratory males that were later released into seminatural enclosures in the field; (d) COURTING, males from male-female pairs in which the male actively courted the female (and deposited at least one spermatophore); (e) SOLO, males that were individually isolated from conspecifics; and (f) MALE-MALE, males that were placed together in pairs, and in which one male actively courted the other male. In three groups (COURTING, SOLO, and MALE-MALE), salamanders were placed in containers for observation and each male was observed for at least 2 hr prior to a plasma sample being taken. Circulating levels of testosterone, DHT, and corticosterone did not differ significantly for males in these groups. The similarity of androgen levels among the three groups indicated a lack of behaviorally evoked change under experimental conditions designed to reveal a behavior-androgen response. Male A. opacum differ taxonomically from other amphibians showing a behavior-androgen response (three species of toads in the genus Bufo) and also lack amplexus and male-male combat during competition for mates. The effects of confinement were indicated by levels of testosterone and DHT in LABORATORY males that were significantly lower than average levels of males in the following groups: MIGRATING, LAB-FIELD, and MALE-MALE. We inferred that LAB-FIELD males, following their release to seminatural enclosures, were able to regain plasma androgen levels typical of migrating males. This increase is one of very few demonstrations for amphibians of an increase in androgen levels upon release from laboratory confinement. Levels of corticosterone did not differ significantly between males that were active in the field and males that were kept in the laboratory. The similarity of corticosterone levels among these groups differs from the typical pattern of elevated corticosterone and depressed androgen levels in captive amphibians. Maximal corticosterone levels in breeding male A. opacum may act differently than in other species in which chronic elevations inhibit the pituitary-gonadal axis. (C) 1996 Academic Press, Inc. C1 AUBURN UNIV, DEPT ZOOL & WILDLIFE, AUBURN, AL 36849 USA. SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. RP Houck, LD (reprint author), UNIV CHICAGO, DEPT ECOL & EVOLUT, 940 E 57TH ST, CHICAGO, IL 60637 USA. NR 51 TC 24 Z9 26 U1 0 U2 13 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0016-6480 J9 GEN COMP ENDOCR JI Gen. Comp. Endocrinol. PD NOV PY 1996 VL 104 IS 2 BP 243 EP 252 DI 10.1006/gcen.1996.0167 PG 10 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA VT696 UT WOS:A1996VT69600014 PM 8930615 ER PT J AU Chesser, RK Baker, RJ AF Chesser, RK Baker, RJ TI Effective sizes and dynamics of uniparentally and diparentally inherited genes SO GENETICS LA English DT Article ID ANIMAL MITOCHONDRIAL-DNA; POPULATION SIZES; EVOLUTION; PHILOPATRY; DIVERSITY; FLOW; SYSTEMATICS; MIGRATION; DISPERSAL; PATERNITY AB Models to determine the temporal dynamics and spatial heterogeneity for maternally and paternally inherited genes were derived for populations that may or may not exhibit spatial subdivision. Results were compared to those for diparentally inherited genes. The models permit definition of parameters for mean and variance of litter sizes, breeding group (subpopulation) sizes, and numbers of female mates per male, dispersal rates, and multiple paternity. Exact solutions for asymptotic effective size and spatial divergence (F-LS) for maternal and paternal genes are derived. It is shown that solutions for effective size and F-LS are transformations of the same quadratic equation. When compared to values for diparentally inherited genes, it is shown that effective sizes for maternal genes may be considerably higher when female dispersal is low as in many mammalian taxa. Likewise, effective sizes for paternal genes may be higher than for diparentally inherited traits when male dispersal is relatively low, as in many species of birds. The traditional assumption that the effective size for maternal genes is approximately equal to the number of females is seldom realized. Spatial heterogeneity and temporal dynamics of genes are inextricably linked as is shown by the interdependency of effective size and spatial heterogeneity. C1 UNIV GEORGIA,DEPT GENET,ATHENS,GA 30602. TEXAS TECH UNIV,DEPT BIOL SCI,LUBBOCK,TX 79409. RP Chesser, RK (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 43 TC 93 Z9 94 U1 0 U2 5 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 SN 0016-6731 J9 GENETICS JI Genetics PD NOV PY 1996 VL 144 IS 3 BP 1225 EP 1235 PG 11 WC Genetics & Heredity SC Genetics & Heredity GA VP826 UT WOS:A1996VP82600032 PM 8913763 ER PT J AU Arcot, SS Adamson, AW Lamerdin, JE Kanagy, B Deininger, PL Carrano, AV Batzer, MA AF Arcot, SS Adamson, AW Lamerdin, JE Kanagy, B Deininger, PL Carrano, AV Batzer, MA TI Alu fossil relics - Distribution and insertion polymorphism? SO GENOME RESEARCH LA English DT Letter ID HUMAN GENOME; HUMAN-POPULATION; FAMILY MEMBERS; DNA-SEQUENCES; SOURCE GENES; REPEATS; SUBFAMILY; EVOLUTION; AMPLIFICATION; CHROMOSOME AB Screening of a human genomic library with an oligonucleotide probe specific for one of the young subfamilies of Alu repeats (Ya5/8) resulted in the identification of several hundred positive clones. Thirty-three of these clones were analyzed in detail by DNA sequencing. Oligonucleotide primers complementary to the unique sequence regions flanking each Alu repeat were used in PCR-based assays to perform phylogenetic analyses, chromosomal localization, and insertion polymorphism analysts within different human population groups. All 33 Alu repeats were present only in humans and absent from orthologous positions in several nonhuman primate genomes. Seven Alu repeats were polymorphic for their presence/absence in three different human population groups, making them novel identical-by-descent markers for the analysis of human genetic diversity and evolution. Nucleotide sequence analysis of the polymorphic Alu repeats showed an extremely low nucleotide diversity compared with the subfamily consensus sequence with an average age of 1.63 million years old. The young Alu insertions do not appear to accumulate preferentially on any individual human chromosome. C1 LOUISIANA STATE UNIV,MED CTR,STANLEY S SCOTT CANC CTR,DEPT PATHOL,NEW ORLEANS,LA 70112. LOUISIANA STATE UNIV,MED CTR,STANLEY S SCOTT CANC CTR,DEPT BIOCHEM & MOL BIOL,NEW ORLEANS,LA 70112. ALTON OCHSNER MED FDN & OCHSNER CLIN,MOL GENET LAB,NEW ORLEANS,LA 70121. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. OI Deininger, Prescott/0000-0002-1067-3028 FU NHGRI NIH HHS [HG 00770] NR 44 TC 37 Z9 37 U1 0 U2 0 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD NOV PY 1996 VL 6 IS 11 BP 1084 EP 1092 DI 10.1101/gr.6.11.1084 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VV874 UT WOS:A1996VV87400006 PM 8938432 ER PT J AU Boren, J Lee, I Callow, MJ Rubin, EM Innerarity, TL AF Boren, J Lee, I Callow, MJ Rubin, EM Innerarity, TL TI A simple and efficient method for making site-directed mutants, deletions, and fusions of large DNA such as P1 and BAC clones SO GENOME RESEARCH LA English DT Article ID ENDONUCLEASE RARE CLEAVAGE; APOLIPOPROTEIN-B; TRANSGENIC MICE; MUTAGENESIS; GENE AB This study addresses two important technical problems: how to perform targeted alterations such as site-directed mutagenesis and deletions in large fragments of DNA and how to construct full-length from two partly overlapping bacterial artificial chromosome (BAC) plasmids. Given the size al td the lack of convenient unique restriction sites in these large-insert bacterial clones, these are nontrivial tasks. Here we describe a simple and efficient protocol based on RecA-assisted restriction endonuclease (RARE) cleavage, a method that enables sequence-specific cleavage of genomic DNA. The same protocol has been used with minor modifications to introduce site-specific mutations into an apolipoprotein-B 90-kb P1 clone, to generate deletions in a 160-kb BAG, and to generate a 160-kb BAC containing the complete 92-kb gene for low-density lipoprotein-related protein-1 (LRP-1) from two smaller overlapping BACs (''BAC marriage''). C1 UNIV CALIF SAN FRANCISCO,CARDIOVASC RES INST,SAN FRANCISCO,CA 94140. UNIV CALIF SAN FRANCISCO,DEPT PATHOL,SAN FRANCISCO,CA 94140. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. RP Boren, J (reprint author), UNIV CALIF SAN FRANCISCO,GLADSTONE INST CARDIOVASC DIS,SAN FRANCISCO,CA 94140, USA. FU NHLBI NIH HHS [HL-47660] NR 11 TC 39 Z9 40 U1 1 U2 4 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD NOV PY 1996 VL 6 IS 11 BP 1123 EP 1130 DI 10.1101/gr.6.11.1123 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA VV874 UT WOS:A1996VV87400011 PM 8938437 ER PT J AU Kim, Y Kirkpatrick, RJ Cygan, RT AF Kim, Y Kirkpatrick, RJ Cygan, RT TI Cs-133 NMR study of cesium on the surfaces of kaolinite and illite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; SOLID-STATE NMR; ADSORBED WATER; CHEMICAL-SHIFTS; CLAY-MINERALS; SPECTROSCOPY; CATIONS; CHARGE; NA-23; SORPTION AB Cs-133 MAS NMR of Cs-exchanged illite, kaolinite, boehmite, and silica gel is shown to be a powerful tool to investigate the adsorption sites and atomic dynamics of Cs on mineral surfaces. Cesium is adsorbed on these mineral surfaces in primarily two ways: at sites relatively tightly bonded to the surface (Stern layer, Cs1) and at more loosely bonded sites in the diffuse (Gouy) layer (Cs2). For illite, both edge sites and crystallite basal surfaces are important adsorption sites. For kaolinite, edge sites, expandable layers, and probably crystallite basal surfaces are important. The Cs-133 NMR chemical shifts for the Cs1 site become more shielded (more negative) as the Si/Al ratio of the substrate phase increases, paralleling the chemical shift variations of other cations and consistent with this site being relatively tightly bonded to the surface. The Cs-133 NMR chemical shifts of Cs2 do not vary systematically with solid composition due to the larger distance of these sites from the surface and weaker electrostatic attraction to the surface compared to Cs1. Rather, the Cs2 chemical shifts are significantly influenced by relative humidity (R. H.) and Cs population (Cs/H2O ratio) on the surface. The Cs1 chemical shifts vary less with these parameters. Cs2 is removed by washing with 1-5 mL of deionized water due to its weak attraction to the surface. The Cs1 chemical shifts become less shielded after washing and with decreasing solution concentration due to a decrease in the Cs surface density. At 100% R. H., Cs in the two sites undergoes motional averaging at frequencies > 100 kHz. With decreasing R. H., peaks for Cs on the two sites are resolved due to decreasing exchange frequencies related to a decreasing number of adsorbed water layers. Motional averaging at 100% R. H. is verified by low temperature experiments with illite. C1 SANDIA NATL LABS, DEPT GEOCHEM, ALBUQUERQUE, NM 87185 USA. RP Kim, Y (reprint author), UNIV ILLINOIS, DEPT GEOL, URBANA, IL 61801 USA. NR 69 TC 72 Z9 73 U1 2 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD NOV PY 1996 VL 60 IS 21 BP 4059 EP 4074 DI 10.1016/S0016-7037(96)00257-8 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VR990 UT WOS:A1996VR99000006 ER PT J AU Vaniman, DT Chipera, SJ AF Vaniman, DT Chipera, SJ TI Paleotransport of lanthanides and strontium recorded in calcite compositions from tuffs at Yucca Mountain, Nevada, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID RARE-EARTH ELEMENTS; CHEMICAL EVOLUTION; MANGANESE OXIDE; SILICIC TUFF; PATTERNS; WATERS; SR AB Secondary calcite occurs in both saturated and unsaturated hydrologic zones (SZ and UZ, respectively) in the tuffs at Yucca Mountain, Nevada, USA. In the upper UZ, the major constituents of the calcite crystal structure (C, O) have surface origins. At greater depth there is a ''barren zone,'' straddling the water table, where calcite is rare and mixing of surface and subsurface sources may occur. Deep in the SZ, distinctive Mn calcites reflect deep sources, including Ca released as analcime or albite formed and carbonates derived from underlying Paleozoic rocks. In the UZ and in the barren zone, above the deep Mn calcites, variations in calcite lanthanide chemistry can be used to distinguish rhyolitic from quartz-latitic sources. Lanthanide ratios and Sr contents of calcites record the chemical evolution of waters flowing through the UZ and upper SZ. Variations in calcite chemistry in the UZ and in the barren zone show that (1) Sr, which is readily exchanged with clays or zeolites, is essentially removed from some flowpaths that are in contact with these minerals and (2) traces of Mn oxides found in the tuffs have a significant effect on groundwater chemistry in the UZ and in the barren zone by removing almost all Ce from solution (evidenced by characteristic Ce depletions in calcite throughout this zone). Extreme Ce removal may be a result of Ce oxidation (Ce3+ --> Ce4+) at the surfaces of some Mn oxides, particularly rancieite. Higher Sr contents and lack of Ce depletions in the deeper Mn calcites reflect different ages, origins, and transport systems. The calcite record of lanthanide and Sr transport in the UZ shows that minor minerals (clays and zeolites) and even trace minerals (Mn oxides) will affect the compositions of groundwaters that flow over distances greater than a few tens of meters. RP Vaniman, DT (reprint author), LOS ALAMOS NATL LAB, MS D462, LOS ALAMOS, NM 87545 USA. NR 43 TC 36 Z9 36 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD NOV PY 1996 VL 60 IS 22 BP 4417 EP 4433 DI 10.1016/S0016-7037(96)00227-X PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VX318 UT WOS:A1996VX31800011 ER PT J AU Reneau, SL Dethier, DP AF Reneau, SL Dethier, DP TI Late Pleistocene landslide-dammed lakes along the Rio Grande, White Rock canyon, New Mexico SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID ESPANOLA BASIN; PALEOCLIMATIC INFERENCES; DEPOSITS; NEVADA; AGE; GROUNDWATER; VALLEY AB Massive slump complexes composed of Pliocene basaltic rocks and underlying Miocene and Pliocene sediments flank the Rio Grande along 16 km of northern White Rock Canyon, New Mexico, The toe area of at least one slump complex was active in the late Pleistocene, damming the Rio Grande at least four times during the period from 18 to 12 C-14 ka and impounding lakes that extended 10-20 km upriver, Stratigraphic relationships and radiocarbon age constraints indicate that three separate lakes formed between 13.7 and 12.4(14)C ka. The age and dimensions of the ca. 12.4 ka lake are best constrained; it had an estimated maximum depth of approximate to 30 m, a length of approximate to 13 km, a surface area of approximate to 2.7 km(2), and an initial volume of approximate to 2.5 x 10(7) m(3), The landslide dam responsible for this lake was apparently stable, and the lake filled completely with laminated silt-rich lacustrine sediment and overlying coarse sands and gravels that represent bed load of the Rio Grande, A lake that formed at less than or equal to 17.5 ka was approximate to 21 km long and apparently failed catastrophically, recorded by probable outburst flood deposits that extend downriver from the landslide dam, An older (greater than or equal to 43 C-14 ka) landslide-dammed lake is less well constrained, but it had a maximum depth of at least 57 m, an estimated minimum length of 25 km, and a surface area of 25 km(2), Deposition of coarse sands and gravels of the Rio Grande over lacustrine sediments indicates that the landslide dam responsible for this older lake also was stable; extrapolation of historic Rio Grande sediment yield data suggests that this lake persisted for 100-1000 yr, The stability of the dam may have been due to armoring of the outflow channel with basalt boulders. The youngest landslide-dammed lakes formed during a period of significantly wetter regional climate, strongly suggesting that climate changes were responsible for reactivation of the slump complexes, We are not certain about the exact triggering mechanisms for these landslides, but they probably involved removal of lateral support due to erosion of the slope base by the Rio Grande during periods of exceptionally high flood discharge or rapid incision; increased pore pressures associated with higher water tables; higher seepage forces at sites of ground-water discharge; or some combination of these processes, Seismic shaking could also have contributed to triggering of some of the landslides, particularly if aided by wet antecedent conditions. C1 WILLIAMS COLL,DEPT GEOL,WILLIAMSTOWN,MA 01267. RP Reneau, SL (reprint author), LOS ALAMOS NATL LAB,MS D462,GEOL & GEOCHEM GRP,LOS ALAMOS,NM 87545, USA. NR 52 TC 29 Z9 33 U1 0 U2 8 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD NOV PY 1996 VL 108 IS 11 BP 1492 EP 1507 DI 10.1130/0016-7606(1996)108<1492:LPLDLA>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA VW100 UT WOS:A1996VW10000010 ER PT J AU Holland, HD Horita, J Seyfried, WE AF Holland, HD Horita, J Seyfried, WE TI On the secular variations in the composition of Phanerozoic marine potash evaporites SO GEOLOGY LA English DT Article ID INCLUSIONS; CHEMISTRY; MAGNESIUM; SEAWATER; OCEAN AB In a recent paper, L. A. Hardie proposed that the secular changes in the mineralogy of marine nonskeletal limestones and in the mineralogy of marine potash evaporites during the Phanerozoic are the result of changes in the composition of seawater caused primarily by fluctuations in the flux of seawater through mid-ocean ridges, He suggested that even quite small variations (25%) in this flux have a profound effect on the composition of seawater, We show that the effects of changes in the hydrothermal flux are much smaller than he proposed. Nevertheless, a doubling of the hydrothermal flux could probably alter the composition of seawater sufficiently to affect the mineralogy of marine potash evaporites. An alternative explanation for the variations in the mineralogy of these deposits invokes differences in the degree of dolomitization during the evaporation of seawater. The apparent near constancy of the K+ content of seawater during the Phanerozoic supports this hypothesis, It seems likely that during periods of rapid seafloor spreading the rate of seawater cycling is greater than today, that sea level is higher, that very large carbonate platforms are more abundant, and that changes in seawater chemistry together with increases in dolomitization during the evaporation of seawater lead to MgSO4-free potash deposits, The relative importance of these several effects can probably be determined with certainty only when we have analyses of relatively unaltered seawater from the several Phanerozoic periods. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV MINNESOTA,DEPT GEOL & GEOPHYS,MINNEAPOLIS,MN 55455. RP Holland, HD (reprint author), HARVARD UNIV,DEPT EARTH & PLANETARY SCI,20 OXFORD ST,CAMBRIDGE,MA 02138, USA. NR 27 TC 45 Z9 53 U1 2 U2 13 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD NOV PY 1996 VL 24 IS 11 BP 993 EP 996 DI 10.1130/0091-7613(1996)024<0993:OTSVIT>2.3.CO;2 PG 4 WC Geology SC Geology GA VW098 UT WOS:A1996VW09800008 ER PT J AU Morrison, HF Shoham, Y Hoversten, GM TorresVerdin, C AF Morrison, HF Shoham, Y Hoversten, GM TorresVerdin, C TI Electromagnetic mapping of electrical conductivity beneath the Columbia basalts SO GEOPHYSICAL PROSPECTING LA English DT Article ID ARRAY PROFILING EMAP; WASHINGTON; SOUNDINGS; PLATEAU; BASIN AB Sedimentary rocks beneath the Columbia River Basalt Group are recognized as having potential for oil and gas production, but the overlying layered basalts effectively mask seismic reflections from the underlying sediments. Four electromagnetic (EM) methods have been applied on profiles crossing Boylston Ridge, a typical east-west trending anticline of the Yakima Fold Belt, in an attempt to map the resistivity interface between the basalts and the sediments and to map variations in structure and resistivity within the sediments. The EM surveys detected strong variations in resistivity within the basalts, and in particular the continuous magnetotelluric array profiling (EMAP) revealed resistivity lows beneath the surface anticlines. These low resistivity zones probably coincide with fracturing in the core of the anticlines and they appear to correlate well with similar zones of low seismic velocity observed on a nearby seismic profile. The controlled-source EM surveys (in-loop transient, long-offset transient, and variable-offset frequency-domain) were designed in anticipation of relatively uniform high resistivity basalts, and were found to have been seriously distorted by the intrabasalt conductors discovered in the field. In particular, the resistivity sections derived from 1D inversions were found to be inconsistent and misleading. The EMAP survey provided the most information about the subsurface resistivity distribution, and was certainly the most cost-effective. However, both controlled-source and EMAP surveys call for accurate 2D or 3D inversion to accommodate the geological objectives of this project. C1 SHELL DEV CORP,HOUSTON,TX. SCHLUMBERGER DOLL RES CTR,RIDGEFIELD,CT 06877. RP Morrison, HF (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 18 TC 12 Z9 12 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0016-8025 J9 GEOPHYS PROSPECT JI Geophys. Prospect. PD NOV PY 1996 VL 44 IS 6 BP 963 EP 986 DI 10.1111/j.1365-2478.1996.tb00186.x PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VV678 UT WOS:A1996VV67800005 ER PT J AU Richardson, JD Phillips, JL Smith, CW Gray, PC AF Richardson, JD Phillips, JL Smith, CW Gray, PC TI Thermal anisotropies in the solar wind: Evidence of heating by interstellar pickup ions? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VOYAGER-2 AB A recent paper by Gray et al. [1996] shows that the Alfven ion cyclotron instability is generated by newly created pickup ions and heats the thermal solar wind protons in the direction perpendicular to the magnetic field. This instability operates mast effectively in regions where the plasma beta is low, so this mechanism predicts that the ratio of the temperatures perpendicular and parallel to the magnetic field should be larger in low-beta regions of the solar wind. We look for this effect in ISEE-3 and Voyager 2 data. The near-Earth ISEE-3 data show no evidence for greater thermal anisotropies at low beta. Voyager 2 data obtained between 1 and 8 AU show that the ambient proton thermal anisotropy is a function of beta, with parallel temperatures generally greater than perpendicular temperatures except when beta is small. For Voyager 2 data, the average ratio of perpendicular to parallel temperature is about 0.9, but this ratio is similar to 2 when beta is less than 0.1 and similar to 4 when beta is less than 0.01. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV DELAWARE,BARTOL RES INST,NEWARK,DE 19716. RP Richardson, JD (reprint author), MIT,SPACE RES CTR,CAMBRIDGE,MA 02139, USA. NR 15 TC 15 Z9 15 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1996 VL 23 IS 22 BP 3259 EP 3262 DI 10.1029/96GL02909 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VQ924 UT WOS:A1996VQ92400048 ER PT J AU Forsyth, RJ Balogh, A Smith, EJ Murphy, N McComas, DJ AF Forsyth, RJ Balogh, A Smith, EJ Murphy, N McComas, DJ TI The underlying magnetic field direction in Ulysses observations of the southern polar heliosphere - Reply SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article C1 JET PROP LAB,PASADENA,CA 91109. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Forsyth, RJ (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1996 VL 23 IS 22 BP 3281 EP 3282 DI 10.1029/96GL02381 PG 2 WC Geosciences, Multidisciplinary SC Geology GA VQ924 UT WOS:A1996VQ92400055 ER PT J AU Vasco, DW Peterson, JE Majer, EL AF Vasco, DW Peterson, JE Majer, EL TI A simultaneous inversion of seismic traveltimes and amplitudes for velocity and attenuation SO GEOPHYSICS LA English DT Article ID P-WAVE; PORE FLUIDS; LONG VALLEY; CALIFORNIA; ROCKS; TOMOGRAPHY; TIME; SANDSTONES; CALDERA; MEDIA AB It is possible to efficiently use traveltime and amplitude information to infer variations in velocity and Q. With little additional computation, terms accounting for source radiation pattern and receiver coupling may be included in the inversion. The methodology is based upon a perturbation approach to paraxial ray theory. The perturbation approach linearizes the relationship between velocity deviations and traveltime and amplitude anomalies. Using the technique, we infer the velocity and attenuation structure at a fractured granitic site near Raymond, California. A set of four well pairs are examined and each is found to contain two zones of strong attenuation. The velocity variations contain an upper low velocity region corresponding to the uppermost attenuating zone. The location of these zones agrees with independent well-log and geophysical data. The velocity and attenuation anomalies appear to coincide with extensively fractured sections of the borehole and may indicate fracture zones rather than individual fractures. RP Vasco, DW (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,CTR COMPUTAT SEISMOL,BERKELEY,CA 94720, USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 50 TC 28 Z9 32 U1 0 U2 2 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD NOV-DEC PY 1996 VL 61 IS 6 BP 1738 EP 1757 DI 10.1190/1.1444091 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VW785 UT WOS:A1996VW78500016 ER PT J AU Cheng, NG House, L AF Cheng, NG House, L TI Minimum traveltime calculation in 3-D graph theory SO GEOPHYSICS LA English DT Article ID FINITE-DIFFERENCE CALCULATION C1 LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. NR 12 TC 31 Z9 35 U1 0 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD NOV-DEC PY 1996 VL 61 IS 6 BP 1895 EP 1898 DI 10.1190/1.1444104 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VW785 UT WOS:A1996VW78500029 ER PT J AU Istok, JD Rautman, CA AF Istok, JD Rautman, CA TI Probabilistic assessment of ground-water contamination .2. Results of case study SO GROUND WATER LA English DT Article AB The first paper in this series (Rautman and Istok, 1996) presented a geostatistical framework for obtaining a probabilistic assessment of ground-water contamination. This paper presents the results of a case study that applies this framework to define the spatial extent and severity of nitrate and Dacthal (dimethyl tetrachloroterephthalate or DCPA, a herbicide) contamination in the unsaturated and saturated zones for a 150 km(2) site near Ontario, Oregon. Sediment samples collected from 35 boreholes were used to compute vertical accumulations of nitrate and DCPA in the unsaturated zone. Measured nitrate and DCPA concentrations in ground-water samples collected from 42 wells were used to compute vertical accumulations of nitrate and DCPA in the saturated zone. Sample variograms were fit with nugget and spherical models to describe the pattern of spatial continuity of nitrate and DCPA concentrations and accumulations. Conditional, sequential Gaussian simulation was used to generate 100 simulations for each variable on a 0.5 X 0.5 km grid. Probabilistic summaries of these simulations were used to develop (a) maps showing the probability of contamination exceeding specified theshold values, (b) probability distributions for contaminant accumulation and concentration at unsampled locations, (c) probabilistic descriptions for the location of contaminant-plume boundaries, and (d) probability distributions for the total contaminated area and tot al contaminant mass. The results demonstrate that interpretations of site characterization data to determine the extent and magnitude of contamination at a site will vary depending upon the level of uncertainty that will be tolerated by the decision maker. This case study also illustrates the potential applicability and utility of the probabilistic approach for the interpretation of site characterization data and the design of future data collection activities. C1 SANDIA NATL LABS,GEOHYDROL DEPT,ALBUQUERQUE,NM 87185. RP Istok, JD (reprint author), OREGON STATE UNIV,DEPT CIVIL ENGN,CORVALLIS,OR 97331, USA. NR 21 TC 20 Z9 20 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD NOV-DEC PY 1996 VL 34 IS 6 BP 1050 EP 1064 DI 10.1111/j.1745-6584.1996.tb02171.x PG 15 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA VQ575 UT WOS:A1996VQ57500014 ER PT J AU Fisenne, IM Keller, HW Keller, EW AF Fisenne, IM Keller, HW Keller, EW TI Pb-210 in indoor air by total alpha measurement SO HEALTH PHYSICS LA English DT Article DE scintillation chamber; Pb-210; spectrometry, alpha; air sampling AB Pb-210 has been measured in indoor air by two methods, Low flow rate pumps and membrane filters were used to collect the samples, The air filter samples were stored for 1.7 y, after which total alpha activity was determined by scintillation counting, (210)pb was then chemically separated and measured by alpha spectrometry. The efficacy of determination of (210)pb by total alpha measurement was empirically proven, The average air concentration determined by total alpha counting was 340 mu Bq Pb-210 m(-3) and 360 mu Bq Pb-210 m(-3) by radiochemical analysis. RP Fisenne, IM (reprint author), US DOE, ENVIRONM MEASUREMENTS LAB, 201 VARICK ST 5TH FLOOR, NEW YORK, NY 10014 USA. NR 11 TC 5 Z9 5 U1 1 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 NOV PY 1996 VL 71 IS 5 BP 723 EP 726 DI 10.1097/00004032-199611000-00013 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VM896 UT WOS:A1996VM89600016 PM 8887518 ER PT J AU Straume, T Marchetti, AA Anspaugh, LR Khrouch, VT Gavrilin, YI Shinkarev, SM Drozdovitch, VV Ulanovsky, AV Korneev, SV Brekeshev, MK Leonov, ES Voigt, G Panchenko, SV Minenko, VF AF Straume, T Marchetti, AA Anspaugh, LR Khrouch, VT Gavrilin, YI Shinkarev, SM Drozdovitch, VV Ulanovsky, AV Korneev, SV Brekeshev, MK Leonov, ES Voigt, G Panchenko, SV Minenko, VF TI The feasibility of using I-129 to reconstruct I-131 deposition from the Chernobyl reactor accident SO HEALTH PHYSICS LA English DT Article DE I-131; I-129, Chernobyl; soil ID ATOMIC-BOMB SURVIVORS; THYROID-CANCER; POST-CHERNOBYL; FOOD-CHAIN; MODEL; BELARUS; SAMPLES; UKRAINE; IODINE; PLANT AB Radioiodine released to the atmosphere from the accident at the Chernobyl nuclear power station in the spring of 1986 resulted in large-scale thyroid-gland exposure of populations in Ukraine, Belarus, and Russia, Because of the short half life of I-131 (8.04 d), adequate data on the intensities and patterns of iodine deposition were not collected, especially in the regions where the incidence of childhood-thyroid cancer is now increasing, Results are presented from a feasibility study that show that accelerator-mass-spectrometry measurements of I-129 (half life 16x10(6) y) in soil can be used to reconstruct I-131-deposition density and thus help in the thyroid-dosimetry effort that is now urgently needed to support epidemiologic studies of childhood-thyroid cancer in the affected regions. C1 MINIST HLTH, INST BIOPHYS, MOSCOW, RUSSIA. INST RADIAT MED, MINSK, BYELARUS. GSF MUNICH, NATL RES CTR ENVIRONM HLTH, INST RADIAT PROTECT, D-85764 MUNICH, GERMANY. RP Straume, T (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, LIVERMORE, CA 94550 USA. RI Shinkarev, Sergey /B-3254-2017 NR 32 TC 44 Z9 45 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 NOV PY 1996 VL 71 IS 5 BP 733 EP 740 DI 10.1097/00004032-199611000-00015 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VM896 UT WOS:A1996VM89600018 PM 8887520 ER PT J AU Rokni, SH Benson, EC Burke, DL Jenkins, TM Liu, JC Nelson, G Nelson, WR Smith, HE Tenenbaum, P Vylet, V Walz, DR AF Rokni, SH Benson, EC Burke, DL Jenkins, TM Liu, JC Nelson, G Nelson, WR Smith, HE Tenenbaum, P Vylet, V Walz, DR TI Radiation protection systems for the Final Focus Test Beam at SLAC SO HEALTH PHYSICS LA English DT Article DE accelerators; shielding; neutrons; radiation protection AB The Final Focus Test Beam (FFTB) is a new beam line at the Stanford Linear Accelerator Center designed to test new beam optics concepts, hardware, and techniques necessary to achieve and measure the small spot sizes required for future generations of high-energy e(+)e(-) linear colliders. The FFTB takes a 47 GeVc(-1), 1 kW electron beam at the end of the Stanford Linear Accelerator Center linear accelerator and transports it to the FFTB beam dump, A radiation protection system was designed and installed for the FFTB with the primary goal that the integrated dose equivalent outside the shielding resulting from beam loss would not exceed 10 mSv y(-1). This system is comprised of shielding, a beam containment system and a personnel protection system. This paper presents various aspects of radiation safety at Stanford Linear Accelerator Center that were considered in the design of the FFTB radiation protection system. Beam tests were conducted in which the performance of various beam containment devices and the shielding effectiveness were evaluated, Preliminary results from these tests are presented. RP Rokni, SH (reprint author), STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. NR 15 TC 5 Z9 5 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 NOV PY 1996 VL 71 IS 5 BP 786 EP 794 DI 10.1097/00004032-199611000-00024 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 VM896 UT WOS:A1996VM89600027 PM 8887529 ER PT J AU Hardy, EP Krey, PW AF Hardy, EP Krey, PW TI Plutonium in the environs of the former Rocky Flats plant SO HEALTH PHYSICS LA English DT Letter C1 US DOE, ENVIRONM MEASUREMENTS LAB, NEW YORK, NY 10014 USA. NR 5 TC 0 Z9 0 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 NOV PY 1996 VL 71 IS 5 BP 796 EP 796 PG 1 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VM896 UT WOS:A1996VM89600030 PM 8887532 ER PT J AU Likhtarev, IA Kovgan, LN Vavilov, SE Gluvchinsky, RR Perevoznikov, ON Litvinets, LN Anspaugh, LR Kercher, JR Bouville, A AF Likhtarev, IA Kovgan, LN Vavilov, SE Gluvchinsky, RR Perevoznikov, ON Litvinets, LN Anspaugh, LR Kercher, JR Bouville, A TI Predictive and retrospective dose assessment - Response SO HEALTH PHYSICS LA English DT Letter C1 LAWRENCE LIVERMORE NATL LAB, DOSE RECONSTRUCT PROGRAM, LIVERMORE, CA 94550 USA. NCI, BETHESDA, MD 20892 USA. RP Likhtarev, IA (reprint author), UKRAINE ACAD TECHNOL SCI, UKRAINIAN RADIAT PROTECT INST, UA-252050 KIEV, UKRAINE. NR 17 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD NOV PY 1996 VL 71 IS 5 BP 798 EP 799 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VM896 UT WOS:A1996VM89600033 ER PT J AU Hessel, H Mittermuller, J Zitzelsberger, H Weier, HU Bauchinger, M AF Hessel, H Mittermuller, J Zitzelsberger, H Weier, HU Bauchinger, M TI Combined immunophenotyping and FISH with sex chromosome-specific DNA probes for the detection of chimerism in epidermal Langerhans cells after sex-mismatched bone marrow transplantation SO HISTOCHEMISTRY AND CELL BIOLOGY LA English DT Article ID MIXED HEMATOPOIETIC CHIMERISM; FRAGMENT LENGTH POLYMORPHISMS; IN-SITU HYBRIDIZATION; INSITU HYBRIDIZATION; Y-CHROMOSOME; GENETIC-MARKERS; FOLLOW-UP; COMBINATION; ENGRAFTMENT; ANTIGENS AB Langerhans cells (LC) of the skin represent bone marrow-derived dendritic antigen-presenting cells and are therefore important in pathophysiological processes such as rejection, graft-versus-host disease, and graft-versus-leukemia-reaction after bone marrow transplantation (BMT). For understanding of these diseases, the evaluation of the chimeric status of LC following BMT is of great interest. To analyze the sex chromosome constitution of LC in the skin, we established a modified and refined technique of combined immunophenotyping and fluorescence in situ hybridization (FISH) and investigated frozen sections of skin biopsies from nine patients after allogeneic sex-mismatched BMT and of two healthy donors for control. LC were specifically labeled using a fluorescent CD1a antibody and hybridized simultaneously with X and Y chromosome-specific DNA probes. The results of this practical application on nine leukemia patients show the appearance of donor-type LC and the persistence of host-type LC at various times (36 up to 1395 days) after sex-mismatched BMT. Complete chimerism of LC could not be detected in any case. The frequency of recipient-specific LC ranged from 7% to 92% and showed no correlation with time postgrafting. We conclude from our results of 1461 analyzed LC that combined immunophenotyping and interphase cytogenetic analysis by FISH is the method of choice for the assessment of chimerism in a particular cell type after sex-mismatched BMT. Its practical application on other tissues affected by BMT-related pathophysiological processes reveals further knowledge of the time-dependent course of chimeric patterns after BMT. C1 GSF,NATL RES CTR ENVIRONM & HLTH,INST RADIOBIOL,D-85758 OBERSCHLEISSHEIM,GERMANY. GSF,NATL RES CTR ENVIRONM & HLTH,INST CLIN HAEMATOL,D-85758 OBERSCHLEISSHEIM,GERMANY. UNIV MUNICH,INST STRAHLENBIOL,MUNICH,GERMANY. LAWRENCE BERKELEY LAB,DIV LIFE SCI,CTR MOL CYTOGENET,BERKELEY,CA. NR 34 TC 22 Z9 25 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0301-5564 J9 HISTOCHEM CELL BIOL JI Histochem. Cell Biol. PD NOV PY 1996 VL 106 IS 5 BP 481 EP 485 DI 10.1007/BF02473310 PG 5 WC Cell Biology; Microscopy SC Cell Biology; Microscopy GA VR843 UT WOS:A1996VR84300005 PM 8950606 ER PT J AU Hofstadler, SA Severs, JC Smith, RD Swanek, FD Ewing, AG AF Hofstadler, SA Severs, JC Smith, RD Swanek, FD Ewing, AG TI High performance Fourier transform ion cyclotron resonance mass spectrometric detection for capillary electrophoresis SO HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY LA English DT Article DE