FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Gibson, BF AF Gibson, BF BE Donnelly, TW TI S = -1 and S = -2 few-body hypernuclei SO INTERSECTIONS BETWEEN PARTICLE AND NUCLEAR PHYSICS - 6TH CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th Conference on the Intersections of Particle and Nuclear Physics CY MAY 27-JUN 02, 1997 CL BIG SKY, MT SP ANL, Bates, ABNL, FNAL, IUCF, LANL, LBNL, TJNAF, TRIUMF AB The S=-1 and S=-2 few-body bound states are the focus of this discussion. Implications for our understanding of the baryon-baryon interaction are examined. Octet-octet coupling effects not found in conventional, non-strange nuclei are highlighted. TJNAF wave function tests for the S=-1 sector are noted. The need to identify S=-2 hypernuclei to explore the S=-2 strong interaction and to test model predictions is emphasized. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gibson, BF (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-712-X J9 AIP CONF PROC PY 1997 IS 412 BP 927 EP 930 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA BK14L UT WOS:000071320100147 ER PT S AU Isaac, MCP Chan, YD Clark, R Deleplanque, MA Dragowsky, MR Fallon, P Goldman, ID Nishiizumi, K Larimer, RM Lee, IY Macchiavelli, AO MacLeod, RW Norman, EB Schroeder, LS Stephens, FS AF Isaac, MCP Chan, YD Clark, R Deleplanque, MA Dragowsky, MR Fallon, P Goldman, ID Nishiizumi, K Larimer, RM Lee, IY Macchiavelli, AO MacLeod, RW Norman, EB Schroeder, LS Stephens, FS BE Donnelly, TW TI Search for strange matter via heavy ion activation SO INTERSECTIONS BETWEEN PARTICLE AND NUCLEAR PHYSICS - 6TH CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th Conference on the Intersections of Particle and Nuclear Physics CY MAY 27-JUN 02, 1997 CL BIG SKY, MT SP ANL, Bates, ABNL, FNAL, IUCF, LANL, LBNL, TJNAF, TRIUMF AB In this paper we present the results of an experiment performed at LBNL's 88-Inch Cyclotron using GAMMASPHERE in which we searched for strange matter by applying the heavy ion activation technique to samples of meteorites. Our exploratory experiment improved existing experimental limits by 3 orders of magnitude. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Isaac, MCP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-712-X J9 AIP CONF PROC PY 1997 IS 412 BP 931 EP 934 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA BK14L UT WOS:000071320100148 ER PT S AU Goodman, M AF Goodman, M CA Soudan 2 Collaborat BE Donnelly, TW TI The atmospheric neutrino flavor ratio in Soudan 2 SO INTERSECTIONS BETWEEN PARTICLE AND NUCLEAR PHYSICS - 6TH CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th Conference on the Intersections of Particle and Nuclear Physics CY MAY 27-JUN 02, 1997 CL BIG SKY, MT SP ANL, Bates, ABNL, FNAL, IUCF, LANL, LBNL, TJNAF, TRIUMF AB The Soudan 2 collaboration has measured the atmospheric neutrino flavor ratio with 2.63 kiloton years of exposure. Our measured flavor ratio is 0.67 +/- 0.15(stat) +0.04-0.06(syst). The neutrino induced horizontal muon flux has been measured to be Phi(mu) = (4.12 +/- 1.1 +/- 0.58) x 10(-13) cm(-2) sr(-1) s(-1). C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Goodman, M (reprint author), Argonne Natl Lab, HEP362, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-712-X J9 AIP CONF PROC PY 1997 IS 412 BP 962 EP 968 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA BK14L UT WOS:000071320100154 ER PT B AU Beardmore, KM Cai, D GronbechJensen, N AF Beardmore, KM Cai, D GronbechJensen, N BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI Molecular Dynamics Simulation of low energy boron and arsenic implant into silicon SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB We have studied the implantation of boron and arsenic ions into silicon by classical Molecular Dynamics simulation. Single ion implant into the dimer reconstructed Si(100)(2x1) surface has been examined at energies between 0.25 keV and 5.0 keV, at both normal incidence and at nonchanneling incidence. By using a new model for electronic stopping, developed for semi-conductors and containing only one fitted parameter, we have been able to accurately calculate the depth profile of the implanted B and As atoms. The results of the calculations are compared to the predictions from a Binary Collision (BC) model for the dopant profile, and to experimental data. This allows us to examine the low energy limits on the validity of the BC approximation, with the aim of producing modifications to the BC model to extend its validity into the sub-keV regime. RP Beardmore, KM (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 535 EP 538 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00139 ER PT B AU Cai, D GronbechJensen, N Snell, CM Beardmore, KM Tasch, AF Morris, S AF Cai, D GronbechJensen, N Snell, CM Beardmore, KM Tasch, AF Morris, S BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI An electronic stopping power model for Monte Carlo and molecular dynamics simulation of ion implantation into silicon SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB We develop a phenomenological model of electronic stopping power for modeling the physics of ion implantation into crystalline silicon. In the framework of effective charge theory, this electronic stopping power for an ion is factorized into (i) a globally averaged effective charge taking into account effects of close and distant collisions by target electrons with the ion, and (ii) a local charge density dependent electronic stopping power for a proton. This model is implemented into both molecular dynamics and Monte Carlo simulations. There is only one free parameter in the model, namely, the one electron radius r(s)(o) for unbound electrons. By fine tuning this parameter, it is shown that the model can work successfully for both boron and arsenic implants. We report that the results of the dopant profile simulation for both species are in excellent agreement with the experimental profiles measured by secondary-ion mass spectroscopy (SIMS) over a wide range of energies and with different incident directions. This model also provides a good physically-based damping mechanism for molecular dynamics simulations in the electronic stopping power regime, as evidenced by the striking agreement of dopant profiles calculated in the molecular dynamics simulations with the SIMS data. RP Cai, D (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 543 EP 546 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00141 ER PT B AU Zhu, JG White, CW Budai, JD Withrow, SP Henderson, DO AF Zhu, JG White, CW Budai, JD Withrow, SP Henderson, DO BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI Effects of ion beam mixing on the formation of SiGe nanocrystals by ion implantation SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB Nanocrystals or SiGe alloy have been formed inside a SiO2 matrix by the ion implantation technique. It is demonstrated that the sequence of implantation of Si and Ge ions affects the nanocrystal formation significantly. This is explained by the ion-beam mixing effect during sequential implantation. The size distributions of the SiGe nanocrystals can also be controlled by annealing conditions. RP Zhu, JG (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 690 EP 693 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00179 ER PT B AU Zolper, JC Pearton, SJ Wilson, RG Stall, RA AF Zolper, JC Pearton, SJ Wilson, RG Stall, RA BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI Implant activation and redistribution of dopants in GaN SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB Gallium nitride (GaN) and related III-Nitride materials (AlN, InN) have recently been the focus of extensive research for photonic and electronic device applications. As this material system matures, ion implantation doping and isolation is expected to play an important role in advance device demonstrations. To this end, we report the demonstration of implanted p-type doping with Mg-24+P-31 and Ca-40 as well as n-type doping with Si in GaN. These implanted dopants require annealing similar to 1100 degrees C to achieve electrical activity, but demonstrate limited redistribution at this temperature. The redistribution of other potential dopants in GaN (such as Be, Zn, and Cd) will also be reported. Results for a GaN junction field effect transistor (JFET), the first GaN device to use implantation doping, will also be presented. RP Zolper, JC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 705 EP 708 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00183 ER PT B AU Wengrow, AB Leung, KN Perkins, LT Pickard, DS Rickard, ML Williams, MD Tucker, M AF Wengrow, AB Leung, KN Perkins, LT Pickard, DS Rickard, ML Williams, MD Tucker, M BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI Application of a pulsed, RF-driven, multicusp source for low energy plasma immersion ion implantation SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB The multicusp ion source has the capability of producing large volumes of uniform, quiescent, high density plasmas. Due to the versatility of the multicusp source, a plasma chamber suited for plasma immersion ion implantation (PIII) was readily constructed. Conventional PIII pulses the bias voltage applied to the substrate which is immersed in a CW mode plasma. However, in the interest of finding a more efficient and improved means of implantation, a method by which the plasma itself is pulsed was developed. Typically pulse lengths of 500 mu s are used and are much shorter than that of the substrate voltage pulse (similar to 5 to 15 ms). This approach, together with low gas pressures and low bias voltages, permits the constant energy implantation of an entire wafer simultaneously without glow discharge. Results show that this process can yield implant currents of up to 2.5 mA/cm(2), and thus very short implant times can be achieved. Uniformity of the ion flux will also be discussed. Furthermore, as this method can be scaled to any dimension, it could be made to handle any size wafer. RP Wengrow, AB (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 760 EP 763 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00197 ER PT B AU White, CW Budai, JD Withrow, SP Zhu, JG Pennycook, SJ Magruder, RH Henderson, DO AF White, CW Budai, JD Withrow, SP Zhu, JG Pennycook, SJ Magruder, RH Henderson, DO BE Ishidida, E Current, M Banerjee, S Larson, L Mehta, S Tasch, A Smith, TC Romig, T TI Ion beam synthesis of nanocrystals and quantum dots in optical materials SO ION IMPLANTATION TECHNOLOGY - 96 LA English DT Proceedings Paper CT 11th International Conference on Ion Implantation Technology CY JUN 16-21, 1996 CL AUSTIN, TX SP SEMATECH, Univ Texas, Amer Vacuum Soc, IEEE, Appl Mat, Varian, Eaton AB High-dose ion implantation has been used to synthesize a wide range of nanocrystals and quantum dots, and these structures can be encapsulated in a number of host materials using this technique. RP White, CW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 0 TC 0 Z9 0 U1 0 U2 2 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3289-X PY 1997 BP 824 EP 827 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BH58Z UT WOS:A1997BH58Z00213 ER PT B AU Novak, PL Varley, DA Nousen, DL Luczynski, GW AF Novak, PL Varley, DA Nousen, DL Luczynski, GW GP IEEE TI Web publishing: New roles and new partnerships for communicators SO IPCC 97 PROCEEDINGS - 1997 IEEE INTERNATIONAL PROFESSIONAL COMMUNICATION CONFERENCE: CROSSROADS IN COMMUNICATION LA English DT Proceedings Paper CT 1997 IEEE International Professional Communication Conference (IPCC 97) on Crossroads in Communication CY OCT 22-25, 1997 CL SALT LAKE CITY, UT SP IEEE Profess Commun Soc AB New electronic publishing technologies, particularly the World Wide Web, are rapidly displacing traditional paper-based methods. Lower costs, faster turn-around, and access to a much larger and broader audience are among the reasons so many organizations are migrating to electronically published documents. However, the same aspects of this technology that have such great appeal to companies can also make them vulnerable in ways they may not have learned to recognize and manage. Web publishing has greatly changed the roles of both communication professionals and information release/information security professionals. Because available tools make Web authoring easy, anyone can create and publish information with little or no involvement from corporate communications staff. Likewise, the ease with which any desktop computer can become a Web sewer makes anyone and everyone a publisher and an information manager. In many cases, the people responsible for these sewers are not communications professionals; in nearly all cases, they are not trained in information release or information security. This situation can put a company's image and its competitive advantage at great risk. This paper discusses some of the unique risks of electronic publishing, and describes the changing roles of staff at Pacific Northwest who developed the review and approval process for publishing corporate information on the Web. RP Novak, PL (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4184-8 PY 1997 BP 203 EP 210 PG 8 WC Computer Science, Information Systems; Communication SC Computer Science; Communication GA BJ87E UT WOS:A1997BJ87E00024 ER PT B AU Girill, TR AF Girill, TR GP IEEE TI Contributions of the open-commentary journal to the documentation profession SO IPCC 97 PROCEEDINGS - 1997 IEEE INTERNATIONAL PROFESSIONAL COMMUNICATION CONFERENCE: CROSSROADS IN COMMUNICATION LA English DT Proceedings Paper CT 1997 IEEE International Professional Communication Conference (IPCC 97) on Crossroads in Communication CY OCT 22-25, 1997 CL SALT LAKE CITY, UT SP IEEE Profess Commun Soc AB ACM SIGDOC's Journal of Computer Documentation (JCD) features open peer commentary on all its major articles. This paper compares the role that commentary plays in JCD with its role, actual and proposed, in other professional journals, and contrasts that role with prepublication refereeing. JCD's preference for commentary rich in ostensive and comparative features is explained by their benefits for documentation practitioners, just as including literature-awareness commentaries offers practitioners a greater voice on journal pages. And JCD's annual reprint-commentary combinations provide unusual opportunities for continuing professional education. RP Girill, TR (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-72,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-4184-8 PY 1997 BP 295 EP 302 PG 8 WC Computer Science, Information Systems; Communication SC Computer Science; Communication GA BJ87E UT WOS:A1997BJ87E00034 ER PT B AU Goldbach, AJ Johnson, JA Saboungi, ML Curtiss, LA Cook, AR Meisel, D AF Goldbach, AJ Johnson, JA Saboungi, ML Curtiss, LA Cook, AR Meisel, D GP SOC IMAGING SCI & TECHNOL TI Identification and characterization of polyselenides and their radical ions SO IS&T 50TH ANNUAL CONFERENCE, FINAL PROGRAM AND PROCEEDINGS LA English DT Proceedings Paper CT 50th Annual Meeting of the Society-of-Imaging-Science-and-Technology CY MAY 18-23, 1997 CL CAMBRIDGE, MA SP Soc Imaging Sci & Technol RP Goldbach, AJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Johnson, Jacqueline/P-4844-2014; OI Johnson, Jacqueline/0000-0003-0830-9275; Cook, Andrew/0000-0001-6633-3447 NR 0 TC 1 Z9 1 U1 2 U2 2 PU SOC IMAGING SCIENCE & TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 BN 0-89208-199-6 PY 1997 BP 63 EP 63 PG 1 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BJ88J UT WOS:A1997BJ88J00020 ER PT B AU Chen, KS Witkowski, WR AF Chen, KS Witkowski, WR GP SOC IMAGING SCI & TECHNOL TI Design optimization of a liquid-distribution chamber-slot die using the DAKOTA toolkit SO IS&T 50TH ANNUAL CONFERENCE, FINAL PROGRAM AND PROCEEDINGS LA English DT Proceedings Paper CT 50th Annual Meeting of the Society-of-Imaging-Science-and-Technology CY MAY 18-23, 1997 CL CAMBRIDGE, MA SP Soc Imaging Sci & Technol AB In the present study of design optimization of a liquid-distribution chamber-slot die, the DAKOTA (Design Analysis Kit for OpTimizAtion) toolkit, which is being developed by Sandia National Laboratories, was employed to navigate the search for the optimal die shape. This shape minimizes nonuniformity of Bow at the slot exit for a given set of liquid properties and operating conditions. Three-dimensional, steady Newtonian-liquid flow fields inside the chamber-slot die were computed using FIDAP, a commercial computer code based on the finite element method. The objective function of Bow nonuniformity at the slot exit is formulated as the percentage of coating material across the slot width having local-flowrate deviation greater than 1% from the mean. Computation of the objective function requires the integration of the velocity profile over the outflow plane. Two constraints, namely maximum hydrodynamic pressure and average residence time, were imposed in the optimization problem. The modified method of feasible directions algorithm was used to optimize the die geometry and to reduce the flow nonuniformity at the slot exit from 16.5% (initial design) to 3.2% (final design) for the chosen liquid properties and process conditions. Our case study demonstrates that liquid-distribution chamber-slat dies can be systematically optimized using DAKOTA. RP Chen, KS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC IMAGING SCIENCE & TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 BN 0-89208-199-6 PY 1997 BP 480 EP 484 PG 5 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BJ88J UT WOS:A1997BJ88J00131 ER PT B AU Chen, KS Cairncross, RA AF Chen, KS Cairncross, RA GP SOC IMAGING SCI & TECHNOL TI Non-deterministic analysis of a liquid polymeric-film drying process SO IS&T 50TH ANNUAL CONFERENCE, FINAL PROGRAM AND PROCEEDINGS LA English DT Proceedings Paper CT 50th Annual Meeting of the Society-of-Imaging-Science-and-Technology CY MAY 18-23, 1997 CL CAMBRIDGE, MA SP Soc Imaging Sci & Technol AB In this study we employed the Monte Carlo/Latin Hypercube sampling technique to generate input parameters for a liquid polymeric-film drying model with prescribed uncertainty distributions. The one-dimensional drying model employed in this study was that developed by Cairncross et al.(1) We found that the non-deterministic analysis with Monte Carlo/ Latin Hypercube sampling provides a useful tool for characterizing the two responses (residual solvent volume and the maximum solvent partial vapor pressure) of a liquid polymeric-film drying process. More precisely, we found that the non-deterministic analysis via Monte Carlo/Latin Hypercube sampling not only provides estimates of statistical variations of the response variables but also yields more realistic estimates of mean values, which can differ significantly from those calculated using deterministic simulation. For input-parameter uncertainties in the range from two to ten percent of their respective means, variations of response variables were found to be comparable to the mean values. RP Chen, KS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC IMAGING SCIENCE & TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 BN 0-89208-199-6 PY 1997 BP 548 EP 553 PG 6 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BJ88J UT WOS:A1997BJ88J00147 ER PT B AU Dubchak, I Muchnik, I Kim, SH AF Dubchak, I Muchnik, I Kim, SH BE Gaasterland, T Karp, P Karplus, K Ouzounis, C Sander, C Valencia, A TI Protein folding class predictor for SCOP: approach based on global descriptors SO ISMB-97 - FIFTH INTERNATIONAL CONFERENCE ON INTELLIGENT SYSTEMS FOR MOLECULAR BIOLOGY, PROCEEDINGS LA English DT Proceedings Paper CT 5th International Conference on Intelligent Systems for Molecular Biology (ISMB-97) CY JUN 21-25, 1997 CL HALKIDIKI, GREECE SP Cultural Capital Europe 1997, Thessaloniki, GlaxoWellcome PLC, Int Soc Computat Biol, SmithKline Beecham Corp, Silicon Graph, Sun Microsyst, US DOE, US NIH, US Natl Sci Fdn, Univ Patras, Greece AB This work demonstrates new techniques developed for the prediction of protein folding class in the context of the most comprehensive Structural Classification of Proteins (SCOP). The prediction method uses global descriptors of a protein in terms of the physical, chemical and structural properties of its constituent amino acids. Neural networks are utilized to combine these descriptors in a specific way to discriminate members of a given folding class from members of all other classes. It is shown that a specific amino acid's properties work completely differently on different folding classes. This creates the possibility of finding an individual set of descriptors that works best on a particular folding class. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dubchak, I (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 1-57735-022-7 PY 1997 BP 104 EP 107 PG 4 WC Biochemistry & Molecular Biology; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Medical Informatics SC Biochemistry & Molecular Biology; Computer Science; Medical Informatics GA BK49D UT WOS:000072320000015 ER PT B AU Xu, Y Mural, RJ Uberbacher, EC AF Xu, Y Mural, RJ Uberbacher, EC BE Gaasterland, T Karp, P Karplus, K Ouzounis, C Sander, C Valencia, A TI Inferring gene structures in genomic sequences using pattern recognition and expressed sequence tags SO ISMB-97 - FIFTH INTERNATIONAL CONFERENCE ON INTELLIGENT SYSTEMS FOR MOLECULAR BIOLOGY, PROCEEDINGS LA English DT Proceedings Paper CT 5th International Conference on Intelligent Systems for Molecular Biology (ISMB-97) CY JUN 21-25, 1997 CL HALKIDIKI, GREECE SP Cultural Capital Europe 1997, Thessaloniki, GlaxoWellcome PLC, Int Soc Computat Biol, SmithKline Beecham Corp, Silicon Graph, Sun Microsyst, US DOE, US NIH, US Natl Sci Fdn, Univ Patras, Greece DE multiple gene structure prediction; expressed sequence tags; sequence comparison and analysis; pattern recognition; and dynamic programming AB Computational methods for gene identification in genomic sequences typically have two phases: coding region prediction and gene parsing. While there are many effective methods for predicting coding regions (exons), parsing the predicted exons into proper gene structures, to a large extent, remains an unsolved problem. This paper presents an algorithm for inferring gene structures from predicted exon candidates, based on Expressed Sequence Tags (ESTs) and biological intuition/rules. The algorithm first finds all the related ESTs in the EST database (dbEST) for each predicted exon, and infers the boundaries of one or a series of genes based on the available EST information and biological rules. Then it constructs gene models within each pair of gene boundaries, that are most consistent with the EST information. By exploiting EST information and biological rules, the algorithm can (1) model complicated multiple gene structures, including embedded genes, (2) identify falsely-predicted exons and locate missed exons, and (3) make more accurate exon boundary predictions. The algorithm has been implemented and tested on long genomic sequences with a number of genes. Test results show that very accurate (predicted) gene models can be expected when related ESTs exist for the predicted exons. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Xu, Y (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ARTIFICIAL INTELLIGENCE PI MENLO PK PA 445 BURGESS DR, MENLO PK, CA 94025 USA BN 1-57735-022-7 PY 1997 BP 344 EP 353 PG 10 WC Biochemistry & Molecular Biology; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Medical Informatics SC Biochemistry & Molecular Biology; Computer Science; Medical Informatics GA BK49D UT WOS:000072320000052 ER PT B AU Barton, DL Tangyunyong, P AF Barton, DL Tangyunyong, P GP ASM INT TI Scanning fluorescent microthermal imaging SO ISTFA '97 - PROCEEDINGS OF THE 23RD INTERNATIONAL SYMPOSIUM FOR TESTING AND FAILURE ANALYSIS LA English DT Proceedings Paper CT 23rd International Symposium for Testing and Failure Analysis CY OCT 27-31, 1997 CL SANTA CLARA, CA SP ASM Int AB We have developed scanning fluorescent microthermal imaging (SFMI), a new failure analysis technique. The fluorescent microthermal imaging (FMI) technique has been used for over a decade in its original form [1-2]. FMI normally relies on the use of a cooled, slow-scan CCD camera and a flood beam fluorescence pump source, usually an ultraviolet are lamp. Interest in FMI has grown greatly over the past few years [3-9] due largely to its unique combination of high spatial and thermal resolution. In this paper, we demonstrate that the existing infrastructure found on a scanning laser microscope (SLM) is capable of acquiring the necessary images for SFMI using its scanned laser source and a point detector. The implications of this work are significant in that now high spatial and thermal resolution images can be made using an SLM without the need of additional, expensive hardware. RP Barton, DL (reprint author), SANDIA NATL LABS,POB 5800,1515 EUBANK SE,M-S 1081,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 BN 0-87170-619-9 PY 1997 BP 41 EP 49 PG 9 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BJ65P UT WOS:A1997BJ65P00006 ER PT B AU Peterson, KA Tangyunyong, P Barton, DL AF Peterson, KA Tangyunyong, P Barton, DL GP ASM INT TI Failure analysis for micro-electrical-mechanical systems (MEMS) SO ISTFA '97 - PROCEEDINGS OF THE 23RD INTERNATIONAL SYMPOSIUM FOR TESTING AND FAILURE ANALYSIS LA English DT Proceedings Paper CT 23rd International Symposium for Testing and Failure Analysis CY OCT 27-31, 1997 CL SANTA CLARA, CA SP ASM Int AB Micro-Electrical Mechanical Systems (MEMS) is an emerging technology with demonstrated potential for a wide range of applications including sensors and actuators for medical, industrial, consumer, military, automotive and instrumentation products. Failure analysis (FA) of MEMS is critically needed for the successful design, fabrication, performance analysis and reliability assurance of this new technology. Many devices have been examined using techniques developed for integrated circuit analysis, including optical inspection, scanning laser microscopy (SLM), scanning electron microscopy (SEM), focused ion beam (FIB) techniques, atomic force microscopy (AFM), infrared (IR) microscopy, light emission (LE) microscopy, acoustic microscopy and acoustic emission analysis. For example, the FIB was used to microsection microengines that developed poor performance characteristics. Subsequent SEM analysis clearly demonstrated the absence of wear on gear, hub, and pin joint bearing surfaces, contrary to expectations. Another example involved the use of infrared microscopy for thermal analysis of operating microengines. Hot spots were located, which did not involve the gear or hub, but indicated contact between comb structures which drive microengines. Voltage contrast imaging proved useful on static and operating MEMS in both the SEM and the FIB and identified electrostatic clamping as a potentially significant contributor to failure mechanisms in microengines. This work describes MEMS devices, FA techniques, failure modes, and examples of FA of MEMS. RP Peterson, KA (reprint author), SANDIA NATL LABS,MS 1081,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 BN 0-87170-619-9 PY 1997 BP 133 EP 142 PG 10 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BJ65P UT WOS:A1997BJ65P00019 ER PT B AU Campbell, AN Tanner, DM Soden, JM Stewart, DK Doyle, A Adams, E Gibson, M Abramo, M AF Campbell, AN Tanner, DM Soden, JM Stewart, DK Doyle, A Adams, E Gibson, M Abramo, M GP ASM INT TI Electrical and chemical characterization of FIB-deposited insulators SO ISTFA '97 - PROCEEDINGS OF THE 23RD INTERNATIONAL SYMPOSIUM FOR TESTING AND FAILURE ANALYSIS LA English DT Proceedings Paper CT 23rd International Symposium for Testing and Failure Analysis CY OCT 27-31, 1997 CL SANTA CLARA, CA SP ASM Int AB The electrical and chemical properties of insulators produced by codeposition of siloxane compounds or TEOS with oxygen in a focused ion beam (FIB) system were investigated. Metal-insulator-metal capacitor structures were fabricated and tested. Specifically, leakage current and breakdown voltage were measured and used to calculate the effective resistance and breakdown field. Capacitance measurements were performed on a subset of the structures. It was found that the siloxane-based FIB-insulators had superior electrical properties to those based on TEOS. Microbeam Rutherford backscattering spectrometry analysis and Fourier transform infrared spectroscopy were used to characterize the films and to help understand the differences in electrical behavior as a function of gas chemistry and deposition conditions. Finally, a comparison is made between the results presented here, previous results for FIB-deposited insulators, and typical thermally-grown gate oxides and interlevel dielectric SiO2 insulators. RP Campbell, AN (reprint author), SANDIA NATL LABS,FAILURE ANAL DEPT,POB 5800,M-S 1081,DEPT 2275,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 BN 0-87170-619-9 PY 1997 BP 223 EP 230 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BJ65P UT WOS:A1997BJ65P00032 ER PT B AU Hames, BR Kurek, B AF Hames, BR Kurek, B GP CANADIAN PULP & PAPER ASSOC TI MnO2-oxalate complex: A natural and abiotic ligninolytic system SO ISWPC - 9TH INTERNATIONAL SYMPOSIUM ON WOOD AND PULPING CHEMISTRY - ORAL PRESENTATIONS LA English DT Proceedings Paper CT 9th International Symposium on Wood and Pulping Chemistry (9th ISWPC) CY JUN 09-12, 1997 CL MONTREAL, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, Canadian Soc Chem, China Tech Assoc Paper Ind, EUCEPA, Japan TAPPI, Paprican, TAPPI, Tech Assoc Austr & New Zealand Pulp & Paper Assoc AB This paper report for the first time efficient modification/degradation of in situ lignin by manganese metallocomplexes formed by the association of MnO2 accumulated as black deposits during wood decay and oxalic acid, produced by fungi or resulting from oxidative degradation of cell wall components. The catalysts formed through interaction between MnIV and organic acid were shown to modify either chemical and physical properties of wood cell wall. In particular, lignin structural analysis by thioacidolysis has revealed a strong decrease in the lignin content of beta-O-4 linked Guaiacyl and Syringyl structures, the former one being predominantly attacked. The system is however remarkably specific of aromatic compounds as no hemicellulose nor cellulose degradation could be evidenced in the conditions used here. The exact nature of the Mn complex(es) remains however to be determined, as well as the chemical reactions resulting in Lignin structural modification. C1 NATL RENEWABLE ENERGY LAB,IND TECHNOL DIV,GOLDEN,CO. RP Kurek, B (reprint author), INRA,CHIM BIOL LAB,F-78850 THIVERVAL GRIGNON,FRANCE. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL PQ H3B 2X9, CANADA BN 1-896742-14-9 PY 1997 BP G51 EP G54 PG 4 WC Chemistry, Analytical; Engineering, Chemical; Materials Science, Paper & Wood SC Chemistry; Engineering; Materials Science GA BJ19P UT WOS:A1997BJ19P00042 ER PT B AU Bozell, JJ Black, SK Cahill, D Johnson, DK AF Bozell, JJ Black, SK Cahill, D Johnson, DK GP CANADIAN PULP & PAPER ASSOC TI Clean fractionation of lignocellulosic-purification and characterization of the hemicellulose component SO ISWPC - 9TH INTERNATIONAL SYMPOSIUM ON WOOD AND PULPING CHEMISTRY - POSTER PRESENTATIONS LA English DT Proceedings Paper CT 9th International Symposium on Wood and Pulping Chemistry (9th ISWPC) CY JUN 09-12, 1997 CL MONTREAL, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, Canadian Soc Chem, China Tech Assoc Paper Ind, EUCEPA, Japan TAPPI, Paprican, TAPPI, Tech Assoc Austr & New Zealand Pulp & Paper Assoc AB The Clean Fractionation process provides rapid access to all three polymeric components of lignocellulosics. However, the aqueous hemicellulose fraction has been more difficult to purify than either the lignin or cellulose fraction. Hemicellulose sugars are present along with the acid promoter and other organic acids, residual organic solvent, and low molecular weight lignin fragments. We have investigated several approaches for the purification of this fraction to give a pure stream of hemicellulose derived sugars. The paper will discuss the different purification methods employed, the effect of separation conditions on the sugar composition of the hemicellulose fraction, and characterization of the hemicellulose components present. RP Bozell, JJ (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL PQ H3B 2X9, CANADA BN 1-896742-15-7 PY 1997 BP 111 EP 114 PG 4 WC Chemistry, Applied; Chemistry, Multidisciplinary; Materials Science, Paper & Wood SC Chemistry; Materials Science GA BJ19Q UT WOS:A1997BJ19Q00010 ER PT B AU Kelley, SS Wang, XM Myers, MD Johnson, DK Chum, HL AF Kelley, SS Wang, XM Myers, MD Johnson, DK Chum, HL GP CANADIAN PULP & PAPER ASSOC TI Biomass oil-modified phenol formaldehyde resins. SO ISWPC - 9TH INTERNATIONAL SYMPOSIUM ON WOOD AND PULPING CHEMISTRY - POSTER PRESENTATIONS LA English DT Proceedings Paper CT 9th International Symposium on Wood and Pulping Chemistry (9th ISWPC) CY JUN 09-12, 1997 CL MONTREAL, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, Canadian Soc Chem, China Tech Assoc Paper Ind, EUCEPA, Japan TAPPI, Paprican, TAPPI, Tech Assoc Austr & New Zealand Pulp & Paper Assoc AB Fast pyrolysis can be used to convert a wide variety of biomass feedstocks into a low viscosity oil. A phenolic-rich (PN) fraction can then be extracted from this pyrolysis oil and used for preparation of phenol formaldehyde (PF) resins. Differences in the chemical properties of the PN fraction have a distinct impact on the performance of PF resins. When 25-45 weight percent of the monomeric phenol was replaced with PN the performance properties of properly formulated PN/PF resins compared favorably with those of commercial PF resins. RP Kelley, SS (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL PQ H3B 2X9, CANADA BN 1-896742-15-7 PY 1997 BP 471 EP 474 PG 4 WC Chemistry, Applied; Chemistry, Multidisciplinary; Materials Science, Paper & Wood SC Chemistry; Materials Science GA BJ19Q UT WOS:A1997BJ19Q00043 ER PT S AU Cole, EI Soden, JM Tangyunyong, P Candelaria, PL Beegle, RW Barton, DL Henderson, CL Hawkins, CF AF Cole, EI Soden, JM Tangyunyong, P Candelaria, PL Beegle, RW Barton, DL Henderson, CL Hawkins, CF GP IEEE IEEE IEEE TI Transient power supply voltage (v(DDT)) analysis for detecting IC defects SO ITC - INTERNATIONAL TEST CONFERENCE 1997, PROCEEDINGS: INTEGRATING MILITARY AND COMMERCIAL COMMUNICATIONS FOR THE NEXT CENTURY SE INTERNATIONAL TEST CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT International Test Conference 1997 (ITC) CY NOV 01-06, 1997 CL WASHINGTON, D.C. SP IEEE Comp Soc, Test Technol Tech Comm, IEEE Philadelphia Sect AB Transient power supply voltage (v(DDT)) analysis is a new testing technique demonstrated as a powerful alternative and complement to I-DDQ testing. v(DDT) analysis takes advantage of the limited response time of a voltage supply to the changing power demand of an IC during operation. Changes in the V-DD response time can be used to detect increases in the power demand of a microcontroller with resolutions of 20 nA at 100 kHz, 1 mu A at 1 MHz, and 2.5 mu A at 1.5 MHz. These current sensitivities have been shown for ICs with very low I-DDQ (< 100 nA) and for an IC with an intrinsic I-DDQ > 300 mu A. The present system uses 100 cycle averaging to compensate for low frequency "jitter". The v(DDT) signal acquisition protocols, frequency versus sensitivity tradeoffs, hardware considerations, noise limitations, data examples, and areas for future research are described. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Cole, EI (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 16 Z9 16 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1089-3539 BN 0-7803-4210-0 J9 INT TEST CONF P PY 1997 BP 23 EP 31 DI 10.1109/TEST.1997.639590 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BK13L UT WOS:000071293600003 ER PT S AU Henderson, CL Soden, JM AF Henderson, CL Soden, JM GP IEEE IEEE IEEE TI Signature analysis for IC diagnosis and failure analysis SO ITC - INTERNATIONAL TEST CONFERENCE 1997, PROCEEDINGS: INTEGRATING MILITARY AND COMMERCIAL COMMUNICATIONS FOR THE NEXT CENTURY SE INTERNATIONAL TEST CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT International Test Conference 1997 (ITC) CY NOV 01-06, 1997 CL WASHINGTON, D.C. SP IEEE Comp Soc, Test Technol Tech Comm, IEEE Philadelphia Sect AB A method of signature analysis is presented that is based on ATE data, experiential knowledge of failure modes and mechanisms, or a combination of both. This method can be used on low numbers of failures or even single failures. It uses the Dempster-Shafer theory to calculate failure mechanism confidence. This method can be used for rapid diagnosis of complex IC failures, as illustrated by the defect shown in Fig. 1. The model is developed and an example is given based on Sandia's 0.5 mu m CMOS IC technology. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Henderson, CL (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1089-3539 BN 0-7803-4210-0 J9 INT TEST CONF P PY 1997 BP 310 EP 318 DI 10.1109/TEST.1997.639632 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BK13L UT WOS:000071293600040 ER PT S AU Soden, JM Henderson, CL AF Soden, JM Henderson, CL GP IEEE IEEE IEEE TI IC diagnosis: Industry issues SO ITC - INTERNATIONAL TEST CONFERENCE 1997, PROCEEDINGS: INTEGRATING MILITARY AND COMMERCIAL COMMUNICATIONS FOR THE NEXT CENTURY SE INTERNATIONAL TEST CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT International Test Conference 1997 (ITC) CY NOV 01-06, 1997 CL WASHINGTON, D.C. SP IEEE Comp Soc, Test Technol Tech Comm, IEEE Philadelphia Sect C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Soden, JM (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1089-3539 BN 0-7803-4210-0 J9 INT TEST CONF P PY 1997 BP 435 EP 435 DI 10.1109/TEST.1997.639648 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BK13L UT WOS:000071293600056 ER PT B AU Sandoval, DL Clark, TT Riley, JJ AF Sandoval, DL Clark, TT Riley, JJ BE Fulachier, L Lumley, JL Anselmet, F TI Buoyancy-generated variable-density turbulence SO IUTAM SYMPOSIUM ON VARIABLE DENSITY LOW-SPEED TURBULENT FLOWS SE FLUID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT IUTAM Symposium on Variable Density Low-Speed Turbulent Flows CY JUL 08-10, 1996 CL MARSEILLE, FRANCE SP Int Union Theoret & Appl Mech, Assoc Univ Mecan, Ctr Natl Etudes Spatiales, CNRS, CEA, DRN, Cadarache, Commiss European Communities, Dantec, Deltalab, Dept Bouches Rhone, Elect France, Gaz France, Int Sci Fdn, US, Kluwer Acad Publ, Netherlands, Minist Def, direct Gen Armement, Quantel, Reg Provence alpes Cote Azur, Soc Natl Etudes & Construct Moteurs Avions, Spectra Phys, Univ Provence, Aix Marseille I, France, Ville Marseille RP Sandoval, DL (reprint author), LOS ALAMOS NATL LAB,APPL THEORET & COMPUTAT PHYS GRP XNH MSF664,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4602-5 J9 FLUID MEC A PY 1997 VL 41 BP 173 EP 180 PG 8 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BJ82N UT WOS:A1997BJ82N00022 ER PT B AU Beiu, V Draghici, S Makaruk, HE AF Beiu, V Draghici, S Makaruk, HE BE Borges, DL Martins, W TI On limited fan-in optimal neural networks SO IVTH BRAZILIAN SYMPOSIUM ON NEURAL NETWORKS, PROCEEDINGS LA English DT Proceedings Paper CT IVth Brazilian Symposium on Neural Networks CY DEC 03-05, 1997 CL GOIANIA, BRAZIL SP Brazilian Comp Soc, Int Neural Networks Soc, FINEP, CNPq, Fed Univ Goias, Sch Elect Engn DE neural networks; VLSI; fan-in; Boolean circuits; threshold circuits; F-n,F-m functions AB Because VLSI implementations do not cope well with highly, interconnected nets-the area of a chip growing as the cube of the fan-in [25]-this paper analyses the influence of limited fan-in on the size and VLSI optimality of such nets. Two different approaches will show that VLSI- and size-optimal discrete neural networks can be obtained for small (i.e. lower than linear) fan-in values. They have applications to hardware implementations of neural networks. The first approach is based on implementing a certain sub-class of Boolean functions, F(n,m)functions [34]. We will show that this class of functions can be implemented in VLSI-optimal (i.e., minimising AT(2)) neural networks of small constant fan-ins. The second approach is based on implementing Boolean functions for which the classical Shannon's decomposition can be used. Such a solution has already been used to prove bounds on neural networks with fan-ins limited to 2 [26]. We will generalise the result presented there to arbitrary fan-in, and prove that the size is minimised by small fan-in values, while relative minimum size solutions can be obtained for fan-ins strictly lower than linear. Finally, a size-optimal neural network having small constant fan-ins will be suggested for F-n,F-m functions. C1 Univ Calif Los Alamos Natl Lab, Space & Atmospher Div NIS1, Los Alamos, NM 87545 USA. RP Beiu, V (reprint author), Univ Calif Los Alamos Natl Lab, Space & Atmospher Div NIS1, MS D466, Los Alamos, NM 87545 USA. RI Beiu, Valeriu/F-7799-2015; OI Beiu, Valeriu/0000-0001-8185-956X; Draghici, Sorin/0000-0002-0786-8377 NR 0 TC 2 Z9 2 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8071-7 PY 1997 BP 19 EP 30 DI 10.1109/SBRN.1997.645844 PG 12 WC Computer Science, Artificial Intelligence SC Computer Science GA BK08C UT WOS:000071092500004 ER PT J AU TerAkopian, GM Oganessian, YT Popeko, GS Daniel, AV Hamilton, JY Kormicki, J Ramayya, AV Ma, WC Rasmussen, J Stoyer, MA Chu, SY Gregorich, KE Mohar, MF Prussin, SG Kliman, J Morhac, M Cole, JD Aryaeinejad, R Dardenne, YK Driget, M AF TerAkopian, GM Oganessian, YT Popeko, GS Daniel, AV Hamilton, JY Kormicki, J Ramayya, AV Ma, WC Rasmussen, J Stoyer, MA Chu, SY Gregorich, KE Mohar, MF Prussin, SG Kliman, J Morhac, M Cole, JD Aryaeinejad, R Dardenne, YK Driget, M TI Angular moments of fission fragments obtained in spontaneous fission of Cf-252 SO IZVESTIYA AKADEMII NAUK SERIYA FIZICHESKAYA LA Russian DT Article C1 DUBNA JOINT NUCL RES INST, DUBNA 141980, RUSSIA. VANDERBILT UNIV, DEPT PHYS & ASTRON, NASHVILLE, TN 37235 USA. LAWRENCE BERKELEY LAB, BERKELEY, CA USA. SLOVAK ACAD SCI, INST PHYS, BRATISLAVA, SLOVAKIA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. NR 11 TC 2 Z9 2 U1 1 U2 2 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., MOSCOW, 113095, RUSSIA SN 1026-3489 J9 IZV AKAD NAUK FIZ+ JI Izv. Akad. Nauk Ser. Fiz. PD JAN PY 1997 VL 61 IS 1 BP 185 EP 190 PG 6 WC Physics, Multidisciplinary SC Physics GA WQ887 UT WOS:A1997WQ88700025 ER PT B AU Tsai, YS AF Tsai, YS BE Hsu, JP Leung, G TI The investigation of CP violation through the decay of polarized tau leptons II SO JINGSHIN PHYSICS SYMPOSIUM IN MEMORY OF PROFESSOR WOLFGANG KROLL LA English DT Proceedings Paper CT JingShin Physics Symposium in Memory of Professor Wolfgang Kroll CY AUG 16-17, 1996 CL UNIV MASSACHUSETTS DARTMOUTH, DARTMOUTH, MA HO UNIV MASSACHUSETTS DARTMOUTH AB Under the assumption that CP violation is caused by exchange of a new boson, we propose to measure the magnitudes and CP-violating phases of the coupling constants of this boson to five different vertices in tau decay. This can be accomplished by studying the decay of polarized tau leptons produced at an e(+) e(-) collider whose beams are polarized. These five coupling constants could be used to construct a future theory of CP violation. If CP is violated in any channel of tau decay, it will imply that there exists a new charged boson other than the W boson responsible for CP violation. It will also imply that CP violation is much more prevalent than the standard theory predicts and this may enable us to understand the preponderance of matter over antimatter in the present universe. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Tsai, YS (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3126-1 PY 1997 BP 25 EP 38 PG 14 WC Physics, Applied; Physics, Particles & Fields SC Physics GA BK58C UT WOS:000072614700003 ER PT S AU Feitelson, DG Jette, MA AF Feitelson, DG Jette, MA BE Feitelson, DG Rudolph, L TI Improved utilization and responsiveness with gang scheduling SO JOB SCHEDULING STRATEGIES FOR PARALLEL PROCESSING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 3rd Workshop on Job Scheduling Strategies for Parallel Processing at IPPS'97 CY APR 05, 1997 CL GENEVA, SWITZERLAND ID DISTRIBUTED HIERARCHICAL CONTROL; PROCESSOR ALLOCATION; MULTIPROCESSORS; SYSTEMS AB Most commercial multicomputers use space-slicing schemes in which each scheduling decision has an unknown impact on the future: should a job be scheduled, risking that it will block other larger jobs later, or should the processors be left idle for now in anticipation of future arrivals? This dilemma is solved by using gang scheduling, because then the impact of each decision is limited to its time slice, and future arrivals can be accommodated in other time slices. This added flexibility is shown to improve overall system utilization and responsiveness. Empirical evidence from using gang scheduling on a Cray T3D installed at Lawrence Livermore National Lab corroborates these results, and shows conclusively that gang scheduling can be very effective with current technology. C1 Hebrew Univ Jerusalem, Inst Comp Sci, IL-91904 Jerusalem, Israel. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Feitelson, DG (reprint author), Hebrew Univ Jerusalem, Inst Comp Sci, IL-91904 Jerusalem, Israel. NR 33 TC 78 Z9 79 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-63574-2 J9 LECT NOTES COMPUT SC PY 1997 VL 1291 BP 238 EP 261 PG 24 WC Computer Science, Theory & Methods SC Computer Science GA BM08D UT WOS:000077560200011 ER PT B AU Lingenfelter, AC AF Lingenfelter, AC BE Tillack, D Thompson, R TI Welding metallurgy of nickel alloys in gas turbine components SO JOINING AND REPAIR OF GAS TURBINE COMPONENTS, CONFERENCE PROCEEDINGS FROM MATERIALS SOLUTION '97 LA English DT Proceedings Paper CT Materials Solutions 97 on Joining and Repair of Gas Turbine Components CY SEP 15-18, 1997 CL INDIANAPOLIS, IN SP ASM Int AB Materials for gas turbine engines are required to meet a wide range of temperature and stress application requirements. The properties needed to meet the turbine engine requirements have been achieved by specific alloy additions, heat treatment, and thermal mechanical processing. These alloys exhibit a combination of creep resistance, creep rupture strength, yield and tensile strength over a wide temperature range, resistance to environmental attack (including oxidation, nitridation, sulphidation and carburization), fatigue and thermal fatigue resistance, metallurgical stability, and useful thermal expansion characteristics. These properties are exhibited by a series of solid-solution-strengthened and precipitation-hardened nickel, iron, and cobalt alloys. A thorough understanding of the metallurgy and metallurgical processing of these materials is imperative to successfully fusion weld them. This same basic understanding is required for repair of a component with the added dimension of the potential effects of thermal cycling and environmental exposure the component will have endured in service. This article explores the potential problems in joining and repair welding these materials. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lingenfelter, AC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 0-87170-608-3 PY 1997 BP 3 EP 6 PG 4 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK12L UT WOS:000071242600001 ER PT J AU Bhattacharya, T Lacaze, R Morel, A AF Bhattacharya, T Lacaze, R Morel, A TI Large q expansion of the 2D q-states Potts model SO JOURNAL DE PHYSIQUE I LA English DT Article ID 1ST-ORDER PHASE-TRANSITIONS; FINITE-SIZE DATA; FREE-ENERGY; ALGORITHM; POINTS; 1ST AB We present a recursive method to calculate a large q expansion of the 2d q-states Potts model free energies based on the Fortuin-Kasteleyn representation of the model. With this procedure, we compute directly the ordered phase partition function up to order 10 in 1/root q. The energy cumulants at the transition can be obtained with suitable resummation and come out large for q less than or similar to 15. The size of these cumulants has important implications for finite size scaling predictions, explaining in particular recent discrepancies between the values for the pure phase specific heats obtained from current finite size scaling analysis of extrema and those obtained at the transition point by different methods. C1 CEA SACLAY, SPHT, F-91191 GIF SUR YVETTE, FRANCE. LOS ALAMOS NATL LAB, GRP T8, LOS ALAMOS, NM 87544 USA. UNIV PARIS 11, ASCI, F-91405 ORSAY, FRANCE. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 31 TC 11 Z9 11 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4304 J9 J PHYS I JI J. Phys. I PD JAN PY 1997 VL 7 IS 1 BP 81 EP 103 PG 23 WC Physics, Multidisciplinary SC Physics GA WD390 UT WOS:A1997WD39000004 ER PT J AU Herdt, GC Jung, DR Czanderna, AW AF Herdt, GC Jung, DR Czanderna, AW TI Penetration of deposited Ag and Cu overlayers through alkanethiol self-assembled monolayers on gold SO JOURNAL OF ADHESION LA English DT Article; Proceedings Paper CT 18th Annual Meeting of the Adhesion-Society CY FEB 12-22, 1995 CL HILTON HEAD ISL, SOUTH CAROLINA SP Adhes Soc DE self-assembled monolayers (SAMs); polymer-metal interactions; polymer-metal interfaces; XPS/ISS analysis of polymer-metal interfaces; metal penetration through SAMs; metal penetration through polymers; Cu interactions with hydroxyl; Ag interactions with COOH; Ag and Cu deposited on CH3; CN, CH2OH, and COOH SAM end groups ID ORGANIZED MOLECULAR ASSEMBLIES; RAY PHOTOELECTRON-SPECTROSCOPY; ION-SCATTERING SPECTROSCOPY; OXIDIZED ALUMINUM SURFACE; NORMAL-ALKANOIC ACIDS; METAL OVERLAYERS; FUNCTIONAL-GROUPS; 11-MERCAPTOUNDECANOIC ACID; ELECTRONIC-STRUCTURE; BINDING-ENERGIES AB The purpose of our research is to study the reactions, interactions, or penetration between vacuum deposited metals (M) and the organic functional end groups (OFGs) of self-assembled monolayers (SAMs) on Au films under controlled conditions. Metal/SAM/Au systems are models for understanding bonding at M/organic interfaces and the concomitant adhesion between the different materials. In broad terms, the M/OFGs form interacting interfaces (e.g., Cr/COOH or Cu/COOH) in which the deposit resides on top of the OFGs or weakly interacting interfaces through which the overlayer penetrates and resides at the SAM/gold interface. We present a review of XPS results from weakly interacting systems (Cu/CH2OH, CU/CN, Ag/CH3, Ag/COOH) and discuss in more depth the time-temperature dependence of the disappearance of the metal from the M/SAM interface following deposition using ISS on the Ag/CH3 and Ag/COOH systems. XPS and ISS were used to characterize five alkanethiols terminated with CH3, COOH(C-11 and C-16 chain lengths), CN and CH2OH before and after depositing up to 1.0 nm Ag or Cu at ca. 10(-7) torr. XPS spectra indicate that no strong interaction occurs between the deposited Ag and the COOH organic functional group, although a stronger interaction is evident on a C-16 COOH, and a unidentate is formed for Cu on the CH2OH. An interaction between Cu and CN is evident, and penetration into the SAM occurs to a greater extent than for Cu on CH2OH. The Ag interaction with CH3 is weak. ISS compositional depth profiles for Ag on COOH and CH3, taken From 113 to 293 K, indicate that Ag remains on the surface of the C-11 COOH for up to 1 h after deposition, whereas Ag penetrates CH3 in less than 5 min at 295 K. The time for Ag to penetrate into a C-16 COOH is several times longer than for the C-11 COOH and depends on the SAM temperature. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Czanderna, AW (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 68 TC 14 Z9 15 U1 0 U2 8 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0021-8464 J9 J ADHESION JI J. Adhes. PY 1997 VL 60 IS 1-4 BP 197 EP 222 DI 10.1080/00218469708014419 PG 26 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA YY951 UT WOS:000072204300015 ER PT J AU Landis, EN Nagy, EN Keane, DT AF Landis, EN Nagy, EN Keane, DT TI Microtomographic measurements of internal damage in portland-cement-based composites SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article AB The internal cracking patterns of a series of small mortar specimens were observed using a technique called X-ray microtomography. The experiments were arranged such that three-dimensional images of internal cracks could be made at several different times during the load history of the sample. This arrangement allowed progressive crack growth to be observed at micron-scale resolution in a single specimen. The specimens were loaded in compression. Image processing routines were used to make quantitative measurements of internal crack growth and damage progression. Preliminary measurements indicate that the maximum increase in crack area occurs around the peak load. Three-dimensional renderings qualitatively illustrate features of internal cracking such as the effects of different microstructural features. C1 NORTHWESTERN UNIV,SYNCHROTRON RES CTR,DND,CAT,APS,ANL,ARGONNE,IL 60439. RP Landis, EN (reprint author), UNIV MAINE,DEPT CIVIL & ENVIRONM ENGN,5711 BOARDMAN HALL,ORONO,ME 04469, USA. NR 10 TC 4 Z9 4 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0893-1321 J9 J AEROSPACE ENG JI J. Aerosp. Eng. PD JAN PY 1997 VL 10 IS 1 BP 2 EP 6 DI 10.1061/(ASCE)0893-1321(1997)10:1(2) PG 5 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA VZ004 UT WOS:A1997VZ00400002 ER PT J AU Ressler, C Tatake, JG Kaizer, E Putnam, DH AF Ressler, C Tatake, JG Kaizer, E Putnam, DH TI Neurotoxins in a vetch food: Stability to cooking and removal of gamma-glutamyl-beta-cyanoalanine and beta-cyanoalanine and acute toxicity from common vetch (Vicia sativa L) legumes SO JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY LA English DT Article DE common vetch; Vicia sativa L; legumes; nutrition; chicks; food toxins; detoxification; beta-cyanoalanine; gamma-glutamyl-beta-cyanoalanine; pyroglutamic acid AB Because the neurotoxic common vetch (Vicia sativa L.) legume seems to have come into some use in man's diet, we have investigated, using Pico-Tag analysis, the stability of the vetch neurotoxins to cooking. When heated in water at 100 degrees C for 3 h, gamma-glutamyl-beta-cyanoalanine (gamma-gluBCA) cyclized extensively to form pyroglutamic acid and beta-cyanoalanine (BCA). By contrast three specimens of common vetch seeds containing 0.42-0.74% gamma-gluBCA and 0.01-0.03% BCA retained these principles without loss. A modified cooking procedure replacing the broth during cooking with fresh water and washing the seeds well yielded cooked seeds without detectable neurotoxins. A nutritional study confirmed that the toxins responsible for causing weight loss and mortality in chicks were removed. Lengthy steeping in water at room temperature also effectively removed the neurotoxins from dehulled split seeds but incompletely from intact seeds. These procedures improve the quality of common vetch seed as a source of protein for man. C1 LAWRENCE LIVERMORE NATL LAB,DEPT AGRON & RANGE SCI,DAVIS,CA 95616. RP Ressler, C (reprint author), UNIV CONNECTICUT,CTR HLTH,DEPT PHARMACOL,FARMINGTON,CT 06030, USA. NR 25 TC 21 Z9 21 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-8561 J9 J AGR FOOD CHEM JI J. Agric. Food Chem. PD JAN PY 1997 VL 45 IS 1 BP 189 EP 194 DI 10.1021/jf9603745 PG 6 WC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology SC Agriculture; Chemistry; Food Science & Technology GA WD696 UT WOS:A1997WD69600036 ER PT J AU Ziegler, SF Ramsdell, F Singhal, MC Generoso, W Wilkinson, JE Appleby, MW AF Ziegler, SF Ramsdell, F Singhal, MC Generoso, W Wilkinson, JE Appleby, MW TI A large scale screen utilizing chromosomal rearrangement mutants for novel genes involved in immunoregulation. SO JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY LA English DT Meeting Abstract C1 DARWIN MOL CORP,BOTHELL,WA. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,COLL VET MED,KNOXVILLE,TN. NR 0 TC 0 Z9 0 U1 0 U2 2 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0091-6749 J9 J ALLERGY CLIN IMMUN JI J. Allergy Clin. Immunol. PD JAN PY 1997 VL 99 IS 1 SU S BP 135 EP 135 PN 2 PG 1 WC Allergy; Immunology SC Allergy; Immunology GA WH142 UT WOS:A1997WH14200134 ER PT J AU Torigoe, C Goldstein, B Wofsy, C Metzger, H AF Torigoe, C Goldstein, B Wofsy, C Metzger, H TI Competition of receptor phosphorylation between discrete aggregates of Fc epsilon RI. SO JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY LA English DT Meeting Abstract C1 NIAMS,ARB,NIH,BETHESDA,MD. LOS ALAMOS NATL LAB,DIV THEORET,THEORET BIOL & BIOPHYS GRP,LOS ALAMOS,NM. UNIV NEW MEXICO,DEPT MATH & STAT,ALBUQUERQUE,NM 87131. NR 0 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 0091-6749 J9 J ALLERGY CLIN IMMUN JI J. Allergy Clin. Immunol. PD JAN PY 1997 VL 99 IS 1 SU S BP 1780 EP 1780 PN 2 PG 1 WC Allergy; Immunology SC Allergy; Immunology GA WH142 UT WOS:A1997WH14201774 ER PT J AU Duckworth, DC Smith, DH McLuckey, SA AF Duckworth, DC Smith, DH McLuckey, SA TI Improved signal-to-noise ratio in glow discharge ion trap mass spectrometry via pulsed discharge operation's SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT 44th ASMS Conference on Mass Spectrometry and Allied Topics CY MAY 12-16, 1996 CL PORTLAND, OR SP ASMS DE glow discharge ion trap mass spectrometry; elemental analysis; direct solids analysis; noise; pulsed discharge; gated ion injection ID COUPLED PLASMA SOURCE; PROFILES; SAMPLES AB An improvement in the S/N ratio is reported for the analysis of trace elements in brass by glow discharge ion trap mass spectrometry, This was achieved by synchronizing the pulsed discharge voltage with the ion injection and acquisition events; 'on' during ion injection and 'off' during data acquisition, Two modes of operation were Evaluated: (1) a high duty cycle pulse, which allowed a continuous injection over the duration of the;pulse; and (2) a low duty cycle pulse with multiple data gates, which allowed gated injections of ions at selected regions of the pulse profile, The latter afforded a means of selective ion injection since discharge and;residual gas species are formed at different times in the pulse event than analyte ions, Improvements in S/N ratios greater than 40-fold were observed, primarily due to a reduction in background and background noise after the discharge was extinguished. Evidence is presented which suggests that electrons emanating from the ion source are the precursors of most of the noise, Detection limits for various elements were 0.2-0.5 ppm. RP Duckworth, DC (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009; Duckworth, Douglas/B-7171-2015 OI McLuckey, Scott/0000-0002-1648-5570; Duckworth, Douglas/0000-0002-8161-5685 NR 27 TC 21 Z9 21 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD JAN PY 1997 VL 12 IS 1 BP 43 EP 48 DI 10.1039/a605312b PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WE480 UT WOS:A1997WE48000014 ER PT J AU Tyler, JA Rose, KA AF Tyler, JA Rose, KA TI Effects of individual habitat selection io a heterogeneous environment on fish cohort survivorship: A modelling analysis SO JOURNAL OF ANIMAL ECOLOGY LA English DT Article DE density-dependent survivorship; spatial covariance; ESS; habitat selection; individual-based model; computer simulation ID IDEAL FREE DISTRIBUTION; PERCH PERCA-FLAVESCENS; YOUNG YELLOW PERCH; POPULATION-DYNAMICS; PATCHY ENVIRONMENT; COMMUNITY STRUCTURE; PREDATOR AVOIDANCE; SPATIAL VARIATION; TRAETH MELYNOG; TRAVEL COSTS AB 1. This work investigates how cohort survivorship predictions are affected by the rules used for moving individuals between habitats in a variety of prey and predator environments. 2. We present an individual-based simulation model of the survival of a juvenile, planktivorous fish cohort over the growing season in a spatially explicit environment. The model represents the environment as a 10 x 10 grid of cells (habitats) that can wry in food density and predator number. 3. Juvenile fish begin with identical characteristics, then grow, move between cells, and die based on their individual experiences. Juveniles use one of four moving-between-cell (cell-departure) rules. random, maximize growth, minimize mortality risk, and minimize the ratio of mortality risk to growth. The model includes size-dependent rules for juvenile consumption, encounters between juveniles and predators, and juvenile death. Predators have three different distributions: uncorrelated, correlated with zooplankton, and correlated with juveniles. 4. Three simulation experiments were conducted to address how cohort survivorship is affected by the environment's spatial heterogeneity, the cell-departure rule of juveniles, and the initial cohort number (Experiment 1); which cell-departure rule individual juveniles should use (Experiment 2); and how survivorship predictions differ between this explicit, spatially heterogeneous model and a similar, spatially homogeneous model (Experiment 3). 5. Experiment 1 showed that predator distribution, juvenile number, zooplankton density and cell-departure rule had important effects on cohort survivorship. Experiment 2 showed that no single cell-departure rule was consistently the evolutionarily stable strategy (ESS), and that survivorship of cohorts using the ESS cell-departure rule(s) was lower than that of cohorts using the eel-departure rule with the highest single-year survivorship. Experiment 3 showed that density effects on juvenile survivorship can be much greater in a spatially explicit model, with individuals using fitness-based cell-departure rules than in an analogous, spatially homogeneous model. 6. The results of this work indicate that the cell-departure rule used by individuals can have an important effect on cohort survivorship. In addition, none of the state- and time-independent cell-departure rules investigated was an ESS, suggesting that such static rules may not be an appropriate mechanism for modelling individual habitat selection in a dynamic environment. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RP Tyler, JA (reprint author), SUNY COLL BUFFALO, GREAT LAKES CTR, 1300 ELMWOOD AVE, BUFFALO, NY 14222 USA. NR 75 TC 26 Z9 26 U1 0 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8790 EI 1365-2656 J9 J ANIM ECOL JI J. Anim. Ecol. PD JAN PY 1997 VL 66 IS 1 BP 122 EP 136 DI 10.2307/5970 PG 15 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA WG600 UT WOS:A1997WG60000012 ER PT J AU Haarmann, TK AF Haarmann, TK TI Honey bees as indicators of radionuclide contamination: exploring colony variability and temporal contaminant accumulation SO JOURNAL OF APICULTURAL RESEARCH LA English DT Article DE honey bees; Apis mellifera; contamination; ecotoxicology; radionuclide; environmental monitoring; colony variability; ecological risk assessments; tritium; sodium-22 ID POLLUTION; METALS AB Two aspects of using honey bees, Apis mellifera, as indicators of environmental radionuclide contamination were investigated: colony variability and temporal contaminant accumulation. Two separate field experiments were conducted in areas with bioavailable radionuclide contamination. Bees were collected from colonies, analysed for concentrations of radionuclides, and the results were compared using graphical and statistical methods. The first experiment indicates that generally a low variability exists between samples collected within the same colony. A higher variability exists between samples collected from adjacent colonies. Levels of tritium and sodium-22 found in samples taken from similar colonies were inconsistent, while levels of cobalt-57, cobalt-60 and manganese-54 were consistent. A second experiment investigated the accumulation of radionuclides over time by comparing colonies that had been in the study area for different periods of time. This experiment demonstrated that there is indeed a significant accumulation of radionuclides within colonies. C1 UNIV NEW MEXICO,DEPT BIOL,ALBUQUERQUE,NM 87131. RP Haarmann, TK (reprint author), LOS ALAMOS NATL LAB,ECOL GRP,LOS ALAMOS,NM 87545, USA. NR 24 TC 6 Z9 6 U1 1 U2 5 PU INT BEE RESEARCH ASSOC PI CARDIFF PA JOURNALS LIBRARIAN, 18 NORTH RD, CARDIFF CF1 3DY, WALES SN 0021-8839 J9 J APICULT RES JI J. Apic. Res. PY 1997 VL 36 IS 2 BP 77 EP 87 PG 11 WC Entomology SC Entomology GA XW780 UT WOS:A1997XW78000003 ER PT J AU Porter, LJ Yip, S Yamaguchi, M Kaburaki, H Tang, MJ AF Porter, LJ Yip, S Yamaguchi, M Kaburaki, H Tang, MJ TI Empirical bond-order potential description of thermodynamic properties of crystalline silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; SI; TRANSITIONS; PRESSURE; LATTICE; SYSTEMS; PHASES; ENERGY AB Thermodynamic properties of silicon (diamond cubic phase) are calculated using an empirical many-body potential developed by Tersoff [Phys. Rev. Lett. 56, 632 (1986)] based on the concept of bond order. It is shown that this model gives predictions in good agreement with experiment for those properties governed by energetics (free energy, entropy, and heat capacity). The thermal expansion coefficient is less well described, which is traced to the fact that the model potential, in its present version, is overly stiff and therefore unable to account properly for the volume dependence of the transverse acoustic modes. Furthermore, sensitivity of the potential to whether each atom remains bonded to only four neighbors indicates that the short-range nature of the potential may necessitate model improvement before it is suitable for studies of thermomechanical properties at elevated temperatures or large deformations. (C) 1997 American Institute of Physics. C1 JAPAN ATOM ENERGY RES INST,CTR PROMOT COMPUTAT SCI & ENGN,TOKAI,IBARAKI 31911,JAPAN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Porter, LJ (reprint author), MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139, USA. NR 34 TC 61 Z9 61 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 JAN 1 PY 1997 VL 81 IS 1 BP 96 EP 106 DI 10.1063/1.364102 PG 11 WC Physics, Applied SC Physics GA WA947 UT WOS:A1997WA94700015 ER PT J AU Draney, ML AF Draney, ML TI Ground-layer spiders (Araneae) of a Georgia piedmont floodplain agroecosystem: Species list, phenology and habitat selection SO JOURNAL OF ARACHNOLOGY LA English DT Article ID NO-TILLAGE AGROECOSYSTEMS; GRAZED PASTURE; ARTHROPODS; PATTERNS AB Monthly pitfall trapping in 1990 and 1991 at Horseshoe Bend Experimental Area, Clarke County, Georgia, yielded 112 species of spiders belonging to 25 families. Examination of additional collections brings the site total to 145 species in 26 families, including southern or southeastern range extensions for Agelenopsis kastoni, Sphodros atlanticus, Bathyphantes pallidus, Eridantes erigonoides, Floricomus tallulae, Grammonota inornata, and Walckenaeria carolina, and a northeastern range extension for Paratheridula perniciosa. Ceraticelus emertoni and Neriene redacta are also reported from Georgia for the first time. The proportional distribution of pitfall-trapped species within families does not differ significantly from that reported for Berry's (1966) pitfall trapping in the North Carolina Piedmont (about 450 km away), suggesting regional similarity of the Piedmont ground-layer spider fauna. Data on phenology and relative catch of species among the four habitats sampled (conventional and no-tillage agricultural fields, grassy field borders, and the surrounding deciduous riparian forest) are given for the most abundant species. Habitat selection of 15 abundant species was statistically analyzed; most of the species' populations displayed strong preferences for particular habitats. It is clear that species "spillover" from adjacent habitats contributes to the faunal richness of each habitat, and that maintenance of a mosaic of habitats within an agroecosystem landscape maximizes spider biodiversity. C1 Univ Georgia, Dept Entomol, Athens, GA 30602 USA. RP Draney, ML (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 47 TC 19 Z9 23 U1 1 U2 4 PU AMER ARACHNOLOGICAL SOC PI NEW YORK PA C/O NORMAN I PLATNICK, AMER MUSEUM NATURAL HISTORY, CENTRAL PK WEST AT 79TH ST, NEW YORK, NY 10024 USA SN 0161-8202 J9 J ARACHNOL JI J. Arachnol. PY 1997 VL 25 IS 3 BP 333 EP 351 PG 19 WC Entomology SC Entomology GA YP884 UT WOS:000071325700012 ER PT J AU Cai, YP Wolk, CP AF Cai, YP Wolk, CP TI Nitrogen deprivation of Anabaena sp strain PCC 7120 elicits rapid activation of a gene cluster that is essential for uptake and utilization of nitrate SO JOURNAL OF BACTERIOLOGY LA English DT Article ID CYANOBACTERIUM SYNECHOCOCCUS PCC-7942; SPINACH NITRITE REDUCTASE; NUCLEOTIDE-SEQUENCE; ESCHERICHIA-COLI; EXPRESSION; TRANSPORT; INDUCTION; FIXATION; ASSIMILATION; VARIABILIS AB A transposon bearing luxAB, encoding luciferase, as a reporter of transcription was used to identify genes that are activated rapidly upon deprivation of Anabaena sp. strain PCC 7120 of fixed nitrogen, The three transposon-marked loci that were identified as responding most rapidly and strongly are closely linked and situated within nirA and nrtC and between nrtD and narB, genes whose products are responsible for uptake and reduction of NO2- and NO3-. A strain bearing a transcriptional fusion of narB to luxAB was constructed, Luminescence catalyzed by LuxAB was used to report on the expression of the interrupted genes, Whether these genes are regulated only coordinately is discussed. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 51 TC 52 Z9 54 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 JAN PY 1997 VL 179 IS 1 BP 258 EP 266 PG 9 WC Microbiology SC Microbiology GA VZ792 UT WOS:A1997VZ79200034 PM 8982006 ER PT J AU Cai, YP Wolk, CP AF Cai, YP Wolk, CP TI Anabaena sp strain PCC 7120 responds to nitrogen deprivation with a cascade-like sequence of transcriptional activations SO JOURNAL OF BACTERIOLOGY LA English DT Article ID BLUE-GREEN-ALGA; CYANOBACTERIUM ANABAENA; HETEROCYST DEVELOPMENT; SIGMA-FACTOR; PATTERN FORMATION; RNA-POLYMERASE; PCC-7120; GENE; EXPRESSION; DIFFERENTIATION AB Anabnena sp. strain PCC 7120 adapts to deprivation of fixed nitrogen bg undergoing physiological and genetic changes that include formation of N-2-fixing heterocysts. Whether or not certain of the genes involved are interdependently expressed has been studied. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 39 TC 47 Z9 50 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 JAN PY 1997 VL 179 IS 1 BP 267 EP 271 PG 5 WC Microbiology SC Microbiology GA VZ792 UT WOS:A1997VZ79200035 PM 8982007 ER PT J AU Hawkins, D Bey, M AF Hawkins, D Bey, M TI Muscle and tendon force-length properties and their interactions in vivo SO JOURNAL OF BIOMECHANICS LA English DT Article DE muscle; tendon; interactions ID MEDIAL GASTROCNEMIUS-MUSCLE; SKELETAL-MUSCLES; RAT; COMPLEX; SOLEUS; MODEL AB Many attempts have been made to model muscle and/or muscle-tendon (MT) behavior for the purpose of predicting muscle forces in vivo. One important parameter often considered in such models is muscle length. This study was conducted to evaluate (I) the force-length properties of a MT complex and the range of these properties over which the muscle operates in vivo, and (2) the effect that tendon compliance has on a muscle's force-length behavior. The rat tibialis anterior (TA) MT complex was used as the experimental model. Muscle and tendon lengths as they occurred in the body during ankle joint motion ranging from 20 degrees to 90 degrees of flexion were determined for both passive and active muscle. Force-length (FL) properties for the tendon, passive muscle, and active muscle were determined from a partially isolated MT preparation. Results suggest that during movement involving a normal range of joint motion, the TA muscle operates within an optimal region of its FL relationship, generating minimal passive force and nearly constant active force. However, the passive force increases rapidly for extreme foot extension while the active force decreases for both extreme foot flexion and extension. For the rat TA muscle, the effect of tendon compliance does not alter the active force generated by the muscle over a normal joint range of motion. However, tendon compliance does effect the muscle's ability to generate force at the extremes of joint motion. Copyright (C) 1996 Elsevier Science Ltd. C1 LAWRENCE LIVERMORE NATL LAB,BIOMED ENGN GRAD GRP,DAVIS,CA 95616. RP Hawkins, D (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT EXERCISE SCI,DAVIS,CA 95616, USA. NR 32 TC 48 Z9 48 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9290 J9 J BIOMECH JI J. Biomech. PD JAN PY 1997 VL 30 IS 1 BP 63 EP 70 DI 10.1016/S0021-9290(96)00094-2 PG 8 WC Biophysics; Engineering, Biomedical SC Biophysics; Engineering GA VY603 UT WOS:A1997VY60300009 PM 8970926 ER PT J AU Wolfarth, DL Han, DW Bushar, G Parks, NL AF Wolfarth, DL Han, DW Bushar, G Parks, NL TI Separation and characterization of polyethylene wear debris from synovial fluid and tissue samples of revised knee replacements SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article AB A study was made of in vivo-generated polyethylene wear particles as separated from synovial fluid samples and from tissue samples surrounding total knee arthroplasty. A comparison of particle size and morphology between the two particle groups was made to assess any effects of selective tissue capture, and macrophage encapsulation and digestion. In addition, a Raman spectroscopy technique was evaluated that enables positive identification of individual wear particles. The particles of the same size range found in the synovial fluid and tissue samples exhibited a comparable morphology. Notably, submicron-sized debris was present in both the synovial fluid and tissue samples surrounding knees with osteolysis. The novel micro-Raman analysis of individual particles was successful in the categorizing of wear debris as polyethylene or nonpolyethylene. (C) 1997 John Wiley & Sons, Inc. C1 SANDIA NATL LABS, LIVERMORE, CA 94551 USA. US FDA, CTR DEVICES & RADIOL HLTH, ROCKVILLE, MD 20857 USA. ANDERSON ORTHOPAED RES INST, ARLINGTON, VA 22206 USA. NR 17 TC 30 Z9 31 U1 0 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD JAN PY 1997 VL 34 IS 1 BP 57 EP 61 DI 10.1002/(SICI)1097-4636(199701)34:1<57::AID-JBM8>3.0.CO;2-M PG 5 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA VY898 UT WOS:A1997VY89800008 PM 8978653 ER PT J AU Nunez, L Rogers, RD AF Nunez, L Rogers, RD TI Synthesis and structural characterization of [H-2(diaza-18-crown-6)][CuCl4]center dot H2O SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE diaza-18-crown-6; copper chloride; X-ray structure ID CRYSTAL-STRUCTURE; CHEMISTRY; COPPER(II); COMPLEX AB A protonated diaza-18-crown-6 copper(II) chloride complex was crystallized from a mixture of YCl3, BaCl2, and Cu(C2H3O2)(2) in 3:1 CH3OH/CH3CN. [H-2(diaza-18-crown-6)][CuCl4]. H2O crystallizes in the centric space group, with: a = 7.429(2) Angstrom, b = 10.099(3) Angstrom, c = 14.779(9) Angstrom, alpha = 83.76(5)degrees, beta = 81.70(3)degrees, gamma = 75.59(3)degrees, and D-calc = 1.53 g/cm(3) for Z = 2. The [CuCl4](2-) anion is a distorted tetrahedron and is hydrogen-bonded to two unique diazacrown molecules. The bonding results in zig-zag contacts that form a polymeric network diagonally oriented in the be plane. One of the two unique azacrown molecules maintains a slightly distorted D-3d conformation stabilized by hydrogen bonding from a disordered water molecule and to the [CuCl4](2-) anion. The hydrogen bonding of the disordered water molecule bridges one form of the protonated macrocycle and forms polymeric chains along the a direction. The other unique azacrown molecule adopts a distorted C-2 configuration and has no interactions with the water molecule. C1 UNIV ALABAMA,DEPT CHEM,TUSCALOOSA,AL 35487. RP Nunez, L (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Rogers, Robin/C-8265-2013; G, Neela/H-3016-2014 OI Rogers, Robin/0000-0001-9843-7494; NR 14 TC 2 Z9 2 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD JAN PY 1997 VL 27 IS 1 BP 5 EP 10 PG 6 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA WT174 UT WOS:A1997WT17400001 ER PT J AU North, SW Hall, GE AF North, SW Hall, GE TI Vector and scalar correlations in statistical dissociation: The photodissociation of NCCN at 193 nm SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FREQUENCY-MODULATION SPECTROSCOPY; TRANSFORM DOPPLER SPECTROSCOPY; PRODUCT STATE DISTRIBUTIONS; PHASE-SPACE THEORY; VELOCITY DISTRIBUTIONS; UNIMOLECULAR REACTIONS; MOLECULAR-BEAM; CYANOGEN; DYNAMICS; ENERGY AB Nascent Doppler profiles of CN (X(2) Sigma(+)) fragments from the 193 nm photodissociation of NCCN have been measured using high-resolution transient frequency modulated (FM) absorption spectroscopy. This new method is highly suited for Doppler spectroscopy of nascent photoproducts. The experimental line shapes suggest an asymptotic available energy of 5300 +/- 100 cm(-1) and are well described by a model in which the available energy is partitioned between a statistical reservoir (4700 cm(-1)) and a modest exit barrier (600 cm(-1)). we have determined state dependent v . j correlations. A trend of j becoming increasingly perpendicular to v for the higher rotational states is in accord with phase space theory, although the observed correlations are more than twice as strong. The v . j correlations can be quantitatively modeled by further restricting the phase space model with an approximate conservation of the K-quantum number, the projection of total angular momentum about the linear axis of NCCN. Global rotational and vibrational product distributions have also been measured. The highest accessible rotational states are underpopulated, compared to a phase space calculation. The global vibrational distribution is substantially colder than the phase space theory predictions. Vibrational branching ratios for coincident fragments have been measured as a function of the detected CN state from a close analysis of high signal-to-noise Doppler profiles. The correlated vibrational distribution, P(upsilon(1), upsilon(2)), shows an excess of vibrationless coincident fragments, at the expense of dissociation to give one ground state and one vibrationally excited CN fragment. The correlated formation of two vibrationally excited CN fragments is as likely as the phase space prediction, yet the formation of upsilon = 2 is strongly suppressed. The fragment vector and scalar correlations provide a highly detailed view of the loose transition state typical for reactions well described by statistical reaction theories. (C) 1997 American Institute of Physics. RP North, SW (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI North, Simon/G-5054-2012; Hall, Gregory/D-4883-2013 OI North, Simon/0000-0002-0795-796X; Hall, Gregory/0000-0002-8534-9783 NR 74 TC 31 Z9 31 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1997 VL 106 IS 1 BP 60 EP 76 DI 10.1063/1.473023 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WA178 UT WOS:A1997WA17800009 ER PT J AU Zhao, HQ Cheung, YS Heck, DP Ng, CY Tetzlaff, T Jenks, WS AF Zhao, HQ Cheung, YS Heck, DP Ng, CY Tetzlaff, T Jenks, WS TI A 193-nm-laser photofragmentation time-of-flight mass spectrometric study of dimethylsulfoxide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID 193 NM; TRANSLATIONAL ENERGY; GAUSSIAN-2 THEORY; PHOTODISSOCIATION; ACETONE; DISTRIBUTIONS; STEPWISE; DYNAMICS AB The photodissociation of dimethylsulfoxide [(CH3)(2)SO] at 193.3 nm has been investigated using the molecular beam time-of-flight (TOF) mass spectrometric technique. in addition to CH3 and SO, CH3SO is also observed as a stable primary product, indicating that CH3SO+CH3 is an important 3 product channel for the 193.3 nm photodissociation of (CH3)(2)SO. The analysis of the TOF data provides evidence that SO is formed via a stepwise mechanism: (CH3)(2)SO+hv (193.3 nm) --> CH3SO+CH3-->2CH(3) + SO. The analysis also indicates that approximate to 53% of the primary CH3SO radicals undergo further dissociation to produce CH3+SO, yielding a quantum yield of approximate to 1.53 for CH3. Within the sensitivity of our experiment, the product channel of CH3SCH3 + O is not found. The angular distribution for the formation of CH3SO + CH3 is found to be isotropic, an observation consistent with a predissociation mechanism, in which the dissociation of photoexcited (CH3)(2)SO is slow compared to its rotational period. The energetics for selected dissociation reactions of (CH3)(2)SO have also been investigated by ab initio calculations at the G2(MP2) level of theory. The experimental dissociation energy at 0 K (53 +/- 2 kcal/mol) for the CH3-SOCH3 bond obtained here is in excellent agreement with the theoretical prediction of 52.6 kcal/mol. (C) 1997 American Institute of Physics. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 24 TC 16 Z9 16 U1 0 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 JAN 1 PY 1997 VL 106 IS 1 BP 86 EP 93 DI 10.1063/1.473025 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WA178 UT WOS:A1997WA17800011 ER PT J AU Thompson, WH Miller, WH AF Thompson, WH Miller, WH TI On the ''direct'' calculation of thermal rate constants .2. The flux-flux autocorrelation function with absorbing potentials, with application to the O+HCl->OH+Cl reaction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; MECHANICAL RATE CONSTANTS; TRANSITION-STATE THEORY; ARRANGEMENT DECOUPLING POTENTIALS; FLOPPY TRIATOMIC-MOLECULES; BOUNDARY-CONDITIONS; QUANTUM-MECHANICS; RATE COEFFICIENTS; SCATTERING; DYNAMICS AB We present a method for obtaining the thermal rate constant directly (i.e., without first solving the state-to-state reactive scattering problem) from the time integral of the Aux-flux autocorrelation function, C-ff(t). The quantum mechanical trace involved in calculating C-ff(t) is efficiently evaluated by taking advantage of the low rank of the Boltzmannized flux operator. The time propagation is carried out with a Hamiltonian which includes imaginary absorbing potentials in the reactant and product exit channels. These potentials eliminate reflection from the edge of the finite basis and ensure that C-ff(t) goes to zero at long times. In addition, the basis can then be contracted to represent a smaller area around the interaction region. We present results of this method applied to the O + HCl reaction using the J-shifting and helicity conserving approximations to include nonzero total angular momentum. The calculated rate constants are compared to experimental and previous theoretical results. Finally, the effect of deuteration (the O + DCl reaction) on the rate constant is examined. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Thompson, WH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Thompson, Ward/0000-0002-3636-6448 NR 77 TC 89 Z9 90 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1997 VL 106 IS 1 BP 142 EP 150 DI 10.1063/1.474109 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WA178 UT WOS:A1997WA17800016 ER PT J AU Asher, RL Ruscic, B AF Asher, RL Ruscic, B TI On the heats of formation of trifluoromethyl radical CF3 and its cation CF3+ SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SMALL ORGANIC-MOLECULES; THERMAL-DECOMPOSITION; PHOTOELECTRON-SPECTRA; STRATOSPHERIC OZONE; GROUND-STATE; BOND-ENERGY; PHOTOIONIZATION; IONIZATION; DISSOCIATION; CF4+ AB The CF+ and CF3+ fragment ion yield curves from C2F4 have been remeasured by photoionization mass spectrometry. Fits with appropriate model curves yield the appearance potentials AP(0)(CF3+/C2F4)=13.721+/-0.005 eV and AP(0)(CF+/C2F4)=13.777+/-0.005 eV and an accurate difference in ionization potentials, IP(CF)-IP(CF3)=0.055+/-0.003 eV. With the existing photoelectron value IP(CF)=9.11+/-0.01 eV, this produces IP(CF3)=9.05(5)+/-0.01(1) eV. The CF3+ fragments from CF3Cl, CF3Br, and CF3I have also been remeasured, and their ion yield curves fitted with model functions. The experimentally derived AP(0)(CF3+/CF3Cl) <12.867+/-0.008 eV has been found to be only an upper limit. The analogous CF3+ fragment yield curves from CF3Br and CF3I produce AP(0)(CF3+/CF3Br)=12.095+/-0.005 eV and AP(0)(CF3+/CF3I)=11.384+/-0.005 eV, leading to D-0(CF3-Br)=70.1+/-0.3 kcal/mol (70.8+/-0.3 kcal/mol at 298 K) and D-0(CF3-I)=53.7+/-0.3 kcal/mol (54.3+/-0.3 kcal/mol at 298 K). Based on tabulated values for Delta H-f(0)-(CF3Br) and Delta H-f(o)(CF3I), which appear to be inconsistent by similar to 1 kcal/mol, a compromise value of Delta H-f298(o)(CF3)=-111.4+/-0.9 kcal/mol (-110.7+/-0.9 kcal/mol at 0 K) is selected, resulting in Delta H-f(o) (298)(CF3+)=97.4+/-0.9 kcal/mol (98.1+/-0.9 kcal/mol at 0 K). Additionally, IP(CF4)=AP(0)(CF3+/CF4)=14.67+/-0.04 eV can be inferred. From data on C2F4, Delta H-f298(o)(CF)=62.5+/-1.1 kcal/mol (61.7+/-1.1 kcal/mol at 0 K) can be deduced. Many earlier I literature values for appearance potentials of CF3+ from CF(3)X, leading to very low Delta H-f(o)(CF3+) and/or IP(CF3) values, are demonstrated to be in error. (C) 1997 American Institute of Physics. RP Asher, RL (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 58 TC 79 Z9 79 U1 0 U2 8 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 JAN 1 PY 1997 VL 106 IS 1 BP 210 EP 221 DI 10.1063/1.473982 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WA178 UT WOS:A1997WA17800024 ER PT J AU Callegari, A Srivastava, HK Merker, U Lehmann, KK Scoles, G Davis, MJ AF Callegari, A Srivastava, HK Merker, U Lehmann, KK Scoles, G Davis, MJ TI Eigenstate resolved infrared-infrared double-resonance study of intramolecular vibrational relaxation in benzene: First overtone of the CH stretch SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ULTRAVIOLET DOUBLE-RESONANCE; SUPERSONIC BEAM; MOLECULES; SPECTRA; SPECTROSCOPY; DYNAMICS; MODES AB The first eigenstate resolved, near the infrared spectrum of benzene in the region of thr first C-H stretch overtone (6000 cm(-1)) has been obtained with an IR-IR double-resonance molecular beam optothermal spectrometer. Using a hierarchical tree analysis and level spacing statistics, we show that the intramolecular vibrational relaxation occurs nonergodically over at least seven different time scales ranging from 100 fs to 2 ns. (C) 1997 American Institute of Physics. C1 PRINCETON UNIV,DEPT CHEM,PRINCETON,NJ 08544. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 25 TC 43 Z9 43 U1 3 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1997 VL 106 IS 1 BP 432 EP 435 DI 10.1063/1.473205 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WA178 UT WOS:A1997WA17800043 ER PT J AU Reedy, ED Mello, FJ Guess, TR AF Reedy, ED Mello, FJ Guess, TR TI Modeling the initiation and growth of delaminations in composite structures SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID SUBLAMINATE ANALYSIS AB A method for modeling the initiation and growth of discrete delaminations in shell-like composite structures is presented. The laminate is divided into two or more sublaminates, with each sublaminate modeled with four-noded quadrilateral shell elements. A special, eight-noded hex constraint element connects opposing sublaminate shell elements, and makes the two opposing shell elements act as a single shell element until a prescribed failure criterion is satisfied. Once the failure criterion is met, the connection is broken, and a discrete delamination initiates or grows. This approach has been implemented in a three-dimensional finite element code. This code uses explicit time integration, and can analyze shell-like structures subjected to large deformations and complex contact conditions. Tensile, compressive, and shear laminate failures are also modeled. This paper describes the eight-noded hex constraint element used to model the initiation and growth of a delamination, and discusses associated implementation issues. In addition, calculated results for double cantilever beam and end notched flexure specimens are presented and compared to measure data to assess the ability of the present approach to model a growing delamination. Results are also presented for a diametrally compressed ring to demonstrate the capability for analyzing progressive failure in a highly deformed composite structure. RP Reedy, ED (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 58 Z9 61 U1 0 U2 4 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1997 VL 31 IS 8 BP 812 EP 831 PG 20 WC Materials Science, Composites SC Materials Science GA WY078 UT WOS:A1997WY07800004 ER PT J AU Zhu, YT Blumenthal, WR Lowe, TC AF Zhu, YT Blumenthal, WR Lowe, TC TI Determination of non-symmetric 3-D fiber-orientation distribution and average fiber length in short-fiber composites SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE fiber-orientation distribution; non-symmetric; average fiber length; fiber inclination angle ID METAL-MATRIX COMPOSITE; IMAGE-ANALYSIS AB A mathematical procedure is proposed for recovering from image analysis the three-dimensional (3-D) non-symmetric density distribution of fiber orientation and the average fiber length in short-fiber composites. The determination of fiber-orientation distribution and average fiber length is essential for assessing the mechanical and physical properties of a short-fiber composite. The average fiber length can be obtained from one micrograph, while the determination of 3-D fiber orientation requires micrographs from two orthogonal planar faces of a composite sample. In addition, a simple procedure is proposed to obtain the single-angle fiber-orientation distribution from one micrograph. This distribution is often needed for predicting the mechanical and physical properties in the direction normal to the plane of the photographed sample cross section. In processing the fiber-orientation density data obtained from a micrograph, a cumulative fiber-orientation density curve is used to derive the fiber-orientation function, which is simpler and more accurate than the histogram that has been commonly used. Previously reported procedures all assume symmetries in fiber-orientation distribution, and are therefore highly idealized. Without assuming any symmetry, the present procedure improves upon previous works. RP Zhu, YT (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MST-5,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 22 TC 33 Z9 33 U1 0 U2 7 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1997 VL 31 IS 13 BP 1287 EP 1301 PG 15 WC Materials Science, Composites SC Materials Science GA XK700 UT WOS:A1997XK70000002 ER PT J AU Wereszczak, AA Ferber, MK ParviziMajidi, A AF Wereszczak, AA Ferber, MK ParviziMajidi, A TI Directional dependence of fracture toughness in hot-pressed SiC-whisker reinforced alumina at room and elevated temperatures SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE fracture toughness; whisker; crack deflection; ceramic composite; elevated temperatures ID SILICON-CARBIDE WHISKERS; AL2O3 MATRIX COMPOSITE; TOUGHENING MECHANISMS; ORIENTATION; SPECIMENS AB The directional dependence of fracture toughness was investigated in commercially available hot-pressed SiC-whisker reinforced alumina composites at room and elevated temperatures. Whisker orientation was transversely isotropic with respect to the pressing axis in these composites. Composite bend bars were chevron-notched and loaded in four-point bending to induce stable crack propagation in two different crack systems: defined here as a combination of crack plane and direction with reference to the pressing axis. The average fracture toughness, K-lc, was found to be approximately 30% less for a crack system with its crack plane parallel and crack direction perpendicular to the pressing axis compared to a crack system with both its crack plane and direction parallel to the pressing axis through 1200 degrees C. The crack systems with the lower fracture toughness exhibited a characteristic high concentration of whiskers aligned parallel to the crack direction within the crack plane; this appeared to he associated with decreased or unpromoted crack deflection. This fracture mechanism evidently dominated the fracture process through 1200 degrees C because measured fracture toughnesses were independent of temperature; crack-wake toughening mechanisms, whose efficiency is a function of the residual thermal stresses, are expected to be temperature-dependent. C1 UNIV DELAWARE,CTR COMPOSITE MAT,NEWARK,DE 19716. UNIV DELAWARE,DEPT MECH ENGN,NEWARK,DE 19716. 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 17 TC 3 Z9 3 U1 0 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 1997 VL 31 IS 19 BP 1905 EP 1920 PG 16 WC Materials Science, Composites SC Materials Science GA YB747 UT WOS:A1997YB74700002 ER PT J AU Gibbons, MR Hewett, DW AF Gibbons, MR Hewett, DW TI Characterization of the Darwin direct implicit particle-in-cell method and resulting guidelines for operation SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PLASMA SIMULATION AB We investigate the linear dispersion and other properties of the Darwin Direct Implicit Particle-in-cell (DADIPIC) method in order to deduce guidelines for its use in the simulation of long time-scale, kinetic phenomena in plasmas. The Darwin part of this algorithm eliminates the Courant constraint for light propagation across a grid cell in a time step and divides the field solution into several elliptic equations. The direct implicit method is only applied to the electrostatic field relieving the need to resolve plasma oscillations. Linear theory and simulations verifying the theory are used to generate the desired guidelines as well as show the utility of DADIPIC for a wide range of low frequency, electromagnetic phenomena. We find that separation of the fields has made the task of predicting algorithm behavior easier and produced a robust method without restrictive constraints. (C) 1997 Academic Press RP Gibbons, MR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 1 PY 1997 VL 130 IS 1 BP 54 EP 66 DI 10.1006/jcph.1996.5475 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WD030 UT WOS:A1997WD03000004 ER PT J AU Clement, TP Peyton, BM Skeen, RS Jennings, DA Petersen, JN AF Clement, TP Peyton, BM Skeen, RS Jennings, DA Petersen, JN TI Microbial growth and transport in porous media under denitrification conditions: Experiments and simulations SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE biofilm; porous media; bacteria transport; denitrification; detachment; model; in situ bioremediation ID PHYSICAL-PROPERTIES; BIOFILM DETACHMENT; SHEAR-STRESS; MODEL; SUBSTRATE; AQUIFER; KINETICS; NUTRIENT; SOLUTES; SOILS AB Soil column experiments were conducted to study bacterial growth and transport in porous media under denitrifying conditions. The study used a denitrifying microbial consortium isolated from aquifer sediments sampled at the U.S. Department of Energy's Hanford site. One-dimensional, packed-column transport studies were conducted under two substrate loading conditions. A detailed numerical model was developed to predict the measured effluent cell and substrate concentration profiles. First-order attachment and detachment models described the interphase exchange processes between suspended and attached biomass. Insignificantly different detachment coefficient values of 0.32 and 0.43 day(-1), respectively, were estimated for the high and low nitrate loading conditions (48 and 5 mg l(-1) NO3, respectively). Comparison of these values with those calculated from published data for aerobically growing organisms shows that the denitrifying consortium had lower detachment rate coefficients. This suggests that, similar to detachment rates in reactor-grown biofilms, detachment in porous media may increase with microbial growth rate. However, available literature data are not sufficient to confirm a specific analytical model for predicting this growth dependence. C1 PACIFIC NW LAB, RICHLAND, WA 99337 USA. WASHINGTON STATE UNIV, DEPT CHEM ENGN, PULLMAN, WA 99164 USA. RI Petersen, James/B-8924-2008; OI Peyton, Brent/0000-0003-0033-0651 NR 39 TC 64 Z9 66 U1 1 U2 14 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 JAN PY 1997 VL 24 IS 3-4 BP 269 EP 285 DI 10.1016/S0169-7722(96)00014-9 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA WD980 UT WOS:A1997WD98000005 ER PT J AU Wang, RR Monteiro, OR Miyase, A AF Wang, RR Monteiro, OR Miyase, A TI Analysis of modified Ti surface for titanium-ceramic bonding SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 CASE WESTERN RESERVE UNIV,CLEVELAND,OH 44106. LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 378 EP 378 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68000379 ER PT J AU Breunig, T Marshall, GW Kinney, JH WuMagidi, IC Marshall, S AF Breunig, T Marshall, GW Kinney, JH WuMagidi, IC Marshall, S TI X-ray tomographic microscopy of dentin demineralization for various acids. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 666 EP 666 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68000666 ER PT J AU Pazo, A Saiz, E Marshall, SJ Marshall, GW Tomsia, AP AF Pazo, A Saiz, E Marshall, SJ Marshall, GW Tomsia, AP TI Glass coatings on Ti implant alloys SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 1513 EP 1513 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68001510 ER PT J AU Palmer, RJ Ringelberg, DB White, DC AF Palmer, RJ Ringelberg, DB White, DC TI Comparative analysis of total lipid from dental plaque and calculus. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 1716 EP 1716 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68001715 ER PT J AU Marshall, S WuMagidi, IC Balooch, M Kinney, JH Marshall, GW AF Marshall, S WuMagidi, IC Balooch, M Kinney, JH Marshall, GW TI Mechanical properties of the resin-dentin interdiffusion zone. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2414 EP 2414 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002410 ER PT J AU Marshall, SJ Tomsia, AP Marshall, GW AF Marshall, SJ Tomsia, AP Marshall, GW TI Resin-dentin interdiffusion zone thickness. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2415 EP 2415 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002407 ER PT J AU Otis, LL Colston, BW Armitage, G Everett, M AF Otis, LL Colston, BW Armitage, G Everett, M TI Optical imaging of periodontal tissues. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. UNIV CONNECTICUT,SCH DENT MED,FARMINGTON,CT 06032. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2956 EP 2956 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002952 ER PT J AU Kinney, JH Oliveira, JS Haupt, DL Marshall, GW Marshall, SJ AF Kinney, JH Oliveira, JS Haupt, DL Marshall, GW Marshall, SJ TI A stochastic geometric model of tubule distributions in human dentin. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 2981 EP 2981 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68002973 ER PT J AU Marshall, GW Inai, N WuMagidi, IC Balooch, M Kinney, JH Marshall, S Tagami, J AF Marshall, GW Inai, N WuMagidi, IC Balooch, M Kinney, JH Marshall, S Tagami, J TI AFM study of citric and phosphoric acid etching of dentin. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. TOKYO MED & DENT UNIV,TOKYO 113,JAPAN. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1997 VL 76 SI SI BP 3226 EP 3226 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA WB680 UT WOS:A1997WB68003222 ER PT J AU Garino, T AF Garino, T TI The production of thixotropic suspensions by control of dispersant concentration SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Article AB The effect of dispersant concentration on the rheological behavior of suspensions of sub-micron aluminum oxide particles in either water or dodecane was studied using a double concentric cylinder rheometer. In the electrosterically stabilized aqueous system, the suspensions underwent a sharp transition from coagulated to dispersed as the concentration of the dispersant, ammonium poly(methacrylate), was increased. In the sterically stabilized dodecane system, as the concentration of the dispersant, 12-hydroxy stearic acid ester, was increased, the initially coagulated suspensions became highly thixotropic at concentrations less than that needed for stability. The difference in behavior between these two systems is caused by the way that the interparticle forces are affected by the concentration of dispersant for the two types of stabilization mechanisms. The technique of inducing thixotropy by control of the dispersant concentration has certain advantages including wide applicability and not requiring special additives. RP Garino, T (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0193-2691 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PY 1997 VL 18 IS 3 BP 273 EP 288 DI 10.1080/01932699708943736 PG 16 WC Chemistry, Physical SC Chemistry GA WW285 UT WOS:A1997WW28500005 ER PT J AU Chui, HC Biefeld, RM Hammons, BE Breiland, WG Brennan, TM Jones, ED Moffat, HK Kim, MH Grodzinski, P Chang, KH Lee, HC AF Chui, HC Biefeld, RM Hammons, BE Breiland, WG Brennan, TM Jones, ED Moffat, HK Kim, MH Grodzinski, P Chang, KH Lee, HC TI Tertiarybutylarsine for metalorganic chemical vapor deposition growth of high purity, high uniformity films SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE AlGaAs; GaAs; InGaAs; low p-type carrier concentration; tertiarybutylarsine (TBA) ID QUANTUM-WELL LASERS; TERTIARY-BUTYLARSINE; PHASE EPITAXY; MOVPE GROWTH; GAAS; ALGAAS/GAAS; HETEROSTRUCTURES; SINGLE AB We have performed an extensive study of GaAs, Al0.22Ga0.78As, and In0.16Ga0.84As grown using tertiarybutylarsine (TEA) in an ultra-high purity metalorganic chemical vapor deposition multi-wafer reactor. Key results include: high purity TEA AlGaAs layers with the lowest p-type carrier concentrations (4 x 10(14) cm(-3)) reported to date; 4K photoluminescence bound exciton Linewidths as narrow as 4.3 meV; C, O. Si, and S concentrations below the secondary ion mass spectrometry detection limit; and InGaAs/GaAs quantum wells with 20K PL linewidths as narrow as 3.5 meV. We also observe a strong dependence of growth rates and doping efficiency on group-V partial pressure, possibly due to a competition between excess group-V species and group-III or Si species for group-III surface sites. Finally, we demonstrate record uniformity using TEA with an AlGaAs thickness variation of only +/-1.4% across a 4 inch wafer. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. MOTOROLA INC,PHOENIX CORP RES LABS,TEMPE,AZ 85284. NR 23 TC 6 Z9 6 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JAN PY 1997 VL 26 IS 1 BP 37 EP 42 DI 10.1007/s11664-997-0131-7 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA WF039 UT WOS:A1997WF03900009 ER PT J AU Warne, LK Chen, KC AF Warne, LK Chen, KC TI An approximate solution of a static cylindrical mixed boundary value problem SO JOURNAL OF ELECTROSTATICS LA English DT Article DE Laplace's equation; mixed boundary conditions; cylindrical geometry; Bessel functions; conduction problem; oil well logging AB An approximate solution to a mixed boundary value problem in potential theory is given. The boundary value problem consists of an insulating cylindrical column with a band electrode in a conducting space, which represents a well logging problem. Alternatively, the same form also approximately solves the problem of a conducting column with a band electrode in an insulating space representing, for example, a conducting connector plug (with injected electrostatic discharge current). C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 7 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 J9 J ELECTROSTAT JI J. Electrost. PD JAN PY 1997 VL 39 IS 1 BP 53 EP 63 DI 10.1016/S0304-3886(96)00039-3 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA WG081 UT WOS:A1997WG08100005 ER PT J AU Liu, KC Brinkman, CR Ding, JL Lin, SB AF Liu, KC Brinkman, CR Ding, JL Lin, SB TI Predictions of tensile behavior and strengths of a Si3N4 ceramic at high temperatures based on a viscoplastic model SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 40th International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 05-08, 1995 CL HOUSTON, TX ID CREEP AB Tensile deformation and rupture behavior were simulated using a viscoplastic model developed recently. The model was formulated based on the state variable approach, which provides flexibility and versatility for characterizing the time-dependent behavior of ceramic materials under general thermomechanical loading conditions. Simulations portrayed by the model were compared with experimental tensile data obtained under two different tensile stressing rates, Results showed that the model was capable of simulating deformation behavior for all practical engineering purposes, but estimated high-temperature fracture strengths somewhat conservatively. C1 WASHINGTON STATE UNIV,DEPT MECH & MAT ENGN,PULLMAN,WA 99164. RP Liu, KC (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 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 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 1997 VL 119 IS 1 BP 200 EP 204 DI 10.1115/1.2815549 PG 5 WC Engineering, Mechanical SC Engineering GA WH336 UT WOS:A1997WH33600030 ER PT J AU Bowyer, TW Abel, KH Hensley, WK Panisko, ME Perkins, RW AF Bowyer, TW Abel, KH Hensley, WK Panisko, ME Perkins, RW TI Ambient Xe-133 levels in the northeast US SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article AB Measurements of Xe-133 (tau(1/2) = 5.2 days) atmospheric concentrations were performed during the fall of 1993 and throughout 1995 on 'noble gas concentrates' from the northeastern US, These samples were obtained from a commercial air-reduction plant in Allentown, Pennsylvania. Following chromatographic purification of the xenon gas, the Xe-133 activity was determined using a high-purity germanium gamma-ray spectrometer. The average Xe-133 concentrations were in the range 1-3 mBq m(-3), which is consistent with nuclear power plant noble gas releases in the region surrounding the sampling point, but approximately 50-100 times lower than those reported in Albany, NY approximately 300 km to the northeast from 1975 through 1984. The lower atmospheric concentrations are also consistent with the 100-fold reduction in radioxenon release from 25 nuclear reactors in that legion, Only an upper limit could be established for the Xe-135 level (tau(1/2) = 9.1 h), which was about 0.03 of the Xe-133 level, These background levels are of concern in monitoring for atmospheric radioxenons to assure compliance with a Comprehensive nuclear Test Ban Treaty (CTBT). Published by Elsevier Science Ltd. RP Bowyer, TW (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 8 TC 19 Z9 19 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1997 VL 37 IS 2 BP 143 EP 153 DI 10.1016/S0265-931X(97)00005-2 PG 11 WC Environmental Sciences SC Environmental Sciences & Ecology GA XY960 UT WOS:A1997XY96000002 ER PT J AU Singh, D Wagh, AS Cunnane, JC Mayberry, JL AF Singh, D Wagh, AS Cunnane, JC Mayberry, JL TI Chemically bonded phosphate ceramics for low-level mixed-waste stabilization SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-ENVIRONMENTAL SCIENCE AND ENGINEERING & TOXIC AND HAZARDOUS SUBSTANCE CONTROL LA English DT Article AB Novel chemically bonded phosphate ceramics are being developed and fabricated for low-temperature stabilization and solidification of mixed-waste streams that are not amenable to conventional high-temperature stabilization processes because volatiles, such as heavy-metal chlorides and fluorides, and/or pyrophorics are present in the wastes. Phosphates of Mg, Mg-Na, and Zr are being developed as candidate matrix materials. In this paper, we present the fabrication procedures for phosphate waste forms with surrogate compositions of three typical mixed-waste streams, namely ash, cement sludges, and salts. This study was focused, but not limited to, magnesium phosphate-ash wastestream final waste Term. The performance of the final waste forms, such as compression strength, leachability of the contaminants, and durability in aqueous environments were conducted. In addition, parametric studies have been conducted to establish the optimal ash waste loading in the magnesium phosphate binder system. Based on the results, we present potential applications of phosphate-bonded ceramics in the treatment of various mixed-waste streams. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. SCI APPLICAT INT CORP,IDAHO FALLS,ID 83405. RP Singh, D (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Wagh, Arun/0000-0002-8678-7574 NR 10 TC 25 Z9 25 U1 3 U2 8 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1077-1204 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Environ. Sci. Eng. Toxic Hazard. Subst. Control PY 1997 VL 32 IS 2 BP 527 EP 541 PG 15 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WJ815 UT WOS:A1997WJ81500016 ER PT J AU Kong, PC Reimann, GA AF Kong, PC Reimann, GA TI Group IVB oxide enhancement of the iron-enriched basalt waste form SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-ENVIRONMENTAL SCIENCE AND ENGINEERING & TOXIC AND HAZARDOUS SUBSTANCE CONTROL LA English DT Article AB The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified by adding sufficient TiO2 and ZrO2 to develop zirconolite (ZrCaTi2O7) crystals in addition to those crystals that normally form in a cooling basalt. Zirconolite is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium that have endured more than 2 billion years of natural processes have been found. On this basis, zirconolite is considered an ideal host crystal for transuranic elements in wastes. Zirconolite crystals were developed in laboratory melts of IEB which contained 5 wt % each of TiO2 and ZrO2 and were slow-cooled in the 1200-1000C range. Actinide surrogates were incorporated into zirconolite rather than precipitated in residual glass. Zirconolite crystals should stabilize and immobilize dilute transuranics (TRUs) found in heterogeneous low-level wastes as effectively as they do in the Synroc used for high-level-wastes. Synroc requires hot-pressing equipment but zirconolite may be precipitated from a cooling basaltic melt. RP Kong, PC (reprint author), LOCKHEED MARTIN IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 19 TC 1 Z9 1 U1 0 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1077-1204 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Environ. Sci. Eng. Toxic Hazard. Subst. Control PY 1997 VL 32 IS 4 BP 1207 EP 1223 PG 17 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WV897 UT WOS:A1997WV89700024 ER PT J AU Sreenivasarao, K Warren, GW McKinley, MD Gao, G AF Sreenivasarao, K Warren, GW McKinley, MD Gao, G TI Hydrometallurgical treatment of municipal solid waste fly ash for simultaneous detoxification and metal recovery SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-ENVIRONMENTAL SCIENCE AND ENGINEERING & TOXIC AND HAZARDOUS SUBSTANCE CONTROL LA English DT Article ID INCINERATOR AB Fly ash from municipal solid waste (MSW) incinerators is frequently classified as a characteristic hazardous waste, due to low levels of Pb and Cd. In some cases the fly ash also contains a significant amount of Zn, up to 15%. The objective of this investigation was to lay the foundation for a potential hydrometallurgical process for simultaneous detoxification and recovery of metal values, particularly Zn, Pb, and Cd. This study has provided a more complete characterization of the By ash particularly with regard to those parameters which are important to a hydrometallurgical process, such as the forms in which Pb and Zn occur and leaching characteristics in several different lixiviants including various concentrations of hydrochloric, acetic, and sulfuric acid, Results show that Pb is present in at least two forms, PbSO4 and PbCl2. Similarly, three forms of Zn are indicated: (I) a water soluble form, probably chloride or sulfate or both, (2) an acid soluble form, likely Zn oxide, and (3) a much less soluble form. These sources represent roughly 26%, 44%, and 30%, respectively, of the total Zn content. Extraction of Pb; Cd, and Zn can be accomplished quickly and effectively in a 1 M HCl + 1 M NaCl solution, at a solid to liquid ratio of 1:10, resulting in extractions of approximately 85, 83, and 65%, respectively. A Zn concentration of about 15 g/L after cementation can be achieved, which is suitable for electrowinning. In addition the leaching residue is not hazardous according to the TCLP test. Pb and Cd in the leaching solution can be recovered by cementation with Zn dust. Suggested areas for future investigation are presented. C1 UNIV ALABAMA,DEPT MET & MAT ENGN,TUSCALOOSA,AL 35487. ARGONNE NATL LAB,DIV ENERGY SYST,ARGONNE,IL 60439. UNIV ALABAMA,DEPT CHEM ENGN,TUSCALOOSA,AL 35487. FORD MOTOR CO,ELECT TECH CTR,DEARBORN,MI 48121. NR 11 TC 11 Z9 11 U1 1 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1077-1204 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Environ. Sci. Eng. Toxic Hazard. Subst. Control PY 1997 VL 32 IS 4 BP 1225 EP 1245 PG 21 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WV897 UT WOS:A1997WV89700025 ER PT J AU Fresquez, PR Armstrong, DR Pratt, LH AF Fresquez, PR Armstrong, DR Pratt, LH TI Radionuclides in bees and honey within and around Los Alamos National Laboratory SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-ENVIRONMENTAL SCIENCE AND ENGINEERING & TOXIC AND HAZARDOUS SUBSTANCE CONTROL LA English DT Article DE food chain; tritium; uranium; strontium; plutonium; cesium ID POLYCHLORINATED-BIPHENYLS; CS-137 AB Honeybees are effective monitors of environmental pollution. Los Alamos National Laboratory (LANL), in fact, has maintained a network of honeybee colonies within and around LANL for 17 years (1979 through 1995); the objectives for maintaining this honeybee network were to (I) determine the bioavailability of certain radionuclides in the environment with respect to LANL operations (H-3, (CO)-C-57, (CO)-C-60, (EU)-E-152, K-40, Be-7, Na-22, Mn-54, Rb-83, (CS)-C-137, Pu-238, Pu-239, Sr-90, Am-241, and U-tot) and (2) estimate the committed effective dose equivalent (CEDE) and the corresponding risk of excess cancer fatalities (RECF) to people who may consume honey from hives located around the perimeter of the Laboratory (Los Alamos [LA] and White Rock/Pajarito Acres [WR/PA], New Mexico). Based on the 17-year average, bees from nine out of eleven hives and honey from six out of eleven hives on LANL lands contained H-3 that was significantly higher (p <0.05) than background. The highest average concentration of 3H in bees (434 pCi mL(-1)) collected over the years was from LANL's Technical Area (TA) 54-a low-level radioactive waste disposal site. Similarily, the highest average concentration of H-3 in honey (709 pCi mL(-1)) was collected from a hive located near three H-3 storage ponds at LANL TA-53. The average concentrations of H-3 in bees and honey from background hives was 1.1 pCi mL(-1) and 1.6 pCi mL(-1), respectively. Although the concentration of H-3 in bees and honey from most LANL and perimeter (WR/PA) hives were significantly higher than background, most areas, with the exception of TA-53 and TA-51, generally exhibited decreasing H-3 concentrations over time, Also, all other radionuclides in honey collected from perimeter hives around LAIVL were not significantly different from background, Overall, the maximum total net positive CEDE-based on the average concentration plus two std dev of all the radionuclides measured over the years after the subtraction of background-from consuming 11 lb of honey collected from LA and WR/PA, was 0.031 mrem y(-1) and 0.006 mrem y(-1), respectively. The highest CEDE was <0.04% of the International Commission on Radiological Protection permissible dose limit of 100 mrem y(-1) from all pathways and corresponds to a RECF of 1.6 x 10(-8) (0.016 in a million)-far below the Environmental Protection Agency's guideline of 1 x 10(-6) (one in a million). RP Fresquez, PR (reprint author), LOS ALAMOS NATL LAB,ENVIRONM SAFETY & HLTH DIV,LOS ALAMOS,NM 87545, USA. NR 34 TC 2 Z9 2 U1 0 U2 5 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1077-1204 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Environ. Sci. Eng. Toxic Hazard. Subst. Control PY 1997 VL 32 IS 5 BP 1309 EP 1323 PG 15 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XC890 UT WOS:A1997XC89000003 ER PT J AU Kim, HJ Song, YH Lee, KH AF Kim, HJ Song, YH Lee, KH TI High-frequency electromagnetic inversion for a dispersive layered earth SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 13th Workshop on Electromagnetic Induction in the Earth CY JUL 12-18, 1996 CL ONUMA INT SEMINAR HOUSE, HOKKAIDO, JAPAN HO ONUMA INT SEMINAR HOUSE AB Electrical properties in most geologic materials have been known to be frequency dependent, and resulting dispersion relationship can be a useful diagnostic tool for investigating the shallow subsurface. In this paper we investigate the determination of dispersive electrical properties of the shallow subsurface with inversion of high-frequency electromagnetic (EM) fields. We have limited the dispersive characteristics to the electrical permittivity and used the Cole-Cole model to describe the frequency dependence of the permittivity. For horizontally layered earth models high-frequency EM fields are successfully inverted via Marquardt-Levenberg least-squares method and simulated annealing method. Inversion experiments show that the simulated annealing yields slightly better parameter resolution than the least-squares inversion. C1 Pugyong Natl Univ, Pusan 608737, South Korea. Korea Inst Geol Min & Mat, Taejon 305350, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kim, HJ (reprint author), Pugyong Natl Univ, Pusan 608737, South Korea. NR 11 TC 12 Z9 12 U1 1 U2 1 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1997 VL 49 IS 11-12 BP 1439 EP 1450 PG 12 WC Geosciences, Multidisciplinary SC Geology GA ZE801 UT WOS:000072832300015 ER PT J AU Avdeev, DB Kuvshinov, AV Pankratov, OV Newman, GA AF Avdeev, DB Kuvshinov, AV Pankratov, OV Newman, GA TI High-performance three-dimensional electromagnetic modelling using modified Neumann series. Wide-band numerical solution and examples SO JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY LA English DT Article; Proceedings Paper CT 13th Workshop on Electromagnetic Induction in the Earth CY JUL 12-18, 1996 CL ONUMA INT SEMINAR HOUSE, HOKKAIDO, JAPAN HO ONUMA INT SEMINAR HOUSE ID DIFFERENCE-EQUATIONS; INTEGRAL-EQUATIONS; FINITE-DIFFERENCE; NONUNIFORM MEDIA; SCATTERING; APPROXIMATION; INVERSION; TIME AB We present a new, accurate, high-performance, wide-band three-dimensional (3-D) solver for the electromagnetic (EM) field scattering problem in an isotropic earth. The solver relates to those based on the volume integral equation (IE) approach and exploits a modified Neumann series (MNS) technique to solve Maxwell's equations. The solver allows for the conduction, polarization and displacement currents to be taken into account and admits for 3-D earth excitation by arbitrary electric or/and magnetic sources. We estimate the solver efficiency for scatterers discretized into N-x x N-y x N-z prisms, where it requires only about 6N(x)N(y)N(z)(log(2)(2N(x))log(2)(2N(y)) + 6N(z)) multiplications to get one term of the MNS expansion and about 200 NxNyNz2 bytes of memory. Our experience show that the number of terms N which are to be summed up to get the solution to 1% accuracy doesn't exceed fifty for the models with the conductivity contrast of up to 100. We demonstrate the solver versatility for magnetotellurics (MT) and controlled-source simulations. EM fields arising from a 3-D model with two high-contrast thin layers residing in layered earth were simulated due to a 10 Hz electric dipole located at the surface. When the layers were discretized into 16,384 prisms our code on a Pentium-100 MHz took T similar to 58 minutes, M similar to 7 Mbytes and N similar to 280. We also modeled the 0.1 Hz and 0.01 Hz MT responses within 3-D model with 1 Ohm.m and 100 Ohm.m blocks. When the blocks were discretized into 8,000 prisms the code took T similar to 5 minutes, M similar to 8 Mbytes, and N similar to 25. Finally fields for a crosswell model including a 3-D conducting target were simulated for 0.1 kHz and 10 kHz electric and magnetic dipoles in the wellbores. While the target was discretized into 6,250 prisms the code took T similar to 16 minutes, M similar to 13 Mbytes, and N similar to 24. All simulations showed from very good to excellent agreement with those of the other 3-D solvers. C1 Russian Acad Sci, Inst Geoelectromagnet Res, Troitsk 142092, Moscow Region, Russia. Sandia Natl Labs, Org 6116, Albuquerque, NM 87185 USA. RP Avdeev, DB (reprint author), Russian Acad Sci, Inst Geoelectromagnet Res, Troitsk 142092, Moscow Region, Russia. RI Newman, Gregory/G-2813-2015 NR 30 TC 51 Z9 53 U1 1 U2 4 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158, JAPAN SN 0022-1392 J9 J GEOMAGN GEOELECTR JI J. Geomagn. Geoelectr. PY 1997 VL 49 IS 11-12 BP 1519 EP 1539 PG 21 WC Geosciences, Multidisciplinary SC Geology GA ZE801 UT WOS:000072832300019 ER PT J AU Smith, CW Phillips, JL AF Smith, CW Phillips, JL TI The role of coronal mass ejections and interplanetary shocks in interplanetary magnetic field statistics and solar magnetic flux ejection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NORTH-SOUTH ASYMMETRY; WIND; ESCAPE; EVENTS; STARS AB We examine the role of coronal mass ejections (CMEs) and interplanetary shocks in modifying the large-scale winding of the interplanetary magnetic field (IMF) by extracting CME and shock observations from the ISEE 3 data set and analyzing periods of the disturbed and: undisturbed solar wind separately We use the full ISEE 3 data set representing the entire L(1) mission (1978 - 1982). We conclude that CMEs, the shocks upstream of CMEs, and other interplanetary shocks are responsible for the apparent overwinding of the IMF spiral relative to the Parker prediction. The IMF winding angle asymmetry is preserved following the removal of the interplanetary disturbances. We also examine the IMF components, the IMF magnitude and the solar wind speed, and the dependence of those averages and asymmetries on CMEs and shock disturbances. An estimate is. obtained for the anomalous azimuthal field contained within CMEs which apparently results from the closed-field topology. We provide new evidence for a nonzero field component crossing the heliospheric current sheet. Last, we examine the role of CMEs and shocks in the measurement of solar magnetic flux ejection. We provide estimates for the average amount of flux transported by CMEs and the error in flux transport analyses that include shock data, and we examine the possible north-south asymmetry of the flux. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Smith, CW (reprint author), UNIV DELAWARE, BARTOL RES INST, NEWARK, DE 19716 USA. NR 33 TC 22 Z9 22 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1997 VL 102 IS A1 BP 249 EP 261 DI 10.1029/96JA02678 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WA692 UT WOS:A1997WA69200023 ER PT J AU Ng, LC Pines, DJ AF Ng, LC Pines, DJ TI Characterization of ring laser gyro performance using the Allan variance method SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article C1 UNIV MARYLAND,DEPT AEROSP ENGN,COLLEGE PK,MD 20742. RP Ng, LC (reprint author), LAWRENCE LIVERMORE NATL LAB,ELECT ENGN DIV,TECH STAFF,LIVERMORE,CA 94511, USA. NR 9 TC 22 Z9 25 U1 1 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 1997 VL 20 IS 1 BP 211 EP 214 DI 10.2514/2.4026 PG 4 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA WC645 UT WOS:A1997WC64500037 ER PT J AU Avise, JC Pierce, PC VandenAvyle, MJ Smith, MH Nelson, WS Asmussen, MA AF Avise, JC Pierce, PC VandenAvyle, MJ Smith, MH Nelson, WS Asmussen, MA TI Cytonuclear introgressive swamping and species turnover of bass after an introduction SO JOURNAL OF HEREDITY LA English DT Article ID NATURAL-POPULATIONS; MITOCHONDRIAL-DNA; SMALLMOUTH BASS; HYBRID ZONES; GENE FLOW; HYBRIDIZATION; DISEQUILIBRIA; ASSOCIATIONS; NUCLEAR; SYSTEM AB Species-specific RFLP markers from mitochondrial DNA (mtDNA) were identified and employed in conjunction with previously reported data for nuclear allozyme markers to examine the genetic consequences of an artificial introduction of spotted bass (Micropterus punctulatus) into a north Georgia reservoir originally occupied by native smallmouth bass (M. dolomieui). The cytonuclear genetic data indicate that within 10-15 years following the unauthorized introduction, a reversal in these species' abundances has occurred and that more than 99% of the population sample analyzed here consists of spotted bass or products of interspecific hybridization. This demographic shift, perhaps ecologically or environmentally mediated, has been accompanied by introgressive swamping; more than 95% of the remaining smallmouth bass nuclear and cytoplasmic alleles are present in individuals of hybrid ancestry. Dilocus cytonuclear disequilibria were significantly different from zero, with patterns indicative of an excess of homospecific genetic combinations (relative to expectations from single-locus allelic frequencies) and a disproportionate contribution of smallmouth bass mothers to the hybrid gene pool, Results document dramatic genetic and demographic changes following the human-mediated introduction of a nonnative species. C1 UNIV GEORGIA, SCH FOREST RESOURCES, GEORGIA COOPERAT FISH & WILDLIFE RES UNIT, ATHENS, GA 30602 USA. UNIV GEORGIA, SCH FOREST RESOURCES, NATL BIOL SERV, ATHENS, GA 30602 USA. SAVANNAH RIVER ECOL LAB, AIKEN, SC USA. RP Avise, JC (reprint author), UNIV GEORGIA, DEPT GENET, ATHENS, GA 30602 USA. NR 32 TC 43 Z9 44 U1 0 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 EI 1465-7333 J9 J HERED JI J. Hered. PD JAN-FEB PY 1997 VL 88 IS 1 BP 14 EP 20 PG 7 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA WH725 UT WOS:A1997WH72500003 ER PT J AU Schmidt, S Padukone, N AF Schmidt, S Padukone, N TI Production of lactic acid from wastepaper as a cellulosic feedstock SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE lactic acid; simultaneous saccharification and fermentation; biomass; cellulose; xylose; wastepaper ID WHEY PERMEATE; CELL RECYCLE; FERMENTATION; GROWTH AB Lactic acid promises to be an important commodity chemical in the future as a monomer for the production of biodegradable polylactic acid (PLA), As the demand for lactic acid increases, the need to explore alternative feedstock sources and process options that are inexpensive and efficient is bound to gain importance, This paper reports the results of a study of the production of lactic acid from wastepaper as a representative cellulosic feedstock, using a batch, bench-scale simultaneous saccharification and fermentation (SSF) process, The effect on process performance of operating parameters such as pH, temperature, enzyme loading, solids concentration, and enzyme preparation has been examined, A lactic acid product yield of 84% of theoretical was achieved at a solids loading of 5%, using 25 filter paper units (FPU) of cellulase per gram of cellulose, at 45 degrees C and pH 5.0, The pH and temperature of operation have been selected to achieve good performance of both the cellulase and the microoganism in the SSF process, Our studies show that a feedstock such as wastepaper offers considerable promise and opportunity in the future for development of a biomass-based process for lactic acid production. RP Schmidt, S (reprint author), NATL RENEWABLE ENERGY LAB,ALTERNAT FUELS DIV,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 19 TC 53 Z9 54 U1 0 U2 16 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 JAN PY 1997 VL 18 IS 1 BP 10 EP 14 DI 10.1038/sj.jim.2900339 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WM859 UT WOS:A1997WM85900003 ER PT J AU Larsen, N Overbeek, R Pramanik, S Schmidt, TM Selkov, EE Strunk, O Tiedje, JM Urbance, JW AF Larsen, N Overbeek, R Pramanik, S Schmidt, TM Selkov, EE Strunk, O Tiedje, JM Urbance, JW TI Towards microbial data integration SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE database; integration; microbes; phylogeny AB There are currently 100-200 microbiology-related databases in existence, although it is impossible to find answers to queries that span even a few of these, The Center for Microbial Ecology (CME) at Michigan State University seeks to change this situation by coordinating the creation of an Integrated Microbial Database (IMD), accessible through the World Wide Web (WWW), Such a system will contain up-to-date phylogeny and taxonomy, gene sequences (including genomes), biochemical data, metabolic models, ecological and phenotypic data, Current main obstacles to creation of an IMD are the lack of a single freely available organismal nomenclature with synonyms and the availability of much critical data, An IMD will have major impacts on microbial biology: currently intractable fundamental questions might be answered, experiments could be refocused, and new commercial possibilities created, An IMD should remain freely available and be created under an open development model. C1 MICHIGAN STATE UNIV,CTR MICROBIAL ECOL,E LANSING,MI 48824. ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. RUSSIAN ACAD SCI,INST THEORET & EXPT BIOPHYS,PUSHCHINO 142192,MOSCOW REGION,RUSSIA. TECH UNIV MUNICH,LEHRSTUHL MIKROBIOL,D-80290 MUNICH,GERMANY. RP Larsen, N (reprint author), MICHIGAN STATE UNIV,DEPT MICROBIOL,GILTNER HALL,E LANSING,MI 48824, USA. OI Schmidt, Thomas/0000-0002-8209-6055 NR 0 TC 3 Z9 3 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 JAN PY 1997 VL 18 IS 1 BP 68 EP 72 DI 10.1038/sj.jim.2900366 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WM859 UT WOS:A1997WM85900014 ER PT J AU Hoover, K Schultz, CM Lane, SS Bonning, BC Hammock, BD Duffey, SS AF Hoover, K Schultz, CM Lane, SS Bonning, BC Hammock, BD Duffey, SS TI Effects of diet-age and streptomycin on virulence of Autographa californica M nucleopolyhedrovirus against the tobacco budworm SO JOURNAL OF INVERTEBRATE PATHOLOGY LA English DT Article DE Autographa californica nuclear polyhedrosis virus; Heliothis virescens; antibiotics; streptomycin; diet age; virulence; relative growth rate ID BACILLUS-THURINGIENSIS; DIGESTIVE PHYSIOLOGY; HELIOTHIS; PROTEIN; LARVAE; PLANT AB Addition of the antibiotic streptomycin to two artificial diets routinely used in bioassays of neonate larvae of Heliothis virescens (tobacco budworm) infected with Autographa californica M nucleopolyhedrovirus (AcMNPV) increased lethal times of the virus. After storage of diets for 3 weeks at 4 degrees C, lethal times of infected larvae were significantly slower compared to those for larvae bioassayed using diets stored for 2 weeks or less. The effect of diet-age on rate of mortality was not the result of a change in total protein content or pH of the diet, but was apparently the result of some other alteration in the quality of the diet (e.g. microbial spoilage, palatibility, and/or nutritional value unrelated to total protein). Although we did not determine why lethal times were slower in response to streptomycin concentration or diet-age, we did find that slower lethal times were correlated with slower relative growth rates (RGR) of infected larvae. In addition, RGR of infected larvae decreased as a function of increasing streptomycin concentration, diet-age, and the interaction of the two factors. These results demonstrate that it is difficult to obtain consistent and comparable bioassay results if antibiotic composition and diet-age are not controlled. We suggest a standardized diet or highly standardized procedures for a given diet be developed that permits comparison of bioassays among and within laboratories. (C) 1997 Academic Press. C1 LAWRENCE LIVERMORE NATL LAB,DEPT ENTOMOL,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT ENVIRONM TOXICOL,DAVIS,CA 95616. NR 24 TC 7 Z9 7 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2011 J9 J INVERTEBR PATHOL JI J. Invertebr. Pathol. PD JAN PY 1997 VL 69 IS 1 BP 46 EP 50 DI 10.1006/jipa.1996.4620 PG 5 WC Zoology SC Zoology GA WJ837 UT WOS:A1997WJ83700007 PM 9028927 ER PT J AU Narayanan, P Valdez, YE Robinson, JP Lehnert, BE AF Narayanan, P Valdez, YE Robinson, JP Lehnert, BE TI Regulation of macrophage-mediated uptake of apoptotic neutrophils by interleukin-8. SO JOURNAL OF LEUKOCYTE BIOLOGY LA English DT Meeting Abstract C1 PURDUE UNIV,PURDUE UNIV CYTOMETRY LABS,W LAFAYETTE,IN 47907. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0741-5400 J9 J LEUKOCYTE BIOL JI J. Leukoc. Biol. PY 1997 SU S BP 30 EP 30 PG 1 WC Cell Biology; Hematology; Immunology SC Cell Biology; Hematology; Immunology GA YG406 UT WOS:A1997YG40600032 ER PT J AU Pan, LH Singh, MA Salomons, GJ Gupta, JA Capel, MS AF Pan, LH Singh, MA Salomons, GJ Gupta, JA Capel, MS TI Strain energy effects on the ordering process in diblock styrene-butadiene copolymer SO JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS LA English DT Article ID MICROPHASE SEPARATION TRANSITION; X-RAY-SCATTERING; DISORDER TRANSITION; BLOCK-COPOLYMERS; PHASE-TRANSITIONS; CLUSTER GROWTH; KINETICS; POLYMERS; DYNAMICS; SOLIDS AB The technique of time-resolved small-angle x-ray scattering is used to monitor the disorder-order transformation occurring in asymmetric, diblock styrene-butadiene. A rapid thermal quench is applied to drive the system from its initial high-temperature disordered state to a low-temperature ordered structure, a body-centered cubic lattice of styrene spheres characterized by a series of concentric Debye rings in the two-dimensional scattering profile. At relatively late times in the microdomain ordering process, the uniform Debye rings were seen to rapidly develop nonuniformities indicating the existence of preferred orientation with a fiber texture, the [110] axis of the bcc structure defining the fiber axis. These results are interpreted in the context of a developing transformation strain energy during the ordering process and shown to be consistent with accompanying changes in lattice spacing as well as earlier observations of apparent fluctuations in the ordering process. C1 QUEENS UNIV,DEPT PHYS,KINGSTON,ON K7L 3N6,CANADA. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 39 TC 1 Z9 1 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0022-2348 J9 J MACROMOL SCI PHYS JI J. Macromol. Sci.-Phys. PY 1997 VL B36 IS 1 BP 137 EP 151 DI 10.1080/00222349708220420 PG 15 WC Polymer Science SC Polymer Science GA WG117 UT WOS:A1997WG11700009 ER PT J AU Pratt, LM Szostak, R Khan, IM Bibler, J AF Pratt, LM Szostak, R Khan, IM Bibler, J TI Alkaline degradation of resorcinol-formaldehyde resins: Solid-state NMR, thermal adsorption and desorption analysis, and molecular modeling SO JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY LA English DT Article ID OPTIMIZATION; PARAMETERS AB Resorcinol-formaldehyde resins, used for alkali metal-cation exchange, were shown to degrade more rapidly in the metallated form compared to the protonated form. Solid-state C-13 NMR showed additional peaks in the partially degraded resin corresponding to quinone and other carbonyl functionalities, which are absent in the undegraded resin. Semiempirical molecular orbital calculations were used in conjunction with the experimental data to elucidate the degradation mechanism. C1 WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29808. RP Pratt, LM (reprint author), CLARK ATLANTA UNIV,DEPT CHEM,ATLANTA,GA 30314, USA. NR 9 TC 4 Z9 4 U1 0 U2 4 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1060-1325 J9 J MACROMOL SCI PURE JI J. Macromol. Sci.-Pure Appl. Chem. PY 1997 VL A34 IS 2 BP 281 EP 289 DI 10.1080/10601329708014955 PG 9 WC Polymer Science SC Polymer Science GA WL981 UT WOS:A1997WL98100004 ER PT J AU Chakarian, V Idzerda, YU Kao, CC Chen, CT AF Chakarian, V Idzerda, YU Kao, CC Chen, CT TI Circular polarized soft X-ray resonant magnetic scattering studies of FeCo/Mn/FeCo multilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium E on Magnetic Ultrathin Films, Multilayers and Surfaces at the 1996 European-Materials-Research-Society Spring Meeting CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc, Ford Motor Co, Thompson CSF, YKK, Toshiba, SMI, Hitachi, Holm SI DE X-ray scattering; magnetic dichroism; multilayers; magnetic ordering ID DICHROISM; EDGES AB We present some of our recent results of circular polarized soft X-ray resonant magnetic scattering studies, a technique which combines the power of X-ray scattering and magnetic circular dichroism. The energy, angle, and polarization dependence of the reflectivity near the L-edges of the each element provides a new means for determining multilayer magnetic ordering in a heteromagnetic multilayer in an element-specific manner. As an example, the results from a Fe25Co75/Mn/Fe25Co75 trilayer are presented. C1 USN,RES LAB,WASHINGTON,DC 20375. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Chakarian, V (reprint author), BROOKHAVEN NATL LAB,USN,RES LAB,BLDG 5108,UPTON,NY 11973, USA. NR 12 TC 25 Z9 25 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 JAN PY 1997 VL 165 IS 1-3 BP 52 EP 55 DI 10.1016/S0304-8853(96)00471-4 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WF862 UT WOS:A1997WF86200013 ER PT J AU DecheletteBarbara, A Tonnerre, JM SaintLager, MC Bartolome, F Berar, JF Raoux, D Fischer, HM Piecuch, M Chakarian, V Kao, CC Gailhanou, M Lefevre, S Bessiere, M AF DecheletteBarbara, A Tonnerre, JM SaintLager, MC Bartolome, F Berar, JF Raoux, D Fischer, HM Piecuch, M Chakarian, V Kao, CC Gailhanou, M Lefevre, S Bessiere, M TI X-ray anomalous diffraction and resonant magnetic scattering X-ray study of FexMn1-x/Ir(001) superlattices SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium E on Magnetic Ultrathin Films, Multilayers and Surfaces at the 1996 European-Materials-Research-Society Spring Meeting CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc, Ford Motor Co, Thompson CSF, YKK, Toshiba, SMI, Hitachi, Holm SI DE superlattices; anomalous diffraction; magnetic scattering ID ALLOYS; PHASE AB X-ray anomalous diffraction in different geometries and X-ray resonant magnetic scattering have been used to investigate FexMn1-x/Ir(001) superlattices. The influence of the alloy stoichiometry on the structural and magnetic properties has been studied and compared with the bulk alloy properties. The structural results are compared with the magnetic results in order to understand the outstanding properties of these systems. C1 UNIV NANCY 1,PHYS SOLIDES LAB,URA 155 CNRS,F-54506 VANDOEUVRE NANCY,FRANCE. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV PARIS 11,MESR,CEA,CNRS,LURE,F-91405 ORSAY,FRANCE. RP DecheletteBarbara, A (reprint author), CNRS,CRISTALLOG LAB,BP 166,F-38042 GRENOBLE 09,FRANCE. RI Bartolome, Fernando/K-1700-2014; Gailhanou, Marc/F-8251-2014 OI Bartolome, Fernando/0000-0002-0047-1772; Gailhanou, Marc/0000-0002-7747-703X NR 13 TC 5 Z9 5 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 JAN PY 1997 VL 165 IS 1-3 BP 87 EP 91 DI 10.1016/S0304-8853(96)00478-7 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WF862 UT WOS:A1997WF86200020 ER PT J AU Berger, A Fullerton, EE AF Berger, A Fullerton, EE TI Phase diagram of imperfect ferromagnetic/antiferromagnetic bilayers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium E on Magnetic Ultrathin Films, Multilayers and Surfaces at the 1996 European-Materials-Research-Society Spring Meeting CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc, Ford Motor Co, Thompson CSF, YKK, Toshiba, SMI, Hitachi, Holm SI DE multilayers; exchange coupling; phase diagram; interface magnetism ID CR; SUPERLATTICES; TRANSITION; ORDER AB The phase diagram for ferromagnetic/antiferromagnetic bilayers with imperfect interfaces is calculated, using an Ising spin-1/2 model which is solved numerically in the mean field approximation for finite temperatures. We identify three stable phases: (i) domains in the ferromagnet, (ii) domains in the antiferromagnet and (iii) domain wails near the interfaces with homogeneous order within the layers. Phase transitions between these phases occur as a function of temperature, relative film thicknesses and step density. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Berger, A (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. RI Fullerton, Eric/H-8445-2013; Berger, Andreas/D-3706-2015 OI Fullerton, Eric/0000-0002-4725-9509; Berger, Andreas/0000-0001-5865-6609 NR 8 TC 24 Z9 24 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1997 VL 165 IS 1-3 BP 471 EP 474 DI 10.1016/S0304-8853(96)00595-1 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WF862 UT WOS:A1997WF86200121 ER PT J AU Smith, W Gosselin, M Legendre, L Wallace, D Daly, K Kattner, G AF Smith, W Gosselin, M Legendre, L Wallace, D Daly, K Kattner, G TI New production in the Northeast Water Polynya: 1993 SO JOURNAL OF MARINE SYSTEMS LA English DT Article; Proceedings Paper CT Northeast Water Polynya Symposium CY MAY 01-05, 1995 CL HELSINGOR, DENMARK DE Arctic; polynya; production; nitrogen ID PHYTOPLANKTON GROWTH; NITROGEN UPTAKE; NITRATE UPTAKE; GREENLAND SEA; BLOOM; N-15 AB The Northeast Water Polynya has been suggested as acting as a sink for carbon, especially during the spring and summer when phytoplankton growth is active, During 1993 the polynya was sampled for the entire growing period (late May through mid-August) in order to more accurately assess the magnitude, controls and patterns of new and total (ammonium, nitrate and urea) nitrogen production, This represents the first assessment of new production throughout an entire season in the Arctic. We found that, in 1993, new production, based on N-15-tracer techniques and integrated over the euphotic zone, was 0.141 mmol N m(-2) h(-1) (0.361 g C m(-2) d(-1) when converted using observed C/N ratios). Measured f ratios averaged 0.65 and demonstrate that the system, to a great extent, was using nitrate as a nitrogen source. In general f ratios were greatest early in the season and minimal in mid-summer. Urea uptake was highly variable and contributed slightly less than ammonium to phytoplankton nitrogen demand. Nitrate uptake at stations with low (< 0.5 mu M) nitrate concentrations was significantly reduced, implying that nitrate concentrations limited phytoplankton growth late in the growing season, Long-term new production rates calculated from nutrient depletion patterns from the polynya as a whole as well as a time-series constructed from a single location were ca. 0.144-0.281 g C m(-2) d(-1). The relationship between new production as measured by incubations and nutrient depletion budgets suggests that phytoplankton growth is the dominant factor influencing the nitrogen budget of the polynya. The amount of material available for removal from the euphotic zone is limited and constrains the degree to which the polynya can act as a regional carbon sink. C1 UNIV QUEBEC,DEPT OCEANOG,RIMOUSKI,PQ G5L 3A1,CANADA. UNIV LAVAL,DEPT BIOL,GIROQ,ST FOY,PQ G1K 7P4,CANADA. BROOKHAVEN NATL LAB,DIV OCEAN SCI,UPTON,NY 11973. ALFRED WEGENER INST POLAR & MARINE RES,D-27515 BREMERHAVEN,GERMANY. RP Smith, W (reprint author), UNIV TENNESSEE,DEPT ECOL & EVOLUT BIOL,KNOXVILLE,TN 37996, USA. RI Gosselin, Michel/B-4477-2014 OI Gosselin, Michel/0000-0002-1044-0793 NR 31 TC 45 Z9 45 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD JAN PY 1997 VL 10 IS 1-4 BP 199 EP 209 DI 10.1016/S0924-7963(96)00067-X PG 11 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA WM639 UT WOS:A1997WM63900018 ER PT J AU Farkas, D Zhou, SJ Vailhe, C Mutasa, B Panova, J AF Farkas, D Zhou, SJ Vailhe, C Mutasa, B Panova, J TI Embedded atom calculations of unstable stacking fault energies and surface energies in intermetallics SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID DISLOCATION NUCLEATION; CRACK-TIP; INTERATOMIC POTENTIALS; CORE STRUCTURES; METALS; MODEL; BEHAVIOR AB We performed embedded atom method calculations of surface energies and unstable stacking fault energies for a series of intermetallics for which interatomic potentials of the embedded atom type have recently been developed. These results were analyzed and applied to the prediction of relative ductility of these materials using the various current theories. Series of alloys with the B2 ordered structure were studied, and the results were compared to those in pure body-centered cubic (bcc) Fe. Ordered compounds with L1(2) and L1(0) structures based on the face-centered cubic (fee) lattice were also studied. It was found that there is a correlation between the values of the antiphase boundary (APE) energies in B2 alloys and their unstable stacking fault energies. Materials with higher APE energies tend to have higher unstable stacking fault energies, leading to an increased tendency to brittle fracture. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Farkas, D (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT MAT SCI & ENGN,BLACKSBURG,VA 24061, USA. NR 29 TC 23 Z9 23 U1 1 U2 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JAN PY 1997 VL 12 IS 1 BP 93 EP 99 DI 10.1557/JMR.1997.0015 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA WC271 UT WOS:A1997WC27100015 ER PT J AU LaraCurzio, E Ferber, MK AF LaraCurzio, E Ferber, MK TI Stress-rupture of continuous fibre ceramic composites at intermediate temperatures SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article RP LaraCurzio, E (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 TC 12 Z9 12 U1 0 U2 1 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 JAN 1 PY 1997 VL 16 IS 1 BP 23 EP 26 DI 10.1023/A:1018528212773 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA WC323 UT WOS:A1997WC32300008 ER PT J AU Martinez, L Flores, O Amaya, M Duncan, A Viswanathan, S Lawrynowics, D Lavernia, EJ AF Martinez, L Flores, O Amaya, M Duncan, A Viswanathan, S Lawrynowics, D Lavernia, EJ TI The role of alumina particulate in microstructural and forging properties of spray-atomized and -deposited Fe-Al ordered intermetallic compounds SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article; Proceedings Paper CT Symposium on Spray Forming - Experiment, Analysis, and Applications CY FEB 09-13, 1997 CL ORLANDO, FL DE iron aluminides; spray atomization and deposition; Al(2)O(3) particulate; metal matrix composite ID METAL-MATRIX COMPOSITES; PARTICLE ENGULFMENT; RAPID SOLIDIFICATION; ATOMIZATION; INTERFACE; BEHAVIOR; PRECIPITATION; TEMPERATURE; VELOCITY; ALLOYS AB Spray atomization and deposition, hot isostatic pressing, and forging at high temperatures were used for processing FeAl40 at% intermetallic compounds alloyed with boron and fine alumina particulates. Optical microscopy and SEM studies are described. Spray atomization and deposition improved the microstructure of FeAl 40 intermetallic compounds compared to that of standard casting techniques, which are prone to develop a high porosity, segregation, and cracking. Boron in spray-atomized FeAl 40 improved grain boundary cohesion, causing the material to change failure mode from intergranular to mixed intergranular and transgranular. Al(2)O(3) particle addition during spray atomization induced significant grain refinement and material strengthening. The forgeability of the samples of FeAl 40 + B/Al(2)O(3) was considerably improved relative to the FeAl 40 material. HIPing minimized porosity and increased forging ductility. Al(2)O(3), particulates in the FeAl matrix, furthermore, contributed to the shifting of the fracture mode from integranular to mostly transgranular. C1 Univ Nacl Autonoma Mexico, Inst Fis, Cuernavaca 62251, Morelos, Mexico. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Calif Irvine, Dept Chem Engn & Mat Sci, Irvine, CA 92717 USA. RP Martinez, L (reprint author), Univ Nacl Autonoma Mexico, Inst Fis, AP 48-3, Cuernavaca 62251, Morelos, Mexico. NR 47 TC 13 Z9 13 U1 0 U2 0 PU CONSULTANTS BUREAU/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1064-7562 J9 J MATER SYNTH PROCES JI J. Mater. Synth. Process PD JAN PY 1997 VL 5 IS 1 BP 65 EP 76 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA YX238 UT WOS:000072020200011 ER PT J AU Brewster, ME Fann, GI Yang, ZY AF Brewster, ME Fann, GI Yang, ZY TI Wavelets for electronic structure calculations SO JOURNAL OF MATHEMATICAL CHEMISTRY LA English DT Article AB Molecular electronic structure calculations have a multi-scale character through the presence of a set of singularities corresponding to atomic nuclei, and thus there exists a potential to improve the efficiency of these calculations using fast wavelet transform techniques. We report on the development of a one dimensional prototype benchmark problem of sufficient complexity to capture the features of 3-D problems that are being solved today in quantum electronics calculations. Theoretical estimates of decay across scales and spatial distribution of wavelet coefficients for the solutions of the 1-D and 3-D problems are derived and verified experimentally. Equivalence in a multi-resolution context of the solutions of the 1-D prototype and the 3-D problem is established. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Brewster, ME (reprint author), Pacific NW Lab, Environm Mol Sci Lab, K1-96, Richland, WA 99352 USA. RI Athan, Tara/C-8633-2009 NR 9 TC 8 Z9 8 U1 0 U2 1 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 0259-9791 J9 J MATH CHEM JI J. Math. Chem. PY 1997 VL 22 IS 2-4 BP 117 EP 142 DI 10.1023/A:1019171830287 PG 26 WC Chemistry, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Chemistry; Mathematics GA ZC259 UT WOS:000072558900002 ER PT J AU Nieto, MM Truax, DR AF Nieto, MM Truax, DR TI Displacement-operator squeezed states .1. Time-dependent systems having isomorphic symmetry algebras SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID COHERENT STATES; GENERAL POTENTIALS AB In this paper we use the Lie algebra of space-time symmetries to construct states which are solutions to the time-dependent Schrodinger equation for systems with potentials V(x, tau)=g((2))(tau)x(2) + g((1))(tau)x + g((0))(tau). We describe a set of number-operator eigenstates states, {Psi(n)(x, tau)}, that form a complete set of states but which, however, are usually not energy eigenstates. From the extremal state, Psi(0), and a displacement squeeze operator derived using the Lie symmetries, we construct squeezed states and compute expectation values for position and momentum as a function of time, tau. We prove a general expression for the uncertainty relation for position and momentum in terms of the squeezing parameters. Specific examples, all corresponding to choices of V(x,tau) and having isomorphic Lie algebras, will be dealt with in the following paper (II). 1997 American Institute of Physics. C1 UNIV CALGARY,DEPT CHEM,CALGARY,AB T2N 1N4,CANADA. RP Nieto, MM (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 24 TC 9 Z9 9 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JAN PY 1997 VL 38 IS 1 BP 84 EP 97 DI 10.1063/1.531836 PG 14 WC Physics, Mathematical SC Physics GA WC066 UT WOS:A1997WC06600007 ER PT J AU Nieto, MM Truax, DR AF Nieto, MM Truax, DR TI Displacement-operator squeezed states .2. Examples of time-dependent systems having isomorphic symmetry algebras SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article AB In this paper, results from the previous paper (I) are applied to calculations of squeezed states for such well-known systems as the harmonic oscillator, free par tide, linear potential, oscillator with a uniform driving force, and repulsive oscillator. For each example, expressions for the expectation values of position and momentum are derived in terms of the initial position and momentum, as well as in the (alpha,z)- and in the (z,alpha)-representations described in I. The dependence of the squeezed-state uncertainty products on the time and on the squeezing parameters is determined for each system. (C) 1997 American Institute of Physics. C1 UNIV CALGARY,DEPT CHEM,CALGARY,AB T2N 1N4,CANADA. RP Nieto, MM (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JAN PY 1997 VL 38 IS 1 BP 98 EP 114 DI 10.1063/1.531837 PG 17 WC Physics, Mathematical SC Physics GA WC066 UT WOS:A1997WC06600008 ER PT J AU Chandler, DP Schreckhise, RW Smith, JL Bolton, H AF Chandler, DP Schreckhise, RW Smith, JL Bolton, H TI Electroelution to remove humic compounds from soil DNA and RNA extracts SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE electroelution; humics; PCR; rRNA; soil; 16S ID POLYMERASE CHAIN-REACTION; BACTERIAL-DNA; RAPID METHOD; SUBSURFACE SEDIMENTS; AMPLIFIABLE DNA; AMPLIFICATION; HYBRIDIZATION; PURIFICATION; SEPARATION; BIOMASS AB The application of nucleic acid techniques to detect, identify, and monitor specific genes or organisms in soils or sediments is often complicated by the inhibitory effects of humic compounds that copurify with nucleic acids. A rapid electroelution technique was developed to separate inhibitory compounds from extracts of soil DNA and RNA. This technique was used in conjunction with PCR to detect nifH, terrestrial ammonia-oxidizer (TAO) 16S rRNA genes and TAO 16S rRNA from a variety of surface soils and contaminated sediments. After electroelution of crude nucleic acid extracts, PCR sensitivity was increased up to a factor of 10(4) relative to DNA templates that had not been electroeluted. Without electroelution of crude DNA extracts, target genes often remained undetected. Likewise, electroelution of crude RNA extracts increased RT-PCR sensitivity (for TAO 16S rRNA) by a factor of 10(3) relative to RNA extracts that had not been further purified. The electroelution technique will therefore be useful for rendering environmental nucleic acids extracted from soil and sediment more amenable to PCR methods and nucleic acid analysis. C1 FRED HUTCHINSON CANC RES CTR, SEATTLE, WA 98104 USA. WASHINGTON STATE UNIV, USDA ARS, PULLMAN, WA 99161 USA. RP Chandler, DP (reprint author), PACIFIC NW LAB, ENVIRONM MICROBIOL GRP, POB 999,MAILSTOP K4-06, RICHLAND, WA 99352 USA. RI Bolton, Harvey/E-5583-2011 NR 23 TC 27 Z9 30 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD JAN PY 1997 VL 28 IS 1 BP 11 EP 19 DI 10.1016/S0167-7012(96)00957-8 PG 9 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA WU711 UT WOS:A1997WU71100002 ER PT J AU Ramsey, RS McLuckey, SA AF Ramsey, RS McLuckey, SA TI Charge concentration in electrospray ionization: Mass spectrometry for sensitive detection of proteins SO JOURNAL OF MICROCOLUMN SEPARATIONS LA English DT Article DE mass spectrometry; protein analysis; electrospray ionization; gas-phase reaction; detection limits ID CAPILLARY ZONE ELECTROPHORESIS; INDUCED FLUORESCENCE DETECTION; QUADRUPOLE ION-TRAP; MICRO-ELECTROSPRAY; DETECTION LIMITS; NATIVE PROTEINS; SINGLE CELLS; CYTOCHROME-C; PEPTIDES; ATTOMOLE AB A novel method of detecting proteins at low concentration based upon electrospray ionization-mass spectrometry and gas-phase proton transfer reactions is described. In this technique the signal that is spread over a broad mass range due to the distribution of multiply charged ions generated in electrospray is focused into a singly-charged, low mass ion. The experiments performed on a quadrupole ion trap involve accumulating the ions of the biopolymer, allowing these ions to react with a strong neutral base, and recording the intensity of the singly-charged product in a final mass analysis scan. Concentration detection limits for high-mass proteins may be improved by over two orders of magnitude using this approach. Targeted compounds can be detected at low nanomolar levels using moderate reaction times with a strong base. (C) 1997 John Wiley & Sons, Inc. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 34 TC 7 Z9 7 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1040-7685 J9 J MICROCOLUMN SEP JI J. Microcolumn Sep. PY 1997 VL 9 IS 7 BP 523 EP 528 DI 10.1002/(SICI)1520-667X(1997)9:7<523::AID-MCS1>3.0.CO;2-3 PG 6 WC Chemistry, Analytical SC Chemistry GA XW698 UT WOS:A1997XW69800001 ER PT J AU Subirats, M Iskander, MF White, MJ Kiggans, JO AF Subirats, M Iskander, MF White, MJ Kiggans, JO TI FDTD simulation of microwave sintering in large (500/4000 liter) multimode cavities SO JOURNAL OF MICROWAVE POWER AND ELECTROMAGNETIC ENERGY LA English DT Article DE microwave furnace; multimode microwave cavity; FDTD; sintering; ceramics; heat transfer; drying; large-scale microwave sintering AB The recently developed multigrid 3D Finite-Difference Time-Domain (FDTD) code and the 3D Finite-Difference Heat-Transfer (FDHT) code were integrated and used to simulate realistic material processing (drying and sintering) in microwave furnaces. The objective ir to use results from these numerical simulations to help develop large-scale microwave-sintering processes and to explore the feasibility of the commercial utilization of the microwave processing of materials technology. This paper presents results obtained from the simulation of realistic sintering experiments carried out in both 500- and 4000-liter multimode microwave cavities operating at 2.45 GHz. The ceramic ware being sintered was placed inside a cubical/cylindrical crucible box made of ceramic materials that have higher electrical conductivities than the ceramic samples. A higher conductivity crucible helps increase the amount of microwave power absorption and hence stimulates the microwave heating process, particularly at lower temperatures. The dimensions of the crucible box were made sufficiently large to accommodate up to 5 layers of ceramic samples with 16 to 20 cup-like samples per layer. Simulation results provided guidelines regarding selection of crucible-box materials, crucible-box geometry, and the possibility of using rings of highly conducting materials instead of the crucible box to improve the efficiency and uniformity of heating. The effect of the material type to be used as shelves between the layers of the ceramic samples, the fraction volume of the load vs. that of the furnace, and the effect of the insulation electrical conductivity on the efficiency and uniformity of healing were also simulated. Simulation results illustrating the trade offs involved in these rather complex sintering processes are discussed and compared graphically. For the simulation cases reported in this paper, it is shown that: (1) ceramics processed in BN crucibles present an increase of 44% in uniformity and 52% in the average microwave power absorbed with respect to those processed with the SiC crucibles; (2) crucibles containing SiC may present a non-uniform heating pattern due to the excessive heating in the crucible walls and the microwave shielding effect of the SiC; (3) a cylindrical crucible box creates more uniform and higher (20%) microwave power absorption in the ceramic samples than cubical ones; (4) shelves composed of SiC allow 25% less electric-field penetration and decrease the uniformity of heating in the ceramic load by 56% compared to shelves composed of BN; (5) increasing the number of layers results in lower fields and poor uniformity in each layer although the overall efficiency increases; and (6) while an increase in the conductivity of the insulation may stimulate the sintering process, excessively large values of the conductivity of the insulation beyond sigma = 10(4) S/m decreases the penetration of the electromagnetic (EM) fields to the sample and hence reduces the uniformity of the heating. Results from these simulations and the corresponding analysis, including those related to increasing the uniformity and the efficiency when SiC crucibles are used, will help in identifying important trends in optimizing the design of large-scale microwave-sintering systems Several solutions are proposed to increase the uniformity and efficiency of the heating when SiC crucible boxes are used The first suggests the use of a lower weight percentage of SiC in the material of the crucible box Another suggestion is to reduce the thickness of the SiC crucible wall to a maximum of 0.25 cm Microwave power deposition and uniformity may also be improved by using a non-solid crucible, created from highly electrically conducting rings, rather than solid crucible plates or cylinders. increasing the diameter of the rings (relative to wavelength) also results in higher and more uniform patterns in the ceramic ware. A diameter of four times the wavelength is suggested Detailed results validating these findings are presented in the following sections. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Subirats, M (reprint author), UNIV UTAH,DEPT ELECT ENGN,MEB 3280,SALT LAKE CITY,UT 84112, USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 8 TC 3 Z9 3 U1 0 U2 2 PU INT MICROWAVE POWER INST PI MANASSAS PA 10210 LEATHERLEAF COURT, MANASSAS, VA 22111 SN 0832-7823 J9 J MICROWAVE POWER EE JI J. Microw. Power Electromagn. Energy PY 1997 VL 32 IS 3 BP 161 EP 170 PG 10 WC Engineering, Chemical; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YF287 UT WOS:A1997YF28700005 ER PT J AU Shore, BW Li, LF Feit, MD AF Shore, BW Li, LF Feit, MD TI Poynting vectors and electric field distributions in simple dielectric gratings SO JOURNAL OF MODERN OPTICS LA English DT Article ID ENERGY-FLOW DISTRIBUTION AB We discuss, with illustrations drawn from the simple example of a dielectric grating under total internal reflection illumination, the use of electric field, energy density and Poynting vector as tools for understanding phenomena associated with dielectric gratings. The electric field has greatest direct observational interest and exhibits patterns of nodes and antinodes that are both expected and intuitive. The energy density, although not directly linked with photoelectric response, has readily understood global patterns. The Poynting vector has more elaborate structure, involving patterns of curls, but the patterns are sensitive to small changes in illumination angle or groove depth. Plots of Poynting vectors may not be as useful for dielectric structures as they are for metals. C1 UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. RP Shore, BW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Feit, Michael/A-4480-2009 NR 8 TC 2 Z9 2 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD JAN PY 1997 VL 44 IS 1 BP 69 EP 81 DI 10.1080/09500349708232900 PG 13 WC Optics SC Optics GA WC469 UT WOS:A1997WC46900005 ER PT J AU Ramshaw, JD AF Ramshaw, JD TI General remarks on spectral entropy vs. statistical entropy SO JOURNAL OF NON-EQUILIBRIUM THERMODYNAMICS LA English DT Article ID SYSTEMS AB Crepeau and Herzel [1] (CH) have recently compared the spectral entropy of Powell and Percival [2] with the standard statistical (Boltzmann-Gibbs-Shannon) entropy in three simple physical systems. Here we compare and contrast these two entropies in a more general way by considering their values for an arbitrary stationary process X(t). C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ramshaw, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-018, Livermore, CA 94551 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU WALTER DE GRUYTER & CO PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0340-0204 J9 J NON-EQUIL THERMODY JI J. Non-Equilib. Thermodyn. PY 1997 VL 22 IS 4 BP 392 EP 393 PG 2 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA ZH920 UT WOS:000073161100006 ER PT J AU Hogan, J AF Hogan, J TI Helium transport and exhaust experiments in tokamaks SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE tokamak; helium exhaust and control; particle transport and confinement; active pumping ID DIII-D TOKAMAK; STATES-OF-AMERICA; H-MODE DISCHARGES; TFTR TOKAMAK; ASH EXHAUST; EDGE PLASMA; DIVERTOR; REACTOR; LIMITER; BEAM AB This is a review of recent experiments on helium transport and exhaust in tokamaks. The experiments are discussed in the light of requirements placed on alpha particle confinement for sustained ignition. The ratio of alpha particle replacement time to energy confinement time must be sufficiently small, and is used as a figure-of-merit for assessing the performance of experiments. The attainment of adequate helium removal depends most sensitively on recycling processes, pumping and boundary screening. Since no experiments exactly modeling the geometry or conditions in next step reactors have been performed, heavy emphasis is placed on identifying and understanding fundamental processes so that valid extrapolation is possible. Experiments have thus been carried out for basic regimes (L- and ELMy H-mode confinement, conventional high recycling divertor) and for improved performance conditions, both for the core (ELM-free ii-mode, VH-mode, supershot, reverse shear, high beta(pol) mode) and in the edge/divertor (completely detached H-mode, detached limiter). The core helium transport database has been accumulated mainly by gas puffing experiments, where the helium source is localized at the edge. Experiments with a central helium source from helium neutral beam injection find similar behavior, for the basic confinement regimes. Work is underway to make this comparison for improved confinement regimes. Results of integrated helium transport and exhaust experiments generally show adequate helium exhaust for next step reactors, but a widely used technique for helium exhaust (argon frost pumping) has been found to have important limitations for exploration of improved divertor (gas target) regimes. There has been less activity in the study of improved core and divertor operational modes, but a database is beginning to accumulate. While the figure-of-merit parameters for helium removal are favorable for next step reactors predicated on the basic core and divertor modes, the lack of similarity with next step devices requires the use of validated models even in this case, and these have been improved considerably. RP Hogan, J (reprint author), OAK RIDGE NATL LAB,DIV FUS ENERGY,POB 2008,OAK RIDGE,TN 37831, USA. NR 78 TC 16 Z9 16 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 68 EP 81 DI 10.1016/S0022-3115(97)80031-1 PG 14 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700007 ER PT J AU Hill, DN AF Hill, DN TI A review of ELMs in divertor tokamaks SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE tokamak; divertor plasma; SOL plasma; energy deposition; particle and energy balance ID H-MODE DISCHARGES; SCRAPE-OFF LAYER; DIII-D TOKAMAK; PLASMA-CONFINEMENT; ASDEX UPGRADE; TRANSITION; BOUNDARY; PROFILES; REGIME AB Edge localized modes (ELMs) are the focus of increasing attention by the edge physics community because of the potential impact that the large divertor heat pulses due to ELMs would have on the divertor design of future high power tokamaks such as ITER. This paper reviews what is known about ELMs, with an emphasis on their effect on the scrape-off layer and divertor plasmas. ELM effects have been measured in the ASDEX-U, C-Mod, COMPASS-D, DIII-D, JET, JFT-2M, JT-60U and TCV tokamaks,and are reported here. At least three types of ELMs have been identified and their salient features determined. Type 1 giant ELMs can cause the sudden loss of up to 10-15% of the plasma stored energy, but their amplitude (Delta W/W) does not increase with heating power. Type 3 ELMs are observed near the II-mode power threshold and produce small energy dumps (1-3% of the stored energy). All ELMs increase the scrape-off layer plasma and produce particle fluxes on the divertor targets which are as much as ten times larger than the quiescent phase between ELMs. The divertor heat pulse is largest on the inner target, unlike that of L-mode or quiescent PI-mode; some tokamaks report radial structure in the heat flux profile which is suggestive of islands or helical structures. The power scaling of type 1 ELM amplitude and frequency has been measured in several tokamaks and has recently been applied to predictions of the ELM size in ITER. Concern over the expected ELM amplitude has led to a number of experiments aimed at demonstrating active control of ELMs. Impurity gas injection with feedback control on the radiation loss in ASDEX-U suggests that a promising mode of operation (the CDH-mode) with very small type 3 ELMs can be maintained with heating power well above the II-mode threshold, where giant type 1 ELMs are normally observed. While ELMs have many potential negative effects, the beneficial effect of ELMs in providing density control and limiting the core plasma impurity content in high confinement II-mode discharges should not be overlooked. RP Hill, DN (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 66 TC 61 Z9 61 U1 4 U2 19 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. PY 1997 VL 241 BP 182 EP 198 DI 10.1016/S0022-3115(97)80039-6 PG 17 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700015 ER PT J AU Skinner, CH Amarescu, E Ascione, G Blanchard, W Barnes, CW Batha, SH Beer, M Bell, MG Bell, R Bitter, M Bretz, NL Budny, R Bush, CE Camp, R Casey, M Collins, J Cropper, M Chang, Z Darrow, DS Duong, HH Durst, R Efthimion, PC Ernst, D Fisch, NJ Fonck, RJ Fredrickson, E Fu, GY Furth, HP Gentile, CA Gibson, M Gilbert, J Grek, B Grisham, LR Hammett, G Hawryluk, RJ Herrmann, HW Hill, KW Hosea, J Janos, A Jassby, DL Jobes, FC Johnson, DW Johnson, LC Kamperschroer, J Kalish, M Kugel, H Langford, J Langish, S LaMarche, PH LeBlanc, B Levinton, FM Machuzak, J Majeski, R Manikam, J Mansfield, DK Mazzucato, E McGuire, KM Mika, R McKee, G Meade, DM Medley, SS Mikkelsen, DR Mynick, HE Mueller, D Nagy, A Nazikian, R Ono, M Owens, DK Park, H Paul, SF Pearson, G Petrov, M Phillips, CK Raftopoulos, S Ramsey, A Raucci, R Redi, MH Rewoldt, G Rogers, J Roquemore, AL Ruskov, E Sabbagh, SA Schilling, G Schivell, JF Schmidt, GL Scott, SD Sesnic, S Stratton, BC Strachan, JD Stevenson, T Stotler, DP Synakowski, E Takahashi, H Tang, W Taylor, G Tighe, W Timberlake, JR vonHalle, A vonGoeler, S Walters, RT White, RB Wilson, JR Winston, J Wong, KL Young, KM Zarnstorff, MC Zweben, SJ AF Skinner, CH Amarescu, E Ascione, G Blanchard, W Barnes, CW Batha, SH Beer, M Bell, MG Bell, R Bitter, M Bretz, NL Budny, R Bush, CE Camp, R Casey, M Collins, J Cropper, M Chang, Z Darrow, DS Duong, HH Durst, R Efthimion, PC Ernst, D Fisch, NJ Fonck, RJ Fredrickson, E Fu, GY Furth, HP Gentile, CA Gibson, M Gilbert, J Grek, B Grisham, LR Hammett, G Hawryluk, RJ Herrmann, HW Hill, KW Hosea, J Janos, A Jassby, DL Jobes, FC Johnson, DW Johnson, LC Kamperschroer, J Kalish, M Kugel, H Langford, J Langish, S LaMarche, PH LeBlanc, B Levinton, FM Machuzak, J Majeski, R Manikam, J Mansfield, DK Mazzucato, E McGuire, KM Mika, R McKee, G Meade, DM Medley, SS Mikkelsen, DR Mynick, HE Mueller, D Nagy, A Nazikian, R Ono, M Owens, DK Park, H Paul, SF Pearson, G Petrov, M Phillips, CK Raftopoulos, S Ramsey, A Raucci, R Redi, MH Rewoldt, G Rogers, J Roquemore, AL Ruskov, E Sabbagh, SA Schilling, G Schivell, JF Schmidt, GL Scott, SD Sesnic, S Stratton, BC Strachan, JD Stevenson, T Stotler, DP Synakowski, E Takahashi, H Tang, W Taylor, G Tighe, W Timberlake, JR vonHalle, A vonGoeler, S Walters, RT White, RB Wilson, JR Winston, J Wong, KL Young, KM Zarnstorff, MC Zweben, SJ TI Plasma wall interaction and tritium retention in TFTR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TFTR; tritium inventory and economy; helium exhaust and control; wall particle retention; wall conditioning ID FUSION TEST REACTOR; ENHANCED CONFINEMENT; BUMPER LIMITER; DT EXPERIMENTS; 1ST WALL; TOKAMAK; DEUTERIUM; DISCHARGES; TRANSPORT; OPERATION AB The Tokamak Fusion Test Reactor (TFTR) has been operating safely and routinely with deuterium-tritium fuel for more than two years. In this time, TFTR has produced a number of record breaking results including core fusion power, similar to 2 MW/m(3), comparable to that expected for ITER. Advances in wall conditioning via lithium pellet injection have played an essential role in achieving these results. Deuterium-tritium operation has also provided a special opportunity to address the issues of tritium recycling and retention. Tritium retention over two years of operation was approximately 40%. Recently the in-toms tritium inventory was reduced by half through a combination of glow discharge cleaning, moist-air soaks, and plasma discharge cleaning. The tritium inventory is not a constraint in continued operations. Recent results from TFTR in the context of plasma wall interactions and deuterium-tritium issues are presented. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. FUS PHYS & TECHNOL, TORRANCE, CA USA. OAK RIDGE NATL LAB, OAK RIDGE, TN USA. GEN ATOM CO, SAN DIEGO, CA USA. UNIV WISCONSIN, MADISON, WI 53706 USA. MIT, CAMBRIDGE, MA 02139 USA. AF IOFFE PHYS TECH INST, ST PETERSBURG 194021, RUSSIA. UNIV CALIF IRVINE, IRVINE, CA 92717 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. RP PRINCETON UNIV, PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. RI Sabbagh, Steven/C-7142-2011; Hammett, Gregory/D-1365-2011; Ernst, Darin/A-1487-2010; White, Roscoe/D-1773-2013; Stotler, Daren/J-9494-2015 OI Hammett, Gregory/0000-0003-1495-6647; Ernst, Darin/0000-0002-9577-2809; White, Roscoe/0000-0002-4239-2685; Stotler, Daren/0000-0001-5521-8718 NR 75 TC 64 Z9 64 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 214 EP 226 DI 10.1016/S0022-3115(97)80041-4 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700017 ER PT J AU Koniges, AE Eder, DC Scott, HA Wurz, H Kappler, F AF Koniges, AE Eder, DC Scott, HA Wurz, H Kappler, F TI Side radiation damage from ablated vapor following an ITER-scale disruption SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE disruptions; plasma-wall interaction simulator; divertor plasma; physical erosion AB Disruptions and giant ELMs in ITER will deposit a large power load on the divertor plates. The amount of ablated material is important for plate lifetime and in determining the amount of plate material that escapes to the core region. The ablated vapor is effective at mitigating continued ablation via radiation shielding of the surface. Calculations in 1D have shown that the radiation, generated in the vapor following absorption of the energy from the core, is usually at least a factor of 10 more likely to leave the vapor in the direction of the core as compared to striking the divertor plate. However, the ablated vapor also emits in the direction of the side walls. We discuss the effect of this ancillary side radiation for two divertor designs. The 2D plasma profiles of temperature and density are modeled as a Gaussian fit to 1D data. These are used in a non-local thermodynamic equilibrium (NLTE) radiation transport code to give a detailed calculation of the side radiation. The radiation field is non-isotropic and couples regions with different densities and temperatures. We find that the side-wall radiation incident on different wall locations is comparable to the flux incident on the strike plate. Vapor shielding calculations are required to determine the amount of ablated material from these side-wall structures. Future 2D calculations of this type will aid in deciding the optimum divertor design for ITER. C1 FORSCHUNGSZENTRUM,KARLSRUHE,GERMANY. RP Koniges, AE (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 8 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 244 EP 249 DI 10.1016/S0022-3115(96)00508-9 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700019 ER PT J AU Wising, F Krasheninnikov, SI Sigmar, DJ Knoll, DA Rognlien, TD LaBombard, B Lipschultz, B McCracken, G AF Wising, F Krasheninnikov, SI Sigmar, DJ Knoll, DA Rognlien, TD LaBombard, B Lipschultz, B McCracken, G TI Simulation of plasma flux detachment in Alcator C-Mod and ITER SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE Alcator C-Mod; ITER; divertor plasma; fluid simulation; detached plasma AB Understanding the physics of divertor detachment is important since detached operation in ITER could reduce the target heat flux drastically, while aiding helium ash removal. In order to model detachment properly we have incorporated a parallel Navier-Stokes neutral model in UEDGE. In simulations of Alcator C-Mod we reproduce the partial detachment observed in experiments. A bifurcation to a MARFE has been found, similar to experiments. Volume recombination is a very important effect in removing the ion current to the target and we observe strong plasma flux detachment. Similar results have been found for ITER, with an order of magnitude decrease of the peak heat flux and a strong reduction of the target ion flux. Detachment has been induced with both neon and carbon. C1 MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Wising, F (reprint author), CHALMERS UNIV TECHNOL,INST ELECTROMAGNET FIELD THEORY & PLASMA PHYS,S-41296 GOTHENBURG,SWEDEN. RI Lipschultz, Bruce/J-7726-2012 OI Lipschultz, Bruce/0000-0001-5968-3684 NR 8 TC 6 Z9 6 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 273 EP 277 DI 10.1016/S0022-3115(97)80048-7 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700024 ER PT J AU Krasheninnikov, SI Pigarov, AY Soboleva, TK Sigmar, DJ AF Krasheninnikov, SI Pigarov, AY Soboleva, TK Sigmar, DJ TI Plasma-neutral gas interaction in a tokamak divertor: Effects of hydrogen molecules and plasma recombination SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE ALCATOR C-MoD; divertor plasma; 1D model; detached plasma; particle balance ID IONOSPHERES AB We investigate the influence of hydrogen molecules on plasma recombination using a collisional-radiative model for multispecies hydrogen plasmas and tokamak detached divertor parameters. The rate constant found for molecular activated recombination of a plasma can be as high as 2 x 10(-10) cm(3)/s, confirming our pervious estimates. We investigate the effects of hydrogen molecules and plasma recombination on self-consistent plasma-neutral gas interactions in the recycling region of a tokamak divertor. We treat the plasma flow in a fluid approximation retaining the effects of plasma recombination and employing a Knudsen neutral transport model for a 'gas box' divertor geometry. For the model of plasma-neutral interactions we employ we find: (a) molecular activated recombination is a dominant channel of divertor plasma recombination; and (b) plasma recombination is a key element leading to a decrease in the plasma flux onto the target and substantial plasma pressure drop which are the main features of detached divertor regimes. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. UNIV NACL AUTONOMA MEXICO,INST CIENCIAS NUCL,MEXICO CITY 04510,DF,MEXICO. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123098,RUSSIA. RP Krasheninnikov, SI (reprint author), MIT,CTR PLASMA FUS,167 ALBANY ST,CAMBRIDGE,MA 02139, USA. NR 26 TC 23 Z9 23 U1 0 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. PY 1997 VL 241 BP 283 EP 287 DI 10.1016/S0022-3115(97)80050-5 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700026 ER PT J AU Hassanein, A Belan, V Konkashbaev, I Nikandrov, L Safronov, V Zhitlukhin, A Litunovsky, V AF Hassanein, A Belan, V Konkashbaev, I Nikandrov, L Safronov, V Zhitlukhin, A Litunovsky, V TI Modeling and simulation of melt-layer erosion during a plasma disruption SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE plasma-wall interaction simulator; energy deposition; plasma disruptions; erosion and particle deposition; vaporization and melting AB Metallic plasma-facing components (PFCs) e.g. beryllium and tungsten, will be subjected to severe melting during plasma instabilities such as disruptions, edge-localized modes and high power excursions. Because of the greater thickness of the resulting melt layers relative to that of the surface vaporization, the potential loss of the developing melt-layer can significantly shorten PFC lifetime, severely contaminate the plasma and potentially prevent successful operation of the tokamak reactor. Mechanisms responsible for melt-layer loss during plasma instabilities are being modeled and evaluated. Of particular importance are hydrodynamic instabilities developed in the liquid layer due to various forces such as those from magnetic fields, plasma impact momentum, vapor recoil and surface tension. Another mechanism found to contribute to melt-layer splashing loss is volume bubble boiling, which can result from overheating of the liquid layer. To benchmark these models, several new experiments were designed and performed in different laboratory devices for this work; the results are examined and compared. Theoretical predictions (A*THERMAL-S and SPLASH codes) are generally in good agreement with the experimental results. The effect of in-reactor disruption conditions, which do not exist in simulation experiments, on melt-layer erosion is discussed. C1 TROITSK INST INNOVAT & FUS RES,TROITSK,RUSSIA. EFREMOV SCI RES INST,ST PETERSBURG,RUSSIA. RP Hassanein, A (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 15 TC 25 Z9 27 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 288 EP 293 DI 10.1016/S0022-3115(97)80051-7 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700027 ER PT J AU Brooks, JN Causey, R Federici, G Ruzic, DN AF Brooks, JN Causey, R Federici, G Ruzic, DN TI Assessment of erosion and surface tritium inventory issues for the ITER divertor SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE ITER; erosion and particle deposition; tritium inventory; low z wall material; high z wall material ID REDEPOSITION AB We analyzed sputtering erosion and tritium codeposition for the ITER vertical target divertor design using erosion and plasma codes (WBC/REDEP/DEGAS+) coupled to available materials data. Computations were made for a beryllium, carbon, and tungsten coated divertor plate, and for three edge plasma regimes. New data on tritium codeposition in beryllium was obtained with the tritium plasma experiment (TPE) facility. This shows codeposited H/Be ratios of the order of 10% for surface temperatures less than or equal to 300 degrees C, beryllium thereby being similar to carbon in this respect. Hydrocarbon transport calculations show significant loss (10-20%) of chemically sputtered carbon for detached conditions (T-e approximate to 1 eV at the divertor), compared to essentially no loss (100% redeposition) for higher temperature plasmas. Calculations also show a high, non-thermal, D-T molecular flux for detached conditions. Tritium codeposition rates for carbon are very high for detached conditions (similar to 20 g T/1000 s discharge), due to buildup of chemically sputtered carbon on relatively cold surfaces of the divertor cassette. Codeposition is lower (similar to 10X) for higher edge temperatures (similar to 8-30 eV) and is primarily due to divertor plate buildup of physically sputtered carbon. Peak net erosion rates for carbon are of the order of 30 cm/burn yr. Erosion and codeposition rates for beryllium are much lower than for carbon at detached conditions, but are similar to carbon fdr the higher temperatures. Both erosion and tritium codeposition are essentially nil for tungsten for the regimes studied. C1 SANDIA NATL LABS, LIVERMORE, CA 94550 USA. ITER JWS GARCHING COCTR, D-85748 GARCHING, GERMANY. UNIV ILLINOIS, URBANA, IL 61801 USA. RP ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 20 TC 37 Z9 38 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 294 EP 298 DI 10.1016/S0022-3115(97)80052-9 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700028 ER PT J AU Mahdavi, MA Staebler, GM Wood, RD Whyte, DG West, WP AF Mahdavi, MA Staebler, GM Wood, RD Whyte, DG West, WP TI Stability of a radiative mantle in ITER SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE tokamak; divertor; boundary plasma; SOL plasma; radiative cooling ID DIVERTOR AB We report results of a study to evaluate the efficacy of various impurities for heat dispersal by a radiative mantle and radiative divertor (including SOL). We have derived a stability criterion for the mantle radiation which favors low Z impurities and low ratios of edge to core thermal conductivities. Since on the other hand the relative strength of boundary line radiation to core bremsstrahlung favors high Z impurities, we find that for the ITER physics phase argon is the best gaseous impurity for mantle radiation. For the engineering phase of ITER, more detailed analysis is needed to select between krypton and argon. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. INRS ENERGIE & MAT,VARENNES,PQ,CANADA. RP Mahdavi, MA (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 12 TC 5 Z9 5 U1 1 U2 1 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. PY 1997 VL 241 BP 305 EP 309 DI 10.1016/S0022-3115(97)80054-2 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700030 ER PT J AU Ezumi, N Mori, S Ohno, N Takagi, M Takamura, S Suzuki, H Park, J AF Ezumi, N Mori, S Ohno, N Takagi, M Takamura, S Suzuki, H Park, J TI Density threshold for plasma detachment in gas target SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE divertor simulator; detached plasma ID DIVERTOR AB The simulated gas target divertor experiment has been performed to investigate the fundamental physics of plasma detachment in the linear plasma device, TPD-I, which has a high heat flux and high density plasma in steady state. The existence of a density threshold for plasma detachment was observed in our experiment. It is found that the electron-ion temperature relaxation process is a key to determine the density dependence of the plasma detachment. C1 NAGOYA UNIV, DEPT ELECT ENGN, GRAD SCH ENGN, NAGOYA, AICHI 46401, JAPAN. NATL INST FUS SCI, NAGOYA, AICHI 46401, JAPAN. PRINCETON UNIV, PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP NAGOYA UNIV, DEPT ENERGY ENGN & SCI, GRAD SCH ENGN, NAGOYA, AICHI 46401, JAPAN. NR 11 TC 14 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 349 EP 352 DI 10.1016/S0022-3115(97)80062-1 PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700038 ER PT J AU Catto, PJ Knoll, DA Krasheninnikov, SI Connor, JW AF Catto, PJ Knoll, DA Krasheninnikov, SI Connor, JW TI Divertor scaling laws for tokamaks SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE scaling law; divertor plasma; detached plasma; atomic physics AB The breakdown of two body scaling laws is illustrated by using the two dimensional plasma code UEDGE coupled to an advanced Navier-Stokes neutrals transport package to model attached and detached regimes in a simplified geometry. Two body similarity scalings are used as benchmarks for runs retaining non-two body modifications due to the effects of (i) multi-step processes altering ionization and radiation via the excited states of atomic hydrogen and (ii) three body recombination. Preliminary investigations indicate that two body scaling interpretations of experimental data fail due to (i) multi-step processes when a significant region of the plasma exceeds a plasma density of 10(19) m(-3) or (ii) three body recombination when there is a significant region in which the temperature is less than or equal to 1 eV while the plasma density is greater than or equal to 10(20) m(-3). These studies demonstrate that two body scaling arguments are often inappropriate in the divertor and the first results for alternate scalings are presented. C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. IV KURCHATOV ATOM ENERGY INST,MOSCOW 123182,RUSSIA. UKAEA EURATOM FUS ASSOC,ABINGDON OX14 3DB,OXON,ENGLAND. RP Catto, PJ (reprint author), MIT,CTR PLASMA FUS,MW16-236 167 ALBANY ST,CAMBRIDGE,MA 02139, USA. NR 15 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 369 EP 373 DI 10.1016/S0022-3115(97)80066-9 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700042 ER PT J AU Matthews, GF Allen, S Asakura, N Goetz, J Guo, H Kallenbach, A Lipschultz, B McCormick, K Stamp, M Samm, U Stangeby, PC Steuer, KH Taroni, A Unterberg, B West, P AF Matthews, GF Allen, S Asakura, N Goetz, J Guo, H Kallenbach, A Lipschultz, B McCormick, K Stamp, M Samm, U Stangeby, PC Steuer, KH Taroni, A Unterberg, B West, P TI Scaling radiative plasmas to ITER SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE impurity transport; density limit; scaling law; radiation energy sink; detached plasma ID IMPURITY AB In the radiative regime non-intrinsic impurities have been used to produce divertor power loads which would be considered acceptable when extrapolated to ITER. However, it has been a matter of concern that the maximum Z(eff) currently deemed acceptable for ITER has been exceeded by a large margin in radiative plasma experiments in large divertor machines such as JET, JT60-U, AUG and DIII-D. This paper points out that without a suitable scaling law, comparisons of Z(eff) between current machines and ITER are meaningless. Results from a multi-machine database are presented which show that there appears to be a remarkably simple and robust scaling which relates Z(eff) to line averaged density, total radiated power and main plasma surface area. A similar scaling has been found in code simulations with EDGE2D and DIVIMP. The consequences for ITER are discussed. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA GU, NAKA, IBARAKI 31101, JAPAN. MIT, CTR PLASMA FUS, CAMBRIDGE, MA 02139 USA. MAX PLANCK INST PLASMA PHYS, EURATOM ASSOC, D-85748 GARCHING, GERMANY. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST PLASMA PHYS, EURATOM ASSOC, D-5170 JULICH, GERMANY. UNIV TORONTO, INST AEROSP STUDIES, TORONTO, ON, CANADA. GEN ATOM CO, SAN DIEGO, CA 92186 USA. RP JET JOINT UNDERTAKING, ABINGDON OX14 3EA, OXON, ENGLAND. RI Lipschultz, Bruce/J-7726-2012; OI Lipschultz, Bruce/0000-0001-5968-3684; Unterberg, Bernhard/0000-0003-0866-957X NR 14 TC 45 Z9 45 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 450 EP 455 DI 10.1016/S0022-3115(97)80080-3 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700056 ER PT J AU Balboni, J Cohen, SA Munsat, T AF Balboni, J Cohen, SA Munsat, T TI Arc jets for divertor component testing SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE divertor plasma; divertor simulator; plasma-wall interactions simulator; fusion technology AB This paper describes the potential for are jet facilities to simulate the thermal and chemical environment inside a fusion-reactor power and particle exhaust section to provide the fusion materials science and plasma physics communities with data on their models and component designs. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Balboni, J (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 483 EP 488 DI 10.1016/S0022-3115(97)80085-2 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700061 ER PT J AU Park, J Bennett, TK Goeckner, MJ Cohen, SA AF Park, J Bennett, TK Goeckner, MJ Cohen, SA TI Plasma-neutral interaction in thermally collapsed plasma SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE divertor simulator; detached plasma ID DIVERTOR AB A systematic experimental study of the power, length, and gas pressure dependence of plasma density and temperature profiles in thermally collapsed magnetized helium plasmas has been performed on the Princeton divertor simulator apparatus. The recombination edge and recombination radiation from highly excited levels (to n = 12) have been identified. The importance of radiation and neutral particles to heat transport has been demonstrated. A region of stable plasma detachment has been found and is suggested as being suitable for divertor operational space. RP Park, J (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Goeckner, Matthew/A-8217-2009 NR 18 TC 0 Z9 0 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. PY 1997 VL 241 BP 489 EP 493 DI 10.1016/S0022-3115(97)80086-4 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700062 ER PT J AU Owen, LW Loarer, T Grosman, A Meslin, B Klepper, CC Mioduszewski, PK Uckan, T AF Owen, LW Loarer, T Grosman, A Meslin, B Klepper, CC Mioduszewski, PK Uckan, T TI Modeling of neutral pressure and pumping in the Tore Supra ergodic divertor and outboard pump limiter SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE Tore Supra; ergodic divertor; neutral confinement and transport; Monte Carlo simulation; 3D model AB Active control of the core plasma density and partial depletion of the wall particle content have been achieved in experiments on Tore Supra with the plasma leaning on either the ergodic divertor (ED) or the pump limiters. Measurements of neutral pressures in the ED and outboard pump limiter (OPL) are modeled with 1D parallel transport equations (continuity and momentum balance) for the SOL plasma coupled to 2D neutral particle transport simulations. SOL density and temperature profiles from reciprocating Langmuir probe measurements for a range of volume-averaged densities are renormalized, where necessary, to agree with Langmuir probe measurements in the OPL throat and constitute the upstream boundary conditions for the 1D calculations. Good agreement with measured pressures and exhaust rates are obtained for both the ED and OPL in scans that span a factor of 2-3 in volume-averaged density. The importance of a self-consistent treatment of the plasma and neutral particle transport in the neighborhood of the neutralizer plate is demonstrated, particularly in the stranger recycling regimes characteristic of densities at the high end of the scans. Plasma flow reversal near the plasma/plenum interface is predicted to occur at the higher densities due to the large local ionization source. Predictions of pressure buildup in the plenum behind the prototype vented neutralizer plate agree with experiment if it is assumed that both the tops and partially the sides of the needles comprising the plate are wetted by the plasma. A discharge in which the ED pumps are active is analyzed; the calculated pressure and exhaust rate agree with experiment. The core fueling rate is the same as without pumping, suggesting, as is seen in the experiment, a small density decay rate and significant wall particle depletion. C1 CEN CADARACHE,EURATOM ASSOC,CEA,F-18108 ST PAUL DURANCE,FRANCE. RP Owen, LW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 499 EP 504 DI 10.1016/S0022-3115(97)80088-8 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700064 ER PT J AU Harris, JH Hutter, T Hogan, JT Basiuk, V Beaumont, B Becoulet, A Bremond, S Carter, MD Goniche, M Goulding, RH Guilhem, D Haste, GR Hoffman, DJ Litaudon, X Nguyen, F AF Harris, JH Hutter, T Hogan, JT Basiuk, V Beaumont, B Becoulet, A Bremond, S Carter, MD Goniche, M Goulding, RH Guilhem, D Haste, GR Hoffman, DJ Litaudon, X Nguyen, F TI Plasma-surface interactions with ICRF antennas and lower hybrid grills in Tore Supra SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TORE SUPRA; boundary plasma; RF heating; sheath physics AB The edge plasma interactions of the actively cooled radio-frequency heating launchers in Tore Supra ion-cyclotron range of frequencies (ICRF) antennas and lower-hybrid (LH) grills are studied using infrared video imaging. On the two-strap ICRF antennas, operated in fast-wave electron heating or current drive mode, hot spots with temperatures of 500-900 degrees C are observed by the end of 2 s power pulses of 2 MW per antenna. The steady-state temperature distribution is determined principally by the relative phase of the two antenna straps: dipole (heating) phasing results in significantly less antenna heating than does 90 degrees (current drive) phasing. Transient heat fluxes of 1-20 MW/m(2) are measured on the lateral protection bumpers at ICRF turn-on; these fluxes are primarily a function of plasma and radio frequency (rf) control. The remarkable feature of the lower hybrid edge interaction is the production of beams of heat flux in front of the grills; these beams propagate along the helical magnetic field lines and can deliver fluxes of 5-10 MW/m(2) over areas of several cm(2) to plasma-facing components. Both the ICRF and LH phenomena appear to result from the acceleration of particles by the near fields of the launchers. Modeling of the heat flux deposition on components and its relation to sputtering processes is presented. C1 CTR ETUD CADARACHE,EURATOM ASSOC,CFA FUS,ST PAUL DURANCE,FRANCE. RP Harris, JH (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 8 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 511 EP 516 DI 10.1016/S0022-3115(97)80090-6 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700066 ER PT J AU Nygren, R Lutz, T Walsh, D Martin, G Chatelier, M Loarer, T Guilhem, D AF Nygren, R Lutz, T Walsh, D Martin, G Chatelier, M Loarer, T Guilhem, D TI Runaway electron damage to the Tore Supra phase III outboard pump limiter SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE Tore Supra; limiter; boundary plasma; energy deposition; disruptions ID DISRUPTIONS; JET AB Operation of the Phase III outboard pump limiter (OPL) in Tore Supra in 1994 was terminated prematurely when runaway electrons generated during the current decay following a disruption pierced a leading edge tube on the electron side and caused a water leak. The location, about 20 mm outside the last closed flux surface during normal operation, and the infrared (IR) images of the limiter indicate that the runaways moved in large outward steps, i.e., tens of millimeters, in one toroidal revolution. For plasma (runaway) currents in the range of 150 to 250 kA, the drift orbits open to the outside. Basic trajectory computations suggest that such motion is possible under the conditions present for this experiment. Activation measurements made on sections of the tube to indicate the area of local damage are presented here. An understanding of this event may provide important guidance regarding potential damage from runaways in future tokamaks. C1 CTR CADARACHE,F-13108 ST PAUL DURANCE,FRANCE. RP Nygren, R (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 TC 33 Z9 33 U1 0 U2 1 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. PY 1997 VL 241 BP 522 EP 527 DI 10.1016/S0022-3115(96)00557-0 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700068 ER PT J AU Guilhem, D Hogan, J VanHoutte, D Lipa, M Loarer, T Chappuis, P Hoang, T Schlosser, J Mitteau, R AF Guilhem, D Hogan, J VanHoutte, D Lipa, M Loarer, T Chappuis, P Hoang, T Schlosser, J Mitteau, R TI Long pulse operation with actively cooled limiters SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE Tore Supra; boundary plasma; energy deposition; limiter; sheath physics AB We present here the major results obtained with actively cooled plasma facing components during long pulse operation (plasma duration > 3 x surface temperature time constant = steady-state). Shots up to 120 s have been achieved in Tore Supra when the plasma was leaning on the large inner toroidal actively cooled limiter with a moderate deposited power density heat flux (up to 0.3 MW/m(2)). For larger power density heat flux up to 4.5 MW/m(2) (design value), modular limiters have been used. A prerequisite for any actively cooled limiter is the absence of any cooling defect (crack II to the surface in the tile or non-correct bonding). If a defect is present it leads to a super-brilliance event (with its corresponding local power heat flux increase) which propagates. This deleterious effect is unfortunately a runaway effect. C1 OAK RIDGE NATL LAB, DIV FUS ENERGY, OAK RIDGE, TN USA. RP Guilhem, D (reprint author), CEN CADARACHE, CEA, EURATOM ASSOC, F-13108 ST PAUL LES DURANCE, FRANCE. NR 9 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 542 EP 547 DI 10.1016/S0022-3115(97)80096-7 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700072 ER PT J AU Schaffer, MJ Wade, MR Maingi, R MonierGarbet, P West, WP Whyte, DG Wood, RD Mahdavi, MA AF Schaffer, MJ Wade, MR Maingi, R MonierGarbet, P West, WP Whyte, DG Wood, RD Mahdavi, MA TI Direct measurement of divertor exhaust neon enrichment in DIII-D SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE impurity transport; divertor exhaust; plasma flow; wall particle retention; DIII-D ID IMPURITY AB We report first direct measurements of divertor exhaust gas impurity enrichment, eta(exh) = (exhaust impurity concentration) divided by (core impurity concentration), for both unpumped and D-2 puff-with-divertor-pump conditions. The experiment was performed with neutral beam heated, ELMing H-mode, single-null diverted deuterium plasmas with matched core and exhaust parameters in the DIII-D tokamak. Neon gas impurity was puffed into the divertor. Neon density was measured in the exhaust by a specially modified Penning gauge and in the core by absolute charge exchange recombination spectroscopy. Neon particle accounting indicates that much of the puffed neon entered a temporary unmeasured reservoir, inferred to be the graphite divertor target, which makes direct measurements necessary to calculate divertor enrichments. D-2 puff into the SOL with pumping increased eta(exh) threefold over either unpumped conditions or D-2 puff directly into the divertor with pumping. These results show that SOL flow plays an important role in divertor exhaust impurity enrichment. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. EURATOM,CEA FUS CONTROLEE,CADRACHE,FRANCE. INRS ENERGIE & MAT,VARENNES,PQ,CANADA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Schaffer, MJ (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 11 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 585 EP 589 DI 10.1016/S0022-3115(97)80104-3 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700080 ER PT J AU Rognlien, TD Crotinger, JA Porter, GD Smith, GR Kellman, AG Taylor, PL AF Rognlien, TD Crotinger, JA Porter, GD Smith, GR Kellman, AG Taylor, PL TI Simulation of the scrape-off layer plasma during a disruption SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE SOL plasma; divertor plasma; DIII-D; fluid simulation; disruptions ID TOKAMAK AB The evolution of the scrape-off layer (SOL) during a disruption in the DIII-D tokamak is modeled using the 2-D UEDGE transport code. The focus is on the thermal quench phase when most of the energy content of the discharge is rapidly transported across the magnetic separatrix where it then flows to material surfaces or is radiated. Comparisons between the simulation and an experiment on the DIII-D tokamak are made with the heat flux to the divertor plate, and temperature and density profiles at the SOL midplane. The temporal response of the heat flux to the divertor plate is calculated. The sensitivity of the solution to assumptions of electron heat-flux models and impurity radiation is investigated. C1 GEN ATOM CO,SAN DIEGO,CA 92186. RP Rognlien, TD (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 590 EP 594 DI 10.1016/S0022-3115(97)80105-5 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700081 ER PT J AU Allen, SL Hill, DN Carlstrom, TN Nilson, DG Stockdale, R Hsieh, CL Petrie, TW Leonard, AW Ryutov, D Porter, GD Maingi, R Wade, MR Cohen, R Nevins, W Fenstermacher, ME Wood, RD Lasnier, CJ West, WP Brown, MD AF Allen, SL Hill, DN Carlstrom, TN Nilson, DG Stockdale, R Hsieh, CL Petrie, TW Leonard, AW Ryutov, D Porter, GD Maingi, R Wade, MR Cohen, R Nevins, W Fenstermacher, ME Wood, RD Lasnier, CJ West, WP Brown, MD TI First measurements of electron temperature and density with divertor Thomson scattering in radiative divertor discharges on DIII-D SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; plasma temperature diagnostic; detached plasma; poloidal divertor; divertor plasma ID PROBE AB We have obtained the first measurements of n(e) and T-e in the DIII-D divertor region with a multi-pulse (20 Hz) divertor Thomson scattering (DTS) system. Eight measurement locations are distributed vertically up to 21 cm above the divertor plate. Two-dimensional distributions have been obtained by sweeping the divertor plasma across the DTS measurement location. Several operating modes have been studied, including Ohmic, L-mode, ELMing K-mode, and radiative divertor operation with puffing of D-2 and impurities. Mapping of the data to either the (L-pol, phi) or (R, Z) planes with the EFIT equilibrium is used to analyze the 2D profiles. We find that in ELMing H-mode: n(e), T-e, and P-e are relatively constant along field lines from the X-point to the divertor plate, especially near the separahix field line. With D, puffing, the DTS profiles indicate that T-e in a large part of divertor region below the X-point is dramatically reduced from similar to 30-40 eV in ELMing H-mode to 1-2 eV. This results in a fairly uniform low-T-e divertor, with an increased electron density in the range of 2 to 4 x 10(20) m(-3). Detailed comparisons of the spatial profiles of n(e), T-e, and electron pressure P-e, are presented for several operating modes. In addition, these data are compared with initial calculations from the UEDGE fluid code. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Allen, SL (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 14 TC 20 Z9 20 U1 3 U2 7 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. PY 1997 VL 241 BP 595 EP 601 DI 10.1016/S0022-3115(97)80106-7 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700082 ER PT J AU Baker, DR Maingi, R Owen, LW Porter, GD Jackson, GL AF Baker, DR Maingi, R Owen, LW Porter, GD Jackson, GL TI Modeling of the recycling particle flux and electron particle transport in the DIII-D Tokamak SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; Tokamak; particle fuelling; particle transport and confinement AB One of the most difficult aspects of performing an equilibrium particle transport analysis in a diverted tokamak is the determination of the particle flux which enters the plasma after recycling from the divertor plasma, the divertor target plates or the vessel wall. An approach which has been utilized in the past is to model the edge, scrape-off layer (SOL) and divertor plasma to match measured plasma parameters and then use a neutral transport code to obtain an edge recycling flux while trying to match the measured divertor D-alpha emissivity. previous simulations were constrained by electron density (n(e)) and temperature (T-e), ion temperature (T-i) data at the outer midplane, divertor heat flux from infrared television cameras and n(e), T-e and particle flux at the target from fixed Langmuir probes, along with the divertor D-alpha emissivity. In this paper, we present results of core fueling calculations from the 2D modeling for ELM-free discharges, constrained by data from the new divertor diagnostics. In addition, we present a simple technique for estimating the recycling flux just after the L-H transition and demonstrate how this technique is supported by the detailed modeling. We will show the effect which inaccuracies in the recycling flux have on the calculated particle flux in the plasma core. For some specific density profiles, it is possible to separate the convective flux from the conductive flux. The diffusion coefficients obtained show a sharp decrease near a normalized radius of 0.9 indicating the presence of a transport barrier. C1 OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. OAK RIDGE NATL LAB,OAK RIDGE,TN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Baker, DR (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 9 TC 4 Z9 4 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. PY 1997 VL 241 BP 602 EP 605 DI 10.1016/S0022-3115(96)00572-7 PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700083 ER PT J AU Evans, TE Kellman, AG Humphreys, DA Schaffer, MJ Taylor, PL Whyte, DG Jernigan, TC Hyatt, AW Lee, RL AF Evans, TE Kellman, AG Humphreys, DA Schaffer, MJ Taylor, PL Whyte, DG Jernigan, TC Hyatt, AW Lee, RL TI Measurements of non-axisymmetric halo currents with and without 'killer' pellets during disruptions in the DIII-D tokamak SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; tokamak; disruptions; electric potential and current AB Non-axisymmetric halo currents are always observed during disruptive instabilities in DIII-D. These halo currents appear to have a helical structure which rotates toroidally in the electron current drift direction with frequencies ranging between 200 and 400 Hz prior to and during the initial plasma current quench phase of the disruption. Sometimes the halo current rotation locks at random toroidal phase angles during the plasma current quench. The total halo current rarely exceeds 30% of the pre-disruptive plasma current (I-po) and peak-to-average toroidal peaking factors (TPF) are usually less than 3 during most disruptions. Neon 'killer' pellets have proven very effective in reducing both the total halo current amplitude, often by as much as 50%, and the TPF from similar to 3 to similar to 1.2. C1 INRS ENERGIE & MAT,VARENNES,PQ,CANADA. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Evans, TE (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 10 TC 38 Z9 38 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 606 EP 611 DI 10.1016/S0022-3115(96)00573-9 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700084 ER PT J AU Hogan, JT Maingi, R Mioduszewski, PK Hutter, T Klepper, CC Wade, MR AF Hogan, JT Maingi, R Mioduszewski, PK Hutter, T Klepper, CC Wade, MR TI Core/divertor/wall particle dynamics in the DIII-D tokamak SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE tokamak; DIII-D; active pumping; wall pumping ID TORE SUPRA; RELEASE AB A wall model developed for the analysis of Tore Supra wall loading experiments has been applied to an experiment on DIII-D which demonstrated a substantial capacity for retention of deuterium gas in an all-graphite environment, and which showed the efficacy of the pumped divertor to deplete a gas-loaded wall. The Tore Supra model has been extended and applied to evaluate the particle exchange mechanisms between the core, divertor, and wall. Data-constrained plasma modeling is done for the discharges of the load/unload sequence. The poloidal distribution of the charge exchange flux profile to the divertor and outer wall is determined from the Eirene neutral transport code, to estimate the effective working areas for particle exchange and saturation. The deposition and saturation of the hydrogenic efflux in the aC:H layer and graphite is modeled with the 1-D WDIFFUSE code, applied to the regions fuelled by charge exchange flux to predict the instantaneous local wall recycling coefficient. A mechanism is proposed to explain the previous paradoxical result that exhaust quickly (similar to 3 s) balances the only particle input, due to beam fueling, whereas a long term net wall depletion is observed over similar to 10 discharges. The saturation and depletion of wall layers fuelled by energetic charge exchange particles provides such a mechanism. C1 CE CADARACHE,CEA,EURATOM ASSOC,DRFC,F-13108 ST PAUL DURANCE,FRANCE. RP Hogan, JT (reprint author), OAK RIDGE NATL LAB,DIV FUS ENERGY,POB 2008,OAK RIDGE,TN 37831, USA. NR 16 TC 6 Z9 6 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 612 EP 617 DI 10.1016/S0022-3115(97)80109-2 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700085 ER PT J AU Jackson, GL Staebler, GM Allen, SL Brooks, NH Evans, TE Ferron, JR Leonard, AW Maingi, R Petrie, TW Schaffer, MJ Wood, RD West, WP Whyte, DG AF Jackson, GL Staebler, GM Allen, SL Brooks, NH Evans, TE Ferron, JR Leonard, AW Maingi, R Petrie, TW Schaffer, MJ Wood, RD West, WP Whyte, DG TI Impurity feedback control for enhanced divertor and edge radiation in DIII-D discharges SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; poloidal divertor; radiation energy sink ID H-MODE DISCHARGES; ASDEX UPGRADE; TOKAMAK AB Radiated power fractions above 90% have been achieved in DIII-D using impurity feedback control. Heat flux reductions up to a factor of 6 and confinement enhancements of 1.6 x ITER-89P L-mode scaling have been obtained with a radiated power fraction above 90%. When the outer separatrix strike point was positioned for pumping with the DIII-D cryopump, ELMing H-mode (Type HI ELMs) was triggered with neon feedback injection in conjunction with a constant deuterium gas puff rate. Changes in the ELM frequency, energy confinement and central neon concentrations as a function of radiated power are presented. Observations of detached discharges with H-mode confinement similar to the ASDEX-U CDH-mode are also discussed. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. INRS,VARENNES,PQ,CANADA. RP Jackson, GL (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 10 TC 12 Z9 12 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. PY 1997 VL 241 BP 618 EP 622 DI 10.1016/S0022-3115(96)00575-2 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700086 ER PT J AU Leonard, AW Suttrop, W Osborne, TH Evans, TE Hill, DN Herrmann, A Lasnier, CJ Thomas, DN Watkins, JG West, WP Weinlich, M Zohm, H AF Leonard, AW Suttrop, W Osborne, TH Evans, TE Hill, DN Herrmann, A Lasnier, CJ Thomas, DN Watkins, JG West, WP Weinlich, M Zohm, H TI Divertor heat and particle flux due to ELMs in DIII-D and ASDEX-upgrade SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; ASDEX-upgrade; edge-localized-modes; energy deposition AB We characterize the divertor target plate heat and particle fluxes that occur due to edge localized modes (ELMs) during H-mode in DIII-D and ASDEX-upgrade. During steady-state ELMing H-mode the fraction of main plasma stored energy lost with each ELM varies from 6% to 2% as input power increases above the W-mode power threshold. The ELM energy is deposited near the strikepoints on the divertor target plates in a fast time scale of less than or equal to 1 ms. The spatial profile of the ELM heat pulse is flatter and broader, up to about a factor of 2, than that of the heat flux between ELMs. On ASDEX-upgrade the inboard strike-point receives the greatest fraction, greater than or equal to 75%, of ELM divertor heat flux, while on DIII-D the in/out split is nearly equal. The toroidal asymmetry of the heat pulse has produced a peaking factor on DIII-D of no more than 1.5. The particle flux, as measured by Langmuir probes, has also been found to be localized near the divertor strike-points. The increased particle flux during ELMs is a significant fraction of the total time-integrated divertor plate particle flux. C1 MAX PLANCK INST PLASMA PHYS,GARCHING,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Leonard, AW (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 11 TC 36 Z9 36 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. PY 1997 VL 241 BP 628 EP 632 DI 10.1016/S0022-3115(97)80112-2 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700088 ER PT J AU Moyer, RA Cuthbertson, JW Evans, TE Porter, GD Watkins, JG AF Moyer, RA Cuthbertson, JW Evans, TE Porter, GD Watkins, JG TI The role of turbulent transport in DIII-D edge and divertor plasmas SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; turbulence; particle transport and confinement; detached plasma ID TOKAMAK EDGE; MODE AB Reciprocating Langmuir probes have been used to investigate turbulent transport in DIII-D edge and divertor plasmas. The turbulent particle flux on the outboard midplane exceeds the particle flux from the 2-D local transport code UEDGE by a large enough factor to allow for substantial poloidal asymmetry in the turbulent transport. Changes in the turbulent effective diffusion coefficient in the edge agree qualitatively with particle confinement changes. Potential fluctuations (, in the divertor in attached ELM-free conditions are comparable to on the outboard midplane. ELMs transiently enhance to 2 in attached plasmas and to 2-20 in detached plasmas. Such strong turbulence (e<(phi)over tilde T-f(e)> > 1) in the divertor may affect the mean energy of ions striking the divertor target plates by altering the sheath potential and therefore affect target plate erosion rates. C1 GEN ATOM CO,SAN DIEGO,CA 92185. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Moyer, RA (reprint author), UNIV CALIF SAN DIEGO,FUS ENERGY RES PROGRAM,SAN DIEGO,CA 92093, USA. NR 22 TC 37 Z9 37 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 633 EP 638 DI 10.1016/S0022-3115(97)80113-4 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700089 ER PT J AU Petrie, TW Allen, SL Carlstrom, TN Hill, DN Maingi, R Nilson, D Brown, M Buchenauer, DA Evans, TE Fenstermacher, ME Jong, RA Lasnier, CJ Leonard, AW Mahdavi, MA Porter, GD Wade, MR West, WP AF Petrie, TW Allen, SL Carlstrom, TN Hill, DN Maingi, R Nilson, D Brown, M Buchenauer, DA Evans, TE Fenstermacher, ME Jong, RA Lasnier, CJ Leonard, AW Mahdavi, MA Porter, GD Wade, MR West, WP TI Investigation of electron parallel pressure balance in the scrapeoff layer of deuterium-based radiative divertor discharges in DIII-D SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; SOL plasma; divertor plasma; momentum sink; detached plasma ID EDGE PLASMA; TOKAMAKS AB Electron density, temperature and parallel pressure measurements at several locations along field lines connecting the midplane scrapeoff layer (SOL) with the outer divertor are presented for both attached and partially-detached divertor cases: I-p = 1.4 MA, q(95) = 4.2 and P-input similar to 6.7 MW under ELMing H-mode conditions. At the onset of the Partially Detached Divertor (PDD), a high density, low temperature plasma forms in the divertor SOL (divertor MARFE). The electron pressure drops by a factor of 2 between the midplane separatrix and the X-point and then an additional similar to 3-5 times between the X-point and the outboard separatrix strike point. These results are in contrast to the attached (non-PDD) case, where electron pressure in the SOL is reduced by, at most, a factor of two between the midplane and the divertor target. Divertor MARFEs generally have only marginal adverse impact on important H-mode characteristics, such as confinement time. In fact, PDD discharges at low input power (i.e., approximately twice the L-H-mode threshold power) maintain good H-mode characteristics until a high density, low temperature plasma abruptly forms inside the separatrix near the X-point (X-point MARFE). Concurrent with the appearance of this X-point MARFE is a degradation in both energy confinement and the plasma fueling rate and an increase in the carbon impurity concentration inside the core plasma. The formation of the X-point MARFE is consistent with a thermal instability resulting from the temperature dependence of the carbon radiative cooling rate in the range similar to 7-30 eV. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Petrie, TW (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 20 TC 23 Z9 23 U1 0 U2 1 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. PY 1997 VL 241 BP 639 EP 644 DI 10.1016/S0022-3115(97)80114-6 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700090 ER PT J AU Watkins, JG Moyer, RA Cuthbertson, JW Buchenauer, DA Carlstrom, TN Hill, DN Ulrickson, M AF Watkins, JG Moyer, RA Cuthbertson, JW Buchenauer, DA Carlstrom, TN Hill, DN Ulrickson, M TI Reciprocating and fixed probe measurements of density and temperature in the DIII-D divertor SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; divertor plasma; edge localized modes; Langmuir probe ID TOKAMAKS AB This paper describes divertor density and temperature measurements using both a new reciprocating Langmuir probe (XPT-RCP) which plunges vertically above the divertor floor up to the X-point height and swept, single, Langmuir probes fixed horizontally across the divertor floor. These types of measurements are important for testing models of the SOL and divertor which then are used to determine engineering design criteria for plasma facing components in reactor size tokamaks. The 6 mm diameter fixed single probes (19 domed and 2 flat at radially equivalent locations) are incorporated into the lower divertor floor at 19 radial locations and swept at 250 Hz. These probes are critical for determining plasma detachment from the floor during operation with high density, highly radiating diverters. By sweeping the divertor strike point across the fixed probes, different regions of the target plate incident flux profile can be sampled and a high resolution spatial profile can be obtained from each probe tip as the strike point moves past. The X-point reciprocating probe (XPT-RCP) provides n(e) and T-e profiles with high spatial (2 mm) and temporal (0.5 ms) resolution from the target plate to the X-point along a single vertical chord at the same radial location as a fixed probe tip at a different azimuthal location. The probe n(e) and T-e are compared to the divertor Thomson scattering (DTS) n(e) and T-e (eight vertical points at 20 Hz, R-Thomson = RX-point-rcp). Recent observations have also shown divertor densities from 3 x 10(19) to 4 x 10(20) m(-3) near the target plate with the highest densities observed with D-2 gas puffing. Electron temperature is typically of the order of 15-25 eV at the target rising to about 70 eV near the X-point. Lower temperature, higher density plasmas are observed along the inner leg. Generally good agreement among the XPT-RCP, the fixed floor probes, and the DTS is observed. Differences between these diagnostic measurements will also be discussed with respect to different operating regimes and conditions. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92103. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Watkins, JG (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 10 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 645 EP 649 DI 10.1016/S0022-3115(96)00580-6 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700091 ER PT J AU Bastasz, R Wampler, WR Whaley, JA Whyte, DG Parks, PB Brooks, NH West, WP Wong, CPC AF Bastasz, R Wampler, WR Whaley, JA Whyte, DG Parks, PB Brooks, NH West, WP Wong, CPC TI Characterization of energetic deuterium striking the divertor of the DIII-D tokamak SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; divertor plasma; energy deposition; neutral particle diagnostic; disruptions ID SILICON AB Measurements of the deuterium particle flux and energy to the divertor of the DIII-D tokamak during a series of plasmas that terminated in disruptions have been made using a silicon collector probe installed on the DiMES (divertor materials exposure system) mechanism; During the steady state portion of each discharge, the probe was located in the private flux region, but immediately before disrupting the plasma, by injecting either Ar or Dp gas, the strike point of the outer divertor leg was positioned over the probe. Comparison of the amount of retained D in the probe for the two types of disruptions indicates that much of the trapped D could have resulted from exposure in the private flux zone prior to the disruption. Measurements of the depth distribution of the trapped D in the Si imply that the incident ion energy was approximately 100 eV at normal incidence arid decreased slightly at oblique angles. The measurements give an upper bound to the energy of deuterons striking the divertor floor in the vicinity of the strikepoint during disruptions. C1 INRS ENERGIE & MAT,VARENNES,PQ,CANADA. GEN ATOM CO,SAN DIEGO,CA 92138. RP Bastasz, R (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 10 TC 4 Z9 4 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. PY 1997 VL 241 BP 650 EP 654 DI 10.1016/S0022-3115(97)80116-X PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700092 ER PT J AU Jackson, GL Lazarus, EA Navratil, GA Bastasz, R Brooks, NH Garnier, DT Holtrop, KL Phillips, JC Marmar, ES Taylor, TS Thomas, DM Wampler, WR Whyte, DG West, WP AF Jackson, GL Lazarus, EA Navratil, GA Bastasz, R Brooks, NH Garnier, DT Holtrop, KL Phillips, JC Marmar, ES Taylor, TS Thomas, DM Wampler, WR Whyte, DG West, WP TI Enhanced performance discharges in the DIII-D tokamak with lithium wall conditioning SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE DIII-D; wall conditioning; lithium; negative central shear; pellet injection AB Lithium wall conditioning has been used in a recent campaign evaluating high performance negative central shear (NCS) discharges. During this campaign, the highest values of stored energy (4.4 MJ), neutron rate (2.4 x 10(16)/s), and nT(i) tau (7 x 10(20) m(-3) keV s) achieved to date in DIII-D were obtained. High performance NCS discharges was achieved prior to beginning Lithium conditioning, but it is clear that shot reproducibility and performance were improved by lithium conditioning. Central and edge oxygen concentrations were reduced, after lithium conditioning. Lithium conditioning, consisting of up to four pellets injected at the end of the preceding discharge, allowed the duration of the usual inter-shot helium glow discharge to be reduced and reproducible high auxiliary power discharges, P-NBI less than or equal to 22 MW, were obtained with plasma currents up to 2.4 Mg. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. COLUMBIA UNIV,NEW YORK,NY. SANDIA NATL LABS,LIVERMORE,CA. MIT,CAMBRIDGE,MA 02139. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. INRS ENERGIE & MAT,VARENNES,PQ,CANADA. RP Jackson, GL (reprint author), GEN ATOM CO,BOX 85608,SAN DIEGO,CA 92186, USA. OI Garnier, Darren/0000-0002-0718-1073 NR 14 TC 24 Z9 25 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 655 EP 659 DI 10.1016/S0022-3115(97)80117-1 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700093 ER PT J AU Whyte, DG Brooks, JN Wong, CPC West, WP Bastasz, R Wampler, WR Rubenstein, J AF Whyte, DG Brooks, JN Wong, CPC West, WP Bastasz, R Wampler, WR Rubenstein, J TI DiMES divertor erosion experiments on DIII-D SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE divertor plasma; erosion particle deposition; plasma facing components AB Thin metal films (similar to 100 nm thick) of Be, W, V and Mo, were deposited on a Si depth-marked graphite sample and exposed to the steady-state outer strike point on DIII-D in order to measure their respective erosion rates. Gross erosion rates and redeposition lengths are found to decrease with the atomic number of the metallic species, as expected. The maximum net erosion rate for carbon, which occurs near the separatrix, increased from 4 to 16 nm/s when the incident heat flux was increased from 0.7 to 2 MW/m(2). Comparisons of the measured carbon erosion with REDEP code calculations show good agreement for both the absolute net erosion rate and its spatial variation. Visible spectroscopic measurements of singly ionized Be (BeII 4674 Angstrom) have determined that the erosion process reaches steady-state during the exposure. C1 INRS ENERGIE & MAT,VARENNES,PQ,CANADA. ARGONNE NATL LAB,ARGONNE,IL 60439. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV ILLINOIS,URBANA,IL 61801. RP Whyte, DG (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 9 TC 35 Z9 35 U1 0 U2 1 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. PY 1997 VL 241 BP 660 EP 665 DI 10.1016/S0022-3115(97)80118-3 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700094 ER PT J AU Maingi, R Terreault, B Haas, G Jackson, GL Zuzak, W Mioduszewski, PK Mahdavi, MA Wade, MR Chiu, S Schaffer, MJ Hogan, JT Klepper, CC AF Maingi, R Terreault, B Haas, G Jackson, GL Zuzak, W Mioduszewski, PK Mahdavi, MA Wade, MR Chiu, S Schaffer, MJ Hogan, JT Klepper, CC TI Comparison of wall/divertor deuterium retention and plasma fueling requirements on the DIII-D, TdeV and ASDEX upgrade tokamaks SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE particle fueling; particle balance; wall pumping; wall particle retention ID GAS AB We present a comparison of the wall deuterium retention and plasma fueling requirements of three diverted tokamaks, DIII-D, TdeV and ASDEX Upgrade, with different fractions of graphite coverage of stainless steel or Inconel outer walls and different healing modes. Data from particle balance experiments on each tokamak demonstrate well-defined differences in wall retention of deuterium gas, even though all three tokamaks have complete graphite coverage of divertor components and all three are routinely boronized. This paper compares the evolution of the change in wall loading and net fueling efficiency for gas during dedicated experiments without helium glow discharge cleaning on the DIII-D and TdeV tokamaks. On the DIII-D tokamak, it was demonstrated that the wall loading could be increased by > 1250 Torr 1 (equivalent to 150 x plasma particle content) plasma inventories resulting in an increase in fueling efficiency from 0.08 to 0.25, whereas the wall loading on the TdeV tokamak could only be increased by < 35 Torr 1 (equivalent to 50 x plasma particle content) plasma inventories at a maximum fueling efficiency similar to 1. Data from the ASDEX Upgrade tokamak suggests qualitative behavior of wall retention and fueling efficiency similar to DIII-D. C1 GEN ATOM CO,SAN DIEGO,CA 92186. INRS,VANDOEUVRE NANCY,FRANCE. MAX PLANCK INST PLASMA PHYS,GARCHING,GERMANY. CTR CANADIEN FUS MAGNET,VARENNES,PQ,CANADA. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Maingi, R (reprint author), OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37830, USA. NR 15 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 672 EP 677 DI 10.1016/S0022-3115(96)00585-5 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700096 ER PT J AU Scholz, T Boedo, J Bolt, H Duwe, R Finken, KH Gray, D Hassanein, A AF Scholz, T Boedo, J Bolt, H Duwe, R Finken, KH Gray, D Hassanein, A TI Exposure of CFC-materials to high transient heat loads in the TEXTOR tokamak SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TEXTOR; disruptions; material probe; carbon fibre composites ID PLASMA-FACING MATERIALS; SIMULATION; DISRUPTION; ITER AB Transient high heat flux events like ELMs, vertical displacement events and disruptions can cause the thermal ablation of plasma facing material. Until now experimental work in this field had been carried out by exposing material specimens to heat loads by electron or laser beam or by tests in pulsed plasma accelerators. In the present work carbon specimens were directly exposed to intense plasma fluxes in the TEXTOR tokamak. The exposure was performed with a fast probe allowing the insertion of the material over a distance of 9 cm into the edge plasma for a duration of 80 ms. The results of in-situ diagnostic measurements and of the post-experiment examination of the specimens rue compared with a reference experiment by electron beam and with numerical analyses. Results indicated that the heat flux to the probe surfaces and the probe erosion is much lower than expected. C1 FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, EURATOM ASSOC, D-52425 JULICH, GERMANY. UNIV CALIF SAN DIEGO, FUS ENERGY PROGRAM, SAN DIEGO, CA 92093 USA. ARGONNE NATL LAB, FUS POWER PROGRAM, ARGONNE, IL 60439 USA. NR 8 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 848 EP 852 DI 10.1016/S0022-3115(97)80152-3 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700128 ER PT J AU Pitts, RA Nieswand, C Weisen, H Anton, M Behn, R Chavan, RF Dutch, MJ Duval, BP Franke, S Hofmann, F Joye, B Lister, JB Llobet, X Martin, Y Moret, JM Petrzilka, J Pietrzyk, ZA Piffl, V Reinke, P Rensink, ME Smith, GR vanToledo, W AF Pitts, RA Nieswand, C Weisen, H Anton, M Behn, R Chavan, RF Dutch, MJ Duval, BP Franke, S Hofmann, F Joye, B Lister, JB Llobet, X Martin, Y Moret, JM Petrzilka, J Pietrzyk, ZA Piffl, V Reinke, P Rensink, ME Smith, GR vanToledo, W TI Divertor target profiles and recycling studies in TCV single null lower standard discharges SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TCV; particle fuelling; wall conditioning; divertor plasma; Langmuir probe ID PLASMAS AB A 'standard', single null lower diverted discharge has been developed to enable continuous monitoring of the first wall conditions and to characterise the effectiveness and influence of wall conditioning in the TCV tokamak. Measurements over a period encompassing nearly 2000 ohmic discharges of varying configuration and input power show the global confinement time and main plasma impurity concentrations to be good general indicators of the first wall condition, whilst divertor target profiles demonstrate strikingly the short term beneficial effects of He glow. Good agreement, consistent with a reduction in recycling at the plates is found between the predictions of the fluid code UEDGE and the observed outer divertor profiles of T-e and n(e) before and after He glow. C1 ACAD SCI CZECH REPUBL, INST PLASMA PHYS, PRAGUE, CZECH REPUBLIC. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP Pitts, RA (reprint author), ECOLE POLYTECH FED LAUSANNE, EURATOM ASSOC, CTR RECH PHYS PLASMAS, PHB ECUBLENS, BATIMENT PPB, CH-1015 LAUSANNE, SWITZERLAND. NR 6 TC 5 Z9 5 U1 0 U2 1 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. PY 1997 VL 241 BP 867 EP 872 DI 10.1016/S0022-3115(97)80156-0 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700132 ER PT J AU Skinner, CH Kamperschroer, J Mueller, D Nagy, A Stotler, DP AF Skinner, CH Kamperschroer, J Mueller, D Nagy, A Stotler, DP TI Measurements of tritium recycling and isotope exchange in TFTR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TFTR; tritium inventory and economy; line emission diagnostic; Monte Carlo simulation; wall particle retention ID FUSION TEST REACTOR; 1ST WALL; TOKAMAK; DEUTERIUM; HYDROGEN; LIMITERS; JET AB Tritium Balmer-alpha (T-alpha) emission, along with H-alpha and D-alpha is observed in the current D-T experimental campaign in TFTR. The data are a measure of the fueling of the plasma by tritium accumulated in the TFTR limiter and the spectral profile maps neutral hydrogenic velocities. T-alpha is relatively slow to appear in tritium neutral beam heated discharges, (T-alpha/(H-alpha + D-alpha + T-alpha) = 11% after 8 tritium-only neutral beam discharges). In contrast, the T-alpha fraction in a sequence of six discharges fueled with tritium puffs, increased to 44%. Larger transient increases (up to 75% T-alpha) were observed during subsequent tritium gas puffs. Analysis of the Doppler broadened spectral profiles revealed overall agreement with the dissociation, charge exchange, sputtering and reflection velocities predicted by the neutral Monte-Carlo code DEGAS with some deficiency in the treatment of dissociation products in the 10-100 eV range. RP Skinner, CH (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Stotler, Daren/J-9494-2015 OI Stotler, Daren/0000-0001-5521-8718 NR 22 TC 12 Z9 13 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. PY 1997 VL 241 BP 887 EP 891 DI 10.1016/S0022-3115(96)00626-5 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700136 ER PT J AU Bush, CE Bell, RE LeBlanc, B Mansfield, DK Synakowski, EJ Budny, RV Hill, KW Houlberg, W Mazzucato, E Mioduszewski, P Park, H Skinner, CH Zarnstorff, MC AF Bush, CE Bell, RE LeBlanc, B Mansfield, DK Synakowski, EJ Budny, RV Hill, KW Houlberg, W Mazzucato, E Mioduszewski, P Park, H Skinner, CH Zarnstorff, MC TI Core V-phi and T-i profiles and transport in TFTR DD and DT plasmas with lithium conditioning SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TFTR; radial electric field; improved confinement mode; wall conditioning; transport and confinement ID FUSION-TEST-REACTOR; CONFINEMENT; SHEAR AB High performance DT plasmas have been obtained using neutral beam heating with lithium (Li) conditioned graphite walls in TFTR. Values of tauE > 300 ms have been obtained with neutron source rates of > 10(18) n/s and n tau T approximate to 10(21). Also, ion temperature (T-i)> 40 keV and toroidal velocity (V-phi)> 800 km/s have been obtained. The T-i(R, t) and V-phi(R, t) profiles show strong gradients near the plasma core with del V-phi > 35 X 10(6)/s and E X B shearing rate > 2 X 10(5)/s realized. This strong E X B flow shear is consistent with formation of a 'transport barrier' in the plasma core. Measured V-phi, T-i, and carbon density, n(c), profiles from charge-exchange recombination spectroscopy (CHERS) and neoclassical calculations of poloidal velocity, V-phi, are used to assess the roles of the pressure and velocity contributions to E-r (or E X B) with varying Li conditioning. The profiles and gradients and resulting confinement and transport are found to vary with the amount of Li applied and the Li deposition technique. Correlations between the V-phi and T-i profiles and rccycling and impurity behavior as implied from edge carbon and D-alpha light and Li deposition are also observed. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Bush, CE (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 892 EP 896 DI 10.1016/S0022-3115(97)80161-4 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700137 ER PT J AU Mueller, D Blanchard, W Collins, J Hosea, J Kamperschroer, J LaMarche, PH Nagy, A Owens, DK Skinner, CH AF Mueller, D Blanchard, W Collins, J Hosea, J Kamperschroer, J LaMarche, PH Nagy, A Owens, DK Skinner, CH TI Tritium removal from TFTR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE TFTR; erosion and particle deposition; tritium inventory and economy; tokamak; fusion; technology ID FUSION TEST REACTOR; CARBON; RELEASE; WALL AB Continued operation of the tokamak fusion test reactor (TFFR) with a mixture of deuterium and tritium fueling has permitted the opportunity to measure the retention of tritium in the graphite limiter and to investigate the use of discharge cleaning techniques and venting to remove the tritium. The tritium was introduced into TFTR by neutral beam injection and by gas puffing. The limiter is subject to erosion and codeposition. While short term retention was high, the retention averaged over the 1993-1995 D-T campaign was 52 +/- 15%. The tritium removal techniques resulted in lowering the in-vessel inventory from 16.4 kCi (1 Ci = 2.076 X 10(19) tritium atoms and 10 kCi = 1.04 g) at the end of 1995 operation to 7.2 kCi at the start of the 1996 experimental program. RP Mueller, D (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 19 TC 40 Z9 40 U1 0 U2 1 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. PY 1997 VL 241 BP 897 EP 901 DI 10.1016/S0022-3115(96)00628-9 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700138 ER PT J AU Komori, A Ohyabu, N Masuzaki, S Morisaki, T Suzuki, H Takahashi, C Sakakibara, S Watanabe, K Watanabe, T Minami, T Morita, S Tanaka, K Ohdachi, S Kubo, S Inoue, N Yamada, H Nishimura, K Okamura, S Matsuoka, K Motojima, O Fujiwara, M Iiyoshi, A Klepper, CC Lyon, JF England, AC Greenwood, DE Lee, DK Overbey, DR Rome, JA Schechter, DE Wilson, CT AF Komori, A Ohyabu, N Masuzaki, S Morisaki, T Suzuki, H Takahashi, C Sakakibara, S Watanabe, K Watanabe, T Minami, T Morita, S Tanaka, K Ohdachi, S Kubo, S Inoue, N Yamada, H Nishimura, K Okamura, S Matsuoka, K Motojima, O Fujiwara, M Iiyoshi, A Klepper, CC Lyon, JF England, AC Greenwood, DE Lee, DK Overbey, DR Rome, JA Schechter, DE Wilson, CT TI Local island divertor experiments on CHS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE CHS; island divertor; divertor plasma; active pumping; improved confinement mode ID LARGE HELICAL DEVICE; DESIGN AB A local island divertor (LLD) was installed on the Compact Helical System (CHS) to demonstrate the principle of LLD and to study its effects on the edge plasma. The particle flow was observed to be guided to the back side of the externally created magnetic island along field lines, and pumped out by a cryogenic pump with high pumping efficiency. As a result, a factor of about 2 reduction in the average core density was seen compared with non-LID discharges at the same gas puff rate. In addition to the demonstration of these fundamental divertor functions, we observed a modest improvement of energy confinement, which could be due to the edge plasma control by the local island divertor. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Komori, A (reprint author), NATL INST FUS SCI,NAGOYA,AICHI 46401,JAPAN. RI Sakakibara, Satoru/E-7542-2013 OI Sakakibara, Satoru/0000-0002-3306-0531 NR 9 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PY 1997 VL 241 BP 967 EP 971 DI 10.1016/S0022-3115(97)80175-4 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700151 ER PT J AU Causey, RA Longhurst, GR Harbin, W AF Causey, RA Longhurst, GR Harbin, W TI Tritium retention in S-65 beryllium after 100 eV plasma exposure SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE plasma-wall interaction simulator; low Z material; wall particle retention; tritium inventory and economy AB The tritium plasma experiment (TPE) has been used to measure the retention of tritium in S-65 beryllium under conditions similar to that expected for the international thermonuclear experimental reactor (ITER). Beryllium samples 2 mm thick and 50 mm in diameter were exposed to a plasma of tritium and deuterium. The particle flux striking the samples was varied from approximately 1 x 10(17) (D + T)/cm(2) s up to about 3 x 10(18) (D + T)/cm(2) a. The beryllium samples were negatively biased to elevate the energy of the impinging ions to 100 eV. The temperature of the samples was varied from 373 K to 973 K. Exposure times of 1 h were used. Subsequent to the plasma exposure, the samples were outgassed in a separate system where 99% He and 1% H-2 gas was swept over the samples during heating. The sweep gas along with the released tritium was sent through an ionization chamber, through a copper oxide catalyst bed, and into a series of glycol bubblers. The amount of released tritium was determined both by the ionization chamber and by liquid scintillation counting of the glycol. Tritium retention in the beryllium disks varied from a high of 2.4 x 10(17) (D + T)/cm(2) at 373 K to a low of 1 x 10(16) (D + T)/cm(2) at 573 K. For almost every case, the tritium retention in the beryllium was less than that calculated using the C = 0 boundary condition at the plasma facing surface. It is believed that this lower than expected retention is due to rapid release of tritium from the large specific surface area created in the implant zone due to the production of voids, bubbles, and blisters. C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Causey, RA (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 7 TC 16 Z9 16 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. PY 1997 VL 241 BP 1041 EP 1046 DI 10.1016/S0022-3115(97)80190-0 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700166 ER PT J AU Takiyama, K Katsuta, T Toyota, H Watanabe, M Mizuno, K Ogawa, T Oda, T AF Takiyama, K Katsuta, T Toyota, H Watanabe, M Mizuno, K Ogawa, T Oda, T TI Low-energetic He-atom beam as a diagnostic probe for electric field measurement in the plasma edges SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 12th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 20-24, 1996 CL ST RAPHAEL, FRANCE SP Assoc EURATOM CEA Fus Controlee, European Comm, DGII, Conseil Reg Provence, Alpes, Cote d Azur DE JFT-2M; SOL plasma; boundary plasma; radial electric field; atomic physics ID LASER-INDUCED FLUORESCENCE AB Two types of low-energetic He-atom beam sources were constructed for direct measurement of electric field distribution in tokamak plasma edge region with aid of laser-induced fluorescence (LIF) technique. One is a continuous plasma flow extracted from an electron cyclotron resonance (ECR) plasma source. The plasma parameters were measured by Langmuir probes, while density profiles and velocity of metastable He atoms (2(1)S) in the plasma flow were measured by LIF methods. It was found that extremely high density metastable atoms of similar to 10(11) cm(-3) were created at 7 cm apart from the outlet of the source. Formation mechanism of such high density 2(1)S atoms was briefly discussed on the basis of atomic processes. Another is a pulsed free jet having a pair of discharge electrodes to produce the 2(1)S atoms in the jet. High density 2(1)S atoms(similar to 10(10) cm(-3)) were found to be created in the discharged jet by means of the optical absorption method. C1 LAWRENCE LIVERMORE NATL LAB,PLASMA PHYS RES INST,LIVERMORE,CA. UNIV CALIF DAVIS,LIVERMORE,CA 95616. JAPAN ATOM ENERGY RES INST,TOKAI,IBARAKI 31911,JAPAN. RP Takiyama, K (reprint author), HIROSHIMA UNIV,FAC ENGN,DEPT APPL PHYS & CHEM,HIGASHIHIROSHIMA 739,JAPAN. NR 14 TC 8 Z9 8 U1 2 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. PY 1997 VL 241 BP 1222 EP 1227 DI 10.1016/S0022-3115(97)80224-3 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XF377 UT WOS:A1997XF37700200 ER PT J AU Shoup, SS Bamberger, CE Haverlock, TJ Peterson, JR AF Shoup, SS Bamberger, CE Haverlock, TJ Peterson, JR TI Aqueous leachability of lanthanide and plutonium titanates SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID WASTE; SYNROC AB The leachabilities of titanate and zircono-titanate solid solutions, Ce2Ti2O7, Er1.78Ce0.22Ti2O7, Er1.78Pu0.22Ti2O7 (9.5 wt% Pu) Er1.78Ce0.22Ti0.5Zr1.5O7, SrCe2Ti4O12, SrPu2Ti4O12 (50.7 wt% Pu) and Sr2Ce2Ti5O16, have been investigated in WIPP 'A' brine, 0.1 M NaCl, and 0.1 M HCl solutions using a modified MCC-3 procedure with a duration of 60 days. The concentrations of plutonium leached by the brine were less than 1 ppm. Where cerium was used as a surrogate for plutonium, its concentration in WIPP brine was below the limit of detection (10 ppm) established for the inductively coupled plasma (ICP) atomic emission spectrometer used. Concentrations of strontium leached by WIPP brine from stable strontium-containing titanate compounds, considered as possible immobilizers of both Sr-90 and actinide elements, were on the order of 30-60 ppm. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. NR 24 TC 15 Z9 16 U1 0 U2 11 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 JAN PY 1997 VL 240 IS 2 BP 112 EP 117 DI 10.1016/S0022-3115(96)00671-X PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WF897 UT WOS:A1997WF89700003 ER PT J AU Petri, MC Dayananda, MA AF Petri, MC Dayananda, MA TI Isothermal diffusion in uranium-plutonium-zirconium alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID FAST-REACTOR; FUEL; INTERDIFFUSION AB Isothermal diffusion couple experiments were performed at 1023 K to investigate diffusion phenomena in body-centered cubic U-Pu-Zr alloys. The U-Pu-Zr alloys covered the uranium-rich comer of the ternary phase diagram with plutonium concentrations up to 27 at.% and zirconium concentrations up to 20 at.%, Ternary interdiffusion coefficients were calculated at the common composition between two couples with intersecting diffusion paths. The cross interdiffusion coefficient for zirconium ((D) over tilde(ZrPu)(U)) is negative and has a magnitude twice that of the main coefficient ((D) over tilde(ZrZr)(U)). In contrast, (D) over tilde(PuZr)(U) is negligible compared with (D) over tilde(PuPu)(U). (D) over tilde(PuPu)(U) is an order of magnitude greater than (D) over tilde(ZrZr)(U). Average effective interdiffusion coefficients were determined for all components over concentration ranges on the two sides of the Matano plane as well as for the entire diffusion zone of the couples. In general, these coefficients increase with increasing plutonium concentration and decrease with increasing zirconium concentration. C1 PURDUE UNIV,SCH MAT ENGN,W LAFAYETTE,IN 47907. RP Petri, MC (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 12 Z9 12 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JAN PY 1997 VL 240 IS 2 BP 131 EP 143 DI 10.1016/S0022-3115(96)00669-1 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WF897 UT WOS:A1997WF89700006 ER PT J AU Bottoni, M Ahuja, S Lyczkowski, R AF Bottoni, M Ahuja, S Lyczkowski, R TI Physical modeling and numerical simulation of subcooled boiling in one- and three-dimensional representations of bundle geometry SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE subcooled boiling; homogenous equilibrium model; two-phase flow; multi-dimensions; pressure drop; LMFBR type reactors; fuel pins; fuel element clusters; numerical simulation ID FLOW; DYNAMICS AB Numerical simulation of subcooled boiling in one-dimensional geometry with the Homogeneous Equilibrium Model (HEM) may yield difficulties related to the very low sonic velocity associated with the HEM. These difficulties do not arise with subcritical flow. Possible solutions of the problem include introducing a relaxation of the vapor production rate. Three-dimensional simulations of subcooled boiling in bundle geometry typical of fast reactors can be performed by using two systems of conservation equations, one far the HEM and the other for a Separated Phases Model (SPM), with a smooth transition between the two models. The suitability of this approach for modeling subcooled boiling in three dimensional geometry has been proved by simulating numerically two selected experiments in 7- and 37-pin electrically heated bundles typical of fast reactor subassemblies. C1 ARGONNE NATL LAB, DIV ENERGY SYST, ARGONNE, IL 60439 USA. RP ARGONNE NATL LAB, DIV ENERGY TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 20 TC 0 Z9 0 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD JAN PY 1997 VL 34 IS 1 BP 30 EP 40 DI 10.1080/18811248.1997.9732053 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WK951 UT WOS:A1997WK95100005 ER PT J AU Borovsky, JE Elphic, RC Funsten, HO Thomsen, MF AF Borovsky, JE Elphic, RC Funsten, HO Thomsen, MF TI The Earth's plasma sheet as a laboratory for flow turbulence in high-beta MHD SO JOURNAL OF PLASMA PHYSICS LA English DT Review ID STEADY MAGNETOSPHERIC CONVECTION; MAGNETIC-FIELD CORRELATION; ELECTRIC WAVE SPECTRA; SOLAR-WIND; ISOTROPIC TURBULENCE; MAGNETOHYDRODYNAMIC TURBULENCE; BOUNDARY-LAYER; STATISTICAL CHARACTERISTICS; VELOCITY AUTOCORRELATION; PARTICLE-ACCELERATION AB The bulk flows and magnetic-field fluctuations of the plasma sheet are investigated using single-point measurements from the ISEE-2 Fast Plasma Experiment and fluxgate magnetometer. Ten several-hour-long intervals of continuous data (with 3 s and 12 s time resolution) are analysed. The plasma-sheet flow appears to be strongly 'turbulent' (i.e. the flow is dominated by fluctuations that are unpredictable, with rms velocities much greater than mean velocities and with field fluctuations approximate to mean fields). The flow velocities are typically sub Alfvenic. The flow-velocity probability distribution P(upsilon) is constructed, and is found to be well fitted by exponential functions. Autocorrelation functions A(tau) are constructed, and the autocorrelation times tau(corr) for the flow velocities are found to be about 2 min. From the flow measurements, an estimate of the mixing length in the plasma sheet is produced, yielding L-mix approximate to 2 Earth radii; correspondingly, the plasma-sheet material appears to be well mixed in density and temperature. An eddy viscosity for the plasma sheet is also estimated. Power spectra, which are constructed from the v(t) and B(t) time series, have portions that are power laws with spectral indices that are near the range of those expected for turbulence theories. The plasma sheet may provide a laboratory for the study of turbulence in parameter regimes different from that of solar-wind turbulence: the plasma sheet is a beta much greater than 1, hot-ion plasma, and the turbulence may be strongly driven rather than well developed. The turbulent nature of the flow and the disordered nature of the magnet ic field hare implications for the transport of plasma-sheet material, for the penetration of the solar-mind electric field into the plasma sheet, and for the calculation of particle orbits in the magnetotail. RP LOS ALAMOS NATL LAB, SPACE & ATMOSPHER SCI GRP, LOS ALAMOS, NM 87545 USA. RI Funsten, Herbert/A-5702-2015 OI Funsten, Herbert/0000-0002-6817-1039 NR 148 TC 202 Z9 203 U1 0 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-3778 EI 1469-7807 J9 J PLASMA PHYS JI J. Plasma Phys. PD JAN PY 1997 VL 57 BP 1 EP 34 DI 10.1017/S0022377896005259 PN 1 PG 34 WC Physics, Fluids & Plasmas SC Physics GA WY352 UT WOS:A1997WY35200001 ER PT J AU ElZein, Y Yi, SJ Lonngren, KE Alexeff, I Sheridan, TE Hsuan, H AF ElZein, Y Yi, SJ Lonngren, KE Alexeff, I Sheridan, TE Hsuan, H TI Plasma sheath evolution from perturbed electrodes in a negative-ion plasma SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID MATRIX SHEATH AB The two-dimensional spatial and temporal evolution of the components of a plasma surrounding an electrode whose potential is suddenly decreased is investigated numerically. The electrode contains a localized convex or a localized concave volt age perturbation. The quasineutral plasma consists of positive ions and various proportions of negative ions and electrons. The results are compared and contrasted with those obtained with a uniform electrode under identical plasma conditions. C1 UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. UNIV TENNESSEE,DEPT ELECT ENGN,KNOXVILLE,TN 37996. GLENVILLE STATE COLL,DIV SCI & MATH,GLENVILLE,WV 26351. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08563. RP ElZein, Y (reprint author), UNIV IOWA,DEPT ELECT & COMP ENGN,IOWA CITY,IA 52242, USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD JAN PY 1997 VL 57 BP 47 EP 57 DI 10.1017/S0022377896005193 PN 1 PG 11 WC Physics, Fluids & Plasmas SC Physics GA WY352 UT WOS:A1997WY35200003 ER PT J AU Turner, L AF Turner, L TI Remarks on statistical mechanics of discrete and continuous media with application to the magnetohydrodynamic dynamo SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID TURBULENCE; PINCH; RELAXATION AB In this paper commemorating the 60th birthday of David Montgomery, issues tantalizing to me that evolved from my collaborations with him are highlighted: sustainment of the magnetohydrodynamic dynamo, relationships between discrete and continuous models of media, and closures for nonlinear theories of discrete and continuous media. In particular, it is speculated that a tractable statistical model of a magnetohydrodynamic dynamo may arise from a proper formulation of a solenoidal expansion basis for the magnetic and velocity fields in the context of an appropriate closure, such as the eddy-damped quasinormal Markovian model. RP Turner, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 28 TC 2 Z9 2 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD JAN PY 1997 VL 57 BP 59 EP 71 DI 10.1017/S0022377896005302 PN 1 PG 13 WC Physics, Fluids & Plasmas SC Physics GA WY352 UT WOS:A1997WY35200004 ER PT J AU Chen, SY Kraichnan, RH AF Chen, SY Kraichnan, RH TI Inhibition of turbulent cascade by sweep SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID INTERSTELLAR TURBULENCE; ISOTROPIC TURBULENCE; FIELD AB The effects of large-scale sweeping velocity on the turbulent, cascade to small scales are examined for two problems: the advection of a passive scaler by a multivariate-Gaussian velocity field and incompressible Alfven-wave turbulence. In both cases, the sweeping produces anisotropy and reduces the strength of cascade. If the direction of the sweep velocity varies with time, a balance is reached between this anisotropy and isotropizing effects associated with the change of direction. C1 LOS ALAMOS NATL LAB,COMPLEX SYST GRP,LOS ALAMOS,NM 87545. RP Chen, SY (reprint author), IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. RI Chen, Shiyi/A-3234-2010 NR 16 TC 14 Z9 14 U1 3 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD JAN PY 1997 VL 57 BP 187 EP 193 DI 10.1017/S0022377896005326 PN 1 PG 7 WC Physics, Fluids & Plasmas SC Physics GA WY352 UT WOS:A1997WY35200012 ER PT J AU Martinez, DO Chen, S Doolen, GD Kraichnan, RH Wang, LP Zhou, Y AF Martinez, DO Chen, S Doolen, GD Kraichnan, RH Wang, LP Zhou, Y TI Energy spectrum in the dissipation range of fluid turbulence SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID ISOTROPIC TURBULENCE; NUMERICAL TURBULENCE; VELOCITY; FLOWS AB High-resolution, direct numerical simulations of three-dimensional incompressible Navier-Stokes equations are carried out to study the energy spectrum in the dissipation range. An energy spectrum of the form A (k/k(d))(alpha)exp[-beta k/k(d)] is confirmed. The possible values of the parameters alpha and beta, as well as their dependence on Reynolds numbers and length scales, are investigated, showing good agreement with recent theoretical predictions. A 'bottleneck'-type effect. is reported at k/k(d) approximate to 4, exhibiting a possible transition from near-dissipation to far-dissipation. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. IBM CORP,THOMAS J WATSON RES CTR,DIV RES,YORKTOWN HTS,NY 10598. UNIV DELAWARE,DEPT MECH ENGN,NEWARK,DE 19716. NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23861. RP Martinez, DO (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Chen, Shiyi/A-3234-2010; Wang, Lian-Ping/N-7516-2016 OI Wang, Lian-Ping/0000-0003-4276-0051 NR 21 TC 40 Z9 41 U1 2 U2 7 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD JAN PY 1997 VL 57 BP 195 EP 201 DI 10.1017/S0022377896005338 PN 1 PG 7 WC Physics, Fluids & Plasmas SC Physics GA WY352 UT WOS:A1997WY35200013 ER PT J AU Piepel, GF AF Piepel, GF TI Survey of software with mixture experiment capabilities SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article DE design of experiments; mixture experiments; response surface methodology ID DESIGNS AB Vendors of statistical experimental design and data analysis software packages were contacted to gather information on software having mixture experiment capabilities. A total of 15 packages having mixture experiment capabilities were identified. The mixture experiment design capabilities, data analysis capabilities, and miscellaneous information about the software (e.g., type of interface, hardware requirements, and cost) are summarized in table form. Mailing addresses, email addresses, phone numbers, and fax numbers of the software vendors are also provided. RP Piepel, GF (reprint author), PACIFIC NW LAB, STAT GRP, POB 999, RICHLAND, WA 99352 USA. NR 12 TC 2 Z9 2 U1 1 U2 1 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA ASQC MEMBERSHIP MANAGER 611 E. WISCONSIN AVENUE, MILWAUKEE, WI 53202 SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD JAN PY 1997 VL 29 IS 1 BP 76 EP 85 PG 10 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA WD265 UT WOS:A1997WD26500009 ER PT J AU Liikala, TL Evans, JC AF Liikala, TL Evans, JC TI Comparison of two soil gas methods used during a field investigation SO JOURNAL OF SOIL CONTAMINATION LA English DT Article DE soil gas; Petrex; site characterization; volatile organic compounds; gas chromatography; mass spectrometry AB Soil gas surveys were employed to help determine the nature and extent of contamination resulting from the past operation of source area ST58, the Old Quartermaster Service Station, at Eielson Air Force Base, Alaska. Two intrusive methods were used for comparison, active conventional gas extraction and the passive Petrex method. Results were comparable, with gasoline identified as the main subsurface contaminant in both surveys. Close spatial correlation was also achieved among screening instruments and laboratory analyses. Contaminant concentrations corresponded very well with unsealed blueprints showing the locations of the above-ground storage tanks and associated piping, subsequent test pit soil samples, and excavation results. The contamination probably occurred as a result of surface spills and leaks from discontinuities and/or breaks in the underground piping. A finer grid was employed in the Petrex method survey and produced better-resolved contours. The use of conventional gas extraction provided rapid results but was labor intensive. The Petrex method survey was less labor intensive but required a longer turnaround time for analytical results. Costs for the two methods were nearly equal. Both methods appear appropriate for other shallow applications in unconsolidated materials where contamination is known to exist. RP Liikala, TL (reprint author), PACIFIC NW LAB, WATER & LAND RESOURCES DEPT, POB 999, RICHLAND, WA 99352 USA. NR 12 TC 1 Z9 1 U1 0 U2 4 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1997 VL 6 IS 4 BP 339 EP 354 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA XP917 UT WOS:A1997XP91700001 ER PT J AU Harris, MT Singhal, A Look, JL SmithKristensen, JR Lin, JS Toth, LM AF Harris, MT Singhal, A Look, JL SmithKristensen, JR Lin, JS Toth, LM TI FTIR spectroscopy, SAXS and electrical conductivity studies of the hydrolysis and condensation of zirconium and titanium alkoxides SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 8th International Workshop on Glasses and Ceramics from Gels CY SEP 18-22, 1995 CL ALGARVE, PORTUGAL DE zirconium butoxide; titanium butoxide; kinetics; hydrolysis; condensation ID SOL-GEL CHEMISTRY; ANGLE X-RAY; SILICON ALKOXIDES; KINETICS; PARTICLES AB A continuous flowing-rapid mixing technique was combined with FTIR, SAXS and electrical conductivity to study the early stages of polymer formation and growth during the acid-catalyzed hydrolysis and condensation of titanium and zirconium alkoxides. Reaction times as short as 80 milliseconds were investigated. FTIR spectroscopy was used to monitor the water and M-OR concentrations during the reaction. Hydrolysis of similar to 25-50% of the alkoxy groups was facile. The FTIR and SAXS data showed that condensation was also very rapid. The activity and mobility of the ions in the solution were monitored by electrical conductivity measurements. The decrease in the normalized solution conductivity during the reaction correlated with the loss of [M-OR]. Furthermore, the radius of gyration of the growing polymers increased rapidly in regimes where the conductivity and [M-OR] decreased fastest. This finding suggests that the mobility of some of the charge carrying species decreases because of the growth in size of the polymers. C1 PROCTER & GAMBLE CO,MIAMI VALLEY LABS,CINCINNATI,OH 45239. UNIV MINNESOTA,SCH MED,MINNEAPOLIS,MN 55455. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Harris, MT (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. NR 31 TC 27 Z9 27 U1 2 U2 25 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PY 1997 VL 8 IS 1-3 BP 41 EP 47 DI 10.1007/BF02436815 PG 7 WC Materials Science, Ceramics SC Materials Science GA WQ334 UT WOS:A1997WQ33400006 ER PT J AU Ozer, N Lampert, CM AF Ozer, N Lampert, CM TI Structural and optical properties of sol-gel deposited proton conducting Ta2O5 films SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 8th International Workshop on Glasses and Ceramics from Gels CY SEP 18-22, 1995 CL ALGARVE, PORTUGAL DE optical properties; proton conductor; tantalum oxide; electrochromic devices ID TANTALUM OXIDE; COATINGS AB Proton conducting tantalum oxide films were deposited on ITO (Indium Tin Oxide) coated glass, fused silica and soda-lime glass substrates by spin coating using a sol-gel process. The coating solutions were prepared using Ta(OC2H5)(5) as a precursor. X-ray diffraction studies determined that the sol-gel films, heat treated at temperatures below 400 degrees C, were amorphous. Films heat treated at higher temperatures were crystalline with the hexagonal delta-Ta2O5 structure. The solar transmission values (T-s) of tantala films on glass generally range from 0.8-0.9, depending on thickness. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the UV-VIS-NIR regions. The refractive index values calculated at lambda = 550 nm increased from n = 1.78 to 1.97 with increasing heat treatment from 150 to 450 degrees C. The films heat treated at different temperatures showed low absorption, with extinction coefficients of smaller than k = 1 x 10(-3) in the visible range. Impedance spectroscopic investigations performed on Ta2O5 films revealed that these films have a protonic conductivity of 3.2 x 10(-4) S/m. The films are suitable for proton conducting layers in electrochromic (EC) devices. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY & ENVIRONM DIV,BERKELEY,CA 94720. RP Ozer, N (reprint author), ISTANBUL UNIV,FAC SCI,DEPT PHYS,ISTANBUL,TURKEY. NR 16 TC 44 Z9 44 U1 0 U2 29 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PY 1997 VL 8 IS 1-3 BP 703 EP 709 DI 10.1023/A:1018396900214 PG 7 WC Materials Science, Ceramics SC Materials Science GA WQ334 UT WOS:A1997WQ33400117 ER PT J AU Idemoto, Y Richardson, JW Koura, N Kohara, S Loong, CK AF Idemoto, Y Richardson, JW Koura, N Kohara, S Loong, CK TI Crystal structure of LiKCO3 by neutron powder diffraction analysis SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION AB The crystal structure of LiKCO3 was determined by neutron powder diffraction. A final weighted R-factor of 4.54% was obtained for the refinement of 2373 reflections by the Rietveld method from a sample synthesized using (Li2CO3)-Li-7 and K2CO3 (99.9% pure). Slight distortion of the CO32- units in the monoclinic cell was observed; the O(1)-C-O(2) angle and C-O(3) length are larger than the other C-O bond lengths and O-C-O angles. These local-structure characteristics can be explained by the difference in the ionic size of Li+ and K+, and the different electrostatic interactions between the cations and CO32- units. (C) 1997 Academic Press. C1 SCI UNIV TOKYO,FAC SCI & TECHNOL,DEPT IND CHEM,NODA,CHIBA 278,JAPAN. RP Idemoto, Y (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 6 Z9 6 U1 1 U2 9 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 JAN PY 1997 VL 128 IS 1 BP 156 EP 159 DI 10.1006/jssc.1996.7153 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA WP160 UT WOS:A1997WP16000025 ER PT J AU Benezeth, P Palmer, DA Wesolowski, DJ AF Benezeth, P Palmer, DA Wesolowski, DJ TI Dissociation quotients for citric acid in aqueous sodium chloride media to 150 degrees C SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE citric acid; dissociation constants; thermodynamics; potentiometry; ionic strength ID ORGANIC-ACIDS; HYDROLYSIS; 175-DEGREES-C; 300-DEGREES-C; 25-DEGREES-C; ELECTROLYTES; DISSOLUTION; IONIZATION; QUARTZ; WATER AB The three molal dissociation quotients for citric acid were measured potentiometrically with a hydrogen-electrode concentration cell from 5 to 150 degrees C in NaCl solutions at ionic strengths of 0.1, 0.3, 0.6, and 1 molal. The molal dissociation quotients and available literature data at infinite dilution were fitted by empirical equations in the all-anionic form involving an extended Debye-Huckel term and up to five adjustable parameters involving functions of temperature and ionic strength. This treatment yielded the following thermodynamic quantities for the first dissociation equilibrium at 25 degrees C: log K-1a = -3.127+/-0.002, Delta H(1a)degrees = 4.1+/-0.2 kJ-mol(-1), Delta S(1a)degrees = -46.3+/-0.7 J-K-1-mol(-1), and Delta Cp(1a)degrees = -162+/- 7 J-K-1-mol(-1); for the second acid dissociation equilibrium at 25 degrees C: log K-2a = -4.759+/-0.001, Delta H(2a)degrees = 2.2+/-0.1, Delta S(2a)degrees = -83.8+/-0.4, and Delta Cp(2a)degrees = -192+/- 15, and for the third dissociation equilibrium at 25 degrees C: log K-3a = -6.397+/-0.002, Delta H(3a)degrees = -3.6=/-0.2, Delta S(3a)degrees = -134.5+/-0.7, and Delta Cp(3a)degrees = -231+/-7. RP Benezeth, P (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,BLDG 4500S,OAK RIDGE,TN 37831, USA. RI BENEZETH, Pascale/H-7969-2014 OI BENEZETH, Pascale/0000-0002-1841-2383 NR 39 TC 21 Z9 22 U1 4 U2 13 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD JAN PY 1997 VL 26 IS 1 BP 63 EP 84 PG 22 WC Chemistry, Physical SC Chemistry GA WQ846 UT WOS:A1997WQ84600005 ER PT J AU Burkard, F Chen, F Kuziemko, GM Stevens, RC AF Burkard, F Chen, F Kuziemko, GM Stevens, RC TI Electron density projection map of the botulinum neurotoxin 900-kilodalton complex by electron crystallography SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article ID TWO-DIMENSIONAL CRYSTALS; 2-DIMENSIONAL CRYSTALLIZATION; B HEMAGGLUTININS; LIPID LAYERS; TOXIN; MACROMOLECULES; MEMBRANE AB The 900-kDa botulinum neurotoxin complex serotype A has been crystallized by the lipid-layer two-dimensional crystallization technique. Based on the binding characteristics of the hemagglutinating portion of the complex, a number of ganglioside/ lipid mixtures were tested but only lactosyl ceramide/1- -palmityl-2-oleoyl-sn-glycero-3-phosphocholine was found to crystallize the complex. The optimum lipid mixture contained 75 mass % lactosyl ceramide and 25 mass % 1-palmityl-2-oleoyl-sn-glycero-3-phosphocholine. Using protein concentrations from 5 to 500 mu g/ml and pH 5 acetate buffer, we have obtained crystals that diffract to better than 15 Angstrom when prepared in negative stain,A projection map with a resolution of 30 Angstrom was calculated with unit cell dimensions of a = b = 157 Angstrom and P3 symmetry. The complex is triangular in shape with six distinct lobes observed, Additionally, six smaller structures protrude from the triangular core. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,GRAD GRP BIOPHYS,BERKELEY,CA 94720. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 FU NIGMS NIH HHS [GM36884, GM51487] NR 24 TC 14 Z9 14 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PY 1997 VL 120 IS 1 BP 78 EP 84 DI 10.1006/jsbi.1997.3910 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA YE758 UT WOS:A1997YE75800010 PM 9356295 ER PT J AU Nieplocha, J Harrison, RJ AF Nieplocha, J Harrison, RJ TI Shared memory programming in metacomputing environments: The global array approach SO JOURNAL OF SUPERCOMPUTING LA English DT Article DE metacomputing; shared-memory programming; NUMA memory architecture; global arrays; distributed arrays ID PERFORMANCE AB The performance of the Global Array shared-memory nonuniform memory-access programming model is explored in a wide-area-network (WAN) distributed supercomputer environment. The Global Array model is extended by introducing a concept of mirrored arrays that thanks to the caching and user-controlled consistency of the shared data structure scan reduce the application sensitivity to the network latency. Latencies and bandwidths for remote memory access are studied, and the performance of a large application from computational chemistry is evaluated using both fully distributed and also mirrored arrays. Excellent performance can be obtained with mirroring if even modest (0.5 MB/s) network bandwidth is available. RP Nieplocha, J (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 17 TC 10 Z9 10 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0920-8542 J9 J SUPERCOMPUT JI J. Supercomput. PY 1997 VL 11 IS 2 BP 119 EP 136 DI 10.1023/A:1007955822788 PG 18 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA YE690 UT WOS:A1997YE69000003 ER PT J AU Hahn, U SchulteSchrepping, H Balewski, K Schneider, JR Ilinski, P Lai, B Yun, W Legnini, D Gluskin, E AF Hahn, U SchulteSchrepping, H Balewski, K Schneider, JR Ilinski, P Lai, B Yun, W Legnini, D Gluskin, E TI Measurements of emittance and absolute spectral flux of the PETRA undulator at DESY Hamburg SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE hard X-rays; undulators; spectral flux; emittance AB The first synchrotron radiation beamline using a 4 m-long undulator at the 12 GeV storage ring PETRA delivers hard X-ray photons usable up to 300 keV. The photon intensity is measured on an absolute scale in the energy range between 16 and 60 keV and compared with calculated intensities. The experimental set-up described is also used to measure the horizontal and vertical emittance of the source. C1 ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. RP Hahn, U (reprint author), DESY,DEUTSCHES ELEKTRONEN SYNCHROTRON,HAMBURGER SYNCHROTONSTRAHLUNGSLABOR HASYLAB,NOTKESTR 85,D-22607 HAMBURG,GERMANY. NR 6 TC 10 Z9 10 U1 1 U2 2 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 JAN 1 PY 1997 VL 4 BP 1 EP 5 DI 10.1107/S0909049596010734 PN 1 PG 5 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA WF649 UT WOS:A1997WF64900001 PM 16699198 ER PT J AU McNaney, JM Havens, R Ritchie, RO AF McNaney, JM Havens, R Ritchie, RO TI Elastic compliance of the compact tension specimen comprising two linear-elastic materials bonded with a thin layer SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE compact-tension geometry; bimaterial ''sandwich'' specimen; crack-length monitoring; compliance methods; back-face strain (BFS); crack-opening displacement (GOD); load-line displacement (LLD) ID STRENGTH; FRACTURE AB Although the compact-tension C(T) specimen is widely used in conventional fracture mechanics testing, its application to the fracture behavior of layered structures, in the assessment of the toughness and fatigue crack growth behavior of bimaterial interfaces, for example, has been limited due to problems in identifying the crack length. Accordingly, to provide a basis for crack-length monitoring in the sandwich C(T) specimen, comprising two materials bonded with a thin layer under linear-elastic conditions, the linear-elastic compliance based on back-face strain, crack-opening displacement and load-line displacement has been determined for a wide range of substrate/layer material combinations using finite-element analyses. Calculations for sandwich systems, with elastic moduli ratios varying from 0.2 to 5 and with joining layer thicknesses between 0.4 and 2% of the specimen width, show that for crack sizes between 0.25 to 0.75 of the specimen width, the compliance is significantly different from that of the bulk substrates, except when the layer is very thin and the modulus ratio approaches unity. It is concluded that crack-opening displacements are preferable for the monitoring and detection of interfacial and near-interfacial cracks in this specimen geometry, as the compliance based on these displacements is the least sensitive to errors from either measurement site or crack location. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP McNaney, JM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Ritchie, Robert/A-8066-2008; McNaney, James/F-5258-2013 OI Ritchie, Robert/0000-0002-0501-6998; NR 16 TC 2 Z9 2 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JAN PY 1997 VL 25 IS 1 BP 28 EP 35 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA WE659 UT WOS:A1997WE65900005 ER PT J AU Lackey, WJ Vaidyaraman, S More, KL AF Lackey, WJ Vaidyaraman, S More, KL TI Laminated C-SiC matrix composites produced by CVI SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CHEMICAL-VAPOR INFILTRATION; TOUGHNESS AB A new type of composite, which consists of a reinforcement phase plus a matrix composed of many alternate thin layers of two different materials, has been prepared. CVI appears to be an appropriate process for the fabrication of this class of materials. We have successfully fabricated such a composite using the forced flow-thermal gradient CVI process. A carbon fibrous preform was infiltrated with alternate layers of C and SIC having thicknesses of 0.01 to 0.5 mu m. For a fixed cycle time, layer thicknesses increased with distance from the fiber surface. Crack deflection patterns indicate that the laminated matrix may contribute to mechanical toughness. C1 GEORGIA INST TECHNOL,SCH CHEM ENGN,ATLANTA,GA 30332. OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. RP Lackey, WJ (reprint author), GEORGIA INST TECHNOL,GEORGIA TECH RES INST,ATLANTA,GA 30332, USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 24 TC 24 Z9 24 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1997 VL 80 IS 1 BP 113 EP 116 DI 10.1111/j.1151-2916.1997.tb02798.x PG 4 WC Materials Science, Ceramics SC Materials Science GA WF896 UT WOS:A1997WF89600014 ER PT J AU Liu, YM He, Y Chu, FM Mitchell, TE Wadley, HNG AF Liu, YM He, Y Chu, FM Mitchell, TE Wadley, HNG TI Elastic properties of laminated calcium aluminosilicate/silicon carbide composites determined by resonant ultrasound spectroscopy SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMIC-MATRIX COMPOSITES; MECHANICAL-PROPERTIES; CONSTANTS; FAILURE; DAMAGE AB The elastic properties of unidirectional and 0 degrees/90 degrees crossply Nicalon-SiC-fiber-reinforced calcium aluminosilicate (CAS/SIC) ceramic-matrix composites have been measured using a resonant ultrasound spectroscopy (RUS) technique. This approach has allowed the nondestructive determination of the complete set of independent second-order elastic stiffness constants of these ceramic composites. These stiffness data have been used to obtain the orientation dependence of Young's modulus and the shear modulus. The results are in reasonably good agreement with the limited experimental data obtained from mechanical testing. The RUS measurements reveal that the unidirectional CAS/SiC composite is well modeled by transverse isotropic symmetry, indicating relatively isotropic fiber spacing in the transverse plane. The analysis indicates that the overall elastic anisotropy is also small for unidirectional and 0 degrees/90 degrees laminated CAS ceramic-matrix composites, a result that can be attributed to the relatively low modulus ratio of the Nicalon SiC fiber to the CAS matrix and to the moderate fiber volume fraction. C1 UNIV VIRGINIA,SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,CHARLOTTESVILLE,VA 22903. RP Liu, YM (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, USA. NR 22 TC 5 Z9 5 U1 2 U2 3 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 JAN PY 1997 VL 80 IS 1 BP 142 EP 148 DI 10.1111/j.1151-2916.1997.tb02802.x PG 7 WC Materials Science, Ceramics SC Materials Science GA WF896 UT WOS:A1997WF89600018 ER PT J AU Murphy, MW Armstrong, TR Smith, PA AF Murphy, MW Armstrong, TR Smith, PA TI Tape casting of lanthanum chromite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COMBUSTION SYNTHESIS; SLIP ADDITIVES; DISPERSANTS; TECHNOLOGY; POWDERS; ALUMINA AB The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycine-nitrate-synthesized La0.7Ca0.31CrO3 powder, An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of green tapes, and the sintered microstructure, The tape casting formulation incorporated 66:34 methyl ethyl ketone/ethyl alcohol solvent, an aliphatic phosphate ester dispersant, and 80 wt% (35 vol%) solids, The best binder/plasticizer system was 12 wt% (15 vol%) poly(isobutyl methacrylate) and 5 wt% (6.3 vol%) benzyl butyl phthalate plasticizer (binder:plasticizer = 2.3), Cast tapes were sintered at 1300 degrees C for 2 h, producing a bulk density of 96.2% theoretical, with linear shrinkage of 22% and an approximate grain size of 1.3 mu m. RP Murphy, MW (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 18 TC 38 Z9 39 U1 1 U2 7 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 JAN PY 1997 VL 80 IS 1 BP 165 EP 170 DI 10.1111/j.1151-2916.1997.tb02805.x PG 6 WC Materials Science, Ceramics SC Materials Science GA WF896 UT WOS:A1997WF89600021 ER PT J AU Forslund, DW Cook, JL AF Forslund, DW Cook, JL TI The importance of Java and CORBA in medicine SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Article AB One of the most powerful tools available for telemedicine is a multimedia medical record accessible over a wide area and simultaneously editable by multiple physicians. The ability to do this through an intuitive interface linking multiple distributed data repositories while maintaining full data integrity is a fundamental enabling technology in healthcare. We discuss the role of distributed object technology using Java and CORBA in providing this capability including an example of such a system (TeleMed) which can be accessed through the World Wide Web. Issues of security, scalability, data integrity, and usability are emphasized. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Natl Jewish Ctr Immunol & Resp Med, Denver, CO 80206 USA. RP Forslund, DW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PY 1997 SU S BP 364 EP 368 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA V3182 UT WOS:000171774300074 ER PT J AU Hart, JW Goldbaum, M Cote, B Kube, P Nelson, MR AF Hart, JW Goldbaum, M Cote, B Kube, P Nelson, MR TI Automated measurement of retinal vascular tortuosity SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Article AB Automatic measurement of blood vessel tortuosity is a useful capability for automatic ophthalmological diagnostic tools. We describe a suite of automated tortuosity measures for blood vessel segments extracted from RGB retinal images. The tortuosity measures were evaluated in two classification tasks: (1) classifying the tortuosity of blood vessel segments and (2) classifying the tortuosity of blood vessel networks. These tortuosity measures were able to achieve a classification rate of 91% for the first problem and 95% on the second problem, which confirms that they capture much of the ophthalmologists' notion of tortuosity. C1 Sandia Natl Labs, Appl & Numer Math Dept, Livermore, CA 94550 USA. Univ Calif San Diego, Dept Comp Sci & Engn, San Diego, CA 92103 USA. Univ Calif San Diego, Dept Ophthalmol, San Diego, CA 92103 USA. RP Hart, JW (reprint author), Sandia Natl Labs, Appl & Numer Math Dept, Livermore, CA 94550 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PY 1997 SU S BP 459 EP 463 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA V3182 UT WOS:000171774300093 ER PT J AU Kargupta, H Stafford, B Hamzaoglu, I AF Kargupta, H Stafford, B Hamzaoglu, I TI Web based parallel/distributed medical data mining using software agents SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Meeting Abstract C1 Los Alamos Natl Lab, Div X, Computat Sci Methods Grp, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PY 1997 SU S BP 866 EP 866 PG 1 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA V3182 UT WOS:000171774300197 ER PT J AU Hall, BD Abbott, GB Doebbert, G Snader, J Walsh, JM AF Hall, BD Abbott, GB Doebbert, G Snader, J Walsh, JM TI Tele-reporting for cost-effective public health SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Meeting Abstract C1 Calif Dept Hlth Serv, Sacramento, CA USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Western Consortium Publ Hlth, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PY 1997 SU S BP 1015 EP 1015 PG 1 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA V3182 UT WOS:000171774300344 ER PT J AU Virtanen, S Schmuki, P Davenport, AJ Vitus, CM AF Virtanen, S Schmuki, P Davenport, AJ Vitus, CM TI Dissolution of thin iron oxide films used as models for iron passive films studied by in situ x-ray absorption near-edge spectroscopy SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID IN-SITU; METAL-OXIDES; XANES; PERCHLORATE; DEPOSITION; CORROSION; REDUCTION; MAGNETITE; BORATE; STEEL AB This paper reports results from x-ray absorption near-edge spectroscopy (XANES) studies during polarization of thin sputter-deposited iron oxide films in acidic solutions. The dissolution rate of iron oxides in acidic solutions was found to be strongly increased by the presence of Fe2+ in the oxide. During anodic polarization in acidic solutions, it is found that dissolution is accelerated by chloride anions in comparison with sulfates. In HCl solutions of increasing concentration, not only does the pH decrease, but also the increasing chloride concentration accelerates dissolution. On the other hand, the dissolution rate in sulfuric acid does not depend on the sulfate (bisulfate) concentration. During anodic polarization, the dissolution rate is fairly independent of the potential, except at very high anodic potentials, and the XANES spectra reveal no changes in the average oxide valence during anodic polarization. Thus the dissolution that takes place is mostly chemical rather than electrochemical. During cathodic polarization, the dissolution rate is independent of the anion in the electrolyte. The findings are interpreted in terms of the negative surface charge of n-type oxides at potentials lower than the flatband potential, retarding anion adsorption on the surface. Hence it is suggested that the detrimental role of chloride anions on the stability of iron oxide films is due to a surface complexation effect. The findings and their relevance to the stability of natural passive films on iron surfaces are discussed. RP Virtanen, S (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,DEPT APPL SCI,UPTON,NY 11973, USA. RI Davenport, Alison/J-6089-2013; Virtanen, Sannakaisa/N-3699-2015 OI Davenport, Alison/0000-0003-0853-515X; Virtanen, Sannakaisa/0000-0002-7179-7593 NR 35 TC 35 Z9 35 U1 0 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 JAN PY 1997 VL 144 IS 1 BP 198 EP 204 DI 10.1149/1.1837385 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WG070 UT WOS:A1997WG07000034 ER PT J AU Meeks, E Larson, RS Vosen, SR Shon, JW AF Meeks, E Larson, RS Vosen, SR Shon, JW TI Modeling chemical downstream etch systems for NF3/O-2 mixtures SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTRON-IMPACT-IONIZATION; KINETIC DATA EVALUATION; VAPOR-DEPOSITION; CROSS-SECTIONS; ATMOSPHERIC CHEMISTRY; MATHEMATICAL-MODEL; IUPAC SUBCOMMITTEE; PHOTOCHEMICAL DATA; FLUORINE-ATOMS; RATE CONSTANTS AB Analysis of chemical downstream etch processes investigates ion and radical generation in a plasma source, the transport of species through a transport tube to the process chamber, and resulting etch behavior in the downstream reactor. Downstream etching of silicon dioxide or polysilicon material on a wafer results from chemical etching by F atoms, while ion flux to the wafer must be minimal to avoid ion-induced device damage. In the plasma source, results for NF3 chemistry show that F is the dominant neutral species, while NF2+ and F- are the dominant ions. Comparison of species concentrations in a plasma source with mass spectrometry data available in the literature shows good quantitative agreement. Inclusion of a quartz-etch mechanism within the plasma source reproduces observed erosion rates of quartz applicators used in these systems. Ions persist a small distance beyond electrons in the transport tube region due to negative ion content, but the ion density is reduced to very low levels after traversing the length of the transport tube. The addition of oxygen generally reduces the F-atom concentration downstream and changes the ion composition. Analysis of the reacting flow in the downstream chamber shows the role of species diffusion in determining the etch uniformity and species concentration profiles. Predicted downstream etch rates agree well with measured data over a wide range of process conditions. RP SANDIA NATL LABS, LIVERMORE, CA 94551 USA. NR 69 TC 35 Z9 36 U1 0 U2 2 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 1997 VL 144 IS 1 BP 357 EP 366 DI 10.1149/1.1837410 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WG070 UT WOS:A1997WG07000059 ER PT J AU Omatete, OO Janney, MA Nunn, SD AF Omatete, OO Janney, MA Nunn, SD TI Gelcasting: From laboratory development toward industrial production SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT International Conference on Shaping of Advanced Ceramics CY APR 25-27, 1995 CL MOL, BELGIUM SP Belg Ceram Soc, European Ceram Soc, Vlaamse Instelling Technol Onderzoek ID ADVANCED CERAMICS; COST AB Gelcasting, a ceramic forming process, was developed to overcome some of the limitations of other complex-shape forming techniques such as injection molding and slip casting. In gelcasting, a concentrated slurry of ceramic powder in a solution of organic monomers is poured into a mold and then polymerized in situ to form a green body, in the shape of the mold cavity. Thus, it is a combination of polymer chemistry with slip processing and represents minimal departure from standard ceramic processing. The simplicity of the process has attracted industrial partners and by collaboration between them and the developers, the process is being advanced from the laboratory toward industrial production. (C) 1996 Elsevier Science Limited. RP Omatete, OO (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 27 TC 213 Z9 243 U1 6 U2 45 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1997 VL 17 IS 2-3 BP 407 EP 413 DI 10.1016/S0955-2219(96)00147-1 PG 7 WC Materials Science, Ceramics SC Materials Science GA WC618 UT WOS:A1997WC61800043 ER PT J AU Breder, K Tennery, VJ AF Breder, K Tennery, VJ TI Dynamic fatigue behavior of two SiC and a SiCp reinforced Al2O3 at elevated temperatures SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article ID SILICONIZED SILICON-CARBIDE; HEAT-EXCHANGER MATERIALS; OIL-MIXTURE COMBUSTION; DAMAGE-ENHANCED CREEP; STRENGTH DEGRADATION; COAL SLAGS; ALUMINA; PHENOMENOLOGY; DEFORMATION; MECHANISMS AB Dynamic fatigue behavior of a siliconized SiC, a sintered beta-SiC, and a SiCp (silicon carbide particle)-reinforced Al2O3 formed by directed oxidation of Al metal, which are considered for use in heat exchangers in coal-fired power plants, were evaluated at 1100 and 1400 degrees C in air. Four-point flexure specimens were tested at Jive stressing rates from 37 MPa s(-1) to 0.0001 MPa s(-1) resulting in total times to failure up to 1200 h. Thirty specimens of each material were rested at the fast-fracture condition and 10 specimens were tested at the four dynamic fatigue conditions at each temperature. At 1100 degrees C none of the materials exhibited any loss of strength as a function of stressing rate and very little tendency to creep was observed At 1400 degrees C the sintered beta-SiC exhibited no strength toss, while the siliconized SiC showed a significant loss of strength and some signs of creep at stressing rates less than 0.01 MPa s(-1). The SiCp reinforced Al2O3 exhibited extensive creep at stressing rates ranging from 0.01 to 0.0001 MPa s(-1) at 1400 degrees C, in fact at the slower stressing rates the creep was dominant and the specimens could not be brought to fracture in the four point flexure fixtures. Extensive fractography showed that the failure mode for the sintered beta-SiC was indeed a fast-fracture mode at all temperatures and stressing rates, the specimens mostly failing from pores in the microstructure. The siliconized SiC failed partly from pores and partly from metal inclusions at 1100 degrees C and fast stressing rates, and at 1400 degrees C at slower stressing rates slow crack growth was observed to occur with the Si-metal inclusions as starting points. The failure modes in SiCp reinforced Al2O3 changed from fast fracture from residual Al-alloy rich areas to a creep failure at intermediate stressing rates at 1400 degrees C. (C) 1997 Elsevier Science Limited. RP Breder, K (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 40 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1997 VL 17 IS 13 BP 1579 EP 1586 DI 10.1016/S0955-2219(97)00032-0 PG 8 WC Materials Science, Ceramics SC Materials Science GA YH116 UT WOS:A1997YH11600007 ER PT J AU Pimienta-Barrios, E Nobel, PS Robles-Murguia, C Mendez-Moran, L Pimienta-Barrios, E Yepez-Gonzalez, E AF Pimienta-Barrios, E Nobel, PS Robles-Murguia, C Mendez-Moran, L Pimienta-Barrios, E Yepez-Gonzalez, E TI Ethnobotany, productivity, and ecophysiology of Pitaya (Stenocereus queretaroensis) SO JOURNAL OF THE PROFESSIONAL ASSOCIATION FOR CACTUS DEVELOPMENT LA English DT Article DE cacti; Stenocereus; aridity; ethnobotany; ecophysiology ID WATER RELATIONS; GROWTH; CACTI; PLANTS; DESERT AB Pitaya (Stenocereus queretaroensis) is a columnar cactus that produces attractively colored edible fruits in both wild and cultivated populations in the subtropical semiarid lands of Mexico. Pitaya is a relatively recently domesticated fruit, which during the last 10 years has emerged as a fruit crop whose cultivation is feasible using relatively low inputs of anthropogenic energy or water and whose fruits ripen during the spring season, before summer when the local markets are flooded with other fresh summer fruits. These agronomic traits have increased the economic viability of small farms in semiarid subtropical lands of Mexico. This article summarizes the work on agroecological and biological aspects of Stenocereus queretaroensis conducted during the last seven years in the subtropical semiarid lands of the Sayula Basin, Jalisco, Mexico. Our work is oriented to the development of basic knowledge of the plant and its environment, which allowed us to define opportunities and needs for basic and applied research, oriented to the domestication of pitaya under the modern precepts of sustainable development. C1 Univ Guadalajara, CUCBA, Div Cencias Biol & Ambientales, Dept Ecol, Guadalajara, Jalisco, Mexico. Univ Calif Los Angeles, Dept Biol, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, UCLA DOE Lab, Los Angeles, CA 90024 USA. Univ Guadalajara, CUCBA, Div Ciencias Agron, Dept Agr Prod, Guadalajara, Jalisco, Mexico. RP Pimienta-Barrios, E (reprint author), Univ Guadalajara, CUCBA, Div Cencias Biol & Ambientales, Dept Ecol, Guadalajara, Jalisco, Mexico. RI Yepez, Enrico/C-2802-2014 NR 50 TC 3 Z9 4 U1 0 U2 7 PU PROFESSIONAL ASSOC CACTUS DEVELOPMENT PI DALLAS PA C/O PUBLICATIONS DEPT, 11335 CRESTBROOK DR, DALLAS, TX 75230 USA J9 J PROF ASSOC CACTUS JI J. Prof. Assoc. Cactus Dev. PY 1997 VL 2 BP 29 EP 47 PG 19 WC Horticulture SC Agriculture GA 128GW UT WOS:000076398400005 ER PT J AU Garthwaite, PH Brown, PJ Hand, DJ Wold, S Cox, DR Zidek, JV terBraak, CJF Stone, M Brooks, R Goutis, C Lindley, DV Burnham, AJ MacGregor, JF Viveros, R Hastie, T Tibshirani, R Helland, IS Jones, MC Sasieni, PD Southworth, R Taylor, CC Sundberg, R Thomas, EV Tong, H AF Garthwaite, PH Brown, PJ Hand, DJ Wold, S Cox, DR Zidek, JV terBraak, CJF Stone, M Brooks, R Goutis, C Lindley, DV Burnham, AJ MacGregor, JF Viveros, R Hastie, T Tibshirani, R Helland, IS Jones, MC Sasieni, PD Southworth, R Taylor, CC Sundberg, R Thomas, EV Tong, H TI Predicting multivariate responses in multiple linear regression - Discussion SO JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES B-STATISTICAL METHODOLOGY LA English DT Editorial Material ID PARTIAL LEAST-SQUARES; DISCRIMINANT-ANALYSIS; CONTINUUM REGRESSION; STEIN ESTIMATION; SHRINKAGE; CALIBRATION; COMPONENTS C1 UNIV KENT, CANTERBURY, KENT, ENGLAND. UMEA UNIV, S-90187 UMEA, SWEDEN. UNIV OXFORD NUFFIELD COLL, OXFORD OX1 1NF, ENGLAND. DEINST LANDBOUWKUNDING ONDERZOEK, WAGENINGEN, NETHERLANDS. UCL, LONDON WC1E 6BT, ENGLAND. UNIV CARLOS III MADRID, MADRID, SPAIN. MCMASTER UNIV, HAMILTON, ON, CANADA. STANFORD UNIV, STANFORD, CA 94305 USA. UNIV TORONTO, TORONTO, ON M5S 1A1, CANADA. UNIV OSLO, N-0316 OSLO, NORWAY. OPEN UNIV, MILTON KEYNES MK7 6AA, BUCKS, ENGLAND. HEBREW UNIV JERUSALEM, JERUSALEM, ISRAEL. IMPERIAL CANC RES FUND, LONDON WC2A 3PX, ENGLAND. UNIV LEEDS, LEEDS LS2 9JT, W YORKSHIRE, ENGLAND. UNIV STOCKHOLM, S-10691 STOCKHOLM, SWEDEN. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP UNIV ABERDEEN, ABERDEEN AB9 1FX, SCOTLAND. RI Garthwaite, Paul/A-3664-2009; Jones, Chris/A-3687-2009; ter Braak, Cajo/G-7006-2011 OI ter Braak, Cajo/0000-0002-0414-8745 NR 48 TC 0 Z9 0 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1369-7412 EI 1467-9868 J9 J R STAT SOC B JI J. R. Stat. Soc. Ser. B-Stat. Methodol. PY 1997 VL 59 IS 1 BP 37 EP 54 PG 18 WC Statistics & Probability SC Mathematics GA WU416 UT WOS:A1997WU41600003 ER PT J AU Allen, BP Pauley, EF Sharitz, RR AF Allen, BP Pauley, EF Sharitz, RR TI Hurricane impacts on liana populations in an old-growth southeastern bottomland forest SO JOURNAL OF THE TORREY BOTANICAL SOCIETY LA English DT Article DE woody vines; lianas; hurricane damage; old-growth; bottomland hardwoods; Rhus radicans; Campsis radicans; Vitis spp.; disturbance response ID HOST LIQUIDAMBAR-STYRACIFLUA; WESTERN POISON OAK; TOXICODENDRON-DIVERSILOBUM; VINE COMPETITION; SOUTH-CAROLINA; WATER; TREES; PHOTOSYNTHESIS; DISTURBANCE; UNDERSTORY AB Old-growth bottomland hardwood and slough forests of the Congaree Swamp National Monument, Columbia, SC, were exposed to winds of up to 155 km/hr during Hurricane Hugo in September 1989. Liana distribution and population changes were examined in ten 1 ha plots in 1989-90 and 1994. Prior to the hurricane, vines were not randomly distributed among host tree species. In the bottomland hardwood communities, Liquidambar styraciflua L. and Fraxinus spp. supported relatively more vines, and Ilex spp., Carpinus caroliniana Waiter., and Nyssa spp. had fewer vines than other tree species. Liquidambar styraciflua was more likely to host Rhus radicans than were other tree species. Small trees with lianas suffered disproportionally greater damage from the hurricane than small trees with no lianas; trees of all sizes that supported three or more lianas were more likely to be damaged. Declines in liana populations appear to be related to high tree damage and to hydrologic regime. In sloughs, declines in liana stem density were greater than the levels of canopy damage would predict. Large woody vines that survived grew slowly over the four years following the hurricane. C1 COASTAL CAROLINA UNIV,DEPT BIOL,CONWAY,SC 29528. RP Allen, BP (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 59 TC 32 Z9 33 U1 2 U2 6 PU TORREY BOTANICAL SOCIETY PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0040-9618 J9 J TORREY BOT SOC JI J. Torrey Bot. Soc. PD JAN-MAR PY 1997 VL 124 IS 1 BP 34 EP 42 DI 10.2307/2996596 PG 9 WC Plant Sciences SC Plant Sciences GA XF238 UT WOS:A1997XF23800004 ER PT J AU Wunderlich, B AF Wunderlich, B TI Learning about calorimetry SO JOURNAL OF THERMAL ANALYSIS LA English DT Article; Proceedings Paper CT Proceedings of the 11th International Congress on Thermal Analysis and Calorimetry CY AUG 12, 1996 CL N AMER THERMAL ANAL SOC, PHILADELPHIA, PA HO N AMER THERMAL ANAL SOC DE calorimetry; glass transition; heat capacity; history; melting transition; nonequilibrium; temperature modulated calorimetry; TMC ID GLASS-TRANSITION; HEAT-CAPACITY; MACROMOLECULES; POLYETHYLENE AB Calorimetry deals with the energetics of atoms, molecules, and phases and can be used to gather experimental details about one of the two roots of our knowledge about matter. The other root is structural science. Both are understood from the microscopic to the macroscopic scale, but the effort to learn about calorimetry has lagged behind structural science. Although equilibrium thermodynamics is well known, one has learned in the past little about metastable and unstable states. Similarly, Dalton made early progress to describe phases as aggregates of molecules. The existence of macromolecules that consist of as many atoms as are needed to establish a phase have led, however, to confusion between colloids (collections of microphases) and macromolecules which may participate in several micro- or nanophases. This fact that macromolecules can be as large or larger than phases was first established by Staudinger as late as 1920. Both fields, calorimetry and macromolecular science, found many solutions for the understanding of metastable and unstable states. The learning of modern solutions to the problems of materials characterization by calorimetry is the topic of this paper. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Wunderlich, B (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 25 TC 11 Z9 11 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 1 BP 7 EP 16 DI 10.1007/BF01987417 PG 10 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XD480 UT WOS:A1997XD48000003 ER PT J AU Wunderlich, B Okazaki, I AF Wunderlich, B Okazaki, I TI Modulated differential scanning calorimetry in the glass transition region .4. Model calculations based on poly(ethylene terephthalate) SO JOURNAL OF THERMAL ANALYSIS LA English DT Article; Proceedings Paper CT Proceedings of the 11th International Congress on Thermal Analysis and Calorimetry CY AUG 12, 1996 CL N AMER THERMAL ANAL SOC, PHILADELPHIA, PA HO N AMER THERMAL ANAL SOC DE enthalpy relaxation; glass transition; heat capacity; heat flow calorimeter; hysteresis; poly(ethylene terephthalate); temperature-modulated calorimetry; TMC ID TEMPERATURE AB Temperature-modulated calorimetry (TMC) allows the experimental evaluation of the kinetic parameters of the glass transition from quasi-isothermal experiments. In this paper, model calculations based on experimental data are presented for the total and reversing apparent heat capacities on heating and cooling through the glass transition region as a function of heating rate and modulation frequency for the modulated differential scanning calorimeter (MDSC). Amorphous poly(ethylene terephthalate) (PET) is used as the example polymer and a simple first-order kinetics is fitted to the data. The total heat flow carries the hysteresis information (enthalpy relaxation, thermal history) and indications of changes in modulation frequency due to the glass transition. The reversing heat flow permits the assessment of the first and higher harmonics of the apparent heat capacities. The computations are carried out by numerical integrations with up to 5000 steps, Comparisons of the calculations with experiments ape possible. As one moves further from equilibrium, i.e. the liquid state, cooperative kinetics must be used to match model and experiment. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Wunderlich, B (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 15 TC 35 Z9 35 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 1 BP 57 EP 70 DI 10.1007/BF01987421 PG 14 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XD480 UT WOS:A1997XD48000007 ER PT J AU Boller, A Wunderlich, B AF Boller, A Wunderlich, B TI Multiple melting peak analysis with gel-spun ultra-high molar mass polyethylene SO JOURNAL OF THERMAL ANALYSIS LA English DT Article; Proceedings Paper CT Proceedings of the 11th International Congress on Thermal Analysis and Calorimetry CY AUG 12, 1996 CL N AMER THERMAL ANAL SOC, PHILADELPHIA, PA HO N AMER THERMAL ANAL SOC DE double melting peak; DSC; fiber; polyethylene ID STRUCTURAL-CHANGES; UHMW-POLYETHYLENE; FIBERS; BEHAVIOR; DSC AB The multiple melting peaks observed on differential scanning calorimetry (DSC) of ultrahigh molar-mass polyethylene fibers (UHMMPE) are analysed as a function of sample mass. Using modern DSC capable of recognizing single fibers of microgram size, it is shown that the multiple peaks are in part or completely due to sample packing. Loosely packed fibers fill the entire volume of the pan with rather large thermal resistance to heat flow. On melting, the fibers contract and flow to collect ultimately at the bottom of the pan. This process seems to be able to cause an artifact of multistage melting dependent on the properties of the fibers. A method is proposed to greatly reduce, or even eliminate, errors of this type. The crucial elements of the analysis of melting behavior and melting temperature are decreasing the sample size and packing the individual fibers in a proper geometry, or to introduce inert media to enhance heat transport. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 18 TC 11 Z9 11 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 1 BP 343 EP 349 DI 10.1007/BF01987456 PG 7 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XD480 UT WOS:A1997XD48000042 ER PT J AU Wunderlich, B AF Wunderlich, B TI Detection of multiple nanophases by DSC SO JOURNAL OF THERMAL ANALYSIS LA English DT Article; Proceedings Paper CT Proceedings of the 11th International Congress on Thermal Analysis and Calorimetry CY AUG 12, 1996 CL N AMER THERMAL ANAL SOC, PHILADELPHIA, PA HO N AMER THERMAL ANAL SOC DE DSC; glass transition; heat capacity; melting transition; nanophases; polymers ID HEAT-CAPACITY; THERMODYNAMIC PROPERTIES; LINEAR MACROMOLECULES; GLASS-TRANSITION; POLYMERS AB Polymer molecules have contour lengths which may exceed the dimension of microphases. Especially in semicrystalline samples a single molecule may traverse several phase areas, giving rise to structures in the nanometer region. While microphases have properties that are dominated by surface effects, nanometer-size domains are dominated by interaction between opposing surfaces. Calorimetry can identify such size effects by shifts in the phase-transition temperatures and shapes, as well as changes in heat capacity. Specially restrictive phase structures exist in drawn fibers and in mesophase structures of polymers with alternating rigid and flexible segments. On several samples shifts in glass and melting temperatures will be documented. The proof of rigid amorphous sections at crystal interfaces will be given by comparison with structure analyses by X-ray diffraction and detection of motion by solid state NMR. Finally, it will be pointed out that nanophases need special attention if they are to be studied by thermal analysis since traditional 'phase' properties may not exist. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Wunderlich, B (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 35 TC 4 Z9 4 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 1 BP 513 EP 520 DI 10.1007/BF01987478 PG 8 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XD480 UT WOS:A1997XD48000064 ER PT J AU Pyda, M Wunderlich, B AF Pyda, M Wunderlich, B TI Computation of heat capacities of solid state benzene, p-oligophenylenes and poly-p-phenylene SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE benzene; biphenyl; heat capacity; poly-p-phenylene; p-quaterphenyl; p-terphenyl ID THERMODYNAMIC PROPERTIES; LINEAR MACROMOLECULES; PHASE-TRANSITIONS; PARA-QUATERPHENYL; PARA-TERPHENYL; BIPHENYL AB Heat capacities (C-p) of solid benzene, biphenyl, p-terphenyl, p-quaterphenyl, and poly-p-phenylene were analyzed using the ATHAS Scheme of computation. The calculated heat capacities based on approximate vibrational spectra of solid benzene and the series of oligomers containing additional phenylene groups were compared to experimental data newly measured and from the literature to identify possible additional large-amplitude motion. The skeletal heat capacity was fitted to the Tarasov equation to obtain the one- and three-dimensional vibration frequencies Theta(1) and Theta(3) using a new optimization approach. Their relationship to the number of phenylene groups n is: Theta(1) = 426.0-150.3/n; and Theta(3) = 55.4 + 81.8/n. Except for benzene, the quantitative thermal analyses do not show significant contributions from large-amplitude motion below the melting temperatures. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Pyda, M (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 37 TC 3 Z9 3 U1 0 U2 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 2 BP 685 EP 692 DI 10.1007/BF01996752 PG 8 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XJ183 UT WOS:A1997XJ18300014 ER PT J AU Zhang, G Wunderlich, B AF Zhang, G Wunderlich, B TI Heat capacity of solid state proteins .1. Thermal analysis SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE heat capacity; lactoglobulin; lysozyme; ovalbumin; solid state; vibrational spectrum ID CARBON BACKBONE POLYMERS; LINEAR MACROMOLECULES; THERMODYNAMIC PROPERTIES; SKELETAL VIBRATIONS; POLY(AMINO ACID)S; ADDITION SCHEME; TEMPERATURE; DENATURATION; POLYAMIDES; COLLAGEN AB In an ongoing effort to understand the thermodynamic properties of proteins, ovalbumin, lactoglobulin, lysozyme are studied by adiabatic and differential scanning calorimetry over wide temperature ranges. The heat capacities of the samples in their pure, solid states are linked to an approximate vibrational spectrum with the ATHAS analysis that makes use of known group vibrations and a set of parameters, Theta(1) and Theta(3), of the Tarasov function for the skeletal vibrations. Good agreement is found between experiment and calculation with rms errors mostly within +/-3%. The analyses were also carried out with an empirical addition scheme using data from polypeptides of naturally occurring amino acids. Due to space limitation, only selected results are reported. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Zhang, G (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 40 TC 3 Z9 3 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 2 BP 823 EP 829 DI 10.1007/BF01996766 PG 7 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XJ183 UT WOS:A1997XJ18300028 ER PT J AU Boller, A Okazaki, I Ishikiriyama, K Zhang, G Wunderlich, B AF Boller, A Okazaki, I Ishikiriyama, K Zhang, G Wunderlich, B TI Determination of cell asymmetry in temperature-modulated DSC SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE asymmetry correction; calibration; heat flux calorimeter; heat capacity; power compensated calorimeter; temperature modulated differential scanning calorimetry; TMDSC ID DIFFERENTIAL SCANNING CALORIMETRY AB The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on the symmetry of the twin calorimeters. This symmetry is of particular importance for the temperature-modulated DSC (TMDSC) since positive and negative deviations from symmetry cannot be distinguished in the most popular analysis methods. Three different DSC instruments capable of modulation have been calibrated for asymmetry using standard non-modulated measurements and a simple method is described that avoids potentially large errors when using the reversing heat capacity as the measured quantity. It consists of overcompensating the temperature-dependent asymmetry by increasing the mass of the sample pan. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 11 TC 29 Z9 29 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PY 1997 VL 49 IS 2 BP 1081 EP 1088 DI 10.1007/BF01996796 PG 8 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XJ183 UT WOS:A1997XJ18300058 ER PT J AU Morse, K Weihs, TP Hamza, AV Balooch, M Jiang, Z Bogy, DB AF Morse, K Weihs, TP Hamza, AV Balooch, M Jiang, Z Bogy, DB TI Nanomechanical properties of SiC films grown from C-60 precursors using atomic force microscopy SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID SILICON; CARBIDE AB The mechanical properties of SiC films grown via C-60 precursors were determined using atomic force microscopy (AFM). Conventional silicon nitride and diamond-tipped steel AFM cantilevers were employed to determine the film hardness, friction coefficient, and elastic modulus. The hardness is found to be 26 GPa by nanoindentation of the film with a Berkovich diamond tip. The friction coefficient for the silicon nitride tip on the SiC film is about one half to one third that for silicon nitride sliding on a silicon substrate. By combining nanoindentation and AFM measurements an elastic modulus of similar to 300 GPa is estimated for these SiC films. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV CALIF BERKELEY, DEPT MECH ENGN, BERKELEY, CA 94720 USA. RI Weihs, Timothy/A-3313-2010 NR 15 TC 4 Z9 4 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JAN PY 1997 VL 119 IS 1 BP 26 EP 30 DI 10.1115/1.2832475 PG 5 WC Engineering, Mechanical SC Engineering GA WE854 UT WOS:A1997WE85400004 ER PT J AU Cardinale, GF Medlin, DL Mirkarimi, PB McCarty, KF Howitt, DG AF Cardinale, GF Medlin, DL Mirkarimi, PB McCarty, KF Howitt, DG TI Orientation-dependence of elastic strain energy in hexagonal and cubic boron nitride layers in energetically deposited BN films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID STRESS-INDUCED FORMATION; BORON-NITRIDE; THIN-FILMS AB Using anisotropic elasticity theory, we analyze the relative thermodynamic stabilities of strained graphitic (hexagonal) BN and cubic BN (cBN) single-crystal structures for all orientations ofbiaxial stress and strain fields relative to the crystallographic directions. In hBN, the most thermodynamically stable orientation has the graphitic basal planes oriented roughly 45 degrees relative to either the plane of stress or strain. For cBN, the lowest-energy configuration differs for the constant stress or constant strain assumptions. Importantly, these most-stable orientations of hBN and cBN differ from those found experimentally for graphitic BN and cBN in polycrystalline BN films produced by energetic deposition processes. Therefore, the observed textures are not those that minimize elastic strain energy. We discuss possible origins other than elastic strain-energy effects for the observed textures. (C) 1997 American Vacuum Society. C1 UNIV CALIF DAVIS,DEPT CHEM ENGN & MAT SCI,DAVIS,CA 95616. RP Cardinale, GF (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 34 TC 29 Z9 29 U1 0 U2 9 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 JAN-FEB PY 1997 VL 15 IS 1 BP 196 EP 200 DI 10.1116/1.580465 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WD690 UT WOS:A1997WD69000032 ER PT J AU Vartuli, CB Pearton, SJ Lee, JW MacKenzie, JD Abernathy, CR Shul, RJ AF Vartuli, CB Pearton, SJ Lee, JW MacKenzie, JD Abernathy, CR Shul, RJ TI Electron cyclotron resonance etching of III-V nitrides in IBr/Ar plasmas SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GALLIUM NITRIDE; GAN; INN; ALN; GROWTH AB The etch characteristics of GaN, InN, InAlN, AlN, and InGaN were measured for a new plasma chemistry, IBr/Ar, in an electron cyclotron resonance plasma discharge. The effects of plasma composition (12.5%-100% IBr), microwave (400-1000 W) and rf power (50-250 W) on the etch rates for these materials were examined. The etch rates for GaN depended strongly on plasma composition, while the etch rates were only weakly dependent on microwave power in the range 400-800 W for ail materials. The etch rates for all materials generally increased with increasing rf power, indicating that higher ion energies are much more efficient in enhancing sputter desorption of the etch products. While the etch rates were slower than with either ICl/Ar or Cl-2/Ar, the etched surface of GaN was found to be extremely smooth, with little loss of N from the surface at low rf powers, and no significant residue on the surface. (C) 1997 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 28 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JAN-FEB PY 1997 VL 15 IS 1 BP 98 EP 102 DI 10.1116/1.589260 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA WH688 UT WOS:A1997WH68800014 ER PT J AU Stilianakis, NI Boucher, CAB DeJong, MD VanLeeuwen, R Schuurman, R DeBoer, RJ AF Stilianakis, NI Boucher, CAB DeJong, MD VanLeeuwen, R Schuurman, R DeBoer, RJ TI Clinical data sets of human immunodeficiency virus type 1 reverse transcriptase-resistant mutants explained by a mathematical model SO JOURNAL OF VIROLOGY LA English DT Article ID HIGH-LEVEL RESISTANCE; HIV-INFECTION; IN-VIVO; ZIDOVUDINE THERAPY; DRUG-RESISTANCE; T-LYMPHOCYTES; MUTATIONS; DYNAMICS; DISEASE; SENSITIVITY AB Treatment of human immunodeficiency virus type 1 (HIV-1) infection during the clinical latency phase with drugs inhibiting reverse transcriptase (RT) reduces the HIV-1 RNA load and increases the CD4(+) T-cell count, Typically, however, the virus evolves mutations in the RT gene that circumvent the drugs. We develop a mathematical model for this situation, The model distinguishes quiescent from activated CD4(+) T cells, incorporates the fact that only activated cells can become productively infected by HIV-1, embodies empirical estimates for the drug resistance and the mutation frequency for each of the HIV-1 drug-resistant mutants, and assumes the antiviral immune response to remain constant over the course of the experiments, We analyze clinical data on the evolution of drug-resistant mutants for the RT inhibitors lamivudine and zidovudine, The results show that the evolutionary sequence of the drug-resistant mutants in both data sets is accounted for by our model, given that lamivudine is more effective than zidovudine, Thus, current empirical estimates of the mutation frequencies and the drug resistances of the mutants suffice for explaining the data, We derive a critical treatment level below which the wild-type HIV-1 RNA load can rebound before the first drug-resistant mutant appears, Our zidovudine data confirm this to be the case, Thus, we demonstrate in the model and the data that the rebound of the HIV-1 RNA load in the case of zidovudine is due to the outgrowth of wild-type virus and the first drug-resistant mutant, whereas that in the case of lamivudine can only be due to the drug-resistant mutants, The evolution of drug resistance proceeds slower in the case of zidovudine because (i) zidovudine is not as effective as lamivudine and (ii) the first zidovudine drug-resistant mutant is competing with the rebounding wild-type virus. C1 UNIV UTRECHT,NL-3584 CH UTRECHT,NETHERLANDS. LOS ALAMOS NATL LAB,DIV THEORET,GRP T10,LOS ALAMOS,NM 87545. UNIV UTRECHT,DEPT CLIN MICROBIOL,NL-3508 GA UTRECHT,NETHERLANDS. UNIV AMSTERDAM,ACAD MED CTR,NATL AIDS THERAPY EVALUAT CTR,NL-1012 WX AMSTERDAM,NETHERLANDS. RI De Boer, Rob/B-6050-2011 OI De Boer, Rob/0000-0002-2130-691X NR 37 TC 49 Z9 50 U1 0 U2 2 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 JAN PY 1997 VL 71 IS 1 BP 161 EP 168 PG 8 WC Virology SC Virology GA VX292 UT WOS:A1997VX29200020 PM 8985335 ER PT J AU Mayr, GA Freimuth, P AF Mayr, GA Freimuth, P TI A single locus on human chromosome 21 directs the expression of a receptor for adenovirus type 2 in mouse A9 cells SO JOURNAL OF VIROLOGY LA English DT Article ID FIBER PROTEIN; BINDING DOMAIN; HELA-CELLS; GENE; INFECTION; ATTACHMENT; SEQUENCES; DNA; CONSTRUCTION; SEROTYPE-3 AB The receptors on human cells which mediate adsorption of adenoviruses hare not been identified. We found that murine A9 cells and Chinese hamster ovary (CHO) cells failed to bind significant levels of radiolabeled adenovirus type 2 (Ad2) virions but that derivatives of these cells carrying human chromosome 21 exhibited high levels of virus binding that was specific for the viral fiber protein. G418-resistant A9 cell transformants expressing Ad2 receptors were detected at a frequency of about 10(-4) following cotransfection with high-molecular-weight DNAs from mouse cells containing human chromosome 21 and plasmid DNA containing a neomycin resistance gene. The Ad2 receptors on the transformed A9 cells were similar to those on human cells with respect to their concentration on the cell membrane, their affinity for the viral fiber protein, and their ability to direct virus into cells along a pathway leading to delivery of the viral DNA genome into the cell nucleus. Furthermore, identical human DNA fragments were present in three independent mouse cell transformants expressing Ad2 receptors, supporting the conclusion that these human DNA fragments correspond to a gene or locus on chromosome 21 that directs the expression of Ad2 receptors in these cells. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 47 TC 35 Z9 36 U1 0 U2 0 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 JAN PY 1997 VL 71 IS 1 BP 412 EP 418 PG 7 WC Virology SC Virology GA VX292 UT WOS:A1997VX29200050 PM 8985365 ER PT J AU Ganeshan, S Dickover, RE Korber, BTM Bryson, YJ Wolinsky, SM AF Ganeshan, S Dickover, RE Korber, BTM Bryson, YJ Wolinsky, SM TI Human immunodeficiency virus type 1 genetic evolution in children with different rates of development of disease SO JOURNAL OF VIROLOGY LA English DT Article ID HIV-1 INFECTION; V3 LOOP; 1-INFECTED INDIVIDUALS; SEQUENCE DIVERSITY; IN-VIVO; PROGRESSION; INFANTS; MOTHERS; AIDS; TRANSMISSION AB The rate of development of disease varies considerably among human immunodeficiency virus type I (HIV-1)-infected children. The reasons for these observed differences are not clearly understood but most probably depend on the dynamic interplay between the HIV-1 quasispecies virus population and the immune constraints imposed by the host. To study the relationship between disease progression and genetic diversity, we analyzed the evolution of viral sequences within six perinatally infected children by examining proviral sequences spanning the C2 through V5 regions of the viral envelope gene by PCR of blood samples obtained at sequential visits. PCR product DNAs from four sample time points per child were cloned, and 10 to 13 clones from each sample were sequenced. Greater genetic distances relative to the time of infection were found for children with low virion-associated RNA burdens and slow progression to disease relative to those found for children with high virion-associated RNA burdens and rapid progression to disease. The greater branch lengths observed in the phylogenetic reconstructions correlated with a higher accumulation rate of nonsynonymous base substitutions per potential nonsynonymous site, consistent with positive selection for change rather than a difference in replication kinetics. Viral sequences from children with slow progression to disease also showed a tendency to form clusters that associated with different sampling times. These progressive shifts in the viral population were not found in viral sequences from children with rapid progression to disease. Therefore, despite the HIV-1 quasispecies being a diverse, rapidly evolving, and competing population of genetic variants, different rates of genetic evolution could be found under different selective constraints. These data suggest that the evolutionary dynamics exhibited by the HIV-1 quasispecies virus populations are compatible with a Darwinian system evolving under the constraints of natural selection. C1 NORTHWESTERN UNIV,SCH MED,DEPT MED,CHICAGO,IL 60611. UNIV CALIF LOS ANGELES,DEPT PEDIAT,LOS ANGELES,CA 90095. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RI Wolinsky, Steven/B-2893-2012; OI Wolinsky, Steven/0000-0002-9625-6697; Korber, Bette/0000-0002-2026-5757 FU NICHD NIH HHS [HD-306291, HD-31756]; PHS HHS [R-143994-0] NR 94 TC 123 Z9 127 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 JAN PY 1997 VL 71 IS 1 BP 663 EP 677 PG 15 WC Virology SC Virology GA VX292 UT WOS:A1997VX29200083 PM 8985398 ER PT J AU Dimmel, DR Kuroda, K Pan, XQ Bozell, JJ AF Dimmel, DR Kuroda, K Pan, XQ Bozell, JJ TI Pulping catalysts from lignin .8. Nitrogen dioxide oxidation of lignins to benzoquinones SO JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY LA English DT Article ID ETHER BONDS; TRIMETHYLSILYL IODIDE; CLEAVAGE; PRODUCTS; WOOD AB Several lignin samples have been oxidized with nitrogen dioxide (NO2) in methanol to give low yields of benzoquinones. The yields of 2,6-dimethoxy-p-benzoquinone (DMBQ) from hardwood lignins were highest when the lignin was first extracted to provide a lower molecular weight lignin fraction. The yields of DMBQ were also improved by degrading the lignin to smaller fragments prior to NO2 oxidation. One of the best pretreatments in this regards was heating with copper oxide in aqueous NaOH. Thioacidolysis analysis indicated that p-aryl ether linkages were effectively cleaved by the CuO treatment and that the product mixture contained increased levels of vanillin and syringaldehyde. The best yields of DMBQ from a fractionated lignin and a pretreated lignin were about 10 and 15%, respectively, which corresponds to about 40-60% of the available syringyl units in the lignin. The yields were highest from organosolv Lignins; such lignins are probably less condensed than kraft lignins. The yields were slightly improved when N-hydroxy-succinimide was present. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Dimmel, DR (reprint author), INST PAPER SCI & TECHNOL,500 10TH ST NW,ATLANTA,GA 30318, USA. NR 28 TC 2 Z9 2 U1 2 U2 9 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0277-3813 J9 J WOOD CHEM TECHNOL JI J. Wood Chem. Technol. PY 1997 VL 17 IS 3 BP 235 EP 258 DI 10.1080/02773819708003130 PG 24 WC Materials Science, Paper & Wood SC Materials Science GA XZ192 UT WOS:A1997XZ19200003 ER PT J AU Salit, ML Griesmeyer, JM AF Salit, ML Griesmeyer, JM TI System-ready behaviors for integration SO LABORATORY ROBOTICS AND AUTOMATION LA English DT Article AB A generic eel of behaviors is described for devices so that they can be reliably and readily used as subsystems in an automated systems environment. The automated systems discussed here are constructed of multiple functional subsystems, arrayed hierarchically under a system supervisor. Such systems are typical of those popularly deployed in the chemical laboratory. These systems have had mixed success in the analytical chemistry arena, largely because they are difficult to construct-integrate-and because it is difficult to engineer them to operate reliably. The behaviors described in this article are intended to make devices more simple to integrate as subsystems into a system and to ensure they will operate reliably in that role. (C) 1997 John Wiley & Sons, Inc. C1 SANDIA NATL LABS,INTELLIGENT SYST & ROBOT CTR,ALBUQUERQUE,NM 87185. RP Salit, ML (reprint author), NIST,CTR ANALYT CHEM,CHEM SCI & TECHNOL LAB,CHEM BLDG B154,GAITHERSBURG,MD 20899, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-7533 J9 LAB ROBOTICS AUTOMAT JI Lab. Robot. Autom. PY 1997 VL 9 IS 3 BP 113 EP 118 DI 10.1002/(SICI)1098-2728(1997)9:3<113::AID-LRA3>3.0.CO;2-3 PG 6 WC Automation & Control Systems; Chemistry, Analytical; Robotics SC Automation & Control Systems; Chemistry; Robotics GA XK568 UT WOS:A1997XK56800002 ER PT B AU Meza, JC Plantenga, TD Judson, RS AF Meza, JC Plantenga, TD Judson, RS BE Biegler, LT Coleman, TF Conn, AR Santosa, FN TI Novel applications of optimization to molecule design SO LARGE-SCALE OPTIMIZATION WITH APPLICATIONS, PT 3: MOLECULAR STRUCTURE AND OPTIMIZATION SE IMA VOLUMES IN MATHEMATICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT Workshop on Large-Scale Optimization CY JUL 10-28, 1995 CL UNIV MINNESOTA, INST MATH & ITS APPLICAT, MINNEAPOLIS, MN SP Inst Math & Its Applicat HO UNIV MINNESOTA, INST MATH & ITS APPLICAT DE global optimization; constrained optimization; nonlinear programming; molecular conformation AB We present results from the application of two conformational search methods: genetic algorithms (GA) and parallel direct search methods for finding all of the low energy conformations of a molecule that are within a certain energy of the global minimum. Genetic algorithms are in a class of biologically motivated optimization methods that evolve a population of individuals where individuals who are more "fit" have a higher probability of surviving into subsequent generations. The parallel direct search method (PDS) is a type of pattern search method that uses an adaptive grid to search for minima. In addition, we present a technique for performing energy minimization based on using a constrained optimization method. C1 Sandia Natl Labs, Dept Comp Sci, Livermore, CA 94551 USA. RP Meza, JC (reprint author), Sandia Natl Labs, Dept Comp Sci, MS 9214, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 2 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-98288-4 J9 IMA V MATH PY 1997 VL 94 BP 73 EP 97 PG 25 WC Mathematics, Applied SC Mathematics GA BL01A UT WOS:000074038500005 ER PT B AU More, JJ Wu, ZJ AF More, JJ Wu, ZJ BE Biegler, LT Coleman, TF Conn, AR Santosa, FN TI Issues in large-scale global molecular optimization SO LARGE-SCALE OPTIMIZATION WITH APPLICATIONS, PT 3: MOLECULAR STRUCTURE AND OPTIMIZATION SE IMA VOLUMES IN MATHEMATICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT Workshop on Large-Scale Optimization CY JUL 10-28, 1995 CL UNIV MINNESOTA, INST MATH & ITS APPLICAT, MINNEAPOLIS, MN SP Inst Math & Its Applicat HO UNIV MINNESOTA, INST MATH & ITS APPLICAT AB We discuss the formulation of optimization problems that arise in the study of distance geometry, ionic systems, and molecular clusters. We show that continuation techniques based on global smoothing are applicable to these molecular optimization problems, and we outline the issues that must be resolved in the solution of large-scale molecular optimization problems. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP More, JJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 7 Z9 7 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-98288-4 J9 IMA V MATH PY 1997 VL 94 BP 99 EP 121 PG 23 WC Mathematics, Applied SC Mathematics GA BL01A UT WOS:000074038500006 ER PT J AU Buyko, AM Burenkov, OM Chernyshev, VK Garanin, SF Kuznetsov, SD Kuzyayev, AI Mokhov, VN Morozov, IV Pavlovsky, ES Petrukhin, AA Startsev, AI Yakubov, VB Anderson, BG Ekdahl, CA Kammerdiner, J Lindemuth, IR Reinovsky, RE Rodriguez, P Sheehey, PJ Veeser, LR Younger, SM Zerwekh, B AF Buyko, AM Burenkov, OM Chernyshev, VK Garanin, SF Kuznetsov, SD Kuzyayev, AI Mokhov, VN Morozov, IV Pavlovsky, ES Petrukhin, AA Startsev, AI Yakubov, VB Anderson, BG Ekdahl, CA Kammerdiner, J Lindemuth, IR Reinovsky, RE Rodriguez, P Sheehey, PJ Veeser, LR Younger, SM Zerwekh, B TI Changing mass liner system for generation of soft X rays SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT Zababakhins Scientific Talks CY SEP 16-20, 1995 CL SNEZHINSK, RUSSIA SP All Russian Fed Nucl Ctr VNIITF. Snezhinsk AB Powerful pulse installations are usually used to produce large yields of X-ray radiation. With an increase of the stored energy up to 100 MJ, the cost of a single experiment on these installations becomes comparable to the cost of a shot with explosive magnetic generators (EMG), according to expert estimates. The physical scheme of a device with a changeable mass liner for large soft X-ray (in the range of 0.3 to 0.5 keV) yields generation is investigated. The scheme investigated is substantially free from difficulties connected with high precision liners and fast switches for current pulse sharpening. C1 LANL,LOS ALAMOS,NM. RP Buyko, AM (reprint author), RFNC,VNIIEF,ARZAMAS 607190 16,NIZNY NOVGOROD,RUSSIA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 1 BP 133 EP 138 PG 6 WC Physics, Applied SC Physics GA WZ438 UT WOS:A1997WZ43800015 ER PT J AU Giordano, G Matone, G Luccio, A Miceli, L AF Giordano, G Matone, G Luccio, A Miceli, L TI Coherence in Compton scattering at large angles SO LASER AND PARTICLE BEAMS LA English DT Article ID LASER-LIGHT; X-RAYS; BEAMS; RADIATION AB Compton scattering of laser light by an electron beam at large angles, in particular at 90 degrees, produces coherent hard radiation if the density of the electron beam is high enough. In this case, the intensity of the scattered radiation is greatly enhanced in a small cone around the forward direction of propagation of the electron beam. As an example, the production of 1-KeV coherent X rays is discussed. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Giordano, G (reprint author), IST NAZL FIS NUCL,LAB NAZL FRASCATI,POB 13,I-00044 FRASCATI,ITALY. NR 17 TC 2 Z9 2 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 1 BP 167 EP 177 PG 11 WC Physics, Applied SC Physics GA WZ438 UT WOS:A1997WZ43800019 ER PT J AU Lomaev, MI Panchenko, AN Skakun, VS Sosnin, EA Tarasenko, VF Adamson, MG Myers, BR Wang, FT AF Lomaev, MI Panchenko, AN Skakun, VS Sosnin, EA Tarasenko, VF Adamson, MG Myers, BR Wang, FT TI Excilamp producing up to 130 W of output power and possibility of its applications SO LASER AND PARTICLE BEAMS LA English DT Article ID QUASI-CONTINUOUS OPERATION; MICROWAVE-DISCHARGE; EXCIMER; RADIATION; BARRIER; NM AB Results of an experimental of a coaxial exciplex lamp pumped by glow discharge are presented. An average power of radiation in the wavelength region below 250 nm and as about 130 W has been achieved. Efficiency of the excilamp operation based on input power of 14% was demonstrated. The possibility of applications of this excilamp is discussed. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Lomaev, MI (reprint author), RUSSIAN ACAD SCI,INST HIGH CURRENT ELECT,TOMSK 634055,RUSSIA. RI Tarasenko, Victor/P-1748-2014; Lomaev, Mikhail/D-8045-2014 OI Lomaev, Mikhail/0000-0001-9067-4954 NR 24 TC 13 Z9 13 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 2 BP 339 EP 345 PG 7 WC Physics, Applied SC Physics GA XL043 UT WOS:A1997XL04300011 ER PT J AU Villa, F Luccio, A AF Villa, F Luccio, A TI Test of a high-gradient low-emittance electron gun SO LASER AND PARTICLE BEAMS LA English DT Article ID GENERATOR AB A maximum electric field E = 2.65 GV/m with an accelerated electron current of 1 KA has been obtained, for pulse lengths of 130 ps, in an electron gun based on Pulse Power Technology. This is the highest accelerating field ever achieved in the presence of such a large current. Measurements of beam emittance and energy from 0.4 to 2.65 MeV show that the scaling of the invariant emittance with electric field and with beam current is consistent with theoretical predictions. A few applications of high-gradient acceleration are discussed. C1 FRANTEL INC,LOS GATOS,CA 95030. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Villa, F (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 46 TC 2 Z9 2 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 3 BP 427 EP 447 PG 21 WC Physics, Applied SC Physics GA YC338 UT WOS:A1997YC33800006 ER PT J AU Olson, RE MacFarlane, JJ AF Olson, RE MacFarlane, JJ TI Numerical simulation of radiation-driven targets for light-ion inertial confinement fusion SO LASER AND PARTICLE BEAMS LA English DT Article ID DESIGN; POWER; LIBRA AB Light ion beam inertial confinement fusion (ICF) is a concept in which intense beams of low atomic number ions would be used to drive ICF targets to ignition and gain. Here, results from numerical simulations are presented describing the operation of an indirect-drive light-ion ICF target designed for a commercial power plant application The simulations indicate that the ICF target, consisting of an X-ray-driven capsule embedded in a spherical foam-filled hohlraum, will produce a fusion energy output of over 500 MJ when driven with lithium ion beams containing a total input energy of 8 MJ. C1 UNIV WISCONSIN,FUS TECHNOL INST,MADISON,WI 53706. RP Olson, RE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 23 TC 5 Z9 5 U1 1 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 3 BP 461 EP 470 PG 10 WC Physics, Applied SC Physics GA YC338 UT WOS:A1997YC33800008 ER PT J AU Parsa, Z AF Parsa, Z TI Symposium summary report: New Modes of Particle Acceleration Technique and Sources, August 19-23, 1996 SO LASER AND PARTICLE BEAMS LA English DT Editorial Material ID ELECTRON ACCELERATION; PLASMA-WAVES; LASER-PULSE; DRIVEN RP Parsa, Z (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 3 BP 473 EP 480 PG 8 WC Physics, Applied SC Physics GA YC338 UT WOS:A1997YC33800010 ER PT J AU Campbell, EM Holmes, NC Libby, SB Remington, BA Teller, E AF Campbell, EM Holmes, NC Libby, SB Remington, BA Teller, E TI The evolution of high-energy-density physics: From nuclear testing to the superlasers SO LASER AND PARTICLE BEAMS LA English DT Review ID RAYLEIGH-TAYLOR INSTABILITY; RICHTMYER-MESHKOV INSTABILITY; X-RAY LASER; INERTIAL CONFINEMENT FUSION; RADIATION-DRIVEN SHOCK; FLUID NITROGEN; HIGH-PRESSURE; 3-DIMENSIONAL SIMULATIONS; TEMPERATURE-MEASUREMENTS; ABSORPTION-MEASUREMENTS AB We describe the role for the next-generation "superlasers" in the study of matter under extremely high-energy-density conditions in comparison with previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues that must be addressed by experiment: equations of state, hydrodynamic instabilities, and the transport of radiation. We describe some of the advantages the large lasers will have in a comprehensive, laboratory-based experimental program. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Campbell, EM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 152 TC 26 Z9 27 U1 1 U2 9 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1997 VL 15 IS 4 BP 607 EP 626 PG 20 WC Physics, Applied SC Physics GA YN983 UT WOS:000071229600013 ER PT B AU Paul, JD Hall, CR Mozzano, S Grant, S AF Paul, JD Hall, CR Mozzano, S Grant, S BE Linden, KJ TI Development of a passive electrical-to-optical pulse converter for the production of high resolution fiducial signals SO LASER DIODE AND LED APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Diode and LED Applications III CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE fiber-coupled laser diode; optical isolation; saturable-core transformer; low-jitter timing; high-resolution fiducial; streak cameras AB The analysis of many high explosives (HE) involves the use of rotating-mirror cameras and high speed film. Fiducial timing spots are made on the film to provide temporal reference to the experimenter during subsequent evaluation. The writing speed of the ''streak'' camera is 10 millimeters per microsecond, thus, the optical fiducial pulse width must be on the order of tens of nanoseconds to generate a useful spot size. For this application, a useful spot size corresponds to a width of 200-300 micrometers. Present systems employ light-emitting diodes for this task, mounting them at the focal point of the camera. However, the size and clarity of the current timing spot on the film is less than optimum. Furthermore, experiments involving high explosives require the isolation of the electronic instrumentation from the experimental hardware and passive operation is always preferred if not required. This is due to safety requirements as well as instrumentation ground loop and EMP concerns. Another restriction is the diminished sensitivity of the high-speed film to wavelengths above 600 nanometers, which narrows the field of possible optical sources considerably. A passive, fiber-coupled system based upon a 635 nanometer laser diode has been developed and tested. The development process, final design and test results are presented and the improved signal resolution is compared with current technology. RP Paul, JD (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2411-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 3000 BP 178 EP 187 DI 10.1117/12.263490 PG 10 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BH07E UT WOS:A1997BH07E00020 ER PT B AU Yan, M Torres, R Runkel, M Woods, B Hutcheon, I Zaitseva, N DeYoreo, J AF Yan, M Torres, R Runkel, M Woods, B Hutcheon, I Zaitseva, N DeYoreo, J BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Impurity and laser-induced damage in the growth sectors of rapidly grown KDP crystals SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE impurities; laser induced damage; KDP; crystals AB We report the experimental results of impurity contamination and laser-induced damage investigations on rapidly grown potassium dihydrogen phosphate (KDP) crystals. Using absorption spectroscopy and chemical analysis, we determind the impurity distribution in the different growing sectors of KDP single crystals. The level of impurity was dependent on the starting materials and growth rate. We also studied the influence of impurities on the laser-induced damage in fast grown KDP. The laser damage threshold in the impurity-rich prismatic sector is same as in the high purity pyramidal sector within the experiemntal error. Meanwhile, the laser damage threshold (LDT) at the boundary of the prismatic and pyramidal sectors is less than half of that in the bulk. Furthermore, we found that the thermal annealing of the crystal eliminated the weakness of this sector boundary and increased its LDT to the same level as in the bulk of the crystal. Our result suggests that laser damage occured in the vicinity of a high, localized strain field. RP Yan, M (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-250,LIVERMORE,CA 94550, USA. NR 0 TC 12 Z9 12 U1 1 U2 4 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 11 EP 16 DI 10.1117/12.274277 PG 6 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00002 ER PT B AU Woods, B Runkel, M Yan, M Staggs, M Zaitseva, N Kozlowski, M DeYoreo, J AF Woods, B Runkel, M Yan, M Staggs, M Zaitseva, N Kozlowski, M DeYoreo, J BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Investigation of damage in KDP using light scattering techniques SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE KDP; DKDP; bulk damage; optical scatter; thermal conditioning; strain birefringence AB Interest in producing high damage threshold KH2PO4 (KDP) and (DxH1-x)(2)PO4 (DKDP)(also called KD*P) for frequency conversion and optical switching applications is driven by the requirements of the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL). At present only the best crystals meet the NIF system requirements at the third harmonic (351nm) and only after a laser conditioning process. Neither the mechanism for damage in bulk KDP nor the mechanism for conditioning is understood. As part of a development effort to increase the damage thresholds of KDP and DKDP, we have been developing techniques to pinpoint the locations where damage will initiate in the bulk material. After we find these locations we will use other measurement techniques to determine how these locations differ from the other surrounding material and why they cause damage. This will allow crystal growers to focus their efforts to improve damage thresholds. Historically, damage thresholds have increased it is believed as a consequence of increased purity of the growth solution and through the use of constant filtration during the growth process(1). As a result we believe that damage is caused by defects in the crystals and have conducted a series of experiments using light scatter to locate these defects and to determine when and where damage occurs. In this paper we present results which show a low correlation between light scatter from bulk defects in KDP and the initiation sites for damage. We have also studied the effects of thermal conditioning on light scatter, strain induced birefringence and damage threshold. We have seen evidence that regions of high strain also exhibit lower damage threshold than the surrounding lower strain material. When thermally conditioned, these crystals show a decrease in some of the strong linear scattering features and a decrease in the strain birefringence while the damage threshold in these regions increased to that of the surrounding bulk material. RP Woods, B (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-490,LIVERMORE,CA 94550, USA. NR 0 TC 12 Z9 12 U1 2 U2 6 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 20 EP 31 DI 10.1117/12.274275 PG 12 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00004 ER PT B AU Cooke, DW Bennett, BL Muenchausen, RE Thomas, JC Cockroft, NJ Quagliano, JR Petrin, RR Maggiore, CJ Paffett, MT Wayne, DM Taylor, TN Hawley, M Jacco, JC Scripsick, MP AF Cooke, DW Bennett, BL Muenchausen, RE Thomas, JC Cockroft, NJ Quagliano, JR Petrin, RR Maggiore, CJ Paffett, MT Wayne, DM Taylor, TN Hawley, M Jacco, JC Scripsick, MP BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Pyroelectricity and its role in optical damage of potassium titanyl phosphate crystals SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE KTP; photochromic damage; electrochromic damage; pyroelectric effects; optical scintillations; nonlinear optical crystals; second harmonic generation; optical damage AB The origin of optical damage in potassium titanyl phosphate (KTP) crystals has been vigorously investigated since its introduction as a nonlinear optical material in 1976. It is well known that this material exhibits a laser damage threshold that limits its use in many high average-power applications, especially frequency doubling of Nd-doped lasers. Both photochromic and electrochromic damage can be induced in KTP. Until recently, it was thought that these two types of damage were distinctly different, possibly involving different mechanisms; however, new data show that electrochromic-like damage can be induced in KTP by laser irradiation only, implying the existence of an internal electric field. We have recently observed bursts of light (optical scintillations) when heating KTP crystals at 0.1 - 1.0 Ws in the temperature range 8 - 675 K. The scintillations correspond to molecular nitrogen emission occurring during the electrical breakdown of air near the crystal surface, and imply the existence of pyroelectric fields in KTP exceeding 30 kV/cm. These gelds (and concomitant currents) were induced by 10.6 mu m laser irradiation. The observation of pyroelectric effects, heretofore not considered in KTP damage models, provides an important new insight into the possible cause of the recently observed ''electrochromic-like'' photochromic damage in KTP. RP Cooke, DW (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MST-4,MS E546,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 41 EP 47 DI 10.1117/12.274280 PG 7 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00006 ER PT B AU Campbell, JH Hurst, PA Heggins, DD Steele, WA Bumpas, SE AF Campbell, JH Hurst, PA Heggins, DD Steele, WA Bumpas, SE BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Laser induced damage and fracture in fused silica vacuum windows SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE fused silica; laser damage; glass fracture; spatial filter lens AB Laser induced damage, that initiates catastrophic fracture, has been observed in large (up to 61-cm diameter), fused silica lenses that also serve as vacuum barriers in high-fluence positions on the Nova and Beamlet lasers. In nearly all cases damage occurs on the vacuum (tensile) side of the lens. The damage can lead to catastrophic crack growth if the flaw (damage) size exceeds the critical flaw size for SiO2. If the elastic stored energy in the lens is high enough, the lens will fracture into many pieces resulting in an implosion. The consequences of such an implosion can be severe, particularly for large vacuum systems. Three parameters control the degree of fracture in the vacuum barrier window: 1) the elastic stored energy (i.e. tensile stress) 2) the ratio of the window thickness to flaw depth and 3) secondary crack propagation. Fracture experiments have been carried out on 15-cm diameter fused silica windows that contain surface flaws caused by laser damage. The results of these experiments, combined with data from window failures on Beamlet and Nova have been used to develop design criteria for a ''fail-safe'' lens (that is, a lens that may catastrophically fracture but will not implode). Specifically the window must be made thick enough such that the peak tensile stress is less than 500 psi (3.4 MPa) and the corresponding ratio of the thickness to critical flaw size is less that 6. Under these conditions a properly mounted window, upon failure, will break into only two pieces and will. not implode. One caveat to these design criteria is that the air leak through the window fracture and into the vacuum must be rapid enough too reduce the load on the window before secondary crack growth occurs. Finite element stress calculations of a window before and immediately following fracture into two pieces show that the elastic stored energy is redistributed if the fragments ''lock'' in place and thereby bridge the opening. In such cases, the peak stresses at the flaw site can increase leading to further (i.e. secondary) crack growth. RP Campbell, JH (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-487,LIVERMORE,CA 94550, USA. NR 0 TC 11 Z9 11 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 106 EP 125 DI 10.1117/12.274227 PG 20 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00014 ER PT B AU Genin, FY Michlitsch, K Furr, J Kozlowski, MR Krulevitch, P AF Genin, FY Michlitsch, K Furr, J Kozlowski, MR Krulevitch, P BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Laser-induced damage of fused silica at 355 and 1064 nm initiated at aluminum contamination particles on the surface SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE surface contamination; laser-induced damage; functional damage; damage morphology; fused silica; metal contamination; 355 nm; 1064 nm AB Contamination particles of controlled size and shape were deposited onto 1.14 cm thick fused silica windows by sputtering Al through a mask. The particles were 1 mu m thick circular dots, 10 to 250 mu m in diameter. Al shavings were also deposited on the windows to investigate the effects of particle-substrate adhesion. The silica windows were then illuminatedrepetitivlyusing a 3-ns, 355 nm and an 8.6-ns, 1064 nm laser. The tests were conducted at near normal incidence with particles on the input and output surfaces of the window. During the first shot, a plasma ignited at the metal particle and damage initiated on the fused silica surface. The morphological features of the damage initiated at the metal dots were very reproducible but different for input and output surface contamination. For input surface contamination, minor damage occurred where the particle was located;such damage ceased to grow with the removal of contaminant material. More serious damage (pits and cracks) n as initiated on the output surface (especially at 355 nm) and grew to catastrophic proportions after few shots. Output surface contaminantswere usually ejected on the initial shot, leaving a wave pattern on the surface. No further damage occurred with subsequent shots unless a shot (usually the first shot) cracked the surface; such behavior was mostly observed at 355 nm and occasionally for large shavings at 1064 nm. The size of the damaged area scaled with the size of the particle (except when catastrophic damage occurred). The onset of catastrophic damage on the output surface occurred only when particles exceeded a critical size. The damage behavior of the sputtered dots was found to be qualitatively. similar to that of the shavings. The artificial contamination technique accelerated the study by allowing better control of the Lest conditions. RP Genin, FY (reprint author), LAWRENCE LIVERMORE NATL LAB,LASER MAT DEPT,POB 808,L-476,LIVERMORE,CA 94550, USA. NR 0 TC 12 Z9 12 U1 0 U2 4 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 126 EP 138 DI 10.1117/12.274242 PG 13 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00015 ER PT B AU Newnam, BE DeShazer, LG AF Newnam, BE DeShazer, LG BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Surface damage resistance of calcite crystals to nanosecond-pulse, 694-nm laser radiation SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers RP Newnam, BE (reprint author), LOS ALAMOS NATL LAB,LER,ADTT,H854,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 147 EP 147 DI 10.1117/12.274295 PG 1 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00017 ER PT B AU Wilcox, RB Browning, DF AF Wilcox, RB Browning, DF BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Integrated optic modulator and splitter damage at 1053nm SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE damage tests; fiber laser; modulator; lithium niobate; fiber optic components AB We are designing and developing a single mode fiber laser and modulation system for use in an inertial confinement fusion research laser, the National Ignition Facility (NIF). Our fiber and integrated optic oscillator / modulator system generates optical pulses of around 30 nanoseconds duration, at one kilohertz, with up to 500 nanojoules of energy. This is enough to potentially damage some of the single mode fiber and waveguide components. To test these components, we have built a test system using a diode-pumped Nd:YLF laser, producing 10 microjoules in 120 nanoseconds at 500 hertz. This system has been used to test commercial lithium niobate integrated optic modulators, silica-on-silicon waveguide splitters, lens-coupled dichroic mirror splitters, and other fiber optic components. We present results of damage tests and efforts to improve performance. RP Wilcox, RB (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-444,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 251 EP 257 DI 10.1117/12.274274 PG 7 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00033 ER PT B AU Stolz, CJ Genin, FY Reitter, TA Molau, N Bevis, RP vonGunten, MK Smith, DJ Anzellotti, JF AF Stolz, CJ Genin, FY Reitter, TA Molau, N Bevis, RP vonGunten, MK Smith, DJ Anzellotti, JF BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Effect of SiO2 overcoat thickness on laser damage morphology of HfO2/SiO2 Brewster's angle polarizers at 1064 nm SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE laser-induced damage; hafnia-silica polarizers; laser damage morphology; electric-field distribution; thermal gradients; stress gradients; silica overcoat AB HfO2/SiO2 Brewster's angle polarizers are being developed at Lawrence Livermore National Laboratory for the National Ignition Facility. Damage threshold studies using a 3-ns pulse length 1064-nm laser have revealed a number of different damage morphologies such as nodular ejection pits, plasma scalds, and overcoat delaminations. Of these laser damage morphologies, delaminations have the most negative impact on fusion laser performance. By increasing the thickness of the SiO2 overcoat, the delamination morphology is eliminated without significantly modifying the spectral characteristics of the coating. A model of the thermal mechanical response of the overcoats is presented for various SiO, overcoat thicknesses. The overcoat thickness influences the electric-field profile resulting in different thermal gradients between the outer SiO2 and HfO2 layers. This modeling effort attempts to understand the relationship between the thermal stress distribution in the overcoat and the occurrence of delamination. RP Stolz, CJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-487,LIVERMORE,CA 94550, USA. NR 0 TC 18 Z9 19 U1 0 U2 5 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 265 EP 272 DI 10.1117/12.274272 PG 8 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00035 ER PT B AU Genin, FY Stolz, CJ Kozlowski, MR AF Genin, FY Stolz, CJ Kozlowski, MR BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Growth of laser-induced damage during repetitive illumination of HfO2-SiO2 multilayer mirror and polarizer coatings SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE laser-induced damage; damage growth; damage morphology; hafnia-silica mirrors and polarizers; 1064 nm AB As designers want to increase the peak fluence of high power laser, it becomes necessary to tolerate some damage on mirrors and polarizers. To quantify how the different types of damage morphologies initiate and grow during repetitive illumination, hafnia-silica multilayer mirror and polarizer coatings were laser damage tested. The coatings were prepared bye-beam evaporation and irradiated with a 3-ns-pulse at 1064 nm. The morphology of laser-induced damage was recoded after each shot to determine the types of damage that cause massive unstable failure and lower the optic's functional damage threshold. The results of the tests were summarized on damage stability maps plotting the average damage size as a function of the number of shots for fluences ranging from 10 to 40 J/cm(2). The maps indicate that the commonly observed damage morphologies (i.e. pits, flat bottom pits, scalds and outer layer delamination) have distinct growth behaviors and influence the value of the functional damage threshold differently. While pits are stable up to fluences as high as 40 J/cm(2). flat bottom pits can grow during repetitive illumination above a critical fluence of about 35 J/cm(2). Scalds are formed in the first shot and never grow at fluences below 40 J/cm(2). Finally, delaminates are highly unstable and have the potential for damaging the coating catastrophically above 15 J/cm(2). The results show that the delaminate damage morphology should be prevented. This knowledge has allowed coatings development efforts to focus on eliminating the origin of such damage morphology. RP Genin, FY (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-476,LIVERMORE,CA 94550, USA. NR 0 TC 25 Z9 25 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 273 EP 282 DI 10.1117/12.274244 PG 10 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00036 ER PT B AU Exarhos, GJ Dennis, T AF Exarhos, GJ Dennis, T BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI CW laser compaction of aqueous solution deposited metal oxide films SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE laser induced fluorescence; lithography; microstructure; phase transformation; thin film; topology; zirconia AB Zirconium dioxide films were spin cast onto silica or silicon substrates from an aqueous solution comprised of the precursor metal nitrate and an organic complexant such as glycine. The hydrated films so derived consist of an amorphous organic phase in which the metal cations and nitrate anions are homogeneously dispersed. Heating to temperatures above 200 degrees C leads to film dehydration followed by an auto-catalyzed oxidation reaction whereby the bound nitrate oxidizes the organic matrix leaving behind an intact stoichiometric and crystalline metal oxide film. Films are characterized using AFM, XRD, and optical methods. Transformation processes in these films have been studied in detail by means of spectroscopic ellipsometry and laser induced fluorescence from films doped with a suitable rare earth probe ion such as Sm+3. In the latter case, the measured fluorescence emission spectra are used to identify the hydrated, dehydrated, amorphous and crystalline metal oxide phases which evolve during processing. These transformations also have been induced upon visible CW laser irradiation at fluences in excess of 1 MW/cm(2). Under these conditions, the film dehydrates and compacts within the footprint of the incident laser beam rendering this region of the film water insoluble. Post irradiation washing of the film with water removes all vestiges of the film outside of the beam footprint suggesting a possible use of this technique for lithography applications. Films subjected to laser irradiation and post irradiation heating have been characterized with respect to thickness, phase composition, crystallite size and optical constants. RP Exarhos, GJ (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,MS K2-44,RICHLAND,WA 99352, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 307 EP 314 DI 10.1117/12.274284 PG 8 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00040 ER PT B AU Genin, FY Stolz, CJ Reitter, T Kozlowski, MR Bevis, RP vonGunten, MK AF Genin, FY Stolz, CJ Reitter, T Kozlowski, MR Bevis, RP vonGunten, MK BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Effect of electric field distribution on the morphologies of laser-induced damage in hafnia-silica multilayer polarizers SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE laser-induced damage; hafnia-silica polarizers; damage morphology; conditioning; 1064 nm; electric field distribution; stress gradients; beam incidence angle AB Hafnia-silica multilayer polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The polarizers were designed to operate at a wavelength of 1064 nm at Brewster's angle (56 degrees). The polarizers were tested with a 3-ns laser pulse at 45 degrees, 56 degrees, and 65 degrees incidence angle in order to vary the electric field distribution in the multilayer, study their effects on the damage morphology, and investigate the possible advantages of off-use angle laser conditioning. The morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies (pit, flat bottom pit, scald, and outer layer delamination) were observed. These damage morphologies were found to depend strongly on the angle of incidence of the laser beam. In particular, massive delamination observed at 45 degrees and 56 degrees incidence, did not occur at 65 degrees. Instead, large and deep pits were found at 65 degrees. The electric field distribution, the temperature rise and the change in stress in the multilayer were calculated to attempt to better understand the relationship between damage morphology, electric field peal; locations, and maximum thermal stress gradients. The calculations showed a two-fold increase in stress change in the hafnia top layers depending on the incidence angle. The stress gradient in the first hafnia-silica interface was found to be highest for 45 degrees, 56 degrees, and 65 degrees, respectively. Finally the maximum stress was deeper in the multilayer at 65 degrees. Although the limitations of such simple thermal mechanical model are obvious, the results can explain that outer layer delamination is more likely at 45 degrees and 56 degrees than 65 degrees and that damage sites are expected to be deeper at 65 degrees. RP Genin, FY (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-476,LIVERMORE,CA 94550, USA. NR 0 TC 10 Z9 12 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 342 EP 352 DI 10.1117/12.274243 PG 11 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00044 ER PT B AU Chow, R Taylor, JR Wu, ZL Krupka, R Yang, TL AF Chow, R Taylor, JR Wu, ZL Krupka, R Yang, TL BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI High reflector absorptance measurements by the surface thermal lensing technique SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE weak absorption measurement; surface thermal lensing; photothermal radiometry; optical thin films AB Surface thermal lensing is an alternate configuration of a photothermal deflection system that was used to measure low levels of optical absorption. The thermal lensing configuration facilitated the alignment of the pump and probe laser beams by using a larger diameter probe beam. This technique was applied to high performance optical coatings, specifically high reflectors at 511 nm, zero degrees angle of incidence. The absorptance of these coatings was previously measured using a high power copper vapor laser system. A high power copper laser beam is focused onto a similar to 2 mm diameter spot. A thermal camera senses the temperature rise with respect to the rest of the coating. The temperature change, power density and beam diameter were used with an empirical formula that yields optical absorption. The surface thermal lensing technique was able to resolve absorption levels lower than that achieved with the copper laser method. RP Chow, R (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-340,LIVERMORE,CA 94550, USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 354 EP 361 DI 10.1117/12.274226 PG 8 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00046 ER PT B AU Feit, MD Rubenchik, AM Faux, DR Riddle, RA Shapiro, A Eder, DC Penetrante, BM Milam, D Genin, FY Kozlowski, MR AF Feit, MD Rubenchik, AM Faux, DR Riddle, RA Shapiro, A Eder, DC Penetrante, BM Milam, D Genin, FY Kozlowski, MR BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Modeling of laser damage initiated by surface contamination SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers AB We are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, ''splashing'' of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations. On the entrance optical surface, small particles can ablate nearly completely. In this case, only relatively weak shockwaves are launched into the substrate, but some particulate material may be left on the surface to act as a diffraction mask and cause further absorption. Diffraction by wavelength scale scattering centers can lead to significant intensity modulation. Larger particles will not be completely vaporized. The shockwave generated in this case is larger and can lead to spallation of contaminant material which then may be deposited in the substrate. A gaseous atmosphere can lead to radiation trapping with concomitant increases in temperature and pressure near the surface. In addition, supersonic ionization waves in air may be generated which greatly extend the plasma plume spatially and temporally. Contaminants on the exit optical surface behave differently. They tend to heat and pop off completely in which case significant damage may not occur. Since plasma formed at the interface of the optic and absorbing particle is confined, much stronger pressures are generated in this case. Imaging of contaminants resulting in ''writing'' a diffraction pattern on the exit surface due to contamination on the entrance surface has been observed experimentally and predicted theoretically. Such imprinted damage regions can seed damage from subsequent pulses. RP Feit, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-438,LIVERMORE,CA 94550, USA. RI Feit, Michael/A-4480-2009 NR 0 TC 17 Z9 18 U1 0 U2 10 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 417 EP 424 DI 10.1117/12.274234 PG 8 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00052 ER PT B AU Milam, D Hunt, JT Manes, KR Williams, WH AF Milam, D Hunt, JT Manes, KR Williams, WH BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Modeling of filamentation damage induced in silica by 351-nm laser pulses SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers AB A major risk factor that must be considered in design of the National Ignition Facility is the possibility for catastrophic self-focusing of the 351-nm beam in the silica optical components that are in the final section of the laser. Proposed designs for the laser are analyzed by the beam-propagation code PROP92. A 351-nm self-focusing experiment, induction of tracking damage, was done to provide data for validation of this code. The measured self-focusing lengths were correctly predicted by the code. RP Milam, D (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,L-490,LIVERMORE,CA 94550, USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 425 EP 428 DI 10.1117/12.274283 PG 4 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00053 ER PT B AU Ferris, KF Exarhos, GJ Risser, SM AF Ferris, KF Exarhos, GJ Risser, SM BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Microstructural and dielectric susceptibility effects on predictions of dielectric properties SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE electric fields; dielectric constant; microstructure; effective medium approximation AB In modeling the dielectric properties of inhomogeneous materials, the treatment of the electric field interactions differentiate the usual modeling formalisms (such as the Maxwell-Garnett and Bruggeman effective medium methods) and their accuracy. In this paper, we show that the performance of effective medium methods is dependent upon a number of variables - defect concentration, alignment, and the dielectric constant of the material itself. Using our previously developed finite element model of an inhomogeneous dielectric, we have developed models for a number of dielectric films of varying dielectric constant and microstructures. Alignment of defects parallel to the applied field and the larger defect aspect ratios increase the overall dielectric constant. The extent of these effects is dependent on the dielectric constant of the bulk component. RP Ferris, KF (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,MAT & CHEM SCI CTR,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 430 EP 440 DI 10.1117/12.274236 PG 11 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00055 ER PT B AU Rainer, F Anderson, A Burnham, A Milam, D Turner, R AF Rainer, F Anderson, A Burnham, A Milam, D Turner, R BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Lifetime survivability of contaminated target-chamber optics SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE B4C; contamination; first-wall material; laser damage; lifetime; target chamber AB Target chambers used for Inertial Confinement Fusion (ICE) expose laser optics to a very hostile environment not only from high-fluence laser irradiation but also x-ray irradiation and particulate debris from targets and chamber wall materials. Expendable debris shields provide the first line of defense to more costly optics upstream in the laser beam path to contaminants generated within the target chamber. However, the replacement of a large number of debris shields is also an expensive proposition so that extending their usable lifetime within the chamber is of crucial importance. We have conducted tests to show that optics can both be cleaned and damaged by laser irradiation at 355 nm after being contaminated with potential chamber-wall materials such as B4C and Al2O3. Such optics can survive from one to hundreds of laser shots depending on the degree of contamination and laser fluence levels. Similarly, we have studied the survivability of optics that have been exposed to direct contamination from representative target materials irradiated in the target chamber. We have also studied the effects on optics that were not directly exposed to targets yet received secondary exposure from the above directly-exposed samples. RP Rainer, F (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-487,LIVERMORE,CA 94550, USA. NR 0 TC 3 Z9 3 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 463 EP 473 DI 10.1117/12.274291 PG 11 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00058 ER PT B AU Feit, MD Rubenchik, AM AF Feit, MD Rubenchik, AM BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI Laser intensity modulation by nonabsorbing defects SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers AB Nonabsorbing defects can lead to laser damage. Defects such as voids, microcracks and localized stressed concentrations, even if they differ from the surrounding medium only by refractive index, can serve as positive or negative lenses for the incident laser light. The resulting interference pattern between refracted and diffracted light can result in intensity increases on the order of a factor of 2 some distance away from a typical negative microlens, and even larger for a positive microlens. Thus, the initial damage site can be physically removed from the defect which initiates damage. The parameter that determines the strength of such lensing is (Ka)2 Delta epsilon where the wavenumber K is 2 pi/lambda, 2a is the linear size of the defect and Delta epsilon is the difference in dielectric coefficient between matrix and scatterer. Thus, even a small change in refractive index results in a significant effect for a defect large compared to a wavelength. Geometry is also important. Three dimensional leg. voids) as well as linear and planar leg. cracks) microlenses can all have strong effects. The present paper evaluates the intensification due to spherical voids and high refractive index inclusions. RP Feit, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-438,LIVERMORE,CA 94550, USA. RI Feit, Michael/A-4480-2009 NR 0 TC 3 Z9 3 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 475 EP 480 DI 10.1117/12.274235 PG 6 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00060 ER PT B AU Setchell, RE AF Setchell, RE BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI An optimized fiber delivery system for Q-switched, Nd:YAG lasers SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers DE high-intensity fiber transmission; laser damage in optical fibers AB Interest in the transmission of high intensities through optical fibers is being motivated by an increasing number of applications. Using different laser types and fiber materials, various studies are encountering transmission limitations due to laser-induced damage processes. For a number of years we have been investigating these limiting processes during the transmission of Q-switched, multimode, Nd:YAG laser pulses through step-index, multimode, fused-silica fiber. We have found that fiber transmission is often limited by a plasma-forming breakdown occurring at the fiber entrance face. This breakdown can result in subtle surface modifications that leave the entrance face more resistant to further breakdown or damage events. Catastrophic fiber damage can also occur as a result of a variety of mechanisms, with damage appearing at fiber entrance and exit faces, within the initial ''entry'' segment of the fiber path, and at other internal sites due to fiber fixturing and routing effects. System attributes that will affect breakdown and damage thresholds include laser characteristics, the design and alignment of laser-to-fiber injection optics, and fiber end-face preparation. In the present work we have combined insights gained in past studies in order to establish what thresholds can be achieved if all system attributes can be optimized to some degree. Our multimode laser utilized past modifications that produced a relatively smooth, quasi-Gaussian profile. The laser-to-fiber injection system achieved a relatively low value for the ratio of peak-to-average fluences at the fiber entrance face, incorporated a mode scrambler to generate a broad mode power distribution within the initial segment of the fiber path, and had improved fixturing to insure that the fiber axis was collinear with the incident laser beam. Test fibers were from a particular production lot for which initial-strength characteristics were established and a high-stress proof test was performed. Fiber end faces were prepared by a careful mechanical polishing schedule followed by surface conditioning using a CO2 laser. In combination, these factors resulted in higher thresholds for breakdown and damage than we had achieved previously in studies that utilized a simple lens injection system. Probability distribution functions were fitted to the threshold data, providing a means for estimating the probability for transmission failure at lower laser energies. RP Setchell, RE (reprint author), SANDIA NATL LABS,POB 5800,MS 0445,ALBUQUERQUE,NM 87185, USA. NR 0 TC 17 Z9 17 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 608 EP 619 DI 10.1117/12.274264 PG 12 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00075 ER PT B AU Donohoe, RJ Skelton, JA AF Donohoe, RJ Skelton, JA BE Bennett, HE Guenther, AH Kozlowski, MR Newnam, BE Soileau, MJ TI In situ characterization of visible and near-infrared Raman throughput from fiber optics in a high intensity gamma radiation environment SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1996 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 28th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1996 CY OCT 07-09, 1996 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Sandia Natl Labs, Bennett Opt Res, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Los Alamos Natl Lab, NIST, Soc Photo Opt Instrumentat Engineers RP Donohoe, RJ (reprint author), LOS ALAMOS NATL LAB,CST-4,MS-C345,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2370-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2966 BP 626 EP 631 DI 10.1117/12.274294 PG 6 WC Optics SC Optics GA BH93D UT WOS:A1997BH93D00077 ER PT S AU Key, MH AF Key, MH BE Miley, GH Campbell, EM TI The Edward Teller Medal Lecture: High intensity lasers and the road to ignition SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Key, MH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 3 EP 12 PG 10 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600001 ER PT S AU Zimmerman, GB AF Zimmerman, GB BE Miley, GH Campbell, EM TI Monte Carlo methods in ICF SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB Monte Carlo methods appropriate to simulate the transport of x-rays, neutrons, ions and electrons in Inertial Confinement Fusion targets are described and analyzed. The Implicit Monte Carlo method of x-ray transport handles symmetry within indirect drive ICF hohlraums well, but can be improved 50X in efficiency by angular biasing the x-rays towards the fuel capsule. Accurate simulation of thermonuclear burn and burn diagnostics involves detailed particle source spectra, charged particle ranges, inflight reaction kinematics, corrections for bulk and thermal Doppler effects and variance reduction to obtain adequate statistics for rare events. It is found that the effects of angular Coulomb scattering must be included in models of charged particle transport through heterogeneous materials. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Zimmerman, GB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 23 EP 41 PG 19 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600004 ER PT S AU Crandall, DH AF Crandall, DH BE Miley, GH Campbell, EM TI Status of the US Inertial Fusion Program and the National Ignition Facility SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH C1 US DOE, Off Inertial Fus, Washington, DC 20585 USA. RP Crandall, DH (reprint author), US DOE, Off Inertial Fus, DP-18, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 45 EP 47 PG 3 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600005 ER PT S AU Hogan, WJ Campbell, EM AF Hogan, WJ Campbell, EM BE Miley, GH Campbell, EM TI Directions of ICF research in the United States SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hogan, WJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 48 EP 55 PG 8 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600006 ER PT S AU Pointon, TD Boine-Frankenheim, O Mehlhorn, TA AF Pointon, TD Boine-Frankenheim, O Mehlhorn, TA BE Miley, GH Campbell, EM TI Time-implicit fluid/particle hybrid simulations of the anode plasma dynamics in ion diodes SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB Applied-B ion diode experiments with Li+1 ion sources on the PBFA II and SABRE ion accelerators show that early in the pulse the beam is essentially pure Li+1, but is rapidly overwhelmed by impurity ions, called the 'parasitic load'. Furthermore, the increasing parasitic current rapidly drops the diode voltage, limiting the accelerator power that can be coupled into the beam. This 'impedance collapse' is believed to arise from the desorption of impurity neutrals from the anode surface. These neutrals charge-exchange with the ions, rapidly expanding into the anode-cathode gap where they are ionized by beam ions or secondary electrons. In order to model these processes we are developing a 1 1/2 D electrostatic multifluid/PIC (hybrid) code, designed to self-consistently simulate collisional plasma/neutral systems with an arbitrary number of interacting species, over greatly varying density regimes and together with applied electric and magnetic fields. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Pointon, TD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 67 EP 75 PG 9 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600008 ER PT S AU Glenzer, SH Back, CA Suter, LJ Pollaine, SM MacGowan, BJ Blain, MA De Groot, JS Estabrook, KG Hammel, BA Hammer, JH Landen, OL Lindl, JD Wilde, BH AF Glenzer, SH Back, CA Suter, LJ Pollaine, SM MacGowan, BJ Blain, MA De Groot, JS Estabrook, KG Hammel, BA Hammer, JH Landen, OL Lindl, JD Wilde, BH BE Miley, GH Campbell, EM TI Thomson scattering from inertial confinement fusion plasmas SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB Thomson scattering has been developed at the Nova laser facility as a direct and accurate diagnostic to characterize inertial confinement fusion plasmas. Flat disks coated with thin multilayers of gold and beryllium were Irradiated with one laser beam to produce a two ion species plasma with a controlled amount of both species. Thomson scattering spectra from these plasmas showed two ion acoustic waves belonging to gold and beryllium. The phase velocities of the ion acoustic waves are shown to be a sensitive function of the relative concentrations of the two ion species and are in good agreement with theoretical calculations. These open geometry experiments further show that an accurate measurement of the ion temperature can be derived from the relative damping of the two ion acoustic waves. Subsequent Thomson scattering measurements from methane-filled, ignition-relevant hohlraums apply the theory for two ion species plasmas to obtain the electron and ion temperatures with high accuracy. The experimental data provide a benchmark for two-dimensional hydrodynamic simulations using LASNEX, which is presently in use to predict the performance of future megajoule laser-driven hohlraums of the National Ignition Facility (NIF). The data are consistent with modeling using significantly inhibited heat transport al the peak of the drive. Applied to NIF targets, this flux limitation has little effect on x-ray production. The spatial distribution of x-rays is slightly modified but optimal symmetry can be re-established by small changes in power balance or pointing. Furthermore, we find that stagnating plasma regions on the hohlraum axis are well described by the calculations. This result implies that stagnation in gas-filled hohlraums occurs too late to directly affect the capsule implosion in ignition experiments. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Glenzer, SH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 95 EP 113 PG 19 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600011 ER PT S AU Mason, RJ Kopp, RA Vu, HX Wilson, DC Goldman, SR Watt, RG Willi, O AF Mason, RJ Kopp, RA Vu, HX Wilson, DC Goldman, SR Watt, RG Willi, O BE Miley, GH Campbell, EM TI Foam-buffered laser-matter interactions SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB Recent experiments indicate that low-density foam buffer layers can significantly mitigate the perturbing effects of beam non-uniformities in direct drive laser-matter interactions. Results of a computational study with a 2D ALE code are reported here. Typical targets consisted of 50 mu m of 50 mg/cm(3) C10H8O4 foam attached to a 10 mu m foil and covered with 250 Angstrom of gold. These targets were exposed to similar to 1.2 ns, flat topped, green light pulses at similar to 1.4 x 10(14) W/cm(2) intensity, bearing 30 mu m lateral perturbations. Without the buffer layers the foils were severely disrupted after 1 ns of laser illumination. Buffering could provide stability for more than 2 ns of full shell acceleration. Our study shows that the high thermal conductivity of the foam results in flattened shocks in the foam plasma, communicating a smoothed laser drive to die accelerated shells. Preheat from the gold hastens conversion of solid foam to a heated plasma. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mason, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 140 EP 148 PG 9 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600016 ER PT S AU Savchenko, VI Panteleev, AA Starostin, AN AF Savchenko, VI Panteleev, AA Starostin, AN BE Miley, GH Campbell, EM TI The influence of quantum interference on spontaneous emission SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB Spontaneous relaxation of a three-level degenerate scheme is investigated. Two upper levels are coupled by the same quantum mode to tile lower level. It is shown that the quantum interference does not modify spontaneous relaxation in free space unless the angular momenta of the upper levels are equal. However in a cavity interference can lead to modified spontaneous emission for any combination of the upper levels. Interaction of the atom with the laser field may lead to complete suppression of spontaneous emission if the lower level is the ground state. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Savchenko, VI (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 371 EP 378 PG 8 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600043 ER PT S AU Feit, MD Garrison, JC Komashko, A Musher, SL Rubenchik, AM Turitsyn, SK AF Feit, MD Garrison, JC Komashko, A Musher, SL Rubenchik, AM Turitsyn, SK BE Miley, GH Campbell, EM TI Relativistic self-focusing in underdense plasma SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB An improved cavitation model shows that stable beam channeling and electron cavitation occur for relativistic laser intensities even at powers hundreds of times larger than the critical power for self-focusing. Numerical calculations for long pulses (100 ps) demonstrate strong self-focusing at weakly relativistic intensities. The destructive effects of self-focusing are increasingly suppressed at high intensity. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Feit, MD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-439, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 411 EP 425 PG 15 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600048 ER PT S AU Libby, SB Graziani, FR More, RM Kato, T AF Libby, SB Graziani, FR More, RM Kato, T BE Miley, GH Campbell, EM TI Systematic investigation of NLTE phenomena in the limit of small departures from LTE SO LASER INTERACTION AND RELATED PLASMA PHENOMENA - 13TH INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 13th International Conference on Laser Interaction and Related Plasma Phenomena (LIRPP 97) CY APR 13-18, 1996 CL NAVAL POSTGRAD SCH, MONTEREY, CA SP Univ Illinois, Fus Studies Lab, Lawrence Livermore Natl Lab, US DOE, IEEE Nucl & Plasma Soc, Amer Nucl Soc, Fus Energy Div, Naval Postgrad Sch, Fus Power Associates HO NAVAL POSTGRAD SCH AB In this paper, we begin a systematic study of Non-Local Thermal Equilibrium (NLTE) phenomena in near equilibrium (LTE) high energy density, highly radiative plasmas. It is shown that the principle of minimum entropy production rate characterizes NLTE steady states for average atom rate equations in the case of small departures form LTE. With the aid of a novel hohlraum-reaction box thought experiment, we use the principles of minimum entropy production and detailed balance to derive Onsager reciprocity relations for the NLTE responses of a near equilibrium sample to non-Planckian perturbations in different frequency groups. This result is a significant symmetry constraint on the linear corrections to Kirchoff's law. We envisage applying our strategy to a number of test problems which include: the NLTE corrections to the ionization state of an ion located near the edge of an otherwise LTE medium; the effect of a monochromatic radiation field perturbation on an LTE medium; the deviation of Rydberg state populations from LTE in recombining or ionizing plasmas; multi-electron temperature models such as that of Busquet; and finally, the effect of NLTE population shifts on opacity models. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Libby, SB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-696-4 J9 AIP CONF PROC PY 1997 IS 406 BP 637 EP 644 PG 8 WC Optics; Physics, Applied; Physics, Fluids & Plasmas SC Optics; Physics GA BK14M UT WOS:000071320600075 ER PT B AU Sanders, PG Keske, JS Kornecki, G Leong, KH AF Sanders, PG Keske, JS Kornecki, G Leong, KH BE Fabbro, R Kar, A Matsunawa, A TI Capabilities of infrared weld monitor SO LASER MATERIALS PROCESSING CONFERENCE, PTS 1 & 2: ICALEO '97 LA English DT Proceedings Paper CT Laser Materials Processing Conference CY NOV 17-20, 1997 CL CATAMARAN RESORT HOTEL, SAN DIEGO, CA HO CATAMARAN RESORT HOTEL DE laser welding; infrared; process monitoring; penetration AB A non-obtrusive, pre-aligned, solid-state device has been developed to monitor the primary infrared emissions during laser welding. The weld monitor output is a 100-1000 mV signal that depends on the beam power and weld characteristics. The DC level of this signal is related to weld penetration, while AC portions of the output can be correlated with surface irregularities and part misalignment or contamination. Changes in DC behavior are also noted for both full and deep penetration welds. Full penetration welds are signified by an abrupt reduction in the weld monitor output. Bead on plate welds were made on steel, aluminum, and magnesium with both a CW CO2 laser and a pulsed Nd:YAG laser to explore the relationships between the weld characteristics and the weld monitor output. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RP Sanders, PG (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU LASER INST AMERICA PI ORLANDO PA 12424 RESEARCH PKWY, STE 130, ORLANDO, FL 32826 USA BN 0-912035-56-0 PY 1997 BP C1 EP C10 PG 10 WC Engineering, Manufacturing; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BK84A UT WOS:000073607300042 ER PT B AU Leong, KH Geyer, HK Sabo, KR Sanders, PG AF Leong, KH Geyer, HK Sabo, KR Sanders, PG BE Fabbro, R Kar, A Matsunawa, A TI Predicting threshold laser beam irradiances for melting and welding SO LASER MATERIALS PROCESSING CONFERENCE, PTS 1 & 2: ICALEO '97 LA English DT Proceedings Paper CT Laser Materials Processing Conference CY NOV 17-20, 1997 CL CATAMARAN RESORT HOTEL, SAN DIEGO, CA HO CATAMARAN RESORT HOTEL DE lasers; threshold irradiance; laser beam welding AB A model based on conservation of energy for a moving heat source incident on a flat plate is used to predict the threshold laser beam irradiance required to initiate melting on a metal surface. With the use of a nondimensional variable and its solution, the threshold irradiance can be predicted with the use of a simple equation that is a function of the absorptivity of the surface, thermal conductivity of the metal, temperature increase for melting, diameter of the laser beam at the surface and the nondimensional variable value for the ratio of the thermal diffusivity of the metal to the product of the beam diameter and velocity used. Laser beam irradiances exceeding these predicted values are required for welding. The model predictions are validated with experimental results of beam irradiances required for welding different metals. C1 Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RP Leong, KH (reprint author), Argonne Natl Lab, Technol Dev Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU LASER INST AMERICA PI ORLANDO PA 12424 RESEARCH PKWY, STE 130, ORLANDO, FL 32826 USA BN 0-912035-56-0 PY 1997 BP G1 EP G8 PG 8 WC Engineering, Manufacturing; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BK84A UT WOS:000073607300109 ER PT J AU Shore, BW Feit, MD Perry, MD Rubenchik, A Stuart, B AF Shore, BW Feit, MD Perry, MD Rubenchik, A Stuart, B TI Brief intense laser fields in bulk matter SO LASER PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Laser Physics (LPHYS 96) CY JUL 22-26, 1996 CL MOSCOW, RUSSIA ID COLLATERAL DAMAGE; OPTICAL-BREAKDOWN; FEMTOSECOND; NANOSECOND; ABLATION; PULSES; IONIZATION; DEPENDENCE; OXIDE; SKIN AB The intense fields in laser pulses produce a wide variety of nonperturbative and nonlinear effects within individual atoms or molecules (e.g., harmonic generation, multiphoton ionization, etc.). Aggregates of atoms (e.g., vapors, clusters, metals, glass, etc.) subject to intense pulses exhibit a variety of breakdown (or damage) phenomena that derive from the strong-field effects in individual atoms and the collective effect of bulk matter. We review some of these connections, with particular emphasis on recent investigations in our laboratory of short-pulse laser-induced changes to transparent dielectric solids. Although the phenomena of laser-induced breakdown and damage have great complexity in general and requires elaborate details ranging from electron collision physics to strength of materials and fracture, simplifications become possible for short pulses. In particular, the brevity of the laser pulse implies that the threshold for material damage is primarily determined by conduction electrons. We comment on the implications of the simplifying physics that becomes applicable for short pulses, and the consequences of this simplification both for theoretical modeling and for useful applications. RP Shore, BW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Feit, Michael/A-4480-2009; Stuart, Brent/K-4988-2015 NR 30 TC 0 Z9 0 U1 0 U2 2 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 SN 1054-660X J9 LASER PHYS JI Laser Phys. PD JAN-FEB PY 1997 VL 7 IS 1 BP 119 EP 125 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA WJ583 UT WOS:A1997WJ58300018 ER PT J AU Solarz, R Beach, R Bibeau, C Campbell, E Krupke, W Marshall, C Page, R Paisner, J Payne, S Perry, M Schaefer, K Scheibner, K AF Solarz, R Beach, R Bibeau, C Campbell, E Krupke, W Marshall, C Page, R Paisner, J Payne, S Perry, M Schaefer, K Scheibner, K TI Current research directions and topics in the Laser Directorate at Lawrence Livermore National Laboratory SO LASER PHYSICS LA English DT Article; Proceedings Paper CT International Workshop on Laser Physics (LPHYS 96) CY JUL 22-26, 1996 CL MOSCOW, RUSSIA RP Solarz, R (reprint author), LAWRENCE LIVERMORE NATL LAB,7000 E AVE,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 2 U1 0 U2 1 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 SN 1054-660X J9 LASER PHYS JI Laser Phys. PD JAN-FEB PY 1997 VL 7 IS 1 BP 234 EP 238 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA WJ583 UT WOS:A1997WJ58300038 ER PT B AU Chen, CL Heglund, DL Ray, MD Harder, D Dobert, R Leung, KP Wu, M Sedlacek, A AF Chen, CL Heglund, DL Ray, MD Harder, D Dobert, R Leung, KP Wu, M Sedlacek, A BE Kamerman, GW TI Application of resonance Raman lidar for chemical species identification SO LASER RADAR TECHNOLOGY AND APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Technology and Applications II CY APR 23-25, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers AB BNL has been developing a remote sensing technique for the detection of atmospheric pollutants based on the phenomenon of resonance Raman LIDAR that has also incorporated a number of new techniques/technologies designed to extend it's performance envelope. When the excitation frequency approaches an allowed electronic transition of the molecule, an enormous enhancement of the inelastic scattering cross-section can occur, often up to 2 to 4 orders-of-magnitude, and is referred to as resonance Raman (RR), since the excitation frequency is in ''resonance'' with an allowed electronic transition. Exploitation of this enhancement along with new techniques such as pattern recognition algorithms to take advantage of the spectral fingerprint and a new laser frequency modulation technique designed to suppress broadband fluorescence, referred to as Frequency Modulated Excitation Raman Spectroscopy (FreMERS) and recent developments in liquid edge filter technology, for suppression of the elastic channel, all help increase the overall performance of Raman LIDAR. RP Chen, CL (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2480-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3065 BP 279 EP 285 DI 10.1117/12.281019 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BJ51D UT WOS:A1997BJ51D00029 ER PT B AU Diegert, C Sackos, J Nellums, R AF Diegert, C Sackos, J Nellums, R BE Kamerman, GW TI Building accurate geometric models from abundant range imaging information SO LASER RADAR TECHNOLOGY AND APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Technology and Applications II CY APR 23-25, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers AB We define two simple metrics for accuracy of models built from range imaging information. We apply the metric to a model built from a recent range image taken at the Laser Radar Development and Evaluation Facility (LDERF), Eglin AFB, using a Scannerless Range Imager (SRI) from Sandia National Laboratories. We also present graphical displays of the residual information produced as a byproduct of this measurement, and discuss mechanisms that these data suggest far further improvement in the performance of this already impressive SRI. RP Diegert, C (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2480-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3065 BP 428 EP 434 DI 10.1117/12.281032 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BJ51D UT WOS:A1997BJ51D00041 ER PT B AU Maitland, DJ Celliers, P Amendt, P DaSilva, L AF Maitland, DJ Celliers, P Amendt, P DaSilva, L BE Jacques, SL Katzir, A TI Simulations of laser-initiated stress waves SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc AB We present a study of the short-timescale (less than 250 ns) fluid dynamic response of water to a fiber-delivered laser pulse of variable energy and spatial profile. The laser pulse was deposited on a stress confinement timescale. The spatial profile was determined by the fiber core radius, r, (110 and 500 microns) and the water absorption coefficient, mu(a), (200 and 50 1/cm). Considering 2D cylindrical symmetry, the combination of fiber radius and absorption coefficient parameters can be characterized as near planar (1/mu(a) greater than r), symmetric (1/mu(a) approximate to r), and side-directed (1/mu(a) less than r). The spatial profile study shows how the stress wave varies as a function of geometry. For example, relatively small absorption coefficients can result is side-propagating shear and tensile fields. RP Maitland, DJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 255 EP 260 DI 10.1117/12.275489 PG 6 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00029 ER PT B AU Glinsky, ME Amendt, PA Bailey, DS London, RA Rubenchik, AM Strauss, M AF Glinsky, ME Amendt, PA Bailey, DS London, RA Rubenchik, AM Strauss, M BE Jacques, SL Katzir, A TI Extended Rayleigh model of bubble evolution with material strength compared to detailed dynamic simulations SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE bubble; stress wave; material failure; acoustic radiation; simulation AB The validity of an extended Rayleigh model for laser generated bubbles in soft tissue is examined. This model includes surface tension, viscosity, a realistic water equation of state, material strength and failure, stress wave emission and linear growth of interface instabilities. It is compared to detailed dynamic simulations using the computer program LATIS. These simulations include stress wave propagation, a realistic water equation of state, material strength and failure, and viscosity. The extended Rayleigh model and the detailed dynamic simulations are compared using 1-D spherical geometry with a bubble in the center and using a 2-D cylindrical geometry of a laser fiber immersed in water with a bubble formed at the end of the fiber. Studies are done to test the validity of the material strength and failure, stress wave emission, and the interface instability terms in the extended Rayleigh model. The resulting bubble radii, material damage radii, the emitted stress wave energies, and the size of the interface distortions are compared. Conclusions are made on the validity of the extended Rayleigh model and on possible improvements to this model. The purpose of this study is to investigate the use of the extended Rayleigh model as a substitute for the detailed dynamic simulations when only limited information is needed. It is also is meant to benchmark the detailed dynamic simulations and highlight the relevant physics. It is shown that the extended Rayleigh model executes over 300 times faster on a computer than the detailed dynamic simulations. RP Glinsky, ME (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 318 EP 334 DI 10.1117/12.275496 PG 17 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00037 ER PT B AU Chapyak, EJ Godwin, RP Vogel, A AF Chapyak, EJ Godwin, RP Vogel, A BE Jacques, SL Katzir, A TI Comparison of numerical simulations and laboratory studies of shock waves and cavitation bubble growth produced by optical breakdown in water SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE bubble dynamics; cavitation; experimental and numerical hydrodynamics; shocks; acoustic radiation; laser medical applications AB In numerical calculations of idealized bubble dynamics test problems, Los Alamos computational tools perform well. A realistic equation of state must be used and geometrical features must be carefully modeled to simulate experiments accurately. In this work, we compare numerical simulations taking these features into account with experiments performed at the Medizinisches Laserzentrum Lubeck. We compare the measured and calculated positions of the shock front and of the bubble wall as a function of time in the laser optical breakdown of water produced by 30-ps 1-mJ Nd:YAG laser pulses. RP Chapyak, EJ (reprint author), LOS ALAMOS NATL LAB,APPL THEORET & COMPUTAT PHYS DIV,LOS ALAMOS,NM 87545, USA. NR 0 TC 14 Z9 14 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 335 EP 342 DI 10.1117/12.275497 PG 8 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00038 ER PT B AU Visuri, SR Celliers, P DaSilva, L Matthews, D AF Visuri, SR Celliers, P DaSilva, L Matthews, D BE Jacques, SL Katzir, A TI Effect of viscosity on bubble and pressure evolution SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE bubble; pressure; acoustic AB The formation and evolution of acoustic waves and vapor bubbles as a result of laser irradiation have received considerable attention, particularly with respect to angioplasty, thrombolysis, and ophthalmic laser applications. Pressure waves and bubbles have been implicated in undesirable tissue damage yet they can be beneficially utilized while limiting their negative impact. Either planar or spherical pressure waves can be produced through manipulation of irradiation parameters and geometry. An OPO laser emitting similar to 5 ns pulses of visible radiation was delivered through an optical fiber to a cuvette containing dye dissolved in either water or glycerin. Absorption was varied by altering the dye concentration and wavelength of the OPO laser and the spot size was varied by employing multiple sizes of optical fiber. A nitrogen-pumped dye laser with a pulse duration of similar to 5 ns was used as an illumination source. A Mach-Zehnder interferometer technique enabled visualization and quantification of the pressure waves; bubble evolution was monitored with shadowgrams. A comparison was made between experimental and theoretical results for water and glycerin. RP Visuri, SR (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 343 EP 350 DI 10.1117/12.275498 PG 8 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00039 ER PT B AU Amendt, PA Strauss, M London, RA Glinsky, ME Maitland, DJ Celliers, PM Visuri, SR Bailey, DS Young, DA Ho, D AF Amendt, PA Strauss, M London, RA Glinsky, ME Maitland, DJ Celliers, PM Visuri, SR Bailey, DS Young, DA Ho, D BE Jacques, SL Katzir, A TI Modeling of bubble dynamics in relation to medical applications SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE short-pulse laser; hydrodynamics; vapor; bubble; shock wave AB In various pulsed-laser medical applications, strong stress transients can be generated in advance of vapor bubble formation. To better understand the evolution of stress transients and subsequent formation of vapor bubbles, two-dimensional simulations are presented in channel or cylindrical geometry with the LATIS (LAser TISsue) computer code. Differences with one-dimensional modelling are explored, and simulated experimental conditions for vapor bubble generation are presented and compared with data. RP Amendt, PA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 362 EP 373 DI 10.1117/12.275500 PG 12 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00041 ER PT B AU Glinsky, ME Bailey, DS London, RA AF Glinsky, ME Bailey, DS London, RA BE Jacques, SL Katzir, A TI LATIS modeling of laser induced midplane and backplane spallation SO LASER-TISSUE INTERACTION VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction VIII CY FEB 09-12, 1997 CL SAN JOSE, CA SP USA Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE bubble; stress wave; material failure; acoustic radiation; simulation AB The computer code LATIS is used to simulate midplane and backplane spallation resulting from short pulsed laser absorption. A 1-D planar geometry is simulated with an exponential laser absorption profile. The laser pulse length is assumed to be much shorter than the sound transit time across the laser absorption length. The boundary conditions are a fixed front plane and free backplane (backplane spall) and a free front plane and a fixed midplane (midplane spall). The NBS/NRC equation of state for water is used with a self-consistent yet empirical material strength and failure model. The failure model includes the effects of void nucleation, growth and coalescence. Definite signatures of the nucleation and coalescence thresholds are found in the back surface motion for backplane spallation. RP Glinsky, ME (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2386-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 2975 BP 374 EP 387 DI 10.1117/12.275502 PG 14 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BJ12Q UT WOS:A1997BJ12Q00042 ER PT B AU Essien, M Keicher, DM AF Essien, M Keicher, DM BE Migliore, LR Schaeffer, RD TI Optical method of penetration sensing for pulsed Nd:YAG laser welding SO LASERS AS TOOLS FOR MANUFACTURING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers as Tools for Manufacturing II CY FEB 12-14, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE laser welding; penetration sensing; high-speed imaging; nondestructive testing AB The ability to monitor and control the depth of a laser weld in real-time is critical in many laser welding applications. Consequently, we have investigated the use of an optical method to sense weld depth. Welds were generated on kovar samples, using a pulsed Nd:YAG laser. The sensing method uses digital high-speed photography to measure the velocity of the plume of vaporized metal atoms ejected from the metal surface. An energy balance equation is then used to relate the plume velocity to the size of the weld. Numerical solution of the energy balance equation yielded values for weld depth that were within 8% of the actual measured values. RP Essien, M (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 2 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2404-8 J9 P SOC PHOTO-OPT INS PY 1997 VL 2993 BP 2 EP 8 DI 10.1117/12.270012 PG 7 WC Engineering, Manufacturing; Optics SC Engineering; Optics GA BH52G UT WOS:A1997BH52G00001 ER PT B AU Leong, KH Sabo, KR Sanders, PG Spawr, WJ AF Leong, KH Sabo, KR Sanders, PG Spawr, WJ BE Migliore, LR Schaeffer, RD TI Laser welding of aluminum alloys SO LASERS AS TOOLS FOR MANUFACTURING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers as Tools for Manufacturing II CY FEB 12-14, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE laser beam welding; aluminum; weld parameters AB Recent interest in reducing the weight of automobiles to increase fuel mileage has focussed attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not been very consistent in the process requirements but more definitive data has been produced recently. This paper reviews the process parameters needed to obtain consistent laser welds on 5000 series aluminum alloys and discusses the research necessary to make laser processing of aluminum a reality for automotive applications. RP Leong, KH (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 7 Z9 7 U1 2 U2 7 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2404-8 J9 P SOC PHOTO-OPT INS PY 1997 VL 2993 BP 37 EP 44 DI 10.1117/12.270039 PG 8 WC Engineering, Manufacturing; Optics SC Engineering; Optics GA BH52G UT WOS:A1997BH52G00005 ER PT B AU Keicher, DM Smugeresky, JE Romero, JA Griffith, ML Harwell, LD AF Keicher, DM Smugeresky, JE Romero, JA Griffith, ML Harwell, LD BE Migliore, LR Schaeffer, RD TI Using the Laser Engineered Net Shaping (LENS) process to produce complex components from a CAD solid model SO LASERS AS TOOLS FOR MANUFACTURING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers as Tools for Manufacturing II CY FEB 12-14, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE laser; solid freeform fabrication; direct fabrication; rapid prototyping; metal fabrication AB The Laser Engineered Net Shaping (LENS(TM)) process, currently under development, has demonstrated the capability to produce near-net shape, fully dense metallic parts with reasonably complex geometrical features directly from a CAD solid model. Results to date show that excellent mechanical properties can be achieved in alloys such as 316 stainless steel and Inconel 625. In fact, due to the highly localized nature of the laser heating, a fine grain structure will occur resulting in a significant increase in yield strength at no expense of ductility. The current approach lends itself to produce components with a dimensional accuracy of +/-.002 inches in the deposition plane and +/-.0.015 inches in the growth direction. These results suggest that this process will provide a viable means for direct fabrication of metallic hardware directly from the CAD solid model. RP Keicher, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 18 Z9 18 U1 1 U2 5 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2404-8 J9 P SOC PHOTO-OPT INS PY 1997 VL 2993 BP 91 EP 97 PG 7 WC Engineering, Manufacturing; Optics SC Engineering; Optics GA BH52G UT WOS:A1997BH52G00011 ER PT B AU Colston, BW Everett, MJ DaSilva, LB Otis, LL Nathel, H AF Colston, BW Everett, MJ DaSilva, LB Otis, LL Nathel, H BE Wigdor, HA Featherstone, JDB Rechmann, P Katzir, A TI Optical coherence tomography for diagnosing periodontal disease SO LASERS IN DENTISTRY III, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Dentistry III CY FEB 08-09, 1997 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE optical coherence tomography; oct; periodontal; dental; low coherence; imaging AB We have, in this preliminary study, investigated the use of optical coherence tomography (OCT) for diagnosis of periodontal disease. We took in vitro OCT images of the dental and periodontal tissues from a young pig and compared them to histological sections. These images distinguish tooth and soft tissue relationships that are important in diagnosing and assessing periodontal diseases. We have imaged the attachment of gingiva to the tooth surface and located the cemento-enamel junction(through tissue). This junction is an important reference point for defining attachment level in the diagnosis of periodontal disease. The boundary between enamel and dentin is also visible for most of the length of the anatomical crown, allowing quantitation of enamel thickness and character. RP Colston, BW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2384-X J9 P SOC PHOTO-OPT INS PY 1997 VL 2973 BP 216 EP 220 PG 5 WC Dentistry, Oral Surgery & Medicine; Engineering, Biomedical; Optics SC Dentistry, Oral Surgery & Medicine; Engineering; Optics GA BH88L UT WOS:A1997BH88L00026 ER PT B AU Chapyak, EJ Godwin, RP Prahl, SA Shangguan, H AF Chapyak, EJ Godwin, RP Prahl, SA Shangguan, H BE Anderson, RR Bartels, KE Bass, LS Gregory, KW Harris, DM Lui, H Malek, RS Muller, GJ Pankratov, MM Perlmutter, AP Reidenbach, HD Tate, LP Watson, GM Katzir, A TI A comparison of numerical simulations and laboratory studies of laser thrombolysis SO LASERS IN SURGERY: ADVANCED CHARACTERIZATION, THERAPEUTICS, AND SYSTEMS VII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Surgery - Advanced Characterization, Therapeutics, and Systems VII CY FEB 08-09, 1997 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE laser thrombolysis; bubble dynamics; numerical methods; hydrodynamics; dissipation AB We compare Los Alamos numerical simulations with Oregon Medical Laser Center laser deposition experiments conducted with gelatin thrombus surrogates specifically chosen for relevance to clinical laser thrombolysis. Initial idealized calculations suggest that a surprisingly large fraction of the absorbed laser energy appears as acoustic radiation.