capillary electrophoresis; mass spectrometry; electrospray ionization; Fourier transform ion cyclotron; resonance; biomolecule analysis ID ELECTROSPRAY-IONIZATION; ZONE ELECTROPHORESIS; PROTEINS AB We describe the current state of the on-line combination of capillary electrophoresis (CE) electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS), and discuss aspects of the FTICR technique relevant to its use as a detection scheme for on-line separations. Aspects including sensitivity, mass resolution, duty cycle, and tandem mass spectrometric capabilities are discussed in the context of online separations with examples from the authors' laboratory. C1 PENN STATE UNIV, DEPT CHEM, UNIVERSITY PK, PA 16802 USA. RP Hofstadler, SA (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Ewing, Andrew/A-3650-2009; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 14 TC 17 Z9 17 U1 0 U2 4 PU DR ALFRED HUTHIG VERLAG GMBH PI HEIDELBERG 1 PA POSTFACH 102869, W-69018 HEIDELBERG 1, GERMANY SN 0935-6304 J9 HRC-J HIGH RES CHROM JI HRC-J. High Resolut. Chromatogr. PD NOV PY 1996 VL 19 IS 11 BP 617 EP 621 PG 5 WC Chemistry, Analytical SC Chemistry GA VX442 UT WOS:A1996VX44200004 ER PT J AU VanHummelen, P Lowe, XR Wyrobek, AJ AF VanHummelen, P Lowe, XR Wyrobek, AJ TI Simultaneous detection of structural and numerical chromosome abnormalities in sperm of healthy men by multicolor fluorescence in situ hybridization SO HUMAN GENETICS LA English DT Article ID INSITU HYBRIDIZATION; INVITRO FERTILIZATION; MEIOTIC SEGREGATION; PARENTAL ORIGIN; ANEUPLOIDY; FREQUENCY; QUALITY; 2-COLOR; NUCLEI; PROBES AB Both structural and numerical chromosome aberrations in sperm represent important categories of paternally transmitted genetic damage. Therefore, a new multiprobe fluorescence in situ hybridization (FISH) method, using DNA probes for three targets (centromere and telomere of chromosome 1, centromere of chromosome 8), was developed to detect human sperm carrying three types of chromosomal defects: (1) terminal duplications or deletions in chromosome 1p, (2) aneuploidy involving chromosomes 1 or 8, and (3) diploidy. Baseline frequencies were determined for three healthy donors who had been previously evaluated for sperm cytogenetics by the human-sperm/hamster-oocyte cytogenetic technique (hamster technique). Among similar to 120 000 sperm analyzed by the new FISH method, the average baseline frequencies of sperm carrying telomeric duplications and deletions of Ip were 3.2 +/- 1.9 and 2.9 +/- 3.6 per 10(4), respectively. Diploid sperm was found in an average frequency of 6.6 +/- 4.0 per 10(4). Average frequencies of disomic sperm for chromosomes 1 or 8 were 1.7 +/- 2.2 and 1.9 +/- 2.3 per 10(4), respectively. Inter-individual differences were observed for deletions of Ip but not for the other sperm phenotypes. A good correlation was obtained between the frequencies of sperm with structural chromosome aberrations detected with the new assay and the frequency of sperm carrying premeiotic or meiotic cytogenetic damage detected with the hamster technique. The observed levels of numerical aberrations with the new FISH assay were within range of the baseline frequencies reported by the hamster technique. The newly developed FISH assay has promising applications in genetic, clinical, physiological and toxicological studies. RP VanHummelen, P (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,L-452,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 37 TC 47 Z9 47 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 NOV PY 1996 VL 98 IS 5 BP 608 EP 615 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA VM743 UT WOS:A1996VM74300019 PM 8882884 ER PT J AU Rosenblum, L Stansfield, S Zyda, M AF Rosenblum, L Stansfield, S Zyda, M TI On apples, oranges, and the interdisciplinary nature of VR SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Editorial Material C1 SANDIA NATL LABS,TECH STAFF,VIRTUAL REAL INTELLIGENT SIMULAT LAB,LIVERMORE,CA 94550. USN,POSTGRAD SCH,DEPT COMP SCI,MONTEREY,CA 93943. RP Rosenblum, L (reprint author), USN,RES LAB,VIRTUAL REAL SYST & RES,DIV INFORMAT TECHNOL,ADV INFORMAT TECHNOL BRANCH,CODE 5580,WASHINGTON,DC 20375, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV PY 1996 VL 16 IS 6 BP 20 EP 22 PG 3 WC Computer Science, Software Engineering SC Computer Science GA VP677 UT WOS:A1996VP67700005 ER PT J AU Risch, JS May, RA Dowson, ST Thomas, JT AF Risch, JS May, RA Dowson, ST Thomas, JT TI A virtual environment for multimedia intelligence data analysis SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article RP Risch, JS (reprint author), PACIFIC NW LAB, REMOTE SENSING GRP, 3200 Q ST, MSIN-K9-55, RICHLAND, WA 99352 USA. NR 12 TC 6 Z9 6 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD NOV PY 1996 VL 16 IS 6 BP 33 EP 41 DI 10.1109/38.544070 PG 9 WC Computer Science, Software Engineering SC Computer Science GA VP677 UT WOS:A1996VP67700007 ER PT J AU Ortiz, GG Hains, CP Lu, B Sun, SZ Cheng, JL Zolper, JC AF Ortiz, GG Hains, CP Lu, B Sun, SZ Cheng, JL Zolper, JC TI Cryogenic VCSEL's with chirped multiple quantum wells for a very wide temperature range of CW operation SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID SURFACE-EMITTING LASER AB Cryogenic optical data links require an efficient optical source with temperature-insensitive continuous-wave (CW) operation at low temperatures. Also, to simplify optical alignment, it is desirable to obtain CW operation over a broad temperature range that spans both the low and high temperatures. By the use of vertical-cavity surface-emitting lasers (VCSEL's) with chirped (nonuniform) multiple quantum wets (MQW's) to broaden the optical gain spectrum, CW operation has been achieved from 5-350 K, with improved characteristics in both the high- and low-temperature regimes. In particular, temperature-insensitive, submilliampere threshold current was achieved at temperatures from 5-50 K, with a threshold current density of 350 A/cm(2), and a threshold voltage that is below 3 V. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Ortiz, GG (reprint author), UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,EECE BLDG,ROOM 125,ALBUQUERQUE,NM 87131, USA. NR 7 TC 11 Z9 11 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 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD NOV PY 1996 VL 8 IS 11 BP 1423 EP 1425 DI 10.1109/68.541537 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VP086 UT WOS:A1996VP08600001 ER PT J AU McConaghy, C Lowry, M Becker, RA Kincaid, BE AF McConaghy, C Lowry, M Becker, RA Kincaid, BE TI The performance of pigtailed annealed proton exchange LiNbO3 modulators at cryogenic temperatures SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article AB Integrated optic modulators have been proposed for transmitting signals from electronic and electrooptic devices which must operate at 77 K and colder. In this letter, the V pi of LiNbO3 modulators at temperatures as cold as 10 K are measured. A similar to 9.25% increase over room temperature values is seen. This increase is attributed primarily to a temperature dependence in r(33). In addition, temperature-induced insertion loss changes are evaluated for two different pigtailing techniques and one is shown to be suitable for cryogenic operation. C1 INTEGRATED OPT CIRCUIT CONSULTANTS,CUPERTINO,CA 95014. BK CONSULTING,APTOS,CA 95003. RP McConaghy, C (reprint author), LAWRENCE LIVERMORE NATL LAB,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD NOV PY 1996 VL 8 IS 11 BP 1480 EP 1482 DI 10.1109/68.541556 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VP086 UT WOS:A1996VP08600020 ER PT J AU Malladi, R Sethian, JA AF Malladi, R Sethian, JA TI A unified approach to noise removal, image enhancement, and shape recovery SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article ID SET CURVATURE FLOW; EDGE-DETECTION; PROPAGATING INTERFACES; ANISOTROPIC DIFFUSION; SHOCK FILTERS; CURVES; ALGORITHMS; MODELS; FRONTS AB We present a unified approach to noise removal, image enhancement, and shape recovery in images. The underlying approach relies on the level set formulation of curve and surface motion, which leads to a class of PDE-based algorithms. Beginning with an image, the first stage of this approach removes noise and enhances the image by evolving the image under flow controlled by min/max curvature and by the mean curvature. This stage is applicable to both salt-and-pepper grey-scale noise and full-image continuous noise present in black and white images, grey-scale images, texture images, and color images. The noise removal/enhancement schemes applied in this stage contain only one enhancement parameter, which in most cases is automatically chosen. The other key advantage of our approach is that a stopping criteria is automatically picked from the image; continued application of the scheme produces no further change. The second stage of our approach is the shape recovery of a desired object; we again exploit the level set approach to evolve an initial curve/surface toward the desired boundary, driven by an image-dependent speed function that automatically stops at the desired boundary. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT MATH, BERKELEY, CA 94720 USA. NR 44 TC 80 Z9 84 U1 2 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1057-7149 EI 1941-0042 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD NOV PY 1996 VL 5 IS 11 BP 1554 EP 1568 DI 10.1109/83.541425 PG 15 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA VR753 UT WOS:A1996VR75300006 PM 18290072 ER PT J AU Skiles, JJ Kustom, RL Ko, KP Wong, V Ko, KS Vong, F Klontz, K AF Skiles, JJ Kustom, RL Ko, KP Wong, V Ko, KS Vong, F Klontz, K TI Performance of a power conversion system for superconducting magnetic energy storage (SMES) SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article; Proceedings Paper CT 1996 IEEE/PES Winter Meeting CY JAN 21-25, 1996 CL BALTIMORE, MD SP IEEE PES AB This paper presents results of laboratory tests of a power conversion system (PCS) for superconducting magnetic energy storage (SMES). The PCS uses a two-quadrant chopper and a voltage source converter. Operating modes of the chopper are discussed. Operation of the SMES to provide independent control of real and reactive power, operation as a static var compensator, low frequency modulation of the real power, and speed of response are demonstrated. A circuit is presented for testing a SMES PCS that does not require a superconducting. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NATL SEMICOND CORP,SANTA CLARA,CA. OPTI CORP,SANTA CLARA,CA. ASIC DESIGNS INC,NAPERVILLE,IL. UNIV S FLORIDA,TAMPA,FL 33620. RP Skiles, JJ (reprint author), UNIV WISCONSIN,MADISON,WI 53706, USA. NR 11 TC 19 Z9 20 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD NOV PY 1996 VL 11 IS 4 BP 1718 EP 1723 DI 10.1109/59.544633 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA VV925 UT WOS:A1996VV92500016 ER PT J AU BiljanovicPaunovic, L Clemons, GK Ivanovic, Z PavlovicKentera, V AF BiljanovicPaunovic, L Clemons, GK Ivanovic, Z PavlovicKentera, V TI Erythropoietin & erythroid progenitors in rats exposed to chronic hypoxia SO INDIAN JOURNAL OF MEDICAL RESEARCH LA English DT Article DE CFU-E; chronic hypoxia; erythropoietin ID CHRONIC NORMOBARIC HYPOXIA; LABORATORY B/B RATS; SERUM ERYTHROPOIETIN; COLONY FORMATION; APLASTIC-ANEMIA; MICE AB In order to better understand the mechanisms affecting erythropoietin (Epo) synthesis and red cell mass. increase under chronic hypoxia, we examined Epo production and erythroid progenitors (CFUE) in rats exposed to normobaric hypoxia for four weeks. Hypoxia induced the rise of hematocrit (Htc), hemoglobin (Hb) concentration and the red blood cell (RBC) number with a plateau in hematocrit values after two weeks. After 24 h of hypoxia, Epo levels were increased 20 ford, followed by a significant decrease. After the first week of hypoxia, the values were still higher than in the controls, but after two weeks Epo levels did not differ significantly from the normal values. The fall of Epo levels coincided with the plateau values of hematocrit, The changes in the CFU-E number followed the changes in Epo concentration: a two fold increase after 24 h of hypoxia; a further increase during the next two weeks reaching a peak on day 14, and then a progressive decrease at the time when Epo concentration was at a normal level. Although decreased, but still higher than normal, the CFU-E number during the last two weeks of hypoxia could be necessary for the maintenance of an achieved steady state under persistent hypoxic conditions with normal Epo concentration sufficient to maintain the existing rate of erythropoiesis. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. RP BiljanovicPaunovic, L (reprint author), INST MED RES,DR SUBOTICA 4,POB 721,YU-11000 BELGRADE,YUGOSLAVIA. NR 33 TC 4 Z9 4 U1 1 U2 1 PU INDIAN COUNCIL MEDICAL RES PI NEW DELHI PA PO BOX 4508 ANSARI NAGAR, NEW DELHI 110029, INDIA SN 0971-5916 J9 INDIAN J MED RES JI Indian J. Med. Res. PD NOV PY 1996 VL 104 BP 304 EP 310 PG 7 WC Immunology; Medicine, General & Internal; Medicine, Research & Experimental SC Immunology; General & Internal Medicine; Research & Experimental Medicine GA VV240 UT WOS:A1996VV24000007 PM 8979523 ER PT J AU Hunter, TB Rice, SF Hanush, RG AF Hunter, TB Rice, SF Hanush, RG TI Raman spectroscopic measurement of oxidation in supercritical water .2. Conversion of isopropyl alcohol to acetone SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB The oxidation of isopropyl alcohol in supercritical water has been investigated using Raman spectroscopy. Results for species concentration as a function of residence-time are presented for temperatures ranging from 400 to 480 degrees C at constant pressure, 24.4 +/- 0.3 MPa, and constant equivalence ratio, 0.88 +/- 0.02. Acetone has been identified as the principal intermediate formed and subsequently destroyed, during the oxidation process. By assuming first-order kinetics for the destruction of both isopropyl alcohol and acetone, effective first-order rate constants have been determined from fits of the experimental data. Assuming Arrhenius behavior, the fits yield rate constants for isopropyl alcohol, k(eff,ipa) = 3.255 x 10(22)(s(-1)) exp[-301.1(kJ . mol(-1))/RT], and for acetone, k(eff,ace) = 1.948 x 10(10)(s(-1)) exp[-137.7(kJ . mol(-1))/RT]. These results indicate that for temperatures greater than 425 degrees C, the destruction of isopropyl alcohol proceeds faster than that of acetone. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 25 TC 20 Z9 21 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD NOV PY 1996 VL 35 IS 11 BP 3984 EP 3990 DI 10.1021/ie9505118 PG 7 WC Engineering, Chemical SC Engineering GA VR705 UT WOS:A1996VR70500019 ER PT J AU Sealock, LJ Elliott, DC Baker, EG Fassbender, AG Silva, LJ AF Sealock, LJ Elliott, DC Baker, EG Fassbender, AG Silva, LJ TI Chemical processing in high-pressure aqueous environments .5. New processing concepts SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID DESTRUCTION; ORGANICS AB A combination of fundamental and applied process research at Pacific Northwest National Laboratory resulted in the development of several new processing concepts. These concepts have in common the use of high-temperature pressurized water as a unique reaction medium for carrying out chemical reactions. Typical operating conditions of these processes range from 300 to 360 degrees C and have pressures to above 200 bar. Investigation of the process chemistry and engineering for these new processing concepts required the development and scale-up of several high-pressure reactor systems which are described. Several new processes involving catalysts and the distinctive properties of pressurized water were patented as part of this effort. These processes, which are at various stages of development, address a broad mix of energy and environmentally related problems. Chemical processing in a high-temperature liquid water environment remains a relatively untapped area for commercial application. RP Sealock, LJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 27 TC 24 Z9 24 U1 1 U2 9 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 NOV PY 1996 VL 35 IS 11 BP 4111 EP 4118 DI 10.1021/ie960119+ PG 8 WC Engineering, Chemical SC Engineering GA VR705 UT WOS:A1996VR70500033 ER PT J AU Lynn, S Schiozer, AL Jaecksch, WL Cos, R Prausnitz, JM AF Lynn, S Schiozer, AL Jaecksch, WL Cos, R Prausnitz, JM TI Recovery of anhydrous Na2SO4 from SO2-scrubbing liquor by extractive crystallization: Liquid-liquid equilibria for aqueous solutions of sodium carbonate, sulfate, and/or sulfite plus acetone, 2-propanol, or tert-butyl alcohol SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB Sodium carbonate is a superior scrubbing agent for removing SO2 from combustion gases, but the resulting sodium sulfate (or sulfite) must be recovered for environmental reasons. Recovery by evaporative crystallization is energy-intensive; extractive crystallization (described below) provides an attractive alternative when technically feasible. Liquid/liquid equilibrium data were determined for two-phase mixtures containing aqueous solutions of sodium carbonate, sulfate, or sulfite and a polar organic solvent: acetone, 2-propanol, and 2-methylpropan-2-ol (i.e., tert-butyl alcohol). In the salt-saturated two-phase region, data were obtained between the lower consolute temperature and 60 degrees C (50 degrees C for acetone). Data were also obtained at 35 degrees C for liquid/liquid systems that were subsaturated with their respective salts and for liquid/liquid systems with overall molar ratios of sodium sulfite/sodium sulfate fixed at 25/75, 50/50, and 75/25. In the latter systems, it was found that the sulfite/sulfate ratios in the organic and aqueous phases were the same; i.e., there is no selectivity by these solvents for one salt relative to the other. The data show that any one of these solvents can be used to extract water from a concentrated solution of either sodium sulfite or sodium sulfate in a countercurrent extractor at 35 degrees C, causing the anhydrous salt to crystallize. The wet solvent can be dried for recycle in a similar countercurrent operation at 35 degrees C, using a saturated solution of Na2CO3 as the drying agent. The number of moles of carbonate required for drying does not exceed the number of moles of sulfite-plus-sulfate precipitated. The process energy is about 10% of that required for single-stage evaporative crystallization of the same liquor. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP Lynn, S (reprint author), UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720, USA. NR 8 TC 21 Z9 24 U1 0 U2 6 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 NOV PY 1996 VL 35 IS 11 BP 4236 EP 4245 DI 10.1021/ie960094e PG 10 WC Engineering, Chemical SC Engineering GA VR705 UT WOS:A1996VR70500049 ER PT J AU Zheng, Z Philip, CV Anthony, RG Krumhansl, JL Trudell, DE Miller, JE AF Zheng, Z Philip, CV Anthony, RG Krumhansl, JL Trudell, DE Miller, JE TI Ion exchange of group I metals by hydrous crystalline silicotitanates SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID ISOTHERM; CESIUM; WASTE; MODEL AB A new hydrous crystalline silicotitanate, labeled TAM-5 or CST, was developed for removing radioactive Cs+ from aqueous nuclear waste. This material is stable to radiation, highly selective for cesium relative to sodium, potassium, rubidium, and protons, and performs well in acidic, neutral, and basic solutions. Various experiments were conducted to determine the ion exchange properties of TAM-5. Two kinds of ion exchange sites exist in the solid, and cation exchange in one site affects the ion exchange properties of the other site. These two types of sites have different thermal effects: with increasing temperature the pH of one increases and the pH of the other one decreases. The total ion exchange capacity is 4.6 mequiv/g, but the cesium ion exchange capacity was less, which shows that not all of the ion exchange sites are available for cesium exchange. Step changes were observed in the ion exchange isotherms. The solid phase behaved ideally prior to the step changes. The apparent capacities within the ideal solid region were 0.57 mequiv/g for Cs+, 1.18 mequiv/g for Rb+, and 1.2 mequiv/g for K+. Both direct competition by rubidium and protons and indirect competition by protons and potassium were observed. The rational selectivities, which were measured from binary ion exchange data, can be used in different solutions including the multicomponent ion exchange systems, because they are constant for an ideal solid. Binary ion exchange isotherms were also developed using the rational selectivity as the parameter for the isotherms of cesium, rubidinium, and potassium. C1 TEXAS A&M UNIV,DEPT CHEM ENGN,KINET CATALYSIS & REACT ENGN LAB,COLLEGE STN,TX 77843. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI Miller, James/C-1128-2011 OI Miller, James/0000-0001-6811-6948 NR 23 TC 45 Z9 45 U1 3 U2 13 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 NOV PY 1996 VL 35 IS 11 BP 4246 EP 4256 DI 10.1021/ie960073k PG 11 WC Engineering, Chemical SC Engineering GA VR705 UT WOS:A1996VR70500050 ER PT J AU Beck, JV Blackwell, B HajiSheikh, A AF Beck, JV Blackwell, B HajiSheikh, A TI Comparison of some inverse heat conduction methods using experimental data SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article AB This paper compares several methods of finding the surface heat flux using transient temperature measurements inside a heat-conducting body. Experimental data is used with a known heat flux history. The methods include function specification with several future approximations, Tikhonov regularization, iterative regularization and specified functions over large time regions with Green's functions. The first three methods are used with the residual principle and the results are quite similar. If the heat flux has a simple time variation over large time regions, taking advantage of that feature can improve the results, as shown by the Green's Function analysis. Copyright (C) 1996 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV TEXAS,DEPT MECH ENGN,ARLINGTON,TX 76019. RP Beck, JV (reprint author), MICHIGAN STATE UNIV,DEPT MECH ENGN,HEAT TRANSFER GRP,E LANSING,MI 48824, USA. NR 16 TC 146 Z9 166 U1 0 U2 22 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 NOV PY 1996 VL 39 IS 17 BP 3649 EP 3657 DI 10.1016/0017-9310(96)00034-8 PG 9 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA UZ852 UT WOS:A1996UZ85200009 ER PT J AU Sakamoto, H Kodama, H Higashimoto, Y Kondo, M Lewis, MS Anderson, CW Appella, E Sakaguchi, K AF Sakamoto, H Kodama, H Higashimoto, Y Kondo, M Lewis, MS Anderson, CW Appella, E Sakaguchi, K TI Chemical synthesis of phosphorylated peptides of the carboxy-terminal domain of human p53 by a segment condensation method SO INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH LA English DT Article DE phosphopeptide synthesis; segment condensation method; peptide thioester; p53; tumor suppressor protein; tetramerization domain; regulatory domain; analytical ultracentrifugation; CD spectroscopy ID SOLID-PHASE SYNTHESIS; DNA-BINDING FUNCTION; PROTEIN SECONDARY STRUCTURE; TUMOR-SUPPRESSOR P53; S-ALKYL THIOESTER; OLIGOMERIZATION DOMAIN; EFFICIENT PROCEDURE; GROWTH ARREST; PHOSPHOPEPTIDES; ACID AB A segment condensation method was developed for the chemical synthesis of large (>90 amino acid) phosphopeptides and was used to produce phosphorylated and non-phosphorylated derivatives of the C-terminal tetramerization and regulatory domains of human p53 (residues 303-393). Efficient condensation synthesis of the 91 residue p53 domain was achieved in two steps. The non-phosphorylated N-terminal segment p53(303-334) (1) and its derivative phosphorylated at serine 315 (1P315), and the nonphosphorylated middle segment p53(335-360) (2), were synthesized as partially protected peptide thioesters in the solid phase using Boc chemistry. The C-terminal segment p53(361-393) (3) and its derivative phosphorylated at serine 392 (3P392) were synthesized as partially protected peptides in the solid phase using Fmoc chemistry. Phosphoamino acid was incorporated into the N-terminal segment (1P315) at the residue corresponding to p53 serine 315 as Boc-Ser(PO3(Bzl)(2))-OH during synthesis. Serine 392 in the C-terminal segment was selectively phosphorylated after synthesis by phosphitylation followed by oxidation. A derivative phosphorylated at serine 378 was synthesized in a one-step condensation of the unphosphorylated N-terminal segment (1) and the phosphorylated long C-terminal segment p53(335-393) (2-3P378). Yields of the ligated peptides after removal of the protecting groups and HPLC purification averaged 60% for the first condensation and 35% for the second condensation. All five p53 peptides exhibited monomer-tetramer association as determined by analytical ultracentrifugation. Circular dichroism spectroscopy revealed that phosphorylation at Ser315 increased the alpha-helical content, which was abolished when Ser392 also was phosphorylated, suggesting an interaction between N-terminal and C-terminal residues of the C-terminal domain of p53. (C) Munksgaard 1996. C1 NCI, NATL INST HLTH, CELL BIOL LAB, BETHESDA, MD 20892 USA. SAGA UNIV, FAC SCI & ENGN, BIOCHEM LAB, SAGA 840, JAPAN. NIH, BIOMED ENGN & INSTRUMENTAT PROGRAM, BETHESDA, MD 20892 USA. BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. RI Sakamoto, Hiroshi/A-3181-2011 NR 46 TC 18 Z9 18 U1 1 U2 4 PU BLACKWELL MUNKSGAARD PI FREDERIKSBERG C PA 1 ROSENORNS ALLE, DK-1970 FREDERIKSBERG C, DENMARK SN 0367-8377 J9 INT J PEPT PROT RES JI Int. J. Pept. Protein Res. PD NOV PY 1996 VL 48 IS 5 BP 429 EP 442 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VV739 UT WOS:A1996VV73900004 PM 8956076 ER PT J AU Lobrich, M Cooper, PK Rydberg, B AF Lobrich, M Cooper, PK Rydberg, B TI Non-random distribution of DNA double-strand breaks induced by particle irradiation SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID FIELD GEL-ELECTROPHORESIS; HEAVY CHARGED-PARTICLES; MAMMALIAN-CELLS; ALPHA-PARTICLES; CHEF ELECTROPHORESIS; RESTRICTION ENZYMES; IONIZING-RADIATION; X-RAYS; REPAIR; INDUCTION AB Induction of DNA double-strand breaks (dsbs) in mammalian cells is dependent on the spatial distribution of energy deposition from the ionizing radiation. For high LET particle radiations the primary ionization sites occur in a correlated manner along the track of the particles, while for X-rays these sites are much more randomly distributed throughout the volume of the cell. It can therefore be expected that the distribution of dsbs linearly along the DNA molecule also varies with the type of radiation and the ionization density. Using pulsed-field gel and conventional gel techniques, we measured the size distribution of DNA molecules from irradiated human fibroblasts in the total range of 0.1 kbp-10 Mbp for X-rays and high LET particles (N ions, 97 keV/mu m and Fe ions, 150 keV/mu m). On a mega base pair scale we applied conventional pulsed-field gel electrophoresis techniques such as measurement of the fraction of DNA released from the well (FAR) and measurement of breakage within a specific Nod restriction fragment (hybridization assay). The induction rate for widely spaced breaks was found to decrease with LET. However, when the entire distribution of radiation-induced fragments was analysed, we detected an excess of fragments with sizes below about 200 kbp for the particles compared with X-irradiation. X-rays are thus more effective than high LET radiations in producing large DNA fragments but less effective in the production of smaller fragments. We determined the total induction rate of dsbs for the three radiations based on a quantitative analysis of all the measured radiation-induced fragments and found that the high LET particles were more efficient than X-rays at inducing dsbs, indicating an increasing total efficiency with LET. Conventional assays that are based only on the measurement of large fragments are therefore misleading when determining total dsb induction rates of high LET particles. The possible biological significance of this non-randomness for dsb induction is discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV GIESSEN,STRAHLENZENTRUM,D-35392 GIESSEN,GERMANY. NR 36 TC 177 Z9 184 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD NOV PY 1996 VL 70 IS 5 BP 493 EP 503 PG 11 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VU457 UT WOS:A1996VU45700001 PM 8947529 ER PT J AU Zollner, S Junge, KE Lange, R Affolder, AA AF Zollner, S Junge, KE Lange, R Affolder, AA TI Optical characterization of Si1-xCx/Si (0<=x<=0.014) semiconductor alloys - Comment SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE silicon; SiC alloys; ellipsometry; strained layer ID DIELECTRIC FUNCTION; SI; SI(001); SPECTRA; LAYERS C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP Zollner, S (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. RI Zollner, Stefan/B-4858-2012 OI Zollner, Stefan/0000-0001-7752-7941 NR 18 TC 3 Z9 3 U1 0 U2 2 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD NOV PY 1996 VL 35 IS 11 BP 5684 EP 5685 DI 10.1143/JJAP.35.5684 PG 2 WC Physics, Applied SC Physics GA VV241 UT WOS:A1996VV24100018 ER PT J AU Stevens, MJ Kremer, K AF Stevens, MJ Kremer, K TI Structure of salt-free linear polyelectrolytes in the Debye-Huckel approximation SO JOURNAL DE PHYSIQUE II LA English DT Article ID OSMOTIC-PRESSURE AB We examine the effects of the common Debye-Huckel approximation used in theories of polyelectrolytes. Molecular dynamics simulations using the Debye-Huckel pair potential of salt-free polyelectrolytes have been performed. The results of these simulations are compared to earlier ''Coulomb'' simulations which explicitly treated the counterions. We report here the comparisons of the osmotic pressure, the end-to-end distance and the single chain structure factor. In the dilute regime the Debye-Huckel chains are more elongated than the Coulomb chains implying that the counterion screening is stronger than the Debye-Huckel prediction. Like the Coulomb chains the Debye-Huckel chains contract significantly below the overlap density in contradiction to all theories. Entropy thus plays an important and sorely neglected role in theory. C1 MAX PLANCK INST POLYMER RES,D-55021 MAINZ,GERMANY. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI Kremer, Kurt/G-5652-2011; MPIP, Theory/I-9884-2014 NR 23 TC 50 Z9 50 U1 0 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4312 J9 J PHYS II JI J. Phys. II PD NOV PY 1996 VL 6 IS 11 BP 1607 EP 1613 PG 7 WC Mechanics; Physics, Atomic, Molecular & Chemical SC Mechanics; Physics GA VP068 UT WOS:A1996VP06800007 ER PT J AU Branagan, DJ Kramer, MJ McCallum, RW AF Branagan, DJ Kramer, MJ McCallum, RW TI Transition metal carbide formation in the Nd2Fe14B system and potential as alloying additions SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Nd2Fe14B; transition metal carbides; precipitate formation; magnetic properties ID B PERMANENT-MAGNETS; ELECTRON-MICROSCOPY; MICROSTRUCTURE; NB AB Precipitates controlling grain growth in rapidly solidified Nd2Fe14B-type magnets are commercially important for inhibiting gain growth during heat treatments or thermomechanical processing. Compound additions of Group IVA, VA, and VIA transition metals along with C were added to the Nd2Fe14B (2-14-1) system. Transition metal carbide (TMC) formation was found for the Group IVA and VA transition metals. All the TMC precipitates observed formed with a 1:1 stoichiometry. To be successful as alloying additions in the 2-14-1 system, additional criteria besides carbide formation are necessary. The alloying ability of each transition metal carbide system was graded using criteria that dealt with phase stability, liquid and equilibrium solid solubility, and high temperature carbide stability. The Group IVA TMC alloys satisfied the proposed alloying criteria and were found to be excellent additions. The Group VA alloys, while forming carbides, only partially satisfied the proposed alloying criteria. Finally, the Group VIA alloys did not form TMCs. C1 IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 33 TC 40 Z9 40 U1 0 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 1 PY 1996 VL 244 IS 1-2 BP 27 EP 39 DI 10.1016/S0925-8388(96)02421-8 PG 13 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VZ095 UT WOS:A1996VZ09500007 ER PT J AU Branagan, DJ McCallum, RW AF Branagan, DJ McCallum, RW TI Changes in glass formation and glass forming ability of Nd2Fe14B by the addition of TiC SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Nd2Fe14B; TiC addition; glass forming ability ID FE-B ALLOYS; MAGNETIC-PROPERTIES; CURIE-TEMPERATURE; AMORPHOUS-ALLOYS; CRYSTALLIZATION; CO AB The glass forming ability (GFA) of a stoichiometric Nd2Fe14B alloy modified with TiC additions was studied. Structural, magnetic, and thermal measurements of as-quenched melt-spun ribbons indicate increasing enhancement of GFA with increasing amounts of TiC addition. The limit of the glass formation range and the amount of glass formed at a particular cooling rate also increased with TiC addition. Enhanced GFA was concurrent with changes in the intrinsic properties of the glass. The crystallization temperature, as well as the transformation rate of crystallization, was raised by TiC addition. The intrinsic magnetic properties of the glass were changed with reductions in saturation magnetization and Curie temperature T-c with increasing amounts of TiC addition. The intrinsic glass changes were related to changes in the local short range order of the glass and are consistent with a reduction in free volume and an increased packing efficiency. These changes in local structure of the glass increase the glass stability, which means that less undercooling is needed to prevent crystallization. Thus, at a particular cooling rate, a higher percentage of glass will be formed and the GFA is increased. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 39 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 1 PY 1996 VL 244 IS 1-2 BP 40 EP 47 DI 10.1016/S0925-8388(96)02419-X PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VZ095 UT WOS:A1996VZ09500008 ER PT J AU McKamey, CG Gubbi, AN Lin, Y George, EP AF McKamey, CG Gubbi, AN Lin, Y George, EP TI Grain-growth behavior and low-pressure oxygen compatibility of an Ir-0.3 wt.% W alloy SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Ir-based alloys; oxidation; grain growth; Auger analyses AB The grain-growth behavior in a low-pressure oxygen-containing atmosphere of an Ir-0.3 wt.% W alloy (designated DOP-26) currently used for cladding of the 238-plutonium oxide fuel in radioisotope thermoelectric generators (RTGs) was studied. A small amount of added thorium improves the impact properties of this alloy partly by segregating to grain boundaries where it provides strengthening and partly by forming Ir,Th precipitates in the matrix which refine grain size. However, a previous preliminary study showed that, in an atmosphere containing a low partial pressure of oxygen (on the order of 1 mPa), the dissolution of the Ir5Th precipitates and diffusion of thorium to the surface to form ThO2 was thermodynamically favorable, leading to anomalous growth of near-surface grains. In this study, specimens were exposed to an oxygen partial pressure of 1.3 mPa at temperatures of 1230, 1280 and 1330 degrees C for times up to 3000 h. The grain-growth behavior in a vacuum of 0.7 mPa was also determined as a comparison. The results substantiated the earlier study and showed that anomalous growth of near-surface grains does occur in this alloy. The results also indicated a marked difference in the kinetics of grain growth in the vacuum versus low-pressure oxygen atmospheres. RP McKamey, CG (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI George, Easo/L-5434-2014 NR 23 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 1 PY 1996 VL 244 IS 1-2 BP 175 EP 183 DI 10.1016/S0925-8388(96)02425-5 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA VZ095 UT WOS:A1996VZ09500030 ER PT J AU Tran, TD Feikert, JH Pekala, RW Kinoshita, K AF Tran, TD Feikert, JH Pekala, RW Kinoshita, K TI Rate effect on lithium-ion graphite electrode performance SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article ID INTERCALATION; ANODES; BATTERIES; CELLS AB The electrochemical performance of lithium-ion graphite electrodes with particle diameter in the range of 6-44 mu m was evaluated at different discharge (intercalation)/charge (deintercalation) rates (C to C/60). The electrode capacity depends on both the average particle size and rate. With a simple rate programme, the electrode performance is dependent on the cycling rate, The capacity of small graphite particles (6 mu m) at C/2 rate was 80% of that achieved at C/24 rate (similar to 372 mAh g(-1)). The capacity of large graphite particles (44 mu m) obtained at fast rates (C/2) was only 25% of that obtained under near-equilibrium conditions (C/24). The electrode capacity, however, is nearly independent of the charge rate when the electrode is fully intercalated using a modified rate programme containing a constant-voltage hold at 0.005 V (vs Li+/Li) for several hours. The electrochemical behaviour is related to the physicochemical properties of the graphite particles. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP Tran, TD (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 21 TC 51 Z9 51 U1 1 U2 16 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD NOV PY 1996 VL 26 IS 11 BP 1161 EP 1167 PG 7 WC Electrochemistry SC Electrochemistry GA VU427 UT WOS:A1996VU42700010 ER PT J AU Imre, DG Abramson, EH Daum, PH AF Imre, DG Abramson, EH Daum, PH TI Quantifying cloud-induced shortwave absorption: An examination of uncertainties and of recent arguments for large excess absorption SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SURFACE ATMOSPHERE SYSTEM; SOLAR-RADIATION; AIRCRAFT MEASUREMENTS; WARM POOL; STRATOCUMULUS; BUDGET; MODELS; PHYSICS; IMPACT; FIELDS AB The quantification of cloud-induced shortwave atmospheric absorption is a painstaking task and often the subject of contention. Several analytical methods previously used for this purpose are examined in detail applying each method to a set of collocated satellite and surface measurements of radiant fluxes taken in April of 1994 in Oklahoma. It is demonstrated that, if care is not taken, conclusions regarding cloud-induced absorption can be as much a function of the chosen analytical methods as they are of the data themselves. It is argued that the best method for determining the cloud radiative forcing ratio is from the slope of a plot of the cloud radiative forcing ratio at the surface versus the cloud radiative forcing at the top of the atmosphere and/or a normalized analog. Application of this method shows that clouds in Oklahoma, on average, induced an absorption of 4% more of the solar insolation than did clear sky. An examination is made of three recent papers that have reported cloud-induced atmospheric absorption in large excess over that which has been generally considered possible. It is shown that, once uncertainties and biases in the analytical methods are considered, the results of all three papers are consistent with conventional formulations of cloud-radiation interactions. RP BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. OI abramson, evan/0000-0001-5278-0836 NR 27 TC 32 Z9 35 U1 0 U2 0 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 NOV PY 1996 VL 35 IS 11 BP 1991 EP 2010 DI 10.1175/1520-0450(1996)035<1991:QCISAA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV053 UT WOS:A1996VV05300005 ER PT J AU Lee, HN AF Lee, HN TI A semi-Lagrangian spectral algorithm for pollutant transport and diffusion studies SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID ADVECTION; MODEL; SCHEMES; DEPOSITION; EQUATIONS; UPSTREAM AB A semi-Lagrangian model was developed based on the atmospheric transport-diffusion equation, employing the semi-Lagrangian technique incorporated with the spectral method. The numerical algorithms of the semi-Lagrangian technique and the spectral method for solving the transport-diffusion equation, subjected to boundary conditions, are described. The model simulated the transport and diffusion of pollutants from an elevated point source. The accuracy of the algorithms was revealed by numerical tests compared with analytical solutions in cases of simple profiles of the mean wind and the eddy diffusivity. To demonstrate the feasibility of the algorithms for studying air pollution in the atmospheric boundary layer, the model, using realistic profiles of the mean wind and the eddy diffusivity, simulated the distributions of pollutant concentrations under various atmospheric stabilities. As will be shown, the algorithms are capable of producing excellent results,making them attractive and promising for regional studies of pollutant transport and diffusion in the atmosphere. RP US DOE, ENVIRONM MEASUREMENTS LAB, 201 VARICK ST, 5TH FLOOR, NEW YORK, NY 10014 USA. NR 20 TC 1 Z9 1 U1 0 U2 0 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 NOV PY 1996 VL 35 IS 11 BP 2129 EP 2135 DI 10.1175/1520-0450(1996)035<2129:ASLSAF>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV053 UT WOS:A1996VV05300016 ER PT J AU Tonkyn, RG Barlow, SE Orlando, TM AF Tonkyn, RG Barlow, SE Orlando, TM TI Destruction of carbon tetrachloride in a dielectric barrier/packed-bed corona reactor SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-BEAM; DECOMPOSITION; FORMALDEHYDE; MECHANISMS; ATTACHMENT; PLASMAS; ENERGY AB The destruction of low concentrations (<1000 ppm) of gas-phase carbon tetrachloride (CCl4) using a low-temperature, dielectric barrier/packed-bed corona reactor was studied. We compare, in particular, the destruction efficiencies using either borosilicate or zirconia oxide (ZrO2) packing materials in dry and moist air, and nitrogen buffer gases. Measurements of contaminant removal in the effluent gas were made at atmospheric pressure as a function of energy dissipated in the reactor. In dry N-2, destruction of CCl4 was most efscient using ZrO2 beads, whereas, in dry air, contaminant removal was approximately equal for borosilicate glass and ZrO2. The presence of water in the gas stream reduced the CCl4 destruction efficiency under all conditions. This reduction was likely a synergistic effect that involves changes in the plasma density, scavenging of low energy secondary electrons, and possible surface passivation. Assuming the primary step in CCl4 destruction is dissociative electron attachment, an estimate of the average density of low energy electrons as a function of input energy was made. We relate the enhancement in CCl4 destruction using the ZrO2 beads in N-2 to a slight increase in the number density of low energy secondary electrons. A discussion of the importance of energy density measurements and a useful phenomenological kinetic model consistent with the observed results are presented. (C) 1996 American Institute of Physics. C1 PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. NR 34 TC 57 Z9 59 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1996 VL 80 IS 9 BP 4877 EP 4886 DI 10.1063/1.363530 PG 10 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700013 ER PT J AU Yu, KM Moll, AJ Walukiewicz, W AF Yu, KM Moll, AJ Walukiewicz, W TI Amphoteric behavior and precipitation of Ge dopants in InP SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ION-IMPLANTATION; ELECTRICAL CHARACTERISTICS; EPITAXIAL REGROWTH; GALLIUM-ARSENIDE; IV ELEMENTS; GAAS; DAMAGE; CARBON; SUBSTITUTIONALITY; TEMPERATURE AB We have directly correlated the electrical behavior, the impurity lattice site location, ion damage, and the local bonding environments of Ge-dopant ions implanted into InP. We have found that after rapid thermal annealing the free electron concentration in the samples implanted at room temperature (RT) are always higher than those implanted at liquid nitrogen temperature (LNT). Although the macroscopic structure seems to be insensitive to the implantation temperature, significantly more local disorder is created in the LNT implanted amorphous layers. Moreover, the amphoteric bonding structure of the Ge atoms is found to be well established already in the as-implanted amorphous InP. After high temperature annealing (>800 degrees C), the Ge atoms rearrange locally with more of the Ge substituting the In site than the P site resulting in n-type conductivity. The solid solubility of Ge in the InP is measured to be similar to 1.4-1.6 X 10(20)/cm(3) while the free electron concentration is estimated to saturate at similar to 3.4 X 10(19)/cm(3). The relatively low electron concentration can be explained by Ge precipitation and the compensation of Ge-In donors by Ge-P accepters in the RT implanted case. The further reduction in electron concentration in the LNT implanted samples is believed to be related to the high residual damage found in these samples. The high solubility of Ge in InP can be attributed to the availability of two possible sublattice sites for the dopant and the compensation of the local strains due to the amphoteric substitution of the Ge. The concentration ratio of the Ge-In to Ge-P determined in the heavily implanted material has been used to estimate the difference in the formation energy of Ge substituting those two different sites. RP LAWRENCE BERKELEY LAB, CTR ADV MAT, DIV SCI MAT, BERKELEY, CA 94720 USA. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 41 TC 4 Z9 4 U1 0 U2 3 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 NOV 1 PY 1996 VL 80 IS 9 BP 4907 EP 4915 DI 10.1063/1.363533 PG 9 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700016 ER PT J AU Lu, J Deshpande, SV Gulari, E Kanicki, J Warren, WL AF Lu, J Deshpande, SV Gulari, E Kanicki, J Warren, WL TI Ultraviolet light induced changes in polyimide liquid-crystal alignment films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID POLYMER; SURFACES; XPS AB Ultraviolet light induced changes in polyimide liquid-crystal alignment films were investigated. Infrared, UV-visible, x-ray photoelectron spectroscopy, and electron-spin-resonance measurements indicated that bond breaking and subsequent oxidation reactions occur in polyimide films (SE7210, OCG284, DuPont 2555 and 2540) during the broadband UV illumination in air. Mechanical rubbing has no effect on the optical and magnetic properties but it causes the removal of the UV-exposed film. Capacitance-voltage measurements indicate that there is a slight decrease in dielectric constant and creation of net negative charges in the film after UV exposure. Surface tension of polyimide films before and after UV illumination and changes in the pretilt angle of the polyimide surface following UV exposure have also been studied. The decrease in pretilt angle following UV illumination is attributed to an increase in surface tension. Our results indicate that a simple UV technique can be used to achieve domain divided liquid-crystal pixel electrode design with improved viewing characteristics. (C) 1996 American Institute of Physics. C1 UNIV MICHIGAN, CTR DISPALY TECHNOL & MFG, ANN ARBOR, MI 48109 USA. SANDIA NATL LABS, ADV MAT LAB, ALBUQUERQUE, NM 87185 USA. RI Kanicki, Jerzy/E-2753-2016 OI Kanicki, Jerzy/0000-0002-3649-8360 NR 29 TC 66 Z9 66 U1 0 U2 8 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 NOV 1 PY 1996 VL 80 IS 9 BP 5028 EP 5034 DI 10.1063/1.363467 PG 7 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700033 ER PT J AU Poles, E Goldberg, SY Fainberg, B Huppert, D Hanna, MC Rosenwaks, Y AF Poles, E Goldberg, SY Fainberg, B Huppert, D Hanna, MC Rosenwaks, Y TI Super band-gap time-resolved luminescence study of degenerate electron-hole plasma in thin GaAs epilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SURFACE-RECOMBINATION VELOCITY; HOT CARRIERS; PICOSECOND RELAXATION; QUANTUM-WELLS; INTERFACES; INP; SEMICONDUCTORS; SPECTROSCOPY; KINETICS; EQUATION AB Super band-gap time-resolved photoluminescence is employed to measure the transport properties of degenerate electron-hole gas in thin GaAs epilayers. It is found that the luminescence decay at wavelengths shorter then the energy gap wavelength is much faster then expected from a simple diffusion-reabsorption model. The results are explained by using a transport model based on Fermi-Dirac carrier statistics and nonparabolic band structure. We have found that only by introducing the above two phenomena the photoluminescence spectra at all energies can be fitted. The importance of the results in studies of hot carrier energy loss rates is discussed. (C) 1996 American Institute of Physics. C1 NATL RENEWABLE LAB,GOLDEN,CO 80401. TEL AVIV UNIV,FAC ENGN,DEPT PHYS ELECT,IL-69978 RAMAT AVIV,ISRAEL. RP Poles, E (reprint author), TEL AVIV UNIV,SCH CHEM,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,IL-69978 RAMAT AVIV,ISRAEL. NR 32 TC 5 Z9 5 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1996 VL 80 IS 9 BP 5129 EP 5137 DI 10.1063/1.363494 PG 9 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700048 ER PT J AU Lubben, D Modine, FA AF Lubben, D Modine, FA TI Enhanced ionic conduction mechanisms at Lil/Al2O3 interfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SOLID LITHIUM IODIDE; COMPOSITE ELECTROLYTES; ELECTRICAL-CONDUCTIVITY; DEFECT CHEMISTRY; 2-PHASE SYSTEMS; PARTICLE-SIZE; AL2O3; CAF2; MONOHYDRATE; FILMS AB Electrical conduction in LiI thin films has been measured in situ during growth as a function of film thickness and temperature. Films grown at 27 degrees C exhibited an enhancement of the ionic conduction of similar to 40X the bulk value in a region extending similar to 100 nm above the interface. The enhanced conduction was not stable and decreased with a log(time) dependence during annealing at the growth temperature. The activation energy for conduction was 0.47+/-0.03 eV, approximately equal to the value for extrinsic conduction in bulk LiI. Films grown at 100 degrees C, on the other hand, showed no enhancement near the interface, and a nearly linear increase in conductance with thickness after an initial nucleation stage. The conductivity of these films was stable at and above the growth temperature and exhibited an activation energy of 0.75+/-0.03 eV, which is comparable to the value for intrinsic LiI. X-ray diffraction measurements on the samples showed that all films were cubic LiI. Films grown near room temperature had a strong (002) orientation while those grown at elevated temperatures were (111) with a mosaic spread of <0.4 degrees. The data show conclusively that there is no enhancement due to space-charge layer formation at the film/substrate interface. On the other hand, the data are all consistent with a model that assumes the conduction enhancement is caused by the overlapping strain fields of dislocations formed during growth. RP OAK RIDGE NATL LAB, DIV SOLID STATE, POB 2008, OAK RIDGE, TN 37831 USA. NR 38 TC 24 Z9 24 U1 1 U2 19 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 NOV 1 PY 1996 VL 80 IS 9 BP 5150 EP 5157 DI 10.1063/1.363497 PG 8 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700051 ER PT J AU Yuan, J He, SY AF Yuan, J He, SY TI The Pseudomonas syringae hrp regulation and secretion system controls the production and secretion of multiple extracellular proteins SO JOURNAL OF BACTERIOLOGY LA English DT Article ID YERSINIA YSC HOMOLOGS; HYPERSENSITIVE RESPONSE; HARPIN(PSS) SECRETION; FLAGELLAR BIOGENESIS; BACTERIA; COMPONENTS; PLANTS; LOCUS AB Pseudomonas syringae pv. tomato DC3000 produces seven to eight major extracellular proteins (EXPs) in a minimal medium inducing hrp genes. Using a polyclonal antibody against DC3000 EXPs, we have determined that the production and secretion of five EXPs (EXP-60, EXP-45, EXP-43, EXP-22, and EXP-10) are under the control of the Hrp regulation and secretion system. C1 MICHIGAN STATE UNIV,PLANT RES LAB,DOE,MSU,E LANSING,MI 48824. UNIV KENTUCKY,DEPT PLANT PATHOL,LEXINGTON,KY 40546. NR 27 TC 104 Z9 104 U1 0 U2 3 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD NOV PY 1996 VL 178 IS 21 BP 6399 EP 6402 PG 4 WC Microbiology SC Microbiology GA VP984 UT WOS:A1996VP98400048 PM 8892851 ER PT J AU McIntyre, BJ Salmeron, M Somorjai, GA AF McIntyre, BJ Salmeron, M Somorjai, GA TI Formation and morphology of hydrocarbon clusters on Pt(111) produced by the thermal decomposition (coking) of propylene under high pressures of H-2 and CO observed in situ by scanning tunneling microscopy SO JOURNAL OF CATALYSIS LA English DT Article ID COADSORBATE-INDUCED COMPRESSION; ETHYLIDYNE FORMATION; CRYSTAL-SURFACES; METAL-SURFACES; REACTOR CELL; PLATINUM; ACETYLENE; ETHYLENE; TEMPERATURES; ADSORPTION AB A scanning tunneling microscope that operates inside an atmospheric pressure chemical reactor cell has been used to study the structure of a Pt(111) model catalyst surface during the thermal decomposition of propylene (coking). Carbonaceous clusters were produced by partial dehydrogenation and polymerization of the hydrocarbon, Flat (1 and 2 Angstrom high) clusters formed with lateral dimensions of several tens of angstroms, The clusters were found to be mobile when the degree of dehydrogenation was low but became immobile with more extensive dehydrogenation, The amount of dehydrogenation and the structure of the hydrocarbon cluster depended upon annealing temperature (in the range from 300 to 800 K) and gas environment (vacuum, CO, H-2/propylene). (C) 1996 Academic Press, Inc. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 31 TC 14 Z9 14 U1 0 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9517 J9 J CATAL JI J. Catal. PD NOV PY 1996 VL 164 IS 1 BP 184 EP 193 DI 10.1006/jcat.1996.0374 PG 10 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VV301 UT WOS:A1996VV30100018 ER PT J AU Permana, H Ng, KYS Peden, CHF Schmieg, SJ Lambert, DK Belton, DN AF Permana, H Ng, KYS Peden, CHF Schmieg, SJ Lambert, DK Belton, DN TI Adsorbed species and reaction rates for NO-CO over Rh(111) SO JOURNAL OF CATALYSIS LA English DT Article ID REFLECTION-ABSORPTION-SPECTROSCOPY; SILICA-SUPPORTED RHODIUM; ENERGY LOSS CHARACTERIZATION; DISTINCT ADSORPTION STATES; CARBON-MONOXIDE; INFRARED-SPECTROSCOPY; VIBRATIONAL FREQUENCIES; MECHANISTIC IMPORTANCE; VACUUM ENVIRONMENTS; SIMULTANEOUS BRIDGE AB We have studied the reaction of NO with CO over a Rh(111) catalyst by monitoring the infrared (IR) intensity of surface CO and NO at various partial pressures of NO (P-NO), CO (P-CO), and sample temperatures (T). Reaction rates for the products (CO2, N2O, and N-2) were previously measured at the same conditions in our apparatus [J. Phys. Chem. 99, 16344 (1995)], Surface coverages were observed both at P-NO = 8 Torr, where the reaction yields mostly N2O and the selectivity is insensitive to either P-CO (1 to 40 Ton) or T (<673 K), and at P-NO = 0.8 Torr; where the major product changes from N2O below 635 K to N-2 above 635 K. Changes in the surface coverages of NO and CO correlate well with the observed changes in N2O selectivity. Below 635 K, where N2O formation is favored, NO dominates the surface, Above 635 K, where N-2 formation is preferred, CO is the majority surface species. Our IR data support a model in which product N2O and N-2 are formed as adsorbed N reacts with either adsorbed NO or N, respectively, In an additional kinetic experiment, we used isotopically labeled N2O to show that gas phase N2O is not an intermediate to N-2 formation at 648 K-this helps to rule out an alternative model. In our IR experiments, two types of spectra were obtained with a Fourier transform IR spectrometer, Polarization spectra were obtained using two fixed polarizers, one before the sample, oriented to pass approximately equal amounts of s- and p-polarized light, and one after the sample that selected s- or p-polarized light. Spectra obtained with s- and p-polarized light were ratioed. We also obtained conventional reflectance absorbance IR spectra. In a separate calibration experiment with NO on Rh(111) in ultrahigh vacuum we observed five IR bands at 1448, 1530, 1590, 1643, and 1693 cm(-1). We attribute all of these to bridging NO, most likely at threefold hollow sites. As NO coverage increases up to saturation, the distribution of population among these bands (and their individual frequencies) gradually changes-the average vibrational frequency of the NO increases from similar to 1440 to similar to 1650 cm(-1). From the linear dependence of the integrated IR absorption on NO coverage we find that the vibrational polarizability of the adsorbed NO is 0.20 +/- 0.02 Angstrom(3). a factor 6.5 larger than for free NO. This increase, proportionally larger than for CO on transition metal surfaces, is explained by the facile charge transfer that accompanies donor-acceptor bonding between NO and Rh(111). (C) 1996 Academic Press, Inc. C1 GM CORP, CTR RES & DEV, PHYS & PHYS CHEM DEPT, WARREN, MI 48090 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. WAYNE STATE UNIV, DEPT CHEM ENGN, DETROIT, MI 48202 USA. OI Schmieg, Steven/0000-0002-1507-207X; Peden, Charles/0000-0001-6754-9928; Ng, K Y Simon/0000-0002-7578-487X NR 76 TC 95 Z9 95 U1 4 U2 13 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 NOV PY 1996 VL 164 IS 1 BP 194 EP 206 DI 10.1006/jcat.1996.0375 PG 13 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VV301 UT WOS:A1996VV30100019 ER PT J AU Szanyi, J Paffett, MT AF Szanyi, J Paffett, MT TI The adsorption of NO and reaction of NO with O-2 on H-, NaH-, CuH-, and Cu-ZSM-5: An in situ FTIR investigation SO JOURNAL OF CATALYSIS LA English DT Article ID SELECTIVE CATALYTIC REDUCTION; NITRIC-OXIDE DECOMPOSITION; OXYGEN-RICH ATMOSPHERES; SOLID ACID CATALYSTS; STRETCHING IR BANDS; STOCHASTIC-THEORY; NITROGEN-DIOXIDE; MOLECULAR-SIEVE; HYDROGEN-BONDS; GASEOUS CUCL AB The adsorption of NO and the reaction of NO with O-2 On H-, NaH-, CuH-, and Cu-ZSM-5 zeolites were studied at 300 K using in situ Fourier transform infrared spectroscopy (FTIR), At this temperature, NO readily adsorbs on the Cu+ sites of CuH- and Cu-ZSM-5 catalysts and decomposition of NO is observed for all catalysts, although the rate of decomposition is vastly different on these materials. In comparison, this reaction is negligible over the Hand NaH-ZSM-5 samples. The time evolution of several nitrogen-containing molecules after controlled O-2 exposure to the NO/ZSM-5 systems has allowed the spectral correlation of these species, These nitrogen-containing species can interact with either the protonic sites of bridging hydroxyls forming hydrogen bonding complexes or the metal cations producing primarily surface nitrates and nitrites. The hydrogen bonded NxOy complexes were characterized with their IR absorption features: (a) NO2, 2133 cm(-1); (b) N2O3, 1875 and 1587 cm(-1); and (c) N2O4, 2185 and 1745 cm(-1). The stretching vibrational frequency of the acidic OH groups of ZSM-5 redshifts due to the interaction with nitrogen-containing molecules and forms ''ABC'' band structures characteristic of medium and strong hydrogen bonding complexes. Although the adsorbed NxOy species (N2O3, N2O4) interacting with the Bronsted protons exhibit characteristics of a strong Lewis base, adsorption enthalpies are sufficiently weak that their existence is not observed even after brief evacuation. Nitric oxide, oxygen coadsorption produces metal cation (Na+ and Cu-n+) bonded surface species possessing IR absorption bands between 1400 and 1650 cm(-1) characteristic of nitrite and nitrate species. The thermal stability of the nitrite and nitrate adsorbed species is much greater than the NxOy species nucleated at free Bronsted acid sites. (C) 1996 Academic Press, Inc. RP Szanyi, J (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,CST-18,MS J-565,LOS ALAMOS,NM 87545, USA. NR 46 TC 99 Z9 102 U1 3 U2 28 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 NOV PY 1996 VL 164 IS 1 BP 232 EP 245 DI 10.1006/jcat.1996.0378 PG 14 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA VV301 UT WOS:A1996VV30100022 ER PT J AU Gittins, CM Rohlfing, EA Rohlfing, CM AF Gittins, CM Rohlfing, EA Rohlfing, CM TI Experimental and theoretical characterization of the S-1-S-0 transition of benzo[a]pyrene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTRAMOLECULAR VIBRATIONAL REDISTRIBUTION; AROMATIC-HYDROCARBONS; SPECTROMETRY; PERYLENE; STATES; FIELD AB We use fluorescence excitation and two-color resonance-enhanced multiphoton ionization (REMPI) spectroscopy to characterize the S-1-S-0 transition of benzo[a]pyrene, B[a]P. In addition, two-color REMPI with a tunable ionization laser provides an improved measurement of the molecular ionization potential, 7.103+/-0.004 eV. Ab initio calculations are performed to determine the vibrational frequencies for the 90 vibrational modes in the S-1 and S-0 electronic states. Our results indicate that the single-excitation configuration interaction (CIS) level of theory provides an excellent representation of excited-state frequencies for this large molecule. Virtually all of the vibronic bands between similar to 380 nm and 397 nm, as well as numerous bands between 373 nm and 380 nm, are assigned with the aid of the calculated vibrational frequencies. In total, 27 of the 61 a' symmetry vibrational modes and 5 of the 29 a '' vibrational modes in the S-1 state have now been assigned. (C) 1996 American Institute of Physics. RP Gittins, CM (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 33 TC 27 Z9 27 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1996 VL 105 IS 17 BP 7323 EP 7335 DI 10.1063/1.472591 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP288 UT WOS:A1996VP28800009 ER PT J AU Gentile, AC Evensky, DA Durant, JL Brown, NJ Koszykowski, ML AF Gentile, AC Evensky, DA Durant, JL Brown, NJ Koszykowski, ML TI Convergence and path cancellation in quantum Monte Carlo real time path integration SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POWER-SERIES EXPANSION; EVOLUTION OPERATOR; PROPAGATOR; DYNAMICS AB We find that poor resolution of the tails of the distribution of integrands obtained inhibits convergence in Monte Carlo calculation of real time path integrals. We show that many methods previously tried to improve convergence neither resolve nor diminish the tails effectively. We find that large contributions to the integrand come from paths that have a large variance from the zero-path and/or that have few zero crossings. The results of crude dampings based on where such paths are poorly sampled suggest that exploring cancellations of paths characterized by path variance and zero crossings may be effective in improving convergence. (C) 1996 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Gentile, AC (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 25 TC 2 Z9 2 U1 1 U2 1 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 NOV 1 PY 1996 VL 105 IS 17 BP 7613 EP 7616 DI 10.1063/1.472547 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP288 UT WOS:A1996VP28800038 ER PT J AU Baranyai, A AF Baranyai, A TI Phase space compression and entropy of nonequilibrium steady states SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VARIATIONAL PRINCIPLE; GAUSSIAN THERMOSTAT; MOLECULAR-DYNAMICS; EQUILIBRIUM AB We show that the variational principle of Evans and Baranyai [Phys. Rev. Lett. 67, 2597 (1991)] can be derived from a macroscopic entropy definition of nonequilibrium steady states. This definition claims that the entropy of nonequilibrium steady states is the sum of the equilibrium entropy of the system under the same external conditions (fixed internal energy, E, volume, V, and number of particles N), and an additional term which can be measured by the minimum excess work performed on the system by the external field, F-e, by bringing it from its equilibrium state to the final steady state. (C) 1996 American Institute of Physics. C1 OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. EOTVOS LORAND UNIV, LAB THEORET CHEM, H-1518 BUDAPEST, HUNGARY. RP Baranyai, A (reprint author), UNIV TENNESSEE, DEPT CHEM ENGN, KNOXVILLE, TN 37996 USA. NR 17 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1996 VL 105 IS 17 BP 7723 EP 7726 DI 10.1063/1.472555 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP288 UT WOS:A1996VP28800049 ER PT J AU Sirota, EB Wu, XZ AF Sirota, EB Wu, XZ TI The rotator phases of neat and hydrated 1-alcohols SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-DIFFRACTION; LIQUID NORMAL-ALKANES; LONG-CHAIN ALCOHOLS; AIR-WATER-INTERFACE; N-ALKANES; LANGMUIR MONOLAYER; SURFACE; MIXTURES; TRANSITIONS; SCATTERING AB We report an x-ray scattering study of the rotator phases in both dry and hydrated 1-alcohols CH3-(CH2)(n-1)-OH(12 less than or equal to n less than or equal to 26). Hydration was accomplished by using both fixed composition and controlled relative humidity. A hexagonal phase and two tilted phases are reported in the temperature versus chain length and temperature versus humidity phase diagrams. Hydration tends to drive the system from one tilted rotator state to the other, and then to the untilted hexagonal phase. The hexagonal phase shows a six-layer periodicity illustrating the crossover between trilayer alkane behavior and bilayer surfactant behavior. Hydration and chain-length mixing increase the temperature range of the rotator phase, The rotator phase will take in about 1 H2O per 2 alcohols which is twice the saturated water content of the liquid phase. This is shown to explain the unusual rise in the melting temperature with hydration. (C) 1996 American Institute of Physics. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP Sirota, EB (reprint author), EXXON RES & ENGN CO,CORP RES SCI LABS,ROUTE 22 E,ANNANDALE,NJ 08801, USA. RI Sirota, Eric/A-7633-2009 NR 44 TC 53 Z9 53 U1 0 U2 6 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 NOV 1 PY 1996 VL 105 IS 17 BP 7763 EP 7773 DI 10.1063/1.472559 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP288 UT WOS:A1996VP28800054 ER PT J AU Leheny, RL Menon, N Nagel, SR Price, DL Suzuya, K Thiyagarajan, P AF Leheny, RL Menon, N Nagel, SR Price, DL Suzuya, K Thiyagarajan, P TI Structural studies of an organic liquid through the glass transition SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SUPERCOOLED LIQUIDS; NEUTRON-DIFFRACTION; FORMING LIQUIDS; GLYCEROL AB We have performed neutron diffraction experiments on deuterated propylene glycol, an organic glass former, at temperatures ranging from where its dynamical response approaches that of normal liquids to below the point where relaxation times appear to diverge. Our studies extend over a very broad range of scattering wave vector (0.012.0.CO;2 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800005 ER PT J AU Auer, LH Rosenberg, ND Birdsell, KH Whitney, EM AF Auer, LH Rosenberg, ND Birdsell, KH Whitney, EM TI The effects of barometric pumping on contaminant transport SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE hydrology; unsaturated zone; soil remediation AB Variation in the ambient atmospheric pressure results in subsurface motion of air in porous and fractured earth materials. This is known as barometric pumping. We analyze this phenomenon for unfractured media and demonstrate that if hydrodynamic dispersivity is included, barometric pumping can significantly decrease the retention time of volatile subsurface contaminants. Formulae are derived which give analytically the dependence of the effect on the amplitude and frequency of the barometric pump as well as on the material properties. In addition, numerical modeling results using a method which carefully avoids spurious numerical dispersion are presented. Field data will appear to follow a standard diffusive transport model; but in the systems in which barometric pumping is significant, the value for D will need to be greater than that derived from isobaric tests. In addition to enhancing the diffusion, pumping also sweeps out pore gases near the surface and thus, reduces the distance a subsurface contaminant must diffuse before it mixes with the atmosphere. These barometric pumping mechanisms will be enhanced by the presence of fractures, which permit pressure variations to propagate deep into the ground. Because barometric pumping affects the rate of contaminant transport from the subsurface, this process may play an important role in the environmental remediation of volatile organic chemicals in the vadose zone. C1 LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. NR 9 TC 61 Z9 61 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD NOV PY 1996 VL 24 IS 2 BP 145 EP 166 DI 10.1016/S0169-7722(96)00010-1 PG 22 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA VV030 UT WOS:A1996VV03000003 ER PT J AU Zhang, K Mogilevsky, R Hinks, DG Mitchell, J Schultz, AJ Wang, Y Dravid, V AF Zhang, K Mogilevsky, R Hinks, DG Mitchell, J Schultz, AJ Wang, Y Dravid, V TI Crystal growth of (La,Sr)(2)CuO4 by float zone melting SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID SINGLE-CRYSTALS; PHASE-DIAGRAM; LA2-XSRXCUO4; SR; SUPERCONDUCTORS; LA2CUO4; SYSTEM AB High quality single crystals of La2-xSrxCuO4 (x=0.15, 0.20) have been successfully grown using the floating zone method. Stoichiometric feed rods were prepared with a density high enough to directly zone refine, The chemical composition of the molten zone was allowed to establish itself during the first few zone lengths, thus no nonstoichiometric seed rod was necessary, Neutron diffraction shows the boule is composed of several large grains. The grain boundaries are found to be Sr-rich, containing La2SrCu2O6. Electron microscopy, X-ray back-reflection Laue and AC susceptibility data are used to characterize the crystals. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60208. RI Dravid, Vinayak/B-6688-2009 NR 17 TC 5 Z9 5 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 1996 VL 169 IS 1 BP 73 EP 78 DI 10.1016/0022-0248(95)01003-3 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VQ726 UT WOS:A1996VQ72600009 ER PT J AU Chen, PJ AF Chen, PJ TI A coupled solid/fluids mixture theory that suffices for diffusion problems SO JOURNAL OF ELASTICITY LA English DT Article DE diffusion; coupled solid/fluids behavior; mixture theory; continuum mechanics AB In this paper, I begin with the general formulation of mixture theory by Bowen and present the derivation of a minimal set of field equations, constitutive relations, and material parameters suitable for the solutions of meaningful diffusion problems. The specific results are for a single solid and two fluids, and they may be extended to any number of fluids. I allude to the results of three problems, viz. (1) the injection of a fluid into a geological formation saturated with another fluid, (2) the drainage of two dissimilar fluids from a geological formation due to in-situ fluid pore pressures, and (3) the process of squeezing a sponge dry, in order to illustrate the general applicability of the derived theory. RP Chen, PJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0374-3535 J9 J ELASTICITY JI J. Elast. PD NOV PY 1996 VL 45 IS 2 BP 117 EP 134 DI 10.1007/BF00042486 PG 18 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA WJ054 UT WOS:A1996WJ05400003 ER PT J AU Chen, PJ Rudeen, DK AF Chen, PJ Rudeen, DK TI Clarifications and further implications of the concept of motion in mixture theories SO JOURNAL OF ELASTICITY LA English DT Article C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. RP Chen, PJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0374-3535 J9 J ELASTICITY JI J. Elast. PD NOV PY 1996 VL 45 IS 2 BP 135 EP 137 DI 10.1007/BF00042487 PG 3 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA WJ054 UT WOS:A1996WJ05400004 ER PT J AU Chen, PJ Rudeen, DK AF Chen, PJ Rudeen, DK TI Application of a coupled solid/fluids mixture theory: Process of squeezing a sponge SO JOURNAL OF ELASTICITY LA English DT Article AB In this paper, we present the details of the solution of one of three problems obtained via the application of a coupled solid/fluids mixture theory developed recently by Chen. The problem is that of the process of squeezing a sponge. A fluid saturated solid is sandwiched between two infinitely stiff plates, one plate is held fixed and the other applies increasing pressure at its interface with the solid. Results concerning the stress of the solid, volume fraction, bulk density, chemical potential and pressures of the fluid, and the characteristics of fluid mass discharge are reported. The results are consistent with our expectations and experiences. C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. RP Chen, PJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0374-3535 J9 J ELASTICITY JI J. Elast. PD NOV PY 1996 VL 45 IS 2 BP 139 EP 152 DI 10.1007/BF00042488 PG 14 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA WJ054 UT WOS:A1996WJ05400005 ER PT J AU Fan, Z Mohammad, SN Kim, W Aktas, O Botchkarev, AE Suzue, K Morkoc, H Duxstad, K Haller, EE AF Fan, Z Mohammad, SN Kim, W Aktas, O Botchkarev, AE Suzue, K Morkoc, H Duxstad, K Haller, EE TI Ohmic contacts and Schottky barriers to n-GaN SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials Science of Contacts, Metallization and Interconnects, at the 1996 TMS Annual Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP TMS DE GaN; ohmic contacts; Schottky barriers; Ti/Al/Ni/Au ID GALLIUM NITRIDE; HEIGHT; DIODES; LAYER AB Gallium nitride is a highly promising wide bandgap semiconductor with applications in high power electronic devices and optoelectronic devices. For these devices to be realized, metallization, both ohmic and rectifying must be available. In this manuscript, we discuss the properties of ohmic contacts and Schottky barriers on n-type GaN. The most recent ohmic metallization scheme involves Ti/Al based composites, namely Ti/Al/Ni/Au (150 Angstrom/2200 Angstrom/400 Angstrom/500 Angstrom.) preceded by a reactive ion etching (RIE) process which most likely renders the surface highly n-type. With annealing at 900 degrees C for 30 s, contacts with specific resistivity values less than rho(s) = 1 x 10(-7) Omega cm(2) for a doping level of 4 x 10(17) cm(-3) were obtained. Schottky barriers with Ti, Cr, Pd, Au, Ni, and Pt have been reported; however, we will concentrate here on Pt based structures as they yield a large barrier height of 1.1 eV. Both capacitance-voltage and current-voltage analyses have been carried out as a function of temperature to gain insight into the current conduction processes involved. Attention must now be turned to the modifications needed to render these contacts reliable. C1 UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL 61801. UNIV CALIF BERKELEY,DEPT MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Fan, Z (reprint author), UNIV ILLINOIS,MAT RES LAB,104 S GOODWIN AVE,URBANA,IL 61801, USA. NR 30 TC 40 Z9 40 U1 1 U2 22 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 NOV PY 1996 VL 25 IS 11 BP 1703 EP 1708 DI 10.1007/s11664-996-0025-0 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VT299 UT WOS:A1996VT29900006 ER PT J AU Chu, F Jia, QX Landrum, G Wu, XD Hawley, M Mitchell, TE AF Chu, F Jia, QX Landrum, G Wu, XD Hawley, M Mitchell, TE TI Microstructures and electrical properties of SrRuO3 thin films on LaAlO3 substrates SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials Science of Contacts, Metallization and Interconnects, at the 1996 TMS Annual Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP TMS DE conductive SrRuO3; LaAlO3 substrate; microstructures; thin films ID ELECTRODES AB Conductive SrRuO3 thin films have been deposited using pulsed laser deposition on LaAlO3 substrates at different substrate temperatures, Structural and microstructural properties of the SrRuO3/LaAlO3 system have been studied using x-ray diffraction, scanning electron microscopy, and scanning tunneling microscopy, Electrical properties of SrRuO3 thin films have been measured. It was found that the film deposited at 250 degrees C is amorphous, showing semiconductor-like temperature dependence of electrical conductivity. The film deposited at 425 degrees C is crystalline with very fine grain size (100 similar to 200 Angstrom), showing both metallic and semiconductor-like temperature dependence of electrical conductivity in different temperature regions. The film deposited at 775 degrees C shows a resistivity of 280 mu Omega . cm at room temperature and a residual resistivity ratio of 8.4, Optimized deposition conditions to grow SrRuO3 thin films on LaAlO3 substrates have been found. Possible engineering applications of SrRuO3 thin films deposited at different temperatures are discussed, Bulk and surface electronic structures of SrRuO3 are calculated using a semi-empirical valence electron linear combination of atomic orbitals approach, The theoretical calculation results are employed to understand the electrical properties of SrRuO3 thin films. RP Chu, F (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008; OI Landrum, Gregory/0000-0001-6279-4481 NR 15 TC 10 Z9 11 U1 0 U2 10 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 NOV PY 1996 VL 25 IS 11 BP 1754 EP 1759 DI 10.1007/s11664-996-0031-2 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA VT299 UT WOS:A1996VT29900012 ER PT J AU Rost, TL Bryant, JA AF Rost, TL Bryant, JA TI Root organization and gene expression patterns SO JOURNAL OF EXPERIMENTAL BOTANY LA English DT Review DE root apex; root anatomy; root development; gene expression ID PISUM-SATIVUM-L; LYCOPERSICON-ESCULENTUM MILL; RICH GLYCOPROTEIN GENE; DAUCUS-CAROTA L; CELL-PROLIFERATION; DNA-REPLICATION; MESSENGER-RNA; ARABIDOPSIS EMBRYO; NUCLEAR-PROTEIN; APICAL MERISTEM AB New tools of microscopy, molecular biology, and genetics are making it possible for biologists to study roots with new vigour. Such investigations have enabled plant biologists to notice the symmetry, pattern, and simplicity of root structures so that there is now an exciting rebirth in the study of roots. The literature of root biology, development and structure is vast. In this short review we will concentrate on describing our notion of how roots are organized structurally, and then discuss what is known about tissue- and zone-specific gene expression in roots. C1 UNIV EXETER,WASHINGTON SINGER LABS,DEPT BIOL SCI,EXETER EX4 4QG,DEVON,ENGLAND. RP Rost, TL (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV BIOL SCI,PLANT BIOL SECT,DAVIS,CA 95616, USA. NR 105 TC 31 Z9 34 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0022-0957 J9 J EXP BOT JI J. Exp. Bot. PD NOV PY 1996 VL 47 IS 304 BP 1613 EP 1628 DI 10.1093/jxb/47.11.1613 PG 16 WC Plant Sciences SC Plant Sciences GA WA292 UT WOS:A1996WA29200001 ER PT J AU Crooker, NU Burton, ME Siscoe, GL Kahler, SW Gosling, JT Smith, EJ AF Crooker, NU Burton, ME Siscoe, GL Kahler, SW Gosling, JT Smith, EJ TI Solar wind streamer belt structure SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HELIOSPHERIC CURRENT SHEET; PLANAR MAGNETIC-STRUCTURES; HEAT-FLUX DROPOUTS; PLANETARY SECTOR BOUNDARIES; DIRECTIONAL DISCONTINUITIES; CORONAL STREAMERS; FIELD; ELECTRONS; RECONNECTION; FLUCTUATIONS AB In the course of 2 days in October 1978, ISEE 3 encountered 14 magnetic field reversals, five pronounced and several lesser high-beta regions called ''plasma sheets,'' two distinct entropy regimes, two heat flux dropouts (HFDs), and planar magnetic structure led by a shock wave. The complexity of the interval afforded an excellent opportunity to determine the relationships between these streamer belt structures, their geometry and topology, and the resulting implications for the structure of the heliospheric current sheet (HCS). None of the results of three tests applied to the data support a wavy or folded HCS hypothesis. In particular, a test for true magnetic polarity using primarily heat flux data indicated that the field reversals occurred in a predominantly toward sector with three pockets of true away polarity and three of false away polarity. The results are consistent with a view in which current sheets bound intertwined flux ropes, some of which coil back on themselves, possibly as remnants of transient coronal activity. A comparison between joint occurrences of the various structures showed that the most intense plasma sheets in the interval coincided with true polarity reversals, that nearly every reversal, whether true or false, corresponded to at least a weak plasma sheet, and that plasma sheets occurred within HFD intervals. The plasma sheet/HFD relationship was statistically confirmed in a search for plasma sheets in published HFDs. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. PHILLIPS LAB,GEOPHYS DIRECTORATE,BEDFORD,MA 01731. RP Crooker, NU (reprint author), BOSTON UNIV,CTR SPACE PHYS,725 COMMONWEALTH AVE,BOSTON,MA 02215, USA. NR 40 TC 43 Z9 44 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24331 EP 24341 DI 10.1029/96JA02412 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500001 ER PT J AU Kahler, SW Crooker, NU Gosling, JT AF Kahler, SW Crooker, NU Gosling, JT TI The topology of intrasector reversals of the interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; SOLAR-WIND ELECTRONS; SECTOR BOUNDARIES; CLOUDS; EVENTS; ASSOCIATION; EVOLUTION; POLARITY; SHOCK; MODEL AB A technique has been developed recently to determine the polarities of interplanetary magnetic fields relative to their origins at the Sun by comparing energetic electron flow directions with local magnetic field directions. Here we use heat flux electrons from the Los Alamos National Laboratory (LANL) plasma detector on the ISEE 3 spacecraft to determine the field polarities. We examine periods within well-defined magnetic sectors when the field directions appear to be reversed from the normal spiral direction of the sector. About half of these intrasector field reversals (IFRs) are cases in which the polarities match those of the surrounding sectors, indicating that those fields have been folded back toward the Sun. The more interesting cases are those with polarity reversals. We find no clear cases of isolated reverse polarity fields, which suggests that islands of reverse polarity in the solar source dipole field probably do not exist. The IFRs with polarity reversals are strongly associated with periods of bidirectional electron flows, suggesting that those fields occur only in conjunction with closed fields. We propose that both those IFRs and the bidirectional flows are signatures of coronal mass ejections (CMEs). In that case, many interplanetary CMEs are larger and more complex than previously thought, consisting of both open and closed field components. C1 BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Kahler, SW (reprint author), USAF,PHILLIPS LAB,GPSG,HANSCOM AFB,BEDFORD,MA 01731, USA. NR 40 TC 37 Z9 37 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24373 EP 24382 DI 10.1029/96JA02232 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500005 ER PT J AU Angelopoulos, V Sergeev, VA Mozer, FS Tsuruda, K Kokubun, S Yamamoto, T Lepping, R Reeves, G FriisChristensen, E AF Angelopoulos, V Sergeev, VA Mozer, FS Tsuruda, K Kokubun, S Yamamoto, T Lepping, R Reeves, G FriisChristensen, E TI Spontaneous substorm onset during a prolonged period of steady, southward interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND ORIGIN; MAGNETOSPHERIC SUBSTORMS; DISTANT MAGNETOTAIL; PLASMA SHEET; NEAR-EARTH; CONVECTION; GEOTAIL; EVENTS; SATELLITE; ISEE-3 AB We document a clear case of spontaneous substorm onset under conditions of steady southward interplanetary magnetic field on January 22, 1993. The substorm occurred at 0415 UT with an intensification at 0455 UT during an interval of convection bay activity but had most of the features associated with substorms. These features include high-latitude and midlatitude magnetic bays at ground magnetometers, and magnetic field compression and energetic particle injection at geosynchronous altitude. In addition, a plasmoid release was observed in the distant tail plasma sheet by the Geotail spacecraft ata GSM position (-96, 1, -6) R(E). We conclude that spontaneous-onset substorms occur occasionally even during steady convection bay events. Such substorms and ''classical'' substorms progress in a very similar manner, Irrespective of possible differences in their onset mechanism. C1 DANISH METEOROL INST,DK-2100 COPENHAGEN,DENMARK. NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA,AICHI 442,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. ST PETERSBURG STATE UNIV,INST PHYS,ST PETERSBURG 198904,RUSSIA. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. RP Angelopoulos, V (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. RI Reeves, Geoffrey/E-8101-2011; Sergeev, Victor/H-1173-2013 OI Reeves, Geoffrey/0000-0002-7985-8098; Sergeev, Victor/0000-0002-4569-9631 NR 64 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24583 EP 24598 DI 10.1029/96JA02515 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500025 ER PT J AU Angelopoulos, V Mitchell, DG McEntire, RW Williams, DJ Lui, ATY Krimigis, SM Decker, RB Christon, SP Kokubun, S Yamamoto, T Saito, Y Mukai, T Mozer, FS Tsuruda, K Reeves, GD Hughes, WJ FriisChristensen, E Troshichev, O AF Angelopoulos, V Mitchell, DG McEntire, RW Williams, DJ Lui, ATY Krimigis, SM Decker, RB Christon, SP Kokubun, S Yamamoto, T Saito, Y Mukai, T Mozer, FS Tsuruda, K Reeves, GD Hughes, WJ FriisChristensen, E Troshichev, O TI Tailward progression of magnetotail acceleration centers: Relationship to substorm current wedge SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; PLASMA SHEET; CURRENT DISRUPTION; MAGNETIC-FIELD; ENERGETIC PARTICLES; GEOTAIL; EXPANSION; DYNAMICS; ISEE-3; FLOW AB During a fortuitous near-alignment of the IMP 8 and Geotail spacecraft along the magnetotail axis, geomagnetic activity monitors on the ground and at geosynchronous altitude detected the evolution of a magnetospheric substorm, We searched for evidence of the neutral line formation and evolution during this substorm, There exists evidence for multiple, time-varying, localized (<9 R(E)) acceleration regions in the magnetotail at the time, Late in the expansion phase of the substorm a reversal of the predominant direction of the energetic particle anisotropy as well as the plasma flow velocity from tailward to Earthward was observed at Geotail at X=-61 R(E). The tailward-to-Earthward anisotropy reversal is consistent with a tailward progression of the acceleration centers at Geotail, This phenomenon could be identified as the tailward retreat of the neutral line, However, the tailward progression of the activity is in reality the re appearance of new acceleration regions at gradually more tailward sites, Although the large temporal and spatial development is consistent with that of a reconnection geometry, the local Geotail acceleration is bursty and quite possibly localized, An ensuing increase of the northward magnetic field component seen at IMP 8 at X=-32 R(E) is consistent with a tailward expansion of the substorm current wedge out to that distance, Current wedge formation at IMP 8 was delayed by several minutes relative to the anisotropy reversal at Geotail, We interpret this as evidence that the location of current wedge and the location of magnetotail particle acceleration are separated by at least 30 R(E) during the late expansion phase of this substorm, Given the similar to 9 R(E) cross-tail separation of TMP 8 and Geotail, there still exists some uncertainty as to the three dimensional evolution of the acceleration and dipolarization regions in the late expansion phase of this substorm, Given the scarcity of similar IMP 8-Geotail conjunctions during the distant tail Geotail phase, a full understanding of that evolution has to await a future multiprobe mission. C1 UNIV MARYLAND,DEPT PHYS & ASTRON,COLLEGE PK,MD 20742. JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723. DANISH METEOROL INST,DK-2100 COPENHAGEN,DENMARK. BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA,AICHI 442,JAPAN. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. ST PETERSBURG STATE UNIV,ARCTIC & ANTARCTIC RES INST,ST PETERSBURG 199226,RUSSIA. RP Angelopoulos, V (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 64 TC 22 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24599 EP 24619 DI 10.1029/96JA01665 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500026 ER PT J AU Smith, AJ Freeman, MP Reeves, GD AF Smith, AJ Freeman, MP Reeves, GD TI Postmidnight VLF chorus events, a substorm signature observed at the ground near L=4 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERE; PULSATIONS; SATELLITE; PLASMA; MODEL AB Clouds of energetic electrons, injected sporadically into the nightside magnetosphere during substorm expansion phase onsets, can generate VLF whistler mode noise through the gyroresonance instability, which may then be observed on the ground or in space. Although these substorm-related chorus events (SCEs) have been reported occasionally in the literature, there seems to have been no systematic study, probably because of the lack, until now, of a well-adapted experimental technique. The VLF/ELF Logger Experiment (VELOX) instrument, located at Halley, Antarctica (76 degrees S, 26 degrees W, L = 4.3), is, however, particularly well suited to a systematic study of this aspect of the substorm phenomenon. The data exist almost continuously from January 1992 onward, at 1-s time resolution in eight quasi-logarithmically spaced frequency bands covering the range 0.25-10 kHz. For this paper, 327 days of continuous data from 1992 have been analyzed. The 243 SCEs identified were observed on about 50% of days, almost exclusively in the 2300-0600 MLT local time range, and were characterized by limited duration (typically, similar to 10 min at 1.5 kHz) and upward frequency; drift of a band of usually weak and relatively unstructured chorus at a rate of similar to 200 Hz min(-1) between 0.5 and 5 kHz (corresponding to parallel electron energies in the range similar to 10-100 keV). This drift is consistent with the combined eastward and inward motion of the resonant electrons due to azimuthal gradient-curvature drift and radial E x B drift under the action of substorm-enhanced westward electric fields of order 1 mVm(-1) near the equatorial plane. The limited MLT viewing window of the station implies an overall detection efficiency for SCEs of similar to 20%. The inferred annual mean substorm rate, 1366 +/- 188 year(-1), and inter substorm interval, 5.5 +/- 0.8 hours, are similar to the values derived using other techniques. However, the distribution of intervals between successive SCEs is different from that for substorm-related particle injections at geostationary orbit; in particular, the mode is around I hour rather than 2-3 hours. The SCE as seen by a VELOX-type VLF receiver with a wide field of view is an important alternative ground-observable substorm signature, complementary to those (such as bays and Pi 2 pulsations) indicated by magnetometers. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Smith, AJ (reprint author), BRITISH ANTARCTIC SURVEY,HIGH CROSS,MADINGLEY RD,CAMBRIDGE CB3 0ET,ENGLAND. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 26 TC 44 Z9 44 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24641 EP 24653 DI 10.1029/96JA02236 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500028 ER PT J AU Gosling, JT Thomsen, MF Le, G Russell, CT AF Gosling, JT Thomsen, MF Le, G Russell, CT TI Observations of magnetic reconnection at the lobe magnetopause SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID POLAR-CAP CONVECTION; DAYSIDE MAGNETOPAUSE; EARTHS MAGNETOPAUSE; SOLAR-WIND; FIELD; FLOW; INTERPLANETARY; SHEAR; MAGNETOSPHERE; LAYER AB Measurements made by the Fast Plasma Experiment on ISEE 2 provide direct evidence for the rereconnection of the open field lines of the tail lobes with the interplanetary magnetic field at the lobe magnetopause. The evidence, obtained on seven different dates at locations well removed from the noon-midnight plane, consists primarily of observations of accelerated magnetosheath plasma within the lobe magnetopause current layer. These accelerations were either sunward or tailward, depending on the position of the satellite relative to the rereconnection site. Such accelerations have been observed in both the northern and the southern hemispheres, on both the dawn and the dusk sides of the magnetosphere, and both sunward and tailward of the dawn-dusk terminator. Except for one event, all of the lobe magnetopause reconnection events examined here occurred at times of large local field shears at the magnetopause; these large field shears were associated primarily with large x and y magnetic field components rather than with the z component. In each case the magnetosheath plasma crossing into the magnetopause current layer was heated as well as accelerated. Often, this newly heated and accelerated plasma, which was confined to the current layer where the field rotated from its magnetosheath orientation to its magnetospheric orientation, coexisted as a double-ion beam with unaccelerated mantle plasma that had entered the magnetosphere earlier upstream from the rereconnection site. The change in velocity experienced by the newly entered plasma within the current layer was usually in reasonable accord with stress balance at the magnetopause. Apparent accelerations and decelerations observed upstream from the magnetopause in two of these events were associated with secondary, field-aligned ion populations that appeared to result from reflection of magnetosheath ions at the magnetopause. C1 UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90095. RP Gosling, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. RI Le, Guan/C-9524-2012 OI Le, Guan/0000-0002-9504-5214 NR 32 TC 26 Z9 26 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24765 EP 24773 DI 10.1029/96JA02254 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500039 ER PT J AU Thomsen, MF McComas, DJ Reeves, GD Weiss, LA AF Thomsen, MF McComas, DJ Reeves, GD Weiss, LA TI An observational test of the Tsyganenko (T89a) model of the magnetospheric field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC-FIELD; GEOSYNCHRONOUS ORBIT; GEOMAGNETIC-FIELD; PLASMA ANALYZER; SOLAR-WIND; SPACECRAFT; MAGNETOTAIL; PARAMETERS; SHEET AB The range of magnetic field tilt angles observed at several satellites in geosynchronous orbit is compared with the ranges predicted for the same locations by the different Kp parameterizations of the Tsyganenko 1989a magnetic field model as a function of local time and season. The data are examined separately for satellite locations near the magnetic equator and slightly off the equator. The model predicts reasonably well the observed basic variation in the tilt angle with location, and it permits a range of field inclinations adequate to encompass the majority of the observed angles for the dawn, dusk, and night quadrants. On the dayside of the magnetosphere the model exhibits very little variation in tilt over the entire range of parameterizations and cannot reproduce the observed range of tilt angles. Near the magnetic equator the majority of observed tilt angles lie within the model range, with roughly equal numbers of cases that are overstretched or understretched with respect to the model range. Off the equator the models tend to be more stretched than is generally observed. With some modest season-to-season differences these results are valid for all four seasons. RP Thomsen, MF (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 21 TC 37 Z9 37 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24827 EP 24836 DI 10.1029/96JA02318 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500044 ER PT J AU Datskou, I Hutchison, J Ince, S AF Datskou, I Hutchison, J Ince, S TI Estimation of secondary waste loads generated during environmental restoration activities SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE waste loads; environmental restoration; waste management; capping; soil washing AB The US Department of Energy's (DOE's) Environmental Restoration (ER) program is responsible for remediating thousands of contaminated sites across the DOE complex. A major concern during remediation is the secondary waste generated as a result of ER site remediation. The treatment, storage and disposal (TSD) of secondary waste generated as a result of ER site remediation is the responsibility of the waste management (WM) program. In order to manage TSD operations on ER generated waste, WM needs accurate and consistent estimates of the volume of secondary waste generated. This paper discuss three remedial processes and presents estimates of waste volumes generated during these processes. C1 INTEGRATED ENVIRONM SERV,TORRANCE,CA 90504. CLEMSON UNIV,ENVIRONM SYST ENGN,CLEMSON,SC 29632. RP Datskou, I (reprint author), OAK RIDGE NATL LAB,ASSESSMENT TECHNOL SECT,POB 2008,BLDG 1062,OAK RIDGE,TN 37831, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD NOV PY 1996 VL 51 IS 1-3 BP 35 EP 45 DI 10.1016/S0304-3894(96)01837-7 PG 11 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WB584 UT WOS:A1996WB58400003 ER PT J AU Huesemann, MH Truex, MJ AF Huesemann, MH Truex, MJ TI The role of oxygen diffusion in passive bioremediation of petroleum contaminated soils SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE oxygen; petroleum contaminated soil; passive bioremediation ID FUEL SPILLS; BIODEGRADATION; COEFFICIENT AB In passive bioremediation of petroleum hydrocarbon contaminated soils, oxygen diffusion is the primary mechanism for supplying the oxygen which is required for microbial hydrocarbon biodegradation processes. It is the objective of this research to theoretically evaluate whether passive bioremediation can be a feasible treatment alternative for petroleum contaminated soils. In this paper we derive equations for the steady-state oxygen concentration profiles which are expected to develop as a result of simultaneous oxygen diffusion and consumption in hydrocarbon contaminated soils. These equations are used to estimate the maximum oxygen penetration distance and the total cleanup time for several environmental scenarios such as surface and subsurface soil contamination as well as contaminated soil piles. It was found that oxygen is expected to penetrate most contaminated soils for up to several meters if hydrocarbon biodegradation rates are similar to those measured during bioventing respiration tests, i.e. approximately 2.5-10 ppm TPH day(-1). Both the depth of oxygen penetration and the total passive bioremediation cleanup time were found to be strongly dependent on the magnitude of the diffusion coefficient for oxygen in soil (D-s). As expected, increased oxygen penetration distances and decreased cleanup times are associated with increased D-s values. Since the magnitude of D-s is inversely related to the soil moisture content, it is imperative to maintain moderately low soil moisture levels in order to maximize the effectiveness of passive bioremediation treatment. Passive bioremediation is expected to be a feasible and cost-effective treatment alternative for TPH contaminated soils in cases where the minimization of cleanup times is not a major remediation objective. RP Huesemann, MH (reprint author), PACIFIC NW LAB, BIOPROC GRP, POB 999, RICHLAND, WA 99352 USA. NR 27 TC 42 Z9 43 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD NOV PY 1996 VL 51 IS 1-3 BP 93 EP 113 DI 10.1016/S0304-3894(96)01834-1 PG 21 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WB584 UT WOS:A1996WB58400007 ER PT J AU Ogden, KL Ogden, GE Hanners, JL Unkefer, PJ AF Ogden, KL Ogden, GE Hanners, JL Unkefer, PJ TI Remediation of low-level mixed waste: Cellulose-based materials and plutonium SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE radioactive waste; biodegradation; cheese cloth; remediation cost analysis; plutonium; cellulose-based material AB Low-level mixed radioactive wastes containing cellulose-based materials and plutonium have been generated during various nuclear processing activities. Biological digestion of the organic- or cellulose- based material was examined as an environmentally acceptable and effective method of treatment for these and other similar wastes. Cellulase enzyme was used to initiate biodegradation prior to 90% destruction of the cellulose material by a sewage sludge consortium. Plutonium did not significantly effect the biodegradation. Bench-scale experimental data were used to design a batch treatment system. A cost and sensitivity analysis was performed to determine the optimal reactor size, materials of construction and media type. The sensitivity analysis indicated that while a 12-month treatment scenario using a carbon steel ball mill, sludge digester and vacuum thickener was the least expensive scenario evaluated on a levelized cost basis ($800 per ton of waste degraded per month), the 12-month scenario using stainless steel construction and the alternative dewatering system offered the most cost-effective treatment alternative and better corrosion resistance (levelized cost of $1130 per ton per month). The dewatering system consisting of a disk centrifuge and sludge dryer is capable of doubling the sludge solids content and produce an overall waste reduction of 67%. The proposed waste treatment system offers a cost savings of up to 31% compared to conventional disposal practices. C1 PIMA COMMUNITY COLL,DEPT ENVIRONM SCI & EMERGENCY SERV,TUCSON,AZ 85709. LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL LAB,LOS ALAMOS,NM 87545. RP Ogden, KL (reprint author), UNIV ARIZONA,DEPT CHEM & ENVIRONM ENGN,TUCSON,AZ 85721, USA. NR 7 TC 3 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD NOV PY 1996 VL 51 IS 1-3 BP 115 EP 130 DI 10.1016/S0304-3894(96)01798-0 PG 16 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WB584 UT WOS:A1996WB58400008 ER PT J AU Lyon, BF Holmes, JA Kosiewicz, ST Wilbert, KA Travis, CC AF Lyon, BF Holmes, JA Kosiewicz, ST Wilbert, KA Travis, CC TI Estimation of corrosion on carbon steel TRU waste drums using the Poisson distribution SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE carbon steel drum; corrosion; Poisson process; transuranic waste AB The number of container failures due to corrosion is estimated as a function of time for 55-gallon painted carbon steel drums under earthen cover. The calculations are performed using an empirical statistical model that assumes that the corrosion depths are given by a Poisson probability distribution parameterized by an average corrosion rate. Uncertainties in the average corrosion rate for both pitting and general corrosion are addressed, as is uncertainty in the drum wall thickness. Times for specific fractions of the population of drums to breach can be estimated in a manner that incorporates uncertainties in the corrosion process. To improve corrosion predictions, it is recommended that more data on the corrosion of carbon steel drums under earthen cover be collected in the future. C1 LOS ALAMOS NATL LAB,WASTE MANAGEMENT PROGRAM OFF,LOS ALAMOS,NM. RP Lyon, BF (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,1060 COMMERCE PK,MS-6480,OAK RIDGE,TN 37830, USA. NR 15 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD NOV PY 1996 VL 51 IS 1-3 BP 165 EP 179 DI 10.1016/S0304-3894(96)01799-2 PG 15 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WB584 UT WOS:A1996WB58400011 ER PT J AU Butler, RJ Baughn, JW AF Butler, RJ Baughn, JW TI The effect of the thermal boundary condition on transient method heat transfer measurements on a flat plate with a laminar boundary layer SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA Japanese DT Article DE forced convection; measurement techniques; transient and unsteady heat transfer C1 LAWRENCE LIVERMORE NATL LAB,DEPT MECH & AERONAUT ENGN,DAVIS,CA 95616. RP Butler, RJ (reprint author), USAF ACAD,DEPT AERONAUT,COLORADO SPRINGS,CO 80840, USA. NR 30 TC 21 Z9 21 U1 0 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1996 VL 118 IS 4 BP 831 EP 837 DI 10.1115/1.2822577 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA VV656 UT WOS:A1996VV65600003 ER PT J AU Metting, FB AF Metting, FB TI Biodiversity and application of microalgae SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE microalgae; cyanobacteria; biodiversity; applied phycology ID BLUE-GREEN-ALGAE; MOLECULAR-DATA; ASCORBIC-ACID; CHLOROPHYLL-B; CYANOBACTERIA; MARINE; MARICULTURE AB The algae are a polyphyletic, artificial assemblage of O-2-evolving, photosynthetic organisms (and secondarily nonphotosynthetic evolutionary descendants) that includes seaweeds (macroalgae) and a highly diverse group of microorganisms known as microalgae. Phycology, the study of algae, developed historically as a discipline focused on the morphological, physiological and ecological similarities of the subject organisms, including the prokaryotic blue-green algae (cyanobacteria) and prochlorophytes, Eukaryotic algal groups represent at least five distinct evolutionary lineages, some of which include protists traditionally recognized as fungi and protozoa, Ubiquitous in marine, freshwater and terrestrial habitats and possessing broad biochemical diversity, the number of algal species has been estimated at between one and ten million, most of which are microalgae. The implied biochemical diversity is the basis for many biotechnological and industrial applications. RP Metting, FB (reprint author), PACIFIC NW LAB, POB 999,MSIN P7-54,902 BATTELLE BLVD, RICHLAND, WA 99352 USA. NR 99 TC 160 Z9 182 U1 13 U2 102 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD NOV-DEC PY 1996 VL 17 IS 5-6 BP 477 EP 489 DI 10.1007/BF01574779 PG 13 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WM858 UT WOS:A1996WM85800018 ER PT J AU HunterCevera, JC Jeffries, TW Eveleigh, DE AF HunterCevera, JC Jeffries, TW Eveleigh, DE TI Introduction SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Editorial Material C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. USDA,FOREST PROD LAB,MADISON,WI 53705. RUTGERS STATE UNIV,NEW BRUNSWICK,NJ 08903. RI Jeffries, Thomas/I-8576-2012 OI Jeffries, Thomas/0000-0001-7408-4065 NR 0 TC 0 Z9 0 U1 0 U2 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD NOV-DEC PY 1996 VL 17 IS 5-6 BP R6 EP R6 DI 10.1007/BF01574686 PG 1 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WM858 UT WOS:A1996WM85800001 ER PT J AU Latli, B Than, C Morimoto, H Williams, PG Casida, JE AF Latli, B Than, C Morimoto, H Williams, PG Casida, JE TI [6-Chloro-3-pyridylmethyl-H-3]neonicotinoids as high-affinity radioligands for the nicotinic acetylcholine receptor: Preparation using (NaBH4)-H-3 and (LiBH4)-H-3 SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE imidacloprid analogs; insecticide; lithium borotritide; nicotinic acetylcholine receptor; radioligand; sodium borotritide; tritium-labelling ID IMIDACLOPRID BINDING-SITE; INSECTICIDES AB (NaBH4)-H-3 and (LiBH4)-H-3 at 78% and 97% isotopic enrichments, respectively, were used in the synthesis of H-3-labeled 1-(6-chloro-3-pyridyl)methyl-2-nitromethyleneimidazolidine (CH-IMI) and N'-[(6-chloro-3-pyridyl)methyl]-N-''-cyano-N'-methylacetamidine (acetamiprid) (two very potent insecticides) and of 1-(6-chloro-3-pyridyl)methyl-2-iminoimidazolidine (desnitro-IMI) (a metabolite of the commercial insecticide imidacloprid). 6-Chloronicotinoyl chloride was treated with either (NaBH4)-H-3 in methanol or (LiBH4)-H-3 in tetrahydrofuran and the resulting alcohol transformed to 2-chloro-5-chloromethylpyridine, which was then coupled to N-cyano-N'-methylacetamidine to give [H-3]acetamiprid (45 Ci/mmol). 2-Chloro-5-chloro[H-3]methylpyridine was also reacted with ethylenediamine and the product was either refluxed in absolute ethanol with 1,1-bis(methylthio)-2-nitroethylene to provide [H-3]CH-IMI or reacted in toluene with a solution of cyanogen bromide to produce [H-3]desnitro-IMI (each 55 Ci/mmol). C1 LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. RP Latli, B (reprint author), UNIV CALIF BERKELEY,DEPT ENVIRONM SCI POLICY & MANAGEMENT,ENVIRONM CHEM & TOXICOL LAB,BERKELEY,CA 94720, USA. NR 22 TC 25 Z9 26 U1 1 U2 6 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 NOV PY 1996 VL 38 IS 11 BP 971 EP 978 PG 8 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA VP536 UT WOS:A1996VP53600003 ER PT J AU Matsuda, M Katsumata, K Shapiro, SM Shirane, G AF Matsuda, M Katsumata, K Shapiro, SM Shirane, G TI Neutron scattering study in the spin-1/2 ladder system: Sr14Cu24O41 SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors CY AUG 02-06, 1996 CL KARLSRUHE, GERMANY AB Inelastic neutron scattering measurements have been performed on the S=1/2 quasi-one-dimensional system Sr14Cu24O41, which has both simple chains, and two-leg ladders of copper ions. We have observed that both the chain and the ladder exhibit a spin gap, which originate from a dimerized state. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Matsuda, M (reprint author), RIKEN,INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. RI Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 13 TC 3 Z9 3 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD NOV PY 1996 VL 105 IS 3-4 BP 467 EP 472 DI 10.1007/BF00768430 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VX652 UT WOS:A1996VX65200031 ER PT J AU Emerson, JP Wright, DA Woodfield, BF Gordon, JE Fisher, RA Phillips, NE AF Emerson, JP Wright, DA Woodfield, BF Gordon, JE Fisher, RA Phillips, NE TI Dependence of the low-temperature specific heat of YBa2Cu3O7-delta on delta and magnetic field: Concentrations of spin-2 and spin-1/2 paramagnetic centers SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors CY AUG 02-06, 1996 CL KARLSRUHE, GERMANY ID SUPERCONDUCTORS AB Specific heat data on two samples of YBa2Cu3O7-delta with relatively low concentrations of paramagnetic centers show the presence of both spin-2 and spin-1/2 moments. Measurements on one sample following incremental increases in delta show that for delta less than or equal to 0.2 approximately one spin-1/2 moment is produced for each 100 O vacancies, with no substantial increase in the linear term of the specific heat. For several reasons it is concluded that these O-vacancy related moments are different from those that have figured in previously reported correlations with parameters characteristic of the superconductivity. RP Emerson, JP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MSD,BERKELEY,CA 94720, USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD NOV PY 1996 VL 105 IS 3-4 BP 891 EP 896 DI 10.1007/BF00768495 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VX652 UT WOS:A1996VX65200096 ER PT J AU Wright, DA Emerson, JP Woodfield, BF Reklis, SF Gordon, JE Fisher, RA Phillips, NE AF Wright, DA Emerson, JP Woodfield, BF Reklis, SF Gordon, JE Fisher, RA Phillips, NE TI Dependence of the low-temperature specific heat of YBa2Cu3O7-delta on delta and magnetic field: The H-1/2 term for H not equal 0; Absence of evidence for a T-2 term for H=0 SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors CY AUG 02-06, 1996 CL KARLSRUHE, GERMANY ID SUPERCONDUCTORS AB Specific-heat measurements with improved precision on two new samples of YBa2Cu3O7-delta, with relatively low concentrations of paramagnetic centers are reported. For one sample the measurements were made for different values of delta. The data are analyzed and the data reported earlier for another sample reanalyzed, with an improved fitting expression. In each case, the data give a well defined (HT)-T-1/2 term in the mixed state. No persuasive evidence for a T-2 term in the superconducting state is found. RP Wright, DA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MSD,BERKELEY,CA 94720, USA. NR 7 TC 7 Z9 7 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD NOV PY 1996 VL 105 IS 3-4 BP 897 EP 902 DI 10.1007/BF00768496 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VX652 UT WOS:A1996VX65200097 ER PT J AU vanderBeek, CJ Indenbom, MV Berseth, V Li, TW Benoit, W AF vanderBeek, CJ Indenbom, MV Berseth, V Li, TW Benoit, W TI Onset of bulk pinning in BSCCO single crystals SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Physics and Chemistry of Molecular and Oxide Superconductors CY AUG 02-06, 1996 CL KARLSRUHE, GERMANY ID BI2SR2CACU2O8 CRYSTALS; FLUX-CREEP; IRREVERSIBILITY; BARRIERS AB The long growth defects often found in Bi2Sr2CaC2O8 ''single'' crystals effectively weaken the geometrical barrier and lower the field of first flux penetration. This means that the intrinsic (bulk) magnetic properties can be more easily accessed using magnetic measurements. Thus, the onset of strong bulk flux pinning in the sample bulk is determined to lie at T approximate to 40 Ii; indepedent of whether the field strength is above or below the field of the second peal in the magnetisation. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. LEIDEN UNIV,KAMERLINGH ONNES LAB,NL-2300 RA LEIDEN,NETHERLANDS. RP vanderBeek, CJ (reprint author), ECOLE POLYTECH FED LAUSANNE,INST GENIE ATOM,CH-1015 LAUSANNE,SWITZERLAND. NR 12 TC 3 Z9 3 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD NOV PY 1996 VL 105 IS 3-4 BP 1047 EP 1052 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA VX652 UT WOS:A1996VX65200122 ER PT J AU Brundage, RT Powell, RL Beitz, JV Liu, GK AF Brundage, RT Powell, RL Beitz, JV Liu, GK TI Measurement of homogeneous line widths and ground-state splittings of trivalent curium in fluoride glasses SO JOURNAL OF LUMINESCENCE LA English DT Article DE actinide; glass; coherence; fluorescence ID OPTICAL-TRANSITIONS; LINEWIDTHS; IONS AB We measured the homogeneous width of the D-6(7/2) to S-8(7/2) transition of trivalent curium in a fluorophosphate and a fluorozirconate glass as a function of temperature from 15 to 100 K by resonant fluorescence line narrowing (FLN). The line width varies as T-2 over the entire temperature range, and is an order of magnitude larger than homogeneous widths observed for trivalent lanthanide ions in fluoride glasses. Estimates of the ground-state splitting are also possible from the FLN spectra. We present a simple model that puts limits on the range of splittings possible in the glass and compare them to splittings measured in crystals. C1 MACALESTER COLL,ST PAUL,MN 55105. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Brundage, RT (reprint author), ST CLOUD STATE UNIV,DEPT PHYS ASTRON & ENGN SCI,720 4TH AVE S,ST CLOUD,MN 56301, USA. NR 26 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD NOV PY 1996 VL 69 IS 3 BP 121 EP 129 DI 10.1016/0022-2313(96)00089-0 PG 9 WC Optics SC Optics GA VR396 UT WOS:A1996VR39600001 ER PT J AU Rogers, DJ Maeda, Y Krishnan, KM AF Rogers, DJ Maeda, Y Krishnan, KM TI Investigations of the compositional distribution in epitaxially grown Co-Cr thin films with enhanced saturation magnetisation SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE Co-Cr film; compositional separation; magnetic recording; nuclear magnetic resonance; chemical etching ID RECORDING MEDIA; SEPARATION; INHOMOGENEITIES AB The compositional distribution in a Co78Cr22 film grown epitaxially on Ru/mica by electron beam evaporation was investigated using spin-echo Co-59 nuclear magnetic resonance (NMR) and preferential chemical etching of Co. NMR revealed evidence for the occurrence of drastic compositional separation producing a Go-enriched component containing almost pure Co. Chemical etching revealed a particularly fine distribution of Go-enriched regions. These results are consistent with the proposition that the enhanced saturation magnetisation (M(s)) observed in these films is attributable to enhanced compositional inhomogeneities. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Rogers, DJ (reprint author), NIPPON TELEGRAPH & TEL PUBL CORP, BASIC RES LABS, 3-1 MORINOSATO WAKAMIYA, ATSUGI, KANAGAWA 24301, JAPAN. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD NOV PY 1996 VL 163 IS 3 BP 393 EP 396 DI 10.1016/S0304-8853(96)00351-4 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA VX642 UT WOS:A1996VX64200021 ER PT J AU Girt, E Altounian, Z Mao, M Swainson, IP Donaberger, RL AF Girt, E Altounian, Z Mao, M Swainson, IP Donaberger, RL TI Neutron diffraction study of Fe substitutions in Nd(2)Fe(17-delta)X(delta) (X=Al,Si,Ga,Mo,W) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Letter ID SOLID-SOLUTIONS; MAGNETIC-ANISOTROPY; MOSSBAUER; SM2FE17-XSIX; SI AB In Nd(2)Fe(17-delta)X(delta) (X = Al, Si, Ga, Mo, W and delta = 0 to 1.5, depending on the concentration), the X elements substitute for Fe atoms without changing the crystal structure. Neutron diffraction measurements show that Al, Si, and Ga elements tend to substitute for Fe with a strong preference for the 18h site while Mo, and W tend to substitute for Fe with a strong preference for the 6c site. This substitution can be explained by considering the enthalpy of mixing using Miedema's model. We find that the enthalpy of mixing for Nd-(Al,Si,Ga) compounds is more negative than that for Fe-(Al,Si,Ga) compounds and this drives Al, Si and Ga to occupy the 18h site which has the largest number of Nd nearest neighbours. The enthalpy of mixing for Nd-(Mo,W) has a large and positive value and the enthalpy of mixing for Fe-(Mo,W) is zero. This drives Mo and W to the site with the smallest number of Nd nearest neighbours. We show that the site volume plays a minimal role in the substitution of the X elements, only affecting the substitution in the 9d site. C1 MCGILL UNIV,DEPT PHYS,CTR PHYS MAT,MONTREAL,PQ H3A 2T8,CANADA. LAWRENCE LIVERMORE NATL LAB,ADV MICROTECHNOL PROGRAM,LIVERMORE,CA 94551. AECL RES,NEUTRON & CONDENSED MATTER SCI,CHALK RIVER,ON K0J 1P0,CANADA. RI Altounian, Zaven/A-2073-2008 NR 15 TC 27 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD NOV PY 1996 VL 163 IS 3 BP L251 EP L256 DI 10.1016/S0304-8853(97)80003-0 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA VX642 UT WOS:A1996VX64200001 ER PT J AU Ma, H AF Ma, H TI High-frequency baroclinic wave motions in an equatorial ocean current and related temperature fluctuations SO JOURNAL OF MARINE RESEARCH LA English DT Article AB This paper uses a theoretical model to demonstrate the existence of a group of equatorially trapped, high-frequency (wave-periods shorter than one week), meso-to-small-scale (wave-lengths shorter than 100 km), baroclinic waves which are embedded in a geostrophic current with only vertical shear. Due to their relatively large vertical and meridional velocities, these high-frequency equatorial waves may play an important role in transporting momentum as well as heat energy in the vertical and transequatorial directions. RP Ma, H (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,BLDG 490D,UPTON,NY 11973, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520 SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD NOV PY 1996 VL 54 IS 6 BP 1073 EP 1096 DI 10.1357/0022240963213790 PG 24 WC Oceanography SC Oceanography GA WC901 UT WOS:A1996WC90100002 ER PT J AU Tang, Q Harrata, AK Lee, CS AF Tang, Q Harrata, AK Lee, CS TI Comparison of protein separations in capillary zone electrophoresis and capillary isoelectric focusing interfacing with electrospray mass spectrometry SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE capillary zone electrophoresis; capillary isoelectric focusing; electrospray ionization mass spectrometry ID ON-COLUMN TRANSIENT; DETECTION LIMITS; IONIZATION; PRECONCENTRATION; PERFORMANCE; IMPROVEMENT; PEPTIDES AB On-line capillary zone electrophoresis/electrospray ionization mass spectrometry (CZE-ESMS) and capillary isoelectric focusing/electrospray ionization mass spectrometry (CIEF/ESMS) were employed for protein analysis. The separation mechanisms and the detection limits of CZE/ESMS and CIEF/ESMS were compared by using model proteins including cytochrome c (horse heart), ribonuclease A (bovine pancreas), myoglobin (horse heart), carbonic anhydrase I (human erythrocytes) and beta-lactoglobulin A (bovine milk). The effect of a moving ionic boundary inside the electrophoresis capillary on the separation resolution of model proteins by CZE/ESMS and CIEF/ESMS is described. In CZE/ESMS, the formation of a moving ionic boundary due to the replacement of background electrolyte counterions with sheath liquid counterions can be eliminated by using a common counterion in both the background electrolyte and the sheath liquid. Additionally, the moving ionic boundary in CIEF/ESMS is minimized by combining cathodic mobilization with a gravity-induced hydrodynamic Baiu. The concentration detection limits of model proteins in a full-scan CIEF/ESMS analysis are in the region of 10(-7) M, similar to 20-50 times lower than that achievable using CZE/ESMS. Sample preconcentration taking place during the focusing step in CIEF is responsible for the improved detection limits. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. NR 20 TC 15 Z9 15 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD NOV PY 1996 VL 31 IS 11 BP 1284 EP 1290 DI 10.1002/(SICI)1096-9888(199611)31:11<1284::AID-JMS422>3.3.CO;2-V PG 7 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA VU428 UT WOS:A1996VU42800012 ER PT J AU Modine, FA Duggal, AR Robinson, DN Churnetski, EL Bartkowiak, M Mahan, GD Levinson, LM AF Modine, FA Duggal, AR Robinson, DN Churnetski, EL Bartkowiak, M Mahan, GD Levinson, LM TI Electrical properties of polyethylene highly filled with carbon SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID POSITIVE-TEMPERATURE-COEFFICIENT; CROSSLINKED POLYETHYLENE; COMPOSITES; BEHAVIOR; POLYMERS AB Carbon-filled polyethylene composites were fabricated and tested to establish the practical lower limit of their electrical resistivity at room temperature and to investigate the trade-offs between low resistivity and the magnitude of the resistance anomaly (i.e., a large positive temperature coefficient of resistivity) that appears when such composites are heated through the polyethylene crystalline melting transition. Carbon blacks with large particle size and low surface area provided low-resistivity composites having large resistance anomalies. The largest resistance anomalies were found in composites that were well mixed, but the room-temperature resistivity also increased in composites that were cycled repetitively through the crystalline-melting transition. A mixture of carbon blacks of two different sizes provided a lower resistance than was found in a material with the same fill of only the coarser black. By controlling the composition and the processing, composites were made with room-temperature resistivities lower than 0.2 ohm cm and resistance changes of at least 2 orders of magnitude. A resistance change of as much as 5 orders of magnitude was obtained for composites with room-temperature resistivities of only 1 ohm cm. C1 GE CO,CORP RES & DEV,SCHENECTADY,NY 12301. OAK RIDGE Y-12 PLANT,DEV DIV,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Modine, FA (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 16 TC 21 Z9 21 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1996 VL 11 IS 11 BP 2889 EP 2894 DI 10.1557/JMR.1996.0365 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA VT784 UT WOS:A1996VT78400030 ER PT J AU Norton, MG Bentley, J AF Norton, MG Bentley, J TI Reflection electron microscopy observations of twinning in LaAlO3 SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID SURFACES C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Norton, MG (reprint author), WASHINGTON STATE UNIV,SCH MECH & MAT ENGN,PULLMAN,WA 99164, USA. NR 9 TC 1 Z9 1 U1 1 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD NOV 1 PY 1996 VL 15 IS 21 BP 1851 EP 1853 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA VR273 UT WOS:A1996VR27300007 ER PT J AU Schwarz, RI AF Schwarz, RI TI Modeling tendon morphogenesis in vivo based on cell density signaling in cell culture SO JOURNAL OF MATHEMATICAL BIOLOGY LA English DT Article DE tendon; cell density; morphogenesis; collagen; cell proliferation ID COLLAGEN-SYNTHESIS; PATTERN-FORMATION; EXPRESSION; DIFFERENTIATION; ASCORBATE; INVITRO; FIBRILS; STATE; SKIN AB A mathematical model of tendon morphogenesis is presented that is consistent with the dramatic transitions seen in this tissue as it progresses from rapid growth early in development to no growth in the adult. To accomplish this change, the embryonic chick tendon is hypercellular with each cell dedicating half of its protein production to procollagen but over time, as growth subsides, the tissue gradually becomes hypocellular with each cell producing only about 1% procollagen. Making this transition from the embryonic to the adult state, forming a roughly cylindrical tissue composed of similar to 90% collagen, and linking the correct muscle to the right bone, is a complex task. The proposed solution requires only two factors: an activator of growth and an inhibitor complex, composed of the activator and another molecule that modifies the activity of the activator. From a diverse set of cell culture observations, these two factors were deduced as the primary components of the mechanism that allows cells to signal their presence to their neighbors. Since cell density signaling is the principal regulator of both collagen synthesis and cell proliferation,its components should play the key role in tendon development. A mathematical model based on the changes in the concentrations of these factors with cell density correlates well with the transitions observed in vivo. Furthermore, the model predicts that in the maturing chicken there should be a high cell density region at the muscle tendon interface. Experimental observations of frozen sections of tendon from a 4 month old chicken confirm this prediction. RP Schwarz, RI (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BLDG 83,BERKELEY,CA 94720, USA. NR 26 TC 5 Z9 7 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0303-6812 J9 J MATH BIOL JI J. Math. Biol. PD NOV PY 1996 VL 35 IS 1 BP 97 EP 113 DI 10.1007/s002850050045 PG 17 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA VW438 UT WOS:A1996VW43800007 PM 9002242 ER PT J AU Bastacky, J AF Bastacky, J TI Surface and internal structure correlation: High-voltage and scanning electron microscopies of wholemount alveolar walls of human lung SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE capillaries; correlative microscopy; cryo; HVEM; microvasculature; red blood cells; SEM; stereo; three-dimensional reconstruction; white blood cells ID ENHANCED LIGHT-MICROSCOPY; CELLS; SECTIONS; STEREO AB We found that the high-voltage electron microscope (HVEM) operating at 1.5 MeV was able to transilluminate and form a focused transmission image of whole-mounts of alveolar walls from human lung, a tissue sufficiently thin to require no embedment and sectioning, Resultant micrographs resembled a composite of scanning and transmission electron microscope images: surface and internal structure of the alveolar wall were visualized in a single micrograph. Although the scanning electron microscope extracts some subsurface information in the secondary electron mode, the HVEM produced better images of both surface and subsurface features. Lungs were fixed, dehydrated, critical point dried, and metal coated as for conventional scanning electron microscopy, then individual alveolar walls were excised by hand and mounted on transmission electron microscope grids. Regions of the alveolar wall up to 10 mu m thick were delineated with the high-voltage electron microscope. Cell surface characteristics were correlated with cell type as identified by underlying cell internal structure, Whole white blood cells within capillaries of the alveolar wall were identified by the configuration of their nuclei. Features of the nucleus and surface of alveolar type II cells were recorded simultaneously. Whole red blood cells were imaged within intact capillaries that branched and wove from one alveolar surface to the other. HVEM analysis of excised alveolar septa allows definitive correlation of surface and underlying structures in single micrographs of broad portions of the alveolar wall and is an alternative to embedment, microtomy and serial section reconstruction for this uniquely thin tissue. RP Bastacky, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. FU NCRR NIH HHS [RR00592]; NHLBI NIH HHS [HL52161] NR 22 TC 1 Z9 1 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD NOV PY 1996 VL 184 BP 88 EP 94 PN 2 PG 7 WC Microscopy SC Microscopy GA VV500 UT WOS:A1996VV50000003 PM 8972097 ER PT J AU Sun, EY Becher, PF Hwang, SL Waters, SB Pharr, GM Tsui, TY AF Sun, EY Becher, PF Hwang, SL Waters, SB Pharr, GM Tsui, TY TI Properties of silicon-aluminum-yttrium oxynitride glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID O-N GLASSES; RAMAN; MICROHARDNESS; CERAMICS; NITRIDE; SPECTRA AB The thermal and mechanical properties of two Si-Al-Y-O-N systems, including linear thermal expansion coefficient, glass transition temperature, elastic modulus, hardness and fracture toughness, were characterized. Results are compared with those previously reported in the literature in an attempt to expand our knowledge of silicon oxynitride glasses. It is found that increasing the nitrogen content generally results in decreasing the linear thermal expansion coefficient while increasing the glass transition temperature, the elastic modulus and the hardness. These observations are consistent with previous studies on similar oxynitride glasses. Present work also that the Y:Al cation ratio has a stronger effect on the thermal properties of the glasses than does the nitrogen content, a factor not systematically examined before. The outcome of this work adds to the database on oxynitride glasses which is essential in research on silicon nitride ceramics. C1 RICE UNIV, DEPT MAT SCI, HOUSTON, TX 77251 USA. RP Sun, EY (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. NR 36 TC 57 Z9 59 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD NOV PY 1996 VL 208 IS 1-2 BP 162 EP 169 DI 10.1016/S0022-3093(96)00510-8 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA WB294 UT WOS:A1996WB29400017 ER PT J AU Iwase, A Rehn, LE Baldo, PM Funk, L AF Iwase, A Rehn, LE Baldo, PM Funk, L TI Annihilation of freely migrating defects by cascade remnants in Cu-1% Au alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ION-IRRADIATION; SEGREGATION; METALS; COPPER AB The effects of cascade remnants on freely migrating defects (FMD) were studied by measuring radiation-induced segregation in Cu-1%Au at 400 degrees C during simultaneous irradiation with 1.5 MeV He and (400-800) keV heavy ions (Ne, Ar or Cu). Radiation induced segregation during single-ion irradiation with He, Ne, Ar and Cu, and the effects of pre-irradiation with the same ions, were also investigated. The large segregation observed during 1.5 MeV He-only irradiation was dramatically suppressed under simultaneous Cu irradiation. This suppression disappeared immediately after the Cu irradiation ceased, indicating that it was caused by a transient population of cascade remnants, i.e., vacancy and/or interstitial clusters. For simultaneous inert-gas (He and Ne Or Ar) irradiation, a similar suppression of the radiation induced segregation was observed. However, in contrast to the Cu-irradiation results, the suppression persisted after the Ne or Ar beam was turned off. The present results demonstrate that the energetic displacement cascades created by heavy ions introduce additional point-defect annihilation sites, which reduce the steady-state concentration of FMD. This finding implies that recombination dominates defect annihilation under the present irradiation conditions, which is indeed what is observed experimentally. As the cascade remnants produced by the Cu ions are thermally unstable at 400 degrees C, the suppression of radiation induced segregation occurs only during simultaneous irradiation. During Ne and Ar irradiation, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist during subsequent He-only irradiation. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Iwase, A (reprint author), JAPAN ATOM ENERGY RES INST,ADV SCI RES CTR,TOKAI,IBARAKI 31911,JAPAN. NR 23 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD NOV PY 1996 VL 238 IS 2-3 BP 224 EP 236 DI 10.1016/S0022-3115(96)00457-6 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WC947 UT WOS:A1996WC94700011 ER PT J AU Singh, BN Edwards, DJ Toft, P AF Singh, BN Edwards, DJ Toft, P TI Effects of neutron irradiation on mechanical properties and microstructures of dispersion and precipitation hardened copper alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID CASCADE DAMAGE CONDITIONS; DEFECT ACCUMULATION; PHASE-STABILITY; BEHAVIOR; METALS; FCC AB Tensile specimens of Cu-Al2O3, CuCrZr and CuNiBe alloys were irradiated with fission neutrons to fluences of 5 x 10(22), 5 x 10(23) and 1 x 10(24) n/m(2) (E > 1 MeV) at 47 degrees C. Tensile properties and Vickers hardness were determined at 22 degrees C. Microstructures of irradiated as well as unirradiated specimens were examined using a transmission electron microscope and the fractured surfaces were investigated in a scanning electron microscope, The most significant effect of irradiation is a drastic decrease in the ductility of copper alloys at a dose level as low as 0.2 dpa. The loss of ductility appears to be related to the intrinsic hardness of the grain interior and not to the grain boundary embrittlement. It is suggested that the irradiation-induced hardening and the lack of uniform elongation may be understood in terms of difficulty in dislocation generation due to pinning of grown-in dislocation by defect clusters (loops) and/or impurity atoms. C1 PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. RP Singh, BN (reprint author), RISO NATL LAB, DEPT MAT, DK-4000 ROSKILDE, DENMARK. NR 15 TC 50 Z9 50 U1 2 U2 10 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 NOV PY 1996 VL 238 IS 2-3 BP 244 EP 259 DI 10.1016/S0022-3115(96)00441-2 PG 16 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WC947 UT WOS:A1996WC94700013 ER PT J AU Feinendegen, DL Ohlenschlaeger, U Grossmann, K Holschbach, M Shreeve, WW Feinendegen, LE AF Feinendegen, DL Ohlenschlaeger, U Grossmann, K Holschbach, M Shreeve, WW Feinendegen, LE TI Lipid metabolism in the liver studied in vivo with two isomers of labeled fatty acid analogs SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE lipid metabolism; hepatic metabolism; labeled fatty acids ID 15-(ORTHO-I-123-PHENYL)-PENTADECANOIC ACID; OPPA; DOXORUBICIN; MYOCARDIUM; INVIVO; TRACER; PPPA; ADRIAMYCIN; KINETICS; TISSUES AB The two radioiodinated fatty acid analogs 15-(para-I-131-phenylpentadecanoic acid (pPPA) and 15-(ortho-I-131-phenyl)-pentadecanoic acid (oPPA) are isomers with individually different routes in lipid metabolism but with near equal transport kinetics into tissue. Methods: Normal adult male Wistar rats (n = 79) and those with liver cell damage from adriamycin treatment (n = 84) received 1.48 - 1.85 MBq I-131-pPPA or I-131-oPPA (specific activity, 33.3 - 46.3 GBq/mu M) into the jugular vein. At 1, 2, 3, 5, 7, 10 and 20 min, livers of up to five animals per group were examined for total tracer uptake and tracer incorporation into various lipid fractions. Results: Uptake of both isomers into the total liver plateaued at about 2 min; the ratio oPPA/pPPA in normal liver averaged 2.63 and was significantly higher than the average ratio of 1.50 after adriamycin treatment. This fall in ratio was mainly due to an increase of pPPA uptake. Significant differences of the respective ratios were found in the plateau for the phospholipids (9.7 versus 3.0), cholesterol (2.4 versus 0.7) and triglycerides (2.0 versus 0.4). Conclusion: The dual-tracer technique with pPPA and oPPA promises to be clinically useful for the diagnosis of liver disease by imaging the ratios of tracer uptake in the total liver and by in vitro analysis of the uptake ratio in serum triglycerides. C1 RES CTR JUELICH,INST MED & CHEM,JULICH,GERMANY. BARMEN HOSP,DEPT NUCL MED,WUPPERTAL,GERMANY. INST RADIOL,LEVERKUSEN,GERMANY. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP Feinendegen, DL (reprint author), UNIV BERN,INSELSPITAL,CLIN PLAST & RECONSTRUCT SURG,CH-3008 BERN,SWITZERLAND. NR 23 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 22090-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD NOV PY 1996 VL 37 IS 11 BP 1841 EP 1845 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VR846 UT WOS:A1996VR84600032 PM 8917189 ER PT J AU Chen, SS Cai, Y Zhu, S AF Chen, SS Cai, Y Zhu, S TI Flow-induced vibration of tubes in cross-flow SO JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID INSTABILITY MECHANISMS; STABILITY-CRITERIA AB This paper presents an unsteady-flow theory for flow-induced vibration of tubes in cross-flow. It includes a general description of motion-dependent fluid forces, characteristics of fluid-force coefficients, and mathematical models. Detailed results are presented for the constrained mode in the lift direction for various tube arrangements. RP Chen, SS (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,BLDG 335,ARGONNE,IL 60439, USA. NR 10 TC 4 Z9 4 U1 2 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0892-7219 J9 J OFFSHORE MECH ARCT JI J. Offshore Mech. Arct. Eng. Trans. ASME PD NOV PY 1996 VL 118 IS 4 BP 253 EP 258 DI 10.1115/1.2833913 PG 6 WC Engineering, Ocean; Engineering, Mechanical SC Engineering GA VX148 UT WOS:A1996VX14800003 ER PT J AU Choi, IH Yu, PY AF Choi, IH Yu, PY TI Optical investigation of defects in AgGaS2, and CuGaS2 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE semiconductors; Raman spectroscopy; defects; luminescence ID RESONANT RAMAN-SCATTERING; ENERGY-GAP; COMPOUND SEMICONDUCTORS; PRESSURE-DEPENDENCE; ABSORPTION AB Defects in two chalcopyrite semiconductors AgGaS2 and CuGaS2 have been studied by a combination of several optical techniques including absorption, emission, Raman scattering and their excitation spectroscopies. From these measurements we have determined the binding energies of both shallow and deep donors and accepters in the two materials. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. NR 23 TC 29 Z9 29 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD NOV PY 1996 VL 57 IS 11 BP 1695 EP 1704 DI 10.1016/0022-3697(96)00039-X PG 10 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA VU481 UT WOS:A1996VU48100018 ER PT J AU Casten, RF Zamfir, NV AF Casten, RF Zamfir, NV TI The evolution of nuclear structure: The NpNn scheme and related correlations SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Review ID EVEN-EVEN NUCLEI; P-N INTERACTIONS; RARE-EARTH NUCLEI; IDENTICAL BANDS; SHELL-MODEL; SUPERDEFORMED NUCLEI; VALENCE NUCLEONS; ACTINIDE NUCLEI; BINDING-ENERGY; HEAVY-NUCLEI AB The evolution of collective nuclear structure is discussed from a horizontal perspective, that is, as a function of the number of valence protons and neutrons. Starting from an explicit recognition of the importance of the valence residual p-n interaction in the equilibrium shape and structure of nuclei, the phenomenological NpNn scheme is presented, and validated via an analysis of empirical p-n interaction strengths. Applications of the NpNn scheme are presented which exploit this paradigm of structural evolution. The physics underlying occasional deviations from the NpNn scheme is extracted and new signatures of structure and of nuclear shape components are developed which will be useful for the study of exotic nuclei with radioactive beams. Finally, the smooth correlations of many observables with NpNn leads to a study of the correlations between different collective observables themselves. The remarkable results stemming from this approach are summarized. C1 YALE UNIV,NEW HAVEN,CT 06520. CLARK UNIV,WORCESTER,MA 01610. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. RP Casten, RF (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Zamfir, Nicolae Victor/F-2544-2011 NR 73 TC 65 Z9 66 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD NOV PY 1996 VL 22 IS 11 BP 1521 EP 1552 DI 10.1088/0954-3899/22/11/002 PG 32 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA VT266 UT WOS:A1996VT26600002 ER PT J AU Monge, MA Pareja, R Gonzalez, R Chen, Y AF Monge, MA Pareja, R Gonzalez, R Chen, Y TI Positronium deuteride and hydride in MgO crystals SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article; Proceedings Paper CT 5th International Workshop on Positron and Positronium Chemistry (PPC5) CY JUN 09-14, 1996 CL LILLAFURED, HUNGARY SP Eotvos Univ, Inst Chem, Budapest, Hungarian Acad Sci, KFKI Res Inst Particle & Nucl Phys ID HYDROGEN AB Low-temperature positron lifetime and Doppler broadening measurements were made in MgO crystals containing D- or H- ions in order to investigate the temperature dependence of the positron trapping by D- and H- ions and elucidate the possible formation of PsD (PsH) states. Positrons are trapped at D- and H- ions once the oxygen vacancies, which are more effective positron traps, am eliminated by annealing the crystals at high temperatures in a reducing atmosphere. From the temperature dependence of the annihilation parameters the positron trapping coefficients for D- and H- centers were shown to increase with temperature between 100-300 K. The lifetime of the PsD (PsH) state is (650 +/- 30) ps and temperature independent. The dissociation rate of the PsD (PsH) state into D (H) and Ps is also temperature independent. No isotopic effect was observed. C1 US DEPT ENERGY,DIV MAT SCI,OFF BAS ENERGY SCI,WASHINGTON,DC 20585. RP Monge, MA (reprint author), UNIV CARLOS III MADRID,DEPT FIS,C BUTARQUE 15,MADRID 28911,SPAIN. OI Monge, Miguel A./0000-0002-0425-6789 NR 9 TC 1 Z9 1 U1 0 U2 2 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD NOV PY 1996 VL 211 IS 1 BP 23 EP 29 DI 10.1007/BF02036251 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XQ089 UT WOS:A1996XQ08900004 ER PT J AU Hulett, LD Xu, J McLuckey, SA Schrader, DM AF Hulett, LD Xu, J McLuckey, SA Schrader, DM TI The interaction of slow positrons with organic molecules above and below positronium formation thresholds SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES LA English DT Article; Proceedings Paper CT 5th International Workshop on Positron and Positronium Chemistry (PPC5) CY JUN 09-14, 1996 CL LILLAFURED, HUNGARY SP Eotvos Univ, Inst Chem, Budapest, Hungarian Acad Sci, KFKI Res Inst Particle & Nucl Phys ID MASS-SPECTROMETRY; ANNIHILATION; IONIZATION AB A review is given of the ionization of organic molecules by monoenergetic positrons having energies in the range of 0.5-15 eV. Two mechanisms, unique to positrons, are described If the kinetic energy of the positron is above the positronium formation threshold, such that electrons can be removed from the molecules to form free positronium atoms, the ionization/fragmentation behavior can be explained qualitatively by a modification of the Ore gap theory. To explain how positrons can ionize and fragment molecules when their kinetic energies are below the positronium formation threshold, it is necessary to assume that energy is transferred to the molecule by the annihilation process. Ionization cross sections far positrons having kinetic energies below the positronium formation threshold are sensitive to molecular size, structure and bond types. Continuing work involves a search for positronium compound formation and measurements of the kinetic energy distributions of ions. C1 MARQUETTE UNIV, DEPT CHEM, MILWAUKEE, WI 53233 USA. RP OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. OI McLuckey, Scott/0000-0002-1648-5570 NR 14 TC 1 Z9 1 U1 1 U2 1 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH AR JI J. Radioanal. Nucl. Chem.-Artic. PD NOV PY 1996 VL 210 IS 2 BP 309 EP 325 DI 10.1007/BF02056375 PG 17 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XQ088 UT WOS:A1996XQ08800005 ER PT J AU Lyon, WS AF Lyon, WS TI Sleep, mistakes and failure SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-LETTERS LA English DT Editorial Material RP Lyon, WS (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 3 TC 0 Z9 0 U1 1 U2 2 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 0236-5731 J9 J RADIOAN NUCL CH LE JI J. Radioanal. Nucl. Chem.-Lett. PD NOV 1 PY 1996 VL 214 IS 4 BP 263 EP 267 DI 10.1007/BF02164367 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XQ102 UT WOS:A1996XQ10200001 ER PT J AU Pin, FG Morgansen, KA Tulloch, FA Hacker, CJ Gower, KB AF Pin, FG Morgansen, KA Tulloch, FA Hacker, CJ Gower, KB TI Motion planning for mobile manipulators with a non-holonomic constraint using the FSP (full space parameterization) method SO JOURNAL OF ROBOTIC SYSTEMS LA English DT Article; Proceedings Paper CT 2nd World Automation Congress (WAC 96) CY MAY 27-30, 1996 CL MONTPELLIER, FRANCE ID REDUNDANT MANIPULATORS; OBSTACLE AVOIDANCE; CONFIGURATION; SYSTEMS; ROBOTS AB The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (DOF) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a varying set of contraints such as a non-holonomic constraint on the platform motion, obstacles in the workspace, and various limits on the joint motions. A method, which we named the Full Space Parameterization (FSP), has recently been developed to resolve such underspecified systems with constraints that may vary in time and in number during a single trajectory. In this article, we first review the principles of the FSP and give analytical solutions for constrained motion cases with a general optimization criterion for resolving the redundancy. We then focus on the solutions to (1) the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators), which makes the dimensions of the joint displacement vector components non-homogeneous, and (2) the treatment of a non-holonomic constraint on the platform motion. Sample implementations on several large-payload mobile manipulators with up to 11 DOF are discussed. Comparative trajectories involving combined motions of the platform and manipulator for problems with obstacle and joint limit constraints, and with nonholonomic contraints on the platform motions, are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems. (C) 1996 John Wiley & Sons, Inc. RP OAK RIDGE NATL LAB, ROBOT & PROC SYST DIV, POB 2008, OAK RIDGE, TN 37831 USA. NR 20 TC 17 Z9 17 U1 0 U2 1 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0741-2223 J9 J ROBOTIC SYST JI J. Robot. Syst. PD NOV PY 1996 VL 13 IS 11 BP 723 EP 736 DI 10.1002/(SICI)1097-4563(199611)13:11<723::AID-ROB4>3.0.CO;2-X PG 14 WC Robotics SC Robotics GA VL832 UT WOS:A1996VL83200005 ER PT J AU Veers, PS AF Veers, PS TI The little ironies of wind energy - Foreword SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Editorial Material RP Veers, PS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 197 EP 197 DI 10.1115/1.2871774 PG 1 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400001 ER PT J AU Miller, S Migliore, PG Quandt, GA AF Miller, S Migliore, PG Quandt, GA TI An evaluation of several wind turbine trailing-edge aerodynamic brakes SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB An investigation was undertaken to identify the aerodynamic performance of five separate trailing-edge control devices and to evaluate their potential for wind turbine overspeed control applications. A modular two-dimensional wind tunnel model was constructed and aerodynamic performance data were acquired. To further interpret their potential, the controls were evaluated using a performance analysis computer program and a generic wind turbine geometry. On the basis of the investigation results, the Spoiler-Flap control configuration was deemed best suited for turbine braking applications. This particular control exhibited a good suction coefficient behavior over a broad angle-of-attack range and good turbine braking capabilities, especially at low tip-speed ratios. C1 NATL RENEWABLE ENERGY LAB,WIND TECHNOL DIV,GOLDEN,CO 80401. RP Miller, S (reprint author), WICHITA STATE UNIV,NATL INST AVIAT RES,WICHITA,KS 67260, USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 198 EP 203 DI 10.1115/1.2871776 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400002 ER PT J AU Sutherland, HJ AF Sutherland, HJ TI Frequency domain analysis of the fatigue loads on typical wind turbine blades SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The fatigue analysis of a wind turbine blade typically depends on converting time-series data to a series of load cycles using one of sever-al cyclic counting algorithms. However, many structural analysis techniques yield frequency-domain stress spectra, and a large body of experimental loads (stress) data is reported in the frequency domain. To permit the fatigue analysis of this class of data, a series of computational algorithms based on Fourier analysis techniques has been developed. The principle underlying these algorithms is the use of an Inverse Fast Fourier Transform (FFT) to transform the frequency spectrum to an equivalent time series suitable for cycle counting. In addition to analyzing the fatigue loads along the primary blade axes, this analysis technique also permits the examination of ''off-axis'' bending loads. These algorithms, which have been incorporated in the LIFE2 fatigue analysis code for wind turbines, are illustrated and evaluated with data from typical wind turbine blades. RP Sutherland, HJ (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87107, USA. NR 18 TC 0 Z9 1 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 204 EP 211 DI 10.1115/1.2871779 PG 8 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400003 ER PT J AU Somers, DM Tangler, JL AF Somers, DM Tangler, JL TI Wind tunnel test of the S814 thick root airfoil SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The objective of this wind-tunnel test was to verify, the predictions of the Eppler Airfoil Design and Analysis Code for a very thick airfoil having a high maximum lift coefficient designed to be largely insensitive to leading-edge roughness effects. The 24 petcent thick S814 airfoil was designed with these characteristics to accommodate aerodynamic and structural considerations for the root region of a wind-turbine blade. In addition, the airfoil's maximum lift-to-drag ratio was designed to occur at a high lift coefficient. To accomplish the objective, a two-dimensional wind tunnel test of the S814 thick root airfoil was conducted in January 1994 in the low-turbulence wind tunnel of the the Delft University of Technology Low Speed Laboratory, The Netherlands. Data were obtained with transition free and transition fixed for Reynolds numbers of 0.7, 1.0, 1.5, 2.0, and 3.0 x 10(6). For the design Reynolds number of 1.5 x 10(6), the maximum lift coefficient with transition free is 1.32, which satisfies the design specification. However, this value is significantly lower than the predicted maximum lift coefficient of almost almost 1.6. With transition fixed at the leading edge, the maximum lift coefficient is 1.22. The small difference in maximum lift coefficient between the transition-free and transition-fixed conditions demonstrates the airfoil's minimal sensitivity to roughness effects. The S814 root airfoil was designed to complement existing NREL low maximum-lift-coefficient tip-region airfoils for rotor blades 10 to 15 meters in length. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Somers, DM (reprint author), AIRFOILS INC,601 CRICKLEWOOD DR,STATE COLL,PA 16803, USA. NR 9 TC 3 Z9 4 U1 1 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 217 EP 221 DI 10.1115/1.2871781 PG 5 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400005 ER PT J AU Veers, PS AF Veers, PS TI Fatigue reliability of wind turbine fleets: The effect of uncertainty on projected costs SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The cost of repairing or replacing failed components depends on the number and timing of failures. Although the total probability of individual component failure is sometimes interpreted as the percentage of components likely to fail, this perception is often far from correct. Different amounts of common versus independent uncertainty can cause different numbers of components to be at risk of failure. The FAROW tool for fatigue and reliability analysis of wind turbines makes it possible for the first time to conduct a detailed economic analysis of the effects of uncertainty on fleet costs. By dividing the uncertainty into common and independent parts, the percentage of components expected to fail in each year of operation is estimated. Costs are assigned to the failures and the yearly costs and present values are computed If replacement cost is simply a constant multiple of the number of failures, the average, or expected cost is the same as would be calculated by multiplying by the probability of individual component failure. However, more complicated cost models require a breakdown of how many components are likely to fail. This breakdown enables the calculation of costs associated with various probability of occurrence levels, illustrating the variability in projected costs. Estimating how the numbers of components expected to fail evolves over time is also useful in calculating the present value of projected costs and in understanding the nature of the financial risk. RP Veers, PS (reprint author), SANDIA NATL LABS,WIND ENERGY TECHNOL DEPT,MS 0708,ALBUQUERQUE,NM 87185, USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 222 EP 227 DI 10.1115/1.2871782 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400006 ER PT J AU Muljadi, E Flowers, L Green, J Bergey, M AF Muljadi, E Flowers, L Green, J Bergey, M TI Electric design of wind-electric water pumping systems SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB Wind turbine technology has been used to pump water since ancient history. Direct mechanically coupled wind turbines are the most common method for pumping water to croplands and livestock. Many more recent wind turbines are electrically coupled, with the water pump connected to the wind turbine via a motor-generator connection. With electrical coupling, the distance and location of the water pump is independent of the location of the wind turbine. Therefore, the wind turbine can be located at an optimal wind energy site while the water pump is close to the water well or water tank. This paper analyzes a water-pumping system consisting of a wind turbine, a permanent magnet synchronous generator an induction motor, and a centrifugal-type water pump. C1 BERGEY WINDPOWER CO,NORMAN,OK 73069. RP Muljadi, E (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 8 TC 12 Z9 12 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 246 EP 252 DI 10.1115/1.2871786 PG 7 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400010 ER PT J AU Muljadi, E Butterfield, CP Migliore, P AF Muljadi, E Butterfield, CP Migliore, P TI Variable speed operation of generators with rotor speed feedback in wind power applications SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up, and reduce torque lending. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. In extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used. RP Muljadi, E (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD NOV PY 1996 VL 118 IS 4 BP 270 EP 277 DI 10.1115/1.2871793 PG 8 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA VV394 UT WOS:A1996VV39400013 ER PT J AU Kennedy, BJ Vogt, T AF Kennedy, BJ Vogt, T TI Structural and bonding trends in ruthenium pyrochlores SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID NEUTRON POWDER DIFFRACTION; CRYSTAL-STRUCTURE; ELECTRICAL-PROPERTIES; SPECTROSCOPY; REFINEMENT; OXIDES AB The structures of four semiconducting ruthenium pyrochlores, Ln(2)Ru(2)O(7) (Ln = Pr, Nd, Tb, and Yb) have been determined by Rietveld refinement of powder neutron diffraction data, These structures, when compared with those of other Ru containing pyrochlores, especially the metallically conducting pyrochlores, demonstrate that the differences in the Ru-O bond distances between metallic and semiconducting ruthenium pyrochlores are small and highlight the importance of the easily polarizable group 13/15 cations in facilitating large Ru-O-Ru angles, While Ru-O-Ru angles greater than 133 degrees are undoubtedly necessary to facilitate metallic conductivity, it appears that electron delocalization from the A site cation is at least equally important. (C) 1996 Academic Press, Inc. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Kennedy, BJ (reprint author), UNIV SYDNEY,SCH CHEM,SYDNEY,NSW 2006,AUSTRALIA. RI Vogt, Thomas /A-1562-2011; OI Vogt, Thomas /0000-0002-4731-2787; Kennedy, Brendan/0000-0002-7187-4579 NR 34 TC 63 Z9 63 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 1 PY 1996 VL 126 IS 2 BP 261 EP 270 DI 10.1006/jssc.1996.0337 PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA VT435 UT WOS:A1996VT43500016 ER PT J AU Cheetham, AK Rao, CNR Vogt, T AF Cheetham, AK Rao, CNR Vogt, T TI Magnetic structure and giant magnetoresistance of ferromagnetic La1-delta Mn1-delta O3 - An example of double-exchange striction? SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Letter ID DEFECT STRUCTURE; LAMNO3 AB A neutron powder diffraction study of the structure of the rhombohedral phase of La1-deltaMn1-deltaO3 (delta = 0.04) as a function of temperature has been carried out, The crystal structure is well described at all temperatures by a model in R - 3c (a = 5.52264(5) and c = 13.3309(5) at 300 K) and the low temperature data contain magnetic contributions to the Bragg scattering due to ferromagnetic ordering below T-c similar to 200 K. The spin is canted at approximately 45 degrees from [001]. The Mn-O-Mn angle decreases on cooling to T-c, but shows a slight increase on further cooling, presumably due to the onset of a double-exchange striction effect. Resistivity and magnetization data corroborate the neutron findings and reveal an insulator to metal transition close to T-c with a negative giant magnetoresistance value of similar to 50% at this temperature. The results confirm the striking similarity between the structural, magnetic, and conducting properties of rhombohedral La1-deltaMn1-deltaO3 and those of the solid solution La(1-x)A(x)MnO(3) (x similar to 0.3). (C) 1996 Academic Press, Inc. C1 INDIAN INST SCI,SOLID STATE & STRUCT CHEM UNIT,BANGALORE 560012,KARNATAKA,INDIA. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Cheetham, AK (reprint author), UNIV CALIF SANTA BARBARA,MAT RES LAB,SANTA BARBARA,CA 93106, USA. RI Rao, C.N.R./B-1569-2009; Vogt, Thomas /A-1562-2011; Ahirwal, Ashish /F-2532-2013 OI Rao, C.N.R./0000-0003-4088-0615; Vogt, Thomas /0000-0002-4731-2787; Ahirwal, Ashish /0000-0002-9127-6541 NR 24 TC 39 Z9 40 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 1 PY 1996 VL 126 IS 2 BP 337 EP 341 DI 10.1006/jssc.1996.0347 PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA VT435 UT WOS:A1996VT43500026 ER PT J AU Hinkle, JD Peterson, LD Doebling, SW AF Hinkle, JD Peterson, LD Doebling, SW TI Analysis of nonlinear mechanisms in a precision deployable structure using measured flexibility SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB An experimental method of quantifying the nonlinear effects of varying preload on mechanisms within a deployable structure is presented. Local flexibility are obtained from modal test data to examine the effects of the structure's nonlinear component mechanisms in situ. This technique allows the structural stiffness to be assessed separately from the structural mass so that variations in flexibility can be observed independent of the inertial loading of gravity off-load masses. Experimental application of the technique is also presented for a precision reconfigurable truss test bed. The variation of flexibility for three levels of off-load load mass is studied to show the effect of gravity preload on mechanism stiffnesses. The results indicate flexibilities are more indicative of the effects of gravity preload than are individual modal parameters. C1 LOS ALAMOS NATL LAB, ENGN ANAL GRP, ENGN SCI & APPL DIV, LOS ALAMOS, NM 87545 USA. RP Hinkle, JD (reprint author), UNIV COLORADO, DEPT AEROSP ENGN SCI, CTR AEROSP STRUCT, BOULDER, CO 80309 USA. NR 16 TC 1 Z9 1 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 1996 VL 33 IS 6 BP 848 EP 852 DI 10.2514/3.26848 PG 5 WC Engineering, Aerospace SC Engineering GA VX930 UT WOS:A1996VX93000014 ER PT J AU Morris, RE Weigel, SJ Norby, P Hanson, JC Cheetham, AK AF Morris, RE Weigel, SJ Norby, P Hanson, JC Cheetham, AK TI In situ single-crystal X-ray diffraction study of crystallization kinetics in clathrasil Dodecasil-3C SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE in situ X-ray diffraction; zeolite synthesis; crystallization kinetics ID IN-SITU; ZEOLITES; INSITU AB The formation of single crystals of the clathrasil dodecasil-3C from a solvothermal synthesis has been followed by in situ diffraction techniques using synchrotron radiation and an image-plate area detector. The high intensity of the X-ray beam, coupled with the ability to record time-resolved two-dimensional data using the image plates, allowed the crystallization kinetics to be studied and rate expressions to be fitted to the crystallization curves. C1 UNIV CALIF SANTA BARBARA,MAT RES LAB,SANTA BARBARA,CA 93106. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Morris, RE (reprint author), UNIV ST ANDREWS,SCH CHEM,PURDIE BLDG,ST ANDREWS KY16 9ST,FIFE,SCOTLAND. RI Morris, Russell/G-4285-2010; Hanson, jonathan/E-3517-2010; Norby, Poul/B-9047-2014 OI Morris, Russell/0000-0001-7809-0315; Norby, Poul/0000-0002-2590-7050 NR 12 TC 10 Z9 10 U1 1 U2 7 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD NOV 1 PY 1996 VL 3 BP 301 EP 304 DI 10.1107/S0909049596010965 PN 6 PG 4 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA VU588 UT WOS:A1996VU58800010 PM 16702696 ER PT J AU Doskey, PV Aldstadt, JH Kuo, JM Costanza, MS AF Doskey, PV Aldstadt, JH Kuo, JM Costanza, MS TI Evaluation of an in situ, on-line purging system for the cone penetrometer SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID ORGANIC-COMPOUNDS; CANISTERS AB Materials that will be used to construct an in situ, on-line purging system for the cone penetrometer were evaluated. Transfer efficiencies for volatile organic compounds (VOCs) through stainless steel, nickel, aluminum, and Teflon(R) tubings were determined using a gas-phase mixture of VOCs containing trichloromethane, tetrachloromethane, 1,1,1-trichloroethane, tetrachloroethene, hexane, benzene, toluene, and 1,2-dimethylbenzene. The water content of the gas stream had an insignificant effect on the quantitative transfer of VOCs through Teflon(R) tubing but was critical to efficiently transfer the compounds through metal tubing, particularly nickel. Transfer efficiencies for all eight analytes in moist gas streams through stainless steel were greater than 95%. Toluene, tetrachloroethene, and 1,2-dimethylbenzene were transferred with 93%, 81%, and 80% efficiency, respectively, when they were drawn through Teflon(R) PFA (perfluoroalkoxy) tubing. In general, the retention of the VOCs by Teflon(R) increases with decreasing aqueous solubility of the analyte. The efficiencies at which VOCs were purged from aqueous standards in Teflon(R) PFA, Type 304 stainless steel, and glass vessels were similar. Stainless steel was superior to nickel, aluminum, and the Teflon(R) polymers as a material for an in situ, on-line purging system for the cone penetrometer. RP Doskey, PV (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD NOV PY 1996 VL 46 IS 11 BP 1081 EP 1085 PG 5 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VT096 UT WOS:A1996VT09600007 PM 28071520 ER PT J AU Butt, DP Albert, D Taylor, TN AF Butt, DP Albert, D Taylor, TN TI Kinetics of thermal oxidation of silicon nitride powders SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID VAPOR-DEPOSITED SI3N4; SIO2-SI3N4 INTERFACE; OXYGEN AB The kinetics of thermal oxidation of H.C. Starck M-11 and Ube SN-E10 Si3N4 powders was evaluated in the temperature range 650 degrees-1200 degrees C using isothermal and nonisothermal thermogravimetric analysis, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy, Between 700 degrees and 1200 degrees C, the isothermal kinetics was modeled equally well using the Ginstling-Brounshtein and Zuravlev-Lesokhin-Tempel'man equations. Despite their similar particle sizes and surface areas, the two powders exhibited different oxidation kinetics, The activation energies for oxidation of the M-11 and SN-E10 powders were determined to be 400 and 540 kJ/mol, respectively, between 1000 degrees and 1200 degrees C, and 230 and 260 kJ/mol, respectively, between 700 degrees and 1000 degrees C. The parabolic rate constants for oxidation of the two powders were comparable to those reported in the literature for monolithic, chemically-vapor-deposited Si3N4 at the higher temperatures, At lower temperatures, the oxidation kinetics of the M-11 powder was nearly linear, whereas the kinetics of the SN-E10 powder remained power-law dependent. RP Butt, DP (reprint author), LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 29 TC 19 Z9 19 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1996 VL 79 IS 11 BP 2809 EP 2814 DI 10.1111/j.1151-2916.1996.tb08712.x PG 6 WC Materials Science, Ceramics SC Materials Science GA VV521 UT WOS:A1996VV52100002 ER PT J AU Webb, JE Singh, RN Lowden, RA AF Webb, JE Singh, RN Lowden, RA TI Thermal shock damage in a two-dimensional Woven-Fiber-Reinforced-CVI SiC-matrix composite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CHEMICAL-VAPOR INFILTRATION; SILICON-CARBIDE; CERAMICS; RESISTANCE; BEHAVIOR; EXPANSION AB Thermal shock damage in a two-dimensional woven-Nicalon(TM)-fiber-reinforced-CVI SiC-matrix composite was induced by water quenching and characterized by optical microscopy as a function of quench temperature difference (Delta T) and number of quench cycles, Mechanical damage generated in flexure on quenched and unquenched specimens also was characterized and compared to the thermal shock damage, The observed thermal shock damage consisted of small matrix cracks and fiber-matrix interfacial debonding on the surface, and large interior cracks in the matrix that formed between and parallel to the fiber cloths, At low Delta T values, only small matrix cracks on the surface were observed, and they mere related to initial decreases in Young's modulus, At higher AT values, larger cracks between the fiber cloths in the specimen interior were observed and related to decreases in the ultimate strength, Cyclic quenching resulted in progressive thermal shock damage that was consistent with Young's modulus measurements. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RP Webb, JE (reprint author), UNIV CINCINNATI, DEPT MAT SCI & ENGN, CINCINNATI, OH 45221 USA. NR 30 TC 16 Z9 16 U1 1 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1996 VL 79 IS 11 BP 2857 EP 2864 DI 10.1111/j.1151-2916.1996.tb08719.x PG 8 WC Materials Science, Ceramics SC Materials Science GA VV521 UT WOS:A1996VV52100009 ER PT J AU Campbell, GH AF Campbell, GH TI Sigma 5(210)/[001] symmetric tilt grain boundary in yttrium aluminum garnet SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID RESOLUTION ELECTRON-MICROSCOPY; ATOMIC-STRUCTURE; COMPUTER-SIMULATION; NICKEL-OXIDE; CRYSTALS; CREEP; TWIN AB The Sigma 5 (210)/[001] symmetric tilt grain boundary in yttrium aluminum garnet (YAG) was produced by diffusion bonding precisely oriented single crystals. The crystals were cleaned and bonded in an ultra-high-vacuum environment, The atomic structure of the boundary was characterized by high-resolution transmission electron microscopy. Model atomic structures were created by geometric construction to form the coincident site lattice model boundary, Comparison of model structures with high-resolution micrographs was performed by high-resolution image simulation. Many aspects of the boundary structure were properly represented by the models, but some details of the high-resolution images indicated that differences existed. RP Campbell, GH (reprint author), LAWRENCE LIVERMORE NATL LAB,CHEM & MAT SCI DIRECTORATE,LIVERMORE,CA 94551, USA. RI Campbell, Geoffrey/F-7681-2010 NR 24 TC 12 Z9 12 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1996 VL 79 IS 11 BP 2883 EP 2891 DI 10.1111/j.1151-2916.1996.tb08722.x PG 9 WC Materials Science, Ceramics SC Materials Science GA VV521 UT WOS:A1996VV52100012 ER PT J AU Eiden, GC Barinaga, CJ Koppenaal, DW AF Eiden, GC Barinaga, CJ Koppenaal, DW TI Plasma source ion trap mass spectrometry: Enhanced abundance sensitivity by resonant ejection of atomic ions SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID INVERSE FOURIER-TRANSFORM; FILTERED NOISE FIELD; LASER-DESORBED IONS; COLLISIONAL ACTIVATION; SELECTIVE INJECTION; MULTIPOLE FIELDS; EXCITATION; RESOLUTION; ENERGY; SIMULATION AB An experimental study of resonant ion excitation in an rf quadrupole ion trap is reported. Atomic ions are generated in an inductively coupled plasma and injected into the ion trap where, after collisional cooling, they are irradiated by a low-voltage, dipole coupled waveform. Single frequency, narrowband, and broadband excitation pulses have been used. Absorption lineshapes (plots of observed ion signal versus excitation frequency) are shown for variations in buffer gas pressure and the amplitude and duration of the single frequency pulses. The absorption lineshapes are usually asymmetric and tail toward lower frequencies. At sufficiently low buffer gas pressure or potential well depth, the lineshapes broaden and become more asymmetric to the point that absorption by ions with adjacent mass-to-charge ratios overlaps. This overlapping absorption reduces the selectivity with which a single mass-to-charge ratio ion can be excited and ejected relative to nearby mass-to-charge ratio ions. The rate of ion ejection is different on the low versus high frequency edges of the absorption lines. This difference in ejection rates provides an important key to understanding the shape of the absorption lines. All of these observations are explained in terms of the known kinematic behavior of ions in real traps, that is, traps with substantial higher order symmetry components in the trapping field (''nonlinear'' fields). The importance of the nonlinearity of the trapping field in understanding the observed lineshapes and their time dependencies is discussed. We also report resonant ejection results obtained using multiple frequency (narrow or broad bandwidth) excitation. Multiple frequency excitation allows ions with different mass-to-charge ratio values to be ejected from the trap using one excitation waveform. The finite ion storage capacity of the ion trap is thereby reserved for the ion(s) of interest. We show that ejection of Y-89 ions can be similar to 10(5) times more efficient than ejection of ions at either m/z 88 or 90. (C) 1996 American Society for Mass Spectrometry RP Eiden, GC (reprint author), PACIFIC NW LAB, ATOM & MOL CHEM SECT, POB 999, MS P8-08, RICHLAND, WA 99352 USA. NR 71 TC 24 Z9 24 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD NOV PY 1996 VL 7 IS 11 BP 1161 EP 1171 DI 10.1016/S1044-0305(96)00075-X PG 11 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA VP553 UT WOS:A1996VP55300010 PM 24203079 ER PT J AU Kok, GL Cisper, ME Hemberger, PH AF Kok, GL Cisper, ME Hemberger, PH TI Air analysis using Tenax collection with jet-separator enrichment and ion trap mass spectrometric analysis SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID VOLATILE ORGANIC-COMPOUNDS; ATMOSPHERIC-PRESSURE; THERMAL-DESORPTION; IONIZATION SOURCE; ONLINE; VOCS; TA AB A dual adsorbent trap inlet system has been developed for an ion trap mass spectrometer (ITMS) to provide a rapid and sensitive system for screening of volatile organic compounds in air. The system employs three stages of concentration: preconcentration on an adsorbent Tenax trap, focusing in a cryogenic collection trap, and jet separator enrichment immediately prior to analysis by ITMS. Ten minute integrated samples are collected and analyzed immediately. The detection limit is 0.9 parts-per-trillion by volume (pptrv) based on toluene as the analyte, and the reproducibility is 2% or better. Ambient air was analyzed for toluene on April 4, 1996 in Los Alamos, New Mexico, and concentrations ranged from 11-158 pptrv. (C) 1996 American Society for Mass Spectrometry C1 LOS ALAMOS NATL LAB,ENVIRONM SCI & WASTE TECHNOL GRP,LOS ALAMOS,NM. RP Kok, GL (reprint author), NATL CTR ATMOSPHER RES,RES AVIAT FACIL,POB 3000,BOULDER,CO 80307, USA. NR 29 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD NOV PY 1996 VL 7 IS 11 BP 1172 EP 1176 DI 10.1016/S1044-0305(96)00138-9 PG 5 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA VP553 UT WOS:A1996VP55300011 PM 24203080 ER PT J AU Chen, ZH Moehs, PJ Sachleben, RA AF Chen, ZH Moehs, PJ Sachleben, RA TI NMR studies on the Li+ and Na+ complexes of dibenzo-14-crown-4 lariat ethers SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID CATION BINDING-PROPERTIES; HIGH LITHIUM SELECTIVITY; 14-CROWN-4 DERIVATIVES; MOLECULAR-STRUCTURE; CROWN-ETHERS; SODIUM COMPLEXES; ALKALI-METAL; HOMOGENEOUS SOLUTION; SOLVENT-EXTRACTION; CRYSTAL-STRUCTURE AB The Li+ and Na+ complexes of a series of substituted dibenzo-14-crown-4 ethers bearing alkyl, ether, hydroxylic and carboxylic functional groups have been investigated in solution by H-1 and C-13 NMR spectroscopy. As was found previously for the uncomplexed ligands, the orientation of the sidearm relative to the crown cavity in the complexes depends on the nature of the atom linking the sidearm to the macrocyclic ring. Most significantly, when the sidearm is attached to the macrocyclic ring through an ether linkage the sidearm is oriented towards the cavity, resulting in intramolecular interactions between the bound carbon and secondary donor groups on the sidearm, which appear to be stronger for sodium than for lithium. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. SAGINAW VALLEY STATE UNIV,DEPT CHEM,UNIV CTR,MI 48710. NR 50 TC 2 Z9 2 U1 1 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD NOV PY 1996 IS 11 BP 2549 EP 2554 DI 10.1039/p29960002549 PG 6 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA VT288 UT WOS:A1996VT28800044 ER PT J AU Widelov, A Markovic, NM Rass, PN AF Widelov, A Markovic, NM Rass, PN TI Electrochemical and surface spectroscopic studies of thin films of bismuth ruthenium oxide (Bi2Ru2O7) SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID OXYGEN REDUCTION; ELECTRODES; PYROCHLORES; ELECTROCATALYSIS; STABILITY; CELLS; RU AB Thin, nonporous films of bismuth ruthenium oxide having the pyrochlore crystal structure were prepared by ion beam deposition. The films were grown on metal disks machined to fit into a rotating: ring-disk electrode. The electrocatalytic properties of these films for O-2 reduction and evolution were studied in 1 M KOH using the rotating ring-disk electrode method in conjunction with spectroscopic studies of the surfaces before and after electrochemical analysis. The crystalline pyrochlore film was found to be an extremely poor oxygen reduction catalyst, but it could be activitated in situ by a procedure that created a highly porous amorphous structure by dissolution of bismuth cations into the solution. We found in separate experiments that bismuth ions in solution increased the oxygen reduction activity of a nonporous ruthenium oxide surface, and suggest that there is an analogous effect on the activity of the residual, ruthenium-rich oxide surface by bismuth ions in solution following activation. RP Widelov, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 27 TC 5 Z9 5 U1 2 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 NOV PY 1996 VL 143 IS 11 BP 3504 EP 3511 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VU821 UT WOS:A1996VU82100023 ER PT J AU Vartuli, CB Pearton, SJ Lee, JW Abernathy, CR Mackenzie, JD Zolper, JC Shul, RJ Ren, F AF Vartuli, CB Pearton, SJ Lee, JW Abernathy, CR Mackenzie, JD Zolper, JC Shul, RJ Ren, F TI Wet chemical etching of AlN and InAlN in KOH solutions SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GALLIUM NITRIDE; GAN; GROWTH; PLASMAS; GAAS; INN AB Wet chemical etching of AlN and InxAl1-xN was investigated in KOH-based solutions as a function of etch temperature and material quality. The etch rates for both materials increased with increasing etch temperatures, which was varied from 20 to 80 degrees C. The crystal quality of AlN prepared by reactive sputtering was improved by rapid thermal annealing at temperatures to 1100 degrees C, with a decreased wet etch rate of the material measured with increasing anneal temperature. The etch rate decreased approximately an order of magnitude at 80 degrees C etch temperature after an 1100 degrees C anneal. The etch rate for In0.19Al0.8N grown by metallorganic molecular beam epitaxy was approximately three times higher for material on Si than on GaAs. This corresponds to the superior crystalline quality of the material grown on GaAs. Etching of InxAl1-xN was also examined as a function of In composition. The etch rate initially increased as the In composition changed from 0 to 36%, and then decreased to 0 A/min for InN. We also compared the effect of doping concentration on etch rate. Two InAlN samples of similar crystal quality were also etched; one was fully depleted with n < 10(16) cm(-3) (2.6% In) and the other n similar to 5 x 10(18) cm(-3) (3.1% In). At low etch temperature, the rates were similar, but above 60 degrees C the n-type sample etched faster, approximately three times faster at 80 degrees C. The activation energy for these etches is very low, 2.0 +/- 0.5 kcal mol(-1) for the sputtered AIN. The activation energies for InAlN were dependent on In composition and were in the range 2 to 6 kcal mol(-1) CaN and InN layers did not show any etching in KOH at temperatures up to 80 degrees C. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Vartuli, CB (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 34 TC 33 Z9 34 U1 5 U2 19 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 NOV PY 1996 VL 143 IS 11 BP 3681 EP 3684 DI 10.1149/1.1837271 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VU821 UT WOS:A1996VU82100050 ER PT J AU Warren, WL Seager, CH Robertson, J Kanicki, J Poindexter, EH AF Warren, WL Seager, CH Robertson, J Kanicki, J Poindexter, EH TI Creation and properties of nitrogen dangling bond defects in silicon nitride thin films SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID HYDROGENATED AMORPHOUS-SILICON; INDUCED PARAMAGNETIC DEFECTS; ELECTRON-SPIN-RESONANCE; SI-N FILMS; SLOW PROCESSES; MODEL; CENTERS; ENERGY AB The photocreation mechanisms and properties of nitrogen dangling bonds in amorphous hydrogenated silicon nitride (a-SiNx:H) thin films are investigated. We find that the photocreation is strongly dependent on film deposition conditions, illumination temperature, and postdeposition thermal treatment. Our results suggest that Ii largely passivates N dangling bonds and/or precursor sites in the as-deposited films. The N-H bonds can then dissociate by a high-temperature deposition or postdeposition anneal (T > 500 degrees C), leaving behind charged N sites which become paramagnetic after exposure to UV Light. The N dangling bond is found to be an electrically active point defect. Its electrical and magnetic properties can be explained by assuming that the N defect centers can be cycled between its positive, negative, and neutral charge states. C1 UNIV CAMBRIDGE,DEPT ENGN,CAMBRIDGE CB2 1PZ,ENGLAND. UNIV MICHIGAN,CTR DISPLAY TECHNOL,ANN ARBOR,MI 48105. USA,RES LAB,FT MONMOUTH,NJ 07703. RP Warren, WL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 34 TC 20 Z9 21 U1 1 U2 5 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 NOV PY 1996 VL 143 IS 11 BP 3685 EP 3691 DI 10.1149/1.1837272 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VU821 UT WOS:A1996VU82100051 ER PT J AU Yang, SH Snell, CM Morris, SJ Tian, S Parab, K Obradovich, B Morris, M Tasch, AF AF Yang, SH Snell, CM Morris, SJ Tian, S Parab, K Obradovich, B Morris, M Tasch, AF TI A Monte Carlo binary collision model for BF2 implants into (100) single-crystal silicon SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ION-IMPLANTATION; STOPPING POWER; COMPUTER-SIMULATION; DEFECT DISTRIBUTION; DOPANT DIFFUSION; DAMAGE; SEMICONDUCTORS; AMORPHIZATION AB This paper describes a physically based Monte Carlo model and simulator for accurate simulation of BF2 ion implantation in (100) single-crystal silicon. An improved electronic stopping model and a damage generation model have been developed and implemented in the simulator. These new, physically based, models greatly improve the capability for predicting BF2 as-implanted profiles. The profile dependence on the implant tilt and rotation angles as well as on the implant dose and energy can be very well predicted over the energy range from 15 to 65 keV. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Yang, SH (reprint author), UNIV TEXAS,MICROELECT RES CTR,AUSTIN,TX 78712, USA. NR 32 TC 4 Z9 4 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD NOV PY 1996 VL 143 IS 11 BP 3784 EP 3790 DI 10.1149/1.1837290 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VU821 UT WOS:A1996VU82100069 ER PT J AU Faulkner, D Fisk, WJ Walton, JT AF Faulkner, D Fisk, WJ Walton, JT TI Energy savings in cleanrooms from demand-controlled filtration SO JOURNAL OF THE INSTITUTE OF ENVIRONMENTAL SCIENCES LA English DT Article DE cleanroom; demand-controlled filtration; energy savings; particle counter AB In cleanrooms, very low particle concentrations are maintained by recirculation of air at a high rate (e.g., 600 room air volumes/hr) through highly efficient air filters. Results are reported in a Class M3.5 (Class 100) cleanroom with 28 m(2) (300 ft(2)) floor area, where significant energy savings were realized by controlling the rate of air recirculation through the filters in response to real-time measurements of particle concentrations. An inexpensive, $2500, optical particle counter was used to measure particle concentrations. The effect of varying the recirculation airflow rate on particle concentrations was investigated. Changes in recirculation fan speeds of 10 percent or greater did not cause a noticeable particle release from filters or resuspension from indoor surfaces. With new automatic control systems in operation, there were occasional, usually fewer than 10/day, nonconsecutive 1-min episodes in which the particle concentration exceeded Class M3.5 (Class 100) status. Depending upon the choice for baseline energy use, the energy consumption of the recirculating fans was reduced by 60 to 80 percent, and the estimated payback period for a 90 m(2) (1,000 ft(2)) Class M3.5 (Class 100) cleanroom isfrom 1 to 4 yr. RP Faulkner, D (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 2 TC 4 Z9 4 U1 1 U2 1 PU INST ENVIRONMENTAL SCI PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 SN 1052-2883 J9 J INST ENVIRON SCI JI J. Inst. Environ. Sci. PD NOV-DEC PY 1996 VL 39 IS 6 BP 21 EP 27 PG 7 WC Engineering, Environmental; Environmental Sciences; Instruments & Instrumentation SC Engineering; Environmental Sciences & Ecology; Instruments & Instrumentation GA WA184 UT WOS:A1996WA18400005 ER PT J AU Bateman, VI Brown, FA Davie, NT AF Bateman, VI Brown, FA Davie, NT TI Use of a beryllium Hopkinson bar to characterize a piezoresistive accelerometer in shock environments SO JOURNAL OF THE INSTITUTE OF ENVIRONMENTAL SCIENCES LA English DT Article; Proceedings Paper CT 42nd Annual Technical Meeting of the Institute-of-Environmental-Sciences CY MAY, 1996 CL ORLANDO, FL SP Inst Environm Sci DE accelerometer; high shock; high acceleration; high frequency; Hopkinson bar; beryllium Hopkinson bar; cross-axis sensitivity AB The characteristics of a piezoresistive accelerometer in shock environments are being studied at Sandia National Laboratories in the Mechanical Shock Testing Laboratory. A Hopkinson bar capability has been developed to extend our understanding of the piezoresistive accelerometer, in two mechanical configurations, in the high-frequency, high-shock environments where measurements are being made. In this paper the beryllium Hopkinson bar configuration with a laser doppler vibrometer as the reference measurement is described. The in-axis performance of the piezoresistive accelerometer for frequencies of dc-50 kHz and shock magnitudes of up to 70,000 g as determined from measurements with a beryllium Hopkinson bar are presented. Preliminary results of characterizations of the accelerometers subjected to cross-axis shocks in a split beryllium Hopkinson bar configuration are presented. RP Bateman, VI (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 16 TC 3 Z9 4 U1 1 U2 2 PU INST ENVIRONMENTAL SCI PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 SN 1052-2883 J9 J INST ENVIRON SCI JI J. Inst. Environ. Sci. PD NOV-DEC PY 1996 VL 39 IS 6 BP 33 EP 39 PG 7 WC Engineering, Environmental; Environmental Sciences; Instruments & Instrumentation SC Engineering; Environmental Sciences & Ecology; Instruments & Instrumentation GA WA184 UT WOS:A1996WA18400007 ER PT J AU Schulberg, MT Allendorf, MD Outka, DA AF Schulberg, MT Allendorf, MD Outka, DA TI Aspects of nitrogen surface chemistry relevant to TIN chemical vapor deposition SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; FLOW-TUBE KINETICS; TITANIUM NITRIDE; THIN-FILMS; AMMONIA ADSORPTION; NH3; DECOMPOSITION; GROWTH; CVD; TETRAKIS(DIMETHYLAMIDO)TITANIUM AB NH3 is an important component of many chemical vapor deposition (CVD) processes for TiN films, which are used for diffusion barriers and other applications in microelectronic circuits. In this study? the interaction of NH(3)( )with TiN surfaces is examined with temperature programmed desorption (TPD) and Auger electron spectroscopy. NH3 has two adsorption states on TiN: a chemisorbed state and a multilayer state. A new method for analyzing TPD spectra in systems with slow pumping speeds yields activation energies for desorption for the two states of 24 kcal/mol and 7.3 kcal/mol, respectively. The sticking probability into the chemisorption state is similar to 0.06. These results are discussed in the context of TiN CVD. In addition, the high temperature stability of TiN is investigated. TIN decomposes to its elements only after heating to 1300 K, showing that decomposition is unlikely to occur under CVD conditions. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. NR 49 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1996 VL 14 IS 6 BP 3228 EP 3235 DI 10.1116/1.580218 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VV247 UT WOS:A1996VV24700037 ER PT J AU Skinner, CH Blanchard, W Kamperschroer, J LaMarche, P Mueller, D Nagy, A Scott, S Ascione, G Amarescu, E Camp, R Casey, M Collins, J Cropper, M Gentile, C Gibson, M Hosea, J Kalish, M Langford, J Langish, S Mika, R Owens, DK Pearson, G Raftopoulos, S Raucci, R Stevenson, T VonHalle, A Voorhees, D Walters, T Winston, J AF Skinner, CH Blanchard, W Kamperschroer, J LaMarche, P Mueller, D Nagy, A Scott, S Ascione, G Amarescu, E Camp, R Casey, M Collins, J Cropper, M Gentile, C Gibson, M Hosea, J Kalish, M Langford, J Langish, S Mika, R Owens, DK Pearson, G Raftopoulos, S Raucci, R Stevenson, T VonHalle, A Voorhees, D Walters, T Winston, J TI Measurements of tritium retention and removal on the Tokamak Fusion Test Reactor SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID BUMPER LIMITER; 1ST WALL; TFTR; GRAPHITE; DEUTERIUM; RELEASE; CARBON; BEAMS; JET AB Recent experiments on the Tokamak Fusion Test Reactor have afforded an opportunity to measure the retention of tritium in a graphite limiter that is subject to erosion, codeposition, and high neutron flux. The tritium was injected by both gas puff and neutral beams. The isotopic mix of hydrogenic recycling was measured spectroscopically and the tritium fraction T/(H+D+T) transiently increased to as high as 75%. Some tritium was pumped out during the experimental run and some removed in a subsequent campaign using various clean-up techniques. While the short term retention of tritium was high, various conditioning techniques were successful in removing approximate to 8000 Ci and restoring the tritium inventory to a level well below the administrative limit. (C) 1996 American Vacuum Society. RP Skinner, CH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 32 TC 32 Z9 32 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD NOV-DEC PY 1996 VL 14 IS 6 BP 3267 EP 3274 DI 10.1116/1.580224 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VV247 UT WOS:A1996VV24700043 ER PT J AU Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Shul, RJ Zolper, JC Lovejoy, ML Baca, AG HagerottCrawford, M AF Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Shul, RJ Zolper, JC Lovejoy, ML Baca, AG HagerottCrawford, M TI Thermal stability of W, WSix, and Ti/Al ohmic contacts to InGaN, InN, and InAlN SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID LIGHT-EMITTING-DIODES; FIELD-EFFECT TRANSISTOR; MOLECULAR-BEAM EPITAXY; GAN; GROWTH; BLUE AB W, WSi0.44, and Ti/Al contact properties were examined on n(+)In(0.65)Ga(0.35)N, InN, and In0.75Al0.25N. W was found to produce low specific contact resistance (rho(c) similar to 10(-7) Omega cm(2)) ohmic contacts to InGaN, with significant reaction between metal and semiconductor occurring at 900 degrees C mainly due to out diffusion of In and N. WSix showed an as-deposited rho(c) of 4 x 10(-7) Omega cm(2) but this degraded significantly with subsequent annealing at greater than or equal to 600 degrees C. Ti/Al contacts were stable to similar to 600 degrees C (rho(c) similar to 4 x 10(-7) Omega cm(2) at less than or equal to 600 degrees C). The surfaces of these contacts remained smooth to 800 degrees C for W and WSix and 650 degrees C for Ti/Al. InN contacted with W and Ti/Al produced ohmic contacts with rho(c) similar to 10(-7) Omega cm(2) and for WSix rho(c) similar to 10(-6) Omega cm(2). All remained smooth to similar to 600 degrees C, but exhibited significant interdiffusion of In, N, W, and Ti, respectively, at higher temperatures. The contact resistances for all three metalization schemes were greater than or equal to 10(-4) Omega cm(2) on InAlN, and degraded with subsequent annealing. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Vartuli, CB (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 19 TC 10 Z9 10 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3520 EP 3522 DI 10.1116/1.588791 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100020 ER PT J AU Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Lambers, ES Zolper, JC AF Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Lambers, ES Zolper, JC TI High temperature surface degradation of III-V nitrides SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID PRESSURE SOLUTION GROWTH; MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; THERMAL-STABILITY; EQUILIBRIUM PRESSURE; OHMIC CONTACTS; GAN; INN AB The surface stoichiometry, surface morphology, and electrical conductivity of AlN, GaN, InN, InGaN, and InAlN were examined at rapid thermal annealing temperatures up to 1150 degrees C. The sheet resistance of the AlN dropped steadily with annealing, but the surface showed signs of roughening only above 1000 degrees C. Auger electron spectroscopy (AES) analysis showed little change in the surface stoichiometry even at 1150 degrees C. GaN root mean square (rms) surface roughness showed an overall improvement with annealing, but the surface became pitted at 1000 ''C, at which point the sheet resistance also dropped by several orders of magnitude, and AES confirmed a loss of N from the surface. The InN surface had roughened considerably even at 650 degrees C, and scanning electron microscopy showed significant degradation. In contrast to the binary nitrides, the sheet resistance of InAlN was found to increase by similar to 10(2) from the as grown value (3.2 x 10(-3) Omega cm) after annealing at 800 degrees C and then remain constant up to 1000 degrees C, while that of InGaN increased by two orders of magnitude between 700 and 900 degrees C. The rms roughness increased above 800 and 700 degrees C, respectively, for InAlN and InGaN samples. In droplets began to form on the surface at 900 degrees C for InAlN and at 800 degrees C for InGaN, and then evaporate at 1000 degrees C, leaving pits. AES analysis showed a decrease in the N concentration in the top 500 Angstrom of the sample for annealing greater than or equal to 800 degrees C in both materials. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP UNIV FLORIDA, DEPT MAT SCI & ENGN, GAINESVILLE, FL 32611 USA. NR 35 TC 49 Z9 49 U1 3 U2 21 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3523 EP 3531 DI 10.1116/1.588792 PG 9 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100021 ER PT J AU Parmeter, JE Shul, RJ Howard, AJ Miller, PA AF Parmeter, JE Shul, RJ Howard, AJ Miller, PA TI Treatment of InP surfaces in radio frequency H-2 and H-2/CH4/Ar plasmas: In situ compositional analysis, etch rates, and surface roughness SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID III-V SEMICONDUCTORS; HYDROGEN PLASMA; ATOMIC-HYDROGEN; LOW-ENERGY; CYCLOTRON; CH4/H2/AR; GAAS; DEGRADATION; DISCHARGES; SUBSTRATE AB The surface composition, etch rates, and surface roughness of indium phosphide (InP) surfaces treated in radio frequency (rf) hydrogen and hydrogen/argon/methane plasmas have been investigated using in situ Auger spectroscopy and ex situ scanning electron microscopy and atomic force microscopy. In agreement with most previous studies, hydrogen plasmas are found to completely remove surface carbon and oxygen impurities, but at the expense of some degree of surface phosphorus depletion. This depletion can be minimized by utilizing brief plasma exposure times and low rf power settings. Oxygen removal is found to be rate limiting in the production of a clean surface. InP etching in hydrogen/argon/methane can be performed either in a low density, capacitively coupled plasma mode, or in a high density, inductively coupled plasma mode. For operation in the low density regime, the etched surfaces have a constant and nearly stoichiometric composition, independent of plasma parameters. Etch rates vary from similar to 20-400 Angstrom/min, while the root mean square (rms) surface roughness varies from similar to 20 to >400 Angstrom. Both of these quantities show definite trends with changing plasma parameters, and, in particular, high etch rates and low surface roughness are both favored by increasing total plasma pressure and methane how rate. Within the ranges studied, the etch rate is most strongly affected by the amount of hydrocarbon species reaching the surface, which can remove indium in the form of indium alkyl products. However, sputtering effects are also shown to be significant. Etching InP in the high density plasma mode gives an etch rate of similar to 700 Angstrom/min, but only at the expense of severe surface phosphorus depletion and rms surface roughness of similar to 2000 Angstrom. The breakdown of methane within the plasma under these conditions may serve to inhibit indium alkyl formation, and hence lead to the observed phosphorus depletion. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS,DEPT 1322,ALBUQUERQUE,NM 87185. SANDIA NATL LABS,DEPT 1128,ALBUQUERQUE,NM 87185. RP Parmeter, JE (reprint author), SANDIA NATL LABS,DEPT 5848,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Schaff, William/B-5839-2009 NR 31 TC 9 Z9 9 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3563 EP 3574 DI 10.1116/1.588798 PG 12 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100027 ER PT J AU Lee, JW Vartuli, CB Abernathy, CR MacKenzie, JD Mileham, JR Pearton, SJ Shul, RJ Zolper, JC HagerottCrawford, M Zavada, JM Wilson, RG Schwartz, RN AF Lee, JW Vartuli, CB Abernathy, CR MacKenzie, JD Mileham, JR Pearton, SJ Shul, RJ Zolper, JC HagerottCrawford, M Zavada, JM Wilson, RG Schwartz, RN TI Etching processes for fabrication of GaN/InGaN/AlN microdisk laser structures SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID ALN; NITRIDE; GAN; INN AB Several new wet and dry etch processes required for fabrication of microdisk lasers in the III nitrides have been developed. ICl/Ar electron cyclotron resonance plasmas produce etch rates of 1.3 mu m/ min for GaN and 1.15 mu m/min for InN at 1000 W microwave power and 250 W Of rf power. These rates are substantially faster than previously investigated Cl-2/Ar or CH4/H-2 plasma chemistries. Selectivities of 5-6 over AlN are obtained for these materials. Wet chemical etching of AlN and InxAl1-xN in KOH-based solutions was found to be a strong function of etch temperature and material quality. The activation energy for these materials was in the range 2-6 kcal/mol, typical of diffusion-controlled processes. The KOH solutions did not etch GaN or InN at temperature as high as 80 degrees C. (C) 1996 American Vacuum Society. C1 UNIV FLORIDA, DEPT MAT SCI & ENGN, GAINESVILLE, FL 32611 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. USA, RES LAB, RES TRIANGLE PK, NC 27709 USA. HUGHES RES LABS, MALIBU, CA 90265 USA. NR 19 TC 11 Z9 11 U1 0 U2 8 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3637 EP 3640 DI 10.1116/1.588740 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100041 ER PT J AU Kania, DR Gaines, DP Sweeney, DS Sommargren, GE LaFontaine, B Vernon, SP Tichenor, DA Bjorkholm, JE Zernike, F Kestner, RN AF Kania, DR Gaines, DP Sweeney, DS Sommargren, GE LaFontaine, B Vernon, SP Tichenor, DA Bjorkholm, JE Zernike, F Kestner, RN TI Precision optical aspheres for extreme ultraviolet lithography SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer AB We have demonstrated significant advances in the production of aspheric optics for extreme ultraviolet lithography. An optic has been fabricated with an aspheric departure of 1.5 mu m, a figure error of 0.7 nm rms, and a nanoroughness of 0.25 nm rms. Further improvements are required in the figure and nanoroughness to reach high throughput and near diffraction limited performance in an extreme ultraviolet lithography system. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. TINSLEY LABS,RICHMOND,CA 94806. RP Kania, DR (reprint author), LAWRENCE LIVERMORE NATL LAB,ADV MICROTECHNOL PROGRAM,LIVERMORE,CA 94551, USA. NR 7 TC 6 Z9 6 U1 2 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3706 EP 3708 DI 10.1116/1.588652 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100056 ER PT J AU Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD AF Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD TI Development of ion sources for ion projection lithography SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer AB Multicusp ion sources are capable of generating ion beams with low axial energy spread as required by the ion projection lithography (IPL). Longitudinal ion energy spread has been studied in two different types of plasma discharge: the filament discharge ion source characterized by its low axial energy spread, and the rf-driven ion source characterized by its long source lifetime. For He+ ions, longitudinal ion energy spreads of 1-2 eV were measured for a filament discharge multicusp ion source which is within the IPL source requirements. Ion beams with larger axial energy spread (similar to 7 eV) were observed in the rf-driven source. A double-chamber ion source has been designed which combines the advantages of low axial energy spread of the filament discharge ion source with the long Lifetime of the rf-driven source. The energy spread of the double chamber source is approximately 2 eV. (C) 1996 American Vacuum Society. C1 UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720. RP Lee, Y (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 4 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3947 EP 3950 DI 10.1116/1.588701 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100105 ER PT J AU RayChaudhuri, AK Krenz, KD Nissen, RP Haney, SJ Fields, CH Sweatt, WC MacDowell, AA AF RayChaudhuri, AK Krenz, KD Nissen, RP Haney, SJ Fields, CH Sweatt, WC MacDowell, AA TI Initial results from an extreme ultraviolet interferometer operating with a compact laser plasma source SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID LITHOGRAPHY; OPTICS AB When characterizing an extreme ultraviolet (EUV) lithographic optical system, visible light interferometry is limited to measuring wave front aberration caused by surface figure error while failing to measure wave front errors induced by the multilayer coatings. This necessitates the development of interferometric techniques at an EUV camera's operational wavelength (at-wavelength testing), which is typically around 13 nm. While a laser plasma source (LPS) is being developed as a lithography production source, it has generally considered that only an undulator located at a synchrotron facility can provide the necessary laserlike point source brightness for EUV interferometry. Although an undulator-based approach has been successfully demonstrated, it would be advantageous to test a camera in its operational configuration with an LPS. We are developing the latter approach by utilising extended source size schemes to provide usable flux throughput. A slit mounted at the source plane can provide the necessary spatial coherence for lateral shearing interferometry. Initial results from and EUV lateral shear interferometer based on the Ronchi test are presented. (C) 1996 American Vacuum Society. C1 UNIV CALIF BERKELEY,DEPT ELECT ENGN & COMP SCI,BERKELEY,CA 94720. SANDIA NATL LABS,OPT & EXPLORATORY TECHNOL DEPT,ALBUQUERQUE,NM 87185. AT&T BELL LABS,LUCENT TECHNOL,UPTON,NY 11973. RP RayChaudhuri, AK (reprint author), SANDIA NATL LABS,ADV ELECT MFG DEPT,LIVERMORE,CA 94550, USA. NR 13 TC 6 Z9 8 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3964 EP 3968 DI 10.1116/1.588624 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100109 ER PT J AU Fields, CH Oldham, WG RayChaudhuri, AK Krenz, KD Stulen, RH AF Fields, CH Oldham, WG RayChaudhuri, AK Krenz, KD Stulen, RH TI Direct aerial image measurements to evaluate the performance of an extreme ultraviolet projection lithography system SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer AB We report the application of direct aerial image monitoring to measure the performance of an extreme ultraviolet lithography (EUVL) test bed. There are several issues which might limit the possibility of performing image monitoring experiments on EUVL systems. These issues include: source flux, signal-to-noise ratios, and EUV scanning aperture fabrication. We report the results of initial aerial image scans of equal lines and spaces as well as preliminary measurements of scatter produced by the EUV camera. (C) 1996 American Vacuum Society. C1 SANDIA NATL LABS,LIVERMORE,CA 94550. RP Fields, CH (reprint author), UNIV CALIF BERKELEY,550-0 CORY HALL,BERKELEY,CA 94720, USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 4000 EP 4003 DI 10.1116/1.588631 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100116 ER PT J AU Wendt, JR Vawter, GA Smith, RE Warren, ME AF Wendt, JR Vawter, GA Smith, RE Warren, ME TI Fabrication of subwavelength, binary, antireflection surface-relief structures in the near infrared SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID GRATINGS AB Subwavelength, binary surface-relief structures are artificial materials with an effective index of refraction that can be tailored by varying the duty cycle of the binary pattern. These structures have the significant advantage of requiring only a single Lithography and etch step for fabrication. We demonstrate a specifically designed antireflection structure in a material system (GaAs) and at a wavelength (975 nm) directly integrable with GaAs-based vertical cavity surface-emitting lasers and which exhibits strong polarization-dependent properties. Fabrication is performed using electron beam lithography and reactive-ion-beam etching. The observed reflectivity is 2% for TE polarization and 23% for TM polarization, a difference in reflectivity of over a factor of 10 for the two polarizations. (C) 1996 American Vacuum Society. RP Wendt, JR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 13 TC 6 Z9 6 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 4096 EP 4099 DI 10.1116/1.588598 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100137 ER PT J AU Nguyen, KB Cardinale, GF Tichenor, DA Kubiak, GD Berger, K RayChaudhuri, AK Perras, Y Haney, SJ Nissen, R Krenz, K Stulen, RH Fujioka, H Hu, C Bokor, J Tennant, DM Fetter, LA AF Nguyen, KB Cardinale, GF Tichenor, DA Kubiak, GD Berger, K RayChaudhuri, AK Perras, Y Haney, SJ Nissen, R Krenz, K Stulen, RH Fujioka, H Hu, C Bokor, J Tennant, DM Fetter, LA TI Fabrication of metal-oxide-semiconductor devices with extreme ultraviolet lithography SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 40th International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIBPN) CY MAY 28-31, 1996 CL ATLANTA, GA SP Amer Vacuum Soc, IEEE Electron Device Soc, Opt Soc Amer ID FIELD-EFFECT TRANSISTORS; DESIGN AB This article reports results from the successful fabrication of metal-oxide-semiconductor (MOS) devices with extreme ultraviolet lithography. n-type MOS transistors with gate lengths of 0.1 mu m were fabricated and demonstrated good device characteristics. The alignment strategy, mask layout, mask fabrication, and device characteristics will be reported. (C) 1996 American Vacuum Society. C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. AT&T BELL LABS,LUCENT TECHNOL,HOLMDEL,NJ 07733. RP Nguyen, KB (reprint author), SANDIA NATL LABS,POB 969,MS 9409,LIVERMORE,CA 94551, USA. RI Bokor, Jeffrey/A-2683-2011 NR 8 TC 6 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 4188 EP 4192 DI 10.1116/1.588618 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100157 ER PT J AU Weber, J Fenyo, EM Beddows, S Kaleebu, P Bjorndal, A Osmanov, S Heyward, W Esparza, J GalvaoCastro, B vandePerre, P Karita, E Wasi, C Sempala, S Tugume, B Biryahwaho, B RubsamenWaigmann, H vonBriesen, H Esser, R Grez, M Holmes, H Newberry, A Ranjbar, S Tomlinson, P Bradac, J McCutchan, F Louwagie, J Hegerich, P LopezGalindez, C Olivares, I Dopazo, J Mullins, JI Delwart, EL Bachmann, HM Goudsmit, J deWolf, F Hahn, BH Gao, F Yue, L Saragosti, S Schochetman, G Kalish, M Luo, CC George, R Pau, CP CheingsongPopov, R Nara, P Albert, J Myers, G Korber, B AF Weber, J Fenyo, EM Beddows, S Kaleebu, P Bjorndal, A Osmanov, S Heyward, W Esparza, J GalvaoCastro, B vandePerre, P Karita, E Wasi, C Sempala, S Tugume, B Biryahwaho, B RubsamenWaigmann, H vonBriesen, H Esser, R Grez, M Holmes, H Newberry, A Ranjbar, S Tomlinson, P Bradac, J McCutchan, F Louwagie, J Hegerich, P LopezGalindez, C Olivares, I Dopazo, J Mullins, JI Delwart, EL Bachmann, HM Goudsmit, J deWolf, F Hahn, BH Gao, F Yue, L Saragosti, S Schochetman, G Kalish, M Luo, CC George, R Pau, CP CheingsongPopov, R Nara, P Albert, J Myers, G Korber, B TI Neutralization serotypes of human immunodeficiency virus type 1 field isolates are not predicted by genetic subtype SO JOURNAL OF VIROLOGY LA English DT Article ID VIRAL GENOTYPE; HIV TYPE-1; ANTIBODIES; CELL AB Human immunodeficiency virus type 1 (HIV-1) primary isolates from four geographical locations in Thailand, Brazil, Rwanda, and Uganda, representing genetic subtypes A, B, C, D, and E, were examined for autologous and heterologous neutralization by panels of human HIV+ polyclonal plasma. In independent linked experiments in three laboratories using diverse methodologies and common reagents, no defined pattern of genetic subtype-specific neutralization was observed. Most plasma tested were broadly cross-neutralizing across two or more genetic subtypes, although the titer of neutralization varied across a wide range. We conclude that the genetic subtypes of HIV-1 are not classical neutralization serotypes. C1 KAROLINSKA INST,MICROBIOL & TUMOUR BIOL CTR,S-10401 STOCKHOLM,SWEDEN. WHO,GLOBAL PROGRAMME AIDS,CH-1211 GENEVA,SWITZERLAND. OSWALDO CRUZ FDN,SALVADOR,BA,BRAZIL. NATL HIV AIDS REFERENCE LAB,KIGALI,RWANDA. MAHIDOL UNIV,DEPT MICROBIOL,BANGKOK 10700,THAILAND. UGANDA VIRUS RES INST,ENTEBBE,UGANDA. GEORG SPEYER HAUS CHEMOTHERAPEUT FORSCHUNGSINST,FRANKFURT,GERMANY. NATL INST BIOL STAND & CONTROLS,LONDON NW3 6RB,ENGLAND. NIAID,DIV AIDS,BETHESDA,MD 20892. WALTER REED ARMY INST RES,HENRY M JACKSON FDN LAB,ROCKVILLE,MD. INST SALUD CARLOS III,CTR NACL BIOL CELULAR & RETROVIRUS,MADRID,SPAIN. STANFORD UNIV,SCH MED,DEPT MICROBIOL & IMMUNOL,STANFORD,CA 94305. UNIV AMSTERDAM,ACAD MED CTR,HUMAN RETROVIRUS LAB,NL-1105 AZ AMSTERDAM,NETHERLANDS. UNIV ALABAMA,DEPT MED,BIRMINGHAM,AL 35294. INST COCHIN,PARIS,FRANCE. CTR DIS CONTROL & PREVENT,ATLANTA,GA 30333. ST MARYS HOSP,SCH MED,LONDON,ENGLAND. NCI,VIRUS BIOL UNIT,FREDERICK,MD 21701. SWEDISH INST INFECT DIS CONTROL,STOCKHOLM,SWEDEN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Weber, J (reprint author), ST MARYS HOSP,UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,DEPT COMMUNICABLE DIS,LONDON W2,ENGLAND. RI Dopazo, Joaquin/A-9270-2014; Lopez-Galindez, Cecilio/A-3603-2008; Van de Perre, Philippe/B-9692-2008 OI Dopazo, Joaquin/0000-0003-3318-120X; Lopez-Galindez, Cecilio/0000-0002-2324-9584; Van de Perre, Philippe/0000-0002-3912-0427 NR 27 TC 113 Z9 113 U1 0 U2 3 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 NOV PY 1996 VL 70 IS 11 BP 7827 EP 7832 PG 6 WC Virology SC Virology GA VL792 UT WOS:A1996VL79200052 PM 8892904 ER PT J AU James, BR Gwo, JP Toran, L AF James, BR Gwo, JP Toran, L TI Risk-cost decision framework for aquifer remediation design SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID SENSITIVITY ANALYSIS; PEEL INLET; WORTH; EUTROPHICATION; MODEL AB The writers present a framework for increasing the effectiveness of remedial design decisionmaking at ground-water contamination sites where there is uncertainty in many parameters that affect remediation design. It is specifically designed for broad, ''big picture'' analyses, such as in the preliminary stages of remedial design. The presented framework is used to (1) select the best remedial design from a suite of possible ones; (2) estimate if additional data collection is cost-effective; and (3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost analysis, and regional sensitivity analysis (RSA). The framework is demonstrated using a hypothetical contamination problem where radionuclide strontium (Sr-90) is leaching from a trench into the ground water. Three remediation design alternatives are considered: monitoring only, isolating the source trench, and installing a plume containment and treatment system. Uncertainty in remediation design performance is due to uncertainty in 13 flow and transport parameters including hydraulic conductivity and source strength. The methodology can be applied to a variety of remediation problems. C1 OAK RIDGE NATL LAB,CTR COMPUTAT SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP James, BR (reprint author), BRU RISK RES,1235 SUNSET DR,SALTSPRING ISL,BC V8K 1E2,CANADA. NR 20 TC 20 Z9 20 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD NOV-DEC PY 1996 VL 122 IS 6 BP 414 EP 420 DI 10.1061/(ASCE)0733-9496(1996)122:6(414) PG 7 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA VN872 UT WOS:A1996VN87200004 ER PT J AU Duan, WM Hedrick, DB Pye, K Coleman, ML White, DC AF Duan, WM Hedrick, DB Pye, K Coleman, ML White, DC TI A preliminary study of the geochemical and microbiological characteristics of modern sedimentary concretions SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SULFATE-REDUCING BACTERIA; FATTY-ACIDS; ORGANIC-MATTER; COMMUNITY STRUCTURE; NUTRITIONAL-STATUS; MICROBIAL BIOMASS; SALT-MARSH; REDUCTION; OXIDATION; PYRITE AB Parallel mineralogical, geochemical, and lipid biomarker analyses of sedimentary siderite concretions and their host sediments were undertaken to give detailed information about the microbially mediated diagenetic processes involved. Concretions were collected from two contrasting environments at Warham, north Norfolk-typical brownish silty marsh sediment and black anaerobic mud from a creek bank-but no major differences in their mineralogy or geochemistry were found. Samples consisted of siderite, amorphous iron oxides, and iron sulfides with more carbonate present in the outer than in the inner parts. Subsamples from the concretions were found to be more similar to each other in their sulfide and organic carbon contents than to the host sediments. The microbiological characteristics revealed by lipid biomarker analysis showed considerable variation between concretions and host sediments, between individual concretions, and between inner and outer parts of the concretions. The predominant sulfate-reducing bacteria were more numerous in the concretions than in host sediments, but varied greatly within the concretions. The biomarker i17:1 omega 7c for Desulfovibrio was enriched within the concretions, suggesting that these bacteria, which are capable of reducing iron directly, played an important role in concretion formation. The lipid biomarker data indicated that the bacterial community changed during concretion formation and that different conditions for preservation existed in the concretions compared with the host sediments. C1 UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP Duan, WM (reprint author), UNIV READING,POSTGRAD RES INST SEDIMENTOL,POB 227,READING RG6 6AB,BERKS,ENGLAND. RI Coleman, Max/A-1303-2007 OI Coleman, Max/0000-0002-5514-1826 NR 45 TC 12 Z9 15 U1 0 U2 6 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 1996 VL 41 IS 7 BP 1404 EP 1414 PG 11 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA WU273 UT WOS:A1996WU27300004 ER PT J AU Zhang, G Gerdes, S Wunderlich, B AF Zhang, G Gerdes, S Wunderlich, B TI Heat capacities of solid, globular proteins SO MACROMOLECULAR CHEMISTRY AND PHYSICS LA English DT Article ID CARBON BACKBONE POLYMERS; LINEAR MACROMOLECULES; THERMODYNAMIC PROPERTIES; THERMAL-PROPERTIES; POLY(AMINO ACID)S; TEMPERATURE; DENATURATION; POLYAMIDES; COLLAGEN AB In an ongoing effort to understand the thermodynamic properties of proteins, solid-state heat capacities of poly(amino acid)s of all 20 naturally occurring amino acids and 4 copoly(amino acid)s were previously determined using our Advance THermal Analysis System (ATHAS). Recently, poly(L-methionine) and poly(L-phenylalanine) were further studied with new low-temperature measurements from 10 to 340 K. In addition, an analysis was performed on Literature data of a first protein, zinc bovine insulin dimer C508H752O150N130S12Zn. Good agreement was found between experiment and calculation. In the present work, we have investigated four additional anhydrous globular proteins, alpha-chymotrypsinogen, P-lactoglobulin, ovalbumin, and ribonuclease A. The heat capacity of each protein was measured from 130 to 420 K with differential scanning calorimetry, and the data were analyzed with both the ATHAS empirical addition scheme and a fitting to computations using an approximate vibrational spectrum. For the solid state, agreement between measurement and computation scheme could be accomplished to an average and root mean square percentage error of 0.5 +/- 3.2% for alpha-chymotrypsinogen, -0.8 +/- 2.5% for beta-lactoglobulin, -0.4 +/- 1.8% for ovalbumin, and -0.7 +/- 2.2% for ribonuclease A. With these calculations, it was possible to link the macroscopic heat capacities to their microscopic causes, the group and skeletal vibrational motion. For each protein one set of parameters of the Tarasov function, Theta(1) and Theta(3), represent the skeletal vibrational contributions to the heat capacity. They are obtained from a new optimization procedure [alpha-chymotrypsinogen: 631 K and 79 K (number of skeletal vibrators N-s = 3005); beta-lactoglobulin: 582 K and (79 K) (N-s = 2188); ovalbumin: 651 K and (79 K) (N-s = 5008) and ribonuclease A: 717 K and (79 K) (N-s = 1574), respectively]. Enthalpy, entropy, and Gibbs free energy can be derived for the solid state. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Zhang, G (reprint author), OAK RIDGE NATL LAB,DIV ANALYT & CHEM SCI,OAK RIDGE,TN 37831, USA. NR 41 TC 12 Z9 12 U1 0 U2 4 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4 FX#001-41-61-317-94-11, CH-4052 BASEL, SWITZERLAND SN 1022-1352 J9 MACROMOL CHEM PHYSIC JI Macromol. Chem. Phys. PD NOV PY 1996 VL 197 IS 11 BP 3791 EP 3806 DI 10.1002/macp.1996.021971124 PG 16 WC Polymer Science SC Polymer Science GA VU056 UT WOS:A1996VU05600024 ER PT J AU Zhou, R Embury, JD Wood, JT Smith, JL AF Zhou, R Embury, JD Wood, JT Smith, JL TI High-strength, high-conductivity copper-steel composite SO MATERIALS CHARACTERIZATION LA English DT Article ID PULSED MAGNETS; WIRE; DEFORMATION; ALLOY AB The construction of high-field, pulsed magnets requires not only high electrical conductivity, but also high mechanical strength of the material. The composite made of oxygen-free, high-conductivity copper and carbon steel has an ultimate tensile strength of more than 1.6GPa with a room temperature conductivity of 62% IACS (international annealed copper standard). This composite is superior to the materials currently available and meets the specification of the materials needed in the 100 tesla pulsed magnet. (C) Elsevier Science Inc., 1996. C1 MCMASTER UNIV,DEPT MAT SCI & ENGN,HAMILTON,ON,CANADA. RP Zhou, R (reprint author), LOS ALAMOS NATL LAB,SUPERCONDUCT & TECHNOL CTR,LOS ALAMOS,NM 87545, USA. NR 17 TC 10 Z9 15 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD NOV PY 1996 VL 37 IS 5 BP 239 EP 243 DI 10.1016/S1044-5803(96)00179-9 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA WV387 UT WOS:A1996WV38700001 ER PT J AU Hirvonen, JP Nastasi, M Jervis, TR Zocco, TG AF Hirvonen, JP Nastasi, M Jervis, TR Zocco, TG TI Ion beam processing, microstructure and tribology of Fe-Ti-C layers SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE ion beam processing; microstructures; tribology ID AISI-304 STAINLESS-STEEL; MECHANICAL-PROPERTIES; WEAR; FRICTION; FILMS AB Different processing routes can be used to produce Fe-Ti-C surfaces for tribological purposes. In this paper we focus on the utilization of ion beam mixing, or ion beam mixing combined with ion implantation. It turns out that a microstructural evolution varies accordingly but can be understood qualitatively on the basis of thermodynamic driving forces and kinetics. The relationship between microstructure, hardness, and tribological characteristics is complex, and enhanced tribological performance is found with several different combinations of extremely small embedded titanium carbide (TiC) embedded in an amorphous Fe-Ti-C matrix. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Hirvonen, JP (reprint author), VTT MFG TECHNOL,FIN-02044 ESPOO,FINLAND. NR 25 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD NOV-DEC PY 1996 VL 46 IS 2-3 BP 123 EP 131 DI 10.1016/S0254-0584(97)80005-3 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VV439 UT WOS:A1996VV43900005 ER PT J AU Yu, N Sickafus, KE Nastasi, M AF Yu, N Sickafus, KE Nastasi, M TI Electron irradiation induced crystallization of amorphous MgAl2O4 SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE ceramics; electron irradiation; magnesium aluminate spinel; amorphization; phase transformations; crystallization; microstructure ID SPINEL; MICROSTRUCTURE; AMORPHIZATION; CERAMICS AB Using transmission electron microscopy (TEM), an electron beam was used to irradiate cross-sectional TEM specimens of an amorphous MgAl2O4 thin film on a single crystal spinel substrate. Amorphous MgAl2O4 thin films of 160 nm thickness were initially formed by 400 keV Xe ion irradiation at liquid nitrogen temperatures in single crystal spinel substrates. It was observed that electron irradiation at 300 keV induced a phase transformation from an amorphous to a metastable crystalline structure. Crystallization of amorphous MgAl2O4 was observed to occur hath at the amorphous/crystalline interface by epitaxial growth and in the amorphous region by nucleation and growth. Under large doses of electron irradiation, a polycrystalline metastable phase was formed over the entire amorphous region. In contrast, thermal annealing at 600 degrees C for 1 h only produced negligible crystallization at the amorphous/crystalline interface. The major driving force for crystallization is the energy difference between the amorphous phase and the metastable crystalline phase. Electron irradiation provides the necessary defects to kinetically drive the transformation. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 24 TC 8 Z9 10 U1 2 U2 9 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD NOV-DEC PY 1996 VL 46 IS 2-3 BP 161 EP 165 DI 10.1016/S0254-0584(97)80009-0 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA VV439 UT WOS:A1996VV43900010 ER PT J AU Tesmer, JR Maggiore, CJ Nastasi, M Barbour, JC AF Tesmer, JR Maggiore, CJ Nastasi, M Barbour, JC TI A review of high energy backscattering spectrometry SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Review DE high energy backscattering spectrometry; resonances; applications ID FILMS; IONS AB The technique and application of high-energy backscattering (HEBS) is reviewed in this paper. The advantages and limitations of the technique are discussed as well as the origins of the resonances in the cross sections which are fundamental for its application. Methods for determining the cross sections are presented including the fabrication of targets for measuring th cross sections. Applications for both alpha and proton HEBS are presented. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Tesmer, JR (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 27 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD NOV-DEC PY 1996 VL 46 IS 2-3 BP 189 EP 197 DI 10.1016/S0254-0584(97)80013-2 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VV439 UT WOS:A1996VV43900014 ER PT J AU Cook, BA Harringa, JL Loughin, S AF Cook, BA Harringa, JL Loughin, S TI Fullerite additions as a phonon scattering mechanism in p-type Si-20 at.% Ge SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE silicon-germanium alloys; phonon scattering mechanism; fullerite; lattice thermal conductivity ID SIGE ALLOYS AB In a series of experiments to evaluate the possibility of reducing the lattice thermal conductivity in silicon-germanium alloys through the formation of an inert, intragranular nanophase, a number of p-type Si-20 at.% Ge alloys, nominally doped with 0.5 at.% boron, were prepared with varying amounts of fullerite, a mixture of 90% C-60 + 10% C-70. The fullerite, in the form of a fine black powder with a particle size of 0.7 nm, was shown by X-ray diffraction (XRD) to be nearly amorphous. The alloys were synthesized by mechanical alloying (MA) and the fullerite was added during various stages of preparation. Following consolidation by hot pressing, the compacts were found to be fully dense and homogeneous. Slices of each compact were characterized by the Hall effect at room temperature and also by electrical resistivity, the Seebeck coefficient, and thermal diffusivity measurements to 1000 degrees C. Addition of 0.2-0.8 wt.% fullerite by a simple mechanical blending operation resulted in an overall decrease in the carrier concentration of up to 35% in alloys hot pressed at 1200 degrees C, compared with 3.0 x 10(20) cm(-3) for baseline alloys without fullerite additions. Higher hot-pressing temperatures resulted in bath an increase in the carrier concentration and carrier mobility. A reduction in thermal conductivity of up to 22% compared with standard p-type alloys was observed in samples containing 0.8 wt.% additions. In this study, a maximum integrated average figure of merit, Z, between 300 and 1000 degrees C of 0.65 x 10(-3) degrees C-1 was obtained, corresponding to 0.4 wt.% addition of fullerite, which is 30-35% higher than that of 'standard' p-type Si-Ge alloys doped with 0.25 at.