(1) We build on these results here by investigating geometrical effects, material property variations, and sources of dissipation including viscosity and plastic flow, as well as acoustic radiation, in an effort to explain flow effects observed in the experiments. In particular, strong jetting is observed in the simulations when the gelatin is given a kinematic viscosity in excess of similar to 1.0 cm(2)/s. Jetting is clearly evident in the experiments. RP Chapyak, EJ (reprint author), LOS ALAMOS NATL LAB,APPL THEORET & COMPUTAT PHYS DIV,LOS ALAMOS,NM 87545, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2381-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 2970 BP 28 EP 34 DI 10.1117/12.275023 PG 7 WC Engineering, Biomedical; Optics; Surgery SC Engineering; Optics; Surgery GA BH93E UT WOS:A1997BH93E00004 ER PT B AU Small, W Celliers, PM Kopchok, GE Reiser, KM Heredia, NJ Maitland, DJ Eder, DC London, RA Heilbron, M Hussain, F White, RA DaSilva, LB Matthews, DL AF Small, W Celliers, PM Kopchok, GE Reiser, KM Heredia, NJ Maitland, DJ Eder, DC London, RA Heilbron, M Hussain, F White, RA DaSilva, LB Matthews, DL BE Anderson, RR Bartels, KE Bass, LS Gregory, KW Harris, DM Lui, H Malek, RS Muller, GJ Pankratov, MM Perlmutter, AP Reidenbach, HD Tate, LP Watson, GM Katzir, A TI In vivo argon laser vascular welding using thermal feedback: Open and closed loop patency and collagen crosslinking SO LASERS IN SURGERY: ADVANCED CHARACTERIZATION, THERAPEUTICS, AND SYSTEMS VII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Surgery - Advanced Characterization, Therapeutics, and Systems VII CY FEB 08-09, 1997 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc DE tissue welding; tissue fusion; infrared thermometry; feedback control AB An in vivo study of vascular welding with a fiber-delivered argon laser was conducted using a canine model. Longitudinal arteriotomies and venotomies were treated on femoral vein and artery. Laser energy was delivered to the vessel wall via a 400 mu m optical fiber. The surface temperature at the center of the laser spot was monitored in real time using a hollow glass optical fiber-based two-color infrared thermometer. The surface temperature was limited by either a room-temperature saline drip or direct feedback control of the laser using a mechanical shutter to alternately pass and block the laser. Acute patency was evaluated either visually (leak/no leak) or by in vivo burst pressure measurements. Biochemical assays were performed to investigate the possible laser-induced formation or destruction of enzymatically mediated covalent crosslinks between collagen molecules. Viable welds were created both with and without the use of feedback control. Tissues maintained at 50 degrees C using feedback control had an elevated crosslink count compared to controls, while those irradiated without feedback control experienced a decrease. Differences between the volumetric heating associated with open and closed loop protocols may account for the different effects on collagen crosslinks. Covalent mechanisms may play a role in argon laser vascular fusion. RP Small, W (reprint author), LAWRENCE LIVERMORE NATL LAB,L-399,POB 808,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2381-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 2970 BP 252 EP 256 DI 10.1117/12.275050 PG 5 WC Engineering, Biomedical; Optics; Surgery SC Engineering; Optics; Surgery GA BH93E UT WOS:A1997BH93E00033 ER PT J AU Neev, J Nelson, JS Critelli, M McCullough, JL Cheung, E Carrasco, WA Rubenchik, AM DaSilva, LB Perry, MD Stuart, BC AF Neev, J Nelson, JS Critelli, M McCullough, JL Cheung, E Carrasco, WA Rubenchik, AM DaSilva, LB Perry, MD Stuart, BC TI Ablation of human nail by pulsed lasers SO LASERS IN SURGERY AND MEDICINE LA English DT Article DE lasers; hard tissue ablation; nail; laser-tissue interactions; laser-induced plasma ID STRATUM-CORNEUM; DURATION AB Background and Objective: The hard and resistant structure of the nail plate forms a natural barrier that limits the penetration of topical drugs. To overcome this barrier, the use of pulsed laser systems has been suggested. The purpose of this study was to evaluate the effect of four laser systems on nail plate ablation rates, ablation efficiencies, and subsequent craters morphology. Study Design/Material and Methods: Solid state Er:YAG (2.94 mu m, 250 mu s), a Ho:YSGG (2.08 mu m, 250 mu s), a XeC1 Excimer (308 nm, 15 ns), and a novel solid-state ultrashort pulse laser (1.05 mu m, 350 fs) were used. Ablation rates, surface morphology, and extent of collateral damage were evaluated using light and electron microscopy. Results: Best ablation efficiencies were demonstrated with the ultrashort pulsed laser (1 mu m/mJ), whereas maximum material removal per pulse was obtained with the Er:YAG laser (80 mu m/pulse). Scanning electron microscopy showed cracking damage with both Ho:YSGG and Er:YAG. XeC1 and the ultrashort pulse system left tissue surfaces free of cracks or thermal damage. Conclusion: With its minimal acoustical and mechanical impact, high efficiency, and negligible collateral damage, the ultrashort pulse laser at 3 J/cm(2) was found to be the optimal laser system for nail ablation. (C) 1997 Wiley-Liss, Inc. C1 UNIV CALIF IRVINE,DEPT DERMATOL,IRVINE,CA 92717. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Neev, J (reprint author), UNIV CALIF IRVINE,BECKMAN LASER INST & MED CLIN,1002 HLTH SCI RD E,IRVINE,CA 92715, USA. RI Stuart, Brent/K-4988-2015 FU NCRR NIH HHS [5P41RR01192]; NIAMS NIH HHS [IR29-AR41638-O1A1, IRO1AR42437-O1A1] NR 12 TC 21 Z9 22 U1 1 U2 7 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-8092 J9 LASER SURG MED JI Lasers Surg. Med. PY 1997 VL 21 IS 2 BP 186 EP 192 DI 10.1002/(SICI)1096-9101(1997)21:2<186::AID-LSM10>3.0.CO;2-D PG 7 WC Dermatology; Surgery SC Dermatology; Surgery GA XP795 UT WOS:A1997XP79500010 PM 9261796 ER PT J AU Maitland, DJ Walsh, JT AF Maitland, DJ Walsh, JT TI Quantitative measurements of linear birefringence during heating of native collagen SO LASERS IN SURGERY AND MEDICINE LA English DT Article DE anisotropic optical properties of tissue; polarized light; dynamic changes in optical properties; rat tail tendon; entropy; enthalpy; Arrhenius; first-order kinetic reaction ID DAMAGE; TISSUE AB Background and Objective: Linear birefringence is an anisotropic property of rat tail tendon, which is largely composed of collagen. Our goal is to show that the dynamic range and sensitivity of the linear birefringence loss of collagen during heating are sufficient for kinetic modeling of the reaction. Study Design, Materials and Methods: The linear birefringence loss was quantified for tendon denatured via both a heated-isotonic-saline bath and a heated stage. All measurements were made with a polarizing transmission microscope equipped with a Berek compensator. Results: The data show that the loss of linear birefringence is a first-order kinetic reaction. The native rat tail tendon birefringence, Delta n = 3.0 +/- 0.6 x 10(-3) (mean +/- std. err.), is lost after denaturation occurs (Delta n = 0). Application of the Arrhenius equation to the linear birefringence data yields the activation energy (E-a = 89 +/- 1 kcal/mole), pre-exponential coefficient (A = e(130+/-1) s(-1)), enthalpy (Delta H = 88 +/- 1 kcal/mole) and entropy (Delta S = 197 +/- 2 cal/degrees K.mole). Conclusion: This study shows that dynamic changes in linear birefringence can be used to monitor thermally induced changes in collagen. (C) 1997 Wiley-Liss, Inc. C1 NORTHWESTERN UNIV,DEPT BIOMED ENGN,EVANSTON,IL 60208. RP Maitland, DJ (reprint author), LAWRENCE LIVERMORE NATL LAB,MED PHOTON LAB,POB 808,L-399,LIVERMORE,CA 94551, USA. RI Walsh, Joseph/B-7636-2009 FU NIGMS NIH HHS [R01GM50534] NR 23 TC 84 Z9 87 U1 0 U2 4 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0196-8092 J9 LASER SURG MED JI Lasers Surg. Med. PY 1997 VL 20 IS 3 BP 310 EP 318 DI 10.1002/(SICI)1096-9101(1997)20:3<310::AID-LSM10>3.0.CO;2-H PG 9 WC Dermatology; Surgery SC Dermatology; Surgery GA WV947 UT WOS:A1997WV94700010 PM 9138260 ER PT B AU Graczyk, DG Essling, AM Huff, EA Smith, FP Snyder, CT AF Graczyk, DG Essling, AM Huff, EA Smith, FP Snyder, CT BE Huglen, R TI Analytical chemistry of aluminum salt cake SO LIGHT METALS 1997 LA English DT Proceedings Paper CT Technical Session on Light Metals 1997, at the 126th TMS Annual Meeting CY FEB 09-13, 1997 CL ORLANDO, FL SP Minerals Met Mat Soc, Aluminium Comm AB Chemical characterization of aluminum salt cake, or of intermediate or final products from processing salt cake, offers interesting challenges to the analytical chemist because the component phases resist dissolution (a key first step in most analysis procedures) and because process chemists and engineers need information on specific components such as leachable salts or aluminum metal in addition to overall elemental composition. Our laboratory had an opportunity to meet some of these challenges first-hand while providing analysis support to a project studying conversion of salt cake fines to value-added oxide products. In the course of this work, we adapted or devised analysis methods for determining leachable salt, total halides (Cl and Fl, aluminum metal, and elemental composition. Leaching of salt cake fines was accomplished by ultrasonic agitation with deionized water. We analyzed the leachate for anions (chloride, fluoride, nitrate, phosphate, sulfate) by ion chromatography and for cations by inductively coupled plasma atomic emission spectrometry (ICP-AES). Only chloride appeared at measurable concentrations among the anions. Charge balances between cations and chloride were near unity, indicating that all major dissolved species were chloride salts. For the total halides determination, we first brought the chloride and fluoride components into solution by decomposition with a potassium hydroxide fusion. The dissolved chloride and fluoride were measured by ion chromatography. Aluminum metal present in the fines was determined by a hydrogen evolution procedure, which we adapted to permit determination of sub-milligram quantities of metallic aluminum. In our approach, we reacted the aluminum metal with hydrochloric acid in a closed system containing a measured amount of high-purity helium. After reaction, we measured the hydrogen to helium ratio by mass spectrometry to determine the quantity of H-2 evolved. Recoveries of aluminum metal standards (approximately 30 mg Al) averaged 93%. Comparison of the acid evolution with caustic reaction of the aluminum metal showed results from the two methods to be virtually identical but reaction was faster in the acid medium. Metallic elements were determined in the salt cake materials by total dissolution and ICP-AES measurement of dissolved metals. Decomposition of the salt cake with mineral acids left undissolved residues that had to be brought into solution by fusion with sodium carbonate. A better dissolution was obtained by fusing the salt cake materials with lithium tetraborate, although this approach does not permit determination of lithium or boron in the dissolved sample. used as a starting point for accurate aluminum assay of salt cake materials by classical 8-hydroxyquinolate gravimetry. C1 Argonne Natl Lab, Div Chem Technol, Analyt Chem Lab, Argonne, IL 60439 USA. RP Graczyk, DG (reprint author), Argonne Natl Lab, Div Chem Technol, Analyt Chem Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-362-7 PY 1997 BP 1135 EP 1140 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32P UT WOS:000071821400162 ER PT B AU Sreenivasarao, K Patsiogiannis, F Hryn, JN AF Sreenivasarao, K Patsiogiannis, F Hryn, JN BE Huglen, R TI Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis SO LIGHT METALS 1997 LA English DT Proceedings Paper CT Technical Session on Light Metals 1997, at the 126th TMS Annual Meeting CY FEB 09-13, 1997 CL ORLANDO, FL SP Minerals Met Mat Soc, Aluminium Comm AB Electrodialysis was investigated as a possible technology for the cost-effective recovery of salt from salt cake leach solutions. We used a pilot-scale electrodialysis stack consisting of five membrane pairs, each with an effective area of 0.02 m(2). The diluate stream contained synthetic NaCl, KCl, mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl2). We concentrated and precipitated NaCl and KCl salts from the concentrate stream when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in the overall efficiency of salt recovery by electrodialysis. C1 Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. RP Sreenivasarao, K (reprint author), Argonne Natl Lab, Div Energy Syst, 9700 S Cass Ave,Bldg 362, Argonne, IL 60439 USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-362-7 PY 1997 BP 1153 EP 1158 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BK32P UT WOS:000071821400165 ER PT J AU Behrenfeld, MJ Falkowski, PG AF Behrenfeld, MJ Falkowski, PG TI Photosynthetic rates derived from satellite-based chlorophyll concentration SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID OCEANIC PRIMARY PRODUCTION; ULTRAVIOLET-B RADIATION; MIDDLE ATLANTIC BIGHT; MARINE-PHYTOPLANKTON; SKELETONEMA-COSTATUM; NATURAL ASSEMBLAGES; CONTINENTAL-SHELF; NORTH-ATLANTIC; LIGHT; GROWTH AB We assembled a dataset of C-14-based productivity measurements to understand the critical variables required for accurate assessment of daily depth-integrated phytoplankton carbon fixation (PPeu) from measurements of sea surface pigment concentrations (C-sat). From this dataset, we developed a light-dependent, depth-resolved model for carbon fixation (VGPM) that partitions environmental factors affecting primary production into those that influence the relative vertical distribution of primary production (P-z) and those that control the optimal assimilation efficiency of the productivity profile (P-opt(B)). The VGPM accounted for 79% of the observed variability in P-z and 86% of the variability in PPeu by using measured values of P-opt(B). Our results indicate that the accuracy of productivity algorithms in estimating PPeu is dependent primarily upon the ability to accurately represent variability in P-opt(B). We developed a temperature-dependent P-opt(B), model that was used in conjunction with monthly climatological images of C-sat, sea surface temperature, and cloud-corrected estimates of surface irradiance to calculate a global annual phytoplankton carbon fixation (PPannu) rate of 43.5 Pg C yr(-1). The geographical distribution of PPannu was distinctly different than results from previous models. Our results illustrate the importance of focusing P-opt(B) model development on temporal and spatial, rather than the vertical, variability. RP Behrenfeld, MJ (reprint author), BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI Reboreda, Rosa/A-2518-2012 NR 87 TC 1161 Z9 1221 U1 24 U2 213 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JAN PY 1997 VL 42 IS 1 BP 1 EP 20 PG 20 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA XK601 UT WOS:A1997XK60100001 ER PT J AU DeGrandpre, MD Hammar, TR Wallace, DWR Wirick, CD AF DeGrandpre, MD Hammar, TR Wallace, DWR Wirick, CD TI Simultaneous mooring-based measurements of seawater CO2 and O-2 off Cape Hatteras, North Carolina SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MIDDLE ATLANTIC BIGHT; CARBON-DIOXIDE; BIOLOGICAL PRODUCTION; SEA-SURFACE; OXYGEN; OCEAN; VARIABILITY; PCO2 AB We deployed CO2 and O-2 sensors on the U.S. continental shelf off Cape Hatteras, North Carolina, during late summer 1994. A continuous 32-d gas record was obtained at 20 m in 25 m of water, below the thermocline for most of the period. Analysis of the correlation between CO2 and O-2 indicates that biological and advective processes dominated the gas variability, with small or insignificant fluxes due to air-sea exchange, vertical eddy diffusion, and carbonate dissolution or formation. The observed O-2:CO2 correlation was 1.39, within the range predicted for the photosynthetic quotient. Photosynthesis and respiration appeared to be tightly coupled, resulting in no net community production in these waters during the late summer. It is evident from these results that the combination of mooring-based CO2 and O-2 measurements will be a powerful tool for studying the marine carbon cycle. C1 WOODS HOLE OCEANOG INST,DEPT MARINE CHEM & GEOCHEM,WOODS HOLE,MA 02543. BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973. NR 32 TC 49 Z9 50 U1 2 U2 10 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 JAN PY 1997 VL 42 IS 1 BP 21 EP 28 PG 8 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA XK601 UT WOS:A1997XK60100002 ER PT S AU Liberman, V Malba, V Bernhardt, AF AF Liberman, V Malba, V Bernhardt, AF BE Lagendijk, A Treichel, H Uram, KJ Jones, AC TI A study of anisotropy of spin cast and vapor deposited polyimide films using internal reflection techniques SO LOW-DIELECTRIC CONSTANT MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium H on Low-Dielectric Constant Materials, at the 1996 MRS Fall Meeting CY DEC 02-03, 1996 CL BOSTON, MA SP Mat Res soc AB We have compared anisotropy of spin cast and vapor deposited polyimide (VDP) films, using internal reflection infrared spectroscopy. The films were deposited directly on the internal reflection element. We find that spin cast films are more anisotropic than their VDP counterparts, with the polyimide chains tending to align parallel to the substrate. Both films are found to contain more and less ordered regions. Within the ordered regions, the plane of the phenyl ring tends to align parallel to the substrate. RP Liberman, V (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-271,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-347-9 J9 MATER RES SOC SYMP P PY 1997 VL 443 BP 15 EP 20 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Engineering; Materials Science GA BJ57H UT WOS:A1997BJ57H00002 ER PT S AU Bruinsma, PJ Hess, NJ Bontha, JR Liu, J Baskaran, S AF Bruinsma, PJ Hess, NJ Bontha, JR Liu, J Baskaran, S BE Lagendijk, A Treichel, H Uram, KJ Jones, AC TI Low K mesoporous silica films through template-based processing SO LOW-DIELECTRIC CONSTANT MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium H on Low-Dielectric Constant Materials, at the 1996 MRS Fall Meeting CY DEC 02-03, 1996 CL BOSTON, MA SP Mat Res soc AB Low dielectric-constant mesoporous silica films were prepared by condensation of a silicate network around surfactant micellar structures. Adherent, porous films 0.5-1.0 mu m in thickness, and containing an ordered assemblage of approximate to 2 nm diameter pores were synthesized by spin-coating water/ethanol-based solutions containing a silica precursor and surfactant template. In this paper, film deposition conditions are described, and film thickness, porosity, refractive index and dielectric constant measured by ellipsometry are presented. Using a coating solution containing tetraethyl orthosilicate (TEOS) and a cationic cetyltrimethylammonium chloride (CTAC) surfactant template, the film porosity and dielectric properties were controlled over a wide range by adjusting the CTAC/TEOS molar ratio. With the CTAC/TEOS ratio between 0.1 and 0.15, the pores were highly ordered in hexagonal arrays after heat treatment at 550 degrees C. With a CTAC/TEOS ratio of 0.21, films with a pore volume of approximate to 64% (approximate to 36 vol% silica) could be synthesized. The measured index of refraction for these highly porous films at 500 nm wavelength was 1.16, indicating that these films are potentially useful as low K interlayer dielectrics. RP Bruinsma, PJ (reprint author), PACIFIC NW NATL LAB,POB 999,RICHLAND,WA 99352, USA. OI Hess, Nancy/0000-0002-8930-9500 NR 0 TC 41 Z9 42 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-347-9 J9 MATER RES SOC SYMP P PY 1997 VL 443 BP 105 EP 110 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Engineering; Materials Science GA BJ57H UT WOS:A1997BJ57H00013 ER PT S AU Sullivan, JP Denison, DR Barbour, JC Newcomer, PP Apblett, CA Seager, CH Baca, AG AF Sullivan, JP Denison, DR Barbour, JC Newcomer, PP Apblett, CA Seager, CH Baca, AG BE Lagendijk, A Treichel, H Uram, KJ Jones, AC TI Thermal stability of fluorinated SiO2 films: Effects of hydration and film-substrate interaction SO LOW-DIELECTRIC CONSTANT MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium H on Low-Dielectric Constant Materials, at the 1996 MRS Fall Meeting CY DEC 02-03, 1996 CL BOSTON, MA SP Mat Res soc AB The thermal stability of fluorinated SiO2 films (SiOF) was found to be dependent on F content and the type of substrate upon which the film was deposited. SiOF films with a range of F concentrations were deposited using an electron cyclotron resonance (ECR) plasma upon Si, Al/Si, TiN/Al/Si, and Al/SiO2/Si substrates. Following deposition, the films were deliberately hydrated and/or annealed and their stability assessed. Hydration was found to only affect the high F content films. Capacitance changes with annealing in the high F content films were found to occur beginning at 200 degrees C. These changes, which were independent of substrate type, likely occurred due to desorption of H2O in the films. After annealing of the high F content films up to 400 degrees C, a reduction in F content was found for SiOF films on some substrates. Significant reductions were found for SiOF films on Al/Si substrates, while little or no change was found for films on TiN/Al/Si, Al/SiO2/Si, or Si substrates. Local chemical analysis of those films which showed F reduction indicated that the F profile was approximately uniform throughout the layer and did not pile-up at the interface. The substrate-dependent thermal instability exhibited by these films suggests the chemical nature or qualities of the substrate may play a role in the F reduction reaction. RP Sullivan, JP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-347-9 J9 MATER RES SOC SYMP P PY 1997 VL 443 BP 149 EP 154 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Engineering; Materials Science GA BJ57H UT WOS:A1997BJ57H00019 ER PT S AU Hrubesh, LW Buckley, SR AF Hrubesh, LW Buckley, SR BE Case, C Kohl, P Kikkawa, T Lee, WW TI Temperature and moisture dependence of dielectric constant for bulk silica aerogels SO LOW-DIELECTRIC CONSTANT MATERIALS III SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Low-Dielectric Constant Materials III, at the 1997 MRS Spring Meeting CY APR 01-04, 1997 CL SAN FRANCISCO, CA SP Mat Res Soc AB The dielectric constants of silica aerogels are among the lowest measured for any solid material. The silica aerogels also exhibit low thermal expansion and are thermally stable to temperatures exceeding 500 degrees C. However, due to the open porosity and large surface areas for aerogels, their dielectric constants are strongly affected by moisture and temperature. This paper presents data for the dielectric constants of silica aerogels as a function of moisture content at 25 degrees C, and as a function of temperature, for temperatures in the range from 25 degrees C to 450 degrees C. Dielectric constant data are also given for silica aerogels that are heat treated in dry nitrogen at 500 degrees C, then cooled to 25 degrees C for measurements in dry air. All measurements are made on bulk aerogel spheres at 22GHz microwave frequency, using a cavity perturbation method. The results of the dependence found here for bulk materials can be inferred to apply also to thin films of silica aerogels having similar nano-structures and densities. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Hrubesh, LW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. NR 0 TC 6 Z9 6 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-380-0 J9 MATER RES SOC SYMP P PY 1997 VL 476 BP 99 EP 104 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK42M UT WOS:000072112700014 ER PT B AU Cox, AN Guzik, JA Soukup, MS AF Cox, AN Guzik, JA Soukup, MS BE Nota, A Lamers, HJG TI Linear pulsations of strange modes in LBVs SO LUMINOUS BLUE VARIABLES : MASSIVE STARS IN TRANSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Luminous Blue Variables - Massive Stars in Transition CY OCT 06-12, 1996 CL KONA, HI SP Astron Soc Pacific C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cox, AN (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-40-6 J9 ASTR SOC P PY 1997 VL 120 BP 133 EP 137 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK80A UT WOS:000073440700025 ER PT B AU Guzik, JA Cox, AN Despain, KM Soukup, MS AF Guzik, JA Cox, AN Despain, KM Soukup, MS BE Nota, A Lamers, HJG TI A nonlinear study of luminous blue variables and possible outbursts SO LUMINOUS BLUE VARIABLES : MASSIVE STARS IN TRANSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Luminous Blue Variables - Massive Stars in Transition CY OCT 06-12, 1996 CL KONA, HI SP Astron Soc Pacific C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Guzik, JA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 11 Z9 11 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-40-6 J9 ASTR SOC P PY 1997 VL 120 BP 138 EP 142 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK80A UT WOS:000073440700026 ER PT J AU Allmen, MC Kegelmeyer, WP AF Allmen, MC Kegelmeyer, WP TI The computation of cloud base height from paired whole-sky imaging cameras SO MACHINE VISION AND APPLICATIONS LA English DT Article DE stereo; optical flow; cloud base height; whole-sky imaging camera AB We have developed a novel approach to the extraction of cloud base height (CBH) from pairs of whole-sky imagers (WSIs). The core problem is to spatially register cloud fields from widely separated WSIs; this complete, triangulation provides the CBH measurements. The wide camera separation and the self-similarity of clouds defeats standard matching algorithms when applied to static views of the sky. In response, we use optical flow methods that exploit the fact that modern WSIs provide image sequences. We will describe the algorithm, a confidence metric for its performance, a method to correct the severe projective effects of the WSI camera, and results on real data. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. NR 7 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0932-8092 J9 MACH VISION APPL JI Mach. Vis. Appl. PY 1997 VL 9 IS 4 BP 160 EP 165 DI 10.1007/s001380050037 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA WT237 UT WOS:A1997WT23700002 ER PT B AU Tobin, KW Gleason, SS Karnowski, TP AF Tobin, KW Gleason, SS Karnowski, TP BE Rao, AR Chang, N TI Feature analysis and classification of manufacturing signatures based on semiconductor wafermaps SO MACHINE VISION APPLICATIONS IN INDUSTRIAL INSPECTION V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Machine Vision Applications in Industrial Inspection V CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE feature analysis; feature ranking; feature selection; pattern recognition; classification; fuzzy pair-wise classifier; semiconductor; wafer inspection; electronic wafermap AB Automated tools for semiconductor wafer defect analysis are becoming more necessary as device densities and wafer sizes continue to increase. Trends towards larger wafer formats and smaller critical dimensions have caused an exponential increase in the volume of defect data which must be analyzed and stored. To accommodate these changing factors, automatic analysis tools are required that can efficiently and robustly process the increasing amounts of data, and thus quickly characterize manufacturing processes and accelerate yield learning. During the first year of this cooperative research project between SEMATECH and the Oak Ridge National Laboratory, a robust methodology for segmenting signature events prior to feature analysis and classification was developed. Based on the results of this segmentation procedure, a feature measurement strategy has been designed based on interviews with process engineers coupled with the analysis of approximately 1500 electronic wafermap files. In this paper, the authors represent an automated procedure to rank and select relevant features for use with a fuzzy pair-wise classifier and give examples of the efficacy of the approach taken. Results of the feature selection process are given for two uniquely different types of class data to demonstrate a general improvement in classifier performance. RP Tobin, KW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2440-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3029 BP 14 EP 25 PG 12 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Optics SC Automation & Control Systems; Computer Science; Engineering; Optics GA BH70K UT WOS:A1997BH70K00002 ER PT J AU Korszun, ZR AF Korszun, ZR TI Neutron macromolecular crystallography SO MACROMOLECULAR CRYSTALLOGRAPHY, PT A SE METHODS IN ENZYMOLOGY LA English DT Review ID HYDROGEN-BONDING GEOMETRIES; DIFFRACTION ANALYSIS; SOLVENT STRUCTURE; X-RAY; RESOLUTION; PROTEIN; TRYPSIN; CRYSTALS; REFINEMENT; LOCATION RP Korszun, ZR (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 48 TC 7 Z9 7 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 276 BP 218 EP 232 DI 10.1016/S0076-6879(97)76061-0 PG 15 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BH42P UT WOS:A1997BH42P00015 PM 27799096 ER PT S AU Westbrook, EM Naday, I AF Westbrook, EM Naday, I BE Carter, CW Sweet, RM TI Charge-coupled device-based area detectors SO MACROMOLECULAR CRYSTALLOGRAPHY, PT A SE Methods in Enzymology LA English DT Review ID X-RAY-DETECTORS; CCD-BASED DETECTOR; MACROMOLECULAR CRYSTALLOGRAPHY; PROTEIN CRYSTALLOGRAPHY; SYNCHROTRON-RADIATION; ANOMALOUS DIFFRACTION; SPATIAL DISTORTIONS; QUANTUM EFFICIENCY; STORAGE PHOSPHOR; HIGH-RESOLUTION C1 ARGONNE NATL LAB, ELECT & COMP TECHNOL DIV, ARGONNE, IL 60439 USA. RP ARGONNE NATL LAB, STRUCT BIOL CTR, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 66 TC 50 Z9 51 U1 0 U2 6 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 BN 0-12-182177-3 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 276 BP 244 EP 268 DI 10.1016/S0076-6879(97)76063-4 PG 25 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BH42P UT WOS:A1997BH42P00017 PM 9048377 ER PT J AU Hendrickson, WA Ogata, CM AF Hendrickson, WA Ogata, CM TI Phase determination from multiwavelength anomalous diffraction measurements SO MACROMOLECULAR CRYSTALLOGRAPHY, PT A SE METHODS IN ENZYMOLOGY LA English DT Review ID RESTRICTION-ENDONUCLEASE BAMHI; HIGH-RESOLUTION STRUCTURE; X-RAY-DIFFRACTION; CRYSTAL-STRUCTURE; SYNCHROTRON-RADIATION; SELENOMETHIONYL PROTEIN; MAD ANALYSIS; ISOMORPHOUS REPLACEMENT; 3-DIMENSIONAL STRUCTURE; SCATTERING FACTORS C1 BROOKHAVEN NATL LAB,HOWARD HUGHES MED INST,UPTON,NY 11973. RP Hendrickson, WA (reprint author), COLUMBIA UNIV,HOWARD HUGHES MED INST,DEPT BIOCHEM & MOL BIOPHYS,NEW YORK,NY 10032, USA. NR 84 TC 287 Z9 289 U1 4 U2 21 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 276 BP 494 EP 523 DI 10.1016/S0076-6879(97)76074-9 PG 30 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BH42P UT WOS:A1997BH42P00028 PM 27799111 ER PT J AU Terwilliger, TC AF Terwilliger, TC TI Multiwavelength anomalous diffraction phasing of macromolecular structures: Analysis of MAD data as single isomorphous replacement with anomalous scattering data using the MADMRG program SO MACROMOLECULAR CRYSTALLOGRAPHY, PT A SE METHODS IN ENZYMOLOGY LA English DT Review ID CRYSTAL-STRUCTURE; SYNCHROTRON RADIATION; INFORMATION; ERRORS RP Terwilliger, TC (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545, USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 12 TC 42 Z9 42 U1 1 U2 8 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0076-6879 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 276 BP 530 EP 537 DI 10.1016/S0076-6879(97)76076-2 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BH42P UT WOS:A1997BH42P00030 PM 9048380 ER PT S AU Abola, EE Sussman, JL Prilusky, J Manning, NO AF Abola, EE Sussman, JL Prilusky, J Manning, NO BE Carter, CW Sweet, RM TI Protein data bank archives of three-dimensional macromolecular structures SO MACROMOLECULAR CRYSTALLOGRAPHY, PT B SE Methods in Enzymology LA English DT Review ID TOOLS; FILE C1 WEIZMANN INST SCI, DEPT BIOL STRUCT, IL-76100 REHOVOT, ISRAEL. WEIZMANN INST SCI, BIOINFORMAT UNIT, IL-76100 REHOVOT, ISRAEL. RP Abola, EE (reprint author), BROOKHAVEN NATL LAB, DEPT BIOL, PROT DATA BANK, UPTON, NY 11973 USA. OI Sussman, Joel/0000-0003-0306-3878 NR 18 TC 172 Z9 173 U1 0 U2 2 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0076-6879 BN 0-12-182178-1 J9 METHOD ENZYMOL JI Methods Enzymol. PY 1997 VL 277 BP 556 EP 571 DI 10.1016/S0076-6879(97)77031-9 PG 16 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA BJ57S UT WOS:A1997BJ57S00029 PM 9379928 ER PT S AU Fullerton, EE Sowers, CH Pearson, JP Wu, XZ Lederman, D Bader, SD AF Fullerton, EE Sowers, CH Pearson, JP Wu, XZ Lederman, D Bader, SD BE Hadjipanayis, GC TI Structure and magnetism of epitaxial rare-earth-transition-metal films SO MAGNETIC HYSTERESIS IN NOVEL MAGNETIC MATERIALS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on Magnetic Hysteresis in Novel Magnetic Materials CY JUL 01-12, 1996 CL MYKONOS, GREECE SP NATO, Sci Affairs Div RP Fullerton, EE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 0 TC 0 Z9 0 U1 2 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-132X BN 0-7923-4604-1 J9 NATO ADV SCI I E-APP PY 1997 VL 338 BP 467 EP 478 PG 12 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BJ51T UT WOS:A1997BJ51T00048 ER PT S AU Krishnan, KM Brewer, MA Kobayashi, T Nakanishi, A Young, A AF Krishnan, KM Brewer, MA Kobayashi, T Nakanishi, A Young, A BE Hadjipanayis, GC TI Giant moment in sputtered Fe-N films grown epitaxially on Si (001) SO MAGNETIC HYSTERESIS IN NOVEL MAGNETIC MATERIALS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on Magnetic Hysteresis in Novel Magnetic Materials CY JUL 01-12, 1996 CL MYKONOS, GREECE SP NATO, Sci Affairs Div RP Krishnan, KM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-132X BN 0-7923-4604-1 J9 NATO ADV SCI I E-APP PY 1997 VL 338 BP 561 EP 565 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BJ51T UT WOS:A1997BJ51T00062 ER PT S AU Sellers, CH Branagan, DJ Hyde, TA Lewis, LH Panchanathan, V AF Sellers, CH Branagan, DJ Hyde, TA Lewis, LH Panchanathan, V BE Hadjipanayis, GC TI Permanent magnet powders produced by gas atomization SO MAGNETIC HYSTERESIS IN NOVEL MAGNETIC MATERIALS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on Magnetic Hysteresis in Novel Magnetic Materials CY JUL 01-12, 1996 CL MYKONOS, GREECE SP NATO, Sci Affairs Div AB Gas atomization processing is an alternative to melt spinning for the production of isotropic Nd2Fe14B powders for bonded magnet (and other) applications. A new approach is presented in which alloys are designed for gas atomization processing specifically, resulting in improved magnetic properties and corrosion resistance. The hysteresis properties of powders as a function of composition, particle size, and heat treatment will be discussed and compared with studies by electron microscopy, magnetic force microscopy, and x-ray diffraction. RP Sellers, CH (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-132X BN 0-7923-4604-1 J9 NATO ADV SCI I E-APP PY 1997 VL 338 BP 651 EP 655 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BJ51T UT WOS:A1997BJ51T00070 ER PT S AU Bedrossian, PJ Gibbons, MR Cerjan, CJ AF Bedrossian, PJ Gibbons, MR Cerjan, CJ BE Tobin, J Chambliss, D Kubinski, D Barmak, K Dederichs, P deJonge, W Katayama, T Schuhl, A TI Domain topology of micron-scale, ferromagnetic pancakes SO MAGNETIC ULTRATHIN FILMS, MULTILAYERS AND SURFACES - 1997 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on the Structure and Properties of Magnetic Ultrathin Films, Multilayers, Surfaces, and Nanostructures CY MAR 31-APR 04, 1997 CL SAN FRANCISCO, CA SP Ford Res Lab, Digital Instruments, Fujitsu Ltd, GMW Associates, Hitachi Ltd, Cent Res Lab, Komag Inc, Lake Shore Cryotronics Inc, Lawrence Livermore Natl Lab, Dept Energy, MDC Vacuum Prod Corp, MMR Technol, Phys Electr Inc, Princeton Measurements Corp, Tencor Instruments, Toshiba Corp, US Inc AB Planar, micron-scale ellipses patterned from 700 Angstrom-thick Co films exhibit nearly-complete suppression of hysteresis when magnetized in-plane along their short axes. Using a combination of Magnetic Force Microscopy and Vibrating Sample Magnetometry, we find that the suppression of hysteresis is associated with the continuous deformation of a dipole field configuration. The presence of hysteresis for in-plane, long-axis magnetization is associated with transitions between topologically inequivalent configurations. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bedrossian, PJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-379-7 J9 MATER RES SOC SYMP P PY 1997 VL 475 BP 277 EP 282 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK23Q UT WOS:000071594300037 ER PT S AU Kim, SK Chernov, VA Kortright, JB Koo, YM AF Kim, SK Chernov, VA Kortright, JB Koo, YM BE Tobin, J Chambliss, D Kubinski, D Barmak, K Dederichs, P deJonge, W Katayama, T Schuhl, A TI Anisotropic local structure of Co-Pd alloy and Pd/Co multilayer films having perpendicular magnetic anisotropy SO MAGNETIC ULTRATHIN FILMS, MULTILAYERS AND SURFACES - 1997 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on the Structure and Properties of Magnetic Ultrathin Films, Multilayers, Surfaces, and Nanostructures CY MAR 31-APR 04, 1997 CL SAN FRANCISCO, CA SP Ford Res Lab, Digital Instruments, Fujitsu Ltd, GMW Associates, Hitachi Ltd, Cent Res Lab, Komag Inc, Lake Shore Cryotronics Inc, Lawrence Livermore Natl Lab, Dept Energy, MDC Vacuum Prod Corp, MMR Technol, Phys Electr Inc, Princeton Measurements Corp, Tencor Instruments, Toshiba Corp, US Inc AB Anisotropic short-range structure in Co-Pd alloy and Pd/Co multilayer films is determined using polarized Co K-edge extended x-ray absorption fine structure. A local modulation of Co fraction exists along the growth direction in the alloy films. Pd underlayer and Pd spacers alternated with the alloy layer influence an effective strain anisotropy. Pd/Co multilayers have an alloy-like region near nominal interfaces by diffuse interface. Pd spacers in the multilayer play a role in coherency strain rather than on broken symmetry of Co atoms. Local structural anisotropy of both strain and chemical environment contribute to the perpendicular magnetic anisotropy observed in these films. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Kim, SK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-379-7 J9 MATER RES SOC SYMP P PY 1997 VL 475 BP 399 EP 404 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK23Q UT WOS:000071594300056 ER PT S AU Morais, J Denecke, R Ynzunza, RX Menchero, JG Liesegang, J Fadley, CS AF Morais, J Denecke, R Ynzunza, RX Menchero, JG Liesegang, J Fadley, CS BE Tobin, J Chambliss, D Kubinski, D Barmak, K Dederichs, P deJonge, W Katayama, T Schuhl, A TI Angle- and temperature-dependent magnetic circular dichroism in Gd(0001) core-level photoemission SO MAGNETIC ULTRATHIN FILMS, MULTILAYERS AND SURFACES - 1997 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on the Structure and Properties of Magnetic Ultrathin Films, Multilayers, Surfaces, and Nanostructures CY MAR 31-APR 04, 1997 CL SAN FRANCISCO, CA SP Ford Res Lab, Digital Instruments, Fujitsu Ltd, GMW Associates, Hitachi Ltd, Cent Res Lab, Komag Inc, Lake Shore Cryotronics Inc, Lawrence Livermore Natl Lab, Dept Energy, MDC Vacuum Prod Corp, MMR Technol, Phys Electr Inc, Princeton Measurements Corp, Tencor Instruments, Toshiba Corp, US Inc AB Recent results on the dependence of the magnetic circular dichroism on the angle and temperature for thick (100 ML) films of Gd(0001) are presented. Strong dichroic effects were observed in 4d core-level photoemission for the magnetized films, which showed excellent agreement with an atomic many-particle description recently published [1]. The angular dependence of the magnetic dichroism has been discussed taking into account photoelectron diffraction effects. In addition, an indication of a higher surface Curie temperature has been observed in the temperature-dependent measurements. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Morais, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Morais, Jonder/E-5022-2013 OI Morais, Jonder/0000-0002-4143-1208 NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-379-7 J9 MATER RES SOC SYMP P PY 1997 VL 475 BP 419 EP 423 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK23Q UT WOS:000071594300058 ER PT S AU Goodman, KW Tobin, JG Schumann, FO Willis, RF Gammon, JW Pappas, DP Kortright, JB Denlinger, JD Rotenberg, E Warwick, A Smith, NV AF Goodman, KW Tobin, JG Schumann, FO Willis, RF Gammon, JW Pappas, DP Kortright, JB Denlinger, JD Rotenberg, E Warwick, A Smith, NV BE Tobin, J Chambliss, D Kubinski, D Barmak, K Dederichs, P deJonge, W Katayama, T Schuhl, A TI Effects of symmetry on circular and linear magnetic dichroism in angle-resolved photoemission spectra of Gd/Y(0001) and Fe-Ni/Cu(001) SO MAGNETIC ULTRATHIN FILMS, MULTILAYERS AND SURFACES - 1997 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on the Structure and Properties of Magnetic Ultrathin Films, Multilayers, Surfaces, and Nanostructures CY MAR 31-APR 04, 1997 CL SAN FRANCISCO, CA SP Ford Res Lab, Digital Instruments, Fujitsu Ltd, GMW Associates, Hitachi Ltd, Cent Res Lab, Komag Inc, Lake Shore Cryotronics Inc, Lawrence Livermore Natl Lab, Dept Energy, MDC Vacuum Prod Corp, MMR Technol, Phys Electr Inc, Princeton Measurements Corp, Tencor Instruments, Toshiba Corp, US Inc AB We have observed circular and linear magnetic dichroisms in angle-resolved photoemission spectra of 50-monolayer Gd films grown on Y(0001) and 6-monolayer Fe-Ni alloy films grown on Cu(001). The 4f level of Gd and the Fe 3p level of the Fe-Ni alloy were measured. A different geometry was used for the magnetic circular dichroism than was used to measure the magnetic linear dichroism. The geometries were chosen so that the magnetic circular dichroism is predicted to be closely related to the magnetic linear dichroism for four-fold symmetric Fe-Ni/Cu(001) but not for three-fold symmetric Gd-Y(0001). Experimental results are presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Goodman, KW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Rotenberg, Eli/B-3700-2009; Schumann, Frank /K-9364-2014 OI Rotenberg, Eli/0000-0002-3979-8844; NR 0 TC 4 Z9 4 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-379-7 J9 MATER RES SOC SYMP P PY 1997 VL 475 BP 493 EP 497 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK23Q UT WOS:000071594300070 ER PT S AU Kwei, GH Argyriou, DN Billinge, SJL Lawson, AC Neumeier, JJ Ramirez, AP Subramanian, MA Thompson, JD AF Kwei, GH Argyriou, DN Billinge, SJL Lawson, AC Neumeier, JJ Ramirez, AP Subramanian, MA Thompson, JD BE Tobin, J Chambliss, D Kubinski, D Barmak, K Dederichs, P deJonge, W Katayama, T Schuhl, A TI Lattice effects in perovskite and pyrochlore CMR materials SO MAGNETIC ULTRATHIN FILMS, MULTILAYERS AND SURFACES - 1997 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 9th International Symposium on the Structure and Properties of Magnetic Ultrathin Films, Multilayers, Surfaces, and Nanostructures CY MAR 31-APR 04, 1997 CL SAN FRANCISCO, CA SP Ford Res Lab, Digital Instruments, Fujitsu Ltd, GMW Associates, Hitachi Ltd, Cent Res Lab, Komag Inc, Lake Shore Cryotronics Inc, Lawrence Livermore Natl Lab, Dept Energy, MDC Vacuum Prod Corp, MMR Technol, Phys Electr Inc, Princeton Measurements Corp, Tencor Instruments, Toshiba Corp, US Inc AB Colossal magnetoresistance (CMR) in doped lanthanum manganite thin films (La1-xMxMnO3, where M is a divalent ion) has been shown to result in a factor of 10(6) suppression of the resistance. The driving force for the CMR transition is thought to be the double-exchange (DE) interaction. Many studies of both the crystal structure and the local structure of the La1-xMxMnO3 (with M = Ca, Sr and Ba, as well as Pb) system have now been carried out. As expected, these systems all show a strong coupling of the lattice to the CMR transition. On the other hand, neutron diffraction data and x-ray absorption studies for the Tl2Mn2O7 pyrochlore, which also exhibits CMR, shows no deviations from ideal stoichiometry, mixed valency, or Jahn-Teller distortions of the MnO6 octahedron. We present results of crystallographic and local structural studies of these two important classes of CMR materials. compare the differences in structural response, and discuss the implications of these findings ro our understanding of these materials. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kwei, GH (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 6 Z9 6 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-379-7 J9 MATER RES SOC SYMP P PY 1997 VL 475 BP 533 EP 544 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BK23Q UT WOS:000071594300076 ER PT S AU Shirane, G AF Shirane, G BE McMorrow, DF Jensen, J Ronnow, HM TI Magnetism of cuprate oxides SO MAGNETISM IN METALS SE KONGELIGE DANSKE VIDENSKABERNES SELSKAB: MATEMATISK-FYSISKE MEDDELELSER LA English DT Proceedings Paper CT Symposium in Memory of Allan Mackintosh - Magnetism in Metals CY AUG 26-29, 1996 CL COPENHAGEN, DENMARK AB A review is given of the current neutron scattering experiments on cuprate oxides. We first discuss the extensive neutron measurements on high T-c oxides; La2-xSrxCuO4 and related La1.6-xNd0.4SrxCuO4. The second topic is the spin-Peierls system Cu1-xZnxGeOs3 where a new type of antiferromagnetic phase has been discovered. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Shirane, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROYAL DANISH ACADEMY SCIENCES & LETTERS PI COPENHAGEN V PA H C ANDERSENS BLVD 35, DK-1553 COPENHAGEN V, DENMARK SN 0023-3323 BN 87-7304-287-0 J9 KONG DANSK VIDENSK PY 1997 VL 45 BP 281 EP 290 PG 10 WC Physics, Applied; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter SC Physics GA BK35V UT WOS:000071898900015 ER PT S AU Gibbs, D AF Gibbs, D BE McMorrow, DF Jensen, J Ronnow, HM TI Two recent examples of x-ray magnetic scattering studies SO MAGNETISM IN METALS SE KONGELIGE DANSKE VIDENSKABERNES SELSKAB: MATEMATISK-FYSISKE MEDDELELSER LA English DT Proceedings Paper CT Symposium in Memory of Allan Mackintosh - Magnetism in Metals CY AUG 26-29, 1996 CL COPENHAGEN, DENMARK AB Recent results concerned with x-ray resonant magnetic scattering studies of the induced Lu magnetization in Dy-Lu alloys (Everitt et al., 1995) and of magnetic disordering of UO2 surfaces (Watson et al., 1996) are reviewed. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Gibbs, D (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROYAL DANISH ACADEMY SCIENCES & LETTERS PI COPENHAGEN V PA H C ANDERSENS BLVD 35, DK-1553 COPENHAGEN V, DENMARK SN 0023-3323 BN 87-7304-287-0 J9 KONG DANSK VIDENSK PY 1997 VL 45 BP 345 EP 358 PG 14 WC Physics, Applied; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter SC Physics GA BK35V UT WOS:000071898900019 ER PT B AU Jones, PW AF Jones, PW BE Hoffmann, GR Kreitz, N TI The Los Alamos Parallel Ocean Program (POP) and coupled model on MPP and clustered SMP architectures SO MAKING ITS MARK LA English DT Proceedings Paper CT 7th ECMWF Workshop on the Use of Parallel Processors in Meteorology CY NOV 02-06, 1996 CL READING, ENGLAND SP European Ctr Medium Range Weather Forecasts AB The Los Alamos Parallel Ocean Program has been developed and used on a variety of parallel computers. Implementation and portability of the model is described and performance results are presented. Recent improvements for efficient performance on cache-based microprocessors and SMP architectures are also described. Efforts to couple POP with a new sea ice model and atmospheric general circulation models on parallel computers are discussed. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Jones, PW (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3350-7 PY 1997 BP 226 EP 238 PG 3 WC Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BM17V UT WOS:000077914900018 ER PT B AU von Laszewski, G AF von Laszewski, G BE Hoffmann, GR Kreitz, N TI An interactive parallel programming environment applied in atmospheric science SO MAKING ITS MARK LA English DT Proceedings Paper CT 7th ECMWF Workshop on the Use of Parallel Processors in Meteorology CY NOV 02-06, 1996 CL READING, ENGLAND SP European Ctr Medium Range Weather Forecasts DE graphical program design; visual programming; metacomputing; Java; data assimilation AB This article introduces an interactive parallel programming environment (IPPE) that simplifies the generation and execution of parallel programs. One of the tasks of the environment is to generate message-passing parallel programs for homogeneous and heterogeneous computing platforms. The parallel programs are represented by using visual objects. This is accomplished with the help of a graphical programming editor that is implemented in Java and enables portability to a wide variety of computer platforms. In contrast to other graphical programming systems, reusable parts of the programs can be stored in a program library to support rapid prototyping. In addition, runtime performance data on different computing platforms is collected in a database. A selection process determines dynamically the software and the hardware platform to be used to solve the problem in minimal wall-clock time. The environment is currently being tested on a Grand Challenge problem, the NASA four-dimensional data assimilation system. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP von Laszewski, G (reprint author), Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3350-7 PY 1997 BP 311 EP 325 PG 3 WC Computer Science, Interdisciplinary Applications; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BM17V UT WOS:000077914900024 ER PT B AU Nickens, PR Cadoret, NA Wright, MK AF Nickens, PR Cadoret, NA Wright, MK BE Harmon, D TI Building an erosion monitoring approach for cultural resources: An example from the Hanford Reach of the Columbia River SO MAKING PROTECTION WORK: PROCEEDINGS OF THE 9TH CONFERENCE ON RESEARCH AND RESOURCE MANAGEMENT IN PARKS AND ON PUBLIC LANDS LA English DT Proceedings Paper CT 9th Conference on Research and Resource Management in Parks and on Public Lands - Making Protection Work CY MAR 17-21, 1997 CL ALBUQUERQUE, NM SP George Wright Soc, US Natl Park Serv, US Geol Survey, Biol Resources Div, E Natl Park & Monument Assoc, US Natl Park Serv, Park Planning & Special Studies Div C1 Pacific NW Natl Lab, Richland, WA 99352 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU GEORGE WRIGHT SOCIETY, INC. PI HANCOCK PA PO BOX 65, HANCOCK, MI 49930-0065 USA PY 1997 BP 123 EP 131 PG 9 WC Environmental Studies; Public Administration; Sociology SC Environmental Sciences & Ecology; Public Administration; Sociology GA BN83M UT WOS:000083133100025 ER PT J AU Justice, MJ Stephenson, DA AF Justice, MJ Stephenson, DA TI Mouse chromosome 13 SO MAMMALIAN GENOME LA English DT Article C1 UNIV LONDON UNIV COLL,DEPT GENET & BIOMETRY,LONDON NW1 2HE,ENGLAND. RP Justice, MJ (reprint author), OAK RIDGE NATL LAB,DIV BIOL,POB 2009,OAK RIDGE,TN 37831, USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PY 1997 VL 7 SI SI BP S223 EP S237 DI 10.1007/s003359900325 PG 15 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA XM207 UT WOS:A1997XM20700013 PM 9233396 ER PT B AU Becker, RH Gregg, MD Laurent-Muehleisen, SA White, RL Helfand, DJ McMahon, RG Oegerle, W Friedman, S Richards, G York, D Rockosi, C Impey, C AF Becker, RH Gregg, MD Laurent-Muehleisen, SA White, RL Helfand, DJ McMahon, RG Oegerle, W Friedman, S Richards, G York, D Rockosi, C Impey, C BE Arav, N Shlosman, I Weymann, RJ TI BAL quasars in the VLA FIRST survey SO MASS EJECTION FROM ACTIVE GALACTIC NUCLEI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Mass Ejection from Active Galactic Nuclei CY FEB 19-21, 1997 CL CARNEGIE OBSERV, PASADENA, CA SP NASA HO CARNEGIE OBSERV AB The VLA FIRST survey has proven to be surprisingly effective at locating broad absorption line (BAL) quasars. Surprising in so far as previous quasar surveys have failed to find any radio-loud BAL quasars, so a radio-selected sample of quasars would seem to be the wrong place to look for them. Nonetheless, the FIRST survey has not only been finding BAL quasars, it has been finding rare types of BAL quasars including radio-loud BAL quasars. In this paper we summarize the current status of BAL quasars in the FIRST survey. C1 Univ Calif Davis, Dept Phys, Lawrence Livermore Natl Lab, IGPP, Livermore, CA 95616 USA. RP Becker, RH (reprint author), Univ Calif Davis, Dept Phys, Lawrence Livermore Natl Lab, IGPP, Livermore, CA 95616 USA. RI White, Richard/A-8143-2012; Oegerle, William/C-9070-2012 NR 0 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-48-1 J9 ASTR SOC P PY 1997 VL 128 BP 31 EP 34 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK80H UT WOS:000073445300005 ER PT B AU Brotherton, MS van Breugel, W Dey, A Antonucci, R AF Brotherton, MS van Breugel, W Dey, A Antonucci, R BE Arav, N Shlosman, I Weymann, RJ TI Spectropolarimetry of FIRST 0840+3633 SO MASS EJECTION FROM ACTIVE GALACTIC NUCLEI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Mass Ejection from Active Galactic Nuclei CY FEB 19-21, 1997 CL CARNEGIE OBSERV, PASADENA, CA SP NASA HO CARNEGIE OBSERV AB We present Keck spectropolarimetry of a rare "Iron Lo-BAL QSO," FIRST 0840+3633. The continuum is similar to 4% polarized near 2000 Angstrom rest-frame, but falls to similar to 2% at longer wavelengths, and maintains a relatively constant position angle of 50 degrees. The emission lines are unpolarized. The polarization increases up to similar to 8% in the low-ionization absorption troughs of Mg II lambda 2800 and Al III lambda 1860. The polarization and its position angle vary in a complicated manner across the metastable Fe II absorption lines, suggesting that more than one mechanism is at work or that the system geometry is complex. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Brotherton, MS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, 7000 East Ave,POB 808,L413, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-48-1 J9 ASTR SOC P PY 1997 VL 128 BP 84 EP 87 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK80H UT WOS:000073445300013 ER PT S AU Saririan, K AF Saririan, K BE Levy, M Iliopoulos, J Gastmans, R Gerard, JM TI Gaugino condensation, loop corrections, and S-duality constraint SO MASSES OF FUNDAMENTAL PARTICLES: CARGESE 1996 SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES B, PHYSICS LA English DT Proceedings Paper CT NATO Advanced Study Institute on Masses of Fundamental Particles CY AUG 05-17, 1996 CL CARGESE, FRANCE SP NATO, Univ Pierre & Marie Curie, Ecole Normale Super, Katholieke Univ Leuven, CNRS, Inst Natl Phys Nucl & Phys Particules RP Saririan, K (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0258-1221 BN 0-306-45694-X J9 NATO ADV SCI I B-PHY PY 1997 VL 363 BP 329 EP 339 PG 11 WC Physics, Particles & Fields SC Physics GA BJ84A UT WOS:A1997BJ84A00018 ER PT J AU Dini, JW AF Dini, JW TI Properties of coatings: Comparisons of electroplated, physical vapor deposited, chemical vapor deposited, and plasma sprayed coatings SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article ID THIN-FILMS; ION-BOMBARDMENT; CUTTING TOOLS; CHROMIUM; PVD; MICROSTRUCTURE; MICROPOROSITY; TOPOGRAPHY; MICROSCOPY; TRIVALENT AB Properties of coatings (structure, porosity, density, stress, corrosion, hydrogen permeation, adhesion, tribology, fatigue and thermal contact conductance) produced by a number of deposition methods including electrodeposition, physical vapor deposition, chemical vapor deposition, and flame spraying are compared. In most cases, the films did not exhibit similar properties. In addition, process conditions often could be varied for any given coating process and this, in turn, would affect microstructure and hence the properties. No coating system provided best results for all these properties. In some cases, electroplated films provided superior results while in others PVD or CVD were best. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 79 TC 8 Z9 8 U1 2 U2 7 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1997 VL 12 IS 3 BP 437 EP 472 DI 10.1080/10426919708935157 PG 36 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA XE980 UT WOS:A1997XE98000006 ER PT J AU Natesan, K AF Natesan, K TI Corrosion performance of alumina scales in coal gasification environments SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 2nd International Workshop on Corrosion in Advanced Power Plants CY MAR 03-05, 1997 CL TAMPA, FL SP Elect Power Res Inst, California, Palo Alto, CEC Joint Res Ctr, Inst Adv Mat, Netherlands, Petten, Oak Ridge Natl Lab, Tennessee, Oak Ridge DE corrosion; alumina; surface modification ID SULFIDIZING ENVIRONMENTS; ALLOYS AB Corrosion of metallic structural materials in complex gas environments of coal gasification is a potential problem. The corrosion process is dictated by concentrations of two key constituents: sulfur as H2S and Cl as HCl. This paper examines the corrosion performance of alumina scales that are thermally grown on Fe-base alloys during exposure to O/S mixed-gas environments. The results are compared with the performance of chromia-forming alloys in similar environments. The paper also discusses the available information on corrosion performance of alloys whose surfaces were enriched with Al by the pack-diffusion process, by the electrospark deposition process, or by weld overlay techniques. RP Natesan, K (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 3 Z9 3 U1 0 U2 3 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 2 BP 137 EP 145 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YF664 UT WOS:A1997YF66400011 ER PT J AU Wright, IG AF Wright, IG TI A review of experience of wastage in fluidized-bed boilers SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 2nd International Workshop on Corrosion in Advanced Power Plants CY MAR 03-05, 1997 CL TAMPA, FL SP Elect Power Res Inst, California, Palo Alto, CEC Joint Res Ctr, Inst Adv Mat, Netherlands, Petten, Oak Ridge Natl Lab, Tennessee, Oak Ridge DE fluidized-bed boilers; wastage AB Fluidized-bed boilers based on variants of bubbling bed, circulating bed and pressurized designs are in wide commercial use in a range of sizes, and burn a variety of fuels. There is experience of localized metal loss on the fireside circuit of these units with some experiencing none while others, often of identical design, required urgent attention to allow acceptable operating periods. Nevertheless, wastage by combinations of corrosive attack and wear has not proved to limit significantly the application of this technology but, in some cases, has resulted in a heavy maintenance burden. In this paper, the current experience of such fireside wastage is reviewed, and the practical measures adopted to combat it are examined together with the apparent causes of the wastage. A review of the current state of mechanistic understanding of the causes of wastage suggests that understanding is developing slowly, partly because of the large number of variables involved. Mechanism-based solutions to the wastage problems still appear to be a useful goal, since they would reduce the maintenance costs associated with wastage, and improve the competitive position of fluidized-bed boiler technology. RP Wright, IG (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 47 TC 2 Z9 2 U1 0 U2 0 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 3 BP 277 EP 288 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YJ683 UT WOS:A1997YJ68300012 ER PT J AU Hou, PY MacAdam, S Zhang, H Stringer, J AF Hou, PY MacAdam, S Zhang, H Stringer, J TI Summary of results from the Berkely in-bed tube erosion simulator SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 2nd International Workshop on Corrosion in Advanced Power Plants CY MAR 03-05, 1997 CL TAMPA, FL SP Elect Power Res Inst, California, Palo Alto, CEC Joint Res Ctr, Inst Adv Mat, Netherlands, Petten, Oak Ridge Natl Lab, Tennessee, Oak Ridge DE fluidized bed combustors; in-bed particles and tubes ID FLUIDIZED-BED; WASTAGE; COMBUSTORS; WEAR; ENVIRONMENT; PRESSURE AB The Berkeley rig was designed to simulate the particle hammering interactions between in-bed particles and tubes within bubbling fluidized bed combustors. To achieve this in a controlled manner, a rod shaped specimen is actuated a shea distance within a partially fluidized bed, consisting quartz particles with an average size of 800 mu m. The rig has been used to investigate the characteristics of tube metal loss and its dependence on temperature. Most of the tests were performed isothermally by varying the bed temperature within the studied range, some were carried out by internally cooling the specimen while keeping the bed temperature constant at 700 degrees C. This paper reviews the results that have been obtained from these simulations. Earlier conclusions from cold model studies are summarized, and the effects of temperature, temperature gradient, bed condition and bed material deposits on tube wastage are presented and discussed. C1 ELECT POWER RES INST,PALO ALTO,CA 94304. RP Hou, PY (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 32 TC 7 Z9 8 U1 0 U2 1 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 3 BP 325 EP 335 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YJ683 UT WOS:A1997YJ68300016 ER PT J AU Natesan, K AF Natesan, K TI Rapporteur's report SO MATERIALS AT HIGH TEMPERATURES LA English DT Editorial Material RP Natesan, K (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 3 BP 383 EP 384 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YJ683 UT WOS:A1997YJ68300022 ER PT J AU Pint, BA AF Pint, BA TI Characterization of the high temperature oxidation of TBC-coated oxide-dispersed beta-NiAl substrates SO MATERIALS AT HIGH TEMPERATURES LA English DT Article DE beta-NiAl; thermal barrier coatings; Al2O3 scales; spallation; voids ID THERMAL BARRIER COATINGS; PREDICTION MODEL DEVELOPMENT; ALLOYS; LIFE; MECHANISM; SCALES AB A Y2O3-stabilized ZrO2 coating on three different oxide-dispersed (Y2O3, ZrO2 and A1(2)0(3)) beta-NiA1 substrates was studied to evaluate the spallation behaviour of the coating and its effect on the oxidation behavior of these alloy substrates. Spallation of the coating during cyclic testing at 1200 degrees C primarily occurred at the A1(2)0(3) scale-substrate interface and was dependent on the adhesion of the scale to the substrate. Uncoated, Y(2)0(3)-dispersed beta-NiA1 had the best A1(2)0(3) scale adhesion and the coated beta-NiA1 substrate had the longest coating lifetime. Al(2)0(3)-dispersed beta-NiA1 exhibited the poorest scale adhesion and the coating completely spalled after two 2-hour cycles. For this model-type system, the growth of voids at the metal-scale interface appears to be critical in determining scale adhesion and thus coating lifetime. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pint, BA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 25 TC 11 Z9 11 U1 0 U2 0 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81,, NORTHWOOD, MIDDX, ENGLAND HA6 3DN SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 1997 VL 14 IS 4 BP 403 EP 412 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YV830 UT WOS:000071867600002 ER PT S AU deBoer, MP Michalske, TA AF deBoer, MP Michalske, TA BE Reed, ML Elwenspoek, M Johansson, S Obermeier, E Fujita, H Uenishi, Y TI Improved autoadhesion measurement method for micromachined polysilicon beams SO MATERIALS FOR MECHANICAL AND OPTICAL MICROSYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium I - Materials in Microsystems, at the 1996 MRS Fall Meeting CY DEC 04-05, 1996 CL BOSTON, MA SP Mat Res Soc AB We have measured autoadhesion (e.g. stiction) of individual polysilicon beams by interferometric optical microscopy. Untreated cantilever beams were dried from water in air, while treated beams were coated with a hydrophobic molecular coating of octadecyltrichlorosilane (ODTS). Adhesion values obtained for beams adhered to the substrate over a long length (large d) are independent of beam length with values of 16.7 and 4.4 mJ/m(2) for untreated and treated samples respectively. These values can be understood in terms of differences in surface chemistry and polysilicon roughness. Using the shortest length beam which remains attached to the substrate, adhesion values were 280 and 16 mJ/m(2) respectively. These higher values may be a result of capillarity effects. We recommend that measurements be made on beams in which d is large, in contrast to the current practice of noting the shortest beam adhered. RP deBoer, MP (reprint author), SANDIA NATL LABS,DEPT 1114,MAIL STOP 1413,ALBUQUERQUE,NM 87185, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-348-7 J9 MATER RES SOC SYMP P PY 1997 VL 444 BP 87 EP 92 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied SC Engineering; Materials Science; Physics GA BH52A UT WOS:A1997BH52A00009 ER PT S AU Monteiro, OR Brown, IG Sooryakumar, R Chirita, M AF Monteiro, OR Brown, IG Sooryakumar, R Chirita, M BE Reed, ML Elwenspoek, M Johansson, S Obermeier, E Fujita, H Uenishi, Y TI Elastic properties of diamond like carbon thin films: A brillouin scattering study SO MATERIALS FOR MECHANICAL AND OPTICAL MICROSYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium I - Materials in Microsystems, at the 1996 MRS Fall Meeting CY DEC 04-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Diamondlike carbon (DLC) thin films have been widely used as hard coatings in a variety of applications where increased wear resistance and hardness are required. Vacuum are DLC films are among the hardest, with measured hardness values of up to 68 Gpa. In our deposition process a repetitively pulsed bias voltage is applied to the substrate, which controls the energy of the incoming C ions. DLC chemical and mechanical properties are strongly affected by the energy of the depositing ions. In this paper, we relate the mechanical properties of these films to the deposition parameters, and describe our initial Brillouin scattering measurements of the elastic constants of monolithic DLC films. Evidence for bulk longitudinal and surface Rayleigh excitation in films with thickness of 50 and 500 nm has been observed. Since the DLC films are amorphous, they are modeled as isotropic solids and the elastic constants C11 and C44 are derived. RP Monteiro, OR (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-348-7 J9 MATER RES SOC SYMP P PY 1997 VL 444 BP 93 EP 98 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied SC Engineering; Materials Science; Physics GA BH52A UT WOS:A1997BH52A00010 ER PT S AU Myers, SM Follstaedt, DM Knapp, JA Christenson, TR AF Myers, SM Follstaedt, DM Knapp, JA Christenson, TR BE Reed, ML Elwenspoek, M Johansson, S Obermeier, E Fujita, H Uenishi, Y TI Hardening of nickel alloys by ion implantation of titanium and carbon SO MATERIALS FOR MECHANICAL AND OPTICAL MICROSYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium I - Materials in Microsystems, at the 1996 MRS Fall Meeting CY DEC 04-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Dual ion implantation of titanium and carbon was shown to produce an amorphous surface layer in annealed bulk nickel, in electroformed Ni, and in electroformed Ni75Fe25-Diamond-tip nanoindentation coupled with finite-element modeling quantified the elastic and plastic mechanical properties of the implanted region. The amorphized matrix, with a thickness of about 100 nn, has a yield stress of approximately 6 GP and an intrinsic hardness near 16 GPa, exceeding by an order of magnitude the corresponding values for annealed bulk Ni. Implications for micro-electromechanical systems are discussed. RP Myers, SM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-348-7 J9 MATER RES SOC SYMP P PY 1997 VL 444 BP 99 EP 104 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied SC Engineering; Materials Science; Physics GA BH52A UT WOS:A1997BH52A00011 ER PT S AU Ahuja, S DiVenere, A Ross, C Chien, HT Raptis, AC AF Ahuja, S DiVenere, A Ross, C Chien, HT Raptis, AC BE George, EP Gotthardt, R Otsuka, K TrolierMcKinstry, S WunFogle, M TI Parameter optimization of a microfabricated surface acoustic wave sensor for inert gas detection SO MATERIALS FOR SMART SYSTEMS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Smart Systems II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, USA Res Off, Furukawa Elect Co Ltd, Oak Ridge Natl Lab, PIOLAX Inc AB This work is related to designing, fabricating, and testing a surface acoustic wave sensor to be used for detecting metastable inert gases, particularly helium. The assembly consists of two microsensor configurations: (a) a reference device with no deposition at the delay line and (b) a sensing device with an Au-activated TiO2 e-beam-deposited thin film on the delay line. The interdigitated transducers and delay lines are fabricated by photolithography techniques on a single Y-cut LiNbO3 substrate oriented for Z-propagation of the acoustic waves. Variation in electrical conductivity of the Au-activated TiO2 film due to exposure to metastable He is translated as a frequency change in the assembly. Various characteristics of the surface acoustic microsensor have been studied to better understand and optimize the variation of acoustic wave velocity and the operating frequency of the microdevice. Methods for the TiO2 thin-film deposition are discussed. RP Ahuja, S (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-363-0 J9 MATER RES SOC SYMP P PY 1997 VL 459 BP 75 EP 80 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BH71E UT WOS:A1997BH71E00010 ER PT S AU Nagy, KL Cygan, RT Scotto, CS Brinker, CJ Ashley, CS AF Nagy, KL Cygan, RT Scotto, CS Brinker, CJ Ashley, CS BE Vandiver, PB Druzik, JR Merkel, JF Stewart, J TI Use of coupled passivants and consolidants on calcite mineral surfaces SO MATERIALS ISSUES IN ART AND ARCHAEOLOGY V SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Issues in Art and Archaeology V CY DEC 03-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Deterioration of monuments, buildings, and works of art constructed of carbonate-based stone potentially can be arrested by applying a combination of chemical passivants and consolidants that prevent hydrolytic attack and mechanical weakening. We used molecular modeling and laboratory synthesis to develop an improved passivating agent for the calcite mineral surface based on binding strength and molecular packing density. The effectiveness of the passivating agent with and without a linked outer layer of consolidant against chemical weathering was determined through leaching tests conducted with a pH-stat apparatus at pH 5 and 25 degrees C. For the range of molecules considered, modeling results indicate that the strongest-binding passivant is the trimethoxy dianionic form of silylalkylaminocarboxylate (SAAC). The same form of silylalkylphosphonate (SAP) is the second strongest binder and the trisilanol neutral form of aminoethylaminopropylsilane (AEAPS) is ranked third. Short-term leaching tests on calcite powders coated with the trisilanol derivative of SAAC, the triethoxy neutral form of SAP, and the trimethoxy neutral form of AEAPS show that the passivant alone does nor significantly slow the dissolution rate. However, all passivants when linked to the sol consolidant result in decreased rates. Combined AEAPS plus consolidant results in a coating that performs better than the commercial product Conservare(R) OH and at least as well as Conservare(R) H. The modeling results indicate that there may be a threshold binding energy for the passivant above which the dissolution rate of calcite is actually enhanced. More strongly-binding passivants may aid in the dissolution mechanism or dissociate in aqueous solution exposing the calcite surface to water. RP Nagy, KL (reprint author), SANDIA NATL LABS,DEPT GEOCHEM,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-366-5 J9 MATER RES SOC SYMP P PY 1997 VL 462 BP 301 EP 306 PG 6 WC Archaeology; Art; Materials Science, Multidisciplinary SC Archaeology; Art; Materials Science GA BJ83R UT WOS:A1997BJ83R00031 ER PT S AU Paquin, RA Howells, MR AF Paquin, RA Howells, MR BE Takacs, PZ Tonnessen, TW TI Mirror materials for synchrotron radiation optics SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE materials; metals; mirrors; optics; silicon silicon carbide; synchrotron radiation; x-ray AB Current optical finishing technology limits the choices for synchrotron radiation materials to a relatively few materials: fused silica and ULE(TM), silicon CVD silicon CVD silicon carbide, and electroless nickel. We review, in a general way, those materials and several others that can be finished to the required figure and finish levels, generally considered to be < 3 microradians rms and < 5 Angstrom rms. With the objective of material choices for synchrotron beam line mirrors in mind, we briefly discuss dimensional stability, cooling, bending, polishing, and manufacturing procedures. After discussing specific materials: those previously mentioned and aluminum, Glidcop(TM), invars, and steels, we conclude that metals are best from an engineering and cost standpoint, but ceramics, including silicon me best from a polishing standpoint. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 0 TC 12 Z9 12 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 2 EP 16 DI 10.1117/12.295549 PG 15 WC Optics SC Optics GA BK18Y UT WOS:000071450900001 ER PT S AU Renner, TR Franck, K Howells, M Irick, S Padmore, HA Rah, SY AF Renner, TR Franck, K Howells, M Irick, S Padmore, HA Rah, SY BE Takacs, PZ Tonnessen, TW TI The construction and performance of a one meter long elliptically bent steel mirror SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE synchrotron radiation; x ray mirrors; bent mirrors; adaptive optics AB An elliptically bent mirror of total length 1.25 m has been developed at the Advanced Light Source (ALS) for focusing soft x-rays. The mirror is used to produce a small, high flux density illuminated field of view for a Photo-Emission Electron Microscope (PEEM). The requirement to collect the maximum horizontal aperture with the need to highly demagnify the source leads to a mirror with a wide range of curvatures along the surface. This combined with the need to produce a low slope error surface at a reasonably low cost has required us to develop a mirror based on the controlled bending of a flat substrate. This is an extension of several other mirror projects at the ALS where controlled bending of glass and metal substrates has been used in micro-focusing applications [1,2,3]. Those mirrors however are a maximum of 200 mm long, and in this paper we describe the new challenges we have faced and the solutions we have adopted in developing a long and highly elliptical mirror. The mirror described here is manufactured from a low carbon steel (1006) which is capable of good dimensional stability, it is electroless nickel plated for polishing, and is bent into an elliptical shape by the application of unequal couples. We describe the minor fabrication process, the mechanical details of the bending mechanism and the experimentally measured slope error from an ellipse. The final mirror has an rms roughness of 6 Angstrom (rms), a full aperture (1.1 m) slope error of 14 mu rad (rms), and a slope error of <3 mu rad when optimized over approximately 2/3 of the required optical length (0.917 m). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Renner, TR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 17 EP 26 DI 10.1117/12.295558 PG 10 WC Optics SC Optics GA BK18Y UT WOS:000071450900002 ER PT S AU Howells, MR Casstevens, J AF Howells, MR Casstevens, J BE Takacs, PZ Tonnessen, TW TI Achievement of a superpolish on bare stainless steel SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE superpolish; x-ray mirror; metal mirror; precipitation-hardening stainless steel; synchrotron radiation AB We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 Angstrom, as measured by an optical profiler with a bandwidth 0.29-100 mm(-1). The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufactureability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible reasons for its unusual stability and polishability. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Howells, MR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 35 EP 40 DI 10.1117/12.295567 PG 6 WC Optics SC Optics GA BK18Y UT WOS:000071450900004 ER PT S AU Takacs, PZ Furenlid, K Furenlid, L AF Takacs, PZ Furenlid, K Furenlid, L BE Takacs, PZ Tonnessen, TW TI X-ray-induced damage observations on ZERODUR mirrors SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE radiation damage; x-ray damage; synchrotron mirrors; synchrotron beam lines; ZERODUR; fused silica; x-rays; x-ray optics AB Catastrophic damage has been observed in some ZERODUR mirrors used as first mirrors in two beam lines at the National Synchrotron Light Source (NSLS). Despite the high reflectivity of the coatings used on these mirrors, a significant flux of high energy photons penetrates below the coating and is absorbed in the substrate. Although model calculations indicate that the local temperature does not increase significantly, we suspect that over long time periods the absorbed flux produces structural changes in the material, leading to a build-up of surface stress, gross figure changes, and growth of fractures. These changes are probably related to the nature of the two-phase glass-ceramic composition of the ZERODUR material. Metal mirrors and single-phase materials do not exhibit such catastropic damage under similar exposure conditions. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Takacs, PZ (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 77 EP 85 DI 10.1117/12.295570 PG 9 WC Optics SC Optics GA BK18Y UT WOS:000071450900008 ER PT S AU Underwood, JH Batson, PJ Beguiristain, R Gullikson, EM AF Underwood, JH Batson, PJ Beguiristain, R Gullikson, EM BE Takacs, PZ Tonnessen, TW TI Elastic bending and water cooling strategies for producing high quality synchrotron-radiation mirrors in silicon. SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB Single crystal silicon has become readily obtainable and relatively inexpensive as a result of the production facilities set up to serve the semiconductor industry. It also has desirable properties for x-ray mirrors; it can be polished to a high degree of smoothness, has good mechanical properties, and high thermal conductivity. Polycrystalline silicon, which has greater mechanical strength, is also available. For these reasons we have used silicon mirrors exclusively at two bending magnet beamlines and one undulator beamline at the Advanced Light Source. We describe here two implementations of silicon mirrors: 1) a fixed radius design for high heat loads, which is side cooled by contacting to a water cooled block with Ga-In eutectic, and b) designs in which a variable radius and/or an elliptical mirror figure ate achieved by elastically bending a flat strip of the appropriate cross-sectional profile. Computed and measured performance figures are presented for each case. C1 Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94702 USA. RP Underwood, JH (reprint author), Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94702 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 88 EP 95 DI 10.1117/12.295550 PG 8 WC Optics SC Optics GA BK18Y UT WOS:000071450900009 ER PT S AU MacDowell, AA Celestre, R Chang, CH Franck, K Howells, MR Locklin, S Padmore, HA Patel, JR Sandler, R AF MacDowell, AA Celestre, R Chang, CH Franck, K Howells, MR Locklin, S Padmore, HA Patel, JR Sandler, R BE Takacs, PZ Tonnessen, TW TI Progress towards sub-micron hard x-ray imaging using elliptically bent mirrors SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE x-ray; micro-focusing; x-ray diffraction; bent mirrors; adaptive optics AB Of the many methods used to focus x-rays, the use Of mirrors With an elliptical curvature shows the most promise of providing a sub-micron white light focus. Ocr group has been developing the techniques of controlled bending of mirror substrates in order to produce the desired elliptical shape. We have been successful in producing surfaces with the required microradian slope error tolerances. Details of the bending techniques used, results from laboratory slope error measurements using a Long Trace Profiler (LTP) and data from the measurement of focus shape using knife edge and imaging methods using x-rays in the 5-12 KeV energy range are presented. The development of a white light focusing opens many possibilities in diffraction and spectroscopic studies. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Div Accelerator & Fus Res, Berkeley, CA 94720 USA. RP MacDowell, AA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Div Accelerator & Fus Res, Berkeley, CA 94720 USA. NR 0 TC 10 Z9 10 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 126 EP 133 DI 10.1117/12.279374 PG 8 WC Optics SC Optics GA BK18Y UT WOS:000071450900014 ER PT S AU Takacs, PZ Qian, SN AF Takacs, PZ Qian, SN BE Takacs, PZ Tonnessen, TW TI Metrology laboratory requirements for third-generation synchrotron radiation sources SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE optical metrology; mirrors; synchrotron radiation; surface finish; surface figure; roughness; surface profile; facilities AB New third-generation synchrotron radiation sources that are now, or will soon, come on line will need to decide how to handle the testing of optical components delivered for use in their beam lines. In many cases it is desirable to establish ant inhouse metrology laboratory to do the work. We review the history behind the formation of the Optical Metrology Laboratory at Brookhaven National Laboratory and the rationale for its continued existence. We offer suggestions to those who may be contemplating setting up similar facilities, based on our experiences over the past two decades. C1 Brookhaven Natl Lab, Upton, NY 11901 USA. RP Takacs, PZ (reprint author), Brookhaven Natl Lab, Upton, NY 11901 USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 160 EP 167 DI 10.1117/12.295555 PG 8 WC Optics SC Optics GA BK18Y UT WOS:000071450900017 ER PT S AU MacDowell, AA Wood, OR Bjorkholm, JE AF MacDowell, AA Wood, OR Bjorkholm, JE BE Takacs, PZ Tonnessen, TW TI Interferometric testing of EUV lithography cameras SO MATERIALS, MANUFACTURING, AND MEASUREMENT FOR SYNCHROTRON RADIATION MIRRORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials, Manufacturing, and Measurement for Synchrotron Radiation Mirrors CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE EUV lithography; EUV interferometry; optical testing AB Phase-measuring, lateral-shearing interferometry has been carried out on a multilayer-coated extreme-ultraviolet (EUV) Schwarzschild camera at the multilayer coating's center wavelength. The measured wavefront error was 0.096 waves rms at a wavelength of 13.5 nm. The interferometer employed in the measurement was developed to evaluate the image quality and improve the alignment of cameras for EW lithography and was previously shown to have a sensitivity of 0.021 waves rms or better at an operating wavelength of 13 nm. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP MacDowell, AA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, M-S 2-400, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2574-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3152 BP 202 EP 210 DI 10.1117/12.279372 PG 9 WC Optics SC Optics GA BK18Y UT WOS:000071450900021 ER PT S AU Zhu, J DelaRubia, TD Mailhiot, C AF Zhu, J DelaRubia, TD Mailhiot, C BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Ab initio pseudopotential calculations of carbon impurities in Si SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB Ab initio planewave pseudopotential method is used to study carbon diffusion and pairing in crystalline silicon. The calculation is performed with a 40 Ry planewave cutoff and 2x2x2 special k-point sampling with a supercell of 64 atoms. It is found that substitutional carbon attracts interstitial Si forming a [001] C interstitial with a large binding energy of 1.45 eV. The interstitial carbon is mobile and can migrate with a migration energy of 0.5 eV. The interstitial carbon can bind further to another substitutional carbon forming a substitutional carbon-interstitutional carbon pair with a binding energy of 1.0 eV. This model is used to understand the effect of high C concentration on the transient enhanced diffusion in Si. RP Zhu, J (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L412,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 33 EP 38 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00005 ER PT S AU Caturla, MJ delaRubia, TD AF Caturla, MJ delaRubia, TD BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Dose rate effects during damage accumulation in Silicon SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB We combine molecular dynamics and Monte Carlo simulations to study damage accumulation and dose rate effects during irradiation of Silicon. We obtain the initial stage of the damage produced by heavy and light ions using classical molecular dynamics simulations. While heavy ions like As or Pt induce amorphization by single ion impact, light ions like B only produce point defects or small clusters of defects. The amorphous pockets generated by heavy ions are stable below room temperature and recrystallize at temperatures below the threshold for recrystallization of a planar amorphous-crystalline interface. The damage accumulation during light ion irradiation is simulated using a Monte Carlo model for defect diffusion. In this approach, we study the damage in the lattice as a function of dose and dose rate. A strong reduction in the total number of defects left in the lattice is observed for lower dose rates. RP Caturla, MJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 89 EP 93 PG 5 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00013 ER PT S AU Follstaedt, DM Myers, SM Lee, SR Reno, JL Dawson, RL Han, J AF Follstaedt, DM Myers, SM Lee, SR Reno, JL Dawson, RL Han, J BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Interaction of cavities and dislocations in semiconductors SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB Transmission electron microscopy of He-implanted Si-Ge and InGaAs shows an attractive interaction between cavities and dislocations. Calculation indicates that cavities are attracted to dislocations through surrounding strain fields, and strong binding (100s of eV) occurs when a cavity intersects the core. In a strained SiGe/Si heterostructure, He implantation enhances relaxation rates, and cavities bound to misfit dislocations show evidence of increasing relaxation at equilibrium by lowering dislocation energies. The interaction is expected for all crystalline solids, and gives insight into voids in GaN/sapphire and bubbles in He-implanted metals. RP Follstaedt, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 229 EP 234 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00035 ER PT S AU Zuhr, RA Magruder, RH Anderson, TS AF Zuhr, RA Magruder, RH Anderson, TS BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Optical properties of multi-component cadmium-silver nanocluster composites formed in silica by sequential ion implantation SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB The formation and optical properties of nanometer dimension metal colloid composites formed by the sequential implantation of Cd then Ag and by single element implantations of Cd and Ag in silica were characterized by transmission electron microscopy (TEM) and optical spectroscopy. A nominal dose of 6x10(16) ions/cm(2) as determined by current integration was used for both ion species. The doses used for the sequential implantations were a 1 to 1 ratio of Cd to Ag. Sequential implantations of Cd and Ag led to the formation of both multi-component metal nanoclusters and elemental nanoclusters. The electron diffraction measurements indicated that the polycrystalline particles of Ag(5)Cdg and elemental Ag were formed. The optical response was consistent with results expected from effective medium theory. RP Zuhr, RA (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 411 EP 416 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00060 ER PT S AU Barbour, JC Potter, BG Follstaedt, DM Knapp, JA Sinclair, MB AF Barbour, JC Potter, BG Follstaedt, DM Knapp, JA Sinclair, MB BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Er-doped amorphous and crystalline Al2O3 and La2O3 films grown with low energy ions from an ECR plasma SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB The effects of low energy ions from a biased electron cyclotron resonance plasma during growth of Al2O3 and La2O3 are used to modify the density and crystalline quality of these oxide films. The type of phase formed for Al2O3 is varied with the ion-assisted growth from amorphous to crystalline gamma-Al2O3. The photoluminescence (PL) properties of different Er-doped Al- and La-oxide phases are examined, and through comparison of the PL spectra, the local environment of Er in these oxide materials is discussed. RP Barbour, JC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 465 EP 470 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00069 ER PT S AU Anders, A Kong, F Chen, Y Monteiro, OR McLarnon, FR Brown, IG AF Anders, A Kong, F Chen, Y Monteiro, OR McLarnon, FR Brown, IG BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Plasma and ion beam tools for enhanced battery electrode performance SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB Plasma and ion beam methods such as gas and metal ion implantation, plasma immersion ion implantation (PIII), and metal plasma immersion ion implantation and deposition (MePIIID) are introduced as powerful tools to modify the properties of battery electrodes. Three kinds of rechargeable electrochemical cells have been investigated: the lead-acid cell, the nickel alkaline-electrolyte cell, and the lithium cell. It was experimentally shown that (i) metal ion implantation of Ti, V, Cr, Ni, and W into lead and lead-antimony electrodes reduced the corrosion current by more than one order of magnitude, (ii) cobalt ion implantation into nickel electrodes enhanced the interconversion of Ni(OH)(2) to NiOOH and the associated cycle life, (iii) nitrogen-PIII resulted in the formation of a nitrided lithium layer on lithium which stabilized the surface against corrosion, (iv) MePIIID with a tungsten plasma reduced the pitting corrosion of aluminum, a current collector for a lithium battery. RP Anders, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,PLASMA APPLICAT GRP,DIV ACCELERATOR & FUS RES,BERKELEY,CA 94720, USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 0 TC 0 Z9 0 U1 3 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 543 EP 554 PG 12 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00081 ER PT S AU Ager, J Brown, I Monteiro, O Knapp, JA Follstaedt, DM Nastasi, M Walter, KC Maggiore, CJ AF Ager, J Brown, I Monteiro, O Knapp, JA Follstaedt, DM Nastasi, M Walter, KC Maggiore, CJ BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Growth and mechanical and tribological characterization of multi-layer hard carbon films SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB Vacuum-arc deposition is used to deposit multilayer carbon films by modulating the sample bias during deposition The effect of varying the sublayer thickness in multilayer films consisting of alternating layers of ''hard'' (68.4 GPa, -100 V bias) and ''soft'' (27.5 GPa, -2000 V bias) was investigated. Films consisting of equal thickness layers of hard and soft material and an individual layer thickness varying from 10 to 35 nm were deposited. Mechanical property measurements were obtained by finite element modeling of nanoindentation load-displacement curves. The film hardness values were about 20% below the average of the component layers and relatively independent of the layer thickness. TEM investigation revealed deterioration of the multilayer structure when the sublayer thickness was below 15 nm due to implantation damage of the hard layers caused by the energetic C+ ions of the soft layers (-2000 V bias) deposited over them. Pin-on-disk wear tests show that the wear rate drops when sublayer thickness is decreased below 20 nm and remains constant with further decreases in the layer thickness. RP Ager, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 581 EP 585 PG 5 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00086 ER PT S AU Monteiro, OR DelplanckeOgletree, MP Brown, IG Ager, JW AF Monteiro, OR DelplanckeOgletree, MP Brown, IG Ager, JW BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Deposition and properties of doped diamondlike carbon films produced by dual-source vacuum arc plasma immersion SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB Diamond-like carbon films with mechanical properties approaching those of diamond have been consistently produced by cathodic vacuum are based techniques. These films have been successfully used in applications where enhanced hardness and wear resistance are required Such DLC films have two major drawbacks that prevent their application in other areas: a high level of internal stresses, which promotes failure by spallation of thick films; and the loss of mechanical properties at temperatures higher than 300 degrees C. In this paper we describe the effect of doping elements on the room-temperature mechanical properties and on the thermal stability of DLC films upon annealing in air. The effect of the presence of W and Ti was investigated and compared to pure DLC. The films were produced by dual-source metal plasma immersion ion implantation and deposition with magnetic filtering to remove macroparticles from the plasma; dopant content was controlled by varying the relative pulse duration of the two plasma sources. Microstructural and chemical characterization of the films are presented. C1 FREE UNIV BRUSSELS,B-1050 BRUSSELS,BELGIUM. RP Monteiro, OR (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 16 Z9 16 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 599 EP 604 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00089 ER PT S AU Knapp, JA Follstaedt, DM Barbour, JC Myers, SM Ager, JW Monteiro, OR Brown, IG AF Knapp, JA Follstaedt, DM Barbour, JC Myers, SM Ager, JW Monteiro, OR Brown, IG BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Evaluating mechanical properties of thin layers using nanoindentation and finite-element modeling: Implanted metals and deposited layers SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB We present a methodology based on finite-element modeling of nanoindentation data to extract reliable and accurate mechanical properties from thin, hard films and surface-modified layers on softer substrates. The method deduces the yield stress, Young's modulus, and hardness from indentations as deep as 50% of the layer thickness. RP Knapp, JA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 617 EP 625 PG 9 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00092 ER PT S AU Walter, KC Williams, JM Woodring, JS Nastasi, M Poker, DB Munson, CM AF Walter, KC Williams, JM Woodring, JS Nastasi, M Poker, DB Munson, CM BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Properties of ion implanted Ti-6Al-4V processed using beamline and PSII techniques SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB The surface of Ti-6Al-4V (Ti64) alloy has been modified using beamline implantation of boron. In separate experiments, Ti64 has been implanted with nitrogen using a plasma source ion implantation (PSII) technique utilizing either ammonia (NH3), nitrogen (N-2), or their combinations as the source of nitrogen ions. Beamline experiments have shown the hardness of the N-implanted surface saturates at a dose level of similar to 4 x 10(17) at/cm(2) at similar to 10 GPa. The present work makes comparisons of hardness and tribological tests of (1) B implantation using beamline techniques, and (2) N implanted samples using ammonia and/or nitrogen gas in a PSII process. The results show that PSII using N-2 or NH3 gives similar hardness as N implantation using a beamline process. The presence of H in the Ti alloy surface does not affect the hardness of the implanted surface. Boron implantation increased the surface hardness by as much as 2.5x at the highest dose level. Wear testing by a pin-on-disk method indicated that nitrogen implantation reduced the wear rate by as much as 120x, and boron implantation reduced the wear rate by 6.5x. Increased wear resistance was accompanied by a decreased coefficient of friction. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Walter, KC (reprint author), LOS ALAMOS NATL LAB,MS-K762,LOS ALAMOS,NM 87545, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 627 EP 632 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00093 ER PT S AU Bedrossian, PJ Caturla, MJ DelaRubia, TD AF Bedrossian, PJ Caturla, MJ DelaRubia, TD BE Alexander, DE Cheung, NW Park, B Skorupa, W TI Defect diffusion during annealing of low-energy ion-implanted silicon SO MATERIALS MODIFICATION AND SYNTHESIS BY ION BEAM PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Modification and Synthesis by Ion Beam Processing, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Appl Mat, Implant Div, Argonne Natl Lab, Danfys A S, Diamond Semiconductor Grp Inc, Eaton Corp, Semiconductor Equipment Div, FHR GmbH, Forschungszentrum Rossendorf e V, High Voltage Engn, Sentech Instruments Berlin, Varian Associates Inc, Ion Implant Syst, Wacker Siltron AG, Zentrum Mikroelektr Dresden GmbH AB We present a new approach for investigating the kinetics of defect migration during annealing of low-energy, ion-implanted silicon, employing a combination of computer simulations and atomic-resolution tunneling microscopy. Using atomically-clean Si(111)-7x7 as a sink for bulk point defects created by 5 keV Xe and Ar irradiation, we observe distinct, temperature-dependent surface arrival rates for vacancies and interstitials. A combination of simulation tools provides a detailed description of the processes that underly the observed temperature-dependence of defect segregation, and the predictions of the simulations agree closely with the experimental observations. RP Bedrossian, PJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-342-8 J9 MATER RES SOC SYMP P PY 1997 VL 438 BP 715 EP 720 PG 6 WC Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BH43C UT WOS:A1997BH43C00106 ER PT J AU Gourdin, WH Weinland, SL Campbell, GH AF Gourdin, WH Weinland, SL Campbell, GH TI Mechanical behavior of diffusion-bonded bicrystals of boron-doped Ni3Al SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE mechanical tests; artificial bicrystal; boundary; boron segregation ID ENVIRONMENTAL EMBRITTLEMENT; POLYCRYSTALLINE NI3AL; UNIDIRECTIONAL SOLIDIFICATION; STOICHIOMETRIC NI3AL; FRACTURE; DUCTILITY; SEGREGATION; BOUNDARIES AB We report the results of mechanical tests on a Sigma 5 (210) [001] symmetric tilt boundary in a diffusion-bonded artificial bicrystal of boron-doped Ni0.76Al0.24. We find that heat treatments designed to induce boron segregation appear to strengthen the boundary, whereas heat treatments designed to discourage segregation weaken it. However, the bonding of the bicrystal is non-uniform, and this introduces significant uncertainty into our data because of our very small sample size (six). Nevertheless, we conclude that such artificial bicrystals offer considerable flexibility in the study of the effects of orientation on boundary strength and solute segregation in nickel aluminides, as well as in other metals and intermetallics. RP Gourdin, WH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. RI Campbell, Geoffrey/F-7681-2010 NR 22 TC 5 Z9 5 U1 2 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 JAN PY 1997 VL 222 IS 1 BP 28 EP 34 DI 10.1016/S0921-5093(96)10499-8 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WD748 UT WOS:A1997WD74800005 ER PT J AU Heinlein, C Grepstad, J Riechert, H Averbeck, R AF Heinlein, C Grepstad, J Riechert, H Averbeck, R TI Plasma preconditioning of sapphire substrate for GaN epitaxy SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT European-Materials-Research-Society 1996 Spring Meeting, Symposium C: UV, Blue and Green Light Emission from Semiconductor Materials CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc DE gallium nitride; nitridation; plasma cleaning; sapphire ID MOLECULAR-BEAM EPITAXY; GROWTH; NITRIDE AB The crystalline quality of molecular beam epitaxy (MBE)-grown layers of GaN on sapphire strongly depends on the initial stage of film nucleation and growth. Thus, pre-conditioning of the substrate is of vital importance. In this study we use X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) to examine in situ the case for surface cleaning and nitridation of c-plane sapphire substrates upon annealing in UHV and exposure to radio frequency (rf) plasmas of hydrogen and nitrogen, respectively. We find that low temperature (200-300 degrees C) heat treatment in a hydrogen plasma offers effective removal of adventitious surface contaminants, contrary to annealing in vacuum. Moreover, our XPS data provide unambiguous evidence for formation of surface nitride upon heat treatment in nitrogen plasma at 300-700 degrees C, in agreement with conclusions inferred from reflection high energy electron diffraction (RHEED). The surface nitride is found to remain stable on subsequent exposure to atmosphere. (C) 1997 Elsevier Science S.A. C1 SLAC,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA. SIEMENS AG,CORP RES & DEV,D-8000 MUNICH,GERMANY. RP Heinlein, C (reprint author), NTNU,DEPT PHYS ELECT,OS BREGSTADSPLASS 2A,N-7034 TRONDHEIM,NORWAY. RI Riechert, Henning/G-4178-2016 NR 16 TC 25 Z9 25 U1 1 U2 12 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 JAN PY 1997 VL 43 IS 1-3 BP 253 EP 257 DI 10.1016/S0921-5107(96)01878-8 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WX008 UT WOS:A1997WX00800051 ER PT S AU Caturla, MJ delaRubia, TD Bedrossian, PJ AF Caturla, MJ delaRubia, TD Bedrossian, PJ BE Balogh, AG Walter, G TI Modeling of ion implantation and diffusion in Si SO MATERIALS SCIENCE APPLICATIONS OF ION BEAM TECHNIQUES SE Materials Science Forum LA English DT Article; Proceedings Paper CT International Symposium on Materials Science Applications of Ion Beam Techniques / 1st German/Australian Workshop on Ion Beam Analysis CY SEP 09-12, 1996 CL SEEHEIM, GERMANY SP Deut Forschungsgemeinsch, Bundesminist Bild Wissensch Forsch & Technol, Hessisches Minist Wissensch & Kunst, Gesell Schwerionenforsch, TH Darmstadt, TH Darmstadt, Vereinig Freunden, TH Darmstadt, Fachgebiet Dune Schichten Fachbereichs Materialswissensch, Johann Wolfgang Goethe Univ, Inst Kernphys, Frankfurt Main, TH Darmstadt, Inst Kernphys DE ion implantation; diffusion; molecular dynamics; Monte Carlo ID COMPUTER-SIMULATION; SILICON AB Classical molecular dynamics simulations are used to study the damage produced during the implantation of semiconductors with different ion masses and energies between 1-25 keV. The time scale for these type of simulations is only on the order of ns, and therefore problems like transient enhanced diffusion of dopants or formation of extended defects can not be studied with these models. Monte Carlo simulations, including as input the results obtained from molecular dynamics calculations, are used to extend the simulation time, and in particular, to study processes like ion implantation and defects diffusion in semiconductors. As an example we show results for diffusion of the damage produced by implantation of silicon with 5 keV Xe ions at low doses. The results of the simulations are compared with experiments in order to validate the model. RP LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RI Caturla, Maria /D-6241-2012 OI Caturla, Maria /0000-0002-4809-6553 NR 30 TC 1 Z9 1 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI DURNTEN-ZURICH PA KREUZSTRASSE 10, 8635 DURNTEN-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-767-6 J9 MATER SCI FORUM PY 1997 VL 248-2 BP 41 EP 48 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BJ36H UT WOS:A1997BJ36H00005 ER PT S AU Lee, EH Rao, GR Mansur, LK AF Lee, EH Rao, GR Mansur, LK BE Balogh, AG Walter, G TI Hardness enhancement and crosslinking mechanisms in polystyrene irradiated with high energy ion-beams SO MATERIALS SCIENCE APPLICATIONS OF ION BEAM TECHNIQUES SE Materials Science Forum LA English DT Article; Proceedings Paper CT International Symposium on Materials Science Applications of Ion Beam Techniques / 1st German/Australian Workshop on Ion Beam Analysis CY SEP 09-12, 1996 CL SEEHEIM, GERMANY SP Deut Forschungsgemeinsch, Bundesminist Bild Wissensch Forsch & Technol, Hessisches Minist Wissensch & Kunst, Gesell Schwerionenforsch, TH Darmstadt, TH Darmstadt, Vereinig Freunden, TH Darmstadt, Fachgebiet Dune Schichten Fachbereichs Materialswissensch, Johann Wolfgang Goethe Univ, Inst Kernphys, Frankfurt Main, TH Darmstadt, Inst Kernphys DE ion-beam; surface modification; radiation effects; crosslinking; scission; LET effects; hardness ID POLYMERS; IMPLANTATION AB Recent work at ORNL has demonstrated that surface hardness values several times larger than that of steel can be produced by employing high energy ion-beams (HEIB) in the several hundred keV to a few MeV range. In the present study, detailed crosslinking mechanisms have been studied for polystyrene irradiated with 350 keV H+ and 1 MeV Ar+, by analyzing hardness variations in response to irradiation parameters such as ion species, energy, and fluence. In addition, ion track analysis has been used to interpret the experimental data. It has been demonstrated that high linear energy transfer (LET) is important for crosslinking. For low LET conditions, induced active free radicals along the track are so sparsely dispersed that little interaction occurs among radicals. Input energy tends to localize at an intra-molecular chain segment, leading to chain scission. On the other hand, for high LET conditions, massive ionization induces a high concentration of free radicals over many neighboring molecular chains thereby facilitating crosslinking. These mechanisms are explored in detail in the present study and effective crosslinking radii at hardness saturation are derived based on experimental data. RP Lee, EH (reprint author), OAK RIDGE NATL LAB, POB 2008, OAK RIDGE, TN 37831 USA. NR 25 TC 26 Z9 26 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-767-6 J9 MATER SCI FORUM PY 1997 VL 248-2 BP 135 EP 146 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BJ36H UT WOS:A1997BJ36H00021 ER PT S AU Schenkel, T Briere, MA SchmidtBocking, H Bethge, K Schneider, D AF Schenkel, T Briere, MA SchmidtBocking, H Bethge, K Schneider, D BE Balogh, AG Walter, G TI Electronic sputtering and desorption effects in TOF-SIMS studies using slow highly charged ions like Au69+ SO MATERIALS SCIENCE APPLICATIONS OF ION BEAM TECHNIQUES SE Materials Science Forum LA English DT Article; Proceedings Paper CT International Symposium on Materials Science Applications of Ion Beam Techniques / 1st German/Australian Workshop on Ion Beam Analysis CY SEP 09-12, 1996 CL SEEHEIM, GERMANY SP Deut Forschungsgemeinsch, Bundesminist Bild Wissensch Forsch & Technol, Hessisches Minist Wissensch & Kunst, Gesell Schwerionenforsch, TH Darmstadt, TH Darmstadt, Vereinig Freunden, TH Darmstadt, Fachgebiet Dune Schichten Fachbereichs Materialswissensch, Johann Wolfgang Goethe Univ, Inst Kernphys, Frankfurt Main, TH Darmstadt, Inst Kernphys DE Time of Flight SIMS; graphite; SiO2; highly charged ions; electronic sputtering ID SURFACE; EMISSION AB Secondary ion yields from highly oriented pyrolytic graphite (HOPG) and SiO2 (native oxide on float zone silicon) targets at impact of slow (v approximate to 0.3 v(Bohr)) highly charged ions like Th70+ have been measured by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). A direct comparison of collisional and electronic effects in secondary ion production using a beam of charge state equilibrated 300 keV Xe1+ shows a secondary ion yield increase by a factor of greater than or equal to 100. C1 UNIV FRANKFURT, INST KERNPHYS, D-60486 FRANKFURT, GERMANY. RP Schenkel, T (reprint author), LAWRENCE LIVERMORE NATL LAB, PHYS & SPACE TECHNOL DIRECTORATE, LIVERMORE, CA 94550 USA. NR 14 TC 9 Z9 9 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-767-6 J9 MATER SCI FORUM PY 1997 VL 248-2 BP 413 EP 417 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BJ36H UT WOS:A1997BJ36H00077 ER PT S AU Horn, KM Dodd, PE Doyle, BL AF Horn, KM Dodd, PE Doyle, BL BE Balogh, AG Walter, G TI Highly focused ion beams in integrated circuit testing SO MATERIALS SCIENCE APPLICATIONS OF ION BEAM TECHNIQUES SE Materials Science Forum LA English DT Article; Proceedings Paper CT International Symposium on Materials Science Applications of Ion Beam Techniques / 1st German/Australian Workshop on Ion Beam Analysis CY SEP 09-12, 1996 CL SEEHEIM, GERMANY SP Deut Forschungsgemeinsch, Bundesminist Bild Wissensch Forsch & Technol, Hessisches Minist Wissensch & Kunst, Gesell Schwerionenforsch, TH Darmstadt, TH Darmstadt, Vereinig Freunden, TH Darmstadt, Fachgebiet Dune Schichten Fachbereichs Materialswissensch, Johann Wolfgang Goethe Univ, Inst Kernphys, Frankfurt Main, TH Darmstadt, Inst Kernphys DE single event upset; ion beam-induced charge collection; ion microbeam; radiation testing ID INDUCED CHARGE AB The nuclear microprobe has proven to be a useful tool in radiation testing of integrated circuits. This paper reviews single event upset and ion beam induced charge collection imaging techniques, with special attention to damage-dependent effects. Comparisons of charge collection measurements with three-dimensional charge transport simulations of charge collection are then presented for isolated p-channel field effect transistors under conducting and non-conducting bias conditions. RP Horn, KM (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-767-6 J9 MATER SCI FORUM PY 1997 VL 248-2 BP 427 EP 432 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BJ36H UT WOS:A1997BJ36H00079 ER PT S AU Kim, KH Hanson, PJ Barnett, MO Lindberg, SE AF Kim, KH Hanson, PJ Barnett, MO Lindberg, SE BE Sigel, A Sigel, H TI Biogeochemistry of mercury in the air-soil-plant system SO METAL IONS IN BIOLOGICAL SYSTEMS, VOL 34: MERCURY AND ITS EFFECTS ON ENVIRONMENT AND BIOLOGY SE METAL IONS IN BIOLOGICAL SYSTEMS LA English DT Review ID CHLORIDE CONCENTRATION; ATMOSPHERIC MERCURY; COMPENSATION POINT; ELEMENTAL MERCURY; VOLATILE MERCURY; SURFACE EXCHANGE; HUMIC SUBSTANCES; SULFIDE MINERALS; ORGANIC-MATTER; WATER C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RP Kim, KH (reprint author), SANG JI UNIV, INST ENVIRONM SCI, KANGWON DO 220702, SOUTH KOREA. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 103 TC 15 Z9 15 U1 5 U2 15 PU MARCEL DEKKER PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0161-5149 BN 0-8247-9828-7 J9 MET IONS BIOL SYST JI Metal Ions Biol. Syst. PY 1997 VL 34 BP 185 EP 212 PG 28 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary; Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Biochemistry & Molecular Biology; Chemistry; Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA BH23E UT WOS:A1997BH23E00007 ER PT J AU Yoo, MH Hishinuma, A AF Yoo, MH Hishinuma, A TI Deformation twinning in TiAl: Effects of defect clustering SO METALS AND MATERIALS-KOREA LA English DT Article ID TITANIUM ALUMINIDES; ROOM-TEMPERATURE; ALLOYS; INTERSECTIONS; BEHAVIOR; DISSOCIATION; DISLOCATIONS; IRRADIATION; CRYSTALS; ENERGY AB Possible roles of point defect clustering in the formation of deformation twins in gamma-TiAl are critically assessed by reviewing the available models of dislocation-assisted twin nucleation and experimental data on deformation twinning in Ti-56 at.% Al single crystals and two-phase Ti-47 at.% Al alloys. According to the pole mechanism for twinning in the L1(0) structure, a reasonable combination of the stress concentration (n approximate to 27) and the vacancy supersaturation (c/c(0) approximate to 13) is needed to overcome the critical stages of twin formation. The so-called radiation-induced ductility reported in Ti-47 at.% Al alloys is attributed to the effective formation of twin embryos in the presence of interstitial-type Frank loops and the subsequent nucleation and growth of twins during plastic deformation. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Japan Atom Energy Res Inst, Dept Mat Sci & Engn, Tokai, Ibaraki 31911, Japan. RP Yoo, MH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 54 TC 7 Z9 7 U1 0 U2 12 PU KOREAN INST METALS MATERIALS PI SEOUL PA POSCO CENTER, 4TH FL (EAST WING), 892 DAECHI-4-DONG, KANGNAM-KU, SEOUL 135-777, SOUTH KOREA SN 1225-9438 J9 MET MATER-KOREA JI Met. Mater.-Korea PY 1997 VL 3 IS 2 BP 65 EP 74 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZC772 UT WOS:000072616500001 ER PT J AU Graf, T Marti, K Xue, S Herzog, GF Klein, J Middleton, R Metzler, K Herd, R Brown, P Wacker, JF Jull, AJT Masarik, J Koslowsky, VT Andrews, HR Cornett, RJJ Davies, WG Greiner, BF Imahori, Y McKay, JW Milton, GM Milton, JCD AF Graf, T Marti, K Xue, S Herzog, GF Klein, J Middleton, R Metzler, K Herd, R Brown, P Wacker, JF Jull, AJT Masarik, J Koslowsky, VT Andrews, HR Cornett, RJJ Davies, WG Greiner, BF Imahori, Y McKay, JW Milton, GM Milton, JCD TI Exposure history of the Peekskill (H6) meteorite SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID COSMOGENIC NUCLIDES; CHONDRITE KNYAHINYA; AL-26; BE-10; TRACKS; CL-36; ORBIT AB The Peekskill H6 meteorite fell on 1992 October 9. We report extensive measurements of cosmic-ray produced stable nuclides of He, Ne, and Ar, of the radionuclides Na-22, Co-60, C-14, Cl-36, Al-26, and Be-10, and of cosmic-ray track densities. After correction for shielding via the Ne-22/Ne-21 ratio, the concentrations of cosmic-ray produced He-3, Ne-21 and Ar-38 give an average exposure age of 25 Ma, which is considered to be a lower limit on the true value. The Be-10/Ne-21 age is 32 Ma and falls onto a peak in the H-chondrite exposure age distribution. The activities of Al-26, C-14, Cl-36, and Be-10 are all close to the maximum values expected for H-chondrites. Together with cosmic-ray track densities and the Ne-22/Ne-21 ratio, these radionuclide data place the samples at a depth >20 cm in a meteoroid with a radius >40 cm. In contrast, the Co-60 activity requires a near-surface location and/or a much smaller body. Calculations show that a flattened geometry for the Peekskill meteoroid does not explain the observations in the context of a one-stage irradiation. A two-stage model can account for the data. We estimate an upper bound of 70 cm on the radius of the earlier stage of irradiation and conclude that Peekskill's radius was <70 cm when it entered the Earth's atmosphere. This size limit is somewhat smaller than the dynamic determinations (Brown et al., 1994). C1 ETH ZURICH, CH-8092 ZURICH, SWITZERLAND. RUTGERS STATE UNIV, DEPT CHEM, NEW BRUNSWICK, NJ 08903 USA. UNIV PENN, DEPT PHYS, PHILADELPHIA, PA 19014 USA. HUMBOLDT UNIV BERLIN, D-10115 BERLIN, GERMANY. GEOL SURVEY CANADA, OTTAWA, ON K1A 0E8, CANADA. UNIV WESTERN ONTARIO, DEPT PHYS, LONDON, ON N6A 3K7, CANADA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV ARIZONA, NSF, ACCELERATOR FACIL, TUCSON, AZ 85721 USA. MAX PLANCK INST CHEM, ABT KOSMOCHEM, D-55020 MAINZ, GERMANY. AECL RES, CHALK RIVER LABS, CHALK RIVER, ON K0J 1J0, CANADA. RP Graf, T (reprint author), UNIV CALIF SAN DIEGO, DEPT CHEM, LA JOLLA, CA 92093 USA. RI Klein, Jeffrey/E-3295-2013 NR 29 TC 14 Z9 14 U1 0 U2 5 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 JAN PY 1997 VL 32 IS 1 BP 25 EP 30 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XK171 UT WOS:A1997XK17100010 ER PT J AU McSween, HY Riciputi, LR Paterson, BA AF McSween, HY Riciputi, LR Paterson, BA TI Fractionated sulfur isotopes in sulfides of the Kaidun meteorite SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID CARBONACEOUS CHONDRITES; ION MICROPROBE; CM CHONDRITES; COMPONENTS; MANTLE; SHRIMP AB The Kaidun meteorite contains carbonaceous chondrite (CM1) clasts that have been highly altered by reactions with hydrothermal fluids. Pyrrhotite in these clasts occurs as unusual needles wrapped by sheaths of phyllosilicate, and pentlandite forms veins that crosscut aggregates of phyllosilicate and garnet but not pyrrhotite. The isotopic compositions of S(delta(34)S(CDT)) in individual sulfide grains, measured by ion microprobe, are fractionated compared to troilite in ordinary chondrites. The S in Kaidun sulfides is isotopically light (as much as -4.2 parts per thousand for pyrrhotite and -5.7 parts per thousand for pentlandite), unlike sulfides in other carbonaceous chondrites, which are enriched in S-34. The unusual S-isotopic composition of these texturally unique sulfides supports the hypothesis that Kaidun CMI clasts were pervasively altered under extreme thermal conditions, possibly by fluids that had lost isotopically heavy SO2. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP McSween, HY (reprint author), UNIV TENNESSEE,DEPT GEOL SCI,KNOXVILLE,TN 37996, USA. NR 35 TC 11 Z9 11 U1 1 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 JAN PY 1997 VL 32 IS 1 BP 51 EP 54 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XK171 UT WOS:A1997XK17100012 ER PT J AU Fedorov, VV Muller, WG AF Fedorov, VV Muller, WG TI Another view on optimal design for estimating the point of extremum in quadratic regression SO METRIKA LA English DT Article DE optimum design; turning point; reparametrization ID RESPONSE-SURFACE; MODELS AB In this paper we illustrate how certain design problems can be simplified by reparametrization of the response function. This alternative viewpoint provides further insights than the more traditional approaches, like minimax, Bayesian or sequential techniques. It will also improve a practitioner's understanding of more general situations and their ''classical'' treatment. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. UNIV ECON,DEPT STAT,A-1090 VIENNA,AUSTRIA. RI Muller, Werner/K-7193-2012 OI Muller, Werner/0000-0002-3564-766X NR 15 TC 16 Z9 16 U1 0 U2 0 PU PHYSICA VERLAG GMBH PI HEIDELBERG PA TIERGARTENSTRASSE 17, 69121 HEIDELBERG, GERMANY SN 0026-1335 J9 METRIKA JI Metrika PY 1997 VL 46 IS 2 BP 147 EP 157 DI 10.1007/BF02717171 PG 11 WC Statistics & Probability SC Mathematics GA XY111 UT WOS:A1997XY11100003 ER PT B AU Stallard, BR Kaushik, S AF Stallard, BR Kaushik, S BE Jones, SK TI Novel near-field optical probe for 100-nm critical dimension measurements SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE IC metrology; near-field optics; waveguide resonator AB Although the theoretical resolution for a conventional optical microscope is about 300 nm, it is normally difficult to obtain satisfactory critical dimension (CD) measurements below about 600 nm. E-beam technology has been popular for sub-500 nm metrology but also has well known limitations. Scanning probe and near-field optical methods have high spatial resolution. Yet they are ill-suited for routine CD metrology of high aspect ratio features because of a combination of short working distances (< 10 nm) and large tips. In this paper we present the concept and initial modeling results for a novel near-field optical probe that has the potential of overcoming these limitations. The idea is to observe resonance shifts in a waveguide cavity that arise from the coupling of the evanescent field of the waveguide to perturbations beneath the waveguide plane. The change in resonance frequency is detected as a change in the transmission of a monochromatic probe beam through the waveguide. The transmitted intensity, together with the appropriate signal processing, gives the topography of the perturbation. Our model predicts that this probe is capable of determining the width of photoresist lines as small as 100 nm. The working distance is much more practical than other probe techniques at about 100 to 250 nm. RP Stallard, BR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 367 EP 374 DI 10.1117/12.275934 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00033 ER PT B AU Tobin, KW Gleason, SS Karnowski, TP Cohen, SL Lakhani, F AF Tobin, KW Gleason, SS Karnowski, TP Cohen, SL Lakhani, F BE Jones, SK TI Automatic classification of spatial signatures on semiconductor wafermaps SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XI CY MAR 10-12, 1997 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE semiconductor; spatial signature; automatic inspection; wafermap analysis; pattern recognition; fuzzy classifier; classifier training AB This paper describes Spatial Signature Analysis (SSA), a cooperative research project between SEMATECH and Oak; Ridge National Laboratory for automatically analyzing and reducing semiconductor wafermap defect data to useful information. Trends towards larger wafer formats and smaller critical dimensions have caused an exponential increase in the volume of visual and parametric defect data which must be analyzed and stored, therefore necessitating the development of automated tools for wafer defect analysis. Contamination particles that did not create problems with 1 micron design rules can now be categorized as killer defects. SSA is an automated wafermap analysis procedure which performs a sophisticated defect clustering and signature classification of electronic wafermaps. This procedure has been realized in a software system that contains a signature classifier that is user-trainable, Known examples of historically problematic process signatures are added to a training database for the classifier. Once a suitable training set has been established, the software can automatically segment and classify multiple signatures from a standard electronic wafermap file into user-defined categories. it is anticipated that successful integration of this technology with other wafer monitoring strategies will result in reduced time-to-discovery and ultimately improved product yield. RP Tobin, KW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2464-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 3050 BP 434 EP 444 PG 11 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology SC Engineering; Instruments & Instrumentation; Microscopy; Optics; Imaging Science & Photographic Technology GA BJ21W UT WOS:A1997BJ21W00040 ER PT B AU Flounders, AW Carichner, SC Singh, AK Volponi, JV Schoeniger, JS Wally, K AF Flounders, AW Carichner, SC Singh, AK Volponi, JV Schoeniger, JS Wally, K BE Gourley, PL Katzir, A TI Immobilization, stabilization and patterning techniques for enzyme based sensor systems SO MICRO- AND NANOFABRICATED ELECTRO-OPTICAL MECHANICAL SYSTEMS FOR BIOMEDICAL AND ENVIRONMENTAL APPLICATIONS, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1st SPIE Conference on Microfabricated and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers AB Sandia National Laboratories has recently opened the Chemical and Radiation Detection Laboratory (CRDL) in Livermore, CA to address the detection needs of a variety of government agencies (e.g., Department of Energy, Environmental Protection Agency, Department of Agriculture) as well as provide a fertile environment for the cooperative development of new industrial technologies. This laboratory consolidates a variety of existing chemical and radiation detection efforts and enables Sandia to expand into the novel area of biochemically based sensors. One aspect of our biosensor effort is further development and optimization of enzyme modified field effect transistors (EnFETs). Recent work has focused upon covalent attachment of enzymes to silicon dioxide and silicon nitride surfaces for EnFET fabrication. We are also investigating methods to pattern. immobilized proteins; a critical component for development of array-based sensor systems. Novel enzyme stabilization procedures are key to patterning immobilized enzyme layers while maintaining enzyme activity. Results related to maximized enzyme loading, optimized enzyme activity and fluorescent imaging of patterned surfaces will be presented. RP Flounders, AW (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2389-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2978 BP 58 EP 61 DI 10.1117/12.269980 PG 2 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH52D UT WOS:A1997BH52D00007 ER PT B AU Smith, RL Hsueh, YT Collins, SD Fiaccabrino, JC Koudelka, M AF Smith, RL Hsueh, YT Collins, SD Fiaccabrino, JC Koudelka, M BE Gourley, PL Katzir, A TI Electrochemiluminescence at microelectrodes for biosensing SO MICRO- AND NANOFABRICATED ELECTRO-OPTICAL MECHANICAL SYSTEMS FOR BIOMEDICAL AND ENVIRONMENTAL APPLICATIONS, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1st SPIE Conference on Microfabricated and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE microelectrode; electrochemiluminescence; ruthenium; biosensor; microsensor; DNA AB This paper presents a new method for obtaining highly efficient electrochemiluminescence (ECL) of tris(2,2'-bipyridine) ruthenium (TBR) in aqueous solutions and a biosensor which utilizes this method. An interdigitated, microelectrode array is employed with? electrode widths and spacings of 5 mu m. The microelectrode is supported on a silicon nitride coated silicon substrate and occupies 1 mm(2). Each microelectrode is I mm long and 5 microns wide. The diffusion enhancement produced by the microelectrode geometry, the small electrode spacing and the electrode material ate all critical parameters for high ECL efficiency. ECL has been detected from TBR concentrations as low as 1 mu M, using a silicon PIN photodiode detector at room temperature. For biosensing applications, TBR is attached to the molecule of interest and ECL is then generated at the electrode surfaces. Cell configuration and the results of preliminary studies of the detection of TBR labeled DNA, attached to paramagnetic beads are presented. RP Smith, RL (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. RI Smith, Rosemary/H-7359-2015; Collins, Scott/A-5806-2016 OI Smith, Rosemary/0000-0001-8483-6777; Collins, Scott/0000-0003-0204-5109 NR 0 TC 3 Z9 3 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2389-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2978 BP 64 EP 68 DI 10.1117/12.269955 PG 3 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH52D UT WOS:A1997BH52D00008 ER PT B AU Collins, SD Sidick, E Knoesen, A Baskin, RJ AF Collins, SD Sidick, E Knoesen, A Baskin, RJ BE Gourley, PL Katzir, A TI Micromachined optical trap for use as a microcytology workstation SO MICRO- AND NANOFABRICATED ELECTRO-OPTICAL MECHANICAL SYSTEMS FOR BIOMEDICAL AND ENVIRONMENTAL APPLICATIONS, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1st SPIE Conference on Microfabricated and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE optical tweezers; micromachining; cytology AB A micromachined optical ''trap'' to capture and move micron sized dielectric particles is presented. The trap consists of four single mode optical fibers mutually aligned to have a common optical beam intersection at the center of a micromachined housing. The intersection of the beams forms an optical ''cross-hair'' which captures dielectric microparticles with a strong optical gradient force field, and holds them for further manipulation, visualization, and/or analysis. The stability and magnitude of the trapping force fields are comparable to the single beam ''optical tweezers'' technique, but are considerably more versatile. RP Collins, SD (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. RI Collins, Scott/A-5806-2016 OI Collins, Scott/0000-0003-0204-5109 NR 0 TC 8 Z9 9 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2389-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2978 BP 69 EP 74 DI 10.1117/12.269956 PG 4 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH52D UT WOS:A1997BH52D00009 ER PT B AU French, T Gourley, PL McDonald, AE AF French, T Gourley, PL McDonald, AE BE Gourley, PL Katzir, A TI Optical properties of fluids in microfabricated channels SO MICRO- AND NANOFABRICATED ELECTRO-OPTICAL MECHANICAL SYSTEMS FOR BIOMEDICAL AND ENVIRONMENTAL APPLICATIONS, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1st SPIE Conference on Microfabricated and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE microchannel; microcavity; Fabry-Perot etalon; fluorescence; intracavity laser spectroscopy; biocavity laser AB Microfabricated channels are widely thought to be the key to realizing chemical analysis on a microscopic scale. Chemical and biological information in the microchannels is often probed with optical techniques such as fluorescence, Raman and absorption spectroscopy. However, the optical effects of a microchannel are not well characterized. For example, it is important to understand the optics of the channel in order to optimize optical coupling efficiency. We consider various designs for enhancing the sensitivity of fluorescence detection in a microchannel. RP French, T (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2389-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2978 BP 123 EP 128 DI 10.1117/12.269976 PG 4 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH52D UT WOS:A1997BH52D00015 ER PT B AU Gourley, PL McDonald, AE AF Gourley, PL McDonald, AE BE Gourley, PL Katzir, A TI Semiconductor microlasers with intracavity microfluidics for biomedical applications SO MICRO- AND NANOFABRICATED ELECTRO-OPTICAL MECHANICAL SYSTEMS FOR BIOMEDICAL AND ENVIRONMENTAL APPLICATIONS, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1st SPIE Conference on Microfabricated and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE microfabrication; microfluidics; semiconductors; glass; microcavities; lasers; spectroscopy; biomedical; cells; surface tension; capillarity; micro-optical-electrical-mechanical systems AB Microfrabricated electro-optical-mechanical systems are expected to play an important role in future biomedical, biochemical and environmental technologies. Semiconductor photonic materials and devices are attractive components of such systems because of their ability to generate, transmit, modulate, and detect light. In this paper we report investigations of light-emitting semiconductor/glass microcavities filled with simple fluids. We examine surface tension for transporting liquids into the intracavity space and study the influence of the liquid on the spectral emission of the microcavity. RP Gourley, PL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 3 Z9 3 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2389-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2978 BP 186 EP 196 DI 10.1117/12.269968 PG 3 WC Engineering, Biomedical; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH52D UT WOS:A1997BH52D00023 ER PT B AU Davies, BR Barron, CC Sniegowski, JJ Rodgers, MS AF Davies, BR Barron, CC Sniegowski, JJ Rodgers, MS BE Motamedi, ME Herzig, HP TI SAMPLE (Sandia agile MEMS prototyping, layout tools, and education) SO MICROELECTRONIC STRUCTURES AND MEMS FOR OPTICAL PROCESSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microelectronic Structures and MEM for Optical Processing III CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST AB The SAMPLE (Sandia Agile MEMS Prototyping, Layout tools, and Education) service makes Sandia's state-of-the-art surface-micromachining fabrication process, known as SUMMiT, available to US industry for the first time. The service provides a short course and customized computer-aided design (CAD) tools to assist customers in designing micromachine prototypes to be fabricated in SUMMiT. Frequent small-scale manufacturing runs then provide SAMPLE designers with hundreds of sophisticated MEMS (MicroElectroMechanical Systems) chips. SUMMiT (Sandia Ultra-planar, Multi-level MEMS Technology) offers unique surface-micromachining capabilities, including four levels of polycrystalline silicon (including the ground layer), flanged hubs, substrate contacts, one-micron design rules, and chemical-mechanical polishing (CMP) planarization. This paper describes the SUMMiT process, design tools, and other information relevant to the SAMPLE service and SUMMiT process. RP Davies, BR (reprint author), SANDIA NATL LABS,INTELLIGENT MICROMACHINE DEPT,POB 5800 MS 1080,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2658-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3226 BP 11 EP 21 DI 10.1117/12.284568 PG 3 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BJ57P UT WOS:A1997BJ57P00002 ER PT B AU Tanner, DM Smith, NF Bowman, DJ Eaton, WP Peterson, KA AF Tanner, DM Smith, NF Bowman, DJ Eaton, WP Peterson, KA BE Chau, K French, PJ TI First reliability test of a surface micromachined microengine using SHiMMeR SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE micro-mechanical component reliability; micromachine reliability; failure in micromachines; MEMS reliability AB The first-ever reliability stress test on surface micromachined microengines(1) developed at Sandia National Laboratories (SNL) has been completed. We stressed 41 microengines at 36,000 RPM and inspected the functionality at 60 RPM. We have observed an infant mortality region, a region of low failure rate (useful life), and no signs of wearout in the data. The reliability data are presented and interpreted using standard reliability methods. Failure analysis results on the stressed microengines are presented. In our effort to study the reliability of MEMS, we need to observe the failures of large numbers of parts to determine the failure modes. To facilitate testing of large numbers of micromachines, we designed and built an automated system that has the capability to simultaneously test 256 packaged micromachines. The Sandia High Volume Measurement of Micromachine Reliability (SHiMMeR) system has computer controlled positioning and the capability to inspect moving parts. The development of this parallel testing system is discussed in detail. RP Tanner, DM (reprint author), SANDIA NATL LABS,POB 5800,MS 1081,ALBUQUERQUE,NM 87185, USA. NR 0 TC 37 Z9 37 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 14 EP 23 DI 10.1117/12.284512 PG 10 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00002 ER PT B AU Miller, SL LaVigne, G Rodgers, MS Sniegowski, JJ Waters, JP McWhorter, PJ AF Miller, SL LaVigne, G Rodgers, MS Sniegowski, JJ Waters, JP McWhorter, PJ BE Chau, K French, PJ TI Routes to failure in rotating MEMS devices experiencing sliding friction SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE microengine; friction; failure mechanisms; rotating devices; MEMS failure modes AB Gear systems rotating on hubs have been operated to failure using Sandia's microengine as the actuation device. Conventional failure modes such as fatigue induced fracture did not occur, indicating that the devices are mechanically extremely robust. The generic route to failure observed for all rotating devices involves sticking of structures that are in sliding contact. This sticking evidently results from microscopic changes in the sliding surfaces during operation. The rate at which these changes occur is accelerated by excessive applied forces, which originate from non-optimized designs or inappropriate drive voltages. Precursors to failure are observed, enabling further understanding of the microscopic changes that occur in the sliding surfaces that ultimately lead to failure. RP Miller, SL (reprint author), SANDIA NATL LABS,MAIL STOP 1080,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 25 Z9 25 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 24 EP 30 DI 10.1117/12.284523 PG 7 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00003 ER PT B AU Senft, DC Dugger, MT AF Senft, DC Dugger, MT BE Chau, K French, PJ TI Friction and wear in surface micromachined tribological test devices SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE MEMS; surface micromachined; tribology; friction; wear AB We report on the design, construction, and initial testing of surface micromachined devices for the measurement of friction and wear. The devices measure friction coefficients on both horizontal deposited polysilicon surfaces and vertical etched polysilicon surfaces. The contact geometry of the rubbing surfaces is well-defined, and a method is presented for the determination of the normal and frictional forces. Initial observations on test devices which have been dried with supercritical CO2 and devices coated with octadecyltrichlorosilane (ODTS) suggest that the coatings increase the lifetime of the devices and the repeatability of the results. RP Senft, DC (reprint author), SANDIA NATL LABS,POB 5800,MS 0340,ALBUQUERQUE,NM 87185, USA. NR 0 TC 54 Z9 54 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 31 EP 38 DI 10.1117/12.284533 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00004 ER PT B AU Lee, AP McConaghy, CF Krulevitch, PA Campbell, EW Sommargren, GE Trevino, JC AF Lee, AP McConaghy, CF Krulevitch, PA Campbell, EW Sommargren, GE Trevino, JC BE Chau, K French, PJ TI Electrostatic comb drive for vertical actuation SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE electrostatic comb drive; vertical actuation; vertical position control; interferometry AB The electrostatic comb finger drive has become an integral design for microsensor and microactuator applications. This paper reports on utilizing the levitation effect of comb fingers to design vertical-to-the-substrate actuation for interferometric applications. For typical polysilicon comb drives with 2 mu m gaps between the stationary and moving fingers, as well as between the microstructures and the substrate, the equilibrium position is nominally 1-2 mu m above the stationary comb fingers. This distance is ideal for many phase shifting interferometric applications. Theoretical calculations of the vertical actuation characteristics are compared with the experimental results, and a general design guideline is derived from these results. The suspension flexure stiffnesses, gravity forces, squeeze film damping, and comb finger thicknesses are parameters investigated which affect the displacement curve of the vertical microactuator. By designing a parallel plate capacitor between the suspended mass and the substrate, in situ position sensing can be used to control the vertical movement, providing a total feedback-controlled system. Fundamentals of various capacitive position sensing techniques are discussed. Experimental verification is carried out by a Zygo distance measurement interferometer. RP Lee, AP (reprint author), LAWRENCE LIVERMORE NATL LAB,MICROTECHNOL CTR,ELECT ENGN TECHNOL DIV,MS L-222,LIVERMORE,CA 94550, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 109 EP 119 DI 10.1117/12.284506 PG 11 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00012 ER PT B AU Rodgers, MS Sniegowski, JJ Miller, SL Barron, CC McWhorter, PJ AF Rodgers, MS Sniegowski, JJ Miller, SL Barron, CC McWhorter, PJ BE Chau, K French, PJ TI Advanced micromechanisms in a multi-level polysilicon technology SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE microengine; mirror; gear train; transmission; microactuator; polysilicon AB Quad-level polysilicon surface micromachining technology, comprising three mechanical levels plus an electrical interconnect layer, is giving rise to a new generation of micro-electromechanical devices and assemblies. Enhanced components can now be produced through greater flexibility in fabrication and design. New levels of design complexity that include multilevel gears, single-attempt locks, and optical elements have recently been realized. Extensive utilization of the fourth layer of polysilicon differentiates these latter generation devices from their predecessors.' This level of poly enables the fabrication of pin joints, linkage arms, hinges on moveable plates, and multi-level gear assemblies. The mechanical design aspects of these latest micromachines will be discussed with particular emphasis on a number of design modifications that improve the power, reliability, and smoothness of operation of the microengine.(2) The microengine is the primary actuation mechanism that is being used to drive mirrors out of plane and rotate 1600-mu m diameter gears.(3) Also discussed is our most advanced micromechanical system to date, a complex proof-of-concept batch-fabricated assembly that, upon transmitting the proper electrical code to a mechanical lock, permits the operation of a micro-optical shutter. RP Rodgers, MS (reprint author), SANDIA NATL LABS,MAIL STOP 1080,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 120 EP 130 DI 10.1117/12.284507 PG 11 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00013 ER PT B AU Holswade, SC Dickey, FM AF Holswade, SC Dickey, FM BE Chau, K French, PJ TI Optical measurement of micromachine engine performance SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE micromachines; optical probe; performance analysis AB Understanding the mechanisms that impact the performance of Microelectromechanical Systems (MEMS) is essential to the development of optimized designs and drive signals, as well as the qualification of devices for commercial applications. Silicon micromachines include engines that consist of orthogonally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small as 50 mu m in diameter and can be driven at rotation rates exceeding 300,000 rpm. Optical techniques offer the potential for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. We describe the development of Micromachine Optical Probe (MOP) technology for the evaluation of micromachine performance. The MOP approach is based on the detection of optical signals scattered by the gear teeth or other physical structures. We present experimental results for a prototype system designed to measure engine parameters as well as long term performance data. RP Holswade, SC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 4 Z9 5 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 131 EP 140 DI 10.1117/12.284508 PG 10 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00014 ER PT B AU Martin, PM Bennett, WD Hammerstrom, DJ Johnston, JW Matson, DW AF Martin, PM Bennett, WD Hammerstrom, DJ Johnston, JW Matson, DW BE Chau, K French, PJ TI Laser micromachined and laminated microchannel components for chemical sensors and heat transfer applications SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE micromachining; laser; sensor; stacked; chemical AB The fabrication of microchannel chemical sensors with seven laminated individual functional modules is described. The sensors, used to detect chromium in nuclear and chemical waste streams, were fabricated using laser micromachining, bulk silicon micromachining, photolithographic techniques, sputter coating deposition, and anodic and adhesive bonding processes. The size of the sensor was 2 cm by 2.2 cm, with a total thickness of 2.2 cm. It consisted of two or more reservoir modules to hold the liquids being evaluated, two or more micropump modules to pump the liquids through the sensor, a chemical mixing module, a reaction module, and a sensor module with electrical circuitry for connection to external measurement equipment. The fluids were directed through the layers by interconnecting flow channels. The reservoir modules were fabricated by machining Pyrex and anodic bonding to silicon. The chemical mixing module was fabricated by wet etching Pyrex and anodic bonding to silicon. The reaction module contained a serpentine 200-mu m-wide channel, and was formed by laser micromachining polyimide. The first prototype of this sensor employed external micropumps, while the second prototype will use off-the-shelf piezoelectric micropumps. The detector layer consisted of iridium, silver, and platinum sensor pads connected to gold contact strips. The modules were joined using adhesive bonding, and an electrostatic (anodic) technique was used for silicon-Pyrex bonding. RP Martin, PM (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,MSIN K3-59,RICHLAND,WA 99352, USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 258 EP 265 DI 10.1117/12.284536 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00028 ER PT B AU Manginell, RP Smith, JH Ricco, AJ Hughes, RC Moreno, DJ Huber, RJ AF Manginell, RP Smith, JH Ricco, AJ Hughes, RC Moreno, DJ Huber, RJ BE Chau, K French, PJ TI Electro-thermal modeling of a microbridge gas sensor SO MICROMACHINED DEVICES AND COMPONENTS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Micromachined Devices and Components CY SEP 29, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE catalytic gas sensor; modeling; SPICE; mu-CVD; in situ monitoring; CMOS; IR microscope AB Fully CMOS-compatible, surface-micromachined polysilicon microbridges have been designed, fabricated, and tested for use in catalytic, calorimetric gas sensing. To improve sensor behavior, extensive electro-thermal modeling efforts were undertaken using SPICE. The validity of the SPICE model was verified by comparing its simulated behavior with experimental results. The temperature distribution of an electrically-heated microbridge was measured using an infrared (TR) microscope. Comparisons among the measured distribution, the SPICE simulation, and distributions obtained by analytical methods show that heating at the ends of a microbridge has important implications for device response. Additional comparisons between measured and simulated current-voltage characteristics, as well as transient response characteristics, further support the accuracy of the model. A major benefit of electro-thermal modeling with SPICE is the ability to simultaneously simulate the behavior of a device and its control/sensing electronics. Results for the combination of a unique constant-resistance control circuit and microbridge gas sensor are given. Models of in situ techniques for monitoring catalyst deposition are shown to be in agreement with experiment. Finally, simulated chemical response of the detector is compared with the data, and methods of improving response through modifications in bridge geometry are predicted. RP Manginell, RP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. OI Ricco, Antonio/0000-0002-2355-4984 NR 0 TC 4 Z9 5 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2656-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3224 BP 360 EP 371 DI 10.1117/12.284537 PG 12 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BJ87J UT WOS:A1997BJ87J00040 ER PT B AU Fleming, JG Barron, CC Stallard, B Kaushik, S AF Fleming, JG Barron, CC Stallard, B Kaushik, S BE Michalske, TA Wendman, MA TI Fabrication of large area gratings with sub-micron pitch using mold micromachining SO MICROMACHINING AND IMAGING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachining and Imaging Conference CY FEB 13, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE micromachining; mold; batch fabrication; diffraction grating AB In this work, we have applied mold micromachining and standard photolithographic techniques to the fabrication of parts integrated with 0.4 micron pitch diffraction gratings. In principle, the approach should be scaleable to considerably finer pitches. We have achieved this by relying on the thickness of deposited or grown films, instead of photolithography, to determine the grating pitch. The gratings can be made to extend over large areas and the entire process is compatible with batch processing. Literally thousands of parts can be batch fabricated from a single lot of six inch wafers. In the first stage of the process we fabricate a planarized silicon dioxide pad over which the silicon nitride wave guide runs. The grating is formed by first patterning and etching single crystalline silicon to form a series of trenches with well defined pitch. The silicon bounding the trenches is then thinned by thermal oxidation followed by stripping of the silicon dioxide. The trenches are filled by a combination of polysilicon depositions and thermal oxidations. Chemical mechanical polishing (CMP) is used to polish back these structures resulting in a series of alternating 2000 Angstrom wide lines of silicon and silicon dioxide. The thickness of the lines is determined by the oxidation time and the polysilicon deposition thickness. The silicon lines are selectively recessed by anisotropic reactive ion etching, thus forming the mold for the grating. The mold is filled with low stress silicon nitride deposited by chemical vapor deposition. A wave guide is then patterned into the silicon nitride and the mold is locally removed by a combination of deep silicon trench etching and wet KOH etching. This results in a suspended diffraction grating/membrane over the KOH generated pit. RP Fleming, JG (reprint author), SANDIA NATL LABS,POB 5800,MS 1084,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2420-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3009 BP 7 EP 14 DI 10.1117/12.271222 PG 8 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BH80A UT WOS:A1997BH80A00002 ER PT B AU Matzke, CM Houston, JE AF Matzke, CM Houston, JE BE Michalske, TA Wendman, MA TI Wafer level thin-film solder bonding of a hybrid sensor for interfacial force microscopy SO MICROMACHINING AND IMAGING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachining and Imaging Conference CY FEB 13, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy AB Scanning probe techniques have shown dramatic growth recently and are presently making significant impact on surface and interfacial problems in material science. The Interfacial Force Microscope (IFM) is a scanning force-probe technique similar to the atomic force microscope (AFM) but distinguished by its use of a self balancing, differential-capacitance force sensor. This sensor eliminates the mechanical instability found in the displacement sensors used in the AFM and greatly expands the IFM's range of applicability. However, IFM sensors presently in use consist of chemically milled metal sheets epoxied to insulating substrates and are individually assembled, a process which is tedious, time consuming and unreliable. The hybrid design is necessitated by the need to have reasonably large capacitance values and low compliance on the moveable components. In addition,the deflection detection is done by an RF bridge circuit which makes semiconductor-based designs difficult. Thus, the hybrid scheme avoids the release of features with severe aspect ratios and the deposition of thick films which are difficult in the normal microelectronics-type fabrication. In order to correct difficulties with the present design, we have developed a process which includes a multi-sensor, wafer-level layout and a newly developed In thin-film solder assembly technique. In this paper, we discuss the details of our fabrication process and demonstrate its viability by showing actual IFM results obtained with the new sensors. RP Matzke, CM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2420-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3009 BP 25 EP 32 DI 10.1117/12.271225 PG 8 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BH80A UT WOS:A1997BH80A00004 ER PT B AU Semin, DJ Ambrose, WP Goodwin, PM Wendt, JR Keller, RA AF Semin, DJ Ambrose, WP Goodwin, PM Wendt, JR Keller, RA BE Michalske, TA Wendman, MA TI A near-field optical microscopy nanoarray SO MICROMACHINING AND IMAGING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachining and Imaging Conference CY FEB 13, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE near-field scanning optical microscopy (NSOM); nanoarray; lithography; microscopy; fluorescence; imaging; charge transfer devices; single molecule detection AB Multiplexing near-field scanning optical microscopy (NSOM) by the use of a nanoarray with parallel imaging is studied. The fabrication, characterization, and utilization of nanoarrays with similar to 100 nm diameter apertures spaced 500 nm center-to-center is presented. Extremely uniform nanoarrays with similar to 10(8) apertures were fabricated by electron beam lithography and reactive ion etching. The nanoarrays were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In this paper we utilize these nanoarrays in a laser-illuminated microscope with parallel detection on a charge-coupled device (CCD). Detection of B-phycoerythrin (B-PE) molecules using near-field illumination is presented. In principle, our system can be used to obtain high lateral resolution NSOM images over a wide-field of view (e.g. 50-100 mu m) within seconds. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. RP Keller, RA (reprint author), LOS ALAMOS NATL LAB,CST-1,MS M888,LOS ALAMOS,NM 87544, USA. NR 0 TC 4 Z9 4 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2420-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3009 BP 109 EP 118 DI 10.1117/12.271219 PG 10 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BH80A UT WOS:A1997BH80A00014 ER PT B AU Barron, CC Davies, BR Sniegowski, JJ Rodgers, MS Comtois, JH Michalicek, MA AF Barron, CC Davies, BR Sniegowski, JJ Rodgers, MS Comtois, JH Michalicek, MA BE Chang, SC Pang, SW TI SAMPLE (Sandia Agile MEMS Prototyping, Layout tools, and Education) SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Micromachining and Microfabrication Process Technology III CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE silicon micromachining; microelectromechanical systems (MEMS); surface micromachining; chemical-mechanical polishing (CMP) AB The SAMPLE (Sandia Agile MEMS Prototyping, Layout tools, and Education) service makes Sandia's state-of-the-art surface-micromachining technology, known as SUMMiT, available to US industry for the first time. The Sandia Ultra-planar Multi-level MEMS Technology (SUMMiT) offered through SAMPLE is the world's most advanced surface-micromachining technology, with three independently patternable ultra-low-stress mechanical polysilicon levels (in addition to the electrical polysilicon layer), one-micron design rules, flanged hubs, and CMP planarization of the third sacrificial oxide to provide planar structures in the third mechanical polysilicon layer(MMPoly3). Participants in the SAMPLE program learn about MEMS and the SUMMiT process through the Sandia MEMS Short Course and then use Sandia's specialized design and layout tools to design their own micromachines to be fabricated in SUMMiT. RP Barron, CC (reprint author), SANDIA NATL LABS,MICROELECT DEV LAB,POB 5800,MAIL STOP 1080,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2655-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3223 BP 10 EP 16 DI 10.1117/12.284476 PG 7 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BJ78P UT WOS:A1997BJ78P00002 ER PT B AU Davies, BR Montague, S Smith, JH Lemkin, M AF Davies, BR Montague, S Smith, JH Lemkin, M BE Chang, SC Pang, SW TI Micromechanical structures and microelectronics for acceleration sensing SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Micromachining and Microfabrication Process Technology III CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE micromachined sensors; capacitive sensors; accelerometer AB MEMS is an enabling technology that may provide low-cost devices capable of sensing motion in a reliable and accurate manner. This paper describes work in MEMS accelerometer development at Sandia National Laboratories. This work leverages a process for integrating both the micromechanical structures and microelectronics circuitry of a MEMS accelerometer on the same chip. The design and test results of an integrated MEMS high-g accelerometer will be detailed. Additionally a design for a high-g fuse component (low-G or approximate to 25 G accelerometer) will be discussed in the paper (where 1 G approximate to 9.81 m/s). In particular, a design team at Sandia was assembled to develop a new micromachined silicon accelerometer which would be capable of surviving and measuring high-g shocks. Such a sensor is designed to be cheaper and more reliable than currently available sensors. A promising design for a suspended plate mass sensor was developed and the details of that design along with test data will be documented in the paper. Future development in this area at Sandia will focus on implementing accelerometers capable of measuring 200 kilo-g accelerations. Accelerometer development at Sandia will also focus on multi-axis acceleration measurement with integrated microelectronics. RP Davies, BR (reprint author), SANDIA NATL LABS,INTELLIGENT MICROMACHINE DEPT,POB 5800 MS 1080,ALBUQUERQUE,NM 87185, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2655-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3223 BP 237 EP 244 DI 10.1117/12.284486 PG 8 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BJ78P UT WOS:A1997BJ78P00028 ER PT B AU Matson, DW Martin, PM Bennett, WD Stewart, DC Johnston, JW AF Matson, DW Martin, PM Bennett, WD Stewart, DC Johnston, JW BE Chang, SC Pang, SW TI Laser micromachined microchannel solvent separator SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Micromachining and Microfabrication Process Technology III CY SEP 29-30, 1997 CL AUSTIN, TX SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, NIST, Solid State Technol DE micromachining; laser; membrane; separations; chemical AB The fabrication of components for a microchannel chemical solvent separation unit is described. The performance of this unit is intended to employ enhanced kinetic effects due to short contact times encountered in to facilitate extraction of one dissolved species from one solvent into another. Components for the device are fabricated by laser micromachining, photochemical machining, and photolithographic patterning. The separation unit consists of a series of parallel flow and counterflow microchannels separated by micromachined membranes and assembled into a single unit by a lamination process. In a sample design, channel width, membrane width and length are 100 mu m, 1 cm, and 8 cm respectively. Test membranes were fabricated from stainless steel using photochemical machining and from polyimide by using two distinct laser micromachining processes. Use of the lamination fabrication method allows flexibility in the design of the microchannels within the unit. Preliminary results of membrane tests and a brief discussion of future efforts are included. RP Matson, DW (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,MSIN K3-59,RICHLAND,WA 99352, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2655-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3223 BP 253 EP 259 DI 10.1117/12.284495 PG 7 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BJ78P UT WOS:A1997BJ78P00030 ER PT S AU Jesson, DE Chen, KM Pennycook, SJ Thundat, T Warmack, RJ AF Jesson, DE Chen, KM Pennycook, SJ Thundat, T Warmack, RJ BE Cullis, AG Hutchison, JL TI Mechanisms of strain-induced surface ripple formation and dislocation multiplication in SixGe1-x thin films SO MICROSCOPY OF SEMICONDUCTING MATERIALS 1997 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT Royal-Microscopical-Society Conference on Microscopy of Semiconducting Materials CY APR 07-10, 1997 CL UNIV OXFORD, OXFORD, ENGLAND SP Royal Microscop Soc, Inst Phys, Electron Microscopy & Anal Grp, Mat Res Soc, Royal Soc, JEOL UK Ltd, Oxford Instruments Ltd HO UNIV OXFORD ID GROWTH; GE; RELAXATION; EVOLUTION; INAS; GAAS; NUCLEATION; SI(100); ISLANDS; LAYERS AB We discuss the stress driven roughening transition of Si1Ge1-x thin films. In the case of annealed films, nucleation effects dominate the nature of the surface ripple which formed by a cooperative nucleation mechanism. Facetting can however be suppressed at high supersaturations, resulting in a transition with characteristics of the Asaro-Tiller-Grinfeld instability. The relationship between morphological evolution and dislocation nucleation and multiplication is considered. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Hlth Sci Res Div, Oak Ridge, TN 37831 USA. RP Jesson, DE (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. NR 21 TC 1 Z9 1 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 BN 0-7503-0464-2 J9 INST PHYS CONF SER PY 1997 IS 157 BP 239 EP 246 PG 8 WC Microscopy; Physics, Multidisciplinary; Physics, Condensed Matter SC Microscopy; Physics GA BK38G UT WOS:000071954600046 ER PT S AU Dieker, C Ruvimov, S Sohn, H Washburn, J Liliental-Weber, Z AF Dieker, C Ruvimov, S Sohn, H Washburn, J Liliental-Weber, Z BE Cullis, AG Hutchison, JL TI Twinning of As precipitates in LT-GaAs SO MICROSCOPY OF SEMICONDUCTING MATERIALS 1997 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT Royal-Microscopical-Society Conference on Microscopy of Semiconducting Materials CY APR 07-10, 1997 CL UNIV OXFORD, OXFORD, ENGLAND SP Royal Microscop Soc, Inst Phys, Electron Microscopy & Anal Grp, Mat Res Soc, Royal Soc, JEOL UK Ltd, Oxford Instruments Ltd HO UNIV OXFORD ID TEMPERATURE-GROWN GAAS; LAYERS AB Twinning in As precipitates after 850 degrees C annealing of LT-GaAs layers has been revealed by transmission electron microscopy. It was shown that twins are formed on (<10(1)over bar 4>) planes and that voids are often present in the same precipitates. Formation of such twins does not preserve the 3m orientation relationship as in the twinning observed in layers annealed at 600 degrees C in larger precipitates. A large number of precipitates have two parallel twins. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dieker, C (reprint author), Lawrence Berkeley Lab, Ms 62-203, Berkeley, CA 94720 USA. RI Schaff, William/B-5839-2009; Liliental-Weber, Zuzanna/H-8006-2012; Kim, youngjae/I-7780-2012 NR 11 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 BN 0-7503-0464-2 J9 INST PHYS CONF SER PY 1997 IS 157 BP 283 EP 286 PG 4 WC Microscopy; Physics, Multidisciplinary; Physics, Condensed Matter SC Microscopy; Physics GA BK38G UT WOS:000071954600055 ER PT S AU Bedrossian, PJ Caturla, MJ DelaRubia, TD AF Bedrossian, PJ Caturla, MJ DelaRubia, TD BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Defect diffusion during annealing of low-energy ion-implanted silicon SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB We present a new approach for investigating the kinetics of defect migration during annealing of low-energy, ion-implanted silicon, employing a combination of computer simulations and atomic-resolution tunnelling microscopy. Using atomically-clean Si(111)-7x7 as a sink for bulk point defects created by 5 keV Xe and Ar irradiation, we observe distinct, temperature-dependent surface arrival rates for vacancies and interstitials. A combination of simulation tools provides a detailed description of the processes that underly the observed temperature-dependence of defect segregation, and the predictions of the simulations agree closely with the experimental observations. RP Bedrossian, PJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 53 EP 58 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00008 ER PT S AU Zhu, J DelaRubia, TD Mailhiot, C AF Zhu, J DelaRubia, TD Mailhiot, C BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Ab initio pseudopotential calculations of carbon impurities in Si SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Ab initio planewave pseudopotential method is used to study carbon diffusion and pairing in crystalline silicon. The calculation is performed with a 40 Ry planewave cutoff and 2x2x2 special K-point sampling with a supercell of 64 atoms. It is found that substitutional carbon attracts interstitial Si forming a <001> C interstitial with a large binding: energy of 1.45 eV. The interstitial carbon is mobile and can migrate with a migration energy of 0.5 eV. The interstitial carbon can bind further to another substitutional carbon forming a substitutional carbon-interstitutional carbon pair with a binding energy of 1.0 eV. This model is used to understand the effect of high C concentration on the transient enhanced diffusion in Si. RP Zhu, J (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-412,LIVERMORE,CA 94551, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 59 EP 64 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00009 ER PT S AU Caturla, MJ delaRubia, TD AF Caturla, MJ delaRubia, TD BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Dose rate effects during damage accumulation in silicon SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB We combine molecular dynamics and Monte Carlo simulations to study damage accumulation and dose rate effects during irradiation of Silicon. We obtain the initial stage of the damage produced by heavy and light ions using classical molecular dynamics simulations. While heavy ions like As or Pt induce amorphization by single ion impact, light ions Like B only produce point defects or small clusters of defects. The amorphous pockets generated by heavy ions are stable below room temperature and recrystallize at temperatures below the threshold for recrystallization of a planar amorphous-crystalline interface. The damage accumulation during light ion irradiation is simulated using a Monte Carlo model for defect diffusion. In this approach, we study the damage in the lattice as a function of dose and dose rate. A strong reduction in the total number of defects left in the lattice is observed for lower dose rates. RP Caturla, MJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 125 EP 129 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00019 ER PT S AU McHugo, SA Weber, ER Myers, SM Petersen, GA AF McHugo, SA Weber, ER Myers, SM Petersen, GA BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Competition between gettering by implantation-induced cavities in silicon and internal gettering associated with SiO2 precipitation SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The gettering behavior of Cu and Fe was investigated in CZ silicon containing both internal-gettering sites in the bulk due to SiO2 precipitation and a device-side layer of cavities formed by He ion implantation and annealing. The objective was to quantify the effectiveness of impurity gettering at cavities relative to the widely used internal-gettering process. Both rapid thermal anneals and furnace anneals were used during the gettering sequences to reveal transient effects as well as the final, thermodynamically-equilibrated condition. For temperatures of 700, 800 and 850 degrees C, the cavity gettering was observed to dominate the internal gettering as indicated both by the number of gettered atoms in the cavities and the residual solution concentration in the device region. The results are interpreted in detail by numerically solving the diffusion equation with sink-related source terms based on earlier, fundamental studies of the underlying mechanisms of internal and cavity gettering. RP McHugo, SA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE CTR,BERKELEY,CA 94720, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 149 EP 154 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00023 ER PT S AU Follstaedt, DM Myers, SM Lee, SR Reno, JL Dawson, RL Han, J AF Follstaedt, DM Myers, SM Lee, SR Reno, JL Dawson, RL Han, J BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Interaction of cavities and dislocations in semiconductors SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Transmission electron microscopy of He-implanted Si-Ge and InGaAs shows an attractive interaction between cavities and dislocations. Calculation indicates that cavities are attracted to dislocations through surrounding strain fields, and strong binding (100s of eV) occurs when a cavity intersects the core. In a strained SiGe/Si heterostructure, He implantation enhances relaxation rates, and cavities bound to misfit dislocations show evidence of increasing relaxation at equilibrium by lowering dislocation energies. The interaction is expected for all crystalline solids, and gives insight into voids in GaN/sapphire and bubbles in He-implanted metals. RP Follstaedt, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 209 EP 214 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00033 ER PT S AU Allen, CW Ryan, EA AF Allen, CW Ryan, EA BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI In situ ion beam research in Argonne's intermediate voltage electron microscope SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Since Fall 1995, a state-of-the-art intermediate voltage electron microscope (IVEM) has been operational in the HVEM-Tandem Facility with in situ ion irradiation capabilities similar to those of the HVEM of the Facility. A 300 kV Hitachi H-9000NAR is interfaced to the two ion accelerators of the Facility, with a demonstrated point-to-point spatial resolution for imaging of 0.25 nm with the ion beamline attached to the microscope. The IVEM incorporates a Faraday cup system for ion dosimetry with measurement aperture 6.5 cm from the TEM specimen, which was described in Symposium A of the 1995 MRS Fall Meeting. The IVEM is now employed for a variety of in situ ion beam studies ranging from low dose ion damage experiments with GaAs, in which damage zones individual displacement cascades are observed, to implantation studies in metals, in which irradiation-induced noble gas precipitate mobility is studied in real time. In this presentation, the new instrumentation and its specifications will be described briefly, several basic concepts relating to in situ experiments in transmission electron microscopes will be summarized and examples of in situ experiments will be presented which exploit the experimental capabilities of this new user facility instrumentation. RP Allen, CW (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 22 Z9 22 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 277 EP 287 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00044 ER PT S AU Heinisch, HL AF Heinisch, HL BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Cascade defects beyond the primary damage state SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Atomic scale computer simulations are used to investigate the intracascade evolution of the defect distributions of cascades in copper over macroscopic times. Starting with cascades generated using molecular dynamics, the diffusive transport and interactions of the defects are followed for hundreds of seconds in stochastic annealing simulations. The temperature and energy dependencies of annihilation, clustering and free defect production are determined for individual cascades. The simulation results illustrate the strong influence on intracascade evolution of the defect configuration existing in the primary damage state. Other significant factors affecting the evolution of the defect distribution are the large differences in mobility and stability of vacancy and interstitial defects and the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades. The latter factor introduces a cascade energy dependence of defect evolution that is apparent only beyond the primary damage state, amplifying the need for performing many more cascade simulations at higher energies. RP Heinisch, HL (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 301 EP 306 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00046 ER PT S AU Daulton, TL Kirk, MA Rehn, LE AF Daulton, TL Kirk, MA Rehn, LE BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Transmission electron microscopy study in-situ of radiation-induced defects in copper at elevated temperatures SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Neutrons and high-energy ions incident upon a solid can initiate a displacement collision cascade of lattice atoms resulting in localized regions within the solid containing a high concentration of interstitial and vacancy point defects. These point defects can collapse into various types of dislocation loops and stacking fault tetrahedra(SFT) large enough that their lattice strain fields are visible under diffraction-contrast imaging using a Transmission Electron Microscope(TEM). The basic mechanisms driving the collapse of point defects produced in collision cascades is investigated in situ with TEM for fcc-Cu irradiated with heavy (100 keV Kr) ions at elevated temperature. The isothermal stability of these clusters is also examined in situ. Areal defect yields were observed to decrease abruptly for temperatures greater than 300 degrees C. This decrease in defect yield is attributed to a proportional decrease in the probability of collapse of point defects into clusters. The evolution of the defect density under isothermal conditions appears to be influenced by three different rate processes active in the decline of the total defect density. These rate constants can be attributed to differences in the stability of various types of defect clusters and to different loss mechanisms. Based upon observed stabilities, estimations for the average binding enthalpies of vacancies to SFT are calculated for copper. RP Daulton, TL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 313 EP 318 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00048 ER PT S AU Doraiswamy, N Kestel, B Alexander, DE AF Doraiswamy, N Kestel, B Alexander, DE BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI In-situ irradiation studies on the effects of helium on the microstructural evolution of V-3.8Cr-3.9Ti SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The role of helium on the microstructural evolution of V-3.8Cr-3.9Ti has been investigated by in-situ transmission electron microscopy observations of as-prepared and He implanted (<10 appm) samples subjected to 200keV He irradiation at room temperature. Quantitative analysis of the defects showed an increase in the defect density and size with irradiation in both types of samples. The unimplanted sample showed a defect density consistent with electron irradiation experiments. In comparison, the He preimplanted sample had slightly larger defects and a substantially greater increase in the number density of defects. This result is consistent with a mechanism of He trapping by the formation of He-vacancy-X (X=C,N,O) complexes. RP Doraiswamy, N (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 337 EP 341 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00052 ER PT S AU Rice, PM Snead, LL Alexander, DJ Zinkle, SJ AF Rice, PM Snead, LL Alexander, DJ Zinkle, SJ BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Microstructure of V-4Cr-4Ti following low temperature neutron irradiation SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The V-4Cr-4Ti alloy displays excellent mechanical properties, including a ductile-to-brittle transition temperature (DBTT) below -200 degrees C in the unirradiated condition. Specimens of this alloy were fission neutron-irradiated in the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) to a dose of 0.4 dpa at temperatures from 100 to 275 degrees C. Mechanical testing showed significant irradiation hardening in the alloy which increased with increasing irradiation temperature. Charpy impact testing also showed a dramatic increase in the DBTT on the order of 200 to 350 degrees C. The mechanical property changes are correlated with preliminary results from the transmission electron microscopy (TEM) analysis of the defect microstructure resulting from the low-dose neutron irradiations. The TEM analysis of the irradiated material showed a nearly constant defect density of similar to 1.6 x 10(23) m(-3), with an average defect diameter of slightly greater than 3 nm. RP Rice, PM (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 0 TC 8 Z9 8 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 343 EP 348 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00053 ER PT S AU Birtcher, RC Donnelly, SE AF Birtcher, RC Donnelly, SE BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Plastic flow induced by single ion impacts on gold SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB In situ transmission electron microscopy has been used to follow room temperature irradiation of thinned bulk and 62 nm thick gold films with Xe ions in the energy range 50 to 400 keV. Energy spikes resulting from single ion impacts give rise to surface craters and holes which exist until annihilation by subsequent ion impacts. Video recording provided details with a time-resolution of 33 milliseconds. Craters were produced on the irradiated surface at all ion energies and on the opposite surface when the ions had sufficient energy to traverse the specimen. Crater sizes were as large as 12 nm for the higher energy irradiations. On average, approximately 6% of impinging ions result in craters. A single 200 keV Xe ion may produce a hole in thin gold foils. Hole formation involves the movement by plastic flow of massive amounts of material; on the order of tens of thousand Au atoms per ion impact. Individual ion impacts also result 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 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 355 EP 360 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00055 ER PT S AU Alonso, E Caturla, MJ Tang, M Huang, H delaRubia, TD AF Alonso, E Caturla, MJ Tang, M Huang, H delaRubia, TD BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Molecular dynamics simulation of cascade damage in gold SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB High-energy cascades have been simulated in gold using molecular dynamics with a modified embedded atom method potential. The results show that both vacancy and interstitial clusters form with high probability as a result of intracascade processes. The formation of clusters has been interpreted in terms of the high pressures generated in the core of the cascade during the early stages. We provide evidence that correlation between interstitial and vacancy clustering exists. RP Alonso, E (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 367 EP 372 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00057 ER PT S AU Ding, FR Birtcher, RC Kestel, BJ Baldo, PM AF Ding, FR Birtcher, RC Kestel, BJ Baldo, PM BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Mixing of Al into uranium silicides reactor fuels SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB SEM observations have shown that irradiation induced interaction of the aluminum cladding with uranium silicide reactor fuels strongly affects both fission gas and fuel swelling behaviors during fuel burn-up. We have used ion beam mixing, by 1.5 MeV Kr, to study this phenomena. RES and the Al-27(p, gamma)Si-28 resonance nuclear reaction to was used to measure radiation induced mixing of Al into U3Si and U3Si2 after irradiation at 300 degrees C. Initially U mixes into the Al layer and Al mixes into the U3Si. At a low doses, the Al layer is converted into UAl4 type compound while near the interface the phase U(Al.93Si.07)(3) grows. Under irradiation, Al diffuses out of the UAl4 surface layer, and the lower density ternary, which is stable under irradiation, is the final product. Al mixing into U3Si2 is slower than in U3Si, but after high dose irradiation the Al concentration extends much father into the bulk. In both systems Al mixing and diffusion is controlled by phase formation and growth. The Al mixing rates into the two alloys are similar to that of Al into pure uranium where similar aluminide phases are formed. RP Ding, FR (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 MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 413 EP 417 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00065 ER PT S AU Bruemmer, SM Cole, JI Carter, RD Was, GS AF Bruemmer, SM Cole, JI Carter, RD Was, GS BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Defect microstructures and deformation mechanisms in irradiated austenitic stainless steels SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Microstructural evolution and deformation behavior of austenitic stainless steels are evaluated for neutron, heavy-ion and proton irradiated materials. Radiation hardening in austenitic stainless steels is shown to result from the evolution of small interstitial dislocation loops during light-water-reactor (LWR) irradiation. Available data on stainless steels irradiated under LWR conditions have been analyzed and microstructural characteristics assessed for the critical fluence range (0.5 to 10 dpa) where irradiation-assisted stress corrosion cracking susceptibility is observed. Heavy-ion and proton irradiations are used to produce similar defect microstructures enabling the investigation of hardening and deformation mechanisms. Scanning electron, atomic force and transmission electron microscopies are employed to examine tensile test strain rate and temperature effects on deformation characteristics. Dislocation loop microstructures are found to promote inhomogeneous planar deformation within the matrix and regularly spaced steps at the surface during plastic deformation. Twinning is the dominant deformation mechanism at rapid strain rates and at low temperatures, while dislocation channeling is favored at slower strain rates and at higher temperatures. Both mechanisms produce highly localized deformation and large surface slip steps. Channeling, in particular, is capable of creating extensive dislocation pileups and high stresses at internal grain boundaries which may promote intergranular cracking. RP Bruemmer, SM (reprint author), PACIFIC NW NATL LAB,RICHLAND,WA 99352, USA. OI Cole, James/0000-0003-1178-5846 NR 0 TC 19 Z9 19 U1 0 U2 10 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 437 EP 444 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00068 ER PT S AU Spooner, S AF Spooner, S BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Small angle neutron scattering modeling of copper-rich precipitates in steel SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The magnetic-to-nuclear scattering intensity ratio observed in the scattering from copper-rich precipitates in irradiated pressure vessel steels is much smaller than the value of 11.4 expected for a pure copper precipitate in iron. A model for precipitates in pressure vessel steels which matches the observed scattering typically incorporates manganese, nickel, silicon and other elements and it is assumed that the precipitate is non-magnetic. In the present work consideration is given to the effect of composition gradients and ferromagnetic penetration into the precipitate on the small angle scattering cross section for copper-rich clusters as distinguished from conventional precipitates. The calculation is an extension of a scattering model for micelles which consist of shells of varying scattering density. A discrepancy between recent SANS scattering experiments on pressure vessel stells was found to be related to applied magnetic field strength. The assumption of cluster structure and its relation to atom probe FIM findings as well as the effects of insufficient field for magnetic saturation is discussed. RP Spooner, S (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 489 EP 494 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00074 ER PT S AU Kenik, EA AF Kenik, EA BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Radiation-induced segregation in alloy X-750 SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The microstructural and microchemical evolution of an Alloy X-750 heat under neutron irradiation has been studied in order to understand the origin of irradiation-assisted stress corrosion cracking. Both clustering of point defects and radiation-induced segregation (RIS) at interfaces and boundaries have been observed. Although no significant changes in the precipitate structure were observed, boundaries exhibited additional depletion of Cr and Fe and enrichment of Ni. RP Kenik, EA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 527 EP 532 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00080 ER PT S AU Bloomer, TE Lyu, DY Kameda, J AF Bloomer, TE Lyu, DY Kameda, J BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Comparative study on intergranular segregation of sulfur and phosphorus induced during neutron irradiation and thermal ageing in vanadium-20 wt.% titanium alloys SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Intergranular impurity segregation induced during neutron irradiation (9.8 x 10(24) n/m(2) at 438 degrees C) and thermal ageing has been studied in V-20 wt.% Ti alloys undoped, P doped and S doped all containing residual C and O. Neutron irradiation induced intergranular segregation and desegregation of S in undoped and S doped alloys, respectively. Thermal ageing resulted in a large increase in the S segregation in the undoped and S doped alloys. However, all unirradiated, aged and irradiated P doped alloys showed negligible S segregation. The vanadium alloys had smaller P segregation, compared to the S segregation in the undoped and S doped alloys. The irradiation and ageing enhanced the P segregation in a different fashion depending on the alloys. The grain boundary enrichment of C, O and Ti was reduced during the irradiation but promoted by the thermal ageing. The underlying mechanisms controlling intergranular impurity segregation caused by irradiation or thermal ageing are discussed in light of the impurity solubility change and dynamic interaction of defect and impurity fluxes. RP Bloomer, TE (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 545 EP 550 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00083 ER PT S AU Giacobbe, MJ Lam, NQ Okamoto, PR Zaluzec, NJ Stubbins, JF AF Giacobbe, MJ Lam, NQ Okamoto, PR Zaluzec, NJ Stubbins, JF BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Effects of ion implantation and temperature on radiation-induced segregation in Ni-9Al alloys SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The effects of Ne and Sc implantation on radiation-induced segregation (RIS) in Ni-9at.%Al were studied in-situ utilizing the high-voltage electron microscope/Tandem accelerator facility at Argonne National Laboratory. A highly-focused 900-keV electron beam generated radial defect fluxes which, in turn, induced the transport of Al atoms toward the center of the electron-irradiated area via the inverse-Kirkendall effect. The radial segregation rate of Al atoms was monitored by measuring the diameter of the gamma'-Ni3Al zone which formed in the Al-enriched area during irradiation. Ne and Sc implantation effects on RIS were investigated at 550 degrees C, while Ne effects were also examined at 625 degrees C to determine the influence of temperature on the ability of Ne to act as defect trapping sites, causing RIS suppression. It was found that the RIS suppression effect of Ne increased with increasing irradiation temperature, and that Sc had a small RIS suppression effect which increased with increasing Sc implantation dose. Ne bubbles which formed during implantation are believed to be responsible for its strong suppression effect. RP Giacobbe, MJ (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 MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 551 EP 556 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00084 ER PT S AU Simonen, EP Bruemmer, SM AF Simonen, EP Bruemmer, SM BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Radiation-induced minor element segregation at austenitic stainless steel grain boundaries SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Measurement of minor element compositions at irradiated grain boundaries in austenitic stainless steels indicates that Si is the only element that significantly responds to radiation-induced segregation. Other minor elements, such as P or S, do not exhibit elevated grain boundary concentrations after irradiation. A rate theory evaluation of segregation is in accord with ion-induced Si enrichment, but reveals complexities in the interpretation of extrapolating behavior from ion-irradiation to neutron-irradiation behavior. The model calibrated to measured high-rate, ion-induced segregation greatly overestimates measured low-rate, neutron-irradiation segregation of Si. RP Simonen, EP (reprint author), PACIFIC NW NATL LAB,POB 999,P8-15,RICHLAND,WA 99352, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 569 EP 574 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00087 ER PT S AU Snead, LL Zinkle, SJ AF Snead, LL Zinkle, SJ BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Threshold irradiation dose for amorphization of silicon carbide SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electron and xenon irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be similar to 0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10(-3) dpa/s and with fission neutrons irradiated at 1 x 10(-6) dpa/s irradiated to 15 dpa in the temperature range of similar to 340 +/- 10 K. RP Snead, LL (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 0 TC 23 Z9 23 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 595 EP 606 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00090 ER PT S AU Weber, WJ Ewing, RC AF Weber, WJ Ewing, RC BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Radiation effects in glass waste forms for high-level waste and plutonium disposal SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB A key challenge in the permanent disposal of high-level waste (HLW), plutonium residues/scraps, and excess weapons plutonium in glass waste forms is the development of predictive models of long-term performance that are based on a sound scientific understanding of relevant phenomena. Radiation effects from beta-decay and alpha-decay can impact the performance of glasses for HLW and Pu disposition through the interactions of the alpha-particles, beta-particles, recoil nuclei, and gamma-rays with the atoms in the glass. Recently, a scientific panel convened under the auspices of the DOE Council on Materials Science to assess the current state of understanding, identify important scientific issues, and recommend directions for research in the area of radiation effects in glasses for HLW and au disposition. The overall finding of the panel was that there is a critical lack of systematic understanding on radiation effects in glasses at the atomic, microscopic, and macroscopic levels. The current state of understanding on radiation effects in glass waste forms and critical scientific issues are presented. RP Weber, WJ (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 0 TC 0 Z9 0 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 607 EP 618 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00091 ER PT S AU Newcomer, PP Venturini, EL Schone, H Doyle, BL Myers, KE AF Newcomer, PP Venturini, EL Schone, H Doyle, BL Myers, KE BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI HRTEM of extended defects in Tl-2212 thin films SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Many applications of high temperature superconductors, HTS, require the presence of lattice defects in the material structure to suppress the motion of magnetic vortices and enhance the critical current density, J(c). The microstructure of Tl2Ba2CaCu2O8-delta (Tl-2212) thin films which have extended defects induced by high energy Au and Cu ion irradiation is studied using high resolution transmission electron microscopy, HRTEM, with slow scan digital imaging. In order to optimize the HTS properties and better analyze the consequent microstructural modification, the fluence is varied. At moderate fluences, resulting in similar to 4% reduction of the superconducting, large enhancements of J(c) and vortex pinning potential are observed. The density and microstructure of isolated defects and surrounding structure will be discussed and compared to damage profiles calculated using the TRIM code. Correlation will be made between the HRTEM results and the changes in HTS properties. RP Newcomer, PP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 639 EP 644 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00095 ER PT S AU Zinkle, SJ AF Zinkle, SJ BE Robertson, IM Was, GS Hobbs, LW delaRubia, TD TI Irradiation spectrum and ionization-induced diffusion effects in ceramics SO MICROSTRUCTURE EVOLUTION DURING IRRADIATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium B on Microstructure Evolution During Irradiation, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB There are two main components to the irradiation spectrum which need to be considered in radiation effects studies on nonmetals, namely the primary knock-on atom energy spectrum and ionizing radiation. The published low-temperature studies on Al2O3 and MgO suggest that the defect production is nearly independent of the average primary knock-on atom energy, in sharp contrast to the situation for metals. On the other hand, ionizing radiation has been shown to exert a pronounced influence on the microstructural evolution of both semiconductors and insulators under certain conditions. Recent work on the microstructure of ion-irradiated ceramics is summarized, which provides evidence for significant ionization-induced diffusion. Polycrystalline samples of MgO, Al2O3, and MgAl2O4 were irradiated with various ions ranging from 1 MeV H+ to 4 MeV Zr+ ions at temperatures between 25 and 650 degrees C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructure of the irradiated specimens. Dislocation loop nucleation was effectively suppressed in specimens irradiated with light ions, whereas the growth rate of dislocation loops was enhanced. The sensitivity to irradiation spectrum is attributed to ionization-induced diffusion. The interstitial migration energies in MgAl2O3 and Al2O3 are estimated to be less than or equal to 0.4 eV and less than or equal to 0.8 eV, respectively for irradiation conditions where ionization-induced diffusion effects are expected to be negligible. RP Zinkle, SJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 0 TC 35 Z9 35 U1 0 U2 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-343-6 J9 MATER RES SOC SYMP P PY 1997 VL 439 BP 667 EP 678 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA BJ12F UT WOS:A1997BJ12F00099 ER PT J AU Aldstadt, JH Martin, AF AF Aldstadt, JH Martin, AF TI Analytical chemistry and the cone penetrometer: In situ chemical characterization of the subsurface SO MIKROCHIMICA ACTA LA English DT Review DE cone penetrometer testing; sampling; sensors; in situ analysis; site characterization ID FLUORESCENCE; SYSTEM; PROBE; CONTAMINATION; AQUIFER; SENSORS; SOILS AB The development of novel microanalytical techniques for in situ chemical characterization of the terrestrial subsurface environment has grown significantly over the last decade, particularly those instruments that are interfaced to the cone penetrometer. Cone penetrometer testing (CPT) has emerged as an effective means to introduce samplers and probes for in situ analysis of contaminants in soil and groundwater matrices. A variety of in situ chemical samplers for CPT have been developed that can be driven into the subsurface to collect soil gas, groundwater, or soil samples at depth, thus providing a means of determining the vertical and horizontal extent of contamination. Cone penetrometer testing is also being explored as a means to deliver in situ subsurface sensor probes, including probes based on laser-induced fluorescence, Raman, and infrared spectroscopies for organics; on laser-induced breakdown and X-ray fluorescence spectroscopies for heavy metals; and on passive gamma-ray spectroscopy for radionuclides. The range of analytical technologies used in CPT for the determination of organic and inorganic species in the subsurface is described. RP Aldstadt, JH (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ENVIRONM CHEM GRP,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 62 TC 12 Z9 12 U1 1 U2 5 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 VL 127 IS 1-2 BP 1 EP 18 DI 10.1007/BF01243159 PG 18 WC Chemistry, Analytical SC Chemistry GA XM056 UT WOS:A1997XM05600001 ER PT J AU Reffner, JA Carr, GL Williams, GP AF Reffner, JA Carr, GL Williams, GP TI Infrared microspectroscopy with synchrotron radiation SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE infrared microspectroscopy; synchrotron radiation; infrared; polymer AB The brightness, spectral distribution, and low noise of synchrotron radiation are major advantages for Fourier-transform infrared microspectroscopy. The infrared radiant emission from the National Synchrotron Light Source (NSLS) is 100-1000 times brighter than that from a 1500 K thermal-emission source [1]. Using synchrotron radiation, an Ir mu s (Nicolet Corp.) microspectrometer system demonstrated spatial resolution unequaled by conventional sources. With this system, spectra with a signal-to-noise ratio greater than 200:1 could be collected in less than 5 seconds From a 6 x 6 mu m sample area (defined by dual confocal remote apertures). With 6 x 6 mu m confocal dual apertures, the system clearly resolved 4 mu m wide layers in a multilayered laminate. C1 NORTHROP GRUMMAN CORP,BETHPAGE,NY 11714. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Reffner, JA (reprint author), SPECTRA TECH INC,POB 869,2 RES DR,SHELTON,CT 06484, USA. NR 3 TC 1 Z9 1 U1 2 U2 5 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 339 EP 341 PG 3 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400077 ER PT J AU Wetzel, DL Reffner, JA Williams, GP AF Wetzel, DL Reffner, JA Williams, GP TI Synchrotron-powered FT-IR microspectroscopy: Single cell interrogation SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE infrared; microspectroscopy; FT-IR; synchrotron AB Excellent spatial resolution is achieved with an integrated FT-IR microspectrometer (IR mu s, Spectra-Tech) in which the globar (thermal) source is replaced by synchrotron radiation. The infrared portion of the spectrum extracted From the vacuum ultraviolet storage ring of the National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory, is not only brighter, but is free from thermal noise and concentrated into a small area. Passing the beam with low divergence through an aperture does not severely attenuate the throughput as is the case with a thermal source. Spectra obtained with 5 and 6 mu m diameter apertures from adjacent tissue in a mouse retina, a wheat aleurone cell and cell wall, and two cells in wheat primary root, have shown localized chemical differences. Functional group contour maps and 3D maps of mouse cerebellum, a grass vascular bundle and a cross-section of rye illustrate the utility of the system described. C1 SPECTRA TECH INC, SHELTON, CT 06484 USA. BROOKHAVEN NATL LAB, NATL SYNCHROTRON LIGHT SOURCE DEPT, U2B, UPTON, NY 11973 USA. RP Wetzel, DL (reprint author), KANSAS STATE UNIV, MICROBEAM MOL SPECT LAB, SHELLENBERGER HALL, MANHATTAN, KS 66506 USA. NR 7 TC 2 Z9 2 U1 0 U2 2 PU SPRINGER WIEN PI WIEN PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 353 EP 355 PG 3 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400081 ER PT J AU Bajic, SJ McClelland, JF Jones, RW AF Bajic, SJ McClelland, JF Jones, RW TI Utilizing Fourier-transform infrared photoacoustic spectroscopy to analyze underground storage tank waste material SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE FT-IR-photoacoustic spectroscopy; waste and sludge analysis AB Hazardous underground storage tank waste from nuclear fuel processing activities poses a very challenging analytical problem. The waste is very heterogeneous and radioactive. Radiation hazards require that sample size and handling be kept to a minimum. A method is presented to determine the chemical composition of the waste tank sludge by using FT-IR-photoacoustic spectroscopy with submilligram sized samples and minimal sample handling. Preparation of samples for analysis as well as data on samples obtained from cores taken from underground storage waste tanks at the Westinghouse Hanford site in Richland, WA, is presented. C1 MTEC PHOTOACOUST INC,AMES,IA 50014. RP Bajic, SJ (reprint author), IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 611 EP 612 PG 2 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400155 ER PT J AU McClelland, JF Jones, RW Bajic, SJ Power, JF AF McClelland, JF Jones, RW Bajic, SJ Power, JF TI Depth profiling by FT-IR photoacoustic spectroscopy SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE depth profiling; photoacoustic spectroscopy; photoacoustic phase AB Adding photoacoustic phase data to photoacoustic magnitude data allows for more complete and more quantitative depth profiling of samples with depth dependent composition. Phase modulation is used here to quantitatively measure layer depths in discretely layered samples. The expectation minimum principle is used to derive complete depth profiles of samples with smooth concentration gradients from rapid scan phase and magnitude data. C1 MTEC PHOTOACOUST INC, AMES, IA 50014 USA. MCGILL UNIV, DEPT CHEM, MONTREAL, PQ H3A 2K6, CANADA. RP McClelland, JF (reprint author), IOWA STATE UNIV, AMES LAB, US DOE, AMES, IA 50011 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 613 EP 614 PG 2 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400156 ER PT J AU Powell, GL Barber, TE MarreroRivera, M Williams, DM Smyrl, NR Neu, JT AF Powell, GL Barber, TE MarreroRivera, M Williams, DM Smyrl, NR Neu, JT TI Oil analysis on metal surfaces by using DR-FT-IR mapping techniques SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE infrared; reflectance; diffuse; surface analysis AB The use of remote-sensing diffuse-reflectance optics to obtain Fourier-transform mid-infrared spectra from sand-blasted gold, aluminum, and steel surfaces as a function of position in order to monitor the spatial distribution of oil over the surface is described, and used to map the spread of an 0.85 mu g safflower oil droplet with time, to calibrate the spectra for film thickness near 1 mu m, and to monitor the oil oxidation that limited the extent of the stain. C1 SURFACE OPT CORP,SAN DIEGO,CA 92131. RP Powell, GL (reprint author), OAK RIDGE CTR MFG TECHNOL,OAK RIDGE,TN 37831, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 655 EP 656 PG 2 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400169 ER PT J AU Weeks, SJ McClelland, JF Wright, SL Jones, RW AF Weeks, SJ McClelland, JF Wright, SL Jones, RW TI Transient infrared spectroscopy for on-line analysis of solids and viscous liquids SO MIKROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Fourier Transform Spectroscopy (ICOFTS) CY AUG 27-SEP 01, 1995 CL BUDAPEST, HUNGARY SP Fed Eur Chem Soc, Hung Acad Sci, Working Comm Laser Phys Spectro HAS, Minist Cult Educ Hungary, Austrian Soc Anal Chem, Hung Nat Comm Technol Develop, Inst Isotopes HAS, Univ Veszprem, Central Res Inst Chem HAS DE FT-IR; on-line process control; transient infrared spectroscopy AB Transient infrared spectroscopy (TIRS) is described as a developing technology that overcomes sample opacity, thickness and self-absorption problems to gain useful mid-IR spectral information from moving solids and viscous liquids for real-time, on-line process control. The utility of the technique is demonstrated by showing examples as diverse as monitoring the cure levels for acrylic coatings on polycarbonate sheets and monitoring the waste loading percentage for nuclear waste treatment by polymer microencapsulation. C1 MTEC PHOTOACOUST INC,AMES,IA 50014. PIONEER HI BRED INT INC,JOHNSTON,IA 50131. RP Weeks, SJ (reprint author), AMES LAB,AMES,IA 50011, USA. NR 2 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0026-3672 J9 MIKROCHIM ACTA JI Mikrochim. Acta PY 1997 SU 14 BP 801 EP 802 PG 2 WC Chemistry, Analytical SC Chemistry GA WW404 UT WOS:A1997WW40400213 ER PT B AU Dickey, FM Holswade, SC Smith, NF Miller, SL AF Dickey, FM Holswade, SC Smith, NF Miller, SL BE Motamedi, ME Hornbeck, LJ Pister, KSJ TI An optical probe for micromachine performance analysis SO MINIATURIZED SYSTEMS WITH MICRO-OPTICS AND MICROMECHANICS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Miniaturized Systems with Micro-Optics and Micromechanics II CY FEB 10-12, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE micromachines; optical probe; performance analysis AB Understanding the mechanisms that impact the performance of Microelectromechanical Systems (MEMS) is essential to the development of optimized designs and fabrication processes, as well as the qualification of devices for commercial applications. Silicon micromachines include engines that consist of orthogonally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small as 50 mu m in diameter and can be driven at rotation rates exceeding 300,000 rpm. Optical techniques offer the potential for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. We describe the development of Micromachine Optical Probe (MOP) technology for the evaluation of micromachine performance. The MOP approach is based on the detection of optical signals scattered by the gear teeth or other physical structures. We present experimental results obtained with a prototype optical probe and micromachines developed at Sandia National Laboratories. RP Dickey, FM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2419-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 3008 BP 52 EP 61 DI 10.1117/12.271440 PG 10 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BH70G UT WOS:A1997BH70G00006 ER PT B AU Liebetrau, AM Chen, G Gao, F AF Liebetrau, AM Chen, G Gao, F BE Scott, DW TI Uncertainty analysis for computer modeling systems SO MINING AND MODELING MASSIVE DATA SETS IN SCIENCE, ENGINEERING, AND BUSINESS WITH A SUBTHEME IN ENVIRONMENTAL STATISTICS SE COMPUTING SCIENCE AND STATISTICS (SERIES) LA English DT Proceedings Paper CT 29th Symposium on the Interface between Computing Science and Statistics CY MAY 14-17, 1997 CL HOUSTON, TX SP Univ Texas M D Anderson Cancer Ctr, Univ Texas Hlth Sci Ctr, Sch Public Hlth, W M Keck Ctr Computational Biol AB Complex natural and human phenomena are being studied with increasingly complex computer modeling systems in which a number of component models are linked to replicate the underlying phenomenon. The computer models in such systems are often sophisticated models in their own right, each with heavy computing requirement. When joined with other similar models, they may produce a system model with very long computing times, often on the order of several days. Conventional methods of sensitivity and uncertainty analysis are intractable for modeling systems that requires so much computer time. New methods of uncertainty analysis are required for system models constructed in this manner. In this paper, we propose a hierarchical approach for uncertainty analysis for complex computer modeling systems. This approach allows us to use a series of approximations for component models - can "move" from more complex ones (i.e. many variables, long computing times, etc.) to less complex ones or vice versa. This is an effective strategy for simplifying complex modeling systems. The simplified system model employs analogues of major component models that are linked so as to retain the essential structure of the underlying system. A key requirement of the simplified system model is that it require much less computing time than its underlying parent. The simplified system model is then employed for nearly all exploratory sensitivity and uncertainty analysis, thereby greatly reducing the number of runs of the parent model. The strategy is particularly effective when a structured logic diagram is used to represent the underlying system. With such a representation, the value of obtaining additional information (refined models, additional data, etc.) at key modeling points to reduce uncertainty in model outputs is readily assessed. In this way, various alternatives for gathering information and model development can be systematically examined until an effective variance reduction strategy is found. We have found the SIMULIMK code to be particularly well suited for the computation required to implement this strategy. We illustrate our methods with an example drawn from a program to resolve safety issues concerning the waste storage tanks at the Hanford site. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liebetrau, AM (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU INTERFACE FOUNDATION NORTH AMERICA PI FAIRFAX PA PO BOX 7460, FAIRFAX, VA 22039-7460 USA BN 1-886658-04-8 J9 COMP SCI STAT PY 1997 VL 29 IS 1 BP 10 EP 18 PG 9 WC Operations Research & Management Science; Mathematics, Applied; Statistics & Probability SC Operations Research & Management Science; Mathematics GA BM60M UT WOS:000079222400002 ER PT B AU McKay, MD Morrison, JD AF McKay, MD Morrison, JD BE Scott, DW TI Structural model uncertainty in stochastic simulation SO MINING AND MODELING MASSIVE DATA SETS IN SCIENCE, ENGINEERING, AND BUSINESS WITH A SUBTHEME IN ENVIRONMENTAL STATISTICS SE COMPUTING SCIENCE AND STATISTICS (SERIES) LA English DT Proceedings Paper CT 29th Symposium on the Interface between Computing Science and Statistics CY MAY 14-17, 1997 CL HOUSTON, TX SP Univ Texas M D Anderson Cancer Ctr, Univ Texas Hlth Sci Ctr, Sch Public Hlth, W M Keck Ctr Computational Biol AB Prediction uncertainty in stochastic simulation models can be described by a hierarchy of components: stochastic variability at the lowest level, input and parameter uncertainty at a higher level, and structural model uncertainty at the top. It is argued that a usual paradigm for analysis of input uncertainty is not suitable for application to structural model uncertainty. An approach more likely to produce an acceptable methodology for analyzing structural model uncertainty is one that uses characteristics specific to the particular family of models. C1 Los Alamos Natl Lab, Technol & Safety Assessment Div, Los Alamos, NM 87545 USA. RP McKay, MD (reprint author), Los Alamos Natl Lab, Technol & Safety Assessment Div, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU INTERFACE FOUNDATION NORTH AMERICA PI FAIRFAX PA PO BOX 7460, FAIRFAX, VA 22039-7460 USA BN 1-886658-04-8 J9 COMP SCI STAT PY 1997 VL 29 IS 1 BP 19 EP 24 PG 6 WC Operations Research & Management Science; Mathematics, Applied; Statistics & Probability SC Operations Research & Management Science; Mathematics GA BM60M UT WOS:000079222400003 ER PT B AU Fitzgerald, M AF Fitzgerald, M BE Scott, DW TI An interactive graphical tool for exploring sequential dependencies in categorical data SO MINING AND MODELING MASSIVE DATA SETS IN SCIENCE, ENGINEERING, AND BUSINESS WITH A SUBTHEME IN ENVIRONMENTAL STATISTICS SE COMPUTING SCIENCE AND STATISTICS (SERIES) LA English DT Proceedings Paper CT 29th Symposium on the Interface between Computing Science and Statistics CY MAY 14-17, 1997 CL HOUSTON, TX SP Univ Texas M D Anderson Cancer Ctr, Univ Texas Hlth Sci Ctr, Sch Public Hlth, W M Keck Ctr Computational Biol AB This report describes an interactive graphical tool, written iu XLISP-STAT, for exploratory data analysis of dependencies in sequences of categorical data. Both global and local views of the dependency structure can be insightful, and allowing the user the flexibility to change critical parameters and switch between views in a simple, interactive, point-and-click environment can make the task of exploring dependencies amongst a large number of categories feasible and lead to a better understanding of the sequential properties of the data. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fitzgerald, M (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop F600, Los Alamos, NM 87545 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU INTERFACE FOUNDATION NORTH AMERICA PI FAIRFAX PA PO BOX 7460, FAIRFAX, VA 22039-7460 USA BN 1-886658-04-8 J9 COMP SCI STAT PY 1997 VL 29 IS 1 BP 433 EP 438 PG 6 WC Operations Research & Management Science; Mathematics, Applied; Statistics & Probability SC Operations Research & Management Science; Mathematics GA BM60M UT WOS:000079222400110 ER PT B AU Wehner, MF Eltgroth, PG Mirin, AA Duffy, PB Caldeira, KG Bolstad, JH Wang, H Matarazzo, CM Creach, UE AF Wehner, MF Eltgroth, PG Mirin, AA Duffy, PB Caldeira, KG Bolstad, JH Wang, H Matarazzo, CM Creach, UE BE Clymer, MG Mechoso, CR TI Comprehensive climate system modeling on massively parallel computers SO MISSION EARTH: MODELING AND SIMULATION FOR A SUSTAINABLE GLOBAL SYSTEM LA English DT Proceedings Paper CT 1997 Western MultiConference on Mission Earth - Modeling and Simulation for a Sustainable Global System CY JAN 12-15, 1997 CL PHOENIX, AZ SP Soc Comp Simulat Int DE climate system modeling; massively parallel computing AB A better understanding of both natural and human induced changes to the Earth's climate is necessary for policy makers to make informed decisions regarding energy usage and other greenhouse gas producing activities. To achieve this, substantial increases in the sophistication of climate models are required. Coupling between the climate subsystems of the atmosphere, oceans, cryosphere and biosphere is only now beginning to be explored in global models. The enormous computational expense of such models is one significant factor limiting progress. A comprehensive climate system model targeted to distributed memory massively parallel processing (MPP) computers is under development at the Lawrence Livermore National Laboratory. This class of computers promises the necessary computational power to permit the timely execution of climate models of substantially more sophistication than current generation models. Our strategy for achieving high performance on large numbers of processors is to exploit the multiple layers of parallelism naturally contained within highly coupled global climate models. The centerpiece of this strategy is the concurrent execution of multiple independently parallelized components of the climate system model. This methodology allows the assignment of an arbitrary number of processors to each of the major climate subsystems. Hence, a higher total number of processors may be efficiently used. Furthermore, load imbalances arising from the coupling of submodels may be minimized by adjusting the distribution of processors among the submodels. RP Wehner, MF (reprint author), LAWRENCE LIVERMORE NATL LAB,CLIMATE SYST MODELING GRP,POB 808 L-256,LIVERMORE,CA 94551, USA. RI Caldeira, Ken/E-7914-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC COMPUTER SIMULATION INT PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92177 BN 1-56555-106-0 PY 1997 BP 37 EP 42 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mathematics, Applied; Meteorology & Atmospheric Sciences SC Computer Science; Engineering; Mathematics; Meteorology & Atmospheric Sciences GA BH94R UT WOS:A1997BH94R00006 ER PT B AU Miller, NL Kim, JW AF Miller, NL Kim, JW BE Clymer, MG Mechoso, CR TI The UC-LLNL Regional Climate System Model SO MISSION EARTH: MODELING AND SIMULATION FOR A SUSTAINABLE GLOBAL SYSTEM LA English DT Proceedings Paper CT 1997 Western MultiConference on Mission Earth - Modeling and Simulation for a Sustainable Global System CY JAN 12-15, 1997 CL PHOENIX, AZ SP Soc Comp Simulat Int DE regional climate system model; simulated precipitation; runoff; agroeconomics AB The UC-LLNL Regional Climate System Model has been under development since 1991. This unique system simulates climate from the global scale down to the watershed catchment scale, and consists of data pre- and post-processors, and four model components. The four model components are (1) a mesoscale atmospheric simulation model, (2) a soil-plant-snow model, (3) a watershed hydrology-riverflow model, and (4) a suite of crop response models. The first three model components have been coupled, and the system includes two-way feedbacks between the soil-plant-snow model and the mesoscale atmospheric simulation model. This three-component version of RCSM has been tested, validated, and successfully used for operational quantitative precipitation forecasts and seasonal water resource studies over the southwestern U.S. We are currently implementing and validating the fourth component, the Decision Support System for Agrotechnology Transfer (DSSAT). A description of the UC-LLNL RCSM and some recent results are presented. RP Miller, NL (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Miller, Norman/E-6897-2010 NR 0 TC 5 Z9 5 U1 0 U2 0 PU SOC COMPUTER SIMULATION INT PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92177 BN 1-56555-106-0 PY 1997 BP 55 EP 59 PG 5 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mathematics, Applied; Meteorology & Atmospheric Sciences SC Computer Science; Engineering; Mathematics; Meteorology & Atmospheric Sciences GA BH94R UT WOS:A1997BH94R00008 ER PT B AU Neil, GR Benson, SV Shinn, MD Davidson, PC Kloeppel, PK AF Neil, GR Benson, SV Shinn, MD Davidson, PC Kloeppel, PK BE Farrukh, UO Basu, S TI Optical modeling of the Jefferson laboratory IR demo PEL SO MODELING AND SIMULATION OF HIGHER-POWER LASER SYSTEMS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Modeling and Simulation of Higher-Power Laser Systems IV CY FEB 12-13, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE free-electron laser (FEL); photocathode; injector; wavelength; optical; accelerator AB The Thomas Jefferson National Accelerator Facility (formerly known as CEBAF) has embarked on the construction of a 1 kW free-electron laser operating initially at 3 microns that is designed for laser-material interaction experiments and to explore the feasibility of scaling the system in power and wavelength for industrial and Navy defense applications. The accelerator system for this IR Demo includes a 10 MeV photocathode-based injector, a 32 MeV CEBAF-style superconducting radio-frequency linac, and single-pass transport which accelerates the beam from injector to wiggler, followed by energy-recovery deceleration to a dump. The electron and optical beam time structure in the design consists of a train of picosecond pulses at a 37.425 MHz pulse repetition rate. The initial optical configuration is a conventional near-concentric resonator with transmissive outcoupling. Future upgrades of the system will increase the power and shorten the operating wavelength, and utilize a more advanced resonator system capable of scaling to high powers, The optical system of the laser has been modeled using the GLAD(R) code by using a Beer's-law region to mimic the FEL interaction. Effects such as mirror heating have been calculated and compared with analytical treatments. The magnitude of the distortion for several materials and wavelengths has been estimated. The advantages as well as the limitations of this approach are discussed. RP Neil, GR (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 0 TC 11 Z9 11 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2400-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 2989 BP 160 EP 171 DI 10.1117/12.273666 PG 12 WC Optics SC Optics GA BH79W UT WOS:A1997BH79W00014 ER PT J AU Charbon, C LeSar, R AF Charbon, C LeSar, R TI A 2D stochastic micro-macro model of equiaxed eutectic solidification SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID MICROSTRUCTURE FORMATION; GROWTH; COLUMNAR; ALLOYS AB We propose a model of equiaxed eutectic solidification that couples macroscopic heat diffusion with a microscopic description of nucleation and growth of the eutectic grains. The heat equation is solved numerically by means of an implicit finite difference method. The evolution of solid fraction is deduced from a stochastic model of nucleation and growth which uses the local temperature (interpolated from the FDM mesh) to determine the local grain density and the local growth rate. The model predicts the evaluations of both temperature and solid fraction at any point of the sample. Moreover, a realistic appearance of the recalescence on the cooling curves, as well as a detailed picture of the microstructure, are predicted. We apply the model to the solidification of grey cast iron. RP Charbon, C (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI LeSar, Richard/G-1609-2012 NR 27 TC 14 Z9 14 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JAN PY 1997 VL 5 IS 1 BP 53 EP 65 DI 10.1088/0965-0393/5/1/004 PG 13 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WQ665 UT WOS:A1997WQ66500004 ER PT B AU Balay, S Gropp, WD McInnes, LC Smith, BF AF Balay, S Gropp, WD McInnes, LC Smith, BF BE Arge, E Bruaset, AM Langtangen, HP TI Efficient management of parallelism in object-oriented numerical software libraries SO MODERN SOFTWARE TOOLS FOR SCIENTIFIC COMPUTING LA English DT Proceedings Paper CT International Workshop on Modern Software Tools for Scientific Computing CY SEP 16-18, 1996 CL OSLO, NORWAY SP SINTEF Appl Math, Univ Oslo, Dept Informat & Math, Norwegian Res Council Norway AB Parallel numerical software based on the message passing model is enormously complicated. This paper introduces a set of techniques to manage the complexity, while maintaining high efficiency and ease of use. The PETSc 2.0 package uses object-oriented programming to conceal the details of the message passing, without concealing the parallelism, in a high-quality set of numerical software libraries. In fact, the programming model used by PETSc is also the most appropriate for NUMA shared-memory machines, since they require the same careful attention to memory hierarchies as do distributed-memory machines. Thus, the concepts discussed are appropriate for all scalable computing systems. The PETSc libraries provide many of the data structures and numerical kernels required for the scalable solution of PDEs, offering performance portability. RP Balay, S (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 586 Z9 592 U1 1 U2 6 PU BIRKHAUSER BOSTON PI CAMBRIDGE PA 675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139-2333 BN 0-8176-3974-8 PY 1997 BP 163 EP 202 PG 40 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BH72F UT WOS:A1997BH72F00008 ER PT B AU Boyle, JM Harmer, TJ Winter, VL AF Boyle, JM Harmer, TJ Winter, VL BE Arge, E Bruaset, AM Langtangen, HP TI The TAMPR program transformation system: Simplifying the development of numerical software SO MODERN SOFTWARE TOOLS FOR SCIENTIFIC COMPUTING LA English DT Proceedings Paper CT International Workshop on Modern Software Tools for Scientific Computing CY SEP 16-18, 1996 CL OSLO, NORWAY SP SINTEF Appl Math, Univ Oslo, Dept Informat & Math, Norwegian Res Council Norway AB Writing correct numerical software is a complex, demanding, and, at times, even a boring, task. In this chapter, we describe an approach to constructing software-program specification and transformation-and allied tools that can help not only to ensure the correctness of numerical computations but also automate much of the drudge-work involved in preparing such software. This approach to software construction holds out the exciting prospect of enabling the numerical analyst or specialist in scientific computing to concentrate on correctly capturing the problem to be solved, while delegating the details of programming the software and adapting it to specialized computing environments to automated tools. RP Boyle, JM (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU BIRKHAUSER BOSTON PI CAMBRIDGE PA 675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139-2333 BN 0-8176-3974-8 PY 1997 BP 353 EP 372 PG 20 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BH72F UT WOS:A1997BH72F00017 ER PT J AU Ivanov, IB Yershov, GM Barsky, VE Belgovskii, AI Kirillov, EV Kreindlin, EY Parinov, SV Mologina, NV Mirzabekov, AD AF Ivanov, IB Yershov, GM Barsky, VE Belgovskii, AI Kirillov, EV Kreindlin, EY Parinov, SV Mologina, NV Mirzabekov, AD TI Identification of gene mutations on oligonucleotide microchips SO MOLECULAR BIOLOGY LA English DT Article DE sequencing; hybridization; DNA diagnostics; microchip ID SEQUENCE DETERMINATION; BETA-THALASSEMIA; DNA; HYBRIDIZATION; PROBES AB The technology of sequencing by hybridization to oligonucleotide microchips (SHOM) makes it possible to analyze the DNA sequence by hybridizing the DNA with a set of oligonucleotides immobilized on a ''microchip'' gel matrix fixed on a glass plate. The method has been used to detect beta-thalassemia mutations by hybridizing fluorescently labeled DNA to a set of immobilized octamers and decamers or by staining hybridized DNA with ethidium bromide. It has been shown that contiguous stacking hybridization significantly expands the possibilities of the SHOM technology The results obtained allow one to hope that SHOM will find wide application in medical diagnostics. C1 RUSSIAN ACAD SCI,VA ENGELHARDT MOL BIOL INST,MOSCOW 117984,RUSSIA. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 29 TC 4 Z9 4 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 0026-8933 J9 MOL BIOL+ JI Mol. Biol. PD JAN-FEB PY 1997 VL 31 IS 1 BP 133 EP 140 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XE985 UT WOS:A1997XE98500022 ER PT J AU Mang, JT Kumar, S Hammouda, B AF Mang, JT Kumar, S Hammouda, B TI Lyotropic liquid crystals under simple couette and oscillatory shear SO MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS LA English DT Article; Proceedings Paper CT 16th International Liquid Crystal Conference CY JUN 24-28, 1996 CL KENT STATE UNIV, KENT, OH SP Kent State Univ, Dept Phys, Kent State Univ, Dept Chem, Kent State Univ, Liquid Crystal Inst, Int Liquid Crystal Soc, Natl Sci Fdn, Sci & Technol Ctr Adv Liquid Crystalline Opt Mat, Samsung Electr Co Ltd, Gordon & Breach Sci Publ, USN, Off Naval Res, Natl Sci Fdn, Cystaloid Electr, Minolta Ltd, Soc Informat Display, Blake Ind, EM Ind Inc, Instec Inc, Linkam Sci Instruments, ROLIC Ltd, Siemens Energy & Automat Inc, Aerosp Display Syst, McNeil Travel HO KENT STATE UNIV ID A PHASE-TRANSITION; LANDAU THEORY; FLOW; NEMATICS AB Small angle neutron scattering (SANS) has been utilized to investigate the flow properties of the discotic micellar isotropic (I), nematic (N) and lamellar (L-alpha) phases in aqueous solutions of cesium perfluoro-octanate. Under simple shear, no preferred orientation was observed in the I phase. The N phase aligned with the nematic director along the shear gradient velocity, providing the first evidence for a positive value of the viscosity parameter, alpha(2). The L-alpha phase oriented with lamellae parallel to the shear plane. A reorientation of the director near the N-L-alpha transition was witnessed upon cooling from the N phase at a constant shear rate and is attributed, primarily to a change in the value of alpha(2) as a result of increasing lamellar correlations in the nematic phase. The application of oscillatory shear induced significant shifts in the phase boundaries, including nematic-like order some 7 K into the quiescent I phase. C1 KENT STATE UNIV,DEPT PHYS,KENT,OH 44242. KENT STATE UNIV,INST LIQUID CRYSTAL,KENT,OH 44242. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Mang, JT (reprint author), LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. NR 21 TC 6 Z9 6 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1058-725X J9 MOL CRYST LIQ CRYS A JI Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A-Mol. Cryst. Liq. Cryst. PY 1997 VL 303 BP 255 EP 266 DI 10.1080/10587259708039432 PG 12 WC Crystallography SC Crystallography GA YE814 UT WOS:A1997YE81400037 ER PT J AU Mang, JT Hjelm, RP AF Mang, JT Hjelm, RP TI Sans investigation of the pressure- and temperature-dependent structure of the bile salt lecithin system SO MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS LA English DT Article; Proceedings Paper CT 16th International Liquid Crystal Conference CY JUN 24-28, 1996 CL KENT STATE UNIV, KENT, OH SP Kent State Univ, Dept Phys, Kent State Univ, Dept Chem, Kent State Univ, Liquid Crystal Inst, Int Liquid Crystal Soc, Natl Sci Fdn, Sci & Technol Ctr Adv Liquid Crystalline Opt Mat, Samsung Electr Co Ltd, Gordon & Breach Sci Publ, USN, Off Naval Res, Natl Sci Fdn, Cystaloid Electr, Minolta Ltd, Soc Informat Display, Blake Ind, EM Ind Inc, Instec Inc, Linkam Sci Instruments, ROLIC Ltd, Siemens Energy & Automat Inc, Aerosp Display Syst, McNeil Travel HO KENT STATE UNIV ID VESICLES AB We used small angle neutron scattering to investigate the pressure and temperature dependent particle structure in mixed colloids of egg yolk phosphatidylcholine with the bile salt, glycocholate in D2O. The concentrations and compositions of the mixtures, at ambient temperature and pressure, corresponded to the mixed vesicle region of the isotropic (I) phase. Upon increasing the hydrostatic pressure at ambient temperature, interesting morphological changes were observed. At a pressure of 6.9 MPa, the system is best described by a coexistence of the mixed, spherical single bilayer vesicle, stacked lamellar and stacked ribbon phases. At higher pressures, the system transformed to a stacked ribbon phase. Analysis of scattering data as a function of temperature, at ambient pressure, revealed that a vesicle phase remained stable with the average spherical radius decreasing as the temperature was increased from 15 to 40 degrees C. RP Mang, JT (reprint author), LOS ALAMOS NATL LAB,NLNSC,LOS ALAMOS,NM 87545, USA. RI Lujan Center, LANL/G-4896-2012 NR 6 TC 4 Z9 4 U1 0 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1058-725X J9 MOL CRYST LIQ CRYS A JI Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A-Mol. Cryst. Liq. Cryst. PY 1997 VL 299 BP 439 EP 443 DI 10.1080/10587259708042025 PG 5 WC Crystallography SC Crystallography GA XZ070 UT WOS:A1997XZ07000060 ER PT J AU Sulzer, B Perelson, AS AF Sulzer, B Perelson, AS TI Immunons revisited: Binding of multivalent antigens to B cells SO MOLECULAR IMMUNOLOGY LA English DT Article DE crosslinking; immunon; ligand depletion; signal-transducing aggregates; B cell response ID CELLULAR-STIMULATION; QUANTIZED MODEL; HAPTEN VALENCE; IMMUNOGENICITY; RECEPTOR; P53/56(LYN); SURFACE AB The T-independent B cell response induced by highly multivalent hapten-polymer preparations has been studied extensively. The in vitro measured dose-response curve lends to be roughly bell-shaped with the peak response occurring at very low ligand concentrations, between 0.1-1 ng/ml for a variety of different ligands. Furthermore. polymers with more than approximately 10 haptens tend to be stimulatory, whereas polymers with fewer than 10 haptens conjugated, tend to be inhibitory. These observations have been perplexing when viewed within the context of standard theories of receptor ligation by multivalent ligands. We present a new analysis of these previous experiments that reconciles the differences between theory and experiment. From this theory it is concluded that the peak in the observed dose-response curve only weakly reflects properties of the ligand and the affinity of surface immunoglobulin for the hapten, but depends strongly on the density of antigen-specific B cells in the culture. The number of responding cells decreases at low ligand concentrations, because cells have to share limiting amounts of ligand and not because of the decreasing probability of receptors and ligands meeting each other. Our theory leads to the same conclusion as made by previous researchers, namely that a minimum number of receptor sites, of the order of 10, need to be bound to a single ligand in order to stimulate a B cell. While this conclusion was based on the lack of immunogenicity of antigens carrying less than a minimum number of haptens, the quantitative results of this study, derived from fitting experimental dose-response curves obtained with highly multivalent antigens, provide evidence for the immunon hypothesis that is based upon the degree of receptor aggregation. Our theory also provides quantitative agreement with experimental observations on systems, in which both stimulatory and non-stimulatory polymers are mixed in the same system. (C) 1997 Elsevier Science Ltd. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. FU NCRR NIH HHS [RR06555] NR 24 TC 32 Z9 33 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0161-5890 J9 MOL IMMUNOL JI Mol. Immunol. PD JAN PY 1997 VL 34 IS 1 BP 63 EP 74 DI 10.1016/S0161-5890(96)00096-X PG 12 WC Biochemistry & Molecular Biology; Immunology SC Biochemistry & Molecular Biology; Immunology GA XC150 UT WOS:A1997XC15000007 PM 9182877 ER PT S AU Bignozzi, CA Schoonover, JR Scandola, F AF Bignozzi, CA Schoonover, JR Scandola, F BE Meyer, GJ TI A supramolecular approach to light harvesting and sensitization of wide-bandgap semiconductors: Antenna effects and charge separation SO MOLECULAR LEVEL ARTIFICIAL PHOTOSYNTHETIC MATERIALS SE PROGRESS IN INORGANIC CHEMISTRY LA English DT Review ID ENERGY-GAP LAW; PHOTOINDUCED ELECTRON-TRANSFER; PHOTOSYNTHETIC REACTION CENTER; MLCT EXCITED-STATES; RUTHENIUM(II) POLYPYRIDINE COMPLEXES; BRIDGED POLYNUCLEAR COMPLEXES; COLLOIDAL TITANIUM-DIOXIDE; EMISSION SPECTRAL PROFILES; TRANSITION-METAL COMPLEXES; MIXED-LIGAND COMPLEXES C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. RP Bignozzi, CA (reprint author), UNIV FERRARA, DIPARTMENTO CHIM, I-44100 FERRARA, ITALY. NR 266 TC 164 Z9 164 U1 0 U2 13 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0079-6379 BN 0-471-12535-0 J9 PROG INORG CHEM JI Prog. Inorgan. Chem. PY 1997 VL 44 BP 1 EP 95 PG 95 WC Chemistry, Inorganic & Nuclear SC Chemistry GA BG76H UT WOS:A1997BG76H00001 ER PT S AU White, DC Ringelberg, DB Macnaughton, SJ Alugupalli, S Schram, D AF White, DC Ringelberg, DB Macnaughton, SJ Alugupalli, S Schram, D BE Eganhouse, RP TI Signature lipid biomarker analysis for quantitative assessment in situ of environmental microbial ecology SO MOLECULAR MARKERS IN ENVIRONMENTAL GEOCHEMISTRY SE ACS Symposium Series LA English DT Review CT Symposium on the Application of Molecular Markers in Environmental Geochemistry, at the 212th National Meeting of the American-Chemical-Society CY AUG 25-29, 1996 CL ORLANDO, FL SP Amer Chem Soc, Div Environm Chem Inc, Amer Chem Soc, Div Geochem Inc ID FATTY-ACID PROFILES; GRAM-NEGATIVE BACTERIA; COMMUNITY STRUCTURE; SEDIMENTS; BIOMASS; CHROMATOGRAPHY; CYCLOPROPYL; SUBSURFACE; EXTRACTION; SAMPLES AB Examination of the lipid components of microbes in recent sediments has provided a convenient, quantitative, and comprehensive method to define the viable biomass, community composition, and nutritional/physiological activities of the biological communities in the sediments. The lipid extraction provides both a concentration and purification of the lipids from the soils and sediments. The subsequent fractionation, purification, and derivatization, sets up the definitive separation and structural identification by capillary gas chromatography with mass spectral identification of each component. As a part of this signature lipid biomarker (SLB) analysis, the lipid extraction also lyses the cells and allows for recovery of purified nucleic acids for subsequent gene probing with and without enzymatic amplification. This polyphasic analysis adds powerful specificity to the analysis of community microbial ecology. Since the SLB analysis involves detection by mass spectrometry, rates of incorporation of nonradioactive C-13 and N-15 mass-labeled precursors into signature biomarkers can be utilized to gain insight into specific metabolic activities. Application of electrospray and other external ionization sources to ion-trap mass spectrometry will greatly increase the specificity and sensitivity of the SLB analysis. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. MICROBIAL INSIGHTS INC, KNOXVILLE, TN 37953 USA. RP White, DC (reprint author), UNIV TENNESSEE, CTR ENVIRONM BIOTECHNOL, 10515 RES DR, KNOXVILLE, TN 37932 USA. NR 40 TC 24 Z9 24 U1 5 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3518-X J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 671 BP 22 EP 34 PG 13 WC Chemistry, Multidisciplinary; Geochemistry & Geophysics SC Chemistry; Geochemistry & Geophysics GA BJ87C UT WOS:A1997BJ87C00002 ER PT J AU Baranyai, A Cummings, PT AF Baranyai, A Cummings, PT TI Directional dependence of the random kinetic energy in planar Couette flow SO MOLECULAR PHYSICS LA English DT Article ID NONEQUILIBRIUM-MOLECULAR-DYNAMICS; EQUILIBRIUM; SHEAR; CONSTRAINT; PRINCIPLE; VISCOSITY; FLUIDS AB Non-equilibrium steady state systems do not obey the equipartition theorem in that the distribution of the random kinetic energy among the three directions is not independent of the mechanism which removes the dissipative heat. This becomes important beyond the linear regime because system properties will be functions of the thermostatting mechanism as well. For homogeneous non-equilibrium molecular dynamics simulations, in most of the cases, the simplest synthetic thermostat is used in which, analogously to equilibrium algorithms, the friction coefficient is identical in the x, y and z directions. The simplicity is attractive, but computer simulation results are presented that demonstrate that this may not be the most sensible choice physically. C1 OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. EOTVOS LORAND UNIV, LAB THEORET CHEM, H-1518 BUDAPEST 112, HUNGARY. RP Baranyai, A (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 NR 22 TC 7 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JAN PY 1997 VL 90 IS 1 BP 35 EP 41 DI 10.1080/002689797172831 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF617 UT WOS:A1997WF61700004 ER PT J AU Binbrek, OS Torrie, BH VonDreele, R Powell, BM AF Binbrek, OS Torrie, BH VonDreele, R Powell, BM TI The two solid phases of chlorodifluoromethane SO MOLECULAR PHYSICS LA English DT Article ID CRYSTAL-STRUCTURES AB The crystal structure of the two phases of chlorodifluoromethane (CHClF2) were determined at 70 K and 10 K using Rietveld refinement of neutron powder profiles. The upper phase is tetragonal P4(2)/n (C-4h(4)) with eight molecules in the unit cell occupying general positions. The lattice constants are a = 10 . 3711(1) Angstrom and c = 5 . 5915(2) Angstrom. The lower phase is monoclinic P112/n (C-2h(4)) with eight molecules in the unit cell with dimensions a = 10 . 1106(2), b = 10 . 4830(2), c = 5 . 5868(2) Angstrom and gamma = 90 . 319(2)degrees. The asymmetric unit has two molecules in general positions. The phase transition is of a displacive type but there are no large changes in the molecular positions or orientations at the transition. C1 UNIV WATERLOO,GUELPH WATERLOO PROGRAM GRAD WORK PHYS,DEPT PHYS,WATERLOO,ON N2L 3G1,CANADA. LOS ALAMOS NATL LAB,LANSCE,LOS ALAMOS,NM 87545. AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. RP Binbrek, OS (reprint author), KING FAHD UNIV PETR & MINERALS,DHAHRAN 31261,SAUDI ARABIA. NR 19 TC 5 Z9 5 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JAN PY 1997 VL 90 IS 1 BP 49 EP 54 DI 10.1080/002689797172859 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF617 UT WOS:A1997WF61700006 ER PT S AU Agamalian, MM Alamo, RG Londono, JD Mandelkern, L Spooner, S Stehling, FC Wignall, GD AF Agamalian, MM Alamo, RG Londono, JD Mandelkern, L Spooner, S Stehling, FC Wignall, GD BE Briber, RM Han, CC Peiffer, DG TI Ultra-high resolution small-angle neutron scattering investigations of liquid-liquid phase separation in linear low-density polyethylene SO MORPHOLOGICAL CONTROL IN MULTIPHASE POLYMER MIXTURES SE MATERIALS RESEARCH SOCIETY CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Morphological Control in Multiphase Polymer Mixtures CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Previous small-angle neutron scattering (SANS) studies [1] of heterogeneous ethylenehexene linear low-density polyethylene (LLDPE) copolymers have confirmed the existence of a dispersed minority phase (volume fraction phi similar to 10(-2)) consisting of highly branched, amorphous material. However, these experiments were conducted via a pinhole SANS spectrometer with an upper resolution limit similar to 10(3) Angstrom, whereas microscopy indicates that the dimensions of the disperse phase extend to the mu m-range. We have therefore complemented these investigations via a Bonse-Hart ultra-small angle neutron scattering (USANS) instrument which increases the instrumental resolution in reciprocal space by a factor similar to 100, and thus particle size up to 30 mu m can be resolved. The sensitivity of the USANS camera has recently been increased by two orders of magnitude by using the modified channel cut crystals [2], and the performance is therefore comparable to the best x-ray Bonse-Hart cameras. Xylene extraction removes the highly branched molecules and hence the volume fraction of the disperse phase is higher (phi similar to 0.3) in the extracted material. RP Agamalian, MM (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Agamalian, Michael/0000-0002-9112-2534 NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0886-7860 BN 1-55899-365-7 J9 MAT RES S C PY 1997 VL 461 BP 205 EP 210 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Polymer Science SC Materials Science; Polymer Science GA BJ28F UT WOS:A1997BJ28F00030 ER PT J AU Hellman, ES LilientalWeber, Z Buchanan, DNE AF Hellman, ES LilientalWeber, Z Buchanan, DNE TI Epitaxial growth and orientation of GaN on (100)gamma-LiAlO2 SO MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH LA English DT Article ID CRYSTALS AB The (1 0 0) face of gamma-LiAlO2 has attracted attention as a possible substrate for GaN epitaxial growth. This is partly because this face has an excellent lattice and structural match to (1 (1) over bar 0 0) GaN. This orientation would have a misfit of only -1.4% along the c-direction and -0.1% along the b-direction of LiAlO2. We find that in practice this orientation relationship does not occur; instead, (0 0 0 1) oriented GaN grows with a small tilt (0.6 degrees towards the c-direction) between the film and substrate. Although the misfit along the substrate b direction is large (-6.3%) for this orientation, the tilt perfectly accommodates the -1.4% misfit in the c direction. We present characterization of these films by RHEED, X-ray diffraction, and TEM. We propose that the tilt is driven by a reduction of interface energy which occurs in polar, incoherent interfaces. C1 AT&T BELL LABS, LUCENT TECHNOL, NAPERVILLE, IL 60566 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. NR 17 TC 55 Z9 60 U1 0 U2 6 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 1092-5783 J9 MRS INTERNET J N S R JI Mrs. Internet J. Nitride Semicond. Res. PY 1997 VL 2 IS 27-31 BP U32 EP U42 AR 30 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA XX198 UT WOS:A1997XX19800004 ER PT S AU Sheehy, B Walker, B Lafon, R Widmer, M Gambhir, A DiMauro, LF Agostini, P Kulander, KC AF Sheehy, B Walker, B Lafon, R Widmer, M Gambhir, A DiMauro, LF Agostini, P Kulander, KC BE Lambropoulos, P Walther, H TI Single and multiple electron dynamics in the strong field limit SO MULTIPHOTON PROCESSES 1996 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 7th International Conference on Multiphoton Processes CY SEP 30-OCT 04, 1996 CL GARMISCH PARTENKI, GERMANY SP Max Planck Gesell Forder Wissensch eV, Bayer Staatsminist Unterricht Kultus Wissensch & Kunst, Dtsche Forschungsgemeinsch DFG, Int Union Pure & Appl Chem, Int Union Pure & Appl Phys, Coherent GmbH, Spectra Phys GmbH, Lambda Phys GmbH ID ABOVE-THRESHOLD IONIZATION; RESCATTERING; HELIUM; RINGS; LASER AB High precision photoelectron energy and angular distributions in helium and neon atoms for a broad intensity range reflect the change in the continuum dynamics that occurs as the ionization process evolves into the pure tunneling regime. Elastic rescattering of the laser-driven free electron from its parent ion core leaves a distinct signature on the spectra, providing a direct quantitative test of the various theories of strong field multiphoton ionization. We show that it takes a relatively complete semi-classical rescattering model to accurately reproduce the observed photoelectron distributions. However, the calculated inelastic rescattering rate fails to reproduce the measured nonsequential double ionization yields. C1 CTR ETUD SACLAY, SERV PHOTON ATOM & MOL, F-91191 GIF SUR YVETTE, FRANCE. LAWRENCE LIVERMORE NATL LAB, TAMP GRP, LIVERMORE, CA 94551 USA. RP Sheehy, B (reprint author), BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RI Walker, Barry/F-8532-2011; Lambropoulos, Peter/H-2431-2011 NR 18 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0951-3248 BN 0-7503-0443-X J9 INST PHYS CONF SER PY 1997 VL 154 BP 106 EP 117 PG 12 WC Optics; Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical; Physics, Multidisciplinary; Physics, Mathematical SC Optics; Physics GA BH40C UT WOS:A1997BH40C00012 ER PT B AU Creutz, M AF Creutz, M BE Karsch, F Monien, B Satz, H TI Self-organized criticality SO MULTISCALE PHENOMENA AND THEIR SIMULATION LA English DT Proceedings Paper CT International Conference on Multiscale Phenomena and Their Simulation CY SEP 30-OCT 04, 1996 CL BIELEFELD, GERMANY AB I review the concept of self-organized criticality, wherein dissipative systems naturally drive themselves to a critical state with important phenomena occurring over a wide range of length and time scales. Several exact results are demonstrated for the Abelian sandpile. RP Creutz, M (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3090-7 PY 1997 BP 49 EP 58 PG 10 WC Computer Science, Theory & Methods; Mathematics, Applied; Physics, Nuclear; Physics, Particles & Fields SC Computer Science; Mathematics; Physics GA BJ58P UT WOS:A1997BJ58P00005 ER PT B AU Lee, TSH AF Lee, TSH BE Lee, TSH Roberts, W TI Reaction theories for N* excitations in pi N and gamma N reactions SO N* PHYSICS: PROCEEDINGS OF THE FOURTH CEBAF/INT WORKSHOP SE PROCEEDINGS FROM THE INSTITUTE FOR NUCLEAR THEORY LA English DT Proceedings Paper CT 4th CEBAF/INT Workshop on N(star) Physics CY SEP 09-13, 1996 CL UNIV WASHINGTON, INST NUCL THEORY, SEATTLE, WA SP Continuous Electron Beam Accelerator Facil, Inst Nucl Theory HO UNIV WASHINGTON, INST NUCL THEORY AB The importance of developing reaction theories for investigating N* physics is illustrated in an analysis of pion photoproduction on the nucleon. It is shown that the gamma N --> Delta transition amplitudes predicted by the constituent quark model are in agreement with the values extracted from the gamma N --> pi N data only when the contributions from the reaction mechanisms calculated using a dynamical approach are taken into account in the analysis. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Lee, TSH (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3138-5 J9 PROC INST NUCL THEOR PY 1997 VL 4 BP 19 EP 28 PG 10 WC Physics, Nuclear SC Physics GA BK21L UT WOS:000071548200003 ER PT S AU Eastman, JA Choi, US Li, S Thompson, LJ Lee, S AF Eastman, JA Choi, US Li, S Thompson, LJ Lee, S BE Komarneni, S Parker, JC Wollenberger, HJ TI Enhanced thermal conductivity through the development of nanofluids SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids required in many industrial applications. To overcome this limitation, a new class of heat transfer fluids is being developed by suspending nanocrystalline particles in liquids such as water or oil. The resulting ''nanofluids'' possess extremely high thermal conductivities compared to the liquids without dispersed nanocrystalline particles. For example, 5 volume % of nanocrystalline copper oxide particles suspended in water results in an improvement in thermal conductivity of almost 60% compared to water without nanoparticles. Excellent suspension properties are also observed, with no significant settling of nanocrystalline oxide particles occurring in stationary fluids over time periods longer than several days. Direct evaporation of Cu nano-particles into pump oil results in similar improvements in thermal conductivity compared to oxide-in-water systems, but importantly, requires far smaller concentrations of dispersed nanocrystalline powder. RP Eastman, JA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,BLDG 212,ARGONNE,IL 60439, USA. OI Eastman, Jeff/0000-0002-0847-4265 NR 0 TC 191 Z9 200 U1 0 U2 23 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 3 EP 11 PG 9 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00001 ER PT S AU Li, SP Eastman, JA Thompson, LJ Bjormander, C Foster, CM AF Li, SP Eastman, JA Thompson, LJ Bjormander, C Foster, CM BE Komarneni, S Parker, JC Wollenberger, HJ TI Nanocrystalline BaTiO3 from the gas-condensation process SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Nanocrystalline BaTiO3 can be prepared by the gas condensation method at a temperature as low as 700 degrees C, with an average particle size as small as 18nm. The stoichiometry of nanocrystalline BaTiO3 particles can be controlled precisely and reproducibly. Nanocrystalline BaTiO3 powders, fabricated by a novel e-beam evaporation method, show good sintering behavior with a high density at a temperature as low as 1200 degrees C. These samples exhibit a relatively larger dielectric constant than that of coarse-grained BaTiO3. In addition, a thermal analysis has been also carried out to determine the lowest temperature for forming nanostructured BaTiO3 from Ba/Ti oxidized clusters at ambient pressure. RP Li, SP (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Eastman, Jeff/0000-0002-0847-4265 NR 0 TC 5 Z9 5 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 45 EP 50 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00006 ER PT S AU Maya, L Paranthaman, M Thompson, JR Thundat, T Stevenson, RJ AF Maya, L Paranthaman, M Thompson, JR Thundat, T Stevenson, RJ BE Komarneni, S Parker, JC Wollenberger, HJ TI Ferromagnetic nanocomposite films from thermally labile nitride precursors SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB A series of nanocomposite films containing nickel or cobalt nitride dispersed in a ceramic matrix of aluminum nitride, boron nitride or silicon nitride, were prepared by reactive sputtering of selected alloys or compounds such as nickel aluminide or cobalt silicide. Thermal treatment of the nitride composites in vacuum at less than or equal to 500 degrees C leads to selective loss of nitrogen from CoN or Ni3N to generate dispersions of the metal in the ceramic matrix. This treatment may be performed in a localized manner by means of a focused laser beam to generate microscopic features that are imaged by magnetic force microscopy. The films are potentially useful for data storage with superior chemical and mechanical stability provided by the ceramic matrix and high encoding density made possible because of the size of the magnetic particles of less than 10 nm generated in the thermal treatment. The films were characterized by chemical and physical means including FTIR, TEM, MFM and magnetic measurements. Preliminary results on similar iron composites are also described. RP Maya, L (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 0 TC 0 Z9 0 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 213 EP 218 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00032 ER PT S AU Keppens, V Mandrus, D Rankin, J Boatner, LA AF Keppens, V Mandrus, D Rankin, J Boatner, LA BE Komarneni, S Parker, JC Wollenberger, HJ TI The formation of metal/metal-matrix nanocomposites by the ultrasonic dispersion of immiscible liquid metals SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Ultrasonic energy has been used to disperse one liquid metallic component in a second immiscible liquid metal, thereby producing a metallic emulsion. Upon lowering the temperature of this emulsion below the melting point of the lowest-melting constituent, a metal/metal-matrix composite is formed. This composite consists of sub-micron-to-micron-sized particles of the minor metallic phase that are embedded in a matrix consisting of the major metallic phase. The zinc-bismuth case was used as a model system, and ultrasonic dispersion of a minor bismuth liquid phase was used to synthesize metal/metal-matrix composites. These materials were subsequently characterized using scanning electron microscopy and energy-dispersive x-ray analysis. RP Keppens, V (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,MS 6056,OAK RIDGE,TN 37831, USA. RI Mandrus, David/H-3090-2014; Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 243 EP 248 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00037 ER PT S AU Follstaedt, DM Knapp, JA Barbour, JC Myers, SM Dugger, MT AF Follstaedt, DM Knapp, JA Barbour, JC Myers, SM Dugger, MT BE Komarneni, S Parker, JC Wollenberger, HJ TI Energetic-particle synthesis of nanocomposite Al alloys SO NANOPHASE AND NANOCOMPOSITE MATERIALS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials II, at the 1996 MRS Fall Meeting CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc AB Ion implantation of O into Al and growth of Al(O) layers using electron-cyclotron resonance plasma and pulsed laser depositions produce composite alloys with a high density of nanometer-size oxide precipitates in an Al matrix. The precipitates impart high strength to the alloy and reduced adhesion during sliding contact, while electrical conductivity and ductility are retained. Implantation of N into Al produces similar microstructures and mechanical properties. The athermal energies of deposited atoms are a key factor in achieving these properties. RP Follstaedt, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-361-4 J9 MATER RES SOC SYMP P PY 1997 VL 457 BP 249 EP 254 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BH71D UT WOS:A1997BH71D00038 ER PT S AU Martin, JE Anderson, RA Tigges, CP AF Martin, JE Anderson, RA Tigges, CP BE Shalaev, VM Moskovits, M TI Composite materials with field-induced anisotropy SO NANOSTRUCTURED MATERIALS: CLUSTERS, COMPOSITES, AND THIN FILMS SE ACS Symposium Series LA English DT Review CT Symposium on Nanostructured Materials - Clusters, Composites, and Thin Films, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CA SP Amer Chem Soc, Div Phys Chem AB Composite materials consisting of a polymerizable liquid phase and a dispersed colloidal phase can be structured by a uniaxial or rotating electric or magnetic field and cured to form a material with anisotropic properties. We report the results of a computer simulation of the evolution of structure in these materials and characterize the structures that emerge through the anisotropy of their conductivity and permittivity. We find significant anisotropies are induced in these samples, in good agreement with experimental data we have collected. The anisotropies formed by a rotating field are found to be just the inverse of those produced by a uniaxial field. RP Martin, JE (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 5 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3536-8 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 679 BP 54 EP 69 PG 16 WC Chemistry, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Chemistry; Materials Science GA BJ87D UT WOS:A1997BJ87D00006 ER PT S AU Ying, ZC Zhu, JG Compton, RN Allard, LF Hettich, RL Haufler, RE AF Ying, ZC Zhu, JG Compton, RN Allard, LF Hettich, RL Haufler, RE BE Shalaev, VM Moskovits, M TI Synthesis of doped fullerene clusters and boron-nitrogen tubules using laser ablation SO NANOSTRUCTURED MATERIALS: CLUSTERS, COMPOSITES, AND THIN FILMS SE ACS Symposium Series LA English DT Review CT Symposium on Nanostructured Materials - Clusters, Composites, and Thin Films, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CA SP Amer Chem Soc, Div Phys Chem ID METALLOFULLERENE; NANOTUBES; CARBON; C-60 AB A variety of nanostructured materials, including clusters, nanoparticles, nanotubules, and thin films, can be produced by using the laser-ablation technique. This paper reports our synthesis of (i) metal endohedral fullerene clusters, (ii) nitrogen doped fullerene clusters, and (iii) boron-nitrogen nanotubules and nanoparticles employing the laser-ablation technique. These novel materials have been characterized by electron microscopy, mass spectrometry, and x-ray photoemission spectroscopy. The boron-nitrogen nanoparticles and nanotubules have been separated from other laser-ablation products, including boron particles and boron-nitride flakes, using a hydrogen-peroxide treatment. C1 UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. COMSTOCK INC, OAK RIDGE, TN 37830 USA. RP Ying, ZC (reprint author), NEW MEXICO STATE UNIV, DEPT PHYS, LAS CRUCES, NM 88003 USA. RI Hettich, Robert/N-1458-2016 OI Hettich, Robert/0000-0001-7708-786X NR 23 TC 3 Z9 3 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3536-8 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 679 BP 169 EP 182 PG 14 WC Chemistry, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Chemistry; Materials Science GA BJ87D UT WOS:A1997BJ87D00013 ER PT S AU Zhu, JG White, CW Withrow, SP Budai, JD Mu, R Henderson, DO AF Zhu, JG White, CW Withrow, SP Budai, JD Mu, R Henderson, DO BE Shalaev, VM Moskovits, M TI Synthesis and physical properties of semiconductor nanocrystals formed by ion implantation SO NANOSTRUCTURED MATERIALS: CLUSTERS, COMPOSITES, AND THIN FILMS SE ACS Symposium Series LA English DT Review CT Symposium on Nanostructured Materials - Clusters, Composites, and Thin Films, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CA SP Amer Chem Soc, Div Phys Chem ID GAAS NANOCRYSTALS; QUANTUM DOTS; SIO2; GE; MICROCRYSTALS; EXCITONS; SILICON; FILMS; SIGE AB Nanocrystals of elemental and compound semiconductor materials have been fabricated using the ion implantation technique. The nanocrystal formation is controlled by the implantation and annealing conditions, as exemplified by the nanocrystals of Si, Ge and GaAs formed inside SiO2 matrices. Strong red photoluminescence (PL) peaked around 750 nm has been observed in samples containing Si nanocrystals in SiO2. Difference in the absorption bandgap energies and the PL peak energies is discussed. The dielectric properties of SiO2 with Ge nanocrystal inclusions have been studied using infrared reflectance spectrometry. Cavity mode predicted by the Maxwell-Garnett theory has been observed in the samples implanted with a high dose of Ge. Significant influence of implantation sequence on the formation of compound semiconductor nanocrystals are demonstrated with the GaAs in the SiO2 system. Optical absorption measurements show that Ga particles have already formed in the as-implanted stage if Ga is implanted first. A single surface phonon mode has been observed in the infrared reflectance measurement from samples containing GaAs nanocrystals. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. FISK UNIV, DEPT PHYS, NASHVILLE, TN 37208 USA. RP Zhu, JG (reprint author), NEW MEXICO STATE UNIV, DEPT PHYS, LAS CRUCES, NM 88003 USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 24 TC 0 Z9 0 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3536-8 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 679 BP 198 EP 212 PG 15 WC Chemistry, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Chemistry; Materials Science GA BJ87D UT WOS:A1997BJ87D00015 ER PT S AU Murakoshi, K Yanagida, S Capel, M Castner, EW AF Murakoshi, K Yanagida, S Capel, M Castner, EW BE Shalaev, VM Moskovits, M TI Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters SO NANOSTRUCTURED MATERIALS: CLUSTERS, COMPOSITES, AND THIN FILMS SE ACS Symposium Series LA English DT Review CT Symposium on Nanostructured Materials - Clusters, Composites, and Thin Films, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CA SP Amer Chem Soc, Div Phys Chem ID SOLVATION DYNAMICS; DYE-SENSITIZATION; TIO2 ELECTRODES; SOLAR-CELL; ZNO; CONVERSION; LIGHT; FILMS; FEMTOSECOND; ELECTRICITY AB We have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows us to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors. C1 BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RP Murakoshi, K (reprint author), OSAKA UNIV, GRAD SCH ENGN, SUITA, OSAKA 565, JAPAN. RI Murakokshi, Kei/I-8701-2014 NR 35 TC 20 Z9 20 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3536-8 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 679 BP 221 EP 238 PG 18 WC Chemistry, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Chemistry; Materials Science GA BJ87D UT WOS:A1997BJ87D00017 ER PT S AU Jellinek, J Krissinel, EB AF Jellinek, J Krissinel, EB BE Shalaev, VM Moskovits, M TI Nickel-aluminum alloy clusters: Structural and dynamical properties SO NANOSTRUCTURED MATERIALS: CLUSTERS, COMPOSITES, AND THIN FILMS SE ACS Symposium Series LA English DT Review CT Symposium on Nanostructured Materials - Clusters, Composites, and Thin Films, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CA SP Amer Chem Soc, Div Phys Chem ID ELECTRONIC-STRUCTURE; BIMETALLIC CLUSTERS; COMPUTER-SIMULATION; METAL-CLUSTERS; NI CLUSTERS; AL AB Structural and dynamical properties of mixed NinAlm alloy clusters mimicked by a many-body potential are studied computationally for all the possible compositions n and m such that n+m=13. It is shown that the manifold of the usually very large number of the different possible structural forms can be systematized by introducing classes of structures corresponding to the same concentration of the components, geometry and type of the central atom. General definitions of mixing energy and mixing coefficient are introduced, and it is shown that the energy ordering of the structural forms within each class is governed by the mixing coefficient. The peculiarities of the solid-to-liquid-like transition are described as a function of the concentration of the two types of atoms. These peculiarities are correlated with and explained in terms of the energy spectra of the structural forms. Class-dependent features of the dynamics are described and analyzed. RP Jellinek, J (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 37 TC 5 Z9 5 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3536-8 J9 ACS SYM SER JI ACS Symp. Ser. PY 1997 VL 679 BP 239 EP 254 PG 16 WC Chemistry, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Chemistry; Materials Science GA BJ87D UT WOS:A1997BJ87D00018 ER PT J AU Wilcoxon, JP Craft, SA AF Wilcoxon, JP Craft, SA TI Liquid chromatographic analysis and characterization of inorganic nanoclusters SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB We describe the application of the techniques of high pressure liquid chromatography (HPLC) to analyze and characterize various types of inorganic nanoclusters. Both metal and semiconductor nanoclusters were grown in inverse micelles and we demonstrate how the nanoclusters can be separated from the surfactants and other byproducts of the reaction by using a variety of HPLC columns. We also discuss passivation of the cluster surface to prevent aggregation. The HPLC columns separate the clusters based upon a combination of size exclusion and chemical affinity mechanisms and the optical properties of the purified clusters are determined on-line using a variety of detectors. These include a photodiode array for collecting absorbance spectra, a fluorescence detector to monitor luminesence, and a conductivity detector to monitor surface charge on the nanoclusters. We illustrate the analysis of nanoclusters using HPLC by showing data from semiconductor Si, MoS2 nanoclusters and Au nanoclusters. An extremely novel luminesence was observed from very small metal nanoclusters. (C) 1997 Acta Metallurgica Inc. RP Wilcoxon, JP (reprint author), SANDIA NATL LABS,ORG 1152,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 6 TC 19 Z9 19 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 85 EP 88 DI 10.1016/S0965-9773(97)00024-X PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900013 ER PT J AU Rawers, JC Krabbe, R Cook, DC Kim, TH AF Rawers, JC Krabbe, R Cook, DC Kim, TH TI Differences in the microstructure of iron mechanically processed powder alloyed with interstitial and substitutional elements SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID FE POWDER AB Mechanically processing iron powder with interstitial and substitutional elements resulted in different microstructures (grain size, rms-strains, and phases) depending upon the alloying composition. Alloying iron powder with substitutional elements (approximately 4 at% Al, Cr, Nb, and Ti) resulted in a microstructure similar to mechanically processed iron powder: grain size approximate to 7nm, local rms strain approximate to 0.5% and bcc-Fe nanograins. Small reductions in grain size and increase in rms strain occurred with increasing radius of the substitute alloy atoms. Substitutional atoms were not uniformly distributed throughout the bcc-Fe matrix, but were distributed in clusters within the nanosgrains and/or as a thin coating on the grain boundaries. Alloying iron powder with interstitial elements (4-8 at% C and N) resulted in significantly different microstructures: decrease in grain size and increase in rms-strain occurred with increasing the interstitial concentration and a bct-Fe nanograin phase developed. Interstitial atoms were also predominately distributed in clusters and/or in a thin region along or in the grain boundaries of the iron nanograins. (C) 1997 Acta Metallurgica Inc. C1 OLD DOMINION UNIV,NORFOLK,VA 23529. RP Rawers, JC (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 8 TC 12 Z9 12 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 145 EP 148 DI 10.1016/S0965-9773(97)00039-1 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900028 ER PT J AU Goshchitskii, BN Kirk, MA Sagaradze, VV Lapin, SS AF Goshchitskii, BN Kirk, MA Sagaradze, VV Lapin, SS TI Formation of a submicrocrystal FCC structure under irradiation with high-energy particles SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB The influence of a high-dose (up to 200 dpa) irradiation with 1.5 MeY Kr+ ions at 500-700 degrees C on the formation of a submicrocrystal structure of Cr-Ni stainless steels was analyzed. In Cr16Ni15Mo3 and Cr16Ni8Mo3 unaging steels dislocations rearrange themselves to subgrains subject to the irradiation dose of 10 dpa at 600 degrees C, thus favoring formation of fine (30-50 nm) subgrains misoriented up to 1-3 degrees. An increase in the irradiation dose up to 160 dpa leads to recrystallization and appearance of fine misoriented crystals 50-100 nm in size. If dislocations are pinned with dispersed Ni3Ti particles (Cr16Ni15Mo3Ti1 aging steels), the subgrains are formed only after the irradiation dose of 160-200 dpa Therefore the radiation method of producing nanocrystals is comparable as to its efficiency with a strong deformation. (C) 1997 Acta Metallurgica Inc. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Goshchitskii, BN (reprint author), RUSSIAN ACAD SCI,INST MET PHYS,URAL DIV,EKATERINBURG,RUSSIA. RI Goshchitskii, Boris/K-4210-2013; Sagaradze, Victor/J-5570-2013 OI Goshchitskii, Boris/0000-0002-5292-1683; Sagaradze, Victor/0000-0002-6426-3382 NR 6 TC 2 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 189 EP 192 DI 10.1016/S0965-9773(97)00050-0 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900039 ER PT J AU Rawers, J Slavens, G Krabbe, R Groza, J AF Rawers, J Slavens, G Krabbe, R Groza, J TI Hot-press consolidation and tensile strength characterization of mechanically alloyed nanostructured Fe-Al and Fe-C powder. SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB Previous studies of nanostructured materials have typically concentrated on characterization of microscopic properties, principally because of the inability to produce samples of sufficient size to determine macroscopic properties. In this study consolidation of mechanically alloyed Fe-Al and Fe-C powders was accomplished by hot-pressing. Microstructure characterizations of both the attritor processed powder and the consolidated material were determined using X-ray diffraction and SEM. Consolidated samples were of sufficient size (25 mm in diameter and 5-7 mm thick) to determine macroscopic properties most notably: tensile strengths. Tensile strength increased with increasing density reaching a optimal strength of 700 to 900 MPa as the compacts reached full density. The maximum nanostructure tensile strength is consistent with tensile properties of HSLA steels. Compact characteristics (density, hardness, tensile strength) were determined as a function of hot-pressing conditions (processing temperature, time, pressure). During consolidation Fe-C samples developed second phase spinel and carbide precipitates. During consolidation Fe-Al samples developed a duplex submicron- and nanograin bcc-Fe microstructures and nanograins of (Fe,Al)(3)O-4. The grains of the consolidated samples were free of grain disorder, e.g., dislocations, twins, etc.. With few exceptions, density and grain size increased with increasing hot-press processing time, temperature, and/or pressure. (C) 1997 Acta Metallurgica Inc. C1 UNIV CALIF DAVIS,DAVIS,CA. RP Rawers, J (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 7 TC 15 Z9 16 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 197 EP 200 DI 10.1016/S0965-9773(97)00052-4 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900041 ER PT J AU Thomas, G Hutten, A AF Thomas, G Hutten, A TI Characterization of nano-magnetic structures SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID ELECTRON-MICROSCOPY; ALLOYS AB Since many important magnetic properties are affected (and thus can be manipulated) by microstructural features, it is important to characterize the physical and magnetic structures at the highest resolutions. Unfortunately, the resolution of electron microscopes is optimized for a given wavelength by high field lenses (similar to 1-2 tesla), which can easily saturate the specimen. Thus, to obtain high resolution structural and magnetic information in the same instrument is not possible, unless it is specially designed or sufficiently flexible. An example of the latter is the improved magnetic resolution obtained on the 800 kV Berkeley ARM and its applications to domains in Co-X binary alloys. Much of the restriction on high resolution revolves around specimens very thin in the beam direction (less than or equal to 200 Angstrom) and the signal-to-noise problem. Even with high resolution, sufficient image contrast is necessary to define the mesostructure. This paper discusses some of these issues, together with the problem of identification of atomic species, and effects associated with interfaces. Examples are drawn from current work on hard magnets, oxides and GMR in alloys. (C) 1997 Acta Metallurgica Inc. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. INST SOLID STATE & MAT RES,D-01069 DRESDEN,GERMANY. RP Thomas, G (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. RI Hutten, Andreas/B-3524-2011 NR 22 TC 7 Z9 7 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 271 EP 280 DI 10.1016/S0965-9773(97)90067-2 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900056 ER PT J AU Lemke, H Thomas, G Medlin, DL AF Lemke, H Thomas, G Medlin, DL TI Magnetic properties of Nd-Fe-B films analyzed by Lorentz microscopy SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID PERMANENT-MAGNETS AB A JEOL4000EX microscope operated in the Lorentz mode was used to analyze the magnetic structure in pulsed laser deposited films. The films consist of grains of 20 nm with Nd2Fe14B as the hardmagnetic phase. The thickness of the grain boundary is between 1 and 2 nm. Most domains follow the grain boundaries, some, however, seem to intrude the grains. The influence of film thickness on the magnetic properties is emphasized. An increase of film thickness from 100 nm to 200 nm leads to a decrease in domain size from 500 nm to 100 nm, while the crystalline properties remain the same. (C) 1997 Acta Metallurgica Inc. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. SANDIA NATL LABS,SURFACE & MICROSTRUCT RES DEPT,LIVERMORE,CA 94550. RP Lemke, H (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 7 TC 10 Z9 10 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 371 EP 374 DI 10.1016/S0965-9773(97)00086-X PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900075 ER PT J AU Croft, M Sills, D Sahiner, A Jankowski, AF Ansari, PH Kemly, E Lu, F Jeon, Y Tsakalakos, T AF Croft, M Sills, D Sahiner, A Jankowski, AF Ansari, PH Kemly, E Lu, F Jeon, Y Tsakalakos, T TI Fe-FCC layer stabilization in [111]-textured Fe/Pt multilayers SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID PERPENDICULAR MAGNETIC-ANISOTROPY AB Multilayered Fe/Pt films were deposited on Si-(111) substrates and manifest a fcc-Pt-(lll) structure. The results of extensive X-ray absorption spectroscopy (XAS) measurements are reported on materials with varying Fe-layer thickness. On the basis of both XAS near edge and EXAFS analysis it is possible to clearly identify the Fe-fcc versus Fe-bcc structure in the Fe-layers. The basis of the near edge Fe-phase identification will be supported by theoretical modeling and discussed in terms of literature results. The Fe-bcc/Fe-fcc phase diagram is discussed in terms of the Fe and Pt layer thicknesses. The effective Fe-fcc lattice parameter is estimated to be in the 3.9-4.0 Angstrom range and the effective Fe-bcc lattice parameter is estimated to be 0.04 Angstrom expanded as compared to bulk alpha-Fe. (C) 1997 Acta Metallurgica Inc. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. SETON HALL UNIV,S ORANGE,NJ 07079. UNIV KENTUCKY,LEXINGTON,KY 40506. RUTGERS STATE UNIV,DEPT CERAM,PISCATAWAY,NJ 08855. JEONJU UNIV,DEPT PHYS,JEONJU 560759,SOUTH KOREA. RP Croft, M (reprint author), RUTGERS STATE UNIV,DEPT PHYS,PISCATAWAY,NJ 08855, USA. NR 14 TC 2 Z9 2 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 413 EP 422 DI 10.1016/S0965-9773(97)00094-9 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900083 ER PT J AU Sanders, PG Rittner, M Kiedaisch, E Weertman, JR Kung, H Lu, YC AF Sanders, PG Rittner, M Kiedaisch, E Weertman, JR Kung, H Lu, YC TI Creep of nanocrystalline Cu, Pd, and Al-Zr SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID DUCTILE; ALLOY AB Creep tests were carried out over a range of temperatures (0.24 - 0.64 T-m) and stresses on samples of nanocrystalline Cu, Pd, and Al-Zr made by inert gas condensation and compaction. The measured creep rates are two to four orders of magnitude smaller than the values predicted by the equation for Coble creep. At moderate temperatures, the creep rates are comparable or lower than the corresponding coarse-grain rates. Except for the tests performed at the highest homologous temperatures, all creep curves can be fit by the equation for logarithmic creep. The samples in the as-prepared state are highly twinned, and it is believed that the prevalence of low-energy grain boundaries together with inhibition of dislocation activity caused by the small grain sizes are responsible for the low strain rates. (C) 1997 Acta Metallurgica Inc. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Sanders, PG (reprint author), NORTHWESTERN UNIV,EVANSTON,IL 60208, USA. RI Weertman, Julia/B-7540-2009 NR 15 TC 84 Z9 91 U1 3 U2 27 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 433 EP 440 DI 10.1016/S0965-9773(97)00096-2 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900085 ER PT J AU Jankowski, AF Wall, MA Hayes, JP Alexander, KB AF Jankowski, AF Wall, MA Hayes, JP Alexander, KB TI Properties of boron/boron-nitride multilayers SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID THIN-FILMS; BORON; DEPOSITION; HARDNESS; SUPERLATTICES; SUBSTRATE; GROWTH AB Boron-Nitride films are of interest for their high hardness and wear resistant properties. Large intrinsic stresses and poor adhesion which often accompany high hardness materials can be moderated through the use of a layered structure. Alternate layers of boron (B) and boron-nitride (BN) are formed by modulating the composition of the sputter gas during deposition from a pure B target. The thin films are characterized with transmission electron microscopy to evaluate the microstructure and with nanoindentation to determine hardness. Layer pair spacing and continuity effects on hardness are evaluated for the B/BN films. (C) 1997 Acta Metallurgica Inc. C1 OAK RIDGE NATL LAB,MARTIN MARIETTA ENERGY SYST,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Jankowski, AF (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 21 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 467 EP 471 DI 10.1016/S0965-9773(97)00102-5 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900091 ER PT J AU Gray, GT Lowe, TC Cady, CM Valiev, RZ Aleksandrov, IV AF Gray, GT Lowe, TC Cady, CM Valiev, RZ Aleksandrov, IV TI Influence of strain rate & temperature on the mechanical response of ultrafine-grained Cu, Ni, AND Al-4Cu-0.5Zr SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID SEVERE PLASTIC-DEFORMATION; COPPER; SIZE AB In this paper the mechanical properties of three bulk ultrafine-grained (UFG) materials produced by Equal Channel Angular Pressing (EGA) are presented. Although the influence of strain rate and temperature on the mechanical behavior of pure Cu and Ni and a variety of their alloys has been extensively studied, the effect of strain rate and temperature on nanocrystalline materials remains poorly understood. In this paper the influence of strain rate, varied between 0.001 and similar to 4500 s(-1), and temperature on the compressive mechanical behavior of UFG- Cu, Ni, and Al-4Cu-0.5Zr is shown. The temperature and strain-rate sensitivity of all three metals was found to be significantly higher than that typical for annealed FCC polycrystalline metals. The yield strength values measured for the UFG-Cu and Ni were found to lie both above those extrapolated for classical Hall-Fetch data on these materials supporting the importance of substructure, in addition to average grain size, to yield strength. (C) 1997 Acta Metallurgica Inc. C1 UFA STATE AVIAT TECH UNIV,UFA,RUSSIA. RP Gray, GT (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 11 TC 122 Z9 123 U1 5 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 477 EP 480 DI 10.1016/S0965-9773(97)00104-9 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900093 ER PT J AU Makinson, JD Weins, WN Schalek, R Axtell, SC Wang, H Dinwiddie, RB AF Makinson, JD Weins, WN Schalek, R Axtell, SC Wang, H Dinwiddie, RB TI Isochronal annealing behavior of mechanically milled nanocrystalline copper based iron alloys SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF AB Powders of copper, with zero to 50 weight percent iron were mechanically milled for 20 hours in a SPEX 8000 high-energy ball mill. The milled powders were cold pressed into compacts and were isochronally annealed in vacuum to 605 degrees C. Room temperature thermal diffusivity and x-ray diffracting particle sizes were measured as a function of annealing temperature. The as-pressed specimens had an average diffracting crystallite size of 12 nm and a thermal diffusivity of 0.112 cm(2)/s for copper, which decreased to 0.013 cm(2)/s with the addition of 50% iron. After the five annealing steps, the diffusivity of the copper increased to 0.745 cm(2)/s while in the copper 50% iron increased to 0.146 cm(2)/s. (C) 1997 Acta Metallurgica Inc. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Makinson, JD (reprint author), UNIV NEBRASKA,CTR MAT RES & ANAL,DEPT MECH ENGN,LINCOLN,NE 68588, USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 5 TC 0 Z9 0 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 519 EP 522 DI 10.1016/S0965-9773(97)00114-1 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900103 ER PT J AU Keblinski, P Phillpot, SR Wolf, D Gleiter, H AF Keblinski, P Phillpot, SR Wolf, D Gleiter, H TI Relationship between nanocrystalline and amorphous microstructures by molecular dynamics simulation SO NANOSTRUCTURED MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Conference on Nanostructured Materials CY JUL 08-12, 1996 CL KONA, HI SP NIST, ONR, DOE, XEROX, ELSEVIER, ACTA METALLURGICA, NSF ID GRAIN-BOUNDARIES; SILICON AB A recently developed molecular-dynamics simulation method for the growth of fully dense nanocrystalline materials by crystallization from the melt was used together with the Stillinger-Weber three-body potential to synthesize nanocrystalline silicon with a grain size up to 75 Angstrom. The structures of the highly-constrained grain boundaries (GBs), triple lines and point grain junctions were found to be highly disordered and similar to the structure of amorphous silicon. These and our earlier results for fcc metals suggest that a nanocrystalline microstructure may be viewed as a two-phase system, namely an ordered crystalline phase in the grain interiors connected by an amorphous, intergranular, glue-like phase. The analysis of the structures of bicrystalline GBs in the same materials reveals the presence of an amorphous intergranular equilibrium phase only in the high-energy but not the low-energy GBs, suggesting that only high-energy boundaries are present in nanocrystalline microstructures. (C) 1997 Acta Metallurgica Inc. C1 FORSCHUNGSZENTRUM KARLSRUHE,D-76021 KARLSRUHE,GERMANY. RP Keblinski, P (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 25 TC 17 Z9 18 U1 3 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PY 1997 VL 9 IS 1-8 BP 651 EP 660 DI 10.1016/S0965-9773(97)00144-X PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XB969 UT WOS:A1997XB96900133 ER PT J AU Brenner, JR Harkness, JBL Knickelbein, MB Krumdick, GK Marshall, CL AF Brenner, JR Harkness, JBL Knickelbein, MB Krumdick, GK Marshall, CL TI Microwave plasma synthesis of carbon-supported ultrafine metal particles SO NANOSTRUCTURED MATERIALS LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; IRON PARTICLES; MAGNETIC-PROPERTIES; COBALT CATALYSTS; RHODIUM; FE; CO2-LASER; NICKEL; NANOPARTICLES; PYROLYSIS AB Microwave plasma decomposition of metal carbonyls has been used to synthesize a series of carbon-supported monometallic (Fe, Co) and bimetallic (Go-Mo) materials. The average metal particle diameters in all cases were less than 10 nm. By using 10% H-2/Ar instead of pure Ar as a carrier gas, the mean particle diameters could be decreased to less than 2 nm. Although the distribution of particles is slightly broader than those generated by other nanoparticle synthesis methods, the mean diameter of the particles generated using 10% H-2/Ar is as small as any previously reported for Fe-, Co-, Ni-, or Mo-containing compounds. The ultrafine metal particles were dispersed on moderate surface area amorphous carbon support matrixes derived from the concomitant microwave decomposition of the toluene solvent. RP Brenner, JR (reprint author), ARGONNE NATL LAB,CHEM & ENERGY SYST DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Marshall, Christopher/D-1493-2015 OI Marshall, Christopher/0000-0002-1285-7648 NR 69 TC 26 Z9 30 U1 2 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JAN-FEB PY 1997 VL 8 IS 1 BP 1 EP 17 DI 10.1016/S0965-9773(97)00071-8 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA WP914 UT WOS:A1997WP91400001 ER PT J AU Altoe, MVP Echer, CE Thomas, G AF Altoe, MVP Echer, CE Thomas, G TI TEM study of nanocrystalline NdFeB SO NANOSTRUCTURED MATERIALS LA English DT Article ID PERMANENT AB A detailed study is reported of the microstructure in a nanocrystalline alloy, Nd4Fe78B18, consisting of a mixture of hard (Nd2Fe14B) and soft (Fe3B) magnetic phases, utilizing conventional and analytical transmission electron microscopy (TEM). The nanocrystalline microstructures were fabricated by annealing the melt-spun amorphous Nd4Fe78B18 ribbons by means of conventional (furnace) annealing techniques and also by the so-called flash-annealing process. Enhanced remanence and coercivity were reported previously for the flash-annealed alloys. Furnace-annealed ribbons contained 20-30 nm equiaxed grains with Fe/Nd = 17-19.6. Also observed were large (50-100 nm) equiaxed grains of alpha-Fe. For flash-annealed ribbons, significant amounts of Nd2Fe23B3, a metastable cubic phase, were observed, as well as a marked difference in the second phase morphology. For the flash-annealed ribbon whose hysteresis loop showed good coupling of the magnetic phases, a refined microstructure was found and the large alpha-Fe grains were absent. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Altoe, MVP (reprint author), UNIV SAO PAULO,INST FIS,CP 66318,BR-05389970 SAO PAULO,BRAZIL. NR 5 TC 2 Z9 2 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JAN-FEB PY 1997 VL 8 IS 1 BP 19 EP 28 DI 10.1016/S0965-9773(97)00072-X PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA WP914 UT WOS:A1997WP91400002 ER PT B AU Shah, MB Rao, NSV Olman, V Uberbacher, EC Mann, RC AF Shah, MB Rao, NSV Olman, V Uberbacher, EC Mann, RC BE Works, G TI FaceID: A face detection and recognition system SO NATIONAL AND INTERNATIONAL LAW ENFORCEMENT DATABASES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on National and International Law Enforcement Databases CY NOV 19-20, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers, NIST, Off Natl Drug Control Policy, Oak Ridge Natl Lab, Sandia Natl Labs, Sci Applicat Int Corp, Harris Corp, MITRE Corp, Lawrence Livermore Natl Lab, Idaho Natl Engn Lab, Natl Inst Justice, US Customs, Fed Bur Investigat, Amer Soc Photogrammetry & Remote Sensing, Calif Peace Officers Assoc, Natl Forens Sci Technol Ctr DE face detection; face recognition; template matching; correlation coefficient; neural networks AB A face detection system that automatically locates faces in gray-level images is described. Also described is a system which matches a given face image with faces in a database. Face detection in an image is performed by template matching using templates derived from a selected set of normalized faces. Instead of using original gray level images, vertical gradient images were calculated and used to make the system more robust against variations in lighting conditions and skin color. Faces of different sizes are detected by processing the image at several scales. Further, a coarse-to-fine strategy is used to speed up the processing, and a combination of whole face and face component templates are used to ensure low false detection rates. The input to the face recognition system is a normalized vertical gradient image of a face, which is compared against a database using a set of pretrained feedforward neural networks with a winner-take-all fuser. The training is performed by using an adaptation of the backpropagation algorithm. This system has been developed and tested using images from the FERET(8) database and a set of images obtained from Rowley, et al(9) and Sung and Poggio.(11) RP Shah, MB (reprint author), OAK RIDGE NATL LAB,DIV MATH & COMP SCI,INTELLIGENT SYST SECT,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2342-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 2940 BP 90 EP 99 DI 10.1117/12.266281 PG 10 WC Optics SC Optics GA BH27T UT WOS:A1997BH27T00009 ER PT J AU Pennypacker, C AF Pennypacker, C GP TERC TI Why do scientists want teachers and students to do real research? SO NATIONAL CONFERENCE ON STUDENT & SCIENTIST PARTNERSHIPS - CONFERENCE REPORT LA English DT Proceedings Paper CT National Conference on Student and Scientist Partnerships CY OCT 23-25, 1996 CL NATL ACAD SCI, WASHINGTON, DC SP TERC, Concord Consortium, Natl Sci Fdn HO NATL ACAD SCI RP Pennypacker, C (reprint author), LAWRENCE BERKELEY LAB,1 CYLOTON RD,BLDG 50,ROOM 232,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TERC SSP CONFERENCE PI CAMBRIDGE PA 2067 MASSACHUSETTS AVENUE, CAMBRIDGE, MA 02140 PY 1997 BP 48 EP 52 PG 3 WC Education, Scientific Disciplines SC Education & Educational Research GA BJ19R UT WOS:A1997BJ19R00007 ER PT J AU Pennypacker, C AF Pennypacker, C GP TERC TI Hands On Universe: Lawrence Berkeley Laboratory SO NATIONAL CONFERENCE ON STUDENT & SCIENTIST PARTNERSHIPS - CONFERENCE REPORT LA English DT Proceedings Paper CT National Conference on Student and Scientist Partnerships CY OCT 23-25, 1996 CL NATL ACAD SCI, WASHINGTON, DC SP TERC, Concord Consortium, Natl Sci Fdn HO NATL ACAD SCI RP Pennypacker, C (reprint author), LAWRENCE BERKELEY LAB,1 CYLOTON RD,BLDG 50,ROOM 232,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TERC SSP CONFERENCE PI CAMBRIDGE PA 2067 MASSACHUSETTS AVENUE, CAMBRIDGE, MA 02140 PY 1997 BP 75 EP 77 PG 3 WC Education, Scientific Disciplines SC Education & Educational Research GA BJ19R UT WOS:A1997BJ19R00014 ER PT J AU Pennypacker, C Rock, BN AF Pennypacker, C Rock, BN GP TERC TI Promoting partnerships for the good of science SO NATIONAL CONFERENCE ON STUDENT & SCIENTIST PARTNERSHIPS - CONFERENCE REPORT LA English DT Proceedings Paper CT National Conference on Student and Scientist Partnerships CY OCT 23-25, 1996 CL NATL ACAD SCI, WASHINGTON, DC SP TERC, Concord Consortium, Natl Sci Fdn HO NATL ACAD SCI RP Pennypacker, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BLDG 50,ROOM 232,1 CYLOTON RD,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TERC SSP CONFERENCE PI CAMBRIDGE PA 2067 MASSACHUSETTS AVENUE, CAMBRIDGE, MA 02140 PY 1997 BP 95 EP 97 PG 3 WC Education, Scientific Disciplines SC Education & Educational Research GA BJ19R UT WOS:A1997BJ19R00020 ER PT S AU Datye, AK Shroff, MD Harrington, MS Sault, AG Jackson, NB AF Datye, AK Shroff, MD Harrington, MS Sault, AG Jackson, NB BE dePontes, M Espinoza, RL Nicolaides, CP Scholtz, JH Scurrell, MS TI The role of catalyst activation on the activity and attrition of precipitated iron Fischer-Tropsch catalysts SO NATURAL GAS CONVERSION IV SE Studies in Surface Science and Catalysis LA English DT Article; Proceedings Paper CT 4th International Natural Gas Conversion Symposium CY NOV 19-23, 1995 CL KRUGER PK, SOUTH AFRICA SP AVIS, ROBERTSON, South African Airways, SASOL Pty Ltd, Sud Chem AG AB The role of activation treatments on catalyst activity was studied for a precipitated Fe2O3-CuO-K2O catalyst. In particular, it was shown that reduction of the catalyst to alpha-Fe yielded a catalyst that was inactive in F-T synthesis. The inactivity after severe H-2 reduction was traced to S migration to the surface of alpha-Fe. This S migration did not occur when the catalyst was reduced only to Fe3O4, wherein the S may remain in the bulk of the catalyst and therefore not affect catalyst activity. Catalyst activity was related to the formation of iron carbide during catalyst activation, hence CO activation yielded a catalyst with greater initial activity than H-2 or syngas activation. C1 UNIV NEW MEXICO, NSF, CTR MICROENGINEERED CERAM, ALBUQUERQUE, NM 87131 USA. SANDIA NATL LABS, PROC RES DEPT, ALBUQUERQUE, NM 87185 USA. RP Datye, AK (reprint author), UNIV NEW MEXICO, DEPT CHEM & NUCL ENGN, ALBUQUERQUE, NM 87131 USA. OI Datye, Abhaya/0000-0002-7126-8659 NR 9 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82352-2 J9 STUD SURF SCI CATAL PY 1997 VL 107 BP 169 EP 174 PG 6 WC Chemistry, Physical; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA BJ22F UT WOS:A1997BJ22F00023 ER PT S AU Balachandran, U Dusek, JT Maiya, PS Ma, B Mieville, RL Kleefisch, MS Udovich, CA Fleisch, TH Bose, AC AF Balachandran, U Dusek, JT Maiya, PS Ma, B Mieville, RL Kleefisch, MS Udovich, CA Fleisch, TH Bose, AC BE dePontes, M Espinoza, RL Nicolaides, CP Scholtz, JH Scurrell, MS TI Development of dense ceramic membranes for methane conversion SO NATURAL GAS CONVERSION IV SE Studies in Surface Science and Catalysis LA English DT Article; Proceedings Paper CT 4th International Natural Gas Conversion Symposium CY NOV 19-23, 1995 CL KRUGER PK, SOUTH AFRICA SP AVIS, ROBERTSON, South African Airways, SASOL Pty Ltd, Sud Chem AG AB The most significant cost associated with partial oxidation of methane to syngas is that of the oxygen plant. In this paper, we offer a technology, based on dense ceramic membranes, that uses air as the oxidant for methane conversion reactions, thus eliminating the need for the oxygen plant. Certain ceramic materials exhibit both electronic and ionic conductivities (of particular interest is oxygen-ion conductivity). These materials transport not only oxygen ions (functioning as selective oxygen separators) but also electrons back from the reactor side to the oxygen/reduction interface. No external electrodes are required, and, if the driving potential of transport is adequate, the partial oxidation reactions should be spontaneous. Such a system will operate without an externally applied potential. Oxygen is transported across the ceramic material in the form of oxygen ions, not oxygen molecules. Recent reports in the literature suggest that dense ceramic membranes made of these mixed conductors can successfully separate oxygen from air at flux rates that could be considered commercially feasible. Thus, these membranes have the potential to improve the economics of methane conversion processes [1-5]. In principle, the dense ceramic materials can be shaped into hollow-tube reactors, in which air passes over the outside of the membrane and methane flows through the inside. The surfaces can also be reversed. The membrane is permeable to oxygen at high temperatures, but not to nitrogen or other gases. Thus, only oxygen from air can be transported through the membrane to the inside of the reactor surface, where it reacts with methane. Other geometric forms, such as honeycombs or corrugations, of the reactor are possible and can provide substantially greater surface areas for reaction [6]. C1 AMOCO EXPLORAT PROD, NAPERVILLE, IL 60566 USA. US DOE, PITTSBURGH ENERGY TECHNOL CTR, PITTSBURGH, PA 15236 USA. RP Balachandran, U (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 13 TC 5 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82352-2 J9 STUD SURF SCI CATAL PY 1997 VL 107 BP 409 EP 414 PG 6 WC Chemistry, Physical; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA BJ22F UT WOS:A1997BJ22F00062 ER PT J AU Raves, ML Harel, M Pang, YP Silman, I Kozikowski, AP Sussman, JL AF Raves, ML Harel, M Pang, YP Silman, I Kozikowski, AP Sussman, JL TI Structure of acetylcholinesterase complexed with the nootropic alkaloid, (-)-huperzine A SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID ACTIVE-SITE GORGE; HUPERZINE-A; ANTICHOLINESTERASE ACTIVITY; MOLECULAR-DYNAMICS; BINDING; PROTEIN; INHIBITOR; CHOLINESTERASES; PARAMETERS; REFINEMENT AB (-)-Huperzine A (HupA) is found in an extract from a club moss that has been used for centuries in Chinese folk medicine. Its action has been attributed to its ability to strongly inhibit acetylcholinesterase (AChE), The crystal structure of the complex of AChE with optically pure HupA at 2.5 Angstrom resolution shows an unexpected orientation for the inhibitor with surprisingly few strong direct interactions with protein residues to explain its high affinity, This structure is compared to the native structure of AChE devoid of any inhibitor as determined to the same resolution, An analysis of the affinities of structural analogues of HupA, correlated with their interactions with the protein, shows the importance of individual hydrophobic interactions between HupA and aromatic residues in the active-site gorge of AChE C1 WEIZMANN INST SCI,DEPT BIOL STRUCT,IL-76100 REHOVOT,ISRAEL. WEIZMANN INST SCI,DEPT NEUROBIOL,IL-76100 REHOVOT,ISRAEL. GEORGETOWN UNIV,SCH MED,INST COGNIT & COMPUTAT SCI,WASHINGTON,DC 20007. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. OI Sussman, Joel/0000-0003-0306-3878 NR 45 TC 303 Z9 321 U1 3 U2 27 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JAN PY 1997 VL 4 IS 1 BP 57 EP 63 DI 10.1038/nsb0197-57 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WA810 UT WOS:A1997WA81000016 PM 8989325 ER PT S AU Ceplecha, Z Jacobs, C Zaffery, C AF Ceplecha, Z Jacobs, C Zaffery, C BE Remo, JL TI Correlation of ground- and space-based bolides SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs ID METEOROIDS; INFLUX; EARTH AB Data on large meteoroid impacts into the Earth's atmosphere are available up to over ten meter sizes from global satellite observations by optical sensors, while data from ground-based photographic observations of meteoric fireballs (bolides) are available only up to meter sizes. However, the ground-based observations yield very precise data on the motion and ablation of these bodies, as well as their light curves. The space-based observations yield very precise light curves. Using data of the brightest Prairie Network bolides, ablation coefficients are determined for 48 bolides brighter than magnitude -10 and compared to relative time changes of their brightness. This way the known classification scheme for photographic bolides (based mostly on observed ablation coefficient) is related to maximum increase and decrease of their brightness. The same classification scheme is applied to 16 light curves of somewhat larger bodies observed globally by DOD satellites. Size range of these bodies is found to be from 2 to 15 m with median value of 3 to 4 m. Only separation of type I + II (38%) from type IIIA + IIIB (62%) is possible. Increase of relative strength of populations of cometary meteoroids (namely of the IIIB type) observed for photographic meteors up to a size of 5 m continues to larger sizes up to 15 m. Majority of meteoroids in the size range from 2 to 15 m are cometary bodies with the weakest known structure. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP Ceplecha, Z (reprint author), ACAD SCI CZECH REPUBL, ONDREJOV 25165, CZECH REPUBLIC. NR 13 TC 6 Z9 6 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 145 EP 154 DI 10.1111/j.1749-6632.1997.tb48339.x PG 10 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00012 ER PT S AU Crawford, DA AF Crawford, DA BE Remo, JL TI Comet Shoemaker-Levy 9 fragment size estimates: How big was the parent body? SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs ID JUPITER; COLLISION; ATMOSPHERE; IMPACT AB The impact of Comet Shoemaker-Levy 9 on Jupiter in July, 1994 was the largest, most energetic impact event on a planet ever witnessed. Because it broke up during a close encounter with Jupiter in 1992, it was bright enough to be discovered more than a year prior to impact, allowing the scientific community an unprecedented opportunity to assess the effects such an event would have. Many excellent observations were made from Earth-based telescopes, the Hubble Space Telescope (HST), and the Galileo spacecraft en route to Jupiter. In this paper, these observations are used in conjunction with computational simulations performed with the CTH shock-physics hydrocode to determine the sizes of the fifteen fragments that made discernible impact features on the planet. To do this, CTH was equipped with a radiative ablation model and a postprocessing radiative ray-trace capability that enabled light-flux predictions (often called the impact flash) for the viewing geometries of Galileo and ground-based observers. The five events recorded by Galileo were calibrated to give fragment size estimates. Compared against ground-based and HST observations, these estimates were extended using a least-squares analysis to assess the impacts of the remaining ten fragments. Some of the largest impacts (L, G, and K) were greater that 1 km in diameter, but the density of the fragments was low, about 0.25 g/cm(3). The volume of the combined fifteen fragments would make a sphere 1.8 km in diameter. Assuming a prebreakup density of 0.5 g/cm(3), the parent body of Shoemaker-Levy 9 had a probable diameter of 1.4 km. The total kinetic energy of all the impacts was equivalent to the explosive yield of 300 Gigatons of TNT. RP Crawford, DA (reprint author), SANDIA NATL LABS, COMPUTAT PHYS & MECH DEPT, POB 5800, MS 0820, ALBUQUERQUE, NM 87185 USA. NR 26 TC 21 Z9 21 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 155 EP 173 DI 10.1111/j.1749-6632.1997.tb48340.x PG 19 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00013 ER PT S AU Boslough, MBE Crawford, DA AF Boslough, MBE Crawford, DA BE Remo, JL TI Shoemaker-Levy 9 and plume-forming collisions on Earth SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs ID COMET SHOEMAKER-LEVY-9; NUMERICAL SIMULATIONS; G-IMPACT; JUPITER; TELESCOPE; METEORITE; EXPLOSION; SIGNATURE; FIREBALL; WAVES AB Computational models for the July, 1994 collision of comet Shoemaker-Levy 9 with Jupiter have provided a framework for interpreting the observational data. Imaging, photometry, and spectroscopy data from ground-based, Hubble Space Telescope, and Galileo spacecraft instruments are consistent with phenomena that were dominated by the generation of incandescent fireballs that were ballistically ejected to high altitudes, where they formed plumes that subsequently collapsed over large areas of Jupiter's atmosphere. Applications of similar computational models to collisions into Earth's atmosphere show that a very similar sequence of events should take place for NEO impacts with energies as low as 3 megatons, recurring on 100 year timescales or less. This result suggests that the 1908 Tunguska event was a plume-forming atmospheric explosion, and that some of the phenomena associated with it might be related to the ejection and collapse of a high plume. Hazards associated with plume growth and collapse should be included in the evaluation of the impact threat to Earth, and opportunities should be sought for observational validation of atmospheric impact models by exploiting data already being collected from the natural flux of multikiloton to megaton sized objects that constantly enter Earth's atmosphere on annual to decadal timescales. RP Boslough, MBE (reprint author), SANDIA NATL LABS, DEPT COMPUTAT PHYS & MECH, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 80 TC 29 Z9 29 U1 2 U2 2 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 236 EP 282 DI 10.1111/j.1749-6632.1997.tb48345.x PG 47 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00018 ER PT S AU Revelle, DO AF Revelle, DO BE Remo, JL TI Historical detection of atmospheric impacts by large bolides using acoustic-gravity waves SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs ID EARTH; METEOROIDS; ASTEROIDS AB During the period from about 1960 to the early 1980's a number of large bolides (meteor-fireballs) entered the atmosphere which were sufficiently large to generate blast waves during their drag interaction with the air. For example, the remnant of the blast wave from a single kiloton class event was subsequently detected by up to six ground arrays of microbarographs which were operated by the U.S. Air Force during this presatellite period. Data have also been obtained from other sources during this period as well and are also discussed in this summary of the historical data. The Air Force data have been analyzed in terms of their observable properties in order to infer the influx rate of NEOs (near-Earth objects) in the energy range from 0.2 to 1100 kt. The determined influx is in reasonable agreement with that determined by other methods currently available such as Rabinowitz [21], Ceplecha[4], [5] and by Chapman and Morrison [8] despite the fact that due to sampling deficiencies only a portion of the ''true'' flux of large bodies has been obtained by this method, i.e., only sources at relatively low elevations have been detected. Thus the weak, fragile cometary bodies which do not penetrate the atmosphere as deeply are less likely to have been sampled by this type of detection system. Future work using the proposed CTBT (Comprehensive Test Ban Treaty) global scale infrasonic network will be likely to improve upon this early estimate of the global influx of NEOs considerably. RP Revelle, DO (reprint author), LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, LOS ALAMOS, NM 87545 USA. NR 46 TC 59 Z9 59 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 284 EP 302 DI 10.1111/j.1749-6632.1997.tb48347.x PG 19 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00020 ER PT S AU Hills, JG Mader, CL AF Hills, JG Mader, CL BE Remo, JL TI Tsunami produced by the impacts of small asteroids SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs AB The fragmentation of a small asteroid in the atmosphere greatly increases its cross section for aerodynamic braking, so ground impact damage (craters, earthquakes, and tsunami) from a stone asteroid is nearly negligible if it is less than 200 meters in diameter. A larger one impacts the ground at nearly its velocity at the top of the atmosphere producing considerable impact damage. The protection offered by Earth's atmosphere is insidious in that smaller, more frequent impactors such as Tunguska only produce air blast damage and leave no longterm scars on the Earth's surface, while objects 2.5 times larger than it, which hit every few thousand years, cause coherent destruction over many thousands of kilometers of coast. Smaller impactors give no qualitative warning of the enormous destruction wrought when an asteroid larger than the threshold diameter of 200 meters hits an ocean. A water wave generated by an impactor has a long range because it is two-dimensional, so its height falls off inversely with distance from the impact. When the wave strikes a continental shelf, its speed decreases and its height increases to produce tsunamis. The average runup in height between a deep-water wave and its tsunami is more than an order of magnitude. Tsunamis produce most of the damage from asteroids with diameters between 200 meters and 1 km. An impact anywhere in the Atlantic by an asteroid 400 meters in diameter would devastate the coasts on both sides of the ocean by tsunami over 100 meters high. An asteroid 5 km in diameter hitting in mid Atlantic would produce tsunami that would inundate the entire upper East Coast of the United States to the Appalachian Mountains. Studies of ocean sediments may be used to determine when coastal areas have been hit by tsunamis in the past. Tsunami debris has been found to be associated with the Cretaceous-Tertiary impact and should be detectable for smaller impacts. RP Hills, JG (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 19 TC 29 Z9 29 U1 0 U2 7 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 381 EP 394 DI 10.1111/j.1749-6632.1997.tb48352.x PG 14 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00025 ER PT S AU Toon, OB Zahnle, K Morrison, D Turco, RP Covey, C AF Toon, OB Zahnle, K Morrison, D Turco, RP Covey, C BE Remo, JL TI Environmental perturbations caused by the impacts of asteroids and comets SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs C1 UNIV CALIF LOS ANGELES, LOS ANGELES, CA 90095 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Toon, OB (reprint author), NASA, AMES RES CTR, MS 245-3, MOFFETT FIELD, CA 94035 USA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 401 EP 402 DI 10.1111/j.1749-6632.1997.tb48357.x PG 2 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00030 ER PT S AU Powell, J Maise, G Ludewig, H Todosow, M AF Powell, J Maise, G Ludewig, H Todosow, M BE Remo, JL TI High-performance ultra-light nuclear rockets for near-earth objects interaction missions SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs AB The performance capabilities and technology features of ultra compact nuclear thermal rockets based on very high power density (30 Megawatts per liter) fuel elements are described. Nuclear rockets appear particularly attractive for carrying out missions to investigate or intercept near-Earth objects (NEOs) that potentially could impact on the Earth. Many of these NEO threats, whether asteroids or comets, have extremely high closing velocities, i.e., tens of kilometers per second relative to the Earth. Nuclear rockets using hydrogen propellant enable flight velocities 2 to 3 times those achievable with chemical rockets, allowing interaction with a potential NEO threat at a much shorter time, and at much greater range. Two versions of an ultra compact nuclear rocket based on very high heat transfer rates are described: the PBR (Particle Bed Reactor), which has undergone substantial hardware development effort, and MITEE (MIniature ReacTor EnginE) which is a design derivative of the PBR. Nominal performance capabilities for the PBR are: thermal power similar or equal to 1000 MW thrust similar or equal to 45,000 lbsf, and weight similar or equal to 500 kg. For MITEE, nominal capabilities are: thermal power 100 MW; thrust similar or equal to 4500 lbsf, and weight similar or equal to 50 kg. Development of operational PBR/MITEE systems would enable spacecraft launched from LEO (low-Earth orbit) to investigate intercept NEO's at a range of similar to 100 million kilometers in times of similar to 30 days. RP Powell, J (reprint author), BROOKHAVEN NATL LAB, DEPT ADV TECHNOL, UPTON, NY 11973 USA. NR 6 TC 4 Z9 4 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 447 EP 467 DI 10.1111/j.1749-6632.1997.tb48360.x PG 21 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00033 ER PT S AU Canavan, GH AF Canavan, GH BE Remo, JL TI Optimal detection of near-earth object threats SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs AB Detection of near-Earth Objects (NEOs) has concentrated on search at long range. Improved technology and search strategies could significantly increase search rates and decrease survey times. RP Canavan, GH (reprint author), LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 539 EP 543 DI 10.1111/j.1749-6632.1997.tb48364.x PG 5 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00037 ER PT S AU Shafer, BP Garcia, MD Managan, RA Remo, JL Rosenkilde, CE Scammon, RJ Snell, CM Stellingwerf, RF AF Shafer, BP Garcia, MD Managan, RA Remo, JL Rosenkilde, CE Scammon, RJ Snell, CM Stellingwerf, RF BE Remo, JL TI Momentum coupling to NEOs SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs AB We considered the coupling of momentum to near-Earth objects (NEOs) for the purposes of collision avoidance or collision damage mitigation through trajectory modification. The momentum sources considered were pulsed lasers, kinetic energy impactors, and nuclear (or conventional) explosives, detonated above or below the surface of the NEO by the nonnuclear and nuclear momentum sources listed above. We did not address the system tradeoffs or the environmental implications of momentum source delivery. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. QUANTAMETR INC, ST JAMES, NY 11780 USA. RP Shafer, BP (reprint author), LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 8 TC 8 Z9 8 U1 1 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 552 EP 565 DI 10.1111/j.1749-6632.1997.tb48367.x PG 14 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00040 ER PT S AU Furnish, MD Remo, JL AF Furnish, MD Remo, JL BE Remo, JL TI Ice issues, porosity, and snow experiments for dynamic NEO and comet modeling SO NEAR-EARTH OBJECTS: UNITED NATIONS INTERNATIONAL CONFERENCE SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT International Conference on Near-Earth Objects CY APR 24-26, 1995 CL NEW YORK, NY SP Amer Museum Nat Hist, Explorers Club, NASA, Planetary Soc, Quantametrics Inc, Sandia Natl Labs, UN Off Outer Space Affairs AB Category 0 NEO bodies, such as many comets, appear to be comprised largely of porous ice. Quasi-static and dynamic properties of ice are expected to control the corresponding properties of Category 0 NEO material. These properties depend on temperature, strain rate, and possibly sample history. Corrections must be made for porosity and the presence of impurities such as silicates. These corrections reflect the added complexity of energy partitioning in a porous, inhomogeneous material as well as added P.Delta V work during compression. A study of the dymanic (shock) properties of natural snow over the stress range 0-4 GPa is described. Comparison of the results of this study with computational modeling suggests that existing ice models with introduced porosity are applicable in some regimes, while water models with introduced porosity provide better fidelity in other regimes. C1 QUANTAMETR INC, ST JAMES, NY 11780 USA. RP Furnish, MD (reprint author), SANDIA NATL LABS, INSTRUMENTAT DEV DEPT, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 32 TC 2 Z9 2 U1 0 U2 0 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-040-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 822 BP 566 EP 582 DI 10.1111/j.1749-6632.1997.tb48368.x PG 17 WC Astronomy & Astrophysics; Multidisciplinary Sciences SC Astronomy & Astrophysics; Science & Technology - Other Topics GA BJ16N UT WOS:A1997BJ16N00041 ER PT J AU Gifford, AN Gardner, EL Ashby, CR AF Gifford, AN Gardner, EL Ashby, CR TI The effect of intravenous administration of delta-9-tetrahydrocannabinol on the activity of A10 dopamine neurons recorded in vivo in anesthetized rats SO NEUROPSYCHOBIOLOGY LA English DT Article DE cannabis; cannabinoid; delta-9-tetrahydrocannabinol; dopamine; ventral tegmental area; electrophysiology; reinforcement; reward ID FREELY MOVING RATS; FIRING PATTERN AB In this pilot study, we examined the effect of the intravenous administration of delta-9-tetrahydrocannabinol (THC) on the activity of spontaneously active A10 dopamine (DA) neurons of anesthetized, male albino rats, This was accomplished using the technique of in vivo extracellular single-unit recording, The administration of THC (0.05-1.6 mg/kg i,v,) did not significantly alter either the basal firing rate or the firing pattern of spontaneously active A10 DA neurons compared to vehicle controls. Our findings suggest that, unlike a number of drugs of abuse, THC does not alter the activity of A10 DA neurons and that the previously reported THC-induced increase in brain DA levels is not due to its action on firing rate or pattern in A10 DA neurons. C1 ST JOHNS UNIV,PHS DEPT,JAMAICA,NY 11439. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. ALBERT EINSTEIN COLL MED,DEPT PSYCHIAT,BRONX,NY 10467. ALBERT EINSTEIN COLL MED,DEPT NEUROSCI,BRONX,NY 10467. FU NIDA NIH HHS [R01 DA03622]; NIMH NIH HHS [R29 MH52155] NR 15 TC 20 Z9 21 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0302-282X J9 NEUROPSYCHOBIOLOGY JI Neuropsychobiology PY 1997 VL 36 IS 2 BP 96 EP 99 DI 10.1159/000119369 PG 4 WC Neurosciences; Psychiatry; Psychology SC Neurosciences & Neurology; Psychiatry; Psychology GA XQ676 UT WOS:A1997XQ67600008 PM 9267859 ER PT B AU Harker, YD Nigg, DW Mitchell, HE Wheeler, FJ Jones, JL AF Harker, YD Nigg, DW Mitchell, HE Wheeler, FJ Jones, JL BE Vourvopoulos, G TI Neutron sources for BNCT using low-power research reactors or compact charged particle accelerators SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Since 1986, the Idaho National Engineering Laboratory (INEL) has been involved in the development of. epithermal neutron sources for BNCT. The INEL effort was instrumental in the implementation of an epithermal neutron beam at the Brookhaven Medical Research Reactor at Brookhaven National Laboratory. Recently, the INEL's effort has been directed toward developing advanced filter designs for use with low-power research reactors such as the 250kW and 1MW class TRIGA reactors which are located at various sites and universities throughout the world. This work has focused on utilizing advanced filter materials that more effectively reduce fast neutron contamination in the epithermal neutron beam and at the same time optimize neutron economy. The INEL has also been involved in developing two concepts of producing neutron sources for BNCT using charged particle accelerators. The first concept involves the use of an electron accelerator/photoneutron source. The second concept involves the use of a charged particle beam (proton or deuteron) in which the particle energy is just above the threshold energy of the [p (or d), n] reaction. This paper will a review of the progress made by INEL in modifying the WSU TRIGA reactor and conceptual development of an electron accelerator based photoneutron source for BNCT. The near threshold particle accelerator development will be discussed in a separate paper at this conference. RP Harker, YD (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 48 EP 54 DI 10.1117/12.267933 PG 7 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00007 ER PT B AU Harker, YD Harmon, F Seamans, J Serrano, S Trammell, W Yost, L Zhou, XL Hamm, R AF Harker, YD Harmon, F Seamans, J Serrano, S Trammell, W Yost, L Zhou, XL Hamm, R BE Vourvopoulos, G TI Accelerator neutron sources for neutron capture therapy using near threshold charged particle reactions SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Compact neutron sources for neutron capture therapy hold the promise of permitting wide availability for this therapeutic modality for cancer treatment. Most accelerator based neutron source concepts for this purpose are centered on (p,n) reactions using bombarding energies several hundred keV to 1-2 MeV above the reaction threshold producing high neutron yield. The neutron energies in the range of hundreds of keV to 1-2 MeV require considerable moderation and/or filtration, which reduces the output epithermal neutron flux, and fast neutron contamination is always present. Operating with proton energies closer to the threshold decreases neutron yield but allows for smaller, more efficient filters and moderators, which results in less reduction of the epithermal flux by the moderator/filter assembly. Work by this collaboration is examining the balance between total neutron yield and filter/moderator efficiency in order to achieve intense epithermal beams with low fast neutron contamination. As the first stage of this project, neutron yield and spectrum measurements on Be-9(p,n) and Li-7(p,n) reactions have been made and the results will be presented along with neutronic calculations for these systems. A radio frequency quadrupole accelerator is being used in this work. RP Harker, YD (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 80 EP 83 DI 10.1117/12.267872 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00014 ER PT B AU Bourke, MAM Dunand, DC Lawson, AC Priesmeyer, HG AF Bourke, MAM Dunand, DC Lawson, AC Priesmeyer, HG BE Vourvopoulos, G TI Phase transformations in engineering materials SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos DE phase transformation; pulsed neutrons; engineering materials; superelastic; martensitic AB Phase transformations in engineering materials are inevitably related to mechanical behaviour and are often precursors to residual stress and distortion. Neutron scattering in general is a valuable tool for studying their effects, and pulsed neutrons are of special value, because of the inherently comprehensive crystallographic coverage they provide in each measurement. At the Manuel Lujan neutron scattering center several different research programs have addressed the relationships between phase transformation / mechanical behaviour and residual strains. Three disparate examples are presented; 1) Stress induced transformation in a NiTi shape memory alloy, 2) Cryogenically induced transformation in a quenched 5180 steel, and 3) Time resolved evolution of strain induced martensite in 304 stainless steel. In each case a brief description of the principal result will be discussed in the context of using neutrons for the measurement. RP Bourke, MAM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 131 EP 135 DI 10.1117/12.267883 PG 5 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00024 ER PT B AU Bourke, MAM Roberts, JA Davis, D AF Bourke, MAM Roberts, JA Davis, D BE Vourvopoulos, G TI Macrostrain measurement using radial collimators at LANSCE SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos DE neutron; macrostrain; radial collimators; NPD; sampling volume AB A series of ''short'' radial collimators have been implemented in the 90 degrees scattering geometries on the neutron powder diffractometer at Los Alamos. The capability to perform macrostrain measurements has been improved by the commensurate ability to rapidly select a sampling volume appropriate to the specimen. The compact design of the collimators was dictated by the need to fit them in a cylindrical vacuum chamber as well as providing space in which to manipulate a specimen in three dimensions. Collimators of different vane lengths were fabricated to give 4 different resolutions for which 2/3 of the diffracted intensity comes from distances of 0.75, 1.25, 2.5 and 4mm along the incident beam. Qualifying scans and a demonstration on a cracked ring, containing a steep stress gradient, are included. RP Bourke, MAM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 136 EP 139 DI 10.1117/12.267884 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00025 ER PT B AU Hjelm, RP Wampler, W Gerspacher, M AF Hjelm, RP Wampler, W Gerspacher, M BE Vourvopoulos, G TI The structure of carbon black-elastomer composites by small-angle neutron scattering and the method of contrast variation SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB We have been exploring the use of small-angle neutron scattering and the method of contrast variation to give a new look at very old problem-reinforcement of elastomers by carbon black in durable rubber products. Carbon black has a hierarchy of structures consisting of particles covalently bound into aggregates, which in turn associate by weak interactions into agglomerates. We found that in one carbon black, HSA, the aggregates are rod-like, containing an average of 4-6 particles. The aggregates have an outer graphitic shell and an inner core of lower density carbon. The core is continuous throughout the carbon black aggregate. Contrast variation of swollen HSA-polyisoprene gels shows that the HSA is completely embedded in polyisoprene and that the agglomerates are formed predominantly by end on associations of the rodlike aggregates. The surface structure of the carbon black appears smooth over length scales above about 10 Angstrom. Further studies using production carbon blacks suggest that these structural characteristics are generally present in commercial rubber composites. RP Hjelm, RP (reprint author), LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. RI Lujan Center, LANL/G-4896-2012 NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 144 EP 147 DI 10.1117/12.267886 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00027 ER PT B AU Harker, YD Blackwood, LG Yoon, WY Meachum, TR AF Harker, YD Blackwood, LG Yoon, WY Meachum, TR BE Vourvopoulos, G TI Performance evaluation of the Passive Active Neutron (PAN) radioassay system at Idaho National Engineering Laboratory SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos DE NDA; neutron; assay; plutonium; TRU; waste; PAN AB The Idaho National Engineering Laboratory is using the Passive Active Neutron (PAN) radioassay system to assay 208 liter drums for plutonium in transuranic waste. PAN systems similar to INEL's are in use to perform like tasks at other U. S. DOE sites and later versions of the PAN are in use throughout the world. The PAN system, developed by Los Alamos National Laboratory, uses both passive neutron coincidence counting and thermal neutron interrogation/differential die-away to determine the amount of plutonium (or uranium) in a waste drum. This paper discusses a modified statistical sampling and verification approach to determine the total uncertainty of a PAN system measurement when applied in the assay of real waste. In this approach a statistical review is performed on real waste drum radiographs, waste generator data and PAN assay data to identify the variations of the physical, chemical and measurement characteristics pertaining to a waste category. Using data from the statistical review, the performance of the PAN assay system is simulated using computer models of the assay system with regard to the waste form under review. The simulated responses, in terms of plutonium mass in these cases, are compared with the known input masses to assess total uncertainty. To demonstrate the method, the results of this approach will be presented for PAN measurements on two waste categories at INEL. RP Harker, YD (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 198 EP 201 DI 10.1117/12.267898 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00038 ER PT B AU Jones, JL AF Jones, JL BE Vourvopoulos, G TI Detection of pulsed, bremsstrahlung-induced, prompt neutron capture gamma-rays with a HPGe detector SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB The Idaho National Engineering Laboratory (INEL) is developing a novel photoneutron-based nondestructive evaluation technique which uses a pulsed, high-energy (up to 8-MeV) electron accelerator and gamma-ray spectrometry. Highly penetrating pulses of bremsstrahlung photons are produced by each pulse of electrons. Interrogating neutrons are generated by the bremsstrahlung photons interacting within a photoneutron source material. The interactions of the neutrons within a target result in the emission of elemental characteristic gamma-rays. Spectrometry is performed by analyzing the photoneutron-induced, prompt gamma-rays acquired between accelerator pulses with a unique, high-purity germanium (HPGe) gamma-ray detection system using a modified transistor reset preamplifier. The detection system, the experimental configuration, and the accelerator operation used to characterize the detection system performance are described. Using a 6.5-MeV electron accelerator and a beryllium metal photoneutron source, gamma-ray spectra were successfully acquired for Al, Cu, polyethylene, NaCl, and depleted uranium targets as soon as 30 mu s after each bremsstrahlung (or x-ray) flash. RP Jones, JL (reprint author), IDAHO NATL ENGN LAB,POB 1625,MS 2802,IDAHO FALLS,ID 83415, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 202 EP 205 DI 10.1117/12.267899 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00039 ER PT B AU Sagalovsky, L Smith, DL Micklich, BJ Fink, CL Yule, TJ AF Sagalovsky, L Smith, DL Micklich, BJ Fink, CL Yule, TJ BE Vourvopoulos, G TI Application of Bayesian statistical analysis to illicit substance detection using non-destructive interrogation techniques SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Non-destructive interrogation systems designed to locate illicit substances in sealed containers involve decision making when the available objective information is incomplete. The greater the quantity of information, the more reliable is the determination of the unknown content. Therefore, it is important to be able to utilize all possible measured data pertaining to the unknown object. Among the data which can be considered are X-ray measurements, fast-neutron transmission measurements, cargo manifest data and, possibly, information of a physical, chemical or even psychological nature. The Bayesian approach provides a statistical framework for merging diverse information about any object, including a priori knowledge, subjective knowledge and objective knowledge gained from current measurements. This paper outlines the fundamental principles of Bayesian analysis and explores possible applications to the detection of illicit substances. RP Sagalovsky, L (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 227 EP 230 DI 10.1117/12.267906 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00045 ER PT B AU Yule, TJ Micklich, BJ Fink, CL Sagalovsky, L AF Yule, TJ Micklich, BJ Fink, CL Sagalovsky, L BE Vourvopoulos, G TI Fast neutron transmission spectroscopy for illicit substance detection SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Fast-Neutron Transmission Spectroscopy (FNTS) is being investigated for detection of explosives in luggage or other small containers. This technique uses an accelerator to generate nanosecond-pulsed deuteron beams that strike a target, producing a white source of neutrons. Elemental distributions along projections through the interrogated object are obtained by analyzing neutron transmission data. Tomographic reconstruction is used to determine the spatial variations of individual elemental densities. Elemental densities are combined in a detection algorithm that indicates the presence or absence of explosives. The elemental unfolding and tomographic reconstruction algorithms have been validated by application to experimental data. System studies have been performed to study the operational characteristics and limitations of a FNTS system, and to determine the system's sensitivity to several important parameters such as flight path length and the position of the interrogated object. RP Yule, TJ (reprint author), ARGONNE NATL LAB,TECHNOL DEV DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 239 EP 242 DI 10.1117/12.267909 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00048 ER PT B AU Gavron, A Morley, K Morris, C Seestrom, S Ullmann, J Yates, G Zumbro, J AF Gavron, A Morley, K Morris, C Seestrom, S Ullmann, J Yates, G Zumbro, J BE Vourvopoulos, G TI High energy neutron radiography SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. We discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos. RP Gavron, A (reprint author), LOS ALAMOS NATL LAB,MS E540,LOS ALAMOS,NM 87545, USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 326 EP 331 DI 10.1117/12.267925 PG 6 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00064 ER PT B AU Morris, C Armijo, V Atencio, LG Bridge, A Gavron, A Hart, G Morley, K Mottershead, T Yates, GJ Zumbro, J AF Morris, C Armijo, V Atencio, LG Bridge, A Gavron, A Hart, G Morley, K Mottershead, T Yates, GJ Zumbro, J BE Vourvopoulos, G TI An integrating image detector for high energy neutrons SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB We describe an integrating cathode-pad read-out wire chamber for imaging high energy neutrons. This technology allows construction of a detector with a wide dynamic range (10(4)), which is gatable, easily read out, and provides millimeter scale resolution. Results from a prototype 48 x 48 pixel array are presented. RP Morris, C (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 351 EP 357 DI 10.1117/12.267930 PG 7 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00069 ER PT B AU Seestrom, SJ Bowman, JD Crawford, BE Delheij, PPJ Haseyama, T Knudson, JN Lowie, LY Masaike, A Matsuda, Y Mitchell, GE Roberson, NR Penttila, S Popov, YP Postma, H Sharapov, EI Stephenson, S Yen, YF Yuan, V AF Seestrom, SJ Bowman, JD Crawford, BE Delheij, PPJ Haseyama, T Knudson, JN Lowie, LY Masaike, A Matsuda, Y Mitchell, GE Roberson, NR Penttila, S Popov, YP Postma, H Sharapov, EI Stephenson, S Yen, YF Yuan, V BE Vourvopoulos, G TI Study of parity nonconservation with epithermal neutrons SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB I describe a new generation of experiments studying the weak interaction between nucleons. Measurements of the effect of this interaction are few in number and the significance of the observed effects are generally small. It is well known that the weak interaction violates parity. This was first experimentally established by C. S. Wu through measurement of an asymmetry of electrons emitted in the beta-decay of polarized Co-60. The measured asymmetry was large because beta decay is a weak interaction process. For a process in which the strong interaction can contribute, we expect much smaller asymmetries, of order 10(-7). RP Seestrom, SJ (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 388 EP 397 DI 10.1117/12.267939 PG 10 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00077 ER PT B AU Adams, KJ AF Adams, KJ BE Vourvopoulos, G TI MCNP(TM) Monte Carlo: A precis of MCNP SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB MCNPTM* is,general purpose three-dimensional time-dependent neutron, photon, and electron transport code. It is highly portable and user-oriented, and backed by stringent software quality assurance practices and extensive experimental benchmarks. The cross section database is based upon the best evaluations available. MCNP incorporates state-of-the-art analog and adaptive Monte Carlo techniques. The code is documented in a 600 page manual(1) which is augmented by numerous Los Alamos technical reports which detail various aspects of the code. MCNP represents over a megahour of development and refinement over the past 50 years and an ongoing commitment to excellence. RP Adams, KJ (reprint author), LOS ALAMOS NATL LAB,TRANSPORT METHODS GRP,XTM MS B226,POB 1663,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 418 EP 427 DI 10.1117/12.267945 PG 10 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00082 ER PT B AU Azmy, YY AF Azmy, YY BE Vourvopoulos, G TI Recent advances in neutral particle transport methods and codes SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos DE TORT; DORT; DOS code system; neutral particle transport; multitasking; UNICOS Cray; Adjacent-cell Preconditioning; acceleration; graphics AB An overview of Oak Ridge National Laboratory's (ORNL) three-dimensional neutral particle transport code, TORT, is presented. Special features of the code that make it invaluable for large applications are summarized for the prospective user. Advanced capabilities currently under development and installation in the production release of TORT are discussed in some detail. These include: multitasking on Gray platforms running the UNICOS operating system; Adjacent-cell Preconditioning (AP) acceleration scheme; and graphics codes for displaying computed quantities such as the flux. Further developments for TORT and its companion codes to enhance its present capabilities, as well as expand its range of applications will be discussed. Speculation on the next generation of neutral particle transport codes at ORNL, especially regarding unstructured grids and high order spatial approximations, will also be mentioned. RP Azmy, YY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 435 EP 444 DI 10.1117/12.267947 PG 10 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00084 ER PT B AU Hall, J AF Hall, J BE Vourvopoulos, G TI Monte Carlo modeling of neutron and gamma-ray imaging systems SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos DE numerical modeling; radiation transport; nonintrusive inspection; neutron imaging; photon imaging AB Detailed numerical prototypes are essential to the design of efficient and cost-effective neutron and gamma-ray imaging systems. We have exploited the unique capabilities of an LLNL-developed radiation transport code (COG) to develop code modules capable of simulating the performance of neutron and gamma-ray imaging systems over a wide range of source energies. COG allows us to simulate complex, energy-, angle- and time-dependent radiation sources, model 3-dimensional system geometries with ''real world'' complexity, specify detailed elemental and isotopic distributions and predict the responses of various types of imaging detectors with full Monte Carlo accuracy. COG references detailed, evaluated nuclear interaction databases allowing users to account for multiple scattering, energy straggling, and secondary particle production phenomena which may significantly effect the performance of an imaging system but may be difficult or even impossible to estimate using simple analytical models. In this work we will present examples illustrating the use of these routines in the analysis of industrial radiographic systems for thick target inspection, nonintrusive luggage and cargo scanning systems, and international treaty verification. RP Hall, J (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 465 EP 468 DI 10.1117/12.267953 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00090 ER PT B AU Seestrom, SJ Bowles, TJ Hill, R Greene, GL Morris, CL AF Seestrom, SJ Bowles, TJ Hill, R Greene, GL Morris, CL BE Vourvopoulos, G TI Development of an ultra cold neutron source at MLNSC SO NEUTRONS IN RESEARCH AND INDUSTRY, INTERNATIONAL CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Nuclear Techniques - Neutrons in Research and Industry CY JUN 09-15, 1996 CL IRAKLION, GREECE SP Soc Photo Opt Instrumentat Engineers, AccSys Technol Inc, EMR Schlumberger, Sodern, Western Kentucky Univ, Inst Nucl Phys Demokritos AB Ultra Cold Neutrons (UCN) can be produced at spallation sources using a variety of techniques. To date the technique used has been to Bragg scatter and Doppler shift cold neutrons into UCN front a moving crystal. This is particularly applicable to short-pulse spallation sources. We are presently constructing a UCN source at LANSCE using this method. In addition, large gains in UCN density should be possible using cryogenic UCN sources. Research is under way at Gatchina to demonstrate technical feasibility of a frozen deuterium source. If successful, a source of this type could be implemented at future spallation source, such as the long pulse source being planned at Los Alamos, with a UCN density that may be two orders of magnitude higher than that presently available at reactors. RP Seestrom, SJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2263-0 J9 P SOC PHOTO-OPT INS PY 1997 VL 2867 BP 521 EP 524 DI 10.1117/12.267844 PG 4 WC Optics; Physics, Applied; Physics, Nuclear SC Optics; Physics GA BH32H UT WOS:A1997BH32H00102 ER PT J AU Niemeyer, JC Kerstein, AR AF Niemeyer, JC Kerstein, AR TI Burning regimes of nuclear flames in SN Ia explosions SO NEW ASTRONOMY LA English DT Article DE hydrodynamics; supernovae: general; turbulence ID SUPERNOVAE AB The scaling properties and burning regimes of thermonuclear flames in Chandrasekhar mass Type Ia supernova models are discussed with a special emphasis on consequences for the delayed detonation scenario. We argue that the flame-generated turbulence is buoyancy-driven and thus conforms to Bolgiano-Obukhov scaling instead of the previously assumed Kolmogorov inertial range scaling. Predictions for the flame-surface fractal dimension and the small scale cutoff of surface perturbations change accordingly. In addition, the criterion for the transition from flamelet burning to the distributed burning regime is reformulated and consequences for the delayed detonation scenario are noted. (C) 1997 Elsevier Science B.V. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Niemeyer, JC (reprint author), MAX PLANCK INST ASTROPHYS,KARL SCHWARZSCHILD STR 1,D-85740 GARCHING,GERMANY. OI Niemeyer, Jens/0000-0002-3063-4325 NR 20 TC 40 Z9 40 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1092 J9 NEW ASTRON JI New Astron. PY 1997 VL 2 IS 3 BP 239 EP 244 DI 10.1016/S1384-1076(97)00017-1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ232 UT WOS:A1997XJ23200004 ER PT J AU Gregg, MD AF Gregg, MD TI The Coma-Leo I distance ratio and the Hubble constant SO NEW ASTRONOMY LA English DT Article DE distance scale; galaxies: distances and redshifts; galaxies: elliptical and lenticular, cD ID COLOR MAGNITUDE RELATION; EARLY-TYPE GALAXIES; ELLIPTICAL GALAXIES; PRECISION PHOTOMETRY; FUNDAMENTAL PLANE; CEPHEID VARIABLES; VIRGO CLUSTERS; CCD PHOTOMETRY; SPECTROSCOPY; UNIVERSALITY AB The diameter-velocity dispersion relation in B, V, and K for three early-type galaxies in the Leo I (M96) group is derived from published photometry and kinematic data. The relations in all three colors have slopes which agree well with those for the Coma cluster. The RMS scatter of the Leo I galaxies in each color is extremely small, consistent with the group's compactness. These relations yield estimates of the Coma-Leo I distance ratio of 9.01+/-0.51, 8.77+/-0.43, and 8.82+/-0.31, respectively, with a weighted mean of 8.84+/-0.23. The general agreement among the three colors indicates that the early-type galaxies in Leo I and Coma have similar stellar populations. The Coma-Leo I distance ratio coupled with estimates of the absolute distance to the Leo I group allows the Hubble constant to be determined, free of the uncertainties which arise when working with the Virgo cluster. Several high quality distance estimates are available from a variety of techniques: Cepheids in M96 (Tanvir, N.R., et al., 1995, Natur, 377, 27) and M95 (Graham, J.A., et al., 1997, ApJ, 477, 535), surface brightness fluctuations (Tonry, J.L., et al., 1997, ApJ, 475, 399), planetary nebulae luminosity functions (Ciardullo, R., et al., 1993 ApJ, 419, 479), and the luminosity of the red giant branch tip (Sakai, S., Freedman, W.L., & Madore, B.F., 1996, in: Formation of the Galactic Halo, Inside and Out, eds. H. Morrison & A. Sarajedini, PASP Conf. Series Vol. 92). Adopting a cosmic recession velocity of the Coma cluster in the microwave background frame of 7200+/-300 km s(-1), these distance estimates lead to values of the Hubble constant ranging from 70 to 81 km s(-1) Mpc(-1), with an unweighted mean of 75+/-6 km s(-1) Mpc(-1). RP Gregg, MD (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,L-413,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 35 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1092 J9 NEW ASTRON JI New Astron. PY 1997 VL 1 IS 4 BP 363 EP 371 DI 10.1016/S1384-1076(97)00005-5 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WT974 UT WOS:A1997WT97400002 ER PT B AU Kwiat, PG AF Kwiat, PG BE Ferrero, M vanderMerwe, A TI Production and uses of hyper-entangled states SO NEW DEVELOPMENTS ON FUNDAMENTAL PROBLEMS IN QUANTUM PHYSICS SE FUNDAMENTAL THEORIES OF PHYSICS LA English DT Proceedings Paper CT International Symposium on Fundamental Problems in Quantum Physics CY JUL 21-26, 1996 CL OVIEDO, SPAIN SP European Commiss, DG XII, Brussels, Minist Educ & Cultura, DGICYT, Madrid, Consejeria Cultura Principado Asturias, FICYT, Oviedo, Fundac Principe Austurias, Oviedo, Caja Asturias, Oviedo, Univ Oviedo, Univ Autonoma Madrid, Univ Cantabria, Santander, Univ Complutense Madrid, Sociedad Asturiana Filosofia, Oviedo DE entangled states; quantum states; Bell inequalities; nonlocality; parametric down-conversion AB Entangled states are central to the new field of quantum information, including quantum dense coding, teleportation, and computation. However, only a relatively small class of entangled states has been discussed extensively, much less investigated experimentally. In particular, efforts to date have focussed on two particles entangled in a single degree of freedom, for example polarization, or energy, or momentum direction. Novel phase-matching arrangements in spontaneous parametric down-conversion allow the preparation of pairs of photons that are simultaneously entangled in polarization, momentum-direction, and energy. We shall call such a multiply-entangled state "hyper-entangled". In addition, an even more general state - a non-maximally entangled state - should be realizable, in which the amplitudes of the contributing terms are not equal. C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Kwiat, PG (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, P-23,MS-H803, Los Alamos, NM 87545 USA. RI Ferrero Melgar, Miguel/L-6071-2014 NR 0 TC 0 Z9 0 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4374-3 J9 FUND THEOR PY 1997 VL 81 BP 189 EP 202 PG 14 WC History & Philosophy Of Science; Physics, Multidisciplinary; Physics, Particles & Fields; Physics, Mathematical SC History & Philosophy of Science; Physics GA BK07T UT WOS:000071071900025 ER PT B AU Blau, PJ AF Blau, PJ GP INST MECH ENGINEERS TI Design and validation of laboratory-scale selecting tribomaterials and surface treatments SO NEW DIRECTIONS IN TRIBOLOGY: PLENARY AND INVITED PAPERS FROM THE FIRST WORLD TRIBOLOGY CONGRESS LA English DT Proceedings Paper CT 1st World Tribology Congress - New Directions in Tribology CY SEP 08, 1996-SEP 12, 1997 CL LONDON, ENGLAND SP Inst Mech Engineers, Tribol Grp, NSK RHP, AEA Technol plc, GKN, Climax Molybdenum Co, Pall Ind Hydraul AB Engineering approaches to solving tribology problems commonly involve friction, lubrication, or wear testing, either in the field or in a laboratory setting. Since wear and friction are properties of the materials in the larger context of the tribosystem, the selection of appropriate laboratory tribotesting procedures becomes critically important. Laboratory simulations must exhibit certain key characteristics of the application in order for the test results to be relevant, but they may not have to mimic all operating conditions. The current paper illustrates a step-by-step method to develop laboratory-scale friction and wear simulations based on a tribosystem analysis. Quantitative or qualitative metrics are established and used to validate the effectiveness of the tribosimulation. Sometimes standardized test methods can be used, but frequently a new type of test method or procedure must be developed. There are four factors to be addressed in designing effective simulations: (1) contact macrogeometry and the characteristics of relative motion, (2) pressure-velocity relationships, (3) thermal and chemical environment (including type of lubrication), and (4) the role of third-bodies. In addition, there are two typical choices of testing philosophy: (1) the worst-case scenario and, (2) the nominal-operations scenario. Examples of the development and use of simulative friction and wear tests are used to illustrate major points. RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MECHANICAL ENGINEERING PUBL PI EDMUNDS PA P O BOX 24 NORTHGATE AVE BURY ST, EDMUNDS, SUFFOLK, ENGLAND 1P32 6BW BN 1-86058-099-8 PY 1997 BP 177 EP 190 PG 14 WC Engineering, Mechanical SC Engineering GA BJ71R UT WOS:A1997BJ71R00013 ER PT B AU Cairns, EJ Horne, CR Weiss, BJR Grush, MM Cramer, SP AF Cairns, EJ Horne, CR Weiss, BJR Grush, MM Cramer, SP BE Savadogo, O Roberge, PR TI X-ray absorption spectroscopic investigations of LixMn2O4 SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID MANGANESE-DIOXIDE; LITHIUM INSERTION; EXTRACTION; LIMN2O4; SYSTEM; OXIDES AB This paper discusses the evolution of atomic and electronic structure in LixMn2O4 electrodes as determined by Mn XANES and EXAFS. Varying lithium content was accomplished through coulombic titration of LiMn2O4 within a Li cell containing non-aqueous liquid electrolyte. We have found that there is a significant influence of the electronic structure on this material system. In particular, the Mn(III) sites in LiMn2O4 are subject to a dynamic Jahn-Teller effect. Additionally, the XANES spectrum of LixMn2O4 (x = 1.8 and 2.0) is consistent with a square-planar [Mn(III)O-6] compound whereas the atomic structure, confirmed by EXAFS, suggests that the [Mn(III)O-6] are tetragonally-distorted. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. RP Cairns, EJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Cairns, Elton/E-8873-2012 OI Cairns, Elton/0000-0002-1179-7591 NR 36 TC 3 Z9 3 U1 1 U2 1 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 336 EP 347 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400030 ER PT B AU McBreen, J Mukerjee, S Yang, XQ Thurston, TR Jisrawi, NM AF McBreen, J Mukerjee, S Yang, XQ Thurston, TR Jisrawi, NM BE Savadogo, O Roberge, PR TI In situ synchrotron x-ray studies of LiMn2O4 cathodes SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID ELECTRODE; DIFFRACTION; BATTERIES AB LiCoO2 cathodes are now used in most commercial lithium ion batteries. LiMn2O4 is an attractive low cost alternative. However, it is difficult to make reproducibly. At Brookhaven National Laboratory two in situ synchrotron x-ray techniques, that are available at the National Syncluotron Light Source (NSLS), have been used to investigate LiMn2O4. The techniques are x-ray absorption and high resolution x-ray diffraction. With x-ray absorption it is possible to follow the changes in the Mn oxidation state and the changes in the Mn-O and Mn-Mn bond lengths on cycling. Also it is possible to detect amorphous phases. The high energy x-rays at the diffraction Beam Lines at the NSLS (up to 24 KeV) permit in situ x-ray diffraction, in the transmission mode, in thin lithium and lithium ion cells. The evolution of the structural changes that occur on cycling can be followed. These in situ measurements were done on Li/LiMn2O4 cells with a liquid electrolyte (1 M LiPF6 in a 1:1:3 PC:EC:DMC solvent). C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP McBreen, J (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 11 TC 9 Z9 9 U1 0 U2 9 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 348 EP 357 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400031 ER PT B AU Guidotti, RA Johnson, BJ AF Guidotti, RA Johnson, BJ BE Savadogo, O Roberge, PR TI Effect of solution additives on the performance of PMAN carbon anodes in 1M LiPF6/EC-DMC solutions SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID ELECTROCHEMICAL INTERCALATION; IN-SITU; LITHIUM; BATTERIES; GRAPHITE; ELECTROLYTE; RESISTANCE; 12-CROWN-4 AB A study was undertaken to examine the use of a number of solution additives in 1M LiPF6/ethylene carbonate (EC)-dimethyl carbonate (DMC) solutions to improve the performance of carbon anodes derived from polymethylacrylonitrile (PMAN)-divinylbenzene (DVB) copolymers. The study goals were to improve the cycle life and reduce the formation of the passivation layer during the first reduction, thereby minimizing the irreversible-capacity losses. Additives studied were 12-crown-4 (12-Cr-4) ether, decalin, and dilithium phthalocyanine (Li2Pc). The carbon performance was characterized by galvanostatic cycling cyclic voltammetry, and complex-impedance spectroscopy. Limited success was obtained with 12-Cr-4 ether at 0.25M and decalin at 1 v/o. Poor results were noted with Li2Pc at 0.025M and 0.5M. C1 Sandia Natl Labs, Battery Dev Dept, Albuquerque, NM 87185 USA. RP Guidotti, RA (reprint author), Sandia Natl Labs, Battery Dev Dept, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 0 Z9 0 U1 1 U2 2 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 380 EP 391 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400034 ER PT B AU Guidotti, RA AF Guidotti, RA BE Savadogo, O Roberge, PR TI Effects of partial oxidation of PMAN carbons on their performance as anodes in 1m LiPF6/EC-DMC solutions SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID BATTERIES AB A study was undertaken to examine the effects of partial oxidation on the electrochemical performance of carbons derived from poly(methylacrylonitrile) (PMAN)-divinylbenzene (DVB) co-polymers. Mild oxidation was examined as a possible technique to increase the reversible capacity, improve cycleability, and reduce the amount of irreversible capacity associated with the formation of the passivation layer during the first reduction. Oxidizing conditions involved treatment of the PMAN carbon prepared at 700 degrees C with dry CO2 or with steam at 600 degrees C for one hour. The effects oil the performance in IM LiPF6/ethylene carbonate (EC)-dimethyl carbonate (DMC) solutions were evaluated by galvanostatic cycling tests, complex-impedance spectroscopy, and, to a more limited extent, cyclic voltammetry. Partial oxidation of PMAN carbon showed little or no overall beneficial effects in performance relative to the control. C1 Sandia Natl Labs, Thermal Battery Dev & Mfg Dept, Albuquerque, NM 87185 USA. RP Guidotti, RA (reprint author), Sandia Natl Labs, Thermal Battery Dev & Mfg Dept, POB 5800, Albuquerque, NM 87185 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 401 EP 414 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400036 ER PT B AU Sandi, G Winans, RE Carrado, KA Johnson, CS AF Sandi, G Winans, RE Carrado, KA Johnson, CS BE Savadogo, O Roberge, PR TI Novel carbonaceous materials for lithium secondary batteries SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID CARBONS; CELLS; ELECTRODES; ANODES; FORMS AB Carbonaceous materials have been synthesized using pillared clays (PILCs) as templates. The PILC was loaded with organic materials such as pyrene in the liquid and vapor phase, styrene in the vapor phase, trioxane, ethylene and propylene. The samples were then pyrolyzed at 700 degrees C in an inert atmosphere, followed by dissolution of the inorganic template by conventional demineralization methods. X-ray powder diffraction of the carbons showed broad d(002) peaks in the diffraction pattern, indicative of a disordered or turbostratic system. N-2 BET surface areas of the carbonaceous materials range from 10 to 100 m(2)/g. There is some microporosity (r < I nm) in the highest surface area carbons. Most of the surface area, however, comes from a mixture of micro and mesopores with radii of 2-5 om. Electrochemical studies were performed on these carbons. Button cells were fabricated with capacity-limiting cal bon pellets electrodes as the cathode and metallic lithium foil as the anode. Large reversible capacities (up to 850 mAh/g) were achieved for most of the samples. The irreversible capacity loss was less than 180 mAh/g after the first cycle, suggesting that these types of carbon materials are very stable to lithium insertion and de-insertion reactions. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Sandi, G (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 23 TC 1 Z9 1 U1 0 U2 2 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 415 EP 425 PG 7 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400037 ER PT B AU Mukerjee, S McBreen, J AF Mukerjee, S McBreen, J BE Savadogo, O Roberge, PR TI The effect of Ru and Sn additions to Pt on the electrocatalysis of methanol oxidation: An in situ XAS investigation SO NEW MATERIALS FOR FUEL CELL AND MODERN BATTERY SYSTEMS II LA English DT Proceedings Paper CT 2nd International Symposium on New Materials for Fuel Cell and Modern Battery Systems CY JUL 06-10, 1997 CL MONTREAL, CANADA SP Ecole Polytech Montreal, Dept Met & Genie Materiaux, Quebec Minist Energy & Resources ID X-RAY-ABSORPTION; SMALL ORGANIC-MOLECULES; FUEL-CELLS; ELECTROCHEMICAL OXIDATION; FORMIC-ACID; PLATINUM; TIN; ELECTROOXIDATION; ELECTRODES; SURFACES AB Elements such as Ru and Sn used as ad-atoms or as alloying elements are known to enhance methanol oxidation reaction (MOR). Ru, both as alloying element as well as upd deposited on Pt/C is widely acknowledged for enhancing MOR. Sn on the other hand is more controversial, with evidence indicating enhancements for MOR when present as upd layer and marginally effective when present as an alloying element. In situ XAS is used to investigate some of these inconsistencies in the electrocatalysis of MOR. Results indicate that alloying Sn with Pt (Pt3Sn primary phase) causes partial filling of the Pt 5 d-band vacancies and increase in the Pt-Pt bond distances which is directly opposite to a similar situation with Ru. Upd Sn however does not perturb Pt structurally or electronically. Ru and Sn (both as alloying element and as upd adlayer) are associated with oxygenated species, the nature and strength of the Ru and Sn - oxygen interactions are potential dependent. Hence alloying with Sn renders Pt surface unfavorable for methanol adsorption in contrast to alloying with Ru. Both Ru and Sn however promote MOR via their ability to nucleate oxygenated species on their surface at lower potentials as compared to pure Pt. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. RP Mukerjee, S (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. NR 27 TC 6 Z9 6 U1 0 U2 0 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C/O SERVICE EDITION CP 6079, SUCC CENTRE-VILLE, MONTREAL, QUEBEC H3C 3A7, CANADA BN 2-553-00624-1 PY 1997 BP 548 EP 559 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BM70L UT WOS:000079562400049 ER PT S AU Siemann, RH AF Siemann, RH BE Parsa, Z TI Status and future directions for advanced accelerator research SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB The relationship between advanced accelerator research and future directions for particle physics is discussed. Comments are made about accelerator research trends in hadron colliders, muon colliders, and e(+)e(-) linear colliders. RP Siemann, RH (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 1 EP 10 PG 10 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00001 ER PT S AU Phillips, RM AF Phillips, RM BE Parsa, Z TI RF sources for future colliders SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB As we push particle colliders to 1-TeV center-of-mass collision energy and beyond, we require much more from our RF energy sources, both in terms of the RF performance and the number required for a given machine. In order to conserve real estate, the operating frequency of future colliders is apt to be higher than the S-band used for the SLAG SLC. It is this inevitable trend toward higher frequencies which presents the source designer with the greatest challenge. This paper is about that challenge. For reasons which will become clear, as we go to frequencies substantially above X-band we will require sources other than klystrons, probably of the type referred to as ''fast-wave devices,'' such as FEL or gyro-based amplifiers, or two-beam accelerators. Because these are discussed elsewhere in this conference, I will stick to the klystron as my model in describing the challenges to be overcome, as well as the criteria which must be met by alternative sources for new accelerators. RP Phillips, RM (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 11 EP 20 PG 10 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00002 ER PT S AU Chen, PS Noble, RJ AF Chen, PS Noble, RJ BE Parsa, Z TI Acceleration and collision of ultra-high energy particles using crystal channels SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB We assume that, independent of any near-term discoveries, the continuing goal of experimental high-energy physics (HEP) will be to achieve ultra-high center-of-mass energies early in the next century. To progress to these energies in such a brief span of time will require a radical change in accelerator and collider technology. We review some of our recent theoretical work on high-gradient acceleration of charged particles along crystal channels and the possibility of colliding them in these same strong-focusing atomic channels. An improved understanding of energy and emittance limitations in natural crystal accelerators leads to the suggestion that specially manufactured nano-accelerators may someday enable us to accelerate particles beyond 10(18) eV with emittances limited only by the uncertainty principle of quantum mechanics. RP Chen, PS (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 95 EP 103 PG 9 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00010 ER PT S AU Parsa, Z Shchagin, AV AF Parsa, Z Shchagin, AV BE Parsa, Z TI Parametric X-ray radiation as source of pulsed, polarized, monochromatic, tunable X-ray beam SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB The parametric X-ray radiation (PXR) is a new type of monochromatic, polarized, directed, tunable radiation arising in the vicinity of Bragg directions of a crystal when relativistic particles are passing through the crystal. For the last ten years the PXR properties have been intensively investigated experimentally at moderate incident electron current. In this paper we consider main properties of PXR as a new source of a powerful monochromatic X-ray beam, excited by short high-current electron bunch in a single crystal. It is shown, that using a PXR, one can obtain X-ray beam power of about MW/sr during a short period of time at moderate incident electron energy. Experimental setup for generating pulsed PXR beam is suggested, and possibilities for application of pulsed polarized monochromatic X-ray beams are discussed. RP Parsa, Z (reprint author), BROOKHAVEN NATL LAB,PHYS DEPT 901A,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 135 EP 143 PG 9 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00013 ER PT S AU Leung, KN AF Leung, KN BE Parsa, Z TI High current short pulse ion sources SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB High current short pulse ion beams can be generated by using a multicusp source. This is accomplished by switching the are or the RF induction discharge on and off. An alternative approach is to maintain a continuous plasma discharge and extraction voltage but control the plasma flow into the extraction aperture by a combination of magnetic and electric fields. Short beam pulses can be obtained by using a fast electronic switch and a de bias power supply It is also demonstrated that very short beam pulses (similar to 10 mu s) with high repetition rate can be formed by a laser-driven LaB6 or barium photo-cathode. RP Leung, KN (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 155 EP 164 PG 10 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00015 ER PT S AU Parsa, Z Pato, MP AF Parsa, Z Pato, MP BE Parsa, Z TI Inverse Free Electron Laser acceleration with a Square Wave Wiggler SO NEW MODES OF PARTICLE ACCELERATION - TECHNIQUES AND SOURCES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Symposium on New Modes of Particle Acceleration - Techniques and Sources CY AUG 19-23, 1996 CL INST THEORET PHYS, SANTA BARBARA, CA SP Natl Sci Fdn HO INST THEORET PHYS AB We present an Inverse Free Electron Laser with a Square Wave Wiggler (IFELSW) as a new acceleration scheme and show Analytically end numerically about factor of 2 gain in the energy when compared to the standard IFEL with the Sinusoidal [1] field Wiggler. RP Parsa, Z (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS 901A,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-728-6 J9 AIP CONF PROC PY 1997 IS 396 BP 179 EP 189 PG 11 WC Physics, Particles & Fields SC Physics GA BJ69S UT WOS:A1997BJ69S00017 ER PT B AU Wehner, MF Mirin, AA Bolstad, JH Creach, UE Duffy, PB Dannevik, WP Eltgroth, PG Matarazzo, CM Chan, B AF Wehner, MF Mirin, AA Bolstad, JH Creach, UE Duffy, PB Dannevik, WP Eltgroth, PG Matarazzo, CM Chan, B BE Delic, G Wheeler, MF TI Climate systems modeling on massively parallel processing computers at Lawrence Livermore National Laboratory SO NEXT GENERATION ENVIRONMENT MODELS AND COMPUTATIONAL METHODS SE SIAM PROCEEDINGS SERIES LA English DT Proceedings Paper CT Next Generation Environmental Models Computational Methods (NGEMCOM) Workshop CY AUG 07-09, 1995 CL NATL ENVIRONM SUPERCOMP CTR, BAY CITY, MI SP US EPA, Natl Risk Management Res Lab, Subsurface Protect & Remediat Div, US EPA, Natl Exposure Res Lab, Ecosyst Res Div, US EPA, Enterprise Technol Serv Div, Natl Environm Supercomp Ctr HO NATL ENVIRONM SUPERCOMP CTR AB A comprehensive climate system model is under development at Lawrence Livermore National Laboratory. The basis for this model is a consistent coupling of multiple complex subsystem models, each describing a major component of the Earth's climate. Among these are general circulation models of the atmosphere and ocean, a dynamic and thermodynamic sea ice model, and models of the chemical processes occurring in the air, sea water, and near-surface land. The computational resources necessary to carry out simulations at adequate spatial resolutions for durations of climatic time scales exceed those currently available. Distributed memory massively parallel processing (MPP) computers promise to affordably scale to the computational rates required by directing large numbers of relatively inexpensive processors onto a single problem. We have developed a suite of routines designed to exploit current generation MPP architectures via domain and functional decomposition strategies. These message-passing techniques have been implemented in each of the component models and in their coupling interfaces. Production runs of the atmospheric and oceanic components performed on the National Environmental Supercomputing Center (NESC) Gray T3D are described. RP Wehner, MF (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV ATMOSPHER SCI,CLIMATE SYST MODELING GRP,POB 808,L-256,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SIAM PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 BN 0-89871-378-1 J9 SIAM PROC S PY 1997 BP 21 EP 29 PG 9 WC Computer Science, Interdisciplinary Applications; Environmental Sciences; Water Resources SC Computer Science; Environmental Sciences & Ecology; Water Resources GA BH23R UT WOS:A1997BH23R00002 ER PT B AU Almgren, AS Bell, JB Colella, P Howell, LH Welcome, ML AF Almgren, AS Bell, JB Colella, P Howell, LH Welcome, ML BE Delic, G Wheeler, MF TI A high resolution adaptive projection method for regional atmospheric modeling SO NEXT GENERATION ENVIRONMENT MODELS AND COMPUTATIONAL METHODS SE SIAM PROCEEDINGS SERIES LA English DT Proceedings Paper CT Next Generation Environmental Models Computational Methods (NGEMCOM) Workshop CY AUG 07-09, 1995 CL NATL ENVIRONM SUPERCOMP CTR, BAY CITY, MI SP US EPA, Natl Risk Management Res Lab, Subsurface Protect & Remediat Div, US EPA, Natl Exposure Res Lab, Ecosyst Res Div, US EPA, Enterprise Technol Serv Div, Natl Environm Supercomp Ctr HO NATL ENVIRONM SUPERCOMP CTR AB In this paper we discuss an adaptive mesh refinement algorithm for modeling a low Mach number approximation to atmospheric flow. The techniques described in this paper were developed to solve the incompressible Navier-Stokes equations, but have been extended to model atmospheric flow as governed by the anelastic approximation and a relatively simple set of equations for conservation of mass and momentum. In this simple case we omit temperature from the equations and compute density from the continuity equation rather than from the equation of state. We solve these equations on a composite (i.e., multilevel) grid structure, which allows for different degrees of refinement in different regions of the flow. The method is based on a projection formulation in which we first solve advection-diffusion equations to predict intermediate velocities, and then project these velocities onto a space of vector fields satisfying the divergence constraint. The advection-diffusion step uses a specialized second-order upwind method for differencing the nonlinear advection terms that provides a robust treatment of these terms. The diffusion step uses a Crank-Nicholson discretization with standard spatial approximations. Our approach to adaptive refinement uses a nested hierarchy of grids with simultaneous refinement of the grids in both space and time. The integration algorithm on the grid hierarchy is a recursive procedure in which coarse grids are advanced, finer grids are advanced multiple steps to reach the same time as the coarse grids, and the fine and coarse grid data are then synchronized. Second-order accuracy of the method is demonstrated elsewhere for incompressible flow. Here we show results using the anelastic approximation for three-dimensional calculations of a hot gas released into a wind-sheared adiabatically stratified atmosphere. RP Almgren, AS (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,MS 50-D,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SIAM PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 BN 0-89871-378-1 J9 SIAM PROC S PY 1997 BP 69 EP 79 PG 11 WC Computer Science, Interdisciplinary Applications; Environmental Sciences; Water Resources SC Computer Science; Environmental Sciences & Ecology; Water Resources GA BH23R UT WOS:A1997BH23R00006 ER PT B AU Miller, NL AF Miller, NL BE Delic, G Wheeler, MF TI An automated land analysis system (ALAS) for applications at a range of spatial scales: Watershed to global SO NEXT GENERATION ENVIRONMENT MODELS AND COMPUTATIONAL METHODS SE SIAM PROCEEDINGS SERIES LA English DT Proceedings Paper CT Next Generation Environmental Models Computational Methods (NGEMCOM) Workshop CY AUG 07-09, 1995 CL NATL ENVIRONM SUPERCOMP CTR, BAY CITY, MI SP US EPA, Natl Risk Management Res Lab, Subsurface Protect & Remediat Div, US EPA, Natl Exposure Res Lab, Ecosyst Res Div, US EPA, Enterprise Technol Serv Div, Natl Environm Supercomp Ctr HO NATL ENVIRONM SUPERCOMP CTR AB An Automated Land Analysis System (ALAS) has been developed for the determination of land surface characteristics. ALAS is a direct response to the need for a conceptualization of convergence scales between hydrologic and atmospheric models as defined by the World Climate Research Programme. ALAS determines topographic surface characteristics at a range of scales for a given digital elevation data set and is expected to be posted on the World Wide Web with a built-in user's manual. RP Miller, NL (reprint author), LAWRENCE LIVERMORE NATL LAB,GLOBAL CLIMATE RES DIV,CLIMATE SYST MODELING GRP,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SIAM PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 BN 0-89871-378-1 J9 SIAM PROC S PY 1997 BP 169 EP 173 PG 5 WC Computer Science, Interdisciplinary Applications; Environmental Sciences; Water Resources SC Computer Science; Environmental Sciences & Ecology; Water Resources GA BH23R UT WOS:A1997BH23R00018 ER PT B AU Ashby, SF Falgout, RD Tompson, AFB AF Ashby, SF Falgout, RD Tompson, AFB BE Delic, G Wheeler, MF TI A scalable approach to modeling groundwater flow on massively parallel computers SO NEXT GENERATION ENVIRONMENT MODELS AND COMPUTATIONAL METHODS SE SIAM PROCEEDINGS SERIES LA English DT Proceedings Paper CT Next Generation Environmental Models Computational Methods (NGEMCOM) Workshop CY AUG 07-09, 1995 CL NATL ENVIRONM SUPERCOMP CTR, BAY CITY, MI SP US EPA, Natl Risk Management Res Lab, Subsurface Protect & Remediat Div, US EPA, Natl Exposure Res Lab, Ecosyst Res Div, US EPA, Enterprise Technol Serv Div, Natl Environm Supercomp Ctr HO NATL ENVIRONM SUPERCOMP CTR AB We describe a fully scalable approach to the simulation of groundwater flow on a hierarchy of computing platforms, ranging from workstations to massively parallel computers. Specifically, we advocate the use of scalable conceptual models in which the subsurface model is defined independently of the computational grid on which the simulation takes place. We also describe a scalable multigrid algorithm for computing the groundwater flow velocities. We are thus able to leverage both the engineer's time spent developing the conceptual model and the computing resources used in the numerical simulation. We have successfully employed this approach at the Lawrence Livermore National Laboratory (LLNL) site, where we have run simulations ranging in size from just a few thousand spatial zones (on workstations) to more than eight million spatial zones (on the GRAY T3D), all using the same conceptual model. RP Ashby, SF (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR APPL SCI COMP,POB 808,L-561,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SIAM PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 BN 0-89871-378-1 J9 SIAM PROC S PY 1997 BP 201 EP 215 PG 15 WC Computer Science, Interdisciplinary Applications; Environmental Sciences; Water Resources SC Computer Science; Environmental Sciences & Ecology; Water Resources GA BH23R UT WOS:A1997BH23R00021 ER PT S AU Kelsey, RL Hartley, RT Webster, RB AF Kelsey, RL Hartley, RT Webster, RB GP IEEE COMP SOC TI An object-based methodology for knowledge representation in SGML SO NINTH IEEE INTERNATIONAL CONFERENCE ON TOOLS WITH ARTIFICIAL INTELLIGENCE, PROCEEDINGS SE PROCEEDINGS - INTERNATIONAL CONFERENCE ON TOOLS WITH ARTIFICIAL INTELLIGENCE LA English DT Proceedings Paper CT 9th IEEE International Conference on Tools with Artificial Intelligence CY NOV 03-08, 1997 CL NEWPORT BEACH, CA SP IEEE Comp Soc, Tech Comm PAMI, Pan Amer Ctr Earth & Environm Studies AB An object-based methodology for knowledge representation and its Standard Generalized Markup Language (SGML) implementation is presented. The methodology includes class, perspective, domain, and event constructs for representing knowledge within an object paradigm. The perspective construct allows for representation of knowledge from multiple and varying viewpoints. The event construct allows actual use of knowledge to be represented. The SGML implementation of the methodology facilitates usability, structured, yet flexible knowledge design, and sharing and re-use of knowledge class libraries. RP Kelsey, RL (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1082-3409 BN 0-8186-8204-3 J9 PROC INT C TOOLS ART PY 1997 BP 304 EP 311 DI 10.1109/TAI.1997.632270 PG 8 WC Computer Science, Artificial Intelligence SC Computer Science GA BJ93L UT WOS:A1997BJ93L00042 ER PT B AU Chen, IMA Kosky, AS Markowitz, VW Szeto, E AF Chen, IMA Kosky, AS Markowitz, VW Szeto, E GP IEEE COMP SOC TI Developing and accessing scientific databases with the Object-Protocol Model (OPM) data management tools SO NINTH INTERNATIONAL CONFERENCE ON SCIENTIFIC AND STATISTICAL DATABASE MANAGEMENT, PROCEEDINGS LA English DT Proceedings Paper CT 9th International Conference on Scientific and Statistical Database Management (9SSDBM) CY AUG 11-13, 1997 CL EVERGREEN STATE COLL, OLYMPIA, WA HO EVERGREEN STATE COLL RP Chen, IMA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INFORMAT & COMP SCI DIV,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7953-0 PY 1997 BP 114 EP 115 DI 10.1109/SSDM.1997.621167 PG 2 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ47Y UT WOS:A1997BJ47Y00014 ER PT B AU Lenz, HJ Shoshani, A AF Lenz, HJ Shoshani, A GP IEEE COMP SOC TI Summarizability in OLAP and statistical data bases SO NINTH INTERNATIONAL CONFERENCE ON SCIENTIFIC AND STATISTICAL DATABASE MANAGEMENT, PROCEEDINGS LA English DT Proceedings Paper CT 9th International Conference on Scientific and Statistical Database Management (9SSDBM) CY AUG 11-13, 1997 CL EVERGREEN STATE COLL, OLYMPIA, WA HO EVERGREEN STATE COLL AB Summarizability of OLAP and Statistical Databases is an a extremely important property because violating this condition can lead to erroneous conclusions and decisions. In this paper we explore the conditions for summarizability. We introduce a framework for specifying precisely the context in which statistical objects are defined. We use a three step process to define normalized statistical objects. Using this framework, we identify three necessary conditions for summarizability. We provided specific tests for each of the conditions that can be verified either from semantic knowledge, or by checking the statistical database itself. We also provide the reasoning for our belief that these three summarizability conditions are sufficient as well. RP Lenz, HJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 65 Z9 69 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7953-0 PY 1997 BP 132 EP 143 DI 10.1109/SSDM.1997.621175 PG 12 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ47Y UT WOS:A1997BJ47Y00019 ER PT B AU Chen, IMA Kosky, AS Markowitz, VM Szeto, E AF Chen, IMA Kosky, AS Markowitz, VM Szeto, E GP IEEE COMP SOC TI Constructing and maintaining scientific database views in the framework of the object-protocol model SO NINTH INTERNATIONAL CONFERENCE ON SCIENTIFIC AND STATISTICAL DATABASE MANAGEMENT, PROCEEDINGS LA English DT Proceedings Paper CT 9th International Conference on Scientific and Statistical Database Management (9SSDBM) CY AUG 11-13, 1997 CL EVERGREEN STATE COLL, OLYMPIA, WA HO EVERGREEN STATE COLL AB Scientific databases (ScDBs) are used to archive and retrieve data describing objects of scientific inquiry Since these ScDBs must provide continuous and efficient access to large communities of scientists, they are often developed with reliable commercial relational database management systems (DBMSs) or file systems. However, relational DBMSs and flat fries do not provide constructs for representing directly ScDB-specific objects and experimental procedures, and therefore they are often hard to develop, maintain, and explore. In this paper, we present a retrofitting tool for constructing and maintaining ScDB views using an object-oriented data model, and describe our experience with retrofitting ScDBs that have been originally developed using relational DBMSs and file systems. The retrofitting tool is part of a data management toolkit based on the Object-Protocol Model (OPM). The OPM toolkit provides facilities for developing databases defined using OPM and for querying and browsing such ScDBs in terms of OPM constructs. The OPM retrofitting tool allows constructing (one or several) OPM views for ScDBs that have not been originally developed with the OPM tools. ScDBs with native OPM schemas or retrofitted OPM views can be browsed and queried via OPM interfaces, reorganized, or incorporated into apt OPM-based database federation. RP Chen, IMA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INFORMAT & COMP SCI DIV,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7953-0 PY 1997 BP 237 EP 248 PG 12 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ47Y UT WOS:A1997BJ47Y00028 ER PT B AU Leonowich, JA AF Leonowich, JA BE Hardy, K Meltz, M Glickman, R TI Introduction and physics of non-ionizing radiations (NIR) SO NON-IONIZING RADIATION: AN OVERVIEW OF THE PHYSICS AND BIOLOGY LA English DT Proceedings Paper CT 1997 Health-Physics-Society Summer School CY JUN 23-27, 1997 CL UNIV INCARNATE WORD, SAN ANTONIO, TX SP Hlth Phys Soc, S Texas Chapter, Univ Texas Hlth Sci Ctr, Ctr Environm Radiat Toxicol HO UNIV INCARNATE WORD RP Leonowich, JA (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MEDICAL PHYSICS PUBLISHING PI MADISON PA 4513 VERNON BLVD, MADISON, WI 53705 BN 0-944838-80-4 PY 1997 BP 1 EP 16 PG 16 WC Biology; Public, Environmental & Occupational Health; Physics, Applied SC Life Sciences & Biomedicine - Other Topics; Public, Environmental & Occupational Health; Physics GA BJ51K UT WOS:A1997BJ51K00001 ER PT B AU Sutherland, BM AF Sutherland, BM BE Hardy, K Meltz, M Glickman, R TI Ultraviolet radiation hazards to humans SO NON-IONIZING RADIATION: AN OVERVIEW OF THE PHYSICS AND BIOLOGY LA English DT Proceedings Paper CT 1997 Health-Physics-Society Summer School CY JUN 23-27, 1997 CL UNIV INCARNATE WORD, SAN ANTONIO, TX SP Hlth Phys Soc, S Texas Chapter, Univ Texas Hlth Sci Ctr, Ctr Environm Radiat Toxicol HO UNIV INCARNATE WORD RP Sutherland, BM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU MEDICAL PHYSICS PUBLISHING PI MADISON PA 4513 VERNON BLVD, MADISON, WI 53705 BN 0-944838-80-4 PY 1997 BP 109 EP 125 PG 17 WC Biology; Public, Environmental & Occupational Health; Physics, Applied SC Life Sciences & Biomedicine - Other Topics; Public, Environmental & Occupational Health; Physics GA BJ51K UT WOS:A1997BJ51K00008 ER PT B AU Anderson, LE AF Anderson, LE BE Hardy, K Meltz, M Glickman, R TI Biological and health effects of ELF fields: Laboratory studies SO NON-IONIZING RADIATION: AN OVERVIEW OF THE PHYSICS AND BIOLOGY LA English DT Proceedings Paper CT 1997 Health-Physics-Society Summer School CY JUN 23-27, 1997 CL UNIV INCARNATE WORD, SAN ANTONIO, TX SP Hlth Phys Soc, S Texas Chapter, Univ Texas Hlth Sci Ctr, Ctr Environm Radiat Toxicol HO UNIV INCARNATE WORD AB There is now a reasonable battery of evidence from a large number of laboratories that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with neural or neuroendocrine systems. Such effects include increased neuronal excitability; chemical and hormonal changes in the nervous system; altered behavioral responses, some of which are related to sensing the presence of the field; and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major focus of ongoing research in the laboratory is to determine whether the epidemiological-based association suggested between EMF exposure and cancer risk can be supported in studies using animal models. Three major challenges exist for ongoing laboratory research: 1) knowledge about the mechanisms underlying observed bioeffects is incomplete; 2) understanding of the physical aspects of exposure and dose that produce biological responses is not available; and 3) health consequences resulting from ELF exposure are unknown. There is presently no clear and convincing evidence from animal or cellular studies that demonstrates deleterious effects of ELF fields. There are, however, some studies, though largely unreplicated, that are suggestive of potential health impacts. From the perspective of laboratory studies, this presentation will discuss biological responses to ELF magnetic and/or electric field exposures. RP Anderson, LE (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MEDICAL PHYSICS PUBLISHING PI MADISON PA 4513 VERNON BLVD, MADISON, WI 53705 BN 0-944838-80-4 PY 1997 BP 143 EP 156 PG 14 WC Biology; Public, Environmental & Occupational Health; Physics, Applied SC Life Sciences & Biomedicine - Other Topics; Public, Environmental & Occupational Health; Physics GA BJ51K UT WOS:A1997BJ51K00010 ER PT B AU Smith, MH AF Smith, MH BE Hardy, K Meltz, M Glickman, R TI Electromagnetic compatibility issues in public and occupational settings SO NON-IONIZING RADIATION: AN OVERVIEW OF THE PHYSICS AND BIOLOGY LA English DT Proceedings Paper CT 1997 Health-Physics-Society Summer School CY JUN 23-27, 1997 CL UNIV INCARNATE WORD, SAN ANTONIO, TX SP Hlth Phys Soc, S Texas Chapter, Univ Texas Hlth Sci Ctr, Ctr Environm Radiat Toxicol HO UNIV INCARNATE WORD RP Smith, MH (reprint author), BATTELLE MEM INST,PACIFIC NW LABS,POB 999,RICHLAND,WA 99352, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MEDICAL PHYSICS PUBLISHING PI MADISON PA 4513 VERNON BLVD, MADISON, WI 53705 BN 0-944838-80-4 PY 1997 BP 157 EP 167 PG 11 WC Biology; Public, Environmental & Occupational Health; Physics, Applied SC Life Sciences & Biomedicine - Other Topics; Public, Environmental & Occupational Health; Physics GA BJ51K UT WOS:A1997BJ51K00011 ER PT B AU Geiger, K AF Geiger, K BE Jamin, M Nachtmann, O Domokos, G KovesiDomokos, S TI Non-equilibrium QCD of high-energy multi-gluon dynamics SO NON-PERTURBATIVE PARTICLE THEORY & EXPERIMENTAL TESTS SE JOHNS HOPKINS WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 20th Johns Hopkins Workshop on Current Problems in Particle Theory - Non-Perturbative Particle Theory and Experimental Tests CY JUN 27-29, 1996 CL HEIDELBERG, GERMANY SP Eotvos Lorand Univ, Univ Florence, Univ Goteborg, Univ Heidelberg, Johns Hopkins Univ, Univ Lanzhou AB I discuss an approach to derive from first principles, a real-time formalism to study the dynamical interplay of quantum and statistical-kinetic properties of non-equilibrium multi-parton systems produced in high-energy QCD processes. The ultimate goal (from which one is still far away) is to have a practically applicable description of the space-time evolution of a general initial system of gluons and quarks, characterized by some large energy or momentum scale, that expands, diffuses and dissipates according to the self-and mutual-interactions, and eventually converts dynamically into final state hadrons. For example, the evolution of parton showers in the mechanism of parton-hadron conversion in high-energy hadronic collisions, or, the description of formation, evolution and freezeout of a quark-gluon plasma, in ultra-relativistic heavy-ion collisions. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Geiger, K (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3162-8 J9 JOHNS HOP W PY 1997 BP 263 EP 283 PG 21 WC Physics, Particles & Fields SC Physics GA BK59B UT WOS:000072647500010 ER PT B AU Thomas, S AF Thomas, S BE Jamin, M Nachtmann, O Domokos, G KovesiDomokos, S TI Supersymmetry in the very early universe SO NON-PERTURBATIVE PARTICLE THEORY & EXPERIMENTAL TESTS SE JOHNS HOPKINS WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 20th Johns Hopkins Workshop on Current Problems in Particle Theory - Non-Perturbative Particle Theory and Experimental Tests CY JUN 27-29, 1996 CL HEIDELBERG, GERMANY SP Eotvos Lorand Univ, Univ Florence, Univ Goteborg, Univ Heidelberg, Johns Hopkins Univ, Univ Lanzhou AB Supersymmetric hat directions can have a number of important consequences in the very early universe. Depending on the form of the SUSY breaking potential arising from the finite energy density at early times, coherent production of scaler condensates fan result along such directions. This leads a cosmological disaster for Polonyi type hat directions with only Planck suppressed couplings, but can give rise to the baryon asymmetry for standard model flat directions. Flat directions are also natural candidates to act as inflatons. Achieving density fluctuations of the correct magnitude generally requires an additional hidden SUSY breaking sector. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Thomas, S (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3162-8 J9 JOHNS HOP W PY 1997 BP 353 EP 364 PG 12 WC Physics, Particles & Fields SC Physics GA BK59B UT WOS:000072647500014 ER PT B AU Lewandowski, A Bingham, C Shatz, N Bortz, JC AF Lewandowski, A Bingham, C Shatz, N Bortz, JC BE Winston, R TI Performance validation of an irradiance redistribution guide SO NONIMAGING OPTICS: MAXIMUM EFFICIENCY LIGHT TRANSFER IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th International Conference on Nonimaging Optics - Maximum Efficiency Light Transfer CY JUL 27-28, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE solar energy; solar concentrators; solar furnaces; secondary concentrators; nonimaging concentrators; irradiance distribution; flux redistribution; flux measurement AB Science Applications International Corporation has used a unique nonimaging-optical global optimization computer code, NICOS, to design an innovative secondary concentrator for the National Renewable Energy Laboratory (NREL). NICOS allows for the optimal design of such devices to achieve a variety of irradiance distributions on a desired target. The case of interest to NREL called for a uniform irradiance of concentrated sunlight over a relatively large area and at a reasonable working distance from the exit of the device. Because the irradiance at the nominal focal point of NREL's High-Flux Solar Furnace (HFSF) was reshaped from a near-Gaussian distribution to a nearly uniform one, the designs generated have been called irradiance redistribution guides (IRG). A design featuring reentrant optics was selected for fabrication and testing. This IRG has been fabricated and tested at the HFSF to compare predicted and measured performance. The IRG's performance is close to the theoretical predictions. Much of the performance difference can be explained by discrepancies between the actual HFSF performance relative to that assumed in the NICOS predictions. This IRG will be useful for applications in which uniform solar concentration at moderate flux is required. In general, the design methodology and resulting devices can provide a new way to satisfy diverse flux tailoring needs. RP Lewandowski, A (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2561-3 J9 P SOC PHOTO-OPT INS PY 1997 VL 3139 BP 225 EP 236 DI 10.1117/12.279218 PG 12 WC Optics SC Optics GA BJ74N UT WOS:A1997BJ74N00025 ER PT S AU Sheffield, RL Bisognano, J Brau, C Hogan, M Kim, KJ Milton, S Nuhn, HD Pagani, C Pierini, P Reiser, M Schmerge, J Serafini, L Teng, L Winick, H Cornacchia, M AF Sheffield, RL Bisognano, J Brau, C Hogan, M Kim, KJ Milton, S Nuhn, HD Pagani, C Pierini, P Reiser, M Schmerge, J Serafini, L Teng, L Winick, H Cornacchia, M BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Report of the working group on production and dynamics of high brightness beams SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB This paper summarizes the main discussions of the Working Group on the Production and Dynamics of High Brightness Beams. The following topics are covered in this paper: proposed new electron sources and needed research on existing sources, discussions on issues relating to the description of phase space on non-thermalized electron beam distributions and the theoretical modeling on non-thermalized electron beam distributions, and the present status of the theoretical modeling of beam transport in bends. RP Sheffield, RL (reprint author), LOS ALAMOS NATL LAB,MS H851,LOS ALAMOS,NM 87545, USA. RI Pierini, Paolo/J-3555-2012 OI Pierini, Paolo/0000-0002-3062-6181 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 11 EP 18 PG 8 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00002 ER PT S AU Berg, SJ Bisognano, J Bruening, O Byrd, J Chae, YC Colestock, P Corbett, J Dikansky, N Heifets, S Litvenenko, V Miano, G Migliorati, M Ng, KY Palumbo, L Pierini, P Raubenheimer, T Reiser, M Tavares, P Tzenov, S Warnock, R Wurtele, JS AF Berg, SJ Bisognano, J Bruening, O Byrd, J Chae, YC Colestock, P Corbett, J Dikansky, N Heifets, S Litvenenko, V Miano, G Migliorati, M Ng, KY Palumbo, L Pierini, P Raubenheimer, T Reiser, M Tavares, P Tzenov, S Warnock, R Wurtele, JS BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Report of the working group on plasma phenomena in beams SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB This working group was charged with reviewing the general area of plasma phenomena in beams. The group reviewed our present understanding and discussed critical issues for a wide variety of topics, including longitudinal and transverse wakefield instabilities in high intensity rings, numerical computation of wakes at short scare length, ion instabilities, wakefields and emittance growth from coherent synchrotron radiation, the nature of self-amplified spontaneous emission (SASE), soliton theory and its role in beam physics, the control of transverse instabilities by feedback or by temporal variation of ring parameters, and the use of plasma concepts in beam dynamics, particularly applications of beam echo measurements. RP Berg, SJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Pierini, Paolo/J-3555-2012; Berg, Joseph/E-8371-2014; Miano, Giovanni/L-3507-2014; wurtele, Jonathan/J-6278-2016 OI Pierini, Paolo/0000-0002-3062-6181; Berg, Joseph/0000-0002-5955-6973; Miano, Giovanni/0000-0002-5765-799X; wurtele, Jonathan/0000-0001-8401-0297 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 23 EP 29 PG 7 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00004 ER PT S AU Colestock, PL Assadi, S Spentzouris, LK AF Colestock, PL Assadi, S Spentzouris, LK BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Nonlinear collective phenomena in high energy synchrotrons SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB A broad spectrum of nonlinear collective effects have been identified and analyzed in the field of plasma. physics which have direct analogs in high energy beams, though the spatial and time scales for these phenomena in beams differ markedly from those in typical laboratory plasmas. These effects range from the weakly nonlinear wave-wave scattering to those involving a stronger nonlinearity such as nonlinear Landau damping. The importance of studying these phenomena lies in the fact that such processes are likely involved in the saturation of instabilities and the consequent emittance growth. We report on observations of such phenomena in our hadron beams that bear a close resemblance to the classical nonlinear coherent phenomena. in plasma physics and discuss implications for understanding and diagnosing nonlinear effects in beams. RP Colestock, PL (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 87 EP 95 PG 9 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00008 ER PT S AU Byrd, JM Barry, W AF Byrd, JM Barry, W BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Controlling the vertical mode coupling instability with feedback in the advanced light source SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB We present the results of experiments to control the mode coupling instability in the vertical direction using a feedback system. Presently, we can raise the instability threshold from similar to 20 mA to 35 mA. The maximum current threshold is reached when the feedback is operated in a resistive mode. RP Byrd, JM (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 167 EP 173 PG 7 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00016 ER PT S AU Byrd, J Chao, A Heifets, S Minty, M Raubenheimer, T Seeman, J Stupakov, G Thomson, J Zimmermann, F AF Byrd, J Chao, A Heifets, S Minty, M Raubenheimer, T Seeman, J Stupakov, G Thomson, J Zimmermann, F BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Ion instability experiments on the ALS SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB We report the results of experiments to study ion effects at the Advanced Light Source (ALS) in two pressure regimes. At the nominal pressure of 0.25 nTorr, we observe small vertical coherent beam oscillations for the nominal filling pattern (2.5% gap) that correlate with the expected ion frequency for nitrogen or carbon monoxide. The signals disappear for larger gaps in the filling pattern. We observe little increase in Vertical beam size. We have also made experiments to look for unconventional ion effects [1,2] st elevated gas pressures that may be important for future accelerators. In these experiments, Ne introduce a single gas species (helium) into the storage ring, raising the pressure approximately two orders of magnitude above the nominal pressure. For filling patterns with gaps in the bunch train large enough that conventional ion trapping should not play a role, we observe roughly a doubling of the vertical beam size along with coherent beam oscillations. We compare the results of the experiments with the predictions of one possible mechanism: the fast beam-ion instability. RP Byrd, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 175 EP 190 PG 16 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00017 ER PT S AU Fischer, W Schmidt, F AF Fischer, W Schmidt, F BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Chaotic particle motion in hadron storage rings exhibiting decreasing betatron amplitudes SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB In the regime of stabilized resonances chaotic motion is a precondition for particle loss in hadron storage rings. But chaoticity does not necessarily lead to loss on a limited time scale. A variety of phenomena can be observed, among them particles with decreasing betatron amplitudes. Chaotic proton motion, created by strong nonlinearities and tune modulation, was studied in an experiment at the CERN SPS. The particle motion was investigated over several minutes in the vicinity of an 8th order resonance. Element-by-element tracking and a theoretical analysis preceded and accompanied the experimental work. RP Fischer, W (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 201 EP 207 PG 7 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00019 ER PT S AU Heifets, S Chao, A AF Heifets, S Chao, A BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Study of microwave instability SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB Longitudinal stability of a bunch is studied above the threshold of microwave instability using a moment expansion approach. We derive a system of nonlinear equations describing bunch dynamics and study it in computer simulations. RP Heifets, S (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 251 EP 263 PG 13 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00023 ER PT S AU Heifets, S Raubenheimer, T AF Heifets, S Raubenheimer, T BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Plasma possibilities in the NLC SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB Basic idea and preliminary analysis are presented of a possibility to compensate the energy spread and to collimate beam in the next generation of linear colliders (NLC) using tunneling ionization of a gas by the beam. RP Heifets, S (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 265 EP 273 PG 9 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00024 ER PT S AU Ng, KY AF Ng, KY BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Microwave instability in alpha-like quasi-isochronous buckets SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB The problem of microwave instability inside an alpha-like quasi-isochronous bucket is addressed. The coupling impedance at wavelengths shorter than the length of the short bunches is found to be not small. The Keil-Schnell criterion is modified for such a bucket using the concept of self-bunching. The mechanism of particle loss during a microwave growth is examined. RP Ng, KY (reprint author), UNIV RES ASSOCIATES INC,FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 307 EP 316 PG 10 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00028 ER PT S AU Ng, KY Bai, M Brabson, B Chu, CM Kang, X Jeon, D Lee, SY Riabko, A Zhao, X AF Ng, KY Bai, M Brabson, B Chu, CM Kang, X Jeon, D Lee, SY Riabko, A Zhao, X BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Particle dynamics inside a quasi-isochronous storage ring SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB Quasi-isochronous alpha-like bucket can be important in providing ultra short bunches. The instability of a bunch inside the bucket is found to be severely affected by rf phase modulation. The synchrotron tune drops to zero at the bucket edge very rapidly, indicating the possibility of a thick chaotic layer due to overlapping of resonance islands. The approach to chaos comes from a sequence of bifurcation into 2:1 parametric resonances. When quantum excitation is included in addition to radiation damping, the instability is worsened. The steady-state particle distribution in the longitudinal phase space is Gaussian in the phase coordinate and non-Gaussian in the momentum coordinate, unless the bunch is small. The size of the bunch is governed only by the ''thermal Energy'' E-th = D-2/2A, where D and A are, respectively, the normalized diffusion and damping coefficients. The quantum lifetime of the particle bunch, for the D and ii that have been enhanced by the smallness of the phase-slip factor, is studied and turns out to be much longer than expected. Phase modulation tends to enhance quantum diffusion at high frequencies, but leads to stochastic resonances instead at low frequencies. RP Ng, KY (reprint author), UNIV RES ASSOC INC,FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 317 EP 341 PG 25 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00029 ER PT S AU Parsa, Z Forest, E AF Parsa, Z Forest, E BE Chattopadhyay, S Cornacchia, M Pellegrini, C TI Symplectic integration SO NONLINEAR AND COLLECTIVE PHENOMENA IN BEAM PHYSICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Nonlinear and Collective Phenomena in Beam Physics CY SEP 02-06, 1996 CL ARCIDOSSO, ITALY SP Int Comm Future Accelerators, US DOE, Natl Inst Nucl Phys, Italy, Natl Lab High Energy Phys, Japan, Lawrence Berkeley Lab, US, Stanford Linear Accelerator Ctr, US, Univ Calif Los Angeles, US, Univ Rome La Sapienza AB The purpose of this article is to provide a summary of the useful tools related to symplectic integration. This article is neither exhaustive nor meant to be a historical survey. Instead we will present the state of symplectic integration for periodic accelerators with an emphasis on tools most useful to our field. We will also discuss the Yoshida formulation and a new application to non-symplectic problems such as radiation in rings. RP Parsa, Z (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-668-9 J9 AIP CONF PROC PY 1997 IS 395 BP 355 EP 368 PG 14 WC Physics, Particles & Fields SC Physics GA BJ69R UT WOS:A1997BJ69R00031 ER EF