% boron prepared by conventional methods. Larger amounts of fullerite caused a decrease in Z. Observation of selected samples by transmission electron microscopy (TEM) revealed that the fullerite reacted with silicon to form nanophase SiC inclusions. C1 LOCKHEED MARTIN CORP,PHILADELPHIA,PA 19101. RP Cook, BA (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 18 TC 15 Z9 15 U1 3 U2 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV PY 1996 VL 41 IS 2 BP 280 EP 288 DI 10.1016/S0921-5107(96)01665-0 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA VZ350 UT WOS:A1996VZ35000014 ER PT J AU Wright, S Ralph, D AF Wright, S Ralph, D TI A superlinear infeasible-interior-point algorithm for monotone complementarity problems SO MATHEMATICS OF OPERATIONS RESEARCH LA English DT Article DE infeasible-interior-point methods; monotone nonlinear complementarity; superlinear convergence AB We use the globally convergent framework proposed by Kojima, Noma, and Yoshise to construct an infeasible-interior-point algorithm for monotone nonlinear complementarity problems. Superlinear convergence is attained when the solution is nondegenerate and also when the problem is linear with a strictly complementary solution. Numerical experiments confirm the efficacy of the proposed approach. C1 UNIV MELBOURNE,DEPT MATH,PARKVILLE,VIC 3052,AUSTRALIA. RP Wright, S (reprint author), ARGONNE NATL LAB,DIV COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 14 TC 33 Z9 33 U1 0 U2 0 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0364-765X J9 MATH OPER RES JI Math. Oper. Res. PD NOV PY 1996 VL 21 IS 4 BP 815 EP 838 DI 10.1287/moor.21.4.815 PG 24 WC Operations Research & Management Science; Mathematics, Applied SC Operations Research & Management Science; Mathematics GA VU970 UT WOS:A1996VU97000004 ER PT J AU Elata, D Berryman, JG AF Elata, D Berryman, JG TI Contact force-displacement laws and the mechanical behavior of random packs of identical spheres SO MECHANICS OF MATERIALS LA English DT Article DE contact mechanics; granular material AB The contact force-displacement law of two identical elastic spheres can independently display: nonlinear response, path dependence and dissipation due to slip. Omitting relative roll and torsion between the two spheres, a general contact force-displacement law is derived analytically by integrating the differential form of the Hertz-Mindlin solution along the contact displacement path. The Hertz-Mindlin contact law and a different contact law formulated by K, Walton are special cases of this general contact law. Implementation of the contact law in numerical codes may be cumbersome because it requires a full description of the contact load history. Some simplified contact force-displacement laws proposed in the literature that overcome this difficulty are shown to be thermodynamically inconsistent (i.e,, unphysical) since they permit energy generation at no cost. The mean-field approximation and statistical averaging for calculating macroscopic stress-strain relations are discussed with respect to various contact force-displacement laws. C1 LAWRENCE LIVERMORE NATL LAB,DIV EARTH SCI,LIVERMORE,CA 94551. RI Berryman, James/A-9712-2008; OI Elata, David/0000-0002-3816-6669 NR 13 TC 34 Z9 34 U1 2 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD NOV PY 1996 VL 24 IS 3 BP 229 EP 240 DI 10.1016/S0167-6636(96)00034-8 PG 12 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA VZ193 UT WOS:A1996VZ19300005 ER PT J AU Altschuler, E AF Altschuler, E TI Gastric Helicobacter pylori infection as a cause of idiopathic Parkinson disease and non-arteric anterior optic ischemic neuropathy SO MEDICAL HYPOTHESES LA English DT Article ID CORONARY HEART-DISEASE AB The mechanisms of pathogenesis for both idiopathic Parkinson disease and nonarteritic anterior optic ischemic neuropathy are unknown. A study has shown that, in both diseases, there is a higher prevalence of gastrointestinal ulcers than in age- and sex-matched controls or than in the reported rates for the general population. It is proposed that gastric Helicobacter pylori infection may be a cause of both these diseases. C1 UNIV CALIF SAN DIEGO,BRAIN & PERCEPT LAB,LA JOLLA,CA 92093. LAWRENCE LIVERMORE NATL LAB,INST SCI COMP RES,LIVERMORE,CA 94551. RP Altschuler, E (reprint author), UNIV CALIF SAN DIEGO,SCH MED,9500 GILMAN DR,LA JOLLA,CA 92093, USA. NR 18 TC 28 Z9 32 U1 0 U2 1 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH, MIDLOTHIAN, SCOTLAND EH1 3AF SN 0306-9877 J9 MED HYPOTHESES JI Med. Hypotheses PD NOV PY 1996 VL 47 IS 5 BP 413 EP 414 DI 10.1016/S0306-9877(96)90223-6 PG 2 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA VT276 UT WOS:A1996VT27600010 PM 8951807 ER PT J AU Yoo, CH Lee, HM Chan, JW Morris, JW AF Yoo, CH Lee, HM Chan, JW Morris, JW TI M(2)C precipitates in isothermal tempering of high Co-Ni secondary hardening steel SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID COARSENING RESISTANCE; M2C CARBIDES; MO AB The effects of isothermal tempering on the coarsening behavior of hexagonal M(2)C precipitates and the secondary hardening reaction in ultrahigh-strength AerMet 100 steel were investigated. The tempering temperatures were 468 degrees C, 482 degrees C, and 510 degrees C, and the tempering time spanned the range from 1 ro 400 hours. Experimental studies of the coarsening behavior of the carbides were made by utilizing transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffractometry (XRD). The hardness at the secondary hardening peak was about HRc 55. The average length and diameter of M(2)C carbides were 4 to 8 nm and 1.5 to 2.5 nm, respectively, al all three tempering temperatures; hence, the aspect ratio was almost 3, an equilibrium value in this case. The size of the M(2)C carbides increased monotonically with time, but the growth kinetics did not exactly follow the classical coarsening behavior. The amount of precipitated austenite increased with tempering time and temperature. M(2)C precipitates were still relatively fine even after 200 hours of tempering. This feature seemed to be closely related to the high hardness maintained after prolonged tampering. C1 KOREA ADV INST SCI & TECHNOL,DEPT MAT SCI & ENGN,TAEJON 305701,SOUTH KOREA. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP Yoo, CH (reprint author), POSCO,STAINLESS DEPT COLD ROLLING TEAM,POHANG 790360,SOUTH KOREA. RI Lee, Hyuck Mo/C-1994-2011 NR 20 TC 27 Z9 31 U1 0 U2 5 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 NOV PY 1996 VL 27 IS 11 BP 3466 EP 3472 DI 10.1007/BF02595438 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VT798 UT WOS:A1996VT79800011 ER PT J AU Chou, YT Li, YZ Liu, CT AF Chou, YT Li, YZ Liu, CT TI Analysis of mean square penetration depth in grain boundary diffusion SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB Exact and approximate expressions for mean square penetration depth (MSPD) in grain boundary diffusion are derived. The MSPDs in boundary diffusion are functionally different from those in lattice diffusion. The quantitative results obtained provide more reliable estimates for the penetration depth of a diffusant in polycrystalline materials, thin films, and bicrystals. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Chou, YT (reprint author), LEHIGH UNIV,DEPT MAT SCI & ENGN,BETHLEHEM,PA 18015, USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 12 TC 2 Z9 2 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 NOV PY 1996 VL 27 IS 11 BP 3473 EP 3477 DI 10.1007/BF02595439 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VT798 UT WOS:A1996VT79800012 ER PT J AU Song, SG Shi, N Gray, GT Roberts, JA AF Song, SG Shi, N Gray, GT Roberts, JA TI Reinforcement shape effects on the fracture behavior and ductility of particulate-reinforced 6061-Al matrix composites SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID METAL CERAMIC COMPOSITES; PLASTIC-DEFORMATION; SIC/A1 COMPOSITES; CRACK INITIATION; VOID GROWTH; NUCLEATION; TEMPERATURE; CAVITIES AB Particle shape effects on the fracture and ductility of a spherical and an angular particulate-reinforced 6061-Al composite containing 20 pet vol Al2O3 were studied using scanning electron microscopy (SEM) fractography and modeled using the finite element method (FEM). The spherical particulate composite exhibited a slightly lower yield strength and work hardening rate but a considerably higher ductility than the angular counterpart. The SEM fractographic examination showed that during tensile deformation, the spherical composite failed through void nucleation and linking in the matrix near the reinforcement/matrix interface, whereas the angular composite failed through particle fracture and matrix ligament rupture. The FEM results indicate that the distinction between the failure modes for these two composites can be attributed to the differences in the development of internal stresses and strains within the composites due to particle shape. C1 LOS ALAMOS NATL LAB, TECH STAFF, LOS ALAMOS, NM 87545 USA. RP Song, SG (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 25 TC 58 Z9 66 U1 1 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD NOV PY 1996 VL 27 IS 11 BP 3739 EP 3746 DI 10.1007/BF02595465 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VT798 UT WOS:A1996VT79800038 ER PT J AU Nishiizumi, K Caffee, MW Jull, AJT Reedy, RC AF Nishiizumi, K Caffee, MW Jull, AJT Reedy, RC TI Exposure history of lunar meteorites Queen Alexandra range 93069 and 94269 SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID NOBLE-GASES; RANGE-93069; MAC88104; SHERGOTTITES; Y791197; SOLAR; MOON AB Cosmic-ray produced C-14 (t(1/2) = 5730 years), Cl-36(3.01 x 10(5) years), Al-26(7.05 x 10(5) years), and Be-10 (1.5 x 10(6) years) in the recently discovered lunar meteorites Queen Alexandra Range 93069 (QUE 93069) and 94269 (QUE 94269) were measured by accelerator mass spectrometry. The abundance pattern of these four cosmogenic radionuclides and of noble gases indicates QUE 93069 and QUE 94269 were a paired fall and were exposed to cosmic rays near the surface of the Moon for at least several hundred million years before ejection. After the meteorite was launched from the Moon, where it had resided at a depth of 65-80 g/cm(2), it experienced a short transition time, similar to 20-50 ka, before colliding with the Earth. The terrestrial age of the meteorite is 5-10 ka. Comparison of the cosmogenic nuclide concentrations in QUE 93069/94269 and MAC 88104/88105 clearly shows that these meteorites were not ejected by a common event from the Moon. C1 LAWRENCE LIVERMORE NATL LAB,GEOSCI & ENVIRONM TECHNOL DIV,LIVERMORE,CA 94551. UNIV ARIZONA,NSF AMS FACIL,TUCSON,AZ 85721. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Nishiizumi, K (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. RI Caffee, Marc/K-7025-2015; OI Caffee, Marc/0000-0002-6846-8967; Reedy, Robert/0000-0002-2189-1303 NR 27 TC 21 Z9 21 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 1996 VL 31 IS 6 BP 893 EP 896 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VY468 UT WOS:A1996VY46800019 ER PT J AU Sigalas, MM Biswas, R Ho, KM AF Sigalas, MM Biswas, R Ho, KM TI Theoretical study of dipole antennas on photonic band-gap materials SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE photonic band-gap materials; antennas; transfer matrix method; reciprocity for radiation patterns ID CRYSTALS AB We study the reflection and transmission properties of two-dimensional (2D) photonic band-gap (PBG) materials with the use of the transfer matrix method. Then, by combining this method with the reciprocity theorem, we calculate the radiation patterns of antennas placed on top of 2D PBG materials. The results are in good agreement with recent theoretical and experimental results in similar systems. We also compare the present method of calculating the radiation patterns with a recently proposed method where the PBG crystal is replaced with an equivalent reflection plane. We show that the present method has several advantages; for example, it can be used even for case where the driven frequency of the antenna is not inside the PBG. (C) 1996 John Wiley & Sons, Inc. RP Sigalas, MM (reprint author), IOWA STATE UNIV,DEPT PHYS & ASTRON,MICROELECT RES CTR,AMES LAB,AMES,IA 50011, USA. NR 19 TC 28 Z9 29 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD NOV PY 1996 VL 13 IS 4 BP 205 EP 209 DI 10.1002/(SICI)1098-2760(199611)13:4<205::AID-MOP9>3.0.CO;2-Q PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA VL891 UT WOS:A1996VL89100009 ER PT J AU Brookman, KW Lamerdin, JE Thelen, MP Hwang, M Reardon, JT Sancar, A Zhou, ZQ Walter, CA Parris, CN Thompson, LH AF Brookman, KW Lamerdin, JE Thelen, MP Hwang, M Reardon, JT Sancar, A Zhou, ZQ Walter, CA Parris, CN Thompson, LH TI ERCC4 (XPF) encodes a human nucleotide excision repair protein with eukaryotic recombination homologs SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID PIGMENTOSUM GROUP-F; COMPLEMENTATION GROUP-F; HAMSTER OVARY CELLS; YEAST DNA-REPAIR; XERODERMA-PIGMENTOSUM; SACCHAROMYCES-CEREVISIAE; MOLECULAR-CLONING; GENE ERCC-1; RAD1 GENE; GROUP-A AB ERCC4 is an essential human gene in the nucleotide excision repair (NER) pathway, which is responsible for removing UV-C photoproducts and bulky adducts from DNA, Among the NER genes, ERCC4 and EXCC1 are also uniquely involved in removing DNA interstrand cross-linking damage, The ERCC1-ERCC4 heterodimer, like the homologous Rad10-Rad1 complex, was recently found to possess an endonucleolytic activity that incises on the 5' side of damage, The ERCC4 gene, assigned to chromosome 16p13.1-p13.2, was previously isolated by using a chromosome 16 cosmid library. It corrects the defect in Chinese hamster ovary (CHO) mutants of NER complementation group 4 and is implicated in complementation group F of the human disorder xeroderma pigmentosum. We describe the ERCC4 gene structure and functional cDNA sequence encoding a 916-amino-acid protein (104 kDa), which has substantial homology with the eukaryotic DNA repair and recombination proteins MEI-9 (Drosophila melanogaster), Rad16 (Schizosaccharomyces pombe), and Radl (Saccharomyces cerevisiae). ERCC4 cDNA efficiently corrected mutants in rodent NER complementation groups 4 and 11, showing the equivalence of these groups, and ERCC4 protein levels were reduced in mutants of both groups, In cells of an XP-F patient, the ERCC4 protein level was reduced to less than 5%, consistent with XPF being the ERCC4 gene, The considerable identity (40%) between ERCC4 and MEI-9 suggests a possible involvement of ERCC4 in meiosis. In baboon tissues, ERCC4 was expressed weakly and was not significantly higher in testis than in nonmeiotic tissues. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. UNIV N CAROLINA,SCH MED,DEPT BIOCHEM & BIOPHYS,CHAPEL HILL,NC 27599. UNIV TEXAS,CTR HLTH SCI,DEPT CELLULAR & STRUCT BIOL,SAN ANTONIO,TX 78284. RI Thelen, Michael/C-6834-2008; Thelen, Michael/G-2032-2014 OI Thelen, Michael/0000-0002-2479-5480; Thelen, Michael/0000-0002-2479-5480 FU NCI NIH HHS [CA61335]; NIEHS NIH HHS [ES05798]; NIGMS NIH HHS [GM32833] NR 87 TC 88 Z9 92 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD NOV PY 1996 VL 16 IS 11 BP 6553 EP 6562 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VN820 UT WOS:A1996VN82000061 PM 8887684 ER PT J AU Savage, JRK Tucker, JD AF Savage, JRK Tucker, JD TI Nomenclature systems for FISH-painted chromosome aberrations SO MUTATION RESEARCH-REVIEWS IN GENETIC TOXICOLOGY LA English DT Article ID IN-SITU HYBRIDIZATION; IONIZING-RADIATION; EXCHANGES; FREQUENCY C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. RP Savage, JRK (reprint author), MRC,RADIOBIOL UNIT,DIDCOT OX11 ORD,OXON,ENGLAND. FU NCI NIH HHS [CA 59431] NR 11 TC 38 Z9 39 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-1110 J9 MUTAT RES-REV GENET JI Mutat. Res.-Rev. Genet. Toxicol. PD NOV PY 1996 VL 366 IS 2 BP 153 EP 161 DI 10.1016/S0165-1110(96)90036-6 PG 9 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA VZ224 UT WOS:A1996VZ22400009 PM 9001582 ER PT J AU Apostolou, S Whitmore, SA Crawford, J Lennon, G Sutherland, GR Callen, DF Ianzano, L Savino, M DApolito, M Notarangelo, A Memeo, E Piemontese, MR Zelante, L Savoia, A Gibson, RA Tipping, AJ Morgan, NV Hassock, S Jansen, S deRavel, TJ VanBerkel, C Pronk, JC Easton, DF Mathew, CG Levran, O Verlander, PC Batish, SD Erlich, T Auerbach, AD CletonJansen, AM Moerland, EW Cornelisse, CJ Doggett, NA Deaven, LL Moyzis, RK AF Apostolou, S Whitmore, SA Crawford, J Lennon, G Sutherland, GR Callen, DF Ianzano, L Savino, M DApolito, M Notarangelo, A Memeo, E Piemontese, MR Zelante, L Savoia, A Gibson, RA Tipping, AJ Morgan, NV Hassock, S Jansen, S deRavel, TJ VanBerkel, C Pronk, JC Easton, DF Mathew, CG Levran, O Verlander, PC Batish, SD Erlich, T Auerbach, AD CletonJansen, AM Moerland, EW Cornelisse, CJ Doggett, NA Deaven, LL Moyzis, RK TI Positional cloning of the Fanconi anaemia group A gene SO NATURE GENETICS LA English DT Article ID EXON AMPLIFICATION; PHYSICAL MAP; ANEMIA; COMPLEMENTATION; LOCALIZATION; STRATEGIES; MUTATION; FACC C1 UMDS, GUYS HOSP, DIV MED & MOL GENET, LONDON SE1 9RT, ENGLAND. ADELAIDE WOMENS & CHILDRENS HOSP, DEPT CYTOGENET & MOL GENET, ADELAIDE, SA 5006, AUSTRALIA. LAWRENCE LIVERMORE NATL LAB, CTR HUMAN GENOME, LIVERMORE, CA 94550 USA. UNIV ORANGE FREE STATE, DEPT HUMAN GENET, ZA-9301 BLOEMFONTEIN, SOUTH AFRICA. UNIV WITWATERSRAND, S AFRICAN INST MED RES, DEPT HUMAN GENET, ZA-2050 WITWATERSRAND, SOUTH AFRICA. FREE UNIV AMSTERDAM, DEPT HUMAN GENET, AMSTERDAM, NETHERLANDS. UNIV CAMBRIDGE, INST PUBL HLTH, GENET EPIDEMIOL UNIT, CAMBRIDGE CB2 1TN, ENGLAND. ROCKEFELLER UNIV, LAB HUMAN GENET & HEMATOL, NEW YORK, NY 10021 USA. LEIDEN UNIV, DEPT PATHOL, LEIDEN, NETHERLANDS. LOS ALAMOS NATL LAB, CTR HUMAN GENOME STUDIES, LOS ALAMOS, NM 87545 USA. OSPED CASA SOLLIEVO SOFFERENZA, I-71013 SAN GIOVANNI ROTONDO, FOGGIA, ITALY. RI Morgan, Neil/A-5475-2009; Sutherland, Grant/D-2606-2012; Callen, David/G-1975-2012; Crawford, Joanna /F-9135-2013; Savoia, Anna/B-6463-2014 OI Morgan, Neil/0000-0001-6433-5692; Crawford, Joanna /0000-0003-0786-6889; Savoia, Anna/0000-0002-2407-2696 FU Fondazione Telethon NR 29 TC 228 Z9 228 U1 1 U2 7 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 1061-4036 EI 1546-1718 J9 NAT GENET JI Nature Genet. PD NOV PY 1996 VL 14 IS 3 BP 324 EP 328 DI 10.1038/ng1196-324 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA VQ146 UT WOS:A1996VQ14600029 ER PT J AU Huang, YX Paxton, WA Wolinsky, SM Neumann, AU Zhang, LQ He, T Kang, S Ceradini, D Jin, ZQ Yazdanbakhsh, K Kunstman, K Erickson, D Dragon, E Landau, NR Phair, J Ho, DD Koup, RA AF Huang, YX Paxton, WA Wolinsky, SM Neumann, AU Zhang, LQ He, T Kang, S Ceradini, D Jin, ZQ Yazdanbakhsh, K Kunstman, K Erickson, D Dragon, E Landau, NR Phair, J Ho, DD Koup, RA TI The role of a mutant CCR5 allele in HIV-1 transmission and disease progression SO NATURE MEDICINE LA English DT Article ID VIRUS TYPE-1 INFECTION; IMMUNODEFICIENCY; COHORT AB A 32-nucleotide deletion (Delta 32) within the beta-chemokine receptor 5 (CCR5) gene has been described in subjects who remain uninfected despite extensive exposure to HIV-1. This allele was found to be common in the Caucasian population with a frequency of 0.0808, but was not found in people of African or Asian ancestry. To determine its role in HIV-1 transmission and disease progression, we analyzed the CCR5 genotype of 1252 homosexual men enrolled in the Chicago component of the Multicenter AIDS Cohort Study (MACS). No infected participant was found to be homozygous for the Delta 32 allele, whereas 3.6% of at-risk but uninfected Caucasian participants were homozygous, showing the highly protective role of this genotype against sexual acquisition of HIV-1. No evidence was found to suggest that heterozygotes were protected against HIV-1 infection, but a limited protective role against disease progression was noted. The Delta 32 allele of CCR5 is therefore an important host factor in HIV-1 transmission and pathogenesis. C1 AARON DIAMOND AIDS RES CTR,NEW YORK,NY 10016. ROCKEFELLER UNIV,NEW YORK,NY 10016. NORTHWESTERN UNIV,SCH MED,DEPT MED,CHICAGO,IL 60611. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NEW YORK BLOOD CTR,LINDSLEY F KIMBALL RES INST,LAB IMMUNOCHEM,NEW YORK,NY 10021. ROCHE MOL SYST,BRANCHBURG,NJ 08876. RI Wolinsky, Steven/B-2893-2012; OI Wolinsky, Steven/0000-0002-9625-6697 FU NIAID NIH HHS [AI 35168, AI 32535, AI 45218] NR 23 TC 977 Z9 1003 U1 6 U2 52 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1078-8956 J9 NAT MED JI Nat. Med. PD NOV PY 1996 VL 2 IS 11 BP 1240 EP 1243 DI 10.1038/nm1196-1240 PG 4 WC Biochemistry & Molecular Biology; Cell Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Cell Biology; Research & Experimental Medicine GA VQ101 UT WOS:A1996VQ10100040 PM 8898752 ER PT J AU Keisler, JM Chopra, OK Shack, WJ AF Keisler, JM Chopra, OK Shack, WJ TI Statistical models for estimating fatigue strain-life behavior of pressure boundary materials in light water reactor environments SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The existing fatigue strain versus life (S-N) data for materials used in nuclear power plant components have been compiled and categorized according to material, loading and environmental conditions. Statistical models have been developed for estimating the effects of the various service conditions on the fatigue life of these materials. The results have been used to estimate the probability of initiating a fatigue crack. Data in the literature were reviewed to evaluate the effects of the size, geometry and surface finish of a component on its fatigue life. Fatigue S-N curves for components have been determined by adjusting the probability distribution curves of smooth test specimens for the effect of mean stress and then applying design margins to account for the uncertainties that arise because of component size, geometry and surface finish. The significance of the effect of the environment on the current code design curve and on the proposed interim design curves published in NUREG/CR-5999 is discussed. Estimations of the probability of fatigue cracking in sample components from boiling water reactors and pressurized water reactors are presented. RP Keisler, JM (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 45 TC 27 Z9 28 U1 1 U2 2 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 NOV PY 1996 VL 167 IS 2 BP 129 EP 154 DI 10.1016/S0029-5493(96)01293-9 PG 26 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WA811 UT WOS:A1996WA81100003 ER PT J AU Naus, DJ Oland, CB Ellingwood, BR Graves, HL Norris, WE AF Naus, DJ Oland, CB Ellingwood, BR Graves, HL Norris, WE TI Aging management of containment structures in nuclear power plants SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 3rd International Conference on Containment Design and Operation CY OCT 19-21, 1994 CL TORONTO, CANADA ID CONCRETE STRUCTURES; MAINTAINING RELIABILITY; INSPECTION REPAIR AB Research is being conducted by Oak Ridge National Laboratory under US Nuclear Regulatory commission (USNRC) sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of non-destructive evaluation techniques, assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. US NUCL REGULATORY COMMISS,WASHINGTON,DC 20555. RP Naus, DJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 29 TC 6 Z9 6 U1 2 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD NOV PY 1996 VL 166 IS 3 BP 367 EP 379 DI 10.1016/S0029-5493(96)01254-X PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VX503 UT WOS:A1996VX50300008 ER PT J AU Taleyarkhan, RP Georgevich, V Kim, SH Valenti, S Simpson, DB Sawruk, W AF Taleyarkhan, RP Georgevich, V Kim, SH Valenti, S Simpson, DB Sawruk, W TI Modeling and analysis of hydrogen detonation events in the Advanced Neutron Source reactor containment SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 3rd International Conference on Containment Design and Operation CY OCT 19-21, 1994 CL TORONTO, CANADA AB This paper describes salient aspects of the modeling, analyses and evaluations for hydrogen detonation in selected regions of the Advanced Neutron Source (ANS) containment during hypothetical severe accident conditions. Shock wave generation and transport modeling and analyses were conducted for two stratified configurations in the dome region of the high bay. Principal tools utilized for these purposes were the CTH and CET89 computer codes. Dynamic pressure loading functions were generated for key locations and used for evaluating structural response behavior for which a finite-element model was developed using the ANSYS code. For the range of conditions analyzed in the two critical dome regions, it was revealed that the ANS containment would be able to withstand detonation loads without failure. C1 GILBERT COMMONWEALTH CO,READING,PA 19607. RP Taleyarkhan, RP (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD NOV PY 1996 VL 166 IS 3 BP 471 EP 480 DI 10.1016/S0029-5493(96)01263-0 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VX503 UT WOS:A1996VX50300017 ER PT J AU Stratton, BC Fonck, RJ McKee, GR Budny, RV Chang, Z Wising, F Odblom, A AF Stratton, BC Fonck, RJ McKee, GR Budny, RV Chang, Z Wising, F Odblom, A TI Observation of sawtooth redistribution of non-thermal, confined alpha particles in TFTR DT discharges SO NUCLEAR FUSION LA English DT Letter ID FUSION TEST REACTOR; OSCILLATIONS; DEUTERIUM; TRITIUM; PLASMAS; POWER; BURN AB Radial profiles of the density of confined alpha particles with energies in the 0.15 to 0.6 MeV range are spectroscopically observed before and after a sawtooth crash in a TFTR deuterium-tritium plasma. A large drop in the core alpha density is seen, indicating expulsion of alphas from the core to the plasma periphery. The measured changes in the alpha density profiles are consistent with predictions based on the Kolesnichenko sawtooth model in this case. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Stratton, BC (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. NR 18 TC 28 Z9 28 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD NOV PY 1996 VL 36 IS 11 BP 1586 EP 1590 DI 10.1088/0029-5515/36/11/I12 PG 5 WC Physics, Fluids & Plasmas SC Physics GA XZ923 UT WOS:A1996XZ92300012 ER PT J AU Matthews, JAJ Berdusis, P Frautschi, M Schuler, J Sadrozinski, H OShaughnessy, K Spiegel, L Palounek, A Ziock, H Bacchetta, N Bisello, D Giraldo, A AF Matthews, JAJ Berdusis, P Frautschi, M Schuler, J Sadrozinski, H OShaughnessy, K Spiegel, L Palounek, A Ziock, H Bacchetta, N Bisello, D Giraldo, A TI Bulk radiation damage in silicon detectors and implications for LHC experiments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID TEMPERATURE-DEPENDENCE; NEUTRON-IRRADIATION; HARDNESS AB Bulk radiation damage to high resistivity n-type silicon detectors was studied with incident pi(+) (190 MeV) and protons (500, 647 or 800 MeV). Silicon bulk damage constants were extracted based on proton fluences, phi up to similar to 8x10(13) cm(-2) and for pi(+) fluences up to similar to 3x10(13) cm(-2). Although the measured damage constants for pi(+) and for proton irradiations were different, a simple empirical relationship was proposed to relate the pi(+) and proton radiation damage data. In addition: (a) Activation time constants for reverse annealing were determined at four temperatures between 0 degrees C and 50 degrees C. (b) 8 silicon detectors were exposed to a second proton fluence of similar to 3x10(13) cm(-2). The resulting changes in the effective dopant concentration, N-eff, were consistent with a model where the bulk radiation effects were purely additive. (c) Following reverse annealing the bulk radiation damage to high resistivity n-type silicon detectors was consistent with the simple functional form: N-eff(phi)=N-eff(0)e(-c phi)-(g(c)+g(y))phi, with c, g(c) and g(y) damage coefficients measured for pi(+) and proton radiation. The measured damage coefficients were used to provide predictions for the depletion voltage for the innermost pixel and silicon strip layers in the large detectors at the LHC. C1 UNIV CALIF SANTA CRUZ,SANTA CRUZ INST PARTICLE PHYS,SANTA CRUZ,CA 95064. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV PADUA,IST NAZL FIS NUCL,SEZ PADOVA,I-35131 PADUA,ITALY. RP Matthews, JAJ (reprint author), UNIV NEW MEXICO,NEW MEXICO CTR PARTICLE PHYS,ALBUQUERQUE,NM 87131, USA. NR 27 TC 18 Z9 18 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 NOV 1 PY 1996 VL 381 IS 2-3 BP 338 EP 348 DI 10.1016/S0168-9002(96)00491-3 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000015 ER PT J AU Arai, Y Arnold, JG Barkell, JW Bevensee, B Broomer, B Chapman, JW Chiba, M Collins, T Corden, MJ Craig, D Davis, DM Dressnandt, N Dunn, A Dunn, WL Ekenberg, T Emery, MS Emura, T Erdos, E Ford, WT Gabriel, TA Goshaw, AT Greene, SV vanHaaren, M Hackworth, DT Hamatsu, R Hanson, G Hirose, T Ikeno, M Jia, QP Johnson, D Kageya, T Keener, P Kitamura, S Lee, AM Leitch, RM Li, Z Luehring, F Mann, J Marshall, T Martin, B Miao, C Murata, T Newcomer, FM Odaka, S OFoghludha, F Ogren, H Oh, SH Ohska, TK Robertson, W Rust, DR Sasaki, O Schultz, G StOnge, KD Sudo, F Swensrud, RL Thompson, BR Toki, W VanBerg, R Vandergriff, DH Vejcik, S Wang, C Warner, D Watase, Y Watson, CR Wente, E Williams, HH Wilson, R Winningham, A Xiao, D Yamauchi, K Zou, B Zuelchner, C AF Arai, Y Arnold, JG Barkell, JW Bevensee, B Broomer, B Chapman, JW Chiba, M Collins, T Corden, MJ Craig, D Davis, DM Dressnandt, N Dunn, A Dunn, WL Ekenberg, T Emery, MS Emura, T Erdos, E Ford, WT Gabriel, TA Goshaw, AT Greene, SV vanHaaren, M Hackworth, DT Hamatsu, R Hanson, G Hirose, T Ikeno, M Jia, QP Johnson, D Kageya, T Keener, P Kitamura, S Lee, AM Leitch, RM Li, Z Luehring, F Mann, J Marshall, T Martin, B Miao, C Murata, T Newcomer, FM Odaka, S OFoghludha, F Ogren, H Oh, SH Ohska, TK Robertson, W Rust, DR Sasaki, O Schultz, G StOnge, KD Sudo, F Swensrud, RL Thompson, BR Toki, W VanBerg, R Vandergriff, DH Vejcik, S Wang, C Warner, D Watase, Y Watson, CR Wente, E Williams, HH Wilson, R Winningham, A Xiao, D Yamauchi, K Zou, B Zuelchner, C TI A modular straw drift tube tracking system for the solenoidal detector collaboration experiment .1. Design SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ALUMINIZED MYLAR TUBES; CHAMBER; CONSTRUCTION; PERFORMANCE; RESOLUTION; MIXTURES; TESTS; SDC AB We have developed the baseline design for a straw drift tube tracking system for the Solenoidal Detector Collaboration (SDC) detector. The system was designed to operate in the high-rate environment of a high luminosity hadron collider. We present an overview of the tracking system and the requirements it was expected to fulfill. We describe the construction and properties of the straw drift tubes. We discuss the design of the carbon-fiber foam-laminate shell, which supported the wire tension and held the straws in alignment. We also present descriptions of the designs of the front-end and digitization electronics as well as the electronics associated with the level 1 track trigger. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523. DUKE UNIV,DEPT PHYS,DURHAM,NC 27706. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. KEK,DIV PHYS,TSUKUBA,IBARAKI 305,JAPAN. UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. OAK RIDGE NATL LAB,OAK RIDGE DETECTOR CTR,OAK RIDGE,TN 37831. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. QUANTUM RES SERV,DURHAM,NC 27713. FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306. TOKYO METROPOLITAN UNIV,DEPT PHYS,HACHIOJI,TOKYO 19203,JAPAN. TOKYO UNIV AGR & TECHNOL,KOGANEI,TOKYO 184,JAPAN. WESTINGHOUSE SCI & TECHNOL CTR,PITTSBURGH,PA 15235. NR 40 TC 11 Z9 11 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1996 VL 381 IS 2-3 BP 355 EP 371 DI 10.1016/S0168-9002(96)00728-0 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000017 ER PT J AU Arai, Y Arnold, JG Barkell, JW Bevensee, B Broomer, B Chapman, JW Chiba, M Collins, T Corden, MJ Craig, D Davis, DM Dressnandt, N Dunn, A Dunn, WL Ekenberg, T Emery, MS Emura, T Erdos, E Ford, WT Gabriel, TA Goshaw, AT Greene, SV vanHaaren, M Hackworth, DT Hamatsu, R Hanson, G Hirose, T Ikeno, M Jia, QP Johnson, D Kageya, T Keener, P Kitamura, S Lee, AM Leitch, RM Li, Z Luehring, F Mann, J Marshall, T Martin, B Miao, C Murata, T Newcomer, FM Odaka, S OFoghludha, F Ogren, H Oh, SH Ohska, TK Robertson, W Rust, DR Sasaki, O Schultz, G StOnge, KD Sudo, F Swensrud, RL Thompson, BR Toki, W VanBerg, R Vandergriff, DH Vejcik, S Wang, C Warner, D Watase, Y Watson, CR Wente, E Williams, HH Wilson, R Winningham, A Xiao, D Yamauchi, K Zou, B Zuelchner, C AF Arai, Y Arnold, JG Barkell, JW Bevensee, B Broomer, B Chapman, JW Chiba, M Collins, T Corden, MJ Craig, D Davis, DM Dressnandt, N Dunn, A Dunn, WL Ekenberg, T Emery, MS Emura, T Erdos, E Ford, WT Gabriel, TA Goshaw, AT Greene, SV vanHaaren, M Hackworth, DT Hamatsu, R Hanson, G Hirose, T Ikeno, M Jia, QP Johnson, D Kageya, T Keener, P Kitamura, S Lee, AM Leitch, RM Li, Z Luehring, F Mann, J Marshall, T Martin, B Miao, C Murata, T Newcomer, FM Odaka, S OFoghludha, F Ogren, H Oh, SH Ohska, TK Robertson, W Rust, DR Sasaki, O Schultz, G StOnge, KD Sudo, F Swensrud, RL Thompson, BR Toki, W VanBerg, R Vandergriff, DH Vejcik, S Wang, C Warner, D Watase, Y Watson, CR Wente, E Williams, HH Wilson, R Winningham, A Xiao, D Yamauchi, K Zou, B Zuelchner, C TI A modular straw drift tube tracking system for the solenoidal detector collaboration experiment .2. Performance SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID VELOCITIES AB Several investigations were conducted to demonstrate the capabilities of a straw drift tube outer tracking system for the SDC detector as described in the previous article. These include electrical properties and aging properties of the tubes as well as measurements of electron drift times in a 2 T magnetic field. Measurements characterizing the radiation hardness of the processes used to fabricate the front-end electronics are also included. We present the performance characteristics of prototype straw modules read out through this front-end electronics as well as some data on the performance of the track trigger system. C1 INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523. DUKE UNIV,DEPT PHYS,DURHAM,NC 27706. KEK,DIV PHYS,TSUKUBA,IBARAKI 305,JAPAN. UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. OAK RIDGE NATL LAB,OAK RIDGE DETECTOR CTR,OAK RIDGE,TN 37831. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. QUANTUM RES SERV,DURHAM,NC 27713. FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306. TOKYO METROPOLITAN UNIV,DEPT PHYS,HACHIOJI,TOKYO 19203,JAPAN. TOKYO UNIV AGR & TECHNOL,KOGANEI,TOKYO 184,JAPAN. WESTINGHOUSE SCI & TECHNOL CTR,PITTSBURGH,PA 15235. NR 16 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1996 VL 381 IS 2-3 BP 372 EP 384 DI 10.1016/S0168-9002(96)00729-2 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000018 ER PT J AU Allison, WWM Alner, GJ Ambats, I Ayres, D Balka, LJ Barr, GD Barrett, WL Benjamin, D Bode, C Border, PM Brooks, CB Cobb, JH Cockerill, DJA Coover, K Cotton, RJ Courant, H Dahlin, BB DasGupta, U Dawson, JW Demuth, DM Edwards, VW Ewen, B Fields, TH GarciaGarcia, C Gallagher, HM Giles, RH Giller, GL Goodman, MC Gray, RN Heppelmann, S Hill, N Hoftiezer, JH Jankowski, DJ Johns, K Joyce, T Kafka, T Kasahara, SMS KirbyGallagher, LM Kochocki, J Leeson, W Litchfield, PJ Longley, NP Lopez, FV Lowe, MJ Marshak, ML Mann, WA May, EN Maxam, D McMaster, L Milburn, R Miller, WH Minor, CP Mondal, N Mualem, L Napier, A Nelson, EM Nickson, R Oliver, W Pearce, GF Perkins, DH Peterson, EA Price, LE Roback, DM Rosen, DB Ruddick, K Saitta, B Schmid, DJ Schlereth, J Schneps, J Schub, MH Seidlein, RV Shield, PD Shupe, MA Spear, S Stassinakis, A Sundaralingam, N Thomson, MA Thron, JL Vassiliev, V Villaume, G Wakely, SP Wall, D Wallis, EWG Weems, L Werkema, SJ West, N Wielgosz, U Woods, CA Yarker, S AF Allison, WWM Alner, GJ Ambats, I Ayres, D Balka, LJ Barr, GD Barrett, WL Benjamin, D Bode, C Border, PM Brooks, CB Cobb, JH Cockerill, DJA Coover, K Cotton, RJ Courant, H Dahlin, BB DasGupta, U Dawson, JW Demuth, DM Edwards, VW Ewen, B Fields, TH GarciaGarcia, C Gallagher, HM Giles, RH Giller, GL Goodman, MC Gray, RN Heppelmann, S Hill, N Hoftiezer, JH Jankowski, DJ Johns, K Joyce, T Kafka, T Kasahara, SMS KirbyGallagher, LM Kochocki, J Leeson, W Litchfield, PJ Longley, NP Lopez, FV Lowe, MJ Marshak, ML Mann, WA May, EN Maxam, D McMaster, L Milburn, R Miller, WH Minor, CP Mondal, N Mualem, L Napier, A Nelson, EM Nickson, R Oliver, W Pearce, GF Perkins, DH Peterson, EA Price, LE Roback, DM Rosen, DB Ruddick, K Saitta, B Schmid, DJ Schlereth, J Schneps, J Schub, MH Seidlein, RV Shield, PD Shupe, MA Spear, S Stassinakis, A Sundaralingam, N Thomson, MA Thron, JL Vassiliev, V Villaume, G Wakely, SP Wall, D Wallis, EWG Weems, L Werkema, SJ West, N Wielgosz, U Woods, CA Yarker, S TI The SOUDAN 2 detector - The operation and performance of the tracking calorimeter modules SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB SOUDAN 2 is a 960-ton tracking calorimeter which has been constructed to search for nucleon decay and other phenomena. The full detector consists of 224 calorimeter modules each weighing 4.3 tons. The modules consist of finely segmented iron instrumented with 1 m long drift tubes of 15 mm internal diameter. The tubes enable three spatial coordinates and dE/dx to be recorded for charged particles traversing the tubes. The spatial resolution is 0.38 cm in the x-y plane and 0.65 cm in the z, or drift, direction. The operation and performance of the modules are discussed. C1 RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. UNIV MINNESOTA, MINNEAPOLIS, MN 55455 USA. UNIV OXFORD, DEPT PHYS, OXFORD OX1 3RH, ENGLAND. TUFTS UNIV, MEDFORD, MA 02155 USA. WESTERN WASHINGTON UNIV, BELLINGHAM, WA 98225 USA. RI Cotton, Richard/K-2175-2012 NR 7 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 1 PY 1996 VL 381 IS 2-3 BP 385 EP 397 DI 10.1016/S0168-9002(96)00775-9 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000019 ER PT J AU Sarantites, D Hua, PF Devlin, M Sobotka, LG Elson, J Hood, JT LaFosse, DR Sarantites, JE Maier, MR AF Sarantites, D Hua, PF Devlin, M Sobotka, LG Elson, J Hood, JT LaFosse, DR Sarantites, JE Maier, MR TI ''The Microball'' - Design, instrumentation and response characteristics of a 4 pi-multidetector exit channel-selection device for spectroscopic and reaction mechanism studies with Gammasphere SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID 4-PI AB A 4 pi multidetector light-charged particle and light fragment detection spectrometer is described. It consists of 95 CsI(T1) a scintillators closely packed to cover the angular range 4.0 degrees-172 degrees, arranged in 9 rings with increasing forward segmentation. The device is optimally designed to be used in conjunction with Gammasphere. The scintillator light is collected by silicon photodiodes that provide high quantum efficiency and minimal mass. The signals are processed through a charge sensitive preamplifier followed by a slow shaper. Particle identification for H-1,H-2,H-3, He-3,He-4 ions and Li, Be and B ions is accomplished by pulse shape discrimination. The geometry, construction, energy calibration, gain stability, associated integrated electronics and the data acquisition system are discussed. The capabilities of this spectrometer as a channel selecting device in conjunction with Gammasphere are discussed. A second version of the device with thicker scintillators, that can stop more energetic charged particles and is useful for reaction mechanism studies, is also described. C1 UNIV CALIF BERKELEY,DIV ENGN,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Sarantites, D (reprint author), WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130, USA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 15 TC 238 Z9 238 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 NOV 1 PY 1996 VL 381 IS 2-3 BP 418 EP 432 DI 10.1016/S0168-9002(96)00785-1 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA VY450 UT WOS:A1996VY45000022 ER EF